JP2017022336A - Heat radiation structure of heat generating element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat radiation structure of heat generating element capable of enhancing cooling efficiency without generating any stress on a solder part connecting a lead terminal of a heat generating element and a through hole in a circuit board.SOLUTION: A heat generating element D has an element body Da and a lead terminal Db protruding outward from the element body. In the heat radiation structure of the heat generating element, an element body is fixed to a cooling plane 4; a front end of the lead terminal is inserted through a through hole 5a formed in a circuit board 5; and a solder part 12 is formed by soldering the front end of the lead terminal and through hole therebetween in a state that the circuit board is fixed at a position above the cooling plane.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a heat dissipation structure for a heating element mounted on a substrate.

In an electric vehicle such as a hybrid vehicle or a fuel vehicle, direct current power supplied from a battery is converted into alternating current power by an inverter device, and thereby an alternating current motor is rotated to generate driving force.
As a switching element constituting the inverter device, a diode called an IGBT or a free wheel diode is mounted on the control board. Since a large current flows through these elements, although the electrical resistance is small, the heat generation amount is large. Here, an element that generates a large amount of heat is referred to as a heating element.

As a heat dissipation structure for the heat generating element, a structure is known in which the heat generated by the heat generating element is released to the heat sink by fixing the heat generating element mounted on the control board to the cooling surface of the heat sink by using the housing of the inverter device as a heat sink. (For example, Patent Document 1).
In Patent Document 1, a lead terminal extending from an element body of a heating element is inserted into a through hole of a control board and connected by soldering, and the element body is mounted in a state of being lifted from the control board.
A heat sink member is integrated with the side surface of the casing, which is a heat sink, and the control board is disposed inside the casing in a state where the element body is mounted and fixed on the heat sink member. Thereby, the heat generated in the element main body as the heat generating element is transferred to the housing via the heat sink member and is radiated.

JP 2014-7362 A

By the way, in Patent Document 1, before the element body is fixed to the heat sink member integrated with the housing, stress is likely to concentrate on the soldering portion connecting the through hole and the lead terminal of the control board. Cracks are likely to occur at the soldering site.
Therefore, the present invention eliminates stress in the solder portion connecting the lead terminal of the heat generating element and the through hole of the substrate, and can increase the cooling efficiency to achieve a high-quality structure. The purpose is to obtain a structure.

  In order to achieve the above object, a heat dissipation structure for a heating element according to one aspect of the present invention is a heat dissipation structure for a heating element that transfers heat to a cooling surface of a heat sink to dissipate heat. Has an element body and a lead terminal projecting outward from the element body, the element body is fixed to the cooling surface, and the tip of the lead terminal is inserted through a through hole provided in the substrate, and In a state where the substrate is fixed above the cooling surface, a solder portion is provided by soldering between the through hole and the leading end side of the lead terminal.

  As described above, according to the heat dissipation structure of the heating element, the element body fixed to the cooling surface and the substrate fixed above the cooling surface do not move relative to each other. Crack generation can be prevented. Further, since the element body is fixed to the cooling surface, the cooling efficiency can be increased.

It is a top view which shows the thermal radiation structure of the heat generating element of 1st Embodiment which concerns on this invention. It is the II-II arrow directional view of FIG. The figure which showed the state which has moved the board | substrate to the cooling surface side so that the lead terminal of a heat generating element may be inserted in a through hole after fixing the element main body of a heat generating element to the cooling surface in 1st Embodiment which concerns on this invention. It is. It is a top view which shows the thermal radiation structure of the heat generating element of 2nd Embodiment which concerns on this invention. FIG. 5 is a view taken along line VV in FIG. 4. In the second embodiment according to the present invention, after the element body of the heating element is temporarily fixed to the cooling surface, the substrate is moved to the cooling surface side so that the lead terminal of the heating element is inserted into the through hole. FIG. It is a top view which shows the thermal radiation structure of the heat generating element of 3rd Embodiment which concerns on this invention. It is a VIII-VIII arrow directional view of FIG. In the third embodiment according to the present invention, after the element body of the heating element is temporarily fixed to the cooling surface, the substrate is moved to the cooling surface side so that the lead terminal of the heating element is inserted into the through hole. FIG.

Hereinafter, a heat dissipation structure for a heat generating element according to one embodiment of the present invention will be described with reference to the drawings as appropriate.
[First Embodiment]
1 to 3 show a heat dissipation structure for a heating element according to a first embodiment of the present invention.
FIG. 1 shows a main part of an inverter device 1 mounted on an electric vehicle, and a power conversion control unit for converting DC power into AC power is arranged inside the casing.

The housing includes a bottomed box-shaped case 2 and a lid (not shown) that closes the upper opening 2 a of the case 2, and the case 2 includes a side wall 3 and a bottom portion 4.
The bottom 4 of the case 2 is a heat sink whose cooling is promoted by contact with a cooling fluid such as cooling air or cooling water.
Inside the case 2 are housed a control substrate 5 and a semiconductor device D such as an IGBT or a free-wheeling diode constituting the power converter unit. This semiconductor device D corresponds to the heating element of the present invention.

The semiconductor device D includes a resin package Da having a rectangular parallelepiped appearance in which a semiconductor chip (not shown) is embedded, and a plurality of lead terminals Db protruding from the side surface of the resin package Da. The lead terminal Db includes a horizontal terminal portion Db1 extending along the bottom portion 4 from the resin package Da, and a rising terminal portion Db2 rising in a direction away from the bottom portion 4 from the tip of the horizontal terminal portion Db1. ing.
In the semiconductor device D, the resin package Da is fixed to the bottom portion 4 by a device pressing fixing portion 6.

The device pressing fixing portion 6 is a plate-like metal member. As shown in FIG. 2, the fixing portion 9 having an insertion hole 9 a through which the screw portion of the device fixing screw 8 passes, and one side of the fixing portion 9. An elastically deformable portion 10 formed by bending and an abutting portion 11 formed at the tip of the elastically deformable portion 10 are provided.
The elastic deformation portion 10 includes a rising portion 10b rising from one side of the fixing portion 9 through the first bent portion 10a and a top end of the rising portion 10b when the fixing portion 9 is fixed to the bottom portion 4. And an inclined portion 10d extending obliquely downward via the two bent portions 10c.

The contact portion 11 is formed by bending the tip end side of the inclined portion 10d of the elastic deformation portion 10 linearly upward, and comes into contact with the upper surface of the resin package Da.
And the fixing part 9 of the device press fixing part 6 is fixed to the bottom part 4 of the case 2 by the device fixing screw 8, so that the elastically deforming part 10 of the device pressing fixing part 6 is against the resin package Da of the semiconductor device D. Then, an elastic restoring force is applied toward the bottom portion 4 and the resin package Da is fixed in a state of being pressed toward the bottom portion 4 side.

The control board 5 covers the semiconductor device D fixed to the bottom part 4 by the device pressing and fixing part 6 from above, and the board support part 4a protrudes from the bottom part 4 of the case 2 and the board provided at other parts of the bottom part 4 It is placed on a support part (not shown) and arranged in parallel with the bottom part 4.
The control board 5 is fixed to the bottom part 4 with a board fixing screw 7 screwed into the board support part 4a and another board support part.
Then, the rising terminal portion Db2 of the lead terminal Db of the semiconductor device D fixed to the bottom portion 4 of the case 2 is inserted into a plurality of through holes 5a having lands of the control substrate 5, and the rising terminal portion Db2 and the through holes 5a The solder part 12 is provided by soldering the space.

Next, the procedure for fixing the semiconductor device D to the bottom 4 of the case 2 and mounting the semiconductor device D on the control board 5 in the heat dissipation structure of the heat generating element of the first embodiment will be described.
First, the resin package Da of the semiconductor device D is placed at a predetermined position on the bottom portion 4.
Next, the fixing portion 9 of the device pressing fixing portion 6 is made to correspond to the screw hole 4b formed in the bottom portion 4, and the screw portion of the device fixing screw 8 inserted into the insertion hole 9a of the fixing portion 9 from above is inserted into the screw hole 4b. Tighten this. Thereby, since the elastic deformation part 10 acts an elastic restoring force on the resin package Da of the semiconductor device D, the device pressing and fixing part 6 fixes the resin package Da in a state where it is pressed against the bottom part 4.

Next, as shown in FIG. 3, the control board 5 is lowered from above the opening 2 a of the case 2 toward the bottom 4, and a plurality of rising terminals rising toward the opening 2 a of the semiconductor device D are formed. The control board 5 is placed on the base support part 4a and other base support parts while the part Db2 is inserted through the plurality of through holes 5a of the control board 5.
Next, the substrate fixing screw 7 passes through the control substrate 5 and is screwed into the substrate supporting portion 4a and the other substrate supporting portion, thereby fixing the control substrate 5 to the bottom portion 4.

Finally, since a plurality of rising terminal portions Db2 of the semiconductor device D protrude from the through holes 5a of the control board 5 from the opening 2a side of the case 2, the through holes 5a and the rising from the opening 2a side can be seen. The solder portion 12 is provided by soldering between the terminal portion Db2 (see FIG. 2).
Here, the heating element according to the present invention corresponds to the semiconductor device D, the element body according to the present invention corresponds to the resin package Da, the substrate according to the present invention corresponds to the control substrate 5, and the press fixing according to the present invention. The portion corresponds to the device pressing and fixing portion 6, the first fixing screw according to the present invention corresponds to the device fixing screw 8, the fixing plate portion according to the present invention corresponds to the fixing portion 9, and the elastic deformation plate according to the present invention. The part corresponds to the elastic deformation part 10, and the contact plate part according to the present invention corresponds to the contact part 11.

Next, the function and effect of the first embodiment will be described.
In the first embodiment, the resin package Da of the semiconductor device D is fixed to the bottom plate 4 of the case 2, and the plurality of rising terminal portions Db2 of the semiconductor device D are inserted into the through holes 5a of the control board 5, and the control is performed. A solder portion 12 is provided between the through hole 5a and the rising terminal portion Db2 in a state where the substrate 5 is mounted on the substrate support portion 4a protruding from the bottom plate 4 and fixed in parallel with the bottom portion 4. Since the soldered device D and the control board 5 do not move relative to each other, no stress is generated in the solder portion 12 and cracks in the solder portion 12 can be prevented.

Further, the semiconductor device D is placed in a state where the resin package Da is in surface contact with the bottom portion 4, and the elastic deformation portion 10 of the device pressing and fixing portion 6 applies an elastic restoring force to the resin package Da, so that the resin package Da is Since it is pressed by the bottom part 4 and the contact area of the resin package Da and the bottom part 4 is enlarged and brought into close contact, the cooling effect of the resin package Da can be sufficiently enhanced.
Therefore, the first embodiment that can sufficiently enhance the cooling effect of the resin package Da while preventing the occurrence of cracks in the solder portion 12 can have a high-quality heat-dissipating element heat dissipation structure.
In the first embodiment, the resin package Da is simply fixed to the bottom portion 4 of the case 2 that is a heat sink in a surface contact state, and no component that promotes heat dissipation is required. Can also be planned.

Since the rising terminal portion Db2 of the semiconductor device D that has passed through the through hole 5a of the control board 5 extends toward the opening 2a of the case 2, the solder between the through hole 5a and the rising terminal portion Db2 is used. The attachment workability can be improved.
Furthermore, the device pressing fixing part 6 has a long length from the fixing part 9 to the abutting part 11, a metal part (not shown) provided in the resin package Da of the semiconductor device D, and a fixing part. A sufficient insulation distance can be ensured between the device fixing screw 8 for fixing 9 to the bottom 4.
Furthermore, the control board 5 of the first embodiment is arranged in a state where the entire semiconductor device D is covered from above, and the control board 5 can be effectively arranged even in a small space in the case 2. it can.

[Second Embodiment]
4 to 6 show a heat dissipation structure for a heating element according to the second embodiment of the present invention.
In addition, the same code | symbol is attached | subjected to the same component as the structure shown in FIGS. 1-3, and the description is abbreviate | omitted.
Also in the second embodiment, the semiconductor device D is fixed to the bottom portion 4 by the device pressing and fixing portion 6.
The control board 15 of the second embodiment is fixed in parallel to the bottom part 4 on a board support part 4 c protruding from the bottom part 4 and a board support part (not shown) provided at other locations of the bottom part 4. And this control board 15 does not cover the device press fixing | fixed part 6 from upper direction, and has covered only a part by the side of the lead terminal Db of resin package Da.
Then, the rising terminal portion Db2 of the lead terminal Db of the semiconductor device D fixed to the bottom portion 4 of the case 2 is inserted into the plurality of through holes 15a having the lands of the control board 15, and the rising terminal portion Db2 and the through holes 15a The solder part 16 is provided by soldering the space.

Next, a procedure for fixing the semiconductor device D to the bottom 4 of the case 2 and mounting the semiconductor device D on the control board 15 in the heat dissipation structure of the heat generating element of the second embodiment will be described.
First, the fixing portion 9 of the device pressing fixing portion 6 is made to correspond to the screw hole 4d formed in the bottom portion 4, and the screw portion of the device fixing screw 8 inserted through the insertion hole 9a of the fixing portion 9 from above is temporarily inserted into the screw hole 4b. Tighten.
Next, the resin package Da of the semiconductor device D is placed in a surface contact state at a predetermined position on the bottom portion 4, the elastic deformation portion 10 of the device pressing and fixing portion 6 is lifted upward, and the contact portion 11 of the elastic deformation portion 10. Is brought into contact with the upper surface of the resin package Da to temporarily fix the resin package Da.

Next, as shown in FIG. 6, the control board 15 is lowered from above the opening 2 a of the case 2 toward the bottom 4, and a plurality of rising terminals of the semiconductor device D rising toward the opening 2 a. The control board 5 is placed on the board support part 4c and other base support parts while inserting the part Db2 into the plurality of through holes 15a of the control board 15.
At this time, by moving the resin package Da temporarily fixed on the bottom portion 4 in the direction of arrow A in FIG. 6 or in the direction orthogonal to the direction of arrow A along the bottom portion 4, a plurality of rising terminal portions Db 2 and Positioning of the through hole 15a is performed.

Then, the device fixing screws 8 are finally tightened by screwing them into the screw holes 4d. Thereby, since the elastic deformation part 10 acts an elastic restoring force on the resin package Da of the semiconductor device D, the device pressing and fixing part 6 fixes the resin package Da in a state where it is pressed against the bottom part 4.
Next, the substrate fixing screw 7 passes through the control substrate 15 and is screwed into the substrate supporting portion 4 c and other substrate supporting portions, thereby fixing the control substrate 15 to the bottom portion 4.
Finally, the solder portion 16 is provided by soldering between the through hole 15a and the rising terminal portion Db2 from the opening 2a side of the case 2 (see FIGS. 4 and 5).

Next, the function and effect of the second embodiment will be described.
In the second embodiment, the semiconductor device D is fixed to the bottom plate 4 of the case 2, and the control substrate 15 mounted on the substrate support portion 4 c protruding from the bottom plate 4 is arranged in parallel to the bottom portion 4. A solder portion 16 is provided between the through hole 15a and the rising terminal portion Db2 in a state where the plurality of rising terminal portions Db2 of D are inserted into the through holes 15a of the control board 15, and soldered in the case 2. In addition, since the device D and the control board 15 do not move relative to each other, no stress is generated in the solder portion 16, and cracking of the solder portion 16 can be prevented.

In addition, the heat dissipation structure for the heat generating element of the second embodiment can sufficiently enhance the cooling effect of the resin package Da while preventing the occurrence of cracks in the solder portion 16 as in the first embodiment, and promotes heat dissipation. Since no parts or the like are required, the cost of parts can be reduced, and the device pressing fixing part 6 in which the length from the fixing part 9 to the contact part 11 is set long is used to provide the resin package Da. A sufficient insulation distance between the metal part (not shown) and the device fixing screw 8 for fixing the fixing part 9 to the bottom part 4 can be ensured.
Further, in the second embodiment, when the plurality of rising terminal portions Db2 of the resin package Da are inserted into the plurality of through holes 15a of the control board 15, the resin package Da temporarily fixed on the bottom portion 4 is placed on the bottom portion 4. Therefore, the work of inserting the rising terminal portion Db2 into the through hole 15a can be easily performed.

[Third Embodiment]
7 to 9 show a heat dissipation structure for a heating element according to a third embodiment of the present invention.
In the third embodiment, as shown in FIG. 8, an insertion hole 20 that communicates vertically is formed at the center of the resin package Da of the semiconductor device D, and the device fixing screw 21 that has passed through the insertion hole 20 from above is the bottom 4. The semiconductor device D is fixed to the bottom portion 4 by being screwed into the screw hole 4e formed in the above.
The control board 15 of the third embodiment is also a member similar to that of the second embodiment, and is mounted on a board support part 4c protruding from the bottom part 4 and a board support part (not shown) provided at another part of the bottom part 4. It is fixed in parallel with the bottom 4 and covers only a part of the resin package Da on the lead terminal Db side.
Then, the rising terminal portion Db2 of the lead terminal Db of the semiconductor device D fixed to the bottom portion 4 of the case 2 is inserted into the plurality of through holes 15a having the lands of the control board 15, and the rising terminal portion Db2 and the through holes 15a A solder portion 17 is provided by soldering the gap.

Next, the procedure for fixing the semiconductor device D to the bottom 4 of the case 2 and mounting the semiconductor device D on the control board 15 in the heat dissipation structure of the heat generating element of the third embodiment will be described.
First, as shown in FIG. 9, the screw of the device fixing screw 21 inserted into the insertion hole 9 a of the fixing portion 9 from above is made to correspond to the fixing portion 9 of the device pressing fixing portion 6 with the screw hole 4 e formed in the bottom portion 4. The part is temporarily tightened into the screw hole 4e.
Next, the resin package Da of the semiconductor device D is placed in a surface contact state at a predetermined position on the bottom portion 4.
Next, the control board 15 is lowered from above the opening 2 a of the case 2 toward the bottom 4, and the plurality of rising terminal parts Db 2 of the semiconductor device D rising toward the opening 2 a are connected to the control board 15. The control board 5 is placed on the board support part 4c and other base support parts while being inserted into the plurality of through holes 15a.

At this time, by moving the resin package Da temporarily fixed on the bottom portion 4 in the direction of arrow A in FIG. 9 or in the direction orthogonal to the direction of arrow A along the bottom portion 4, a plurality of rising terminal portions Db2 and Positioning of the through hole 15a is performed.
Then, the device fixing screw 21 is screwed into the screw hole 4e and finally tightened.
Next, the substrate fixing screw 7 passes through the control substrate 15 and is screwed into the substrate supporting portion 4 c and other substrate supporting portions, thereby fixing the control substrate 15 to the bottom portion 4.
Finally, the solder portion 17 is provided by soldering between the through hole 15a and the rising terminal portion Db2 from the opening 2a side of the case 2 (see FIGS. 7 and 8).
Here, the second fixing screw according to the present invention corresponds to the device fixing screw 21.

Next, the function and effect of the third embodiment will be described.
In the third embodiment, the semiconductor device D is fixed to the bottom plate 4 of the case 2, and the control substrate 15 placed on the substrate support portion 4 c protruding from the bottom plate 4 is arranged in parallel to the bottom portion 4. A solder portion 17 is provided between the through hole 15a and the rising terminal portion Db2 in a state where the plurality of rising terminal portions Db2 of D are inserted into the through holes 15a of the control board 15, and soldered in the case 2. Further, since the device D and the control board 15 do not move relative to each other, no stress is generated in the solder portion 17 and cracks in the solder portion 17 can be prevented.

Further, the heat dissipation structure of the heat generating element of the second embodiment can also sufficiently enhance the cooling effect of the resin package Da while preventing the occurrence of cracks in the solder portion 17 as in the first embodiment, and promotes heat dissipation. Since no parts are required, the cost of parts can be reduced.
Further, in the third embodiment, when the plurality of rising terminal portions Db2 of the resin package Da are inserted into the plurality of through holes 15a of the control board 15, the resin package Da temporarily fixed on the bottom portion 4 is placed on the bottom portion 4. Therefore, the work of inserting the rising terminal portion Db2 into the through hole 15a can be easily performed.
Furthermore, in the third embodiment, the device fixing screw 21 is passed through the insertion hole 20 formed in the central portion of the resin package Da of the semiconductor device D, and the device fixing screw 21 is screwed into the screw hole 4e of the bottom portion 4. Since the structure is adopted, the manufacturing cost can be reduced.

DESCRIPTION OF SYMBOLS 1 Inverter apparatus 2 Case 2a Case opening part 3 Side wall 4 Bottom part 4a, 4c Board | substrate support part 4b, 4d, 4e Screw hole 5,15 Control board 5a, 15a Through hole 6 Device press fixing part 7 Board fixing screw 8 Device fixing screw DESCRIPTION OF SYMBOLS 9 Fixing part 9a Insertion hole 10 Elastic deformation part 10a First bending part 10b Standing part 10c Second bending part 10d Inclination part 11 Contact part 12, 16, 17 Solder part 20 Insertion hole 21 Device fixing screw D Semiconductor device Da Resin package Db Lead terminal Db1 Horizontal terminal part Db2 Rising terminal part

Claims (7)

A heat-dissipating structure for the heat-generating element that transfers heat to the cooling surface of the heat sink to dissipate heat.
The heating element has an element body and a lead terminal protruding outward from the element body,
In the state where the element body is fixed to the cooling surface, the tip of the lead terminal is inserted through a through hole provided in the substrate, and the substrate is fixed at a position above the cooling surface,
A heat dissipation structure for a heating element, wherein a solder portion is provided by soldering between the through hole and the leading end side of the lead terminal.   The heat-radiating structure for a heating element according to claim 1, wherein the element body is in contact with the cooling surface in a surface contact state.   The cooling surface of the heat sink is the bottom surface of a bottomed box-shaped case, the element body is fixed to the bottom surface, and the leading end side of the lead terminal protruding from the element body extends toward the opening of the case. The heat dissipation structure for a heat generating element according to claim 1, wherein the heat dissipation structure is present. The element body is pressed and fixed toward the cooling surface by a pressing fixing portion,
The pressing fixing portion is formed at a fixing plate portion fixed to the cooling surface by a first fixing screw, an elastic deformation plate portion formed by bending from the fixing plate portion, and a tip of the elastic deformation plate portion. A contact plate portion that contacts the element body, and when the fixed plate portion is fixed to the cooling surface, the elastic deformation plate portion is brought into contact with the element body via the contact plate portion. The heat-dissipating structure for a heating element according to any one of claims 1 to 3, wherein an elastic restoring force is applied.   The heat dissipation structure for a heating element according to claim 4, wherein the substrate is fixed in a state where the pressing fixing portion and the element main body fixed to the pressing fixing portion are covered from above.   The substrate is fixed at a position where the pressing fixing portion is not covered from above, and when the tip of the lead terminal is inserted into the through hole provided in the substrate, the first fixing screw is attached to the cooling surface. The heat dissipating structure for a heat generating element according to claim 4, wherein the heat dissipating structure is temporarily tightened. The element body has a structure in which a second fixing screw is passed through and fixed to the cooling surface,
The substrate is fixed at a position where the second fixing screw is not covered from above, and when the leading end of the lead terminal is inserted into the through hole provided in the substrate, the second fixing screw is inserted into the cooling surface. The heat dissipating structure for a heating element according to any one of claims 1 to 3, wherein the heat dissipating structure is temporarily tightened.

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