| 摘要 |
A package for microelectronic circuits includes a frame made of a high molecular weight plastic material, such as a liquid crystal polymer (LCP), attached to a flange, or leadframe. The plastic material is injection molded to the flange. Initial polymerization of the plastic material can occur in a liquid state and results in an intermediate material having an initial melting temperature. After the frame is injection molded, the frame is heated and undergoes further (secondary) polymerization, thereby lengthening polymer chains in the plastic material. These longer polymer chains have higher molecular weight, and the resulting final material has a higher melting temperature, than the intermediate material. The resulting ultra-high molecular weight polymer can withstand high temperatures, such as those encountered during soldering. Thus, after the further (secondary) polymerization, a die can be soldered to the flange, without damaging the plastic frame. |
