Method of making a tester surface with high density probe points
First Claim
1. A method of making a tester surface comprising the steps of:
- providing a substrate having a principal surface and a secondary surface opposite the principal surface;
forming a plurality of cavities in the substrate each extending from the principal surface to a depth in the substrate;
lining the cavities and covering the principal surface with a first layer of a flexible material;
providing a first layer of metal on the first layer of flexible material, including portions of the first layer of flexible material lining the cavities;
forming a second layer of a flexible material over the principal surface and overlying the first layer of metal;
removing a portion of the substrate extending from the secondary surface toward the principal surface so as to expose a portion of the first layer of flexible material at the depth of the cavities;
removing the exposed portion of the first layer of flexible material, so as to expose a portion of the first layer of metal;
forming a metal tip on the exposed portion of the first layer of metal; and
removing the remaining portion of the substrate.
1 Assignment
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Accused Products
Abstract
Each transistor or logic unit on an integrated circuit wafer is tested prior to interconnect metallization. By means of CAD software, the transistor or logic units placement net list is revised to substitute redundant defect-free logic units for defective ones. Then the interconnect metallization is laid down and patterned under control of a CAD computer system. Each die in the wafer thus has its own interconnect scheme, although each die is functionally equivalent, and yields are much higher than with conventional testing at the completed circuit level.
The individual transistor or logic unit testing is accomplished by a specially fabricated flexible tester surface made in one embodiment of several layers of flexible silicon dioxide, each layer containing vias and conductive traces leading to thousands of microscopic metal probe points on one side of the test surface. The probe points electrically contact the contacts on the wafer under test by fluid pressure.
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Citations
16 Claims
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1. A method of making a tester surface comprising the steps of:
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providing a substrate having a principal surface and a secondary surface opposite the principal surface; forming a plurality of cavities in the substrate each extending from the principal surface to a depth in the substrate; lining the cavities and covering the principal surface with a first layer of a flexible material; providing a first layer of metal on the first layer of flexible material, including portions of the first layer of flexible material lining the cavities; forming a second layer of a flexible material over the principal surface and overlying the first layer of metal; removing a portion of the substrate extending from the secondary surface toward the principal surface so as to expose a portion of the first layer of flexible material at the depth of the cavities; removing the exposed portion of the first layer of flexible material, so as to expose a portion of the first layer of metal; forming a metal tip on the exposed portion of the first layer of metal; and removing the remaining portion of the substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification