JP2514384Y2 - Metal base wiring board - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal base wiring board.

[0002]

2. Description of the Related Art Generally, a power module or the like is required to have high withstand voltage and high heat dissipation. Therefore, FIG.
As shown in (A), a circuit pattern 82 mainly made of copper or the like is formed on an entire surface of a metal base substrate 80 mainly made of aluminum or the like via an insulating insulating layer 81 filled with an inorganic filler at a high ratio. A metal-based wiring board made of is used. This metal-based wiring board has a problem in that the mounting density cannot be increased because other types of wiring boards that do not require high withstand voltage and high heat dissipation cannot be laminated to form a multilayer.

Conventionally, in order to solve this problem, FIG.
As shown in (B), the insulating layer 8 on the metal base substrate 80.
8A. A metal base wiring board in which a printed wiring board 84 made of glass epoxy or the like and a flexible printed wiring board (hereinafter, abbreviated as FPC) are arranged in a predetermined region of 1 through an adhesive layer 83, and FIG. As shown in FIG. 3, a metal base wiring board has been devised in which a printed wiring board 84 and an FPC are directly arranged in a predetermined region on a metal base substrate 80 via an adhesive layer 83 so as not to overlap each other.

[0004]

[Problems to be Solved by the Invention] However, FIG.
The metal base wiring board shown in (B) cannot effectively secure a region requiring high withstand voltage and high heat dissipation,
Further, the metal-based wiring board shown in FIG. 8C has a problem in that it has poor withstand voltage characteristics and flowability of materials when forming an adhesive layer, and is currently not in practical use.

The present invention has been made in view of the above points, and an object thereof is to provide a metal base wiring board which can exhibit excellent dielectric strength.

[0006]

According to the present invention, a metal base substrate, a high thermal conductive double-sided substrate disposed on the metal base substrate via an adhesive layer, and the high thermal conductive double-sided substrate are arranged side by side. A circuit board disposed on the metal base substrate via an adhesive layer, wherein the high thermal conductivity double-sided substrate is an insulating layer filled with an inorganic filler, and on one entire surface of one surface of the insulating layer. The first metal layer is formed, and the patterned second metal layer is formed on the other surface of the insulating layer, the first metal layer is the metal base substrate via an adhesive layer. Provided is a metal-based wiring board characterized by being arranged on the above.

Here, as the material of the metal base substrate,
Aluminum, copper, iron, nickel, copper-invar, etc. can be used.

The adhesive used in the adhesive layer is not particularly limited as long as it has adhesiveness, but it is preferable to use an inorganic powder, an inorganic fiber or a metal powder, a metal fiber, or the like having excellent thermal conductivity. desirable. In particular, it is preferable to use a conductive adhesive so that the metal layer formed on the entire surface of one surface of the high thermal conductive double-sided substrate is not electrically isolated.

Epoxy resin, phenol resin or the like can be used as a material for the insulating layer of the high thermal conductive double-sided substrate. As the inorganic filler filled in the insulating layer, alumina, silica, boron nitride or the like can be used. The filling rate of this inorganic filler is preferably 60 to 90% by weight. In addition, it is not preferable to use an insulating film or the like for the insulating layer because sufficient thermal conductivity cannot be obtained.

Copper, copper-aluminum clad or the like can be used as the metal of the metal layer of the high thermal conductivity double-sided substrate.

As the circuit board arranged in parallel with the high thermal conductivity double-sided board, a single-sided or double-sided printed wiring board using glass epoxy or the like as a board material can be used.

[0012]

According to the metal base wiring board of the present invention, the insulating layer having the dielectric strength and the high thermal conductivity can be secured by using the preformed high thermal conductivity double-sided board. That is, it is possible to solve the problem that a sufficient dielectric strength cannot be obtained in the method of forming a temporarily dried adhesive insulating layer on one surface of the metal layer and curing and integrating them. Furthermore, different types of circuit boards can be mounted in a relatively small area.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, as shown in FIG.
On one surface of each of the electrolytic copper foil 10 having a thickness of 105 μm and the electrolytic copper foil 11 for a circuit having a thickness of 105 μm, an insulative epoxy resin filled with about 80% by weight of alumina powder is applied, and at about 90 ° C. The high thermal conductive insulating layer 12 is formed by temporary drying, and each high thermal conductive insulating layer 1 is formed under vacuum pressure.
Two copper foils were attached to each other so that the two were in contact with each other to prepare a double-sided substrate. At this time, the thickness of the high thermal conductive insulating layer 12 was 120 μm.

Next, as shown in FIG. 1B, the insulating layer 1
The thickness of 3 is 0.1 mm, and the thickness of the copper foil 14 is 35 μm.
The glass epoxy double-sided copper clad laminate that is is subjected to through-hole drilling processing, through-hole plating processing is applied to this, and one surface is patterned by a normal method,
A single-sided circuit board as shown in FIG. 1 (C) was produced.

Next, as shown in FIG. 2, the double-sided board and the single-sided circuit board are cut into a predetermined size, and the double-sided board is placed on the upper surface of the electrolytic copper foil for circuit 11 through the conductive adhesive 20. The single-sided circuit board was placed on an aluminum plate 22 having a thickness of 2 mm so that the surface not patterned was the upper surface through the insulating glass epoxy prepreg sheet 21.

After that, as shown in FIG. 3, the copper foils 11 and 30 on the upper surfaces of the double-sided board and the single-sided circuit board are patterned by a usual method, and an insulating treatment is applied to the copper foils 11 and 30 by using a solder resist ink or the like to form the The invented metal-based wiring board was produced.

The double-sided board of the obtained metal-based wiring board is
It has been confirmed that the metal base wiring board exhibits excellent pressure resistance as compared with the conventional metal-based wiring board.

The present invention is not limited to the above embodiment, and as shown in FIG. 4, the double-sided substrate 40 is placed on the aluminum plate 22 via the conductive adhesive 20, and
The circuit board 41 having one surface patterned so as to be juxtaposed with the double-sided board 40 is placed on the aluminum plate 22 via the insulating adhesive 42, and then the double-sided board 4 is placed.
0 and the exposed surface of the circuit board 41 may be patterned.

Further, as shown in FIG. 5 or 6, the same adhesive may be used when the double-sided board 40 and the circuit board 41 are placed on the aluminum plate 22. That is, as shown in FIG. 5, both may be adhered using the conductive adhesive 20, or as shown in FIG. 6, both may be adhered using the insulating adhesive 42. When the conductive adhesive 42 is used as shown in FIG. 5, the wiring 43 and the conductive material are provided in a region corresponding to the circuit board 41 so as to prevent a short circuit between the wiring 43 on the lower surface of the circuit board 41 and the aluminum plate 22. It is necessary to interpose the insulating adhesive 42 with the adhesive 20.

Further, as shown in FIG. 7, solder 50 is used instead of the conductive adhesive 20 of the metal base wiring board shown in FIG.
May be used. In this case, it is necessary to interpose the metal foil 51 for soldering between the insulating adhesive 42 and the solder 50.

[0022]

As described above, since the metal base wiring board of the present invention can secure the thickness of the insulating layer having high pressure resistance and high heat dissipation, it can exhibit excellent dielectric strength and reliability. Can also be improved. In addition, since the unpatterned metal foil is formed on the entire surface of one surface of the insulating layer, it is easy to evaluate the characteristics and electrically stable.

The high thermal conductivity double-sided board according to the present invention is obtained by applying an insulating adhesive on the surfaces of two metal foils.
The manufacturing process can be simplified because it can be manufactured only by pasting it after temporary drying.

Furthermore, since the metal base wiring board of the present invention can exhibit sufficient dielectric strength, it can be applied to metal base boards having different thicknesses and types. For example, conventionally, there is a problem that it is difficult to print the cream solder because a step is generated between the mounting surface of the high thermal conductive double-sided board and the circuit board, but the thickness can be adjusted by the metal base wiring board of the present invention. Therefore, such a problem can be easily solved.

[Brief description of drawings]

1A to 1C are cross-sectional views illustrating a method for manufacturing a metal-based wiring board according to the present invention.

FIG. 2 is a cross-sectional view for explaining a method of manufacturing the metal base wiring board of the present invention.

FIG. 3 is a cross-sectional view for explaining a method of manufacturing the metal base wiring board of the present invention.

FIG. 4 is a cross-sectional view showing another embodiment of the metal base wiring board of the present invention.

FIG. 5 is a cross-sectional view showing another embodiment of the metal base wiring board of the present invention.

FIG. 6 is a cross-sectional view showing another embodiment of the metal base wiring board of the present invention.

FIG. 7 is a cross-sectional view showing another embodiment of the metal base wiring board of the present invention.

FIG. 8 is a cross-sectional view for explaining a conventional metal base wiring board.

[Explanation of symbols]

10 ... Electrolytic copper foil, 11, 30 ... Electrolytic copper foil for circuit, 12 ...
High thermal conductive insulating layer, 13 ... Insulating layer, 14 ... Copper foil, 20 ...
Conductive adhesive, 21 ... Glass epoxy prepreg sheet, 22 ... Aluminum plate, 40 ... Double-sided board, 41 ... Circuit board, 42 ... Insulating adhesive, 43 ... Wiring, 50 ... Solder, 51 ... Metal foil.

Claims (1)

(57) [Scope of utility model registration request] 1. A metal base substrate, and a high thermal conductive double-sided substrate disposed on the metal base substrate via an adhesive layer,
A circuit board arranged side by side on the high thermal conductive double-sided board via an adhesive layer on the metal base substrate, wherein the high thermal conductive circuit board is an insulating layer filled with an inorganic filler; A first metal layer formed on the entire surface of one surface of the insulating layer, and a patterned second metal layer formed on the other surface of the insulating layer.
The metal-based wiring board, wherein the metal layer is disposed on the metal-based substrate via an adhesive layer.