JP2008277338A - Method for assembling electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for assembling an electronic device under a state where the heat dissipation plane of an electronic component is made to be uniformly in contact with a heat dissipating plate. <P>SOLUTION: A step for tightening the enclosure portion of each electronic component with a screw, penetrating a heat dissipating plate 4 from the other side thereof, in a state where each heat dissipation plane of a plurality of electronic components 2 and 3 is in surface contact with one side of the heat dissipation plate 4; a step for inserting each lead terminal of each electronic component which is tightened to the heat dissipating plate 4 into corresponding through-hole of a printed wiring board to penetrate the through-hole; a step for positioning the printed wiring board 1 with respect to the heat dissipating plate 4, by interposing a spacer 6 between them and tightening the printed wiring board 1 to the heat dissipating plate 4 with a screw; and a step for soldering the lead terminal of each electronic component penetrating the through-hole 101 of the printed wiring board 1 to the printed wiring board 1 are performed sequentially. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for assembling an electronic device including a printed wiring board, an electronic component mounted on the printed wiring board, and a heat dissipation plate thermally coupled to a heat dissipation surface of the electronic component.

  In an electronic device equipped with a circuit through which a large current flows, such as a rectifier circuit or an inverter circuit, a heat sink is thermally coupled to an electronic component that generates heat, such as a diode, a power transistor, or a power MOSET mounted on a printed wiring board. Thus, the heat generated from each electronic component is released to the heat sink, thereby preventing the temperature of the electronic component from exceeding the allowable value. In this case, in order to accommodate the electronic device in the case in a compact manner, it is preferable that the heat radiating plate and the printed wiring board are arranged in parallel to face each other.

As a method for assembling this type of electronic device, the one disclosed in Patent Document 1 is known. In the electronic device disclosed in Patent Document 1, the lead terminal of the electronic component is led out from one end side in the width direction perpendicular to the thickness direction of the exterior part in a direction perpendicular to the thickness direction. In the assembling method shown in FIG. 1, first, the lead wires of the respective electronic components are bent at right angles to one side in the thickness direction of the exterior portion so that the lead terminals can be inserted into the through holes of the printed wiring board. Next, with one surface (heat radiating surface) in the thickness direction of the exterior part of each electronic component in contact with the heat radiating plate, temporarily tighten one screw penetrating the other end in the width direction of the exterior part of each electronic component. Temporarily fix each electronic component to the heat sink. After that, place the printed wiring board parallel to the heat sink, insert the tip of each electronic component lead terminal into the through hole of the printed wiring board, and tighten the screws through the holes provided in the printed wiring board. , Fix each electronic component to the heat sink. Next, the tips of the lead terminals of each electronic component are soldered to the printed wiring board.
JP 2006-196517 A

  In the method disclosed in Patent Document 1, since the lead terminals of the electronic components are led out in a direction perpendicular to the thickness direction of the exterior portion, the lead terminals of each electronic component are inserted into the through holes of the printed wiring board. It was necessary to perform a bending process so that it was possible, and it was troublesome.

  In the method disclosed in Patent Document 1, a screw tightening tool such as a screwdriver is inserted when final tightening of a screw for fixing an electronic component and when removing the electronic component from a heat sink during inspection and repair. The number of components that can be mounted on the printed wiring board when there are a large number of electronic components is required. There was a problem that was limited.

  Further, in the method disclosed in Patent Document 1, each electronic component is fixed to the heat sink with one screw that penetrates the exterior portion on the end side opposite to the side from which the lead terminal is derived. Therefore, it is difficult to make the entire heat dissipation surface of the electronic component uniformly contact the heat sink, and if a gap is formed between a part of the heat dissipation surface of the electronic component and the heat sink, There was a problem that the heat dissipation from the electronic parts deteriorated.

  An object of the present invention is to uniformly dissipate the heat dissipation surface of each electronic component on the heat dissipation plate without performing a process of bending the lead terminal of each electronic component or providing a hole for inserting a screw tightening tool in the printed wiring board. It is an object of the present invention to provide an electronic device assembling method in which an electronic device can be assembled while being in contact with the electronic device.

  The present invention relates to a printed wiring board and a plurality of electronic components soldered to the printed wiring board in a state where the lead terminal protrudes from the exterior portion and the lead terminal passes through a through hole provided in the printed wiring board. And a method of assembling an electronic device including a heat sink provided in common to a plurality of electronic components and thermally coupled to an exterior portion of each electronic component.

  In the present invention, as each electronic component, one surface in the thickness direction of the exterior portion is a heat radiating surface, and each lead terminal is straight from the surface opposite to the heat radiating surface in a direction perpendicular to the heat radiating surface. And having a structure in which a plurality of female screw members having screw holes opened on the heat radiating surface side of the exterior portion at the shaft center portion are embedded and fixed in the exterior portion. In the method of the present invention, each heat dissipating surface of each of the plurality of electronic components is in surface contact with one surface of the heat dissipating plate. The process of fastening with a plurality of component fixing screws screwed into the screw holes of the female screw member, and inserting each lead terminal of each electronic component fastened to the heat sink into the corresponding through hole of the printed wiring board The printed wiring board is formed by positioning the printed wiring board with respect to the heat radiating plate by interposing a spacer between the printed wiring board and the heat radiating plate and fastening the printed wiring board to the heat radiating plate with screws. Are fixed to the heat radiating plate, and a step of soldering the lead terminals of the electronic components penetrating through holes of the printed wiring board to the printed wiring board is sequentially performed.

  As described above, in the present invention, as each electronic component, one surface in the thickness direction of the exterior portion is a heat radiating surface, and each lead terminal is perpendicular to the heat radiating surface from the surface opposite to the heat radiating surface. Printed wiring in which the lead terminals of each heat-dissipating element fixed to the heat-dissipating plate are arranged in parallel with the heat-dissipating plate, without bending the lead terminals of each electronic component. It can be inserted into the through hole of the substrate.

  In addition, when the lead terminal is bent and formed, the electronic component is temporarily fixed (electronic component) in order to cope with the misalignment of the leading end of the lead terminal inevitably caused by a springback or the like during the bending process. It is necessary to perform the work of inserting the tip of the lead terminal of the electronic component into the through hole of the printed wiring board (with a certain amount of displacement between the heat sink and the heat sink). If each lead terminal is projected linearly from the surface opposite to the heat dissipation surface in a direction perpendicular to the heat dissipation surface, the position deviation of the tip of each lead terminal will not vary during manufacturing. Therefore, if there is a certain margin in the diameter of the through hole of the printed wiring board, the tip of each lead terminal of the electronic component is fixed with the electronic component fixed to the heat sink in advance. You can perform the work of inserting the through-hole of the printed wiring board. Therefore, according to the present invention, there is no need to perform a process of temporarily tightening a screw for fixing an electronic component, and the number of assembling steps can be reduced.

  In the present invention, each electronic component is fixed to the heat sink with a plurality of screws, the lead terminals of each electronic component are inserted into the through holes of the printed wiring board, and the printed wiring board is positioned and fixed to the heat sink. After that, the lead terminals of each electronic component are soldered to the printed wiring board, so that the entire heat radiation surface of the electronic component is always in contact with the heat radiation plate to prevent variation in heat dissipation. . In addition, it prevents distortion from remaining in the soldered part between each lead terminal and the printed wiring board, and cracks occur in the soldered part between the lead terminal and the printed wiring board due to deterioration over time. It can prevent peeling.

  Furthermore, in the present invention, the electronic component is fastened to the heat sink by a screw penetrating the heat sink from the surface opposite to the surface where the electronic component of the heat sink is disposed, so a screw tightening tool is inserted into the printed wiring board. Even if no hole is provided, it is possible to easily remove the electronic component from the heat sink when the electronic device is inspected and repaired.

  In the above method, after the step of fastening the electronic component to the heat sink with the component fixing screw, the lead terminals of each electronic component fastened to the heat sink are inserted into the corresponding through holes of the printed wiring board. The step of penetrating the through hole and the step of positioning and fixing the printed wiring board with respect to the heat radiating plate are performed, the step of fastening electronic components to the heat radiating plate with the component fixing screws, and the printed wiring board. It is also possible to replace the step of positioning and fixing to the heat sink.

  That is, in another preferred aspect of the present invention, the step of inserting each lead terminal of each electronic component into the corresponding through hole of the printed wiring board and penetrating the through hole, and between the printed wiring board and the heat sink A step of positioning the printed wiring board with respect to the heat sink by interposing a spacer, and fixing the printed wiring board to the heat sink by fastening the printed wiring board to the heat sink with a screw; Screws that penetrate the heat sink from the surface side are screwed into the screw holes of each female screw member embedded in the electronic component, and each heat dissipating surface of each of the electronic components is in surface contact with one surface of the heat dissipating plate. The process of fastening the exterior part of the component to the heat sink with a plurality of screws, and soldering the lead terminals of each electronic component passing through the through hole of the printed wiring board to the printed wiring board Sequentially performed and a step of. Even when such a method is used, the same effect as described above can be obtained.

  The heat radiating plate may be provided independently of the case of the electronic device that accommodates the printed wiring board and the electronic component, and is a plate (side plate, bottom plate, etc.) constituting one wall portion of the case. Also good.

  According to the present invention, as each electronic component, one surface in the thickness direction of the exterior portion is a heat radiating surface, and each lead terminal is perpendicular to the heat radiating surface from the surface opposite to the heat radiating surface. The lead terminals of the electronic components are fixed to the heat sink in advance without bending the lead terminals of the electronic components using the ones that are linearly led to the printed circuit board. Since the work of inserting into the through hole is performed, the step of temporarily tightening the screw for fixing the electronic component can be omitted, and the number of assembly steps can be reduced.

  In the present invention, each electronic component is fixed to the heat sink with a plurality of screws, the lead terminals of each electronic component are inserted into the through holes of the printed wiring board, and the printed wiring board is positioned and fixed to the heat sink. After that, the lead terminals of each electronic component are soldered to the printed circuit board, so that the entire heat dissipation surface of the electronic component is always in contact with the heat dissipation plate to prevent variations in heat dissipation. In addition, it prevents strain from remaining in the soldered part between each lead terminal and the printed wiring board, and cracks occur in the soldered part between the lead terminal and the printed wiring board due to aging. The layer can be prevented from peeling off.

  Furthermore, in the present invention, the electronic component is fastened to the heat sink by a screw penetrating the heat sink from the surface opposite to the surface where the electronic component of the heat sink is disposed, so a screw tightening tool is inserted into the printed wiring board. Even if no hole is provided, it is possible to easily remove the electronic component from the heat sink at the time of inspection and repair of the electronic device.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
1 and 2 are cross-sectional views for explaining embodiments of the present invention. In these drawings, 1 is a printed wiring board, 2 and 3 are electronic components that generate heat, and 4 is a plurality of electronic components 2 and 3. On the other hand, a common heat sink 5 is a component fixing screw for fastening an electronic component to the heat sink, and 6 is interposed between the heat sink 4 and the printed wiring board 1 to dispose the printed wiring board 1 to the heat sink 4. , 7 is a screw for fastening the printed wiring board 1 to the heat radiating plate 4, 8 is a washer fitted to the screw 7, and 9 is a nut screwed to the screw 7.

  The electronic components 2 and 3 are exterior parts 200 and 300 each housing a main body (not shown) of a semiconductor element that generates heat, such as a diode or MOSFET, and a plurality of leads protruding from the exterior parts 200 and 300, respectively. Terminals 201 and 301 are included. In the illustrated example, the plurality of lead terminals 201 of the electronic component 2 are arranged in a row in a direction perpendicular to the drawing sheet, and the plurality of lead terminals 301 of the electronic component 3 are arranged in two rows in a direction perpendicular to the drawing sheet. They are arranged side by side.

  In the electronic components 2 and 3 used in the present invention, one surface 200a and 300a in the thickness direction of the exterior portions 200 and 300 is a flat heat dissipation surface, and the lead terminals 201 and 301 are the heat dissipation surfaces 200a and 200a. The surfaces 200b and 300b opposite to 300a are provided so as to protrude linearly in a direction (thickness direction) perpendicular to the heat radiating surfaces 200a and 300a.

  In addition, a plurality of female screw members 202 and 302 extending through each of the exterior parts 200 and 300 of the electronic components 2 and 3 in the thickness direction are embedded and fixed. Screw holes 202a and 302a are formed in the respective axial center portions of the female screw members 202 and 302. The screw holes of these female screw members are disposed on the heat radiation surfaces 200a and 300a side of the exterior portion and on the surface opposite to the heat radiation surfaces. Openings are made on the 200b and 300b sides. It should be noted that the screw holes in the axial center portions of the female screw members 202 and 302 may be open at least on the heat radiating surface side, and may be closed on the surface side opposite to the heat radiating surface.

  Generally, heat generating components attached to a printed wiring board have various heights, and electronic components having different heights are often mixed. In addition, even in the same type of electronic component, the height often varies from product to product. In the present embodiment, the height of the electronic component 2 is lower than the height of the electronic component 3.

  The electronic components 2 and 3 are arranged in a state in which the heat radiation surfaces 200a and 300a of the respective exterior portions 200 and 300 are in surface contact with one surface 4a of the heat radiation plate 4, and each female screw member from the other surface 4b side of the heat radiation plate 4 The heat sink 4 is fastened to the heat sink 4 by the component fixing screws 5 screwed into the screw holes in the axial center portions of 202 and 302.

  The heat radiating plate 4 is a plate-like member made of a material having good thermal conductivity, and this heat radiating plate may constitute one wall portion of the case of the electronic device and is provided independently of the case. A slab may be used.

  When each electronic component is fastened to the heat radiating plate 4 with screws 5, the entire heat radiating surface of each electronic component is embedded in each electronic component so that the entire heat radiating surface is in contact with one surface 4a of the heat radiating plate. The number of female screw members and the position where a plurality of female screw members are arranged are set. For example, when the exterior part of the electronic component is formed to have a columnar shape, at least three female screw members are provided in a uniform arrangement (at equal angular intervals). When the exterior part of the electronic component has a rectangular parallelepiped shape, at least four female screw members are arranged in the vicinity of the four corners of the exterior part.

  In order to screw the component mounting screws 5 into the screw holes of the axial center portions of the female screw members 202 and 302 in the exterior parts 200 and 300 of the electronic components 2 and 3, the heat sink 4 is penetrated in the thickness direction, and the female screws of the respective electronic components A screw insertion hole 401 that is aligned with a screw hole inside the member is formed. The heat sink 4 is also formed with a plurality of holes 402 through which screws 7 for fastening the printed wiring board 1 to the heat sink 4 are passed.

  The printed wiring board 1 is formed with through-holes 101 through which the lead terminals of the electronic components 2 and 3 pass, and a conductive layer 102 is plated on the inner surface of each through-hole and the peripheral portions of the openings at both ends thereof. Is formed. The printed wiring board 1 further has a hole 103 through which a screw 7 for fastening the printed wiring board to the heat sink is passed.

  The spacer 6 is formed in a sleeve shape, and a hole through which the screw 7 penetrating the hole 103 of the printed wiring board passes is formed in the axial center portion thereof.

  In the assembling method of the present invention, first, as shown in FIG. 1, the electronic components 2, 3 are brought into contact with the one surface 4 a of the heat radiating plate 4 with the heat radiating surfaces 200 a, 300 a of the plurality of electronic components 2, 3. The exterior portions 200 and 300 are fastened with a plurality of component fixing screws 5 that pass through the heat sink 4 from the other side 4b of the heat sink 4 and are screwed into the screw holes of the female screw members 202 and 302. The electronic components 2 and 3 are fixed to the heat sink 4.

  Next, after the lead terminals 201 and 301 of the electronic components 2 and 3 fastened to the heat sink 4 are inserted into the corresponding through-holes 101 of the printed wiring board 1 to penetrate the through-holes, FIG. As shown, the printed wiring board 1 is fastened to the heat sink 4 with screws 7 in a state where the printed wiring board 1 is positioned with respect to the heat sink 4 with a spacer 6 interposed between the printed wiring board 1 and the heat sink 4. By doing so, the process of fixing the printed wiring board 1 with respect to the heat sink 4 is performed. In the process of fastening the printed wiring board 1 to the heat sink 4 with screws 7 and fixing the printed wiring board 1 to the heat sink 4, between the hole 103 of the printed wiring board 1 and the printed wiring board 1 and the heat sink 4. A screw 7 is inserted into a hole inside the interposed spacer 6 and a hole 402 of the heat sink 4, and a washer 8 is fitted to the tip of each screw 7 protruding from the heat sink 4, and then the tip of each screw 7 is inserted. The nut 9 is screwed onto and tightened.

  After fixing the printed wiring board 1 to the heat sink 4 as described above, the step of soldering the lead terminals of the respective electronic components that have passed through the through holes 101 of the printed wiring board 1 to the electrode portions 102 of the printed wiring board To do. In FIG. 2, reference numeral 10 denotes a soldering portion between the lead terminal of each electronic component and the electrode portion 102 of the printed wiring board.

  When the electronic components 2 and 3 having different heights are connected to the printed wiring board 1 as described above, the lead terminals of the electronic components 2 and 3 are first soldered to the printed wiring board 1 as shown in FIG. 4, it is conceivable that the printed wiring board 1 is fastened to the heat sink 4 with screws 7 and the electronic components 2 and 3 are fastened to the heat sink 4 with screws 5. In this case, the heat radiating surface of the electronic component 2 having a low height cannot be brought into contact with the heat radiating plate 4. If the electronic component 2 is forcibly fastened to the heat sink 4 in such a state, stress is generated in the soldering part 10 connecting the lead terminal 201 to the printed wiring board. There is a risk of cracks 11. The lead terminals 201 and 301 of the electronic components 2 and 3 are printed with the heat dissipation surface 202a of the shorter electronic component 2 and the heat dissipation surface 302a of the taller electronic component 3 positioned on the same plane. Although soldering to the board 1 is also conceivable, it is difficult to solder to the printed wiring board in a state in which the positions of the heat radiation surfaces of the electronic components 2 and 3 are accurately located on the same plane. Further, even if the heights of the electronic components 2 and 3 attached to the printed wiring board 1 are the same, there is an error in the dimension of the exterior part of each electronic component, so the case shown in FIGS. 3 and 4 is used. Therefore, it is unavoidable that stress is generated in the soldering portion between the lead terminal and the printed wiring board 1.

  On the other hand, according to the method of the present invention, each electronic component is fixed to the heat radiating plate with a plurality of screws, then the lead terminals of each electronic component are inserted into the through holes of the printed wiring board, and the printed wiring board is further radiated. Since the lead terminals of each electronic component are soldered to the printed wiring board after positioning and fixing to the board, the heat radiation surface of the electronic component is always kept in uniform contact with the heat sink, resulting in variations in heat dissipation. Can be prevented. In addition, since it is possible to prevent distortion from remaining in the soldered portion between each lead terminal and the printed wiring board, cracks may occur in the soldered portion between the lead terminal and the printed wiring board due to deterioration over time. The conductive layer can be prevented from peeling off.

  In the above embodiment, after performing the step of fastening the electronic components 2 and 3 to the heat sink 4 with the component fixing screws 5, the lead terminals of the electronic components 2 and 3 fastened to the heat sink 4 are printed wiring. The step of inserting the corresponding through hole in the board and penetrating the through hole and the step of positioning and fixing the printed wiring board with respect to the heat sink are sequentially performed. The step of fastening to the heat sink and the step of positioning and fixing the printed wiring board with respect to the heat sink can be interchanged.

  That is, the step of inserting each lead terminal of the electronic components 2 and 3 into the corresponding through hole 101 of the printed wiring board 1 to penetrate the through hole, and the spacer 6 between the printed wiring board 1 and the heat sink 4 The printed wiring board 1 is positioned with respect to the heat sink 4 by interposing, and the printed wiring board 1 is fixed to the heat sink 4 by fastening the printed wiring board 1 to the heat sink 4 with screws 7 and nuts 9. A plurality of electronic components 2 by screwing screws 5 penetrating the heat dissipation plate 4 from the other surface 4b side of the heat dissipation plate 4 into the screw holes of the female screw members 202 and 302 embedded in the electronic components 2 and 3, respectively. , 3 with the heat radiating surfaces of the electronic components 2, 3 being fastened to the heat radiating plate with a plurality of screws 5 in a state where the heat radiating surfaces of the electronic components 2, 3 are in surface contact with the one surface 4 a of the heat radiating plate 4. The through hole may be sequentially performed and the step of soldering the lead terminals to the printed circuit board of the electronic component through the. Even when such a method is used, the same effect as described above can be obtained.

  In the above embodiment, the two electronic components 2 and 3 are attached to the printed wiring board. However, the present invention can also be applied to the case where the number of electronic components attached to the printed wiring board is three or more.

  In the above embodiment, the printed wiring board 1 is fastened to the heat sink 4 with screws 7 and nuts 9, but the hole 402 provided in the heat sink 4 is a screw hole and the tip of the screw 7 is the screw hole. The printed wiring board 1 may be fastened to the heat sink 4 by being screwed into the heat sink 4.

In the assembly method of this invention, it is sectional drawing which showed the state which fastened the electronic component to the heat sink with the screw. In the assembling method of this invention, after positioning and fixing a printed wiring board with respect to a heat sink, it is sectional drawing which showed the state which soldered the lead terminal of each electronic component to the printed wiring board. It is sectional drawing which showed the state which soldered the lead terminal of each electronic component to the printed wiring board, before fastening an electronic component to a heat sink with a screw | thread irrespective of the assembly method of this invention. It is sectional drawing which showed the state which fastened the heat generating member to the heat sink with the screw following the process shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printed wiring board 2, 3 Electronic component 200, 300 Electronic component main body 200a, 300a Heat radiation surface 201, 301 Lead terminal 202, 302 Female screw member 4 Heat radiation plate 5 Screw 6 Spacer 7 Screw

Claims (3)

A printed wiring board and a lead terminal that protrudes from an exterior portion, and the lead terminal penetrates through a through hole provided in the printed wiring board and is soldered to the printed wiring board and requires a plurality of heat dissipation A method of assembling an electronic device comprising a component and a heat sink provided in common to the plurality of electronic components and thermally coupled to an exterior portion of each electronic component,
As each electronic component, one surface in the thickness direction of the exterior portion is a heat dissipation surface, and each lead terminal is linear in a direction perpendicular to the heat dissipation surface from the surface opposite to the heat dissipation surface. And having a structure in which a plurality of female screw members having screw holes opened on the heat radiation surface side of the exterior part in the shaft center part are embedded and fixed in the exterior part,
With each heat dissipating surface of each of the plurality of electronic components being in surface contact with one surface of the heat dissipating plate, the exterior portion of each electronic component is passed through the heat dissipating plate from the other surface side of the heat dissipating plate, Fastening with a plurality of component fixing screws screwed into the screw holes;
Inserting each lead terminal of each electronic component fastened to the heat sink into a corresponding through hole of the printed wiring board and penetrating the through hole;
Positioning the printed wiring board with respect to the heat radiating plate by interposing a spacer between the printed wiring board and the heat radiating plate, and fastening the printed wiring board to the heat radiating plate with screws. Fixing the substrate to the heat sink;
Soldering the lead terminal of each electronic component penetrating the through hole of the printed wiring board to the printed wiring board;
A method for assembling an electronic device comprising sequentially performing the steps described above. A printed wiring board, and a plurality of electronic components soldered to the printed wiring board in a state where the lead terminal has a lead terminal protruding from the exterior portion and the lead terminal penetrates a through hole provided in the printed wiring board; A method of assembling an electronic device including a heat sink provided in common to the plurality of electronic components and thermally coupled to a heat dissipation surface of an exterior portion of each electronic component,
As each electronic component, one surface in the thickness direction of the exterior portion is a heat dissipation surface, and each lead terminal is linear in a direction perpendicular to the heat dissipation surface from the surface opposite to the heat dissipation surface. And having a structure in which a plurality of female screw members having screw holes opened on the heat radiation surface side of the exterior part in the shaft center part are embedded and fixed in the exterior part,
Inserting each lead terminal of each electronic component into a corresponding through hole of the printed wiring board and penetrating the through hole; and
Positioning the printed wiring board with respect to the heat radiating plate by interposing a spacer between the printed wiring board and the heat radiating plate, and fastening the printed wiring board to the heat radiating plate with screws. Fixing the substrate to the heat sink;
A screw that penetrates the heat radiating plate from the other surface side of the heat radiating plate is screwed into a screw hole of each female screw member of the electronic component so that each heat radiating surface of the plurality of electronic components is in surface contact with one surface of the heat radiating plate. Fastening the exterior portion of each electronic component to the heat sink with a plurality of screws,
Soldering the lead terminal of each electronic component penetrating the through hole of the printed wiring board to the printed wiring board;
A method for assembling an electronic device comprising sequentially performing the steps described above.   3. The electronic device assembling method according to claim 1, wherein the heat radiating plate is a plate constituting one wall portion of a case for accommodating the printed wiring board and the electronic component.

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