Browse Prior Art Database

Bimetal Wire Gripper

IP.com Disclosure Number: IPCOM000045086D
Original Publication Date: 1983-Jan-01
Included in the Prior Art Database: 2005-Feb-06
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Gaston, CA: AUTHOR [+2]

Abstract

This article concerns a fixture for use in wire bond pull tests. The fixture features a bimetal vice which is infrared heated to clamp the wire to be pull-tested.

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 89% of the total text.

Page 1 of 2

Bimetal Wire Gripper

This article concerns a fixture for use in wire bond pull tests. The fixture features a bimetal vice which is infrared heated to clamp the wire to be pull- tested.

A wire fixture for use in a wire bond strength test that requires no manual manipulation to grip the wire to be tested and, as a result, avoids work hardening of the bond is shown in the figures. The gripping action of the fixture is provided by its bimetal jaw which is actuated with focused, radiant heat.

The three basic elements of the fixture are shown in Fig. 1. As shown in Fig. 1, the basic elements are the fulcrum, the bimetal jaw, and the fixed jaw.

Operation of the fixture requires the wire to be tested to be positioned between the fixed jaw and the bimetal jaw. The heat source is then activated, causing the bimetal jaw to close and grip the wire. Thereafter, the pull test proceeds as with a conventional mechanical fixture. Since there is no manual manipulation or deflection, deformation of the bond wire is minimized. The result is no significant added strain hardening of the wire is experienced. Accordingly, more accurate bond strength measurements may be obtained.

Fig. 2 illustrates a calculation for determining fixture opening and closing needed to accommodate various wire sizes. In accordance with the fixture, the considerations for the bimetal jaw designs are as follows: d=L/2/ over 2t (delta L) over L delta L over L=(C(E)(1) - C (C(E)(2) delta T where: d=jaw deflectio...