Adjusting fillet geometry to couple a heat spreader to a chip carrier

摘要

An electronic structure, and associated method of fabrication, for coupling a heat spreader above a chip to a chip carrier below the chip. Initially provided is a substrate, a chip on a surface of the substrate and coupled to the substrate, and the heat spreader. Then a fillet of at least one adhesive material is formed on the chip and around a periphery of the chip. Additionally, the heat spreader is placed on a portion of the fillet and over a top surface of the chip. The fillet couples the heat spreader to the substrate. An outer surface of the fillet makes a to contact angle of about 25 degrees with the surface of the substrate. The small contact angle not exceeding about 25 degrees prevents cracking of the substrate that would otherwise result from thermal cycling.