JPH0344997A - Manufacture of printed wiring board - Google Patents

Abstract

PURPOSE:To make it possible to manufacture a printed board capable of further improving high density and high accuracy by forming a conductive material extremely thinly laminated with an insulating material. CONSTITUTION:With regards to a manufacturing method of a printed board which comprises a conductive material and an insulating material which are all laminated, a very thin conductive material is bonded with an insulating support material. An insulating material is further laminated with the conductive material, thereby producing laminates. Then, the support material is peeled off. Under the manufacturing method based on this construction, the insulating support member protects the conductive material in the laminating process by bonding the insulating support member with the conductive material so that the conductive material may not be broken nor torn even when an attempt is made to form the conductive material in an extremely thin piece. Furthermore, it is possible to obtain a laminate having an extremely thin conductive layer. Since it is possible to laser process this laminate at low output, smaller lines can be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming a high-density printed wiring board with high precision.

[Conventional technology]

Conventionally, printed wiring boards, especially resin-based boards,
It is formed by laminating or thermocompression bonding a copper foil (18 to 70 μm), which is a conductive material, and a glass base material-epoxy resin or paper base material-phenol resin, etc., which is an insulating material, by laminating or pressing.

[Problem to be solved by the invention]

By the way, it is extremely difficult to form the copper foil used in the above-mentioned printed wiring boards as thin as about 18 μm or less, and when patterning by etching,
There was a problem that the thicker the copper foil layer, the greater the underetching, making it impossible to reduce the pattern width.

In addition, when processing using light such as laser beam processing is an effective means of microfabrication, the processing efficiency of copper foil is low due to its high reflectance, which requires high output power, making it impossible to perform high-definition processing. There was a problem.

The present invention was made to solve the above-mentioned problems, and provides a printed wiring board that enables high density and high precision by laminating a conductive material extremely thinly on an insulating material. The purpose is to provide a manufacturing method for.

[Means for Solving the Problems] In order to solve the above problems, the method for manufacturing a printed wiring board of the present invention includes a method for manufacturing a printed wiring board formed by laminating a conductive material and an insulating material. The method is characterized in that a conductive material is bonded to the member, an insulating material is layered on the conductive material, and then the holding member is removed by peeling off.

[Effect]

In the above method, since the insulating holding member is bonded to the conductive material, the insulating holding member protects the conductive material in the process of laminating the insulating material, so even if the conductive material is formed into an extremely thin shape, The conductive material does not bend or tear, making it possible to form an extremely thin conductive layer.

〔Example〕

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

FIGS. 1(a) to 1(i) are diagrams schematically showing a manufacturing process of a printed wiring board according to an embodiment of the present invention.

In FIG. 1(a), l is a holding member that serves as a reinforcing material to provide workability. - manufactured by Tokyo Slitter Co., Ltd./Somar Kogyo Co., Ltd.). Then, as shown in FIG. 1(b), a solvent-based wax layer 2 is applied onto the holding member 1 to improve mold releasability. Next, as shown in FIG. 1(C), an ultra-thin copper foil 4 with a thickness of approximately 5 μm is layered on the wax layer 2 side of the holding member 1 coated with the wax, and is laminated by pressure bonding with a laminating roller 3. Together, a laminate shown in FIG. 1(d) is formed. Next, as shown in FIG. 1(e), the above-mentioned laminate was oxidized and soft-etched by immersing it in a loWT% solution of ammonium persulfate for 5 minutes (at room temperature), and then 40 g of sodium chlorite was applied. /β・ Immerse for 3 to 7 minutes in a solution of 5 g/4 trisodium phosphate and 15 g/n sodium hydroxide heated to 85°C. As a result, the surface of the copper foil 4 is roughened to form an oxide film to provide excellent adhesion to the insulating material. The surfaces on which the oxide film of the holding member 10 with copper foil formed in this way are formed face each other as shown in FIG. -551 manufactured by Toshiba Chemicals Corporation) at 170℃, 30 Kg/C.
Heat and press at rr+' for 90 minutes. And Figure 1 (g
), by peeling off the holding member film 1 and the wax 2, an ultra-thin copper-clad laminate 11 shown in FIG. 1(h) is formed.

Further, as shown in FIG. 1(i), a printed wiring board 12 is obtained by performing a series of steps on the substrate 11: drilling, through-hole plating, pattern resist formation, etching, and solder resist formation.

Comparative Example: Next, a comparison between the copper-clad laminate 13 made by the conventional lamination method and the ultra-thin copper-clad laminate 11 according to this example will be described.

As shown in FIG. 2(a), in the conventional lamination process, a copper foil 4 (18 to 70
Figure 2 (
A copper-clad laminate 13 shown in b) is formed.

In such a conventional lamination process, the roughened and oxidized copper foil 4 is immediately laid up and laminated with the prepreg, so if the copper foil used is thin, it will cause damage when pressure is applied at the time of layup. The copper foil is bent or torn, resulting in extremely poor workability, making stable formation impossible.

On the other hand, according to the method of this embodiment, since the copper foil is provided with a strong and flexible holding member, the copper foil does not bend or tear during the lamination process.
It becomes possible to form an ultra-thin copper foil layer with a thickness of 0 μm or less.

In addition, in the above embodiment, in FIG. 1(a),
Although a resin film is used as the holding member 6, in the present invention, other materials such as paper and flexible ceramic may also be used. In addition, in FIG. 1(C), copper foil is used as the conductive material, but in the present invention, aluminum,
Metals such as nickel may be used, and constant pressure lamination of metal foils is used to form the conductive material layer.
It is also possible to use other means such as metal plating and CVD of metal materials. Furthermore, the prepreg material 6 in FIG. 1(f) is not limited to glass-epoxy material, but may also be paper-phenol material, polyimide material, or the like.

〔Effect of the invention〕

As explained above, according to the method for manufacturing a printed wiring board of the present invention, an extremely thin layer of conductive material is formed on the holding member, and this is transferred and integrated onto the insulating material side in the lamination step. As a result, a laminate having an extremely thin conductive layer with a thickness of 10 μm or less can be obtained. This laminated board can be processed using a laser at low power, such as drilling micro holes and cutting, and since underetching does not occur during patterning, it is possible to make thinner lines, etc. for printed wiring boards. It is possible to achieve higher density and higher precision.

[Brief explanation of drawings]

FIGS. 1(a) to 1(i) are cross-sectional views schematically showing the manufacturing process of a printed wiring board according to an embodiment of the present invention. FIGS. 2(a) to 2(b) are cross-sectional views of a conventional lamination process and a copper-clad laminate obtained thereby. 1... Holding member 2... Release wax 3... Laminating roller 4... Copper foil 5... Roughened to oxidized surface 6... Insulating material 7... Solder resist

Claims

[Claims] (1) In a method for manufacturing a printed wiring board formed by laminating a conductive material and an insulating material, a conductive material is bonded to an insulating holding member, an insulating material is further laminated to the conductive material, and then the holding member is laminated. A method for producing a printed wiring board, characterized in that the printed wiring board is removed by peeling. (2) The printed wiring board according to claim 1, wherein the conductive material formed on the holding member is subjected to a roughening treatment to improve adhesion when laminating the insulating material. manufacturing method. (3) As the conductive material, copper, aluminum, gold and silver,
2. The method of manufacturing a printed wiring board according to claim 1, wherein a metal material such as nickel is used. (4) The print according to claim 1, wherein the insulating material is a reinforcing material made of glass impregnated with resin, a reinforcing material made of paper impregnated with resin, or a ceramic sintered body. A method of manufacturing a wiring board. (5) The printed wiring board according to claim 1, wherein a releasing wax layer is provided on the insulating holding member, and a conductive material is bonded thereon by pressure bonding, vapor deposition, or plating. Production method. (6) Laminating an insulating material on the conductive material,
Claim 1 characterized in that the thermocompression bonding is performed by applying heat and pressure to melt and harden the insulating material in a semi-hardened state.
A method of manufacturing the printed wiring board described.