Browse Prior Art Database

Flexible Solder Connection and Method of Fabricating

IP.com Disclosure Number: IPCOM000084220D
Original Publication Date: 1975-Oct-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Geldermans, P: AUTHOR

Abstract

In this electrical connection, adapted for electrically joining a substrate and a semiconductor device, a portion of the connection consists of thin-wire strands which impart flexibility.

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 57% of the total text.

Page 1 of 2

Flexible Solder Connection and Method of Fabricating

In this electrical connection, adapted for electrically joining a substrate and a semiconductor device, a portion of the connection consists of thin-wire strands which impart flexibility.

A significant problem in joining semiconductor devices to carriers utilizing rigid bonding techniques, is the fracture of the electrical connections during thermal cycling. Normally, the semiconductor device and the device carrier are formed of different materials having different coefficients of expansion. During the required heating to accomplish joining, and during normal operating conditions, the device and carrier contract and expand at different rates thereby generating stresses. These stresses can fracture the device, the carrier or the joints. The problem is compounded as the size of the devices becomes larger. Rigid electrical connections are formed when solder joints are used to connect the device and substrate.

In this structure, the electrical connection between a semiconductor device and substrate consists of a flexible portion, typically formed of a number of strands of thin copper wire that are joined at each end by solder balls on the device and carrier.

The technique for fabricating the flexible joint is illustrated in Figs. 1-4. In Fig. 1, there is illustrated a carrier 10 provided with pins 12 for mounting on a card or other support and a plurality of solder mounds 14 on the top surface. The connection betwe...