Rough electrical contact surface

• US 6,245,445 B1
• Filed: 03/02/1999
• Issued: 06/12/2001
• Est. Priority Date: 01/12/1996
• Status: Expired due to Fees

• Current Assignee: SV Probe Pte Ltd. (Nidec Corporation)
• Original Assignee: Kulicke and Soffa Industries Incorporated
• Inventors: Lykins, James L. II
• Primary Examiner(s): Jones, Deborah
• Assistant Examiner(s): SAVAGE, JASON L
• Application Number:
  US09/260,273
• Time in Patent Office: 833 Days
• Field of Search: 428/626, 428/209, 428/687, 324/754, 324/757, 438/17, 438/18, 200/279, 208/111
• US Class Current: 428/626
• CPC Class Codes: C25D 5/18 Electroplating using modulated, pulsed or reversing current
• CPC Class Codes: C25D 5/605 Surface topography of the layers, e.g. rough, dendritic or nodular layers
• CPC Class Codes: H01R 13/03 characterised by the material, e.g. plating, or coating materials
• CPC Class Codes: H05K 2201/0373 Conductors having a fine structure, e.g. providing a plurality of contact points with a structured tool
• 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 3/241 characterised by the electroplating method; means therefor, e.g. baths or apparatus
• 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 428/12569 Synthetic resin
• CPC Class Codes: Y10T 428/12993 Surface feature [e.g., rough, mirror]

Abstract

A method for rendering a surface of a contact rough includes submerging the surface of the contact in an electroplating bath having a dissolved metal salt, and pulsing an electric current through the contact and the bath to form a rough metallic structure on the surface of the contact.

Claims

1. A roughened contact comprising:

a contact having a surface; and

a solid metal layer deposited on the surface of the contact, the solid metal layer having spikes protruding away from the contact, the spikes being substantially conical, a side of each of the spikes having an angle from normal of between 10 degrees and about 45 degrees.

5. The contact of claim 1, 2, 3, or 4, wherein the solid metal layer comprises nickel.

6. The contact of claim 1, 2, 3, or 4 further comprising a conductive plating deposited on the surface of the solid metal layer.

7. The contact of claim 1, 2, 3, or 4, wherein the conductive plating comprises gold.

8. The contact of claim 1, 2, 3, or 4, wherein the spikes have a height between about 0.350 microns and about 1.275 microns.

2. A roughened contact comprising:

a contact having a surface; and

a solid metal layer deposited on the surface of the contact, the solid metal layer having spikes protruding away from the contact, the spikes being substantially conical, each of the spikes having a base between about 0.345 microns and about 1.250 microns, a side of each of the spikes having an angle from normal of between 10 degrees and about 45 degrees.

3. A roughened contact comprising:

a contact having a surface; and

a solid metal layer deposited on the surface of the contact, the solid metal layer having spikes protruding away from the contact, the spikes being substantially conical, a side of each of the spikes having an angle from normal of between 10 degrees and about 45 degrees.

4. A roughened contact comprising:

a contact having a surface; and

a solid metal layer deposited on the surface of the contact, the solid metal layer having spikes protruding away from the contact, the spikes being substantially conical, a side of each of the spikes having an angle from normal of between 10 degrees, and about 45 degrees and the spikes having a density of between about 1 and about 2 spikes per square micrometer.

9. A roughened contact comprising:

a contact having a surface;

a solid metal layer deposited on the surface of the contact, wherein the solid metal layer comprises nickel and has spikes protruding away from the contact, wherein the spikes are substantially conical, the spikes have a height between about 0.350 microns and about 1.275 microns, the spikes have a base between about 0.345 microns and about 1.250 microns, wherein a side of each of the spikes has an angle from normal of between about 10 degrees and about 45 degrees, and wherein the spikes have a density of between about 1 and about 2 spikes per square micrometer; and

a conductive plating deposited on the surface of the solid metal surface, wherein the conductive plating comprises gold.

10. A membrane for use in testing a circuit comprising:

a flexible membrane substrate;

a contact on the flexible membrane substrate having a surface; and

a solid metal layer deposited on the surface of the contact, the solid metal layer having spikes protruding away from the contact, the spikes being substantially conical, a side of each of the spikes having an angle from normal of between 10 degrees and about 45 degrees, and the spikes having a base between about 0.345 microns and about 1.250 microns.

13. The membrane of claim 10, 11, or 12, wherein the spikes are substantially conical.

14. The membrane of claim 10, 11, or 12, wherein the solid metal layer comprises nickel.

15. The membrane of claim 10, 11, or 12 further comprising a conductive plating deposited on the surface of the solid metal layer.

16. The membrane of claim 10, 11, or 12, wherein the conductive plating comprises gold.

17. The membrane of claim 10, 11, or 12, wherein the flexible membrane substrate comprises a polyimide film.

11. A membrane for use in testing a circuit comprising:

a flexible membrane substrate;

a contact on the flexible membrane substrate having a surface; and

a solid metal layer deposited on the surface of the contact, the solid metal layer having spikes protruding away from the contact, the spikes being substantially conical, and a side of each of the spikes having an angle from normal of between 10 degrees and about 45 degrees.

12. A membrane for use in testing a circuit comprising:

a flexible membrane substrate;

a contact on the flexible membrane substrate having a surface; and

a solid metal layer deposited on the surface of the contact, the solid metal layer having spikes protruding away from the contact, the spikes being substantially conical, a side of each of the spikes having an angle from normal of between 10 degrees and about 45 degrees, and the spikes having a density of between about 1 and about 2 spikes per square micrometer.