Manufacture of dendrites and their use

• US 6,323,432 B1
• Filed: 08/10/1999
• Issued: 11/27/2001
• Est. Priority Date: 08/10/1999
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Campbell, Jeffrey S., Wike, William T.
• Primary Examiner(s): Reichard, Dean A.
• Assistant Examiner(s): WALKENHORST, DAVID W
• Application Number:
  US09/371,290
• Time in Patent Office: 840 Days
• Field of Search: 174/149.R, 200/511, 264/174.11, 428/625, 117/903, 439/66
• US Class Current: 174/149.00R
• CPC Class Codes: F28F 2215/10 Secondary fins, e.g. projections or recesses on main fins
• CPC Class Codes: F28F 2245/06 having particular radiating, reflecting or absorbing features, e.g. for improving heat transfer by radiation
• CPC Class Codes: H01L 2224/29499 Shape or distribution of the fillers
• CPC Class Codes: H01L 23/3733 having a heterogeneous or anisotropic structure, e.g. powder or fibres in a matrix, wire mesh, porous structures H01L23/3732, H01L23/3737 take precedence
• CPC Class Codes: H01L 23/49811 Additional leads joined to the metallisation on the insulating substrate, e.g. pins, bumps, wires, flat leads H01L23/49827 takes precedence
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01R 13/2414 conductive elastomers
• CPC Class Codes: H05K 2201/0133 Elastomeric or compliant polymer elastomeric conductor H05K2201/0314
• CPC Class Codes: H05K 2201/10977 Encapsulated connections applying non-metallic protective coatings for encapsulating mounted components H05K3/284
• CPC Class Codes: H05K 2201/209 Auto-mechanical connection between a component and a PCB or between two PCBs
• CPC Class Codes: H05K 2203/0307 Providing micro- or nanometer scale roughness on a metal surface, e.g. by plating of nodules or dendrites
• CPC Class Codes: H05K 2203/0723 Electroplating, e.g. finish plating
• 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 3/4007 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: Y10S 117/903 Dendrite or web or cage technique
• CPC Class Codes: Y10T 29/49126 Assembling bases
• CPC Class Codes: Y10T 29/49128 Assembling formed circuit to base
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49156 with selective destruction of conductive paths

Abstract

A technique for making acicular, branched, conductive dendrites, and a technique for using the dendrites to form a conductive compressible pad-on-pad connector are provided. To form the dendrites, a substrate is provided on which dendrites are grown, preferably on a metal film. The dendrites are then removed from the substrate, preferably by etching metal from the substrate. The so formed dendrites are incorporated into a compressible dielectric material, which then forms a compressible pad-on-pad connector between two conducting elements, such as connector pads on electrical devices, e.g. an I/C chip mounted on a substrate, such as a chip carrier.

Claims

1. A material for conducting heat or electricity from one conductive member to another conductive member, the two conductive members being spaced apart, comprising:

a compressible dielectric material, and

a plurality of branched acicular conductive dendrite particles embedded within said compressible material.

2. The invention as defined in claim 1 wherein the compressible dielectric material has two opposed surfaces, and at least some of said particles are interconnected to form a continuous conductive path between said two opposed surfaces of said dielectric material.

3. The invention as defined in claim 1 wherein said dielectric material is elastomeric.

4. The invention as defined in claim 1 wherein the dendrite particles are free of attachment to any substrate.

5. The invention as defined in claim 4 wherein at least some of said dendrite particles embedded within a compressible material contact each other when said compressible material is compressed.

6. In combination,

a pair of spaced conducting members,

a dielectric compressible material interposed between and contacting each of said spaced conducting members,

a plurality of branched acicular conductive dendrite particles embedded in said dielectric material, at least some of which particles form a continuous conductive path between said spaced conducting members.

7. The invention as defined in claim 6 wherein said dielectric material is elastomeric.

8. The invention as defined in claim 6 wherein said dendrite particles interconnect with each other and the spaced conducting members form an essentially continuous conductive network.