Dynamic Chip Pad Volume Analysis Tool
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-18
This article describes a method of inspecting and determining automatically the physical size characteristics of solder pads on semiconductor chips by comparing the solder pad under test to a standard specimen pad. It further logs the location of defective solder pads for later rework purposes. It operates on a "go - no go" basis and is concerned with pad area, pad length and pad volume only. Fig. 1 schematically depicts the apparatus to carry out the method. The "go - no go" decision is based on the results of an image analysis algorithm that is performed by the tool during each pad inspection cycle. The tool contains "upper" and "lower" acceptable limits for pad volume characteristics in its operating circuits, and are used for the "go - no go" decision.