JP2000323636A - Heat sink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat sink for developing the maximum performance of a thyristor for large currents such as a GCT(Gate Commutated Turn-off) thyristor by concentrately cooling a high heating part. SOLUTION: This heat sink is provided with a contact face 14 with a semiconductor heating element, a coolant flow passage 6 arranged adjacently to the contact face 14 whose primary part is shaped like an almost circular-arc, and a coolant entrance 2 and a coolant exit 3 communicated with the flow passage 6. In this case, the flow passage 6 is arranged so that cooling capability on the contact face 14 can be made non-uniform according to the position in the contact face. Thus, the place with high heating values of the semiconductor heating element can be efficiently cooled without increasing the flow rate of the coolant in the flow passage 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink used for cooling a semiconductor heating element. For example, the present invention relates to a GCT (Gate Comb) which generates a large amount of heat for a large current.
The present invention relates to a heat sink suitable for cooling a mutated turn-off thyristor or a GTO (gate turn-off) thyristor.

[0002]

2. Description of the Related Art FIG. 7 is a plan view of a main part showing an example of the internal shape of a conventional heat sink disclosed in Japanese Utility Model Publication No. 6-39502. In FIG. 7, 21 is a heat sink,
Reference numeral 22 denotes a groove forming a flow path of the refrigerant, and reference numerals 23 and 24 denote ports for the refrigerant. In this publication, the heat sink is configured by superimposing the first block and the second block that is plane-symmetrical. However, a simple flat plate is superimposed on the main body provided with the groove 22 that configures the flow path of the refrigerant. Is a more general configuration.

[0003] Among the semiconductor heating elements, for example, there are a GCT thyristor and a GTO thyristor which generate a large amount of heat for a large current. These semiconductor heating elements are often used as a so-called stack type having a structure in which a plurality of semiconductor heating elements are stacked. At that time, each semiconductor heating element is cooled by sandwiching it between heat sinks. Conventionally, in these semiconductor heating elements, it has been necessary to cool the heat generated at, for example, 6 kV and 4 kA by several tens of square centimeters in contact with the heat sink.

[0004] In order to solve such a problem, until now, the width or depth of the flow path has been increased in order to increase the cross-sectional area of the flow path, or Japanese Unexamined Patent Publication No. Hei 8-97337.
The cooling capacity is increased by dividing the flow path into two as shown in Japanese Unexamined Patent Application Publication, or as shown in JP-A-63-241956, heat is taken from the flow path near the inlet side where the refrigerant temperature is low. There has been proposed a heat sink that alternately arranges flow paths near the outlet side where the refrigerant temperature becomes high to achieve uniform cooling capacity.

[0005]

However, in such a conventional technique, the width of the flow path is increased and reduced in order to increase the cross-sectional area of the flow path, or the cross-sectional area of the flow path is increased by dividing the flow path. Therefore, there is a problem in that it tends to secure a larger flow rate, and furthermore, since the number of processing steps or processing time of the heat sink is increased in order to make such a structure, the heat sink becomes expensive. .

In addition, a flow path near the inlet side where the refrigerant temperature is low and a flow path near the outlet side where the refrigerant temperature rises by removing heat are arranged alternately, so that the cooling capacity of the heat sink is uniform. On the other hand, if it is devised so that the cooling can be achieved as much as possible, on the contrary, there is a problem that the cooling capacity of a region to be cooled mainly in the portion to be cooled is deteriorated.

[0007] In addition, conventionally, the coolant passage of the heat sink is provided only in a range surrounded by the outer edge of the contact surface with the semiconductor heating element. Only to secure a flow path to the heating element, there is no refrigerant passage for cooling the heat spreading outward from the contact surface with the heating element, and especially when the cooling capability of the outer edge of the contact surface is required, the cooling capability is reduced. There was a problem that got worse.

[0008] In addition, conventionally, since it has been insistent to make the width of the flow path uniform in order to make the flow velocity uniform, the rate of contact with the refrigerant is low when viewed locally, and a problem may occur in the cooling capacity. there were.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it has been proposed to increase the cooling capacity of a region to be mainly cooled without increasing the flow rate so that a semiconductor heating element can be more efficiently provided. It is intended to obtain a heat sink capable of cooling the heat sink.

[0010]

According to the present invention, there is provided a heat sink comprising: a contact surface with a semiconductor heat generating element; a coolant passage having a substantially arc-shaped main portion provided in the vicinity of the contact surface; And an inlet and an outlet for a refrigerant communicating with the cooling medium, and the flow path is arranged such that the cooling capacity at the contact surface becomes uneven depending on the position within the contact surface.

Further, the flow path has a substantially arc shape having a radius of curvature smaller than that of the main part, and has a portion where the flow of the refrigerant is turned in the opposite direction.

The portion of the flow path near the inlet of the refrigerant is provided near the outer edge of the contact surface, and the portion near the outlet of the refrigerant is provided near the center of the contact surface.

Further, a portion of the flow path near the inlet of the refrigerant is
It is provided outside the outer edge of the contact surface.

[0014] In the flow path, the width of the portion where the flow of the refrigerant is turned in the opposite direction is made wider than the width of the other portions.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a plan view of a main part of a heat sink according to the present invention, and FIG. 2 is a sectional view taken along line AA in FIG. 1 and 2, 1 is a heat sink, 2 is an inlet nipple, 3 is an outlet nipple, 4 is an inlet flow path, 5 is an outlet flow path, and 6 is a substantially arc-shaped refrigerant whose main part flows. A flow path, 7 is a flow path fold that folds the flow of the refrigerant in the reverse direction, and 8 is a curvature change part that is located near the center of the flow path 6 and folds the flow of the refrigerant in the same direction as the flow path fold 7. , 9 is a center hole provided on the heat sink 1 for alignment, 10 is a block formed with a groove 12 constituting the flow path 6, 11 is a lid joined to the block 10 with silver solder, and 13 is a groove 12 It is a pillar that separates each other. In the drawing, a region 14 surrounded by a chain line represents a contact surface that receives heat transfer from the semiconductor heating element. Here, it is assumed that the semiconductor heating element is mounted so that the outer periphery thereof overlaps the outer edge of the contact surface 14 (that is, the area indicated by the dashed line).

In the present embodiment, the planar shape of the flow path 6 is a curved line centered on a substantially circular arc, and is formed by a circular arc having a smaller radius of curvature than the circular arc for folding the flow of the refrigerant in the opposite direction. The curvature changing portion 8 is composed of three portions 7, similarly having an arc having a radius of curvature smaller than the arc.
Each is formed.

If the heat generation amount of the semiconductor heat generating element is not uniformly distributed and the heat generation amount at a specific location is large, the portion of the flow path 6 where the refrigerant temperature is low is intensively arranged at the location where the heat generation amount is larger. There is a need. Here, the temperature of the refrigerant flowing from the inlet side nipple 2 into the heat sink 1 is lower in the inlet side flow path 4 than the refrigerant in the outlet side flow path 5 because the refrigerant does not absorb heat. Therefore, in this embodiment, since the temperature of the refrigerant flowing in the flow path 6 located on the outer side decreases, the cooling capacity is higher in the area closer to the outer periphery of the heat sink, which is a desired area, than in the inner area. This is suitable for centrally cooling the outer peripheral portion of the heating element.

According to the present embodiment, since the cold refrigerant can be arranged on the outer peripheral portion where the calorific value is the largest, the width of the flow path and the column is narrowed to make the flow path deep, Without increasing the cooling capacity by dividing the road into two parts, it is possible to efficiently cool a portion having a large amount of heat without increasing the flow rate. In addition, since only the path of the flow path 6 is changed, an increase in the number of processing steps can be minimized, and the heat sink is inexpensive for the cooling function.

Embodiment 2 FIG. 3 is a plan view of a main part of the heat sink according to the present embodiment. 3, the same reference numerals as those in FIG. 1 indicate the same components. In the drawing, a region 14 surrounded by a chain line represents a contact surface that receives heat transfer from the semiconductor heating element. Here, it is assumed that the semiconductor heating element is mounted so that the outer periphery thereof overlaps the outer edge of the contact surface 14 (that is, the area indicated by the dashed line).

In the present embodiment, the flow path 6 is a curve centered on an arc, and the folded portion 7 formed of an arc having a smaller radius of curvature than the arc for turning the flow of the refrigerant in the opposite direction is formed by three. And two curvature changing portions 8 each having an arc having a radius of curvature smaller than that of the arc, and a contact surface (that is, a region surrounded by a dashed line) receiving heat transfer from the semiconductor heating element. The inlet side flow path 4 mainly having a low refrigerant temperature is provided at the outer edge portion of 14).

For example, in a GCT thyristor, the outer periphery is radiated (heat transfer) in a mesa-shaped wafer even though the gate is considered to be the largest in loss (heat generation) due to current concentration. It has an internal structure that is difficult to handle. In such a case, the region to be cooled mainly in the portion to be cooled is the outer edge of the contact surface 14, and if the heat sink has the configuration in this embodiment, the heat sink having the configuration according to the GCT thyristor is most suitable according to the structural loss characteristics. The outer peripheral portion of the wafer to be cooled can be intensively cooled, so that the heat sink is inexpensive for the cooling function, and the cooling efficiency can be improved.

Embodiment 3 FIG. FIG. 4 is a plan view of a main part of a heat sink according to the present invention. 4, the same reference numerals as those in FIG. 1 indicate the same components. In the drawing, a region 14 surrounded by a chain line represents a contact surface that receives heat transfer from the semiconductor heating element. Here, it is assumed that the semiconductor heating element is mounted so that the outer periphery thereof overlaps the outer edge of the contact surface 14 (that is, the area indicated by the dashed line).

In the present embodiment, the number of the folded portions 7 is two in the second embodiment, but the same as that of the second embodiment except that the number of the folded portions 7 is two. In this case, the same effect as in the second embodiment can be obtained.
Further, the flow path 6 is formed by using the folded portion 7 as one piece and the heat sink 1.
The same effect can be obtained when the flow path 6 is formed spirally in the direction of the center hole 9. Similarly, four or more folded portions may be used.

Embodiment 4 FIG. 5 is a plan view of a main part of the heat sink according to the present embodiment. 5, the same reference numerals as those in FIG. 1 indicate the same components. In the drawing, a region 14 surrounded by a chain line represents a contact surface that receives heat transfer from the semiconductor heating element. Here, it is assumed that the semiconductor heating element is mounted so that the outer periphery thereof overlaps the outer edge of the contact surface 14 (that is, the area indicated by the dashed line).

In this embodiment, the flow path 6 is a curve centered on a circular arc, and the folded portion 7 formed of a circular arc having a smaller radius of curvature than the circular arc for returning the flow of the refrigerant in the opposite direction. And two curvature changing portions 8 each having an arc having a radius of curvature smaller than that of the arc, and a contact surface (that is, a region surrounded by a dashed line) receiving heat transfer from the semiconductor heating element. An inlet-side flow path 4 mainly having a low coolant temperature is provided further outside the outer edge portion of (14).

In the present embodiment, with such a structure, heat spreading outward from the contact surface with the semiconductor heating element can be cooled, and particularly, the cooling capability of the outer edge of the contact surface 14 is required to be improved. Will be suitable for the case. As described above, by providing the flow path 6 in a region slightly wider than the contact surface 14 or a region wider than that, the contact surface 14
Since the refrigerant that takes away heat from the outside is arranged, the cooling performance of the outer peripheral portion can be further improved.

Embodiment 5 FIG. FIG. 6 is a plan view of a main part of the heat sink according to the present embodiment. 6, the same reference numerals as those in FIG. 1 indicate the same components. In the drawing, a region 14 surrounded by a chain line represents a contact surface that receives heat transfer from the semiconductor heating element. Reference numeral 15 denotes a stagnation provided in the folded portion 7 and the curvature changing portion 8.

In the present embodiment, each of the folded portion 7 and the curvature changing portion 8 is provided with a stagnation portion 15 having a width wider than other portions of the flow path 6, so that the stagnation portion 15 can be viewed locally at that portion. In this case, it is possible to suppress the problem that the ratio of the support 13 is high and the ratio of the groove 12 is low, and the ratio of contact with the refrigerant is low, and it is possible to prevent the cooling capacity from being lowered.

[0029]

The heat sink according to the present invention has a contact surface with a semiconductor heat generating element, a flow path of a refrigerant provided in the vicinity of the contact surface and having a substantially circular arc shape, and a flow path of the refrigerant flowing through the flow path. With an inlet and an outlet, the flow path is arranged so that the cooling capacity at the contact surface becomes uneven at a position within the contact surface, without increasing the flow rate of the refrigerant in the flow path. It is possible to efficiently cool a portion of the semiconductor heating element that generates a large amount of heat.

Further, since the flow path has a substantially arc shape having a radius of curvature smaller than that of the main part and has a portion where the flow of the refrigerant is turned in the opposite direction, the width of the column is narrowed and the flow path is deepened. Since it is not necessary to divide the heat sink, it is possible to suppress an increase in the number of processing steps, and to obtain a low-cost heat sink for the cooling function.

Since the portion of the flow path near the inlet of the refrigerant is provided near the outer edge of the contact surface, and the portion near the outlet of the refrigerant is provided near the center of the contact surface, the flow passage is also focused on the portion to be cooled. When the area to be cooled is near the outer edge of the contact surface, the cooling efficiency can be improved.

A portion of the flow path near the refrigerant inlet is
Since it is provided outside the outer edge of the contact surface, it is possible to cool the heat spreading outward from the contact surface with the semiconductor heating element, particularly when the cooling capability of the outer edge of the contact surface is required to be improved. Would be suitable.

In the flow path, the width of the portion where the flow of the refrigerant is turned in the opposite direction is made wider than the width of the other portions. Therefore, when the flow of the refrigerant is viewed locally in the portion where the flow of the refrigerant is turned in the opposite direction. In addition, it is possible to suppress a decrease in the rate of contact with the refrigerant and prevent a decrease in cooling capacity.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of a heat sink according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a plan view of a main part of a heat sink according to a second embodiment of the present invention.

FIG. 4 is a plan view of a main part of a heat sink according to a third embodiment of the present invention.

FIG. 5 is a plan view of a main part of a heat sink according to a fourth embodiment of the present invention.

FIG. 6 is a plan view of a main part of a heat sink according to a fifth embodiment of the present invention.

FIG. 7 is a plan view of a main part of a conventional heat sink.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Heat sink, 2 Inlet nipple, 3 Outlet nipple, 4 Inlet side flow path, 5 Outlet side flow path, 6
Channel, 7 folded part, 8 curvature changing part, 9 center hole, 10 block, 11 lid, 12 groove,
13 pillar part, 14 contact surface with heating element, 15
Stagnation.

Claims (5)

[Claims] A contact surface with the semiconductor heating element, a coolant flow path provided in the vicinity of the contact surface and having a substantially circular arc shape, and an inlet and an outlet for the coolant communicating with the flow passage; The heat sink, wherein the flow path is arranged such that a cooling capacity at the contact surface becomes uneven depending on a position within the contact surface. 2. The heat sink according to claim 1, wherein the flow path has a substantially arc shape having a smaller radius of curvature than the main part, and has a portion that folds the flow of the refrigerant in the opposite direction. 3. The flow path according to claim 1, wherein a portion near the inlet of the coolant is provided near the outer edge of the contact surface, and a portion near the outlet of the coolant is provided near the center of the contact surface. heatsink. 4. The heat sink according to claim 1, wherein a portion of the flow path close to the inlet of the refrigerant is provided outside an outer edge of the contact surface. 5. The heat sink according to claim 2, wherein a width of a portion of the flow path in which the flow of the refrigerant is turned in a reverse direction is wider than widths of other portions.