JPH10189842A - Heat-dissipating structure for heat-generating component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat-dissipating structure, which prevents the stress in the solder part of a lead wire at a heat-generating component by a method, wherein a recessed part into which a part of a heat sink is inserted so as to be arranged is formed in the edge part of a circuit board, a protruding part is formed on the inner face of the side plate of a case so as to face the recessed part and the heat sink to which the heat-generating component is attached is sandwiched between, and held by, the recessed part in the circuit board and the protruding part at the case. SOLUTION: A heat sink 40, which is supported on a circuit board 20 is attached in such a way that the sandwiching and holding piece part of the heat sink 40 is sandwiched between, and held by, a recessed part 23 in the circuit board 20 and a flat face part 12 at a protruding part 11 formed so as to protrude on the inner face of a side plate 6 at a case and that the circuit board 20 is fitted between both side plates 6, 6 at the case. When the heat sink 40 is sandwiched between the recessed part, formed in the circuit board and the protruding part formed at the case, it is possible to eliminate a stress from being applied to the solder part in a lead wire of a heat-generating component. Then, the heat of the heat-generating component can be dissipated from the case.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat radiating structure for a semiconductor component having a semiconductor component requiring heat radiation, such as an inverter device for lighting a discharge lamp.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 14, an inverter device for lighting a discharge lamp has a metal case 5 formed by bending an aluminum plate material into a substantially U-shaped cross section, and covers an upper opening of the case 5. A circuit board 20 made of paper phenol, glass epoxy, or the like, on which electronic parts (not shown) are mounted, is separated from the bottom plate 7 of the case 5. Installed. A semiconductor component 25, for example, a thyristor, is mounted on the circuit board 20 as a heat-generating component having heat radiation.

FIGS. 15 and 16 show a heat dissipation structure of a semiconductor component having the above heat dissipation. A heat-generating component (semiconductor component) 25 having heat radiation is screwed and fixed to a heat-radiating plate 30 formed by bending an aluminum plate material into an L-shape. The heat-generating component (semiconductor component) 25 is tightly fixed to the flat bottom surface 28 of the heat-generating component 25 and the heat sink 30.

The heat generating component 25 has a plurality of lead wires 26 projecting outward from a side surface of the heat generating component 25. The heat-generating component 25 is formed by processing a lead wire 26 of the heat-generating component 25 and connecting the tip of the lead wire 26 to the circuit board 20.
Is inserted into the insertion hole (not shown) formed in the above. then,
Solder 27 is attached to the end of the lead wire 26 and the back surface of the circuit board 20.

[0005] A circuit board 20 including a soldering heat-generating component 25 is fitted between the side plates 6 and 6 of the corresponding case, and screws 3 are inserted.
At 5, the heat radiating plate 30 is tightly fixed to the side plate 6 of the case.

In FIG. 16, the side plate 6 of the case and the radiator plate 30 are sandwiched between clips 36 made of a leaf spring or the like, and the radiator plate 30 is fixed to the side plate 6 in close contact.

As shown in FIGS. 15 and 16, the side plate 6 of the metal case and the metal radiator plate 30 are fixed with the rising piece 31 of the radiator plate in close contact with the side plate 6. Therefore, the heat generated from the heat-generating component 25 is
Is transmitted through the metal heat radiating plate 30 and is radiated into the air through the side plate 6 of the case which is in close contact with the heat radiating plate 30 to keep the temperature rise of the heat generating component 25 within a certain range. .

Further, as another example, Japanese Patent Application Laid-Open No. 8-1673
No. 18, there is a heat dissipating structure of a heat generating component including a metal case having an elastic pressing piece on a side plate and a semiconductor component having heat dissipating and fixed to the case and in close contact with the elastic pressing piece. Have. For this reason, a heat sink having the same width in the width direction of the circuit board is required, which imposes restrictions on component mounting.

In the method of fitting the circuit board 20 including the heat-generating component 25 soldered between the side plates 6 and 6 of the case as shown in FIGS. 15 and 16, the circuit board 20 is attached to the case side plate. The circuit board 20 including the heat-generating component 25 is attached to the case d because there is a gap d resulting from the offset of the circuit board 20 generated when the circuit board 20 is mounted between the casings 6 and 6, and since the heat sink 30 is not fixed to the circuit board 20. When fitted between the side plates 6 and 6, the heat generating component 25 may move.

[0010]

As described above, the heat radiating structure of the conventional heat generating component shown in FIGS. 15 and 16 is a heat radiating plate 3 having a heat generating component 25 soldered to a circuit board 20.
0 was fixed to the side plate 6 of the case with screws, and was held between the heat radiating plate 30 and the side plate 6 of the case, and the heat generated from the heat-generating component 25 was radiated from the case via the heat radiating plate 30.

The heat radiating structure includes a heat generating component 2 having heat radiating.
The heat radiating plate 30 to which the heating component 5 is fixed by the screw 35
5 is only soldered to the circuit board 20, but the circuit board 20 and the heat sink 30 are not fixed.

Further, there is a gap d between the circuit board 20 and the side plate 6 of the case, which is generated when the circuit board 20 is mounted between the side plates 6 and 6 of the case and which is caused by a deviation of the circuit board 20; In addition, the processing dimensions of the lead wire 26 vary. Therefore, when the circuit board 20 to which the heat radiating plate 30 is attached is fitted between the side plates 6 and 6 of the case, the heat generating component 25 moves and the heat generating component 2 soldered to the circuit board 20 is used.
Since an external force is applied to the solder portion 27 of the lead wire 26 of No. 5, stress is applied to the solder portion 27, and there is a problem that the reliability of soldering may be reduced.

Further, when the heat radiating plate 30 is fixed to the side plate 6 of the case, not only fixing parts such as screws 35 and clips 36 are required, but also an extra man-hour is required at the time of assembling, and the cost is increased. There was a problem that became a factor.

Another conventional technique (Japanese Patent Laid-Open No. 8-167318)
In (2), a heatsink of the same width in the width direction of the circuit board is required, which limits the mounting of components and increases the size of the heatsink, reducing the mounting space. There was a problem such as slipping.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and does not reduce the reliability of soldering, and also facilitates the work of attaching a heat radiating plate and does not reduce the mounting space. It is an object to provide a structure.

[0016]

According to a first aspect of the present invention, there is provided a heat dissipating structure for a heat generating component mounted on a circuit board mounted in a metal case. In the heat radiating structure, a heat radiating plate is attached to the heat generating component, and a concave portion in which a part of the heat radiating plate is inserted and arranged is provided at an edge of the circuit board, and a convex portion is formed on an inner surface of a side plate of the case facing the concave portion. And a heat radiating plate to which the heat-generating component is attached is sandwiched between a concave portion of the circuit board and a convex portion of the case.

Further, according to a second aspect of the present invention, in the heat radiating structure of the heat generating component, the heat radiating plate is provided with a supporting portion which penetrates through the circuit board, protrudes downward and is supported by the bottom plate of the case. It is a feature.

In the structure of the first aspect, a concave portion for inserting a part of the heat radiating plate is provided at an edge of the circuit board on which the heat generating component to which the heat radiating plate is mounted is mounted, and an inner surface of a side plate of the case facing the concave portion. And a lead formed on the heat sink is soldered to the circuit board, and the heat sink attached to the circuit board is formed on the recess of the circuit board and on the inner surface of the side plate of the case. It is a structure that is sandwiched by.

With the above-described structure, the pressure applied to the heat sink is applied to the concave portion of the circuit board, so that no stress is applied to the solder portion of the lead wire of the heat-generating component. Further, even if the heat radiating plate is not fixed with a fixing component such as a screw, the heat radiating plate is sandwiched by the case, and a heat radiating effect is obtained.

In the structure according to the second aspect of the present invention, since the heat radiating plate has a structure in which the heat radiating plate penetrates the circuit board and protrudes downward, and is provided with a supporting portion supported by the bottom plate of the case, the heat generating component is soldered to the circuit board. Insulation between the lead wire and the bottom plate of the metal case can be ensured.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of an inverter device for lighting a discharge lamp is the same as that of the prior art except for the heat dissipation structure of the heat-generating components. An embodiment of the present invention will be described below with reference to FIGS. Note that the same components as in the prior art will be described with the same reference numerals.

FIG. 7 is a perspective view showing the appearance of a case for mounting a circuit board on which heat-generating components are mounted. The case 5 is formed by bending a metal plate material such as an aluminum material into a substantially U-shaped cross section as in the prior art. Side plates 6 opened upward and formed on both sides in the longitudinal direction
6 and a bottom plate 7 connecting the lower ends of these side plates 6 and 6.

Support pieces 8 are bent upward to face both ends of the bottom plate 7 of the case 5, and both ends of the circuit board 20 are placed above the support pieces 8 so as to face each other. A mounting recess 9 is formed. Further, rectangular insertion holes 10 are formed in the side plates 6 and 6 of the case 5 so as to face each other.

A circuit board 20 positioned and mounted in the mounting recess 9 shown in FIG. 1 or the like is rectangular and made of paper phenol, glass epoxy, or the like. And electronic components (not shown) such as capacitors. Some of these electronic components include a semiconductor component that generates heat, which is a heat generating component 25, such as a bipolar transistor or a MOS-FE.
There are T, diode, thyristor and the like.

The heat generating component 25 includes the heat generating component 25
A heat radiating plate 40 for radiating heat generated from the heat sink is mounted, and a heat generating component 25 to which the heat radiating plate 40 is mounted is mounted on the circuit board 20.

The heat radiating plate 40 is manufactured by pressing a heat radiating plate material such as an aluminum material. The heat radiating plate 40 has a flat plate-like heat-generating component mounting portion 41 as shown in FIG. A rectangular holding piece 42 bent downward at a right angle from the distal end, and a supporting portion 43 formed so as to protrude outward from both sides of the base of the heat-generating component mounting portion 41 and bent downward at a right angle, 43. Further, a screw hole 44 for fixing the heat generating component 25 is formed in the heat generating component mounting portion 41.

The heat-generating component 25 is attached in close contact with the heat-generating component mounting portion 41 of the heat-dissipating plate 40, and the screw 35 is screwed into a screw hole 44 of the heat-dissipating plate 40 to generate heat on the heat-dissipating plate 40. The component 25 is closely fixed. The fixing of the heat-generating component 25 to the heat radiating plate 40 is performed before the heat-generating component 25 is attached to the circuit board 20. Further, the lead wire 26 protruding from the end surface of the heat generating component 25 is processed so as to be insertable into the insertion hole 21 provided in the circuit board 20.

As shown in FIG. 2, a notch-shaped concave portion 23 for inserting and positioning the holding piece 42 of the heat radiating plate 40 is formed in the edge portion 22 of the circuit board 20. The recess 2
3 has a depth D which is smaller than the material thickness t of the heat sink 40.

On the side plate 6 of the case facing the concave portion 23 provided on the circuit board 20, a convex portion 11 is formed which protrudes inward and has a flat surface 12 at the tip.

The procedure for soldering the lead wires of the heat-generating component to which the heat sink is attached to the circuit board will be described. First, the holding piece 42 of the heat sink 40 to which the heat-generating component 25 is fixed is hooked on the concave portion 23 of the circuit board 20 and the heat-generating component 25
Hole 2 provided in the circuit board 20 with the end of the lead wire 26
1 and solder the tip of the lead wire 26 to the back side of the circuit board 20. In this state, FIGS. 1 and 2
As shown in FIG.
0, and the heat-generating component 25 is
It is arranged on the circuit board 20 in a state where it is separated so as not to hit the upper surface of the circuit board 20. By arranging the heat-generating component 25 apart from the circuit board 20 in this manner, the heat generated from the heat-generating component 25 effectively radiates from the metal case 5 through the heat radiating plate 40 made of an aluminum plate material. .

Heat sink 40 supported on circuit board 20
As shown in FIG. 1, as shown in FIG. 1, the holding piece 42 of the heat radiating plate 40 is held between the recess 23 of the circuit board 20 and the flat surface 12 of the projection 11 formed on the inner surface of the side plate 6 of the case. Reference numeral 20 is attached so as to be fitted between both side plates 6 and 6 of the case.

At this time, as shown in FIG. 3, the circuit board 20 is held on the back side of the opposite side plate 6 provided with the protruding portion 11 so as to be provided with a pair of protruding portions 13, 13. The board 20 is attached so as to be fitted between the projection 11 and the pair of projections 13, 13.

As another method, as shown in FIG. 5, a convex portion 14 having a flat surface is provided at the tip on the opposite side plate 6 provided with the convex portion 11, and the circuit board 20 is connected to the convex portion 11 and the convex portion. 14 so as to be fitted between the flat surface 14 and the flat surface.

As shown in FIG. 6, if the tolerance between the circuit board 20 and the side plates 6 and 6 of the case can be reduced, the protrusion 11 and the side plate of the case can be provided without providing any protrusions or protrusions. 6 can also be held.

Next, a method for assembling an inverter device having a heat-radiating structure for heat-generating components will be described with reference to FIGS.

The lead wire of the heat-generating component 25 attached to the heat sink 40 is attached to the circuit board 20 by soldering, and both ends of the circuit board 20 are mounted on the mounting recesses 9 provided at both ends of the case 5.
Place on. The state where the circuit board 20 is mounted on the mounting recess 9 is as shown in FIG.

Next, the cover 15 is attached to the case 5 as shown in FIG. Then, when the fixing piece 16 provided on the side surface of the cover 15 at a position facing the insertion hole 10 provided on the side plate 6 of the case 5 is bent inward, the fixing piece 16 passes through the insertion hole 10 of the case 5 as shown in FIG. As shown, the cover 15 is fixed to the case 5 while fixing the edge of the circuit board 20.

FIGS. 10 and 12 show the heat radiating structure of the heat generating component according to the second embodiment. The difference between FIGS. 1 and 10 is that the supporting portion 43 provided on the heat radiating plate 40a has the supporting portion A4.
3a and the support portion B43b, the support portion A
43a is provided for holding the heat radiating plate 40a on the circuit board 20, and the supporting portion B43b is provided with the supporting portion A43.
By making the cross section smaller than the cross section a, the through hole 24 is provided in the circuit board 20 with which the tip of the support portion A43a contacts, and is formed so as to penetrate through the through hole 24 and protrude downward to hit the bottom plate 7 of the case.

By doing so, the required height between the bottom plate 7 of the case and the circuit board 20 can be secured, so that the height can be determined even at the heat radiating portion. This is because the lead wire 26 of the heat generating component 25 soldered to the circuit board 20
However, this is effective when it is necessary to maintain a height that does not touch the case 5.

Generally, a sheet-like insulating material 50 is laid on the bottom plate 7 of the case as shown in FIG.
A certain distance is required so that the ends of the lead wires of the components mounted on the circuit board 20 due to vibration or the like do not damage the insulating material 50. As shown in FIG. 13, if there is a margin in the height of the case 5, by increasing the height between the bottom plate of the case and the circuit board, if the height of the heat radiating portion of the heat radiating plate can be secured, The configuration shown in FIG. 13 is also possible. In the present embodiment, only one heat-generating component is attached to the heat sink 40, but this is not a limitation.

Next, the operation of the above embodiment will be described.

In the structure of the first aspect, the heat-generating component is mounted on the heat sink, a concave portion is provided on the circuit board on which the heat-generating component is mounted, and a convex portion is provided on the side plate of the case facing the concave portion. The attached heat sink is sandwiched between the concave portion of the circuit board and the convex portion of the case side plate.

With such a structure, the pressure applied to the heat radiating plate is applied to the concave portion of the circuit board, and no stress is applied to the solder portion of the lead of the heat-generating component. There is no drop.

The mounting of the circuit board on which the heat radiating plate having the heat-generating components is mounted to the case is performed by sandwiching the heat radiating plate between the concave portion of the circuit board and the convex portion of the case. Easy.

Further, since the heat radiating plate can be fixed to the case without fixing with a fixing member such as a screw, the heat generated from the heat generating component is effectively transmitted through the heat radiating plate made of an aluminum plate material to form a metal case. Heat is dissipated from the surface, and a heat radiation effect is obtained.

The structure in which the heat radiating plate is sandwiched between the concave portion of the circuit board and the convex portion of the case does not use fixing parts such as screws, so that the cost can be reduced.

Further, the heat radiating plate for radiating the heat of the heat-generating component only needs to have a size necessary for heat radiating, so that the mounting space is not reduced.

In the structure according to the second aspect of the present invention, since the heat sink has a structure in which it is projected downward from the insertion hole formed in the circuit board and is supported by the bottom plate of the case, it is soldered to the circuit board. Insulation between the lead wire of the heat generating component and the bottom plate of the metal case can be ensured.

[0049]

According to the heat dissipating structure of the heat generating component according to the first aspect of the present invention, the heat dissipating heat generating component is mounted on the heat radiating plate, and the heat radiating plate is provided on the concave portion provided on the circuit board and the side plate of the case. By sandwiching between the protrusions, it is possible to radiate the heat of the heat-generating component from the case without applying stress to the solder part of the lead wire of the heat-generating component, so that the reliability of soldering does not decrease. . In addition, the work of mounting the heat sink can be easily performed. Furthermore, since the heat sink can be fixed to the case without using fixing parts such as screws, the cost does not increase.

The heat radiating plate for radiating the heat of the heat-generating component only needs to have a size necessary for heat radiating, so that the mounting space is not reduced.

According to the heat-radiating structure of the heat-generating component, the insulation between the lead wire of the heat-generating component soldered to the circuit board and the bottom plate of the metal case can be ensured.

[Brief description of the drawings]

FIG. 1 is a sectional side view showing a heat radiation structure of a heat generating component according to a first embodiment of the present invention.

FIG. 2 is a front view showing a state in which a heat radiating plate to which a heat-generating component is fixed according to the embodiment is attached to a circuit board. (B) is a perspective view in which a concave portion is formed in the circuit board.

FIG. 3 is an exemplary perspective view showing a heat radiating plate for fixing the heat-generating component according to the embodiment;

FIG. 4 is a top view showing the first embodiment in which a circuit board having a heat sink attached to the case according to the first embodiment is fitted;

FIG. 5 is a top view showing a second embodiment in which a circuit board having a heat sink attached to the case according to the second embodiment is fitted.

FIG. 6 is a top view showing a third embodiment in which a circuit board having a heat sink attached to the case according to the third embodiment is fitted.

FIG. 7 is an exemplary perspective view showing a case used in the embodiment;

FIG. 8 is a perspective view showing the entire configuration in the embodiment.

FIG. 9 is a cross-sectional side view showing the entire configuration in the embodiment.

FIG. 10 is a sectional side view showing a heat radiation structure of a heat generating component according to a second embodiment of the present invention.

FIG. 11 is an exemplary front view showing a state in which a heat radiating plate to which a heat-generating component is fixed according to the second embodiment is attached to a circuit board;

FIG. 12 is a perspective view showing a heat radiating plate for fixing a heat generating component according to the second embodiment.

FIG. 13 is a sectional side view showing a heat radiation structure of a heat generating component according to a third embodiment of the present invention.

FIG. 14 is a top view showing a general overall configuration.

FIG. 15 is a cross-sectional side view showing a heat radiation structure of a heat-generating component according to the first conventional technique.

FIG. 16 is a cross-sectional side view showing a heat radiation structure of a heat-generating component according to a second conventional technique.

[Explanation of symbols]

 5 ... case, 6 ... case side plate, 7 ... case bottom plate, 11 ... convex portion, 20 ... circuit board, 22 ... circuit board edge, 23 ... concave portion, 25 ... heat-generating component, 40 ... heat radiating plate, 40a ... Heat radiating plate, 43b: Supporting portion supported on the bottom plate.

Claims (2)

[Claims] 1. A heat radiating structure for a heat generating component mounted on a circuit board mounted in a metal case, wherein a heat radiating plate is mounted on the heat generating component and the heat radiating plate is attached to an edge of the circuit board. A concave portion into which a portion is inserted and arranged; a convex portion provided on an inner surface of the side plate of the case facing the concave portion; and a heat sink to which the heat generating component is attached is sandwiched between the concave portion of the circuit board and the convex portion of the case. A heat dissipating structure for a heat generating component. 2. The heat radiating structure for a heat generating component according to claim 1, wherein said heat radiating plate is provided with a supporting portion which penetrates through said circuit board and projects downward and is supported by a bottom plate of said case.