JP2008270537A - Heat dissipation arrangement of electronic part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat dissipation arrangement of electronic parts which improves heat dissipation efficiency of a printed board, and reduces a projection area while the number of parts is decreased for more efficient assembly man-hours. <P>SOLUTION: The heat dissipation arrangement includes a metal core substrate 10 where a plurality of electronic parts including a heating part 5 are formed on one surface, a shield case 11 having a U-shape cross section which is bonded to the other surface of the metal core substrate 10, and a main printed board 1. The shield case 11 having a U-shape cross section is so secured to the main printed board 1 as to cover the electronic parts. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat dissipation structure for an electronic component including a heat generating component mounted on a printed circuit board, and more particularly to a heat dissipation structure for an electronic component that improves heat dissipation efficiency and increases the number of assembly steps.

The following patent documents are known as prior arts that aim to dissipate heat from a heat-generating component mounted on a printed circuit board.
JP-A-3-268348 JP-A-4-245499 Japanese Unexamined Patent Publication No. Hei 8-279689

2A and 2B are main part configuration diagrams showing a conventional example of a heat dissipation mechanism for an electronic component mounted on a printed circuit board, and are a plan view (a) and a Z view (b) of FIG. .
In these drawings, reference numeral 1 denotes a main printed circuit board (for example, a PCB or a PWB board), and two windings (reactors) 2 which are heat generating parts having the same height are provided on one side of the main printed circuit board at a predetermined interval. Open and fixed. In addition, FIG. (A) shows the state where the fins 8a are left and the second shield case 7 is removed.

Reference numeral 3 denotes a first heat transfer sheet formed of, for example, aluminum formed in a rectangular shape, and one surface is disposed in contact with the heads of the two windings 2.
4 is a 1st shield case, it arrange | positions so that one surface may closely_contact | adhere to the 1st heat-transfer sheet | seat 3, and the other surface is an open state. The vicinity of the edge of the first shield case 4 is bent toward the main printed circuit board 1 so that the entire end is in contact with the printed circuit board 1.

  Reference numeral 5 denotes five semiconductor elements attached to the other surface of the main printed circuit board 1. When this semiconductor element 5 is viewed from above, the semiconductor printed circuit board 1 is arranged so as to partially overlap the main printed circuit board 1. Yes. Reference numeral 6 denotes a second heat transfer sheet having the same shape and area as the first heat transfer sheet 3, and one surface is arranged in contact with the head of the semiconductor element 5.

  Reference numeral 7 denotes a second shield case. Similar to the first shield case 4, one edge of the second shield case 7 is bent in the vicinity of the edge toward the main printed circuit board 1 so that the entire end portion is connected to the printed circuit board 1. They are in contact. Reference numeral 8 denotes a heat sink having fins 8 a made of, for example, aluminum, and is fixed in contact with the other surface of the second shield case 7.

In the above-described configuration, the two windings (reactors) 2 are transformers constituting a power source, and heat is transferred to the first shield case 4 via the first heat transfer sheet 3 at the head of the transformer 2, Heat is radiated on the surface of the first shield case 4.
Further, the heat generated from the semiconductor element 5 constituting the power supply circuit is transferred to the second shield case 7 through the second heat transfer sheet 6 and radiated by the fins 8a.

By the way, in the above-described configuration, it is necessary to increase the heat sink size in order to lower the surface temperature of the printed circuit board to a desired value.
According to the applicant's experiment, when the size of the winding is about 13 mm, the projected area on the printed circuit board is
Single side: 2,475 mm ² (= 45 mm × 55 mm) Total of both sides: About 4,950 mm ² was necessary.

  Further, when the first and second shield cases are attached, there is a problem that the main printed board 1 must be assembled from both sides, and the main printed board 1 must be turned over each time.

  The present invention was made to solve the above-mentioned problems of the prior art, and improved heat dissipation efficiency of the printed circuit board, and heat dissipation of the electronic parts designed to improve assembly man-hours by reducing the projected area and the number of parts. The purpose is to provide a mechanism.

In order to achieve such a problem, the structure of the heat dissipation mechanism of the electronic component of the present invention is as follows.
A metal core board on which one or more electronic parts including a heat generating part are formed, a U-shaped shield case attached in close contact with the other side of the metal core board, and a main printed board The electronic printed circuit board is fixed to the main printed circuit board so as to cover the electronic component with the U-shaped shield case.

In claim 2, in the heat dissipation mechanism of the electronic component according to claim 1,
The electronic component head and the surface of the main printed circuit board have a predetermined space in a state where the electronic component is covered with the U-shaped shield case.

In Claim 3, in the heat dissipation mechanism of the electronic component of Claim 1 or 2,
The plurality of electronic components are configured to function as a modularized power supply.

As is apparent from the above description, the present invention has the following effects.
According to Claims 1 and 2, a metal core substrate in which a plurality of electronic components including heat generating components are formed on one surface, and a shield case having a U-shaped cross section attached in close contact with the other surface of the metal core substrate; The main printed circuit board is fixed to the main printed circuit board so as to cover the electronic component with a U-shaped shield case, and the electronic component head and the surface of the main printed circuit board are covered with the electronic component. Since a predetermined space is provided in

Since there is no heat generating component on the main printed circuit board, an increase in the surface temperature of the main printed circuit board can be suppressed.
In addition, the heat resistance side of the semiconductor element itself can be transferred to the shield case through the metal core substrate, and no heat sink is required by only radiating the surface of the shield case, and the shield case can be only one side. .

In addition, since the projected area onto the main printed circuit board is reduced and a space is provided on one surface side, if an electronic circuit is formed in this space, a circuit configuration with a margin can be realized.
According to the experiment, the projection area was 3,575 (= 65 mm × 55 mm), which was 27% reduction compared to the conventional example.

  Furthermore, the shield case is attached only from one side, making assembly easier.

  According to the third aspect, since the plurality of electronic components are configured to function as a modularized power source, only the module can be easily replaced when the power source is broken, thereby improving maintainability. be able to. In addition, it is possible to meet various input power requirements by replacing only the module.

1A and 1B are main part configuration diagrams of a heat dissipation mechanism for an electronic component showing an example of an embodiment of the present invention, and are a plan view (a) and a Z view (b) in FIG.
In FIG. 1, the same elements as those in the conventional example of FIG.
The winding 2 and the semiconductor element 5 are attached to the metal core substrate with a predetermined interval.

  1A and 1B, reference numeral 10 denotes a metal core substrate. Two windings 2 are fixed to one surface of the metal core substrate 10 with a predetermined interval on the right side, and five semiconductors are on the left side. The elements 5 are fixed with a predetermined interval.

  The other surface of the metal core substrate 10 is in close contact with the shield case 11, and the vicinity of the edge of the shield case 11 is bent at about 90 degrees to cover the two windings 2 and the five semiconductor elements 5, and the end portions are It is in contact with the main printed circuit board 1.

  The shield case 11 and the main printed circuit board 1 are fixed by through bolts (not shown) or the like. In addition, the height of the shield case is adjusted so that the distance (space H) between the main printed circuit board 1 and the head of the winding 2 does not affect the main printed circuit board 1 from the heat of the winding 2.

In the above-described configuration, the heat generated from the winding 2 and the semiconductor element 5 propagates to the shield case 11 through the metal core substrate 10 and is released into the atmosphere.
According to the configuration described above, since no heat generating component is present on the main printed circuit board 1, an increase in the surface temperature of the main printed circuit board can be suppressed.

  Further, the semiconductor element itself having a low thermal resistance can be transferred to the shield case 11 by the metal core substrate 10, no heat sink is required only by heat radiation on the shield case surface, and the shield case can be only one side. .

In addition, since the projected area onto the main printed circuit board is reduced and a space is provided on one surface side, if an electronic circuit is formed in this space, a circuit configuration with a margin can be realized.
According to the experiment, the projection area was 3,575 (= 65 mm × 55 mm), which was 27% reduction compared to the conventional example.

  Furthermore, the shield case is attached only from one side, making assembly easier. In addition, since the plurality of electronic components are configured to function as a modularized power source, only the module can be easily replaced when the power source is broken, thereby improving maintainability. In addition, it is possible to meet various input power requirements by replacing only the module.

The above description merely shows a specific preferred embodiment for the purpose of explanation and illustration of the present invention. For example, the arrangement and number of windings and semiconductor elements are not limited to the illustrated example, but are arbitrary. Moreover, although the implementation target of the present invention is the power supply, it can be applied to other than the power supply.
Therefore, the present invention is not limited to the above-described embodiments, and includes many changes and modifications without departing from the essence thereof.

It is a principal part block diagram which shows an example of the thermal radiation mechanism of the electronic component to which this invention is applied. It is a principal part block diagram of the heat dissipation mechanism of the conventional electronic component.

Explanation of symbols

1 Main printed circuit board 2 Winding (reactor)
3 First Heat Transfer Sheet 4 First Shield Case 5 Semiconductor Element 6 Second Heat Transfer Sheet 7 Second Shield Case 8 Heat Sink 8a Fin 10 Metal Core Substrate 11 Shield Case

Claims (3)

  A metal core board on which one or more electronic components including heat generating parts are formed, a U-shaped shield case attached in close contact with the other side of the metal core board, and a main printed board A heat dissipation mechanism for an electronic component, wherein the electronic component is fixed to the main printed circuit board so as to cover the electronic component with a U-shaped shield case.   2. The electronic component according to claim 1, wherein a head of the electronic component and a surface of the main printed board have a predetermined space in a state where the electronic component is covered with the U-shaped shield case. Heat dissipation mechanism.   The heat dissipation mechanism for an electronic component according to claim 1 or 2, wherein the plurality of electronic components function as a modular power source.

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