| 摘要 |
PURPOSE:To suppress the development of resin fin and obtain favorable resin moldings by a method wherein the peripheral edge of a cavity on the mating surfaces of an upper and lower molds are roughened so as to have the same surface roughness of lead frames. CONSTITUTION:On one of a pair of upper and lower molds 14 and 15, a pot is formed, while, on the other mold, a cull 6 is formed at the position opposite to the pot. In addition, runners 7 communicating with the cull 6 are formed on the mating surfaces of the upper and the lower molds 14 and 15 and, at the same time, cavities 8 communicating through gates 9 with the runners 7 are formed along the runners 7. In the cavity 8, a lead frame 10, on which electronic parts are mounted, is installed and, after that, the upper and lower molds 14 and 15 are mated together. Thus, fluidized resin is fed under pressure from the pot through the runner 7 and the gate 9 to the cavity 8. In this case, the mating surfaces at the peripheral edges of the cavities 8 of the upper and lower molds are turned into unevenly roughened surfaces, the surface roughness of each of which is the same surface roughness as the surface roughness of the lead frame 10. The depth of the roughness surface is preferably formed to be 5-15mum. |
