摘要 |
In securing a semiconductor chip to a substrate of ceramic material or the like, a de-focused laser beam having a wave length to which the substrate is substantially opaque is directed over a relatively large area of the reverse side of the substrate. Heat generated at the reverse side of the substrate then flows through the substrate to heat bonding material that is placed between the engaging surfaces of the chip and substrate. In this manner direct heating of the chip is avoided or minimized, and damage to both chip and substrate is also minimized.
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