JP2016189399A - Substrate unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate unit, comprised of a first substrate and a second substrate, capable of enhancing the heat dissipation of a heating component disposed between the first substrate and the second substrate.SOLUTION: A substrate unit 1 includes: a first printed circuit board 2 mounted with a DC-DC converter 21; a second printed circuit board 3 disposed to face the first printed circuit board 2; and an aluminum plate 4 formed from a material with heat dissipation and provided on a surface on the opposite side to a surface facing the first printed circuit board 2 of the second printed circuit board 3. The second printed circuit board 3 has such a partially cut-out shape that the DC-DC converter 21 and the aluminum plate 4 face directly each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a substrate unit having a heat dissipation function.

  Some electronic components mounted on a printed circuit board of an electronic circuit are accompanied by heat generation in operation. If such a heat-generating component is used as it is, it causes thermal runaway due to temperature rise and component deterioration, so it is necessary to dissipate heat by some method. As one method of radiating heat from the heat generating component, a method of providing a heat sink on a printed circuit board on which the heat generating component is mounted can be considered. For example, by using a printed circuit board in which a heat radiating member having high thermal conductivity such as an aluminum plate is attached to the back surface, the heat of the heat generating component mounted on the front surface can be radiated from the heat radiating member.

  A circuit board provided with such a heat sink can be applied in various ways. For example, the prior art disclosed in Patent Document 1 generates heat by placing a heat-generating component in a hole provided in a substrate and attaching a plate-shaped heat sink to the substrate, thereby reducing the distance between the heat-generating component and the heat sink. The heat dissipation of the parts is improved. The prior art disclosed in Patent Document 2 provides a heat sink above the LSI when mounting the LSI on the substrate, and further disposes a member with high thermal conductivity between the LSI and the substrate under the LSI. The heat conductivity from the LSI to the substrate is improved and the heat dissipation is also improved.

JP-A-9-107053 Japanese Patent Laid-Open No. 10-247703

  By the way, when a new circuit is added to the existing first substrate in the circuit board design process, there is often no space left for adding a new circuit on the first substrate. However, if an existing circuit and an additional circuit are to be mounted on a sufficiently large new board, it is inefficient in that it requires a new design and manufacturing of the entire circuit including the existing circuit part. is there. Therefore, by introducing a new second substrate and mounting an additional circuit on the second substrate and connecting it to the first substrate, the existing first substrate can be used as it is.

  Further, when designing a plurality of variations of circuits having slightly different functions, the efficiency of circuit design and the like can be improved by introducing the first substrate and the second substrate. That is, for example, a circuit of a portion common to a plurality of variations is mounted on the first substrate, and a circuit of a portion slightly different depending on the variations is mounted on the second substrate. As a result, the first substrate on which the common circuit is mounted can be used in a plurality of variations of circuits, so that the efficiency of circuit design can be improved and the manufacturing cost of the circuit substrate can be reduced.

  As described above, in the substrate unit composed of the first substrate and the second substrate, the first substrate and the second substrate are generally arranged close to each other due to restrictions such as a space for storing both substrates. Is. If a heat generating component is disposed between the first substrate and the second substrate, heat dissipation of the heat dissipating component may be a problem. In such a substrate unit, it is often difficult to introduce a heat dissipation mechanism in a limited space between the first substrate and the second substrate. In addition, since the prior arts disclosed in Patent Documents 1 and 2 both devise the configuration of the substrate when mounting the heat-generating component on the substrate, it is composed of a first substrate and a second substrate, There are many cases where the invention cannot be applied to a board unit in which a heat generating component is arranged between the first board and the second board. Therefore, in such a situation, there is a possibility that the heat generation of the heat generating component of the board unit cannot be performed.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a substrate unit composed of a first substrate and a second substrate between the first substrate and the second substrate. It is in improving the heat dissipation of the heat-emitting component arrange | positioned in.

<First Aspect of the Present Invention>
A first aspect of the present invention is formed of a first substrate on which a heat generating component is mounted, a second substrate disposed to face the first substrate, and a material having a heat dissipation property. A heat dissipating member provided on a surface opposite to the surface facing the first substrate, and the second substrate is partially removed so that the heat generating component and the heat dissipating member directly face each other. This is a substrate unit having a shape.

  The first substrate is mounted with a heat generating component that requires heat dissipation. On the other hand, the second substrate is provided with a heat radiating member formed of a material having a heat radiating property on one side, and is partially removed so that the heat generating component and the heat radiating member directly face each other. Yes.

  Therefore, the heat generating component of the first substrate can directly transmit heat to the heat dissipation member without passing through the second substrate, and can efficiently dissipate heat. In addition, the space between the first substrate and the second substrate may be the minimum width sandwiching the heat-generating component, so that space saving is not hindered. Furthermore, at this time, the heat-generating component of the first board can be radiated without any change to the circuit mounted on the first board.

  As a result, according to the first aspect of the present invention, in the board unit composed of the first board and the second board, the heat dissipation of the heat generating component disposed between the first board and the second board is improved. The effect that it can be made is obtained.

<Second Aspect of the Present Invention>
According to a second aspect of the present invention, in the first aspect of the present invention described above, the second substrate has the same shape as the outer shape of the heat generating component such that the heat generating component and the heat dissipation member directly face each other. The substrate unit is formed with a through hole or notch.

  The through holes or notches formed in the second substrate are formed in the same shape as the outer shape of the heat-generating component mounted on the first substrate. For this reason, the area for transmitting heat from the heat generating component to the heat radiating member can be maximized, and the size of the through hole or notch provided in the second substrate can be minimized to leave as much space as possible on the second substrate.

  Thereby, according to the 2nd aspect of this invention, in addition to the effect by the 1st aspect of this invention mentioned above, the effect that the 2nd board | substrate can be used more efficiently is acquired.

<Third Aspect of the Present Invention>
According to a third aspect of the present invention, there is provided a substrate unit including the thin film formed of an insulating material between the heat generating component and the heat radiating member in the first or second aspect of the present invention. .

  The heat generating component of the first substrate transfers heat to the heat radiating member attached to the second substrate. At this time, if both the surface of the heat generating component and the surface of the heat radiating member are conductive, unexpected conduction may occur in the heat generating component and the heat radiating member, causing trouble. Therefore, by sandwiching a thin film formed of an insulating material between the heat-generating component and the heat-dissipating member, it is possible to electrically insulate both while suppressing a decrease in thermal conductivity from the heat-generating component to the heat-dissipating member as much as possible. it can.

  Thereby, according to the third aspect of the present invention, in addition to the effects of the first or second aspect of the present invention described above, even when both the surface of the heat generating component and the surface of the heat radiating member have conductivity, The effect of being able to dissipate heat without causing an electrical problem is obtained.

  According to the present invention, in the board unit constituted by the first board and the second board, the heat dissipation of the heat generating component arranged between the first board and the second board can be improved.

It is sectional drawing of the board | substrate unit which concerns on 1st Example of this invention. It is a disassembled perspective view of the board | substrate unit which concerns on 1st Example of this invention. It is a disassembled perspective view of the board | substrate unit which concerns on 2nd Example of this invention. It is a disassembled perspective view of the board | substrate unit which concerns on 3rd Example of this invention. It is sectional drawing of the board | substrate unit which concerns on 4th Example of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First embodiment>
FIG. 1 is a cross-sectional view of a substrate unit 1 according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of the board unit according to the first embodiment of the present invention.

  The board unit 1 includes a first printed circuit board 2 as a “first board”, a second printed circuit board 3 as a “second board”, an aluminum plate 4 as a “heat radiating member”, and a spacer 5. A DC-DC converter 21 as a “heat generating component” is mounted on the first printed circuit board 2.

  The first printed circuit board 2 is a printed circuit board (PCB) on which electronic components are fixed and wired, and is generally used in an electronic circuit, so detailed description thereof is omitted. The first printed circuit board 2 has a DC-DC converter 21 mounted on the front surface, and other electronic components and circuit patterns (not shown).

  The second printed circuit board 3 is a printed circuit board that is generally used in the same manner as the first printed circuit board 2, and electronic components and circuit patterns (not shown) are mounted on the front surface. However, the second printed circuit board 3 is different from the first printed circuit board 2 in that an aluminum plate 4 described below is attached. The second printed circuit board 3 has a first through hole 31 formed by partially removing the board.

  The aluminum plate 4 is a metal plate made of aluminum having excellent heat dissipation, and dissipates heat of the electronic component by absorbing the heat of the electronic component and releasing it into the air. The aluminum plate 4 is integrated with the second printed circuit board 3 by being attached to the entire back surface of the second printed circuit board 3 with an adhesive.

  The spacer 5 is a member for fixing the relative positions of the first printed circuit board 2 and the second printed circuit board 3 while maintaining the distance between them. In order to reinforce the board unit 1, it is desirable to screw the first printed circuit board 2, the second printed circuit board 3, and the spacer 5 as indicated by broken lines. In addition, the gap between the first printed circuit board 2 and the second printed circuit board 3 can be filled with an adhesive having low thermal conductivity.

  The DC-DC converter 21 is an electronic component mounted on the first printed circuit board 2, and is used to perform voltage conversion in the electronic circuit similarly mounted on the first printed circuit board 2. Since the DC-DC converter 21 generates heat during operation, a mechanism for radiating heat is required.

  The board unit 1 is configured by attaching a second printed circuit board 3 integrated with an aluminum plate 4 to the first printed circuit board 2 via a spacer 5. At this time, the second printed circuit board 3 has the front surface of the second printed circuit board 3 facing the front surface of the first printed circuit board 2, and the DC-DC converter 21 passes through the first through hole 31. It arrange | positions so that the aluminum plate 4 may be faced directly. Therefore, the aluminum plate 4 can directly absorb the heat generated by the DC-DC converter 21 and dissipate it from the surface opposite to the DC-DC converter 21.

  As described above, the board unit 1 can efficiently dissipate the heat generated from the DC-DC converter 21 via the aluminum plate 4. At this time, it is not necessary to change the arrangement of electronic components and the circuit pattern of the first printed circuit board 2. Furthermore, since the aluminum plate 4 can dissipate heat generated in the space between the first printed circuit board 2 and the second printed circuit board 3 to the outside, the first printed circuit board 2 and the second printed circuit board The possibility that the heat generated from the DC-DC converter 21 is transmitted to other electronic components mounted on the front surface of 3 can be reduced.

  As a result, the board unit 1 according to the first embodiment of the present invention is the same as the first printed circuit board 2 and the second printed circuit in the board unit 1 including the first printed circuit board 2 and the second printed circuit board 3. The heat dissipation of the DC-DC converter 21 disposed between the substrate 3 and the substrate 3 can be improved.

<Second embodiment>
Next, a second embodiment of the present invention will be described. The substrate unit of the present embodiment is different from the substrate unit of the first embodiment in the shape of the first through hole 31 in the first embodiment. Hereinafter, parts different from the first embodiment will be described, and the same components as those in the first embodiment are denoted by the same reference numerals and detailed description thereof will be omitted.

FIG. 3 is an exploded perspective view of the board unit 1 according to the second embodiment of the present invention.
The second printed circuit board 3 has a second through hole 32 formed by partially removing the board. The second through hole 32 is formed in the same shape as the outer shape of the DC-DC converter 21 at a position corresponding to the DC-DC converter 21. Therefore, the area where the DC-DC converter 21 and the aluminum plate 4 are in contact with each other can be maximized to efficiently dissipate heat, and the area of the board removed from the second printed circuit board 3 can be minimized.

  As a result, the board unit 1 according to the second embodiment of the present invention is the same as the first printed circuit board 2 and the second printed circuit in the board unit 1 constituted by the first printed circuit board 2 and the second printed circuit board 3. The heat dissipation of the DC-DC converter 21 disposed between the substrate 3 and the substrate 3 can be improved. In addition, the second printed circuit board 3 can be left more widely, and the risk of pressing a space for mounting other electronic components and circuit patterns is reduced. Therefore, the second printed circuit board 3 can be used more efficiently.

<Third embodiment>
Next, a third embodiment of the present invention will be described. The board unit of the present embodiment is different from the board unit of the second embodiment in the positions of the second printed circuit board 3 and the aluminum plate 4 in the second embodiment. Hereinafter, parts different from those of the second embodiment will be described, and the same components as those of the second embodiment are denoted by the same reference numerals and detailed description thereof will be omitted.

FIG. 4 is an exploded perspective view of the board unit 1 according to the third embodiment of the present invention.
The position of the second printed circuit board 3 integrated with the aluminum plate 4 may be limited for reasons such as the shape of a housing for housing the board unit 1. For example, as shown in FIG. 4, when the position corresponding to the DC-DC converter 21 is the end of the second printed circuit board 3, a notch 33 may be formed at that position. Accordingly, the DC-DC converter 21 and the aluminum plate 4 directly face each other regardless of the position of the board to be partially removed, so that the board unit can efficiently dissipate heat. 1 can be realized.

  As a result, the board unit 1 according to the third embodiment of the present invention has the first printed circuit board 2 and the second printed circuit board 2 even when the position of the second printed circuit board 3 with respect to the first printed circuit board 2 is restricted. The heat dissipation of the DC-DC converter 21 disposed between the printed circuit board 3 and the printed circuit board 3 can be improved.

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described. The board unit 1 of this embodiment is different from the board units 1 of the first to third embodiments in that an insulating sheet 6 is provided between the aluminum plate 4 and the DC-DC converter 21. Hereinafter, parts different from the first to third embodiments will be described, and the same components as those in the first to third embodiments will be denoted by the same reference numerals and detailed description thereof will be omitted.

FIG. 5 is a sectional view of a substrate unit according to the fourth embodiment of the present invention.
The aluminum plate 4 is attached with a thin-film insulating sheet 6 made of an insulating material at a position facing the DC-DC converter 21. For this reason, even if the surface of the DC-DC converter 21 is not insulated, the possibility of causing trouble due to unexpected conduction between the DC-DC converter 21 and the aluminum plate 4 can be reduced.

  As a result, the board unit 1 according to the fourth embodiment of the present invention has the first printed circuit board 2 and the second printed circuit board without causing any electrical trouble even if the surface of the DC-DC converter 21 is not insulated. The heat dissipation of the DC-DC converter 21 disposed between the circuit board 3 and the circuit board 3 can be improved.

  Thus, according to the present invention, in the board unit 1 constituted by the first printed circuit board 2 and the second printed circuit board 3, the gap between the first printed circuit board 2 and the second printed circuit board 3 is as follows. The heat dissipation of the arranged DC-DC converter 21 can be improved.

DESCRIPTION OF SYMBOLS 1 Board unit 2 1st printed circuit board 3 2nd printed circuit board 4 Aluminum board 5 Spacer 6 Insulation sheet 21 DC-DC converter 31 1st through-hole 32 2nd through-hole 33 Notch

Claims (3)

A first board on which a heat generating component is mounted;
A second substrate disposed opposite the first substrate;
A heat dissipating member formed of a material having a heat dissipation property and provided on a surface of the second substrate opposite to the surface facing the first substrate;
The second substrate is a substrate unit in which the heat generating component and the heat radiating member are partially removed so as to directly face each other.   2. The substrate unit according to claim 1, wherein the second substrate is formed with a through-hole or notch having the same shape as the outer shape of the heat generating component so that the heat generating component and the heat dissipation member directly face each other. The board unit.   3. The board unit according to claim 1, further comprising a thin film formed of an insulating material between the heat generating component and the heat radiating member.

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