Active solid-state devices (e.g. – transistors – solid-state diode – Housing or package – With contact or lead
Reexamination Certificate
1999-04-12
2001-07-10
Clark, Jhihan B (Department: 2815)
Active solid-state devices (e.g., transistors, solid-state diode
Housing or package
With contact or lead
C257S693000, C257S778000, C257S783000, C257S792000
Reexamination Certificate
active
06259155
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to semiconductor packaging and more particularly to a ceramic column grid array package formed with polymer reinforcement of the columns on a chip carrier substrate.
2. Description of Related Art
Ceramic column grid array packages are used in many high performance application specific integrated circuits and microprocessor chips. In a typical manufacturing process of bonding, assembly and test, the wire connections for a ceramic column grid array are attached near the end of the manufacturing cycle, thus minimizing handling damage. A problem with wire column grid array processing is that during printed circuit card rework, the columns on the grid array packages may come off from the package substrate side and stay behind on the printed circuit card. Multiple localized heating on the printed circuit card side to remove these columns is time and labor intensive and may damage the printed circuit card by causing land delaminations.
A purpose of the present invention is to provide an enhanced ceramic column grid array and method for mechanically stabilizing the wires of the column grid on its substrate.
Another purpose of the present invention is to provide an enhanced column grid array which may be reworked wherein the column grids stay with their substrate and do not remain with the printed circuit card.
SUMMARY OF THE INVENTION
The above and other purposes which will be apparent to one skilled in the art are achieved by the present invention which in one aspect a polymer having a low glass transition temperature is coated on the substrate after attachment of the column grid array wires. Upon curing of the polymer, the polymer mechanically reinforces the base or fillet of the column grid array wires to enhance the attachment of the wires to the ceramic column grid substrate. The polymer may be injected or spin coated onto the substrate, then cured at a temperature below the melting point of the wire column solder material. Upon removal of the ceramic column grid array mounted on a printed circuit card, all of the wire grids will remain with the array package and none of the columns will remain with the card itself.
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Dwyer Scott R.
Interrante Mario John
Jackson Raymond Alan
Ray Sudipta Kumar
Zucco Paul A.
Clark Jhihan B
International Business Machines - Corporation
Pepper Margaret A.
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