JP2013157620A - Electronic circuit device for compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive electronic circuit device for a compressor which unfailingly radiates heat generated by an electronic component to the exterior of a housing box, achieves high reliability against the heat generated by the electronic component and changes of the external temperature of the housing box, and achieves good assembly workability.SOLUTION: A heat sink 25 radiating heat of a semiconductor element 29 is placed in thermal contact with an aluminum plate 37 forming a shell of a housing box 1 through an insulation sheet 49. Further, a rubber bush 24 is attached to a protruding part provided at the housing box 1, and the compressed rubber bush 24 places the heat sink 25 in pressure contact with the aluminum plate 37. The structure radiates heat generated by the semiconductor element 29 to the exterior of the housing box 1 and improves the reliability and the assembly workability.

Description

  The present invention relates to an electronic circuit for a compressor for driving a hermetic electric compressor used in a refrigeration apparatus or the like having a configuration in which a printed circuit board on which an electronic component such as a semiconductor element is mounted is stored in a storage box. It relates to the device.

  Conventionally, in an electronic circuit device for a compressor, a printed circuit board on which an electronic component such as a semiconductor element is mounted is stored in the storage box through the opening of the storage box, and the lid of the storage box is covered with a lid. It is the structure which closes an opening part (for example, refer patent document 1).

  Hereinafter, the conventional fixing method will be described with reference to the drawings.

  FIG. 8 is an exploded perspective view of a conventional electronic circuit device for a compressor described in Patent Document 1. In FIG.

  In FIG. 8, a storage box 100 injection-molded with a synthetic resin such as nylon or ABS resin has an opening 108 that is slightly larger than the size of the printed circuit board 104 so that the printed circuit board 104 can be stored therein. doing.

  A semiconductor element 112 for driving a compressor is mounted on the printed circuit board 104, and a heat sink 116 made of a metal having good heat conductivity is attached in close contact with the semiconductor element 112 to reduce the temperature of the semiconductor element 112. Yes.

  Further, a connector 120 is mounted on the printed circuit board 104, and a position where the connector 120 faces is opened in the storage box 100 to form a cord lead-out portion 124.

  Holes 128 are provided at four corners of the printed circuit board 104 so that the printed circuit board 104 can be fixed to the storage box 100 by the board fixing screws 132. Further, mounting holes 136 are formed at four corners of the opening 108 of the storage box 100, and holes 142 are formed at four corners of the lid 140, and the lid fixing screw 146. The lid 140 is fixed to the storage box 100 so that the opening 108 can be closed.

  The operation of the electronic circuit device for a compressor configured as described above will be described below.

  In assembling the electronic circuit device for the compressor, first, the printed circuit board 104 is inserted from the opening 108 of the storage box 100 so that the connector 120 can be connected to the outside through the cord lead-out portion 124. Thereafter, all the four holes 128 of the printed board 104 are fastened in the thickness direction by the board fixing screws 132 and fixed to the storage box 100. Finally, the four holes 142 of the lid 140 are fixed to the opening 108 of the storage box 100 by the lid fixing screws 146, and the printed circuit board 104 is covered by the storage box 100 and the lid 140, and the assembly is completed.

JP 11-317570 A

  However, in the above-described conventional configuration, when the electronic circuit device for the compressor is energized and driven, the heat sink 116 is attached to the semiconductor element 112, but the heat sink 116 is heated with air outside the storage box 100. Since it cannot be replaced, the heat generated by the compressor driving semiconductor element 112 accumulates inside the storage box 100, thereby increasing the temperature of the semiconductor element 112 and reducing the reliability of the semiconductor element 112. It had the problem that.

  In addition, due to the temperature change, stress is applied to the four holes 128 that fix the printed circuit board 104 due to the difference in the linear expansion coefficient between the printed circuit board 104 and the storage box 100. As a result, the printed circuit board 104 It had the problem of breaking.

  The present invention solves the above-described conventional problems, and ensures long-term reliability of the electronic components in a wide range of usage environments such as heat generation of the electronic components and changes in the outside temperature of the storage box, and also facilitates assembly workability. The object is to provide a good and inexpensive electronic circuit device for a compressor.

  In order to solve the above-described conventional problems, an electronic circuit device for a compressor according to the present invention includes a printed circuit board, an electronic component mounted on the printed circuit board, and mounted on the printed circuit board, and heat generated by the electronic component is conducted. A heat sink, a storage box that stores the printed circuit board and has an opening on at least one surface thereof, a rubber bush that is disposed in the storage box and supports the printed circuit board from the side opposite to the opening, and the storage box An aluminum plate attached so as to close the opening; and an insulating sheet sandwiched and fixed between the heat sink and the aluminum plate, and the heat sink is interposed between the aluminum sheet and the aluminum sheet by the rubber bush. Formed so that the heat of the heat sink is conducted to the aluminum plate through the insulating sheet by being in pressure contact with the plate In the case where the heat generated from the semiconductor element is radiated to the outside of the storage box via the heat sink and the aluminum plate, the temperature change occurs, and there is a difference in the linear expansion coefficient between the heat sink and the storage box. However, the rubber bush serves as a cushioning material, so that no gap is formed between the heat sink and the aluminum plate, and an excessive stress is not applied to the printed circuit board and the heat sink.

  Furthermore, since the heat sink and the aluminum plate are insulated by the insulating sheet, even if the heat sink contacts the charging part inside the storage box, the insulating property of the aluminum plate that may be touched by the hand can be maintained. .

  The electronic circuit device for a compressor according to the present invention can dissipate heat generated by a semiconductor element mounted on a printed circuit board to the outside of the storage box, and at the same time, generates heat from the electronic components and changes in the outside temperature of the storage box. Even in this case, heat conduction between the heat sink and the aluminum plate can be ensured and excessive stress due to temperature changes can be prevented, so that a reliable electronic circuit device for a compressor can be reliably controlled by suppressing temperature rise. Can be provided.

  Furthermore, it is possible to provide a highly safe electronic circuit device for a compressor that can maintain the insulating properties of an aluminum plate that may be touched by the hand.

1 is an exploded perspective view of an electronic circuit device for a compressor according to Embodiment 1 of the present invention. The perspective sectional view of the electronic circuit device for compressors in the embodiment The perspective view of the rubber bush in the embodiment Sectional drawing in the AA line in FIG. Front view of aluminum plate in the same embodiment Sectional drawing in the BB line in FIG. Assembly drawing when inserting printed circuit board storage box An exploded perspective view of a conventional electronic circuit device for a compressor

  1st invention accommodates the printed circuit board, the electronic component mounted in the said printed circuit board, the heat sink which is mounted in the said printed circuit board, and the heat_generation | fever of the said electronic component conducts, and the said printed circuit board, At least one surface A storage box provided with an opening, a rubber bush disposed in the storage box and supporting the printed circuit board from the side opposite to the opening, an aluminum plate attached to close the opening of the storage box, An insulating sheet sandwiched and fixed between the heat sink and the aluminum plate, and by the rubber bush, the heat sink is in pressure contact with the aluminum plate via the insulating sheet, so that the heat of the heat sink is the insulating sheet. Since it is formed so as to conduct to the aluminum plate through the semiconductor, the semiconductor mounted on the printed circuit board The heat generated from the element can be dissipated outside the storage box, and even when the heat generated from the electronic components or the outside temperature of the storage box changes, heat conduction between the heat sink and the aluminum plate is ensured, and excessive stress due to temperature changes Therefore, it is possible to provide a highly reliable electronic circuit device for a compressor that reliably suppresses temperature rise.

  In addition, since the heat sink and the aluminum plate are insulated by the insulating sheet, even if the heat sink contacts the live part inside the storage box, the insulating property of the aluminum plate that can be touched by the hand can be maintained. A highly safe electronic circuit device for a compressor can be provided.

  According to a second aspect of the present invention, a plurality of protrusions are provided on the inner surface of the aluminum plate on the storage box side, and the insulating sheet is disposed within a range surrounded by the protrusions, whereby the insulating sheet is placed in the aluminum plate. Since it is formed so as to be arranged at a predetermined position, it is possible to facilitate the mounting of the insulating sheet to the aluminum plate and to make the mounting position of the insulating sheet accurate, and further assembly work. It is possible to provide an electronic circuit device for a compressor that is good, inexpensive, and highly safe.

  In the third aspect of the invention, an adhesive having high thermal conductivity is applied between the insulating sheet and the heat sink, so that the adhesive fills the gap between the heat sink and the insulating sheet that occurs when the heat sink is tilted or deformed. Thus, heat conduction between the heat sink, the aluminum plate, and the insulating sheet can be ensured, and a highly reliable electronic circuit device for a compressor can be provided.

  In the fourth invention, since a thermal diffusion compound is applied between the insulating sheet and the aluminum plate, the thermal resistance between the aluminum plate and the insulating sheet is further reduced, and a highly reliable electronic circuit device for a compressor is provided. be able to.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
1 is an exploded perspective view of an electronic circuit device for a compressor according to a first embodiment of the present invention, FIG. 2 is a perspective sectional view of the electronic circuit device for a compressor according to the first embodiment, and FIG. 3 is the same embodiment. 4 is a cross-sectional view taken along the line AA in FIG. 3, FIG. 5 is a front view of the aluminum plate in the same embodiment, and FIG. 6 is a cross-sectional view taken along the line BB in FIG. FIG. 7 is an assembly view of the printed circuit board when the storage box is inserted.

  1 to 7, an opening 9 that is slightly larger than the size of the printed circuit board 5 is accommodated in a storage box 1 that is injection-molded with a resin such as a modified polyphenylene ether resin. have. The printed circuit board 5 is made of a glass cloth / glass nonwoven cloth epoxy resin, and a connector 13 is mounted thereon.

  The storage box 1 has an opening at a position facing the connector 13 and forms a cord lead-out portion 17.

  A plurality of board mounting holes for mounting the board are provided at four corners of the printed circuit board 5, and one of the board mounting holes 5 a is fixed to the storage box 1 by the board fixing screw 21. Has been.

  In addition, the storage box 1 has a sandwiching portion 23 having a width slightly larger than the thickness of the printed circuit board 5 at a position corresponding to the corner 5b which is the corner adjacent to the corner fixed by the substrate fixing screw 21. ing.

  Projecting portions 1a projecting toward the opening are integrally formed at the two bottom portions of the storage box 1, and a cylindrical rubber bush 24 having a hollow portion is provided on the projecting portion 1a. Are fitted into the cavity of the rubber bush 24, respectively.

  The height of the protruding portion 1 a is higher than the height of the rubber bush 24, and the tip protrudes from the rubber bush 24, and this protruding portion fits into the board mounting hole 5 c of the printed board 5. . The rubber bush 24 is sandwiched and compressed by the storage box 1 and the printed board 5.

  Further, the hole diameter of the board mounting hole 5c is designed so that there is an appropriate clearance when the protruding part 1a is inserted (for example, if the diameter of the protruding part 1a is 3.5 mm, the hole diameter of the board mounting hole 5c). Is 4 mm).

  On the printed circuit board 5, a substantially U-shaped heat sink 25 formed by pressing an aluminum alloy is fixed by screws or caulking (not shown), and a second printed circuit board 26 is mounted by soldering. ing.

  A semiconductor element 29 for driving a compressor, which is an electronic component, is mounted on the second printed circuit board 26, and the semiconductor element 29 is closely attached and fixed to the inner wall side of the heat sink 25 by screws 27. It is arranged so that it can be exchanged.

  Mounting holes 33 are formed at the four corners of the opening 9 of the storage box 1, and holes 41 are formed at the four corners of the pressed aluminum alloy aluminum plate 37. The aluminum plate 37 is fixed to the storage box 1 with the aluminum plate fixing screw 45 so that the opening 9 can be closed.

  An insulating sheet 49 is attached in contact with the inner surface of the aluminum plate 37 (for example, two sheets are overlapped) with a fixing screw 51. The insulating sheet 49 has an electrical insulating performance (for example, 1750V, Has a 1-minute dielectric strength test).

A plurality of projections 37a are formed on the inner side surface of the aluminum plate 37 by press working or the like, and the insulating sheet 49 is attached to the inner side surrounded by the projections 37a with its position regulated by the projections 37a. ing.

  The insulating sheet 49 is preliminarily coated with a heat diffusion compound 55 to improve the close contact between the insulating sheet 49 and the aluminum plate 37 and improve the heat conduction between the insulating sheet 49 and the aluminum plate 37.

  An adhesive 60 having high thermal conductivity is applied to the surface of the heat sink 25 that faces the insulating sheet 49.

  The operation and action of the electronic circuit device for a compressor configured as described above will be described below.

  In assembling the electronic circuit device for the compressor, first, the rubber bush 24 is inserted into the protruding portion 1 a of the storage box 1. Next, the printed circuit board 5 on which the heat sink 25 having the second printed circuit board 26 fixed to the inner wall portion is mounted can be electrically connected to the outside with the connector 13 facing the cord drawing portion 17 of the storage box 1. In addition, the connector 13 is inserted from the opening 9 of the storage box 1.

  At this time, by inserting the connector 13 from the connector 13 side into the opening 9 of the storage box 1 and inserting the connector 13 obliquely, the corner 5b of the sandwiching portion 23 is loosely fitted into the sandwiching portion 23, and then the connector 13 is inserted into the storage box. 1 is placed in a predetermined position so as to be parallel to 1, but at the same time, the two protruding portions 1 a of the storage box 1 are inserted into the board mounting holes 5 c in the printed board 5. Then, the board mounting hole 5 a of the printed board 5 is fixed to the storage box 1 by the board fixing screw 21.

  Thereafter, the adhesive 60 is applied to the upper surface 25a which is a surface facing the insulating sheet 49 of the heat sink 25.

  On the other hand, in the work of attaching the insulating sheet 49 to the aluminum plate 37, the insulating sheet 49 is attached by the aluminum plate fixing screw 45 in the range surrounded by the projections 37a on the inner surface of the aluminum plate 37, but the fixing screw 51 is tightened. In this case, the insulating sheet 49 tries to rotate in the same direction as the rotation direction of the fixing screw 51 around the fixing screw 51. However, since the rotation is prevented by the projection 37a, the insulating sheet 49 is attached to the aluminum plate 37 at a correct position. It is attached. A thermal diffusion compound 55 is applied in advance to the surface of the insulating sheet 49 that contacts the aluminum plate 37.

  Before the adhesive 60 applied to the heat sink 25 is solidified, the aluminum plate 37 with the insulating sheet 49 attached to the inner surface is attached to the opening 9 of the storage box 1 with the aluminum plate fixing screw 45. At this time, the heat sink 25 Since the heat sink 25 is pushed by the aluminum plate 37, the upper surface of the rubber bush 24 below the printed circuit board 5 is protruded in the vertical direction slightly beyond the opening 9 of the storage box 1 (for example, about 2 mm). Will be compressed vertically.

  At this time, the adhesive 60 applied to the upper surface 25 a of the heat sink 25 is compressed by the aluminum plate 37 to which the insulating sheet 49 is attached and the heat sink 25. If the perpendicularity of the heat sink 25 to the printed circuit board 5 is poor at this time, the aluminum plate 37 to which the insulating sheet 49 is attached and the heat sink 25 are in point contact or line contact, and a gap is formed between them. 60 is compressed, and the adhesive 60 having high thermal conductivity fills this gap.

  In the electronic circuit device for a compressor assembled as described above, the semiconductor element 29 generates heat when it is energized and driven. This heat is transferred to the aluminum plate 37 via the heat sink 25, and the storage box 1 Since the heat is radiated to the outside, the temperature of the semiconductor element 29 does not rise excessively, the temperature of the semiconductor element 29 can be reduced, and the reliability of the compressor electronic circuit device can be improved.

  Further, since an insulating sheet 49 is attached between the aluminum plate 37 and the heat sink 25, it is possible to ensure insulation of the aluminum plate 37 even if the aluminum plate 37 and the charging part of the printed circuit board 5 are short-circuited. Even when the electronic circuit device for a compressor is installed in an environment where the hand touches the aluminum plate 37, a safer electronic circuit device for the compressor can be provided.

  In addition, the printed board 5 has a specification in which the board mounting hole 5a is strongly fixed only at one place by the board fixing screw 21 when attached to the storage box 1, and the linear expansion of the printed board 5 and the storage box 1 is achieved. Even when the coefficients are different, since stress due to thermal expansion is not applied to the portion of the board mounting hole 5a, the printed board 5 is not damaged, the heat generated by the electronic components mounted on the printed board 5, and the storage box Even when the temperature of the electronic circuit device for compressor itself rises due to the temperature rise of the outside of 1, the reliability of the electronic circuit device for compressor can be ensured.

  Further, when the temperature of the electronic circuit device for the compressor rises, the rubber bush 24 absorbs the difference in thermal expansion due to the difference in the linear expansion coefficient between the storage box 1 and the heat sink 25, so that the heat sink 25 and the insulating sheet 49 is securely attached to the aluminum plate 37 to which the semiconductor element 29 is attached, the heat generated by the semiconductor element 29 is reliably transferred to the aluminum plate 37, and an excessive temperature rise of the semiconductor element 29 is prevented. Reliability can be improved.

For example, when the temperature of the electronic circuit device for the compressor rises due to energization or a surrounding temperature rise, the storage box 1 and the heat sink 25 thermally expand in the vertical direction, but the linear expansion coefficient of the resin storage box 1 is about 7 since the linear expansion coefficient of the aluminum heat sink 25 while a × ^{-5 /} ° C. is about 2 × ^{-5 /} ° C., in the case where the vertical dimension of the heat sink 25 is 40mm for example, the electronic compressor When the temperature of the circuit device rises by 50K, the vertical dimension of the storage box 1 is 0.1 mm longer than the vertical dimension of the heat sink 25, but the rubber bush 24 is compressed in advance by 2 mm in the vertical direction. Since it is pushed upward vertically, the compression dimension is 1.9 mm, and between the heat sink 25 and the aluminum plate 37 to which the insulating sheet 49 is attached. Never gap occurs.

  In addition, when the rubber bush 24 is attached, the rubber bush 24 is simply inserted into the protruding portion 1a of the storage box 1. Therefore, the rubber bush 24 can be easily assembled and the workability of the compressor electronic circuit device can be improved. be able to.

  In addition, positioning in mounting the printed circuit board 5 by the projecting portion 1a has an effect of preventing the printed circuit board 5 from moving in the horizontal direction, and can improve the assembly workability of the electronic circuit device for the compressor. .

  Further, when attaching the insulating sheet 49 to the aluminum plate 37, the mounting position of the insulating sheet 49 can be reliably attached to a predetermined place by the protrusion 37a only with the fixing screw 51, so that the workability of attaching the insulating sheet 49 is improved. In addition, the insulating sheet 49 can be attached at an accurate position, and an electronic circuit device for a compressor that is safer against electric shock can be provided.

  Further, unless the heat sink 25 is originally attached to the printed circuit board 5 vertically, the upper surface 25a of the heat sink 25, the aluminum plate 37, and the insulating sheet 49 are not in surface contact, but the heat sink 25 is inclined to the printed circuit board 5 due to assembly variations. Even when the contact between the upper surface 25a of the heat sink 25 and the aluminum plate 37 and the insulating sheet 49 becomes a line contact or a point contact, the gap generated between the heat sink 25 and the insulating sheet 49 is bonded with a high thermal conductivity. Since the agent 60 is buried, the heat generated in the semiconductor element 29 can be reliably conducted from the heat sink 25 to the aluminum plate 37, the temperature of the semiconductor element 29 is prevented from rising excessively, and a highly reliable electronic circuit for a compressor. An apparatus can be provided.

  In addition, since the thermal diffusion compound 55 is applied to the contact surface between the insulating sheet 49 and the aluminum plate 37, a gap generated between the insulating sheet 49 and the aluminum plate 37 is removed even when the aluminum plate 37 is deformed. Therefore, the heat generated in the semiconductor element 29 can be reliably conducted from the heat sink 25 to the aluminum plate 37, the temperature of the semiconductor element 29 can be prevented from rising excessively, and the electronic circuit device for a compressor having high reliability. Can be provided.

  As described above, the electronic circuit device for a compressor according to the present invention can improve heat dissipation, improve reliability, improve safety against electric shock, and improve assembly workability. The present invention can be applied not only to an electronic circuit device for a compressor but also to other electronic circuit devices using semiconductor elements.

DESCRIPTION OF SYMBOLS 1 Storage box 1a Protrusion part 5 Printed circuit board 5c Board attachment hole 24 Rubber bush 25 Heat sink 29 Semiconductor element (electronic component)
37 Aluminum plate 37a Protrusion 49 Insulation sheet 55 Thermal diffusion compound 60 Adhesive

Claims (4)

A printed circuit board, an electronic component mounted on the printed circuit board, a heat sink that is mounted on the printed circuit board and conducts heat generated from the electronic component, and stores the printed circuit board, and includes an opening on at least one surface. A box, a rubber bush for supporting the printed circuit board from the side opposite to the opening, an aluminum plate attached so as to close the opening of the storage box, and the heat sink and the aluminum plate are sandwiched and fixed. An insulating sheet, and the rubber bush is formed so that heat of the heat sink is conducted to the aluminum plate through the insulating sheet when the heat sink is in pressure contact with the aluminum plate through the insulating sheet. Electronic circuit device for compressor. A plurality of protrusions are provided on the inner surface of the aluminum plate on the storage box side, and the insulating sheet is disposed within a range surrounded by the protrusions, whereby the insulating sheet is placed at a predetermined position in the aluminum plate. The electronic circuit device for a compressor according to claim 1, wherein the electronic circuit device is formed so as to be disposed at a position. The electronic circuit device for a compressor according to claim 1 or 2, wherein an adhesive is applied between the insulating sheet and the heat sink. The electronic circuit device for a compressor according to any one of claims 1 to 3, wherein a heat diffusion compound is applied between the insulating sheet and the aluminum plate.

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