Verifying backgrind tape lamination pressure uniformity
The process for laminating backgrind tape (protective film) precedes grinding. If the lamination roller pressure distribution is not uniform, the backgrind tape can become wrinkled. If the height of the wafer and the surrounding mounting table are not optimal, wafer cracking and poor backgrind tape lamination occurs. Previously, only trail and error adjustment methods had been available to prevent this.
Product used: Prescale (Extreme low pressure 4LW)
Prescale is placed on the wafer and the surrounding mounting table, after which the lamination roller is operated at the usual pressure. The Prescale is then removed and its color is examined to determine whether pressure had been uniformly applied.