JP4341250B2 - Screen printing plate and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a screen printing plate used for screen printing and a method for producing the same, and more particularly to uniformizing the thickness of the screen printing plate when the screen printing plate is produced by an electroforming technique.
[0002]
[Prior art]
A fine electrode of an electronic component such as an internal electrode of a multilayer ceramic capacitor is often formed by applying a conductive paste by printing. A fine printing pattern is formed on the screen printing plate used at this time, and high dimensional accuracy and thickness accuracy are required.
[0003]
A screen printing plate in which a first metal film having fine permeation holes and a second metal film having a printing hole having a shape corresponding to the shape of a printing pattern are integrally formed by metal plating is improved in printing durability. The thickness of the plate can be freely set by controlling the plating amount. An electroforming technique is used to manufacture such a screen printing plate.
[0004]
By the way, for example, a multilayer ceramic capacitor is obtained by printing a conductive paste serving as an internal electrode on a ceramic green sheet using a screen printing plate, laminating a plurality of the green sheets and firing, and then cutting the laminate. Manufactured. At this time, the internal electrodes of a plurality of capacitors are printed on the green sheet at a time. Therefore, a large number of printing holes having the same shape are formed on the screen printing plate.
[0005]
Here, FIG. 5A shows a plan view of a conventional screen printing plate, and FIG. 5B shows a cross-sectional view thereof. In FIG. 5B, the surface that comes into contact with the printed material such as a green sheet is shown on the upper side, and the surface that comes into contact with the squeegee is shown on the lower side. .
[0006]
The screen printing plate is composed of two layers of metal film, the first metal film 30 is formed with a permeation hole 51 for transmitting paste and the like, and the second metal film 40 is formed with a print hole 52. ing. The print holes 52 have a shape corresponding to a print pattern such as an internal electrode, for example, and the transmission holes 51 are distributed in portions corresponding to the print holes 52. Near the center of the screen printing plate is a printing area 61 in which a large number of printing holes 52 of the same shape are arranged, and in the vicinity of the edge of the screen printing plate, there is an edge portion 62 without the printing holes 52. A marker printing hole 53 for printing a marker used for alignment or the like may be formed in the edge portion 62.
[0007]
In the electroforming technique, an insulating film is formed in a predetermined shape on a conductive substrate, and then electroplating is performed to obtain a metal film. The plating deposition rate by electrolytic plating is determined by the current density, and the deposition rate increases as the current density increases. In the electroforming technique, since an insulating insulating film is used, the area of the conductive surface is reduced in the periphery of the portion covered with the insulating film, current is concentrated, and the current density is increased. Therefore, the plating film becomes thicker at the periphery of the portion covered with the insulating film. Since an insulating film for forming the printing hole 52 is formed in the printing area 61, the current density is increased in the central portion of the printing area 61, and the film thickness of the plating film is increased. On the other hand, in the peripheral portion in the print area 61, the insulating film is not formed further outside, so that the current density is relatively low, and the film thickness is thinner than the central portion of the print area 61. The variation in the film thickness in the print area 61 varies depending on the shape of the print hole 52, but may be about 30% at the maximum in the central portion in the print area 61 and the peripheral portion in the print area 61.
[0008]
In the screen printing plate, the coating material is supplied into the printing hole 52 through the transmission hole 51 from below in FIG. 5B, and the coating material spreading inside the printing hole 52 is printed on the printing material. Therefore, the shape of the printing pattern is substantially the same as the shape of the printing hole 52, and the thickness of the printing pattern is substantially the same as the depth of the printing hole 52, that is, the thickness of the second metal film 40. Therefore, the film thickness of the screen printing plate is very important in determining the printing coating thickness. If a printing plate having a thin film thickness in the peripheral area in the printing area 61 is used, variations in the printing coating thickness occur. In particular, a predetermined print thickness cannot be obtained in the print holes 52 arranged in the peripheral portion in the print area 61.
[0009]
When printing an electrode of an electronic component such as an internal electrode of a multilayer ceramic capacitor by screen printing, since the thickness of the electrode affects the characteristics of the component, precise management of the print thickness is required. If the desired printing thickness cannot be obtained, the desired characteristics cannot be obtained and a defect occurs.
[0010]
As a technique for solving this problem, there is a technique disclosed in Patent Document 1. In this technique, dummy figures are arranged around the print area in order to make the film thickness in the print area uniform.
[0011]
[Patent Document 1]
JP-A-5-239682 [Patent Document 2]
Japanese Patent Laid-Open No. 5-338370
[Problems to be solved by the invention]
In the technique of Patent Document 1 described above, the effect of uniforming the film thickness is greater when the dummy figures are arranged in a wider range. In other words, if the arrangement area of the dummy figure is not sufficiently wide, the film pressure is not sufficiently uniform, and the occurrence of defects cannot be prevented.
[0013]
The area where the dummy figure is placed is the edge around the print area, but as described above, the mark edge for printing the mark for alignment is formed on the edge. In such a case, the arrangement of dummy figures is limited.
[0014]
Also, in order to reduce the manufacturing cost of electronic components such as multilayer ceramic capacitors, it is required to print as many electrodes as possible in one printing, and it is necessary to increase the proportion of the printing area in the entire screen printing plate There is. Therefore, the current situation is that it is difficult to secure a wide edge portion as the dummy figures are sufficiently arranged.
[0015]
Therefore, an object of the present invention is to provide a screen printing plate in which the printing area is made sufficiently uniform while the film thickness in the printing area is made uniform, and a method for manufacturing the same.
[0016]
By the way, Patent Document 2 discloses an invention in which the opening is surrounded by a narrow partition wall by providing a groove close to the edge of the opening. Although the present invention is similar in shape to the present invention, this technique is for making the amount of the exudate to be applied to the back side of the printing plate constant, and has a different effect from the present invention. .
[0017]
[Means for Solving the Problems]
In order to solve the above problems, the screen printing plate according to the present invention includes a first metal film having a transmission hole through which a coating is passed and a second printing hole having a shape corresponding to the shape of the printing pattern. A screen printing plate for printing electrodes of a plurality of electronic components formed by integrating a metal film, wherein the first metal film has a transmission portion in which the transmission holes are distributed substantially corresponding to the print pattern shape. It is formed at a plurality of locations at equal intervals, and at least a part of the second metal film is formed in a band shape surrounding each of the transmission parts, and the band-like shape surrounding the transmission part in the vicinity of the edge of the screen printing plate The width of the second metal film is characterized by being narrower than the width of the band-shaped second metal film surrounding the transmission part at the center of the screen printing plate.
[0018]
Thereby, the thickness of the band-shaped second metal film surrounding the transmission portions formed at equal intervals becomes uniform, and the printing thickness becomes uniform. In addition, unlike the technique disclosed in Patent Document 1, it is not necessary to arrange a large number of dummy figures outside the printing area, so that many printing patterns can be arranged in the screen printing plate.
[0019]
Alternatively, in order to make the thickness of the band-shaped second metal film more uniform, the width of the band-shaped second metal film may be made narrower as it is closer to the edge of the screen printing plate. By forming the band-shaped second metal film so that the width of the band-shaped second metal film is gradually reduced from the vicinity of the center of the screen printing plate toward the vicinity of the edge, the film thickness of the band-shaped second metal film is further increased. It becomes uniform.
[0020]
Further, the method for producing a screen printing plate according to the present invention is a method for producing a screen printing plate for printing electrodes of a plurality of electronic components, and a transmission hole having a shape corresponding to a transmission hole on a conductive substrate. Except for the step of forming the perforation insulating film portions in which the insulating film is distributed so as to substantially correspond to the printed pattern shape at equal intervals in a plurality of locations, and on the base material except for the portion where the perforation insulating film is formed. Forming a first metal film by electroplating, removing the transmission hole insulating film, a plurality of printing hole insulating films having a shape corresponding to a printed pattern shape on the first metal film, and The printing hole insulating film is surrounded by a predetermined interval so that the interval near the end of the first metal film is narrower than the interval near the center of the first metal film. Forming a dummy insulating film A step of forming a second metal film on the first metal film by electrolytic plating, excluding a region where the printing hole insulating film and the dummy insulating film are formed; and the printing hole insulating film and the dummy And a step of removing the insulating film. Alternatively, instead of removing the transmission hole insulating film before forming the second metal film, the method of removing the transmission hole insulating film together with the printing hole insulating film and the dummy insulating film after forming the second metal film. There may be.
[0021]
Thereby, it is possible to make the current density uniform in the portion where the belt-like second metal film is deposited, and as a result, the film thickness of the belt-like second metal film is made uniform.
[0022]
In addition, a dummy insulating film may be formed so as to surround the printing hole insulating film with a predetermined interval, and so that the interval becomes closer to the end of the first metal film.
[0023]
As a result, the current density at the portion where the band-shaped second metal film is deposited becomes more uniform, and as a result, the film thickness of the band-shaped second metal film becomes even more uniform.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
(First Embodiment) An embodiment of the present invention will be described below with reference to the drawings. The production method of the present invention will be described in detail with reference to FIG. In FIG. 1, the right direction in the figure is the center direction of the screen printing plate, and the left direction in the figure is the edge direction of the screen printing plate.
[0025]
First, a conductive base material 10, for example, a stainless steel base material 10, is prepared. As shown in FIG. 1A, an electrically insulating transmission hole insulating film 21 is formed on the base material 10 by a method such as photolithography. Form. The transmission hole insulating film 21 is distributed in a plurality of locations substantially corresponding to the printed pattern shape. Each portion where the transmission hole insulating film 21 is distributed is referred to as a transmission hole insulating film portion 23. The through hole insulating film portions 23 are provided at a plurality of locations in the printing area 61.
[0026]
Next, as shown in FIG. 1B, the first metal film 30 made of nickel, for example, is formed by the first electrolytic plating except the region where the transmission hole insulating film 21 is formed. In the technique described in Patent Document 1, a dummy insulating film is formed to make the thickness of the first metal film 30 uniform. However, since the transmission hole is fine and the area of the transmission hole insulating film 21 corresponding to this is small, when the thickness of the first metal film 30 is 30 μm or less, the transmission hole insulating film 21 It has been found by the present inventors that changes in current density due to influence have little effect on film thickness. Therefore, the first metal film 30 is formed with a uniform thickness without forming a dummy insulating film.
[0027]
Next, as shown in FIG. 1C, the perforation insulating film 21 is dissolved and peeled, and as shown in FIG. 1D, a printing hole having a shape corresponding to the printing pattern is formed on the first metal film 30. An insulating film 22 and a dummy insulating film 24 are formed.
[0028]
Here, the dummy insulating film 24 is not disposed outside the printing area 61 as in the technique described in Patent Document 1, but surrounds each of the printing hole insulating films 22 in the printing area 61. It is formed. The dummy insulating film 24 is used to form a partition wall, which will be described later, with a uniform thickness. In the vicinity of the printing hole insulating film 22 located at the outermost periphery in the printing area 61, the interval between the printing hole insulating film 22 and the dummy insulating film 24 is narrowed so that current is easily concentrated. That is, in the vicinity of the center of the print area 61 (on the right side in FIG. 1), since a large number of print hole insulating films 22 are formed around the print area 61, the current density becomes relatively large. In the vicinity of the print hole insulating film 22 to be disposed, the print hole insulating film 22 is not formed further outside, so that the current density tends to be relatively small. In electrolytic plating, since the deposition rate of the plating film is proportional to the current density, the thickness of the plating film deposited per unit time decreases as the current density decreases. Therefore, the distance between the printing hole insulating film 22 and the dummy insulating film 24 is relatively large near the center of the printing area 61, and the distance between the printing hole insulating film 22 and the dummy insulating film 24 at the outer peripheral portion in the printing area 61. Is relatively small, the current density can be easily increased in the vicinity of the print hole insulating film 22 located on the outer periphery of the print area 61, and the current density in the print area 61 can be made uniform.
[0029]
Next, as shown in FIG. 1D, the second metal film 40 is formed by the second electrolytic plating except for the portion where the printing hole insulating film 22 or the dummy insulating film 24 is formed. Of the second metal film 40, the band-shaped metal film 41 formed in the groove portion between the printing hole insulating film 22 and the dummy insulating film 24, in other words, a metal film surrounding the periphery of the printing hole insulating film 22. Hereinafter, 41 is referred to as a “partition wall 41”.
[0030]
The partition wall 41 that surrounds the periphery of the print hole insulating film 22 located at the outermost periphery in the print area 61 is formed to be narrower than the partition wall 41 of other portions. Since the current density in the printing area 61 becomes substantially uniform due to the effect of the dummy insulating film 24, the partition wall 41 is formed with a uniform thickness. The inner periphery of the partition wall 41 has a shape corresponding to the shape of the print pattern.
[0031]
In the present embodiment, the second metal film 42 other than the partition is formed so as to surround the entire printing area 61, but this portion may not be provided. In addition, the second metal film 42 other than the barrier ribs has a portion where the film thickness is reduced. However, since this portion is a portion that does not participate in the printing of the print pattern, there is no problem even if the film thickness is thin. Absent.
[0032]
As described above, the transmission hole insulating film 21 formed in the first electrolytic plating has a shape corresponding to the shape of the transmission hole, and since the area is small, the degree of current concentration is small. Even if it is not formed, the film thickness is kept constant. However, at the time of the second electrolytic plating, the formed printing hole insulating film 22 corresponds to the shape of the printing pattern and has a larger area than the transmission hole insulating film 21, so that the degree of current concentration is high. According to the experiment by the present inventors, when the film thickness is 8 μm or more, the film thickness of the partition wall 41 in the printing area 61 cannot be formed uniformly without the dummy insulating film 24. Therefore, when the dummy insulating film 24 is not formed, the film thickness variation in the printing area 61 may be about 30% of the film thickness at the maximum. The film thickness variation within 61 can be suppressed to less than 10% of the film thickness. The film thickness of the second metal film 40 varies depending on the use of the printed material, but is about 8 μm to 30 μm. If the film thickness of the second metal film 40 is 8 μm or more, the dummy insulating film 24 is used. If the film is not formed, the film thickness in the printing area 61 cannot be kept uniform.
[0033]
Next, the printing hole insulating film 22 and the dummy insulating film 24 are removed, and the first and second metal films 30 and 40 formed integrally are peeled from the base material, and shown in FIG. A screen printing plate is obtained. A plan view of the screen printing plate is shown in FIG. 2 (a), and a cross-sectional view taken along line AA in FIG. 2 (a) is shown in FIG. 2 (b). The width of the strip-shaped partition wall 41 surrounding the printing hole 52 is narrower than the others at the outermost periphery.
[0034]
FIG. 3 shows a perspective view of the screen printing plate. A strip-shaped partition wall 41 is formed so as to surround a region where the transmission holes 51 are distributed (the transmission portion 54 shown in FIG. 1 (f)) substantially corresponding to the printed pattern shape. The area surrounded by the partition wall 41 is the printing hole 52, and the paste that has passed through the transmission hole 51 from the lower side of the drawing spreads inside the printing hole 52 to form a printed figure, and prints a desired figure on the substrate. be able to.
[0035]
As shown in FIGS. 3 and 2A, a marker printing hole 53 for printing a marker used for alignment or the like may be provided outside the printing area 61 as necessary. In the present invention, since the dummy insulating film 24 is formed in the printing area 61, a region for providing the marker printing hole 53 can be sufficiently secured outside the printing area 61. Since the width of the edge portion 62 can be reduced as compared with the case where it is provided outside the print area 61, the area of the print area 61 can be made wider than before, and the productivity is improved.
[0036]
Although the film thickness is not uniform in the marker printing hole part, since the marker is not used as an electrode of an electronic component, it is not necessary to make the printing thickness of the marker uniform. There is no practical problem with variations.
[0037]
In this example, the printed hole insulating film and the dummy insulating film were formed after the transmissive hole insulating film was peeled off, but the printed hole insulating film and the dummy insulating film were formed without peeling off the transmissive hole insulating film. After forming the second metal film, the transmission hole insulating film may be peeled off simultaneously with the printing hole insulating film and the dummy insulating film.
[0038]
(Second Embodiment) FIG. 4 (a) is a plan view of a screen printing plate according to a second embodiment of the present invention, and FIG. 4 (b) is a sectional view thereof. The manufacturing process of this screen printing plate is the same as that of the first embodiment. However, in the first embodiment, the width of the partition wall 41 surrounding the transmission part 54 is narrower than that of the other ones arranged at the outermost periphery. However, in this embodiment, the width of the partition wall 41 is set so as to gradually decrease from the central portion of the print area 60 toward the peripheral portion. That is, D1>D2> D3.
[0039]
When a screen printing plate is formed by the electroforming technique, the current tends to concentrate most at the center of the printing area 61 and the current density tends to gradually decrease from the center toward the periphery. By setting so that the width of the partition wall 41 gradually becomes narrower toward the portion, the current density in the print area 61 can be made more uniform, and the film of the second metal film 40 in the print area 61 The thickness can be made more uniform.
[0040]
In the first and second embodiments, the transmission hole 51 is illustrated in a substantially square shape, but it is needless to say that the shape of the transmission hole 51 is not limited to this. It may be a slit shape.
[0041]
【The invention's effect】
The present invention is configured as described above, and has the effects described below.
[0042]
That is, by making the interval between the printing hole insulating film and the dummy insulating film narrower than the central portion at the end of the screen printing plate, or gradually narrowing from the central portion toward the end, In other words, the width of the band-shaped second metal film (partition) is made narrower at the end of the screen printing plate than at the center, or gradually becomes narrower from the center to the end. As a result, the current density of the portion where the band-shaped second metal film (partition) is deposited is made uniform, and the band-shaped second metal film (partition) is formed with a uniform thickness. As a result, it is possible to print a plurality of print patterns printed at a time on the screen printing plate with a uniform print thickness.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a manufacturing process of a screen printing plate according to a first embodiment of the present invention.
FIG. 2 is a plan view and a cross-sectional view of a screen printing plate according to a first embodiment of the present invention.
FIG. 3 is a perspective view of the screen printing plate according to the first embodiment of the present invention.
FIG. 4 is a plan view and a cross-sectional view of a screen printing plate according to a second embodiment of the present invention.
FIG. 5 is a plan view and a cross-sectional view showing a conventional screen printing plate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Base material 21 Through-hole insulating film 22 Print-hole insulating film 23 Through-hole insulating film part 24 Dummy insulating film 30 1st metal film 40 2nd metal film 41 Partition 42 Second metal film 51 other than a partition Through-hole 52 Printing hole 53 Marker hole 54 Transmission part 61 Printing area 62 Edge part

Claims (6)

A screen for printing electrodes of a plurality of electronic components formed by integrating a first metal film having a transmission hole that allows a coating to pass therethrough and a second metal film in which a printing hole having a shape corresponding to a printing pattern shape is formed. A print version,
In the first metal film, the transmission portions in which the transmission holes are distributed substantially corresponding to the printed pattern shape are formed at equal intervals in a plurality of locations,
At least a part of the second metal film is formed in a band shape surrounding each of the transmission parts, and the width of the band-shaped second metal film surrounding the transmission part near the edge of the screen printing plate is: A screen printing plate characterized by being narrower than the width of the band-shaped second metal film surrounding the transmission portion at the center of the screen printing plate. A screen for printing electrodes of a plurality of electronic components formed by integrating a first metal film having a transmission hole that allows a coating to pass therethrough and a second metal film in which a printing hole having a shape corresponding to a printing pattern shape is formed. A print version,
In the first metal film, the transmission portions in which the transmission holes are distributed substantially corresponding to the printed pattern shape are formed at equal intervals in a plurality of locations,
At least a part of the second metal film is formed in a band shape so as to surround each of the transmission parts, and the width of the band-shaped second metal film is narrower as it is closer to the edge of the screen printing plate. A screen printing plate characterized by that. A method for producing a screen printing plate for printing electrodes of a plurality of electronic components,
On the conductive base material, a step of forming transmission hole insulating film portions having a shape corresponding to the transmission holes distributed so as to substantially correspond to the printed pattern shape at a plurality of locations at equal intervals ;
A step of forming a first metal film by electrolytic plating on the substrate except for a portion where the transmission hole insulating film is formed;
Removing the transmission hole insulating film;
On the first metal film, a plurality of printing hole insulating films having a shape corresponding to a printing pattern shape, and surrounding the printing hole insulating film with a predetermined distance from the printing hole insulating film, a central portion of the first metal film Forming a dummy insulating film so that the distance in the vicinity of the end of the first metal film is narrower than the distance in the vicinity;
Forming a second metal film by electrolytic plating on the first metal film except for the region where the print hole insulating film and the dummy insulating film are formed;
And a step of removing the printing hole insulating film and the dummy insulating film. A method for producing a screen printing plate for printing electrodes of a plurality of electronic components,
On the conductive base material, a step of forming transmission hole insulating film portions having a shape corresponding to the transmission holes distributed so as to substantially correspond to the printed pattern shape at a plurality of locations at equal intervals ;
A step of forming a first metal film by electrolytic plating on the substrate except for a portion where the transmission hole insulating film is formed;
On the first metal film and the transmission hole insulating film, a plurality of printing hole insulating films having a shape corresponding to a printing pattern shape, and surrounding the printing hole insulating film at a predetermined interval, the first hole is formed. Forming a dummy insulating film so that the interval near the end of the first metal film is narrower than the interval near the center of the metal film;
Forming a second metal film by electrolytic plating on the first metal film except for the region where the print hole insulating film and the dummy insulating film are formed;
And a step of removing the transmission hole insulating film, the printing hole insulating film, and the dummy insulating film. A method for producing a screen printing plate for printing electrodes of a plurality of electronic components,
On the conductive base material, a step of forming transmission hole insulating film portions having a shape corresponding to the transmission holes distributed so as to substantially correspond to the printed pattern shape at a plurality of locations at equal intervals ;
A step of forming a first metal film by electrolytic plating on the substrate except for a portion where the transmission hole insulating film is formed;
Removing the transmission hole insulating film;
On the first metal film, a plurality of printing hole insulating films having a shape corresponding to a printing pattern shape and surrounding the printing hole insulating film at a predetermined interval, the interval is surrounded by the first metal film. Forming a dummy insulating film so as to become narrower as it is closer to the end of
Forming a second metal film by electrolytic plating on the first metal film except for the region where the print hole insulating film and the dummy insulating film are formed;
And a step of removing the printing hole insulating film and the dummy insulating film. A method for producing a screen printing plate for printing electrodes of a plurality of electronic components,
On the conductive base material, a step of forming transmission hole insulating film portions having a shape corresponding to the transmission holes distributed so as to substantially correspond to the printed pattern shape at a plurality of locations at equal intervals ;
A step of forming a first metal film by electrolytic plating on the substrate except for a portion where the transmission hole insulating film is formed;
On the first metal film and the transmission hole insulating film, a printing hole insulating film having a shape corresponding to a printing pattern shape, and surrounding the printing hole insulating film at a predetermined interval,
Forming a dummy insulating film such that the interval is closer to the end of the first metal film,
Forming a second metal film by electrolytic plating on the first metal film except for the region where the print hole insulating film and the dummy insulating film are formed;
And a step of removing the transmission hole insulating film, the printing hole insulating film, and the dummy insulating film.

Images