JPH09246433A - Radiation structure of module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively radiate heat from a mounted electronic component, by providing an inner frame made of an insulating material on a board in such a manner as to surround the electronic component, and providing a radiation board on an upper part of the inner frame in such a manner as to cover the inside of the inner frame. SOLUTION: A frame 4 is fixed on a board 1 in such a manner as to surround an electronic component 2 mounted on the board 1. A radiation board 5 is fitted in a groove of the frame 4. The board 1, the frame 4 and the radiation board 5 form a box-shaped space. A small resin injection hole 6 is provided in the radiation board 5, so that a liquefied resin 7 is injected from the resin injection hole 6 and solidified, thus sealing the electronic component. Heat emitted from the electronic component 2 is transmitted via the injected resin 7 to the radiation board 5 and radiated from the radiation board 5. Since the area of the radiation board 5 may be increased approximately to the size of the board 1, the radiation capability may be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a module including a board on which electronic components are mounted, and more particularly to a heat dissipation structure for the module.

[0002]

2. Description of the Related Art Conventionally, there has been a method of using a dedicated integrated circuit or a hybrid integrated circuit as a method of mounting electronic components on a printed wiring board while increasing the degree of integration. In the case of small-scale production, the cost will increase. As a countermeasure, a wiring pattern is formed on a small ceramic or glass epoxy substrate, and a bare chip, a molded chip, or a plurality of parts such as power-generating parts such as power elements are mounted on the wiring pattern, and wire bonding,
After soldering, there is a method of mounting an electronic component mounting circuit board having lead terminals mounted thereon, a so-called module, on a main printed wiring board.

[0003]

However, it is necessary to radiate heat for power devices and electronic components that generate heat.
In the case of a module, there is a demand for a heat-dissipating structure that is small, efficient, and easy to assemble.

[0004]

In order to solve such a problem, the present invention provides a module in which electronic components are mounted on a substrate, the module being provided on the substrate so as to surround the electronic components. An inner frame made of an insulating material, a heat radiating plate provided in the upper part of the inner frame so as to cover the inner frame, a resin injection hole provided in the heat radiating plate, and a seal injected into the inner frame. It is made of a resin for use.

In a module in which electronic components are mounted on a board, an outer frame made of an insulating material is provided around the board so as to surround the board, and the module is provided inside the outer frame. It is characterized in that it is composed of a circuit on the substrate and a terminal portion which is connected to one end and is connected to the other end for external connection. Further, the heat dissipation plate is provided with an air vent hole.

Further, the inner frame and the heat dissipation plate are integrally formed. Further, an insulating layer is provided on a contact surface of the inner frame with the substrate.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a first embodiment of the present invention, showing a cross section and an appearance of a module. Reference numeral 1 is a ceramic or glass epoxy substrate on which a printed wiring pattern is formed on one or both surfaces by copper foil or the like. Reference numeral 2 denotes an electronic component such as a resistor, a capacitor, a transistor, etc., and a plurality of components such as a bare chip, a molded chip, or a heat generating component such as a power element are mounted on the substrate 1. Reference numeral 3 is a lead terminal for electrically connecting the printed wiring pattern of the substrate 1 to the wiring pattern of the main printed wiring board.

A frame 4 made of resin or the like is fixed to the substrate 1 so as to surround the electronic component 2 mounted on the substrate 1. Reference numeral 5 denotes a heat radiating plate formed of a metal plate having good heat conductivity such as aluminum, and is fitted in the groove of the frame 4.
Further, the frame 4 is assembled before the heat sink 5 is fitted into the groove in a separated state. Then, the substrate 1, the frame 4, the heat sink 5
A box-shaped space is formed by. A small resin injection hole 6 is provided in the heat dissipation plate 5, and the liquefied resin 7 is injected and solidified from the resin injection hole 6 to seal the electronic component.

With the above-described structure, the heat generated from the electronic component 2 is transmitted to the heat dissipation plate 5 through the injected resin 7 and is dissipated. Since the area of the heat dissipation plate 5 can be increased to about the size of the substrate 1, the heat dissipation ability can be increased. In addition, since the heat-generating component 2 and the heat radiating plate 5 can be joined by the resin 7 without an air layer, heat conduction can be improved and the heat radiating ability can be enhanced. Moreover, since the resin 7 is injected into the space defined by the frame 4 and the like, the sealing work can be easily performed without expanding more than necessary.

The injection hole 6 provided in the heat dissipation plate 5 functions as a hole for discharging the air in the box-shaped space when the resin is injected. Therefore, the injected resin is prevented from generating voids (air bubbles) due to the air. Good conduction. The injection hole 6 may be provided with a plurality of holes as required. Therefore, the module thus completed is mounted on the main printed circuit board as one solid part, and has a good heat dissipation capability, so that the module can be miniaturized and the assembling work becomes easy.

Next, a second embodiment will be described. FIG.
FIG. 3 is a diagram showing the configuration of a second embodiment of the present invention, showing the cross section and appearance of the module. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. A frame 11 made of resin is an outer frame that surrounds the end of the printed circuit board 1 so as to surround it. The outer frame 11 has a divided structure and is assembled by sandwiching the printed circuit board 1. A lead terminal 12 connects the circuit of the printed circuit board 1 and an external circuit, and is integrated with the outer frame 11 by a method such as embedding in the outer frame 11. A heat radiation plate 5 made of metal or the like is placed on the upper portion of the outer frame 11 so as to cover the outer frame 11, and is fixed by the resin 7.

Next, the assembling method will be described. First, the printed board 1 is fitted into the groove of the outer frame 11 to surround the end portion of the printed board 1. The printed circuit board 1 becomes the bottom, and the outer frame 1
A predetermined amount of molten resin 7 is poured into a box-shaped space having 1 as a side wall, and while the resin 7 does not solidify, the heat dissipation plate 5 is mounted and pressed to close the space. At this time, the hole 6 provided in the heat sink 5
Since the air in the box and the air contained in the resin 7 are discharged from the box, air bubbles and the like do not form in the poured resin 7 and the corners of the box, and the resin 7 is defined by the outer frame 11. Since it is injected into the open space, it can be easily sealed without expanding more than necessary.

Therefore, the module completed in the same manner as the first embodiment shown in FIG. 1 is mounted on the main printed circuit board as one solid part, and since it has a good heat dissipation capability, it can be miniaturized and the assembling work is easy. Becomes Next, a third embodiment will be described. FIG. 3 is a diagram showing the configuration of a third embodiment of the present invention, showing a cross-section and appearance of the module and an enlarged view of the end portion of the heat sink. The same parts as those in the first and second embodiments are designated by the same reference numerals and the description thereof will be omitted.

Reference numeral 20 denotes a bottomless box-shaped heat dissipation case formed of a heat dissipation material (aluminum plate or the like), and has a shape suitable for covering the electronic component 2 mounted on the substrate 1 (of the electronic component 2). It is a shape that matches the position and size).
For example, the shape of the plane may be a circle, a rectangle, a deformed shape (having different heights), a polygonal shape, or any other shape that covers the electronic component 2 mounted thereon.

Reference numeral 21 denotes a resin injection hole, which has the effect of injecting the resin and exhausting the internal air, and a plurality of holes may be provided. Two
An insulating material layer 2 insulates an end portion of the heat radiating case and a portion where the substrate 1 is in contact with each other. The insulating material layer 22 is for preventing the printed wiring pattern formed on the surface of the printed circuit board 1 from being damaged by the end of the heat dissipation case and short-circuiting the circuit.

With the above construction, also in the present embodiment, as in the first and second embodiments, effective heat dissipation can be achieved and the size can be reduced, and the number of parts is small and the assembling work can be simplified. .

[0017]

As described above in detail, in the present invention, the heat generated from the electronic components mounted on the substrate can be effectively dissipated, the size can be reduced, and the assembling work can be facilitated. Module can be realized.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a third exemplary embodiment of the present invention.

[Explanation of symbols]

 1 --- Substrate 2 --- Electronic component 3 --- Lead terminal 4--Inner frame 5 --- Heat sink

Claims (5)

[Claims] 1. A module in which an electronic component is mounted on a substrate, wherein an inner frame made of an insulating material is provided on the substrate so as to surround the electronic component, and the inner frame is formed so as to cover the inner frame. A heat dissipation structure for a module comprising a heat dissipation plate provided on an upper part of the frame, a resin injection hole provided on the heat dissipation plate, and a sealing resin injected into the inner frame. 2. A module in which electronic components are mounted on a substrate, wherein an outer frame made of an insulating material is provided around the substrate so as to surround the substrate, and an outer frame is provided inside the outer frame. A heat dissipation structure for a module, which is composed of a circuit on a board and one end of which is connected to the circuit and the other end of which is used for external connection. 3. The heat dissipation structure for a module according to claim 2, wherein the heat dissipation plate is provided with an air vent hole. 4. The heat dissipation structure for a module according to claim 1, wherein the inner frame and the heat dissipation plate are integrally formed. 5. The heat dissipation structure for a module according to claim 4, wherein an insulating layer is provided on a contact surface of the frame with the substrate.