The present invention generally relates to thermal management systems for semiconductor devices and, more particularly, to systems for cooling such semiconductor devices during burn-in testing.
In the conventional manufacture of semiconductor devices, semiconductor wafers are first produced in batches. Each semiconductor wafer can contain many individual electronic devices or electronic circuits, which are known as dies. Each die is electrically tested by connecting it to special purpose test equipment. Probes, which are connected to the test equipment, are brought into contact with the die to be tested. This generally occurs at a prober station, which conventionally includes a platform arranged for supporting the wafer. It is important to test each individual circuit chip die while it is still attached in a wafer, and to also test the individual integrated circuit devices once they have been packaged for their intended use. In many testing applications, the tests must be performed at elevated temperatures which, if not regulated, could cause damage to the chip during testing. Accordingly, automated test systems are commonly outfitted with temperature control systems which can control the temperature of a semiconductor wafer or packaged integrated circuit under test.
For example, and referring to
In many cases such support platforms are required to be able to both heat and cool the device. Many types of temperature-controlled support platforms are known and are widely available. Cooling is very often provided by a heat sink that is cooled by a recirculating fluid, or in other designs by passing a fluid through the support platform without recirculating it. The fluid can be a liquid or a gas, usually air in the latter case. The liquid or air can be chilled for greater cooling effect in passing through the support platform, and can be recirculated for greater efficiency. A support platform cooled by means of a fluid chilled to a temperature below ambient temperature enables device probing at temperatures below ambient. In general, conventional heat-sink designs often incorporate simple cooling channels cross-drilled and capped in the support platform.
None of the foregoing systems and methods have been found to be completely satisfactory.
The present invention provides a cooling system for a semiconductor device including an evaporator comprising an upright tubular body having an interior surface and a central passageway with a wick disposed on the interior surface of the body that defines the central passageway. A base seals off the central passageway, with an inlet port arranged in flow communication with an upper portion of the central passageway and an outlet port arranged in flow communication with a lower portion of the central passageway. A coolant is disposed within the central passageway. A condenser is arranged in flow communication with the evaporator.
In another embodiment of the invention, a cooling system for a plurality of semiconductor devices is provided including a plurality of evaporators. Each evaporator includes an upright tubular body having an interior surface and a central passageway with a wick disposed on the interior surface of the body that defines the central passageway. A base seals off each of the central passageways, and also includes an outlet port arranged in flow communication with an upper portion of each of the central passageways and an inlet port arranged in flow communication with a lower portion of each of the central passageways. A coolant is disposed within each of the central passageways. A condenser is arranged in flow communication with each of the evaporators.
In yet another embodiment of the invention, a cooling system for a plurality of semiconductor devices is provided including a plurality of evaporators. Each evaporator includes an upright tubular body having an interior surface and a central passageway with a wick disposed on the interior surface of the body that defines the central passageway. A base seals off each of the central passageways, and also includes an outlet port arranged in flow communication with (i) an upper portion of each of the central passageways and a common outlet conduit, and (ii) an inlet port arranged in flow communication with a lower portion of each of the central passageways and a common inlet conduit. A coolant is disposed within each of the central passageways. A condenser is arranged in flow communication with each of the evaporators through the common outlet conduit and the common inlet conduit.
These and other features and advantages of the present invention will be more fully disclosed in, or rendered obvious by, the following detailed description of the preferred embodiment of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein:
This description of preferred embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. The drawing figures are not necessarily to scale and certain features of the invention may be shown exaggerated in scale or in somewhat schematic form in the interest of clarity and conciseness. In the description, relative terms such as “horizontal,” “vertical,” “up,” “down,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms including “inwardly” versus “outwardly,” “longitudinal” versus “lateral” and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation, as appropriate. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. The term “operatively connected” is such an attachment, coupling or connection that allows the pertinent structures to operate as intended by virtue of that relationship. In the claims, means-plus-function clauses are intended to cover the structures described, suggested, or rendered obvious by the written description or drawings for performing the recited function, including not only structural equivalents but also equivalent structures.
Referring to
Wick 15 is disposed upon interior surface 28 of vessel 10, and may comprise adjacent layers of screening or a sintered powder structure with interstices between the particles of powder. Of course, capillary wick 15 may also other wicking structures, such as, grooves, screen, cables, and felt. In one embodiment, wick 15 may comprise sintered copper powder, sintered aluminum-silicon-carbide (AlSiC) or copper-silicon-carbide (CuSiC) having an average thickness of about 0.1 mm to 1.0 mm. A coolant fluid 29 may comprise any of the well known two-phase vaporizable liquids, e.g., water alcohol, freon, etc.
Conduit network 8 includes an outlet conduit 31 and an inlet conduit 33, both of which often comprise an elongate hollow tubing having a central passageway 37. Conduit network 8 is often formed from stainless steel, copper or its alloys, or the like highly thermally conductive material.
Referring to
Each condenser 11 acts as a heat exchanger transferring heat contained in a mixture of vaporous working fluid and liquid working fluid (not shown) to the ambient surroundings, via an external heat sink, e.g., conventional heat exchangers having the capability to facilitate transfer of thermal energy, and that are often heat transfer devices, such as a fin stack, cold plate or secondary heat exchanger of the type well known in the art.
Referring to
In operation, loop thermosyphon system 2 may be used to cool one or more semiconductor devices F in the following manner. A plurality of semiconductor chips F to be cooled (
It is to be understood that the present invention is by no means limited only to the particular constructions herein disclosed and shown in the drawings, but also comprises any modifications or equivalents within the scope of the claims.
This application claims the benefit of U.S. Provisional Patent Application No. 60/499,483, filed Sep. 2, 2003 and U.S. Provisional Patent Application No. 60/502,125, filed Sep. 11, 2003.
Number | Date | Country | |
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60499483 | Sep 2003 | US | |
60502125 | Sep 2003 | US |