JP2000185387A - Screen printer and method for screen printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a difference of printing patter shapes of a print starting part and a print ending part by a simple method by changing a distance between a screen printing plate and a material to be printed during a squeegee scanning period. SOLUTION: A distance g between a screen printing plate 2 and a printing surface 3a is changed in the state that the both are maintained substantially parallel without changing an angle of the plate 2 and the surface 3a during a squeegee scanning period of scanning a squeegee 1 parallel to the plate 2 from a print starting position A to a print ending position B toward 11 by a squeegee scanning mechanism by bringing the squeegee 1 into contact with the plate 2. As a method for changing the distance g, a position (height) of the plate 2 may be vertically moved in a direction of 12 by a motor 6 or a material-to-be-printed support 4 may be vertically moved in a direction 14 by a motor 7. Or, the plate 2 and the support 4 are simultaneously moved to change the distance g. Thus, a difference of pattern shapes of the print starting part and the print ending part can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing apparatus and a screen printing method used for manufacturing an electronic device, particularly, a ceramic laminated device.

[0002]

2. Description of the Related Art Various types of conductor patterns are formed inside or on the surface of ceramic multilayer devices such as ceramic multilayer capacitors, multilayer filters, multilayer actuators and multilayer sensors. Screen printing is widely used to form these conductor patterns.

[0003] The screen printing apparatus includes a squeegee, a squeegee scanning mechanism for scanning the squeegee, a screen printing plate, and a printing material support portion capable of supporting the printing material substantially parallel to the screen printing plate. . In the normal screen printing method, a squeegee scans the screen plate while pressing it against the substrate underneath, and extrudes the paste for forming the conductor pattern etc. from the part of the screen plate where the emulsion is not applied. A predetermined pattern is formed on a printing substrate. According to this method, printing corresponding to a large number of parts can be performed by one scan of the squeegee. For small components, a single squeegee scan may correspond to thousands to tens of thousands of components.

However, according to the usual method, there is a problem that the shape of the print pattern changes between a print start portion (a squeegee scan start portion) and a print end portion (a squeegee scan end portion). For example, a clear print pattern close to the pattern shape on the screen plate can be obtained at the print start portion, but a problem such as a slight increase in the print pattern due to bleeding of the paste may occur at the print end portion.

[0005] In order to improve such problems, various devices have been devised. For example, JP-A-9-23
As disclosed in Japanese Patent No. 9956, a method of changing the scanning speed of a squeegee has been proposed.

[0006]

However, in the case of the above method, a mechanism for controlling the position and speed of the squeegee is required, so that there is a problem that the apparatus becomes large and the cost of the apparatus increases.

The present invention solves the above-mentioned problems of the conventional screen printing machine, and makes it possible to reduce the difference between the printing pattern shapes of the printing start portion and the printing end portion by a simple method and a screen printing method. The purpose is to provide.

[0008]

Means for Solving the Problems In order to achieve the above object, the present invention has the following constitution.

That is, a screen printing apparatus according to the present invention comprises a screen plate, a printing material support portion capable of supporting a printing surface of a printing material substantially parallel to the screen plate, a squeegee for scanning on the screen plate, A squeegee scanning mechanism that scans the squeegee, and scans the squeegee while pressing the squeegee against the screen plate, so that the paste on the screen plate is printed on the printing surface of the printing material supported by the printing material support. A screen printing apparatus that prints in a predetermined pattern, characterized in that it has a mechanism that can change the distance between the screen plate and the printing surface of the printing medium during the squeegee scanning period.

Further, in the screen printing method of the present invention, the squeegee is scanned while the squeegee is pressed against the screen plate, and the paste on the screen plate is placed on a printing surface of the printing material supported by the printing material support. In a screen printing method for printing on a pattern, the squeegee is scanned while changing a distance between the screen plate and a printing surface of the printing medium.

According to the screen printing apparatus (or the screen printing method) of the present invention, the distance between the screen plate and the printing surface of the printing medium is changed during the squeegee scanning period. The difference in printed pattern shape (size, thickness) can be reduced. Accordingly, it is possible to reduce variations in the characteristics of components manufactured by forming a conductor pattern for a large number of elements by one printing, for example, components such as a multilayer capacitor and a multilayer filter. In addition, the printing area can be increased, which is effective in reducing the manufacturing cost. Furthermore, the range of the viscosity of the paste that can be used is widened, and the development period can be shortened.

Further, a laminated device according to the present invention is obtained by using the above-mentioned screen printing method. The conductor pattern of the multilayer device is formed using screen printing. Therefore, by using the screen printing method of the present invention to form the conductor pattern, it is possible to print a large area at a time, and since the variation in characteristics between components is reduced, the quality of the obtained laminated device is stable. And productivity is improved. That is, when the screen printing method of the present invention is applied to the manufacture of a laminated device, the effects of the screen printing method of the present invention are remarkably exhibited.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows the structure of a screen printing apparatus according to the present invention.

The printing material 3 is placed on the printing material support 4 with the printing surface 3a facing upward. The screen plate 2 is supported by a screen plate support frame 2a substantially in parallel with the printing surface 3a of the substrate 3. Squeegee 1 is screen version 2
, And a squeegee scanning mechanism including a motor 5 and a driving mechanism (e.g., a ball screw) connected thereto, scans from the print start position A to the print end position B in the direction of arrow 11 in parallel with the screen plate 2. Is done. At this time, the paste 8 is extruded from a portion of the screen plate 2 where no emulsion is formed, and a predetermined pattern is formed on the printing substrate 3.

In the screen printing apparatus, the present invention is characterized in that the distance g between the screen plate 2 and the printing surface 3a of the printing material 3 is changed during the squeegee scanning period. This makes it possible to reduce the difference between the printed pattern shape (size, thickness) between the printing start portion and the printing end portion.
As is apparent from FIG. 1, during the squeegee scanning period,
Since the screen plate 2 is pressed against the printing surface 3a by the squeegee 1 and is elastically deformed, the distance g between the screen plate 2 and the printing surface 3a in the present invention is determined by the distance of the screen plate 2 in the apparatus shown in FIG. Means the distance between the lower surface of the screen plate support frame 2a and the printing surface 3a.

In the present invention, the screen plate 2
It is preferable to change the distance g without changing the angle between the printing surface 3a and the printing surface 3a, that is, while keeping the angles substantially parallel to each other. This is because changing the angle not only complicates the structure of the device, but may also suppress the effect of changing the distance g.

As a method of changing the distance g, the position (height) of the screen plate 2 may be moved up and down in the direction of the arrow 12 by the motor 6, or the substrate support 4 may be moved in the direction of the arrow 14 by the motor 7. May be moved up and down. Further, the distance g may be changed by simultaneously moving the screen plate 2 and the substrate support 4. Although not shown, it is needless to say that in the case where the substrate support 4 is moved up and down, the squeegee also needs to be moved up and down in accordance with this. Further, in FIG. 1, the motor 6 for moving the screen plate 2 up and down and the motor 7 for moving the substrate support 4 up and down are separate motors. However, the number of motors can be reduced by devising a mechanical part. It is.

The material of the squeegee 1 is not particularly limited, but urethane rubber is desirable. Although the shape of the squeegee is not particularly limited, as shown in FIG.
It is desirable that the angle θ of the portion in contact with the screen 2 is substantially a right angle.

The type of the screen plate 2 is not limited, but a stainless steel mesh is preferable, but a resin or a metal mask may be used.

The substrate 3 to be printed is not particularly limited, but is preferably a ceramic green sheet, a ceramic substrate, a resin substrate, a metal or the like.

The paste 8 is not particularly limited, but is preferably a metal paste for forming a conductor, a resin paste, a ceramic paste, or the like.

Screen plate 2 or substrate support 4
May be moved monotonously with the scanning of the squeegee 1, or the squeegee scanning interval (A to B in FIG. 1) may be divided into several sections, and the squeegee may be moved for each section (eg, speed, direction, etc.). ) May be changed.

[0024]

EXAMPLE As an example, an example in which a multilayer capacitor is manufactured by the method of the present invention will be described.

A ceramic green sheet of 15 cm square has 1
A conductor paste of 00 (10 × 10) elements is printed at a time. Pd paste was used as the conductor paste.
The screen plate was 32 cm square and made of 325 mesh stainless steel. The portion where the pattern is formed is in the range of 6 cm square. The squeegee is made of urethane rubber and has a width of 12 cm, the tip angle θ is a right angle, and it is lightly chamfered.

In the embodiment, the printing start portion (position A in FIG. 1)
When only the position of the screen plate 2 is changed so that the distance g at the end is 0.9 mm and the distance g at the end portion (the position B in FIG. 1) is 1.2 mm (Example 1), The operation was performed for three types, in which only the position of the portion 4 was changed (Example 2), and when both positions were changed (Example 3).

As a comparative example, it was produced in the same manner as in the above example, except that the distance (g in FIG. 1) between the screen plate 2 and the printing surface 3a of the printing material was not changed during the scanning of the squeegee. In this case, the distance g was 1.0 mm.

The green sheet on which the conductive paste 8 was printed was laminated, pressed, cut into individual pieces, fired, and then formed with terminal electrodes to obtain a multilayer capacitor. The capacitance was measured at 1 kHz and 1 Vrms, and the variation of the capacitance of 100 elements under each printing condition was evaluated by the standard deviation. Table 1 shows the results.

[0029]

[Table 1]

Table 1 shows that the variation in the characteristics of the multilayer capacitor can be greatly reduced by changing the distance g during the scanning of the squeegee.

In this embodiment, the distance g during scanning of the squeegee
Is monotonically increased, but depending on the type of paste and various printing conditions, it may be better to monotonously decrease the distance g. Further, if the squeegee scanning period is finely divided and finely controlled, there is a possibility that the variation can be further reduced.

Further, by appropriately changing the way of changing the distance g, it is possible to cope with a wider variety of pastes, reduce design constraints, and shorten the product development period. Become.

[0033]

According to the screen printing apparatus (or the screen printing method) of the present invention, the distance between the screen plate and the printing surface of the printing medium is changed during the squeegee scanning period. In addition, the difference in the printed pattern shape (size, thickness) can be reduced. This allows
Variations in the characteristics of components manufactured by forming conductor patterns for a large number of elements by one printing, such as multilayer capacitors and multilayer filters, can be reduced.
In addition, the printing area can be increased, which is effective in reducing the manufacturing cost. Furthermore, the range of the viscosity of the paste that can be used is widened, and the development period can be shortened.

Further, by applying the screen printing method of the present invention to the manufacture of a laminated device, it is possible to print a large area at a time and to reduce the variation in characteristics between components. Quality is stable,
Further, productivity is improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an example of a configuration of a screen printing apparatus of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Squeegee 2 Screen plate 2a Screen plate support frame 3 Printed material 3a Printing surface 4 Printed material support part 5 Squeegee drive motor 6 Screen plate drive motor 7 Printed material drive motor 8 Print paste g Screen plate (screen plate support frame) and print material Distance from the printing surface A Printing start position B Printing end position

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Ichiro Kameyama 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. F-term (reference) 2C035 AA06 FC02 FC07 FD02 FD05 FD15 FD43 FF26 5E343 AA02 BB72 DD03 FF04 GG06

Claims (9)

[Claims] A squeegee for scanning the screen plate; a squeegee for scanning the screen plate; and a squeegee scanning mechanism for scanning the squeegee. A screen that scans the squeegee while pressing the squeegee against the screen plate, and prints a paste on the screen plate in a predetermined pattern on a printing surface of a printing material supported by the printing material support portion. A printing apparatus, comprising: a mechanism capable of changing a distance between the screen plate and a printing surface of the printing medium during the squeegee scanning period. 2. The screen printing apparatus according to claim 1, wherein the angle between the screen plate and the printing surface of the printing medium is kept substantially constant when the distance is changed. 3. The screen printing apparatus according to claim 1, wherein the distance between the screen plate and the printing medium is changed by changing the position of the screen plate. 4. The screen printing apparatus according to claim 1, wherein the distance between the screen plate and the printing medium is changed by changing the position of a printing surface of the printing medium. 5. A screen printing method in which a squeegee is scanned while a squeegee is pressed against a screen plate, and a paste on the screen plate is printed in a predetermined pattern on a printing surface of a printing material supported by the printing material support. 5. The screen printing method according to claim 1, wherein the squeegee is scanned while changing a distance between the screen plate and a printing surface of the printing medium. 6. The screen printing method according to claim 5, wherein the angle between the screen plate and the printing surface of the printing medium is kept substantially constant when the distance is changed. 7. The screen printing method according to claim 5, wherein a change in the distance between the screen plate and the printing medium is performed by changing a position of the screen plate. 8. The screen printing method according to claim 5, wherein a change in a distance between the screen plate and the printing medium is performed by changing a position of a printing surface of the printing medium. 9. A laminated device obtained by using the screen printing method according to claim 5. Description: