JP7192469B2 - Mounting structure of insulated circuit board with heat sink to housing - Google Patents

Description

The present invention relates to a structure for attaching an insulating circuit board with a heat sink, in which a heat sink is bonded to an insulating circuit board such as a power module board used in a semiconductor device that controls large currents and high voltages, to a housing.

Power module substrates include insulating circuit substrates in which a circuit layer made of aluminum or an aluminum alloy is formed on one side of an insulating layer made of a ceramic substrate such as aluminum nitride, or insulation in which a copper layer is bonded to a circuit layer. Circuit boards are known. When these are applied to an LED (Light Emitting Diode) heat dissipation module, since no metal layer is provided on the back surface of the ceramic substrate, an insulation circuit is formed during bonding due to the difference in thermal expansion coefficient between the ceramic substrate and the circuit layer. The substrate basically warps in a concave shape when viewed from the circuit layer side. On the other hand, with regard to the insulated circuit board with a heat sink, in which the heat sink is provided on the side opposite to the circuit layer of the insulated circuit board, most warp in a convex shape when viewed from the circuit layer side, but the circuit layer is provided with a copper layer. Depending on the structure, it may warp concavely when viewed from the circuit layer side.

As a method for improving the warpage of such an insulating circuit board with a heatsink, for example, a method for manufacturing a power module board with a heatsink described in Patent Document 1 is known. In this manufacturing method, the heat sink is formed of a material having a high yield stress with respect to the metal layer, and when the heat sink and the power module substrate are joined together, the laminate of the heat sink and the power module substrate is aligned with the heat sink in the stacking direction. A power module substrate with a heatsink with reduced warpage is obtained by keeping the substrate in a heated state for a predetermined period of time and then cooling it.

JP 2015-76551 A

Since the power module substrate with a heat sink manufactured by the method for manufacturing a power module substrate with a heat sink described in the above-mentioned Patent Document 1 has a small amount of warpage, the effect on the module performance of the power module using this is small. rice field. However, when an LED element is used as an electronic component and an insulated circuit board with a heat sink is used as an LED heat dissipation module with a light distribution control function, the mounting position and angle of the LED element on the mounting surface of the circuit layer must be extremely precise. Since it must be controlled, even a slight warp, which was not a problem when used as a power module, causes the optical axis of each light source to shift, making it difficult to use as an LED heat dissipation module.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a structure for mounting an insulated circuit board with a heat sink to a housing, which is capable of improving the flatness of the circuit layer on which electronic components are mounted. and

The structure for attaching an insulating circuit board with a heat sink to a housing according to the present invention comprises: an insulating circuit board having a circuit layer formed on one surface of a ceramic substrate and a metal layer formed on the other surface ; is a structure for mounting an insulated circuit board with a heat sink and a heat sink bonded to the opposite surface by brazing to a housing, wherein the outer peripheral portion of the circuit layer is pressed toward the housing by a pressing member. and the pressing member is fixed to the housing while the heat sink is pressed against the housing.

Here, when the insulated circuit board with the heat sink is along the concave shape, the circuit layer also has a shape (so-called mortar shape) in which the center is the deepest and curves upward toward the outer peripheral portion. For this reason, the flatness of the circuit layer is low, and when an LED element or the like is mounted on the mounting surface located inside the outer peripheral portion of the circuit layer and used as an LED heat dissipation module, the LED element (LED light source) emits light. The optical axis of light deviates, and the light distribution control function deteriorates. On the other hand, in the present invention, the insulated circuit board with a heat sink has the outer peripheral portion of the circuit layer pressed against the housing by fixing the pressing member to the housing while pressing the outer peripheral portion of the circuit layer with the pressing member. A pressing force is generated that presses toward. Therefore, the flatness of the circuit layer can be improved. That is, it is possible to improve the flatness of the mounting surface of the circuit layer on which the LED elements and the like are mounted.

As one aspect of the mounting structure of the insulated circuit board with a heat sink to the housing of the present invention, the pressing member includes a circuit layer contact portion that contacts the outer peripheral portion of the circuit layer, and a circuit layer contact portion that contacts the circuit layer contact portion. a heat sink contacting portion connected to and contacting the heat sink, wherein the heat sink contacting portion is fixed to the housing via the heat sink.

In the above aspect, since the heat sink abutting portion of the pressing member is fixed to the housing through the heat sink, the heat sink is pressed toward the housing, and warping of the heat sink can be improved. Therefore, the heat sink contact portion of the pressing member that contacts the heat sink can reliably contact the heat sink, so that the circuit layer contact portion connected to the heat sink contact portion can reliably cover the outer peripheral portion of the circuit layer. It can be pressed against the body. Therefore, the flatness of the circuit layer can be reliably improved.

In another aspect of the structure for mounting an insulated circuit board with a heat sink to a housing according to another aspect of the present invention, the pressing member includes a circuit layer contact portion that contacts an outer peripheral portion of the circuit layer, and a circuit layer contact portion that contacts the outer peripheral portion of the circuit layer. and a housing abutting part connected to the housing and abutting against the housing, wherein the housing abutting part is fixed to the housing.

In the above aspect, since the housing contacting portion connected to the circuit layer contacting portion of the pressing member is fixed to the housing, the circuit layer contacting portion connected to the housing contacting portion presses the outer circumference of the circuit layer. can be pressed toward the housing. Therefore, regardless of the degree of warping of the heat sink, the flatness of the circuit layer can be reliably improved.

As still another aspect of the structure for mounting an insulated circuit board with a heatsink to a housing according to the present invention, the heatsink has a plurality of fins on the surface opposite to the ceramic substrate, and the housing has and an opening for accommodating the plurality of fins when the insulated circuit board with a heat sink is fixed to the housing.

In the above aspect, even if the heat sink has a plurality of fins, the fins are accommodated in the opening when fixed to the housing, so that the heat dissipation performance of the insulated circuit board with the heat sink can be enhanced.

As still another aspect of the mounting structure of the insulated circuit board with heatsink of the present invention to the housing, the insulation with heatsink is interposed between the heatsink and the surface of the housing that contacts the heatsink via grease. A circuit board is attached to the housing.

The grease preferably contains aluminum powder or carbon powder.
In the above aspect, since the grease is provided between the heat sink and the surface of the housing that contacts the heat sink, the heat of the heat sink can be easily transferred to the housing, and the heat of the heat sink can be dissipated through the housing. Therefore, it is possible to further improve the heat dissipation performance of the insulated circuit board with the heat sink.

In still another aspect of the mounting structure of the insulated circuit board with a heat sink of the present invention to the housing, an LED element is provided on the mounting surface inside the outer peripheral portion of the circuit layer.

In the above aspect, since the mounting surface of the circuit layer on which the LED elements and the like are mounted has a high degree of flatness, it is possible to suppress deviation of the optical axis of the light emitted from the LED elements. Therefore, it can be appropriately used as a housing to which the insulated circuit board with a heat sink is fixed, that is, as an LED heat dissipation module.

According to the present invention, it is possible to improve the flatness of the circuit layer that serves as the mounting surface for electronic components and the like.

1 is a cross-sectional view showing an LED heat dissipation module using a structure for attaching an insulated circuit board with a heat sink to a housing according to the first embodiment of the present invention; FIG. FIG. 2 is a plan view of the LED heat dissipation module shown in FIG. 1; FIG. 4 is a cross-sectional view showing an LED heat dissipation module according to a first modification of the first embodiment; FIG. 4 is a cross-sectional view showing an LED heat dissipation module according to a second modification of the first embodiment; FIG. 4 is a cross-sectional view of an LED heat dissipation module according to a second embodiment of the present invention; FIG. 4 is a cross-sectional view of an LED heat dissipation module according to a third embodiment of the present invention;

[First embodiment]
A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of an LED heat dissipation module 100 according to the first embodiment, and FIG. 2 is a plan view of the LED heat dissipation module 100. As shown in FIG. Note that the cross-sectional view of the LED heat dissipation module 100 in FIG. 1 is a cross-sectional view taken along line A1-A1 in FIG.

[Schematic configuration of LED heat dissipation module]
The LED heat dissipation module 100 according to this embodiment is configured by attaching the insulating circuit board 1 with a heat sink to a housing 50 as shown in FIG. Such an LED heat dissipation module 100 is used, for example, in automobile headlamps and the like.

[Configuration of insulation circuit board with heat sink]
This insulating circuit board 1 with a heatsink is obtained by bonding a heatsink 20 to an insulating circuit board 10, and an LED element 30 is provided on the insulating circuit board 1 with a heatsink. Specifically, the insulating circuit board 10 is a so-called power module board, and four LED elements 30 are mounted on the upper surface of the insulating circuit board 10 as shown in FIGS. becomes. In addition, although the LED element 30 is provided in this embodiment, it is not limited to this, and is, for example, an electronic component including a semiconductor, such as an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal Oxide Semiconductor Field Effect Transistor). , FWD (Free Wheeling Diode), etc. are selected.

In this case, although not shown, the LED element 30 is provided with an upper electrode portion on the upper portion and a lower electrode portion on the lower portion, and the lower electrode portion is joined to the upper surface 121 of the circuit layer 12 by soldering or the like. By doing so, the LED element 30 is mounted on the upper surface 121 of the circuit layer 12 . For example, in the present embodiment, four are mounted on the mounting surface Ar2 located inside the outer peripheral portion Ar1 on the upper surface 121 of the circuit layer 12 . Also, the upper electrode portion of the LED element 30 is connected to the circuit electrode portion of the circuit layer 12 or the like via a lead frame or the like joined by solder or the like, and the LED module 40 is manufactured.

[Configuration of insulation circuit board]
The insulating circuit board 10 includes a ceramic substrate 11 , a circuit layer 12 formed on one surface of the ceramic substrate 11 , and a metal layer 13 formed on the other surface of the ceramic substrate 11 .
The ceramic substrate 11 is an insulating material that prevents electrical connection between the circuit layer 12 and the metal layer 13, and is made of, for example, aluminum nitride (AlN), silicon nitride _{( Si3N4} ), alumina _{( Al2O3} ). etc., and its thickness is 0.2 mm to 1.2 mm.

The circuit layer 12 is bonded to the ceramic substrate 11 . This circuit layer 12 is made of pure aluminum with a purity of 99% by mass or more (for example, pure aluminum in the 1000s according to JIS standards, particularly 1N90 (purity of 99.9% by mass or more: so-called 3N aluminum) or 1N99 (purity of 99.99% by mass). % or more: so-called 4N aluminum), aluminum alloys such as A6063 series, etc. can be used, and the thickness thereof is set to 0.05 mm to 0.2 mm.
The metal layer 13 is made of pure aluminum or an aluminum alloy with a purity of 99% by mass or more, and JIS standard 1000 aluminum, particularly 1N99 (purity of 99.99% by mass or more: so-called 4N aluminum) can be used. The thickness is set between 0.6 mm and 1.6 mm.

The circuit layer 12 and the metal layer 13 are laminated in the order of the circuit layer 12, the ceramic substrate 11, and the metal layer 13 via, for example, an Al--Si or Al--Si--Mg brazing material. are pressed in the stacking direction and heated to be joined to form the insulated circuit board 10 .

[Heat sink configuration]
The heat sink 20 joined to the insulating circuit board 10 is formed by forging an aluminum alloy such as A6063 series. The metal layer 13 of the insulating circuit board 10 is laminated on the upper surface of the heat sink 20 via an Al--Si--Mg brazing material. are joined together to form the insulated circuit board 1 with a heat sink.

Next, a structure for attaching the insulating circuit board 1 (LED module 40) with a heat sink according to the present embodiment to the housing 50 will be described.
As shown in FIGS. 1 and 2, the insulating circuit board 1 with a heat sink is pressed by a pressing member 60 that presses the outer peripheral portion Ar1 of the upper surface 121 of the circuit layer 12 toward the housing 50. It is fixed to body 50 . The pressing member 60 is fixed to the housing 50 by a fixing member 70 configured by a screw, with the pressing member 60 and the heat sink 20 overlapping each other.

[Configuration of Pressing Member]
The pressing member 60 is made of, for example, SUS (stainless steel). 1 and 2, the pressing member 60 includes a circuit layer contact portion 61 contacting the outer peripheral portion Ar1 of the circuit layer 12, and a heat sink connected to the circuit layer contact portion 61 and contacting the heat sink 20. and a contact portion 62 . As shown in FIGS. 1 and 2, the circuit layer contact portion 61 is formed in a rectangular plate shape and has a rectangular opening 611 in the center. The opening 611 is arranged to face the mounting surface Ar2 located inside the outer peripheral portion Ar1 of the upper surface 121 of the circuit layer 12 when the pressing member 60 is fixed to the housing 50 . That is, the LED elements 30 arranged on the mounting surface Ar2 of the circuit layer 12 are exposed to the outside through the opening 611 .

A heat sink contact portion 62 is connected to the outer peripheral end portion of the circuit layer contact portion 61 . The heat sink contacting portion 62 includes a cylindrical portion 621 that extends linearly from the outer peripheral end of the lower surface 612 of the circuit layer contacting portion 61 toward the housing 50 , and a cylindrical portion 621 that extends outward from the lower end of the cylindrical portion 621 . and an extending contact portion 622 . Of these, the contact portion 622 contacts the upper surface of the heat sink 20 with its lower surface 623 as shown in FIG.

Further, the width L1 of the circuit layer contact portion 61 is set to 5 mm to 10 mm, and the range of 2 mm to 5 mm from the opening end contacts the outer peripheral portion Ar1 of the circuit layer 12. FIG. That is, the width dimension L0 of the outer peripheral portion Ar1 is set to 2 mm to 5 mm. The width dimension L2 of the heat sink contact portion 62 (the width dimension of the surface contacting the heat sink 20) is set to 10 mm to 20 mm. Further, the thickness dimension L3 of the pressing member 60 is set to 3 mm to 10 mm, and the thickness dimension of the circuit layer contact portion 61 and the heat sink contact portion 62 (contact portion 622) is the same. Furthermore, the dimension L4 from the lower surface 623 (upper surface of the heat sink 20) of the contact portion 622 to the lower surface 612 of the circuit layer contact portion 61 is set to be the same thickness as the insulating circuit board 10 or slightly smaller, for example, 2 mm to 2.0 mm. It is set at 3mm. Further, the width dimension L5 of the pressing member 60 is set to 20 mm to 45 mm, which is slightly smaller than the width dimension of the heat sink 20. As shown in FIG. Note that the width dimension L5 of the pressing member 60 may be the same as the width dimension of the heat sink 20 .

Such a pressing member 60 is configured such that the lower surface 612 of the circuit layer contact portion 61 is in contact with the outer peripheral portion Ar1 of the circuit layer 12 and the upper surface of the heat sink 20, and the fixing member 70 is in contact with the heat sink. The contact portion 62 and the heat sink 20 are penetrated and fixed to the housing 50 . As a result, the heat sink contact portion 62 is pressed toward the housing 50 , and the outer peripheral portion Ar<b>1 of the circuit layer 12 is pressed toward the housing 50 . Furthermore, the heat sink 20 is also pressed against the housing 50 . This improves the flatness of the mounting surface Ar2 of the circuit layer 12 and the heat sink 20 .

As shown in FIG. 2, the fixing member 70 is provided at each of the four corners of the pressing member 60 and between them. , or more fixing members 70 may be provided. Moreover, although the fixing member 70 is configured by a screw, it is not limited to this, and may be configured by a clamp or the like, for example.

In addition, the insulating circuit board 1 with a heat sink is attached to the housing 50 via grease 41 containing aluminum powder or carbon powder between the heat sink 20 and the surface of the housing 50 that contacts the heat sink 20. there is In this embodiment, the insulating circuit board 1 with a heat sink is fixed to the housing 50 via the grease 41, but the grease 41 may be omitted.

In the present embodiment, the circuit layer contact portion 61 is arranged to overlap the entire area of the outer peripheral portion Ar1 of the circuit layer 12, but is not limited to this. It may be in a shape that does not overlap with the outer peripheral portion Ar1 of the circuit layer 12, or it may be in a shape that presses only two opposite sides of the outer peripheral portion Ar1 of the circuit layer 12. FIG. That is, the shape of the circuit layer 12 does not matter as long as the flatness of the circuit layer 12 can be improved.

In this embodiment, the insulated circuit board 1 with a heat sink is fixed to the housing 50 in a state where the outer peripheral portion Ar1 of the circuit layer 12 is directed toward the housing 50 and pressed by the pressing member 60. degree can be improved. Moreover, since the heat sink 20 is fixed to the housing 50 in a state of being pressed toward the housing 50 by the fixing member 70, warping of the heat sink 20 can be reduced. For this reason, the heat sink contact portion 62 of the pressing member 60 that contacts the heat sink 20 can reliably contact the upper surface of the heat sink 20 . 12 can be reliably pressed toward the housing 50 . That is, the flatness of the mounting surface Ar2 of the circuit layer 12 on which the LED elements 30 and the like are mounted can be improved. Since the mounting surface Ar2 of the circuit layer 12 on which the LED elements 30 and the like are mounted has high flatness, it is possible to prevent the optical axis of the light emitted from the LED elements 30 from shifting. Therefore, it can be appropriately used as the housing 50 to which the insulated circuit board 1 with a heat sink is fixed, that is, as the LED heat dissipation module 100 .

Further, in the above-described embodiment, the grease 41 is provided between the heat sink 20 and the surface of the housing 50 that contacts the heat sink 20 , so that the heat of the heat sink 20 can be easily transferred to the housing 50 . The heat of the heat sink 20 can be dissipated through the . Therefore, the heat dissipation performance of the insulating circuit board 1 with a heat sink can be further enhanced.

[First Modification of First Embodiment]
In the above embodiment, the circuit layer 12 is composed of a single metal layer composed of pure aluminum, an aluminum alloy, or the like with a purity of 99% by mass or more. may be composed of a plurality of metal layers.
FIG. 3 is a cross-sectional view showing a cross section of the LED heat dissipation module 100A according to the first modified example of the first embodiment. In addition, in the following description, the description of the same or substantially the same parts as those of the first embodiment will be omitted or simplified.

As shown in FIG. 3, the circuit layer 12 of this modification includes a first circuit layer 14 bonded to the ceramic substrate 11 and a second circuit layer 15 bonded to the upper surface of the first circuit layer 14. there is Among them, the first circuit layer 14 is made of pure aluminum or an aluminum alloy. On the other hand, the second circuit layer 15 is made of pure copper, oxygen-free copper, or copper alloy. The thickness of the first circuit layer 14 is set to 0.02 mm to 0.2 mm, and the thickness of the second circuit layer 15 is set to 0.2 mm to 1 mm. be done.
Then, the second circuit layer 15, the first circuit layer 14, the ceramic substrate 11, and the metal layer 13 are laminated in this order via, for example, an Al-Si-based or Al-Si-Mg-based brazing material, and these are laminated. By pressurizing and heating in the direction, they are joined to form the insulated circuit board 10A.

In this modified example, since the circuit layer 12A of the insulated circuit board 10A includes the first circuit layer 14 and the second circuit layer 15, the thickness is greater than that of the insulated circuit board 10 of the first embodiment. big. Therefore, in this modification, the dimension L6 from the lower surface 623 (upper surface of the heat sink 20) of the contact portion 622 of the heat sink contact portion 62 to the lower surface 612 of the circuit layer contact portion 61 is larger than the dimension L4, and , the thickness is set to be the same as or slightly smaller than that of the insulating circuit board 10A, for example, 2.5 mm to 2.8 mm.

[Second Modification of First Embodiment]
In the above-described embodiment, the insulating circuit board 10 has the metal layer 13, but the invention is not limited to this, and the metal layer 13 may be omitted.
FIG. 4 is a cross-sectional view showing a cross section of an LED heat dissipation module 100B according to a second modified example of the first embodiment. In addition, in the following description, the description of the same or substantially the same parts as those of the first embodiment will be omitted or simplified.

In this modified example, the insulating circuit board 10B does not have the metal layer 13 . Therefore, a heat sink 20 is directly bonded to the surface of the ceramic substrate 11 opposite to the circuit layer 12 . Further, in this modified example, since the insulating circuit board 10B does not include the metal layer 13, the thickness thereof is smaller than that of the insulating circuit board 10 of the first embodiment. Therefore, in this modification, the dimension L7 from the lower surface 623 (upper surface of the heat sink 20) of the contact portion 622 of the heat sink contact portion 62 to the lower surface 612 of the circuit layer contact portion 61 is smaller than the dimension L4, and , the thickness is set to be the same as or slightly smaller than that of the insulating circuit board 10B, for example, 0.5 mm to 0.7 mm.

[Second embodiment]
Next, a second embodiment of the present invention will be described with reference to the drawings.
FIG. 5 is a cross-sectional view showing a cross section of the LED heat dissipation module 100C according to the second embodiment. The LED heat dissipation module 100C of this embodiment is the same as the first embodiment in that the heat sink 20C has a plurality of pin-shaped fins 201 and the housing 50C has an opening 501 that accommodates the plurality of pin-shaped fins 201. Different from the embodiment.
In addition, in the following description, the description of the same or substantially the same parts as those of the first embodiment will be omitted or simplified.

In this embodiment, as shown in FIG. 5, a plurality of pin-shaped fins 201 are erected on the surface of the heat sink 20C opposite to the bonding surface with the insulating circuit board 10 . The height of the plurality of pin-shaped fins 201 is set to 0.5 to 10 mm. The shape of the fins erected on the heat sink 20C is not particularly limited, and in addition to the pin-shaped fins 201 as in the present embodiment, diamond-shaped fins, strip-shaped fins, or the like can be formed.
Further, the housing 50 has an opening 501, which is arranged to face a plurality of pin-shaped fins 201 erected on the heat sink 20C, and the insulating circuit board 1C with the heat sink is connected to the housing 50. It accommodates a plurality of pin-like fins 201 when fixed to the .

In this embodiment, the grease 41 is not arranged between the heat sink 20C and the housing 50, but the grease 41 may be arranged between them.
In this embodiment, even if the heat sink 20C has a plurality of pin-shaped fins 201, it is accommodated in the opening 501 when fixed to the housing 50, so the heat dissipation performance of the insulated circuit board 1C with the heat sink is can increase

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to the drawings.
FIG. 6 is a cross-sectional view showing a cross section of the LED heat dissipation module 100D according to this embodiment.
The LED heat dissipation module 100D of this embodiment includes a heat sink 20C as in the second embodiment, and the housing 50C includes an opening 501. In addition, instead of the pressing member 60, a pressing member 60D It is different from the first embodiment in that it has
In addition, in the following description, the description of the same or substantially the same parts as those of the first and second embodiments will be omitted or simplified.

As shown in FIG. 6, the pressing member 60D of the present embodiment is connected to the circuit layer contact portion 61D that contacts the outer peripheral portion Ar1 of the circuit layer 12, and the circuit layer contact portion 61D, and contacts the housing 50C. Thus, there is provided a housing contact portion 63 that presses the outer peripheral portion Ar1 of the circuit layer 12 toward the housing 50C by the circuit layer contact portion 61D. This circuit layer contact portion 61D is formed in substantially the same shape as the circuit layer contact portion 61 of the first embodiment, and includes a rectangular opening 611. As shown in FIG. Further, the width dimension L9 of the circuit layer contact portion 61D is set larger than the width dimension L1 of the circuit layer contact portion 61 of the first embodiment. Specifically, as shown in FIG. 6, the width dimension L9 of the circuit layer contact portion 61D is set to 10 mm or more and 30 mm or less, and its outer peripheral edge is located outside the outer peripheral edge of the heat sink 20C. there is Further, as in the first embodiment, a range of 2 mm to 5 mm from the open end of the circuit layer contact portion 61D contacts the outer peripheral portion Ar1 of the circuit layer 12. FIG. That is, the width dimension L0 of the outer peripheral portion Ar1 is the same as that of the first embodiment.

A housing contact portion 63 is connected to the outer peripheral end portion of the circuit layer contact portion 61D. The housing contact portion 63 includes a cylindrical portion 631 that extends linearly from the outer peripheral end of the lower surface 612 of the circuit layer contact portion 61D toward the housing 50C, and a cylindrical portion 631 that extends outward from the lower end of the cylindrical portion 631. and an abutment portion 632 extending along the length of the contact portion. Of these, the contact portion 632 has its lower surface 633 contacting the upper surface of the housing 50C, as shown in FIG. Further, the width dimension L2 of the housing contact portion 63 (the width dimension of the surface in contact with the housing 50C) is smaller than the width dimension L2 of the heat sink contact portion 62 of the first embodiment, for example, 10 mm or more and 15 mm or less. is set to Furthermore, the dimension L11 from the lower surface 633 (upper surface of the housing 50) of the contact portion 632 to the lower surface 612 of the circuit layer contact portion 61D is the same thickness as the portions of the insulating circuit board 10 and the heat sink 20 excluding the pin-shaped fins 201. or slightly smaller, for example, 7 mm to 7.3 mm. Further, the width dimension L8 of the pressing member 60D is set larger than the width dimension L5 of the pressing member 60 of the first embodiment and larger than the width of the heat sink 20C. This width dimension L8 is set to, for example, 60 mm or more.

Such a pressing member 60D is configured such that the lower surface 612 of the circuit layer contact portion 61D is in contact with the outer peripheral portion Ar1 of the circuit layer 12 and the upper surface of the housing 50C, and the fixing member 70 is in contact with the upper surface of the housing 50C. It is fixed to the housing 50C through the housing contact portion 63. As shown in FIG. As a result, the housing contact portion 63 is pressed toward the housing 50C, and the outer peripheral portion Ar1 of the circuit layer 12 is pressed toward the housing 50C. Thereby, the flatness of the mounting surface Ar2 of the circuit layer 12 is improved.
In this embodiment, since the heat sink 20C is not fixed by the fixing member 70, the heat sink 20C may be slightly concave when viewed from the circuit layer 12 side. For this reason, although not shown in FIG. 6, it is preferable to arrange grease 41 between the heat sink 20C and the portion of the housing 50C that contacts the heat sink 20C.

In the present embodiment, the housing contact portion 63 connected to the circuit layer contact portion 61D of the pressing member 60D is fixed to the housing 50C while being pressed toward the housing 50C. The flatness of the circuit layer 12 can be reliably improved regardless of the degree of .

In addition, detailed configurations are not limited to those of the embodiments, and various modifications can be made without departing from the scope of the present invention.
For example, in each of the above-described embodiments, the LED element 30 is mounted on the mounting surface Ar2 of the circuit layers 12 and 12A, but other electronic components may be mounted. That is, the present invention can be applied not only to LED heat radiation modules but also to power modules and the like.

As an insulating circuit board, a ceramic substrate made of silicon nitride (Si ₃ N ₄ ) and measuring 70 mm×70 mm in plan view and having a thickness of 0.32 mm was provided with a circuit layer made of an aluminum alloy of A6063 series on one side and on the other side. An insulated circuit board with a heatsink was manufactured by joining a metal layer made of 4N aluminum to a heatsink having an outer diameter of 100mm x 100mm and a thickness of 4mm. In addition, regarding these bonding, the circuit layer, the ceramic substrate, the metal layer and the heat sink are laminated via an Al-Si-Mg brazing material, and these are bonded by pressing and heating in the lamination direction, and the heat sink An insulated circuit board with

Then, one LED light source composed of a plurality of LED elements is mounted in the center of the circuit layer (mounting surface located inside the outer peripheral portion of the circuit layer) of the insulating circuit board with a heat sink to form an LED module, and this LED module is a housing. An LED heat dissipation module was manufactured by fixing it on the body. In Example 1, the pressure member shown in the first embodiment was used to press the outer peripheral portion of the circuit layer toward the housing and fix it to the housing to form an LED heat dissipation module. The thickness of the insulating circuit board and the distance from the upper surface of the heat sink to the lower surface of the pressing member were the same. On the other hand, in Comparative Example 1, the LED module was screw-fixed to the housing without using the pressing member to form an LED heat radiation module.
For the LED heat dissipation modules of Example 1 and Comparative Example 1 manufactured in this manner, the ratio of the amount of light traveling straight to the total amount of light (light amount ratio) was evaluated.

(Amount of warpage on mounting surface of circuit layer)
The flatness of the mounting surface is determined by measuring the mounting surface (10 mm × 10 mm) located inside the outer periphery of the upper surface of the circuit layer, using Thermoire PS200 manufactured by AkroMetrix, and obtaining the least square surface from the profile of the measurement surface. Using the least squares surface as a reference, the difference between the highest point and the lowest point was warped and measured.

(Light intensity ratio)
The light amount ratio is the ratio of the amount of light traveling straight to the total amount of light, and was measured using an illuminometer (LM331 manufactured by AS ONE). Specifically, the distance from the tip of the LED light source to the detection part of the illuminometer was set to 1000 mm, the diameter of the LED light source was set to 10 mm, and the diameter of the detection part was also set to 10 mm. Under this condition, the ratio of the light amount of light traveling straight from the LED light source to the total light amount of the LED light source was calculated. Table 1 shows the results.

As is clear from Table 1, in Example 1 in which the pressing member pressed the outer peripheral portion of the circuit layer, the warpage of the mounting surface was as small as 5 μm, so the light amount ratio was as high as 25.0%. On the other hand, in the comparative example in which the circuit layer was not pressed by the pressing member, the warpage of the mounting surface was as large as 30 μm, so the light amount ratio was as low as 8.7%. For this reason, it has been found that by attaching the circuit layer to the housing in a state where the outer peripheral portion of the circuit layer is pressed toward the housing by the pressing member, the warpage of the mounting surface can be reduced, and it can be used appropriately as an LED heat dissipation module.

1 1C Insulated circuit board with heat sink 10 10A 10B Insulated circuit board 11 Ceramic substrate 12 12A Circuit layer 13 Metal layer 14 First circuit layer 15 Second circuit layer 20 20C Heat sink 201 Pin-shaped fin 30 LED element 40 LED module 50 50C Housing 501 Opening 60 60D Pressing member 61 61D Circuit layer contacting portion 611 Opening 612 Lower surface 62 Heat sink contacting portion 63 Case contacting portion 621 631 Cylindrical portion 622 632 Contacting portion 623 633 Lower surface 100 100A 100B 100C 100D LED heat dissipation module

Claims (6)

A heat sink comprising: an insulating circuit board having a circuit layer formed on one side of a ceramic substrate and a metal layer formed on the other side; and a heat sink brazed to the side of the metal layer opposite to the circuit layer. A mounting structure for an insulated circuit board with a housing,
The insulation with a heat sink, wherein the outer peripheral portion of the circuit layer is pressed toward the housing by a pressing member, and the pressing member is fixed to the housing while the heat sink is pressed against the housing. Mounting structure to the housing of the circuit board. The pressing member has a circuit layer contact portion that contacts an outer peripheral portion of the circuit layer, and a heat sink contact portion that is connected to the circuit layer contact portion and contacts the heat sink,
2. The structure for attaching an insulated circuit board with a heat sink to a housing according to claim 1, wherein the heat sink abutting portion is fixed to the housing through the heat sink. The pressing member has a circuit layer contacting portion that contacts the outer peripheral portion of the circuit layer, and a housing contacting portion that is connected to the circuit layer contacting portion and contacts the housing. 2. The structure for attaching an insulated circuit board with a heat sink to a housing according to claim 1, wherein the body contact portion is fixed to the housing. The heat sink has a plurality of fins on the surface opposite to the ceramic substrate,
4. The housing according to any one of claims 1 to 3, wherein the housing has an opening that accommodates the plurality of fins when the insulating circuit board with a heat sink is fixed to the housing. A structure for attaching an insulated circuit board with a heat sink to a housing. 5. The insulated circuit board with a heat sink is attached to the housing via grease between the heat sink and a surface of the housing that contacts the heat sink. structure for attaching an insulated circuit board with a heat sink to a housing. 6. The insulated circuit board with a heat sink according to claim 1, wherein an LED element is provided on the mounting surface inside the outer peripheral portion of the circuit layer. mounting structure.

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