A Method for Components Alignment in Flip-Chip-Attach Using Gray Level Image Processing

Abstract

To automate semiconductor bare chip placement operation for the flip-chip-attach, a robust image processing method for realizing high accuracy and reliability is required. This paper proposes a method for measuring a position of a semiconductor bare chip and a chipsite on a module board. Both the position of a solder bumps array on the bottom surface of a semiconductor bare chip and the position of a contact pads array on the surface of a module board are measured in gray level images. Because gray levels of pixels are evaluated relatively and the number of parameters that influence the result of image processing is few in the method, robust and high reliable alignment is performed. As the experimental result, the method provided practical alignment accuracy and reliability for the semiconductor bare chip placement tool.