JP4506992B2 - Cutting method of sheet laminate - Google Patents

Description

  The present invention relates to a method for cutting a sheet laminate used to produce a multilayer electronic component such as a multilayer ceramic capacitor.

  In general, a multilayer electronic component such as a multilayer ceramic capacitor is manufactured by the following process. First, a plurality of ceramic green sheets having internal electrodes are laminated to produce a sheet laminate. Next, after pressing and pressure-bonding the sheet laminated body, the sheet laminated body is cut into a plurality of one-chip regions to obtain laminated green chips. Furthermore, well-known processes such as binder removal, firing and terminal electrode formation are performed on the multilayer green chip to obtain a multilayer electronic component.

  As a technique for cutting the sheet laminate, there is a technique disclosed in Patent Document 1. That is, a recognition mark corresponding to each cutting line is formed in advance on the surface of the sheet laminate before pressurization, and when the sheet laminate is cut, each recognition mark is subjected to image processing, For example, the cutting position is set.

However, in the disclosed technique of Patent Document 1, it is difficult to set the cutting position of the sheet laminate so as to match the position of the internal electrode inside the sheet laminate. Specifically, there may be a problem that a defect that the internal electrode is exposed to an unintended location or a defect in electrical characteristics due to the shift of the internal electrode from the designed position may occur.
JP-A-8-78273

  The subject of this invention is providing the cutting method of the sheet laminated body which can cut | disconnect a sheet laminated body according to the position of the internal electrode in a sheet laminated body.

  In order to solve the above-described problem, in the sheet laminate cutting method according to the first aspect of the present invention, a sheet laminate having an internal electrode is produced. Next, a positioning mark is formed on the surface of the sheet laminate. Further, the sheet laminate is pressurized.

  Next, after pressing the sheet laminate, the position of the internal electrode and the position of the positioning mark are detected by imaging the sheet laminate with X-rays. Then, reference data in which the position of the internal electrode is associated with the position of the positioning mark is created.

  Next, the sheet laminate is cut based on a result of collating the position of the positioning mark with the reference data.

  As a result of diligent research to find out why the cutting position of the sheet laminate does not match the position of the internal electrode inside the sheet laminate, the inventors have recognized by pressing the sheet laminate. It has been found that the relative positional relationship between the mark and the internal electrode is a major factor. That is, when the sheet laminate is pressurized, the sheet laminate is compressed and deformed, so that the internal electrode inside the sheet laminate is also displaced from the original position. For this reason, since the relative positional relationship between the recognition mark and the internal electrode changes, even if the cutting position is set according to the recognition mark after pressurization, the cutting position matches the actual position of the internal electrode. Not exclusively.

  Therefore, in the present invention, after pressing the sheet laminate, the position of the internal electrode and the position of the positioning mark are detected by imaging the sheet laminate with X-rays. Further, reference data in which the position of the internal electrode is associated with the position of the positioning mark is created. Therefore, reference data reflecting the actual position of the internal electrode can be created even when the internal electrode is displaced due to the pressurization of the sheet laminate.

  Next, since the sheet laminate is cut based on the result of collating the position of the positioning mark with the reference data, the sheet laminate can be cut according to the actual position of the internal electrode.

  The temporal order relationship between the pressurization of the sheet laminate and the formation of the positioning marks is arbitrary. The formation of the positioning mark may be performed after pressurization of the sheet laminate, or may be performed before pressurization of the sheet laminate.

  In the sheet laminate cutting method according to the second aspect of the present invention, a first green sheet on which internal electrodes are formed is prepared. Furthermore, a second green sheet on which positioning marks are formed is prepared.

  Next, a sheet laminate including the first green sheet as an inner layer and the second green sheet as an outermost layer is manufactured. Further, the sheet laminate is pressurized.

  Next, after pressing the sheet laminate, the position of the internal electrode and the position of the positioning mark are detected by imaging the sheet laminate with X-rays. Then, reference data in which the position of the internal electrode is associated with the position of the positioning mark is created.

  Next, the sheet laminate is cut based on a result of collating the position of the positioning mark with the reference data.

  Also by the cutting method of the sheet laminated body according to the second aspect described above, the same effect as the cutting method of the sheet laminated body according to the first aspect can be obtained.

  In the sheet laminate cutting method according to the first aspect and the sheet laminate cutting method according to the second aspect, the positioning mark preferably includes a mark formed from a water-soluble paint. And the mark formed from the water-soluble coating material on a lamination | stacking green chip is erase | eliminated by immersing the lamination | stacking green chip obtained by cutting | disconnection of a sheet | seat laminated body in water before baking.

  Preferably, the sheet laminate is cut while detecting a change in the position of the positioning mark due to the cutting operation itself.

  Preferably, the positioning mark includes a first positioning mark and a second positioning mark. The first positioning mark can be detected by X-rays and can be detected by an optical camera. The second positioning mark can be detected by an optical camera.

  Preferably, the position of the first positioning mark is detected by imaging the sheet stack with X-rays. Next, the position of the first positioning mark and the position of the second positioning mark are detected by imaging the sheet stack with an optical camera. Next, the position of the second positioning mark is associated with the position of the internal electrode via the first positioning mark. Then, the sheet stack is cut while observing the second positioning mark with an optical camera.

  Preferably, the first positioning mark is formed on the surface of the sheet laminate in an outer peripheral region where a laminated green chip cannot be obtained when the sheet laminate is cut. In addition, the second positioning mark is formed in one chip region on the surface of the sheet laminate in which individual laminated green chips are obtained when the sheet laminate is cut.

  As described above, according to the present invention, it is possible to provide a sheet laminate cutting method that can cut a sheet laminate in accordance with the position of the internal electrode inside the sheet laminate.

  FIG. 1 is a flowchart for explaining a sheet laminate cutting method according to an embodiment of the present invention. This embodiment will be described as including both the first and second aspects of the present invention.

  First, as shown in step S1, a sheet laminate is produced. Specifically, as shown in FIG. 2, a plurality of internal electrodes 21 are formed on the first ceramic green sheet 11. The first ceramic green sheet 11 can be produced by applying a ceramic paste on a PET film and drying it. The internal electrode 21 can be formed by printing a conductive paste using a screen printing method or the like. The internal electrodes 21 are arranged in a matrix along the length direction X and the width direction Y. FIG. 2 further shows one chip region A1 for forming one laminated green chip. The internal electrode 21 is formed across two one-chip areas A1 adjacent to each other in the width direction Y when viewed in relation to the one-chip area A1.

  Further, a ceramic green sheet having no internal electrode is also produced as the second ceramic green sheet.

  As shown in FIG. 2, the first ceramic green sheet 11 on which the internal electrode 21 is formed is used as the inner layer unit layers 31 to 3n, and the second ceramic green sheet 12 having no internal electrode is used as the outer layer unit layers 41 to 41. 4k and 51-5m are prepared, and the sheet laminated body 10 is produced by laminating these on the laminating table 91.

  Next, as shown in step S2, the sheet laminate is pressurized. Specifically, as shown in FIG. 4, the sheet laminate 10 is placed on a receiving plate 92. Then, the pressure plate 93 is pressed against the sheet laminate 10 from above, and the sheet laminate 10 is pressurized by applying a force P <b> 1 in the stacking direction of the sheet laminate 10. When the sheet laminate 10 is pressurized, the sheet laminate 10 is compressed in the sheet stacking direction and deformed in the sheet spreading direction. For this reason, the internal electrode 21 located inside the sheet laminate 10 is also displaced from the original position.

  Next, as shown in step S3, a positioning mark is formed on the sheet laminate. Specifically, as shown in FIG. 5, positioning marks (23, 25) are formed on the surface 100 of the sheet laminate 10 by printing or the like. The positioning marks (23, 25) include a first positioning mark 23 and a second positioning mark 25. The first positioning mark 23 is provided in the outer peripheral area A2 on the surface 100 of the sheet laminate 10. The outer peripheral area A2 is an area that is cut off when the sheet laminate 10 is cut into individual laminated green chips. The outer peripheral area A2 is set so as to surround one chip area A1 arranged in a matrix. Further, the second positioning mark 25 is provided so as not to protrude from the one-chip area A1.

  The first positioning mark 23 is preferably a mark that can be detected by an X-ray and can be detected by an optical camera. From any paint that satisfies such conditions, for example, a conductor paste for forming the internal electrode 21 Can be formed.

  The second positioning mark 25 is preferably a mark that can be detected by an optical camera, and need not be detectable by X-rays. Rather, from the viewpoint of imaging one chip area A1 with X-rays thereafter, the second positioning mark 25 is preferably a mark that transmits X-rays. Furthermore, the second positioning mark 25 is preferably a mark formed from a water-soluble paint.

  Next, as shown in step S4, the sheet stack is imaged with X-rays. An example of imaging with X-rays will be described with reference to FIG. First, the sheet stack 10 is placed on the table 61 of the X-ray imaging apparatus, and X-rays 63 are irradiated from the bottom of the table 61 by the X-ray source 62. Then, the sheet stack 10 is imaged by detecting the X-rays 63 transmitted through the sheet stack 10 with the detector 65 while moving the platform 61 in the length direction X and the width direction Y by the driving device 64.

  As shown in FIG. 7, the first positioning mark 23 formed on the surface of the sheet laminate 10 and the internal electrode 21 inside the sheet laminate 10 are detected by imaging with X-rays. By processing this detection result with the data processing device 66 (see FIG. 6), as shown in step S5, a reference in which the position of the first positioning mark 23 and the position of the internal electrode 21 are associated on the XY plane. Create data. Therefore, reference data reflecting the actual position of the internal electrode 21 can be created even if the internal electrode 21 is displaced due to the pressurization of the sheet laminate 10.

  After the imaging with X-rays and the creation of reference data are finished, the sheet stack is transferred from the X-ray imaging device to the cutting device.

  Next, as shown in step S6, the cutting position of the sheet laminate is calculated. Specifically, as shown in FIG. 8, the sheet laminate 10 is placed on the base 71 of the cutting device. And while moving the stand 71 in the length direction X and the width direction Y by the driving device 72, the first positioning mark 23 and the second positioning mark 23 are captured by imaging the surface 100 of the sheet laminate 10 with the optical camera 73. The positioning mark 25 is detected (see FIG. 9).

  By collating the detection results of the first and second positioning marks 23 and 25 with the above reference data, the position of the second positioning mark 25 and the position of the internal electrode via the first positioning mark 23 Are superimposed on the XY plane and related. As a result, the cutting positions C1 and C2 suitable for the position of the internal electrode can be calculated as positions viewed from the second positioning mark 25.

  Next, as shown in step S7, the sheet laminated body 10 is cut according to the cutting positions C1 and C2 while observing the position of the second positioning mark 25 with the optical camera 73. Can be cut to fit the actual position.

  As a method for cutting the sheet laminate 10, a rotary blade cutting method or a push cutting method can be adopted. Here, the example which employ | adopted the rotary blade cutting method is demonstrated. As illustrated in FIG. 8, the disk-shaped cutting blade 79 that is rotationally driven by the driving device 78 is applied to the cutting positions C <b> 1 and C <b> 2 of the sheet stacked body 10 to cut the sheet stacked body 10. Thereby, individual laminated green chips can be obtained.

  In addition, it is preferable to cut the sheet stack 10 while detecting a change in the position of the second positioning mark 25 by the cutting operation itself with the optical camera 73. By detecting the change in position of the second positioning mark 25, the cutting positions C1 and C2 can be corrected following the influence of the deformation of the cutting blade 92 on the sheet laminate 10, and high-precision cutting is possible. It becomes.

  Further, since the second positioning mark 25 does not protrude from the one chip area A1, and is formed in the one chip area A1, it is not cut by the cutting blade 79. Therefore, since all of the second positioning marks 25 can be observed without being lost until the cutting process is completed, the cutting accuracy of the cutting blade 79 is deteriorated when the sheet laminated body 10 is cut into individual laminated green chips. Never do.

  However, since the second positioning mark 25 is formed in one chip area A1, it remains on the laminated green chip even after the sheet laminate 10 is cut. For this reason, a process for removing the second positioning mark 25 is required.

  Therefore, as shown in step S8, the second positioning mark on the stacked green chip is erased. In the present embodiment, the laminated green chip is immersed in water in order to erase the second positioning mark on the laminated green chip. Specifically, in a state where the laminated green chip is placed in the barrel container, it is immersed in water and the barrel container is rotated. Thereafter, as shown in step S9, the multilayer green chip is fired to obtain a multilayer chip.

  In the case of the disclosed technique of Patent Document 1, since the recognition mark is formed of a conductive paste, it cannot be erased by immersing it in water, and barrel recognition is performed after firing to remove the recognition mark. However, during firing, the mark may be burned onto the surface of the element body, which may leave scorching on the element surface. The laminated chip after firing is extremely hard, and there is a problem that if the burn-in is performed by barrel polishing and the burn is removed, the laminated chip is scraped off and the roundness of the corner of the laminated chip becomes too large.

  On the other hand, in the sheet laminate cutting method according to the embodiment, a water-soluble paint is used as the paint for the second positioning mark. Therefore, the second positioning mark can be completely removed by immersing the laminated green chip in water before firing. Therefore, it is possible to avoid the problem that the roundness of the corner of the laminated chip becomes too large in order to remove the mark after firing. Also, the second positioning mark can be removed from the soft and brittle laminated green chip before firing.

  Further, as another method for erasing the second positioning mark formed on the surface of the laminated green chip, blasting in which fine particles are jetted and applied to the surface of the laminated green chip can be employed. In the stage before the multilayer green chip is fired, the second positioning mark is not baked on the element body of the multilayer green chip, and thus can be satisfactorily removed by blasting without damaging the element body.

  As blasting, either wet blasting, in which fine particles are sprayed in a slurry mixed with water, or drive blasting, in which fine particles are injected without using water, can be used. In order to erase the second positioning mark formed from the above, wet blasting is more preferable.

  The second positioning mark 25 is as described above. Since the first positioning mark 23 is formed in the outer peripheral area A2 (see FIG. 5) where the laminated green chip cannot be obtained on the surface 100 of the sheet laminate 10, it does not remain on the laminated green chip. Therefore, the process for removing the first positioning mark 23 is not required, and the paint for forming the first positioning mark 23 can be freely selected.

  In the present embodiment, after the step of pressurizing the sheet laminate (step S2), the step of forming the positioning mark on the sheet laminate (step S3) is performed, but on the contrary, the step after step S3 is performed. S2 may be performed.

  In the present embodiment, the first and second ceramic green sheets 11 and 12 are laminated (see FIG. 3), and a positioning mark is formed on the surface 100 of the obtained sheet laminate 10 (FIG. 5). Unlike this, a positioning mark is formed in advance on the second ceramic green sheet that is the outermost layer, and thereafter, the first and second ceramic green sheets are laminated on the surface. It is also possible to produce a sheet laminate having a positioning mark.

  Although the contents of the present invention have been specifically described with reference to the preferred embodiments, various modifications can be made by those skilled in the art based on the basic technical idea and teachings of the present invention. It is self-explanatory.

It is a flowchart for demonstrating the cutting method of the sheet laminated body which concerns on one Embodiment of this invention. It is a figure explaining the cutting method of the sheet laminated body shown in FIG. FIG. 3 is a diagram showing a step after the step shown in FIG. 2. It is a figure which shows the step after the step shown in FIG. It is a figure which shows the step after the step shown in FIG. It is a figure which shows the X-ray imaging device used for the imaging by an X-ray in the cutting method of the sheet | seat laminated body shown in FIG. It is a figure explaining the detection operation of an internal electrode and a positioning mark. It is a figure which shows the cutting device used for the cutting | disconnection of a sheet laminated body. It is a figure for demonstrating the cutting | disconnection of a sheet laminated body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 1st ceramic green sheet 12 2nd ceramic green sheet 10 Sheet laminated body 21 Internal electrode 23 1st positioning mark 25 2nd positioning mark

Claims (9)

Fabricate a sheet laminate with internal electrodes,
Forming a positioning mark on the surface of the sheet laminate,
Pressurizing the sheet laminate,
After pressing the sheet laminate, the position of the internal electrode and the position of the positioning mark are detected by imaging the sheet laminate with X-rays,
Create reference data that associates the position of the internal electrode and the position of the positioning mark,
Cutting the sheet laminate based on the result of collating the position of the positioning mark with the reference data ,
Further, the positioning mark includes a first positioning mark and a second positioning mark,
The first positioning mark can be detected with an X-ray and can be detected with an optical camera,
The second positioning mark can be detected by an optical camera.
Cutting method of sheet laminate. It is the cutting method of the sheet | seat laminated body described in Claim 1, Comprising:
The positioning mark is formed after pressurization of the sheet laminate.
Cutting method of sheet laminate. It is the cutting method of the sheet | seat laminated body described in Claim 1, Comprising:
The positioning mark is formed before pressurization of the sheet laminate.
Cutting method of sheet laminate. Prepare a first green sheet on which internal electrodes are formed,
Prepare a second green sheet with positioning marks,
Producing a sheet laminate comprising the first green sheet in the inner layer and the second green sheet in the outermost layer,
Pressurizing the sheet laminate,
After pressing the sheet laminate, the position of the internal electrode and the position of the positioning mark are detected by imaging the sheet laminate with X-rays,
Create reference data that associates the position of the internal electrode and the position of the positioning mark,
Cutting the sheet laminate based on the result of collating the position of the positioning mark with the reference data ,
Further, the positioning mark includes a first positioning mark and a second positioning mark,
The first positioning mark can be detected with an X-ray and can be detected with an optical camera,
The second positioning mark can be detected by an optical camera.
Cutting method of sheet laminate. A method for cutting a sheet laminate according to any one of claims 1 to 4,
The positioning mark includes a mark formed from a water-soluble paint,
The laminated green chip obtained by cutting the sheet laminate is immersed in water before firing, thereby erasing the mark formed from the water-soluble paint on the laminated green chip.
Cutting method of sheet laminate. A method for cutting a sheet laminate according to any one of claims 1 to 5,
Cutting the sheet laminate while detecting a change in the position of the positioning mark due to the cutting operation itself;
Cutting method of sheet laminate. It is the cutting method of the sheet | seat laminated body described in Claim 1 or 4,
Detecting the position of the first positioning mark by imaging the sheet laminate with X-rays;
Next, the position of the first positioning mark and the position of the second positioning mark are detected by imaging the sheet stack with an optical camera,
Next, the position of the second positioning mark and the position of the internal electrode are associated via the first positioning mark,
Cutting the sheet stack while observing the position of the second positioning mark with an optical camera;
Cutting method of sheet laminate. It is the cutting method of the sheet | seat laminated body described in Claim 7, Comprising:
The first positioning mark is formed on an outer peripheral region where a laminated green chip cannot be obtained when the sheet laminate is cut on the surface of the sheet laminate.
Cutting method of sheet laminate. It is the cutting method of the sheet | seat laminated body described in Claim 7 or 8, Comprising:
The second positioning mark is formed on a surface of the sheet laminate in one chip area where individual laminated green chips are obtained when the sheet laminate is cut.
Cutting method of sheet laminate.

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