JPH08236885A - Aluminum-based base material and wiring board - Google Patents

Abstract

PURPOSE: To provide an aluminum-based base material excellent in a heat radiating property and manufacturable by simple processes and a wiring board by the use of the base material. CONSTITUTION: An aluminum-based base material is composed of an aluminum board or aluminum foil 10, and insulating layers 12, 12A (14, 14A) composed of an aluminum nitride (oxide) of a thickness 0.01-100μm are formed on its surfaces by a nitrogen (oxygen) low temperature plasma method. Alternatively, holes 16 for forming through holes, etc., are provided in the aluminum board or aluminum foil 10, and on the inner walls of these holes insulating layers 12, 12A (14, 14A) are formed. Besides, a wiring board is made by forming a circuit on an aluminum-based base material like this.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum base material having excellent heat dissipation characteristics, and a wiring board using such a base material.

[0002]

2. Description of the Related Art Conventionally, various circuits such as a hybrid integrated circuit are formed on an alumina base material, a metal base material, or a resin base material based on an epoxy resin or a fluororesin. When a wiring board is manufactured using an alumina base material, AgPd, A
After a conductive paste such as g, Au, AuPt, Cu, W, or Mo is printed on the alumina base material by a screen printing method to form a circuit conductor pattern, the conductive paste is baked or cured to form a circuit conductor. Form. When a wiring board is manufactured using a metal base material, a metal foil such as an electrolytic copper foil is laminated on the metal base material on which an insulating layer is formed, and the metal foil is chemically formed using an etching resist formed in a desired pattern. A circuit conductor pattern is formed by etching. Alternatively, a circuit conductor pattern is formed by printing various conductive pastes or performing metal plating by an additive method on the metal base material on which the insulating layer is formed. When a wiring board is manufactured using a resin base material on which a metal foil such as an electrolytic copper foil is laminated in advance, a circuit conductor pattern is formed by chemically etching the metal foil using an etching resist formed in a desired pattern. Form. Then, necessary electronic components are mounted on these wiring boards to complete the hybrid integrated circuit.

Recently, it has been indispensable to further increase the density of electronic circuits in response to the demands for higher frequency of electronic circuits, higher speed of signals, and lighter, thinner and smaller electronic devices. In order to deal with this, multilayer wiring layers are being developed in wiring boards, but measures against heat dissipation from the wiring boards have become a serious problem.

[0004]

A method of producing a multilayer wiring board in which wiring layers are multilayered by using a ceramic material is as follows:
The green sheet laminating method, the printing laminating method, and the thick film laminating method can be mentioned, but the ceramic material has low workability and it is difficult to increase the size of the wiring board. Further, there are problems that the manufacturing process is complicated, the manufacturing time is long, and the manufacturing cost is high. Also,
For example, when a multilayer wiring board is manufactured by a green sheet laminating method using alumina nitride powder, the sintering agent must be added to the alumina nitride powder in an amount of 5 to 10% for manufacturing the wiring board. There is a problem that the heat conduction characteristic of the wiring board is reduced to 1/2 to 1/5 or less by the addition of
Alumina nitride is expensive.

Although it is relatively easy to form the wiring layers of a wiring board into multiple layers by using a resin base material, a wiring board made of a resin base material can radiate heat of the wiring board. It has a problem of poor sex.

For heat dissipation, a metal base wiring board, a metal core wiring board, a enamel wiring board, an alumite wiring board,
Metal wiring boards such as IMST wiring boards have been put to practical use.

As shown in the schematic partial sectional view of FIG. 7A, the metal base wiring board includes a metal base material made of aluminum or a silicon steel plate and a circuit formed by etching a copper foil. , An adhesive layer for adhering the copper foil to the metal substrate. Since the metal base wiring board has the adhesive layer, there is a problem in heat dissipation characteristics. Further, it has a drawback that it is difficult to process through holes and it is difficult to form a multilayer wiring board.

As shown in the schematic partial sectional view of FIG. 7B, the metal core wiring board includes a metal base material made of a steel plate, a circuit formed by etching copper foil, and a copper foil. It consists of an adhesive layer for adhering to a metal substrate and a copper plating layer. Since the adhesive layer is also formed on the inner wall of the through hole, it is possible to perform through hole processing by copper plating, but the adhesive layer is present, so that there is a problem that the heat dissipation characteristics are poor.

The enamel wiring board, as shown in the schematic partial sectional view of FIG.
It consists of a enamel enamel layer and a circuit formed by copper plating. Since the enamel layer is also formed on the inner wall of the through hole, it is possible to perform through hole processing by copper plating and has excellent heat dissipation characteristics, but the enamel is around the hole for the through hole and the metal base material. It has the drawback of bulging, and thus it is difficult to form fine circuits. Further, the process of forming the enamel layer is complicated.

As shown in the schematic partial sectional view of FIG. 7D, the alumite wiring board has a metal base material made of aluminum, an Al ₂ O ₃ / adhesive / Al ₂ O ₃ layer, and It consists of a circuit formed by etching aluminum foil and a plating layer. A heat-resistant polyamide resin, for example, is electrodeposited on the inner wall of the through hole. This anodized wiring board can be processed by through-hole processing by plating and has excellent heat dissipation characteristics, but Al ₂ O ₃ / adhesive / Al
There is a problem that the manufacturing process becomes complicated because the formation of the ₂ O ₃ layer and the electrodeposition of the resin on the inner wall of the through hole are required.

IMST (Insulated Metal Substrate Te
As shown in the schematic partial cross-sectional view of FIG. 7 (E), the wiring board is made of a metal base material made of anodized aluminum on both sides, an adhesive layer, and an etching process of a copper foil. Formed circuit. Since this IMST wiring board uses an adhesive layer, it has a problem in heat dissipation characteristics.
Further, it has a drawback that through-hole processing is difficult.

Therefore, it is a first object of the present invention to provide an aluminum base material which has excellent heat dissipation characteristics and can be manufactured by a simple process. A second object of the present invention is that it has excellent heat dissipation characteristics, can easily process through holes and via holes, can easily form a multilayer wiring board, and can be manufactured by a simple process. An object is to provide an aluminum base substrate. A third object of the present invention is to provide a wiring board using such an aluminum base material.

[0013]

The first object of the present invention is to form an aluminum plate or an aluminum foil, and an insulating layer made of aluminum nitride having a thickness of 0.01 to 100 μm by a nitrogen low-temperature plasma method. This can be achieved by the aluminum base substrate according to the first aspect of the present invention, which is formed on the surface of the aluminum foil.

The above-mentioned first object is further composed of an aluminum plate or aluminum foil, and an insulating layer made of aluminum oxide having a thickness of 0.01 to 100 μm by an oxygen low temperature plasma method is provided on the surface of the aluminum plate or aluminum foil. Second aspect of the present invention characterized by being formed in
This can be achieved by the aluminum-based substrate according to the aspect.

The second object mentioned above is made of an aluminum plate or an aluminum foil, provided with holes for forming through holes or via holes, and made of aluminum nitride having a thickness of 0.01 to 100 μm by a nitrogen low temperature plasma method. This can be achieved by the aluminum base substrate according to the third aspect of the present invention, characterized in that the insulating layer is formed on the surface of the aluminum plate or aluminum foil and the inner wall of the hole.

The second object mentioned above is further made of an aluminum plate or an aluminum foil, provided with holes for forming through holes or via holes, and oxidized to a thickness of 0.01 to 100 μm by an oxygen low temperature plasma method. This can be achieved by the aluminum base substrate according to the fourth aspect of the present invention, characterized in that an insulating layer made of aluminum is formed on the surface of the aluminum plate or aluminum foil and the inner wall of the hole. .

A third object described above is a wiring board comprising an aluminum base material and a circuit formed on at least one surface of the aluminum base material, and the aluminum base material is an aluminum plate or aluminum. A first aspect of the present invention, which is characterized in that an insulating layer made of foil and having a thickness of 0.01 to 100 μm made of aluminum nitride is formed on the surface of the aluminum plate or aluminum foil by a nitrogen low temperature plasma method. It can be achieved by the wiring board according to.

Alternatively, the third object is a wiring board comprising an aluminum base material and a circuit formed on at least one surface of the aluminum base material, wherein the aluminum base material is aluminum. The present invention is characterized in that an insulating layer made of a plate or aluminum foil and made of aluminum oxide having a thickness of 0.01 to 100 μm is formed on the surface of the aluminum plate or aluminum foil by an oxygen low temperature plasma method. This can be achieved by the wiring board according to the second aspect.

Alternatively, the above-mentioned third object is a wiring board comprising an aluminum base material, circuits formed on both sides of the aluminum base material, and through holes for electrically connecting these circuits. The aluminum base material is made of an aluminum plate or an aluminum foil, is provided with holes for forming through holes, and has a thickness of 0.01 to 10 by a nitrogen low temperature plasma method.
The wiring board according to the third aspect of the present invention is characterized in that an insulating layer made of aluminum nitride having a thickness of 0 μm is formed on the surface of the aluminum plate or aluminum foil and the inner wall of the hole. it can.

Further, the third object mentioned above is a wiring board comprising an aluminum base material, circuits formed on both sides of the aluminum base material, and through holes for electrically connecting these circuits. The aluminum base material is made of an aluminum plate or an aluminum foil, is provided with holes for forming through holes, and has a thickness of 0.01 to 100 by an oxygen low temperature plasma method.
The wiring board according to the fourth aspect of the present invention is characterized in that an insulating layer made of aluminum oxide having a thickness of μm is formed on the surface of the aluminum plate or aluminum foil and the inner wall of the hole. it can.

Alternatively, the third object is to laminate a plurality of wiring boards each composed of an aluminum base material and a circuit formed on at least one surface of the aluminum base material, and electrically connect each circuit. A multilayer wiring board having a through hole or a via hole for connection to a substrate, wherein the aluminum base substrate is made of an aluminum plate or an aluminum foil, and is provided with a hole portion for forming the through hole or the via hole. The present invention is characterized in that an insulating layer made of aluminum nitride having a thickness of 0.01 to 100 μm is formed on the surface of the aluminum plate or aluminum foil and the inner wall of the hole by the nitrogen low temperature plasma method. It can be achieved by the wiring board according to the fifth aspect.

Still further, the third object is to laminate a plurality of wiring boards each consisting of an aluminum base substrate and a circuit formed on at least one surface of the aluminum base substrate, and to electrically connect each circuit. A multilayer wiring board having through holes or via holes for electrically connecting, wherein the aluminum base substrate is made of an aluminum plate or aluminum foil, and a hole portion for forming the through holes or via holes is provided. The present invention is characterized in that an insulating layer made of aluminum oxide having a thickness of 0.01 to 100 μm is formed on the surface of the aluminum plate or aluminum foil and the inner wall of the hole by an oxygen low temperature plasma method. Can be achieved by the wiring board according to the sixth aspect.

In these wiring boards according to the first to sixth aspects of the present invention, the circuit can be composed of a metal layer formed by plating or sputtering, or a conductive paste. In the wiring boards according to the third to sixth aspects of the present invention, by embedding a conductive paste in the holes or by a physical vapor deposition method (PVD method) such as plating or sputtering on the inner walls of the holes. Through holes or via holes can be formed by forming the metal layer. The plating can be electroless plating alone or a combination of electroless plating and electrolytic plating. The holes can be formed by drilling or punching. The fifth or sixth aspect of the present invention
In the wiring board according to the aspect (1), an aluminum base material is laminated by using an adhesive, an adhesive sheet, and various prepregs by applying a known technique such as a manufacturing technique for a multilayer printed wiring board. You can

In the aluminum-based substrate of the present invention, the insulating layer made of aluminum oxide is not limited to the oxygen low temperature plasma method, but a known method such as a chromic acid method, a sulfuric acid method, an oxalic acid method, a boric acid method or a phosphoric acid method is used. It may be formed by an anodic oxidation method. Alternatively, the insulating layer made of aluminum oxide may be formed by the sol-gel method.

In the wiring board according to the first or second aspect of the present invention, a circuit is formed on one side or both sides of the aluminum base material. When circuits are formed on both sides of the aluminum base substrate, these circuits are not electrically connected. The wiring board according to the third or fourth aspect of the present invention is a so-called through-hole wiring board in which circuits are formed on both sides of an aluminum base material and these circuits are electrically connected by through holes. A wiring board according to the fifth or sixth aspect of the present invention is
This is a so-called multilayer wiring board.

[0026]

In the aluminum base material or wiring board of the present invention, an insulating layer is formed on the surface of the aluminum plate or aluminum foil, or on the surface of the aluminum plate or aluminum foil and the inner wall of the hole. This insulating layer can be uniformly formed by a simple method and simple equipment, and the aluminum base substrate or the wiring board has excellent heat dissipation characteristics. Further, since the insulating layer can be easily and reliably formed uniformly on the inner wall of the hole for forming the through hole or the via hole for electrically connecting the circuits to each other, the double-sided wiring board or the multilayer A substrate for a wiring board, a double-sided through-hole wiring board, or a multilayer wiring board can be easily manufactured.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings. (Example 1) Example 1 relates to an aluminum base substrate according to the first aspect of the present invention. This aluminum base substrate has an aluminum foil 10 and an insulating layer 1 made of aluminum nitride formed on the surface of the aluminum foil, as shown in the enlarged schematic partial sectional view of FIG.
It consists of two. Aluminum nitride is formed by the nitrogen low temperature plasma method.

FIG. 2 shows an outline of the plasma device 50 used in the nitrogen low temperature plasma method. The plasma device 50 is
Vacuum chamber 52, reaction tube 54, process gas supply system 5
6. An induction coil 58 for generating plasma inside the reaction tube 54, a high frequency generation circuit 60 for applying a high frequency of 13.6 MHz to the induction coil 58, and a heating device 62 including an infrared lamp for heating the reaction tube 62. , An exhaust unit 64 for exhausting the vacuum chamber 52. In order to prevent overheating of the induction coil 58, it is desirable to flow cooling water inside the induction coil. The aluminum foil 70 wound in a roll is unwound from the unwinder section 72,
It is wound into a roll by the winder section 74 via the inside of the reaction tube 54. When using aluminum foil, 50-
It is possible to continuously produce a long product of 200 m. When an aluminum plate is used, the aluminum base material can be produced by so-called batch processing.

Aluminum nitride is formed on the surface of the aluminum foil 70 inside the reaction tube 54. Therefore, the vacuum chamber 52 is set to 1 × 10 ⁻⁴ to 1 × 10 ⁻⁵ Tor.
A vacuum of about r (1.3 × 10 ^{−2 to} 1.3 × 10 ⁻³ Pa) is created, and then nitrogen gas is introduced into the reaction tube 54 from the process gas supply system 56. At this time, if 2 to 10% by volume of hydrogen is mixed in the nitrogen gas, the aluminum nitride film can be uniformly formed on the surface of the aluminum foil.

The insulating layer 12 made of aluminum nitride may have an appropriate thickness of 0.01 to 100 μm depending on the characteristics such as withstand voltage required for the aluminum base material. The formation of aluminum nitride depends on the diffusion rate of nitrogen plasma in aluminum. Therefore, the thickness of the insulating layer 12 made of aluminum nitride can be easily controlled by the heating temperature of the aluminum foil in the reaction tube, the length of the induction coil 58, the length of the plasma treatment time, and the like.

Example 2 Example 2 relates to an aluminum base substrate according to the second aspect of the present invention. This aluminum base substrate is composed of an aluminum foil 10 and an insulating layer 14 made of aluminum oxide formed on the surface of the aluminum foil, as shown in the enlarged schematic partial sectional view of FIG. Has been done. Aluminum oxide is formed by the oxygen low temperature plasma method. The plasma device used in the oxygen low temperature plasma method is basically the same as that in FIG. 2, and the description thereof is omitted. The thickness of the insulating layer 14 made of aluminum oxide is 0.01 to 1 depending on the characteristics such as withstand voltage required for the aluminum base material.
It may have an appropriate thickness of 00 μm. The formation of aluminum oxide depends on the diffusion rate of the oxygen plasma in aluminum. Therefore, the insulating layer 1 made of aluminum oxide depends on the heating temperature of the aluminum foil in the reaction tube, the length of the induction coil 58, the length of the plasma treatment time, and the like.
The thickness of 4 can be easily controlled.

Example 3 Example 3 relates to an aluminum base substrate according to the third aspect of the present invention. As shown in the enlarged schematic partial cross-sectional view of FIG. 1C, this aluminum-based substrate has an aluminum foil 10, an insulating layer 12 made of aluminum nitride formed on the surface of the aluminum foil, and an aluminum layer. Hole 1 formed in foil
6 and an insulating layer 12A made of aluminum nitride formed on the inner wall of the hole 16. Aluminum nitride is formed by the nitrogen low temperature plasma method. The plasma device used in the nitrogen low temperature plasma method is the same as the device shown in FIG. The roll-shaped aluminum foil 70 is preliminarily provided with hole portions 16 for forming through holes or via holes in necessary portions by drilling or punching. Under the same conditions as in Example 1, not only on the surface of the aluminum foil 10 but also on the inner wall of the hole 16 for forming the through hole or the via hole, the insulating layers 12 and 12A made of aluminum nitride and having excellent thermal conductivity. Can be uniformly and easily formed.

Example 4 Example 4 relates to an aluminum base substrate according to the fourth aspect of the present invention. As shown in the enlarged schematic partial cross-sectional view of FIG. 1D, the aluminum base substrate includes an aluminum foil 10 and an insulating layer 14 made of aluminum oxide formed on the surface of the aluminum foil, aluminum. Hole 1 formed in foil
6 and the insulating layer 14A made of aluminum oxide formed on the inner wall of the hole 16. Aluminum oxide is formed by the oxygen low temperature plasma method. The plasma device used in the oxygen low temperature plasma method is substantially the same as the device shown in FIG. Similar to the third embodiment, the roll-shaped aluminum foil 70 is previously provided with holes 16 for forming through holes or via holes in necessary portions by drilling or punching. Under the same conditions as in Example 2, not only the surface of the aluminum foil 10
Holes 16 for forming through holes or via holes
The insulating layers 14 and 14A made of aluminum oxide and having excellent heat conductivity can be uniformly and easily formed on the inner wall of the.

Example 5 Example 5 relates to a wiring board according to the first aspect of the present invention. The wiring board of Example 5 is shown in FIG.
As shown in the enlarged schematic partial cross-sectional view of (A) or (B), it includes an aluminum base substrate and a circuit 20 formed on at least one surface of the aluminum base substrate. Aluminum base material is aluminum foil 1
And an insulating layer 12 made of aluminum nitride and having a thickness of 0.01 to 100 μm by a nitrogen low temperature plasma method.
Are formed on the surface of the aluminum foil 10. The circuit 20 is formed on the insulating layer 12. In the example shown in FIG. 3A, the circuit 20 is formed on one side of the aluminum base substrate. On the other hand, in the example shown in FIG. 3B, the circuit 20 is formed on both sides of the aluminum base substrate.

The wiring board of Example 5 was the same as the insulating layer 1 of the aluminum-based substrate produced by the method described in Example 1.
A conductive paste such as a silver paste or a copper paste is printed by a screen printing method on 2 to form a desired circuit pattern, and the conductive paste is baked or cured, or a PVD method such as plating or sputtering. It can be manufactured by patterning the metal layer formed by the method into a desired pattern.

Example 6 Example 6 relates to a wiring board according to the second aspect of the present invention. The wiring board of Example 6 is shown in FIG.
As shown in the schematic partial cross-sectional view enlarged in (C) or (D), it includes an aluminum base substrate and a circuit 20 formed on at least one surface of the aluminum base substrate. Aluminum base material is aluminum foil 1
And an insulating layer 14 made of aluminum oxide having a thickness of 0.01 to 100 μm formed by an oxygen low temperature plasma method.
Are formed on the surface of the aluminum foil 10. The circuit 20 is formed on the insulating layer 14. In the example shown in FIG. 3C, the circuit 20 is formed on one side of the aluminum base substrate. On the other hand, in the example shown in FIG. 3D, the circuit 20 is formed on both sides of the aluminum base substrate. The wiring board of Example 6 is the same as that of Example 5.
The wiring board can be manufactured by the same method.

(Embodiment 7) Embodiment 7 relates to a wiring board according to the third aspect of the present invention, which is a so-called through-hole wiring board. As shown in the enlarged schematic partial cross-sectional view of FIG. 4B, the wiring board of Example 7 includes an aluminum base substrate and a circuit 2 formed on both sides of the aluminum base substrate.
0A, 20B, and a through hole 22 for electrically connecting these circuits 20A, 20B. The aluminum base material is made of aluminum foil 10, is provided with holes 16 for forming through holes, and has a thickness of 0.01 to 10 by a nitrogen low temperature plasma method.
Insulating layers 12, 12A made of 0 μm aluminum nitride
Are formed on the surface of the aluminum foil 10 and the inner wall of the hole 16.

The wiring board of Example 7 can be manufactured by the following method. First, on the insulating layer 12 of the aluminum base substrate produced by the method described in Example 3,
For example, a conductive paste such as a silver paste or a copper paste is printed by a screen printing method to form a desired circuit pattern, and the conductive paste is baked or cured,
The circuits 20A and 20B are formed (see FIG. 4A).
Then, a conductive paste is embedded in the inside of the hole 16 by a screen printing method to form the through hole 22 which is a connection hole (see FIG. 4B). Alternatively, as shown in FIG. 4C, for example, copper may be formed on the insulating layer 12 on the surface of the aluminum foil 10 and the insulating layer 12A on the inner wall of the hole 16 by a PVD method such as electroless plating or sputtering. By forming a metal thin film made of the above and etching the metal thin film using an etching resist, a circuit 20A similar to that shown in FIG.
20B and the through hole 22 which is a connection hole can be formed. Incidentally, electroless plating can be performed after electroless plating, or electroless plating by a so-called additive method can be adopted.

(Embodiment 8) Embodiment 8 relates to the wiring board according to the fourth aspect of the present invention, which is a so-called through-hole wiring board. As shown in the enlarged schematic partial sectional view of FIG.
Also in the wiring board of Example 8, as in Example 7, the aluminum base material, the circuits 20A and 20B formed on both sides of the aluminum base material, and the circuits 20A and 20B.
It comprises a through hole 22 for electrically connecting B. The aluminum base substrate is made of aluminum foil 10 and has a hole portion 1 for forming a through hole.
6 is provided and has a thickness of 0.01 by the oxygen low temperature plasma method.
To 100 μm aluminum oxide insulating layer 1
4, 14A are the surface of the aluminum foil 10 and the holes 16
Is formed on the inner wall of the. The wiring board of Example 8 can be manufactured by the same manufacturing method as that of the wiring board of Example 7, and thus detailed description thereof will be omitted.

Example 9 Example 9 relates to the wiring board according to the fifth aspect of the present invention and is a so-called multilayer wiring board. Figure 6
As shown in the enlarged partial sectional view of FIG.
The wiring board is formed by laminating a plurality of wiring boards each including an aluminum base material and a circuit 20 formed on at least one surface of the aluminum base material, and a through hole 22 for electrically connecting each circuit 20. Alternatively, it is a multilayer wiring board in which the via holes 24 are formed. The aluminum base material is made of aluminum foil 10 and is provided with holes 16 for forming the through holes 22 or the via holes 24. The aluminum base material is made of aluminum nitride having a thickness of 0.01 to 100 μm by the nitrogen low temperature plasma method. The insulating layers 12 and 12A are formed on the surface of the aluminum foil 10 and the inner wall of the hole 16.

The wiring board of Example 9 can be manufactured by the following method. First, on the insulating layer 12 of the aluminum base substrate produced by the method described in Example 3,
For example, a conductive paste such as a silver paste or a copper paste is printed by a screen printing method to form a desired circuit pattern, and the conductive paste is baked or cured,
The circuit 20 is formed. Then, a conductive paste is embedded in the hole 16A by a screen printing method to form a through hole 22A which is a connection hole (see FIG. 6A). Alternatively, a metal thin film made of, for example, copper is formed on the insulating layer 12 on the surface of the aluminum plate or aluminum foil 10 and on the insulating layer 12A on the inner wall of the hole 16A by a PVD method such as electroless plating or sputtering, and etching is performed. By etching such a metal thin film using a resist, the circuit 20 and the through hole 22A which is a connection hole can be formed.
Incidentally, electroless plating can be performed after electroless plating, or electroless plating by a so-called additive method can be adopted.

Next, as an example, three circuit boards manufactured in this way are prepared. Then, these circuit boards are laminated using, for example, an epoxy-based or polyimide-based adhesive agent sheet 26 or the like (see FIG. 6B).
In order to facilitate stacking, it is desirable to provide each wiring board with a guide hole for alignment. Further, the adhesive sheet 26 is preliminarily perforated at a predetermined portion. The lamination can be performed by applying a multilayer printed wiring board manufacturing technique using, for example, a hot press.

Next, if necessary, a circuit is formed by printing a conductive paste, for example, by a screen printing method on the outermost surface of the laminated multilayer wiring boards. Further, if necessary, a conductive paste is embedded in the hole 16 by a screen printing method to form a through hole 22 and a via hole 24 which are connection holes for electrically connecting the circuits 20. . Alternatively, a metal thin film is formed on the surface of the insulating layer 12 on the outermost surface of the aluminum foil 10 and, if necessary, on the inner wall of the hole 16 by a PVD method such as electroless plating, electroless plating / electrolytic plating, or sputtering. And the through hole 22 or the via hole 24, which is a connection hole for electrically connecting the circuit 20 and the circuit 20, by etching the metal thin film or by electroless plating by the additive method. Form.

Through the above steps, the wiring board shown in FIG. 6C is completed. In the multilayer wiring board of Example 9, three aluminum base materials are laminated, and six wiring layers are formed. Various electronic components are mounted on the wiring board thus obtained to complete the hybrid integrated circuit.

(Example 10) Example 10 relates to a wiring board according to a sixth aspect of the present invention, which is a so-called multilayer wiring board.
The wiring board of Example 10 was formed by laminating a plurality of wiring boards each including an aluminum base substrate and a circuit 20 formed on at least one surface of the aluminum base substrate.
It is a multilayer wiring board in which a through hole 22 or a via hole 24 for electrically connecting 0 is formed. The aluminum base material is made of aluminum foil 10 and is provided with holes 16 for forming the through holes 22 or the via holes 24. The aluminum base material is made of aluminum oxide having a thickness of 0.01 to 100 μm by the oxygen low temperature plasma method. The insulating layer is formed on the surface of the aluminum foil 10 and the inner wall of the hole 16. The structure of Example 10 is the same as the structure of the wiring board described in Example 9 except that the insulating layer is aluminum oxide, and is not shown. The wiring board of Example 10 can be manufactured by the same method as that of the wiring board of Example 9 except that the aluminum base material described in Example 4 is used. Detailed description is omitted.

Although the present invention has been described based on the preferred embodiments, the present invention is not limited to these embodiments. The material used, the type of insulating layer, the number of wiring layers of the wiring board, the processing conditions, and the apparatus used for the processing are examples, and can be appropriately changed depending on the characteristics required for the aluminum base substrate or the wiring board.

[0047]

According to the present invention, it is possible to inexpensively provide an aluminum base material having stable insulating properties and excellent heat dissipation properties. In addition, it is much easier to form a multilayer wiring board than a multilayer circuit wiring board using a green sheet method of aluminum nitride powder, and an ultra-multilayer wiring board having 20 to 40 layers can be manufactured. Moreover, unlike the conventional green sheet method, high temperatures are not used, and the manufacturing process is simple. The manufacturing time is shortened to 1/5 to 1/10 of that of the conventional green sheet method, and the manufacturing cost of the wiring board can be saved. Therefore, according to the present invention, it becomes possible to easily manufacture a low-priced and high-performance hybrid integrated circuit such as a hybrid IC for a thermal head or a power hybrid IC.

[Brief description of drawings]

FIG. 1 is a schematic enlarged partial cross-sectional view of an aluminum base substrate of the present invention.

FIG. 2 is a conceptual diagram of a plasma device suitable for manufacturing the aluminum-based substrate of the present invention.

FIG. 3 is a schematic enlarged partial cross-sectional view of the wiring boards of Examples 5 and 6.

FIG. 4 is a schematic enlarged partial sectional view of a wiring board of Example 7,
7 is a schematic enlarged partial cross-sectional view of an aluminum base substrate and the like for explaining a method for manufacturing a wiring board of Example 7. FIG.

FIG. 5 is a schematic enlarged partial cross-sectional view of a wiring board of Example 8.

FIG. 6 is a schematic enlarged partial sectional view of a wiring board of Example 9;
9 is a schematic enlarged partial cross-sectional view of an aluminum base substrate and the like for explaining a method for manufacturing a wiring board of Example 9. FIG.

FIG. 7 is an enlarged partial cross-sectional view of various conventional metal wiring boards.

[Explanation of symbols]

 10 Aluminum Foil 12,12A Insulating Layer Made of Aluminum Nitride 14,14A Insulating Layer Made of Aluminum Oxide 16,16A Holes 20,20A, 20B Circuit 22,22A Through Hole 24 Beer Hole 26 Adhesive Sheet 50 Plasma Device 52 Vacuum Chamber 54 Reaction tube 56 Process gas supply system 58 Induction coil 60 High frequency generation circuit 62 Heating device 64 Exhaust part 70 Aluminum foil 72 Unwinder part 74 Winder part

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H05K 1/02 H05K 1/02 F

Claims (10)

[Claims] 1. An aluminum plate or an aluminum foil, which has a thickness of 0.01 to 100 by a nitrogen low temperature plasma method.
An aluminum base material, wherein an insulating layer made of aluminum nitride having a thickness of μm is formed on the surface of the aluminum plate or aluminum foil. 2. An aluminum plate or an aluminum foil, which has a thickness of 0.01 to 100 by an oxygen low temperature plasma method.
An aluminum base substrate, wherein an insulating layer made of aluminum oxide having a thickness of μm is formed on the surface of the aluminum plate or aluminum foil. 3. An insulating layer made of an aluminum plate or aluminum foil, provided with holes for forming through holes or via holes, and having an insulating layer made of aluminum nitride and having a thickness of 0.01 to 100 μm by a nitrogen low temperature plasma method. An aluminum base material formed on the surface of an aluminum plate or aluminum foil and on the inner wall of the hole. 4. An insulating layer made of an aluminum plate or an aluminum foil, provided with holes for forming through holes or via holes, and having an insulating layer made of aluminum oxide having a thickness of 0.01 to 100 μm by an oxygen low temperature plasma method. An aluminum base material formed on the surface of an aluminum plate or aluminum foil and on the inner wall of the hole. 5. A wiring board comprising an aluminum base material and a circuit formed on at least one surface of the aluminum base material, wherein the aluminum base material comprises an aluminum plate or an aluminum foil, and a nitrogen low temperature. A wiring board, wherein an insulating layer made of aluminum nitride having a thickness of 0.01 to 100 μm is formed on a surface of the aluminum plate or aluminum foil by a plasma method. 6. A wiring board comprising an aluminum base material and a circuit formed on at least one surface of the aluminum base material, wherein the aluminum base material comprises an aluminum plate or an aluminum foil and has a low oxygen temperature. A wiring board, wherein an insulating layer made of aluminum oxide having a thickness of 0.01 to 100 μm is formed on the surface of the aluminum plate or aluminum foil by a plasma method. 7. A wiring board comprising an aluminum base material, circuits formed on both sides of the aluminum base material, and through holes for electrically connecting these circuits, the aluminum base material. Is made of an aluminum plate or an aluminum foil, has a hole for forming a through hole, and has a thickness of 0.01 by a nitrogen low temperature plasma method.
An insulating layer made of aluminum nitride having a thickness of
A wiring board formed on the surface of the aluminum plate or aluminum foil and on the inner wall of the hole. 8. A wiring board comprising an aluminum base material, circuits formed on both sides of the aluminum base material, and through holes for electrically connecting these circuits, the aluminum base material. Is made of an aluminum plate or aluminum foil, has a hole for forming a through hole, and has a thickness of 0.01 by an oxygen low temperature plasma method.
An insulating layer made of aluminum oxide having a thickness of
A wiring board formed on the surface of the aluminum plate or aluminum foil and on the inner wall of the hole. 9. A through hole or a via hole for electrically connecting each circuit, which is formed by laminating a plurality of wiring boards each comprising an aluminum base substrate and a circuit formed on at least one surface of the aluminum base substrate. Is a multilayer wiring board in which the aluminum base material is made of an aluminum plate or aluminum foil and has holes for forming through holes or via holes. A wiring board, wherein an insulating layer made of aluminum nitride having a thickness of 0.01 to 100 μm is formed on the surface of the aluminum plate or aluminum foil and the inner wall of the hole. 10. A through hole or a via hole for electrically connecting each circuit, which is formed by laminating a plurality of wiring boards each including an aluminum base substrate and a circuit formed on at least one surface of the aluminum base substrate. Is a multilayer wiring board in which the aluminum base material is made of an aluminum plate or aluminum foil and has holes for forming through holes or via holes. A wiring board, wherein an insulating layer made of aluminum oxide having a thickness of 0.01 to 100 μm is formed on the surface of the aluminum plate or aluminum foil and the inner wall of the hole.