JPH04215494A - Laminated board for metal base printed circuit - Google Patents

Abstract

PURPOSE:To facilitate bending at a right angle by superposing an aluminum plate annealed at a high temperature and anodized on its surface and a metal foil through an adhesive layer, heating, and pressurizing to integrate them. CONSTITUTION:An aluminum plate annealed at a high temperature and anodized on its surface and a metal foil are superposed through an adhesive layer, heated, and pressurized to be integrated. The annealing conditions include 300-400 deg.C and 2-4 hours. Thus, the plate having excellent stretchability can be obtained. A circuit board using the plate can be bend at 90 degrees. Further, since thicker aluminum plate than prior art can be used, its thermal capacity is increased, heat dissipation of the board is improved, and deterioration of voltage resistance can be prevented.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a metal-based printed circuit laminate with excellent bending properties, and its purpose is to facilitate the bending of thick aluminum plate-based printed circuit laminates. An object of the present invention is to obtain an aluminum-based printed circuit laminate having excellent heat dissipation properties.

0002

[Prior Art] Conventionally, aluminum-based folded printed circuit laminates have a metal body as a base, a flexible epoxy resin or the like is used as an adhesive layer, a high elongation copper foil is placed on top of the adhesive layer, and then heated. Obtained by pressurizing and integrating. (For example, JP-A-58-33788, JP-A-1-238930)
The configuration described in the publication is known. )

[0003] Generally metal bodies, such as iron, aluminum,
Laminated boards for printed circuits based on brass, copper, etc. are used as hybrid integrated circuit boards and general circuit wiring circuit boards.

[0004] Aluminum-based circuit boards are used for audio amplifiers, voltage regulator motor drivers, air conditioner inverters, and various other hybrid IC boards, and are also used for integration into housings and for grounding. However, these aluminum-based circuit boards have (1) bendability, (2) heat dissipation, and (3)
It has the disadvantage of deterioration of withstand voltage. Regarding bending workability, if the base aluminum plate has a thickness of 1.2 mm or more, it is difficult to bend the base aluminum plate at 90 degrees. Therefore, an aluminum plate with a thickness of 1.0 mm or less is used, but it has a small heat capacity and poor heat dissipation. For this reason, countermeasures have been taken such as making the adhesive layer thinner or filling the adhesive layer with a high amount of inorganic filler, but these are not sufficient. Furthermore, compared to ceramic substrates and resin substrates, they tend to deteriorate withstand voltage when used for long periods of time at high temperatures.

[0005]

[Problems to be Solved by the Invention] An object of the present invention is to use a thick aluminum plate with a high elongation rate to facilitate 90° bending, and to improve reliability by improving the above-mentioned drawbacks. An object of the present invention is to provide an aluminum-based printed circuit laminate.

[0006]

[Means for Solving the Problems] The present invention involves stacking an aluminum plate annealed at high temperature, the surface of which has been anodized, and metal foil via an adhesive layer, and integrating them by heating and pressing. This is a metal-based printed circuit laminate for bending.

[0007]

[Operation] The first feature of the present invention is that an aluminum plate annealed at high temperature and recrystallized is used as a substrate for a printed circuit laminate.

[0008] The conditions for this annealing are a temperature of 300°C or higher, preferably 300 to 400°C, a time of 2 hours or more,
Preferably it is 2 to 4 hours. By performing such treatment, an aluminum plate with good extensibility (elongation rate of 30% or more) can be obtained. Even if this aluminum plate has a thickness of 1.2 to 3.0 mm, a circuit board using this plate can be bent at 90 degrees. Furthermore,
Since a thicker aluminum plate can be used than before, the heat capacity is increased, improving the heat dissipation of the board and preventing deterioration of the withstand voltage.

[0009] This makes it possible to provide a highly reliable aluminum-based circuit board with excellent bending workability.

[0010] Furthermore, in order to improve the adhesion and insulation properties with the circuit metal foil, it is preferable to anodize the circuit side surface.

[0011]

[Examples] The present invention will be explained below with reference to Examples.

[Comparative example] An aluminum plate (A1050 according to JISH4000) with a thickness of 2.0 mm was heated at 250°C.
, annealed and tempered for 2 hours and 30 minutes, anodized the surface, coated with epoxy/nylon resin adhesive to a thickness of 60 μm, and electrolytic copper foil (Mitsui Metals, HTE
Foil) 35μm stacked, 170℃, pressure 60kg/c
Press molding was performed at m2 for 50 minutes to obtain an aluminum-based printed circuit laminate.

[Example 1] Three aluminum plates (same as the comparative example) with a thickness of 2.0 mm were
After annealing and refining at 50°C for 2 hours and 30 minutes, the surface was anodized, an epoxy/nylon resin adhesive was applied to a thickness of 60 μm, and electrolytic copper foil (Mitsui Metals, HTE
Foil) 35μm stacked, 170℃, pressure 60kg/c
Press molding was performed at m2 for 50 minutes to obtain an aluminum-based printed circuit laminate.

[Example 2] An aluminum-based printed circuit laminate was obtained by replacing the electrolytic copper foil of Example 1 with a rolled copper foil (Nippon Mining Co., Ltd., black treated foil).

The aluminum-based printed circuit laminates obtained in Comparative Examples and Examples were measured for 90° bending workability, thermal resistance, and through-layer withstand voltage, and the results are shown in Table 1. As is clear from Table 1, the performance of the aluminum-based printed circuit laminate of the present invention is superior to that of an aluminum-based laminate using an aluminum plate heat-treated at 250°C.

[0016]

[Table 1]

When the thickness of the aluminum plate is 1.0 mm or less, the obtained laminate has very good bending workability (1.
5 mmR), but the heat dissipation is low, so the thermal resistance and the translayer withstand voltage are inferior.

[0018]

[Effects of the Invention] According to the present invention, it is possible to bend an aluminum base laminate using a thick aluminum plate by 90 degrees, and since the aluminum plate has a large heat capacity, heat dissipation is improved, and therefore, It is possible to obtain a highly reliable aluminum-based laminate with reduced voltage resistance deterioration of the insulating layer.

Claims (1)

[Claims] [Claim 1] For bending processing, characterized in that an aluminum plate annealed at a high temperature and whose surface has been anodized and a metal foil are laminated with an adhesive layer interposed therebetween, and integrated by heating and pressure. Metal-based printed circuit laminate.