JP2003133167A - Manufacturing method of laminated electronic parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transcribe an internal electrode and a dielectric of solved steps by an easy alignment in a gravure printing. SOLUTION: An internal electrode 52 arrayed in a predetermined shaped is formed on a surface of a ceramic green sheet 51 by a first gravure printing. A mark for alignment 55 at lamination, a mark for alignment 61 by an electrode pattern, and a mark for detecting a shutter timing 53, are formed simultaneously. In the next place, a dielectric of solved steps 54 is formed by a second gravure printing and a mark for alignment 62 by a dielectric pattern is formed, marks for alignment 61 and 62 are detected by a CCD camera, a deviation from an alignment is calculated from a relation with each relative position which is fed back to a process, and a compensation roll between the first and second gravure printing and a gravure printing roll for the second gravure printing are moved to calibrate a printing position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a laminated electronic component, and more particularly to a method of manufacturing a laminated electronic component in which internal electrodes and a step difference eliminating dielectric are formed by a gravure printing method.

[0002]

2. Description of the Related Art Conventionally, a method of manufacturing a monolithic ceramic capacitor which is a monolithic electronic component is as follows.

A conductive green paste for internal electrodes having a predetermined shape is formed by printing on the surface of a ceramic green sheet to be a dielectric layer, dried, and then a predetermined number of layers are laminated and fired. Then, each chip is formed by cutting into a predetermined shape. next,
Apply an external electrode that conducts to the internal electrode to the end surface of the chip,
A single monolithic ceramic capacitor is formed by firing.

However, in recent years, with the miniaturization and high integration of monolithic ceramic capacitors, the number of laminated dielectric layers forming internal electrodes constituting the capacitors has increased significantly. In the structure of the conventional monolithic ceramic capacitor, the portion having the internal electrode is thicker by the portion having the internal electrode between the portion having the internal electrode and the portion having no internal electrode. If the number of laminated layers is small, a big problem does not occur, but as the number of laminated layers increases, the difference in thickness increases, and the possibility of cracks, voids, etc. inside the chip increases.

As a method for solving such a problem, a monolithic ceramic capacitor has been devised in which a step eliminating dielectric is formed on a portion of the ceramic green sheet where the internal electrodes are not formed.

In such a monolithic ceramic capacitor, the above problems can be solved, but in addition to the conductive paste for the internal electrodes, the slurry for the step eliminating dielectric must be printed on the surface of the ceramic green sheet. Increase to two. Further, the internal electrodes and the step-resolving dielectric material are required to have alignment accuracy during printing.

As the printing method, a screen printing method with high printing accuracy has been generally used.
The electrode needs to have a thickness of about 2 to 3 μm. Further, the screen printing method requires a long lead time in the printing process. This is difficult to miniaturize and is not suitable for mass production.

[0008] From these things, JP-A-8-25037
No. 0, the dielectric layer is about 3 μm,
The thickness of the electrode can be reduced to about 1 μm and the gravure printing method, which is excellent in mass productivity, has come to be used.

Further, in order to improve the alignment accuracy in the gravure printing process, the alignment method as disclosed in JP-A-11-8156 is used.

FIG. 5 shows a method of manufacturing a laminated electronic component,
It is a figure showing the process of the gravure printing of the conductive paste for internal electrodes, and the slurry for a level difference elimination dielectric. In FIG. 5, 1 is a carrier film having a ceramic green sheet formed on the surface, 2 is a tension roll that constantly applies a constant tension to the carrier film, 3 is a compensator roll that adjusts the tension applied to the carrier film by an external command, 4 Is a drying furnace for drying the conductive paste for internal electrodes and the slurry for level difference eliminating dielectric, 5
Is a CCD camera for detecting the position of the internal electrode, 11 is a gravure printing roll having a gravure plate for printing the conductive paste for the internal electrode, and 12 is a gravure printing roll having a gravure plate for printing the slurry for level difference eliminating dielectric. is there.

The carrier film 1 having the ceramic green sheet formed on the surface thereof, which is unwound from the unwinding portion, reaches the gravure printing roll 11 via the plurality of tension rolls 2. The gravure printing roll 11 is provided with a gravure printing plate that transfers a conductive paste in a predetermined shape.
The conductive paste is transferred to a predetermined position on the surface of the ceramic green sheet in a predetermined shape by contacting with, to form an internal electrode before firing. The internal electrode before firing is hereinafter simply referred to as "internal electrode".

The ceramic green sheet on which the internal electrodes are formed passes through the plurality of tension rolls 2, then passes through the compensator roll 3, and again passes through the plurality of tension rolls 2 and reaches the gravure printing roll 12.
The gravure printing roll 12 is provided with a gravure printing plate that transfers a slurry composed of a dielectric powder and an organic binder in a predetermined shape. When the carrier film 1 contacts the gravure printing roll 12, the ceramic green sheet surface Transfer the slurry to a predetermined position.

Here, the CCD camera 5 is installed immediately before the gravure printing roll 12 to recognize the transferred internal electrodes. Based on the recognized internal electrodes, correction contents such as positional deviation are calculated and transmitted to the drive unit of the compensator roll 3. Receiving this signal, the tension and angle of the compensator roll 3 with respect to the carrier film 1 are corrected, and the carrier film 1 is conveyed so that the internal electrodes and the step-resolving dielectric can be printed at regular positions. Transfer the slurry with.

The transferred slurry is dried by passing through the drying furnace 4 to form a step eliminating dielectric material before firing. At the same time, the internal electrodes are also dried by the drying oven 4. The step-eliminating dielectric before firing is hereinafter simply referred to as "step-eliminating dielectric."

After that, the carrier film 1 in which the internal electrodes and the step eliminating dielectric are formed in a predetermined shape on the ceramic green sheet in a predetermined shape is conveyed to the winding section and wound up.

[0016]

However, the gravure printing method in the above-described method for manufacturing a multilayer capacitor includes the following:
There were the following issues to be solved.

FIG. 6A is a partial plan view of the carrier film 1 after the internal electrodes are formed, and FIG. 6B is a partial plan view of the carrier film 1 after the step eliminating dielectric is formed. Note that (b) is a partial plan view in which the step-eliminating dielectric is displaced from the regular position with respect to the internal electrodes.

In FIG. 6, 1 is a carrier film and 5 is a carrier film.
1 is a ceramic green sheet, 52 is an internal electrode, 54
Is a step eliminating dielectric, 56 is an overlapping portion of the internal electrode 52 and the step eliminating dielectric 54, and 57 is a blank portion in which neither the internal electrode 52 nor the step eliminating dielectric 54 is formed.

When the internal electrode 52 and the step difference eliminating dielectric 54 are formed by gravure printing as described above, after the pattern of the internal electrode 52 is recognized by the CCD camera, the gravure for printing the slurry which becomes the step eliminating dielectric 54. It will have a certain distance to the print roll. Although this distance can be easily made constant in terms of equipment, the carrier film 1 is affected by drying after transfer of the conductive paste to be the internal electrodes 52, tension at the time of printing, and the like, causing expansion and contraction variations. Therefore, the position where the pattern of the internal electrode 52 is recognized is not always the same position on the gravure printing plate of the slurry, and the positional deviation shown in FIG. 6B is likely to occur.

If the internal electrode 52 and the step-resolving dielectric 54 are misaligned, that is, if the overlapping portion 56 or the blank portion 57 is formed, the step between the dielectric layers of the laminated internal electrode 52 is promoted, resulting in a structural defect. Further increase the likelihood of occurrence of. An accuracy of 50 μm is required to prevent the occurrence of structural defects.
It has been confirmed that a deviation exceeding μm occurs.

When the plate cylinder of the gravure printing roll forming the internal electrodes or the step eliminating dielectric is removed,
It requires a great deal of time and effort to re-attach and align.

An object of the present invention is to provide a method for manufacturing a laminated electronic component provided with a gravure printing method capable of easily aligning transfer of an internal electrode and a step-eliminating dielectric.

[0023]

SUMMARY OF THE INVENTION According to the present invention, an individual alignment mark is printed at the same time when a conductive paste for an internal electrode is printed and a slurry for a level difference eliminating dielectric is printed, and each alignment mark is read simultaneously. , Alignment is detected based on the relative position, and the gravure printing is performed by aligning the printing position of the conductive paste for the internal electrodes with the printing position of the slurry for the level difference eliminating dielectric so that the displacement is reduced. To manufacture.

Further, according to the present invention, the individual electronic alignment mark is read, and the process of suppressing the error factor such as bleeding which occurs in the image of the read alignment mark is performed to perform the gravure printing to manufacture the laminated electronic component. .

Further, according to the present invention, the color tone of the ceramic green sheet, the conductive paste for the internal electrodes and the slurry for the step eliminating dielectric are made different from each other to perform the position of the gravure printing to manufacture the laminated electronic component.

Further, according to the present invention, the alignment mark is printed on the ceramic green sheet to manufacture a laminated electronic component.

Further, according to the present invention, the illumination used for recognizing the alignment mark is transmitted light to read the alignment mark and perform gravure printing to manufacture the laminated electronic component.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION A method for manufacturing a laminated electronic component according to a first embodiment will be described with reference to FIGS. FIG. 1 is a diagram showing a process of forming an internal electrode and a step eliminating dielectric of a laminated electronic component. 2A is a partial plan view of the carrier film 1 after the internal electrodes are formed, and FIG. 2B is a partial plan view of the carrier film 1 after the step eliminating dielectric is formed. In FIG. 1, 1 is a carrier film having a ceramic green sheet formed on its surface, 2
Is a tension roll that constantly applies a constant tension to the carrier film, 3 is a compensator roll that adjusts the tension applied to the carrier film by an external command, 4a is a drying oven that dries the conductive paste for internal electrodes, and 4b is a step-eliminating dielectric Oven for drying the slurry for use, 5 is a CCD camera for detecting the alignment mark, 6
Is an illuminating device, 7 is a shutter detection sensor, 11 is a gravure printing roll on which a gravure plate for printing conductive paste for internal electrodes is installed, and 12 is a gravure printing roll on which a gravure plate for slurry printing for level difference eliminating dielectrics is installed. . In FIG. 2, 1 is a carrier film, 51 is a ceramic green sheet, 52 is an internal electrode, and 53 is a CCD.
Shutter timing detection mark, reference numeral 54 is a level difference eliminating dielectric, 55 is a stacking alignment mark, 61 is an electrode pattern alignment mark (first alignment mark), and 62 is a dielectric pattern alignment mark ( Second alignment mark).

The carrier film 1 having the ceramic green sheet formed on the surface, which is unwound from the unwinding portion, reaches the gravure printing roll 11 via the plurality of tension rolls 2. The gravure printing roll 11 is provided with a gravure printing plate that transfers a conductive paste in a predetermined shape.
By contacting with, the conductive paste is transferred to a predetermined position on the surface of the ceramic green sheet in a predetermined shape. The transferred conductive paste is dried by passing through the drying oven 4a to form internal electrodes. Thus, FIG.
As shown in (a) of FIG.
The internal electrodes 52 arranged in a predetermined shape are formed on the surface of the. Along with this, the alignment mark 55 at the time of stacking, the alignment mark (first alignment mark) 61 by the electrode pattern used for alignment when transferring the step-resolving dielectric slurry, and the timing at which the CCD camera 5 operates Shutter timing detection mark 5
3 are simultaneously formed at predetermined positions on the surface of the ceramic green sheet 51 at the same time.

The ceramic green sheet 51 on which the internal electrodes 52 are formed passes through the plurality of tension rolls 2, then passes through the compensator roll 3, and again passes through the plurality of tension rolls 2 and reaches the gravure printing roll 12. The gravure printing roll 12 is provided with a gravure printing plate that has a predetermined shape and transfers a slurry composed of a dielectric powder and an organic binder. By contacting the carrier film 1 with the gravure printing roll 12, the surface of the ceramic green sheet 51 The slurry is transferred to the predetermined position of the internal electrode 52 without overlapping. Here, FIG.
As shown in (b) of FIG. 11, a positioning mark (second positioning mark) 62 based on the dielectric pattern is formed near the positioning mark 61 based on the electrode pattern at the same time as the step eliminating dielectric 54.

Immediately after the gravure printing roll 12, CC
An alignment mark detection unit including a D camera 5, an illuminating device 6, and a shutter timing detection sensor 7 is installed, and an alignment mark 61 formed by an electrode pattern and an alignment mark 62 formed by a dielectric pattern are formed on the ceramic green sheet 51. Are detected at the same time.

The ceramic green sheet 51 printed with the slurry by the gravure printing roll 12 is conveyed, and when the shutter timing detection sensor 7 detects the shutter timing detection mark 53, the illuminating device 6 projects light on the ceramic green sheet 51. . At the same time C
The CD camera 5 reads the image of the alignment mark 61 by the electrode pattern and the alignment mark 62 by the dielectric pattern by the transmitted light.

FIG. 3A shows an image 80 of the alignment mark 61 by the electrode pattern and the alignment mark 62 by the dielectric pattern detected by the CCD camera 5.
71 and 72 are bleeding of the electrode pattern and bleeding of the dielectric pattern, respectively. FIG. 3B is a diagram showing the alignment marks 61 and 62 in a state where the image processing of FIG. 3A is performed.

The image shown in FIG. 3A is processed to calculate the amount of positional deviation from the relative positional relationship between the electrode pattern alignment mark 61 and the dielectric pattern alignment mark 62. From this calculation result, the deviation is corrected so as to be small, and is fed back to the alignment during the slurry printing.

As shown in FIG. 3A, bleeding 71, 72 usually occurs on each mark. This bleed 7
Since 1 and 72 change for each printing, they become an error factor in calculating the relative positional relationship. In order to prevent this effect, as image processing, as shown in FIG. 3B, the image itself including the blurs 71 and 72 is filtered by a filter that removes a low-density portion with an appropriate threshold, and the blurs 71 and 72 are processed. In the state in which is excluded, the alignment marks 61 and 62 are detected and the relative positional relationship is calculated.

The feedback method is performed in the following two directions. That is, it is the deviation of the carrier film 1 in the conveying direction and the deviation of the carrier film 1 in the width direction. A gravure printing roll 11 that prints a conductive paste against misalignment in the transport direction
1, the compensator roll 3 is disposed between the gravure printing roll 12 for printing the slurry and the gravure printing roll 11 and the gravure printing roll 12 by moving the position of the compensator roll 3 as shown in FIG. The length of the pass line with the roll 12 is changed. As a result, the slurry printing start position is displaced, so that the deviation in the transport direction can be corrected. Next, with respect to the deviation in the width direction, the deviation is corrected by moving the gravure printing roll 12 in the width direction of the carrier film 1. Here, when the gravure printing roll 12 is moved in the width direction of the carrier film 1, it is necessary to set the movement amount of 1 mm or less per 1 m of the carrier film 1 being conveyed. As a result, it is possible to minimize rubbing between the gravure printing plate and the ceramic green sheet 51 formed on the carrier film 1 due to the movement of the gravure printing roll 12, and it is possible to suppress the abrasion of each.

The slurry thus transferred is dried by passing through the drying furnace 4b to form the step eliminating dielectric 54.

After that, the carrier film 1 in which the internal electrodes 52 and the level difference eliminating dielectric 54 are formed in a predetermined shape on the ceramic green sheet 51 in a predetermined shape is conveyed to the winding section and wound up.

The wound ceramic green sheet 51 is cut into a size including a predetermined number of internal electrodes. Here, for example, in the case of a laminated ceramic capacitor, the cut ceramic green sheet 51 is laminated while being aligned with the alignment mark 55 for lamination as a reference, and pressure-bonded. After that, individual element bodies are cut in the stacking direction so as to be a single capacitor.
The cut element body is baked, after applying the external electrode,
Further, it is fired to form a monolithic ceramic capacitor.

As described above, by disposing the alignment mark detection unit such as the CCD camera 5 after the gravure printing roll 12, the gravure printing roll 11 and the expansion and contraction of the carrier film 1 by the gravure printing roll 12 are affected. The alignment mark is detected later. As a result, the influence of expansion and contraction of the carrier film 1 between both gravure printings can be suppressed, and the positional deviation can be reduced.

In addition, the two alignment marks 61, 62
Even if the gravure printing rolls 11 and 12 are exchanged by forming and simultaneously detecting, the alignment marks 61 and 62 formed by the printing immediately after the exchange are collectively detected and corrected. Matching can be easily performed.

Further, by detecting and correcting the alignment marks 61, 62 immediately after printing by the gravure printing roll 12, feedback can be performed immediately and the occurrence of misalignment can be suppressed.

The alignment mark detecting unit can be illuminated by a reflected light system, but by using a transmitted light system, the alignment mark can be easily detected by a dielectric pattern formed of slurry. can do. That is, since the step eliminating dielectric generally has the same or similar composition as the ceramic green sheet, the color after drying becomes similar. Therefore, it is difficult to detect the alignment mark by using the reflected light. This is the same even before the alignment mark is dried, and it is difficult to set the threshold value. On the other hand, when the transmitted light is used, the alignment mark before being dried has a transmittance different from that of the dried ceramic green sheet because it is in a slurry state. Therefore, it becomes easy to capture the alignment mark.

If a dye or pigment that is burnt with the binder at the time of firing is added to the step-resolving dielectric slurry, the ceramic green sheet and the step-removing dielectric slurry have different colors. Thereby, the detection accuracy of the alignment mark can be further improved.

Further, by forming the alignment marks 61 and 62 on the ceramic green sheet 51, the printability of the alignment marks can be improved. That is, since the carrier film 1 is subjected to a release treatment for peeling the ceramic green sheet 51 later, the conductive paste and the slurry may be repelled. For this reason, the alignment mark cannot be read accurately, and there is a possibility that an error during alignment will increase.

Further, by forming the alignment marks 61, 62 and the like between the patterns on the ceramic green sheet 51, it is possible to reduce the material cost without using an excessive width.

Further, the shutter timing detection mark 5
It is possible to omit one of the patterns by using both 3 and the alignment mark 61 made of the conductive paste.

Next, a method of manufacturing the laminated electronic component according to the second embodiment will be described with reference to FIG.

FIG. 4 is a diagram showing a process of forming an internal electrode and a step eliminating dielectric of a laminated electronic component. In FIG. 4, 1 is a carrier film having a ceramic green sheet formed on its surface, 2 is a tension roll that constantly applies a constant tension to the carrier film, 3 is a compensator roll that adjusts the tension applied to the carrier film by an external command, 4 Is a drying furnace for drying the conductive paste for internal electrodes and the slurry for level difference eliminating dielectric,
Reference numeral 5 is a CCD camera for detecting the alignment mark, 6 is an illuminating device, 7 is a shutter detection sensor, and 10 is a gravure printing roll provided with a conductive paste for internal electrodes and a gravure plate for slurry printing for a dielectric material for eliminating steps.

The manufacturing process shown in FIG. 4 is composed only of the latter printing process shown in the first embodiment, and one gravure printing process is carried out by replacing the plate and passing it twice. An electrode and a step resolution dielectric are formed. Here, the configuration of each of the other parts and the printing method are the same as those in the first embodiment.

With such a structure, the equipment can be downsized and the equipment price can be reduced.

Although the internal electrodes are formed first in the first and second embodiments, the invention is not limited to this, and the step eliminating dielectric may be formed first. .

[0053]

According to the present invention, the alignment marks are individually printed at the same time when the conductive paste for the internal electrodes is printed and the slurry for the level difference eliminating dielectric is printed, and the alignment marks are read at the same time, Performing high-precision gravure printing by detecting misalignment based on the position and aligning the printing position of the conductive paste for internal electrodes with the printing position of the slurry for level difference eliminating dielectric so as to reduce the misalignment. Therefore, it is possible to manufacture a highly accurate laminated electronic component with a high yield.

Further, the alignment after the gravure printing roll exchange can be facilitated, and the productivity can be improved.

Further, according to the present invention, the individual alignment marks are read, and the processing for suppressing the error factors such as bleeding occurring in the image of the read alignment marks is performed, so that the alignment can be performed with higher accuracy. This makes it possible to manufacture a laminated electronic component by performing high-precision gravure printing.

Further, according to the present invention, the ceramic green sheet and the conductive paste for the internal electrodes and the slurry for the step eliminating dielectric are made to have different shades from each other, so that the detection power of the alignment mark is improved and high. It is possible to manufacture a laminated electronic component by accurately performing gravure printing alignment.

Further, according to the present invention, the alignment mark can be reliably formed by printing the alignment mark on the ceramic green sheet, the alignment mark can be detected with high accuracy, and the gravure printing can be performed. Then, the laminated electronic component can be manufactured.

Further, according to the present invention, the illumination used for recognizing the individual alignment marks is transmitted light so that the alignment marks can be read more clearly and gravure printing can be performed with high accuracy. A laminated electronic component can be manufactured.

[Brief description of drawings]

FIG. 1 is a diagram showing a process of forming an internal electrode and a step eliminating dielectric of a laminated electronic component according to a first embodiment.

FIG. 2 is a partial plan view of a carrier film after forming an internal electrode and a partial plan view of a carrier film after forming a step eliminating dielectric.

FIG. 3 is a diagram showing an image of an alignment mark detected by a CCD camera and a diagram showing an image after image processing of the image.

FIG. 4 is a diagram showing a step of forming internal electrodes and a step-eliminating dielectric of the laminated electronic component according to the second embodiment.

FIG. 5 is a diagram showing a process of forming an internal electrode and a step eliminating dielectric of a conventional laminated electronic component.

FIG. 6 is a partial plan view of a carrier film after forming internal electrodes and a partial plan view of a carrier film after forming a step-eliminating dielectric.

[Explanation of symbols]

1-Carrier Film 2-Tension Roll 3-Compensator Roll 4,4a, 4b-Drying Furnace 5-CCD Camera 6-Illumination Device 7-Shutter Detection Sensors 10, 11, 12-Gravure Printing Roll 51-Ceramic Green Sheet 52-Inside Electrode 53-Shutter timing detection mark 54-Step eliminating dielectric 55-Layer alignment mark 56-Overlapping portion 57 of internal electrode 52 and step eliminating dielectric 54-Both internal electrode 52 and step eliminating dielectric 54 No blank area 61-Alignment mark by electrode pattern (first alignment mark) 62-Alignment mark by dielectric pattern (second alignment mark) 71, 72-Bleeding 80-CCD image

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ken Hashimoto             2-10-10 Tenjin, Nagaokakyo, Kyoto Stock             Murata Manufacturing Co., Ltd. (72) Inventor Shinichi Kogawa             2-10-10 Tenjin, Nagaokakyo, Kyoto Stock             Murata Manufacturing Co., Ltd. F term (reference) 5E082 BC38 EE04 EE35 FG06 FG26                       FG46 LL01 LL02 MM04 MM21                       MM26

Claims (5)

[Claims] 1. A method of manufacturing a laminated electronic component, comprising: forming a conductive paste for an internal electrode and a slurry for eliminating a step difference on a surface of a ceramic green sheet by a gravure printing method, and laminating the ceramic green sheets. A first alignment mark is printed at the time of printing the internal electrode conductive paste, and a second alignment mark is printed at the time of printing the step eliminating dielectric slurry; and the first and second alignment marks. Read at the same time,
A print position shift between the conductive paste for internal electrodes and the slurry for level difference eliminating dielectric is detected based on the relative positions of the first and second alignment marks, and the internal electrodes are moved in a direction in which the shift becomes smaller. Of controlling the printing position of the conductive paste for printing or the printing position of the slurry for removing the step difference dielectric material. 2. The method of manufacturing a laminated electronic component according to claim 1, wherein the first and second alignment marks are read, and image processing for suppressing an error factor such as bleeding included in the read image information is performed. . 3. The method for manufacturing a laminated electronic component according to claim 1, wherein the ceramic green sheet, the conductive paste for the internal electrode, and the slurry for the step difference eliminating dielectric have different colors. . 4. The first and second alignment marks are printed on the ceramic green sheet.
4. The method for manufacturing a laminated electronic component according to any one of 3 to 3. 5. The method for manufacturing a laminated electronic component according to claim 1, wherein the illumination used for reading the first and second alignment marks is transmitted light.