JPH07122676A - Manufacture of ceramic device - Google Patents

Abstract

PURPOSE:To provide a high lamination ceramic device having fine pattern of inner electrodes or via holes with high yield by preventing occurrence of irregularities caused by presence or absence of electrode or insulator at the time of print lamination. CONSTITUTION:In order to flatten the surface of an object to be printed, micro holes 35 are made through a screen plate at the positions corresponding to the irregularities. The quantity of ink to be transferred is locally increased before printing is performed thus obtaining a ceramic device having flattened via connections.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mainly used for manufacturing various circuit boards including hybrid ICs and ceramic multilayer boards, composite ceramic electronic parts including various high frequency filters, or various electronic parts individually by using a printing and laminating method. The present invention relates to a method for manufacturing a ceramic electronic component to be manufactured.

[0002]

2. Description of the Related Art Conventionally, a screen printing method has been widely used in the manufacture of various circuit boards including hybrid ICs and ceramic multilayer boards, composite ceramic electronic parts including various filter-related parts, or various single ceramic electronic parts. However, when the ceramic electronic components are printed and laminated by such a screen printing method, irregularities due to the presence or absence of electrodes and insulator patterns are likely to occur, and there is a limit to high lamination and fine vias.

The cause of the unevenness will be described. First, the screen printing method will be described. FIG. 11 is for explaining the principle of screen printing.
In the above, 1 is a frame, 2 is a squeegee, 3 is an ink, 4 is a screen, and the screen 4 is composed of a metal or resin mesh and an emulsion layer in which a predetermined pattern is formed. Reference numeral 5 is a material to be printed, and 3a is a printed ink pattern. The screen 4 is stretched around the frame 1 with a predetermined tension, and when the squeegee 2 moves on the screen 4, the ink 3 is printed on the printing medium 5 to form a printed ink pattern 3a. .

Next, the screen will be described in more detail with reference to FIG. FIG. 12 is a view for explaining the cross section of the screen 4, and 6 is a mesh, which is configured in a mesh shape by fine wires made of metal or resin. 7
Is an emulsion layer and is formed in a predetermined pattern. Generally, the emulsion layer 7 is formed of a photosensitive resin. Reference numeral 8 is a portion called the opening without the emulsion layer 7, and the ink 3 is printed on the surface of the printing medium 5 through the opening 8. The ordinary mesh 6 is woven in a net shape (hereinafter, referred to as a net mesh), but recently, the mesh is also created by using various plating methods and etching methods.

FIG. 13 is for explaining the mesh 9 (hereinafter referred to as an integral mesh) produced by using such a method. Since such an integrated mesh 9 does not have fine wires woven, the mesh thickness can be made smaller than that of the conventional mesh 6, and since the mesh is integrated, it is difficult to stretch and a fine pattern is formed. It has excellent effects in terms of printability and absolute size of printing.

FIG. 14 is a view for explaining the appearance of the screen as seen from the surface of the material to be printed. In FIG. 14, 1
Reference numeral 0 is an emulsion layer, and the mesh 11 can be seen through the gap (corresponding to the opening 8 in FIG. 12) of the emulsion layer 10. When printing using such a screen,
The printability is good for the flat portion, but the printability is poor for the uneven surface, which has been a problem as compared with the prior art.

With reference to FIGS. 15 (a) and 15 (b), description will be made while obliquely observing the manner of printing on the via hole, which is an uneven surface, using the conventional screen plate as described above. Figure 15
In (a) and (b), 12 is a substrate on which an internal electrode 13 is formed. Further, 14 is an insulator, and the internal electrode 13 is exposed through a via hole 15 formed in the insulator 14. Next, as shown in FIG. 15B, when the electrode 16 is formed by printing on the via hole 15, a recess 17 is formed in the via hole 15. At this time, the electrode 16 printed on the via hole 15 only covers the wall surface of the via hole 15 and cannot be buried flat. Therefore, when a hybrid IC or various ceramic laminates are printed in multiple layers, irregularities due to the via holes 15 and irregularities due to the presence or absence of the internal electrodes 13 are likely to occur. Therefore, there is a limit in increasing the number of layers.

Next, the stacking via the via holes will be described in more detail with reference to FIG. FIG. 16 is an example of printing a coil by print lamination. In FIG. 16, 18 is a ferrite layer, 19 is a via connection portion, 20 is a coil pattern, and 21 is a recess. In FIG. 16, the coil pattern 20 forms a coil of several turns through the via connection portion 19. Here, a depression 21 is generated in the via connection portion 19, and this depression 21 is due to the same cause as the depression 17 in FIG. When the aspect ratio of this via hole becomes high, the depression 21 becomes large and becomes a disconnection.

In the case of via connection in a general laminated green sheet, since the via hole is formed in the green sheet of the via portion by punching or the like, by performing suction printing, the electrode material or the like can be easily formed inside the via hole. Can be filled. However, suction printing cannot be performed in the case of a ceramic electronic component in which via holes are not formed in the printing medium as described in the present invention. Therefore, if the via hole becomes finer (the diameter becomes smaller) or the aspect ratio becomes larger (the thickness of the interlayer insulator becomes larger than the diameter), it becomes more difficult to fill the via hole. Therefore, in reality, a pattern for filling vias is prepared to increase the printing process or increase the fluidity of ink to make it easier for ink to flow into the via portion. In terms of cost, the latter is likely to cause problems such as pattern bleeding.

Next, the generation of irregularities due to the thickness of the internal electrodes will be described with reference to FIG. In FIG.
22 is an internal electrode, 23 is a ceramic layer, and 24 is unevenness. As shown in FIG. 17, when the thickness of the ceramic layer 23 is uniform, unevenness 24 corresponding to the number of stacked electrodes is generated on the surface, which hinders the printability of the fine pattern and the multilayering.

Therefore, it has been proposed to process the screen plate itself. For example, JP-A 64-82
945, JP-A-3-72364, JP-A-6
No. 1,299,290, JP-A-54-8003 or JP-A-57-12855 propose a method for producing a screen plate using a laser, which is the emulsion-equivalent portion with the screen left. Is a plate-making method of a screen to remove by a laser, and the finished screen plate is the same as the one obtained by a usual photographic method. In Japanese Utility Model Laid-Open No. 61-152466, there is proposed a screen plate in which a hole for inserting a substrate positioning pin is formed in the screen plate and the hole is covered with elastic rubber. Has the same structure as the normal one. Actual Kaihei 1-171688
The solder printing mask proposed in Japanese Patent Publication has a mesh arranged inside a metal mask.

[0012]

However, in the case of the conventional ceramic electronic component, since printing is performed using such a screen plate, it is possible to arbitrarily increase the amount of ink printed and formed at a predetermined plurality of places. I couldn't. For this reason, when an ink pattern is screen-printed on the surface to be printed having fine irregularities such as via holes on the surface, it is apt to be affected by these irregularities and it is impossible to fill the concave portion with sufficient ink.

For this reason, when such a process is not added, the manufactured ceramic electronic component has a multilayer structure of at most about several layers. In order to achieve a high level of stacking, it is necessary to add a step of filling a predetermined amount of ink in a recessed portion such as a via hole or an electrode in a new printing step, or to add an insulating layer 2 to absorb irregularities. In the case of printing thickly with three layers, the via hole of the insulator could not be made small.

The present invention is intended to solve the above-mentioned conventional problems, and the next pattern is formed by printing while flattening the unevenness generating portion (that is, the thickness of the via hole portion, the thickness of the internal electrode, etc.) which is a problem in the manufacturing process. It is therefore an object of the present invention to provide a method for manufacturing a ceramic electronic component that can be highly laminated.

[0015]

In order to solve this problem, a method of manufacturing a ceramic electronic component according to the present invention is a screen in which fine holes are formed at predetermined positions of opening of an emulsion layer having a predetermined pattern formed on a mesh. This is a method of printing a portion corresponding to the micropores on the electrode layer and the ceramic layer which are formed thick using a plate.

[0016]

According to this method, in the ceramic electronic component composed of the ceramic portion and the electrode portion, the amount of printing ink in a predetermined portion can be locally increased by using the screen plate having the minute holes. Specifically, micropores are formed on the screen plate where it is desired to increase the printing amount of ink, and the micropores are locally located at positions where the printing ink amount is to be increased (gap between electrodes, via holes, etc.). Correspond. In this way, a predetermined amount of printing ink (or a local increase in the amount of printing ink) can be obtained even on the uneven surface of the printing medium. As described above, it is possible to manufacture a ceramic electronic component having excellent surface flatness and mountability and high stacking characteristics.

[0017]

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a view for explaining the manner of via connection in a ceramic two-layer substrate according to the first embodiment of the present invention. FIG. 1A is before the via filling printing. Further, FIG. 1B shows a state after the via filling printing according to the present invention, and it can be seen that the via filling portion is flattened as compared with the conventional example (FIG. 14).

In FIG. 1, reference numeral 25 denotes a base which is composed of a ceramic substrate, a green ceramic layer, a resin film and the like. 26 is a ceramic layer, and this ceramic layer 26
A via hole 27 is formed in this. In FIG. 1A, the first internal electrode 28 formed on the base 25 is exposed in the via hole 27. In FIG. 1B, 29
Is the second internal electrode, and no recess is formed even at the via position 30.

As described above, in the present embodiment, by locally forming the internal electrode at the via connection position to a maximum thickness of 10 times, the local electrode is printed corresponding to, for example, the via hole portion. The film thickness can be increased. Thus, in this embodiment, the surface can be flattened even in the via-filled portion as shown in FIG. In particular, in this embodiment, it is possible to fill the vias having a flat surface and print-form the second internal electrode layer 29 at the same time, which simplifies the printing process and reduces the cost.

Next, with reference to FIG. 2, the manner in which via connection is performed in a ceramic two-layer wiring substrate by using wiring with bumps will be described. In FIG. 2, 31 is a bump, which is formed at a via position 30 (that is, a position where the via hole is aligned). The bump 31 has a maximum thickness of 10 times that of the first internal electrode 28. In the present invention, the bump 31 has the first bump as shown in FIG.
When the internal electrodes 28 are printed on the base 25, they are simultaneously printed. Next, as shown in FIG. 2B, the bump 31 rises from the via hole 27 of the ceramic layer 26 and is connected to the second internal electrode 29. Figure 1
In comparison with FIG. 2, the via hole 27 is less likely to be crushed and the via connection by the smaller via hole 27 is possible.

Next, the processing of fine holes in the screen plate will be described with reference to FIGS. First, FIG. 3 illustrates a printed portion of a screen plate which has been subjected to micro-perforation processing, and FIG.
Describes the printed portion of the screen plate before the micro-punching process. 3 to 4, reference numeral 32 denotes an emulsion layer, and the mesh 33 is exposed at the opening 34 of the emulsion layer 32. Further, the mesh 33 is made by knitting a fine wire such as stainless steel. Further, the fine holes 35 are formed by finely processing at a predetermined position of the opening 34 in FIG. 4 using a laser or the like. Predetermined part of the mesh 33 is 1 of mesh pitch
By making the holes 10 times or more and 10 times or less, the mesh passing property of the ink can be locally improved. Further, the larger the micropores 35, the higher the aperture ratio of the screen plate and the better the ink removal property. However, if the size is 10 times the mesh pitch or less, the mesh 33 is not distorted. Further, if the mesh pitch is 1 time or less, the ink flow is almost unchanged, and the effect of forming a thick ink is hardly obtained. Further, in the case of a net mesh, FIG.
~ As shown in Fig. 4, the micropores 35 are surrounded by the emulsion layer 32, the micropores 35 are formed for each emulsion, and the micropores 35 are formed during the emulsion to prevent the precision and strength of the screen plate from being lowered. The life can be extended.

Next, the screen plate with minute holes will be described in more detail. First, the screen plate is a commercially available stainless steel mesh (250 mesh, mesh pitch is 2
5.4 mm / 250 = 0.016 mm) and the emulsion layer 32 had a thickness of 20 μm. The pattern rule of the emulsion layer 32 was line spacing / line width = 100/100 μm. The diameter of the via hole was 150 μm. Next, minute holes 35 (diameter 130 μm) were formed at the positions of the via holes. The micro holes 35 are formed by fixing the screen plate on an XY stage of a laser device to form the micro holes 35 in a mesh 33 at a predetermined position (here, a via hole position). The laser has a Q switch. Using YAG,
The minimum spot diameter of the laser was defined by setting the aperture in the laser optical path. Further, the target spot diameter of the fine hole 35 was obtained by finely shaking the laser having the minimum spot diameter using a galvanometer. As described above, a total of 700 fine holes 35 were formed in the screen plate.

Next, a two-layer ceramic circuit board was formed on the alumina substrate using the screen plate with the minute holes. First, a non-perforated alumina substrate (4 inch square, 0.5 mm thick) was used as the printing medium. After printing the lower electrode pattern on the alumina substrate, an interlayer insulating layer was printed with a via hole. Finally, at the time of printing the electrode pattern of the uppermost layer, via filling was simultaneously performed using a screen plate with micropores for flattening printing. Here, as the material of the interlayer insulating layer, a commercially available glass ceramic ink having the same thermal expansion coefficient as that of the alumina substrate was used. A commercially available silver-palladium ink was used as the internal electrode layer. The insulator layer has a thickness (= via depth) of 60 to prevent pinholes.
μm. Finally, they were collectively fired at 900 ° C. to complete a two-layer ceramic circuit board.

As described above, in the case of this embodiment, when the electrode pattern of the uppermost layer is printed as shown in FIG. 1, the ink amount in the via connection portion is locally increased, so that the interlayer connection via the via hole is formed. The yield was 99% or more. For reference, even when the via diameter was the same and the depth of the via was 100 μm, the yield of interlayer connection via the via hole was 98% or more. Next, by optimizing the viscosity of the electrode ink, the yield of via connection was further improved while keeping the wiring pattern fine.

For reference, the same multilayer ceramic circuit board was prepared using a conventional screen plate (without micropores, 250 mesh). However, the depth of the via hole is 60 μm
In the case of (the diameter of the via hole is 150 μm), it is very difficult to fill the via hole, and the yield of interlayer connection through the via hole is 5% or less. Therefore, when the diameter of the via hole was expanded to 250 μm, the yield of interlayer connection could be improved to 95% or more.
However, when the depth of the via hole was 100 μm, the yield of interlayer connection dropped to 40% or less, and the yield could not be improved even if the viscosity of the ink was optimized, and conversely the fineness of the wiring pattern was lost. As described above, in the case of the present embodiment, by locally increasing the film thickness of the electrode layer, it was possible to manufacture a ceramic electronic component that can cope with smaller vias and deep vias.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings. FIG. 5 is a partial cross-sectional view for explaining the structure of the printing coil according to the second embodiment of the present invention. In FIG. 5, 36 is a via connection part, 3
7 is a ferrite layer and 38 is a coil pattern.
In, the coil pattern 38 forms a coil of several turns through the via connecting portion 36. In comparison with the conventional coil printing example (FIG. 15), it can be seen that in the second embodiment, the via connection portion 36 does not have the depression 21 (FIG. 15) that was a problem in the conventional example. This is because in the case of Example 2, the aperture ratio of the screen was locally improved and the ink transfer amount was increased.

Next, a more detailed description will be given. First, the screen plate is a commercially available stainless steel mesh (400 mesh,
The mesh pitch is 25.4 mm / 400 = 0.0635
mm), the emulsion layer thickness is 20 μm, the electrode line width is 100 μm, and the via hole diameter is 200 μm.
μm. Next, a micro hole (diameter 15
0 μm) was formed. The micro holes are formed by fixing the screen plate on the XY stage of the laser device,
A fine hole was formed in the mesh at a predetermined position (here, a via hole position). Laser uses YAG with Q switch,
The minimum spot diameter of the laser was defined by setting the aperture in the laser optical path. Further, a laser having the minimum spot diameter was finely shaken by using a galvanometer to obtain a target diameter of the micropore. As described above, a total of 2000 fine holes were formed on the screen plate.

Next, a chip-type inductor component was formed on the alumina substrate by print lamination using the perforated screen plate. First, as a material to be printed, a material obtained by transferring a ferrite raw sheet (thickness: 200 μm) onto a non-perforated alumina substrate (4 inch square, 0.635 mm thick) was used. An interlayer insulating layer is printed with a via hole on this alumina substrate, and then a coil pattern internal electrode layer is printed.
At the same time, flattened via filling printing corresponding to FIG. 1B was also performed.

Here, as the material of the interlayer insulating layer, ferrite ink containing glass having a coefficient of thermal expansion matched with that of the alumina substrate was used. A commercially available silver-palladium ink was used as the electrode pattern. In addition, the ferrite layer was formed by two layers of printing / drying / printing / drying to prevent pinholes.
As a result, the ferrite layer thickness (= via depth) is 70-
By setting the thickness to 80 μm, the unevenness due to the pattern of the internal electrode layer was prevented to some extent. With the above specifications, the internal electrode layer is 1
Ferrite layers and internal electrode layers were alternately printed and laminated until the number of turns reached 0. The sample was printed and laminated for 10 turns, transferred to a ferrite green sheet (thickness: 200 μm), cut into a size of 2.0 × 1.2 mm, formed with external electrodes, and then collectively baked at 950 ° C. .

In the case of this chip inductor, since the ink amount in the via connection portion can be locally increased, the yield of interlayer connection via the via hole was 99% or more. For reference, the depth of the via hole is 100 μm with the same via diameter.
However, the yield of interlayer connection through via holes is 9
8% or more was obtained.

For reference, the same chip inductor was prepared using a conventional screen plate (without micropores, 250 mesh). However, the depth of the via hole is 70 to 80 μm.
In the case of (via hole diameter 200 μm), it is very difficult to fill the via hole, and the yield of interlayer connection via the via hole is 30% or less. Therefore, when the diameter of the via hole was increased to 300 μm, the yield of interlayer connection could be improved to 95% or more. However, the larger the diameter of the via hole, the narrower the magnetic flux cross-sectional area, and therefore the characteristics deteriorated by 40% or more. From the above results, the effect of the present invention was confirmed also in the case of the chip inductor.

(Embodiment 3) A third embodiment of the present invention will be described below with reference to the drawings. The difference between the first and second embodiments and the third embodiment is that in the third embodiment, an integral screen made by nickel plating on the mesh is used. FIG. 6 to FIG. 7 are for explaining the manner of making micro holes in the screen plate by using the integrated plating screen.

First, FIG. 6 illustrates the printed portion of the screen plate that has been subjected to the micro-perforation processing, and FIG. 7 illustrates the printed portion of the screen plate before the micro-perforated processing. 6 to 7, reference numeral 32 denotes an emulsion layer, and the mesh 33 is exposed at the opening 34 of the emulsion layer 32. Further, the fine holes 35 are formed by finely processing at a predetermined position in FIG. 7 using a laser or the like. By perforating a predetermined portion of the mesh 33 to 1 time or more and 10 times or less of the mesh pitch, it is possible to locally improve the mesh passing property of the ink. Also, the micro holes 35
Did not cause distortion in the mesh when the mesh pitch was 10 times or less.

Next, the screen plate with minute holes will be described in more detail. First, the screen plate is a commercially available plated mesh (400 mesh, mesh pitch is 25.4 m).
m / 400 = 0.0635 mm) and the thickness of the emulsion layer 32 was 20 μm. The pattern rule of the emulsion layer 32 was line spacing / line width = 40/40 μm. As described above, the integrated mesh has no unevenness due to the mesh of the mesh on the screen plate surface, and a finer pattern can be printed. The diameter of the via hole was 150 μm. Next, minute holes 35 (diameter 130 μm) were formed at the positions of the via holes. The fine holes 35 were formed by fixing the screen plate on an XY stage of a laser device to form the fine holes 35 in a mesh at a predetermined position (here, a via hole position). Laser uses YAG with Q switch,
The minimum spot diameter of the laser was defined by setting the aperture in the laser optical path. Further, the target spot diameter of the fine hole 35 was obtained by finely shaking the laser having the minimum spot diameter using a galvanometer. As described above, a total of 700 fine holes were formed on the screen plate.

Next, a four-layer ceramic circuit board was formed on an alumina substrate using the screen plate with the minute holes. First, a non-perforated alumina substrate (4 inch square, 0.5 mm thick) was used as the printing medium. After printing a lower electrode pattern on the alumina substrate, an interlayer insulating layer was printed with a via hole. Next, at the time of printing the electrode pattern of the second layer, the via filling was also flattened and printed at the same time by using a screen plate with micro holes. Here, as the material of the interlayer insulating layer, a commercially available glass ceramic ink having the same thermal expansion coefficient as that of the alumina substrate was used. A commercially available silver-palladium ink was used as the electrode pattern. The thickness of the insulator layer (= depth of via) is 60 μm in order to prevent pinholes. In this way, 3 layers of internal electrodes, 1 layer of top layer,
A total of four layers were formed, and finally, they were collectively fired at 900 ° C. to complete a four-layer ceramic circuit board.

As described above, in the case of this embodiment, as shown in FIG. 1, since the ink amount at the position corresponding to the via hole is locally increased every time to fill the via hole in the lower layer, the number of laminated layers increases. However, the yield of interlayer connection via via holes is 99%
That was all. For reference, even when the diameter of the via hole was the same and the depth of the via hole was 100 μm, the yield of interlayer connection via the via hole was 98% or more. Next, by optimizing the viscosity of the electrode ink, the yield of via connection was further improved while keeping the wiring pattern fine.

For reference, the same multilayer ceramic circuit board was prepared using a conventional integrated screen plate (without micropores, 400 mesh). However, the depth of the via hole is 6
In the case of 0 μm (via hole diameter 150 μm), it was very difficult to fill the via. Therefore, even if the ink viscosity and the like were improved, the yield of interlayer connection via the via hole was 5% or less. Therefore, when the diameter of the via hole was expanded to 250 μm, the yield of interlayer connection could be improved to 95% or more.
When the depth of the via hole was 100 μm, the yield of interlayer connection fell to 40% or less. After all, even if you can make up to 2 layers, 4
When the number of layers was more than one, printing and laminating became more difficult. As described above, in the case of the present embodiment, by locally improving the aperture ratio of the screen, the present invention is effective for smaller via holes and deeper via holes even when the number of laminated layers is increased. all right.

(Embodiment 4) A fourth embodiment of the present invention will be described below with reference to the drawings. Example 4 prevents occurrence of irregularities on the surface of the ceramic electronic component due to the presence or absence of internal electrodes. FIG. 8 is a perspective view showing a capacitor as a ceramic electronic component manufactured by flattening and laminating. FIG. 8A shows an embodiment of the present invention, and FIG. 8B shows a conventional one. is there. In FIG. 8, 3
Reference numeral 9 is an internal electrode, and 40 is a dielectric layer. FIG. 8A shows
8 is a ceramic electronic component described in Embodiment 4. FIG.
It can be seen that, as compared with the conventional example of (b), the unevenness due to the thickness of the internal electrode does not occur on the surface of the ceramic electronic component.

FIGS. 9 to 10 show an example of a dielectric printing screen plate in which fine holes are formed in order to prevent unevenness due to the thickness of the internal electrodes. 9 to 10, 41a, 41b, 41c are meshes, 42a, 4c.
2b is a micropore. FIG. 9 shows a case where one mesh is stretched in a single layer, and FIG. 10 shows a case where a plate called a double mesh in which meshes having different pitches are stretched is used.

Next, a more detailed description will be given. First, a commercially available nickel integrated mesh (400 mesh, mesh pitch: 25.4 m) was used for the screen plate for electrodes and dielectric printing.
m / 400 = 0.0635 mm) and the thickness of the emulsion layer was 5 μm. First, the electrodes of the capacitor of the screen printing plate for printing internal electrodes were 1.0 × 0.5 mm (this was used for the electrodes of the capacitor), and the feeding pitch of the capacitor patterns arranged in plural was 0.2 mm. The pattern of the screen plate for dielectric printing was solid (no emulsion), and micropores were formed only between the plurality of capacitor patterns arranged side by side, and a screen plate as shown in FIG. 9 was used. A commercially available silver-palladium ink was used as the electrode material. The thickness of this electrode was 15 μm before firing. A commercially available dielectric material was used. The interelectrode distance (dielectric thickness) of this capacitor was 50 to 60 μm before firing. Next, as shown in FIG. 8A, the internal electrode layer 39 and the dielectric layer 4 are
0 was alternately printed and laminated until the internal electrode 39 had 50 layers. Even when 50 layers were stacked, no unevenness due to the internal electrode layers 39 was generated. After the lamination, the external electrodes were formed after cutting into a predetermined shape and firing.

For reference, an ordinary screen plate (without micropores) was used as a conventional example, and a trial production was carried out in the same manner. However, the internal electrode 39 had irregularities on the surface from the time of printing the second to third layers. The state shown in FIG. As a result 5
It was not possible to print more than one layer.

From the above results, it was found that the print lamination can be performed while flattening by aligning the positions of the micropores with the positions where it is desired to locally increase the ink application amount. It was also confirmed that the number of layers is not limited by printing while flattening.

Further, by using the double mesh as shown in FIG. 10, it is possible to increase the ink film thickness in one printing. With respect to the micro-mesh drilling for such a double mesh, the micro-mesh may be simultaneously formed in two meshes, but as shown in FIG. 10, the micro-mesh may be formed only in one mesh. In this case, the fine holes are formed in the mesh on the printed material side, so that the effect of flattening printing on the printed material is increased. This is a common experience when printing metal masks. In the case of a metal mask, when the diameter of the hole is larger on the printed material side than on the squeegee side, this is similar to the reason why the ink removal property (ink transfer amount) is improved.

(Fifth Embodiment) A fifth embodiment of the present invention will be described below. In Example 4, a screen plate having micropores was used as the screen plate for printing the dielectric layer, but in Example 5, micropores were formed in the screen plate for printing the ferrite layer. Further, as in Example 3, fine holes were also formed in the screen plate for printing the coil wiring.

Next, a more detailed description will be given. First, the screen plate for electrode printing is a nickel integrated mesh (400 mesh, mesh pitch is 25.4 mm / 400 = 0.
The thickness of the emulsion layer is 20 μm.
And The line width of the coil pattern was 70 μm. The diameter of the via hole was 130 μm. Next, fine holes (diameter 100 μm) were formed at the positions of the via holes. The minute holes are formed by fixing the screen plate on an XY stage of a laser device at a predetermined position (here, a via hole position).
Micropores were formed in the mesh. The laser used was a YAG with a Q switch, and the minimum spot diameter of the laser was defined by setting an aperture in the laser optical path.
Further, a laser having the minimum spot diameter was finely shaken by using a galvanometer to obtain a target diameter of the micropore.
As described above, the coil printing screen plate has a total of 2
000 micropores were formed.

Next, fine holes were also formed in the screen plate for printing the ferrite layer so that the electrode thickness could be absorbed. After simulating the formation positions of the through holes so that the micro holes can absorb the thickness of the coil pattern, the micro holes were formed on the actual screen plate.

Next, a chip-type inductor component was formed by print lamination on an alumina substrate using the perforated screen plate. First, as a material to be printed, a material obtained by transferring a ferrite raw sheet (thickness: 200 μm) onto a non-perforated alumina substrate (4 inch square, 0.635 mm thick) was used. An interlayer insulating layer is printed with a via hole on this alumina substrate, and then a coil pattern internal electrode layer is printed.
At the same time, flattened via filling printing corresponding to FIG. 1B was also performed. Here, as the material of the interlayer insulating layer, ferrite ink containing glass having a coefficient of thermal expansion matched with that of the alumina substrate was used.

A commercially available silver-palladium ink was used for the internal electrode layers. In addition, the ferrite layer was formed by two layers of printing / drying / printing / drying to prevent pinholes. Again 2
By shifting the screen plates by a predetermined distance when stacking layers, the unevenness due to the coil pattern was more uniformly prevented. Thus the thickness of the ferrite layer (= the depth of the via hole)
Even when the thickness is 30 to 40 μm, the unevenness due to the pattern of the internal electrode layer can be prevented within a problem-free range. With the above specifications, ferrite layers and internal electrode layers were alternately printed and laminated until the internal electrode layers had 30 turns. The sample was printed and laminated for 30 turns, and then the ferrite raw sheet (thickness 200
μm) was transferred, cut into a size of 2.0 × 1.2 mm, formed with an external electrode, and then collectively baked at 950 ° C.

In the case of this chip inductor, since the ink amount in the via connection portion can be locally increased as in the second embodiment, the yield of interlayer connection via the via hole was 99% or more. For reference, even when the diameter of the via hole is the same and the depth of the via hole is 100 μm, the yield of interlayer connection via the via hole is 98% or more.

Further, in Example 5, since the electrode thickness of the ferrite layer was also flattened, it was possible to print with an electrode width of 70 μm even if the number of laminated layers increased.

For reference, an attempt was made to make the same chip inductor using the conventional screen plate, but the via hole 1
Via connection was not possible by printing with a line width of 70 μm at 30 μm. Further, when the screen plate used for printing the ferrite layer was one without ordinary micropores, unevenness due to the electrode thickness was generated, and it was not possible to stack up to 30 layers. Further, in the case of this example, the line width was thin and the ferrite thickness between the coils was thin, and as a result, the characteristics could be improved by 40% or more.

(Sixth Embodiment) Next, a sixth embodiment will be described. In the examples, a carbon dioxide laser was used to make fine holes in the screen plate.

First, as the carbon dioxide gas laser, a commercially available carbon dioxide gas laser used for punching an alumina substrate or the like was selected. Then, the carbon dioxide laser was locally irradiated from the emulsion layer side of the screen plate prepared according to the usual specifications. At this time, fine holes could be formed in the emulsion layer and the mesh by adjusting the laser power.
Moreover, the irradiation area of the laser could be narrowed by adjusting the focus of the laser. When the via hole printing was performed using the screen plate with fine holes thus created, the same effect as in Example 1 was obtained. It should be noted that the YAG laser can be used to form finer holes in the screen plate, but the carbon dioxide laser is easier to obtain a high output.

(Embodiment 7) A seventh embodiment of the present invention will be described below. In Example 6, a puncher was used to form fine holes in the mesh. As the puncher device, an NC control device used for micro-punching a green sheet was used. The punching die used was 0.1 mm. This puncher formed fine holes in the mesh. As the fine holes formed by punching, the mesh may be simply locally expanded without the metal mold sticking into the holes of the mesh and cutting the mesh.

Particularly, in the case of punching holes, depending on the mesh, damage is likely to occur and the precision of the screen plate may be reduced. For this reason, the fine holes may be formed by sharpening the tip of the punching die and expanding the mesh without damaging it. Here, in the case of a stainless mesh, the precision of the screen plate is not lowered by utilizing the plastic deformation characteristic peculiar to stainless (or metal). In addition, the mesh could be easily expanded locally by inserting the mold into the mesh or inserting a sharp jig into the gap of the mesh and then vibrating.

The screen plate with micropores of the present invention has a wide range of applications in the production of multilayer ceramic composite parts and the like. For example, it can be used to increase the hit rate of the resistance value (yield within a target resistance value range) even in the case of printing a hybrid IC having a low number of stacked layers or a resistor of a chip component. First, in the screen plate to be used, when the target resistance value does not appear, by forming fine holes in the screen plate as necessary, the releasability of the resistor ink and the coating amount can be adjusted. . Further, the screen plate with micropores of the present invention can be used not only for printing resistors but also for printing wiring. Specifically, by forming fine holes at the tip of each pattern such as the start point and end point of the resistor pattern or wiring pattern, the ink removal property at the tip of the pattern is improved, and Improved stability and less likely to cause plate clogging. As a result, printability with stable variations in resistance value and wiring resistance value can be obtained, and product yield can be improved.

Further, by using the method of manufacturing an electronic component of the present invention, for example, for a double mesh screen plate,
Micropores can be formed at a predetermined pitch to increase the aperture ratio of the double mesh screen. In this way, the double mesh with improved aperture ratio improves the ink removal property.
Further, the phenomenon of bubbles being entrapped in the ink, which often causes pinholes in a normal double mesh screen, can be prevented by forming fine holes.

Further, when the alignment accuracy at the time of printing is improved, the wiring rule for via connection can be made landless by using a screen with minute holes. It is also possible to perform printing with an inverted via (bump-like protrusion) by first performing printing using a screen plate with minute holes.
Furthermore, locally, it is a range that can be sufficiently utilized at the time of manufacturing a normal ceramic electronic component by thick film printing up to 10 times. The reason why the thickness is 10 times at the maximum here is that the size of the micro holes is defined to be up to 10 times the mesh pitch. The reason for limiting the maximum number of times to 10 times is that the number of small holes is small (for example, twice as large as the mesh pitch) rather than using one large hole that is large (for example, one hole having 10 times the mesh pitch is formed). It is possible to utilize the precision of the screen plate by using 20 holes of a large size.

[0059]

INDUSTRIAL APPLICABILITY As described above, the present invention prevents the occurrence of irregularities on the surface of a printing medium by providing fine holes at predetermined plural positions in the opening of the screen plate formed from the emulsion layer and the mesh. While forming a fine pattern.

[Brief description of drawings]

1 (a) and 1 (b) are partially cutaway perspective views illustrating a manner of via connection in a ceramic two-layer substrate according to a first embodiment of the present invention.

FIGS. 2A and 2B are partially cutaway perspective views showing an example of wiring with bumps.

FIG. 3 is an explanatory diagram illustrating a printed portion of the screen plate that has been subjected to the micro-perforation processing.

FIG. 4 is an explanatory view for explaining a printed portion of the screen plate before the micro perforation processing.

FIG. 5 is a partial cross-sectional perspective view for explaining the structure of the printing coil according to the second embodiment of the present invention.

FIG. 6 is an explanatory view for explaining a printed portion of the screen plate that has been subjected to the same micro-perforation processing.

FIG. 7 is an explanatory diagram illustrating a printed portion of the screen plate before the same micro-punching processing.

8A and 8B are partially cutaway perspective views showing a ceramic electronic component capacitor manufactured by sequentially laminating and flattening the present invention.

FIG. 9 is a plan view of an example of a screen plate for dielectric printing in which minute holes are formed in order to prevent unevenness due to the thickness of internal electrodes from being generated.

FIG. 10 is a plan view of the same screen plate.

FIG. 11 is a schematic diagram for explaining the principle of general screen printing.

FIG. 12 is an enlarged view for explaining a cross section of the screen.

FIG. 13 is a perspective view for explaining an integrated mesh.

FIG. 14 is a plan view for explaining how the screen is viewed from the surface of the material to be printed.

15 (a) and 15 (b) are partially cutaway perspective views for explaining an oblique view of printing on an uneven surface (via hole) using a conventional screen plate, respectively.

FIG. 16 is a partially cutaway perspective view of an example of printing a coil by conventional print lamination.

FIG. 17 is a partially cutaway perspective view for explaining generation of irregularities due to the thickness of a conventional internal electrode.

[Explanation of symbols]

 25 Base 26 Ceramic Layer 27 Via Hole 28 First Internal Electrode 29 Second Internal Electrode 30 Via Position 31 Bump 32 Emulsion Layer 33 Mesh 34 Opening 35 Micro Hole 36 Via Connection 37 Ferrite Layer 38 Coil Pattern 39 Internal Electrode 40 Dielectric Body layers 41a, 41b, 41c Meshes 42a, 42b Micropores

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical indication location H05K 3/12 D 7511-4E B 7511-4E 3/46 H 6921-4E

Claims (6)

[Claims] 1. An electrode layer or a ceramic layer in which a portion corresponding to a micropore is thickly formed by using a screen plate in which micropores are formed at predetermined positions of an opening of an emulsion layer having a predetermined pattern formed on a mesh. A method for manufacturing a ceramic electronic component formed by printing. 2. The method for manufacturing a ceramic electronic component according to claim 1, wherein the electrode layers and the ceramic layers are alternately laminated. 3. The method of manufacturing a ceramic electronic component according to claim 2, wherein the electrode layer is formed by printing so that the via connection portion is formed by the fine holes of the screen plate. 4. The method of manufacturing a ceramic electronic component according to claim 1, wherein a ferrite material is used as the ceramic layer, and the electrode layer is formed with a plurality of coil-shaped patterns. 5. The ceramic according to claim 1, wherein the screen plate is formed by irradiating laser light to micropores at a predetermined position of the opening of the screen plate which is composed of an emulsion layer having a predetermined pattern formed on a mesh. Electronic component manufacturing method. 6. The printing according to claim 1, wherein a screen plate formed of a plurality of meshes is used to print by using a screen plate in which micropores are formed with a large aperture ratio by the mesh on the printing material side.
A method for manufacturing the described ceramic electronic component.