JP3349468B2 - Heat sink soldering structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sinking structure for a heat sink which is soldered to a printed wiring board in order to efficiently radiate heat generated from a semiconductor such as a power transistor.

[0002]

2. Description of the Related Art Generally, when an electronic component having a large power consumption such as a three-terminal regulator is mounted on a printed wiring board, the electronic component is closely attached to a heat sink in order to efficiently radiate heat generated from the electronic component. Often implemented. Conventionally, a heat sink is mounted on a printed wiring board by screwing, riveting, or soldering with soldering pins.

FIG. 13 shows an example in which a heat sink is mounted on a printed wiring board by soldering pins. In the figure, a press-fit pilot hole 1b for press-fitting a cylindrical soldering pin 2 is formed in a bottom surface 1a of a heat sink 1. In this type of heat sink soldering structure, after one end 2a of the soldering pin 2 is press-fitted into the pilot hole 1b, the other end 2b of the soldering pin 2 protruding from the bottom surface 1a of the heat sink 1 is printed wiring. It is inserted into the through hole 3a of the plate 3. Here, the outer diameter of the soldering pin 2 is slightly smaller than the inner diameter of the through-hole 3a to facilitate mounting. And heat sink 1
Is temporarily mounted on the printed wiring board 3. Other electronic components are also temporarily mounted on the printed wiring board.

Thereafter, the other end 2b of the soldering pin 2 and the land 3c formed on the soldering surface 3b of the printed wiring board 3 are soldered 4 by an automatic soldering device or the like. When soldering 4 is performed, preliminary heating by a heater (not shown) is performed from the soldering surface 3 b side of the printed wiring board 3. After the entire printed wiring board 3 is heated to a predetermined temperature by preheating, it is immersed in the solder bath 5. Then, the printed wiring board 3 is pulled up from the solder bath 5, so that the solder 4 a melted in the solder bath 5 is formed.
However, the soldering pin 2 and the land 3
c, etc., and soldering of the heat sink 1 to the printed wiring board 3 is performed.

[0005]

However, in such a conventional soldering structure of a heat sink, the cylindrical soldering pin 2 is inserted into the heat sink 1 by a press-fitting hole 1.
Since the pin 2 is press-fitted and fixed, the heat of the soldering pin 2 easily escapes to the heat sink 1 at the time of soldering, and there is a problem that the temperature of the soldering pin 2 does not easily rise to a temperature suitable for soldering.

Due to its function, the heat sink 1 has a structure in which heat is easily released by attaching radiating fins or the like.
For this reason, in order to set the heat sink 1 to a predetermined temperature, a large amount of preheating time is required. As a result,
There is a problem that it takes a long time for the soldering process. When the preheating time is extended, there is a possibility that a heat-sensitive component such as a resin component temporarily mounted on the printed wiring board may be deteriorated.

[0007] Due to the vibration at the time of soldering, the heat sink 1 may be soldered in a state of being floated from the printed wiring board 3 or in an inclined state. When power is applied to the printed wiring board 3 on which the soldering is completed, the electronic components mounted on the printed wiring board 3 operate and generate heat.
Heat generated from electronic components such as a three-terminal regulator adhered to the heat sink 1 is transmitted to the heat sink 1. For this reason, the heat sink 1 expands in temperature. As a result, the pressure contact force between the soldering pin 2 and the mounting hole 1b is reduced, and the heat sink 1 may fall off the printed wiring board 3.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and provides a heat sink soldering structure capable of reliably and quickly soldering a heat sink to a printed wiring board. The purpose is to: Another object of the present invention is to provide a heat sink soldering structure capable of reliably supporting a heat sink on a printed wiring board during soldering.

[0009]

According to a first aspect of the present invention, there is provided a heat sink soldering structure, wherein one end of a soldering pin is inserted and fixed in a mounting hole of the heat sink, and the other end of the soldering pin protruding from the mounting hole. Into the through hole provided in the printed wiring board from the component mounting surface of the printed wiring board, and solder the other end protruding from the soldering surface opposite to the component mounting surface to the printed wiring board. In the soldering structure of the heat sink formed as described above, a screw groove is provided on the inner surface of the mounting hole of the heat sink, and the one end side of the soldering pin is screwed or fitted into the screw groove. An engagement portion formed by forming a plurality of protrusions along the axial direction is provided, and the other end of the soldering pin is provided via a slit extending from the other end along the axial direction. A plurality of protruding pieces having flexibility in a cross-sectional direction are provided, and a tip of each of the protruding pieces is abutted on the soldering surface around the through hole, and the protruding piece is bent when the protruding piece is bent. An insertable stop is provided.

According to a second aspect of the present invention, there is provided a heat sink soldering structure according to the first aspect, wherein the soldering pin has a substantially circular cross section.
The engaging portion is provided at a plurality of locations at a predetermined interval in the circumferential direction at the one end of the columnar shape, and a notched concave portion recessed toward the center side from the convex portion is provided between the engaging portions. It is characterized by being provided.

According to a third aspect of the present invention, in the soldering structure for a heat sink according to the first aspect, the soldering pin has a plate shape, and the engaging portion has a plate-like end. On both sides, each is provided with the convex portion having flexibility in the cross-sectional direction, the protruding pieces are provided on both sides of the slit formed along the central axis, and the stopper is It is characterized by being provided outside each protruding piece.

According to a fourth aspect of the present invention, in the soldering structure of a heat sink according to any one of the first to third aspects, the tip end of each of the stoppers faces toward the central axis. An inclined guide portion is provided. According to a fifth aspect of the present invention, there is provided a heat sink soldering structure according to any one of the first to fourth aspects.
In the soldering structure of the heat sink according to the item, the other end side of the engaging portion of the soldering pin is provided with an outwardly protruding portion, and the bottom surface where the mounting hole of the heat sink is opened, A support recess having a shape corresponding to the projection is provided.

(Function) In the soldering structure for a heat sink according to the first aspect, the protrusion of the engaging portion provided at one end of the soldering pin is screwed or fitted into the screw groove provided in the mounting hole of the heat sink. Then, the heat sink and the soldering pins are fixed. Next, the other end of the soldering pin protruding from the heat sink is inserted into the through hole from the component mounting surface of the printed wiring board. At this time, by bending the protruding piece in the central axis direction, the stopper provided at the other end of the soldering pin moves toward the central axis and is inserted into the through hole.

Further, by inserting the soldering pin into the through hole, the stop portion of the soldering pin projects from the soldering surface of the printed wiring board. At this time, the stopper moves outward (radially) due to the restoring force of the projecting piece. Then, the periphery of the through hole of the printed wiring board is clamped by the mounting hole side of the heat sink and the stopper,
A heat sink is supported on the printed wiring board via solder pins.

After that, the other end of the soldering pin and the soldering surface of the printed wiring board are soldered. On this occasion,
Since the fixing of the soldering pin and the heat sink is performed by engaging the convex part of the engaging part with the screw groove of the mounting hole, the convex part and the screw groove come into contact with each other in an elongated plane or linear shape. I have. For this reason, the contact portion between the convex portion and the screw groove is minimized, and the heat transmitted from the soldering pin to the heat sink during soldering is reduced as compared with the case where the cylindrical soldering pin is press-fitted. That is, most of the heat applied to the soldering pins at the time of soldering contributes as necessary heat at the time of soldering. Therefore, the soldering pins rise in a short time to a predetermined temperature suitable for soldering. As a result, the preheating time in the soldering step is significantly reduced as compared with the conventional case, and the time required for the soldering step is shortened.

Since the fixing of the soldering pin and the heat sink is performed by engaging the protrusion of the engaging portion with the screw groove of the mounting hole, the heat sink is attached to the printed wiring board by vibration or the like during soldering. The heat sink is prevented from floating or tilting, and the heat sink is soldered in place. Since the other end of the soldering pin is soldered to the printed wiring board, for example, even when the protrusion of the engaging portion of the soldering pin is formed by a screw groove, unlike a simple screwing, the soldering pin and the heat sink Does not loosen.

Since the fixing of the soldering pin and the heat sink is performed by engaging the projection of the engaging portion with the screw groove of the mounting hole, after soldering, power is supplied to the printed wiring board, and the heat sink is turned on. Is prevented from falling off from the printed wiring board even when expanded by heat. Claim 2
In the soldering structure of the heat sink described above, since the engaging portions of the soldering pins are provided at a plurality of locations at predetermined intervals in the circumferential direction, the locations and lengths of the projections are minimized. As a result, the contact portion between the protrusion and the screw groove is further reduced, and the heat transferred from the soldering pin to the heat sink during soldering is further reduced.

In the soldering structure for a heat sink according to the third aspect, since the soldering pins have a plate shape, the raw material formed into a predetermined shape by extrusion molding, cutting, or the like is simply cut to a predetermined thickness. Thus, soldering pins are easily formed. Since the convex portion provided in the engaging portion of the projecting piece has flexibility in the cross-sectional direction, after soldering, power is supplied to the printed wiring board, and even when the heat sink expands due to heat, Following the change in the shape of the thread groove, the convex portion is elastically deformed by the restoring force. Therefore, the thread groove is always pressed by the projection, and the engagement between the soldering pin and the heat sink is reliably maintained.

In the soldering structure for a heat sink according to the fourth aspect of the present invention, the guide portion is provided at each stop portion with the tip end inclined toward the central axis. Therefore, when the soldering pin is inserted into the through hole, the guide portion is provided. When it comes into contact with the through-hole opening on the component mounting surface side, part of the force applied in the axial direction
The inclination of the guide portion converts the force into a force for bending the protruding piece toward the central axis. Therefore, the stopper is easily inserted into the through-hole only by moving the soldering pin toward the through-hole.

In the soldering structure for a heat sink according to the fifth aspect, since the projecting portion is provided on the other end side of the engaging portion of the soldering pin, when the soldering pin is inserted into the mounting hole of the heat sink, the soldering pin is provided. Is inserted until the protrusion is supported in a support recess provided on the bottom surface of the heat sink. As a result, since the soldering pin is always inserted into the mounting hole by a predetermined length, the length of the soldering pin from the projecting portion to the stop portion is always constant. Therefore,
Regardless of the length of the mounting hole and the precision of the thread groove, the printed wiring board is securely held between the heat sink and the stopper.

Since the support recess is provided at the bottom of the heat sink, the projection is accommodated in the support recess when the soldering pin is inserted into the mounting hole of the heat sink. Therefore, the heat sink is stably arranged on the printed wiring board.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a first embodiment (corresponding to claims 1, 2 and 4) of a heat sink soldering structure according to the present invention. In the figure, a mounting hole 12 is formed in a bottom surface 10 a of a heat sink 10. One end 14 a of the soldering pin 14 is provided in the mounting hole 12.
Is formed with a screw groove 12a for screwing.

The printed wiring board 16 has a through hole 18 for inserting the other end 14b of the soldering pin 14 through the component mounting surface 16a and the soldering surface 16b. A through hole 18 is formed in the soldering surface 16b.
A land 20 is formed around the periphery. The soldering pin 14 has a substantially circular cross section and is integrally formed by cutting phosphor bronze or the like. One end 14a side of the soldering pin 14 has a substantially cylindrical shape.

Around the one end 14a, four notches are formed at predetermined intervals in the circumferential direction to form notch recesses 22. The uncut portions (four portions) engage with each other. A part 24 is formed. In this embodiment,
As shown in FIG. 2, the notch recess 22 and the engagement portion 24
The central angles A1 and A2 are each set to 45 degrees.

As shown in FIG. 1, a thread groove 26 (corresponding to the convex portion) is formed on the outer peripheral surface of each engaging portion 24. Here, the one end 14 a side of the soldering pin 14 is formed in such a size that the screw groove 26 can be screwed into the screw groove 12 a of the mounting hole 12.

On the other end 14b side of the soldering pin 14,
A protruding piece 28 having a circular cross section and protruding in the axial direction B.
Are formed at two locations facing each other. A slit 30 is formed between the projecting pieces 28 along the axial length direction B. Due to the slit 30, each protruding piece 28 has flexibility in the cross-sectional direction C. The degree of bending of the projecting piece 28 against external force is adjusted by the thickness of the projecting piece 28.

At the tip of each protruding piece 28, a stop portion 32 having a substantially arc-shaped cross section protruding outside the protruding piece 28 is formed. A tapered guide portion 34 whose front end side is inclined toward the central axis D is formed at the front end of the stop portion 32.
As shown in FIG. 3, opposing surfaces 32 a that oppose each other are formed at both ends of the arc in each of the stoppers 32. The distance L1 between the facing surfaces 32a is smaller than the inner diameter D1 of the through hole 18 of the printed wiring board 16.

As shown in FIG. 4, the distance L2 outside the stop portion 32 facing each other is set larger than the inner diameter D1 of the through hole 18 of the printed wiring board 16. Outer distance L3 at the tip of guide portion 34 facing each other
Is the inner diameter D1 of the through hole 18 of the printed wiring board 16.
Has been smaller. The distance L4 outside the protruding piece 28 facing each other is equal to the through hole 1 of the printed wiring board 16.
8 is smaller than the inner diameter D1.

The length L5 of the projecting piece 28 is slightly larger than the thickness T1 of the printed wiring board 18. here,
The plate thickness T1 is a value including the thickness of the land 20. The length L6 of the engaging portion 24 is the same as the depth L7 of the mounting hole 12 of the heat sink 10. End 24a of engagement portion 24
Is chamfered according to the shape of the bottom 12b of the mounting hole 12 of the heat sink 10. The tapered shape of the bottom of the mounting hole 12 is determined by the included angle of the drill when the mounting hole 12 is formed.

In this embodiment, the distance L1 of the facing surface 30a, the distance L2 of the stopper 32, and the distance L of the guide 34
3. The distance L4 between the projecting pieces 28 is 2.4 mm,
They are 3 mm, 1.8 mm and 2.5 mm. The length L5 of the protruding piece is set to 1.7 mm, and the length L6
The depth L7 of the mounting hole 12 is set to 3 mm. The inner diameter D1 of the through hole 18 is 2.8 mm, and the thickness T1 of the printed wiring board 16 is 1.6 mm.

In the above-described heat sink soldering structure, the heat sink 10 is soldered to the printed wiring board 16 as described below. That is, first, as shown in FIG. 5, the engagement portion 24 of the soldering pin 14
Until the end 24a of the engaging portion 24 comes into contact with the bottom 12b of the mounting hole 12, it is screwed into the mounting hole 12 of the heat sink 10, and the soldering pin 14 is fixed to the heat sink 10. When the screwing is completed, the bottom surface 1 of the heat sink 10
Only the protruding piece 28 and the stop 32 of the soldering pin 14 protrude from Oa.

Next, as shown in FIG.
The other end 14 b of the soldering pin 14 protruding from 0 is inserted into the through hole 18 from the component mounting surface 16 a side of the printed wiring board 16. Here, when the guide portion 34 at the tip of the stop portion 32 contacts the end of the through hole 18 on the component mounting surface 16a side, a part of the insertion force applied in the axial direction B is reduced due to the inclination of the guide portion 34. 28 is converted into a force that bends the center axis D. Therefore, the stopper 32 is easily inserted into the through-hole 18 only by moving the soldering pin 14 toward the through-hole 18.

Further, by moving the heat sink 10 toward the printed wiring board 16 and inserting the soldering pins 14 into the through holes 18, the stop portions 32 of the soldering pins 14 are printed as shown in FIG. It protrudes from the soldering surface 16b of the wiring board 16. At this time, the stopper 32
Move outward (radially) due to the restoring force of the projecting piece 28. The bottom surface 10 a of the heat sink 10 and the stopper 32 form the through hole 18 of the printed wiring board 16.
Of the printed wiring board 16 via the soldering pins 14.
Supported above and provisionally mounted.

Other electronic components (not shown) are temporarily mounted on the printed wiring board 16. Thereafter, as shown in FIG. 8, the fixing portions 32 of the soldering pins 14 and the lands 20 of the printed wiring board 16 are soldered 36 by an automatic soldering device or the like. FIG. 8 shows a state in which the printed wiring board 16 is pulled up from the solder bath 38. When performing the soldering 36, first, preliminary heating is performed by a heater (not shown) from the soldering surface 10b side of the printed wiring board 10. At this time, the thread groove 26 of the engaging portion 24 and the thread groove 12a of the mounting hole 12 are in linear contact. Further, the engaging portion 24 sets the center angles A1 and A2 to 45 degrees and
It is formed in the place. For this reason, the screw grooves 26, 12a
Contact area is small, and soldering pin 1
4 is less likely to be transmitted to the heat sink 10. Therefore, the printed wiring board 16 is brought to a predetermined temperature required for soldering in a short time.

Next, the printed wiring board 10 is connected to the solder bath 38.
Soak in Then, by lifting the printed wiring board 10 from the solder bath 38, the solder 36a melted in the solder bath 38 is attracted to the soldering pins 14, the lands 20, and the like by the action of surface tension, and the printed wiring of the heat sink 10 is formed. Soldering to the plate 16 is performed.
Here, the molten solder 36a goes around the inside of the stopper 32 through the slit 30, so that the soldering 36 is performed more firmly and reliably. That is, the size of the land 20 is minimized and the heat sink 1
0 is securely fixed on the printed wiring board 16.

Since the periphery (and land 20) of the through hole 18 of the printed wiring board 16 is sandwiched between the bottom surface 10a of the heat sink 10 and the stopper 32, the heat sink 10 is vibrated during soldering.
Is prevented from floating or tilting from the printed wiring board 16, and the heat sink 10 is soldered to a predetermined position.

After soldering, the soldering pins 1
4 and the printed wiring board 16 are integrated with each other, and the heat sink 10 is fixed to the printed wiring board 16 via electronic components (not shown) requiring heat radiation.
4 and the heat sink 10 are not loosened. Furthermore, after the soldering, even if the power is supplied to the printed wiring board 16 and the heat sink 10 expands due to heat, the screwed state of the screw groove 26 of the engaging portion 24 and the screw groove 12a of the mounting hole 12 is maintained. Therefore, the heat sink 10 does not fall off the printed wiring board 16.

In the heat sink soldering structure configured as described above, the screw groove 26 of the engaging portion 24 and the mounting hole 1
2 is in linear contact with the thread groove 12a, and
Since 4 is formed at four positions with the central angles A1 and A2 being 45 degrees, the contact portions of the screw grooves 26 and 12a can be reduced. For this reason, in preheating at the time of soldering, the heat applied to the soldering pins 14 is less likely to be transmitted to the heat sink 10, and the printed wiring board 16 is
It is possible to reach a predetermined temperature required for soldering in a short time. As a result, the preheating time in the soldering step is significantly reduced as compared with the conventional case, and the time required for the soldering step is shortened.

Therefore, it is possible to prevent heat-sensitive components such as other resin-made components temporarily mounted on the printed wiring board 10 from deteriorating. Since the length L6 of the engaging portion 24 is the same as the length 17 of the mounting hole 12, only the soldering pin 14 is screwed in until the end 24a of the engaging portion 24 contacts the bottom 12b of the mounting hole 12. Thus, only the protruding pieces 28 and the stoppers 32 protrude from the bottom surface 10a of the heat sink 10, and the soldering pins 14 can be fixed to the heat sink 10.

Since the guide portion 34 whose tip is inclined toward the center axis D is formed on the other end 14b side of the stop portion 32, the other end 14b of the soldering pin 14 is connected to the through hole 18 of the printed wiring board 16. At the time of insertion, a part of the insertion force applied in the axial length direction B can be converted into a force that bends the protruding piece 28 toward the central axis D due to the inclination of the guide portion 34. For this reason, the stopper 32 can be easily inserted into the through hole 18 only by moving the soldering pin 14 toward the through hole 18.

Since the projecting piece 28 is formed with flexibility, the stopper 32 and the guide 34 can be easily bent when the soldering pin 14 is inserted into the through hole 10. After the soldering pins 14 are inserted into the through holes 10, the stopping portions 3
2 can be moved outward, so that the heat sink 10 can be reliably supported on the printed wiring board 16 via the soldering pins 14.

The bottom surface 10a of the heat sink 10 and the stopper 3
2, the periphery of the through hole 18 (and the land 20) of the printed wiring board 16 is sandwiched, so that the heat sink 10 is prevented from floating or tilting from the printed wiring board 16 due to vibration or the like during soldering. The heat sink 10 can be always soldered to a predetermined position on the printed wiring board 16.

Since the slit 30 is formed between the projecting piece 28 of the soldering pin 14 and the stopper 32, the molten solder 36a is removed during the soldering.
Can be passed around to the inside of the stopper 32, and the soldering 36 can be performed more firmly and reliably. As a result, the size of the land 20 is minimized,
The heavy heat sink 10 can be securely fixed on the printed wiring board 16.

After soldering, the soldering pins 14 and the printed wiring board 16 are integrated, and the heat sink 10
Is fixed to the printed wiring board 16 via an electronic component (not shown) requiring heat radiation, so that the soldering pin 14 and the heat sink 10 can be prevented from loosening. After soldering, even if the power is supplied to the printed wiring board 16 and the heat sink 10 expands due to heat, the threaded state of the screw groove 26 of the engaging portion 24 and the screw groove 12a of the mounting hole 12 is maintained. Therefore, it is possible to prevent the heat sink 10 from falling off the printed wiring board 16.

FIG. 9 shows a second embodiment (corresponding to claims 1, 3 to 5) of a soldering structure for a heat sink according to the present invention. In this embodiment,
After a material such as phosphor bronze is cut into a predetermined shape by cutting, it is cut into a predetermined thickness T2 to form a plate-like soldering pin 40. At one end 40a of the soldering pin 40,
Engaging portions 42 are provided on both sides in the width direction W. Each engagement part 4
2, three acute angle convex portions 44 facing the other end 40 b side are formed at intervals in the axial direction B. Each convex part 4
4 has flexibility in the width direction W.

The soldering pin 40 has a slit 46 extending from the other end 40b along the center axis D. On the soldering pin 40, a bar-shaped protruding portion 48 protruding in the width direction W is formed on the other end 40 b side of each engaging portion 42. A projecting piece 50 extending toward the other end 40b is formed on the other end 40b side of each projecting portion 48.
Each protruding piece 50 can be bent in the width direction W by the slit 46.

At the other end 40b of the protruding piece 50, a stopper 52 protruding in the width direction W is formed. Stop 5
On the other end 40b side of the second 2, a guide portion 54 whose front end side is inclined toward the central axis D is formed. In this embodiment, the mounting hole 12 is provided on the bottom surface 10a of the heat sink 10.
, A supporting recess 56 extending in the width direction W is formed. The support recess 56 is provided with the protrusion 48 of the soldering pin 40.
It is formed in the size which can accommodate.

The same printed wiring board 16 as in the first embodiment is used. Then, as shown in FIG. 10, the distance L8 outside the stop portion 52 facing each other is:
The diameter is larger than the inner diameter D1 of the through hole 18 of the printed wiring board 16. The outer distance L9 at the tip of the guide portion 54 facing each other is smaller than the inner diameter D1 of the through hole 18 of the printed wiring board 16. The distance L10 outside the protruding pieces 50 facing each other is smaller than the inner diameter D1 of the through hole 18 of the printed wiring board 16.

The length L11 of the protruding piece 50 is slightly larger than the thickness T1 of the printed wiring board 18 including the land 20. The length L12 of the engaging portion 42 is the same as or shorter than the depth L13 of the mounting hole 12 of the heat sink 10. The distance L14 between the engaging portions 42 on both sides is smaller than the valley diameter D2 of the mounting hole 12, and the protrusions 44 on both sides are formed.
Is larger than the root diameter D2 of the mounting hole 12.

In the above-described soldering structure of the heat sink, the engaging portion 42 of the soldering pin 40 is fitted into the mounting hole 12 of the heat sink 10 until the protrusion 48 is accommodated in the supporting recess 56. As a result, the soldering pins 4
0 is always inserted into the mounting hole 12 by a predetermined length, so that the length from the projecting portion 48 of the soldering pin 40 to the stop portion 52 is always constant.

The fitting of the soldering pins 40 is easily performed by bending the convex portions 44. When the fitting is completed, the soldering pins 4 are removed from the bottom surface 10a of the heat sink 10.
Only the 0 protruding piece 50 and the stopper 52 protrude.
After the fitting, each of the projections 44 is
a, and the convex portion 44 protrudes toward the bottom surface 10a, so that the soldering pin 40 is prevented from coming off the heat sink 10.

Next, the other end 40b of the soldering pin 40 projecting from the heat sink 10 is inserted into the through hole 18 from the component mounting surface 16a side of the printed wiring board 16. Here, since the protruding piece 50 is bent to the center axis D by the guide portion 54 at the tip of the stop portion 52, the stop portion 52 is easily inserted into the through hole 18. When the stopping portion 52 projects from the soldering surface 16b of the printed wiring board 16, the projecting piece 50 moves outward (radially) due to a restoring force. The bottom surface 10 a of the heat sink 10 and the stopper 52 sandwich the periphery (and the land 20) of the through hole 18 of the printed wiring board 16, and the heat sink 10 is supported on the printed wiring board 16 via the soldering pins 40. And provisionally implemented. Here, since the projecting portion 48 of the soldering pin 40 is housed in the support concave portion 56 of the heat sink 10, the heat sink 10
6 is supported stably.

Thereafter, the soldering pins 40 and the lands 20 of the printed wiring board 16 are soldered in the same manner as in the first embodiment. When power is applied to the printed wiring board after soldering and the heat sink expands due to heat, the convex portion 44 is elastically deformed by a restoring force following the change in the shape of the screw groove 12a of the mounting hole 12. I do. Therefore, the screw groove 12a is always pressed by the convex portion 44, and the engagement between the soldering pin 40 and the heat sink 10 is reliably maintained.

The same effect as in the first embodiment can be obtained in the soldering structure of the heat sink of this embodiment. However, in this embodiment, since the soldering pins 40 are formed in a plate shape, The soldering pins 40 can be easily formed only by cutting the raw material formed into a predetermined shape by extrusion molding, cutting or the like into a predetermined thickness.

A projecting portion 48 projecting in the width direction W is formed on the other end 40 b side of the engaging portion 42, and the bottom surface 1 of the heat sink 10 is formed.
Since the supporting recess 56 for accommodating the projecting portion 48 is formed in the mounting hole 1a, the soldering pin 40 is always fixed to the mounting hole 1 by a predetermined length.
2 and the length from the projecting portion 48 of the soldering pin 40 to the stop portion 52 can be always constant. Therefore, the length of the mounting hole 12 and the thread groove 12a
Regardless of the accuracy of the heat sink 10 and the stop 52
Thus, the printed wiring board 16 can be securely held.

After the soldering pins 40 are fitted into the mounting holes 12, the projecting portions 48 do not project from the bottom surface 10 a of the heat sink 10.
6 can be stably supported. After the soldering pins 40 are fitted into the mounting holes 12, the respective convex portions 44 abut against the screw grooves 12 a of the mounting holes 12 in a pressed state, and the convex portions 44 protrude toward the bottom surface 10 a. Therefore, it is possible to prevent the soldering pins 40 from coming off the heat sink 10.

Since the convex portion 44 of the engaging portion 42 is formed to have flexibility in the width direction W, power is supplied to the printed wiring board 16 after soldering and the heat sink 10 expands due to heat. Also, following the change in the shape of the screw groove 12a of the mounting hole 12, the convex portion 44 is elastically deformed by the restoring force. Therefore, the screw groove 12a is always pressed by the convex portion 44, and the engagement between the soldering pin 40 and the heat sink 10 can be reliably maintained.

FIG. 11 shows a third embodiment (corresponding to claims 1, 4 and 5) of a heat sink soldering structure according to the present invention. In this embodiment, a plate-shaped soldering pin 58 and a soldering pin 60 are used in combination. The solder pins 58, 60
Except for slits 62, 64, and 66, which will be described later, they are formed of the same material and in the same shape as the soldering pins 40 of the above-described second embodiment.
Engaging portion 42, convex portion 44, and projecting portion 4 having the same size as
8, a projecting piece 50, a stopper 52, and a guide 54.

Slits 62 and 64 are formed on the other end 70 of the soldering pins 58 and 60, respectively, toward the one end 68. The widths of the slits 62 and 64 are formed larger than the slits 46 of the soldering pins 40 of the second embodiment. The slit 62 is formed longer than the slit 64. A slit 66 is formed at one end 68 of the soldering pin 60 toward the other end 70. The bottom of the slit 66 is formed at the same position as the bottom of the slit 60 of the soldering pin 58.

As shown in FIG. 12, a support recess 56 is formed in the heat sink 10 in a cross shape around the mounting hole 12. In this embodiment, the same printed wiring board 16 as that in the first and second embodiments is used. In the above-described soldering structure of the heat sink, the slit 62 of the soldering pin 58 and the slit 66 of the soldering pin 60 are fitted to each other, and the soldering pin having a cross-shaped cross section is assembled.

The soldering pins 5 assembled in a cross shape
In FIGS. 8 and 60, each protrusion 44 is located at a position where it can be fitted into the screw groove 12 a of the mounting hole 12 of the heat sink 10, and each projection 48 is located at a position where it can be accommodated in the support recess 56 of the heat sink 10. Each stop 52 is provided with a through hole 18.
Project outside the inner diameter D. Then, in the same manner as in the first and second embodiments described above, one end 68 is fixed to the mounting hole 12 of the heat sink 10, and the other end 70 is inserted into the through hole 18 of the printed wiring board 16 and soldered. .

The same effect as that of the first and second embodiments can be obtained in the heat sink soldering structure of this embodiment, but in this embodiment,
Since the plate-shaped soldering pins 46 and 58 are assembled to form a cross-shaped soldering pin, the heat sink 10 can be stably supported on the printed wiring board 16 even though the material is a plate. it can.

In the first embodiment described above, the example in which the projecting pieces 28 are formed at two places has been described. However, the present invention is not limited to such an embodiment.
It may be formed at three places or four places. Further, in the above-described embodiment, the example in which the soldering pins 14 and 40 are formed from phosphor bronze has been described. However, the present invention is not limited to such an embodiment. The guide may be plated with a metal such as nickel.

In the first embodiment described above, a projecting portion projecting outward is formed on the other end 14b side of the engaging portion 24 of the soldering pin 14, and the heat sink 10
A support recess for accommodating the protruding portion may be formed. In the above-described embodiment, the number of soldering pins to be inserted into the heat sink 10 is not specified, but may be singular or plural, and may be set according to the size and weight of the heat sink 10. Particularly, in the second embodiment, when a plurality of soldering pins 40 are inserted into the heat sink 10, the soldering pins 40 are inserted so as to be orthogonal to each other, so that the heat sink 10 can be stably printed. It can be supported on a plate 16.

[0066]

According to the first aspect of the present invention, the heat transferred from the soldering pins to the heat sink during soldering can be reduced. Therefore, soldering the heat sink to the printed wiring board
Can be done in a short time. The stop provided at the other end of the soldering pin can prevent the heat sink from floating or tilting from the printed wiring board during soldering. Therefore, soldering of the heat sink to the printed wiring board can be reliably performed,
The heat sink can be securely fixed to the printed wiring board.

In the soldering structure of the heat sink according to the second aspect, the contact portion between the protrusion and the screw groove can be reduced, and the heat transmitted from the soldering pin to the heat sink during soldering can be further reduced. it can. According to the third aspect of the present invention, the soldering pins can be easily formed.

The engagement between the soldering pin and the heat sink can be reliably maintained. In the soldering structure of the heat sink according to the fourth aspect, the stopper can be easily inserted into the through-hole only by inserting the soldering pin toward the through-hole. In the heat sink soldering structure according to the fifth aspect, the printed wiring board is securely sandwiched between the heat sink and the stopper regardless of the length of the mounting hole, the accuracy of the screw groove, and the accuracy of the protrusion of the engaging portion. Can be.

[Brief description of the drawings]

FIG. 1 is a first view of a soldering structure of a heat sink of the present invention.
It is a perspective view which shows embodiment.

FIG. 2 is an explanatory diagram showing details of a stopper in FIG. 1;

FIG. 3 is a top view showing details of an engagement portion and a cutout recess in FIG. 1;

FIG. 4 is a sectional view of FIG.

FIG. 5 is a cross-sectional view showing a state where a soldering pin is fixed to a heat sink in the first embodiment.

FIG. 6 is a cross-sectional view showing a state in which soldering pins fixed to a heat sink are inserted into through holes of a printed wiring board in the first embodiment.

FIG. 7 is a cross-sectional view showing a state in which soldering pins are inserted into through holes of a printed wiring board in the first embodiment.

FIG. 8 is a cross-sectional view showing a state in which the printed wiring board is pulled up from a solder bath in the first embodiment.

FIG. 9 shows a second example of the soldering structure of the heat sink of the present invention.
It is a perspective view which shows embodiment.

FIG. 10 is a sectional view of FIG. 9;

FIG. 11 is a plan view showing a third embodiment of the soldering structure of the heat sink according to the present invention.

FIG. 12 is a perspective view showing a state in which soldering pins are assembled in a third embodiment.

FIG. 13 is a cross-sectional view showing a soldering structure of a conventional heat sink.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Heat sink 10a Bottom surface 12 Mounting hole 12a Screw groove 12b Bottom part 14 Solder pin 14a One end 14b Other end 16 Printed wiring board 16a Component mounting surface 16b Soldering surface 18 Through hole 20 Land 22 Notch recess 24 Engagement part 24a End 26 Screw Groove 28 Projection piece 30 Slit 32 Stop part 32a Opposing surface 34 Guide part 36 Solder 36a Solder 38 Solder tank 40 Soldering pin 40a One end 40b Other end 42 Engagement 44 Convex part 46 Slit 48 Projection part 50 Projection piece 52 Stop part 54 Guide portion 56 Support recess 58, 60 Soldering pin 62, 64, 66 Slit 68 One end 70 Other end A1, A2 Center angle B Axis length direction C Cross-sectional direction D Center axis D1 Inner diameter D2 Root diameter L1, L2, L3, L4 Distance L5, L6 Length L7 Depth L , L9, L10 distance L11, L12 length L13 depth L14, L15 interval T1 thickness

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 7-32995 (JP, U) JP-A 57-17197 (JP, U) JP-A 4-44191 (JP, U) JP-A 60- 156792 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 23/40 H05K 7/20

Claims (5)

(57) [Claims] An end of a soldering pin is inserted and fixed in a mounting hole of a heat sink, and the other end of the soldering pin protruding from the mounting hole is inserted into a through hole provided in a printed wiring board. In a soldering structure of a heat sink, wherein the other end protruding from a soldering surface opposite to the component mounting surface and being inserted from a component mounting surface of the board is soldered to the printed wiring board, A screw groove is provided on the inner surface of the hole, and a plurality of protrusions screwed or fitted into the screw groove are formed along the axial direction around the one end of the soldering pin. A plurality of protruding pieces having flexibility in a cross-sectional direction are provided on the other end side of the soldering pin via a slit extending from the other end along an axial length direction. The said The soldering of the heat sink, wherein a tip portion of the protruding piece is provided with a stopper which is in contact with the soldering surface around the through hole and can be inserted into the through hole when the protruding piece is bent. Construction. 2. The soldering structure for a heat sink according to claim 1, wherein the soldering pin has a substantially circular cross section, and the engaging portion is provided at the one end of the columnar shape at a predetermined interval in a circumferential direction. A heat sink soldering structure, characterized in that a notch recess recessed toward the center side from each of the protrusions is provided between each of the engagement portions. 3. The soldering structure for a heat sink according to claim 1, wherein the soldering pin has a plate shape, and the engagement portions are provided on both sides of the plate-shaped one end in a cross-sectional direction. Each of the protrusions is provided with the flexible protrusion, the protrusions are provided on both sides of the slit formed along a central axis, and the stoppers are provided outside the respective protrusions. A heat sink soldering structure. 4. The soldering structure for a heat sink according to claim 1, wherein each of the stoppers is provided with a guide part whose front end is inclined toward the central axis. A soldering structure for a heat sink. 5. The soldering structure for a heat sink according to claim 1, wherein the other end of the engaging portion of the soldering pin has an outwardly projecting portion. A heat sink soldering structure, wherein a support concave portion having a shape corresponding to the projecting portion is provided on a bottom surface of the heat sink where the mounting hole is opened.