Module with metal-ion matrix induced dendrites for interconnection

• US 6,218,629 B1
• Filed: 01/20/1999
• Issued: 04/17/2001
• Est. Priority Date: 01/20/1999
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Brofman, Peter J., Coffin, Jeffrey T., Call, Anson J., Stalter, Kathleen A.
• Primary Examiner(s): Gaffin, Jeffrey
• Assistant Examiner(s): Cuneo, Kamand
• Application Number:
  US09/233,890
• Time in Patent Office: 818 Days
• Field of Search: 174/260, 174/262, 174/264, 174/257, 174/259, 361/767, 361/768, 361/771, 361/783, 257/698
• US Class Current: 174/260
• CPC Class Codes: H01L 2224/29099 Material
• CPC Class Codes: H01L 2224/29101 the principal constituent melting at a temperature of less than 400°C
• CPC Class Codes: H01L 2224/2919 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/29199 Material of the matrix
• CPC Class Codes: H01L 2224/2929 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/29299 Base material
• CPC Class Codes: H01L 2224/29339 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/29347 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/29355 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/8319 Arrangement of the layer connectors prior to mounting
• CPC Class Codes: H01L 2224/838 Bonding techniques
• CPC Class Codes: H01L 24/29 of an individual layer connector
• CPC Class Codes: H01L 24/83 using a layer connector
• 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 2924/00014 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 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/0665 : Epoxy resin
• CPC Class Codes: H01L 2924/0781 : being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• 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 2203/105 : Using an electrical field; Special methods of applying an electric potential electroplating H05K2203/0723
• CPC Class Codes: H05K 3/323 : by applying an anisotropic conductive adhesive layer over an array of pads
• CPC Class Codes: Y10T 29/49126 : Assembling bases
• CPC Class Codes: Y10T 29/49128 : Assembling formed circuit to base
• CPC Class Codes: Y10T 29/49133 : with component orienting
• CPC Class Codes: Y10T 29/49137 : Different components
• CPC Class Codes: Y10T 29/49144 : by metal fusion
• CPC Class Codes: Y10T 29/49146 : with encapsulating, e.g., potting, etc.

Abstract

A module or assembly is formed by interposing a polymer between a carrier and a semiconductor device to be secured to the carrier. The polymer has ionized metallic particles suspended in it. Before setting or curing the polymer, the module is exposed to an electric field which induces migration of the metallic particles to the opposing pads of the carrier and semiconductor device. Such migration ultimately forms metal dendrites extending between mating pad pairs. The dendrites establish a metallurgical bond and conductive paths between the carrier and the overlying semiconductor device. When the polymer is subsequently set, the carrier and device are not only adhered to each other, but the dendrite connections are fixed and structurally reinforced to provide the needed electrically conductive paths.

Claims

1. A semiconductor module comprising:

a carrier having a carrier mating surface with carrier pads thereon;

a semiconductor device secured to the carrier, the device having a semiconductor mating surface opposing the carrier mating surface, and having device pads opposing corresponding ones of the carrier pads to define mating pad pairs;

a polymer interposed between the mating surfaces;

ionized metallic particles suspended in the polymer, certain of the metallic particles being migrated within the polymer to form concentrated regions of the metallic particles, the concentrated regions of the migrated metallic particles in the form of dendrites at locations in the polymer corresponding to the mating pad pairs; and

metallurgical bonds between the pads of the mating pad pairs, the bonds comprising the migrated metallic particles.

2. The module of claim 1, wherein the ionized metallic particles are suspended in the polymer in concentrations of about 5% to about 20% by volume.

3. The module of claim 1, wherein the ionized metallic particles suspended in the polymer have a size range of about 1 to about 25 micrometers.

4. The module of claim 1, wherein the metallic particles are selected from the group consisting of silver, copper, and nickel.

5. The module of claim 1, further comprising a metallic salt suspended in the polymer.

6. The module of claim 5, wherein the metallic salt is suspended in a concentration of about 0.1% by weight of the metallic particles in the polymer.

7. The module of claim 1, wherein the polymer comprises a film having a thickness of about 1 mil to about 5 mils.

8. The module of claim 1, further comprising means for inhibiting lateral migrations of the metallic particles.

9. The module of claim 8, wherein the inhibiting means comprises walls extending between the mating surfaces at locations between adjacent ones of the mating pad pairs.

10. The module of claim 9, further comprising a planar spacer of insulating material, and wherein the walls define passages through the spacer, the spacer being interposed between the mating surfaces, the polymer filling the passages of the spacer.

11. The module of claim 1, wherein at least some of the pads have conductive portions extending outwardly from the plane of the corresponding surface on which said pads are located, and wherein the concentrated regions of the migrated metallic particles are formed adjacent to the conductive portions.