US20010054627A1 - Method and apparatus for dispensing viscous material - Google Patents
Method and apparatus for dispensing viscous material Download PDFInfo
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- US20010054627A1 US20010054627A1 US09/358,981 US35898199A US2001054627A1 US 20010054627 A1 US20010054627 A1 US 20010054627A1 US 35898199 A US35898199 A US 35898199A US 2001054627 A1 US2001054627 A1 US 2001054627A1
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- viscous material
- diaphragm
- compression head
- stencil
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41F—PRINTING MACHINES OR PRESSES
- B41F15/00—Screen printers
- B41F15/14—Details
- B41F15/40—Inking units
- B41F15/42—Inking units comprising squeegees or doctors
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
- H05K3/12—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns
- H05K3/1216—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns by screen printing or stencil printing
- H05K3/1233—Methods or means for supplying the conductive material and for forcing it through the screen or stencil
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
- H05K2203/01—Tools for processing; Objects used during processing
- H05K2203/0104—Tools for processing; Objects used during processing for patterning or coating
- H05K2203/0126—Dispenser, e.g. for solder paste, for supplying conductive paste for screen printing or for filling holes
Abstract
Description
- This application is a continuation in part from pending U.S. patent application Ser. No. 08/716,037 (filed Sep. 19, 1996), which is a continuation of U.S. patent application Ser. No. 08/363,806 (filed Dec. 27, 1994, and now abandoned).
- 1. Field of the Invention
- Embodiments of the present invention relate generally to methods and devices for depositing viscous materials onto a printed wiring board. In one aspect, the present invention relates to methods and devices for compressing viscous materials, such as solder paste, through openings in a perforated substrate, such as a patterned screen or stencil.
- 2. Description of Related Art
- Surface Mount Technology (SMT) involves placing circuit components onto circuit paths embedded on the upper surface of a printed wiring board and then soldering the components in place by a process called “reflow soldering”. Before the circuit component is placed on the printed wiring board, however, it is desirable to apply solder paste to the area on the printed wiring board where the component is to be soldered into place.
- Conventional methods do exist to deposit (“print”) solder paste onto desired areas of a printed wiring board by forcing the paste through openings in a substrate (e.g., a stencil) placed in intimate contact with the printed wiring board.
- U.S. Pat. No. 4,622,239 describes such a method and device for dispensing viscous materials. The method includes forcing a viscous material from a housing through an opening and depositing it onto a stencil between a pair of flexible members (parallel squeegee blades) which depend from the housing on either side of the opening and are in contact with the stencil. The ends of the flexible members are not connected and remain open ended. The viscous material, accordingly, is not contained within an enclosed area when it is deposited on the surface of the stencil. Movement of the housing and the flexible members horizontally across the stencil causes the trailing flexible member to force the viscous material through the openings in the stencil. U.S. Pat. No. 4,720,402 describes a similar method and device except that the leading flexible member is raised off of the stencil during movement of the housing.
- U.S. Pat. Nos. 5,133,120 and 5,191,709 describe methods for filling through-holes of a printed wiring board via a mask with pressurized conductive filler material by means of a nozzle assembly unit having a nozzle tip member. The nozzle tip member, however, is designed only to dispense the pressurized conductive filler material through the mask to a single through-hole. The nozzle tip member then “scans” the printed wiring board for a second through-hole to fill. The nozzle tip member has a blunt end section which rests on the mask and a circular exit, the diameter of which may be increased or decreased by changing the nozzle tip member. The nozzle tip member dispenses the filler material without controlling unwanted flow of “excessive” filler material back through the stencil. Additionally, the nozzle tip member does not define a contained environment where “compression” of the filler material takes place through the mask followed by the immediate shearing off of the filler material within that contained environment from the surface of the stencil. In fact, the nozzle tip member itself provides no effective means for shearing off filler material from the top of the stencil, rather, after the through hole is filled and filler material “backs up” through the stencil, the nozzle tip member moves forward whereupon the “excessive” filler material is then wiped off by a separate, single, flexible squeegee member which is designed for unidirectional use only.
- Unfortunately, these conventional efforts do not provide a contained environment for compression of viscous material through holes in a stencil and shearing of viscous material within the contained environment from the upper surface of the stencil. Reliance upon squeegee movement to force the viscous material, such as solder paste, through the stencil openings can lead to damage and eventual failure of both the squeegee blades and the stencil due to repeated friction. Since conventional efforts do not provide a contained environment in which compression and shearing is accomplished, waste of the viscous material is frequently encountered.
- Conventional efforts, therefore, (1) fail to maximize the efficiency of printing solder paste onto a desired area of a printed wiring board and (2) fail to minimize waste of the solder paste during the printing process. A need therefore exists to develop a method for printing solder paste onto a printed wiring board and a device suitable for use therewith which overcomes the deficiencies of the conventional efforts.
- Other methods which utilize a pneumatically driven piston, or a direct injection or application of air or other gasses, to force viscous material from a syringe, have several drawbacks. For example, air or other gases which are used to directly expel the paste or viscous material from the container, or which are used to selectively move a piston, oftentimes cause undesirable voids in material. Moreover, in order to selectively expel the entire contained quantity of the viscous material from the syringe, the stroke of the pneumatically driven piston must be substantially as long as the syringe. The use of relatively small and inexpensive conventional pistons therefore requires the concomitant use of many short syringes which must be frequently replaced and/or refilled, thereby undesirably increasing production time and concomitantly decreasing production efficiency. The use of longer more expensive pistons allows for the use of larger syringes containing more viscous material and requiring less frequent replacement and/or re-filling. However, these large pistons are relatively heavy, thereby requiring costly and undesirable structural modifications to the compression head, are difficult to package, and/or are difficult and/or awkward to replace.
- The present invention is directed at eliminating the need for a pneumatically driven piston while allowing for the selective distribution of a relatively large amount of viscous material.
- The present invention includes a novel apparatus and method for dispensing viscous material through openings in a stencil. Embodiments of the present invention include a process herein referred to as “compression printing” wherein pressure is applied to a viscous material within a contained environment defined by a compression head cap so as to compress it through openings in a stencil.
- The apparatus of the present invention includes a reservoir containing viscous material which is operably connected to a pressure source. The reservoir is in fluid communication with a housing which terminates in a substantially uniform opening defined by a compression head cap formed from contiguous walls. During operation of the apparatus, the compression head cap is placed in contact with a stencil having a plurality of openings therein. The compression head cap and the stencil form a contained environment. The pressure source then applies pressure against the viscous material contained in the reservoir forcing it from the reservoir into the housing and to the compression head cap. The contiguous walls of the compression head cap act to contain and to direct flow of the pressurized viscous material to the top surface of the stencil and then through the openings in the stencil.
- It is accordingly an object of the present invention to provide a novel apparatus for compressing a viscous material through openings in a stencil by means of a pressure source. It is a further object of the present invention to increase the efficiency of printing viscous material onto a desired area of a printed wiring board and to minimize waste of the viscous material during the printing process.
- According to another object of the present invention, an apparatus is provided for selectively dispensing viscous material. The apparatus includes a selectively expandable diaphragm which selectively and expandably causes said contained viscous material to be dispensed.
- According to yet another object of the present invention, a method to selectively dispense viscous material is provided. The method includes the steps of providing the viscous material; placing the provided viscous material within a container having a dispensing aperture; placing a member over the contained viscous material; providing a selectively inflatable diaphragm in close proximity to the member; and selectively inflating the diaphragm effective to selectively move the member within the container, thereby causing the member to force at least a portion of the contained viscous material through the dispensing aperture.
- Other objects, features or advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings.
- In the course of the detailed description of certain preferred embodiments to follow, reference will be made to the attached drawings, in which,
- FIG. 1 is a perspective view of the apparatus of the present invention, partially exploded.
- FIG. 2 is a side cross-sectional view of a compression head, a compression head cap, a stencil and a printed wiring board of the present invention showing movement of the solder paste through the compression head, the compression head cap and the openings of the stencil onto the printed wiring board.
- FIG. 3 is a bottom perspective view of the compression head cap of the present invention, partially broken away.
- FIG. 4 is an exploded perspective view of the compression head of the present invention showing components of the compression head cap and one embodiment of a diffuser of the present invention.
- FIG. 5 is an exploded perspective view of the compression head of the present invention showing components of the compression head cap and a second embodiment of a diffuser of the present invention.
- FIG. 6 is a cross-sectional view of a viscous material dispenser made in accordance with the teachings of a second embodiment of the invention and having a selectively expandable diaphragm which is shown in a selectively contracted position;
- FIG. 7 is a view similar to that of FIG. 6 but showing the contained diaphragm in a selectively expanded and material dispensing position;
- FIG. 8 is a top view of the viscous material dispensing apparatus shown in FIGS. 6 and 7;
- FIG. 9 is a bottom unassembled perspective view of the cap and retaining ring portion of the viscous material dispensing apparatus shown in FIGS. 6 and 7;
- FIG. 10 is a cross-sectional view of a viscous material dispensing apparatus made in accordance with the teachings of an alternate embodiment of the invention and having a selectively expandable diaphragm which is shown in a selectively contracted position;
- FIG. 11 is a view similar to that of FIG. 10 but showing the contained diaphragm in a selectively expanded and material dispensing position;
- FIG. 12 is a cross-sectional view of a viscous material dispensing apparatus made in accordance with the teachings of another alternate embodiment of the invention and having a selectively expandable diaphragm which is shown in a selectively contracted position;
- FIG. 13 is a view similar to that of FIG. 12 but showing the contained diaphragm in a selectively expanded and material dispensing position;
- FIG. 14 is a cross-sectional view of a viscous material dispensing apparatus made in accordance with the teachings of yet another alternative embodiment of the invention and having a selectively expandable diaphragm which is shown in a selectively contracted position; and
- FIG. 15 is a view similar to that of FIG. 14 but showing the contained diaphragm in a selectively expanded and material dispensing position.
- The principles of the present invention may be applied with particular advantage to obtain an apparatus for compressing a viscous material through openings in a stencil, preferred embodiments of which may be seen at FIGS. 1, 2,3, 4, and 5 which are described more fully below.
- FIG. 1 is a partially exploded perspective view of one embodiment of the apparatus of the present invention. As can be generally seen at FIG. 1, the apparatus has a
pressure source 2 which is operably connected to a reservoir 4 containing a supply of a viscous material, acompression head 6 and acompression head cap 8. - More particularly, FIG. 1 shows a pressure source depicted as an
air cylinder 2 having a piston (not shown) connected to arod 10 contained in acylinder housing 12.Pressure inlet 14 allows for the introduction of air pressure at the top ofair cylinder 2 thereby displacing the piston causingpiston rod 10 to move downward. Theair cylinder 2 is mounted viabase 16 tocylinder mount 18 which in turn is removably mounted to casing 20 via a twist socketconnector having posts 22 and socket grooves, one of which is shown at 24.Base 16 hasair inlet 26 for the introduction of air pressure at the bottom ofair cylinder 2 thereby displacing the piston causingpiston rod 10 to move upward. -
Piston rod 10 extends through opening 28 ofcylinder mount 18 and is fixedly connected tosyringe pusher 30 atcontact 32 which in turn engagesdisplacement piece 34 which is movably disposed within syringe 4 which contains a viscous material.Displacement piece 34 acts as a plunger and is designed to mate with the interior of syringe 4 to ensure effective displacement of viscous material with minimal waste. Pressuresource 2 is designed to mechanically meter out viscous material through operation of thesyringe pusher 30 on thedisplacement piece 34. Thesyringe pusher 30,displacement piece 34 and syringe 4 are all vertically housed in operative fashion within thecylinder mount 18, thecasing 20 and thesyringe housing 36. - The vertical arrangement of the
pressure source 2 and the syringe 4 containing the viscous material is a preferred arrangement which advantageously provides for even and direct pressure in metering out the viscous material onto the top surface of a stencil. It is to be understood thatpressure source 2 is not limited to an air cylinder of the type depicted in FIG. 1, but that other suitable pressure sources may be used by one of ordinary skill in the art based upon the teachings of the present invention. Such pressure sources include those which mechanically, electrically, or hydraulically operate a mechanical force, such as a piston rod and displacement piece, to meter out viscous material from a syringe housing or other reservoir which contains viscous material. In addition, pneumatic pressure may be used directly to force viscous material from a reservoir housing. Also, pressure source and reservoir configurations other than the vertical configuration depicted in FIG. 1 are useful in the present invention. Such configurations include side mounted reservoirs and pressure sources or other configurations readily known to those skilled in the art. - The syringe4 is preferably a disposable unit which can be replaced when desired by disconnecting
cylinder mount 18 from casing 20 via the twist socket connector, removing the syringe and replacing it with an alternate syringe. Examples of disposable syringes useful within the teachings of the present invention include those which are readily commercially available from Methods Engineering, Vauxhall, N.J. The cartridges may be purchased prefilled with suitable viscous materials or they may be purchased empty and then filled with suitable viscous materials, such as solder pastes, which are useful within the practice of the present invention. Useful solder pastes may be readily commercially available from Alpha Metals, Jersey City, N.J. - Typical solder pastes useful with surface mount technology generally contain an alloy of tin, lead and silver in various proportions in combination with other useful solder paste metals, viscosity agents, flux and/or solvents depending upon the desired use of the solder paste. Solder pastes useful in the present invention will become apparent to one of ordinary skill in the art based upon the teachings herein.
- The
syringe housing 36 is mounted to a housing referred to herein as a compression head generally depicted at 6 in FIG. 1 and shown in a cross-sectional side view in FIG. 2. The syringe 4 has flange opening 38 which is inserted into and mates withfirst opening 40 ofcompression head 6 which is described hereafter with reference to both FIGS. 1 and 2 and FIG. 3 which is a bottom perspective view of thecompression head cap 8, partially broken away. Thecompression head 6 terminates in a substantially uniformsecond opening 42 which is defined bycompression head cap 8. Thecompression head cap 8 is formed from contiguous walls which define avolume 44 withincompression head cap 8. The contiguous walls may be either unitary or formed from separate elements and are designed to contactstencil 46 to provide a uniform and substantially flush union withstencil 46 at the point of contact. As can be seen in FIG. 2,stencil 46 hasopenings 48 and is placed in an operable relationship with a printedwiring board 50. Thestencil 46 may be placed in intimate contact with printedwiring board 50 or, as shown in FIG. 2, it may be placed a distance above printedwiring board 50 such that pressure from thecompression head 6 forces thestencil 46 into contact with printedwiring board 50. Althoughstencil 46 is shown in cross-section, it is to be understood thatopenings 48 may have any desired orientation onstencil 46.Further openings 48 may differ in size depending upon the area of the printedwiring board 50 to be printed with the viscous material. Thecompression head cap 8 andstencil 46 together form a containedenvironment 44 for the viscous material during operation of the apparatus of the present invention. - As can be seen in FIG. 1, cross
bar mount 52 is attached tosyringe housing 36 viaflange 54. Cross bar mount 52 is also attached to a mechanism (not shown) for horizontally displacing the apparatus of the present invention along thestencil 46. - The
compression head 6 is preferably formed from metal, such as iron or stainless steel or other material suitable for use with pressurized viscous material. Thecompression head 6 hastop surface 56 which serves as the base to which thesyringe housing 36 is attached. Side surfaces 58 and 60 extending fromtop surface 56 slope away from each other as depicted in FIG. 1 to define an increasing length ofcompression head 6. Front and back surfaces 62 and 64 are contiguous withside surfaces compression head 6. The side surfaces join with the front and back surfaces to define a taperedinterior chamber 66 as shown in FIG. 2 which acts to restrict flow of viscous material throughcompression head 6.Interior chamber 66 terminates in generallyrectangular exit 68.Compression head 6 preferably acts as a nozzle to direct and constrict the flow of viscous material through generallyrectangular exit 68. Thecompression head cap 6 defines avolume 44 surrounding therectangular exit 68 and into which viscous material flows after exiting theinterior chamber 66 ofcompression head 6. As shown in FIG. 2, thevolume 44 is preferably a separate chamber into which the viscous material flows after exiting theinterior chamber 66 viarectangular exit 68. Thecompression head cap 8 defines a generallyrectangular opening 42 which is to be contacted withstencil 48. Thecompression head cap 8 acts to contain and direct the flow of viscous material to thestencil 46. In an alternate embodiment, it is to be understood that theinterior chamber 66 may terminate directly intocompression head cap 8 without the need forrectangular exit 68 orvolume 44. - As can be seen in FIG. 4, the
compression head 6 has twohalf sections 70 which are fixedly connected by screws (not shown) via screw holes 72. Thebottom side section 74 of eachhalf section 70 is provided withledge area 76 to engage thecompression head cap 8. As depicted in FIGS. 2, 3 and 4,compression head cap 8 hasrectangular blades 78 andend caps 80, which define generallyrectangular opening 42.Blades 78 are each fixedly mounted to a correspondingledge area 76 offront surface 62 and backsurface 64, respectively, by means of correspondingrectangular blade holders 82 and screws (not shown) via screw holes 84.Blades 78 each extend along substantially the entire length of correspondingledge area 76. End caps 80 are attached to a correspondingledge area 76 ofbottom side section 74 via corresponding cap mounts 86 and screws (not shown) via screw holes 88. The end caps 80 are contiguous withblades 78 and together form thecompression head cap 8. As can be seen more clearly in FIG. 2,blades 78 parallel the slope of corresponding front and back surfaces 62 and 64, and are, therefore, seen to be angled inward relative to theinterior chamber 66 ofcompression head 8. -
Blades 78 are preferably thin and formed from rigid material such as iron or stainless steel. End caps 80 are preferably formed from a flexible substance such as polyurethane to avoid damage to the stencil during operation of the apparatus of the present invention. Cap mounts 86 andblade holders 82 are formed from any solid material capable of securing the corresponding end cap or blade. - While the
compression head cap 8 is depicted in FIGS. 2, 3, and 4 as being formed from integral parts, it is to be understood that compression head caps having a unitary structure are within the teachings of the present invention. Such unitary compression head caps are formed from a single rectangular shaped unit and are designed to encircle theledge area 76 of thecompression head 6 or otherwise operatively engagecompression head 6. Such compression head caps may be either fixed or removably mounted to the compression head and may have various sizes ofopening 42. - The
compression head 6 andcompression head cap 8, in combination with thepressure source 2 and syringe 4 advantageously provide a vertical down force to move the viscous material evenly and directly to the stencil. Thecompression head cap 8 of the present invention advantageously provides a contained environment to direct and to aid in the extruding of pressurized viscous material through openings in the stencil. The extruded viscous material is then deposited on the pattern of the printed wiring board. The apparatus of the present invention provides for very high speed printing capability while maintaining print definition and reduced cycle time. Waste of viscous material is minimized due to the contained environment provided by thecompression head cap 8. The length of thecompression head cap 8 allows for simultaneous compression printing through a plurality ofopenings 48 instencil 46. Furthermore, the trailingblade 78 relative to the direction of operation advantageously operates to shear off the viscous material contacting the stencil within thecompression head cap 8 when the apparatus of the present invention is horizontally disposed across the stencil. Theblades 78 are rigid and angled to advantageously achieve a smooth shearing of the viscous material. Thecompression head 6 andcompression head cap 8 are advantageously rectangular in shape so that they may operate over a significant area of the stencil with each pass. Additionally, given the dual blade design of thecompression head cap 8, the apparatus of the present invention may operate in both the forward and reverse directions thereby improving the efficiency of the compression printing process of the present invention. - As can be further seen in FIGS. 2 and 4,
compression head 6 hasdiffuser 90 which is fixedly mounted withininterior chamber 66.Diffuser 90 has a plurality ofdiffuser plates 92 which are horizontally disposed withininterior chamber 66 viagrooves 94. Eachdiffuser plate 92 has a series ofopenings 96 through which viscous material is to flow. Eachopening 96 may be either circular or oblong and decreases in average size as the diffuser plates progress from thefirst opening 40 to thecompression head cap 8. Theopenings 96 also increase in number as the diffuser plates progress from thefirst opening 40 to thecompression head cap 8. Thediffuser 90 advantageously serves to break up the flow of viscous material and evenly and uniformly distribute it from side to side of therectangular exit 42. Thediffuser 90 may also serve to reduce the velocity of the viscous material flowing through the compression head and increase the static pressure of the viscous material which aids in the compression printing process. - FIG. 5 shows an alternate embodiment of a
diffuser 90 useful in the present invention. Thediffuser 90 has a plurality ofdiffuser islands 98 which are horizontally disposed in rows withininterior chamber 66. Thediffuser islands 98 may be fixedly installed within theinterior chamber 66 or they may be molded directly within theinterior chamber 66. As with thediffuser 90 of FIG. 4, eachdiffuser island 98 acts to break up the flow of the viscous material and uniformly and evenly distribute it from side to side ofrectangular exit 42. The diffuser islands may be either circular or oblong and decrease in average size as the rows progress from thefirst opening 40 to thecompression head cap 8. Thediffuser islands 98 also increase in number as the rows progress from thefirst opening 40 to thecompression head cap 8. Thediffuser islands 98 of the present invention are advantageous in that they provide for ease of fabrication of the compression head and ease of cleaning. - Operation of the apparatus of the present invention is now described as follows with reference to FIGS. 1 and 2. When compression printing according to the teachings of the present invention, the
compression head cap 8 of the apparatus of the present invention is brought into contact with the top surface ofstencil 46 which forces the stencil downward until it is in intimate contact with the printed wiring board below as shown in FIG. 2. The apparatus is then moved in a horizontal direction, as shown in FIG. 2, across thestencil 46. - During movement of the stencil,
pressure source 2 acts on syringe 4 to forceviscous material 100 from the syringe 4 into theinterior chamber 66 ofcompression head 6 where it is diffused bydiffuser 90 and directed torectangular exit 68. The viscous material then entersvolume 44 ofcompression head cap 8 which provides a contained environment viablades 78 andend caps 80 to direct the pressurized viscous material under pressure to the top surface ofstencil 46. The viscous material is then extruded throughopenings 48 in thestencil 46 over which thecompression head cap 8 travels. The extrudedviscous material 100 is thereby printed on the printedwiring board 50. Movement of thecompression head cap 8 across the stencil surface causes the trailingblade 78 which is angled inwardly relative to theinterior chamber 66 to shear off the viscous material from the top surface ofstencil 46. Once the apparatus has traversed the length of the stencil, the apparatus may simply reverse its direction and continue the compression printing process since thecompression head cap 8 hasdual blades 78 to accomplish the shearing process in either direction of movement. - Operating variables of the apparatus of the present invention, such as run speed and pressure, may be adjusted to accommodate either viscous materials having a wide range of viscosities or stencils with holes having a wide range of diameters. The following data in Table 1 is representative of the parameters at which the apparatus has successfully operated. Print speed is measures in inches per second, air pressure is measured in pounds per square inch, viscosity of the solder paste is measured in centipoises per second, stencil apertures are measured in inches, and the particle sizes of the solder pastes used are between 10-37 microns.
TABLE 1 Print Speed Viscosity Aperture (inches/sec.) (cps) (inches) Low High Air Pressure (psi) Low High Low High 0.94 1.26 20 850K 1.0M 0.0055 >0.025 1.45 1.70 20 850K 1.0M 0.0055 >0.025 2.27 2.31 20 850K 1.0M 0.0055 >0.025 3.10 3.89 30 850K 1.0M 0.0055 >0.025 4.20 4.77 30 850K 1.0M 0.0055 >0.025 5.98 6.62 40-50 850K 1.0M 0.0075 >0.025 6.69 7.23 50-60 850K 1.0M 0.0075 >0.025 7.70 12 50-60 850K 1.0M 0.0075 >0.025 - As indicated by the above data, the apparatus of the present invention successfully operated over a wide range of print speeds, air pressures and stencil openings. The compression printing method disclosed herein advantageously provides for quicker print speeds, better quality of printing, and less waste of solder paste material than is encountered with conventional printing methods.
- While the above-delineated invention provides significant improvement over prior dispensers and dispensing methods, it has several drawbacks. Particularly, the stroke of the pneumatically driven piston must be substantially as long as the syringe in order to selectively expel the entire contained quantity of the viscous material from the syringe. The use of relatively small and inexpensive conventional pistons therefore requires the concomitant use of many short syringes which must be frequently replaced and/or “re-filled”, thereby undesirably increasing production time and concomitantly decreasing production efficiency. The use of longer more expensive pistons allows for the use of larger syringes which contain more viscous material and require less frequent replacement and/or “re-filling” of material. However, these large pistons are relatively heavy, thereby requiring the compression head to be undesirably and structurally modified and “strengthened” in order to accommodate the increased piston weight. These large pistons are also difficult to package and are difficult and awkward to replace and service.
- These drawbacks are addressed by the following additional embodiments which substantially eliminate the need for a pneumatically driven piston or
air cylinder 2 and which allow for the selective distribution of a relatively large amount of contained material. - Referring now to FIGS. 6 through 9, there is shown an
apparatus 200 which selectively dispenses viscous material and which is made in accordance with the teachings of a second embodiment of the invention. -
Apparatus 200 includes a substantially cylindrical and generally hollowelongated housing 202 containing a substantiallyuniform cavity 203 having a generally circular cross-sectional area.Housing 202 is manufactured from a relatively strong and durable conventional and commercially available material, such as plastic or metal, and further includes an integrally formed base orflange portion 206 having four substantially identical openings orapertures 208 which are each adapted to selectively receive a conventional fastener orscrew 210.Cavity 203 terminates withinportion 206 by forming a relatively small and generally circularmaterial dispensing aperture 211.Housing 202 further includes two opposing and laterally extendingconnector posts 212, which are used to selectively allowcap 222 to be removably secured upon thehousing 202. -
Apparatus 200 further includes a generally flat mountingmember 226 having four substantiallyidentical apertures 228 which are each adapted to be selectively and communicatively aligned with a unique one of theapertures 208 and to selectively receive a unique one of thefasteners 210.Apertures fasteners 210 cooperatively and selectively allowhousing 202 to be selectively mounted upon a compression printing head. Mountingmember 226 further forms and/or includes an aperture orchannel 230 and an integrally formed and generally circular raised projection portion 231 which is adapted to be operatively inserted within theaperture 211 and which cooperates with the interior surface ofhousing 202 to form a generallycircular retention groove 233.Aperture 230 communicates withcavity 203, throughaperture 211, and selectively receives and directs the flow of viscous material to the compression head in a manner which will be explained. -
Syringe 204 is adapted to be selectively and removably placed withincavity 203. Particularly,syringe 204 contains a ring orprojection portion 235 which is adapted to be frictionally and removably deployed withingroove 233.Syringe 204 further includes amaterial containment cavity 205 which generally conforms tocavity 203, and a plunger or selectively moveable viscousmaterial displacement piece 214, which, in one embodiment, is substantially similar in function and structure todisplacement piece 34. Particularly,piece 214 is selectively, matably, and movably disposed withinsyringe cavity 205 between a first position in relative close proximity to theupper opening 215 ofsyringe 204, as illustrated in FIG. 7, and a second position in relative proximity to thematerial dispensing aperture 216 which is formed within thesyringe 204, which is illustrated in FIG. 8, and which operatively communicates withaperture 230. -
Apparatus 200 further includes a selectively expandable and generally tubular shaped membrane ordiaphragm 218 having a firstclosed end portion 219 which operatively engages the generallyconcave surface 217 ofdisplacement piece 214, and which is manufactured from a relatively thin, flexible and durable material such as latex, butyl rubber or commercially available “Nitrile” material. In one non-limiting embodiment,diaphragm 218 has a thickness ranging from three thousandths of an inch (0.003″) to ten thousandths of an inch (0.010″), although other thicknesses may be employed. Particularly, in one non-limiting embodiment, the thickness ofdiaphragm 218 decreases along its length with the thickness being minimized near thematerial dispensing aperture 230 ofapparatus 200 and maximized nearopening 215. - Diaphragm further includes a second
open end 225 which is foldably and compressibly secured around a substantiallycircular retaining ring 220, thereby causingopen end 225 to substantially and operatively conform to the shape ofring 220.Ring 220 is selectively, operatively, frictionally and removably contained within an integrally formed and generallycircular channel 223 ofcap 222, thereby securely positioningdiaphragm 218 withinsyringe cavity 205. -
Cap 222 includes a relatively small and generally circularair reception aperture 232 which communicates with the hollow and selectivelyexpandable interior 250 ofdiaphragm 218, thereby allowing for the introduction of a gaseous material, such as air, to be selectively and expandably communicated to theinterior 250 ofdiaphragm 218.Cap 222 is removably mounted uponhousing 202 in a manner which has been previously explained. That is,socket grooves 224, which are similar in function and structure togrooves 24, selectively, removably and cooperatively receive laterally extendingposts 212 which are similar in function and structure to posts 22 (see FIG. 1), thereby allowingcap 222 to be selectively and removably secured tohousing 202. - When mounted upon
housing 202,cap 222 fits snugly and compressibly over retainingring 220 anddiaphragm 218 and supportably positions thering 220 upon theupper lip 227 ofsyringe 204, thereby securingdiaphragm 218 withinhousing 202 and causing substantially all of the gas or air which is introduced throughopening 232 to travel and be expansively retained within theinterior 250 ofdiaphragm 218. - In operation, mounting
piece 226 is selectively placed upon and operatively secured to a print or compression head, such ascompression head 6, by use of conventional and commerciallyavailable fasteners 210. Air or other gaseous material is selectively introduced into theinterior 250 ofdiaphragm 218 through communicatingaperture 232. As the air pressure withindiaphragm 218 increases,diaphragm 218 expands forcingplunger 214 towards the bottom ofsyringe 204, thereby forcingviscous material 100 through communicatingapertures plunger 214 reaches its bottom-most position, which is illustrated in FIG. 7. The rate and force at whichplunger 214 expelsviscous material 100 is selectively controlled in a conventional manner by selectively modifying the pressure introduced throughopening 232, such as by way of a conventional pressure regulator. - In such a manner, the selectively
expandable diaphragm 218 obviates the need for a relatively large piston assembly to selectively causematerial 100 to be desirably dispensed, and concomitantly reduces the overall cost and complexity of theassembly 200. - Referring now to FIGS. 10 and 11, an
apparatus 300 is provided and is made in accordance with the teachings of an alternate embodiment of the invention. Particularly,apparatus 300 is substantially similar toapparatus 200, except that the generallyelastic diaphragm 218 has been replaced with a “bellows”type diaphragm 318. With the exception ofdiaphragm 318,apparatus 300 includes substantially identical components asapparatus 200. Unless otherwise noted, components having a substantially identical structure and function are defined by the same reference numerals as used with respect toapparatus 200, delineated in FIGS. 6 through 9, with the exception that these components will have these reference numerals incremented by 100. In this alternate embodiment,diaphragm 318 is manufactured from a relatively stiff and durable material such as rubber, plastic, metal or a composite and has a plurality of integrally formed “bellows” or selectivelyexpandable pleats 321 which are adapted to selectively and cooperatively expand or contract, thereby expanding andcontracting diaphragm 318. - In operation, air or gas is introduced through
aperture 332 and intointerior 350, thereby causing thepleats 321 to expand at respective, integrally formed and substantially air-tight joints 329. Accordingly, thediaphragm 318 is selectively forced from a compressed or constricted position, as shown in FIG. 10, to a expanded or extended position, as shown in FIG. 11. Asdiaphragm 318 expands from its compressed to its expanded position,plunger 314 is forced towards the bottom ofsyringe 304, thereby forcingviscous material 100 through communicating apertures and/oropenings plunger 314 reaches its bottom-most position, as illustrated in FIG. 11. It should be appreciated that the use of integrally formed and selectively expandable “air-tight” pleats 321 allowsdiaphragm 318 to be manufactured from a relatively thicker and more durable material thandiaphragm 218, thereby resulting in a longer functional life. - In yet another alternate embodiment of the invention, an
apparatus 400 for dispensing viscous material is provided.Apparatus 400 is substantially similar toapparatus 200 with the exception that diaphragm 218 has been replaced with atelescopic diaphragm 418, as illustrated in FIGS. 12 and 13. With the exception ofdiaphragm 418,apparatus 400 includes substantially identical components asapparatus 200. Unless otherwise noted, components having a substantially identical structure and function are defined by the same reference numerals used with respect toapparatus 200, delineated in FIGS. 6 through 9, with the exception that these components will have the reference numerals incremented by 200. - Telescoping
diaphragm 418, in one embodiment, is manufactured from a relatively stiff and durable material such as rubber, plastic, metal or a composite.Diaphragm 418 includes integrally formed and overlapping concentric or tubular shaped segments 450-462. Each segment 450-462, in one non-limiting embodiment, is substantially similar and cylindrical in shape and has a diameter which is slightly smaller than the diameter of the preceding segment (e.g., the diameter ofsegment 462 is slightly smaller than the diameter ofsegment 460 which is slightly smaller than the diameter of segment 458).Diaphragm 418 includes a plurality of conventional and generally circular rubber ormetal seals 464 which reside around the perimeter of eachjuncture 466 occurring and/or formed between adjacent segments 450-462.Seals 464 provide an air-tight seal at eachjuncture 466 and cooperate with the “closed”end 468 ofsegment 462 to substantially prevent the escape of air fromdiaphragm 418. It should be understood that while a diaphragm having six tubular segments is illustrated in this non-limiting example, any number of segments 450-462 may be used without departing from the scope of the invention. - In operation, gas is introduced through
aperture 432 causing the air pressure within theinterior 470 ofdiaphragm 418 to increase, thereby forcing concentric tubular segments 452-462 “downward” toward the bottom (e.g., toward aperture 430) of theassembly 400. As the concentric tubular segments 452-462 are forced “downward”,diaphragm 418 expands from a compressed or constricted position, as shown in FIG. 12, to a expanded or extended position, as shown in FIG. 13. Asdiaphragm 418 expands from its compressed position to its expanded position,plunger 414 is forced towards the bottom ofsyringe 404, thereby forcingviscous material 100 throughopening 416 andcentral channel 430 and into the compression head, untilplunger 414 reaches its bottom-most position, illustrated in FIG. 13. The use of telescoping tubular segments 450-462 allowsdiaphragm 418 to be manufactured from a relatively thicker and more durable material thandiaphragm 218, thereby resulting in a longer functional life. - In yet another alternate embodiment of the invention, an
apparatus 500 for dispensing viscous material is provided and is illustrated in FIGS. 14 and 15.Apparatus 500 is substantially similar toapparatus 200 with the exception that diaphragm 218 has been replaced withdiaphragm 518. With the exception ofdiaphragm 518,apparatus 500 includes substantially identical components asapparatus 200. Unless otherwise noted, components having a substantially identical structure and function are defined by the same reference numerals with respect toapparatus 200, with the exception that these components will have reference numerals incremented by 300. - Particularly,
apparatus 500 includes a selectivelyexpandable diaphragm 518 which has a substantially constant and/or uniform cross sectional area and which has a shape, as shown best in FIG. 15, which generally conforms to thesyringe cavity 505 even when not filled with air or other gaseous material. Particularly,diaphragm 518 is simply folded to fit within the top ofapparatus 500 whenmaterial 100 is not to be dispensed. Upon receipt of air or other gases,diaphragm 518 expands and selectively and operatively movespiece 514 within thecylinder cavity 505, effective to cause thematerial 100 to be selectively emitted fromaperture 530. - It is to be understood that the embodiments of the invention which have been described are merely illustrative of some applications of the principles of the invention. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.
Claims (11)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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US09/358,981 US6302306B1 (en) | 1994-12-27 | 1999-07-22 | Method and apparatus for dispensing viscous material |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US36380694A | 1994-12-27 | 1994-12-27 | |
US08/716,037 US6761926B1 (en) | 1994-12-27 | 1996-09-19 | Method for compressing viscous material through openings |
US09/358,981 US6302306B1 (en) | 1994-12-27 | 1999-07-22 | Method and apparatus for dispensing viscous material |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US08/716,037 Continuation-In-Part US6761926B1 (en) | 1994-12-27 | 1996-09-19 | Method for compressing viscous material through openings |
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US6302306B1 US6302306B1 (en) | 2001-10-16 |
US20010054627A1 true US20010054627A1 (en) | 2001-12-27 |
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US09/358,981 Expired - Fee Related US6302306B1 (en) | 1994-12-27 | 1999-07-22 | Method and apparatus for dispensing viscous material |
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US (1) | US6302306B1 (en) |
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US20040139869A1 (en) * | 2000-12-05 | 2004-07-22 | Seiichi Miyahara | Screen printing apparatus and method of screen printing |
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US20070219502A1 (en) * | 2006-03-15 | 2007-09-20 | Kriesel Marshall S | Fluid dispensing device |
US20080228129A1 (en) * | 2007-03-14 | 2008-09-18 | Kriesel Marshall S | Fluid dispensing apparatus |
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US20050048195A1 (en) * | 2003-08-26 | 2005-03-03 | Akihiro Yanagita | Dispensing system and method of controlling the same |
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Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE451295B (en) | 1985-03-27 | 1987-09-28 | Fagersta El & Diesel Ab | OGONDUSCH |
US4622239A (en) | 1986-02-18 | 1986-11-11 | At&T Technologies, Inc. | Method and apparatus for dispensing viscous materials |
US4720402A (en) | 1987-01-30 | 1988-01-19 | American Telephone And Telegraph Company | Method for dispensing viscous material |
DE3708396A1 (en) * | 1987-03-14 | 1987-10-08 | Robert Dipl Ing Weigl | Spray can with atmospheric air as pressure medium or propellant |
US5405054A (en) * | 1988-11-22 | 1995-04-11 | Fedpak Systems, Inc. | Frozen confection dispensing apparatus |
US5096092A (en) * | 1990-03-13 | 1992-03-17 | Mmm, Ltd. | Food dispensing apparatus utilizing inflatable bladder |
JPH0471293A (en) | 1990-07-11 | 1992-03-05 | Cmk Corp | Filling of conductive substance and the like in through hole and the like in printed-wiring board |
JPH0494593A (en) | 1990-08-10 | 1992-03-26 | Cmk Corp | Forming method for through hole of printed circuit board |
WO1993011059A1 (en) | 1991-11-27 | 1993-06-10 | James Owen Camm | Dispenser |
JP2591744Y2 (en) | 1993-01-20 | 1999-03-10 | ノードソン株式会社 | Dispenser for liquid discharge with liquid enclosing cartridge storage case |
FR2734247B1 (en) * | 1995-05-17 | 1997-06-27 | Oreal | DEVICE FOR PACKAGING AND DISPENSING A LIQUID OR PASTY PRODUCT |
DE19644980A1 (en) | 1996-10-29 | 1998-04-30 | Stoecklin Logistik Ag | Transport and discharge container for highly viscous and pasty products |
-
1999
- 1999-07-22 US US09/358,981 patent/US6302306B1/en not_active Expired - Fee Related
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US20040139869A1 (en) * | 2000-12-05 | 2004-07-22 | Seiichi Miyahara | Screen printing apparatus and method of screen printing |
US6820544B2 (en) | 2000-12-05 | 2004-11-23 | Matsushita Electric Industrial Co., Ltd. | Screen printing apparatus and method of screen printing |
US20050139643A1 (en) * | 2003-12-30 | 2005-06-30 | Texas Instruments Incorporated | Method and system for applying solder |
US20070219502A1 (en) * | 2006-03-15 | 2007-09-20 | Kriesel Marshall S | Fluid dispensing device |
US7828772B2 (en) | 2006-03-15 | 2010-11-09 | Bioquiddity, Inc. | Fluid dispensing device |
US20110092904A1 (en) * | 2006-03-15 | 2011-04-21 | Kriesel Marshall S | Fluid dispensing device |
US7993304B2 (en) * | 2006-03-15 | 2011-08-09 | Bioquiddity, Inc. | Fluid dispensing apparatus |
US20110282284A1 (en) * | 2006-03-15 | 2011-11-17 | Kriesel Marshall S | Fluid dispensing apparatus |
US8672885B2 (en) * | 2006-03-15 | 2014-03-18 | Marshall S. Kriesel | Fluid dispensing device |
US20080228129A1 (en) * | 2007-03-14 | 2008-09-18 | Kriesel Marshall S | Fluid dispensing apparatus |
US7833195B2 (en) * | 2007-03-14 | 2010-11-16 | Bioquiddity, Inc. | Fluid dispensing apparatus |
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