JPS6127740B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a mold for punching and press-forming a desired circuit pattern on a circuit board, and in particular, a method for manufacturing a mold for punching a circuit pattern using a photoetching method. Regarding.

The conventional method of manufacturing this type of mold using the photoetching method, for example, involves a process of uniformly filling resin into the relief grooves of a punched metal foil formed in advance, and a two-step photoresist process. It was meant to be. Here, the resin embedding process is
Treatment is carried out by uniformly filling the relief grooves formed on the surface of the mold material with a corrosion-resistant epoxy resin, etc., but the resin filling process itself requires considerable effort and skill. First, during the photoresist process after filling the resin, not only does it require similar skill to align the film, but also the filled resin must be uniformly removed at the final stage, making it a complicated work step. It was extremely difficult to obtain molds of the required quality compared to the proportion of molds that had gone through the process.

An object of the present invention is to provide a method for manufacturing a die for punching circuit patterns, which solves the problems inherent in the conventional method and makes it possible to easily obtain a die of consistently high quality through a simpler process. It's about doing.

Another object of the present invention is to easily provide both the first and second circuit covering patterns necessary for forming a desired circuit pattern on the surface of the mold material. It is an object of the present invention to provide a new method that can quickly align these two covering patterns.

To this end, according to the method of the present invention, a negative photoresist film or the like is used to form a first circuit pattern so as to occupy the edge or contour of the desired circuit pattern on the surface of the mold material that has been subjected to a predetermined treatment. Starting from forming a covering pattern, this covering pattern
Immediately on top of the turn, a second circuit covering pattern containing the required circuit pattern and having a size moderately larger than the first circuit covering pattern is formed by using a positive photoresist film or the like having a weaker resistance compared to the quality of the pattern. The main point is to form a circuit pattern, and then, after removing the remaining exposed metal part by etching to form an escape groove of the punched metal foil in the part adjacent to the required circuit pattern, the second circuit pattern is removed. The coating pattern for circuits is appropriately peeled off with a stripping solution or a developer after exposure, and the metal portions exposed in the first coating pattern for circuits are removed by etching, and finally the first coating pattern for circuits is removed. The feature is that the outline of the required circuit pattern is formed in the shape of a protruding knife by peeling off.

Hereinafter, the present invention will be described in further detail with reference to an embodiment shown in the accompanying drawings.

The surface of the mold material 1 to be used shown in FIG. Appropriate chemical surface treatment such as pickling with phosphoric acid or the like is carried out. As shown in FIG. 2, a photoresist film 2 is quickly applied to the surface of the mold material 1, which has been subjected to surface preparation treatment, before it is oxidized. This photoresist film 2 is formed by exposing it to light using a negative photoresist film 16 shown in FIG. 3, which will be described later.
It is possible to form the first circuit covering pattern 3 that sufficiently occupies the edge, that is, the outline, of the required circuit pattern shown in FIG. 3. Next, as shown in FIGS. 4 and 5, a positive photoresist film 4 is uniformly coated on the surface of the mold material including this pattern 3, and this film 4 is exposed using positive photoresist films 17 and 18, which will be described later. Then, a second circuit covering pattern 5 which is laminated on the covering pattern 3 and is appropriately larger than the covering pattern 3 is obtained. Here, each of the qualities of the above-mentioned covering patterns 3 and 5 has certain conditions. For example, one covering pattern 3 uses a rubber-based or polycinnamic acid-based negative type photoresist,
The other coating pattern 5 is formed by applying a diazo positive type photoresist to photocuring the first circuit coating pattern 3, and then applying a developer for the second circuit coating pattern 5. Alternatively, it is preferable to use a material that is not removed by a stripping solution and has appropriate resistance. Under these selection conditions, the first circuit coating pattern 3 made of a negative type photoresist after photocuring is eroded by the alkaline developer used for the second circuit coating pattern 5 made of a positive type photoresist. Since the fear is eliminated, it becomes possible to suitably implement the steps of the present invention described below.

The metal portion exposed in the area adjacent to the covering pattern 5 of FIG. 1 obtained as described above is then etched away to a required depth as shown in FIG. . The etching solution used at this time is usually heated to about 50°C and heated to about 37°C.
A Be ferric chloride solution is common, but other etching solutions that do not attack the photoresist or this second circuit coating pattern 5 can be used. Next, when the entire surface of the positive type photoresist film as the covering pattern 5 is exposed and only this positive type photoresist film is removed using a developer, the first circuit covering pattern 3 is formed as shown in FIG. It will appear. Since the developer used here does not attack the negative type photoresist forming the covering pattern 3, the covering pattern 3 formed from FIG. 3 is maintained as it is. In that case, if the negative type photoresist used is resistant to the stripping solution of the positive type photoresist, there is no need to expose the entire surface to light, and the positive type photoresist film can be immediately removed with the stripping solution after the etching shown in FIG. 6. . For example, when using Shippley's AZ (trade name) as a positive type photoresist and Kodatsuk's KTFR (trade name) as a negative type photoresist, it is appropriate to use AZ because it can be easily removed with methyl ethyl ketone. By performing the treatment for a certain period of time, there is no possibility that the KTFR circuit covering pattern 3 will be damaged. By the above method, the positive type photoresist film is peeled off and the mold material in the pattern 3 is etched away to a required depth as shown in FIG. 8, so that a recess 7 can be formed there. The recess 7 requires a depth of about 0.1 mm, and at this time, an overhang (burr) 8 of the side etching is also formed, although it is slight. Next, remove the negative type photoresist as pattern 3 using the specified stripping solution.
Then, the blade part 9 matches the outline of the required circuit pattern.
can be formed. Figure 9. An overhang 8 is left on the blade 9, but this can be removed by dipping it in an etching solution for a short time. In such an overhang portion, the chemical reaction can be carried out quickly, so that it can be carried out without adversely affecting other parts. Further, in order to keep the overhang portion to a small amount, it is effective to add a side etch inhibitor to the etching solution. This is based on the characteristic that a chelate compound is formed with the metal wall surface of the mold, and the etching speed of the wall surface portion where the spray pressure of the etching solution is low is slower than that of the bottom portion where the spray pressure is high. The mold shown in FIG. 1 obtained by removing the overhang portion as described above can be used as a mold as it is.

In the above, in order to form both the first and second circuit covering patterns 3 and 5, as shown in FIG. Positive films 17 and 18 corresponding to the above are prepared in advance. As is clear from FIG. 3, the negative film 16 is constructed to have a line drawing pattern N extending by X mm on both sides from the side edge of the desired circuit pattern O, that is, from the contour line 1, while the negative film 17 is As shown in FIG. 2 2 and FIG. 3 2, a line drawing pattern P ₁ is formed by extending X mm on both sides of a line separated by Y mm from the contour line 1 of the required circuit pattern O. Regarding the other negative film 18, Similarly, the contour line 1 is uniformly expanded by Y mm to form a line drawing pattern _P2 . X
The values of Y and Y can be determined depending on the size of the mold to be manufactured as shown in FIG. 6, and can be defined, for example, by the following equation.

X=C/E+D/2 Y=B/E+D/2 However, the above formula is subject to the following conditions.

2C/E<x<A Here, A: Required circuit pattern dimensions B: Depth of relief groove 6 of punched metal foil C: Depth of recess 7 D: Required size of tip of blade portion 9 E: Etching factor Negative and positive films 16 as described above,
17 and 18 can be easily obtained by suitably manipulating the exposure conditions when reversing the corresponding master film 10. 4 and 5 show one method, in which a transparent polyester film 11 having an appropriate thickness is placed between a master film 10 and an unexposed film 1.
If these are integrated into a sandwich pattern by being interposed between them and exposed to light, it becomes extremely easy to adjust the adjustment of each of the line drawing patterns N or P ₁ and P ₂ . Such adjustment of the line width can be achieved by appropriately changing the thickness of the intervening polyester film 11. For example, when using a polyester film 11 with a thickness of 100 μm, the result is
It is possible to obtain line width thinning or thickening of 110 μm. In addition, by controlling the exposure amount, even more
It is also possible to adjust the line width by a minute amount of 30 μm or less.

The film whose line width has been adjusted by the above method is
To make negative film 16, positive film 1 is made thinner by X mm than the required circuit pattern width as shown in Figure 5.
Prepare negative film 15 that is 4 and X mm thick.
By exposing these two types of films with their film surfaces aligned as shown in the figure, a pattern corresponding to the difference between the positive film 14 and the negative film 15 is formed on the unexposed film 12 with the outline 1 of the desired circuit pattern as the center. It is formed as a pattern with a line width of 2Xmm.
In order to obtain the positive film 17, similarly, centering on the part that is Ymm thicker than the required circuit pattern width, use the positive film 14 that is Xmm thinner and the negative film 15 that is Xmm thicker to make the area Ymm thicker than the required circuit pattern width. It is possible to form a pattern with a line width of 2Xmm centered on the raised area.

Next, a positive film 18 that is Ymm thicker than the required circuit pattern is made in the same manner. Then, about 4 to 5 minutes of negative type photoresist is applied onto the mold material by dipping, spinner, spraying, etc.
1.3 is obtained by applying a .mu.m coating, pre-baking, exposing a line pattern with a line width of 2Xmm centering on the outline 1 of the desired circuit pattern using the negative film 16, and developing it with a specified developer. can. Similarly, apply positive type photoresist 4 to approximately 〓〓〓〓〓
After coating 5 to 7 μm, the above-mentioned positive film 17 is aligned on the line drawing pattern 3 formed by the above-mentioned negative type photoresist through pre-baking, and the above-mentioned positive film 18 is applied on top of the above-mentioned positive film 17.
By aligning the two sheets of positive film and developing with a designated developer, a layered circuit covering pattern 5 can be formed on the pattern 3.

According to the method of the present invention, as described above, after forming both the first and second circuit covering patterns, an escape groove for the punched metal foil is immediately provided. Not only does the work of filling the grooved portion with resin become unnecessary, but also the formation of both of the patterns described above can be made simple and accurate. Therefore, it is possible to efficiently manufacture high-quality molds by reducing the number of man-hours as much as possible.

[Brief explanation of the drawing]

1 to 9 are conceptual diagrams for explaining the process of the present invention, and FIGS. 2 1 to 3 show both negative and positive patterns used in forming both the first and second circuit covering patterns. Film composition diagram, Figure 3 1, 2
2 is an explanatory diagram for FIG. 2, FIGS. 4 and 5 are diagrams showing an example of manufacturing each of the films shown in FIG. 2, and FIG. 6 is a partially enlarged view of a completed mold. 1... Mold material, 3... First circuit covering pattern, 5... Second circuit covering pattern, 6...
Relief groove of punched metal foil, 7... Recessed part, 8... Blade part, 10... Master film, 11... Polyester film, 12... Unexposed film, 16
... Negative film, 17 ... Positive film, 18
...Positive film. 〓〓〓〓〓

Claims (1)

[Claims] 1. In a method of manufacturing a mold for punching and molding a circuit pattern from metal foil, a first circuit covering pattern that occupies the edge of the required circuit pattern is formed on the hardened and smoothed surface of the mold material. , forming a second circuit covering pattern larger than the required circuit pattern on the first circuit covering pattern, and then removing the metal portion exposed on the surface of the mold material to form an escape groove for the punched metal foil; and, after peeling off the second circuit covering pattern and removing the exposed metal portion surrounded by the first circuit covering pattern to a required depth, peeling off the first circuit covering pattern. A method for manufacturing a die for punching a circuit pattern, comprising the steps of: