Work holders – Relatively movable jaws – Jaw features
Reexamination Certificate
2000-01-20
2001-08-28
Hail, III, Joseph J. (Department: 3723)
Work holders
Relatively movable jaws
Jaw features
C269S041000
Reexamination Certificate
active
06279889
ABSTRACT:
FIELD
This invention relates to the field of integrated circuit testing. More particularly the invention relates to a fixture for holding integrated circuits for testing.
BACKGROUND
Integrated circuits are preferably tested in either wafer form or packaged form. When the integrated circuits are in either of these two forms, they are relatively easy to handle. For example, before a wafer is diced into individual integrated circuit chips, the wafer is large and easy to mount and position relative to a test station. Because of the size of the wafer, it is relatively easy to hold the wafer from positions on the wafer that do not physically interfere with either electrically probing or viewing the device under test. Similarly, packaged devices are also relatively easy to test compared to individual devices. Once the individual integrated circuit device is mounted and electrically connected to the packaging, the package is easily mounted and electrically connected to a test station.
However, sometimes it is necessary to test an integrated circuit that is neither in wafer form nor in package form. This need might arise either between the time that the wafer is diced and the individual devices are packaged, or after a device has been removed from its packaging for some reason, such as during failure analysis.
Special problems are encountered when testing individual devices. For example, because of the small size of individual devices, compared to either wafers or packages, they are more difficult to hold. Further, and also because of the small size of individual devices, they tend to be more difficult to hold in a manner that allows the device to be viewed or electrically probed. This problem is compounded when it is important for both the front and back surfaces of the device to be probed or viewed during testing. Further, individual devices tend to be far more fragile than packaged devices, and thus they are more easily damaged during testing than are packaged devices.
What is needed, therefore, is a fixture that allows an individual integrated circuit device to be safely held such that both surfaces of the integrated circuit can be probed, viewed, or both.
SUMMARY
The above and other needs are met by a fixture for holding an integrated circuit. The integrated circuit is of the type having a front side and an opposing back side. Thus, it is desired that the fixture allow for positioning the integrated circuit for simultaneously electrically probing and viewing both the front side and the back side of the integrated circuit.
A supporting brace provides a support that is immobile in at least a first direction, against which to cooperatively brace the integrated circuit. A first jaw piece is disposed adjacent the supporting brace. The first jaw piece receives the integrated circuit and cooperatively aligns the integrated circuit into a position for simultaneously electrically probing and viewing both the front side and the back side of the integrated circuit. The first jaw piece also has a vee shape for receiving a first corner of the integrated circuit.
An adjustable brace provides a movable second position in the first direction relative to the supporting brace, against which to cooperatively brace the integrated circuit with the supporting brace. A second jaw piece is disposed adjacent the adjustable brace. The second jaw piece receives the integrated circuit and cooperatively aligns the integrated circuit into a position for simultaneously electrically probing and viewing both the front side and the back side of the integrated circuit The second jaw piece also has a vee shape for receiving a second corner of the integrated circuit, where the second corner is disposed in an opposing position to the first corner of the integrated circuit.
Retaining means adjustably retain the adjustable brace relative to the supporting brace.
Thus, this embodiment of a fixture according to the present invention holds an individual integrated circuit by opposing corners between two braces. The adjustable brace, in cooperation with the retaining means, provides compressive force in the first direction on the integrated circuit in cooperation with the supporting brace, which is immobile in the first direction. The first jaw piece and the second jaw piece, by holding the integrated circuit at the corners, allow for both the front side and the back side of the integrated circuit to be accessible. Thus, both the front side and the back side of the integrated circuit can be either electrically probed or viewed while the integrated circuit is mounted within the fixture.
In various preferred embodiments of the invention, the retaining means include a thumbscrew, spring, or both. First and second guide rails are preferably provided, disposed in an immobile position relative to the first direction, and receive the adjustable brace and guide it in the first direction toward the supporting brace. The first and second jaw pieces preferably have a thickness that is about twice the thickness of the integrated circuit, and a vee shaped cross section of about 120 degrees. This provides a self centering action on the integrated circuit in two different directions. The self centering action in one direction is provided by the general vee shape of the jaw pieces, and the self centering action in the other direction is provide by the vee shaped cross section. The general vee shape of the jaw pieces is preferably a ninety degree angle, to match the opposing corners of the integrated circuit.
REFERENCES:
patent: 121851 (1871-12-01), Cornish
patent: 2417144 (1947-03-01), Trimble
patent: 513060 (1930-03-01), None
patent: 2809584 (1979-09-01), None
patent: 1352980 (1974-05-01), None
patent: 616014 (1976-12-01), None
patent: 8607232 (1974-05-01), None
Hail III Joseph J.
LSI Logic Corporation
Shanley Daniel
LandOfFree
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