JP5962326B2 - Forced air cooling heat sink - Google Patents

Description

  The present invention relates to a structure of a forced air cooling heat sink that cools a plurality of built-in semiconductor modules in an inverter device that drives a load such as a motor, an uninterruptible power supply, and an active filter.

  Power converters are used in various applications ranging from home appliances to transportation and industrial products, and their capacity ranges from several W (watts) to several MW (megawatts). Since the loss that occurs during switching and steady state of this power converter is converted to heat, it is necessary to quickly dissipate the generated heat and keep the junction temperature of the semiconductor element below the upper limit (150 ° C maximum). .

  Natural air cooling from the surface of the semiconductor element may be used up to the level of several watts (W), but if the generated loss exceeds several tens of watts (W), the fan is forcibly blown into the fins of the heat sink. In many cases, a forced air-cooled heat sink that promotes cooling of the heat sink is employed.

A conventional forced air cooling heat sink will be described with reference to FIGS.
FIG. 6 is an external perspective view of a conventional forced air cooling heat sink.
FIG. 7 shows a part (main body part) of the configuration shown in FIG.

8 is a side sectional view of the configuration shown in FIG.
First, as shown in FIG. 6, an example of a conventional forced air cooling heat sink includes a plurality of semiconductor modules 53 (in the illustrated example, two windward side semiconductor modules 53a and two leeward side semiconductor modules 53b). The heat sink 50 is installed on the upper surface of the heat sink 50, and the heat sink 50 is accommodated in the housing 52. The heat sink 50 is formed of a base 56 and fins 57 as will be described later with reference to FIG. A cooling fan 55 (and an exhaust port (not shown)) is installed on one end surface side of the housing 52, and an intake port 54 is provided on the other end surface. In addition, the cooling fan 55 is arrange | positioned in the housing | casing 52, as shown, for example in FIG.

  The cooling fan 55 forms the airflows 61 and 62 shown in the figure. That is, ambient air flows as airflow 61 (intake air) into the housing 52 from the air inlet 54 and passes through the fins 57 and the like described later (in this case, the temperature rises due to heat radiation from the fins 57). The airflow 62 (exhaust gas) is discharged from one end surface (exhaust port not shown) of the casing 52.

  The plurality of semiconductor modules 53 are electrically connected by the bus bar 51. That is, each semiconductor module 53 is connected to the bus bar 51 by a main terminal (not shown). This is for electrical connection, but heat is also transferred to the bus bar. Of course, the heat generated in each semiconductor module 53 is also transmitted to the heat sink 50 and is radiated from the heat sink 50 (the fins 57).

  The bus bar is generally an elongated metal used in place of the power supply line, but is not limited to this definition. The bus bar is generally made of copper, but is not limited to this example.

In addition, the housing | casing 52 may further be formed so that the upper space (installation space of the several semiconductor module 53) of the heat sink 50 may be covered, as shown in FIG.
FIG. 7 shows the heat sink 50 (in a state where the semiconductor module 53 is mounted) taken out from the housing 52. However, the bus bar 51 is omitted.

  The heat sink 50 is formed by a base 56 that is a good thermal conductor (high thermal conductive material) and a plurality of fins 57 that are thermal good conductors (high thermal conductive material). Note that these are not limited to highly heat conductive materials, that is, materials having high heat conductivity, and may be simple heat conductive materials.

  A plurality of (about 25 in the figure) fins 57 are provided so as to be perpendicular to the lower surface of the base 56 and in parallel with each other. Air flowing into the housing 52 from the air inlet 54 as the airflow 61 passes through the gaps between the fins 57, and heat dissipation from the fins 57 is thereby promoted.

  A plurality of semiconductor modules 53 are mounted on the upper surface side of the base 56. The heat generated in each semiconductor module 53 is transmitted to each fin 57 via the base 56 and is radiated from the fin 57 into the air as described above.

  Further, although omitted in FIG. 7, as described in FIG. 6, a part of the heat generated in each semiconductor module 53 is also transmitted to the bus bar 51 through a main terminal (not shown), but from the bus bar 51. The heat dissipation efficiency of the main body and the bus bar 51 is increased.

FIG. 8 is a cross-sectional view of the forced air-cooling heat sink shown in FIG. 6 and also shows the air flow (airflow) in the housing.
The airflow is indicated by arrows in the figure. As shown in the figure, the casing 52 or the like forms a wind tunnel including the inlet 54, the windward wind tunnel 58a, the installation space of the fins 57, the leeward wind tunnel 58b, and the like. And flows through the fins 57). Air is sucked from the air inlet 54 (airflow (intake) 61) and exhausted to the outside through an exhaust port (not shown) at the rear stage of the cooling fan 5 (airflow (exhaust) 62). In the following description, the cooling fan 5 will not be mentioned one by one with respect to the air flow.

Although not shown in FIG. 6, the housing 52 may be provided not only on the side surface shown in FIG. 6 but also on the upper surface so as to cover the semiconductor module 53 as shown in FIG. 8.
As described above, the air taken in from the intake port 54 passes through the windward wind tunnel 58a and passes between the plurality of fins 57 of the heat sink 50 to reach the leeward wind tunnel 58b. Exhausted. On the other hand, the heat generated in the semiconductor module 53 is transmitted to the fins 57 via the base 56, absorbed by the air passing between the fins 57, and exhausted to the outside.

  As a result, heat generated in the semiconductor module 53 is dissipated from the fins 57 and the like, thereby cooling the semiconductor module 53. In the forced air cooling heat sink, the heat generated from the semiconductor module 53 is radiated from the fins 57 to the air via the base 56, so the temperature of the air passing between the fins 57 is higher on the leeward side than on the leeward side. Become. In other words, the temperature of the air gradually rises while passing between the fins 57.

  For this reason, if the amount of heat generated by the leeward side semiconductor module 53a and the leeward side semiconductor module 53b is the same, the temperature of the leeward side semiconductor module 53b becomes higher than that of the leeward side semiconductor module 53a. On the other hand, the operating temperature of the semiconductor module 53 is limited, and a local temperature rise becomes a bottleneck for operating the apparatus. For this reason, normally, a semiconductor module 53 having a high heat generation temperature (a large amount of heat generation) is disposed on the windward side, and a semiconductor module 53 having a low heat generation temperature (a small heat generation amount) is disposed on the leeward side. The temperature does not exceed the service limit. In other words, the leeward side semiconductor module 53a has a higher heat generation temperature (a larger amount of heat generation) than the leeward side semiconductor module 53b.

  However, this method may not be adopted depending on the layout of the semiconductor module, and the temperature of the leeward side semiconductor module 53b becomes high, and the cooling capacity of the forced air cooling heat sink cannot be fully utilized. Occur.

  Further, as a heat transfer path other than the heat dissipation from the fins 57, there is known a configuration in which there is a path for radiating heat from the semiconductor chip via the main terminal. An example of such a configuration is shown in FIG.

FIG. 9 is a structural diagram of the semiconductor module. This may be a structural example of the semiconductor module 53, but is not limited to this example.
The semiconductor module of the example shown in FIG. 9 has a semiconductor chip 73 that serves as a heat source, and this semiconductor chip 73 is electrically connected to the main terminal 71 via an internal wiring 74. Further, since the internal wiring 74 is also a good thermal conductor, the heat generated in the semiconductor chip 73 is transmitted to the main terminal 71 via the internal wiring 74. In the case where a bus bar (bus bar) 77 is connected to the main terminal 71, the heat is further transferred from the main terminal 71 to the bus bar 77, and is radiated from the bus bar 77 into the air. However, the heat dissipation efficiency is not good as it is.

For this reason, a structure for promoting heat dissipation from the plate 77 is disclosed in Patent Document 1.
The invention of Patent Document 1 uses a plate connected to the main terminal electrode of the power semiconductor as a radiator, and a high efficiency heat dissipation is achieved by a synergistic effect of dissipating not only the heat dissipation surface but also the heat transfer from the element. It is realized.

FIG. 10 is a configuration example of Patent Document 1 described above.
In the configuration of FIG. 10, a plate 82 that electrically connects the main terminals 86 of the plurality of power semiconductors 85 and forms a DC bus line is provided. In addition to a main radiator 81 (corresponding to the fins) responsible for main cooling and a main fan motor 83, a plate 82 and a sub fan motor 84 are provided as sub radiators. The plate 82 is screwed to the main terminal 86 of the power semiconductor 85, and the entire plate 2 is forcibly cooled by blowing air from the sub fan motor 84.

  Since the heat generated by the power semiconductor 85 is transmitted from the main terminal 86 to the plate 82, the heat is dissipated by cooling the plate 82. Since heat is taken out from the main terminal directly coupled to the semiconductor element of the generation source, heat radiation efficiency is high if forced cooling is performed by blowing air. As a result, the burden on the main radiator 81 is reduced, and downsizing and the like can be achieved.

JP 2001-86705 A

  As a method for promoting heat dissipation from a bus bar or the like connected to the main terminal of the semiconductor module, the structure of Patent Document 1 described above has been proposed. However, since air flows around the semiconductor module, the main terminal and control of the semiconductor module are controlled. There arises a problem that the insulation performance is deteriorated due to dust or dust adhering to the terminal.

  For this reason, dust and dirt are usually removed using an air filter, but increasing the collection capacity by making the air filter finer increases the pressure loss and may require a powerful cooling fan. The problem that the maintenance cycle of an air filter becomes short occurs.

  An object of the present invention is to blow air to a plate connected to a main terminal of a semiconductor module without forced air to flow around the semiconductor module, thereby forcibly cooling the main terminal of the semiconductor module. The object is to provide a forced air-cooled heat sink having high heat dissipation efficiency without adhesion.

  The forced air-cooled heat sink of the present invention includes a heat sink in which a semiconductor module is mounted on one surface of a base made of a heat conductive material and a plurality of fins made of a heat conductive material is provided on the other surface, and a housing that houses the heat sink. A forced air-cooling heat sink having a body that forms a wind tunnel that surrounds the fins by a part of the body, and a cooling fan that generates an airflow through which the outside air flows into the wind tunnel and passes through the fins The duct is provided on one surface side of the base and allows a part of the air flowing into the wind tunnel to pass therethrough, and is connected to a duct having one or more openings and a main terminal of the semiconductor module And a plate made of a heat conductive material, which is installed so as to close the one or more openings, and the heat generated in the semiconductor module is Is transmitted via the serial main terminal to the plate, is radiated from the plate to the air passing through the said duct at said one or more openings.

  According to the forced air-cooling type heat sink and the like of the present invention, air can be forcedly cooled by sending air to the plate connected to the main terminal of the semiconductor module without flowing air around the semiconductor module. A forced air-cooled heat sink with high heat dissipation efficiency can be realized without dust or dust adhering to the terminals.

It is an external appearance perspective view of the forced air cooling type heat sink of this example. It is sectional drawing of the forced air cooling type heat sink of this example. It shows the state where the plate in FIG. 1 is removed. (A) is a figure which shows an example of application, (b) is a figure which shows a specific example. (A), (b) is a structure figure of the forced air cooling type heat sink of a prior application. It is an external appearance perspective view of the conventional forced air cooling type heat sink. A part of the configuration shown in FIG. 6 is taken out and shown. It is a sectional side view of the structure shown in FIG. It is a structure diagram of a semiconductor module. It is an example of composition of patent documents 1.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 3 show a forced air-cooling heat sink of this example.
That is, FIG. 1 and FIG. 3 are external perspective views of the main body portion of the forced air cooling heat sink of this example. FIG. 3 shows a state where the plate 13 in FIG. 1 is removed. FIG. 2 is a cross-sectional view of the entire forced air-cooling heat sink of this example.

  FIGS. 1 and 3 are drawings corresponding to FIG. 7 of the conventional drawing (showing the main body portion), and the structure of the entire forced air cooling heat sink is the same as that of FIG. The structure is housed in the body (not shown here), and FIG. 2 can be said to correspond to a cross-sectional view of the entire structure.

  As shown in FIGS. 1 to 3, the main part of the forced air-cooling heat sink according to the present example basically has a heat sink 1 composed of a base 2 and fins 3. That is, the heat sink 1 is formed of a base 2 which is a heat good conductor (particularly a high heat conductive material such as copper) and a plurality of fins 3 which are heat good conductors (particularly a high heat conductive material such as copper). These bases 2 and fins 3 are not limited to high heat conductive materials, that is, materials having high heat conductivity, and may be simple heat conductive materials. In addition, these structures themselves may be the same as the conventional one.

  A windward side semiconductor module 4a and a leeward side semiconductor module 4b are provided on one surface side of the base 2 (the upper surface side in the figure is not limited to this example). Furthermore, a plate (bus bar, flat plate electrode, etc.) 13 connected to the main terminal 11a of each semiconductor module 4 is also provided.

  As described above, the heat sink 1 basically includes the base 2 and the fins 3. However, the state in which the semiconductor module 4 is mounted may be referred to as the heat sink 1.

  On the other surface side of the base 2 (in the figure, the lower surface side is not limited to this example), a plurality of the fins 3 are formed so as to be arranged perpendicular to the other surface and in parallel with each other. . Thus, the heat generated in the upper semiconductor module 4a and the leeward semiconductor module 4b is transmitted to the base 2 and further transferred to the fins 3 to be dissipated. A part of the air (windward airflow 7a) flowing into the forced air-cooling heat sink passes through the fins 3 to improve the heat dissipation efficiency from the fins 3, while the temperature of the air itself increases due to the heat dissipation from the fins 3 It is discharged as a side airflow 7b.

  In addition, when it is not necessary to particularly distinguish the leeward side semiconductor module 4a and the leeward side semiconductor module 4b, the semiconductor module 4 may be described. The same applies to other components.

  In the figure, two leeward semiconductor modules 4a and two leeward semiconductor modules 4b are provided, but the present invention is not limited to this example. In the example shown in the figure, four semiconductor modules are provided on the base 2, two on the windward side of the air flow passing through the fins 3 are the windward semiconductor modules 4 a and two on the leeward side. Is called the leeward semiconductor module 4b. In the figure, all the semiconductor modules 4 have their main terminals 11a connected to a plate (busbar or the like) 13, but the present invention is not limited to this example. That is, there may be a semiconductor module 4 whose main terminal 11a is not connected to the plate (busbar or the like) 13.

  As for the fin 3, for example, as shown in FIG. 2, the windward portion (portion located below the windward semiconductor module 4a) of the air flow passing through the fin 3 is referred to as the windward fin 3a. This part (the part located under the leeward side semiconductor module 4b) may be referred to as the leeward side fin 3b. In other words, the upwind fin 3a may be regarded as the windward fin 3a, and the leeward fin 3b may be regarded as the leeward fin 3b than the base opening 9a described later.

  Further, a sinus 10 is further provided on one surface side (upper surface side in the drawing) of the base 2, and a base opening 9 a (described later) is provided in the base 2. With these configurations, a part of the upwind airflow 7a (main stream) passes through the entire fin 3 as described above, while the other part (branch stream) passes through the sinus 10. The leeward fin 3a does not pass (passes) and passes only the leeward fin 3b.

  As shown in FIGS. 2 and 3, with respect to the base 2, a base opening 9 a is formed between the leeward side semiconductor module 4 a and the leeward side semiconductor module 4 b, and the air (wind Part of the upper airflow 7a; a tributary) flows into the lower side of the base 2 through the base opening 9a, merges with the main flow, passes through the leeward fin 3b, and is discharged as the leeward airflow 7b. The The base opening 9a has, for example, the shape and arrangement shown in FIG. 5B described later, but is not limited to this example.

  The sinus 10 is installed in an empty area (an area other than the installation area of each semiconductor module 4) on the upper surface of the base 2, and is installed so as to cover the base opening 9a. Furthermore, it installs so that a part (branch) of the windward airflow 7a may flow into the cave 10 as described above. Thus, the sinus 10 has an E shape as shown in FIG. 3, for example, but is not limited to this example. In any case, a portion (branch) of the windward airflow 7a passes through the upper surface side of the base 2 without flowing air around each semiconductor module 4 (especially the windward semiconductor module 4a) by the sinus 10. It is configured. Up to this point, it may be substantially the same as the prior application (Japanese Patent Application No. 2011-232901), but in this example, a sinus opening 9b described later is further provided, and the plate 13 connected to the main terminal 11a is provided with the sinus opening. It is installed so as to block the portion 9b. This will be described later.

  Here, as shown in FIG. 2, the forced air-cooled heat sink of this example has the main body portion shown in FIG. Further, a windward side wind tunnel 8a, a leeward side wind tunnel 8b, and the like are formed by the casing 6. Further, a cooling fan 5 and the like are provided. Similarly to the air inlet 54 of FIG. 6, a hole (air inlet 12) is formed in the housing 6 as shown in FIG. 2. Further, although not shown, an exhaust port for discharging the leeward airflow 7 b is also formed in the housing 6.

  Although omitted in FIG. 6, substantially the same as in FIG. 8 and the like, a part of the housing 6 is configured to cover the installation space of the plate 13 and the semiconductor module 4 as shown in FIG. Further, the ceiling portion 6a of the windward wind tunnel 8a and the ceiling portion 6b of the leeward wind tunnel 8b shown in FIG. 2 may be regarded as a part of the housing 6, and the semiconductor module 4 includes the entire housing 6 including these. The outside air does not flow into the installation space. In other words, it can be said that the windward side wind tunnel 8a, the leeward side wind tunnel 8b and the like are formed by the casing 6 including the ceiling portions 6a and 6b. Further, the windward side wind tunnel 8a, the leeward side wind tunnel 8b, and the wind tunnel including the installation space of the fins 3 (basically a wind tunnel for allowing air to pass through the fins 3; a wind tunnel for allowing the main air to flow). It can be said that it is formed.

  On the other hand, a hole 10a shown in FIG. 2 is provided in the lower part of the windward side of the cave 10, and a part (branch) of the air of the windward airflow 7a flows into the sinus 10 through the hole 10a. Note that a hole (not shown) having the same size as the hole 10a (or smaller than the hole 10a) is formed in the ceiling portion 6a of the windward wind tunnel 8a at a position corresponding to the hole 10a.

  Here, with respect to the air flow, for example, an air flow as shown by an arrow in FIG. 2 is formed. This air flow is created by the cooling fan 5. That is, the main air flow (main flow) is that the air (windward airflow 7a) taken from the intake port 12 passes through the fins 3 via the windward wind tunnel 8a and reaches the leeward wind tunnel 8b (wind current). The air passes through the upper wind tunnel 8a → the fin 3 → the leeward wind tunnel 8b in this order) and is released to the outside as the leeward airflow 7b.

  However, a part (branch) of the air that has flowed into the windward wind tunnel 8a passes through the cave 10 and then merges with the main flow along the way through the base opening 9a (this is the sub air flow). Flow).

  The tributary air flows through the end of the plate 13 connected to the main terminal 11a (portion closing the sinus opening 9b) while passing through the sinus 10, so that heat radiation from the plate 13 is promoted. This will be described in detail later. The material of the sinus 10 is an insulator such as FRP (Fiber Reinforced Plastics), and therefore, it may be considered that there is almost no heat transfer from the plate 13 to the sinus 10.

  In this way, the windward airflow 7a flowing into the forced air-cooling heat sink is divided into two directions in the windward wind tunnel 8a, and a part (main air) flows into the lower side of the base 2 and passes through the fins 3. However, the other part (branch air) passes through the cave 10 provided on the upper surface of the base 2. In the example shown in FIG. 2, the tributary air merges in the middle after passing through the cave 10. However, the present invention is not limited to this example. For example, the leeward wind tunnel 8 b and the cooling fan 5 are not directly joined to the main stream. It is good also as a structure discharged | emitted outside via etc. However, it demonstrates according to the example of illustration here.

  The “branch air” flowing into the cave 10 contacts the plate 13 and receives heat radiation without contacting the windward side semiconductor module 4a, and then passes through the base opening 9a as described above. It flows into the lower side and merges with the “main air”. After merging, after passing through the leeward fin 3b, it passes through the leeward wind tunnel 8b, passes through the cooling fan 5, and is discharged as the leeward airflow 7b.

  Further, as shown in FIG. 3, the sinus 10 is provided with one or a plurality of sinus openings 9b on one surface (the upper surface in the figure). On the other hand, as shown in FIG. 2, the plate 13 is connected to the main terminal 11a of each semiconductor module 4 (the main terminal 11a of the leeward side semiconductor module 4a and the leeward side semiconductor module 4b), and each sinus opening 9b. It is provided so as to block. Accordingly, as described above, the “branch air” flows through the plate 13 in each of the sinus openings 9b. With such a configuration, the heat generated in the windward side semiconductor module 4a is transmitted to the plate 13 via the main terminal 11a, and is radiated from the plate 13 to the “branch air”.

  Here, the plate 13 may be a bus bar (also referred to as a bus bar) as an example, but is not limited to this example. The material of the bus bar is generally copper, but the material of the plate 13 is not limited to this example, and may be another metal such as aluminum. Alternatively, the plate 13 is not limited to a metal plate, and may use a substrate wiring pattern.

  Here, the heat generated in each semiconductor module 4 is basically transferred from the base 2 to the fin 3 and dissipated from the fin 3 to the “main air”, but the semiconductor module 4 → the main terminal 11 a → plate. There is also heat that travels through the path of 13 (Busbar, etc.). Conventionally, this heat has poor heat dissipation efficiency from the bus bar, and has caused the temperature of the bus bar and the main terminal to rise. On the other hand, in the invention of the above-mentioned Patent Document 1, by providing a small fan and sending air to the plate, the heat dissipation efficiency is improved, and the heat transmitted from the main terminal to the bus bar is efficiently dissipated. However, as already described, the configuration of Patent Document 1 has a problem in that the insulation performance is deteriorated due to dust and dirt adhering to the main terminal and the control terminal of the semiconductor module.

  In order to solve the above-described conventional problems, in this method, the sinus 10 (perforated duct) having the above-described sinus opening 9b is provided, and the plate 13 (bus bar or the like) that contacts the main terminal 11a of the semiconductor module 4 is provided. Is provided so as to close the sinus opening 9b. With this configuration, air (branch air) can flow to the surface of the plate 13 without flowing air around the semiconductor module 4 (particularly around the main terminal 11a and the control terminal 11b). In addition, heat radiation from the plate 13 can be promoted without attaching dust or dust to the control terminal 11b. Thereby, the amount of heat radiation from the plate 13 increases, and the temperature of the semiconductor module 4 (the semiconductor chip and the like) can be efficiently lowered.

  In this way, air can be passed through the bus bar connected to the main terminal without passing through the main terminal and control terminal of the semiconductor module, increasing the heat dissipation from the bus bar and efficiently generating heat generated in the semiconductor chip and internal wiring. Heat dissipation can reduce the temperature rise of the semiconductor chip.

  In the example shown in the figure, the cave 10 is formed by connecting a base opening 9a installed between the windward side semiconductor module 4a and the leeward side semiconductor module 4b and an air inlet (windward wind tunnel 8a) of the housing. Although arranged, it is not limited to this example. For example, a base opening (a hole formed in the base 2) is not provided at the position of the illustrated base opening 9a, but is provided at the rear stage (not shown) of the leeward side semiconductor module 4b, and the sinus 10 is extended so as to extend the above-described non- A cave (not shown) may be arranged so as to connect the illustrated base opening and the intake port of the housing.

  Or you may make it provide an opening part (not shown) in the upper part (ceiling part 6b) of the leeward side wind tunnel 8b instead of the structural example which provides an opening part in the base 2 mentioned above. In this example, a sinus (not shown; a shape in which the sinus 10 is extended) may be arranged so as to connect the opening (not shown) and the intake port of the housing.

  Here, basically, “branch air” is faster than “main air” (because it has less resistance; conversely, when air passes through a narrow gap between fins 3, the resistance is high. Becomes). That is, the passage amount of air per predetermined cross-sectional area is larger in the “branch air” than in the “main air”. In addition, the amount of heat released from the fin 3 is often larger than the amount of heat released from the plate 13. Due to these two factors, when the “branch air” joins the “main stream air” via the base opening 9a, the temperature of the “branch air” is lower than the temperature of the “main stream air”. As a result, the temperature of the “mainstream air” is lowered by the merge of the “branch air” with the “mainstream air”. That is, the temperature of the air after joining becomes lower than the temperature of “main air”, and this is supplied to the leeward fin 3b. As a result, the heat radiation efficiency from the leeward fin 3b is improved as compared to the case where “mainstream air” is supplied to the leeward fin 3b as it is (the temperature of the leeward semiconductor module 4b can be efficiently reduced). .

  Conventionally, since the temperature of the air after passing through the windward fin 3a is high, there is a problem that the cooling performance of the leeward semiconductor module 4b is deteriorated. However, as described above, this method reduces such a problem. The effect that it is possible is also acquired.

FIG. 4A shows an example of an application target of the forced air cooling heat sink of this example.
For example, the forced air-cooling heat sink of this example is applied to the illustrated inverter, but is not limited to this example.

FIG. 4B shows an external view and an internal circuit configuration of an example of the semiconductor module, which will not be particularly described.
Here, FIGS. 5A and 5B are structural diagrams of the forced air cooling heat sink of the prior application (Japanese Patent Application No. 2011-232901). FIG. 5 (b) shows a state where the duct 20 is removed from the configuration shown in FIG. 5 (a).

5 will be described only with respect to differences from the structure of the present example shown in FIGS.
In the configuration shown in FIG. 5A, first, the plate 13 does not exist. A duct 20 is provided instead of the sinus 10. The difference between the cave 10 and the duct 20 is that the duct 20 is not provided with the respective cave openings 9b.

  Except for the above differences, the configuration shown in FIG. 5A may be regarded as the same as the configuration of the present example shown in FIGS. 1 to 3 (in FIG. 5, FIGS. 1 to 3). Constituent elements that are equivalent to those in FIG.

  Here, the base opening 9a shown in FIG. 2 and the like described above has a shape and arrangement as shown in FIG. 5B, for example. That is, the base opening 9a is, for example, a square hole, but is not limited to this example, and may be a round hole or a hole having another shape such as an elliptical shape. Moreover, although the number of holes is two in the figure, it is not limited to this example, and may be one or three or more.

  Then, by providing the duct 20 so as to cover all the base openings 9a and to allow a part of the windward airflow 7a to flow in and to avoid each semiconductor module, the duct 20 can be formed as shown in FIG. It will be installed in the form shown in (a). In this regard, the sinus 10 may be substantially similar as described above.

  As described above, in the case of the configuration of the prior application (Japanese Patent Application No. 2011-232901), the air passing through the duct 20 does not cool the plate 13 (the plate 13 may not exist in the first place). It flows into the space below the base 2 (between the fins 3) through the base opening 9a.

  In this way, air that does not pass through the windward portion of the fin 3 (portion located below the windward side semiconductor module 4a) (air that has not increased in temperature) passes from the middle to the fin 3 portion via the base opening 9a. By supplying, the temperature of the air passing through the leeward portion of the fin 3 (portion located below the leeward semiconductor module 4b) can be lowered, and the leeward semiconductor module 4b can be efficiently cooled.

In this method, as described above, such an effect can also be obtained (although the effect may be slightly reduced).
As described above, the forced air-cooled heat sink of this example allows a part of the air flowing into the fins 3 to flow into the sinus 10 (branch flow). A cave opening 9b is provided on the upper surface of the cave 10, and a plate (bus bar) 13 (not shown) connected to the main terminal of each semiconductor module 4a, 4b is provided so as to close the cave opening 9b. ing. Thus, in the portion of the sinus opening 9b, the tributary air is passed through the plate 13, thereby forcibly air-cooling the plate 13 and improving the heat radiation efficiency from the plate 13.

  In the forced air-cooled heat sink of this example, the semiconductor module 4 is mounted on one surface (for example, the upper surface) of the base 2 made of the heat conductive material, and the plurality of fins 3 made of the heat conductive material are provided on the other surface (for example, the lower surface). A heat sink 1 and a housing 6 that houses the heat sink 1, and a housing that forms a wind tunnel (windward wind tunnel 8 a, leeward wind tunnel 8 b, installation space for the fin 3, etc.) surrounding the fin 3 by a part thereof. 6 and the cooling fan 5 for generating an airflow that exhausts air through the fins 3 by flowing external air into the wind tunnel, for example, have the configurations listed below.

A duct that is provided on one surface side of the base 2 and allows a part of the air that has flowed into the wind tunnel to pass therethrough, and has one or more openings (sinus openings) on one surface (base-to-surface; upper surface, etc.) A duct having a section 9b) (sinus 10);
A plate 13 (busbar or the like) made of a heat conductive material, connected to the main terminal 11a of the semiconductor module 4 and installed so as to close the one or more openings (sinus opening 9b);
The heat generated in the semiconductor module 4 is transferred to the plate 13 through the main terminal 11a, and is transferred from the plate 13 to the air passing through the duct (the sinus 10) in one or more openings (the sinus opening 9b). Heat is dissipated.

  In the above configuration, the semiconductor module 4 includes an upwind semiconductor module 4a disposed on the upstream side of the airflow passing through the wind tunnel and a leeward semiconductor module 4b disposed on the downstream side. May be.

  Further, in this case, the base 2 has a base opening 9a between the leeward side semiconductor module 4a and the leeward side semiconductor module 4b, and the air passing through the duct (the sinus 10) is The fin 3 corresponding to the leeward side semiconductor module 4b (the leeward side) after flowing into the wind tunnel from the base opening 9a and merging with the air passing through the wind tunnel (air passing through the leeward fin 3a) You may comprise so that it may pass through the fin 3b). As described above, this configuration also provides an effect of improving the cooling efficiency of the leeward side semiconductor module 4b.

DESCRIPTION OF SYMBOLS 1 Heat sink 2 Base 3 Fin 4a Upwind semiconductor module 4b Downwind semiconductor module 5 Cooling fan 6 Case 7a Upwind airflow 7b Downward airflow 8a Upwind wind tunnel 8b Downwind wind tunnel 9a Base opening 9b Terminal 11b Control terminal 12 Air inlet 13 Plate

Claims (4)

A heat sink comprising a semiconductor module mounted on one side of a base made of a heat conducting material and a plurality of fins made of a heat conducting material provided on the other side, and a housing for housing the heat sink, part of which is In a forced air cooling heat sink having a casing that forms a wind tunnel surrounding the fins, and a cooling fan that generates an air current that flows into the wind tunnel and allows the outside air to flow through the fins.
A duct that is provided on one surface side of the base and allows a part of the air that has flowed into the wind tunnel to pass therethrough, and has one or more openings;
A plate made of a heat conducting material, connected to the main terminal of the semiconductor module and installed to close the one or more openings.
Forced air cooling wherein heat generated in the semiconductor module is transmitted to the plate through the main terminal and radiated from the plate to air passing through the duct at the one or more openings. heatsink. The semiconductor module comprises an upwind semiconductor module disposed on the upstream side of the airflow passing through the wind tunnel, and a leeward semiconductor module disposed on the downstream side,
The base has a base opening between the leeward side semiconductor module and the leeward side semiconductor module,
The duct is provided so as to cover the base opening,
The air passing through the duct flows into the wind tunnel from the base opening and merges with the air passing through the wind tunnel, and then passes through the fins corresponding to the leeward semiconductor module. The forced air cooling heat sink according to claim 1. The installation space of the semiconductor module is surrounded by the housing,
The forced air-cooled heat sink according to claim 1 or 2, wherein air flowing through the wind tunnel or air passing through the duct does not flow through the semiconductor module or its main terminal. The forced air cooling heat sink according to claim 1, wherein the plate is a bus bar.