The nut for 13”~15” NB is traditionally used with M2.5 and M3 since 3C products tend to be thin and small size. However, the specification mentioned above can not be applied to7”~10” small NB due to the consideration of mechanical structure , hence the Nut M2 is used. In this research , six sigma management is used in hot melting Nut process to obtain the optimal parameters in order to satisfy RD design specification of all pull strength of Nut. The approach of DMAIC can be used to define the problem of the process , measure and analyze the causes, and the improve and control the key process factors. The processes are also developed using the Top-Down way