Browse Prior Art Database

Method of Ultrasonically Bonding Thermocouples to Silicon

IP.com Disclosure Number: IPCOM000060662D
Original Publication Date: 1986-Apr-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Phelps, DW: AUTHOR [+3]

Abstract

A thermocouple bead is attached to silicon by first ultrasonic bonding a small piece of 0.005 or 0.010 inch diameter aluminum wire to the silicon and then ultrasonic bonding the thermocouple bead to the aluminum.

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Method of Ultrasonically Bonding Thermocouples to Silicon

A thermocouple bead is attached to silicon by first ultrasonic bonding a small piece of 0.005 or 0.010 inch diameter aluminum wire to the silicon and then ultrasonic bonding the thermocouple bead to the aluminum.

Thermocouple wire of 0.001 to 0.003 inch diameter copper/ constantan, chromel/alumel, or iron/constantan is welded with a small, controlled size bead at the weld by means of commercially available equipment. This bead is readily ultrasonically bonded to aluminum wire which is previously ultrasonically bonded to silicon. This method provides a good mechanical and thermal attachment of a thermocouple to a silicon wafer, e.g., to perform thermal studies of silicon wafers in process.

The same method is used to attach thermocouples to the back of silicon chips which have been solder reflow joined to wiring on a ceramic substrate. The thermocouple wires are then ultrasonically bonded to pins (for most accurate results, pins ar the material of the thermocouple wire) in the ceramic substrate and the packaging is completed in the conventional manner, i.e., an aluminum cap is placed over the chip and epoxy bonded to the ceramic substrate edges. The pins provide means for electrical attachment and thus means are provided for making thermal measurements of silicon device chips on test or in operation in computer system environment.

Disclosed anonymously.

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