JPS61125138A - Manufacture of sealed electron part - Google Patents

Abstract

PURPOSE:To eliminate disconnection of a bonding wire generated at the time of sealing resin by a method wherein an electron part element is mounted in a concave section, which is formed by bending a circuit substrate having a circuit pattern on a surface of a substrate and sealing resin is injected into the concave section. CONSTITUTION:An electron part element 5 is mounted on a surface of a circuit substrate 2 which forms a circuit pattern 1. The circuit pattern 1 and the electron part element 5 are connected electrically by a bonding wire. A concave section 7 is formed by bending the same. In this manner, the electron part element 5, which is mounted on the circuit substrate with the bent electron part element, is made to perform sealing resin to protect the element from shock and moisture.

Description

[Detailed Description of the Invention] The present invention relates to a method for producing a sealed electronic component in which an electronic component element is sealed and protected with a sealing resin. As devices were being developed, devices were becoming more highly integrated, and as a result, the amount of heat generated by integrated devices increased (as a whole).
As a result, there has been a demand for the development of packages with high heat dissipation. Furthermore, as power supply circuits and the like are increasingly integrated into ICs, there is a strong demand for power transistors, thyristors, and the like as devices for higher power, and there is also a demand for the development of packages with high heat dissipation in this field.

Conventionally, elements that require a heat dissipation means, such as computer elements, have been provided with heat dissipation fins, and plastic molded products such as power transistors and thyristors have been provided with heat dissipation plates. The heat sink used in plastic molded products is a metal plate that is integrally molded with the lead frame on which the element is mounted, and protrudes from the plastic molded part. In this way, in plastic molded products and ceramic molded products, there are certain limits to improving the thermal conductivity of plastic molds and ceramic molds to ensure heat dissipation, and metals have no choice but to be used as heat dissipation means. Ta.

However, even if this method is used, it is not possible to increase the area of the heat sink for the element very much.
If the area were increased, the device would become larger, which would hinder high-density mounting on printed circuit boards.

In order to overcome this drawback, the applicant has developed a method of embedding an element in a recessed portion by utilizing the workability of a metal substrate.

However, there were problems in that processing the metal substrate was time-consuming and the circuit pattern on the board was cut during board processing.

On the other hand, in the conventional transfer sealing method, bonding wires often break due to pressure being applied during resin sealing. The potting method used to avoid this problem also requires a separate mold.

[Purpose of the invention]

In view of the above points, this invention eliminates the disconnection failure of bonding wires that occurs when electronic component elements are sealed with resin, and easily produces sealed electronic components with high heat dissipation without the need for a botting mold. The purpose of the present invention is to provide a method for manufacturing sealed electronic components that makes it possible to do so.

[Disclosure of the invention]

To achieve the above object, the present invention provides an electronic component element in which a circuit board having a circuit pattern on the surface thereof is bent to form a recess, and an electronic component element is electrically connected to the circuit pattern within the recess. An electronic component element according to the present invention, the gist of which is a method for producing a sealed electronic component, in which a sealing resin is injected into the recess of a circuit board with an electronic component element mounted thereon so as to cover the electronic component element. is IC,LS
l, l - Refers to active elements such as transistors and diodes, and passive elements such as resistors, capacitors, and coils.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an example of a circuit board on which electronic component elements are mounted. As shown in the figure, an electronic component element (power transistor element in this example) 5 is mounted on the surface of a circuit board 2 on which a circuit pattern is formed by etching.

The circuit board 2 is usually a metal plate 3 made of aluminum or iron, on which a thin insulating layer 4 made of epoxy resin is provided. The circuit pattern . . . and the electronic component element 5 are electrically connected by bonding wires 6 . . . (usually gold wires). In this example, the circuit pattern 1 is formed by etching, but is not limited to this, and may be formed by, for example, an additive method. Furthermore, the method of electrically connecting the circuit pattern and the electronic component element is not limited to the wire bonding method, but also the face-down Philips chip method. and bend it to form a recess 7 as shown in FIGS. 2(a) to 2(d). At this time, it is bent so that the electronic component element 5 is mounted in the recess 7. The shape after bending is not limited to those shown in FIGS. 2(a) to (dl).
8), in order to maintain the insulation between the circuit patterns 1, that is, to prevent the surfaces of the recesses from coming into contact with each other at the entrance of the recesses 7, the insulating material 8 is sandwiched between the circuit patterns 8 and 8). It is preferable to Rubber is preferred as the material for the insulating substance. The insulating material 8 does not need to be sandwiched so as to completely block the entrance of the recess 7, but as will be described later, when sealing the resin in the recess 7, it should be closed to the extent that the resin does not flow out from the entrance. is preferred.

The electronic component element 5 may be attached to the circuit board 2 before the circuit board 2 is bent, or may be attached after the circuit board 2 is bent.

In FIG. 2, the same parts as in FIG. 1 are given the same numbers as in FIG. Do the same for the drawings below.

The electronic component elements 5 mounted on the electronic component element-attached circuit board thus bent are sealed with resin to protect them from impact and moisture.

Next, a resin sealing method will be explained.

As a first method, there is a method as shown in FIGS. One of the openings on both sides is closed with the lower plate 9, and the other opening is used as an injection port, and the sealing resin 10 is injected from that part.In the case of FIG. A lid 1) is required to close the area. Since epoxy resin is usually used as the sealing resin, the material for the lower plate 9 is a material that has good mold releasability compared to epoxy resins, such as tetrafluoroethylene resin.

Polymethylpentene and the like are preferred. When the sealing resin is a silicon-based resin, any resin may be used. The lid 1) may be removed after the sealing resin has hardened, or may be used with it attached. If you use it with it attached,
The material of the lid 1) must be an insulating material.

As a second method, there is a method as shown in FIG. As shown in the figure, in this method, a circuit board with an electronic component element is placed with the entrance of the recess 7 facing upward;
The openings on both sides are respectively closed with lids 12 and 12, and the inlet of the recess 7 is used as an injection port, from which the sealing resin 10 is injected. The lid 12.12 may be removed after the sealing resin has hardened, or may be used with it attached. It is not necessary to fill the recess with the sealing resin, and the lid 1) and the lid 12, 12 only need to have a size necessary for resin sealing.

The above is an example of a method for injecting resin into a recess,
The method is not limited to these methods.

In this way, the resin-sealed electronic component is
As shown in the figure, it may be mounted by reflow soldering on a board 13 on which a circuit pattern is formed and used as a surface mount type, or as shown in Fig. 6, a circuit board with a circuit pattern formed thereon may be used as a surface mount type. Attach the lead 14 to the part,
It can also be used as a lead insertion type.

〔Effect of the invention〕

In the method for manufacturing a sealed electronic component according to the present invention, since the circuit board is bent to form the recess, the recess can be easily formed, and furthermore, the sealing resin is injected into the recess. Therefore, compared to the conventional transfer sealing method, molding can be performed without pressure, a mold such as in the botting method is not required, and disconnection defects of the bonding wire can be prevented. Furthermore, compared to a flat-shaped electronic component that occupies the same area, the heat dissipation area is wider, so the heat dissipation performance can be improved. Additionally, conventional power transistors, SIRISK, etc. have heat sinks, so most of them are lead insertion type, but by using the manufacturing method of the present invention, surface mount type electronic components can be easily manufactured.

[Brief explanation of the drawing]

Figure 1 is a perspective view of an example of a circuit board on which electronic component elements are mounted, Figure 2 (al to Fdl are front views of examples of the same circuit board after it is bent), Figure 3 (al, (b) and FIG. 4 are perspective views showing an embodiment of the method for manufacturing a sealed electronic component according to the present invention, and FIG. 5 is a perspective view showing a method for mounting a sealed electronic component on a board according to the present invention. Fig. 6 is a cross-sectional view of the lead attached state. 1...Circuit pattern 2...Circuit board 5...Electronic component element 7...Concave portion 8...Insulating material 1o・
...Encapsulating resin agent Patent attorney Takehiko Matsumoto Figure 1 Figure 3 (a) (b) Figure 5 Figure 6 Procedure Nefu official document (method) % formula % 2. Name of the invention Sealed electronic Parts manufacturing method 3, relationship with the amended case Patent applicant location 1048 Oaza Kadoma, Kadoma City, Osaka Name (583) Matsushita Electric Works Co., Ltd. Representative Director Sadao Fujii 4, agent March 1985 6th (Shipping date 60.3.26)
6. Description and drawings to be amended 7. Contents of amendment (1) Insert "respectively" between "Fig. 4" and "this invention" in the second line of page 10 of the specification. (2) In the attached drawings, Figure 3 is corrected as shown in the attached sheet. Figure 3 (a) (b)

Claims (3)

[Claims] (1) A circuit with an electronic component element in which a circuit board having a circuit pattern on the surface of the board is bent to form a recess, and an electronic component element electrically connected to the circuit pattern is mounted in the recess. A method for manufacturing a sealed electronic component, comprising injecting a sealing resin into the recess of a substrate to cover the electronic component element. (2) The method for manufacturing a sealed electronic component according to claim 1, wherein the recess is formed into a triangular prism shape so that the surfaces of the recess do not touch each other at the entrance, and an insulator is sandwiched between the entrance. (3) The method for manufacturing a sealed electronic component according to claim 1 or 2, wherein when injecting the sealing resin into the recess, the opening of the recess is closed as necessary except for the injection port.