JP2015018857A - High heat dissipation substrate, heat dissipation structure of component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat dissipation structure of an electronic component by using a high heat dissipation substrate.SOLUTION: In order to achieve thermal connection of an electronic component 7, formed of a material having high thermal conductivity, such as a metal, and mounted on the surface of a high heat dissipation board 3 having a through hole and embedding a heat dissipation chip 1, and the heat dissipation chip 1, a heat transfer agent or a heat transfer adhesive 8 fills under the electronic component 7 from the back side of the board through a through hole of the heat dissipation chip 1. Alternatively, a heat dissipation screw 9 formed of a metallic material equivalent to that of the heat dissipation chip 1 is inserted from the back side of the board through a through screw hole 6 of the heat dissipation chip 1 so as to come into contact with the electronic component 7 (heating part).

Description

  The present invention relates to a high heat dissipation substrate having excellent thermal conductivity in the thickness direction of the substrate, and relates to a high heat dissipation substrate capable of easily and appropriately dissipating heat generated by a mounted component.

In recent years, it has become necessary to increase heat dissipation, and to reduce the size, weight, and thickness of printed circuit boards as electronic components are mounted at higher density.
As a printed circuit board excellent in heat dissipation, there is a metal core board using a metal having high thermal conductivity as a core material. However, since the metal core is contained in the entire substrate, there is a problem that the thickness, weight, and cost are increased. In addition to this, since the heat capacity of the entire board becomes large, it is difficult for the solder to rise when mounting insertion parts, etc., and the substrate material with low thermal conductivity existing between the surface-mounted electronic component and the metal core is There were problems such as preventing heat conduction from electronic components to the metal core.

In order to solve the above problem, a substrate in which a heat dissipation chip of a material having high thermal conductivity (heat transfer material) such as copper, aluminum, or an alloy thereof is embedded directly under an electronic component of a normal printed circuit board is disclosed. (See, for example, Patent Document 1). Thus, by locally suppressing the use of a heat transfer material such as a heat dissipation chip, it is possible to reduce the size, weight, and thickness, and to solve the problems of cost and mountability.
Furthermore, since there is no material that hinders heat conduction at the location where the heat dissipation chip is embedded, heat from electronic components can be released more efficiently into the space on the back side of the board or the chassis (chassis frame). The temperature rise of the electronic component can be suppressed.

JP-A-7-86717

However, regardless of insertion mounting or surface mounting, there is usually a space between the electronic component and the substrate, and there is a problem that heat of the electronic component cannot be directly transferred to the heat dissipation chip.
In order to thermally connect the electronic component and the heat dissipating chip, there are the following problems.
Problem 1: It is not possible to insert a thermal conductive agent or sheet under the part after the part is mounted.
Problem 2: If a thermal conductive agent is applied to the bottom surface (or substrate surface) of the component before mounting, the self-alignment effect necessary for automatic soldering is hindered, and a proper solder connection state cannot be obtained. For this reason, it is not automatic soldering by a machine but manual soldering.

  In addition, due to variations in component manufacturing and unevenness of the heat dissipation chip, it is difficult to manage the dimensions of the space between the electronic component and the board, and the amount of heat conductive agent cannot be adjusted later, so there is not enough heat conductive agent. In such a case, there was a problem that the substrate surface could not be sufficiently contacted.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a high heat dissipation substrate excellent in thermal conductivity in the thickness direction of the substrate. It is another object of the present invention to provide a heat dissipation structure capable of efficiently conducting heat generated by an electronic component even when a space is generated between the electronic component and a substrate after the electronic component is mounted. .

  The high heat dissipation substrate according to the present invention is a substrate in which a heat dissipation chip is embedded, and the heat dissipation chip is placed in a space between a lower surface of a component mounted above the heat dissipation chip and the surface of the substrate. Alternatively, a through hole for injecting a heat conductive adhesive is provided.

  According to the present invention, the heat generated by the mounting component can be efficiently conducted in the thickness direction of the substrate by filling the heat conductive agent or the like between the lower surface of the component mounted on the substrate and the surface of the substrate. .

It is sectional drawing which shows the structure of the high thermal radiation board | substrate which concerns on Embodiment 1 of this invention. It is a figure which shows the state which mounted the electronic component in the high thermal radiation board | substrate which concerns on Embodiment 1 of this invention. It is a figure which shows an example of the structure which thermally connects the electronic component which concerns on Embodiment 2 of this invention, a thermal radiation chip, and a chassis frame. It is a figure which shows an example of the other structure which thermally connects the electronic component which concerns on Embodiment 3 of this invention, a thermal radiation chip, and a chassis frame.

  Embodiments of a high heat dissipation substrate according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing a configuration of a high heat dissipation substrate 3 according to an embodiment of the present invention.
A heat dissipation chip 1 is embedded in a high heat dissipation substrate 3 shown in FIGS. The heat dissipation chip 1 is made of a material having high thermal conductivity (heat transfer material) such as copper, aluminum, or an alloy thereof, and is embedded directly under an electronic component or the like mounted on a printed board.
As shown in FIG. 1A, the heat dissipation chip 1 according to the present embodiment is provided with through holes 2 that penetrate the upper and lower surfaces of the heat dissipation chip 1.
As another example, the heat dissipation chip 1 according to the present embodiment is provided with through screw holes 6 penetrating the upper and lower surfaces of the heat dissipation chip 1 as shown in FIG.

2A and 2B are diagrams (cross-sectional views) illustrating a state in which the electronic component 7 is mounted on the high heat dissipation substrate 3 in which the heat dissipation chip 1 illustrated in FIGS. 1A and 1B is embedded. It is.
2A, after the electronic component 7 is mounted on the high heat dissipation substrate 3, a heat conductive agent or a heat conductive adhesive is injected from the through hole 2 on the back side of the high heat dissipation substrate 3, A space 10 between the package lower surface of the electronic component 7 and the upper surface of the high heat dissipation substrate 3 is filled with a heat conductive agent or a heat conductive adhesive.
In this way, by filling the space 10 between the lower surface of the package of the electronic component 7 and the upper surface of the high heat dissipation substrate 3 with the heat conductive agent or the heat conductive adhesive, the variation in the space 10 is alleviated and the electronic component 7 and the heat dissipation are dissipated. The chip 1 is thermally connected. As a result, the heat generated by the electronic component 7 can be released to the back side of the high heat dissipation substrate 3, and the temperature rise of the electronic component 7 can be suppressed.

2B, after the electronic component 7 is mounted on the high heat dissipation substrate 3, the thermal conductivity equivalent to that of the heat dissipation chip 1 is obtained from the through screw hole 6 on the back surface side of the high heat dissipation substrate 3. A heat radiating screw 9 made of a high material is inserted. Note that the protrusion amount can be adjusted so that the heat dissipating screw 9 contacts the lower surface of the package of the electronic component 7.
In this way, by bringing the heat dissipation screw 9 into contact with the lower surface of the package of the electronic component 7, the variation in the space 10 is alleviated and the electronic component 7 and the heat dissipation chip 1 are thermally connected. As a result, the heat generated by the electronic component 7 can be released to the back side of the high heat dissipation substrate 3, and the temperature rise of the electronic component 7 can be suppressed.

  In the example shown in FIGS. 2 (a) and 2 (b), the heat dissipation chip is embedded directly under the electronic component. However, the high heat dissipation substrate and the housing (chassis frame) that accommodates the heat dissipation chip are also in contact with each other. If the heat radiating chip is embedded, the heat generated from the electronic component 7 can be efficiently transmitted to the chassis frame through the heat radiating chip 1 directly under the electronic component 7 → the inner layer conductor pattern → the heat radiating chip in contact with the chassis frame. .

Embodiment 2. FIG.
FIG. 3 is a diagram showing an example of a configuration for thermally connecting the electronic component, the heat dissipation chip, and the chassis frame according to Embodiment 2 of the present invention.
FIG. 3A is a diagram illustrating a configuration example of the high heat dissipation substrate 3 in which the heat dissipation chip 1 provided with the through hole 2 is embedded in a screwed portion with the chassis frame 11.
The chassis frame 11 and the heat dissipation chip 1 are brought into close contact with each other with the screws 12 and the nuts 13, and a more reliable heat dissipation effect can be obtained.
However, since this method expects the thermal connection between the heat dissipation chips to the inner layer conductor pattern, it is manufactured by a method in which the heat dissipation chip and the inner layer conductor are in contact with each other, for example, by pressing the heat dissipation chip into the hole provided with the through-hole plating 14. It is desirable to apply to the high heat dissipation substrate.

On the other hand, FIG. 3B is a diagram illustrating a configuration example of the high heat dissipation substrate 3 when the chassis frame 11 is in contact with the heat dissipation chip 1 under the electronic component 7.
Through screw holes 6 are provided in the heat dissipating chip 1 and the chassis frame 11, and heat dissipating screws 9 are inserted from the back side of the high heat dissipating substrate 7, so that heat is directly applied from the bottom surface of the electronic component 7 to the chassis frame 11. At the same time, the high heat dissipation substrate 3 can be fixed to the chassis frame 11.
The significance of the existence of the heat dissipation chip 1 at this time is that heat dissipation can be improved by increasing the heat capacity and increasing the contact area with the chassis frame 11 (or the space on the back side of the substrate).
In the configuration example shown in FIG. 3, since the chassis frame 11 serves as a heat sink, the heat absorbed by the heat dissipation chip 1 can be efficiently radiated.

Embodiment 3 FIG.
FIG. 4 is a diagram illustrating a configuration example in which the electronic component, the heat dissipation chip, and the chassis frame according to the third embodiment are thermally connected.
4C, the through screw hole 6 of the chassis frame 11 in FIG. 3B is changed to the through hole 2, and the heat radiating screw 9 is fixed by a nut 12 from the back side of the chassis frame 11. In FIG.
By fixing with the nut 12 in this way, the hole in the chassis frame 11 does not need to be a screw hole, and it is possible to prevent weakening of the thermal connection between the heat dissipation chip 1 and the chassis frame 11 due to external force or aging. it can.
However, it should be noted that the contact area between the heat dissipation screw 9 and the chassis frame 11 is reduced when the configuration of FIG. 4C is compared with the case where the hole of the chassis frame 11 is a screw hole.

FIG. 4D is an example in which the configurations described in FIG. 3A and FIG. 3B are combined, and one heat dissipation chip is provided with a through hole 2 and a through screw hole 6, and heat is transmitted from the through hole 2. Fill with conductive agent or heat conductive adhesive.
A heat radiating screw is inserted into the through screw hole 6, so that the highest heat radiating property can be expected in the embodiments described so far.

  With regard to the through screw hole of the heat dissipation chip, if the purpose is only to thermally connect and fix the housing (no need to protrude the heat dissipation screw to the component side), or the amount of protrusion of the heat dissipation screw can be adjusted before mounting the component ( If adjustment from the back side or fixing to the housing is not required), non-penetration may be used.

  As described above, the high heat dissipation substrate and the heat dissipation structure according to the present invention are useful in that the heat generated from the electronic components can be efficiently dissipated to the outside, and in particular, the heat dissipation structure for mounting the high heat generation electronic components. Is suitable.

1 heat dissipation chip, 2 through hole, 3 high heat dissipation substrate, 4 conductor pattern, 5 substrate material, 6 through screw hole, 7 electronic component, 8 heat conductive agent, heat conductive adhesive, etc. 9 heat dissipation screw, 10 electronic component Space between substrate, 11 chassis frame, 12 screws, 13 nuts, 14 through-hole plating.

Claims (4)

A substrate with a heat dissipation chip embedded therein,
The heat radiating chip includes a through hole for injecting a heat conductive agent or a heat conductive adhesive in a space between a lower surface of a component mounted above the heat radiating chip and the substrate surface. substrate. A substrate with a heat dissipation chip embedded therein,
The heat dissipation chip includes a through screw hole through which a heat dissipation screw is brought into contact with a lower surface of a component mounted above the heat dissipation chip. A substrate in which a heat dissipation chip having a through hole penetrating the upper surface and the lower surface is embedded;
Components mounted on the heat dissipation chip;
A space between the lower surface of the component and the substrate, and a heat conductive agent or a heat conductive adhesive filling the through hole;
A heat radiating structure for parts, comprising: A substrate in which a heat dissipation chip having a through screw hole penetrating the upper surface and the lower surface is embedded;
Components mounted on the heat dissipation chip;
A heat dissipating screw screwed at a position passing through the through screw hole and in contact with the lower surface of the component;
A heat radiating structure for parts, comprising:

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