JPH0664344B2 - Screen printing plate - Google Patents

Description

The present invention relates to a screen printing plate.

(Prior Art) Conventionally, when a circuit is formed by electroless copper plating, a screen printing plate is applied to an insulating substrate to apply a plating resist ink to print the plating resist, and then the plating resist is immersed in an electroless plating tank. Has a copper plating tank.

(Problems to be Solved by the Invention) By the way, in the conventional screen printing plate, one kind of emulsion is applied to make a plate. Therefore, for example, when a high-sensitivity agent is used, the plate making time can be shortened and it can be used for a stainless screen having a long exposure time, but the ultraviolet rays and the like used for curing the emulsion diffusely reflect on the screen and are unnecessary. There was a defect that the emulsion was hardened to a part. Further, when a low-sensitivity emulsion is used, there is a drawback in that long-time exposure is required and image distortion and the like occur.

It is an object of the present invention to provide a screen printing plate which improves the above drawbacks, prevents unnecessary emulsion hardening and image distortion, and can be produced in a short time.

(Means for Solving the Problems) In order to achieve the above object, the present invention is characterized in that two or more emulsion layers having different sensitivities are provided in the order of decreasing sensitivity as the distance from the screen increases. It provides a screen printing plate.

(Function) According to the present invention, since two or more emulsion layers having different sensitivities are provided in the order of decreasing sensitivity with increasing distance from the screen, unnecessary emulsions are cured even when light is diffusely reflected by the screen. Can be reduced.

(Example) Hereinafter, the present invention will be described based on illustrated examples.

In FIG. 1, reference numeral 1 denotes a screen in which a gauze made of stainless steel, tetron, nylon or the like is attached to a frame. Reference numeral 2 is a first layer composed of a high-sensitivity emulsion coated on the screen 1. 3 is this high sensitivity first layer 2
Is a second layer consisting of a less sensitive emulsion coated on the surface of.

There are a direct method, a wet direct method, an indirect method and the like for manufacturing the above-mentioned embodiment, and a manufacturing method by the direct method will be described. First, paste the gauze on the frame. Next, as shown in FIG. 2, an emulsion having high sensitivity is applied to the screen 1 constituted by sticking the gauze and dried to form the first layer 2. After forming the high-sensitivity first layer 2, as shown in FIG. 3, a low-sensitivity emulsion is coated on the surface and dried to form the second layer 3. After forming the second layer 3 having a low sensitivity, the negative 4 is placed on the surface of the layer 3 as shown in FIG. 4, exposed, developed and dried. That is, the exposure causes the ultraviolet rays 5 to pass through only a predetermined portion to harden the emulsion 6 only in the portions irradiated with the ultraviolet rays 5. After hardening a part of the emulsion, the remaining uncured emulsion 7 is dissolved in a solvent and removed.

That is, according to the above-mentioned embodiment, even if the ultraviolet ray 5 is diffusely reflected by the screen 1, the portion where the reflected light 8 of the ultraviolet ray 5 spreads is formed by the second layer 3 made of a low-sensitivity emulsion, and therefore unnecessary. The emulsion part, which is a large part, is hardly cured.

For example, the results of producing a 250 mesh stainless screen printing plate are shown in the table. As the emulsion, three types of high sensitivity type F, intermediate sensitivity type P and low sensitivity type S manufactured by US Photo Product Co. are used. There is. High sensitivity type F, intermediate sensitivity type P and low sensitivity type S
Emulsion is a 225-mesh white polyester screen printing plate coated with a thickness of 14 μm, and the sample is cured by irradiating it with ultraviolet light from a high-pressure mercury lamp with an output of 4 KW placed 1 m apart. Exposure is 200 each
^{~500mJ / cm 2, 500~800mJ / cm} 2 and 1000~1500mJ / cm ²
Shall be In Example 1, the first layer has a thickness of 7
To 9 μm and cured by primary exposure to form a second layer with a thickness of 5
It is set to 7 μm and cured by secondary exposure. Example 2 is the first
The thickness of each of the layers to the third layer is 5 to 7 μm, the first layer is cured by the primary exposure, and the second layer and the third layer are cured by the secondary exposure. In Conventional Example 1 and Conventional Example 2, the first layer has a thickness of 14 μm and is exposed and cured by temporary exposure. Further, the fogging width represents the width of the unnecessary hardened portion of the emulsion.

As is clear from Table 1, according to the present invention, the fog width was 1/2 or less as compared with the conventional example, and the printing accuracy was further improved.

In contrast to the present invention, two emulsion layers having different sensitivities are arranged in the order of increasing sensitivity with increasing distance from the screen.
With respect to the comparative example in which the layers were provided, the fog width and the printing resistance (life of the screen printing plate) were measured to find problems. The present invention has the same configuration as that of the first embodiment shown in Table 1. In Comparative Examples A and B, a layer closer to the screen was formed with a low-sensitivity emulsion to a thickness of 7 to 9 μm, and a high-sensitivity emulsion was used on this layer to a thickness of 5 to 7 μm. It is configured to have a sano layer. The measurement results are shown in Table 2.

As is clear from Table 2, according to the present invention, compared with Comparative Examples A and B, the fog width is 2/3 or less and the printing resistance is
2.5 times or more.

(Effects of the Invention) As described above, the present invention provides two or more emulsion layers having different sensitivities in the order of decreasing sensitivity with increasing distance from the screen. Even if it is short, it can be completely cured. Therefore, (a) printing accuracy can be improved, the printed wiring board can be more and more finer in recent years, (b) printing resistance when printing can be improved, and (c) reflected light It is possible to obtain a screen printing plate which has a small effect and has a small fogging width.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIGS. 2 to 4 show the manufacturing process of the embodiment of FIG. 1, and FIG. 2 shows a state in which a high-sensitivity emulsion layer is formed on a screen. A cross-sectional view, FIG. 3 is a cross-sectional view of a state in which a low-sensitivity emulsion layer is formed, and FIG. 4 is a cross-sectional view of an exposed state. 1 ... Screen, 2 ... Layer consisting of high-sensitivity emulsion, 3 ... Layer consisting of low-sensitivity emulsion.

Claims (1)

[Claims] 1. A screen printing plate comprising a frame and a screen on which an emulsion layer is formed.
A screen printing plate comprising two or more emulsion layers having different sensitivities in order of decreasing sensitivity with increasing distance from the screen.