JPH0562090U - 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. Constitution: For the LSI 5 having the protection cap 17 arranged on one surface in a grid pattern and having the pins 16 coated with an insulating film 21 for insulating current, the first recess 18 and the LSI 5 corresponding to the protection cap 17 are provided. The heat-dissipating plate 3 having the second concave portion 20 and the round hole 19 on the opposite surface is attached to the printed wiring board 2 together with the heat conductive rubber 23.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

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

[0002]

[Prior Art]

 The most popular method for cooling electronic circuit components has been to blow cooling air directly onto the electronic circuit. However, as the functions of electronic devices have become more and more decentralized in recent years, 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 past. In such a case, blowing the cooling air directly onto the electronic circuit components is not the preferred method for reliability of electronic equipment. This is because dust floating in the cooling air adheres to electronic circuit parts, which may cause corrosion or dielectric breakdown. By the way, in electronic devices mounted on aircraft, electronic circuit modules for indirect cooling are often used in order to prevent deterioration of reliability due to dust as described above.

Next, a conventional electronic circuit module 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 wiring board 2. Here, the heat dissipation plate 3 is made of a metal plate having good thermal conductivity (for example, an A L alloy), and is punched out in a rectangular shape at a plurality of places, and one surface thereof is arranged so as to be in contact with the printed wiring board 2 as well. There is. Reference numeral 6 is a box-shaped chassis for housing the electronic circuit module 1, and an opening 7 for removing the electronic circuit module 1 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, cooling air 13 supplied from the airframe through the external duct 12 is allowed to flow. Further, on the outer surface of the partition wall 9, there is a U-shaped groove 14 formed so as to form a right angle with the opening portion 7, and the end portion 15 of the electronic circuit module 1 fits into the groove 14 described above. It is inserted from above as if it were plugged in. Here, the heat generated from the IC 4 is conducted to the end portion 15 of the electronic circuit module 1 via the heat dissipation plate 3, and then is dissipated to the cooling air 13 from the heat dissipation fin 11 via the partition wall 9. On the other hand, the heat generated from the LSI 5 is conducted to the printed wiring board 2 via the pins 16 arranged in a grid on one surface of the LSI 5, and then the cooling air 13 is passed through the heat dissipation plate 3, the partition wall 9 and the heat dissipation fin 11. Heat is radiated to. Therefore, the engineer does not blow the cooling air 13 directly onto 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. The reason is that epoxy resin or polyimide resin is often used as the material of the printed wiring board in the heat conduction path of the heat generated from the LSI 5 as described above, but the heat conduction is higher than that of the metal material. Since it is inferior in heat resistance, the thermal efficiency decreases.

The present invention has been made to solve the above problems, and it is an object of the present invention to obtain an electronic circuit module with improved heat dissipation efficiency of an LSI 5 having pins arranged in a grid pattern on one surface as described above. It is intended.

[0006]

[Means for Solving the Problems]

The electronic circuit module according to the present invention has a rectangular flat plate-like outer shape, and has a rectangular flat plate-like cap for protecting the integrated circuit housed therein in the central portion of one surface, and a grid-like outer periphery of the cap. The electronic circuit having the pin arranged in the above, the one surface facing the above electronic circuit component is provided with 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 sink with a second recess of approximately the same size as that of the electronic circuit component is placed. heat conduction La to an insulating coating of electrically insulating material coating you of a further principal component of silicon type Esutoma and AL ₂ O ₃ filler which has a circular hole which the pin of the electronic circuit component is inserted In which the heat radiating plate and the electronic component is arranged in close contact with each other through the over.

[0007]

[Action]

 In this invention, the heat generated from the electronic circuit parts is directly conducted to the heat sink through the heat conductive rubber. Therefore, even when an electronic circuit component having a protective cap and pins arranged in a grid pattern on one surface is mounted, an electronic circuit module with 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 the conventional male circuit module. 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 17 of the LSI 5. Further, a circular hole 19 having a shape slightly larger than the thickness of the pin 16 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 sink 3. The pin 16 is coated with an insulating coating 21 having an electrical insulating property. The insulating film 21 has the above-mentioned pin 16 even if the solder fillet 22 is formed on the printed wiring board 2 when the pin 16 is inserted into the round hole of the heat dissipation plate 3 and soldered to the printed wiring board 2. 16 and the heat sink 3 or the adjacent pins 16 are coated in a range that does not electrically short-circuit. The heat conductive rubber 23 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 conducted by heat conduction to the heat dissipation plate 3 via the heat conduction rubber 23. Therefore, it goes without saying that the heat conductive rubber 23 should be made of a material having excellent heat conductivity, but in order to further improve the tightness of adhesion between the LSI 5 and the heat sink 3, and to prevent short-circuiting between the pins 16. It is also necessary to have the above-mentioned electrical insulation property, and a material containing a silicone-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, the heat dissipation efficiency of an LSI having a protective cap in the center of one surface and having pins arranged in a grid pattern on the outer periphery of the cap is impaired. It can be mounted without any need, and an indirect cooling method that does not blow cooling air directly to electronic circuit parts can be realized, and the reliability of electronic circuit parts 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.

FIG. 2 is a view showing a cross section CC of FIG.

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

FIG. 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.

[Explanation of symbols]

 1 Electronic Circuit Module 2 Printed Wiring Board 3 Heat Sink 4 IC 5 LSI 6 Chassis 7 Opening 8 Cover 9 Partition 10 Ventilation Duct 11 Cooling Air 14 Groove 15 End 16 Pin 17 Cap 18 First Recess 19 Round Hole 20 Second Recessed part 21 Insulating film 22 Solder fillet 23 Thermal conductive rubber

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 therein is provided in a central portion of one surface, and the cap is arranged in a grid shape on an outer periphery thereof. An electronic circuit component having a pin and a surface facing the electronic circuit component are provided with 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 the opposite surface is provided with the electronic component. The second concave portion having the same size as the circuit component is formed, and the metal flat plate-shaped heat dissipation plate arranged so that the pin of the electronic circuit component is inserted into the round hole, and the pin of the electronic circuit component are A heat conductive rubber containing a silicone-based elastomer and an AL ₂ O ₃ -based filler as main components, which has a circular hole to be inserted and is arranged so as to be in close contact with both the electronic circuit component and the heat sink. Electronic times Insulating film made of an electrically insulating material that is coated beyond the range where the pin of the path component is inserted into the heat sink, and a through hole into which the pin of the electronic circuit component is inserted and soldered And an electronic circuit module comprising a printed wiring board arranged so as to come into contact with the surface of the heat dissipation plate which is in contact with the conductive rubber and on the opposite side.