JP3111803B2 - Screen printing plate - Google Patents

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 used for screen printing, and more particularly to an improvement for preventing blurring and bleeding at an edge portion of a printing pattern.

[0002]

2. Description of the Related Art For example, in the field of electronic components, screen printing is used when forming internal electrodes of a multilayer ceramic capacitor. By this screen printing, the conductive paste is printed in a predetermined print pattern so as to form internal electrodes of a predetermined shape. Such a printed pattern of the internal electrodes requires high dimensional accuracy.

FIG. 3 is a perspective view showing a conventional screen printing plate 1 applied to printing of the above-mentioned internal electrodes. The screen printing plate 1 is made of a metal such as nickel, for example, and has a metal film obtained by electroplating as described in Japanese Patent Application Laid-Open No. 5-85077. Since the screen printing plate 1 made of such a metal is unlikely to elongate due to the pressure of the squeegee, it can give a high dimensional accuracy to the print pattern, and is suitable for printing the above-described internal electrodes and the like.

A part of the screen printing plate 1 shown in FIG. 3 is enlarged and shown in a sectional view in FIG. The screen printing plate 1 includes a mesh portion 2 through which paste passes and a plate portion 3 through which paste does not pass. In FIG.
The area to be the mesh portion 2 is shown surrounded by a broken line.

[0005] The above-mentioned mesh portion 2 is provided with a plurality of mesh openings 4 penetrating therethrough and a printing medium 5 is provided.
A concave portion 6 having a planar shape correlated with the print pattern is formed on the side facing (see FIG. 5). Further, the plurality of mesh openings 4 are distributed in a region of the recess 6 except for the margins 7 and 8. Although margins 7 and 8 are shown in FIGS. 3 and 4, such a margin extends over the entire circumference of the recess 6. And
As shown in FIG. 4, the respective dimensions a and b of the margins 7 and 8 are made equal to each other.

[0006]

When printing is performed using the screen printing plate 1 described above, a squeegee (not shown) is moved in the direction of arrow 9 in FIG. By the movement of the squeegee, as shown in FIG. 5, the paste 10 is applied onto the printing medium 5 through the mesh openings 4 and the concave portions 6. However, it has been found that the paste 10 behaves unevenly in the recess 6 due to the movement direction 9 of the squeegee, which causes blurring or bleeding at the edge of the printed pattern.

More specifically, when viewed in the direction 9 of movement of the squeegee, the paste 10 does not sufficiently flow into the start end side margin 7 and is obtained when the screen printing plate 1 is separated from the printing medium 5. The print pattern has a tendency to fade on this start side. On the other hand, in the terminal side margin 8, the excess paste 10 wraps around, so that the printing pattern obtained when the screen printing plate 1 is separated from the printing medium 5 tends to blur on the terminal side.
From these facts, when the internal electrodes for the multilayer ceramic capacitor are printed using such a screen printing plate 1, the capacitance may deviate from a predetermined range, and as a result, the yield of the product is improved. Was an obstacle.

[0008] Therefore, an object of the present invention is to provide a screen printing plate which can reduce the tendency of the above-mentioned blurring and blurring to occur.

[0009]

SUMMARY OF THE INVENTION The present invention is directed to a screen printing plate used for printing a paste on a surface of a printing medium in a predetermined printing pattern.
This screen printing plate includes a mesh portion through which paste passes and a plate portion through which paste does not pass. The mesh portion is provided with a plurality of penetrating mesh openings, and has a concave portion having a planar shape correlated with a printing pattern on a surface side facing the printing medium. Further, the plurality of mesh openings are distributed in a region excluding the margin of the concave portion.

[0010] In the screen printing plate having such a structure, in order to solve the above-mentioned technical problem, in the present invention, the dimension of the margin of the concave portion when viewed in the moving direction of the squeegee, It is characterized in that the margin is shorter than the margin on the terminal side.

[0011]

Therefore, even if the paste tends to run short at the start end of the movement of the squeegee, as described above, the degree of the shortage of the paste within the margin is reduced by shortening the dimension of the margin at the start end. Can be further reduced. On the other hand, in the margin on the end side of the movement of the squeegee, the paste becomes slightly excessive,
Since the size of the margin on the terminal side is made longer, the degree of excess of the paste at this portion can be further reduced.

[0012]

As described above, in the printing pattern printed using the screen printing plate according to the present invention,
Blurring may occur at the edge on the starting side of the squeegee movement,
The occurrence of bleeding at the end edge can be reduced, and a desired print pattern can be obtained with high dimensional accuracy. For example, printing of internal electrodes of a multilayer ceramic capacitor, particularly 2 × 1.25 mm or less,
When the screen printing plate according to the present invention is used for printing the internal electrodes of a multilayer ceramic capacitor having a small external size of 6 × 0.8 mm or less, the accuracy with respect to the capacitance is increased, which contributes to the improvement of the product yield. it can.

In the screen printing plate according to the present invention, it is more preferable that the ratio of the size of the margin on the start end side to the size of the margin on the end side is selected to be (30-60) :( 140-172). The size of the margin on the start end is 7.5 to 15 μm, and the size of the margin on the end is 3
It has been confirmed by experiments that it is more preferable to select each of 5 to 43 μm.

[0014]

FIG. 1 is a perspective view showing a part of a screen printing plate 11 according to an embodiment of the present invention. FIG. 2 shows FIG.
FIG. 3 is an enlarged cross-sectional view showing a part of the screen printing plate 11 shown in FIG.

The screen printing plate 11 is, like the conventional screen printing plate 1, made of a mesh portion 12 through which a paste passes.
And a plate portion 13 that does not allow paste to pass through. This screen printing plate 11 is also disclosed in Japanese Patent Application Laid-Open No. 5-85007.
No. 7 can be produced.

The mesh portion 12 of the screen printing plate 11 is also provided with a plurality of penetrating mesh openings 14, and a plane correlated with a printing pattern (shown by a broken line in FIG. 1) on a surface side facing the printing medium. A concave portion 15 having a shape is formed. Further, the plurality of mesh openings 14 are distributed in an area of the recess 15 except for the margins 16 and 17. The margins including the margins 16 and 17 are formed over the entire circumference of the recess 15.

In FIGS. 1 and 2, an arrow 18 indicates a moving direction of a squeegee (not shown). The size of the margins 16 and 17 when viewed in the squeegee moving direction 18 is the margin 1 on the starting end side of the squeegee moving.
6 is shorter than the terminal side margin 17.
In other words, as shown in FIG. 2, the dimension A of the margin 16 on the start side is shorter than the dimension B of the margin 17 on the end side.

The dimensions A and B described above can be arbitrarily selected within a range in which blurring and bleeding can be reduced when the squeegee is moved in the direction of arrow 18 to print the paste on the printing medium. Experimental examples performed to define the preferable ranges of the dimensions A and B are shown below.

First, regarding the dimension A of the starting end side margin 16, the dimension a shown in FIG.
Was 25 μm, but the occurrence rate of blurring and bleeding when variously changed to make this shorter was investigated. The results are shown in Table 1 below.

[0020]

[Table 1]

As can be seen from Table 1, the dimension A is 8 μm.
m, 10 μm and 15 μm, more generally 7.5 to 15 μm, that is, the conventional dimension a
(30 μm), no blurring or bleeding was observed.

On the other hand, with respect to the dimension B on the terminal side, the occurrence rate of blurring and bleeding when the length B was variously changed so as to be longer was investigated. Table 2 shows the results.

[0023]

[Table 2]

As can be seen from Table 2, the dimension A is 35 μm.
m, 40 μm, 43 μm, more generally 35 to
In the case of 43 μm, in other words, the conventional dimension b (25 μm)
By setting the content to 140 to 172% of m), generation of blur and bleeding was not observed.

From the above, it can be understood that printing defects such as blur and blur can be prevented by appropriately selecting the dimensions A and B.

[Brief description of the drawings]

FIG. 1 shows a screen printing plate 1 according to an embodiment of the present invention.
FIG. 2 is a perspective view showing a part of the first embodiment.

FIG. 2 is an enlarged cross-sectional view showing a part of the screen printing plate 11 shown in FIG.

FIG. 3 is a perspective view showing a part of a conventional screen printing plate 1 of interest to the present invention.

FIG. 4 is an enlarged sectional view showing a part of the screen printing plate 1 shown in FIG.

FIG. 5 is a cross-sectional view showing the behavior of a paste 10 when printing is performed using the screen printing plate 1 shown in FIG.

[Explanation of symbols]

 Reference Signs List 5 Printed object 10 Paste 11 Screen printing plate 12 Mesh portion 13 Plate film portion 14 Mesh opening 15 Concave portion 16 Start margin 17 Termination margin 18 Arrow indicating direction of movement of squeegee

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41N 1/24 B41C 1/14 101

Claims (3)

(57) [Claims] 1. A screen printing plate used for printing a paste on a surface of a printing medium in a predetermined printing pattern, comprising: a mesh portion through which the paste passes; and a plate film portion through which the paste does not pass. The mesh portion is provided with a plurality of penetrating mesh openings, and a concave portion having a planar shape correlated with the printing pattern is formed on a surface side facing the printing medium,
And, in the screen printing plate, wherein the plurality of mesh openings are distributed in an area excluding a margin of the concave portion, a dimension of the margin when viewed in a moving direction of the squeegee is a margin at a start end side of the movement of the squeegee. Screen printing plate, characterized in that the length is shorter than the margin on the terminal side 2. A ratio of the size of the margin on the start end side to the size of the margin on the end side is (30 to 60) :( 14
The screen printing plate according to claim 1, which is selected from 0 to 172). 3. The size of the margin at the start end is 7.5 to 7.5.
15 μm, the size of the margin on the terminal side is 35 to 43 μm
The screen printing plate according to claim 2, wherein each of m is selected.