Elimination of Smashed Ball Defect through Process and Design Improvement
Jonathan C. Pulido
New Product Development and Introduction, STMicroelectronics, Inc., Calamba City, Laguna, 4027, Philippines.
Rennier S. Rodriguez
New Product Development and Introduction, STMicroelectronics, Inc., Calamba City, Laguna, 4027, Philippines.
Frederick Ray I. Gomez *
New Product Development and Introduction, STMicroelectronics, Inc., Calamba City, Laguna, 4027, Philippines.
*Author to whom correspondence should be addressed.
Abstract
This paper presents the modification and improvement done on the wire clamp and top plate (WCTP) design to eliminate the bouncing effect of the silicon die that leads to smashed ball reject during the formation of wire. The protrusion of the unit on the vacuum hole produced movement and slight vibration that affects the consistency of wirebonding. Through changing the standard vacuum hole to micro-holes provides underneath support to the unit and eliminates the overhanging or protrusion during the formation of wire. The implementation of the micro-hole design reduced the defect parts per million (dppm) occurrence to zero.
Keywords: Assembly, smashed ball, WCTP, wirebond process.