JPH0536295Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a hybrid integrated circuit, and particularly to improvements in a hybrid integrated circuit suitable for high-density integration.

(b) Prior art As shown in Figure 2, in a conventional hybrid integrated circuit, a metal plate 21 is formed of aluminum with good thermal conductivity and has a thickness of 0.5 to 1.0 mm, and its surface is coated with an aluminum oxide film. good. An elongated notch hole 22 is formed by press punching in the central part of the metal plate 21, which is the bent part.
A plurality of connected bodies are provided in which the metal substrate 21 and the metal substrate 21 remain as they are. The connecting body has the function of integrally supporting the metal substrate 21 and maintaining its regular shape even when bent. The insulating film 24 is made of polyimide or the like, and is attached to substantially the entire surface of one principal surface of the metal substrate 21 with an adhesive such as epoxy resin. A copper foil that will become the conductive path 25 is pasted on one main surface of the insulating film 24, and this copper foil is selectively etched to form the conductive path 2 in a desired shape.
Form 5. The conductive path 25 has pads arranged at both ends to be soldered to the electrodes of the printed circuit board to be mounted.
A conductive path 25 extends from the pad onto the insulating film 24. Conductive path 25 to which circuit element 26 is fixed
The part is designed to be located on the entire board 21, and a plurality of circuit elements such as semiconductor integrated circuits, chip resistors, or chip capacitors are fixed on the conductive path 25 except for the bent part of the board 21, and the metal board 21 is It is something that bends.

A technique similar to that described above is described in Japanese Patent Application No. 16576/1983.

(c) Problems to be solved by the invention However, since the conventional hybrid integrated circuit has a notch hole 22 provided at the bent portion of the metal substrate 21 and is arranged in a bent position, the portion of the notch hole 22 Since there is no metal substrate 21, there is a problem that the shielding effect deteriorates.

Therefore, in order to solve this problem, as shown in FIG. 3, a groove 12 is provided in the bent part of the metal substrate 11, and the insulating film 13 and the conductive path 14 are bent in the groove 12. Invented the integrated circuit. In this invention, when iron is used for the metal substrate 11, the exposed surface of the metal substrate 11 must be plated with nickel or tin to prevent corrosion.

However, when plating is performed using nickel or tin, when the metal substrate 11 is bent, the bending portion cannot follow the bending of the substrate because both nickel and tin are hard. It has the disadvantage of cracking, and since both metals mentioned above have a smaller ionization tendency than iron, when the substrate is exposed, the substrate corrodes first.

(d) Means for solving the problems The present invention has been made in view of the above-mentioned points, and as shown in FIG. After pasting an insulating film 3 on one main surface, forming a conductive path 4 of a desired shape on the insulating film 3, and fixing a plurality of circuit elements 5 on the conductive path 4, an insulating film 3 is placed in the groove 2. This problem is solved by providing a galvanized layer 6, which has a higher ionization tendency than iron, on the exposed side of the iron substrate 1 of the hybrid integrated circuit, in which the iron substrate 1 is bent so as to accommodate the film 3 and the conductive path 4.

(E) Effect As described above, by providing the galvanized layer 6 of a metal with a higher ionization tendency than iron on the exposed surface side of the iron substrate 1, even if the substrate 1 is bent, the zinc is a soft metal. This eliminates the risk of following the bent portion of the substrate 1 and breaking at the bent portion.

(F) Embodiment The present invention will be explained in detail below based on the embodiment shown in FIG.

As shown in FIG. 1, the hybrid integrated circuit of the present invention includes an iron substrate 1, a groove 2 provided at a bent portion of the iron substrate 1, a flexible insulating film 3, and a conductive film provided on the insulating film 3. path 4 and conductive path 4
A plurality of circuit elements 5 such as semiconductor integrated circuits, chip resistors, or chip capacitors fixed on the top
and a galvanized layer 6 provided on the exposed surface side of the iron substrate 1.

The feature of the present invention is that a galvanized layer 6 is provided on the exposed surface side of the iron substrate 1.
The galvanized layer 6 is formed on the surface of the substrate 1 to a thickness of 10 to 20 microns by a commonly used electroplating method. After forming a galvanized layer 6 on the surface of a substrate 1, grooves 2 are provided at the bent portions of the iron substrate 1. The groove portion 2 has a width of 1.5 to 3.0 mm with respect to the thickness of the substrate 1 of 0.5 to 1.0 mm.
It is formed by etching or mechanically to a depth of 0.15 to 0.5 mm, and its shape can be any shape as long as it can accommodate the insulating film 3 and conductive path 4 when the substrate 1 is bent, such as a V-shape or a concave shape. , a U-shape is preferred. After providing a groove 2 in the bent part of the iron substrate 1, an insulating film 3 made of flexible polyimide resin or the like is pasted on the substrate 1, copper foil is further pasted on that surface, and the copper foil is selected. After etching the desired conductive path 4 and installing the circuit element 5 on the conductive path 4, an insulating film 3 is placed in the groove 2.
Even if the iron substrate 1 is bent to accommodate the conductive path 4, the galvanized layer 6 provided on the exposed surface of the substrate 1 easily follows the bending, so there is a risk that the galvanized layer 6 will crack at the bent portion. There is no such thing.

According to the present invention, by forming the galvanized layer 6 on the exposed surface side of the iron substrate 1, even if the iron substrate is bent, the zinc is soft and can sufficiently follow the bending. Therefore, there is no need to worry about cracking at the bending part as in the conventional case. Even if the galvanized layer cracks at the bend and iron is exposed, zinc has a greater tendency to ionize than iron, so zinc corrodes first and has the advantage of delaying corrosion of the iron substrate.

(g) Effects of the invention As mentioned above, according to the invention, even if the iron substrate is bent, since zinc is hard, it can sufficiently follow the bent part, so it is not possible to bend the iron substrate as in the conventional method. It will not break in some parts. Even if the substrate were to be exposed due to cracking, zinc has a greater tendency to ionize than iron, so zinc corrodes first and has the advantage of delaying corrosion of the substrate.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIGS. 2 and 3 are sectional views showing a conventional example. DESCRIPTION OF SYMBOLS 1... Iron substrate, 2... Groove, 3... Insulating film, 4... Conductive path, 5... Circuit element, 6... Galvanized layer.

Claims (1)

[Claims for Utility Model Registration] (1) An iron substrate, a groove provided in a bent portion of the iron substrate, an insulating film provided on one main surface of the iron substrate, and a desired portion provided on the insulating film. A hybrid integrated circuit comprising a conductive path and a plurality of circuit elements fixed on the conductive path, and wherein the iron substrate is bent so as to accommodate the insulating film and the conductive path in the groove. A hybrid integrated circuit characterized in that a metal layer having a higher ionization tendency than iron is provided on the opposite main surface of the circuit. (2) Utility Model Registration Claim 1: The hybrid integrated circuit according to claim 1, characterized in that zinc is used as the metal layer, which has a greater ionization tendency than iron.