Bond inspection technique for a semiconductor chip
First Claim
1. A bond inspection technique for evaluating the bond interface between a plurality of leads bonded to respective contact pads on a semiconductor chip, comprising:
- initially heating the plurality of leads and bond interfaces to allow heat across the bond interfaces between the leads and the contact pads to be dissipated via the contact pads to the semiconductor chip;
producing at least one thermal intensity map of the semiconductor chip using a camera sensitive to infra-red radiation, said at least one thermal intensity map being indicative of the heat transferred through the bond interfaces wherein the heat transfer is a function of the integrity of the bond interface itself; and
inspecting said at least one thermal intensity map and comparing it against similar data at known good bond interfaces of a similar semiconductor chip to determine the quality of the bond interfaces of the semiconductor chip being evaluated.
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Accused Products
Abstract
A bond inspection technique which determines the integrity of a plurality of package leads (13) bonded to a plurality of contact areas (12) on a semiconductor chip (11). A bonding process heats each package lead (13) bonded to each contact area (12). A camera (16) forms an infra-red intensity image at a predetermined time of the semiconductor chip (11) and ports image data to a computer (18). Infra-red intensity radiated from each bond on the semiconductor chip (11) is compared by the computer (18) with infra-red intensity data of known good and bad bonds. The comparison of each bond determines bond integrity of the semiconductor chip (11).
41 Citations
16 Claims
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1. A bond inspection technique for evaluating the bond interface between a plurality of leads bonded to respective contact pads on a semiconductor chip, comprising:
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initially heating the plurality of leads and bond interfaces to allow heat across the bond interfaces between the leads and the contact pads to be dissipated via the contact pads to the semiconductor chip; producing at least one thermal intensity map of the semiconductor chip using a camera sensitive to infra-red radiation, said at least one thermal intensity map being indicative of the heat transferred through the bond interfaces wherein the heat transfer is a function of the integrity of the bond interface itself; and inspecting said at least one thermal intensity map and comparing it against similar data at known good bond interfaces of a similar semiconductor chip to determine the quality of the bond interfaces of the semiconductor chip being evaluated. - View Dependent Claims (2, 3, 4, 5)
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6. A method for simultaneously characterizing a plurality of package lead bonds on a semiconductor chip comprising:
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initially heating a plurality of package leads and their respective bonds on the semiconductor chip for a predetermined time; placing the plurality of package leads and the semiconductor package in the field of view of a camera sensitive to infra-red radiation; generating a thermal intensity map of said plurality of package lead bonds and the semiconductor chip as heat is transferred therebetween from data output by said camera, said thermal intensity map indicating the heat transferred through each bond interface between said plurality of package leads and the semiconductor chip; and comparing said thermal intensity map to data of substantially similar semiconductor chips with known package lead bond conditions. - View Dependent Claims (7, 8, 9, 10, 11)
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12. A method for inspecting the integrity of a plurality of package leads bonded to a semiconductor chip, comprising:
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focusing a camera sensitive to infra-red radiation on the plurality of package leads and the semiconductor chip; causing heat transfer through each bond interface between the plurality of leads and the semiconductor chip; generating a thermal intensity map of the semiconductor chip and leads fro data output from said camera, said thermal intensity map showing heat transferred through each bond interface; and inspecting and comparing said thermal intensity map against substantially similar semiconductor chip data with known package lead bond conditions. - View Dependent Claims (13, 14, 15, 16)
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Specification