JPS6161489A - Method of producing printed circuit board - 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] The present invention relates to printed wiring boards for manufacturing single-sided printed wiring boards, double-sided printed wiring boards, multilayer printed wiring boards, flexible wiring boards, etc. using a chemical plating method. More specifically, it relates to a method of manufacturing a printed wiring board using an additive method in which conductive circuits are formed by electroless plating (two steps).

[Conventional technology]

Conventionally, conductor circuits on printed circuit boards have been formed by etching or electrolytic plating. By applying an ink resist to the non-etched areas by screen or offset printing, or by providing a cured film layer of photosensitive resin, etching unnecessary areas and removing the resist, etc. from the non-etched areas. This is a method of forming conductor circuits.This method removes the metal conductor by etching, which is not resource-saving and also (
-There was a drawback that the number of steps was large because it required formation and removal of resist, etc. In the electrolytic plating method, a hardened layer of ink resist and photosensitive resin is applied to the non-plated parts of a conductive substrate, electrolytic plating is applied to form a conductive circuit, and this conductive circuit is transferred to a predetermined insulating substrate. However, this method is a very (=complicated) process.

On the other hand, in order to solve the problem of the wide mouth, there is an additive method in which a conductive circuit is formed by electroless plating. Commonly used for this are the CC-4 method and the PSMD method. In the CC-4 method, an adhesive layer with Ni-plating catalytic properties is formed on an insulating substrate, and a hardened layer such as resist is applied to the non-plated parts. is electroless plating (forms a two-strand conductor circuit).

In addition, PSMD method (Photo 5elective M
etal Deposition) forms a plating catalyst layer on an insulating substrate, irradiates the non-plated parts with ultraviolet rays, de-catalyzes the plating catalyst layer corresponding to that part with the ultraviolet rays, and then performs electroless plating to form a conductor circuit. It forms the

[Problem that the invention seeks to solve]

The present invention is an improvement of the electroless plating method and the additive method of forming conductor circuits.

The CC-4 method (-) has the inconvenience of forming an adhesive layer on the substrate and then forming a resist on top of it.
Although the PSMD method can omit the formation of a resist, etc., it is a difficult manufacturing method in which a conductor circuit is formed after ultraviolet treatment.

The present invention eliminates these drawbacks and at the same time provides a completely new method for manufacturing printed wiring boards using an additive method.

[Means for solving problems]

The manufacturing method of the present invention is to manufacture a printed wiring board by forming a conductor circuit by applying electroless plating to a printed circuit board, and the first step is to form a plating catalyst layer on the surface of the board. a second step of thermally decatalyzing the catalyst layer of the non-conductor circuit portion on the surface of the substrate treated in the first step; and activating the catalyst layer on the surface of the substrate treated in the second step. This method is characterized by comprising a third step of chemically treating the substrate, and a fourth step of applying electroless plating to the surface of the substrate treated in the third step to form a desired conductor circuit.

The plating catalyst layer is a general (= used mixed complex solution of Baladicum chloride and stannous chloride (for example, H8l0IB
, a product of Hitachi Chemical Co., Ltd.), by dipping the substrate in the above solution, applying the solution, spraying, etc. (Secondly, the effect of forming the catalyst layer is further improved. Examples of this method include physical roughening methods such as honing treatment, and chemical surface roughening methods using an oxidizing solution.

The method of decatalyzing the catalyst layer is to deactivate the catalyst layer corresponding to the non-conducting circuit portion by heat. For example, it can be carried out by contacting the part of the heating contact body. Examples of the heating contact body include a metal plate, a ceramic plate, etc. To heat the metal plate, etc., a heater is placed inside the metal plate, etc. There are two methods: to build it in, to manufacture the metal plate itself from a heat-generating resistance metal such as nichrome, or to indirectly heat it with infrared rays.

As a method for activating the catalyst layer, use a common plating catalyst activation solution (for example, a hydrofluoric acid-hydrochloric acid aqueous solution, product 0PC-5557 Xelator, Okuno Pharmaceutical Co., Ltd. product), This is carried out by dipping the substrate in the solution, or by applying or spraying the solution.

Examples of the electroless plating solution include an electroless nickel plating solution and an electroless copper plating solution.

Next, the method for manufacturing a printed wiring board according to the present invention will be explained based on the attached drawings. First, as shown in FIG. Apply plating catalyst solution to the surface by immersion, wash with water, dry with infrared light bulb or hot air, etc.
A plating catalyst layer 2 is formed (first step). next (=second
As shown in FIG. process).

Next, as shown in FIG. 6, the plating catalyst layer 2 of the conductor circuit portion is immersed in a plating catalyst activation solution (to form an activation layer 5 from the second step (third step)).

Next, when this is subjected to electroless plating using the usual method (=therefore, electroless plating is applied), as shown in FIG. A board is manufactured.

If the drying temperature using an infrared light bulb or hot air in the first step is too high, the plating catalyst layer will become non-catalytic, so the drying temperature should be 60°C.
It is desirable to dry at the following temperatures:

Furthermore, if the temperature of the metal plate, etc. in the second step is too low, decatalyticization will not proceed, and there is a risk that the non-catalyzed layer will react with the activated layer during activation in the third step.

Also, if it is too high, there is a risk of softening or melting the board, so
00°C to 300°C, preferably 200°C.

The time for close contact is appropriately determined depending on the temperature of the metal plate, the substrate material, etc., but is preferably 1 minute to 10 minutes.

The present invention will be explained in detail from Example 2 below.

Example A polyester film having a thickness of 200 μm was honed to obtain a substrate with a surface roughness of 2 μm. This board is
8l0IB (B Ritsukasei Kogyo Co., Ltd. product).

It was immersed in a plating catalyst solution obtained by mixing concentrated hydrochloric acid and water in a ratio of 1:5:10 for 10 minutes at room temperature, and then immersed in it for 10 minutes.
It was washed with water for ~2 minutes and completely dried with hot air at 50°C to obtain a plating catalyst layer. On this surface, a non-catalytic metal plate made of a 10% thick steel plate with a 10 μm chrome plating and a temperature of 200°C, with the non-conductor circuit part protruding 5% from the conductor circuit part, is attached for 1 minute. let Next (2) 0P the above board
20 of C-555 Accelerator (Okuno Pharmaceutical Product)
Volume % aqueous solution (= immersed at room temperature for 3 minutes, washed with water for 1 to 2 minutes, then used as an electroless nickel plating solution.
When electroless nickel plating was applied by immersing it in a 20% by volume aqueous solution of 0 (nickel sulfate-sodium hyposulfite 1 Nippon Kanigen ■ product) at 70°C for 10 minutes, a flexible printed wiring board made of nickel metal was obtained. Ta.

In the above embodiments, flexible printed wiring boards (two examples were given, but all other printed wiring boards; two can also be applied, and are not limited to polyester films, but can also be applied to other substrates, such as polycarbonate substrates, glass epoxy substrates, etc.)
Needless to say, it can also be applied.

[Effects of the Invention] As described above, according to the present invention, the plating catalyst layer is decatalyzed by heat and a printed wiring board is manufactured by electroless plating, which is a relatively simple process, and in addition, etching, resist formation, etc. This method is highly effective in manufacturing printed wiring boards in large quantities at low cost without requiring peeling. Further, the manufacturing method of the present invention (=Thus, when manufacturing a flexible printed wiring board, a continuous hoop type manufacturing is also possible by using a band-shaped planutic film as a substrate.

[Brief explanation of drawings]

1 to 4 are partially enlarged views of successive steps showing the steps of the manufacturing method of the present invention. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Plated catalyst layer, 6... Heated metal plate, 4... Non-catalyzed layer, 5... Activated layer,
6... Electroless plated metal. However, the thickness of each layer is appropriately enlarged for explanation.

Claims (1)

[Claims] 1. In a method for manufacturing a printed wiring board by forming a conductor circuit by applying electroless plating to an insulating substrate, a plating catalyst layer is provided on the surface of the insulating substrate (hereinafter referred to as the substrate). a first step of forming a catalyst layer on the surface of the substrate treated in the first step, a second step of decatalytizing the catalyst layer of the non-conductor circuit portion on the surface of the substrate treated in the first step; A print characterized by comprising a third step of activating the catalyst layer of the substrate, and a fourth step of applying electroless plating to the surface of the substrate treated in the third step to form a desired conductor circuit. Method of manufacturing wiring boards. 2. The method for manufacturing a printed wiring board according to claim 1, characterized in that the decatalytic treatment in the second step is performed by contacting a heating contact member with a catalyst layer of a non-conducting circuit portion. .