Browse Prior Art Database

Thermal and Acoustic Probes for Copper/Ceramic Connectivity

IP.com Disclosure Number: IPCOM000034794D
Original Publication Date: 1989-Apr-01
Included in the Prior Art Database: 2005-Jan-27
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Ludeke, R: AUTHOR [+2]

Abstract

A technique is described whereby thermal and acoustic probes are used to non-destructively test the delamination of copper at the via walls of glass ceramic semiconductor integrated circuit packages. In prior art, destructive testing was required to determine the existance of a gap at the via walls, specifically between the glass ceramic package and the copper, as shown in Fig. 1. The concept described herein utilizes thermal and acoustic probes so as to eliminate the need to destroy the package during analysis and speeds up the testing process. A pulsed or chopped laser source is used to heat the ceramic near the location of the via, as shown in Fig. 2. Using a thermal probe, the temperature of the copper is recorded.

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 88% of the total text.

Page 1 of 2

Thermal and Acoustic Probes for Copper/Ceramic Connectivity

A technique is described whereby thermal and acoustic probes are used to non-destructively test the delamination of copper at the via walls of glass ceramic semiconductor integrated circuit packages. In prior art, destructive testing was required to determine the existance of a gap at the via walls, specifically between the glass ceramic package and the copper, as shown in Fig. 1. The concept described herein utilizes thermal and acoustic probes so as to eliminate the need to destroy the package during analysis and speeds up the testing process. A pulsed or chopped laser source is used to heat the ceramic near the location of the via, as shown in Fig. 2. Using a thermal probe, the temperature of the copper is recorded. The thermal conductivity is then determined, using the formula: 2T

s KT [[ A1 2x where A is the area of the conduction path. Using this formula, the quality and continuity of the bond between the copper and the ceramic can be determined. The best bond will indicate a greater temperature rise in the copper in a short period of time. The thermal path for defective bonds will be on the order of 250 microns, and for good bonds will be on the order of 20 microns. The next step is to use acoustic pulses at the ceramic package, as shown in Fig. 3, so as to detect the propagation time in the nearby copper area. The acoustic pulses may be laser generated, or induced by a piezo electric driver.

A pi...