Motorola Corporation

Reed Allen George

Dennis Brian Miller

Richard Lee Mangold

Frank Joseph Juskey

A method for selectively marking integrated circuit chips (205, 210) formed on a wafer (200) includes the steps of testing the integrated circuit chips (205, 210)) of the wafer (200) to determine whether the integrated circuit chips (205, 210) are functional, dispensing underfill material (215) only on functional integrated circuit chips (205), and separating, subsequent to the dispensing step, the wafer (200) into individual integrated circuit chips (205, 210). The functional integrated circuit chips (205) are marked with the underfill material (215), while nonfunctional integrated circuit chips (210) are not marked with the underfill material (215).

Method for marking functional integrated circuit chips with underfill

Solder paste (16) is dispensed onto a platen (12) that includes depressions (14) that are preferably conical or in an inverted pyramid shape. The solder paste (16) is formed of a plurality of particles composed of a solder alloy. Excess solder paste (16) is removed, and a predetermined solder paste volume fills the depressions (14). A substrate (18) is superposed onto platen (12) such that solder-wettable bond pads (20) on the substrate (18) register with the depressions (14). The platen (12) is heated to melt the solder alloy, and the solder alloy coalesces to form molten solder droplets (22). The solder droplets (22) are transferred onto the solder-wettable bond pads (20) to form solder bumps (24) bonded to the bond pads (20).

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Chandler, AZ, United States of America

Reed Allen George