Method for fabricating an interconnect for making temporary electrical connections to semiconductor components

• US 6,529,026 B1
• Filed: 10/09/2001
• Issued: 03/04/2003
• Est. Priority Date: 08/22/1997
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Farnworth, Warren M., Akram, Salman
• Primary Examiner(s): Cuneo, Kamand
• Assistant Examiner(s): HOLLINGTON, JERMELE M
• Application Number:
  US09/972,266
• Time in Patent Office: 511 Days
• Field of Search: 324/757, 324/755, 324/760, 324/765, 324/558, 324/158.1, 438/16-18, 257/668-669, 257/773, 257/787, 257/789, 257/793, 298/25, 298/29, 298/32, 298/33, 298/40, 298/43, 298/52, 361/767, 361/768, 361/771, 174/260, 174/267
• US Class Current: 324/754.11
• CPC Class Codes: G01R 1/0483 Sockets for un-leaded IC's having matrix type contact fields, e.g. BGA or PGA devices; Sockets for unpackaged, naked chips for IC's with connecting points around the edges only G01R1/0433
• CPC Class Codes: H05K 3/245 Reinforcing conductive patterns made by printing techniques or by other techniques for applying conductive pastes, inks or powders; Reinforcing other conductive patterns by such techniques
• CPC Class Codes: H05K 3/326 the printed circuit having integral resilient or deformable parts, e.g. tabs or parts of flexible circuits H05K3/365 takes precedence
• 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: Y10T 29/49149 by metal fusion bonding

Abstract

An interconnect for making temporary electrical connections with semiconductor components includes a substrate with patterns of elastomeric contacts adapted to electrically engage contact locations (e.g., bond pads, solder bumps) on the semiconductor components. The elastomeric contacts can be formed of conductive elastomer materials, such as anisotropic adhesives and silver filled silicone, having metal particles for penetrating the contact locations. The substrate also includes patterns of metal conductors having non-oxidizing contact pads, which provide low resistance bonding surfaces for the elastomeric contacts. A method for fabricating the interconnect includes the step of depositing bumps in a required size and shape using stenciling, screen printing, or other deposition process. Following deposition, the bumps can be cured and planarized to form the elastomeric contacts. During a test procedure, the elastomeric contacts can be loaded in compression to compliantly engage the contact locations.

Claims

1. An interconnect for making electrical connections with a semiconductor component having a plurality of bumped contacts comprising:

a substrate;

a plurality of conductors on the substrate; and

a plurality of contacts on the substrate configured to retain and electrically engage the bumped contacts, the contacts comprising indentations at least partially covered with resilient electrically conductive elastomeric layers in electrical communication with the conductors and a plurality of conductive particles in the layers configured to penetrate the bumped contacts.

2. The interconnect of claim 1 wherein each conductive particle comprises a dendritic metal particle.

3. The interconnect of claim 1 further comprising a plurality of non-oxidizing contact pads within the indentations configured to provide surfaces for the layers.

4. The interconnect of claim 1 wherein the layers comprise a material selected from the group consisting of silicone, silver filled silicone and anisotropic adhesives.

5. A method for fabricating an interconnect for making electrical connections with contacts on a semiconductor component comprising:

providing a substrate;

forming a plurality of conductors on the substrate; and

forming a plurality of bumps on the substrate in electrical communication with the conductors, the bumps comprising a resilient electrically conductive elastomeric material and a plurality of conductive particles in the material configured to penetrate the contacts on the component and to provide conductive paths to the conductors.

6. The method of claim 5 wherein the forming the plurality of bumps step comprises screen printing.

7. The method of claim 5 wherein the material is selected from the group consisting of silicone, anisotropic adhesives and silver filled silicone.

8. The method of claim 5 wherein the forming the plurality of bumps step comprises depositing the material in a viscous state and then curing the material in contact with a planar surface.

9. The method of claim 8 wherein the curing step is performed with the material under compression.

10. A method for fabricating an interconnect for making temporary electrical connections with a semiconductor component having bumped contacts comprising:

providing a substrate;

forming a plurality of indentations in the substrate sized to retain the bumped contacts;

at least partially covering the indentations with a plurality of viscous conductive elastomeric layers comprising a plurality of electrically conductive particles configured to penetrate the bumped contacts;

curing the layers; and

forming a plurality of conductors on the substrate in electrical communication with the layers.

11. The method of claim 10 further comprising forming a plurality of non-oxidizing metal layers in the indentations prior to the covering step.

12. The method of claim 10 wherein the layers comprise a material selected from the group consisting of silicone, silver filled silicone and anisotropic adhesives.

13. The method of claim 10 wherein each electrically conductive particle comprises a dendritic metal particle.

14. The method of claim 10 wherein the covering step is performed by stenciling, screen printing or depositing a conductive material.

15. A method for fabricating an interconnect for making electrical connections with a semiconductor component having a plurality of contacts thereon comprising:

providing a substrate;

forming a plurality of conductors on the substrate;

forming a plurality of contact pads on the substrate in electrical communication with the conductors; and

forming a plurality of elastomeric contacts on the substrate by depositing and curing a resilient conductive elastomeric material on the contact pads having a plurality of dendritic metal particles embedded therein configured to penetrate the contacts, the material configured for compression during a test procedure to press the conductive particles into the contacts.

16. The method of claim 15 wherein the contact pads comprise gold or palladium.

17. The method of claim 15 further comprising planarizing the elastomeric contacts by contact with at least one planar surface during curing of the material.

18. The method of claim 15 wherein the elastomeric contacts comprise indentations at least partially covered by the material.

19. An interconnect for making an electrical connection with a semiconductor component having a bumped contact comprising:

a substrate; and

a contact on the substrate configured to electrically engage the bumped contact, the contact comprising an indentation at least partially covered with a resilient electrically conductive elastomeric layer comprising a plurality of conductive particles configured to penetrate the bumped contact, the resilient electrically conductive elastomeric layer configured to provide compliancy for cushioning contact forces and for compensating for dimensional variations.

20. The interconnect of claim 19 wherein the resilient electrically conductive elastomeric layer comprises a material selected from the group consisting of silicone, silver filled silicone and anisotropic adhesives.

21. An interconnect for making an electrical connection with a semiconductor component having a bumped contact comprising:

a substrate; and

a contact on the substrate configured to electrically engage the bumped contact, the contact comprising an indentation and a conductive elastomeric layer on the indentation containing a plurality of conductive particles, the conductive elastomeric material configured for compression by the bumped contact during a test procedure to press the conductive particles into the bumped contact.

22. The interconnect of claim 21 wherein the conductive elastomeric layer comprises a material selected from the group consisting of silicone, silver filled silicone and anisotropic adhesives.