JPS59201480A - Method of producing marking film - 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 Technical Field of the Invention The present invention relates to a method for manufacturing a printed circuit board, and more particularly to a method for manufacturing a marking film.

(bl Technology Background Marks are generally displayed on printed circuit boards using silk printing or photo solder resist, but in this case, printing ink may flow into through-hole plated holes, or characters or symbol marks may be lost. In order to avoid
These marks must be avoided from touching the lands of the printed circuit board. However, silk printing and FoI
・The production of marking film for making masks such as solder resists is difficult to automate because it contains special characters and symbols, and it still relies on manual labor, making it impossible to obtain sufficient quality. It is.

(C1 Conventional technology and problems) To manufacture a marking film, first a bottom drawing of the marking film is created according to the marking drawing, then a negative film of the marking film is created, and then the marking film is created by reversing it. Figure 1 shows the conventional marking film. Figure 1 (fat) shows the method for manufacturing the lower part of the marking film, and Figure 1 (b) shows the completed marking film.

The conventional marking film below is created by placing a transparent film 3 on top of the surface pattern film 1 as shown in Figure 1 (al).
are overlapped, and letters and symbol marks 5 printed in advance on the transparent film are pasted onto the cut-out film 3 while avoiding the land portions 4 of the surface pattern film 1. 1st
The marking film shown in Figure 2 below is created in this way, and the portion 6 where the characters and symbol marks 5 overlap with the land portions 4 of the surface pattern film 1 is cut out. A negative film is produced and further reversed to produce the marking film shown in FIG.

However, when attaching the characters and symbol marks 5 to the cut-out film 3, I did not notice that the characters and symbol marks 5 overlapped with the land portions 4 of the surface pattern film 1, and this was overlooked during the inspection process, resulting in silk printing. It was not until after making a mask such as a photo solder resist and printing it on a printed circuit board that it was noticed that the characters or symbol marks were hanging onto the land portion of the printed circuit board, so that a sufficiently satisfactory quality could not be obtained. Further, it takes a lot of time to delete the portions where the characters or symbol marks 5 overlap the land portions 4 of the surface pattern film 1, or to check for deletions that have been forgotten.

(dl Purpose of the Invention The purpose of the present invention is to remove characters and symbol marks that overlap the land portions in the process of manufacturing marking films by photolithography, and to prevent the characters or symbol marks from hanging on the land portions of printed circuit boards. The purpose of the present invention is to provide a method for manufacturing a marking film.

tel Structure of the invention and its purpose is to create a negative film by photo-reversing the bottom drawing created according to the instructions of the marking drawing, and then to manufacture a marking film from a film that is photo-composed by overlaying the negative film with a surface pattern film similar to a print base. This is achieved by doing.

(fl　Embodiments of the invention The present invention will be explained in detail below with reference to the accompanying drawings.

The same objects are represented by the same symbols throughout the text.

FIG. 3 shows an example of a method for creating the drawing below, in which letters and symbol marks 5 printed in advance on a transparent film are cut out according to the instructions on the marking drawing, and the film 3 is cut out.
Paste the marking film to create the diagram below. However, even if there is a character or symbol mark 5 that is likely to overlap the land portion 4 of the surface pattern film 1, there is no need to cut out that portion.

FIG. 4 is an example of a method for manufacturing a marking film. FIG. 4 (al indicates an example, and FIG. 4(b) shows details.

A negative film 8 is created by photographic reversal from the above-mentioned lower drawing of the marking film. As shown in FIG. 4(b), this negative film 8 has a transparent portion 9 of characters and symbol marks, and when the surface non-coon film 1 is superimposed on this, a surface pattern film of characters and symbol marks is formed. A portion 10 overlapping the land portion 4 of the surface pattern film 1 is removed by the land portion 4 of the surface pattern film 1. In this way, a composite photograph is created by overlapping the negative film 8 and the surface pattern film 1, and a negative film is made from this film and further reversed to produce a marking film.

According to this embodiment, the characters and symbol marks that overlapped with the land parts in the marking film production process shown in FIG. is discovered. Further, when creating a lower diagram, the time required to delete the portion where the characters or symbol mark 5 overlaps the land portion 4 of the surface pattern film 1 or to check for deletion is reduced, and the manufacturing time of the marking film is shortened.

fgl Effects of the Invention As described above, according to the present invention, in the process of making a mask such as silk printing or photo solder resist and printing it on a printed circuit board, it is possible to prevent characters or symbol marks from hanging on the lands of the printed circuit board. It is possible to provide a method for manufacturing a marking film that does not require a marking film.

[Brief explanation of drawings]

Fig. 1 shows a conventional method for producing the bottom drawing of a marking film, Fig. 2 shows a completed marking film, Fig. 3 shows an example of a method for producing the bottom drawing, and Fig. 4 shows an example of a method for producing a marking film. shows. In addition, Fig. 1 (a) shows the method for manufacturing the marking film, Fig. 1 (bl is the bottom drawing of the completed marking film, Fig. 4 ta+ shows an example of the method for producing the marking film, and Fig. 4 (b) shows the details. In the figure, 1 is a surface pattern film, 2 is a marking film (lower diagram), 3 is a transparent film, 4 is a land area, 5 is a letter or symbol mark, 8 is a negative film, 9 is a transparent part of a letter or symbol mark, 10 shows the part where the characters and symbol mark overlap with the land part of the surface pattern film.

Claims (1)

[Claims] 1. A method for producing a marking film, which comprises the steps of photo-reversing a lower drawing of a marking film produced according to a drawing to produce a negative film, and superimposing the negative film on a surface pattern film of a printed circuit board for photocomposition.