Browse Prior Art Database

Pin Bonding Technique

IP.com Disclosure Number: IPCOM000076653D
Original Publication Date: 1972-Apr-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Campagna, FC: AUTHOR [+4]

Abstract

In this method pins are electrolytically bonded to the pads of a substrate.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Pin Bonding Technique

In this method pins are electrolytically bonded to the pads of a substrate.

Pin bonding is usually done with a braze cycle. Because of the high temperature involved, it is necessary to use very expensive moly pins in order to keep the gold coating over the pins from diffusing into the pins during the brazing cycle.

This pin bonding technique permits the use of less expensive KOVAR* or nickel pins, since the bonding process takes place at room temperature.

In this method the substrate 10 is mounted in bracket 11. The pins 12 are suitably jigged in fixture 14. Electrical contact is made to pads 15 through lead 16 attached to bolt 17, in turn contacting metallization 18 and via connection 19. The pads are made and the cathode immersed in electrolytic 20, which is a plating solution. Anode 21 completes the electrolytic cell.

The bonding is achieved by electroplating the pins to the pads. Different types of plating baths can be used, such as, copper sulfate or nickel sulfamate.

The optimum electroplating current density was found to be 20 A/Ft/2/ for the copper sulfate bath and 10 A/Ft/2/ for the nickel sulfamate bath. The pin-to-pad spacing should be at least 0.002 inch.

Higher current densities may be used with a bath having adequate agitation. * Trademark of Westinghouse Electric Corp.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]