JPH0557893U - Electronic circuit device - Google Patents

Abstract

(57) [Abstract] [Purpose] Improve the heat dissipation of heat-generating electronic components, suppress the vibration of the metal case to improve reliability, and use a lightweight and inexpensive three-layer board. It is possible. A heat-generating electronic component 2A of a large number of electronic components 2 mounted on the surface of the circuit board 1 is connected to the circuit board 1 and the electronic components 2 and 2A via a contact member 6 having excellent thermal conductivity. It is fixed to the inner surface of the metal case 3 covering the surface so that the heat generated by the heat-generating electronic component 2A is dissipated from the large metal case 3.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 This invention has a structure in which a large number of electronic components are mounted on the surface of a circuit board, such as a DC-DC converter, and the entire surface is covered with a metal case to protect the electronic components. The present invention relates to an electronic circuit device.

[0002]

[Prior Art]

 A conventional electronic circuit device of this type will be described by taking a case of a horizontal type as an example. As shown in FIG. 3, a large number of electronic components 2 such as transistors, transformers, and chokes are formed on the surface of an aluminum base substrate 1. The metal case 3 covering the surfaces of the electronic component 2 and the substrate 1 is adhered and fixed to the substrate 1 at its peripheral portion. Then, such an electronic circuit device is configured to be attached to the printed wiring board 5 arranged below through the terminal 4 protruding downward from the aluminum base substrate 1.

[0003]

[Problems to be solved by the device]

 In the conventional electronic circuit device as described above, the heat generated from the electronic component 2 is mainly radiated through the aluminum base substrate 1. Therefore, the heat dissipation is insufficient, the thermal influence on the electronic component 2 is large, and the reliability is high. Sexual problems are likely to occur. In particular, in the case of the horizontal type as shown in FIG. 3, the printed wiring board 5 is arranged under the aluminum base substrate 1, so that the heat radiation from the lower portion is blocked by the printed wiring board 5 to further improve the heat radiation performance. Was a bad thing.

The present invention has been made in view of the above circumstances, and it is possible to effectively utilize a metal case to improve heat dissipation, prevent vibration, and improve reliability. It is an object of the present invention to provide an electronic circuit device which can have a shielding effect without inviting an increase.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides an electronic circuit device in which a large number of electronic components are mounted on the surface of a circuit board, and a metal case which covers the surface of these electronic components and the board is provided. The heat-generating component among the components is fixed to the inner surface of the case via a contact member having excellent heat conductivity.

[0006]

[Action]

 According to the above configuration, the heat generated from the heat-generating component of the electronic component is radiated from the large metal case that covers the entire surface of the circuit board via the contact member having excellent thermal conductivity. Therefore, it is possible to prevent the electronic parts from suffering a thermal failure and causing malfunction, and shortening the life of the electronic parts, and it is possible to maintain reliability for a long period of time. Further, since the electronic component and the metal case are fixed by the contact member, it is possible to prevent the case from vibrating due to the high frequency vibration of the electronic component, particularly the inductance component such as the transformer and the choke, and to prevent the peripheral portion of the metal case from being vibrated. It is also possible to omit the adhesion between the substrate and the circuit board.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a horizontal type electronic circuit device among the electronic circuit devices according to the present invention. In FIG. 1, the same components as those of the conventional example shown in FIG. 3 are designated by the same reference numerals. , Their detailed description is omitted.

In FIG. 1, reference numeral 2 A denotes a heat-generating component of the electronic component 2 mounted on the circuit board 1, for example, a transistor or a resistor, and these heat-generating electronic components 2 A are contacts having excellent heat conductivity. It is fixed to the inner surface of the metal case 3 via the member 6. As the contact member 6, it is preferable to use a material having a thermal conductivity of iron or higher, that is, a thermal conductivity of 0.18 Kcal / cm ³ or higher, for example, an aluminum material or a heat sink material equivalent to aluminum. preferable.

For fixing the contact member 6 and the heat-generating electronic component 2A and fixing the contact member 6 and the metal case 3 to each other, an epoxy resin or an adhesive effect equal to or higher than this and thermal conductivity are used. It is preferable to use an adhesive material that has. In this embodiment, the metal case 3 and the peripheral portion of the circuit board 1 are not bonded and fixed.

According to the electronic circuit device configured as described above, the heat generated from the heat-generating electronic component 2A during its operation passes through the contact member 6 having excellent thermal conductivity, and the circuit board 1 and the electronic component 2 , 2A is transmitted to a large metal case 3 that covers the entire surface of the metal 2A, and is discharged from the metal case 3 into the air. As a result, even if the printed wiring board 5 is present below the circuit board 1, sufficient heat dissipation can be obtained as a whole, and thermal adverse effects on the electronic components 2 and 2A can be suppressed to ensure operational reliability. Can be maintained for a long time.

Since the metal case 3 is supported by the electronic component 2A at the intermediate portion by the contact member 6, even if an inductance component such as a transformer or a choke vibrates, the vibration of the metal case 3 itself is suppressed. Further, since the metal case 3 is supported by the electronic component 2A, it is possible to omit the adhesion between the peripheral portion of the metal case 3 and the circuit board 1.

Further, as described above, since the heat dissipation is good, as the circuit board 1, instead of the conventional aluminum-based one, for example, a three-layer board made of copper, an insulating material and copper is used. And are possible. This three-layer substrate is slightly inferior to aluminum in heat dissipation, but is light and inexpensive, and, like aluminum, can have a shielding effect against an external electric field and magnetism. In other words, it is effective in improving the reliability of the electronic circuit device while being low in cost. It is needless to say that the circuit board 1 may be made of aluminum as in the conventional example.

FIG. 2 shows the configuration of a vertical type electronic circuit device which is another embodiment of the electronic circuit device according to the present invention. In the figure, the difference from the horizontal type shown in FIG. 1 is that the terminals 4 projecting from the circuit board 1 are extended downward along the main surface of the circuit board 1 to make a printed wiring board. It is attached to 5. In this case, the circuit board 1 is not shielded by the printed wiring board 5, so that the heat dissipation of the circuit board 1 is improved accordingly, so that the heat dissipation as a whole is further improved.

[0014]

[Effect of the device]

 As described above, according to the present invention, the heat generated from the heat-generating electronic component is transferred to the large metal case that covers the entire surface of the circuit board through the contact parts, and the heat is dissipated from the metal case. The heat dissipation of the whole can be improved.

Further, since the electronic component and the metal case are fixed via the contact member, it is not necessary to bond and fix the case and the peripheral portion of the circuit board, and yet the electronic component, particularly the transformer or the choke, etc. It is possible to prevent the case and the circuit board from vibrating due to the high frequency vibration of. Therefore, it is possible to prevent the electronic parts from malfunctioning due to thermal adverse effects or vibrations and to reduce the life of the electronic parts, and it is possible to significantly improve the reliability of the entire device.

Moreover, since the heat dissipation property is good, it is possible to use a light and inexpensive three-layer substrate as the circuit substrate, which enables the electronic circuit device to be reduced in weight and cost.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a horizontal type electronic circuit device according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view showing a vertical type electronic circuit device according to another embodiment of the present invention.

FIG. 3 is a vertical sectional view showing a conventional electronic circuit device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Circuit board, 2 ... Electronic component, 2A ... Exothermic electronic component,
3 ... Metal case, 6 ... Contact member.

Claims (1)

[Scope of utility model registration request] 1. An electronic circuit device having a large number of electronic components mounted on the surface of a circuit board, and a metal case covering the electronic components and the surface of the circuit board. An electronic circuit device, wherein the electronic circuit device is fixed to the inner surface of the case via a contact member having excellent thermal conductivity.