Dendritic interconnection system

• US 5,759,046 A
• Filed: 12/30/1996
• Issued: 06/02/1998
• Est. Priority Date: 12/30/1996
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Stone, David Brian, Molla, Jaynal Abedin, Ingraham, Anthony Paul
• Primary Examiner(s): NGUYEN, KHIEM M
• Application Number:
  US08/773,922
• Time in Patent Office: 519 Days
• Field of Search: 439/41, 439/42, 439/55, 439/74, 439/78, 439/259, 439/324
• US Class Current: 439/42
• CPC Class Codes: H01R 12/52 connecting to other rigid printed circuits or like structures
• CPC Class Codes: H01R 4/26 Connections in which at least one of the connecting parts has projections which bite into or engage the other connecting part in order to improve the contact H01R4/188, H01R4/203, H01R4/5075 take precedence; using shape memory materials H01R4/01
• CPC Class Codes: H01R 43/02 for soldered or welded connections
• 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

Abstract

A technique of connecting a first member having a first face to a second member having a second face utilizing dendrites is provided. Dendrites are formed on one face of the first member in a given configuration. Dendrite receiving and securing material, preferably solder, is formed on a face of the second member in a configuration confirming substantially to the given configuration of the dendrites on the one face. The first and second members are then placed in a position relative to each other with the dendrites on the one face of the first member in contact with the dendrite receiving and engaging material on the face of the second member. An airtight seal is then provided between the first and second faces surrounding the dendrites and dendrite receiving and engaging material, which forms a sealed chamber between the first and second members. Thereafter, a vacuum is pulled within the sealed chamber, thereby causing the ambient air pressure on the two members to urge the two members toward each other which will embed the dendrites in the dendrite receiving and engaging material to form interconnection therebetween. In order to enhance or improve the bond between the dendrites and the dendrite receiving and securing material, the dendrites and dendrite receiving and securing material each contain a component which can form an intermetallic compound therebetween.

Claims

1. A method of connecting a first member having a first face to a second member having a second face, comprising the steps of;

providing dendrites extending from said first face in a given configuration,

providing dendrite receiving and engaging material on said second face in a configuration corresponding to said given configuration,

placing said members in juxtaposed relationship with said dendrites in contact with said dendrite receiving and engaging material,

providing an essentially air-tight seal between said first and second faces around said dendrites and dendrite receiving and engaging material to thereby form a sealed chamber between said first and second members within said air-tight seal, and

pulling a vacuum within said sealed chamber to thereby allow said dendrites to be embedded on said dendrite receiving and engaging material to form an interconnection therebetween, and maintaining said vacuum to form a functional pair of interconnected members.

2. The invention as defined in claim 1 wherein said dendrite receiving and engaging material is solder.

3. The invention as defined in claim 1 further characterized by the provision of at least one spacer device between said first and second members within said chamber.

4. The invention as defined in claim 3 wherein there is a plurality of spacer devices between said first and second members.

5. The invention as defined in claim 1 wherein said dendrites and said dendrite receiving and engaging material each include first and second elements which form an intermetallic compound;

and

wherein after said pulling of said vacuum, said dendrites and said dendrite receiving and engaging material are heated to form said intermetallic compound.

6. The invention as defined in claim 5 wherein said dendrites include palladium.

7. The invention as defined in claim 6 wherein said dendrite receiving and engaging material includes a solder material containing tin or indium.

8. The invention as defined in claim 4 wherein said spacer devices are spherical balls.

9. The invention as defined in claim 1 wherein the vacuum is at least as low as 1 torr.

10. The invention as defined in claim 1 wherein a third member is provided which engages one of said first and second members and provides a portion of the air-tight seal, and is exposed to ambient pressure.

11. A composite structure of a first member having a first face and a second member having a second face, comprising;

dendrites extending from said first face in a given configuration,

dendrite receiving and engaging material on said second face in a configuration corresponding to said given configuration,

said first and second members being in juxtaposed relationship,

an essentially air-tight seal between said first and second faces around said dendrites and dendrite receiving and engaging material to thereby form a sealed chamber between said first and second members within said air-tight seal, and

a vacuum within said sealed chamber;

said dendrites being embedded in said dendrite receiving and engaging material and maintained therein by ambient pressure action on said first and second members to form a continuing interconnection therebetween.

12. The invention as defined in claim 11 wherein said dendrite receiving and engaging material is solder.

13. The invention as defined in claim 11 further characterized by the provision of at least one spacer device between said first and second members within said chamber.

14. The invention as defined in claim 13 wherein there is a plurality of spacer devices between said first and second members.

15. The invention as defined in claim 11 wherein said dendrites and said dendrite receiving and engaging material each include first and second elements forming an intermetallic compound between said dendrites and said dendrite receiving and engaging material.

16. The invention as defined in claim 15 wherein said dendrite includes palladium.

17. The invention as defined in claim 16 wherein said dendrite receiving and engaging material includes a solder material containing tin or indium.

18. The invention as defined in claim 14 wherein said spacer devices are spherical balls.

19. The invention as defined in claim 11 wherein the vacuum is at least as low as 1 torr.

20. A composite structure of a first member having a first face and a second member having a second face, comprising,

dendrites extending from said first face in a given pattern into a dendrite receiving and securing material disposed on said second face, and said dendrites and said dendrite receiving material including elements forming an intermetallic compound at the interface of said dendrites and said dendrite receiving and securing material.

21. The invention as defined in claim 20 wherein said dendrites are palladium.

22. The invention as defined in claim 21 wherein said dendrite receiving material is a tin-containing solder and said intermetallic compound is PdSn.