JPH04314384A - Manufacture of printed wiring board - Google Patents

Abstract

PURPOSE:To improve marking position accuracy by applying photosensitive liquid-type marking ink to both sides and dried, by laminating and exposing a specified mask film and by developing an unexposed part of photosensitive liquid-type solder resist and ink simultaneously. CONSTITUTION:Photosensitive liquid-type marking ink 6a is applied to one side of a substrate 1 whereto photosensitive liquid-type solder resists 2a, 2b are applied and dried. Then, photosensitive liquid type marking ink 6b is applied to the other side of the substrate 1 and dried. A specified mask film 3b is laminated on both sides of the substrate 1 and positioned, and ultraviolet ray energy is irradiated and exposed. An unexposed part 4b of photosensitive liquid-type solder resists 2a, 2b and an unexposed part 4b of photosensitive liquid-type marking inks 6a, 6b are developed and removed by potassium sodium carbonate water solution simultaneously, and a specified solder resist 5 and a marking 7 are formed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a printed wiring board, and more particularly to a method for manufacturing a printed wiring board including a solder resist process and a marking process.

0002

[Prior Art] For high-density printed wiring boards, a photographic method using a photosensitive liquid solder resist is generally used instead of the conventional screen printing method for solder resist used to prevent solder bridging on printed wiring boards. It is true. Furthermore, in recent years, photographic methods using photosensitive liquid markings have also come to be used for markings used to display parts.

4(a), (b) and FIG. 5(a), (1) regarding the manufacturing method of the solder resist process using this photographic method.
This will be explained using b).

First, as shown in FIG. 4(a), circuits are formed on both sides of the substrate 1. Next, as shown in FIG. 4(b),
A photosensitive liquid solder resist 2a is applied to one side and dried in a hot air circulating oven. Next, a photosensitive liquid solder resist 2b is applied to the other surface of the substrate 1. Furthermore, Fig. 5 (a
), a predetermined mask film 3a is superposed and positioned on both sides of the substrate 1, and exposed. Next, Fig. 5(b)
), the unexposed portion 4a is developed and removed, a predetermined solder resist 5 is formed, and the solder resist 5 is thermally hardened in a hot air circulating oven at about 150°C.

Next, a manufacturing method using a marking process using a photographic method will be explained with reference to FIGS. 6(a) and 6(b) and FIG. 7. First, as shown in FIG. 6(a), the above-mentioned FIG. 5(b)
) A photosensitive liquid marking ink 6a is applied to one side of the substrate on which the solder resist 5 is formed and dried in a hot air circulating oven. Next, a photosensitive liquid marking ink 6b is applied to the other surface of the substrate 1 and dried in a hot air circulating oven. Furthermore, as shown in FIG. 6(b), a predetermined mask film 3b
are superposed and positioned on both sides of the substrate 1, and exposed. Next, as shown in FIG. 7, the unexposed portion 4b is removed by development, a predetermined marking 7 is formed, and the resultant is thermally cured in a hot air circulating oven at about 150°C.

[0006]

[Problems to be Solved by the Invention] This conventional printed wiring board manufacturing method has the following problems.

(1) Since the solder resist is thermally hardened before the marking process, the dimensions of the substrate are greatly expanded and contracted, resulting in poor marking position accuracy.

(2) Since the manufacturing process is long and complicated, productivity is extremely low.

An object of the present invention is to provide a method of manufacturing a printed wiring board with good marking position accuracy and high productivity.

0010

[Means for Solving the Problems] The method for manufacturing a printed wiring board of the present invention includes the steps of applying a photosensitive liquid solder resist to both sides of a circuit-formed circuit board, drying it, overlaying it with a predetermined mask film, and exposing it to light. The method includes a step of applying a photosensitive liquid marking ink to both sides, drying it, overlapping a prescribed mask film, and exposing it to light; and a step of simultaneously developing the unexposed portions of the photosensitive liquid solder resist and the photosensitive liquid marking ink. configured.

[0011]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1(a), (b), FIGS. 2(a), (b)
3(a) and 3(b) are cross-sectional views showing an embodiment of the present invention in the order of steps.

First, as shown in FIG. 1(a), circuits are formed on both sides of a substrate 1. Next, as shown in FIG. 1(b), a photosensitive liquid solder resist 2a is applied to one side of the substrate 1 using a spray coater method, and dried for 10 to 30 minutes in a hot air circulating oven at 80°C to 100°C. . Next, a photosensitive liquid solder resist 2b is applied to the other surface of the substrate 1 using a spray coater method, and dried for 10 to 30 minutes in a hot air circulating oven at 80 to 100°C. Furthermore, as shown in FIG. 2(a), a predetermined mask film 3a is superposed and positioned on both sides of the substrate 1, and exposed to ultraviolet energy of 400 to 1000 mJ/cm<2>. Next, as shown in FIG. 2(b), a photosensitive liquid marking ink 6a is applied by a spray coater method to one surface of the substrate 1 coated with the photosensitive liquid solder resists 2a and 2b, and heated to 80°C to 100°C. Dry in a hot air circulation oven for 10 to 30 minutes. Next, the photosensitive liquid marking ink 6b is applied to the other surface of the substrate 1 using a spray coater method, and dried for 10 to 30 minutes in a hot air circulating oven at 80°C to 100°C. Furthermore, as shown in FIG. 3(a), a predetermined mask film 3b is superposed and positioned on both sides of the substrate 1, and exposed to ultraviolet energy of 400 to 1000 mJ/cm<2>. Next, as shown in FIG. 3(b),
Unexposed portion 4a of photosensitive liquid solder resist 2a, 2b
and the unexposed area 4 of the photosensitive liquid marking ink 6a, 6b.
b is simultaneously developed and removed using a 0.5 to 3.0% aqueous sodium carbonate solution to form a predetermined solder resist 5 and markings 7.

[0014] Furthermore, the coating method of the photosensitive liquid solder resist and the photosensitive liquid marking ink on the substrate may be replaced by the above-mentioned spray coater method and may be carried out by a method such as a curtain coater method, a roller coater method, or a screen printing method. You can also do it.

[0015]

[Effects of the Invention] As explained above, the manufacturing method of the present invention has the following effects.

(1) Since there is no step of thermally curing the photosensitive liquid solder resist before the marking application and curing steps, there is no dimensional expansion or contraction of the substrate, and the marking position accuracy is good.

(2) Since the unexposed areas of the photosensitive liquid solder resist and the unexposed areas of the photosensitive liquid marking ink are developed and removed at the same time, the manufacturing process is shortened and simplified, and productivity is significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of the present invention in the order of steps.

FIG. 2 is a perspective view showing an example of the present invention in the order of steps.

FIG. 3 is a perspective view showing an example of the present invention in the order of steps.

FIG. 4 is a perspective view showing the order of steps for explaining an example of a conventional solder resist forming method.

FIG. 5 is a perspective view showing the order of steps for explaining an example of a conventional solder resist forming method.

FIG. 6 is a perspective view showing an example of a conventional marking forming method in order of steps.

FIG. 7 is a perspective view illustrating an example of a conventional marking forming method.

[Explanation of symbols]

1 Substrates 2a, 2b Photosensitive liquid solder resists 3a, 3
b Mask film 4a, 4b Unexposed area 5 Solder resist 6a, 6b Photosensitive liquid marking ink 7
marking

Claims (1)

[Claims] 1. A step of applying a photosensitive liquid solder resist on both sides of a circuit-formed circuit board, drying it, overlaying a prescribed mask film, and exposing it to light; applying a photosensitive liquid marking ink on both sides, drying it, and applying a prescribed mask film; A method for manufacturing a printed wiring board, comprising the steps of overlapping and exposing films, and simultaneously developing unexposed areas of the photosensitive liquid solder resist and the photosensitive liquid marking ink.