JP4390695B2 - Semiconductor element heat dissipation structure - Google Patents

Description

  The present invention relates to a heat dissipation structure for a semiconductor element, and more particularly to a structure for attaching a heat dissipation means to a plurality of semiconductor elements.

  In a power supply device, a plurality of semiconductor elements of the same type are often provided. In such a case, a structure in which these semiconductor elements are integrally attached by being attached or screwed so as to be arranged side by side with respect to the element attaching surface of the heat sink formed from a drawn material or an extruded material is well known (for example, , See Patent Document 1).

  However, when semiconductor elements are arranged side by side with respect to the element attachment surface of the heat sink, the wiring of the wiring board becomes long and complicated in order to connect the same type of terminals of the respective semiconductor elements. Long and complex wiring can cause noise and surge. Further, in order to form a complicated wiring structure, the area of the wiring board must be increased accordingly.

  Further, a heat sink corresponding to a plurality of semiconductor elements is often manufactured by cutting a drawn material or an extruded material into a predetermined length and opening or cutting the cut material. However, performing secondary processing such as opening on a drawn or extruded material that cannot be made very thin has a higher processing cost than sheet metal processing, and in combination with forming a complicated wiring structure This increases the manufacturing cost of the heat dissipation structure.

  Among heat sinks that can be provided with a plurality of semiconductor elements, there is a heat sink having an E-shaped cross section. For such a heat sink, a configuration is known in which three semiconductor elements are fastened with clips on the front and back sides of the element pasting portion provided in parallel (for example, see Patent Document 2). .

  In this case, the semiconductor elements overlap with each other with the heat sink interposed therebetween, that is, in a vertical arrangement. Therefore, when the semiconductor elements are arranged so as to overlap each other with the heat sink interposed therebetween, the same type of terminals of the respective semiconductor elements are also arranged so as to overlap, so that the wiring structure becomes simpler than when they are arranged side by side. Further, the mounting area of the semiconductor element can be made smaller than the case where the heat sink is arranged side by side with respect to the element pasting surface.

However, since not all semiconductor elements are oriented in the same direction, it is necessary to provide wiring different from other semiconductor elements for semiconductor elements having different orientations. Further, since there is a difference in the distance between terminals of the same type of these semiconductor elements, for example, when these semiconductor elements are turned on, the power balance between them may be lost. When the power balance is lost, a difference appears in these heat generation temperatures. If the power balance is lost in this way, the stability of the operation of the power supply device on which these are mounted may be impaired.
FIG. 4 of JP-A-8-107168 FIG. 1 of Japanese Patent Laid-Open No. 10-256440

  The present invention has been made in view of the above-described circumstances, and a first object thereof is to provide a structure that can be manufactured at a relatively low cost in a heat dissipation structure of a semiconductor element. It is a second object to provide a device that can easily maintain a power balance between semiconductor elements. Furthermore, a third object is to reduce noise and surge caused by wiring on the wiring board.

As means for solving the above-described problems, the present invention provides a semiconductor element heat dissipation structure in which a first element sticking portion formed in a plate shape and the first element sticking portion formed in a plate shape are sandwiched from both left and right sides. And a plate-like second element tension part and a third element tension part arranged in parallel with the first element tension part, a lower end part of the first element tension part, and a second element tension part. A first connecting part connecting the lower end part, a second connecting part connecting the upper end part of the second element attaching part and the upper end part of the third element attaching part, and opening the first connecting part. And a heat dissipating body provided with an opening, and a first element sticking portion and a second element sticking portion provided so as to be interposed, and a terminal projecting from the opening. 1 semiconductor element, the first element pasting portion and the third element And a terminal projecting in the same direction as the terminal of the first semiconductor element from between the first element pasting part and the third element pasting part. The second semiconductor element is provided so as to be in contact with a surface that faces away from the first element sticking part of the third element sticking part, and a terminal is provided in the same direction as the terminal of the first semiconductor element. And a third semiconductor element arranged so as to protrude.

  According to the above means, the first, second and third semiconductor elements are overlapped with the heat dissipating body in which the first element attaching part, the second element attaching part and the third element attaching part are formed in a spiral shape. That is, since the semiconductor elements can be arranged in a column and the orientation of the semiconductor elements can be made uniform, the wiring structure of the wiring board is simplified.

  In the above invention, the heat dissipating member has an equal interval between the first element attaching portion and the second element attaching portion and an interval between the second element attaching portion and the third element attaching portion. Can be.

  Further, in the above invention, the first element pasting portion, the second element pasting portion, the third element pasting portion, the first connecting portion, and the second connecting portion are formed by bending a plate material. Can be formed integrally.

  In the above invention, the second connecting portion and the tip of the first element attaching portion can be separated from each other.

  According to the present invention, it becomes easy for semiconductor elements to maintain the power balance between the semiconductor elements, so that it is possible to improve the stability of the operation of the power supply device on which these semiconductor elements are mounted. Further, since the heat radiating body is formed by bending the plate material, the heat radiating body can be easily manufactured, and the manufacturing cost can be reduced. Furthermore, since the wiring of the wiring board can be shortened, noise and surge can be reduced.

  Examples of the present invention will be described below. In the following description, a heat dissipation structure in a three-terminal semiconductor element is taken up, but the present invention can be preferably applied to semiconductor elements other than three terminals. Further, the present invention is not limited to the embodiments described below, for example, regarding the specific configuration relating to the number of semiconductor elements to be attached, the size of the opening, the attachment part of another heat sink, etc. Various modifications can be made without departing from the scope of the claims.

  FIG. 1 is a perspective view of a heat dissipation structure for a semiconductor device according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of a heat dissipation structure for a semiconductor device according to the first embodiment of the present invention. FIG. 3A is a front view of a heat dissipation structure for a semiconductor device according to the first embodiment of the present invention. FIG. 3B is a rear view of the semiconductor device heat dissipation structure according to the first embodiment of the present invention. FIG. 3c is a side view of the semiconductor device heat dissipation structure according to the first embodiment of the present invention. 1, 2, 3 a, 3 b, and 3 c, 10 is a radiator, 11 is a first element attachment portion, 12 is a second element attachment portion, 13 is a third element attachment portion, and 14 a and 14 b are cut. 15a, 15b is a lower connection part, 16 is an upper connection part, 18a, 18b are screw holes, 19 is a bead core, 20 is a semiconductor element, 21 is a molding resin, 22 is a through hole, 23 is an upper end part, 24 is Lower end portions, 25a, 25b, and 25c are terminals, 30 is a semiconductor element, 33 is an upper end portion, 35c is a terminal, 40 is a semiconductor element, 43 is an upper end portion, 45a, 45b, and 45c are terminals, and 50 is a screw.

  As shown in FIG. 1, the heat dissipation structure of this embodiment performs heat dissipation of three semiconductor elements by a heat radiator 10. The heat radiating body 10 has three element pasting portions, ie, a first element pasting portion 11, a second element pasting portion 12, and a third element pasting portion 13, and heat radiation of the semiconductor element is mainly performed in these portions. Then, it is mounted on a wiring board (not shown) in the state shown in FIG. When mounted on the wiring board, the lower connecting portion 15a and the lower connecting portion 15b located at the bottom of the radiator 10 are in contact with the wiring board or an insulator attached to the wiring board.

  Further, as shown in FIG. 2, the first element sticking portion 11 is disposed between the second element sticking portion 12 and the third element sticking portion 13, and the second element sticking portion 12 and the lower connecting portion 15a are provided at the lower end portion thereof. , 15b. Note that the upper end portion of the first element sticking portion 11 extends above the upper end portion 23 and the upper end portion 33 of these mold resins in order to facilitate heat transfer and heat dissipation of the semiconductor element 20 and the semiconductor element 30. It is preferable.

  The 2nd element sticking part 12 is formed in parallel with the 1st element sticking part 11, and is united via the 1st element sticking part 11, the lower connection part 15a, and the lower connection part 15b in the lower end part. In addition, as shown in FIG. 3a, in order to facilitate the insertion of the semiconductor element 20, the second element sticking part 12 has a notch part 14a and an upward cut part 14a from the inner ends of the lower connecting parts 15a and 15b. A cut portion 14b is formed. That is, even if the distance between the first element pasting portion 11 and the second element pasting portion 12 is slightly changed due to manufacturing variations, the portion between the notched portion 14a and the notched portion 14b is slightly moved, thereby causing this variation. Can be absorbed.

  Furthermore, as shown in FIG. 2, the upper end portion is integrated with the third element attaching portion 13 and the upper connecting portion 16. The 3rd element sticking part 13 is formed in parallel with the 1st element sticking part 11, and is united via the 2nd element sticking part 12 and the upper connection part 16 in the upper end part. After all, as shown in FIG. 3c, the heat radiating body 10 is formed in a spiral shape (spiral shape) as a whole, and is formed so that the first element sticking portion 11 is wound most inwardly. . In addition, the spacing between these element pasting portions is the same. Further, as shown in FIG. 2, screw holes such as screw holes 18a are formed in the vicinity of the center of these element pasting portions.

  The lower connecting portion 15a and the lower connecting portion 15b connect the left and right ends of the lower end portions of the first element attaching portion 11 and the second element attaching portion 12 to the vicinity thereof. Further, an opening for inserting the semiconductor element 20 is provided between the lower connecting portion 15a and the lower connecting portion 15b. The upper connecting portion 16 connects the entire upper ends of the second element attaching portion 12 and the third element attaching portion 13.

  In this embodiment, because the three semiconductor elements of the same type are provided, the intervals between the first element pasting portion 11, the second element pasting portion 12, and the third element pasting portion 13 are the same distance. However, in the present invention, these intervals can be appropriately changed. For example, when different types of semiconductor elements are connected, these intervals are different.

  The structure of the radiator 10 is preferably formed by punching a sheet metal material of one aluminum alloy corresponding to a screw hole or an opening, and further bending it with a Yakken mold or the like. In addition, when processing with a Yakken mold, it is highly desirable to facilitate processing by separating the upper connecting portion 16 and the upper end portion of the first element attaching portion 11 as shown in FIG. When the heat radiating body 10 is manufactured by such a method, it becomes possible to manufacture it at a very low cost compared to the case where the extruded material or the like is secondarily processed. Of course, a similar structure can be formed by connecting a plurality of plate members by welding or the like. Further, the material of the radiator 10 may be another metal such as a copper alloy as long as it is a metal having high heat conductivity.

  Further, as shown in FIG. 2, semiconductor elements 20, 30, and 40 are provided so as to be in contact with the surfaces of the first element pasting portion 11, the second element pasting portion 12, and the third element pasting portion 13. The semiconductor elements 20, 30, and 40 are the same type of three-terminal elements. For example, in the case of the semiconductor element 20, three terminals 25 a, 25 b, and 25 c protrude from the mold resin 21. This configuration is the same in the semiconductor element 30 and the semiconductor element 40. The semiconductor elements 20, 30, and 40 are arranged so that terminals of the same type overlap each other when the radiator 10 is viewed from the front.

  The semiconductor element 20 is inserted between the first element tension part 11 and the second element tension part 12 and is provided in contact with both the first element tension part 11 and the second element tension part 12. Further, the screw 50 shown in FIG. 3A is passed through the through-hole 22 formed in the mold resin 21 to be fixed. The fixing by passing the screw 50 is the same in the semiconductor element 20 and the semiconductor element 30. Further, when the semiconductor element 20 is positioned between the first element attaching portion 11 and the second element attaching portion 12, the semiconductor element 20 is inserted from an opening between the lower connecting portion 15a and the lower connecting portion 15b.

  The semiconductor element 30 is inserted between the first element pasting portion 11 and the third element pasting portion 13 and is provided in contact with both the first element pasting portion 11 and the third element pasting portion 13. The semiconductor element 40 is provided in contact with the outer surface of the third element sticking portion 13. In addition, you may affix these semiconductor elements with the adhesive agent with good heat conductivity with respect to an element sticking surface. In this case, the screw 50 can be omitted.

  Furthermore, the difficulty of breaking the power balance in the semiconductor element output, which is an advantage of this embodiment, will be described. FIG. 7A is an explanatory diagram illustrating a temperature rise distribution of a semiconductor device according to the related art structure. FIG. 7 b is an explanatory diagram showing a temperature rise distribution of the structure of the semiconductor device according to the present invention. FIG. 8a is an explanatory diagram showing a simulation model corresponding to the first embodiment of the present invention. FIG. 8b is an explanatory diagram showing a simulation model corresponding to the structure of the prior art. FIG. 9a is a graph showing the simulation result of the first embodiment of the present invention. FIG. 9b is a graph showing the simulation results of the prior art structure. 8a and 9b, reference numerals 35a, 35b, and 35c denote terminals, reference numerals 101, 102, and 103 denote wirings, and other reference numerals denote the same elements as those in FIG.

  In the models shown in FIGS. 8a and 8b, the semiconductor element 20 and the semiconductor element 30 are the same type of MOSFET, the terminal 25a and the terminal 35a are the gate terminals, the terminal 25b and the terminal 35b are the drain terminals, and the terminal 25c and the terminal 35c are the sources. It is a terminal. Further, in FIG. 8a, the semiconductor element 20 and the semiconductor element 30 are arranged so as to overlap each other so as to correspond to this embodiment, and the respective terminals are connected by linear wirings 101, 102, and 103. On the other hand, in FIG. 8 b, the semiconductor element 20 and the semiconductor element 30 are arranged side by side, and the wirings 101, 102, and 103 correspond to this. These configurations were simulated.

  As a result, as shown in FIG. 9a, in the model corresponding to this embodiment, the voltages U1 and U2 between D and S when the semiconductor element 20 and the semiconductor element 30 are turned on are completely overlapped without deviation. According to the knowledge of the inventor, this is the same for the three semiconductor elements, and it has been found that the power balance is maintained in the model corresponding to this embodiment. Further, as shown in FIG. 7b, since the influence of the wind direction is small, the temperature rise of the semiconductor element can be made uniform.

  On the other hand, in the prior art structure in which the semiconductor element 20 and the semiconductor element 30 are arranged side by side, there is a deviation in the D and S voltages U1 and U2. Furthermore, as shown in FIG. 7a, the temperature rise of the semiconductor element 20 on the leeward side is larger than that of the semiconductor element 30 on the leeward side. Therefore, this embodiment has the advantage that the power balance can be maintained over the prior art structure in which the semiconductor elements are arranged side by side.

  Furthermore, the radiator 10 has a structure particularly suitable for air cooling by forced circulation. As shown in FIG. 3a, a portion between the lower connecting portion 15a and the lower connecting portion 15b of the lower end portion of the first element sticking portion 11 is formed with an opening so that the lower connecting portion 15a and the lower portion are separated by a distance W. It becomes higher than the lower end part of the connection part 15b. Therefore, when the heat dissipation structure of this embodiment is provided on the wiring board, a gap with a distance W is formed between the lower connecting portion 15a and the lower connecting portion 15b with the surface of the wiring board. This gap becomes a flow path for forcedly circulated air.

  According to the inventor's knowledge, when the air circulation in the vicinity of the base of the terminal of the semiconductor element is good, when the bead core 19 is mounted, the bead core 19 is greatly cooled. Such a gap can of course be formed in a heat sink having a prior art structure made of extruded material. However, this type of heat sink is very expensive to cut. The same can be said for screw holes.

  As described above, in this embodiment, since a heat radiator is formed by punching a plate material such as an aluminum alloy and further bending, compared with a normal heat sink that processes an extruded material. Manufacture of a heat radiator becomes very easy. Further, since the three semiconductor elements are arranged so as to overlap with the heat radiating body, the wiring structure of the wiring board becomes very simple, and the wiring structure of the wiring board becomes very simple. Further, since the intervals between the three semiconductor elements can be made uniform, the intervals between the same types of terminals can be made uniform, and it becomes easy to stably maintain the power balance. Furthermore, the vicinity of the terminals of the semiconductor element can be efficiently cooled. In addition, since the wiring of the wiring board is also shortened, noise and surge caused by the wiring can be reduced.

  FIG. 4 is a perspective view of a heat dissipation structure for a semiconductor device according to a second embodiment of the present invention. In FIG. 4, 17 is an intermediate portion, 60 is a semiconductor element, and other reference numerals are the same as those in FIG.

  As shown in FIG. 4, the heat dissipation structure of this embodiment corresponds to a structure obtained by integrating two structures of the first embodiment. According to this structure, in addition to the three semiconductor elements such as the semiconductor element 20, another three semiconductor elements such as the semiconductor element 60 can be provided. Since the three semiconductor elements such as the semiconductor element 60 are not arranged so as to overlap with the semiconductor element 20 or the like, the effect of stably maintaining the power balance between these two semiconductor element groups cannot be obtained. Advantages such as ease of processing of the radiator 10 can be obtained in the same manner as in the first embodiment.

  FIG. 5 is a perspective view of a heat dissipation structure for a semiconductor device according to a third embodiment of the present invention. In FIG. 5, 17a and 17b are intermediate portions, 90 is a semiconductor element, and other reference numerals are the same as those in FIGS.

  As shown in FIG. 5, the heat dissipation structure of this embodiment corresponds to a structure obtained by integrating three structures of the first embodiment. According to this structure, in addition to the three semiconductor elements such as the semiconductor element 20, another six semiconductor elements such as the semiconductor element 60 and the semiconductor element 90 can be provided. Therefore, similarly to the prior art structure in which a large number of semiconductor elements are attached to the front and back of the heat sink, the radiator 10 can be used for heat dissipation of a large number of semiconductor elements. However, since the three semiconductor elements such as the semiconductor element 60 and the like and the semiconductor element 90 and the like are not arranged so as to overlap the semiconductor element 20 and the like, the power balance is stable between these three semiconductor element groups. However, advantages such as the ease of processing of the radiator 10 can be obtained as in the first embodiment.

  FIG. 6 is a perspective view of a heat dissipation structure for a semiconductor device according to a fourth embodiment of the present invention. In FIG. 6, 10a, 10b, 10c, and 10d are radiators, 52b and 52d are screw holes, and 100 is a radiator plate.

  As shown in FIG. 6, the heat dissipation structure of this embodiment is the structure of the four embodiments 2, that is, the heat dissipating bodies 10a, 10b, 10c, 10d are arranged at regular intervals and integrated with the heat dissipating plate 100. It is. Moreover, the heat sink 100 is fixed to the four heat sinks using screw holes such as the screw holes 52b of the heat sink 10b. According to this structure, since the heat radiating plate 100 is provided as auxiliary heat radiating means, the heat radiating bodies 10a, 10b, 10c, and 10d alone are very effective when the heat radiating capability is insufficient.

  In each of the above-described embodiments, the description has been made by taking the three-terminal semiconductor element as an example.

1 is a perspective view of a heat dissipation structure for a semiconductor device according to a first embodiment of the present invention. 1 is an exploded perspective view of a heat dissipation structure for a semiconductor device according to a first embodiment of the present invention. It is a front view of the heat dissipation structure of the semiconductor element which concerns on the 1st Example of this invention. It is a rear view of the heat dissipation structure of the semiconductor element concerning the 1st example of the present invention. It is a side view of the heat dissipation structure of the semiconductor element concerning the 1st example of the present invention. It is a perspective view of the thermal radiation structure of the semiconductor element which concerns on the 2nd Example of this invention. It is a perspective view of the thermal radiation structure of the semiconductor element which concerns on the 3rd Example of this invention. It is a perspective view of the thermal radiation structure of the semiconductor element which concerns on the 4th Example of this invention. It is explanatory drawing which shows the temperature rise distribution of the semiconductor element which concerns on a prior art structure. It is explanatory drawing which shows the temperature rise distribution of the structure of the semiconductor element which concerns on this invention. It is explanatory drawing which shows the simulation model corresponding to the 1st Example of this invention. It is explanatory drawing which shows the simulation model corresponding to a prior art structure. It is a graph which shows the simulation result of the 1st example of the present invention. It is a graph which shows the simulation result of a prior art structure.

Explanation of symbols

10, 10a, 10b, 10c, 10d ... radiator, 11 ... first element tension part, 12 ... second element tension part, 13 ... third element tension part, 14a, 14b, 14c, 14d, 14e, 14f ... notch part, 15a, 15b ... lower connection part, 16 ... upper connection part, 17, 17a, 17b ... intermediate part, 18a, 18b ... screw hole, 19 ... bead core, 20 ... semiconductor element, 21 ... mold resin, 22 ... through hole, 23 ... upper end, 24 ... lower end, 25a, 25b, 25c ... terminal, 30 ... semiconductor element, 33 ... upper end, 35a, 35b, 35c ... terminal, 40 ... semiconductor element, 43 ... upper end, 45a, 45b, 45c ... Terminal, 50 ... Screw, 52b, 52d ... Screw hole, 60 ... Semiconductor element, 90 ... Semiconductor element, 100, 101a, 101b ... Heat sink, 101, 102, 103 ... Wiring

Claims (4)

A first element pinning portion formed in a plate shape, arranged parallel to the plate-like and the first element pinning unit with made in the form of a plate so as to sandwich from each right and left sides of the first element pinning unit A second element pasting portion and a third element pasting portion; a first connecting portion connecting a lower end portion of the first element pasting portion and a lower end portion of the second element pasting portion; and an upper end of the second element pasting portion. A radiator that includes a second connecting portion that connects a portion and an upper end portion of the third element pasting portion, and an opening that opens the first connecting portion;
A first semiconductor element provided so as to be interposed between the first element attaching part and the second element attaching part, and arranged so that a terminal protrudes from the opening;
The first semiconductor element is provided so as to be interposed between the first element pasting portion and the third element pasting portion, and between the first element pasting portion and the third element pasting portion. A second semiconductor element arranged so that the terminal protrudes in the same direction as the terminal;
A third element is provided so as to be in contact with a surface of the third element sticking portion that faces away from the first element sticking portion, and is arranged so that a terminal protrudes in the same direction as the terminal of the first semiconductor element. A semiconductor element of
A heat dissipation structure for a semiconductor element, comprising: The space between the first element pasting portion and the second element pasting portion and the spacing between the first element pasting portion and the third element pasting portion are equal to each other in the heat radiator. 2. A heat dissipation structure for a semiconductor device according to 1. The first element attaching portion, the second element attaching portion, the third element attaching portion, the first connecting portion, and the second connecting portion are integrally formed by bending a plate material. The heat dissipation structure for a semiconductor element according to claim 1, wherein the heat dissipation structure is a semiconductor element. 4. The heat dissipation structure for a semiconductor element according to claim 1, wherein the second connection part and the tip part of the first element pasting part are separated from each other. 5.

Images