JPH04352306A - Electronic circuit device - Google Patents

Abstract

PURPOSE:To provide the title electronic circuit device having the excellent heat dissipation of a transformer while making firm resistance to severe oscillation in relation to the electronic circuit device applicable to automobiles, etc. CONSTITUTION:The title electronic circuit device composed of a printed board 8 soldered with the terminals 6 on the lower part of a transformer 3 with a core 4 and a heat dissipating plate 1 along the outer side of the core 4 with the bent part of the plate 1 fixed using a bonding agent having excellent thermal conductivity can enhance the heat dissipation of the transformer 3 without tilting the center of gravity against severe oscillation thereby enabling the solder cracking and the metallic fatigue of the transformer 3 to be avoided.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit device for an automobile whose characteristics do not deteriorate even under severe vibration conditions.

0002

[Prior Art] Electronic circuit devices installed in automobiles usually supply a constant DC voltage called a 12V battery, but some electronic circuit devices require various voltages as DC voltage. There is something that says. For example, when boosting the voltage of a recently developed high-intensity discharge lamp lighting device, a DC voltage boosting power supply device called a DC/DC converter is used to obtain the necessary voltage. High-intensity discharge lamp lighting devices have higher brightness and higher efficiency than the incandescent lamps and halogen lamps used in conventional headlight systems, and are expected to be commercialized as a promising headlight system in the future. This high-intensity discharge lamp lighting device is a system that lights by discharge, and requires a high voltage and a power equivalent to 40W in a steady state, and a high-power DC/DC converter power supply circuit device is required. It has become necessary.

Furthermore, since this electronic circuit device is mounted near the headlights of a car, it is used in the harshest environment among devices used in cars, and the installation space for the electronic circuit device is limited. Must be made into a small shape. In particular, transformers used in DC/DC converter power supply circuit devices self-heat in order to supply high power.

0004

[Problems to be Solved by the Invention] However, in the conventional configuration described above, the heat resistance of the transformer itself becomes insufficient due to self-heating of the transformer, and the temperature rise within the power supply circuit device adversely affects other components. In addition, the transformer is heavy and has poor vibration durability, which is an important environmental condition for automobiles.

The present invention solves the above-mentioned conventional problems, and suppresses the temperature rise of the transformer itself, as well as the temperature rise inside the electronic circuit device that adversely affects other parts, and also suppresses the temperature rise within the electronic circuit device that adversely affects other parts. Another object of the present invention is to provide an electronic circuit device with good vibration durability and free from solder cracks and metal fatigue.

[0006]

[Means for Solving the Problem] In order to solve this problem, the electronic circuit device of the present invention fixes the terminals of the transformer to the printed circuit board by soldering, and connects the bent portion of the heat sink and the outer surface of the core of the transformer. It has a structure in which it is fixed with an adhesive with good thermal conductivity.

[0007]

[Function] With this configuration, the heat dissipation of the transformer is improved, heat generation of the transformer itself is suppressed, and the center of gravity does not tilt even under severe vibrations of the automobile.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 3, the transformer 2 is composed of a winding 3, a core 4, a bobbin 5, and a terminal 6.
It is fixed to a printed circuit board 8 with solder 9. The heat sink 1 is fixed to the printed circuit board 8 with screws 10 and nuts 11, and the bent portions 1(a) and 1(b) of the heat sink 1 are as follows.
It is arranged along the core 4 of the transformer 2, and the bent parts 1(a), 1(b) and the core 4 of the transformer 2 are bonded with adhesive 7.
It is fixed in place.

Generally, electronic circuit devices such as switching regulators that use a transformer 2 generate heat due to losses in the winding 3 and core 4 of the transformer 2. The heat generated by this loss is transferred to the heat sink 1 along the core 4 of the transformer 2.
Then, heat is radiated to the outside via the adhesive 7, thereby reducing the self-temperature rise of the transformer 2 and the temperature rise inside the electronic circuit device. Moreover, heat dissipation is improved by using a silicone resin adhesive with good thermal conductivity as the adhesive 7. Furthermore, the heat dissipation plate 1 is made of aluminum so that heat dissipation to the outside can be improved. By thermally conductively adhering the heat sink 1 of this electronic circuit device to another heat sink provided externally, large heat dissipation properties can be ensured, resulting in an increase in self-temperature due to the heat generated by the transformer 2 and a rise in temperature within the electronic circuit device. This makes it possible to further reduce the

Generally, the transformer 2 is heavier than other electronic components, and the center of gravity of the transformer 2 is tilted due to vibration, which is an important environmental condition in automobiles, which causes solder cracks and metal fatigue of the terminals 6 of the transformer 2. In the electronic circuit device of this embodiment, the terminals 6 at the lower part of the transformer 2 are soldered to the printed circuit board 8 with solder 9, and the bent parts 1(a), 1(b) of the heat sink 1 and the transformer 2 are connected at the upper part. By fixing the core 4 with the adhesive 7, the center of gravity of the transformer 2 will not tilt due to vibrations of the automobile, and solder cracks and metal fatigue of the terminals 6 of the transformer 2 can be prevented.

0012

Effects of the Invention As is clear from the above description of the embodiments, the present invention has a configuration in which the bent portion provided on the heat sink and the outer surface of the core of the transformer are fixed with an adhesive having good thermal conductivity. An excellent electronic circuit device that controls the temperature rise within the electronic circuit device itself, which adversely affects other components, and has good vibration durability without causing soldering defects or metal fatigue even under severe vibration conditions. It is possible to realize this.

[Brief explanation of drawings]

FIG. 1 is a side view showing a cross section of an electronic circuit device according to an embodiment of the present invention, with a part missing;

[Figure 2] Perspective view of the electronic circuit device

[Figure 3] Exploded perspective view of the electronic circuit device

[Explanation of symbols]

1 Heat sink 1(a), 1(b) Bent part of heat sink 2 Transformer 4 Core 7 Adhesive

Claims (1)

[Claims] 1. An electronic circuit device comprising a transformer having terminals fixed by solder and a printed circuit board on which a fixed heat sink is arranged, the core of the transformer and the heat dissipating plate disposed along the outer surface of the core. An electronic circuit device in which the bent portion of a heat sink is fixed with an adhesive with good thermal conductivity.