JPH06179258A - Precision-retaining screen process printing method - Google Patents

Abstract

PURPOSE:To enable high-precision screen process printing for a long period, by a method wherein this is related to a screen process printing form plate, expansion at the time of squeegee sliding is extremely little and moreover printing is made easy to perform by allowing the whole to hold deflection. CONSTITUTION:This is a precision-retaining screen process printing method using a screen printing form plate superior in precision-retaining properties wherein a screen mesh 2 obtained by braiding metallic fibers such as of stainless steel or tungsten is extended over a frame body 1, which is fixed by uncoating the outer circumferential part 2a with a plated coating and coating the central part 2b with an extremely thin plating film, the outer circumferential part 2a is made more easily deflectable than the central part 2b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing method excellent in durability of precision used for automated precision printed circuit printing such as printed circuits, IC circuits and hybrid circuits.

[0002]

2. Description of the Related Art Recently, screen printing has come to play a major role in the electronic industry, and mass production by automatic printing machines has been carried out. Not only is dimensional accuracy improved, but dimensional accuracy continuity is required even more strictly. ing.

Conventionally, the surface of a gauze in which a screen mesh braided from a stainless steel metal or a synthetic fiber such as polyester or nylon is stretched on a rectangular wooden frame or a plate frame such as iron, aluminum or stainless steel. A photosensitive film is formed on the surface of the plate, and the desired image film is superposed on the film to expose it to UV light, and the non-exposed area is washed with water or a weak alkaline aqueous solution and developed to form a pattern. Is used for screen printing.

More recently, a nickel mesh has been fixed to the entire surface by a chemical plating method or a method such as vacuum deposition of a screen mesh formed by braiding stainless steel metal fibers or synthetic fibers such as polyester or nylon.
The whole knitted part is uniformly integrated and coated with a photosensitive resin or photosensitive resin emulsion on the surface and dried to form a photosensitive film of a predetermined thickness. There is known a screen printing method using an improved screen plate which is exposed to light, and the non-exposed area is washed with water or a weak alkaline aqueous solution for development (see JP-A-60-262689).

[0005]

DISCLOSURE OF THE INVENTION In the above prior art,
Screen printing plates that use fiber gauze made of polyester, nylon, etc. are easy to bend, the gap between them and the surface of the material to be printed can be enlarged, and plate separation is good and sharp printing can be done easily. . However, if the gap is large, the elongation of the gauze will be correspondingly large, and the gauze of the gauze will be misaligned, resulting in a large degree of deformation of the printing pattern formed on the gauze,
There is a problem that it is not suitable for precision screen printing because it causes elongation between patterns and deteriorates accuracy.

Further, the screen plate using a metal gauze has a small elasticity, and the elongation of the gauze when the squeegee slides is formed on the gauze as compared with the fiber gauze. Although the deformation of the printing pattern is small and sharp printing can be performed, as the number of printing increases, as shown in 0% of FIG. However, there is a problem that continuous production of is impossible.

On the other hand, the improved screen plate is made of metal because the surface of the braid of the gauze is fixed with a nickel coating and the braided portion is integrally formed, as compared with the screen plate using a metal gauze. Compared to a screen plate using a gauze made of steel, the amount of elongation and displacement of the gauze during sliding of the squeegee during printing is smaller, and the plastic deformation of the gauze due to printing pressure is less, which improves accuracy. Since the entire screen plate has a small amount of deflection, it has poor elasticity and poor plate separation, lacks in rubability, and has a small opening in the gauze, making it difficult to pass the paste and continuous printing of fine lines of 100 μm cannot be performed. There was a problem.

[0008]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention has a screen mesh braided with metal fibers such as stainless steel, which is stretched around a frame body, and an outer peripheral portion of the screen mesh is stretched. Instead of plating, the central portion forming the printing pattern is coated with an extremely thin coating so that the outer peripheral portion is easier to bend than the central portion to improve printability, and printing accuracy can be maintained for a long time. It is a characteristic screen printing method.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, one embodiment of the present invention shown in the drawings will be described in detail. Reference numeral 1 is a rectangular plate frame made of an aluminum pipe of 880 x 880 mm. Reference numeral 2 is a stainless screen mesh in which stainless steel metal fibers are braided into a 250 mesh, and is stretched around the plate frame 1 to form an outer peripheral portion 2
As shown in FIG. 3, a is not coated with plating as shown in FIG. 3, and the central portion 2b forming the printing pattern is coated with plating coatings 1 to 3 as shown in FIG.
The entire surface is formed with a thickness of about 7 μ. The size of the central portion 2b is 730 × 730 mm, and a non-plated stainless steel screen mesh 2 having a width of 270 mm is formed so as to surround the outer periphery of the central portion 2b.

Next, the operation will be described. As shown in FIGS. 5 and 6, a printing pattern is formed on the stainless steel screen mesh 2b at the central portion, and the central portion 2b is slid by the squeegee 4 to print the ink on the printed material 5.

Next, the experimental results on the elongation and restoration of the gauze during printing and the passage of the paste by the method of the present invention will be described. Samples with different plating thickness were prepared on stainless steel 250 mesh wire diameter 30μ and subjected to autograph.
Got Printing was performed on the same sample in order to see the amount of paste passing, and the data in Table 2 was obtained. At a plating thickness of 1.0 μm to 5.0 μm, there was no change in the paste passage amount even when the opening was narrowed. Therefore, the gauze up to a plating thickness of about 5.0 μm was broken without reducing the ink passage amount. It was found that the elongation can be reduced to about 1/6.

[Table 1]

[Table 2]

Next, in order to examine the easiness of printing, the state in which the frame is covered with gauze is set to 10 kg-f from the embodiment, and +5 at the time of printing.
Assuming that the force of kg-f is high, the sample is prepared by extending it to 15 kg-f by plating the central part of the sample with 3 μm plated on the entire surface and the sample without plating at all. Then, as a result of stretching with an autograph, Table 3 was obtained. As a result, the elongation percentage in the practical range was almost the same for the sample having the center portion plated with 3 μm and the sample having no plating at all, which was made of stainless steel only.

[Table 3]

From this, it can be judged that the ease of printing does not change even when thinly plated. Next, in order to know how this elongation was distributed and remained in the plated portion and the non-plated portion, the samples before and after the elongation test were measured and Table 4 is shown.
Got From this result, the sample having 10% non-plated portions on both ends of the entire length had a residual elongation of 3.5 times that of the entire plating in the entire sample length, but the elongation residual in the plated portion was equivalent. In addition, the sample plated with 50% in the central portion had a three-fold elongation over the entire length as compared with the total plating, but the plated portion had a half elongation. In addition, the total elongation% residue was 1/8 compared to the whole non-plated sample, and it was 1/30 when only the plated part was taken.

[Table 4]

From the above experiment, an automatic printing machine using the screen printing plate obtained by fixing the squeegee driving part with an extremely thin plating without applying the plating to the outer periphery Printing was carried out to test the accuracy maintenance and the sharpness of the printed matter.

FIG. 9 shows the resulting dimensional accuracy data. Although the printing sharpness was almost unchanged, all the plating plates (100%) had bleeding on the way and the plates were washed. It happened to be necessary.

[0016]

According to the present invention, a stainless steel,
A screen mesh made of braided metal fibers such as tungsten is stretched around the frame body, and the outer peripheral portion is not plated and fixed by applying an extremely thin plated coating to the central portion forming the printing pattern, Since the outer peripheral portion is made easier to bend than the central portion, the central portion where the pattern is formed is less likely to be deformed, and the flexibility of the outer peripheral portion can be improved, so that it is easy to rub and high-precision screen printing. It can be performed.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a right side view of FIG.

FIG. 3 is a partially cutaway enlarged view of the peripheral portion of FIG.

FIG. 4 is a partially cut enlarged view of a central portion of FIG.

FIG. 5 is a plan view of FIG. 1 in use.

FIG. 6 is a front view of FIG.

FIG. 7 is a graph of plating thickness and breaking strength of FIG.

FIG. 8 is a graph of plating thickness and elongation of FIG.

FIG. 9 is a graph of the number of prints and the dimensional change of a printed matter according to the present invention.

[Explanation of symbols]

 1 plate frame 2 stainless steel screen mesh 2a outer peripheral portion 2b central portion 3 plating coating 4 squeegee

Claims (1)

[Claims] 1. A stainless steel, tungsten, etc.,
A screen mesh in which metal fibers are braided is stretched around a frame body, the outer peripheral portion is not plated, and the central portion forming the printing pattern is fixed by applying an extremely thin plated coating, and the central portion is fixed. A precision continuous screen printing method using a screen printing plate which is more flexible in the outer peripheral portion and has excellent precision durability.