An automatic optical system for micro-defects inspection on 5 surfaces of a chip

The novelty of three-dimensional integrated circuit (3DIC) chips indicates the thin-chip stacks on both front side and back side, so relative thinness is easily to affect the dicing quality while cutting wafers into species of chips. For the common defects of the chipping and glue, they are usually occurred on chip surfaces of front side, backside and edgesides, accompanied by the cutting process, and it is the dominant role to lower the yield rate. Therefore, the main purpose of the study is to implement the efficient defect inspection system for five surfaces (1 backside and 4 edgesides) of each chip and assess the quality in almost real-time fabricating. Here a new architecture with multiple pick and place heads to suck chips and move synchronously for image acquisition. Additionally, an opto-mechanical module and defect inspection procedures are also proposed and implemented for verifying the chips quality. The preliminary system integration and tests are completed and the inspection performance can be achieved around 95% correctness.