JP2020096124A - Mounting structure of insulated circuit board with heat sink to housing - Google Patents

Abstract

To provide a mounting structure of an insulated circuit board with a heat sink to a housing, which is capable of improving the flatness of a circuit layer which is a mounting surface of an electronic part and the like.SOLUTION: A mounting structure of an insulated circuit board with a heat sink to a housing includes an insulated circuit board having a circuit layer formed on one surface of a ceramic substrate, and a heat sink arranged on the surface of the insulated circuit board opposite to the circuit layer, and a pressing member is fixed to the housing while the outer peripheral portion of the circuit layer is pressed toward the housing by the pressing member.SELECTED DRAWING: Figure 1

Description

The present invention relates to a structure for mounting an insulated circuit board with a heat sink, in which a heat sink is joined to an insulated circuit board such as a power module board used in a semiconductor device for controlling a large current and a high voltage, to a housing.

As a power module substrate, an insulating circuit substrate in which a circuit layer made of aluminum or an aluminum alloy is formed on one surface of an insulating layer made of a ceramic substrate such as aluminum nitride, or an insulation in which a copper layer is bonded to the circuit layer. Circuit boards are known. When these are applied to an LED (Light Emitting Diode) heat dissipation module, a metal layer is not provided on the back surface of the ceramic substrate, and therefore, due to the difference in thermal expansion coefficient between the ceramic substrate and the circuit layer, an insulation circuit is formed at the time of bonding. The substrate basically warps in a concave shape when viewed from the circuit layer side. On the other hand, most insulated circuit boards with a heat sink in which a heat sink is provided on the surface of the insulated circuit board opposite to the circuit layer have a convex shape when viewed from the circuit layer side, but the circuit layer has a copper layer. In some cases, or depending on its configuration, the surface may warp in a concave shape when viewed from the circuit layer side.

As a method for improving the warp of such an insulated circuit board with a heat sink, for example, a manufacturing method of a power module board with a heat sink 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 at the time of joining the heat sink and the power module substrate, a laminated body of the heat sink and the power module substrate is provided with a heat sink in the laminating direction. Is to generate a concave warp when viewed from the opposite side, hold the heated state for a predetermined time, and then cool it to obtain a power module substrate with a heat sink having a reduced warp.

JP, 2005-76551, 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 Patent Document 1 described above has a small warpage, the influence on the module performance of the power module using this is small. It was 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 having a light distribution control function, the mounting position and the angle of the LED element on the mounting surface of the circuit layer are extremely precise. Since it needs to be controlled, even a slight warp, which is not a problem when used as a power module, becomes a factor that shifts the optical axis of each light source, and it may be difficult to use it as an LED heat dissipation module.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a structure for attaching an insulated circuit board with a heat sink to a housing, which can improve the flatness of a circuit layer that is a mounting surface of an electronic component or the like. And

The mounting structure of the insulated circuit board with a heat sink of the present invention to the housing is such that an insulating circuit board having a circuit layer formed on one surface of a ceramic substrate and a surface opposite to the circuit layer of the insulating circuit board. A structure for mounting an insulated circuit board with a heat sink disposed on a housing, wherein the pressing member is configured to press the outer peripheral portion of the circuit layer toward the housing with a pressing member. It is fixed to the case.

Here, when the insulated circuit board with a heat sink is along the concave shape, the circuit layer also has a shape in which the center thereof is deepest and warps upward toward the outer peripheral portion (so-called mortar shape). 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 shifts, and the light distribution control function deteriorates. On the other hand, in the present invention, in the insulated circuit board with the heat sink, the pressing member is fixed to the housing while the outer peripheral portion of the circuit layer is pressed by the pressing member, so that the outer peripheral portion of the circuit layer is fixed to the housing. A pressing force that pushes toward is generated. 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 element and the like are mounted.

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

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

As another aspect of the structure for mounting the insulated circuit board with the 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 the circuit layer contact portion. A housing contact portion that is connected to the housing and contacts the housing, and the housing contact portion is fixed to the housing.

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

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

In the above aspect, even when the heat sink has a plurality of fins, it is housed in the opening when being fixed to the housing, so that the heat dissipation performance of the insulated circuit board with the heat sink can be improved.

As still another aspect of the mounting structure of the insulated circuit board with a heat sink to the housing of the present invention, the insulation with a heat sink is provided via grease between the heat sink and a surface of the housing that abuts the heat sink. 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 radiated through the housing. Therefore, the heat dissipation performance of the insulated circuit board with the heat sink can be further improved.

In still another aspect of the mounting structure of the insulated circuit board with a heat sink to the housing of the present invention, 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 element or the like is mounted has high flatness, it is possible to prevent the optical axis of the light emitted from the LED element from shifting. Therefore, it can be appropriately used as a housing to which an insulated circuit board with a heat sink is fixed, that is, an LED heat dissipation module.

According to the present invention, it is possible to improve the flatness of a circuit layer that is a mounting surface of an electronic component or the like.

It is sectional drawing which shows the LED heat dissipation module using the attachment structure to the housing|casing of the insulated circuit board with a heat sink which concerns on 1st embodiment of this invention. It is a top view of the LED heat dissipation module shown in FIG. It is sectional drawing which shows the LED heat dissipation module which concerns on the 1st modification of the said 1st embodiment. It is sectional drawing which shows the LED heat dissipation module which concerns on the 2nd modification of the said 1st embodiment. It is sectional drawing of the LED heat dissipation module which concerns on 2nd embodiment of this invention. It is sectional drawing of the LED heat dissipation module which concerns on 3rd embodiment of this invention.

[First embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of the LED heat dissipation module 100 in the first embodiment, and FIG. 2 is a plan view of the LED heat dissipation module 100. The sectional view of the LED heat dissipation module 100 in FIG. 1 is a sectional view taken along the line A1-A1 of FIG.

[Schematic configuration of LED heat dissipation module]
As shown in FIG. 1, the LED heat dissipation module 100 according to the present embodiment is configured by attaching an insulated circuit board 1 with a heat sink to a housing 50. Such an LED heat dissipation module 100 is used, for example, in a headlamp of an automobile.

[Structure of insulated circuit board with heat sink]
The insulated circuit board with a heat sink 1 is provided with the LED element 30 on the insulated circuit board with a heat sink 1 in which the heat sink 20 is bonded to the insulated circuit board 10. 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 Although the LED element 30 is provided in the present embodiment, the present invention is not limited to this, and for example, it is an electronic component including a semiconductor such as an IGBT (Insulated Gate Bipolar Transistor) and a MOSFET (Metal Oxide Semiconductor Field 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. As a result, 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. Further, 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.

[Structure of insulated circuit board]
The insulated 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, for example, aluminum nitride (AlN), silicon nitride (Si ₃ N ₄ ), alumina (Al ₂ O ₃ ). The plate 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 having a purity of 99% by mass or more (for example, JIS standard 1000-grade pure aluminum, particularly 1N90 (purity 99.9% by mass or more: so-called 3N aluminum) or 1N99 (purity 99.99% by mass). % Or more: so-called 4N aluminum), aluminum alloy such as A6063 series, or the like can be used, and the thickness thereof is set to 0.05 mm to 0.2 mm.
For the metal layer 13, pure aluminum or aluminum alloy having a purity of 99% by mass or more is used, and in the JIS standard, aluminum of 1000 series, particularly 1N99 (purity 99.99% by mass or more: so-called 4N aluminum) can be used. The thickness is set to 0.6 mm to 1.6 mm.

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

[Structure of heat sink]
The heat sink 20 bonded to the insulated circuit board 10 is formed by forging an aluminum alloy such as A6063 series. The metal layer 13 of the insulated circuit board 10 is laminated on the upper surface of the heat sink 20 via an Al—Si—Mg-based brazing material, and these are pressurized and heated in the laminating direction to heat the insulated circuit board 10 to the heat sink 20. Are joined together to form the insulated circuit board 1 with a heat sink.

Next, a mounting structure of the insulated circuit board with heat sink 1 (LED module 40) of the present embodiment to the housing 50 will be described.
As shown in FIGS. 1 and 2, such an insulated circuit board 1 with a heat sink is a housing in a state of being pressed by a pressing member 60 that presses the outer peripheral portion Ar1 on the upper surface 121 of the circuit layer 12 toward the housing 50. It is fixed to the body 50. The pressing member 60 is fixed to the housing 50 by a fixing member 70 formed of a screw in a state where the pressing member 60 and the heat sink 20 overlap each other.

[Structure of pressing member]
The pressing member 60 is made of, for example, SUS (stainless steel) or the like. As shown in FIGS. 1 and 2, the pressing member 60 includes a circuit layer contact portion 61 that contacts the outer peripheral portion Ar1 of the circuit layer 12, and a heat sink that is connected to the circuit layer contact portion 61 and contacts 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 flat plate shape and has a rectangular opening 611 in the center. The opening 611 is arranged so as 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 element 30 arranged on the mounting surface Ar2 of the circuit layer 12 is exposed to the outside through the opening 611.

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

The width dimension 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 portion contacts the outer peripheral portion Ar1 of the circuit layer 12. That is, the width 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 (width dimension of the surface that contacts the heat sink 20) is set to 10 mm to 20 mm. The thickness dimension L3 of the pressing member 60 is set to 3 mm to 10 mm, and the circuit layer contact portion 61 and the heat sink contact portion 62 (contact portion 622) have the same thickness dimension. Further, the dimension L4 from the lower surface 623 of the contact portion 622 (upper surface of the heat sink 20) to the lower surface 612 of the circuit layer contact portion 61 is set to have the same thickness as the insulated circuit board 10 or slightly smaller, for example, 2 mm to 2. It is set to 3 mm. The width dimension L5 of the pressing member 60 is set to 20 mm to 45 mm, which is set to be slightly smaller than the width dimension of the heat sink 20. The width dimension L5 of the pressing member 60 may be the same as the width dimension of the heat sink 20.

In such a pressing member 60, with the lower surface 612 of the circuit layer contact portion 61 abutting on the outer peripheral portion Ar1 of the circuit layer 12 and the upper surface of the heat sink 20, the fixing member 70 has a heat sink. They penetrate the contact portion 62 and the heat sink 20 and are 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 Ar1 of the circuit layer 12 is pressed toward the housing 50. Furthermore, the heat sink 20 is also pressed by 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 the four corners of the pressing member 60 and one between them, but the fixing member 70 is not limited to this and is provided only at the four corners. Alternatively, more fixing members 70 may be provided. Further, although the fixing member 70 is configured by the screw, the fixing member 70 is not limited to this, and may be configured by a clamp or the like, for example.

In addition, the insulated circuit board with a heat sink 1 is attached to the housing 50 via the grease 41 containing aluminum powder or carbon powder between the heat sink 20 and the surface of the housing 50 that comes into contact with the heat sink 20. There is. In this embodiment, the insulated circuit board 1 with the 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 so as to overlap the entire area of the outer peripheral portion Ar1 of the circuit layer 12, but the present invention is not limited to this, and for example, the four corners of the circuit layer 12 are arranged. The shape may not be arranged so as to overlap with the portion, or the outer peripheral portion Ar1 of the circuit layer 12 may have a shape that presses only two opposing sides. 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 the present embodiment, the insulated circuit board with a heat sink 1 is fixed to the housing 50 in a state where the outer peripheral portion Ar1 of the circuit layer 12 is pressed by the pressing member 60 toward the housing 50. The degree can be improved. Further, since the heat sink 20 is fixed to the housing 50 while being pressed toward the housing 50 by the fixing member 70, the warpage of the heat sink 20 can be improved. Therefore, the heat sink contact portion 62 of the pressing member 60 that contacts the heat sink 20 can surely contact the upper surface of the heat sink 20, and thus the circuit layer contact portion 61 connected to the heat sink contact portion 62 allows the circuit layer The outer peripheral portion Ar1 of 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 element 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 a 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 with heat sink 1 is fixed, that is, the LED heat dissipation module 100.

Further, in the above-described embodiment, since the grease 41 is provided between the heat sink 20 and the surface of the housing 50 that contacts the heat sink 20, it is possible to easily transfer the heat of the heat sink 20 to the housing 50. The heat of the heat sink 20 can be dissipated via the. Therefore, the heat dissipation performance of the insulated circuit board 1 with a heat sink can be further improved.

[First Modification of First Embodiment]
In the above embodiment, the circuit layer 12 is configured to be a single metal layer made of pure aluminum or aluminum alloy having a purity of 99% by mass or more. However, the present invention is not limited to this. May be composed of a plurality of metal layers.
FIG. 3 is a cross-sectional view showing a cross section of an LED heat dissipation module 100A according to a first modification of the first embodiment. In the following description, description of the same or substantially the same parts as those in the first embodiment will be omitted or simplified.

As shown in FIG. 3, the circuit layer 12 of this modified example 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. Of these, 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 a copper alloy. The thickness of the first circuit layer 14 is set to 0.02 mm to 0.2 mm, the thickness of the second circuit layer 15 is set to 0.2 mm to 1 mm, and both have the same shape (rectangular flat plate shape). To 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 with a brazing material of Al-Si system or Al-Si-Mg system, for example, and these are laminated. By pressurizing in a direction and heating, they are joined to form the insulated circuit board 10A.

In addition, 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 thereof is smaller than that of the insulated circuit board 10 of the first embodiment. large. Therefore, in this modification, the dimension L6 from the lower surface 623 of the contact portion 622 of the heat sink contact portion 62 (the upper surface of the heat sink 20) 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 insulated circuit board 10A, for example, 2.5 mm to 2.8 mm.

[Second Modification of First Embodiment]
In the above embodiment, the insulated circuit board 10 has the metal layer 13, but the present 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 modification of the first embodiment. In the following description, description of the same or substantially the same parts as those in the first embodiment will be omitted or simplified.

In this modification, the insulated circuit board 10B does not include the metal layer 13. Therefore, the 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 insulated circuit board 10B does not include the metal layer 13, the thickness thereof is smaller than that of the insulated circuit board 10 of the first embodiment. Therefore, in this modification, the dimension L7 from the lower surface 623 of the contact portion 622 of the heat sink contact portion 62 (the upper surface of the heat sink 20) to the lower surface 612 of the circuit layer contact portion 61 is smaller than the dimension L4, and The thickness is the same as or slightly smaller than that of the insulated circuit board 10B, and is set to, 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. In the LED heat dissipation module 100C of the present embodiment, the heat sink 20C includes a plurality of pin-shaped fins 201, and the housing 50C includes an opening 501 that accommodates the plurality of pin-shaped fins 201. Different from the embodiment.
In the following description, description of the same or substantially the same parts as those in the first embodiment will be omitted or simplified.

In the present 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 joint surface with the insulating circuit board 10. The height of the plurality of pin-shaped fins 201 is 0.5 to 10 mm. The shape of the fins provided upright on the heat sink 20C is not particularly limited, and it is possible to form not only the pin-shaped fin 201 as in the present embodiment but also a diamond-shaped fin or a band-plate-shaped fin.
Further, the casing 50 includes an opening 501, and the opening 501 is arranged so as to face the plurality of pin-shaped fins 201 erected on the heat sink 20C, and the insulated circuit board with a heat sink 1C has the casing 50. The plurality of pin-shaped fins 201 are accommodated when fixed to the.

In the present embodiment, the grease 41 is not arranged between the heat sink 20C and the housing 50, but the present invention is not limited to this, and the grease 41 may be arranged between them.
In the present embodiment, even when the heat sink 20C has a plurality of pin-shaped fins 201, since it is housed in the opening 501 when fixed to the housing 50, the heat dissipation performance of the insulated circuit board with a heat sink 1C. Can be increased.

[Third embodiment]
Next, a third embodiment of the present invention will be described with reference to the drawings.
FIG. 6 is a sectional view showing a section of the LED heat dissipation module 100D according to the present embodiment.
The LED heat dissipation module 100D of the present embodiment includes a heat sink 20C as in the second embodiment, and the housing 50C includes an opening 501. In addition to the pressing member 60, a pressing member 60D is provided. It is different from the first embodiment in that it is provided with.
In the following description, 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, the casing contact portion 63 that presses the outer peripheral portion Ar1 of the circuit layer 12 toward the casing 50C by the circuit layer contact portion 61D. The circuit layer contact portion 61D is formed in substantially the same shape as the circuit layer contact portion 61 of the first embodiment, and has a rectangular opening 611. The width dimension L9 of the circuit layer contact portion 61D is set to be 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 the outer peripheral end portion is located outside the outer peripheral end portion 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. That is, the width L0 of the outer peripheral portion Ar1 is the same as that in the first embodiment.

The housing contact portion 63 is connected to the outer peripheral end of the circuit layer contact portion 61D. The casing contact portion 63 has a cylindrical portion 631 that linearly extends from the outer peripheral end of the lower surface 612 of the circuit layer contact portion 61D toward the casing 50C, and extends outward from the lower end of the cylindrical portion 631. And an abutting portion 632 that extends in a vertical direction. Of these, the lower surface 633 of the contact portion 632 contacts the upper surface of the housing 50C, as shown in FIG. The width dimension L2 of the housing contact portion 63 (width dimension of the surface that contacts 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. Further, the dimension L11 from the lower surface 633 of the contact portion 632 (upper surface of the housing 50) to the lower surface 612 of the circuit layer contact portion 61D has the same thickness as that of the insulating circuit board 10 and the heat sink 20 excluding the pin-shaped fins 201. Or, it is set to be slightly smaller, for example, 7 mm to 7.3 mm. The width L8 of the pressing member 60D is set larger than the width L5 of the pressing member 60 of the first embodiment and larger than the width of the heat sink 20C. The width dimension L8 is set to, for example, 60 mm or more.

In such a pressing member 60D, the fixing member 70 is provided with the lower surface 612 of the circuit layer contact portion 61D brought into contact with the outer peripheral portion Ar1 of the circuit layer 12 and the upper surface of the housing 50C. It penetrates through the housing contact portion 63 and is fixed to the housing 50C. As a result, the housing contact portion 63 is pressed toward the housing 50C, and thus the outer peripheral portion Ar1 of the circuit layer 12 is pressed toward the housing 50C. This improves the flatness of the mounting surface Ar2 of the circuit layer 12.
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 dispose the grease 41 between the heat sink 20C and a portion of the housing 50C that abuts the heat sink 20C.

In the present embodiment, since 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 heat sink 20C warps. The flatness of the circuit layer 12 can be surely improved regardless of the degree.

In addition, the detailed configuration is not limited to the configuration of the embodiment, and various modifications can be made without departing from the spirit 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 the invention is not limited to this, and other electronic components may be mounted. That is, the present invention can be applied not only to the LED heat dissipation module but also to a power module and the like.

As an insulating circuit substrate, a 70 mm×70 mm ceramic substrate having a thickness of 0.32 mm formed of silicon nitride (Si ₃ N ₄ ) in plan view has a circuit layer made of an aluminum alloy of A6063 type on one surface and the other surface. A metal layer made of 4N aluminum was bonded to the above, and a heat sink with an outer diameter of 100 mm×100 mm and a thickness of 4 mm was bonded thereto to manufacture an insulated circuit board with a heat sink. Regarding these joining, the circuit layer, the ceramic substrate, the metal layer, and the heat sink are laminated via the brazing material of Al-Si-Mg system, and these are joined by pressurizing and heating in the laminating direction to form a heat sink. Insulated circuit board was manufactured.

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 insulated circuit board with a heat sink to form an LED module. The LED heat dissipation module was manufactured by fixing it to the body. In Example 1, the pressing member shown in the first embodiment was used to fix the outer peripheral portion of the circuit layer toward the housing and fix the housing 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 a pressing member to obtain an LED heat dissipation module.
With respect to the LED heat dissipation modules of Example 1 and Comparative Example 1 manufactured in this manner, the ratio of the straight light amount to the total light amount (light amount ratio) was evaluated.

(Amount of warpage on the mounting surface of the circuit layer)
As for the flatness of the mounting surface, the mounting surface (10 mm×10 mm) located inside the outer peripheral portion on the upper surface of the circuit layer is used as a measurement surface, and a least square surface is obtained from the profile of the measurement surface using AcroMetrix Thermoire PS200. Using the least squares surface as a reference, the difference between the highest point and the lowest point was warped and measured.

(Light ratio)
The light amount ratio is the ratio of the amount of light that went straight to the total amount of light, and was measured using an illuminance meter (LM331 manufactured by As One Co., Ltd.). Specifically, the distance from the tip of the LED light source to the detection unit of the illuminometer was 1000 mm, the diameter of the LED light source was 10 mm, and the diameter of the detection unit was also 10 mm. Under this condition, the ratio of the light quantity of the light straight from the LED light source to the total light quantity of the LED light source was calculated. The results are shown in Table 1.

As is clear from Table 1, in Example 1 in which the pressing member pressed the outer peripheral portion of the circuit layer, the warp of the mounting surface was as small as 5 μm, and thus 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, since the warp of the mounting surface was as large as 30 μm, the light amount ratio was as low as 8.7%. Therefore, it was found that by mounting the circuit layer in a state in which the pressing member presses the outer peripheral portion of the circuit layer toward the case, the warp of the mounting surface can be reduced and the LED heat dissipation module can be appropriately used.

1 1C Insulated Circuit Board with Heat Sink 10 10A 10B Insulated Circuit Board 11 Ceramics Board 12 12A Circuit Layer 13 Metal Layer 14 First Circuit Layer 15 Second Circuit Layer 20 20C Heat Sink 201 Pin Fin 30 LED Element 40 LED Module 50 50C Housing 501 Opening 60 60D Pressing member 61 61D Circuit layer contact part 611 Opening part 612 Lower surface 62 Heat sink contact part 63 Housing contact part 621 631 Cylindrical part 622 632 Contact part 623 633 Lower surface 100 100A 100B 100C 100D LED heat radiation module

Claims (6)

To a case of an insulated circuit board with a heat sink, which includes an insulated circuit board having a circuit layer formed on one surface of a ceramic substrate and a heat sink arranged on a surface of the insulated circuit board opposite to the circuit layer. The mounting structure of
A structure for mounting an insulated circuit board with a heat sink to a housing, wherein the pressing member is fixed to the housing while the outer peripheral portion of the circuit layer is pressed toward the housing by a pressing member. The pressing member has a circuit layer contact portion that contacts the outer peripheral portion of the circuit layer, and a heat sink contact portion that is connected to the circuit layer contact portion and that contacts the heat sink,
The mounting structure of an insulated circuit board with a heat sink to a housing according to claim 1, wherein the heat sink contact portion is fixed to the housing via the heat sink. The pressing member includes a circuit layer abutting portion that abuts an outer peripheral portion of the circuit layer, and a casing abutting portion that is connected to the circuit layer abutting portion and abuts the casing. The structure for mounting 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,
The said housing|casing has an opening part which accommodates these fins, when the said insulated circuit board with a heat sink is fixed to the said housing|casing, The any one of Claim 1 to 3 characterized by the above-mentioned. Mounting structure of the insulated circuit board with heat sink to the case. 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 abuts the heat sink. Mounting structure of the insulated circuit board with heat sink to the case. An LED element is provided on a mounting surface inside the outer peripheral portion of the circuit layer, and the insulated circuit board with the heat sink according to any one of claims 1 to 5, is mounted on a housing. Mounting structure.

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