The no-load vacuum eutectic solder die bonding process
Eutectic soldering process usually takes with the load own gravity to provide downward force of the chip, the chip closer Solder Lug and die-attach area contact, which inevitably load in with the surface of the chip, either point or face contact has placed enormous demands on the cleanliness of the chip surface. however the silicon powder will lead to damage chip in the role of load, and the load surface is easy to stain, lower the yield of eutectic soldering, and very high chip cleanliness is required. Through improve temperature curve and pressure control to achieve a no-load vacuum eutectic soldering die bonding process. Temperature curve can be improved to achieve uniform welding, in order to reduce the voids, make the die-bonding flat, and also need to introduce air pressure control technology to improve the vacuum eutectic soldering quality and product yield. Pressure, atmosphere control method refers to a chip provides a downward pressure through the internal pressure changes to achieve a no-load process. At present, this process has been put into production use for almost a year, all products yield remained at 99.8%, die shear strength are greater than 2 times the standard, the voids rate <;5%, while saving the cost of briquette production significantly improved production yield.