JPH06140524A - Hybrid integrated circuit - Google Patents

Abstract

PURPOSE:To improve adhesion of a case member to a substrate without damaging an outer shape of the case member. CONSTITUTION:A hybrid integrated circuit which is provided with a conductive path 3 of desired shape is formed on a substrate 1 and on this conductive path 3, a hybrid integrated circuit substrate to which plural circuit elements 4 are connected, a case member 5 which seals the circuit element air-tightly with a hollow structure and is united with the hybrid integrated circuit substrate 1 into one body, and an adhesive agent 6 which is interposed in an area where the case member 5 is made to abut on the substrate l and bonds the substrate 1 to the case member 5 by a heat treatment, wherein a groove 8 is formed at least one position of the case member 5 which is made to abut on the adhesive agent 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid integrated circuit, and more particularly to a sealing structure for a hollow structure hybrid integrated circuit.

[0002]

2. Description of the Related Art Conventionally, a hybrid integrated circuit is as shown in FIG.
A conductive path is formed on a substrate (11) such as a metal substrate, and a plurality of circuit elements (13) are fixed on the conductive path, and the board (11) and a case material for sealing the circuit element (13). A so-called hollow structure type hybrid integrated circuit in which (14) is fixed by a resin adhesive (12) is known.

[0003]

The conventional hybrid integrated circuit as described above has the following problems. That is, since an epoxy impregnated prepreg sheet (hereinafter referred to as a J sheet) is used as the adhesive resin, the pressure inside the space formed by the substrate (11) and the case material (14) is high during the heat curing of the J sheet. As a result, there is a problem that a crack (12A) occurs in a part of the melted adhesive resin (12) and airtightness becomes poor, and a complete hermetic sealing structure cannot be performed. (See Figure 4).
In particular, this problem remarkably occurs when the thermosetting speed of the J sheet is increased.

Therefore, in order to solve such a problem, the applicant of the present invention provides a hole on the upper surface of the case material, and after fixing the case material and the substrate with an adhesive, seals the hole with a heating gote. We filed an application for sealing with a stopper (Japanese Patent Laid-Open No. 52-1.
No. 03,677). Indeed, JP-A-52-103
According to the proposal of Japanese Patent No. 677, the adhesion between the substrate and the case material can be surely achieved. However, it is necessary to bring the sealing lid into contact with the heating iron, and the resin of the sealing lid melts and adheres to the heating iron during heating, and although the sealing lid and the case material adhere to each other, the adhesiveness decreases and A new problem occurs that the appearance becomes poor.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a hybrid integrated circuit in which the adhesion between the case material and the substrate is improved without impairing the external shape. It is a thing.

[0006]

[Means for Solving the Problems]
To achieve the object, a hybrid integrated circuit according to the present invention is a hybrid integrated circuit substrate in which a conductive path having a desired shape is formed on a substrate, and a plurality of circuit elements are connected to the conductive path.
A case material that is integrated with the hybrid integrated circuit board and hermetically seals the circuit element with a hollow structure, and an adhesive that is interposed in a region where the case material and the board contact each other and that fixes the board and the case material by heat treatment. At least one portion of the case material that is brought into contact with the adhesive of the hybrid integrated circuit including the agent is provided with a groove sealed with the adhesive during the heat treatment.

[0007]

In the hybrid integrated circuit configured as described above, by providing the groove filled with the adhesive at the time of heat treatment in at least one place of the case material which is brought into contact with the adhesive,
During the heat treatment process, the internal pressure in the space inside the case material can be made uniform with the outside, and the adhesive does not crack.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A hybrid integrated circuit according to the present invention will be described below with reference to the embodiments shown in FIGS. As the hybrid integrated circuit board (1), a material such as ceramics, epoxy or metal is used, and here an aluminum substrate subjected to an insulation treatment is used. On the substrate (1), a conductive path (3) having a desired shape is formed of a material such as copper via the insulating resin layer (2).

On the conducting path (3), a transistor,
A plurality of circuit elements (4) having a predetermined circuit function such as an LSI chip and a chip resistor are fixedly connected by a brazing material such as solder. A lead terminal (7) for connecting to an external circuit is fixed to at least one side peripheral edge of the substrate (1). The circuit element (4) is hermetically sealed and protected from the outside by adhering the case material (5) and the substrate (1).

The case material (5) is injection-molded into a predetermined shape by using a thermoplastic resin (crystalline engineering plastic) type material such as PET (trade name), PBT (trade name), PPS (trade name). To be done. Case material (5)
The bottom surface of the substrate, that is, the surface in contact with the substrate (1) has a width of about 1
A groove (8) of ˜2 mm and a depth of about 50 to 300 μm is formed. Further, this groove (8) is formed so as to be arranged on the side to which the external lead (7) is fixed, and one groove (8) is formed in this embodiment, but the size of the hybrid integrated circuit, etc. Therefore, the number is appropriately selected.

The substrate (1) and the case member (5) have a thickness of about 30.
It is fixed and integrated by a 0 μm thick adhesive sheet. Such an adhesive sheet is obtained by impregnating a base material made of a polyester nonwoven fabric with an epoxy resin in a B stage state. When the adhesive sheet is placed on the substrate (1) on which the case material (5) is placed and heat-treated under pressure, the epoxy resin in the B stage melts out and the substrate (1) and the case material (5) are bonded together. Adhesive resin (6).

When the substrate (1) and the case member (5) are bonded together, the groove (8) is formed on the surface of the case member (5) that contacts the adhesive sheet, so that the case member (5) at the time of heat treatment is formed. The thermally expanded air in) can be escaped to the outside by the groove (8). As a result, when the substrate (1) and the case material (5) are bonded, the adhesiveness is increased by the thermal expansion generated inside the case material. The sheet does not crack. The groove (8) for releasing the thermally expanded air in the case material (5) to the outside is filled in the groove (8) when the epoxy resin is melted, so that the substrate (1) and the case material (5) are separated from each other. When fixed, it is completely sealed and does not create a gap. If the groove (8) is too deep, it will not be completely filled with epoxy resin.
The size of the groove (8) should be such that the epoxy resin is completely filled in the groove (8).

Further, the groove (8) can remarkably increase the thermosetting speed of the J sheet. That is, while the conventional curing rate required about 8 hours at about 125 ° C., by providing the groove (8) as in the present invention, the same material cures at about 125 ° C. in about 60 minutes. It has become possible.

[0014]

As described in detail above, according to the present invention,
By providing a groove that is filled with the adhesive during the heat treatment in at least one place of the case material that contacts the adhesive, the internal pressure in the space inside the case material that occurs during the heat treatment process can be released to the outside. Does not crack. As a result, the case material and substrate can be fixed in a completely sealed state,
A highly reliable hybrid integrated circuit can be provided.

Further, according to the present invention, by providing the groove as described above, the internal pressure due to the thermal expansion in the case material can be released to the outside, and the adhesive for bonding the substrate and the case material is cured. Since the speed can be increased, the manufacturing process can be shortened.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a hybrid integrated circuit of the present invention.

FIG. 2 is a front view of FIG. 1 viewed from the lead side.

FIG. 3 is a cross-sectional view showing a conventional hybrid integrated circuit.

FIG. 4 is a plan view showing a case where a crack occurs in the adhesive sheet.

[Explanation of symbols]

 (1) Hybrid integrated circuit board (2) Insulating resin layer (3) Conductive path (4) Circuit element (5) Case material (6) Adhesive resin (7) Lead terminal (8) Groove

Claims (2)

[Claims] 1. A conductive path having a desired shape is formed on a substrate,
A hybrid integrated circuit board having a plurality of circuit elements connected on its conductive path, a case member integrated with the hybrid integrated circuit board, and hermetically sealing the circuit element with a hollow structure, and the case material and the substrate. An adhesive agent that is interposed in the contact area and that fixes the substrate and the case material by heat treatment is provided, and a groove is provided in at least one location of the case material that contacts the adhesive agent. And a hybrid integrated circuit. 2. A conductive path having a desired shape is formed on a substrate,
A hybrid integrated circuit board having a plurality of circuit elements connected on its conductive path, a case material integrated with the hybrid integrated circuit board, and hermetically sealing the circuit element with a hollow structure, the case material and the substrate An epoxy-impregnated prepreg sheet material interposed between the contact area and fixing the substrate and the case material by heat treatment, wherein at least one portion of the case material contacted with the sheet material is treated during the heat treatment. A hybrid integrated circuit having a groove sealed with an adhesive.