JPH08227952A - Power module - Google Patents

Abstract

PURPOSE: To obtain enough heat dissipation effect even if a power module generates large heat and thereby improve reliability of a part, etc., by dissipating heat of a heat generation part through a resin mold, a contact piece and a case. CONSTITUTION: A heat generation part 1a such as a transformer and a power transistor, for example, is soldered to one side of a substrate 1 and a part lb which hardly generates heat such as a compact resistance and a capacitor is soldered to the other end through a lead 1c. The substrate 1 is contained inside a metallic case 2 of good heat dissipation property, for example. Furthermore, for example, the heat generation part 1a is held by resin mold 3 such as elastic silicon rubber having good heat conductivity. A contact piece 4 formed integral with the case 1 is in press-contact with an upper surface of the resin mold 3. Therefore, heat generated from the heat generation body 1 is transferred to the contact piece 4 through the resin mold 3 and is further dissipated through a surface of the case 2 and an opening 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power module, and more particularly to a power module having a heat dissipation structure for efficiently dissipating heat generated by heat-generating components to the outside of a case.

[0002]

2. Description of the Related Art Conventionally, the sixth power module has been used.
The one shown in the figure is known. The heat generating component 1a is provided on the substrate 1.
Ordinary component 1b is mounted, and the substrate 1 is fixed in the case 2 by screws 2a. In the power module having the above structure, the heat generated by the heat-generating component 1a is transmitted to the case 2 through the connecting leads 1c or by the convection and conduction of air inside the case 2, and is radiated to the outside through the case 2. It However, when the heat generated by the power module is large, the heat dissipation effect is insufficient in the above-mentioned structure, heat is accumulated inside the power module, and the temperature rises, which causes a problem that the reliability of parts and the like is significantly reduced. Had.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and makes it possible to obtain a sufficient heat dissipation effect even when the heat generated by the power module is large.
This is to provide a power module that does not reduce the reliability of parts and the like.

[0004]

In order to solve the above-mentioned problems, the present invention comprises a substrate on which a heat-generating component is mounted and a case for accommodating the substrate, and the heat-generating component is made of a good heat conductor on the substrate. While being molded with resin, a contact piece whose tip contacts the resin is provided on the inner surface of the case, and the heat of the heat-generating component is radiated through the resin, the contact piece, and the case. The resin is silicon rubber. Further, a plurality of the contact pieces are provided. further,
Further, the contact piece is formed integrally with the case. The contact piece is attached to the case by welding. In addition, the board on which the heat-generating component is mounted is stored in the case,
It is provided on one side of the substrate.

[0005]

With the above construction, in the power module according to the present invention, the heat generated inside the power module is directly conducted from the resin mold to the case through the contact piece and is radiated to the outside.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. In the figure, the same parts as those in the conventional example are designated by the same reference numerals.

FIG. 1 shows the structure of a power module according to the present invention. Reference numeral 1 denotes a substrate mounted on a bottom surface of a case 2 described later with screws 2a. On one side of the substrate 1, for example, a heat-generating component 1a such as a transformer or a power transistor.
However, on the other side, for example, a component 1b such as a small resistor or a capacitor that hardly generates heat is soldered through the lead 1c. Reference numeral 2 denotes a case that accommodates the substrate 1 and is made of, for example, metal and has a good heat dissipation property. Reference numeral 3 denotes a resin obtained by molding the heat generating component 1a from above the substrate 1, for example,
It is made of silicone rubber having good thermal conductivity and elasticity so that the heat-generating component 1a is not stressed. Reference numeral 4 is a contact piece integrally formed with the case 2 as shown in the plan view of FIG. 2. An H-shaped cut is made on the upper surface of the case 2 and both sides of the cut are bent downward, and as a result, the case is cut. An opening 5 is formed on the upper surface of 2. Then, each tip is bent inward at a right angle to form an L-shape and is pressed against the upper surface of the resin mold 3.

According to the above construction, the heat generated from the heating element 1 is transmitted to the contact piece 4 through the resin mold 3 and further dissipated into the outside air through the surface of the case 2 and the opening 5.

Another embodiment shown in FIG. 3 is a case 2
Make a H-shaped notch in the lateral direction of the side of the notch, bend both sides of the notch laterally, and bend the ends of both ends of the notch at right angles to form an L-shape. This is an example in which a contact piece 4a is formed so as to have a large contact area with the resin mold 3 by pressing the side surface of the contact portion 4a, so that a power module having a greater heat dissipation effect can be obtained.

Another embodiment shown in FIG. 4 is the case 2
The upper part of the contact piece 4a which is formed separately from and is bent in an L-shape is welded to a portion indicated by reference numeral 2b inside the upper surface of the case 2, and the contact piece 4a is brought into contact with the upper surface of the resin mold 3. This is an example of application to a power module that does not require an opening on the upper surface of the case 2 and requires confidentiality.

In another embodiment shown in FIG. 5, the case 2 is divided into an upper case 2c and a lower case 2d, and the substrate 1 is sandwiched between the respective cases, and the lower case 2
a screw 2a from the through hole 2b formed in d using a tool or the like.
This is an example of a structure in which the surface area of the case 2 is increased and the heat dissipation effect is further enhanced by the above structure.

[0012]

As described above, in the power module according to the present invention, the heat generated inside the power module can be released to the outside through the resin mold, the contact piece and the case, so that the heat dissipation is good. It is possible to provide a power module in which reliability of parts and the like is improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an essential part for explaining the configuration of a power module according to the present invention.

FIG. 2 is a plan view of relevant parts for explaining the configuration of the power module according to the present invention.

FIG. 3 is a sectional view of an essential part for explaining the configuration of another embodiment of the power module according to the present invention.

FIG. 4 is a sectional view of an essential part for explaining another embodiment of the mounting structure for the contact piece of the power module according to the present invention.

FIG. 5 is a cross-sectional view of an essential part for explaining the configuration of still another embodiment of the power module according to the present invention.

FIG. 6 is a cross-sectional view of essential parts for explaining the configuration of a conventional power module.

[Explanation of symbols]

 1 substrate 1a heat-generating component 1b component 2 case 2a screw 3 resin mold 4 contact piece 5 opening

Claims (7)

[Claims] 1. A substrate having a heat-generating component mounted thereon and a case accommodating the substrate, wherein the heat-generating component is molded on the substrate with a resin made of a good heat conductor, while the tip of the resin is formed on the inner surface of the case. A power module, characterized in that a contact piece that contacts the mold is provided, and the heat of the heat-generating component is radiated through the resin mold, the contact piece and the case. 2. The power module according to claim 1, wherein the resin is silicone rubber. 3. The power module according to claim 1, wherein a plurality of the contact pieces are provided. 4. The power module according to claim 1, wherein the contact piece is formed integrally with the case. 5. The power module according to claim 1, wherein the contact piece is separately attached to the case. 6. The board according to claim 1, wherein the board on which the heat-generating component is mounted is provided on one side of a second board housed in the case. Power module. 7. The case comprises an upper case and a lower case.
The power module described in 5 and 6.