Plastic electronic component package

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. The cupric oxide outer layer has an acicular structure which provides an interlocking mechanism for adhesion to the plastic material molded thereto in forming the package.

1 . A hermetic seal between a metal element and a plastic element comprising:
 an intermediate layer between the metal element and the plastic element, the intermediate layer having:   a layer of a first oxide formed on a surface of the metal element; and   a layer of a second oxide formed on the layer of a first oxide, the second oxide layer having an acicular structure bondable to the plastic element.   
   
   
       2 . The hermetic seal of  claim 1  wherein:
 the first oxide is an oxide of the metal material of the metal element; and   the second oxide is a different oxide form of the first oxide.   
   
   
       3 . The hermetic seal of  claim 2  wherein:
 the metal element has a copper surface at least in the area bondable to the plastic element;   the first oxide is cuprous oxide and the second oxide is cupric oxide.   
   
   
       4 . For use in fabricating a hermetic seal between a high temperature plastic part molded to a copper part, the copper part comprising:
 a first layer of cuprous oxide formed on the surfaces of the copper part at least at the portions to be molded to the high temperature plastic part; and   a second layer of cupric oxide formed on the first layer of cuprous oxide and having an acicular structure bondable to the high temperature plastic part.   
   
   
       5 . A method of fabricating a component having a metal part and a plastic part, the method comprising the steps of:
 providing a metal part;   providing on at least a portion of the surfaces of the metal part an interfacial layer of oxide material; and   molding a high temperature thermoplastic part around the portion of the metal part having the interfacial layer.   
   
   
       6 . The method of  claim 5  wherein the thermoplastic part is an LCP material containing hydroquinine (HQ), teraphalic acid, isophalic acid, 2,6 naphalene, dicarboxyclic acid, 4-hydrobenzoic acid (HBA), bisphenol or biphenol (BP), and hydroxynaphthoic acid;
 and filler particles of at least one of the group consisting of talc, glass fiber, milled glass and flake glass.   
   
   
       7 . The method of  claim 6  wherein the filler particles are in the range of 10-50% by weight. 
   
   
       8 . The method of  claim 7  wherein at least some of the filler particles have a particle size in the range of about 50-350 microns. 
   
   
       9 . The method of  claim 5  wherein the step of providing an interfacial layer includes providing a first oxide on at least a portion of the surfaces of the metal part, and providing a second oxide on the first oxide. 
   
   
       10 . The method of  claim 9  wherein the step of providing the interfacial layer includes providing the interfacial layer on the entire surface of the metal part;
 and further including the step of removing the exposed portions of the interfacial layer from the metal part after molding the high temperature thermoplastic part.   
   
   
       11 . The method of  claim 5  wherein the metal part is copper and wherein the interfacial layer is copper oxide material. 
   
   
       12 . The method of  claim 5  wherein the step of molding comprises injection molding the high temperature thermoplastic part. 
   
   
       13 . The method of  claim 5  wherein the thermoplastic part is an LCP material. 
   
   
       14 . A component having a metal part and a plastic part comprising:
 a high temperature plastic part molded to a metal part; and   a metal part having on at least a portion of the surfaces thereof which are molded to the plastic part an interfacial layer of material effective to improve the adhesion of the high temperature plastic frame to the metal leadframe.   
   
   
       15 . The component of  claim 14  wherein the metal part is composed of copper;
 and wherein an interfacial layer is formed on at least the surfaces of the metal part in contact with the plastic part, the interfacial layer composed of a cuprous oxide layer formed on the surface of the metal part and a cupric oxide layer formed on the surface of the cuprous oxide layer.   
   
   
       16 . The component of  claim 14  wherein the interfacial layer has:
 a first layer formed on a surface of the metal part; and   a second layer formed on a surface of the first layer, the second layer having a surface bonded to the high temperature plastic part.   
   
   
       17 . The component of  claim 16  wherein the metal part has a copper surface;
 the interfacial layer has a first layer of cuprous oxide formed on the copper surface of the metal part; and   a layer of cupric oxide formed on a surface of the cuprous layer, the cupric layer having an acicular structure bonded to the high temperature plastic part.   
   
   
       18 . The component of  claim 14  wherein the plastic part is a high temperature LCP material. 
   
   
       19 . The component of  claim 14  wherein the LCP material has a melting temperature greater than about 300° C. 
   
   
       20 . The component of  claim 14  wherein the LCP material has a melting temperature greater than about 200° C. 
   
   
       21 . The component of  claim 14  wherein the LCP material contains filler particles to provide a CTE compatible with that of the metal part. 
   
   
       22 . The component of  claim 21  wherein the CTE of the LCP material is in the range of about 6-25 ppm/° C. 
   
   
       23 . The component of  claim 21  wherein the filler particles are of nano size. 
   
   
       24 . The component of  claim 21  wherein the filler particles are in the range of about 10-17% by weight. 
   
   
       25 . The component of  claim 14  wherein the metal part is copper. 
   
   
       26 . The component of  claim 14  wherein the metal part is a copper alloy. 
   
   
       27 . The component of  claim 14  wherein the metal part is a ferrous metal having copper su.