Browse Prior Art Database

One Mask Terminal Process

IP.com Disclosure Number: IPCOM000077826D
Original Publication Date: 1972-Sep-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

Chase, EN: AUTHOR [+3]

Abstract

This method provides controlled-collapse semiconductor chip contact terminals for flip-chip bonding, and reduces the number of terminals evaporation masks necessary from two to one.

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One Mask Terminal Process

This method provides controlled-collapse semiconductor chip contact terminals for flip-chip bonding, and reduces the number of terminals evaporation masks necessary from two to one.

A metal mask 10 having openings corresponding to desired contact locations is mounted over previously prepared semiconductor chip 12, including conductive line 14 and insulating layer 16. The masked wafer is placed in an evaporation chamber and a flashing of chromium-copper-gold 18 is deposited. Subsequently, a sufficient quantity of lead 20 and tin 22 is deposited through mask 10 to provide the controlled collapse terminal. Lead-tin evaporation proceeds to a point, such that the final height of the metallurgy is above the original mask height. Utilizing a single mask, as described, eliminates the requirement of a second mask for lead-tin having a larger opening.

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