JP2022169873A - circuit device - Google Patents

Abstract

To provide a circuit device which can be improved in heat dissipation property and can be miniaturized.SOLUTION: A circuit device 1 includes: a placoid substrate 2 having a first surface 2a and a second surface 2b facing the first surface; a first electronic component 4 mounted on the first surface of the substrate; a first heat transfer pad 2a2 provided between the first surface and the first electronic component and including a membranous metal; a joint portion 6 provided between the first heat transfer pad and the first electronic component; a heat sink 5 provided between the joint portion and the first electronic component; a second electronic component 3 mounted on the second side of the substrate; a second heat transfer pad 2b2 provided between the second surface and the second electronic component and including the membranous metal; and a heat transfer pillar 2c which penetrates between the first surface and the second surface of the substrate, has one end connected to the first heat transfer pad, the other end connected to the second heat transfer pad, and includes a metal. The first electronic component, the heat sink, and the second electronic component overlap each other when viewed from the direction perpendicular to the first surface.SELECTED DRAWING: Figure 1

Description

Embodiments of the present invention relate to circuit devices.

A circuit device includes a substrate and electronic components (also called electrical components) provided on the surface of the substrate. Some electronic components generate heat when energized. In addition, some electronic components change their characteristics or shorten their life depending on the temperature. In recent years, there has been a demand for miniaturization of circuit devices, and since electronic components are provided close to each other, it is desired to improve the heat dissipation properties of circuit devices.

Generally, a heat sink having a plurality of fins is used as heat dissipation means. However, since a heat sink having a plurality of fins is a large component compared to electronic components, etc., it is difficult to miniaturize the circuit device if the heat sink is provided on the surface of the substrate.
In this case, it is conceivable to provide a small heat sink for each electronic component, but some electronic components are difficult to attach to the heat sink. Moreover, since a plurality of heat sinks are required, the manufacturing cost may increase.

In some cases, the pattern provided on the surface of the substrate is provided with a heat dissipation pad or the pattern area is enlarged to dissipate heat through the pattern. However, this method increases the area of the substrate, making it difficult to reduce the size of the circuit device.

Therefore, development of a circuit device capable of improving heat dissipation and reducing the size has been desired.

Japanese Utility Model Laid-Open No. 06-11389

A problem to be solved by the present invention is to provide a circuit device that can improve heat dissipation and can be miniaturized.

A circuit device according to an embodiment includes: a plate-shaped substrate having a first surface and a second surface facing the first surface; a first electronic component provided; a first heat transfer pad that is provided between the first surface and the first electronic component and contains a metal and has a film shape; a joint portion provided between a heat transfer pad and the first electronic component; a heat dissipation portion provided between the joint portion and the first electronic component; a second electronic component provided on the second surface side; and a second heat transfer member provided between the second surface and the second electronic component, containing a metal, and having a film shape. a pad; penetrating between the first surface and the second surface of the substrate and containing a metal, one end of which is connected to the first heat transfer pad and the other end of which is connected to the first heat transfer pad; a heat transfer pillar connected with the second heat transfer pad; When viewed from a direction perpendicular to the first surface, the first electronic component, the heat radiating section, and the second electronic component overlap each other.

According to the embodiments of the present invention, it is possible to provide a circuit device that can improve heat dissipation and can be miniaturized.

1 is a schematic diagram for illustrating a circuit device according to an embodiment; FIG. FIG. 10 is a schematic diagram for illustrating a circuit device according to another embodiment; (a), (b) is a schematic diagram for illustrating a thermal radiation part.

Hereinafter, embodiments will be illustrated with reference to the drawings. In addition, in each drawing, the same reference numerals are given to the same constituent elements, and detailed description thereof will be omitted as appropriate.

FIG. 1 is a schematic diagram for illustrating a circuit device 1 according to this embodiment.
As shown in FIG. 1, the circuit device 1 includes, for example, a substrate 2, an electronic component 3 (corresponding to an example of a second electronic component), an electronic component 4 (corresponding to an example of a first electronic component), a heat dissipation It comprises a section 5 , a joint section 6 and a cooling section 7 .

The substrate 2 has a plate shape. The substrate 2 has a surface 2a (corresponding to an example of a first surface) and a surface 2b (corresponding to an example of a second surface) facing the surface 2a. The planar shape of the substrate 2 is not particularly limited. The planar shape of the substrate 2 can be, for example, a square. The planar dimension of the substrate 2 can be appropriately changed according to the specifications of the circuit device 1, the number and arrangement of the electronic components 3 and 4, and the like. Note that the planar dimension is a dimension when viewed from a direction perpendicular to the surface 2a (surface 2b) of the substrate 2. As shown in FIG.
Further, the substrate 2 may have a single layer structure or may have a multilayer structure.

The material of the substrate 2 is not particularly limited. The material of the substrate 2 can be, for example, an inorganic material such as ceramics (for example, aluminum oxide or aluminum nitride) or an organic material such as paper phenol or glass epoxy. Alternatively, the substrate 2 may be a metal core substrate in which the surface of a metal plate is coated with an insulating material.

Although ceramics and metal core substrates have high thermal conductivity and excellent heat dissipation, they are more expensive than organic materials such as glass epoxy. Moreover, as the size of the substrate 2 increases, the manufacturing cost further increases. Therefore, considering cost reduction and versatility, it is preferable to form the substrate 2 using an organic material such as glass epoxy.

A surface 2a of the substrate 2 is provided with, for example, a wiring pattern 2a1. A heat transfer pad 2 a 2 (corresponding to an example of a first heat transfer pad) is provided between the surface 2 a of the substrate 2 and the electronic component 4 . For example, the heat transfer pad 2a2 is provided in a region of the surface 2a of the substrate 2 to which the heat dissipation portion 5 is connected. The heat transfer pad 2a2 has a film shape. It is preferable that the planar dimension of the heat transfer pad 2 a 2 is larger than the planar dimension of the base 5 a of the heat radiating section 5 . Heat transfer pad 2a2 may or may not be electrically connected to wiring pattern 2a1.

A wiring pattern 2b1 is provided on the surface 2b of the substrate 2, for example. Heat transfer pad 2 b 2 (corresponding to an example of a second heat transfer pad) is provided between surface 2 b of substrate 2 and electronic component 3 . For example, the heat transfer pad 2b2 is provided on the surface 2b of the substrate 2 at a position facing the heat dissipation heat transfer pad 2a2. The heat transfer pad 2b2 has a film shape. The planar dimension of the heat transfer pad 2b2 can be, for example, approximately the same as the planar dimension of the heat transfer pad 2a2. Heat transfer pad 2b2 may or may not be electrically connected to wiring pattern 2b1.

As shown in FIG. 1, an electronic component 3 that dissipates heat is mounted on the heat transfer pad 2b2. A general mounting pad need only be electrically connected to the electronic component 3, so it is not necessary to increase the planar dimensions. However, since the heat transfer pad 2b2 conducts heat transfer (heat dissipation) of the heat generated in the electronic component 3, the plane dimension thereof is larger than that of a general mounting pad. Note that the heat transfer pad 2b2 may have the function of a mounting pad for electrical connection with the electronic component 3. FIG.

Further, the substrate 2 is provided with heat transfer pillars 2c penetrating in the thickness direction. That is, the heat transfer pillar 2c penetrates the substrate 2 between the surface 2a and the surface 2b. One end of the heat transfer pillar 2c is connected to the heat transfer pad 2a2. The other end of heat transfer pillar 2c is connected to heat transfer pad 2b2. The heat generated in the electronic component 3 is transferred to the heat transfer pad 2a2 via the heat transfer pad 2b2 and the heat transfer pillar 2c. The heat transmitted to the heat transfer pad 2a2 is transmitted to the heat radiation portion 5 via the joint portion 6, and is radiated from the heat radiation portion 5 to the outside.

At least one heat transfer pillar 2c may be provided.
It is preferable that the heat transfer pillar 2c is provided at a position where the electronic component 3 and the heat radiating portion 5 overlap when viewed from a direction perpendicular to the surface 2a (surface 2b) of the substrate 2. FIG. By doing so, the heat generated in the electronic component 3 can be efficiently transferred to the heat radiating portion 5 .

Wiring pattern 2a1, heat transfer pad 2a2, wiring pattern 2b1, heat transfer pad 2b2, and heat transfer pillar 2c contain metal. For example, they can be formed from a silver-based material, a copper-based material, or the like. For example, these can be formed using a plating method or the like.

The electronic component 3 is provided on the surface 2 b side of the substrate 2 . The electronic component 3 can be, for example, a passive device or an active device. Passive elements are, for example, resistors, capacitors, coils, and the like. Examples of active elements include switching elements such as transistors, rectifying elements such as diodes, light emitting elements such as light emitting diodes and laser diodes, and integrated circuits.

In general, more heat is generated in active devices than in passive devices. Therefore, when a passive element and an active element are provided on the surface 2b of the substrate 2, the active element can be mounted on the heat transfer pad 2b2 and the passive element can be mounted on the mounting pad of the wiring pattern 2b1. However, if the passive element generates a large amount of heat, the passive element may be mounted on the heat transfer pad 2b2. For example, when multiple types of electronic components 3 are provided on the surface 2b of the substrate 2, the electronic component 3 that generates the most heat can be mounted on the heat transfer pad 2b2.

The electronic component 3 may be a surface-mounted electronic component, an electronic component having lead wires, or a chip-like electronic component mounted by a COB (Chip On Board). good. However, if surface-mounted electronic components and chip-shaped electronic components are used, the adhesion to heat transfer pads 2b2 can be enhanced compared to electronic components having lead wires. Therefore, the electronic component 3 to be mounted on the heat transfer pad 2b2 is preferably a surface-mounted electronic component or a chip-like electronic component. By doing so, the heat generated in the electronic component 3 can be efficiently transferred to the heat radiating portion 5 .

The electronic component 4 is provided on the side of the surface 2 a of the substrate 2 . The electronic component 4 can be, for example, a transformer, a relay, a power supply module, a timing device, or the like. As shown in FIG. 1, the electronic component 4 can be provided on the base 5a of the heat radiating section 5. As shown in FIG. The electronic component 4 can be, for example, screwed to the base 5a, soldered, or bonded using an adhesive with high thermal conductivity. The adhesive with high thermal conductivity can be, for example, an adhesive mixed with a filler using an inorganic material. The inorganic material is preferably a material with high thermal conductivity (for example, ceramics such as aluminum oxide and aluminum nitride). The thermal conductivity of the adhesive can be, for example, 0.5 W/(m·K) or more and 10 W/(m·K) or less.

The electronic component 4 can be electrically connected to the wiring pattern 2a1 via wiring or the like, for example. When a plurality of types of electronic components 4 are provided on the surface 2a of the substrate 2, the electronic component 4 that generates the most heat can be provided on the base 5a.

In addition, although the case where the electronic component 3 and the electronic component 4 differ is demonstrated above, the electronic component 3 and the electronic component 4 may be the same. For example, electronic component 3 and electronic component 4 may be passive devices, active devices, transformers, relays, power supply modules, timing devices, and the like. For example, a transistor may be mounted on the heat transfer pad 2 b 2 and the transistor may be provided on the base 5 a of the heat dissipation section 5 .

That is, among the electronic components 3 provided on the surface 2b side of the substrate 2, the electronic component that generates the most heat is provided on the heat transfer pad 2b2, and among the electronic components 4 provided on the surface 2a side of the substrate 2, the An electronic component that generates a large amount of heat may be provided on the base 5a.

The heat dissipation portion 5 is provided between the joint portion 6 and the electronic component 4 .
The radiator 5 has, for example, a base 5a and fins 5b.
The base 5 a has a plate shape and is provided between the heat transfer pad 2 a 2 and the electronic component 4 . For example, the base 5a is provided on the heat transfer pad 2a2 via the joint 6. As shown in FIG.
The fin 5b has a plate shape and is provided on one peripheral edge of the base 5a. The fin 5b intersects the base 5a. The fins 5b extend to the side opposite to the heat transfer pad 2a2 side. The distance H1 between the surface 2a of the substrate 2 and the top of the fins 5b is smaller than the distance H2 between the surface 2a of the substrate 2 and the top of the electronic component 4. FIG. By doing so, it is possible to prevent the dimension of the circuit device 1 in the direction perpendicular to the surface 2a of the substrate 2 from increasing.

Further, a gap can be provided between the electronic component 4 and the fins 5b. In general, the bottom of the electronic component 4 (the end on the installation side) is insulated, but the side of the electronic component 4 may not be insulated. If a gap is provided between the electronic component 4 and the fins 5b, it is possible to suppress short-circuiting between the electronic component 4 and the fins 5b.

The base 5a and the fins 5b can be integrally formed. The heat radiating portion 5 can be formed by, for example, bending a plate material, welding a plate material, or using a die casting method or the like.
The heat radiating portion 5 is formed using a material with high thermal conductivity. The heat radiation part 5 can contain metals, such as an aluminum alloy and a copper alloy, for example.

The joint portion 6 is provided between the heat transfer pad 2 a 2 and the electronic component 4 . For example, the joint portion 6 is provided between the base 5a of the heat dissipation portion 5 and the heat transfer pad 2a2. The joint portion 6 mechanically and thermally joins the base 5a and the heat transfer pad 2a2. The joint 6 preferably has insulating properties and high thermal conductivity. The joining portion 6 can be, for example, a thermally conductive double-sided tape. Also, the joint portion 6 may be formed by curing the above-described adhesive having high thermal conductivity, for example.

The cooling part 7 mainly cools the fins 5 b of the heat radiating part 5 . For example, the cooling unit 7 can be a fan that blows air toward the fins 5b. The type of fan is not particularly limited, but if a propeller fan is used, the amount of air blown can be increased.

Alternatively, a flow path may be provided in the heat radiating section 5 and the coolant may flow through the flow path by the cooling section 7 . That is, the cooling unit 7 may be an air-cooled cooler or a liquid-cooled cooler.
When the cooling unit 7 is an air-cooled or liquid-cooled cooler, the cooling unit 7 can be provided in a housing or the like in which the circuit device 1 is accommodated.

Also, the cooling unit 7 can be a Peltier element. When the cooling part 7 is a Peltier element, for example, the cooling part 7 can be provided in the fins 5b.
The cooling unit 7 is not necessarily required, and can be omitted, for example, when the amount of heat radiated from the heat radiating unit 5 is small.

In circuit device 1 according to the present embodiment, when viewed from a direction perpendicular to surface 2a (surface 2b) of substrate 2, heat transfer pad 2a2, heat transfer pad 2b2, electronic component 3, electronic component 4, and The heat radiating portions 5 are provided at positions overlapping each other.
Therefore, the heat transfer distance between the electronic component 3 and the electronic component 4, which are heat sources, and the heat radiating section 5, which is heat radiating means, can be shortened, so that heat radiation can be improved.

Further, if the electronic component 3, the electronic component 4, and the heat radiating section 5 are provided at positions that overlap each other when viewed from a direction perpendicular to the surface 2a (surface 2b) of the substrate 2, the circuit device 1 can be made smaller. can be improved.
As described above, with the circuit device 1 according to the present embodiment, it is possible to improve heat dissipation and reduce the size.

In this case, if the electronic component 3 generates the most heat on the surface 2b side of the substrate 2 and the electronic component 4 generates the most heat on the surface 2a side of the substrate 2, the heat dissipation of the circuit device 1 is effectively improved. be able to.

FIG. 2 is a schematic diagram illustrating a circuit device 1a according to another embodiment.
As shown in FIG. 2, the circuit device 1a includes, for example, a substrate 2, electronic components 3, electronic components 4, a heat radiating section 15, a joint section 6, and a cooling section .

FIGS. 3A and 3B are schematic diagrams for illustrating the heat radiating section 15. FIG.
FIG. 3(a) is a schematic side view of the heat radiating portion 15 in FIG. 2 as viewed from direction A. FIG.
FIG. 3(b) is a schematic plan view of the heat radiating portion 15 in FIG. 2 as viewed from the direction B. FIG.
As shown in FIGS. 3A and 3B, the radiator 15 has, for example, a base 5a and a pair of fins 5b. The pair of fins 5b are provided at positions facing each other. For example, each of the pair of fins 5b is provided on the periphery of the base 5a facing each other. If the pair of fins 5b are provided at positions facing each other, the airflow can easily pass through the inside of the heat radiating portion 15, so heat radiation can be improved.

The distance H1 between the surface 2a of the substrate 2 and the top of one fin 5b may be the same as or different from the distance between the surface 2a of the substrate 2 and the top of the other fin 5b. good. However, these distances are smaller than the distance H2 between the surface 2 a of the substrate 2 and the top of the electronic component 4 . By doing so, it is possible to prevent the dimension of the circuit device 1a in the direction perpendicular to the surface 2a of the substrate 2 from increasing.

The base 5a and the pair of fins 5b can be integrally formed. The heat radiating portion 15 can be formed by, for example, bending a plate material, welding a plate material, or using a die casting method.
The heat radiating portion 15 is formed using a material with high thermal conductivity. The heat radiation part 15 can contain metals, such as an aluminum alloy and a copper alloy, for example.

In the circuit device 1a according to the present embodiment, when viewed from a direction perpendicular to the surface 2a (surface 2b) of the substrate 2, the heat transfer pad 2a2, the heat transfer pad 2b2, the electronic component 3, the electronic component 4, and The heat radiating portions 15 are provided at positions overlapping each other. Therefore, as in the case of the circuit device 1 described above, it is possible to improve heat dissipation and reduce the size.

In this case, if the electronic component 3 generates the most heat on the surface 2b side of the substrate 2 and the electronic component 4 generates the most heat on the surface 2a side of the substrate 2, heat dissipation can be effectively improved.
Further, since the heat dissipation portion 15 is provided with a pair of fins 5b, it is possible to further improve heat dissipation.

Although some embodiments of the present invention have been illustrated above, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, changes, etc. can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof. Moreover, each of the above-described embodiments can be implemented in combination with each other.

1 circuit device 2 substrate 2a surface 2a1 wiring pattern 2a2 heat transfer pad 2b surface 2b1 wiring pattern 2b2 heat transfer pad 2c heat transfer pillar 3 electronic component 4 electronic component 5 radiator 5a base , 5b fin, 6 junction, 7 cooling part, 15 heat dissipation part

Claims (3)

a plate-like substrate having a first surface and a second surface facing the first surface;
a first electronic component provided on the first surface side of the substrate;
a first heat transfer pad provided between the first surface and the first electronic component, containing a metal, and having a film shape;
a joint provided between the first heat transfer pad and the first electronic component;
a heat radiating portion provided between the joint portion and the first electronic component;
a second electronic component provided on the second surface side of the substrate;
a second heat transfer pad provided between the second surface and the second electronic component, containing a metal, and having a film shape;
The substrate penetrates between the first surface and the second surface, contains a metal, has one end connected to the first heat transfer pad, and has the other end connected to the second heat transfer pad. a heat transfer pillar connected to the heat transfer pad of;
and
A circuit device in which the first electronic component, the heat radiating section, and the second electronic component overlap when viewed from a direction perpendicular to the first surface. The heat dissipation part contains metal,
a plate-shaped base provided between the first heat transfer pad and the first electronic component;
a fin that intersects the base and extends opposite to the first heat transfer pad;
2. The circuit device according to claim 1, comprising: 3. The circuit device according to claim 2, further comprising a cooling part for cooling said fins.

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