JPH06143855A - Screen printing plate and production thereof - Google Patents

Abstract

PURPOSE:To eliminate the build-up of the edge part of a printing film and to enhance the surface accuracy of the printing film in screen printing widely used in the production of various electronic parts as pattern forming technique. CONSTITUTION:An emulsion layer is formed on a screen as a double structure consisting of first and second emulsion layers 11, 12 and the opening area of the first emulsion layer 11 is planned so as to be smaller than a desired printing shape and the opening area of the second emulsion layer 12 is set to the desired printing shape to realize screen printing wherein the build-up of the edge part of a printing film is suppressed and the uniformity of the thickness of the film is excellent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing plate and a method for manufacturing the same in a screen printing method which is widely used for forming wiring patterns and manufacturing electronic parts such as printed capacitors.

[0002]

2. Description of the Related Art A screen printing method is one of the most widely known and practically used techniques for forming desired patterns, and is widely used in various fields, particularly in the electronic component industry.

In addition, with the recent miniaturization and high precision of electronic components, the demand for proportionally high precision and high quality of the printed coating film by screen printing is ever increasing. .

The screen printing method is carried out by using a plate in which an aperture layer having a desired printing shape is prepared by a photolithography method in an emulsion layer formed on a fine mesh screen of stainless steel, nylon, silk or the like. By using a rubber squeegee or the like, a paste mainly composed of a pigment, an organic binder and an organic solvent is extruded from the above-mentioned apertures onto a material to be printed to form a coating film having a desired shape.

Here, the conventional screen printing plate is shown in FIG.
As shown in (a), the emulsion layer 1 is basically a single layer,
Moreover, the area of the opening 5 of the screen 3 is generally designed to be equal to the desired print shape. In addition, 4 in the figure
Indicates a plate frame.

[0006]

However, in the above-mentioned structure, as shown in FIG. 5B, the edge portion E of the printed coating film corresponding to the edge portion of the opening portion of the emulsion layer is in the central portion. There is a problem of swelling in comparison, which is a major problem for printed coatings related to electronic parts, which require high precision in coating thickness. Therefore, in view of the above problems, the present invention aims to provide a screen printing plate and a method for producing the same, which can eliminate the swelling of the edge portion of the printed coating film after drying.

[0007]

In order to achieve the above-mentioned object, the present invention has an opening area of a desired printing shape formed in an emulsion layer of a screen printing plate, which is stretched on a surface of a printing material and a screen. Different from the surface, the opening area of the surface to be printed is equal to the opening area of the desired printing shape, and the opening area of the surface stretched on the other screen is smaller than the desired printing shape. I have.

[0008]

According to the present invention, according to the above-mentioned constitution, the printing paste is pushed and spreads to the edge portion after passing through the opening portion smaller than the desired printing shape, thereby forming the desired printing shape. Therefore, the amount of paste in the edge part can be locally reduced compared to the central part, so it is possible to obtain a printed coating film of uniform thickness that does not swell the edge part after drying compared to the central part. Becomes

[0009]

【Example】

Example 1 An example of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a cross section of a screen printing plate according to an embodiment of the present invention. Here, as components, 11 is a first emulsion layer, 12 is a second emulsion layer,
3 is a screen, 4 is a plate frame, and 5 is a plate-formed aperture.

Next, a method of manufacturing the screen printing plate will be described. First, as shown in the cross-sectional view of FIG. 2A, a commercially available diazo emulsion is dried on a surface of a stainless screen 3 having a mesh number of 250, which is frame-tensioned on a plate frame 4, on a surface to be printed. The first emulsion layer 21 was formed by coating so as to have a thickness of about 10 μm. Next, FIG.
As shown in (b), the length is 4.8 mm and the width is 1.8, the dimensions of which are designed in advance to be smaller than those of a desired print shape prepared in advance.
The mask 6A having a rectangular shape of mm is set at a predetermined position (the drawing conceptually shows the width direction), and plate making is carried out by a normal photoengraving method. As shown in FIG. Emulsion layer 1
An opening having the shape of the mask 6A was formed on the substrate.

On the first emulsion layer 21 thus obtained, as shown in FIG. 2 (d), the same photosensitive emulsion as above was coated again with the same thickness to form the second emulsion layer 22. .
Subsequently, the desired print shape is 5.0 mm in length and 2.0 in width.
A mask 6B having a rectangular shape of mm is prepared, and as shown in FIG. 2 (e), the mask 6B is uniformly sized in each peripheral portion with respect to the opening formed above (in this case, 0.1 mm The position was adjusted so as to protrude, and plate making was carried out in the same manner as described above to form an opening having the shape of the mask 6B in the second emulsion layer 22. At this time, since the apertures of the first emulsion layer 21 maintain their original shape without being affected by the second plate making, as a result, as shown in FIG.
The emulsion layer has a two-layer structure including the first and second emulsion layers 21 and 22 having a step at the edge of the aperture, and the area of the aperture on the screen side is relatively larger than that on the side on which the printed material hits. An extremely small screen printing plate could be produced.

In the above examples, a plate having an emulsion layer having a two-layer structure was obtained by performing the plate making process twice. However, if the shape of the mask is made into a desired printing shape in the final plate making process, the same plate making process is repeated. It is also possible for the emulsion layer to have a multilayer structure of two or more layers.

(Second Embodiment) With reference to the drawings, a second embodiment of the present invention will be described below with reference to a method of manufacturing a screen printing plate having the same structure as that of FIG. 1 in the first embodiment.

First, the gelatin type photosensitive emulsion has a thickness of about 10 μm.
The first and second presensitized film for plate making coated with m are prepared, and then, as shown in the cross-sectional views of FIGS. 6B are brought into close contact with the respective film surfaces to carry out plate making by a normal photoengraving method. The first film 7A is provided with the emulsion layer 31 composed of the mask 6A, and the second film 7B is provided with the emulsion layer 32 composed of the mask 6B. Were formed respectively.

Next, as shown in FIG. 3 (c), first, the emulsion layer 31 side of the first film 7A produced above is placed on a predetermined table with the emulsion layer 31 side facing upward, and the first film 7A is completely different from the first embodiment. The same screen 3 is placed with the surface of the substrate to be printed facing down, and the rubber roller 8 is pressed from the screen 3 side, and then the first film 7A is peeled off to form the first emulsion layer 31. Transferred to screen 3.

Next, as shown in FIG. 3 (d), the apertures of the emulsion layer 32 are formed in the same manner as in the first embodiment with respect to the apertures of the emulsion layer 31 formed above. The second film 7B and the screen 3 are projected so that they are evenly sized at the periphery.
Position, and use the emulsion layer 3 in exactly the same way as above.
An emulsion layer 32 was formed on top of No. 1. In this way, the first and second emulsion layers 2 having a step at the edge of the aperture are formed.
By using an emulsion layer having a layered structure, a screen printing plate was prepared in which the area of the aperture on the screen side was relatively smaller than that on the side on which the printing material hits.

In the above examples, a plate having an emulsion layer having a two-layer structure was obtained by performing the plate-making process twice. However, if the apertures of the emulsion layer formed by transfer in the final plate-making process have desired printing shapes. By repeating the same plate making process, it is possible to form a multilayer structure having two or more emulsion layers.

(Embodiment 3) With respect to the third embodiment of the present invention, a method for manufacturing a screen printing plate having the same configuration as that of FIG. 1 in the first embodiment will be described with reference to the drawings.

First, the PVA type photosensitive emulsion has a thickness of about 10 μm.
Prepare the first photosensitive film for plate making coated with
As shown in FIG. 4 (a), the emulsion layer 41 side of the first film 7C is placed on the upper side, and the screen 3 exactly the same as that of the first embodiment is placed on the upper side of the screen 3 with the surface to be printed on facing down. Put on. Next, water is sprayed from the screen 3 side by spraying or the like, and the rubber roller 8 is pressed to sufficiently dry the water, and then the first film 7C is peeled off to remove the first emulsion layer 4
1 was transferred to screen 3. In this state, a screen printing plate having the emulsion layer as shown in FIG. 2A of the first embodiment was obtained. Therefore, the subsequent work is substantially based on the method of the first embodiment. Therefore, as shown in FIG. 4B, the mask 6A was used to perform plate making on the first emulsion layer 41 by an ordinary photomechanical process in exactly the same manner as in the first embodiment.

Next, on the emulsion layer 41 thus obtained, as shown in FIG. 4C, a photosensitive emulsion of the same thickness is transferred in the same manner as above to form a second emulsion layer 42. did. Subsequently, using the mask 6B that is exactly the same as that in the first embodiment, plate making is performed in exactly the same manner as in the first embodiment, and the mask 6
An emulsion layer 42 having the shape B was formed. At this time the first
In order to maintain the original shape of the opening portion of the emulsion layer 41 of No. 2 without being affected by the second plate making, as shown in FIG.
It was possible to manufacture a screen printing plate in which the area of apertures on the screen side, which is the same as those of the plates prepared in the first and second examples, was relatively smaller than that of the side on which the printing material hits.

In the above examples, a plate having an emulsion layer having a two-layer structure was obtained by performing the plate making process twice, but the same plate making process is repeated if the shape of the mask in the final plate making process is a desired printing shape. Therefore, it is possible to make the emulsion layer have a multilayer structure of two or more layers.

(Embodiment 4) In each of the first, second and third embodiments, as shown in FIG. 1, the emulsion layer has a two-layer structure having a step at the edge of the aperture, and a screen is formed. A screen printing plate was prepared in which the area of the open hole portion on the side was relatively smaller than that on the side on which the object to be printed hits. Since these plates are structurally equivalent and the same effect can be expected in the state at the time of printing, in this example, only the screen plate produced in Example 1 above was used as a representative and the actual printing was performed. An experiment was conducted.

First, a commercially available polyester film as a material to be printed and a commercially available copper paste as a printing paste are prepared, and printing is performed 50 times under the same conditions by a usual screen printing method using a rubber squeegee. Formed. The average thickness at the central portion and the edge portion of the printed coating film is obtained by scanning the surface of the thus obtained printed coating film in the width direction with a contact-type surface roughness meter. The rise rate (%) (hereinafter referred to as Re) was calculated.

Re (%) = (film thickness at the edge portion−film thickness at the central portion) ÷ (film thickness at the central portion) × 100 Further, for comparison, mask layer 6B was used to form an emulsion layer by a usual one-time photoengraving method. A screen printing plate having a thickness of about 20 μm was prepared, printing was performed using the screen printing plate under the same conditions as described above, and then Re measured by the same method as described above was obtained and used as the standard data of the conventional example. The above results are summarized in (Table 1) below.

[0025]

[Table 1] As is clear from this (Table 1), the emulsion layer according to the present example has a two-layer structure having a step at the edge of the aperture, and the area of the aperture on the screen side is larger than that on the side on which the object to be printed hits. It can be seen that, with respect to the printing coating film which was screen-printed using the printing plate which was relatively small, the excellent effect of improving the surface condition of the coating film was obtained.

As described above, according to the present embodiment, in screen printing, the area of the apertures formed in the emulsion layer according to the present invention is different between the contact side of the printed material and the screen side, and the contact side of the printed material. By making the opening area equivalent to the desired printing shape, and using a plate in which the opening area on the other screen side is smaller than the desired printing shape, it is possible to suppress the swelling of the edge portion of the printed coating film, It is possible to significantly improve the uniformity of the thickness of the printed coating film in the central portion and the edge portion.

In the above embodiment, a commercially available copper paste was used as the printing paste and the case of forming a rectangular coating film was described, but the present invention is applicable to all kinds of pastes and printing shapes. It is applicable.

[0028]

As is apparent from the above description of the embodiments, the present invention is such that the area of the apertures formed in the emulsion layer of the screen printing plate is different between the contact side of the printing material and the screen side, and By forming a plate in which the opening area on the side where the printed matter hits is equal to the desired printing shape and the opening area on the other screen side is smaller than the desired printing shape, and by using this, the edge of the printed coating film It is possible to suppress the swelling of the part and to significantly improve the uniformity of the thickness of the printed coating film in the central portion and the edge portion, which enables excellent screen printing, and forms the printed coating film by the screen printing method. It brings epoch-making effect to.

[Brief description of drawings]

FIG. 1 is a sectional view showing the configuration of a screen printing plate according to the present invention.

FIG. 2 is a process diagram of plate making in the first embodiment of the present invention.

FIG. 3 is a process drawing of plate making in the second embodiment of the present invention.

FIG. 4 is a process drawing of plate making in a third embodiment of the present invention.

5A is a cross-sectional view showing the configuration of a conventional screen printing plate, and FIG. 5B is a diagram illustrating the shape of a coating film printed on the conventional screen printing plate.

[Explanation of symbols]

 3 Screen 4 Plate Frame 5 Opening Portion in Screen Plate 11 First Emulsion Layer 12 Second Emulsion Layer

Claims (5)

[Claims] 1. A screen printing plate in which an emulsion layer having an opening having a desired print shape is formed on a screen, and the area of the opening is different between the contact side of the printing object and the screen side. In addition, a screen printing plate in which the opening area on the side of the printed material is equal to the desired printing shape and the opening area on the other screen side is smaller than the desired printing shape. 2. The screen printing plate according to claim 1, wherein the emulsion layer has a multilayer structure of two or more layers. 3. A step of forming a first emulsion layer by a photoengraving method on a screen plate coated with a light-sensitive emulsion by using a mask designed in advance to have a desired printing shape, and a step of forming the first emulsion layer on the first emulsion layer. To the second emulsion layer on the first emulsion layer by a photolithography method using a mask having a desired printing shape, and then applying the above-mentioned photosensitive emulsion to the whole surface of the screen printing plate again. Production method. 4. A first emulsion layer is prepared by a photolithography method using a mask which is designed to be smaller than a desired print shape on a photosensitive emulsion coated on a film serving as a support, and then the first emulsion layer is prepared. The step of transferring the layer to the screen plate by applying pressure in a state of being in close contact with the screen plate, and then using the mask of the desired printing shape to prepare the second emulsion layer in the same manner as above And a step of forming a second emulsion layer by transferring the second emulsion layer onto the first emulsion layer by the same method. 5. A photosensitive emulsion coated on a film serving as a support is transferred to a screen plate by applying pressure while being in close contact with the screen plate, and then a mask designed in advance to have a desired print shape is used. Forming a first emulsion layer by a photolithography method, and then forming the above-mentioned photosensitive emulsion on the first emulsion layer again by transfer,
And a step of forming a second emulsion layer on the first emulsion layer by a photolithography method using a mask having a desired printing shape.