Process along thickness direction

This paper describes a visualization mold with a glass-inserted structure which enables observation of the dynamic melt behavior inside the cavity along the thickness direction. The melt front profile and the behavior of the melt front surface were observed using a high speed video system, and analyzed with an image processor. Several experiments revealed that the melt advanced slipping on the cavity surface or lead frame. It was also found that the surface of the melt front moved from the cavity surface to the lead frame generally due to the difference in the flow resistance between the cavity surface and lead frame. The surface velocity of the melt front was related to the position of the melt front, that is, the surface velocity of the preceding melt front was slower than that of the following one. It suggests that the melt flow is affected by the melt in the opposite cavity beyond the lead frame.