JP5261890B2 - Screen printing version - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain a screen printing plate which suppresses oozing of paste even in the case of forming a printed figure of a thick film and enables attainment of desired printed figures. <P>SOLUTION: The screen printing plate has a plane part 4 having a paste passing area 3 wherein a large number of perforations 2 are formed, while a lateral wall surface 5 is provided on the back side of the plane part 4 so that it has an opening larger than the paste passing area 3, and a recess 6 is formed by the lateral wall surface 5 and the paste passing area 3. The lateral wall surface 5 has a main lateral wall part 7 and a stepped part 8 formed in a spreading state at the open end of the main lateral wall part 7, and the lower surface 8a of the stepped part 8 is made contactable with the surface of a printing object. The plane part 4, the main lateral wall part 7 and the stepped part 8 are formed respectively out of metal films and constituted in a laminate structure. A step difference height d of the stepped part 8 is formed to be smaller than the height D of the main lateral wall part 7. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a screen printing plate, and more particularly to a screen printing plate for forming a thick printed pattern by a screen printing method.

In a multilayer ceramic electronic component such as a multilayer ceramic capacitor, a printed figure (conductive pattern) to be an internal electrode is formed on the surface of a ceramic green sheet mainly composed of a ceramic raw material such as BaTiO ₃ , and then a printed figure is formed. The ceramic green sheets are appropriately laminated to produce a ceramic laminate, and then the ceramic laminate is fired to produce a ceramic sintered body in which internal electrodes are embedded. Manufactured by forming electrodes.

  The conductive pattern is generally manufactured using a screen printing method, and a screen printing plate is required for this purpose. In this screen printing method, a screen printing plate having a large number of through-holes is placed on a substrate (a ceramic green sheet in the case of a multilayer ceramic electronic component), a paste is placed on one end of the screen printing plate, and a squeegee is placed. Is applied to the surface of the screen printing plate by applying a pressure to the surface of the screen printing plate to extrude the paste from the through hole to the back side of the screen printing plate, thereby forming a predetermined printed figure. It is formed on the surface of the substrate.

  As a screen printing plate used in the above-mentioned screen printing method, conventionally, as shown in FIG. 9, a mesh region 102 in which a plurality of mesh holes (through holes) 101. 101... Are not formed, and a concave portion 104 having a planar shape corresponding to a predetermined printed pattern formed on a surface of the mesh region 102 facing the printed material. A screen printing plate 106 in which the surface roughness (Ra value) of the contacting surface is in the range of 0.01 to 0.30 μm has been proposed (Patent Document 1).

  In Patent Document 1, by reducing the surface roughness (Ra value) on the contact surface with the substrate to be in the range of 0.01 to 0.30 μm, a gap is generated on the contact surface between the surface of the substrate and the screen printing plate. This prevents the paste from seeping out from the gap.

JP 2001-277745 A

  However, in Patent Document 1, when the surface of the substrate to be printed is rough, it is not possible to cope with it sufficiently, and there is a problem that the paste may ooze out from the gap on the contact surface.

  In addition, when a thick film printing pattern is formed, the amount of paste filling in the recess 104 increases, so that even if the surface roughness of the screen printing plate in contact with the substrate is reduced, the paste can be effectively exuded. Therefore, there is a problem that it is difficult to obtain a desired printed figure.

  FIG. 10 shows a printing process when the screen printing plate of Patent Document 1 is used.

  That is, as shown in FIG. 10A, a screen printing plate 106 is disposed on the substrate 105, and the paste passing area 102 is reciprocated by a squeegee (not shown), and pressure is applied from above. As a result, the paste 107 is pushed out from the mesh holes 101. Then, when the screen printing plate is removed, as shown in FIG. 10B, the printed figure 108 corresponding to the inner surface shape of the concave portion 104 of the screen printing plate 106 is formed, but the paste 107 flows due to its viscosity. Therefore, as shown in part M of FIG. 10 (c), the outer peripheral portion of the side wall of the printed figure 108 spreads outward and the paste oozes out, so that the printed figure is deformed and a desired figure area or There was a problem that a printed figure having a coating thickness could not be obtained.

  The present invention has been made in view of such circumstances, and is capable of obtaining a desired printed figure by suppressing the oozing of the paste even when a thick printed figure is formed. The purpose is to provide.

In order to achieve the above object, a screen printing plate according to the present invention includes a flat portion having a paste passage region in which a large number of through holes are formed, and one surface side of the flat portion is more than the paste passage region. In the screen printing plate in which a side wall surface is provided so as to have a large opening, and a concave portion is formed by the side wall surface and the paste passage region, the side wall surface has a main side wall portion and an open end of the main side wall portion. A stepped portion formed in an expanded shape, and the planar portion, the main side wall portion, and the stepped portion are each a laminated structure formed of a metal film, and the stepped portion The lower surface of the stepped portion can be brought into contact with the surface of the printing material , and the step height of the stepped portion is smaller than the height of the main side wall portion .

  The screen printing plate of the present invention is characterized in that two or more stepped portions are provided stepwise with the open end as a tip.

  The screen printing plate of the present invention is characterized in that the paste passing through the paste passage region is a conductive paste for forming an internal electrode of a multilayer electronic component.

  In the screen printing plate of the present invention, the paste passing through the paste passage region has a viscosity of 5 to 20 Pa · s.

According to the screen printing plate of the present invention, it is provided with a flat portion having a paste passage region in which a large number of through holes are formed, and has an opening larger than the paste passage region on one surface side of the flat portion. In the screen printing plate in which the side wall surface is provided and a recess is formed by the side wall surface and the paste passage region, the side wall surface is formed in an expanded shape at the main side wall portion and the open end of the main side wall portion. A stepped portion, and the flat surface portion, the main side wall portion, and the stepped portion each have a laminated structure formed of a metal film, and a lower surface of the stepped portion is formed of a printed material. Since the step height of the stepped portion is smaller than the height of the main side wall portion, the printed figure obtained using the screen printing plate has the inner shape of the recess. It has a step that corresponds to the print Flow of the paste is inhibited concentrated surface tension of the paste on the step side. Moreover, since the surface area in a recessed part becomes large, it becomes possible to disperse | distribute the pressure at the time of paste filling. As a result, the paste can be prevented from oozing out, and a printed figure having a desired shape can be obtained even when a printed figure having a thick coating thickness is formed. In addition, since the planar portion, the main side wall portion, and the stepped portion are each a laminated structure formed of a metal film, the dimensional accuracy is high by an electroforming method (electroforming method) using a photolithography technique. A screen printing plate having a fine printing pattern can be easily produced.

  Further, by providing two or more stepped portions in a stepped manner with the open end as a tip, it is possible to further exert the effect of suppressing the bleeding of the paste.

  Further, since the paste passing through the paste passage region is a conductive paste for forming an internal electrode of a multilayer electronic component (viscosity: 5 to 20 Pa · s), the screen printing plate is suitable for manufacturing a multilayer electronic component. Can be used for

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view of an essential part showing an embodiment of a screen printing plate according to the present invention.

  The screen printing plate 1 includes a flat portion 4 having a paste passage region 3 in which a large number of through holes 2 are formed, and is larger than the paste passage region 3 on the back surface side, which is one surface of the flat portion 4. A side wall surface 5 is provided so as to have an opening, and a concave portion 6 is formed by the side wall surface 5 and the paste passage region 3.

  Moreover, the side wall surface 5 has the main side wall part 7 and the step part 8 formed in the open shape at the open end of this main side wall part 7, and the lower surface 8a of the step part 8 is the surface of a to-be-printed material. It is comprised so that contact is possible.

  The step height d of the stepped portion 8 is smaller than the height D of the main side wall portion 7. That is, if the step height d is large, the flow of the paste is not much different from the conventional one, and it is difficult to effectively suppress the seepage of the paste. That is, since the paste exudation depends on the step height d, it is desirable that the step height d of the stepped portion 8 is smaller than the height D of the main side wall portion 7 as described above. In the present embodiment, the step height d of the stepped portion 8 is preferably set to 1.0 to 2.0 μm.

  The flat portion 4, the main sidewall portion 7, and the stepped portion 8 are all formed of a metal film, and have a stacked structure in which a plurality of these metal films are stacked.

  The screen printing plate can be easily manufactured by an electroforming method (electroforming method) using a well-known photolithography technique.

  That is, after applying a photoresist on a metal plate, it is exposed and developed through a metal mask having a predetermined pattern to form a resist pattern, and then electrolytic plating is performed using a plating bath, thereby A first metal film to be the flat portion 4 is formed on a metal plate that does not exist. Next, after applying a photoresist to this surface, exposure and development are performed through a metal mask of a predetermined pattern to form a resist pattern, and then electrolytic plating is performed using a plating bath, thereby the presence of the photoresist. A second metal film to be the main side wall portion 7 is formed on the first metal film that has not been formed. Next, after applying a photoresist to the surface, exposure and development are performed through a predetermined pattern original plate to form a resist pattern, and then electroplating is performed using a plating bath, whereby the presence of the photoresist is present. A third metal film to be the stepped portion 8 is formed on the second metal film that is not formed. Thereafter, the photoresist is dissolved and removed, and the metal plate and the first metal film are peeled off, whereby the screen printing plate is manufactured.

  FIG. 2 shows a printing process in which screen printing is performed using the screen printing plate 1.

  First, the screen printing plate 1 is placed on the substrate 10, the paste is placed on one end of the screen printing plate 1, and a squeegee (not shown) is reciprocated on the screen printing plate 1, and pressure is applied from above. Then, as shown in FIG. 2A, the paste 11 is filled in the recess 6.

  Then, when the screen printing plate 1 is removed from the substrate 10, a printed figure 12 having a step 12 a substantially corresponding to the inner surface shape of the recess 6 is obtained as shown in FIG.

  Since the step 12a is formed in the printed graphic 12 obtained in this way, the surface tension of the paste 11 that becomes the printed graphic 12 is concentrated on the step 12a, and the flow of the paste 11 is suppressed, and the concave portion Since the surface area in 6 becomes large, the pressure at the time of paste filling can be dispersed. And as a result, as shown in FIG.2 (c), it is suppressed that the printed figure 12 deform | transforms and it can suppress effectively that the paste 11 oozes out outward.

  As described above, according to the present embodiment, the side wall surface 5 is formed in an expanded shape on the main side wall portion 7 and the open end of the main side wall portion 7 so as to have an opening larger than the paste passage region 3. Since the screen printing is performed so that the lower surface 8a of the stepped portion 8 is the surface of the substrate, the printed figure 12 has the step 12a, and the outside of the paste 11 Bleeding to the direction can be prevented. Therefore, even when the thickness of the printed figure is thick, it is possible to obtain a printed figure having a desired figure area and capable of suppressing variations in coating thickness.

  FIG. 3 is a cross-sectional view of an essential part showing a second embodiment of the present invention. In the second embodiment, the stepped portion 13 includes a first stepped portion 14 and a second stepped portion. The portion 15 has a two-layer structure, and is formed so as to expand stepwise at the open end of the main side wall portion 7. Also in this case, as in the first embodiment, the step heights d1 and d2 of the first and second stepped portions 14 and 15 are smaller than the height D of the main side wall portion 7, and preferably 1.0 respectively. It is set to ˜2.0 μm.

  As in the first embodiment, the manufacturing method can be easily manufactured by an electroforming method (electroforming method) using a well-known photolithography technique.

  Also in the second embodiment, since the printed figure has a step as in the first embodiment, it is possible to effectively prevent the paste from exuding to the outside, and therefore printing. Even when the thickness of the figure is thick, it is possible to obtain a printed figure having a desired figure area and capable of suppressing variations in coating thickness.

  The present invention is not limited to the above embodiment. In the above embodiment, the stepped portion has been described as having one step and two steps, but it is also preferable that the stepped portion has three or more steps depending on the coating thickness of the printed figure. Further, the screen printing plate of the present invention is not particularly limited in terms of use, but the inside of multilayer electronic components such as multilayer ceramic capacitors that require extremely strict and high accuracy standards for coating thickness and graphic area. It becomes suitable for the conductive paste for electrode formation (viscosity: 5 to 20 Pa · s), and the above-described effects can be sufficiently exhibited.

  Next, examples of the present invention will be specifically described.

As Example 1, a screen printing plate having the front shape shown in FIG. 4 was prepared.
In Example 1, the longitudinal dimension x is 555 μm, the width dimension y is 170 μm, and the recess height z is 26 μm. In addition, a stepped portion is formed at the open end of the recess. Of the recess height z, the dimension b1 is 24 μm, the dimension b2 is 2 μm, and among the longitudinal dimension x, the dimension a1 is 552 μm and the dimension a2 is It is formed to 1.5 μm.

  As Example 2, a screen printing plate having the front shape shown in FIG.

  In this example 2, the longitudinal dimension x and the width dimension y are the same as those in the example 1, but the stepped portion is formed in a two-layer structure, and the dimension b1 is 22 μm out of the recess height z. Of the longitudinal dimension x, b2 is 2 μm and the dimension a1 is 549 μm and the dimension a2 is 1.5 μm.

  Further, as Comparative Examples 1 and 2, screen printing plates having the front shape shown in FIG. 6 were prepared.

In these Comparative Examples 1 and 2, the stepped portion is not formed, and Comparative Example 1 has a recess having a longitudinal dimension x of 555 μm, a width dimension y of 170 μm, and a recess height z of 26 μm. Comparative Example 2 has the same shape as Comparative Example 1 except that the recess height z is 13 μm.

  Table 1 shows the dimensions of the screen printing plates of Examples 1 and 2 and Comparative Examples 1 and 2.

次に、Ｐｄを主成分とする粘度が１２Ｐａ・ｓの導電性ペーストを用意した。

Next, a conductive paste having a viscosity of 12 Pa · s mainly composed of Pd was prepared.

  Then, the screen printing plates of Examples 1 and 2 and Comparative Examples 1 and 2 are arranged on a ceramic green sheet (thickness: 5 μm), screen printing is performed, and the conductive paste is filled in the recesses, and then the screen printing plate Was removed from the ceramic green sheet.

  FIG. 7 is a plan view schematically showing a printed figure, in which the longitudinal dimension x and the width dimension y indicate the internal dimensions of the screen printing plate, that is, the design dimension, and the longitudinal dimension x ′ and the width dimension y ′ indicate screen printing. The actual dimensions are shown later.

  Next, as shown in FIG. 8, the printed figure is divided into 25 in a matrix, and the amount of bleeding Δx (= x′−x) in the longitudinal direction and the amount of bleeding Δy (= y′− in the width direction) in each measurement region. y) was measured with a length measuring machine, and the average values Δxave and Δyave were calculated. An arrow A indicates the printing direction.

  Further, the coating thickness t in each measurement region was measured with a fluorescent X-ray diffractometer, and the average value tave was calculated.

  Furthermore, the printing area in each measurement region was measured using an image analyzer, and the ratio between the standard deviation and the average value, that is, the coefficient of variation CV (CV value) was calculated.

  Table 2 shows the measurement results.

この表２から明らかなように、比較例１は 長手方向の平均滲み量Δｘaveが４．４μｍであり、幅方向の平均滲み量Δｙaveは２４．４μｍであり、いずれも大きく、印刷面積の変動係数ＣＶも１．８３％と大きいことが確認された。

As is apparent from Table 2, in Comparative Example 1, the average blur amount Δxave in the longitudinal direction is 4.4 μm and the average blur amount Δyave in the width direction is 24.4 μm, both of which are large, and the variation coefficient of the printing area CV was also confirmed to be as large as 1.83%.

  Further, in Comparative Example 2, the average bleeding amount Δxave in the longitudinal direction is 9.0 μm, the average bleeding amount Δyave in the width direction is 11.0 μm, and bleeding occurs even when the average coating thickness tave is reduced to 0.50 μm. The amount was large, and the coefficient of variation CV of the printed area was 1.23%, which was confirmed to exceed 1%.

  On the other hand, in Example 1 with a single stepped portion, although the average coating thickness tave is 0.68 μm, which is thicker than Comparative Example 1, the average bleeding amount Δxave in the longitudinal direction is 1.4 μm. Further, the average blur amount Δyave in the width direction is 5.6 μm, and the blur amount can be greatly reduced, and the coefficient of variation CV is also suppressed to 0.91%, which is 1% or less, and variation in printing accuracy can be suppressed. I understood.

  Further, in Example 2 having two steps, the average coating thickness tave is 0.67 μm, which is thicker than Comparative Example 1, but the average amount of bleeding Δxave in the longitudinal direction is 0.6 μm, and the width The average amount of blur Δyave in the direction was 4.8 μm, indicating that the amount of blur can be reduced. It was also found that the coefficient of variation CV was 0.93%, which is 1% or less, and that variations in printing accuracy can be suppressed.

It is principal part sectional drawing which shows one Embodiment (1st Embodiment) of the screen printing plate which concerns on this invention. It is a figure which shows the printing process in the case of performing screen printing using the screen printing plate of FIG. It is principal part sectional drawing which shows 2nd Embodiment of the screen printing plate which concerns on this invention. It is a front view which shows typically the shape of the screen printing plate used in Example 1. FIG. 6 is a front view schematically showing the shape of a screen printing plate used in Example 2. FIG. It is a front view which shows typically the shape of the screen printing plate used for Comparative Examples 1 and 2. FIG. It is the top view which showed typically the printing pattern after screen printing. It is a matrix figure which shows the measurement area | region of a bleeding amount, application | coating thickness, and a printing area. It is principal part sectional drawing which shows the prior art example of a screen printing plate. It is a figure which shows the printing process in the case of performing screen printing using the screen printing plate of FIG.

Explanation of symbols

2 Through-hole 3 Paste passing region 4 Flat portion 5 Side wall surface 6 Recess 7 Main side wall portion 8 Stepped portion 8a Lower surface 13 Stepped portion 14 First stepped portion 15 Second stepped portion 16 Sidewall surface

Claims (4)

A side wall surface is provided so as to have a plane portion having a paste passage region in which a large number of through-holes are formed, and has a larger opening than the paste passage region on one surface side of the plane portion. In the screen printing plate in which a recess is formed in the paste passage area,
The side wall surface has a main side wall part and a stepped part formed in an open shape at the open end of the main side wall part,
The planar portion, the main side wall portion, and the stepped portion are each a laminated structure formed of a metal film,
The lower surface of the stepped portion can be brought into contact with the surface of the substrate ,
And the level | step difference height of the said step part is smaller than the height of the said main side wall part, The screen printing plate characterized by the above-mentioned . 2. The screen printing plate according to claim 1 , wherein two or more stepped portions are provided stepwise with the open end as a tip . 3. The screen printing plate according to claim 1, wherein the paste passing through the paste passage region is a conductive paste for forming an internal electrode of a multilayer electronic component . The screen printing plate according to any one of claims 1 to 3, wherein the paste passing through the paste passage region has a viscosity of 5 to 20 Pa · s .

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