Socket contact with kelvin contact for testing integrated...

Details Socket contact with kelvin contact for testing integrated... Socket contact with kelvin contact for testing integrated...

2000-05-15

2001-09-25

Bradley, Paula (Department: 2833)

Electrical connectors

Having circuit interrupting provision effected by mating or...

C439S070000, C439S330000, C439S515000

Reexamination Certificate

active

06293814

ABSTRACT:

FIELD OF THE INVENTION
The present invention is a test socket for the testing of integrated circuit devices. In particular, the present invention is a test socket provided with “Kelvin” contacts for testing analog integrated circuit devices.
BACKGROUND OF THE INVENTION
Testing of integrated circuit (IC) devices is an essential part of IC device production. For analog or linear products, voltage drop and current flow are two important parameters that need to be determined in the testing of such products. These two parameters are highly affected by the arrangement of the test circuitry, and the quality of the contact points within the tester. For testing systems that use contact fingers, a set of two contact fingers clamping the IC device leads from the top and bottom allows four-terminal circuit for testing. One pair of contact fingers provides the contact for passing the measurement current, while the other contact finger provides the contacts for measuring the voltage drop at the device under test. This allows the testing system to measure any voltage drift or drop due to resistance within the test lead or due to contact resistance, and adjust the voltage accordingly to provide a constant preset voltage for testing to be performed.
Although contact finger sets provide a four terminal circuit, recent trends have been to shift from testing by contact fingers to testing by test sockets. One important reason is that for each type of IC packaging, a different set of contact fingers have to be manufactured. Adapatition from standard sets is not possible. On the other hand, test sockets have the advantage that they can be adapted by the IC manufacturer to be used for testing their IC packages. Therefore, a wide range of standard sockets can be supplied for testing numerous types of IC devices.
There is, however, no test socket in the market that is provided with Kelvin contacts to allow four-terminal measurements. The main difficult is that this feature requires two pairs of contact points for each pair of corresponding leads of the IC device to be tested. In the case of contact finger sets, the two fingers in each pair contact the IC device lead bi-directionally. Therefore, both the top and bottom surface of the lead is utilized, and there is sufficient room for contact to be made effectively. In the case of a contact socket, however, the testing finger contacts the IC device lead in only one direction from the socket side. Due to the short length of the tip and the small diameter of the IC device lead, conventional thinking has been that it is not feasible to provide a Kelvin contact for testing sockets. In addition to the small surface area that is available for contact with the socket finger, friction during testing results in carbon build up at the contact points of the socket fingers, creating further problems with cross contamination. There is therefore a need to provide a testing socket with Kelvin contacts which can avoid the above-stated pitfalls in practical use.
OBJECT OF THE INVENTION
It is an object of the present invention to provide a testing socket with Kelvin contacts.
It is a further object of the present invention to provide a testing socket which allows a IC packaging tester to input and sense a stable and constant electrical voltage for IC device testing.
SUMMARY OF THE INVENTION
The present invention is a test socket for facilitating the testing of integrated circuit (IC) devices. The test socket is provided with “Kelvin” contacts to allow four-terminal testing. A series of conducting strip sets are embedded across a non-conducting base and aligned juxtaposed to each other. Each strip set includes two pairs of electrodes. Each electrode is electrically insulated from another electrode. Two pairs of electrodes are designed such that each pair functions to contact one of the two corresponding leads of an IC device. Within the pair of electrodes, the first electrode has a tail section, and neck section and a head section, and the second electrode has a receiving end and a body.
The tail section of the first electrode and one end of the body of the second electrode is adapted for electrical connection with a test jig. In the resting position, the head section and the receiving end protrude out of the base adjacent to each other without coming into contact, with the receiving end positioned between the head and the base. The neck section of the first electrode connects the head section with the tail section, and is adapted to providing a resilience to bias the head section away from the receiving end. During testing, an IC device is positioned close to the socket, with the leads pressed against the head section of the first electrode. This results in the compression of the neck section, causing the head section to contact the receiving end. The connection between the receiving end and the head occurs very close to the point of contact between the IC lead and the head. Consequently, a Kelvin contact is achieved by passing the measurement voltage in one electrode, and measuring the voltage drop at the IC device on the other electrode.


REFERENCES:
patent: 5245132 (1993-09-01), Luetzow
patent: 3176676 (1991-03-01), None

Affiliated with

Also associated with

Rating

Socket contact with kelvin contact for testing integrated... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Socket contact with kelvin contact for testing integrated..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Socket contact with kelvin contact for testing integrated... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2451342