Electroform spring built on mandrel transferable to other surface

• US 20060085976A1
• Filed: 10/22/2004
• Published: 04/27/2006
• Est. Priority Date: 10/22/2004
• Status: Active Grant

• Current Assignee: FormFactor Incorporated
• Original Assignee: FormFactor Incorporated
• Inventors: Mathieu, Gaetan L., Eldridge, Benjamin N.
• Granted Patent: US 7,621,044 B2
• Time in Patent Office: Days
• US Class Current: 29/874
• CPC Class Codes: C23C 18/1657 Electroless forming, i.e. substrate removed or destroyed at the end of the process
• CPC Class Codes: C23C 18/31 Coating with metals
• CPC Class Codes: C25D 1/10 Moulds; Masks; Masterforms
• CPC Class Codes: C25D 1/20 Separation of the formed objects from the electrodes with no destruction of said electrodes
• CPC Class Codes: G01R 1/06711 Probe needles; Cantilever beams; "Bump" contacts; Replaceable probe pins
• CPC Class Codes: G01R 1/06727 Cantilever beams
• CPC Class Codes: G01R 1/07342 the body of the probe being at an angle other than perpendicular to test object, e.g. probe card
• CPC Class Codes: G01R 3/00 Apparatus or processes specially adapted for the manufacture or maintenance of measuring instruments , e.g. of probe tips
• CPC Class Codes: H05K 2203/0726 Electroforming, i.e. electroplating on a metallic carrier thereby forming a self-supporting structure
• CPC Class Codes: H05K 3/32 electrically connecting electric components or wires to printed circuits
• CPC Class Codes: H05K 3/321 by conductive adhesives
• 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 3/341 Surface mounted components
• CPC Class Codes: H05K 3/4015 using auxiliary conductive elements, e.g. pieces of metal foil, metallic spheres
• CPC Class Codes: H05K 3/4092 Integral conductive tabs, i.e. conductive parts partly detached from the substrate
• CPC Class Codes: H05K 3/42 Plated through-holes or plated via connections
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49147 Assembling terminal to base
• CPC Class Codes: Y10T 29/49149 by metal fusion bonding
• CPC Class Codes: Y10T 29/49151 by deforming or shaping
• CPC Class Codes: Y10T 29/49204 : Contact or terminal manufacturing
• CPC Class Codes: Y10T 29/49208 : by assembling plural parts
• CPC Class Codes: Y10T 29/53378 : including converging conveyors

Abstract

Resilient spring contact structures are manufactured by plating the contact structures on a reusable mandrel, as opposed to forming the contact structures on sacrificial layers that are later etched away. In one embodiment, the mandrel includes a form or mold area that is inserted through a plated through hole in a substrate. Plating is then performed to create the spring contact on the mold area of the mandrel as well as to attach the spring contact to the substrate. In a second embodiment, the mandrel includes a form that is initially plated to form the resilient contact structure and then attached to a region of a substrate without being inserted through the substrate. Attachment in the second embodiment can be achieved during the plating process used to form the spring contact, or by using a conductive adhesive or solder either before or after releasing the spring contact from the mandrel.

Claims

1. A method comprising preparing a mandrel for subsequent formation and mechanical release of a spring element.

2. The method for manufacturing a resilient contact of claim 1, wherein forming the resilient contact comprises plating the resilient contact.

3. The method of claim 2 wherein the plating is performed by electroplating.

4. The method of claim 2 wherein the plating is performed by electroless plating.

5. A method for manufacturing a spring element comprising plating the spring element on a mandrel and releasing the spring element from the mandrel.

6. The method of claim 5 wherein the step of releasing is performed mechanically.

7. The method of claim 5, wherein the step of releasing is performed by thermal shock.

8. The spring element formed by the method of claim 5.

9. A probe card formed by attaching the spring element of claim 8 to a substrate.

10. Integrated circuits formed on a wafer, the integrated circuits tested using a probe card of claim 9.

11. The method of claim 5 further comprising attaching the spring element to a substrate.

12. The method of claim 5, further comprising:

inserting the mandrel through a plated through hole in a substrate prior to the plating.

13. The method of claim 5, wherein the spring element is formed and attached to a region on a substrate by the plating.

14. The method of claim 5, further comprising:

attaching the resilient contact to a metal region after formation of the resilient contact.

15. The method of claim 5, wherein after releasing the resilient contact the mandrel is reused to form another resilient contact.

16. A socket structure with probe contacts prepared by the method of claim 5.

17. A semiconductor wafer or device with contacts prepared by the method of claim 5.

18. A semiconductor device tested using the spring contact formed using the method of claim 5.

19. A packaged device electrically tested by the spring contact formed using the method of claim 5.

20. A mandrel having a surface enabling a resilient contact to be plated thereon and removed so that another resilient contact can be formed on the mandrel.

21. The mandrel of claim 20 comprising a metallic material with an isolation or passivation coating in regions where the resilient contact is not to be formed.

22. The mandrel of claim 20 comprising a non-conductive material with the surface for enabling the resilient contact to be plated comprising a metallized region on the non-conductive material.

23. The mandrel of claim 20 comprising a recessed area for forming a protruding contact tip portion of the resilient contact.

24. An array of mandrels attached together, each mandrel having a surface with material enabling a resilient contact to be electroplated thereon.