Resurfaceable contact pad for silicon or organic redistribution interposer for semiconductor probing
The present invention relates to a method and an apparatus for a resurfaceable contact pad that uses an epoxy to encapsulate contact pads so that the epoxy and encapsulated contact pads are coplanar on a silicon redistribution interposer. These redistribution interposers electrically connect a wafer semi-conductor to a probe card where it is necessary to convert the course pad arrangement of one with a fine pad arrangement of the other through the use of an interposer board. The present invention relates to an apparatus and a method creates resurfaceable contact pads which may be resurfaced one or multiple times with an abrasive sanding operation to recreate a coplanar surface should any contact pad surfaces become damaged, allowing for a more cost-effective repair.
1. An apparatus for resurfaceable contact pads, comprising:
an epoxy to encapsulate contact pads so that the epoxy and encapsulated contact pads are coplanar on a silicon redistribution interposer, said pads being formed by lengthening along a z-axis by one of either electro-plating, electro-less plating or thermal sonic bonding, said redistribution interposer being electrically connected to a wafer semi-conductor to a probe card where it is necessary to convert the course pad arrangement of one with a non-coarse pad arrangement of another one of said pads through the use of an interposer board, said resurfaceable contact pads having a coplanar surface formed by resurfacing one or more times with an abrasive sanding operation.
2. The apparatus for resurfaceable contact pads according to claim 1 wherein said conductive contact pads are encapsulated in an epoxy and said contact pads are equally coplanar with a surface of a surrounding epoxy.
3. The apparatus according to claim 1 wherein said pads are lengthened along a z axis by an electro-plating operation.
4. The apparatus according to claim 3 wherein a suitable temporary mask, of suitable thickness approximately ranging from 0.0005 ″ to 0.005″ thick, such as a photo image-able plating mask is formed over a top surface of the interposer exposing just the pads to be plated and the pads are built up to a designated height forming a column by an electro-plating operation, of a wear resistant, contact resistant having a resistant that approximates that of a noble metal, is performed and the temporary mask is removed and a permanent epoxy is formed around the plated columns.
5. The apparatus according to claim 1 wherein said pads are lengthened along a z axis by an electro-less plating operation.
6. The apparatus according to claim 3 wherein a suitable temporary mask, of suitable thickness typically ranging from 0.0005″ to 0.005″ thick, such as a photo image-able plating mask is formed over a top surface of the interposer exposing just the pads to be plated and the pads are built up to a designated height forming a column by an electro-less plating operation, of a wear resistant, contact resistant having a resistant that approximates a resistant of a noble metal, is performed and the temporary mask is removed and a permanent epoxy is formed around the plated columns.
7. The apparatus according to claim 1 wherein said pads are lengthened along a z axis by a thermal-sonic gold ball bonding electro-plating operation.
8. The apparatus according to claim 3 wherein instead of a temporary photo image-able mask, a photo image-able permanent epoxy can be used.
9. The apparatus according to claim 5 wherein instead of a temporary photo image-able mask, a photo image-able permanent epoxy can be used.