Anisotropic elastomeric interconnecting system

• US 4,778,950 A
• Filed: 04/17/1986
• Issued: 10/18/1988
• Est. Priority Date: 07/22/1985
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Digital Equipment Corporation (HP Inc.)
• Inventors: Beck, Richard, Lee, James C. K., Lee, Chune, Hu, Edward
• Primary Examiner(s): Eley, Timothy V.
• Application Number:
  US06/853,313
• Time in Patent Office: 915 Days
• Field of Search: 29/825, 29/868, 29/876, 29/877, 29/878, 29/25.42, 339/17, 339/59-61, 339/DIG. 3, 174/356 C
• US Class Current: 174/260
• CPC Class Codes: H01L 2224/48 of an individual wire connector
• CPC Class Codes: H01L 2225/0652 Bump or bump-like direct electrical connections from substrate to substrate
• CPC Class Codes: H01L 2225/06527 Special adaptation of electrical connections, e.g. rewiring, engineering changes, pressure contacts, layout
• CPC Class Codes: H01L 2225/06579 TAB carriers; beam leads
• CPC Class Codes: H01L 25/0657 Stacked arrangements of devices
• 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 2924/00011 Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01015 Phosphorus [P]
• CPC Class Codes: H01L 2924/01047 Silver [Ag]
• CPC Class Codes: H01L 2924/01077 Iridium [Ir]
• CPC Class Codes: H01L 2924/15312 being a pin array, e.g. PGA
• CPC Class Codes: H01R 13/2414 conductive elastomers
• CPC Class Codes: H01R 43/007 for elastomeric connecting elements
• CPC Class Codes: H01R 43/16 for manufacturing contact members, e.g. by punching and by bending
• CPC Class Codes: H05K 2201/0133 Elastomeric or compliant polymer
• CPC Class Codes: H05K 2201/0281 Conductive fibers
• CPC Class Codes: H05K 2203/0235 Laminating followed by cutting or slicing perpendicular to plane of the laminate; Embedding wires in an object and cutting or slicing the object perpendicular to direction of the wires
• CPC Class Codes: H05K 3/4007 Surface contacts, e.g. bumps H05K3/4092 takes precedence; deposition of finish layers on pads H05K3/24; forming solder bumps H05K3/3457
• CPC Class Codes: H05K 3/4038 : Through-connections; Vertical interconnect access [VIA] connections H05K3/403, H05K3/42 take precedence
• CPC Class Codes: Y10T 29/435 : Solid dielectric type

Abstract

Electronic assemblies are fabricated by stacking alternate connecting layers and component layers. The component layers may be virtually any rigid structure having contact regions formed on at least one face thereof. The connecting layers are formed from anisotropic elastomeric conductors which in turn are fabricated by stacking a plurality of conductive sheets and insulating sheets, where the conductive sheets have a plurality of parallel electrically conductive elements formed therein. By introducing a curable elastomeric resin into the stacked structure so formed, and then curing the elastomer, a solid elastomeric block having a plurality of parallel electrically conductive elements running its length is obtained. Individual elastomeric conductors suitable as connecting layers interfacing between adjacent component layers are obtained by slicing the block in a direction perpendicular to the conductors.

Claims

1. An electronic assembly comprising alternating component layers and connecting layers, said component layers being rigid structures having at least one planar face with electrical contacts formed thereon and said connecting layers being anisotropic elastomeric conductors positioned between opposed electrical contacts on adjacent component layers, wherein said anisotropic elastomeric conductors are formed by a method comprising:

forming a stack of first and second sheets so that at least one second sheet lies between adjacent first sheets, wherein said first sheets are metal sheets, each metal sheet forming a plurality of electrical conductive elements, said electrically conductive elements running in one direction only, and said second sheets are composed of electrically insulating material;

introducing a curable elastomeric resin to the stack;

curing the elastomeric resin to form a solid matrix having the electrically conductive elements electrically isolated from one another and extending from one side of the block to the opposide side; and

slicing the matrix in a direction transverse to the direction of the electrically conductive elements to yield said anisotropic elastomeric conductors having the elements extending thereacross.

2. An assembly as in claim 1, wherein at least some of the component layers are semiconductor devices.

3. An assembly as in claim 1, wherein at least some of the component layers are ceramic substrates.

4. An assembly as in claim 1, wherein at least some of the component layers are printed circuit boards.

5. A assembly as in claim 1, wherein at least some of the component layers are terminal strips.

6. An assembly as in claim 1, wherein said component layers include a plurality of printed circuit boards each carrying a multiplicity of semiconductor devices and having contact regions formed on both faces, said board being stacked with the conductors interposed between adjacent contact regions.

7. An assembly as in claim 1, wherein the resin is introduced to the stack by coating the first sheets with said resin.

8. An assembly as in claim 1 wherein the maximum width of said electrically conductive elements is 0.005 inches.

9. An assembly as in claim 1, wherein the second sheets are continuous elastomeric sheets.

10. An assembly as in claim 9, wherein the elastomeric resin and the elastomeric sheets are silicone rubber.

11. An assembly as in claim 1 wherein said electrical conductive elements on said first sheets are defined by forming channels therebetween on said first sheets prior to stacking said first and second sheets, and said curable elastomeric resin is introduced into said stack so that it fills said channels between said electrically conductive elements.

12. An assembly as in claim 1 wherein the maximum thickness of said first sheets is 0.003 inches.

13. An assembly as in claim 12 wherein the maximum width of said electrically conductive elements is 0.005 inches.