WO2000052976A1

WO2000052976A1 - Memory module

Info

Publication number: WO2000052976A1
Application number: PCT/EP2000/000019
Authority: WO
Inventors: Gerold Klötzig; Uwe Guth; Ralf Puklowsky
Original assignee: Wichmann Workx Ag Information Technology
Priority date: 1999-02-26
Filing date: 2000-01-04
Publication date: 2000-09-08
Also published as: AU2661900A; DE29903442U1; EP1060648A1

Abstract

The invention relates to a memory module(1) containing a base printed circuit board (2) which comprises storage elements (22, 24, 26, 28, ...) and containing an expansion printed circuit board (4) which comprises additional storage elements (42, 44, 46, 48, ...), whereby the base printed circuit board (2) and the expansion printed circuit board (4) have contact elements (45, ...) which correspond to one another so that the expansion printed circuit board (4) can be connected to the base printed circuit board (2). This configuration makes it possible to expand the (working) memory of a computer or of another device in a simple and/or economical manner.

Description

Memory module

The invention relates to a memory module. The memory module can be provided for a computer or the like. In this context, this should be understood to mean any data processing device, in particular also in embedded systems such as printers, telecommunication devices, network devices, etc.

It is known to provide a graphics card with a plug-in expansion memory ("Millennium" graphics card from Matrox and expansion card No. 8M12 SDRAM PCI). However, this teaching is foreign to the genre because it concerns a graphics card and not a memory module.

In order to expand the main memory (main memory) of a computer or other data processing device, it has so far often been necessary to replace the existing memory modules because only a few slots are provided on the main boards ("mainboards") and these are often already occupied. The previous memory modules can usually no longer be used for other purposes, which is at least a waste and possibly also entails disposal costs.

It is therefore an object of the invention to provide a memory module which enables the (working) memory of a computer or other device to be expanded in a simple and / or economical manner. One object of preferred further developments of the invention is to provide the most flexible type of memory expansion possible, by means of which previous investments have been particularly well protected.

These tasks are wholly or partly by a memory module with the features of claim 1 or claim 4, a memory module with the features of claim 18 and an expansion board with the Features of claim 19 solved. The dependent claims relate to preferred embodiments of the invention.

According to a first aspect of the invention, the memory module has a motherboard and an expansion board, each with memory elements. The two boards have corresponding contact elements, so that the expansion board can be connected to the motherboard. In line with normal usage, the term "connectable" means that the two boards are not connected to each other, but releasably.

According to a second aspect of the invention, a circuit board arrangement is provided with a base board for a computer or the like, which also has storage elements, and an expansion board for the storage elements of the base board, the base board and expansion board having corresponding connection and contact elements, such that the expansion board connects directly to the The motherboard can be connected and connected to it, the motherboard having only storage elements.

The memory capacity of the memory module and thus the main memory can theoretically be expanded by any factors. In preferred embodiments, an expansion by a factor of 1, 5 or 2 is possible. Additional slots on the main board ("mainboard") are not required. This protects the investments already made. Electronic waste to be disposed of as special waste is avoided. Further advantages are that the memory module can be installed in many devices without space problems due to the division on two boards, and that only the corresponding board needs to be replaced in the event of a defective memory module because the motherboard and expansion board can be separated.

In a preferred embodiment, the main memory of the computer carrying the main memory (which, as usual, has plug contacts for plugging into a slot on the main board) is provided with a corresponding connection and fastening option for an expansion card, and the Expansion card has corresponding directly connectable to the motherboard, z. ^~ B. attachable, contacts and fasteners.

The memory module preferably has connecting elements for the mechanical connection of the motherboard and the expansion board. The contact elements can also act as (additional or sole) connecting elements by taking over the function of the mechanical connection of the motherboard and extension board (partially or completely). However, contact elements can also be provided (e.g. contact fields) that do not provide a mechanical connection function. Furthermore, additional connecting elements, for example fixing clips, can also be provided.

The connection and contact elements are preferably arranged such that the boards can be arranged parallel to one another. This design is in contrast to the usual arrangement in which circuit boards are inserted into corresponding sockets in the direction of the surface extension of the circuit board through the contact pieces (contact strips) which are generally arranged on the lower narrow side and which in turn have an insertion direction perpendicular to the motherboard . This should be avoided here, so that the motherboard and expansion board are arranged in parallel.

The boards can particularly preferably be arranged next to one another. In the case just described, the boards could also be arranged in one plane. However, the base and extension board are preferably arranged after assembly in two parallel planes which are as closely spaced apart as possible, preferably in such a way that the projection of the extension board does not exceed the limits of the base board. The projection of the expansion board preferably does not fall below the limits of the motherboard by more than 10 mm or 7 mm or 5 mm.

In particular, it is provided in preferred configurations that the outer dimensions of the motherboard and the expansion board essentially match, with the exception that the area of the contact strip of the motherboard and, if appropriate, a subsequent holding area over the Protrudes outside dimensions of the expansion board. This creates a maximum available board area, without the insertion of the memory module being hindered in conventional sockets.

The contact elements can preferably be brought into contact by pressing them together in a plane parallel to the plane of the circuit board. The contact elements are then preferably those known from Samtec under the name OPC-150-G-D-M-A. In this solution, the function of the mechanical connection of the expansion board to the main board is made using special connecting elements, e.g. Screws taken over, while otherwise the mechanical connection is usually taken over by the plug-in contact elements.

The releasable connection of the motherboard and expansion board is preferably designed as a plug or snap or screw connection. At least one fixing clip can be provided (as the sole connecting element or in addition to other connecting elements). This fixing clip preferably has a pressure surface via which a user can insert the memory module during installation comfortably and without risk of slipping and injury into the corresponding contact strip on the main board ("mainboard"). The at least one fixing clip (preferably two fixing clips) thus serves as an insertion aid for the installation of the memory module.

The memory module is preferably designed as a DIMM memory module (DIMM = dual in-line memory module). This includes embodiments as SO-DIMMs. The memory module preferably fulfills the Intel PC SDRAM specification and / or the JEDEC specification 21 -C, section 4: "Multi-Chip Memory Modules &Cards". The former specification is available from Intel Corporation, Santa Clara, California, USA and is available at http://developer.intel.com/design/chipsets/ memory / sdram.htm. The second specification is available from http://www.jedec.org/download/pub21/default.htm. For example, the memory module can be described in the document "PC SDRAM Registered DIMM Design Support Document, Revision 1.2, October 1998" by Intel Corporation have the same properties. The content of the named documents is hereby fully included in the present application.

The memory module preferably offers a readout function for data relating to the technical properties of the memory module (such as memory size, memory organization, access times, etc.). Such a function is described in detail in the document "PC SDRAM Serial Presence Detect (SPD), Revision 1.2A, December 1997" from Intel Corporation. The contents of this document, which can be obtained from the addresses given above, are hereby fully incorporated into the present application. This readout function also preferably or exclusively takes into account the technical properties of the memory elements of the expansion board. The data for the read-out function can be provided by at least one read-only memory (e.g. ROM or PROM or EPROM or EEPROM) or by wiring on the two boards or for example by solder bridges. Such wiring should also be understood as a "read-only memory" in the sense of the present application.

A read-only memory for providing the readout function is preferably provided on both the motherboard and the expansion board. If only the motherboard is used as an independent memory module, the read-only memory of the motherboard delivers the requested data. If an expansion board is plugged in, the read-only memory of the motherboard is deactivated, and only the read-only memory of the expansion board is used to provide the data for the readout function. In variant embodiments, the data from the two read-only memories can also be combined by a suitable circuit in the second case.

In preferred configurations, the motherboard and the expansion board each have driver circuits for amplifying signals (for example address and control signals). Likewise, a PLL circuit for clock formation can be provided on the motherboard and on the expansion board. In other words, the expansion board does not point in these configurations only memory modules, but could rather (apart from the non-standard connections) work as an independent memory module. Accordingly, the base board and also the expansion board preferably have the full word width of the entire memory module.

In order to offer memory expansion options that are as flexible as possible, in preferred embodiments the motherboard is a functional memory module in itself. It can then also be sold as a separate storage module. The buyer then only purchases a suitable expansion board if necessary to form a complete, two-tier memory module. Even without this feature, if only the motherboard and expansion board are functional together, the invention offers considerable advantages, which have already been described at the beginning.

Further features, advantages and objects of the invention will become apparent from the following detailed description of exemplary embodiments. Reference is hereby made to the accompanying drawings, which are expressly referred to for their clarity and clarity with regard to the disclosure. Show it:

1 is a schematic side view of an embodiment of the invention,

2a to 2d frontal views of the two sides of the motherboard and the expansion board in a slightly modified embodiment compared to FIG. 1,

3 shows a front view of the assembled memory module in the exemplary embodiment according to FIGS. 2a to 2d,

Fig. 4 is an enlarged perspective view of area IV of Fig. 3, and 5 and FIG. 6 are an enlarged side and front view of a fixing clip in the embodiment of FIGS. 3 and 4.

1 schematically shows a side view of a narrow side (shown here substantially thickened) of a memory module 1, also referred to as a circuit board arrangement, according to an exemplary embodiment of the invention. A motherboard 2 has an outer side 20 and an inner side 21 in the finished arrangement. Furthermore, the motherboard 2 carries main memory, namely memory modules 22 and 24 on the outer side 20 and memory modules 26 and 28 on the inner side 21. The motherboard 2 is provided at the bottom with the usual contact strip 30 for insertion into corresponding slots on a motherboard. Since the memory module 1 is a DIMM, the contact strip 30 has outer contacts 31 and inner contacts 32.

In addition to the motherboard 2 and parallel to it is an expansion board 4 with an outer side 40 and an inner side 41 (again related to the arrangement shown in FIG. 1). On the expansion board 4 there are memory expansions, namely memory chips 42 and 44 on the inner side 41 and memory chips 46 and 48 on the outer side 40. The memory expansions can be used to enlarge the working memory as required.

The expansion board 4 can e.g. by appropriate devices (not shown in Fig. 1) are screwed onto the motherboard 2, so that one or more contacts press against corresponding mating contacts on the motherboard (shown schematically as contact elements 45) and the two boards 2, 4 to each other for arrangement according to the invention connect.

The exemplary embodiment described with reference to the following figures differs slightly from the exemplary embodiment according to FIG. 1. Because of the great similarities, the same reference numerals are nevertheless used for corresponding elements. 2a shows the outer side 20 of the motherboard 2 and its component assembly. Nine memory chips 220-228 are arranged on the outer side 20 using a surface mounting technique. Furthermore, driver circuits 230, 231 are provided for amplifying address and control signals. The contact strip 31 has three contact field sections 310, 311, 312, which are separated from one another by notches. On the left narrow side of the motherboard 2 in FIG. 2a, two holding holes 50, 51, a notch 52 and a further hole 53 are provided. Correspondingly, the right narrow side has holding holes 54, 55, a notch 56 and a further hole 57.

The inner side 21 of the motherboard 2 shown in FIG. 2b, like the outer side 20, is provided with nine memory chips 260-268. Here, the contact strip 32 is separated into corresponding contact field sections 320, 321, 322 by the notches already mentioned. A PLL circuit 270 for clock shaping (PLL = phase locked loop) and a read-only memory 271 designed as an EEPROM are provided as further components. Two socket strips 452, 453 contain a multiplicity of contact elements and essentially provide the signals of the contact strip 30 for an expansion board.

If the motherboard 2 just described is inserted into a computer or other device, it works as an independent memory module with a memory bank according to the PC SDRAM specification already mentioned above. The only external differences from known memory modules are the holding holes 50, 51, 54 and 55 and the socket strips 452, 453.

2c, the inner side 41 of the expansion board 4 is shown. In terms of its electrical equipment, this side 41 corresponds mirror-symmetrically to the inner side 21 of the motherboard 2. There are also nine memory modules 420 - 428, a PLL circuit 430 for clock formation and a read-only memory 431 in the form of an EEPROM. Plug strips 450, 451, which have a multiplicity of contact elements, are provided to match the socket strips 452, 453 of the motherboard 2 and are able to form an electrical connection with them. The expansion board 4 has holding holes on its narrow sides 60, 61 or 64, 65 and a recess 62 or 66 each. The expansion board 4 ends without a contact strip in a lower longitudinal edge 63 in FIG. 2c.

The outer side 40 of the expansion board 4 shown in FIG. 2d is mirror-symmetrical with regard to its electrical structure to the outer side 20 of the main board 2. Here, too, there are nine memory modules 460-468 and two driver circuits 470, 471.

For operation as a two-tier memory module, the expansion board 4 with its plug strips 450, 451 is plugged onto the socket strips 452, 453 of the motherboard 2. This results in a memory module according to the PC SDRAM specification already mentioned with two memory banks. Of the four chip select signals present on the contact strip 30, two are routed to the memory modules of the motherboard 2 and two to the memory modules of the expansion board 4.

The two read-only memories 271, 431 each contain data about the memory module 1, as described in the already mentioned document "PC SDRAM Serial Presence Detect (SPD)". The functionality for reading out this data is also specified in this document. The data in the read-only memory 271 correspond to the technical properties of the motherboard 2. If the motherboard 2 is used as an independent memory module, the relevant data can therefore be read from the read-only memory 271.

The data in the read-only memory 431, on the other hand, correspond to the technical properties of the two-storey memory module 1 with motherboard and expansion board 2, 4. By plugging in the expansion board 4, the read-only memory 271 of the motherboard 2 is deactivated. In the exemplary embodiment described here, a contact of the socket strips 452, 453 is connected to a chip selection input of the read-only memory 271, and the corresponding contact of the plug strips 450, 451 is firmly connected to a deactivating signal level on the expansion board 4. With a two-tier memory module 1, only the read-only memory 431 of the expansion board is thus 4 read out. Appropriate measures must of course be taken to ensure that expansion boards 4 are only plugged onto basic boards 2 whose technical data are compatible with the data stored in the read-only memory 431. Such measures can be logistical measures and / or optical identification and / or mechanical coding, for example.

3 shows the plugged-in memory module 1. Mainly the outer side 40 of the expansion board 4 can be seen. In the area of the contact strip 30 (more precisely, its inner side 32) and in a holding area adjoining it on both sides, which extends laterally up to the Notches 52, 56 or the recesses 62, 66, the expansion board 4 has about 3 mm -

5 mm smaller outer dimensions than the motherboard 2. In these areas, the inner side 21 of the motherboard 2 is visible in FIG. 3. Along the remaining outer circumference, the two boards 2, 4 have identical dimensions. Due to this design, a large usable area is available on the expansion board 4 without the insertion of the memory module 1 in conventional versions being hindered by the plugged-on expansion board 4. The thickness of the entire memory module 1 is small and is approximately 9 mm. The boards 2, 4 are arranged approximately parallel to one another.

FIG. 3 shows two fixing clips 70 which act as connecting elements, the more precise structure of which will now be explained with reference to FIGS. 5 and 6. Each fixing clip 70 has two parallel tongues 71, 72 and an upper connecting section 73 in FIGS. 3-6. A flat bearing surface 710 is provided on the tongue 71, on which cylindrical, chamfered holding projections 711, 712 are formed. Accordingly, the tongue 72 has a flat bearing surface 720 and two holding projections 721, 722. The arrangement of the holding projections 711, 712, 721, 722, as shown in FIG. 6, is offset toward a lateral edge of the corresponding contact surfaces 710, 720. The connecting section 73 has two lugs 731, 732 projecting in the direction of the support surfaces 710, 720 and an upper pressure surface 730. The fixing bracket 70 O 00/52976 ₁ - | PCT / EPOO / 00019

consists of an elastic plastic material, for example un reinforced PBT (Pocan).

As shown in FIG. 3 and in the perspective illustration of FIG. 4, the fixing clips 70 in the assembled memory module 1 serve as connecting elements for holding the boards 2, 4 together. In addition, the plug and socket strips 450-453 perform a certain mechanical connection function, so that the memory module 1 has sufficient stability.

The fixing bracket 70 in its orientation shown in FIG. 6 is located on the right in the memory module 1 of FIG. 3 and is shown enlarged in FIG. 4. The inner side 41 of the expansion board 4 lies against the support surface 710, and the holding projections 711 and 712 engage in the holding holes 60, 61, projecting into the expansion board 4 almost up to the outer side 40 thereof. The connecting section 73 engages around the upper edge of the expansion board 4, so that the nose 731 protrudes somewhat into the outer side 40 from above. Correspondingly, the inner side 21 of the motherboard 2 lies against the support surface 720, the holding projections 721 and 722 engage in the holding holes 50, 51, and the nose 732 projects somewhat onto the outer side 20. The other fixing clip 70 on the left side of the 3 is arranged mirror-symmetrically. Because of the asymmetrical design of the fixing clips 70 according to FIG. 6, this arrangement ensures that a maximum assembly area remains on the circuit boards 2, 4 without the fixing clips 70 coming into contact with component connections.

To assemble the memory module 1, two fixing clips 70 are first snapped onto the motherboard 2. During snapping, the nose 732 (or 731) is pushed back by the upper edge of the base plate 2, so that the connecting section 73 is briefly elastically deformed. The expansion board 4 is now pressed onto this assembly, so that on the one hand the electrical connection via the plug and socket strips 450-453 and on the other hand the mechanical connection by snapping the expansion terungsplatine 4 are made in the two fixing clips 70. The memory module 1 is now ready for use.

When installing the memory module 1 in a computer or other device, the pressure surfaces 730 of the fixing clamps 70 serve as an installation aid in order to hold the memory module 1 and to insert it into an intended slot, with a pressure in one direction parallel to the board levels in FIG 3 is exercised downwards. Since the printing surfaces 730 are essentially perpendicular to the printing direction and have a significantly larger surface area than bare sheet edges, the installation is considerably simplified. The risk of slipping and injury is reduced and the installation can be carried out in a more controlled manner. The printing surfaces 730 can be straight or ergonomically curved as well as smooth or corrugated or structured in some other way.

The details contained in the above description of exemplary embodiments are not to be interpreted as limitations on the scope of the invention, but rather as examples of preferred embodiments. Many other modifications are possible and obvious to the person skilled in the art. The scope of the invention should therefore not be determined by the exemplary embodiments shown, but rather by the appended claims and their equivalents.

Claims

claims

1. memory module (1) with a base plate (2) having memory elements (22, 24, 26, 28; 220 - 228, 260 - 268) and a further memory element (42, 44, 46, 48; 420 - 428, 460 - 468) having expansion board (4), the base board (2) and the expansion board (4) having corresponding contact elements (45; 450-453), so that the expansion board (4) can be connected to the base board (2).

2. Memory module (1) according to claim 1, in which connecting elements (45; 450 - 453, 70) are provided for the mechanical connection of the motherboard (2) and expansion board (4).

3. Memory module (1) according to claim 2, wherein the contact elements (45;

450 - 453) also act as connecting elements (45; 450 - 453, 70) by at least partially taking over the function of the mechanical connection of the base board (2) and expansion board (4).

4. Memory module (1) with a base board (2) for a computer or the like, which has exclusively storage elements (22, 24, 26, 28; 220 - 228, 260 - 268), and an expansion board (4) for the storage elements (22, 24, 26, 28; 220 - 228, 260 - 268) of the motherboard (2), the motherboard (2) and extension board (4) having corresponding connection and contact elements (45; 450 - 453, 70), such that the expansion board (4) can be connected directly to the main board (2) and connected to it.

5. Memory module (1) according to one of claims 2 to 4, in which the connection and contact elements (45; 450 - 453, 70) are arranged such that the base board (2) and the expansion board (4) parallel to each other and / or can be arranged side by side.

6. Memory module (1) according to one of claims 1 to 5, in which the contact elements (45; 450 - 453) can be connected by pressing together in a plane parallel to the board levels.

7. Memory module (1) according to one of claims 1 to 6, in which the motherboard (2) has a contact strip (30) for connecting the memory module (1), and in which the lateral outer dimensions of the motherboard (2) and the expansion board ( 4) essentially match, but the area of the contact strip (30) of the motherboard (2) and, if appropriate, an adjoining holding area protrude beyond the lateral outer dimensions of the expansion board (4).

8. Memory module (1) according to one of claims 1 to 7, in which the expansion board (4) on the base board (2) can be plugged and / or snapped on and / or screwed on.

9. memory module (1) according to one of claims 2 to 8, wherein the connecting elements (45; 450 - 453, 70) comprise at least one fixing bracket (70).

10. The memory module (1) according to claim 9, wherein the at least one fixing clip (70) is further configured with a pressure surface (730) as an insertion aid for the installation of the memory module (1).

11. Memory module (1) according to one of claims 1 to 10, which is designed as a DIMM memory module and preferably the Intel PC SDRAM specification and / or the JEDEC specification 21-C, section 4, "Multi-Chip Memory Modules & Cards ".

12. Memory module (1) according to one of claims 1 to 11, which provides a readout function for data, the technical properties of the memory module

(1) relate to at least the technical properties of the memory elements (42, 44, 46, 48; 420 - 428, 460 - 468) of the expansion board (4).

13. Memory module (1) according to claim 12, wherein the motherboard (2) and the expansion board (4) each have a read-only memory (271, 431) for providing the readout function, the read-only memory (271) of the motherboard (2) when connected Expansion board (2) is deactivated.

14. Memory module (1) according to one of claims 1 to 13, wherein the motherboard (2) and the expansion board (4) each have driver circuits (230, 231, 470, 471) to amplify at least address and control signals.

15. Memory module (1) according to one of claims 1 to 14, in which the base board (2) and the expansion board (4) each have a PLL circuit (270, 430) for clock formation.

16. Memory module (1) according to one of claims 1 to 15, in which the

Word width of the motherboard (2) is equal to the word width of the expansion board (4) and equal to the word width of the entire memory module (1).

17. Memory module (1) according to one of claims 1 to 16, in which the base board (2) is a functional memory module in itself.

18, memory module (2), consisting of the motherboard (2) of a memory module (1) according to claim 17.

19. expansion board (4) for a motherboard (2) for forming a memory module (1) according to claim 17.