Method and apparatus for testing unpackaged semiconductor dice

DETAILED DESCRIPTION In accordance with the present invention, an improved method and apparatus for testing unpackaged semiconductor dice are provided.
The method includes forming an interconnect-alignment fixture for an unpackaged die, and then using the interconnect-alignment fixture in a test apparatus for establishing a temporary electrical connection with the die for testing.
The interconnect-alignment fixture is fabricated out of silicon or a similar material using semiconductor fabrication processes.
The fixture includes an interconnect plate and an alignment plate aligned with one another and bonded together as an assembly for use in the test apparatus.
The interconnect plate includes a silicon substrate having contact members formed as raised projections covered with a conductive material.
The raised projections are formed in a pattern that matches a pattern of contact locations (e.
g.
, bond pads) on a semiconductor die and are adapted to penetrate the contact locations on the die to a limited penetration depth.
The conductive material is in electrical communication with conductive traces formed on the substrate to provide a conductive path to the raised projections for applying test signals to the die.
The alignment plate of the fixture includes etched alignment openings adapted to mechanically align the die with the interconnect plate.
In addition, the alignment plate includes etched access openings for electrically connecting the conductive traces on the interconnect plate to the test fixture.
The electrical connection to the conductive traces can be made by wire bonding or using a mechanical electrical connector such as a clip or slide connector.
Preferably the interconnect plate and the alignment plate of the fixture are initially formed as separate wafers using masking, etching and deposition processes employed in semiconductor fabrication.
After being fabricated separately, the wafers are aligned, bonded together and then singulated to form a plurality of separate interconnect-alignment fixtures, each suitable for testing an unpackaged die