JPH0650355U - Heat sink for semiconductor element cooling - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the temperature difference between the upstream element and the downstream element of the cooling air attached to the heat receiving block. [Structure] Among the heat pipes penetrating above and below the heat receiving block 2, the inner diameters of the upper half heat pipes 3A, 3B, 3C are made larger than the inner diameters of the lower half heat pipes 3D, 3E, 3F.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a semiconductor device cooling heat sink having a plurality of heat pipes therein.

[0002]

[Prior art]

 As is well known, in semiconductor devices, the adoption of high-frequency PWM control methods that use high-speed switching elements has increased to improve the performance of power converters, and large-capacity elements are connected in parallel as the capacity of semiconductor devices increases. Has been used. Further, in the high frequency PWM control method, it is necessary to reduce the reactance between the high speed switching elements and suppress the surge voltage generated by switching, so the high speed switching elements are mounted close to each other.

Therefore, since the heat generated in the high-speed switching element is locally concentrated, an air-cooled heat sink has been conventionally used to cool the heat concentrated in the local area.

FIG. 3 is a diagram showing an example of a conventional heat sink for cooling a semiconductor element (hereinafter referred to as a heat sink). A left side view of FIG. 3 is shown in FIG. 3 and 4, the heat sink 11 is a heat receiving block 2 of a substantially square thick plate shown on the left side of FIG. 3 and a parallel columnar shape processed from the right side of FIG. 3 with respect to the heat receiving block 2. Of the heat pipes 3A1, 3B1, 3 C1, 3D1, 3E1, 3F1 into which air is hermetically inserted in the holes and pure water is injected as a refrigerant, and among these heat pipes 3A1, 3B1, 3C 1, 3D1, 3E1, 3F1 It is composed of a plurality of rectangular radiating fins 14 made of an aluminum plate having an intermediate portion inserted in a portion protruding from the heat receiving block 2. Of these, high speed switching elements (hereinafter referred to as elements) 5A, 5B, 5C and 5D of the same rating, which are to be cooled, are attached to both sides of the heat receiving block 2 in the upper, lower, left and right directions in FIG.

FIG. 5 is a right side view showing a state in which the above-mentioned heat sink 11 and the semiconductor stack 12 including the elements 5A, 5B, 5C and 5D are housed in the box 7 of the power conversion device, and FIG. 4 is a left side view (that is, a front view of the power conversion device) of FIG.

In FIG. 5 and FIG. 6, a door 9 shown by a chain double-dashed line is openably and closably attached to the front surface of the box body 7, and an air filter (not shown) is detachably attached to a lower portion of the door 9. An intake port 9a is provided, and an exhaust fan 8 is attached to the inside of the box body 7 at the lower part of the ceiling surface.

Below the exhaust fan 8, the semiconductor stack 12 shown in FIG. 3 has the front end of the heat receiving block 2 close to the door 9 and the rear end thereof slightly upward, and the heat receiving block 2 is vertically arranged to form three stacks. It is stored in the front-back direction.

In the semiconductor stack 12 thus arranged and housed in the box body 7, when the power conversion device is operating, the cooling air flowing into the box body 7 from the intake port 9a as shown by the arrow D is After being heated by the radiation fins 14 of the semiconductor stack 12, the exhaust fan 8 discharges it above the box body 7 as shown by an arrow E to cool it.

On the other hand, in terms of maintenance, by positioning the heat receiving block 2 immediately behind the door 9, the door 9 can be opened for maintenance and inspection so that each element can be easily inspected and replaced from the front of the box. Have been considered to.

Further, in terms of cooling of the elements and mounting density of the box body 7, by mounting four elements on each side of the heat receiving block 2, the element mounting portion and the heat receiving portion can be downsized and By mounting the heat receiving block 2 vertically inside the box body 7, it is considered that the cooling conditions by the cooling air flowing on both sides of the heat receiving block 2 are uniform and the cooling temperatures of the respective elements are equal. There is.

[0011]

[Problems to be solved by the device]

 However, in the heat sink 11 configured as described above and cooled inside the box body 7, the heat pipe 3F1 at the lower end in FIG. 5 among the heat pipes shown in FIG. 3 is well cooled, but is located above. The heat pipe is cooled by the heat pipe below and the cooling air warmed by the radiation fins 14. Then, the cooling temperature rises in order, and the temperature becomes highest in the uppermost heat pipe 3A1. Therefore, the heat receiving block 2 also cools the lower part but does not cool as much as the upper part. Therefore, when the elements 5A and 5C and the elements 5B and 5D are connected in parallel, the elements 5A and 5C attached to the upper part of the heat receiving block 2 are used. The rating of the power converter may be fixed, and the rated capacity of the power converter may drop.

Therefore, an object of the present invention is to reduce the temperature difference between the upstream side element and the downstream side element of the cooling air attached to the heat receiving block and prevent the deterioration of the rating of the power conversion device. To get a cooling heat sink.

[0013]

[Means and Actions for Solving the Problems]

 The present invention is a semiconductor device in which the intermediate portions of a plurality of cooling fins are inserted into a plurality of heat pipes protruding in a row from the end surface of a heat receiving block to which a plurality of semiconductor devices are attached and installed vertically. In the heat sink for cooling, by increasing the inner diameter of the upper half of the heat pipes in the row and decreasing the inner diameter of the lower half of the heat pipes in the row, upstream of the cooling air Of the cooling air attached to the heat receiving block and the downstream side of the cooling pipe by preventing the cooling air heated by the cooling side heat pipe from affecting the downstream side heat pipe. This is a heat sink for semiconductor device cooling that reduces the temperature difference between the elements on the side and prevents the rating of the power converter from decreasing.

[0014]

【Example】

 An embodiment of a heat sink for cooling a semiconductor device according to the present invention will be described below with reference to the drawings. However, the same portions as those of the conventional FIG. 3 and FIG. 4 are denoted by the same reference numerals and the description thereof will be omitted.

FIG. 1 is a view showing a heat sink 1 of the present invention, and FIG. 2 is a left side view of FIG. 1 and 2, the mounting relationship between the heat receiving block 2 and the heat pipes 3A, 3B, 3C, 3D, 3E, 3F and the mounting relationship between the heat receiving block 2 and the elements 5A, 5B, 5C, 5D are the same as those of the conventional one. And the same as FIG. However, the diameters of the heat pipes 3A, 3B, 3C located above the heat receiving block 2 and the diameters of the heat pipes 3D, 3E, 3F located below the heat receiving block 2 are different from those of the conventional heat sink.

That is, the heat pipes 3A, 3B, 3C located on the upper side have slightly larger inner and outer diameters than the conventional heat pipes 3A1, 3B1, 3C1 shown in FIG. The inner and outer diameters of 3E and 3F are slightly smaller than the heat pipes 3D1, 3E 1 and 3F1 shown in FIG. Therefore, the radiation fins 4 have different diameters between the through holes of the heat pipes 3A, 3B and 3C and the through holes of the heat pipes 3D, 3E and 3F.

In the heat sink configured as described above, when the heat sink is housed inside the box body in which the exhaust fan is attached to the ceiling portion of the box body as in the conventional case, the arrow indicating the flow of intake air shown in FIG. In the exhaust gas flow path indicated by arrow D to arrow E, the heat pipe 3F located at the bottom is the cooling air sucked into the box body 7 from the intake port 9a as indicated by arrow D, as in the conventional case. After that, the heat pipes 3E, 3D, 3C, 3B, 3A are cooled by the heat pipes located below and the cooling air warmed under the cooling fins 14.

However, in the heat sink of the present invention, the diameters of the heat pipes 3A, 3B, 3C located on the upper side are large, the amount of water vapor vaporized in the heat receiving portion 2 increases, and the heat receiving portion 2 heat pipes 3A, 3B, 3C, the amount of heat transferred to the right in FIG. 3 can be increased, so that the temperature difference between the ends of the heat pipes 3A, 3B, 3C can be reduced, and even if the heat pipes 3D, 3E located below are heated. , 3F, even if the cooling temperature rises, it is possible to prevent a decrease in heat transfer amount.

Therefore, in the heat receiving block 2 cooled by the upper heat pipes 3A, 3B, 3C and the lower heat pipes 3D, 3E, 3F, the upper half and the lower half are cooled substantially evenly, It is possible to reduce the temperature difference between the elements 5A, 5C and the elements 5B, 5D located above and below.

In the above embodiment, the inner and outer diameters of the heat pipes 3A, 3B, 3C located on the upper side are slightly larger than the inner and outer diameters of the conventional heat pipes, and the heat pipes 3D, 3E, located on the lower side. Although the inner and outer diameters of 3F are slightly smaller than the inner and outer diameters of the conventional heat pipe, the lower heat pipes 3D, 3E, 3F have the same diameter as the conventional one, and the upper heat pipes 3A, 3B, The inner and outer diameters of 3C may be large. On the contrary, only the inner and outer diameters of the lower heat pipes 3D, 3E, 3F may be smaller than those of the conventional heat pipe.

Further, the upper and lower heat pipes may have the same outer diameter and only the inner diameter may be changed. In this case, since the through holes of the heat pipe formed in the heat radiation fins 14 can be made the same vertically, there is an advantage that an increase in processing time can be suppressed.

Further, although there are two types of difference between the inner and outer diameters of the upper and lower heat pipes, the upper and lower heat pipes may be increased in order from bottom to top. Further, in the above embodiment, the heat receiving block is installed vertically in the box.However, even when the heat receiving block is installed horizontally and forcedly ventilates the cooling air from the side, a heat pipe with a small inner diameter is used for cooling air. The same can be done by setting the upstream side of.

[0023]

[Effect of device]

 As described above, according to the present invention, the intermediate portions of the plurality of cooling fins are inserted into the plurality of heat pipes protruding in a row from the end surface of the heat receiving block in which the plurality of semiconductor elements are mounted and installed vertically. In the attached heat sink, the inner diameter of the upper half of the heat pipes in a row is set to be large, and the inner diameter of the heat pipe in the bottom half of the row of heat pipes is set to be small so that the cooling air Since the heat transfer in the downstream heat pipe was prevented from decreasing due to the influence of the cooling air heated by the upstream heat pipe on the downstream heat pipe, the upstream side of the cooling air attached to the heat receiving block was prevented. It is possible to obtain a heat sink for cooling a semiconductor device that can reduce the temperature difference between the device and the device on the downstream side.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of a heat sink for cooling a semiconductor device of the present invention.

FIG. 2 is a left side view of FIG.

FIG. 3 is a diagram showing an example of a conventional semiconductor element cooling heat sink.

FIG. 4 is a left side view of FIG.

FIG. 5 is a right side view showing a box body of a power converter in which a conventional heat sink for cooling a semiconductor element is housed.

6 is a left side view of FIG.

[Explanation of symbols]

1 ... Heat sink, 2 ... Heat receiving block, 3A, 3B, 3
C, 3D, 3E, 3F ... Heat pipe, 4 ... Radiating fins, 5A, 5B, 5C, 5D ... Semiconductor element.

Claims (1)

[Scope of utility model registration request] 1. A semiconductor device having a plurality of cooling pipes and a plurality of heat pipes protruding in a row from an end surface of a heat receiving block to which a plurality of semiconductor devices are attached and which are vertically installed. In the cooling heat sink, an inner diameter of an upper half of the heat pipes in the row is made larger, and an inner diameter of a lower half of the heat pipes in the row is made small. Heat sink for cooling semiconductor devices.