Dismiss
There will be a system update on Friday, May 5th, 6 PM ET. You may experience a brief service interruption.
Browse Prior Art Database

EXTENDED METALIZATION

IP.com Disclosure Number: IPCOM000005935D
Original Publication Date: 1990-Mar-01
Included in the Prior Art Database: 2001-Nov-16
Document File: 1 page(s) / 57K

Publishing Venue

Motorola

Related People

Thomas Bock: AUTHOR

Abstract

In a semiconductor pressure sensor (as shown in FIG. 1) a glass plate (2) has sputtered metalization layers of chrome (4) and nickel (6) on which is formed a solder bump (8) for subsequent electrical connection. Failure analysis of such devices showed that glass fracture occurred at the edge of the metalization layers.

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 83% of the total text.

Page 1 of 1

0 M

MOlDROLA Technical Developments Volume 10 March 1990

EXTENDED METALIZATION

by Thomas Sock

In a semiconductor pressure sensor (as shown in FIG. 1) a glass plate (2) has sputtered metalization layers of chrome
(4) and nickel (6) on which is formed a solder bump (8) for subsequent electrical connection. Failure analysis of such devices showed that glass fracture occurred at the edge of the metalization layers.

   The putative cause of such failures is force interaction between the glass and the metalization, resulting from in- creased tensile stress with each added layer of metalization and solder: each layer is applied at elevated temperature and is allowed to cool to mom temperature, creating compressive stresses in the glass underlying the metalization; since the glass extends beyond the metalization, it is pulled into tension at the metalization's edge as a result of global load equalization.

Thickening of the glass and/or metalization layers were shown to have little or no effect in the maximum stress level in the glass.

   However, the maximum stress level in the glass is significantly reduced if the metalization is extended to the edge of the glass, resulting in only a compressive stress at the glasslmetalization interface. Alternatively, since the extension of the metalization to the edge of the glass may not be electrically acceptable in such a device, the metalization may simply be extended (as shown in FIG. 2) beyond the solder. Such metalization extending...