JPS62125697A - Manufacture of electric circuit forming substrate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a method for manufacturing a board for forming an electric circuit, and further relates to a method for manufacturing a board for forming an electric circuit.
More specifically, the present invention relates to a method for manufacturing a three-layer structure base for forming an electric circuit consisting of a metal foil, a heat-resistant insulating layer, and a metal substrate, which exhibits high adhesive strength without abnormalities such as bulges in appearance.

[Prior Art 1] Conventionally, a three-layer electric circuit forming board consisting of a metal foil, a heat-resistant insulating layer (adhesive, a heat-resistant insulating film, an adhesive), and a metal substrate as shown in Fig. 2(a) is pressed. It was manufactured by the method. In other words, a plurality of materials with a three-layer structure of metal substrate, ML heat insulating layer (adhesive, insulating film, adhesive), and metal foil are stacked together, set in a heat press at room temperature, and air removed about 5 times. , 20~40K
Apply a pressure of g/cm2, heat to raise the temperature, remove air again at a temperature of about 100°C, then apply a pressure of 20-40 kg/cm2, 1. ,i,
Air grafting is carried out again at a temperature of O-160°C, and then at a temperature of 140-160°C, 20-4
The product is treated at a pressure of 0 kg/cm2 for 40 to 60 minutes, and then cooled and taken out from the hot press to use as a base for forming an electric circuit.

According to this heat press method, it takes a long time to manufacture a board for forming an electric circuit, which has a three-layer structure of a metal base, a heat-resistant insulating layer (adhesive, a heat-resistant insulating film, and an adhesive), and a metal foil. The problem is that we have to give 1-.

1. Problems to be Solved by the Invention] The present invention is directed to the above-mentioned J: sea urchin, and to the production of an electric circuit forming substrate having a three-layer structure of metal foil, a heat-resistant insulating layer, and a metal substrate by the conventional buff press method. In view of the problems with Taneno Z in the manufacturing method, as a result of the inventor's intensive research,
Is there any abnormality such as swelling on the appearance of the board for forming the electric circuit?
) and improved adhesive strength, and developed a method for manufacturing a three-layered electrical circuit board consisting of a metal foil, a heat-resistant insulating layer, and a metal substrate with excellent performance.

[Means for Solving the Problems 1 The feature of the method for manufacturing an electric circuit forming JI (board) according to the present invention is that a heat-resistant insulating layer is provided between a long metal foil and a long metal substrate. The long and single-layer structure consisting of metal foil, heat-resistant insulating layer, and metal substrate is then
The cut material of the structure is placed in a heating furnace.1. 'r+, after heating for 2...24 hours at a temperature of 1-120'C, further 120~
Heating for at least 30 minutes at a temperature of 200'C1
There it is.

A method of manufacturing a substrate for forming an electric circuit according to the present invention will be described in detail below.

First, materials used in the method of manufacturing an electric circuit forming board according to the present invention will be explained.

Since the metal foil is a conductor, it is preferable that it is made of a metal with excellent electrical conductivity and has a thickness of 5.-70 .mu.m. Further, this metal foil may be made of aluminum, copper alloy, nickel, silver, or a conductive metal or an alloy thereof.

The heat-resistant insulating layer is composed of an adhesive, a heat-resistant insulating film, an adhesive, or a coated layer of a one-time adhesive.The adhesive and the heat-resistant insulating film will be explained below.

It is best to use an Evo-N adhesive that has relatively good electrical insulation properties, and has good adhesion to other metals.
Additionally, adhesives with good electrical insulation properties, such as those based on polyamide/imide, silicone, acrylic, polyester, and polyurethane, may also be used.

Further, the thickness of the adhesive is preferably determined based on the insulation properties required for the electrical insulation layer including the heat-resistant insulation film, and is preferably about 2(μ) to 200μ. 5. If the heat-resistant insulating layer is made of adhesive only, it is better to make it thicker than this thickness.

The heat-resistant insulating film must have heat resistance that does not have defects such as pinholes, does not melt even when heated, is unaffected by adhesives, and has excellent electrical insulation properties.For example, polyimide Films are preferred. The thickness of this heat-resistant insulating film is preferably 5 to 50 microns. In addition to the insulating film described in 1 above, polyester film, polyetherimide, polysulfone film, etc. can also be used depending on the purpose. This insulating layer is not affected in any way by pattern etching of the metal foil.

The metal substrate has a thickness of 0.3 to 3. Omm steel plate or thickness 0.1~1. Omm T1-base steel plate is used. Additionally, aluminum, aluminum alloys, copper, and copper alloys can also be used.

Next, a method of manufacturing a board for forming an electric circuit according to the present invention will be explained using an example shown in FIG. Note that the metal foil will be described as a copper foil, and the metal substrate will be described as an iron substrate.

That is, although not shown, an adhesive is applied to a long piece of 'jJi1 foil, heated, and then a heat-resistant insulating film is adhered to form a coil. By forming an insulating layer and adhering the adhesive of this heat-resistant insulating layer to a preheated long iron substrate, a three-layer structure of the iron substrate, heat-resistant insulating layer, and copper foil can be assembled into a board for forming an electric circuit. The moon was manufactured (see Figure 2(a)).

In addition, when the heat-resistant insulating layer is only an adhesive layer, since a heat-resistant insulating film is not used, adhesive is applied to the copper foil one or more times to ensure insulation, and after cooling and drying, it is attached to a preheated iron substrate. By adhering, a material for a three-layer electric circuit formation substrate was manufactured (see FIG. 2(b)).

However, in this state, the adhesive is often not sufficiently cured to exhibit sufficient heat resistance and insulation properties, and therefore the next curing treatment is performed.

This three-layer structure material is cut to an appropriate length, and the cut material with the door layer drawn is stacked with spacers in a furnace heated by an appropriate heat source as shown in Figure 1. Table-1-
Place it on the -Tf floor and heat it.

(In the IS1 diagram, there are two materials with a three-layer structure, but it is best to increase the number as much as possible.) ) First, for the first heating, heat for 2 to 24 hours at a temperature of 50 to 12 (1"C). However, at temperatures exceeding 120°C, the difference in thermal expansion coefficients of each material causes a noticeable difference in expansion, which may lead to floating and peeling. If it is less than 2 hours nt1, heating is insufficient, and heating for more than 24 hours is wasteful.

Next, when the first heating [1] is completed, the second heating is carried out at a temperature of 120 to 20
Heating is carried out at a temperature of 0° C. for 30 minutes or more. At this time, even if the temperature is lowered to below 120° C., the first heat treatment has produced adhesive strength to such an extent that each material cannot thermally expand, making it possible to perform a complete curing reaction treatment. In this case, if the heating temperature is less than 12 (]'C, even 3
0 minutes or more - Even if heated, the final curing is sufficient and the desired adhesive strength is reduced by 1υ; temperatures exceeding 200°C are too high and the material peels off, so the heating time is less than 30 minutes. is insufficient, and sufficient adhesive strength cannot be obtained.

[Example 1] An example of the method for manufacturing an electric circuit forming board according to the present invention will be described.

Example curing temperature: 1st reaction temperature: 80°C 5: 2nd reaction temperature: 150°C
Apply 15μ of thermosetting epoxy adhesive to the copper foil adhesion surface and 15μ to the heat-resistant insulating film, and heat the three-layer structure of copper foil, heat-resistant insulating layer (adhesive, heat-resistant insulating film, adhesive), and iron substrate. It was put on a roll and heat fused. The adhesive strength at that time was approximately several hundred g/cm, and the adhesive was in an uncured state. Thereafter, it was cut into appropriate dimensions.

(1) First, cut this three-layered material into ] (
') ()'CI'>temperature for 1 hour, followed by heating at 1
Heating was carried out at a temperature of 50° C. for 1 hour in a free state without applying pressure.

(2) This cut five-layer structure material was heated in a free state without applying pressure at a temperature of 150° C. for 1 hour.

As a result, when heated by the method for manufacturing an electric circuit forming board according to the present invention in (1), the obtained product had no abnormal appearance and was resistant to soldering heat for 5 minutes at a temperature of 26 (1°C). The adhesive strength was excellent at 2 kg/cm, and performance equivalent to that obtained by heat pressing (heating at 150° C. for 1 hour) was obtained.

Note that even when the heat-resistant insulating layer was made of only an adhesive, the same results as in Section 1 were obtained.

Comparative example (2) was observed to have blisters everywhere on the iron substrate interface and the copper foil interface, and these blisters were not bonded, and further blisters appeared when they came into contact with the solder bath. It becomes large and cannot be used as a base for forming an electric circuit.

Therefore, according to the embodiment of the method for manufacturing a board for forming an electric circuit according to the present invention, the product with the three-layer structure of copper foil, heat-resistant insulating layer, and iron substrate has no bulges in the iron substrate and copper foil. It has sufficient performance as a base for forming an electric circuit, and also has high adhesive strength.

[Effects of the Invention 1] As explained above, since the method for manufacturing a board for forming an electric circuit according to the present invention has the above configuration, it has sufficient performance as a board for forming an electric circuit, has high adhesive strength, and , which has an excellent effect of being suitable for mass production.

[Brief explanation of drawings]

FIG. 1 is an explanatory view for explaining the method of manufacturing a board for forming an electric circuit according to the present invention, and FIG. 2 is a cross-sectional view of a three-layer structure of copper foil, a heat-resistant insulating layer, and an iron substrate.

Claims (1)

[Claims] A long material with a three-layer structure consisting of a metal foil, a heat-resistant insulating layer, and a metal substrate, in which a heat-resistant insulating layer is provided between the long metal foil and the long metal substrate, is cut into appropriate dimensions. After heating the cut three-layer material in a heating furnace at a temperature of 50 to 120°C for 2 to 24 hours,
A method for manufacturing a board for forming an electric circuit, comprising heating at a temperature of 200° C. for 30 minutes or more.