JPH0533596U - Electronic circuit module - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the heat dissipation efficiency of an LSI having a protective cap and pins arranged in a grid on one surface. [Structure] For an LSI 5 having a protective cap 6 and pins 7 arranged in a grid pattern on one surface, a first concave portion 18 corresponding to the protective cap 6 and a second concave surface on the opposite side of the LSI 5 are provided.
The insulator 21 having the round hole 22 and the flat hole 23 is incorporated into the heat sink 3 having the concave portion 20 and the round hole 19 and is attached to the printed wiring board 2 together with the heat conductive rubber 25.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to improvement of an electronic circuit module of an electronic device mounted on an aircraft or the like, and is characterized by its heat dissipation structure.

[0002]

[Prior Art]

 Conventionally, the most general method for cooling electronic circuit components is to blow cooling air directly onto the electronic circuit components. However, recently, as the functions of electronic devices are becoming more and more decentralized, there is a growing desire to install electronic devices themselves in places with relatively poor environmental conditions. That is, electronic devices are not always installed in a room where temperature, humidity, dust, etc. are controlled as in the conventional case. In such a case, the method of directly blowing the cooling air to the electronic circuit components is not preferable in terms of reliability of electronic equipment. This is because dust floating in the cooling air may adhere to electronic circuit parts, and the adhered parts may corrode or cause dielectric breakdown. By the way, in an electronic device mounted on an aircraft, an indirect cooling electronic circuit module is often used in order to prevent the reliability from being deteriorated by the dust as described above.

First, a conventional electronic circuit module of this type will be described. FIG. 3 is an external view showing a typical example thereof, and FIG. 4 is a view showing a cross section AA of FIG. Further, FIG. 5 is an external view of an electronic device in which the electronic circuit module shown in FIG. 3 is mounted, and FIG. 6 is a view showing a cross section BB of FIG. In the figure, reference numeral 1 denotes an electronic circuit module, which is composed of a printed wiring board 2, a heat sink 3, and electronic circuit parts such as an IC 4 and an LSI 5 soldered to the printed board 2. Here, the heat dissipation plate 3 is made of a metal (for example, aluminum alloy) plate having good heat conductivity, and is punched out in a rectangular shape at a plurality of locations, and one surface thereof is arranged so as to be in contact with the printed wiring board 2. 6 is a box-shaped chassis for accommodating the electronic circuit module 1, and an opening 7 for removing the electronic circuit module is provided on the upper surface. Reference numeral 8 denotes a cover for covering the opening 7, which is fixed to the chassis 6 at the peripheral portion with screws or the like. A rectangular ventilation duct 10 is formed by a partition wall 9 on two surfaces that form a right angle with the opening 7 of the chassis 6 and face each other. Inside the ventilation duct 10, a radiation fin 11 is provided. In both cases, the cooling air 13 supplied from the machine body through the external duct 12 flows. Further, there is a U-shaped groove 14 formed on the outer surface of the partition wall 9 so as to form a right angle with the opening portion 6, and the end portion 15 of the electronic circuit module 1 fits into the groove 14. Is inserted from above. Here, the heat generated from the IC 4 is conducted to the end portion 15 of the electronic circuit module 1 through the heat radiating plate 3, and then radiated from the heat radiating fins 10 to the cooling air 13 via the partition wall 9. On the other hand, the heat generated from the LSI 5 is conducted to the printed wiring board 2 through the pins 16 arranged in a grid on one surface of the LSI 5, and then to the cooling air 13 via the heat sink 3, the partition wall 9 and the heat radiation fin 10. Is dissipated. Therefore, the cooling air 13 is not blown directly to the electronic circuit parts of the IC 4 and the LSI 5.

[0004]

[Problems to be solved by the device]

 The conventional electronic circuit module as described above has a drawback that the heat dissipation efficiency of the LSI 5 is poor. This is because, as described above, epoxy resin or polyimide resin is often used as the material of the printed wiring board in the heat conduction path generated from the LSI 5. It is an inferior material.

The present invention has been made in order to solve the above problems, and obtains an electronic circuit module in which the heat dissipation efficiency of the LSI 5 having the pins arranged in a grid pattern on one surface as described above is improved. The purpose is that.

[0006]

[Means for Solving the Problems]

An electronic circuit module according to the present invention has a rectangular flat plate-like outer shape, a rectangular flat plate-like cap for protecting an integrated circuit to be housed therein in a central portion of one surface, and a grid on the outer periphery of the cap. The electronic circuit component including the pins arranged in a line, the one surface facing the electronic device has a first recess slightly larger than the outer shape of the cap and a round hole slightly larger than the thickness of the pin, and On the opposite surface, a metal flat plate-shaped heat dissipation plate having a second recess having substantially the same size as that of the electronic circuit component is provided with the same circular hole as that of the heat dissipation plate, which is arranged in the second recess. An insulator having electrical insulation is formed on the surface opposite to the surface in contact with the second recess by chamfering the round hole to form a flat hole, and the pin of the electronic circuit component is inserted into the round hole. , The above pin is inserted While being, arranged to be in close contact with the print wiring board having a through-hole to be soldered, with further having a circular hole in which the pin of the electronic circuit component is inserted, silicone-based elastomer and Al _The heat dissipation plate and the electronic components are arranged so as to be in close contact with each other via a heat conductive rubber whose main component is a ₂ O ₃ based filler.

[0007]

[Action]

 In this invention, the heat generated from the electronic circuit parts is conducted to the direct heat radiation plate via the heat conductive rubber. Therefore, even when an electronic circuit component having a protective cap and pins arranged in a grid pattern is mounted on one surface, an electronic circuit module having good heat dissipation efficiency can be realized.

[0008]

【Example】

1 is an external view showing an embodiment of an electronic circuit module according to the present invention, and FIG. 2 is a view showing a cross section CC of FIG. In the figure, 1 to 7 are equivalent to conventional electronic circuit modules. Reference numeral 18 denotes a rectangular first recess provided on one surface of the heat dissipation plate 3 facing the LSI 5, and has a size slightly larger than the outer shape of the cap 6 of the LSI 5. Further, a circular hole 19 having a diameter slightly larger than the thickness of the pin 7 of the LSI 5 is formed on the same surface side as the first concave portion 18. Further, a second recess 20 having substantially the same size as the LSI 5 is formed on the opposite side of the heat dissipation plate 3. Reference numeral 21 denotes an insulator, which is arranged so as to be in close contact between the second recess 20 of the heat dissipation plate 3 and the printed wiring board 2. The insulator 21 is provided with a round hole 22 having substantially the same size as that of the heat dissipation plate 3, and a chamfered flat hole 23 for the round hole 22 is provided on the surface opposite to the surface in contact with the second recess 20. Has been formed. As for the size of the flat hole 23, even when the solder fillet 24 is formed on the printed wiring board 2 when the pin 7 is inserted into the round hole 22 and soldered to the printed wiring board 2, the pin 7 is formed. And the radiating plate 3 or the adjacent pins 7 have a dimensional relationship such that they are not electrically short-circuited. A heat conductive rubber 25 is arranged between the heat dissipation plate 3 and the LSI 5 to enhance the adhesion between them. Here, the heat generated from the LSI 5 is guided by heat conduction to the heat dissipation plate 3 via the heat conduction rubber 25. Therefore, it goes without saying that the heat conductive rubber 25 must be made of a material having excellent heat conductivity, but it is necessary to further improve the flexibility to improve the adhesion between the LSI 5 and the heat sink 3 and to prevent short-circuiting between the pins 7. It is also necessary to have electrical insulation properties, and a material containing a silicon-based elastomer and an Al ₂ O ₃ -based filler as main components is generally commercially available.

[0009]

[Effect of the device]

 Since the electronic circuit module according to the present invention is configured as described above, an LSI having a protective cap at the center of one surface and having pins arranged in a grid pattern on the outer periphery of the cap can be used for heat dissipation efficiency. It is possible to mount without damage, and it is possible to realize an indirect cooling method in which cooling air is not blown directly to electronic circuit components, and the reliability of electronic circuit components can be significantly improved.

[Brief description of drawings]

FIG. 1 is an external view showing an embodiment of an electronic circuit module according to the present invention.

2 is a diagram showing a cross section CC of FIG. 1. FIG.

FIG. 3 is an external view showing a conventional representative electronic circuit module.

4 is a diagram showing a cross section AA of FIG. 3;

5 is an external view of an electronic circuit on which the electronic circuit module shown in FIG. 3 is mounted.

6 is a diagram showing a cross section BB of FIG. 5;

[Explanation of symbols]

 1 Electronic Circuit Module 2 Printed Wiring Board 3 Heat Sink 4 IC 5 LSI 6 Cap 7 Pin 8 Chassis 9 Opening 10 Cover 11 Partition 12 Ventilation Duct 13 Radiating Fin 14 External Duct 15 Cooling Air 16 Groove 17 End 18 First Recess 19 round hole 20 second recess 21 insulator 22 round hole 23 flat hole 24 solder fillet 25 heat conductive rubber

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H05K 7/20 B 8509-4E

Claims (1)

[Scope of utility model registration request] 1. A rectangular flat plate-shaped outer shape, a rectangular flat plate-shaped cap for protecting an integrated circuit housed inside is formed in a central portion of one surface, and a grid is arranged on the outer periphery of the cap. An electronic circuit component having a pin and one surface facing the electronic circuit component are provided with a first recess slightly larger than the outer shape of the cap and a circular hole slightly larger than the thickness of the pin, and on the opposite surface, A second metal plate-shaped heat dissipation plate, which is formed so as to form a second recess having substantially the same size as that of the electronic circuit component, and is arranged so that the pin of the electronic circuit component is inserted into the round hole, The round hole, which is arranged in the concave portion and has a size substantially the same as that of the radiator plate, is formed on the surface facing the concave portion, and a chamfered round hole is formed on the opposite surface. The pins of the above electronic circuit parts are inserted Has a flat plate-like insulator having electrical insulation and a round hole into which the pin of the electronic circuit component is inserted, and is arranged so as to be in close contact with both the electronic circuit component and the heat sink. The heat conductive rubber containing the above-mentioned silicon elastomer and Al ₂ O ₃ filler as main components, the pins of the electronic circuit parts are inserted, the through holes are soldered, and the heat conduction of the heat dissipation plate is performed. An electronic circuit module comprising a surface that comes into close contact with a rubber and a printed wiring board that is arranged so as to come into contact with the opposite surface.