Temperature controlled high power burn-in board heat sinks

Electric heating – Heating devices – With heater-unit housing – casing – or support means

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C219S209000, C324S760020, C324S765010, C165S185000, C165S080200

Reexamination Certificate

active

06288371

ABSTRACT:

BACKGROUND OF THE INVENTION
The present invention relates to construction and mounting of temperature controlled heat sinks or heat exchanger for burn-in boards where high power is being generated by the circuits on the chips that are being tested on the burn-in board. The heat sinks are made and mounted to have intimate contact with the chips without causing undue loading, and are controlled for cooling, as well as heating, when needed. A helium layer can be provided between the heat sinks and chips when greater heat conductivity is desired between the heat sink and the chip.
In the prior art, burn-in boards for testing integrated circuits in particular have been advanced, and these are usually boards that will mount a number of individual chips, and which are controlled to individually test the circuits on the chips. The tests are carried out in an oven, under an elevated temperature.
It is desirable to control the temperature of the chips to determine that the circuits on the chips are functioning properly. The sequence of testing can be carried out in a known manner. The connections for the burn-in tests are made at the back edge of the burning boards to connectors on the back wall of the oven for the burn-in system. The burn-in board controls are known, and for example, can include controls and connectors such as those shown in U.S. Pat. No. 4,900,948.
SUMMARY OF THE INVENTION
The present invention relates to a temperature controlled heat exchanger or heat sink for a semiconductor chip mounted on a burn-in board. The heat sink is used with very high power consumption circuits which dissipate substantial heat when operated. The heat sinks of the present invention provide adequate cooling to the circuits so that the temperature range of the circuits is maintained within set parameters as sensed by a temperature sensor mounted on the heat sink and controlling the chip.
The burn-in board mounts several individual chips with the surface of the chips facing out from the board, and a separate thermal plate or board is mounted in the oven above each burn-in board. Individual temperature controlled heat sinks are provided for each of the chips on the burn-in board. Individual temperature sensors mounted on the heat sinks for sensing the chip temperature. The heat sinks and temperature sensors are moved into contact with the burn-in boards. The heat sinks, which comprise metal blocks, have passageways through which water can be circulated, as controlled by valves, which are opened and closed in response to the temperature sensor signal indicating temperature shifts of the circuits being tested.
The heat sinks also include a heater assembly, that is shown as a Mica heater, that is a thin layer clamped in place on the heat sink, and controlled to turn on when needed for maintaining a desired temperature on the chip, as sensed by the temperature sensor of each individual heat sink.
The temperature sensor is mounted in a bore in the respective heat sink and extend out to contact the chip surface. The bore is also connected to a source of helium, under low pressure, and when greater thermal conductivity is desired between the chip being tested and the heat sink, a flow of helium is provided through the bore in which temperature sensor is mounted, and the helium will pass out around the sensor and form a thin fluid layer between the heat sink and the circuit surface. This thin layer of helium gives greater thermal conductivity than air, and enhances heat transfer, particularly if there are slight irregularities, which may not even be seen by the naked eye, on the surface of the heat sink and the surface of the chip being tested. By controlling the coolant flow in response to the temperature sensor signals, the heat that is generated by high powered circuits is dissipated adequately and the desired temperature is maintained.
Additionally, the heat sink block is spring mounted in a cup-shaped support, which permits the heat sink to shift slightly, and ensures intimate heat transfer contact between the block and the chip. The heat transfer or thermal conductivity is enhanced by the flow of a thin layer of helium between the mating surfaces. The flow of gas will fill surface irregularities and gaps.


REFERENCES:
patent: 4791364 (1988-12-01), Kufis et al.
patent: 4900948 (1990-02-01), Hamilton
patent: 4969511 (1990-11-01), Person
patent: 4982153 (1991-01-01), Collins et al.
patent: 5001423 (1991-03-01), Abrami et al.
patent: 5086269 (1992-02-01), Nobi
patent: 5164661 (1992-11-01), Jones
patent: 5198752 (1993-03-01), Miyata et al.
patent: 5198753 (1993-03-01), Hamburgen
patent: 5414370 (1995-05-01), Hashinaga et al.
patent: 5582235 (1996-12-01), Hamilton et al.
patent: 5911897 (1999-06-01), Hamilton
patent: 5977785 (1999-11-01), Burward-Hoy
patent: 6-101947 (1994-04-01), None
“Thermal Control Hardware for Accelerated Run-In Testing of Multi-Chip Modules”, IBM Tech. Disclosure Bulletin, vol. 32, No. 5A, pp. 129-130, Oct. 1989.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Temperature controlled high power burn-in board heat sinks does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Temperature controlled high power burn-in board heat sinks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Temperature controlled high power burn-in board heat sinks will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2534809

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.