Chip carrier mounting device

• US 4,705,205 A
• Filed: 05/14/1984
• Issued: 11/10/1987
• Est. Priority Date: 06/30/1983
• Status: Expired due to Term

• Current Assignee: Tyco Electronics Corporation (TE Connectivity Ltd. (United Kingdom))
• Original Assignee: Raychem Limited (TE Connectivity Limited)
• Inventors: Cherian, Gabe, Diaz, Stephen H., Allen, Leslie J.
• Primary Examiner(s): Ramsey, Kenneth J.
• Application Number:
  US06/610,077
• Time in Patent Office: 1,275 Days
• Field of Search: 228/56.3, 228/180.2, 228/185, 174/94 R, 361/408, 339/17 CF, 339/17 N, 339/29 R, 339/275 B, 29/854
• US Class Current: 228/180.22
• CPC Class Codes: B23K 3/06 Solder feeding devices; Solder melting pans
• CPC Class Codes: B23K 35/0222 for use in soldering, brazing B23K35/0205 takes precedence
• CPC Class Codes: H01L 2224/29099 Material
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00013 Fully indexed content
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 13/0465 by soldering H05K13/0469 takes precedence
• CPC Class Codes: H05K 2201/0215 Metallic fillers
• CPC Class Codes: H05K 2201/0314 Elastomeric connector or conductor, e.g. rubber with metallic filler elastomeric dielectric H05K2201/0133
• CPC Class Codes: H05K 2201/0373 Conductors having a fine structure, e.g. providing a plurality of contact points with a structured tool providing micro- or nanometer scale roughness on a metal surface H05K2203/0307
• CPC Class Codes: H05K 2201/1028 Thin metal strips as connectors or conductors
• CPC Class Codes: H05K 2201/10378 Interposers
• CPC Class Codes: H05K 2201/10424 Frame holders
• CPC Class Codes: H05K 2201/10727 Leadless chip carrier [LCC], e.g. chip-modules for cards
• CPC Class Codes: H05K 2201/10946 Leads attached onto leadless component after manufacturing the component
• CPC Class Codes: H05K 2203/0415 Small preforms other than balls, e.g. discs, cylinders or pillars
• CPC Class Codes: H05K 2203/0769 Dissolving insulating materials, e.g. coatings, not used for developing resist after exposure
• CPC Class Codes: H05K 3/325 by abutting or pinching, i.e. without alloying process; mechanical auxiliary parts therefor adaptations of leads inserted in holes for press-fit connections H05K3/308
• CPC Class Codes: H05K 3/3421 Leaded components
• CPC Class Codes: H05K 3/3436 having an array of bottom contacts, e.g. pad grid array or ball grid array components
• CPC Class Codes: H05K 3/3442 : having edge contacts, e.g. leadless chip capacitors, chip carriers
• CPC Class Codes: H05K 3/4015 : using auxiliary conductive elements, e.g. pieces of metal foil, metallic spheres
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

A chip carrier mounting device which is hereinafter also referred to as an "interconnection preform placement device" includes a retaining member having a predetermined pattern of apertures in which are positioned preforms of joint-forming material such as solder. The preform retains its general configuration after the interconnection or soldering process to form a resilient joint which is more capable of withstanding stress, strain and fatique. A method of forming resilient interconnections comprises placing the interconnection retaining member device between parallel patterns of electrically conductive elements, such as the conductive pads on an electronic component and a circuit board, and effecting the bonding of the conductive elements with the preforms. The joint-forming material may be a filled solder composition or a supported solder which substantially maintain their physical shape when the solder is molten, or a conductive elastomer.

Claims

1. A device for providing a plurality of discrete quantities of preformed solder material for forming connections between electrically conductive elements comprising:

a retaining member having a plurality of apertures therein spaced to correspond to preselected points on the electrically conductive elements; and

preforms of solder material disposed in or supported by the apertures whereby the ends of the preforms are adapted to contact preselected points on the electrically conductive elements and wherein the solder material comprises filled solder which contains from about 20% to about 80% by weight based on the total weight of the solder-filler mixture of a filler which is solid at a temperature at which the solder is molten or supported solder and wherein the filled solder or supported solder, separate from the retaining member and apertures thereof, substantially retains its preform physical shape while the solder is in a molten state.

2. A device according to claim 1 wherein the preform of solder material comprises filled solder which substantially retains its preform physical shape while the solder is in a molten state.

3. A device according to claim 2 wherein the filled solder comprises solder within which is disposed discrete particles or filaments which are of a material which is solid at a temperature at which the solder is molten.

4. A device according to claim 2 in combination with an electrically conductive element wherein the preforms are bonded at one end to preselected points on the electrically conductive element.

5. A device according to claim 1 wherein the preform of solder material comprises supported solder which substantially retains its preform physical shape while the solder is in a molten state.

6. A device according to claim 5 wherein the support for the solder comprises a spiral metalic wire or tape.

7. A device according to claim 5 in combination with an electrically conductive element wherein the preforms are bonded at one end to preselected points on the electrically conductive element.

8. A device according to claim 1 wherein the preform of solder material has a height dimension greater than its transverse cross-sectional dimension.

9. A device according to claim 1 wherein the retaining member comprises a combination of conductive and dielectric materials.

10. A device according to claim 1 wherein the retaining member comprises a laminate.

11. A device according to claim 1 wherein the retaining member comprises a dissolvable material.

12. A device according to claim 1 wherein the retaining member comprises a segmented or frangible material.

13. A device according to claim 1 wherein the retaining member provides overvoltage protection for at least one of the electrically conductive elements.

14. A device according to claim 1 wherein the retaining member provides a heat-sink for the electrically conductive elements.

15. A device according to claim 1 wherein the retaining member comprises a heat-recoverable material.

16. A device according to claim 1 in combination with an electrically conductive element wherein the preforms are bonded at one end to preselected points on the electrically conductive element.

17. A method for forming a resilient connection for connection preselected points of first and second electrically conductive elements comprising:

positioning a first electrically conductive element in alignment with one side of a retaining member having apertures spaced to correspond to the preselected points on the electrically conductive elements and having disposed in said apertures preforms of solder material; and

effecting a bond between one end of the preforms and the preselected points on the first electrically conductive element;

wherein the preforms of solder material are filled solder containing from about 20% to about 80% by weight based on the total weight of the solder-filler mixture of a filler which is solid at a temperature at which the solder is molten or supported solder which, separate from the retaining member and apertures thereof, substantially retains its preform physical shape while the solder is in a molten state.

18. A method according to claim 17 which further comprises:

positioning a second electrically conductive element in alignment with the opposite side of the retaining member; and

effecting a bond between the other end of the preforms and the preselected points on the second electrically conductive element.

19. A method according to claim 18 wherein the bonds between ends of the preforms and the preselected points on the first electrically conductive element and the preselected points on the second electrically conductive member are effected simultaneously.

20. A method according to claim 19 comprising the further step of removing the retaining member after the preforms are bonded to both the first and second electrically conductive elements.

21. A method according to claim 18 comprising the further step of removing the retaining member after the preforms are bonded to both the first and second electrically conductive elements.

22. A method according to claim 17 wherein the preforms comprise filled solder or supported solder.

23. A method according to claim 22 wherein the preforms comprise filled solder which comprises solder within which is disposed discrete particles or filaments which are of a material which is solid at a temperature at which the solder is molten.

24. A method according to claim 22 wherein the preforms comprises supported solder wherein the support for the solder is a spiral metalic wire or tape.

25. A method according to claim 22 wherein the retaining member comprises a heat-recoverable material and further comprising adhering the retaining member to the electrically conductive elements, then effecting recovery of the material to pull the electrically conductive elements toward each other.

26. A method according to claim 17 which further comprises the step of removing the retaining member.

27. A method according to claim 26 which further comprises:

positioning, after the retaining member has been removed, a second electrically conductive element in alignment with the other ends of the preforms bonded to the first electrically conductive element; and

effecting a bond between the other end of the preforms and the preselected points on the second electrically conductive element.