Underfill

Underfill technique is used under the BGA to strengthen solder joints, and reinforce the product’s resistance against vibration and thermal shock

Introduction

Underfill technique is used under the BGA to strengthen solder joints, and reinforce the product’s resistance against vibration and thermal shock. When subject to greater temperature changes, the difference in coefficient of thermal expansion between the silicon chip and the PCB substrate often causes relative shifts during thermal shock test, resulting in solder joints falling off or fracturing. Underfill technique effectively strengthens the solder joints between solder balls and circuit board, increases the product’s resistance against vibration and reduces thermal stress damage, increasing product reliability and thus increasing product lifespan.

Underfill Flow

Epoxy is usually used as the underfill. It is dispensed along the edges of the chip and allowed to settle at the bottom of the BGA chip through capillary action. The substrate is then heated to increase the mechanical strength of the solder joints and reinforce the product’s shock resistance

Application

Apacer provides underfill technology to increase product reliability and resistance to various thermal and mechanical shocks, ensuring that products continue to operate normally in high vibration and under extreme changes in environmental temperature. Ideal solution for industrial equipment, such as military, vehicular, outdoor and rugged computers.