Novel copper surface preparation processes for copper alloy lead frame lamination pretreatment in embedded packaging device

In this paper, the interface adhesion and reliability between copper lead frame(C-19210) and resin prepreg material of different copper lead frame lamination pretreatment processes (CZ and brown oxide) was studied. Surface morphology, roughness, peel strength and moisture sensitivity level, MSL3, reliability tests were performed in order to investigate the performance between these pretreatment procedures. CZ (HCl/formic acid system) process for copper etching is commonly used for lamination pretreatment, but it is not suitable to create uniformity coarse surface on copper alloy material. Compare to CZ, brown oxide gives better uniformity morphology, higher Ra/s-ratio and stronger peel strength. Reliability test including precondition + MSL3 (failure rate: BO∶CZ=14∶100) and solder dipping (260, 270, 288 °C × 10 times) were performed to evaluate the bond strength.