JPH02290093A - Hybrid integrated circuit - Google Patents

Abstract

PURPOSE:To obtain microminiaturization of circuits by combining two separated metallic boards with an insulating film and providing pads only at one side of the metallic boards, thereby enabling a packaging area on the other side of metallic boards to be used in a large way. CONSTITUTION:Metallic boards 11 and 12 are connected with adhesives by means of an insulating film 13 in such a way that there is a distance corresponding to the thickness of each board between respective two boards. Copper foils acting as conductive paths 14 are pasted at the opposite main faces of the film 13 and the conductive paths 14 having desired forms are formed by selective etching. Pads 17 for soldering outer leads 16 are placed at one side end parts of the board 12 and the conductive paths 14 are extended from the pads 17 on the insulating film 13. Parts of the conductive paths 14 which bond circuit elements 15 are designed to locate on both sides of the boards 11 and 12. Then, the circuit elements 15 are selected and they are bonded and mounted on the boards 11 and 12. After providing the pads 17 only at one side of the board 12 and also incorporating the circuit elements 15 on the board 12, the film 13 is bent to make the boards 11 and 12 abut on each other. After that, they are bonded and after leaving the leads 16 as they stand, the whole elements are molded with resin 18.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a hybrid integrated circuit, and more particularly to improvements in a hybrid integrated circuit having a folded structure.

(Expression) Conventional technology A conventional hybrid integrated circuit has a metal substrate (one
〉 A thin insulating layer is provided on one main surface to provide a desired conductive path (2), and a circuit element <3> such as a semiconductor integrated circuit, a chip resistor or a chip capacitor is fixed on the conductive path (2), As shown in FIG. 5, the entire structure was formed by molding with resin (5), leaving only the external leads (4).

(c) Problems to be solved by the invention Since such hybrid integrated circuits are formed on the entire surface of the metal substrate (1), a certain height is required to ensure a certain degree of integration, which leads to thinner electronic devices. This was a design consideration. This is mainly due to the fact that the fixing pad (6) of the external lead (4) requires a considerable area.

(2) Means for Solving the Problems The present invention has been made in view of the above-mentioned points.
As shown in Figures to Figure 3, two metal substrates (1
1) (12) are combined with an insulating film (13), a conductive path (14) of a desired shape is provided on the insulating film (13), and one metal substrate (12) on which the conductive path (14) extends
A pad (17) is provided at the end of the other metal substrate (12).
) A chip-shaped integrated circuit element or an active circuit element 15) is mounted only on the top of the substrate (11) and the insulating film (13) between the substrates (11) and (12) are bent. Solve by arranging the surfaces so that they touch.

(E) Operation As above, the two metal substrates separated by the insulation film l1
A pad on an insulating film is provided on only one metal substrate, and a chip-shaped integrated circuit element or an active element is mounted on the other metal substrate, and the opposite main surface of the other substrate is in contact with the other metal substrate. By bending the insulating film between the substrates in this way, lead fixing pads are provided on only one metal substrate, so even if the area is the same, the other metal substrate does not have any pads, so the degree of integration is improved. Furthermore, since the substrate is arranged in a bent manner, the height of the hybrid integrated circuit is halved.

(f) Examples The present invention will be described in detail below based on the examples shown in FIGS. 1 to 3.

As shown in FIGS. 1 and 2, the hybrid integrated circuit of the present invention includes two metal substrates <11> (12) and a substrate (11) (
12) and an insulating film (13) that connects the film (
13) A conductive path (14) provided on the conductive path (14) and a plurality of circuit elements 15) such as semiconductor integrated circuits, active elements, chip resistors, or chip capacitors fixed on the conductive path (14). .

The metal substrates (11) and (12) are made of aluminum with good thermal conductivity and have a plate thickness of 0.5 to 1.0 mm, and the substrates (11 and 12) are separated by their respective thicknesses using an adhesive such as epoxy resin. Connect with an insulating film (13) made of polyimide or the like. There is a conductive path (14) on the opposite main surface of the insulating film (13).
A copper foil is pasted on the substrate, and the copper foil is selectively etched to form a conductive path (14) in a desired shape.

As is clear from FIG. 1, the conductive path (14) is formed by arranging pads (17) to which external leads (16) are soldered to the end of one substrate (12), and connecting the pads (17) to the conductive path (14).
) is extended on the insulating film (13). Circuit element (
The part of the conductive path (14) that fixes the substrate (15)
11) Designed to be located on (12), the board (11)
(12) has a circuit element (15) for bending.
is not provided.

By the way, the circuit elements (15) to be fixed on the respective substrates (11, 12) are selectively and fixedly mounted. That is, the hybrid integrated circuit of the present invention aims to be miniaturized by having a folded structure. However, if the pads (17) are formed on the respective metal substrates (11) and (12), there will be some restrictions on miniaturization depending on the size of the pads (17).Therefore, in the present invention, the pads (17) are formed on one of the metal substrates (11) and (12). It is provided only on the substrate (12) to provide an ultra-miniaturized hybrid integrated circuit. Therefore, circuit elements (15), which are so-called passive elements such as chip resistors and chip capacitors, are fixed on one substrate (12) on which pads (17) are provided, and on the other substrate (11) on which no pads are formed. A chip-shaped integrated circuit element or an active element circuit element (15) and the above-mentioned passive element circuit element (15) are fixed to the substrate.

After assembling the circuit elements (15) onto the respective substrates (11, 12), the insulating film (13) is bent at the separated parts of the substrates (11, 12) to form the substrates as shown in FIG. (11
The opposite major surfaces of each bar 12) are brought into close contact and fixed with adhesive, or the whole is molded with resin (18), leaving an external lead dot 16).

(G) Effects of the Invention According to the present invention, by providing pads only on one metal substrate, a large mounting area on the other metal substrate can be used for mounting circuit elements such as chip-shaped integrated circuit elements. I can do it. As a result, an ultra-miniaturized hybrid integrated circuit can be provided. In addition, the height of a hybrid integrated circuit with the same degree of integration as that of a conventional circuit can be reduced to about half, and by using a flexible insulating film (13), both substrates (11
) < 12) The connection of the conductive path (14) is also no longer necessary, and it can be manufactured by the same method as the conventional method. As a result, while conventionally one side of the board was used, the present invention is equivalent to using both sides of the board, which can greatly contribute to miniaturization of hybrid integrated circuits.

[Brief explanation of drawings]

FIG. 1 is a plan view illustrating a hybrid integrated circuit according to the present invention;
FIG. 2 is a side view thereof, FIG. 3 is a sectional view of a completed hybrid integrated circuit according to the present invention, FIG. 4 is a plan view showing a conventional hybrid integrated circuit, and FIG. 5 is a side view thereof. m) (12) is a metal substrate, (13) is an insulating film,
(14) is a conductive path, (15) is a circuit element, (16)
is an external node, (17) is a pad, and <18> is a resin.

Claims (1)

[Claims] (1) Two metal substrates, an insulating film that connects the metal substrates at a distance, a conductive path of a desired shape provided on the film, and a plurality of chips fixed on the conductive paths on the two metal substrates. the insulating film between the two substrates is bent so that the opposite main surfaces of the substrates are in contact with each other, and the circuit element provided on both the substrates is placed on the bent portion of the insulating film. A pad for connection with the outside is provided only at the end of one of the metal substrates, and a chip-shaped integrated circuit element or an active element is provided on the other metal substrate. A hybrid integrated circuit characterized by a selected arrangement of circuit elements.