Liquid-cooled-type cooling device

A liquid-cooled-type cooling device includes a casing which has a cooling-liquid inlet formed at a rear end portion of the casing and a cooling-liquid outlet formed at a front end portion of the casing. A corrugated fin for forming a plurality of flow channels through which a cooling liquid flows from the rear side toward the front side is disposed within the casing to be located between the cooling-liquid inlet and the cooling-liquid outlet. A heat-generating-body mounting region is provided on an outer surface of a top wall of the casing. Projections which come into contact with front and rear end portions of the corrugated fin to thereby position the corrugated fin in the front-rear direction are provided on an inner surface of the bottom wall of the casing at positions shifted, in the left-right direction, from an inner surface region corresponding to the heat-generating-body mounting region.

BACKGROUND OF THE INVENTION

The present invention relates to a liquid-cooled-type cooling device for cooling a heat-generating body composed of an electronic component such as a semiconductor device.

In the present specification and appended claims, the side toward which cooling liquid flows within flow channels formed by a fin (the lower side ofFIG. 3) will be referred to as “front,” and the opposite side will be referred to as “rear.” Also, the upper, lower, left-hand, and right-hand sides ofFIG. 2will be referred to as “upper,” “lower,” “left,” and “right,” respectively.

There has been conventionally known a liquid-cooled-type cooling device for electronic components (see Japanese Patent Application Laid-Open (kokai) No. 2001-352025). The known liquid-cooled-type cooling device includes a casing which is composed of a top wall, a bottom wall, and a peripheral wall and which has a cooling-liquid inlet formed at a rear end portion of the casing and a cooling-liquid outlet formed at a front end portion of the casing. A fin for forming a plurality of flow channels through which a cooling liquid flows from the rear side toward the front side is disposed within the casing to be located between the cooling-liquid inlet and the cooling-liquid outlet. A portion of the interior of the casing located rearward of the fin serves as an inlet header section which communicates with the cooling-liquid inlet, and a portion of the interior of the casing located frontward of the fin serves as an outlet header section which communicates with the cooling-liquid outlet. A heat-generating-body mounting region is provided on the outer surface of the top wall of the casing and/or the outer surface of the bottom wall of the casing.

However, the liquid-cooled-type cooling device disclosed in the above-mentioned publication has a problem in that the position of the fin may shift in the front-rear direction at the time of manufacture of the cooling device, and, therefore, the fin cannot be accurately disposed at a predetermined position.

SUMMARY OF THE INVENTION

An object of the present invention is to solve the above-mentioned problem and to provide a liquid-cooled-type cooling device which can reliably prevent positional shift of the fin of which shift would otherwise occur when the cooling device is manufactured.

To achieve the above object, the present invention comprises the following modes.

1) A liquid-cooled-type cooling device comprising a casing which has a cooling-liquid inlet formed at a rear end portion of the casing and a cooling-liquid outlet formed at a front end portion of the casing, in which a fin for forming a plurality of flow channels through which a cooling liquid flows from a rear side toward a front side is disposed within the casing to be located between the cooling-liquid inlet and the cooling-liquid outlet, and a heat-generating-body mounting region is provided on an outer surface of a top wall of the casing and/or an outer surface of a bottom wall of the casing, wherein

projections which come into contact with front and rear end portions of the fin to thereby position the fin in a front-rear direction are provided on an inner surface of the top wall of the casing and/or an inner surface of the bottom wall of the casing at positions shifted, in a left-right direction, from an inner surface region corresponding to the heat-generating-body mounting region.

2) A liquid-cooled-type cooling device according to par. 1), wherein front-side projections with which the front end portion of the fin comes into contact are provided such that the front-side projections are spaced from one another along the left-right direction; rear-side projections with which the rear end portion of the fin comes into contact are provided such that the rear-side projections are spaced from one another in the left-right direction; and the rear-side projections are shifted from the front-side projections along the left-right direction.

3) A liquid-cooled-type cooling device according to par. 2), wherein, when a length L (mm) of the fin as measured along the front-rear direction is equal to or greater than a width W (mm) of the fin as measured along the left-right direction, the front-side projections and the rear-side projections are provided such that one front-side projection and one rear-side projection are provided at each of left and right end portions of the casing.

4) A liquid-cooled-type cooling device according to par. 2), wherein, when a width W (mm) of the fin as measured along the left-right direction is greater than a length L (mm) of the fin as measured along the front-rear direction, the front-side projections and the rear-side projections are provided such that one front-side projection and one rear-side projection are provided at each of left and right end portions of the casing, and one or more front-side projections and one or more rear-side projections are provided at an intermediate portion of the casing with respect to the left-right direction.

5) A liquid-cooled-type cooling device according to par. 1), wherein the fin is a corrugated fin which includes wave crest portions, wave trough portions, and connection portions connecting the wave crest portions and the wave trough portions; and a width of the front-side projections and the rear-side projections as measured along the left-right direction is less than two times a spacing between two wave crest portions of the fin adjacent to each other and between two wave trough portions thereof adjacent to each other, and is greater than a spacing between a wave crest portion of the fin and a wave trough portion thereof adjacent to the wave crest portion.

6) A liquid-cooled-type cooling device according to par. 5), wherein a height of the front-side projections and the rear-side projections is greater than a thickness of the fin and equal to or less than half a height of the fin.

7) A liquid-cooled-type cooling device according to par. 5), wherein each of the front-side projections and the rear-side projections assumes the form of a circular cone whose diameter decreases toward the tip end thereof.

8) A liquid-cooled-type cooling device according to par. 7), wherein a relation 0<L−L1<D is satisfied where L represents a length (mm) of the fin as measured along the front-rear direction; L1represents a shortest direct distance (mm) between the front-side projections and the rear-side projections; and D represents an outer diameter (mm) of the proximal ends of the front-side projections and the rear-side projections.

According to the liquid-cooled-type cooling device of par. 1), projections which come into contact with front and rear end portions of the fin to thereby position the fin in the front-rear direction are provided on the inner surface of the top wall of the casing and/or the inner surface of the bottom wall of the casing. Thus, positional shift of the fin in the front-rear direction can be prevented during manufacture of the cooling device. Accordingly, the fin can be accurately disposed at a predetermined position. Further, since the projections are provided on the inner surface of the top wall of the casing and/or the inner surface of the bottom wall of the casing at positions shifted, in the left-right direction, from an inner surface region corresponding to the heat-generating-body mounting region, the projections do not decrease the flow velocity of the cooling liquid flowing through flow channels at positions corresponding to the heat-generating-body mounting region, among the flow channels, which are formed by the fin and extend in the front-rear direction, whereby a drop in the effect of cooling the heat-generating body mounted in the heat-generating-body mounting region is prevented.

According to the liquid-cooled-type cooling device of par. 2), the front-side projections with which the front end portion of the fin comes into contact are provided such that they are spaced from one another along the left-right direction; the rear-side projections with which the rear end portion of the fin comes into contact are provided such that they are spaced from one another in the left-right direction; and the rear-side projections are shifted from the front-side projections along the left-right direction. Therefore, it is possible to minimize a drop in the flow velocity of the cooling liquid flowing through flow channels in which the projections are formed, among the flow channels, which are formed by the fin and extend in the front-rear direction.

According to the liquid-cooled-type cooling devices of par. 3) and par. 4), the number of the projections required to prevent positional shift of the fin in the front-rear direction during manufacture of the cooling device can be minimized. Accordingly, it is possible to minimize the drop in the flow velocity of the cooling liquid flowing through flow channels in which the projections are formed, among the flow channels, which are formed by the fin and extend in the front-rear direction.

According to the liquid-cooled-type cooling device of par. 5), the fin is a corrugated fin which includes wave crest portions, wave trough portions, and connection portions connecting the wave crest portions and the wave trough portions; and the width of the front-side projections and the rear-side projections as measured along the left-right direction is less than two times the spacing between two wave crest portions of the fin adjacent to each other and between two wave trough portions thereof adjacent to each other, and is greater than the spacing between a wave crest portion of the fin and a wave trough portion thereof adjacent to the wave crest portion. Therefore, positional shift of the fin in the front-rear direction, which would otherwise occur during manufacture of the cooling device, can be prevented reliably.

According to the liquid-cooled-type cooling device of par. 6), the height of the front-side projections and the rear-side projections is greater than the thickness of the fin and equal to or less than half the height of the fin. Therefore, positional shift of the fin in the front-rear direction, which would otherwise occur during manufacture of the cooling device, can be prevented reliably. In addition, it is possible to minimize the drop in the flow velocity of the cooling liquid flowing through flow channels in which the projections are formed, among the flow channels, which are formed by the fin and extend in the front-rear direction.

According to the liquid-cooled-type cooling device of par. 8), portions of the front-side projections and the rear-side projections bite on the fin, whereby minute play of the fin can be prevented.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A preferred embodiment of the present invention will next be described with reference to the drawings.

In the following description, the term “aluminum” encompasses aluminum alloys in addition to pure aluminum.

FIGS. 1 to 4show a state in which semiconductor devices, each of which is a heat-generating body, are mounted on a liquid-cooled-type cooling device according to the present invention.

InFIGS. 1 to 4, a liquid-cooled-type cooling device1has a casing2composed of a top wall3, a bottom wall4, and a peripheral wall5. A plurality of heat-generating-body mounting regions10are provided on the outer surface of the top wall3of the casing2such that the regions are separated from one another in the left-right direction. The peripheral wall5of the casing2includes a right side wall6, which extends in the front-rear direction and stands vertically; a left side wall7, which extends in the front-rear direction, stands vertically, and is positioned in opposition to the right side wall6; a rear side wall8, which connects rear end portions of the right and left side walls6and7and stands vertically; and a front side wall9, which connects front end portions of the right and left side walls6and7and stands vertically. In the peripheral wall5of the casing2, a cooling-liquid inlet11is formed at a rear end portion of the right side wall6in a rightward projecting condition, and a cooling-liquid outlet12is formed at a front end portion of the left side wall7in a leftward projecting condition. The cooling-liquid inlet11opens rightward, whereas the cooling-liquid outlet12opens leftward. The casing2is formed of an upper structure member13of aluminum and a lower structure member14of aluminum. The upper structure member13includes the top wall3and an upper peripheral-wall-formation section5A, which serves as an upper half of the peripheral wall5. The lower structure member14includes the bottom wall4and a lower peripheral-wall-formation section5B, which serves as a lower half of the peripheral wall5. A lower end portion of the upper peripheral-wall-formation section5A of the upper structure member13and an upper end portion of the lower peripheral-wall-formation section5B of the lower structure member14have integrally formed outward flanges15and16, respectively. The outward flanges15and16of the upper and lower structure members13and14are brazed together. Each of the upper structure member13and the lower structure member14is formed from an aluminum blank plate through press working.

An aluminum corrugated fin17is disposed in an internal region of the casing2located between the right side wall6and the left side wall7and between the cooling-liquid inlet11and the cooling-liquid outlet12. The corrugated fin17includes wave crest portions17aextending in the front-rear direction, wave trough portions17bextending in the front-rear direction, and vertical connection portions17cconnecting the respective wave crest portions17aand wave trough portions17b. The wave crest portions17aare brazed to the top wall3of the casing2, whereas the wave trough portions17bare brazed to the bottom wall4of the casing2. The corrugated fin17forms a plurality of flow channels18which extend in the front-rear direction and are arranged in the left-right direction and through which cooling liquid flows from the rear side toward the front side, thereby providing a parallel-flow-channel section19including a plurality of flow channels.

A portion of the interior of the casing2located upstream (rearward) of the parallel-flow-channel section19serves as an inlet header section21communicating with the cooling-liquid inlet11. A portion of the interior of the casing2located downstream (frontward) of the parallel-flow-channel section19serves as an outlet header section22communicating with the cooling-liquid outlet12. The internal height of the entire casing2is uniform; i.e., the inlet header section21, the outlet header section22, and the parallel-flow-channel section19have the same height. The rear side wall8and the front side wall9of the casing2extend perpendicular to the right side wall6and the left side wall7.

Projections23A and23B are provided on the inner surface of the bottom wall4of the casing2at positions shifted, in the left-right direction, from inner surface regions corresponding to the heat-generating-body mounting regions10. The projections23A and23B come into contact with front and rear end portions of the corrugated fin17so as to position the corrugated fin17with respect to the front-rear direction. The projections23A and23B are formed by means of deforming the bottom wall4when the lower structure member14is formed through press working, and assume the form of a circular cone whose diameter decreases toward the tip end thereof. The front-side projections23A, with which the front end portion of the corrugated fin17comes into contact, are provided such that they are separated from one another in the left-right direction. Similarly, the rear-side projections23B, with which the rear end portion of the corrugated fin17comes into contact, are provided such that they are separated from one another in the left-right direction. The rear-side projections23B are shifted from the front-side projections23A along the left-right direction. The front-side projections23A are respectively formed at a position located at the left end portion of the casing2, a position shifted slightly leftward from the center of the casing2with respect to the left-right direction, and a position near the right end portion of the casing2. The rear-side projections23B are respectively formed at a position located at the right end portion of the casing2, a position shifted slightly rightward from the center of the casing2with respect to the left-right direction, and a position near the left end portion of the casing2.

In the case where the length L (mm) of the corrugated fin17as measured along the front-rear direction is equal to or greater than the width W (mm) of the corrugated fin17as measured along the left-right direction, preferably, the front-side projections23A and the rear-side projections23B are provided such that at least one front-side projection23A and one rear-side projection23B are provided at each of the left and right end portions of the casing2. In the case where the width W (mm) of the corrugated fin17as measured along the left-right direction is greater than the length L (mm) of the corrugated fin17as measured along the front-rear direction, preferably, the front-side projections23A and the rear-side projections23B are provided such that one front-side projection23A and one rear-side projection23B are provided at each of the left and right end portions of the casing2, and one or more front-side projections23A and one or more rear-side projections23B are provided at an intermediate portion of the casing2with respect to the left-right direction.

Preferably, the width of the front-side projections23A and the rear-side projections23B as measured along the left-right direction; i.e., the outer diameter D (mm) of the proximal end of each projection, is less than two times a spacing S (mm) between two wave crest portions17aof the corrugated fin17adjacent to each other and between two wave trough portions17bthereof adjacent to each other, and is greater than a spacing S1(mm) between a wave crest portion17aof the corrugated fin17and a wave trough portion17bthereof adjacent to the wave crest portion17a(seeFIGS. 2 and 3). Further, preferably, the height of the front-side projections23A and the rear-side projections23B is greater than the thickness of the corrugated fin17and equal to or less than half the height of the corrugated fin17. Further, preferably, a relation 0<L−L1<D is satisfied where L represents the length (mm) of the corrugated fin17as measured along the front-rear direction; L1represents the shortest direct distance (mm) between the front-side projections23A and the rear-side projections23B; and D represents the outer diameter (mm) of the proximal ends of the front-side projections23A and the rear-side projections23B (seeFIG. 3).

Semiconductor devices P, each of which is a heat-generating body, are joined to the outer surface of the top wall3of the casing2via plate-shaped insulating members I to be located in the heat-generating-body mounting regions10.

In the liquid-cooled-type cooling device1having the above-described configuration, a cooling liquid having flowed into the inlet header section21through the cooling-liquid inlet11flows into all of the flow channels18of the parallel-flow-channel section19in a uniformly divided condition, and flows frontward through the flow channels18.

The cooling liquid having flowed frontward through the flow channels18of the parallel-flow-channel section19enters the outlet header section22, flows leftward through the outlet header section22, and flows out of the casing2via the cooling-liquid outlet12.

Heat generated from the semiconductor devices P is transmitted to the cooling liquid which flows through the flow channels18, via the insulating members I, the top wall3of the casing2, and the corrugated fin17. The semiconductor devices P are thus cooled.

Since the front-side projections23A and the rear-side projections23B are provided on the inner surface of the bottom wall4of the casing2at positions shifted, in the left-right direction, from inner surface regions corresponding to the heat-generating-body mounting regions10, the projections do not decrease the flow velocity of the cooling liquid flowing through flow channels18corresponding to the heat-generating-body mounting regions10, among all the flow channels18, which are formed by the corrugated fin17and extend in the front-rear direction, whereby a drop in the effect of cooling the heat-generating bodies P mounted in the heat-generating-body mounting regions10is prevented. Further, since the rear-side projections23B are shifted from the front-side projections23A along the left-right direction, it is possible to minimize a drop in the flow velocity of the cooling liquid flowing through flow channels18in which the front-side projections23A and the rear-side projections23B are formed, among all the flow channels18, which are formed by the corrugated fin17and extend in the front-rear direction. Moreover, since the height of the front-side projections23A and the rear-side projections23B is greater than the thickness of the corrugated fin17and equal to or less than half the height of the corrugated fin17, it is possible to minimize the drop in the flow velocity of the cooling liquid flowing through flow channels18in which the projections23A and23B are formed, among all the flow channels18, which are formed by the corrugated fin17and extend in the front-rear direction.

In the above-described embodiment, the projections23A and23B are provided on the inner surface of the bottom wall4of the casing2; however, the surface on which the projections23A and23B are provided is not limited thereto, and the projections may be provided on the inner surface of the top wall3. Alternatively, the projections may be provided on both the inner surface of the top wall3and the inner surface of the bottom wall4. In the case where the projections are provided on both the inner surface of the top wall3and the inner surface of the bottom wall4, the front-side projections on the inner surface of the top wall3are shifted from the rear-side projections on the inner surface of the top wall3along the left-right direction, and the front-side projections on the inner surface of the bottom wall4are shifted from the rear-side projections on the inner surface of the bottom wall4along the left-right direction. Further, the front-side projections on the inner surface of the top wall3are shifted from the front-side projections on the inner surface of the bottom wall4along the left-right direction, the rear-side projections on the inner surface of the top wall3are shifted from the rear-side projections on the inner surface of the bottom wall4along the left-right direction, the front-side projections on the inner surface of the top wall3are shifted from the rear-side projections on the inner surface of the bottom wall4along the left-right direction, and the rear-side projections on the inner surface of the top wall3are shifted from the front-side projections on the inner surface of the bottom wall4along the left-right direction.