JPS61264783A - Printed wiring board and manufacture thereof - 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 Field of Application] The present invention relates to a printed wiring board and a method for manufacturing the same.

[Prior Art] A widely used method is to print a copper-clad laminate with an etching resist necessary to form a printed wiring section having a desired pattern, and then to etch the resist.

Further, after forming the printed wiring section, after dissolving and removing the etching ink, the solder resist layer is formed by leaving solder parts such as lands and performing solder resist printing.

[Problems to be Solved by the Invention] However, the formation of the solder resist layer is carried out by silk printing, but as printed wiring parts become more precise and denser, the boundary line between the land part and the solder resist part (
Since the surface (surface) is close to the unit of 1/100, a slight misalignment or a gap with the copper foil thickness (35g) in the printed wiring part may cause the solder resist ink to bleed onto the land part. However, this is a major cause of soldering defects.

Therefore, on the contrary, the occurrence of this bleeding phenomenon is a factor that prevents the increase in the density of printed wiring boards.

Therefore, the present invention has been made by focusing on these problems, and proposes a printed wiring board and its manufacturing method that can prevent the bleeding phenomenon caused by solder resist printing and eliminate soldering defects. This is what I am trying to do.

[Means for Solving the Problems] The present invention provides solder resist printing prior to etching of a copper-clad laminate in the production of a printed wiring section to form a molded area in the printed wiring section, etc. A solder resist layer is formed around the soldered portion.

[Function] By applying solder resist printing to the periphery of the soldering parts such as lands in the printed wiring section on the copper-clad laminate before etching, the bleeding phenomenon caused by the gap in the copper foil thickness can be prevented. Solder resist printing can be performed in a blocked state.

[Example] The method for manufacturing a printed wiring board of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a printed wiring board manufactured by the manufacturing method of the present invention, and FIGS. 2 a to 2 e are explanatory diagrams showing the method of manufacturing the printed wiring board.

In Fig. 1, 1 is an insulating board, 2 is a printed wiring section, and 4 is an insulating board.
Reference numeral 5 indicates a land portion in the printed wiring portion, 5 indicates a solder resist layer applied during etching resist printing around the land portion during formation of the land portion, and 6 indicates a solder resist layer applied after etching is completed.

Now, a method for manufacturing printed wiring board 10 having the following configuration will be explained with reference to FIG. 2. First, as shown in FIG. 2a, solder resist printing 13 is applied to the surface of copper foil 12 of copper clad laminate 11 as etching resist printing necessary for forming a printed wiring board.

However, in printing this solder resist printing 13, only the peripheral portion of the land portion in the printed wiring portion is printed.

Thereafter, as shown in FIG. 2, the land portions and other pattern portions of the printed wiring portion are printed with alkali-soluble ink or other solvent-soluble ink 14.

Therefore, after completing the solder resist printing 13 and the etching resist printing necessary for the printed wiring portion by printing with the alkali-soluble ink 14, the copper-clad laminate 1
By etching the copper foil 12 of No. 1, the printed wiring portion 2 and the land portion 4 can be formed (see FIG. 2C).

Furthermore, after the etching is completed, the alkali-soluble ink 14 on the printed wiring section 2 and the land section 4 is removed (see FIG. 2C), and the solder resist printing 15 is applied to the printed wiring section 2 as shown in FIG. By carrying out this process, printed wiring board 10 shown in FIG. 1 can be formed.

[Effects of the Invention] According to the present invention, since the solder resist around the land portion of the printed wiring board is applied directly to the copper-clad laminate before etching, the thickness of the copper resist when applied after etching is It is possible to provide a highly accurate printed wiring board that can improve the bleeding phenomenon without gaps and is compatible with higher density printed wiring boards.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an embodiment of the printed wiring board of the present invention, and FIGS. 2 a to 2 e are explanatory diagrams showing a method of manufacturing the printed wiring board of the present invention. 2.3...Printed wiring part 4...Land part

Claims (3)

[Claims] (1) A printed wiring board having a solder resist layer applied at the time of etching resist printing to the printed wiring part around the soldered parts such as land parts in the printed wiring part. (2) The printed wiring board according to claim 1, wherein the solder resist layer is a double solder resist layer comprising a solder resist layer applied after etching. (3) In a method for manufacturing a printed wiring board in which etching resist is printed on a copper-clad laminate and then etched, the etching resist is printed on soldered parts such as wiring patterns and lands. At the same time, the printed wiring parts other than the soldered parts such as the lands are printed with an alkali-soluble ink or other solvent-soluble ink, and then etched. A method for producing a printed wiring board, characterized in that the production is performed by peeling off ink.