JPS61110487A - Manufacture of printed wiring 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 uses an electroless plating method. [Substrate]--Relates to a method of manufacturing a printed wiring board in which a conductor is formed on a substrate.

BACKGROUND ART As prior art to the present invention, Japanese Unexamined Patent Application Publication No. 58-12874 (January) and Japanese Unexamined Patent Publication No. 58-134497 are disclosed. The technology involves attaching a photosensitive resin film to an insulating substrate, overlapping the negatives, baking and developing to form a permanent mask, and immersing the substrate in an electroless plating solution.
This is an fj method for manufacturing printed wiring boards in which a conductor is formed on an insulating substrate excluding a permanent mask.

Problems to be Solved by the Invention As electronic components become more and more miniaturized, many LSI 1" displays are mounted on printed wiring boards. Widths are rapidly shrinking.Furthermore, the mounting method for electronic components on printed wiring boards is increasing.

Conventionally, in order to form a plating resist layer on a printed wiring board, a screen printing method was often used in the fully additive method of forming a conductive Ti layer based on an electroless plating method. As mentioned above, a photoresist method has been proposed and is becoming popular.

However, with the development of office automation equipment, when electronic components are mounted on printed wiring boards, there are various shapes of chip-type electronic components, especially those with terminal shapes that protrude from the main body of the electronic component, and those with terminals that are attached to the back side. Since we handle a wide variety of products, some of which are closely bonded to each other, and some of which have dozens of terminals, it is no longer possible to provide good support using conventional wiring boards with a metal resist layer of the same height. .

Means for Solving the Problems The present invention uses an insulating substrate with a catalyst attached to the surface as a base material,
A photosensitive resin film is attached to the surface of this base material, a photographic film with a printed pattern is placed on the photosensitive resin film, irradiated with ultraviolet rays, and then developed, and the photosensitive resin film is cured by irradiation with ultraviolet rays. is formed as a plating resist layer of a permanent mask, and the substrate on which this plating resist layer is formed is immersed in an electroless plating solution to form a conductor with a uniform thickness in areas other than the plating resist layer. A method for manufacturing a board, in which the above-mentioned photosensitive resin film is attached [In order to obtain plated resist layers of different thicknesses when pulling, a photosensitive resin film corresponding to the desired thickness is applied! l11 A printed wiring board that forms a plating resist 1 to layer of a desired thickness with high and low heights by laminating several or multiple sheets together. This is the 14J method.

Function The present invention is effective when mounting a wide variety of electronic components on a printed wiring board.
By forming a plating resist layer with a difference in height and thickness in accordance with the terminal mounting shape of the electronic component, the mounting work of the chip component can be carried out reliably.

Embodiment An embodiment of the present invention will be described based on the drawings. Reference numeral 1 designates an insulating substrate, and the base material 3 is a substrate on which at least the surface of the insulating substrate 1 is attached a catalyst 2 that reacts with the reduction of metal cations in the electroless plating solution. A photosensitive resin film 4 of type 5R-3000 manufactured by Hitachi Chemical Co., Ltd. is pasted on the surface. This photosensitive resin film 4 has a film 4 with a thickness of 30 μm attached to the entire surface according to the shape of the chip type electronic component 6.7, and a film 5 with the same thickness of 30 μm applied to a part.
Paste. As a result, one or more photosensitive resin films 4.5 are pasted on the base material 3, and the single film has a thickness of 30 μm and the multiple films have a thickness of 60 μm. It is understood that the photosensitive resin films can be combined as appropriate depending on the desired thickness.

A photosensitive resin film 4.5 is laminated to this base material 3, and a photographic film 12.5 is printed with a pattern 10.11 on it.
13 and irradiate it with ultraviolet light 15. This pattern io
, ii are formed with reverse patterns of the conductor patterns.

When the ultraviolet rays 15 are irradiated, the light rays pass through the photographic film, the irradiated parts of the photosensitive resin films 5A and 6A are cured, and the opaque areas 10.11 where the patterns 10.11 are formed are blocked from the light rays 15. Photosensitivity 11! FT
Film 58.68 is not cured.

After the irradiation with ultraviolet rays 15 is completed, if trichlorethylene is sprayed, the uncured parts 5B, 6B of the photosensitive mum film 5.6 are dissolved and the cured part 5A is formed.

6A remains as it is and forms the plating resist layer 2 of the permanent mask.
0.21. This plating resist layer is a thick plating resist If! A plating resist WJ21 as thin as 120 is obtained.

Next, this substrate 30@U is immersed in a solution consisting of chromium chloride and -fluorinated water N acid to chemically roughen the exposed surface of the base material and improve the adhesion of the plating.

Thereafter, an electroless plating solution having the following composition: copper sulfate pentahydrate 10 g/Z ethylenediaminetetraacetic acid 30 g/1 caustic soda P
)-1 becomes 12 (37%) 3d
/ poor surfactant, some water, 11 liters of water, and the insulating substrate 30 is placed in a solution heated to 70°C for about 3 hours 8!
When the copper plating film thickness has grown to 30μ, the substrate 30
was taken out from the plating solution to obtain a printed wiring board 40. Since the conductor 22 has a uniform thickness of 30 μm, a flat surface with almost the same thickness as the thin plating resist 21 can be obtained, and since the thick plating resist 20 is as thick as 60 μm, a step is formed. Effects of the Invention The method for manufacturing a printed wiring board of the present invention includes laminating one or more photosensitive resin films so that the thickness of the plating resist layer becomes a desired thickness according to the shape of the chip-type electronic component. As a result, a printed wiring board having the same thickness or a difference in thickness compared to the conductor thickness can be obtained, making it possible to easily position electronic components and ensure mounting on the mark 1 wiring board.

[Brief explanation of drawings]

Figure 1 is a sectional view of the present invention, Figure 2 is a sectional view of the base material of the present invention, Figure 3 is a sectional view of a photosensitive resin film pasted, and Figure 4 is a sectional view of the substrate of the present invention.
The figure is a cross-sectional view after removing the photographic film and irradiating it with ultraviolet rays.
The figure shows the developing place 1! l L, cross-sectional view of the plate, Figure 6 is electroless plating 11! l l! II is a cross-sectional view of a substrate on which a conductor is formed, and FIGS. 7(a) to 7(d) are front views of a chip-type electronic component. In the drawings, 1 is an insulating substrate, 2 is a catalyst, 3 is the base material, 4
．． 5 is a photosensitive resin film, 12.13 is a photographic film, 15 is an ultraviolet ray, 20.21 is a plating resist, 22 is a conductor, and 4 is a printed wiring board. Patent Applicant: Hitachi Capacitor Co., Ltd. (Volunteer to write procedural amendments) June 13, 1985

Claims (1)

[Claims] (1) An insulating substrate with a catalyst attached to the surface is used as a base material, a photosensitive resin film is pasted on the surface of this base material, a photographic film with a pattern printed on it is placed on the photosensitive resin film, and ultraviolet rays are irradiated. Afterwards, a photosensitive resin film that is developed and cured by irradiation with ultraviolet rays is formed as a plating resist layer of a permanent mask, and the substrate on which this plating resist layer is formed is immersed in an electroless plating solution to form a plating resist layer. A method of manufacturing a printed wiring board in which a conductor of uniform thickness is formed at locations other than the desired thickness, in order to obtain plating resist layers of different thicknesses when pasting the photosensitive resin film. A method for producing a printed wiring board, which comprises laminating one or more photosensitive resin films corresponding to the above to form a plating resist layer having steps.