US20170141020A1

US20170141020A1 - Stiffened wires for offset bva

Info

Publication number: US20170141020A1
Application number: US15/086,899
Authority: US
Inventors: Grant Villavicencio; Sangil Lee; Roseann Alatorre; Javier A. Delacruz; Scott McGrath
Original assignee: Invensas LLC
Current assignee: Adeia Semiconductor Technologies LLC
Priority date: 2015-11-18
Filing date: 2016-03-31
Publication date: 2017-05-18
Anticipated expiration: 2036-03-31
Also published as: US9659848B1; WO2017087502A1; TW201729369A

Abstract

A component can include a generally planar element, a reinforcing dielectric layer overlying the generally planar element, an encapsulation overlying the reinforcing dielectric layer, and a plurality of wire bonds. Each wire bond can have a tip at a major surface of the encapsulation. The wire bonds can have first portions extending within the reinforcing dielectric layer. The first portions of at least some of the wire bonds can have bends that change an extension direction of the respective wire bond. The reinforcing dielectric layer can have protruding regions surrounding respective ones of the wire bonds, the protruding regions extending to greater peak heights from the first surface of the generally planar element than portions of the reinforcing dielectric layer between adjacent ones of the protruding regions. The peak heights of the protruding regions can coincide with points of contact between the reinforcing dielectric layer and individual wire bonds.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 62/257,223 filed Nov. 18, 2015, the disclosure of which is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

Embodiments of the invention herein relate to various structures and ways of making microelectronic packages which can be used in package on package assemblies, and more particularly, to such structures that incorporate wire bonds for as part of the package-on-package connections.
Microelectronic devices such as semiconductor chips typically require many input and output connections to other electronic components. The input and output contacts of a semiconductor chip or other comparable device are generally disposed in grid-like patterns that substantially cover a surface of the device (commonly referred to as an “area array”) or in elongated rows which may extend parallel to and adjacent each edge of the device's front surface, or in the center of the front surface. Typically, devices such as chips must be physically mounted on a substrate such as a printed circuit board, and the contacts of the device must be electrically connected to electrically conductive features of the circuit board.
Semiconductor chips are commonly provided in packages that facilitate handling of the chip during manufacture and during mounting of the chip on an external substrate such as a circuit board or other circuit panel. For example, many semiconductor chips are provided in packages suitable for surface mounting. Numerous packages of this general type have been proposed for various applications. Most commonly, such packages include a dielectric element, commonly referred to as a “chip carrier” with terminals formed as plated or etched metallic structures on the dielectric. These terminals typically are connected to the contacts of the chip itself by features such as thin traces extending along the chip carrier itself and by fine leads or wires extending between the contacts of the chip and the terminals or traces. In a surface mounting operation, the package is placed onto a circuit board so that each terminal on the package is aligned with a corresponding contact pad on the circuit board. Solder or other bonding material is provided between the terminals and the contact pads. The package can be permanently bonded in place by heating the assembly so as to melt or “reflow” the solder or otherwise activate the bonding material.
Many packages include solder masses in the form of solder balls, typically about 0.1 mm and about 0.8 mm (5 and 30 mils) in diameter, attached to the terminals of the package. A package having an array of solder balls projecting from its bottom surface is commonly referred to as a ball grid array or “BGA” package. Other packages, referred to as land grid array or “LGA” packages are secured to the substrate by thin layers or lands formed from solder. Packages of this type can be quite compact. Certain packages, commonly referred to as “chip scale packages,” occupy an area of the circuit board equal to, or only slightly larger than, the area of the device incorporated in the package. This is advantageous in that it reduces the overall size of the assembly and permits the use of short interconnections between various devices on the substrate, which in turn limits signal propagation time between devices and thus facilitates operation of the assembly at high speeds.
Packaged semiconductor chips are often provided in “stacked” arrangements, wherein one package is provided, for example, on a circuit board, and another package is mounted on top of the first package. These arrangements can allow a number of different chips to be mounted within a single footprint on a circuit board and can further facilitate high-speed operation by providing a short interconnection between packages. Often, this interconnect distance is only slightly larger than the thickness of the chip itself. For interconnection to be achieved within a stack of chip packages, it is necessary to provide structures for mechanical and electrical connection on both sides of each package (except for the topmost package). This has been done, for example, by providing contact pads or lands on both sides of the substrate to which the chip is mounted, the pads being connected through the substrate by conductive vias or the like. Solder balls or the like have been used to bridge the gap between the contacts on the top of a lower substrate to the contacts on the bottom of the next higher substrate. The solder balls must be higher than the height of the chip in order to connect the contacts. Examples of stacked chip arrangements and interconnect structures are provided in U.S. Patent App. Pub. No. 2010/0232129 (“the '129 Publication”), the disclosure of which is incorporated by reference herein in its entirety.
Microcontact elements in the form of elongated posts or pins may be used to connect microelectronic packages to circuit boards and for other connections in microelectronic packaging. In some instances, microcontacts have been formed by etching a metallic structure including one or more metallic layers to form the microcontacts. The etching process limits the size of the microcontacts. Conventional etching processes typically cannot form microcontacts with a large ratio of height to maximum width, referred to herein as “aspect ratio”. It has been difficult or impossible to form arrays of microcontacts with appreciable height and very small pitch or spacing between adjacent microcontacts. Moreover, the configurations of the microcontacts formed by conventional etching processes are limited. Despite all of the above-described advances in the art, still further improvements in making and testing microelectronic packages would be desirable.

BRIEF SUMMARY OF THE INVENTION

In accordance with an aspect of the invention, a component can include a generally planar element having oppositely-facing first and second surfaces extending in first and second transverse directions, a reinforcing dielectric layer overlying the first surface of the generally planar element, an encapsulation overlying the reinforcing dielectric layer, and a plurality of wire bonds. The generally planar element can have a plurality of contacts at the first surface. The encapsulation can have a major surface facing away from the first surface of the generally planar element. Each wire bond can have a base joined with a contact of the plurality of contacts, and a tip remote from the base at the major surface of the encapsulation.
The wire bonds can have first portions extending within at least a portion of the reinforcing dielectric layer and second portions extending within the encapsulation. The first portions of at least some of the wire bonds can have bends that change an extension direction of the respective wire bond in at least one of the first and second directions. The reinforcing dielectric layer can have protruding regions surrounding respective wire bonds of the plurality of wire bonds, the protruding regions extending to greater peak heights from the first surface of the generally planar element than portions of the reinforcing dielectric layer between adjacent ones of the protruding regions. The peak heights of the protruding regions can coincide with points of contact between the reinforcing dielectric layer and individual ones of the wire bonds.
In one embodiment, the component can comprise microelectronic package. The microelectronic package can also include a microelectronic element having oppositely-facing top and bottom surfaces. The bottom surface can face the first surface of the generally planar element and can be mechanically coupled therewith. The major surface of the encapsulation can overlie the top surface of the microelectronic element. In a particular example, the tips of a subset of the at least some of the wire bonds overlie the top surface of the microelectronic element. In an exemplary embodiment, the bases of the wire bonds can define a first minimum pitch between adjacent ones of the bases, and the tips of the wire bonds can define a second minimum pitch between adjacent ones of the tips, the second minimum pitch being greater than the first minimum pitch. In one example, the dielectric layer can overlie the top surface of the microelectronic element.
In a particular embodiment, the reinforcing dielectric layer can include a first reinforcing dielectric layer overlying the first surface of the generally planar element, and a second reinforcing dielectric layer overlying the first reinforcing dielectric layer and defining an upper surface of the reinforcing dielectric layer. In one embodiment, the bends of the first portions of the wire bonds can be first bends, and the at least some of the wire bonds can each include a second bend changing the extension direction of the respective wire bond in at least one of the first and second directions. In a particular example, at least some of the second bends of the wire bonds can be disposed within the reinforcing dielectric layer. In an exemplary embodiment, the reinforcing dielectric layer can be configured to maintain the position of the tips of the wire bonds in a third direction perpendicular to the first and second directions when a force is applied to the tips of the wire bonds in the third direction.
In one example, the microelectronic package described above can also include a plurality of upper terminals joined with corresponding ones of the wire bonds. The upper terminals can be at the major surface of the encapsulation and can be configured to be electrically connected with conductive elements of a component external to the microelectronic package. In a particular embodiment, a microelectronic assembly can comprise the microelectronic package as described above. The microelectronic assembly can also include a second component having terminals, the tips of the wire bonds being electrically connected to the terminals. In one embodiment, a system can include the microelectronic package as described above and one or more other electronic components electrically connected to the microelectronic package. In a particular example, the system can also include a housing, the microelectronic package and the one or more other electronic components being assembled with the housing.
In accordance with another aspect of the invention, a microelectronic package can include a generally planar element having oppositely-facing first and second surfaces extending in first and second transverse directions, a reinforcing dielectric layer overlying the first surface of the generally planar element, an encapsulation overlying the reinforcing dielectric layer, a microelectronic element having oppositely-facing top and bottom surfaces, and a plurality of wire bonds. The generally planar element can have a plurality of contacts at the first surface. The encapsulation can have a major surface facing away from the first surface of the generally planar element. The bottom surface of the microelectronic element can face the first surface of the generally planar element and can be mechanically coupled therewith. The major surface of the encapsulation can overlie the top surface of the microelectronic element.
Each wire bond can have a base joined with a contact of the plurality of contacts, and a tip remote from the base at the major surface of the encapsulation. The wire bonds can have first portions extending within at least a portion of the reinforcing dielectric layer and second portions extending within the encapsulation. The first portions of at least some of the wire bonds can have bends that change an extension direction of the respective wire bond in at least one of the first and second directions. The reinforcing dielectric layer can extend to a greater peak height from the first surface of the generally planar element than the microelectronic element. In an exemplary embodiment, the tips of a subset of the at least some of the wire bonds can overlie the top surface of the microelectronic element. In one example, the bends of the first portions of the wire bonds can be first bends, and the at least some of the wire bonds can each include a second bend changing the extension direction of the respective wire bond in at least one of the first and second directions.
In accordance with yet another aspect of the invention, a method of forming a component can include providing a generally planar element having oppositely-facing first and second surfaces extending in first and second transverse directions, forming a plurality of wire bonds, forming a reinforcing dielectric layer overlying the first surface of the generally planar element, flowing an encapsulation between the reinforcing dielectric layer and a lower surface of a molding film into which tips of the wire bonds extend, and removing the molding film from the encapsulation. The generally planar element can have a plurality of contacts at the first surface. Each wire bond can have a base joined with a contact of the plurality of contacts and a tip remote from the base. First portions of at least some of the wire bonds can have bends that change an extension direction of the respective wire bond in at least one of the first and second directions.
The first portions of the wire bonds can extend within at least a portion of the reinforcing dielectric layer. The reinforcing dielectric layer can have protruding regions surrounding respective wire bonds of the plurality of wire bonds. The protruding regions can extend to greater peak heights from the first surface of the generally planar element than portions of the reinforcing dielectric layer between adjacent ones of the protruding regions. The peak heights of the protruding regions can coincide with points of contact between the reinforcing dielectric layer and individual ones of the wire bonds. The encapsulation can have a major surface facing away from the first surface of the generally planar element. The wire bonds can have second portions extending within the encapsulation. The tips of the wire bonds can be at the major surface of the encapsulation.
In a particular embodiment, the component can comprise a microelectronic package as described above. The microelectronic package can also include a microelectronic element having oppositely-facing top and bottom surfaces. The bottom surface of the microelectronic element can face the first surface of the generally planar element and can be mechanically coupled therewith. The major surface of the encapsulation can overlie the top surface of the microelectronic element. In one embodiment, the protruding regions can wick up the wire bonds and can reach their respective peak heights before the flowing of the encapsulation. In a particular example, the peak heights of the protruding regions may not reach the tips of the wire bonds. In an exemplary embodiment, the method can also include, before the flowing of the encapsulation, depositing the molding film overlying the reinforcing dielectric layer. The tips of the wire bonds can extend into the molding film.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a side sectional view of a microelectronic package including wire bonds extending through an encapsulant between a substrate and a molding film, according to an embodiment of the invention.

FIG. 2 illustrates a side sectional view of a microelectronic package including wire bonds extending through a stiffening layer and an encapsulant between first and second substrates, according to a variation of the microelectronic package of FIG. 1.

FIG. 3 illustrates a side sectional view of a microelectronic package that is a variation of the microelectronic package of FIG. 2.

FIG. 4 illustrates one potential diagrammatic top plan view of the encapsulant and the top and bottom contacts of FIG. 2 or FIG. 3.

FIG. 5 is a schematic depiction of a system according to one embodiment of the invention.

DETAILED DESCRIPTION

A component in the form of an in-process microelectronic package 10 can be fabricated by joining and electrically connecting a plurality of wire bonds 20 and a microelectronic element 30 to a generally planar element in the form of a substrate 40 having a first surface 41 and a second surface 42 opposite the first surface, in accordance with an embodiment of the disclosure, as shown in FIG. 1. Electrically conductive contacts 43 and electrically conductive terminals 44, in the form of contacts or pads, can be arranged, respectively, at the first and second surfaces 41, 42. The in-process microelectronic package 10 can include an encapsulation 50 that is formed extending between the individual wire bonds 20 and overlying the microelectronic element 30 and the substrate 40. A molding film 60 can be placed over tips 21 of the wire bonds 20, to secure the locations of the wire bonds while the encapsulation 50 is formed.
As used in this disclosure, terms such as “upper,” “lower,” “top,” “bottom,” “above,” “below,” and similar terms denoting directions, refer to the frame of reference of the components themselves, rather than to the gravitational frame of reference. With the parts oriented in the gravitational frame of reference in the directions shown in the figures, with the top of drawing being up and the bottom of the drawing being down in the gravitational frame of reference, the top surface of the microelectronic element is, indeed, above the bottom surface of the microelectronic element in the gravitational frame of reference. However, when the parts are turned over, with the top of the drawing facing downwardly in the gravitational frame of reference, the top surface of the microelectronic element is below the bottom surface of the microelectronic element in the gravitational frame of reference.
As used in this disclosure with reference to a component, e.g., an interposer, microelectronic element, circuit panel, substrate, etc., a statement that an electrically conductive element is “at” a surface of a component indicates that, when the component is not assembled with any other element, the electrically conductive element is available for contact with a theoretical point moving in a direction perpendicular to the surface of the component toward the surface of the component from outside the component. Thus, a terminal or other conductive element which is at a surface of a substrate may project from such surface; may be flush with such surface; or may be recessed relative to such surface in a hole or depression in the substrate. As used herein, the terms “about” and “approximately” with respect to a given numerical value means that the actual value is within a typical manufacturing tolerance known to one skilled in the relevant art of the given numerical value.
The plurality of wire bonds 20 can be joined electrically with at least some of the contacts 43. Each of the wire bonds 20 can be bonded at a base 22 thereof, such as a ball bond or a wedge bond, to a respective contact 43. Each of the wire bonds 20 can extend to a tip 21 remote from the base 22 of such wire bond and remote from substrate 20, and can include an edge surface 23 extending from the tip 21 to the base 22. In particular examples, the wire bonds 20 can have a diameter of 2 mils (˜51 microns), less than 2 mils, 1.5 mils (˜38 microns), less than 1.5 mils, 1 mil (˜25 microns), or less than 1 mil.
The tips 21 of the wire bonds 20 can be available for electrical connection, either directly or indirectly as through a solder ball, electrically conductive contact, or other features discussed herein, to conductive elements external to the microelectronic package 10. The particular size and shape of bases 22 of the wire bonds 20 can vary according to the type of material used to form the wire bonds, the desired strength of the connection between the wire bonds and the contacts 43, or the particular process used to form the wire bonds. The wire bonds 20 can have a construction and can be formed on the substrate 40 extending from the contacts 43 in any suitable manner, such as described in U.S. Patent Application Pub. No. 2013/0093087, filed Feb. 24, 2012, which is hereby incorporated by reference herein.
The microelectronic element 30 can be mechanically coupled to the first surface 41 of the substrate 40, e.g., with an adhesive material, with a bottom surface 31 of the microelectronic element confronting the first surface of the substrate. The microelectronic element 30 can have a top surface 32 opposite the bottom surface 31. The microelectronic element can have element contacts (not shown) at either or both of the bottom and top surfaces 31, 32. As described herein, the element contacts of the microelectronic element 30 can also be referred to as “chip contacts.” In one example, the element contacts of the microelectronic element 30 can be at one of the bottom or top surfaces 31 or 32 within a central region thereof. For example, the element contacts can be arranged in one or two parallel rows adjacent the center of the bottom or top surface 31 or 32.
Although in the figures, the particular electrical connection between the microelectronic element 30 and the substrate 40 is not shown, the invention contemplates various types of electrical connections between the microelectronic element and the substrate, including, for example, a “flip-chip” configuration, where element contacts (not shown) at the bottom surface 31 of the microelectronic element 30 can be connected to conductive elements at the first surface 41 of the substrate 40, such as by conductive joining elements (not shown) that are positioned beneath the microelectronic element. In some embodiments, such conductive joining elements can be, for example, masses of a bond metal such as solder, tin, indium, a eutectic composition or combination thereof, or another joining material such as an electrically conductive paste, an electrically conductive adhesive or electrically conductive matrix material or a combination of any or all of such bond metals or electrically conductive materials.
In one example, element contacts at the bottom surface 31 of the microelectronic element 30 can be electrically connected with contacts at the second surface 42 of the substrate 40 by conductive structure (e.g., wire bonds or lead bonds) extending through an aperture in the substrate. In another example, element contacts at the top surface 32 of the microelectronic element 30 can be electrically connected with contacts at the first surface 41 of the substrate 40 by conductive structure (e.g, wire bonds) extending above the top surface of the microelectronic element.
In some embodiments, the microelectronic element 30 can each be a semiconductor chip, a wafer, or the like. For example, the microelectronic element 30 can each comprise a memory storage element such as a dynamic random access memory (“DRAM”) storage array or that is configured to predominantly function as a DRAM storage array (e.g., a DRAM integrated circuit chip). As used herein, a “memory storage element” refers to a multiplicity of memory cells arranged in an array, together with circuitry usable to store and retrieve data therefrom, such as for transport of the data over an electrical interface. In one example, the microelectronic element 30 can have memory storage array function. In a particular embodiment, the microelectronic element 30 can embody a greater number of active devices to provide memory storage array function than any other function.
The microelectronic element 30 can embody a plurality of active devices (e.g., transistors, diodes, etc.), a plurality of passive devices (e.g., resistors, capacitors, inductors, etc.), or both active devices and passive devices. In a particular embodiment, the microelectronic element 30 can be configured to have a predominant function as a logic chip, e.g., a programmable general or special purpose processor, a microcontroller, a field programmable gate array (“FPGA”) device, an application specific integrated circuit (“ASIC”), a digital signal processor, among others, or a predominant function other than as a logic chip, such as a memory, for example, a volatile memory storage area, e.g., dynamic random access memory (“DRAM”), static random access memory (“SRAM”), a nonvolatile memory storage array such as flash memory or magnetic random access memory (“MRAM”). As such, the embodiment of FIG. 1 is in the form of an in-process packaged microelectronic element such as a semiconductor chip assembly that is used in computer or other electronic applications.
Although in the figures, a single microelectronic element 30 is shown in the microelectronic package 10 (and in the other microelectronic packages herein), each microelectronic package in this disclosure can include a plurality of microelectronic elements, arranged either adjacent to one another along the first surface 41 of the substrate 40, in a vertical stack overlying the first surface of the substrate, or in other configurations known in the art.
The substrate 40 may include a dielectric element, which in some cases can consist essentially of polymeric material, e.g., a resin or polyimide, among others, and which may be substantially flat. The dielectric element may be sheet-like and may be thin. Alternatively, the substrate 40 can include a dielectric element having a composite construction such as glass-reinforced epoxy, e.g., of BT resin or FR-4 construction. In particular embodiments, the dielectric element can include one or more layers of organic dielectric material or composite dielectric materials, such as, without limitation: polyimide, polytetrafluoroethylene (“PTFE”), epoxy, epoxy-glass, FR-4, BT resin, thermoplastic, or thermoset plastic materials. In another example, the substrate can include a supporting element of material having a coefficient of thermal expansion (“CTE”) of less than 12 parts per million per degree Celsius (“ppm/° C.”), on which the contacts 41, terminals 42, and other conductive structure can be disposed. For example, such low CTE element can consist essentially of glass, ceramic, semiconductor material, or liquid crystal polymer material, or a combination of such materials. Alternatively, the substrate 40 can be a circuit panel or circuit board. In one example thereof, the substrate 40 can be a module board of a dual-inline memory module (“DIMM”). In one example, the substrate can include a supporting element of material having a CTE of less than 30 ppm/° C.
The first surface 41 and second surface 42 can be substantially parallel to each other and spaced apart at a distance perpendicular to the surfaces defining the thickness of the substrate T. The thickness of the substrate 40 can be within a range of generally acceptable thicknesses for the present application. In one embodiment, the distance between the first surface 41 and the second surface 42 is between about 10-500 μm. For purposes of this discussion, the first surface 41 may be described as being positioned opposite or remote from the second surface 42. Such a description, as well as any other description of the relative position of elements used herein that refers to a vertical or horizontal position of such elements is made for illustrative purposes only to correspond with the position of the elements within the drawings, and is not limiting.
The contacts 43 and the terminals 44 can be flat, thin electrically conductive elements. The contacts 43 and the terminals 44 can be a solid metal material, such as copper, gold, nickel, palladium, or other materials that are acceptable for such an application, including various alloys including one or more of copper, gold, nickel, palladium or combinations thereof. At least some of the contacts 43 can be interconnected to corresponding terminals 44. Such an interconnection may be completed using vias 45 formed in the substrate 40 that can be lined or filled with conductive metal that can be formed of the same material as the contacts 43 and the terminals 44. Optionally, the contacts 43 and the terminals 44 can be further interconnected to one another by traces (not shown) on the substrate 40. The terminals 44 can be configured for electrical interconnection with an external component such as another microelectronic package or a circuit panel, e.g., a circuit board.
First and second transverse directions D1, D2 parallel to the first surface 41 of the substrate 40 (shown in FIG. 4) are referred to herein as “horizontal” or “lateral” directions, whereas the directions (e.g., D3) perpendicular to the first surface are referred to herein as upward or downward directions and are also referred to herein as the “vertical” directions. The directions referred to herein are in the frame of reference of the structures referred to. Thus, these directions may lie at any orientation to the normal “up” or “down” directions in a gravitational frame of reference.
A statement that one feature is disposed at a greater height “above a surface” than another feature means that the one feature is at a greater distance in the same orthogonal direction away from the surface than the other feature. Conversely, a statement that one feature is disposed at a lesser height “above a surface” than another feature means that the one feature is at a smaller distance in the same orthogonal direction away from the surface than the other feature.
The encapsulation 50 can be formed extending between the individual wire bonds 20 and overlying the top surface 32 of the microelectronic element 30 and the first surface 41 of the substrate 40. The encapsulation 50 can be formed from a dielectric material, such as those materials known in the art as being typically used for encapsulations or overmolds. In the embodiment of FIG. 1, the encapsulation 50 can be formed, for example, by film-assisting molding or like techniques, over the portions of the first surface 41 of the substrate 40 that are not otherwise covered by or occupied by the microelectronic element 30, or the contacts 43.
The encapsulation 50, desirably an integral, continuous dielectric layer, can serve to protect the conductive elements within the microelectronic package 10, particularly the wire bonds 20. The encapsulation 50 can also substantially cover the microelectronic element 30, the wire bonds 20, including the bases 22 and at least a portion of edge surfaces 23 thereof. In addition, the encapsulation 50 can be formed over side surfaces 33 of the microelectronic element 30 that extend between the bottom and top surfaces 31, 32. The encapsulation 50 can protect the microelectronic element 30 to avoid electrical short circuiting between the wire bonds 20, and to help avoid malfunction or possible damage due to unintended electrical contact between a wire bond and the microelectronic element.
The encapsulation 50 can allow for a more robust structure that is less likely to be damaged by testing thereof or during transportation or assembly to other microelectronic structures. The encapsulation 50 can be formed from a dielectric material with insulating properties such as that described in U.S. Patent Application Pub. No. 2010/0232129, which is hereby incorporated by reference herein.
In some embodiments, portions of the wire bonds 20 can remain uncovered by the encapsulation 50, which can also be referred to as unencapsulated portions 24, thereby making the wire bonds available for electrical connection to a conductive feature or element located outside of the encapsulation 50. In some embodiments, at least the tips 21 of the wire bonds 20 and optionally portions of the edge surfaces 23 can remain uncovered by the encapsulation 50, such as described in U.S. Patent Application Pub. No. 2013/0093087, which is hereby incorporated by reference herein. In other words, the encapsulation 50 can cover the entire microelectronic package 30 from the first surface 41 and above, with the exception of a portion of the wire bonds 20, such as the tips 21, portions of the edge surfaces 23, or combinations thereof.
The tips 21 of the wire bonds 20 can extend into a molding film 60 while the encapsulation 50 is formed. The molding film 60 can be provided on an inner surface of a mold plate, for example. After the encapsulation 50 is formed within a mold containing the in-process microelectronic package 10 and the molding film, the molding film can be removed from the encapsulation, such as by applying a suitable chemical to detach or dissolve the molding film. In one embodiment, the molding film 60 can be made from a water soluble plastic material such that it can be removed by exposure to water without affecting the other components of the in-process unit or the microelectronic package 10. In another embodiment, the molding film 60 can be removed from the encapsulation 50 after exposure to ultraviolet light. After removal of the molding film 60, the tips 21 of the wire bonds 20 can remain uncovered and, thus, can be available for electrical connection with other components, such as traces, pads, or terminals of another microelectronic assembly or microelectronic package.
In the embodiment of FIG. 1, the tips 21 of the wire bonds 20 can contact the molding film 60 before the encapsulation 50 is formed, and at least some of the tips of the wire bonds can deflect downward (i.e., toward the first surface 41 of the substrate 40) in the direction D3. Such a downward deflection of at least some of the tips 21 of the wire bonds 20 can prevent the affected tips from being at the major surface 51 of the encapsulation 50 for electrical interconnection with other conductive elements. Also, such a downward deflection of at least some of the tips 21 of the wire bonds 20 can result in electrical short circuiting between the wire bonds, and/or malfunction or possible damage due to unintended electrical contact between a wire bond and the microelectronic element 30.
For example, as shown in FIG. 1, one of the tips 21 a of one of the wire bonds 20 a can be deflected downward in the direction D3 by the molding film 60 by a distance D, so that the tip 21 a moves downward to the position 21 b, and the wire bond deflects downward to a position 20 b. Such a downward deflection of the wire bond 20 a can result in unintended electrical contact between the wire bond and the microelectronic element 30, and/or electrical short circuiting between the wire bonds.
Such downward deflection of the tips 21 of the wire bonds 20 can be a significant problem for BVA and BGA interconnects comprising wire bonds that are about 1 mil or less in diameter (about 25 microns or less). Such a downward deflection of the tips 21 of the wire bonds 20 can also be a problem for BVA and BGA interconnects comprising wire bonds that are greater than 1 mil in diameter. The structures described herein can result in reduced stress at the BVA and BGA interconnection interface. Such structures also permit joining of microelectronic structures with a reduced joining unit size, which can reduce diffusion kinetics and the thickness of joined microelectronic structures.
FIG. 2 illustrates a microelectronic assembly 200 including a component in the form of a microelectronic package 210 that is a variation of the microelectronic package 10 of FIG. 1. Elements of the microelectronic package 210 that are not described below should be understood to be the same as the corresponding elements described above with reference to the microelectronic package 10 shown in FIG. 1.
The microelectronic assembly 200 can include a microelectronic package 210 joined to and electrically connected with a second substrate 201, in a manner to be described below. The microelectronic package 210 can include a plurality of wire bonds 220 and a microelectronic element 230 joined and electrically connected to a generally planar element in the form of a substrate 240. At least some of the wire bonds 220 can include first portions 225 adjacent the bases 222 of the wire bonds and second portions 226 adjacent the tips 221 of the wire bonds.
The microelectronic package 210 can include an encapsulation 250 that is formed extending between the second portions 226 of the individual wire bonds 220, and a reinforcing dielectric layer 270 that is formed extending between the first portions 225 of the individual wire bonds 220 and overlying the top surface 232 of the microelectronic element 230 and the first surface 241 of the substrate 240. The major surface 251 of the encapsulation 250 can overlie the top surface 232 of the microelectronic element 230. The tips 221 of the at least some of the wire bonds 220 can be exposed at the major surface 251 of the encapsulation 250.
The reinforcing dielectric layer 270 can be formed before formation of the encapsulation 250. The reinforcing dielectric layer 270 can be mechanically coupled with both the microelectronic element 230 and the first surface 241 of the substrate 240. The encapsulation 250 can overlie the upper surface 271 of the reinforcing dielectric layer 270, and can have a major surface 251 overlying the reinforcing dielectric layer and the top surface 232 of the microelectronic element 230.
The reinforcing dielectric layer 270 can be formed extending between the individual wire bonds 220 and overlying the top surface 232 of the microelectronic element 230 and the first surface 241 of the substrate 240. In the embodiment of FIG. 2, the reinforcing dielectric layer 270 can be formed over the portions of the first surface 241 of the substrate 240 that are not otherwise covered by or occupied by the microelectronic element 230, or the contacts 243. The reinforcing dielectric layer 270 can be an integral, continuous layer formed from a dielectric material. The reinforcing dielectric layer 270 can define an upper surface 271 facing away from the first surface 241 of the substrate 240.
The reinforcing dielectric layer 270 can also substantially cover the microelectronic element 230 and the first portions 225 of the wire bonds 220, including the bases 222 and at least a portion of edge surfaces 223 thereof. In addition, the reinforcing dielectric layer 270 can be formed over side surfaces 233 of the microelectronic element 230 that extend between the bottom and top surfaces 231, 232. The reinforcing dielectric layer 270 can protect the microelectronic element 230 to avoid electrical short circuiting between the wire bonds 220, and to help avoid malfunction or possible damage due to unintended electrical contact between a wire bond and the microelectronic element. In one example, the upper surface 271 of the reinforcing dielectric layer 270 can overlie the top surface 231 of the microelectronic element 230.
The reinforcing dielectric layer 270 can be configured to provide a stiffening function for the first portions 225 of the wire bonds 220. The first portions 225 of the wire bonds 220 can extend within at least a portion of the reinforcing dielectric layer 270. The reinforcing layer 270 can be configured to maintain the position of the tips 221 of the wire bonds 220 in a third direction D3 perpendicular to the first and second directions (D1, D2 of FIG. 4) when a force is applied to the tips of the wire bonds in the third direction.
In a particular example, the reinforcing dielectric layer 270 can have a higher Young's modulus that a Young's modulus of the encapsulation. However, the reinforcing dielectric layer can have a Young's modulus of any suitable value as long as the required stiffening function is provided. In one example, the reinforcing dielectric layer 270 can be made of epoxy, and can have a Young's modulus between 5-50 GPa, and the Young's modulus of the encapsulation 250 can have a value that is lower than, higher than, or the same as the Young's modulus value of the reinforcing dielectric layer.
The upper surface 271 of the reinforcing dielectric layer 270 can have a lower region 272, and protruding regions 273 surrounding respective ones of the wire bonds 220. The lower region 272 can extend between adjacent ones of the protruding regions 273. The lower region 272 can extend to a first peak height A1 from the first surface 241 of the substrate 240, and the protruding regions can extend to second peak heights A2 from the first surface of the substrate. The protruding regions 273 can extend to greater peak heights A2 from the first surface 241 of the substrate 240 than the peak height A1 of portions 272 of the reinforcing dielectric layer 270 between adjacent protruding regions. The peak heights A2 of the protruding regions 273 from the first surface 241 of the substrate 240 can coincide with points of contact between the reinforcing dielectric layer 270 and individual ones of the wire bonds 220. In the examples shown herein, the second peak heights A2 of the protruding regions 273 do not reach the major surface 251 of the encapsulation 250, and the second peak heights A2 of the protruding regions do not reach the tips 221 of the wire bonds 220.
Although the lower region 272 of the upper surface 271 of the reinforcing dielectric layer 270 is shown in FIGS. 2 and 3 as extending to a uniform first peak height A1 from the first surface 241 of the substrate 240, that need not be the case. In some examples, different portions of the lower region 272 of the upper surface 271 of the reinforcing dielectric layer 270 can extend to various first peak heights A1 from the first surface 241 of the substrate 240. In some examples, individual ones of the protruding regions 273 of the upper surface 271 of the reinforcing dielectric layer 270 can each extend a different second peak height A2 from the first surface 241 of the substrate 240. Each protruding region 273 can surround one or more individual ones of the wire bonds 270. Each protruding region 273 can have its second peak height A2 above the first surface 241 of the substrate 240 coinciding with a point of contact with one of the individual ones of the wire bonds 270.
The reinforcing dielectric layer 270 can be formed from a dielectric material with insulating properties such as an epoxy or another suitable polymeric material. The reinforcing dielectric layer 270 can be formed from a dielectric material that is relatively viscous (e.g., more viscous than the material of the encapsulant 250). The reinforcing dielectric layer 270 can be formed of a dielectric material that wets the edge surfaces 223 of the wire bonds 220 and can wick up the edge surfaces during formation to a second peak height A2 from the first surface 241 of the substrate 240. In one example, the protruding regions 273 of the upper surface 271 of the reinforcing dielectric layer 270 can wick up the wire bonds 220 and reach their respective second peak heights A2 before the forming of the encapsulant material 250. In the examples shown herein, the second peak heights A2 of the protruding regions 273 do not reach the tips 221 of the wire bonds 220.
The wire bonds 220 can each have a base 222 joined to a corresponding one of the contacts 243 and a tip 221 remote from the base. At least some of the wire bonds 220 can have first portions 225 extending within at least a portion of the reinforcing dielectric layer 270 and second portions 226 extending within the encapsulation 250. The first portions 225 of at least some of the wire bonds 220 (extending within the reinforcing dielectric layer 270) can each include a first bend 227 changing an extension direction E1 of the respective wire bond in at least one of the first and second directions D1 and D2. In one embodiment, at least some of the first bends 227 of the first portions 225 of the wire bonds 220 can be disposed within the reinforcing dielectric layer 270.
In some examples, the second portions 226 of at least some of the wire bonds 220 (extending within the encapsulation 250) can each include a second bend 228 changing the extension direction E1 of the respective wire bond in at least one of the first and second directions D1 and D2. In one embodiment, at least some of the second bends 228 of the wire bonds 220 can be disposed within the reinforcing dielectric layer 270. In one example, at least some of the first bends 227 and the second bends 228 of the wire bonds 220 can be disposed within the reinforcing dielectric layer 270. As shown in FIG. 2, it may not be necessary that all of the wire bonds 220 have first and/or second bends 227, 228. For example, the wire bond 220′ does not have first or second bends 227, 228.
In a particular example, at least some of the first bends 227 of the wire bonds 220 can be disposed within the reinforcing dielectric layer 270, while at least some of the second bends 228 of the wire bonds 220 can be disposed within the encapsulation 250. In some embodiments, the first and second bends 227, 228 of the wire bonds can permit the tips 221 of a subset 229 of the wire bonds to overlie the top surface 232 of the microelectronic element 230.
The second peak heights A2 of the respective protruding regions 273 can be farther above the first surface 241 of the substrate 240 than the heights A3 of the first bends 227 of the respective wire bonds 220. The heights A4 of the second bends 228 of the respective wire bonds 220 can be farther above the first surface 241 of the substrate 240 than the second peak heights A2 of the respective protruding regions 273.
The first bends 227 and the second bends 228 of the wire bonds 220 can provide a pitch changing function of the wire bonds between the first surface 241 of the substrate 240 and the major surface 251 of the encapsulation 250. As can be seen in the example of FIG. 2, the bases 222 of the wire bonds 220 can define a first minimum pitch P1 between adjacent ones of the bases and the tips 221 of the wire bonds define a second minimum pitch P2 between adjacent ones of the tips, the second minimum pitch being greater than the first minimum pitch. In one example, the first minimum pitch P1 can be 40-200 microns, and the second minimum pitch P2 can be 150-300 microns.
Similar to FIG. 1, a molding film such similar to the molding film 60 can be lowered onto the tips 221 of the wire bonds 220 extending from the first surface 241 of the substrate 240, to secure the locations of the wire bonds while the encapsulation 250 is formed. The molding film can be deposited onto the tips 221 of the wire bonds 220 after forming the reinforcing dielectric layer 270 and before forming the encapsulation 250.
In the example shown in FIG. 2, when the tips 221 of the wire bonds contact the molding film after the reinforcing dielectric layer 270 is formed, the reinforcing dielectric layer can maintain the position of the tips 221 of the wire bonds 220 in the third direction D3 when a force is applied to the tips of the wire bonds in the third direction D3. For example, as shown in FIG. 2, when a molding film is applied to one of the tips 221 a of one of the wire bonds 220 a, the reinforcing dielectric layer 270 can stiffen the wire bond, thereby preventing the tip from deflecting downward in the direction D3 by a distance D to a position 221 b, and preventing the wire bond from deflecting downward to a position 220 b.
In some embodiments, before the flowing of the encapsulant material 250, the molding film can be deposited onto the tips 221 of the wire bonds 220 with the tips extending into the molding film, the molding film overlying the reinforcing dielectric layer 270. After the tips 221 of the wire bonds 220 contact the molding film, the encapsulant material 250 can be flowed between the upper surface 271 of the reinforcing dielectric layer 270 and a lower surface (e.g., the lower surface 61 shown in FIG. 1) of the molding film into which the tips of the wire bonds extend. After the encapsulation 250 is formed within a mold containing the microelectronic package 210 and the molding film, the molding film can be removed from the encapsulation, by any of the removal methods described above with reference to FIG. 1, and the tips 221 of at least some of the wire bonds 220 can be exposed at the major surface 271 of the encapsulation 250.
In some embodiments, the reinforcing dielectric layer 270 can include a first reinforcing dielectric layer overlying the first surface 241 of the substrate 240, and a second reinforcing dielectric layer overlying the first reinforcing dielectric layer and defining the upper surface 271 of the reinforcing dielectric layer. In such embodiments, the first portions 225 can extend through both the first and second reinforcing dielectric layers, and the lower region 272 and the protruding regions 273 of the upper surface 271 of the reinforcing dielectric layer 270 can be formed in the second reinforcing dielectric layer.
As shown in FIG. 2, the microelectronic assembly 200 can also include a second substrate 201. The second substrate 201 can be a component having first and second opposite surfaces 202, 203. The second substrate 201 can have first terminals 204 at the first surface 202 and second terminals 205 at the second surface 203. At least some of the first terminals 204 can be electrically interconnected to corresponding ones of the second terminals 205. Such an interconnection can be completed using vias 206 formed in the substrate, for example, that can be lined or filled with conductive metal that can be formed of the same material as the first and second terminals 204, 205. The second terminals 205 can be configured for electrical interconnection with an external component such as another microelectronic package or a circuit panel, e.g., a circuit board. In the example shown in FIG. 2, the tips 221 of the wire bonds 220 can be electrically connected to the first terminals 204 of the second substrate 201.
In one embodiment, the first terminals 204 can be upper terminals of the package 210 at the major surface 251 of the encapsulation. In such an embodiment, the first terminals 204 can be configured to be electrically connected with conductive elements of a component external to the microelectronic package 210, such as the second substrate 201, another microelectronic package, or a circuit panel, e.g., a circuit board.
FIG. 3 illustrates a microelectronic assembly 300 including a component in the form of a microelectronic package 310 that is a variation of the microelectronic package 210 of FIG. 2. Elements of the microelectronic package 310 that are not described below should be understood to be the same as the corresponding elements described above with reference to the microelectronic package 210 shown in FIG. 2.
The microelectronic assembly 300 can include a microelectronic package 310 joined to and electrically connected with a second substrate 301. The microelectronic package 310 can include a plurality of wire bonds 320 and a microelectronic element 330 joined and electrically connected to a generally planar element in the form of a substrate 340. The microelectronic package 310 can include an encapsulation 350 that is formed extending between second portions 326 of the individual wire bonds 320, and a reinforcing dielectric layer 370 that is formed extending first portions 325 of the individual wire bonds 320 and overlying the top surface 332 of the microelectronic element 330 and the first surface 341 of the substrate 340.
As can be seen in FIG. 3, some of the wire bonds 320 a can have first and second bends 327, 328 that change the extension direction E1 of the wire bond by greater angles than the first and second bends of other wire bonds 320 b. In such an embodiment, the tip 321 and the base 322 of the wire bond 320 a can be offset a greater distance in one or both of the first and second directions D1, D2 than the tip and the base of the wire bond 320 b. In a side view, the path of the wire bonds 320 a would appear to cross the path of the wire bonds 320 b, as shown in FIG. 3.
In the embodiment shown in FIG. 3, the stiffening function of the reinforcing dielectric layer 370 on the wire bonds 320 a can be particularly advantageous. Given that the wire bonds 320 a have first and second bends 327, 328 that cause the tip 321 and the base 322 of the wire bond to be offset a greater distance in one or both of the first and second directions D1, D2 than the wire bonds of FIG. 2, the tips of such wire bonds 320 a may be more easily moved in the third direction D3 than the tips of the wire bonds than FIG. 2. Therefore, compared to the wire bonds 320 b and the wire bonds 220 of FIG. 2, the reinforcing layer 370 may have a greater effect in maintaining the position of the tips 321 of the wire bonds 220 a in the third direction D3 when a force is applied to the tips of the wire bonds in the third direction.
In further variations of the embodiments described above relative to FIGS. 2 and 3, the microelectronic element 230, 330 can be omitted. In such examples, the component can have a structure as described above relative to FIG. 2, for example, but in which the microelectronic element is omitted. In such example, the component can provide a pitch-changing function between the contacts 243 of a substrate and the terminals 204. In a particular example, a microelectronic element can be combined with such a component, for example, by mounting the microelectronic element to the second surface of the substrate after forming the component. Alternatively, the encapsulation of the component can be provided with an opening sized to accommodate placement of the microelectronic element above the substrate's first surface at a time subsequent to the manufacture of the component.
In a further variation, a generally planar element can be provided in place of the substrate 240 shown in FIG. 2. In a particular example, the generally planar element can be a microelectronic element. Referring to FIG. 1, in a particular form of this variation, the generally planar element may lack terminals 44 at the second surface 42 opposite from the first surface 41 of the planar element at which wire bonds are joined to the contacts 43.
FIG. 4 illustrates a component in the form of a microelectronic package 410 that is a variation of the microelectronic packages 210 and 310 of FIGS. 2 and 3. Elements of the microelectronic packages 210 and 310 that are not described below should be understood to be the same as the corresponding elements described above with reference to the microelectronic packages 210 and 310 shown in FIGS. 2 and 3.
As described above with reference to FIG. 2, the first bends and the second bends of the wire bonds can provide a pitch changing function of the wire bonds between the first surface of the substrate and the major surface of the encapsulation. As can be seen in the example of FIG. 4, the contacts 443 to which the bases of the wire bonds can be joined can define a first minimum pitch P1 between adjacent centers thereof, and the upper terminals 404 to which the tips of the wire bonds can be joined can define a second minimum pitch P2 between adjacent centers thereof, the second minimum pitch being greater than the first minimum pitch.
Also, as can be seen in FIG. 4, the number of upper terminals 404 can be less than the number of contacts 443. Therefore, it may be necessary for one or more of the upper terminals 404 to each be connected to at least two of the contacts 443. Such a correspondence is shown in FIG. 4, where the dashed lines 480 enclose exemplary groups of four contacts 443 all shorted together and electrically connected to a single corresponding one of the upper terminals 404. In one example, such shorted-together groups of contacts 443 can be configured to carry power or a reference voltage (i.e., ground).
The microelectronic packages and microelectronic assemblies described above with reference to FIGS. 1-4 above can be utilized in construction of diverse electronic systems, such as the system 500 shown in FIG. 5. For example, the system 500 in accordance with a further embodiment of the invention includes a plurality of modules or components 506 such as the microelectronic packages and microelectronic assemblies as described above, in conjunction with other electronic components 508, 510 and 511.
In the exemplary system 500 shown, the system can include a circuit panel, motherboard, or riser panel 502 such as a flexible printed circuit board, and the circuit panel can include numerous conductors 504, of which only one is depicted in FIG. 5, interconnecting the modules or components 506, 508, 510 with one another. Such a circuit panel 502 can transport signals to and from each of the microelectronic packages and/or microelectronic assemblies included in the system 500. However, this is merely exemplary; any suitable structure for making electrical connections between the modules or components 506 can be used.
In a particular embodiment, the system 500 can also include a processor such as the semiconductor chip 508, such that each module or component 506 can be configured to transfer a number N of data bits in parallel in a clock cycle, and the processor can be configured to transfer a number M of data bits in parallel in a clock cycle, M being greater than or equal to N. In the example depicted in FIG. 5, the component 508 is a semiconductor chip and component 510 is a display screen, but any other components can be used in the system 500. Of course, although only two additional components 508 and 511 are depicted in FIG. 5 for clarity of illustration, the system 500 can include any number of such components.
Modules or components 506 and components 508 and 511 can be mounted in a common housing 501, schematically depicted in broken lines, and can be electrically interconnected with one another as necessary to form the desired circuit. The housing 501 is depicted as a portable housing of the type usable, for example, in a cellular telephone or personal digital assistant, and screen 510 can be exposed at the surface of the housing. In embodiments where a structure 506 includes a light-sensitive element such as an imaging chip, a lens 511 or other optical device also can be provided for routing light to the structure. Again, the simplified system shown in FIG. 5 is merely exemplary; other systems, including systems commonly regarded as fixed structures, such as desktop computers, routers and the like can be made using the structures discussed above.
It will be appreciated that the various dependent claims and the features set forth therein can be combined in different ways than presented in the initial claims. It will also be appreciated that the features described in connection with individual embodiments may be shared with others of the described embodiments.
Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims

1. A component, comprising:

a generally planar element having oppositely-facing first and second surfaces extending in first and second transverse directions, the generally planar element having a plurality of contacts at the first surface;

a reinforcing dielectric layer overlying the first surface of the generally planar element;

an encapsulation overlying the reinforcing dielectric layer, the encapsulation having a major surface facing away from the first surface of the generally planar element; and

a plurality of wire bonds, each wire bond having a base joined with a contact of the plurality of contacts, and a tip remote from the base at the major surface of the encapsulation, the wire bonds having first portions extending within at least a portion of the reinforcing dielectric layer and second portions extending within the encapsulation, the first portions of at least some of the wire bonds having bends that change an extension direction of the respective wire bond in at least one of the first and second directions,

wherein the reinforcing dielectric layer has protruding regions surrounding respective wire bonds of the plurality of wire bonds, the protruding regions extending to greater peak heights from the first surface of the generally planar element than portions of the reinforcing dielectric layer between adjacent ones of the protruding regions, the peak heights of the protruding regions coinciding with points of contact between the reinforcing dielectric layer and individual ones of the wire bonds.

2. The component of claim 1, wherein the component comprises a microelectronic package, the microelectronic package further including a microelectronic element having oppositely-facing top and bottom surfaces, the bottom surface facing the first surface of the generally planar element and mechanically coupled therewith, and wherein the major surface of the encapsulation overlies the top surface of the microelectronic element.

3. The microelectronic package of claim 2, wherein the tips of a subset of the at least some of the wire bonds overlie the top surface of the microelectronic element.

4. The component of claim 1, wherein the bases of the wire bonds define a first minimum pitch between adjacent ones of the bases, and the tips of the wire bonds define a second minimum pitch between adjacent ones of the tips, the second minimum pitch being greater than the first minimum pitch.

5. The microelectronic package of claim 2, wherein the dielectric layer overlies the top surface of the microelectronic element.

6. The component of claim 1, wherein the reinforcing dielectric layer comprises a first reinforcing dielectric layer overlying the first surface of the generally planar element, and a second reinforcing dielectric layer overlying the first reinforcing dielectric layer and defining an upper surface of the reinforcing dielectric layer.

7. The component of claim 1, wherein the bends of the first portions of the wire bonds are first bends, and the at least some of the wire bonds each include a second bend changing the extension direction of the respective wire bond in at least one of the first and second directions.

8. The component of claim 7, wherein at least some of the second bends of the wire bonds are disposed within the reinforcing dielectric layer.

9. The component of claim 1, wherein the reinforcing dielectric layer is configured to maintain the position of the tips of the wire bonds in a third direction perpendicular to the first and second directions when a force is applied to the tips of the wire bonds in the third direction.

10. The microelectronic package of claim 2, further comprising a plurality of upper terminals joined with corresponding ones of the wire bonds, the upper terminals at the major surface of the encapsulation and configured to be electrically connected with conductive elements of a component external to the microelectronic package.

11. A microelectronic assembly comprising the microelectronic package of claim 2, the microelectronic assembly further comprising a second component having terminals, the tips of the wire bonds being electrically connected to the terminals.

12. A system comprising the microelectronic package of claim 2 and one or more other electronic components electrically connected to the microelectronic package.

13. The system of claim 12, further comprising a housing, the microelectronic package and the one or more other electronic components being assembled with the housing.

14. A microelectronic package, comprising:

an encapsulation overlying the reinforcing dielectric layer, the encapsulation having a major surface facing away from the first surface of the generally planar element;

a microelectronic element having oppositely-facing top and bottom surfaces, the bottom surface facing the first surface of the generally planar element and mechanically coupled therewith, the major surface of the encapsulation overlying the top surface of the microelectronic element; and

wherein the reinforcing dielectric layer extends to a greater peak height from the first surface of the generally planar element than the microelectronic element.

15. The microelectronic package of claim 14, wherein the tips of a subset of the at least some of the wire bonds overlie the top surface of the microelectronic element.

16. The microelectronic package of claim 14, wherein the bends of the first portions of the wire bonds are first bends, and the at least some of the wire bonds each include a second bend changing the extension direction of the respective wire bond in at least one of the first and second directions.

17. A method of forming a component, comprising:

providing a generally planar element having oppositely-facing first and second surfaces extending in first and second transverse directions, the generally planar element having a plurality of contacts at the first surface;

forming a plurality of wire bonds, each wire bond having a base joined with a contact of the plurality of contacts and a tip remote from the base, first portions of at least some of the wire bonds having bends that change an extension direction of the respective wire bond in at least one of the first and second directions;

forming a reinforcing dielectric layer overlying the first surface of the generally planar element, the first portions of the wire bonds extending within at least a portion of the reinforcing dielectric layer, the reinforcing dielectric layer having protruding regions surrounding respective wire bonds of the plurality of wire bonds, the protruding regions extending to greater peak heights from the first surface of the generally planar element than portions of the reinforcing dielectric layer between adjacent ones of the protruding regions, the peak heights of the protruding regions coinciding with points of contact between the reinforcing dielectric layer and individual ones of the wire bonds;

flowing an encapsulation between the reinforcing dielectric layer and a lower surface of a molding film into which tips of the wire bonds extend, the encapsulation having a major surface facing away from the first surface of the generally planar element, the wire bonds having second portions extending within the encapsulation; and

removing the molding film from the encapsulation, the tips of the wire bonds being at the major surface of the encapsulation.

18. The method of claim 17, wherein the component comprises a microelectronic package, the microelectronic package further including a microelectronic element having oppositely-facing top and bottom surfaces, the bottom surface facing the first surface of the generally planar element and mechanically coupled therewith, and wherein the major surface of the encapsulation overlies the top surface of the microelectronic element.

19. The method of claim 17, wherein the protruding regions wick up the wire bonds and reach their respective peak heights before the flowing of the encapsulation.

20. The method of claim 19, wherein the peak heights of the protruding regions do not reach the tips of the wire bonds.

21. The method of claim 17, further comprising, before the flowing of the encapsulation, depositing the molding film overlying the reinforcing dielectric layer, the tips of the wire bonds extending into the molding film.