Abstract: A plastic package for an image sensor or other electronic component which comprises a plastic body, preferably of LCP material, molded around a leadframe and defining a cavity in which the image sensor is to be disposed. A lid assembly is provided having a transparent glass lid retained in a plastic lid frame which is weldable or otherwise bondable to the plastic body of the package to enclose the image sensor mounted in the cavity. The leadframe is usually composed of copper or a copper alloy, or a ferrous alloy having a copper coating. An interfacial layer is formed on the surfaces of the leadframe at least in those portions which are in contact with the plastic body which serves to provide substantially improved adhesion between the leadframe and the plastic material to achieve a hermetic bond between the metal and plastic materials. The interfacial layer is composed of a cuprous oxide base layer formed on a surface of the leadframe, and a cupric oxide layer formed on the cuprous oxide layer.

Abstract: 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.

Abstract: A circuit package for housing semiconductor or other integrated circuit devices (“die”) includes a high-copper flange, one or more high-copper leads and a liquid crystal polymer frame molded to the flange and the leads. The flange includes a dovetail-shaped groove or other frame retention feature that mechanically interlocks with the molded frame. During molding, a portion of the frame forms a key that freezes in or around the frame retention feature. The leads include one or more lead retention features to mechanically interlock with the frame. During molding, a portion of the frame freezes in or adjacent these lead retention features. The frame includes compounds to prevent moisture infiltration and match its coefficient of thermal expansion (CTE) to the CTE of the leads and flange. The is frame is formulated to withstand die-attach temperatures. A lid is ultrasonically welded to the frame after a die is attached to the flange.

Abstract: A microcircuit package having a ductile layer between a copper flange and die attach. The ductile layer absorbs the stress between the flange and semiconductor device mounted on the flange, and can substantially reduce the stress applied to the semiconductor device. In addition, the package provides the combination of copper flange and polymeric dielectric with a TCE close to copper, which results in a low stress structure of improved reliability and conductivity.