Challenges to Improve Packages Robustness and Elimination of Mold Compound Sticking on Power Leaded Package

Striving next level of better package robustness reliability level, mold compound plays vital role of the overall package quality. Together with ADEGO specific requirement, formulation optimization on releasing agent, carbon black, flame retardant and ion trapper were introduced in the first phase of improvement. Second phase improvement started where facing challenge of mold releasing performance. This paper explained the extensive research bringing better effective solution. First was the implementation of releasing agent, polyethylene wax to eliminate package crack. Secondly, the study of fine carbon particle size of 90um to overcome particle short between lead and die pad as well as to reduce hard short risk. Third implementation was introduction of ion trapper hydrotalcite type “D”, purpose is to maintain pH level of 5–7 fulfilled ADEGO requirement of C1- content <20ppm. Fourth introduction is flame retardant from metal hydroxide to organic phosphorous in order to minimize leakage issue due to the product has poor ion barrier related to chip design. With these 4 types of composition changed, random runner stick and rough surface were observed during accumulative mold shot. By switching the flame retardant to inorganic material, the mold sticking issue was eliminated during continuous molding. Further research indicates that metal hydroxide contained OH- which act as free ion and easily move around within the compound compositions. In addition, organic phosphorus is soluble in resin and obstructed the cross linking of resin and catalyst. This shows that metal hydroxide will help to improve curability and prolong continuous molding duration.