JP2012080008A - Method of manufacturing multilayer ceramic electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a multilayer ceramic electronic component less susceptible to displacement when a ceramic green block is cut by a dicer.SOLUTION: When manufacturing a multilayer ceramic capacitor, a ceramic green block is prepared. The ceramic green block includes a plurality of ceramic green sheets stacked one upon another, and has a cut mark on a side surface thereof. The ceramic green block is mounted on a table. Then, by applying cutting water to the ceramic green block before cutting and the table, a surface temperature of the ceramic green block before cutting is brought near a surface temperature of the ceramic green block during cutting. Thereafter, the ceramic green block is cut by the dicer to a predetermined size while applying the cutting water to the ceramic green block with reference to the cut mark.

Description

  The present invention relates to a method for manufacturing a multilayer ceramic electronic component, and more particularly, to a method for manufacturing a multilayer ceramic electronic component having internal electrodes, such as a multilayer ceramic electronic component such as a multilayer ceramic capacitor, a multilayer LC composite component, a multilayer piezoelectric actuator, and a multilayer substrate. About.

When manufacturing multi-layer ceramic electronic components such as multi-layer ceramic capacitors, normally, a plurality of ceramic green sheets printed with internal electrode patterns are stacked and pressed to create a ceramic green block. And a process of producing a large number of ceramic green chips. Here, when cutting the ceramic green block, it is necessary to accurately cut the margin between the internal electrode patterns. However, since the internal electrode patterns cannot be seen from the outside, the cut mark serving as a reference for cutting is ceramic. Often provided on the surface of the green block.
A method for manufacturing such a multilayer ceramic electronic component is described in, for example, Japanese Patent Application Laid-Open No. 07-335479 (see Patent Document 1).

JP 07-335479 A

In the method for manufacturing a multilayer ceramic electronic component as described above, there is a dicer as means for cutting the ceramic green block.
However, when cutting with a dicer, the ceramic green block may not be cut as intended, although the alignment is performed with the cut mark as a reference.

  Therefore, a main object of the present invention is to provide a method for manufacturing a multilayer ceramic electronic component that is less likely to be displaced when a ceramic green block is cut with a dicer.

A method of manufacturing a multilayer ceramic electronic component according to the present invention includes a step of preparing a ceramic green block including a plurality of laminated ceramic green sheets and having a cut mark on the surface, and a step of placing the ceramic green block on a table And cutting the ceramic green block into a predetermined size with a dicer while applying cutting water to the ceramic green block with reference to the cut mark. A method for producing a multilayer ceramic electronic component, characterized in that the temperature of the surface of the block is made closer to the temperature of the surface of the ceramic green block at the time of cutting.
In the manufacturing method of the multilayer ceramic electronic component according to the present invention, for example, by cooling or warming the ceramic green block by applying cutting water to the ceramic green block before cutting, the temperature of the surface of the ceramic green block before cutting, It is characterized by being close to the surface temperature of the ceramic green block at the time of cutting.
In the method for manufacturing a multilayer ceramic electronic component according to the present invention, for example, the ceramic green block before cutting is cooled or warmed by applying cutting water to the ceramic green block and table before cutting, thereby cooling the ceramic green block and table. The surface temperature of the ceramic is close to the temperature of the surface of the ceramic green block at the time of cutting.
Furthermore, in the multilayer ceramic electronic component according to the present invention, for example, the temperature of the surface of the ceramic green block at the time of cutting is reduced by bringing the temperature of the cutting water close to the temperature of the surface of the ceramic green block before cutting. It is characterized by being close to the temperature of the surface of the green block.

Upon completion of the present invention, the present inventor conducted extensive research and found that the cutting water had a decrease in cutting accuracy when using a dicer. Cutting water is water that is applied to the ceramic green block when using a dicer for the purpose of suppressing heat during cutting or removing chips. That is, the cutting water causes the ceramic green block to be cooled and contracted, for example, and the position of the cut mark is deviated as compared with the alignment.
Therefore, in the present invention, the temperature of the surface of the ceramic green block before cutting is brought close to the temperature of the surface of the ceramic green block at the time of cutting. More specifically, the ceramic green block is preliminarily cooled or warmed by, for example, cutting water or the like applied to the ceramic green block, or the ceramic green block and the table are preliminarily sprayed with water such as cutting water or the like. Cool or warm the table or bring the temperature of the cutting water closer to the surface temperature of the ceramic green block before cutting.
In the present invention, the temperature of the surface of the ceramic green block before cutting refers to the temperature of the surface of the ceramic green block when alignment is performed based on the cut mark of the ceramic green block before the ceramic green block is cut. Temperature.
In the present invention, the temperature of the surface of the ceramic green block at the time of cutting is the temperature of the surface of the ceramic green block when the ceramic green block is cut with a dicer while cutting water is applied to the ceramic green block.

According to the present invention, in the method of manufacturing a multilayer ceramic electronic component, the temperature of the surface of the ceramic green block before cutting is brought close to the temperature of the surface of the ceramic green block at the time of cutting. The ceramic green block will be aligned in the already contracted or expanded state corresponding to the size of the ceramic green block, or the ceramic green block will be cut in a state corresponding to the size of the ceramic green block before cutting. become. Therefore, according to this invention, it becomes difficult to receive the influence by cutting water at the time of cutting | disconnection of a ceramic green block, and when a ceramic green block is cut | disconnected by a dicer, it becomes difficult to produce position shift.
Further, in the method for manufacturing a multilayer ceramic electronic component according to the present invention, when the ceramic green block before cutting is cooled or warmed with cutting water, there is no need for equipment for applying water other than the cutting water to the ceramic green block before cutting. .
Furthermore, in the method for manufacturing a multilayer ceramic electronic component according to the present invention, when cutting water is applied to the ceramic green block and the table before cutting, the cutting water is also applied to the table on which the ceramic green block is placed in addition to the ceramic green block. Therefore, the temperature of the surface of the ceramic green block becomes stable quickly.
Further, in the method for manufacturing a multilayer ceramic electronic component according to the present invention, if the temperature of the cutting water is brought close to the surface temperature of the ceramic green block before cutting, it is not necessary to adjust the surface temperature of the ceramic green block before cutting. . Therefore, it is not necessary to apply water such as cutting water to the ceramic green block before cutting.

  The above-described object, other objects, features, and advantages of the present invention will become more apparent from the following description of embodiments for carrying out the invention with reference to the drawings.

It is a perspective view which shows an example of the multilayer ceramic capacitor to which this invention is applied. FIG. 2 is an illustrative sectional view taken along line II-II in FIG. 1. FIG. 2 is an essential part illustrative view showing a step of cutting a ceramic green block by a dicer in an example of the method for manufacturing the multilayer ceramic capacitor according to the present invention for manufacturing the multilayer ceramic capacitor shown in FIG. 1. It is a graph which shows the coordinate variation | change_quantity of the cut mark when a block is cooled from 21 degreeC to 13 degreeC in an experiment example, (A) is the coordinate variation | change_quantity of the cut mark in a X direction (the same direction as the longitudinal direction of a block). (Shrinkage amount) is shown, (B) is the coordinate change amount (shrinkage amount) of the cut mark in the Y direction (the direction perpendicular to the X direction when viewed in plan), and the horizontal axis is the measurement coordinate (mm). The vertical axis indicates the amount of change in coordinates (μm) (the difference in coordinates of cut marks before and after movement (μm)). It is a graph which shows the coordinate variation | change_quantity of the cut mark at the time of applying cutting water with respect to a block after the countermeasure in an experiment example, (A) is the coordinate of the cut mark in the X direction (the same direction as the longitudinal direction of a block). The amount of change (shrink amount) is shown, (B) shows the coordinate change amount (shrink amount) of the cut mark in the Y direction (the direction orthogonal to the X direction when viewed in plan), and the horizontal axis shows the measurement coordinates ( mm), and the vertical axis represents the amount of change in coordinates (μm) (difference in coordinates of cut marks before and after movement (μm)).

  FIG. 1 is a perspective view showing an example of a multilayer ceramic capacitor to which the present invention is applied, and FIG. 2 is a cross-sectional view taken along line II-II in FIG. A multilayer ceramic capacitor 10 shown in FIG. 1 includes, for example, a rectangular parallelepiped ceramic body 12.

  The ceramic body 12 includes a plurality of laminated ceramic layers 14, and includes a first main surface 16a and a second main surface 16b facing each other, and a first side surface 18a and a second side surface 18b facing each other. The first end face 20a and the second end face 20b are opposed to each other. The ceramic body 12 preferably has rounded corners 22 and ridges 24, respectively.

As a ceramic material of the ceramic layer 14 for forming the ceramic body 12, for example, a dielectric ceramic composed of main components such as BaTiO ₃ , CaTiO ₃ , SrTiO ₃ , and CaZrO ₃ can be used. Moreover, as a ceramic material of the ceramic layer 14, what added subcomponents, such as a Mn compound, Mg compound, Si compound, Co compound, Ni compound, rare earth compound, to those main components may be used. The thickness of each ceramic layer 14 of the ceramic body 12 is preferably 0.5 μm to 10 μm.

  In the ceramic body 12, a plurality of first internal electrodes 26 a and a plurality of second internal electrodes 26 b are alternately arranged between the ceramic layers 14. As materials for the first internal electrode 26a and the second internal electrode 26b, for example, Ni, Cu, Ag, Pd, an Ag—Pd alloy, Au, or the like can be used, respectively. The thickness of each first internal electrode 26a or the thickness of each second internal electrode 26b is preferably 0.3 μm to 2.0 μm, respectively.

  The first internal electrode 26a includes a first facing portion 28a, a first lead portion 30a, and a first exposed portion 32a. The first facing portion 28a faces the second internal electrode 26b. The first lead portion 30a is drawn from the first facing portion 28a to the first end face 20a of the ceramic body 12. The first exposed portion 32 a is exposed on the first end face 20 a of the ceramic body 12.

  Similarly to the first internal electrode 26a, the second internal electrode 26b includes a second facing portion 28b facing the first internal electrode 26a, and a second facing portion 28b of the ceramic body 12 from the second facing portion 28b. It has the 2nd drawer | drawing-out part 30b pulled out by the end surface 20b, and the 2nd exposed surface 32b exposed to the 2nd end surface 20b of the ceramic element | base_body 12. As shown in FIG.

  A first external electrode 34a and a second external electrode 34b are formed on the outer surface of the ceramic body 12 so as to be electrically connected to the first internal electrode 26a and the second internal electrode 26b, respectively. . As materials of the first external electrode 34a and the second external electrode 34b, for example, one kind of metal selected from the group consisting of Ag, Cu, Au, and Sn, or an alloy containing the metal is used. Can do. The thickness of the first external electrode 34a and the thickness of the second external electrode 34b are preferably 5 μm to 200 μm, respectively.

  The first external electrode 34a covers the first exposed portion 32a of the first internal electrode 26a, covers the first end surface 20a on the outer surface of the ceramic body 12, and the first main surface. 16a, the second main surface 16b, the first side surface 18a, and the second side surface 18b.

  Similarly, the second external electrode 34b covers the second exposed surface 32b of the second internal electrode 26b and the second end surface 20b on the outer surface of the ceramic body 12 and the first external electrode 34b. The main surface 16a, the second main surface 16b, the first side surface 18a and the second side surface 18b are respectively formed on the other end portions.

  One or more plating films may be formed on the surface of the first external electrode 34a and the surface of the second external electrode 34b, respectively. As a material of such a plating film, for example, one kind of metal selected from the group consisting of Cu, Ni, Sn, Pb, Au, Ag, Pd, Al, Bi, and Zn, or an alloy containing the metal is used. Can be used.

  Next, an example of a method for manufacturing a multilayer ceramic capacitor for manufacturing the multilayer ceramic capacitor 10 shown in FIG. 1 will be described.

  First, a ceramic green sheet, a conductive paste for internal electrodes, and a conductive paste for external electrodes are prepared. The ceramic green sheet and various conductive pastes include a binder and a solvent, and a known organic binder or organic solvent can be used.

  Next, the internal electrode conductive paste is printed on the ceramic green sheet in a predetermined pattern by, for example, screen printing to form an internal electrode pattern. At this time, a cut mark pattern is printed and formed around the internal electrode pattern using the same conductive paste as the internal electrode conductive paste.

  Then, a predetermined number of outer layer ceramic green sheets on which the internal electrode pattern and cut mark pattern are not printed are laminated, and ceramic green sheets on which the internal electrode pattern and cut mark pattern are printed are sequentially laminated, A ceramic green block is produced by laminating a predetermined number of ceramic green sheets for outer layers on top.

  Then, the ceramic green block is pressed in the stacking direction by means such as isostatic pressing.

  Then, the pressed ceramic green block is placed on the table, and water is applied to the ceramic green block and the table to cool the ceramic green block and the table, for example. The temperature of the water at this time is preferably the same as the temperature of the cutting water used when cutting with a dicer. More specifically, the cutting water used when cutting with a dicer may be applied to the ceramic green block and the table.

  In addition, cooling of the table is not always essential. However, depending on the ambient temperature condition, the surface of the ceramic green block may not be sufficiently cooled only by water such as cutting water due to the influence of the temperature of the table. (For example, when the dicer equipment is operated after being stopped for a long time, the table temperature approaches the normal temperature.) In such a case, it is preferable to cool the table as well. At this time, the temperature of the table is preferably adjusted to the same level as the temperature of the cutting water used when cutting with the dicer.

  In addition, the place where the cutting by the dicer is performed is often controlled at room temperature, and is usually maintained at about 20 ° C. throughout the year. On the other hand, the temperature of industrial water used as cutting water can vary in the range of about 13 ° C. to 25 ° C. throughout the year. That is, the ceramic green block and the table before cutting are not necessarily cooled by water such as cutting water, and in summer, the temperature of the cutting water may be higher than the room temperature of the place where cutting by the dicer is performed, The ceramic green block and table before cutting may be slightly warmed.

  Then, the outer peripheral edge of the ceramic green block is cut off to expose the cut mark formed by the cut mark pattern on the side surface (front surface) of the ceramic green block.

  Then, alignment is performed based on the cut mark. In this case, a cut mark exposed from the side surface of the ceramic green block is photographed by an imaging mechanism such as a CCD camera, and image data such as the cut mark is analyzed by an arithmetic mechanism to determine a cut position.

  As shown in FIG. 3, the ceramic green block is cut into a predetermined size by a dicer while applying cutting water to the ceramic green block to obtain a large number of ceramic green chips. Thereafter, the corners and ridges of the ceramic green chip may be rounded by barrel polishing or the like.

  Then, the ceramic green chip is fired into a ceramic chip. The firing temperature is preferably 900 ° C. to 1300 ° C., although it depends on the material of the ceramic body and internal electrodes. The fired ceramic chip becomes the ceramic body 12, the first internal electrode 26 a and the second internal electrode 26 b of the multilayer ceramic capacitor 10.

  Then, a conductive paste for external electrodes is applied to both end faces of the fired ceramic chip and baked to form the first external electrode 34a and the second external electrode 34b. Note that one or a plurality of plating films may be formed on the surface of the first external electrode 34a and the surface of the second external electrode 34b by performing plating as necessary.

  As described above, the multilayer ceramic capacitor 10 shown in FIG. 1 is manufactured.

  In the manufacturing method of the above-mentioned multilayer ceramic capacitor, the temperature of the surface of the ceramic green block before cutting is brought close to the surface temperature of the ceramic green block at the time of cutting, so the ceramic green block corresponds to the size of the ceramic green block at the time of cutting. Thus, the alignment is performed in the already contracted or expanded state. Therefore, according to the manufacturing method of the above-mentioned multilayer ceramic capacitor, it becomes difficult to be affected by cutting water when the ceramic green block is cut, and misalignment hardly occurs when the ceramic green block is cut with a dicer. As described above, if the ceramic green block is not easily displaced when the ceramic green block is cut with a dicer, the defect rate is reduced and the yield is improved in the manufactured multilayer ceramic capacitor.

  Moreover, in the manufacturing method of the above-mentioned multilayer ceramic capacitor, since the ceramic green block before cutting is cooled or warmed with cutting water, there is no need for equipment for applying water other than cutting water to the ceramic green block before cutting.

  Furthermore, in the above-described method for manufacturing a multilayer ceramic capacitor, cutting water is applied to the ceramic green block and the table before cutting, that is, the cutting water is also applied to the table on which the ceramic green block is placed in addition to the ceramic green block. Therefore, the surface temperature of the ceramic green block becomes stable quickly.

(Experimental example)
This experimental example verifies the effect of applying the present invention to the positional deviation of the cut mark on the surface of the ceramic green block due to the action of the temperature of the cutting water.

<About the phenomenon of misalignment>
A ceramic green block (hereinafter abbreviated as “block”) prepared with a predetermined specification based on the above description was prepared and set on a table of a dicer. The temperature of the block immediately after this was 21 ° C. equivalent to room temperature.
However, after alignment, when the cutting water was applied to the block in the cutting operation, the block was cooled to 13 ° C. Due to this temperature drop, the block contracted, and a shift occurred between the position of the cut mark recognized at the time of alignment and the position of the cut mark at the time of cutting.

<About deviation amount>
FIG. 4 shows the amount of change in the coordinates of the cut marks when the block is cooled to 13 ° C. by applying cutting water to the 21 ° C. block. FIG. 4 is a graph showing the amount of change in the coordinate of the cut mark when the block is cooled from 21 ° C. to 13 ° C., (A) is the change in the coordinate of the cut mark in the X direction (the same direction as the longitudinal direction of the block). The amount (shrinkage amount) is shown, (B) shows the coordinate change amount (shrinkage amount) of the cut mark in the Y direction (the direction orthogonal to the X direction when viewed in plan), and the horizontal axis shows the measurement coordinates (mm The vertical axis represents the amount of change in coordinates (μm) (the difference in coordinates of cut marks before and after movement (μm)). From the graphs shown in FIGS. 4A and 4B, when the block is cooled from 21 ° C. to 13 ° C., the outer peripheral portion of the block contracts toward the center, and the position of the cut mark is displaced. I understand.

<Measures against misalignment>
A block having the same specifications as above was prepared, and the following two measures (1) and (2) were performed.

(1) Cooling of the block before alignment The operation of cooling the block by applying 13 ° C. cooling water (cutting water) to the block before alignment was added. At this time, the cooling time of the block was set to 60 seconds.

(2) Cooling of the table before alignment An operation of cooling by applying cooling water (cutting water) at 13 ° C. to the table before alignment was added. At this time, the cooling time of the table was set to 15 minutes.

  FIG. 5 shows the amount of change in the coordinates of the cut mark when cutting water is applied to the block after the above measures. FIG. 5 is a graph showing the coordinate change amount of the cut mark when cutting water is applied to the block after the above-mentioned countermeasures, and (A) shows the cut in the X direction (the same direction as the longitudinal direction of the block). The coordinate change amount (shrinkage amount) of the mark is shown, (B) shows the coordinate change amount (shrinkage amount) of the cut mark in the Y direction (the direction orthogonal to the X direction when viewed in plan), and the horizontal axis is The measurement coordinate (mm) is shown, and the vertical axis shows the coordinate change amount (μm) (the difference between the coordinates of the cut mark before and after the movement (μm)). From the graphs shown in FIGS. 5 (A) and 5 (B), it can be seen that there is almost no displacement even when cutting water is applied to the block after the above measures.

Next, another example of a method for manufacturing a multilayer ceramic capacitor for manufacturing the multilayer ceramic capacitor 10 shown in FIG. 1 will be described.
In the manufacturing method of the above-mentioned multilayer ceramic capacitor, the approach of bringing the surface temperature of the ceramic green block before cutting closer to the temperature of the cutting water used at the time of cutting was taken, but in the manufacturing method of the next multilayer ceramic capacitor, Conversely, the temperature of the cutting water is adjusted based on the temperature of the surface of the ceramic green block before cutting.
That is, in this method for manufacturing a multilayer ceramic capacitor, water such as cutting water is not applied to the ceramic green block or table before cutting, as compared with the method for manufacturing a multilayer ceramic capacitor described above. Instead, in this multilayer ceramic capacitor manufacturing method, the temperature of the cutting water applied to the ceramic green block at the time of cutting is brought close to the surface temperature of the ceramic green block before cutting, thereby The temperature is brought close to the surface temperature of the ceramic green block before cutting.

  In this multilayer ceramic capacitor manufacturing method, the temperature of the surface of the ceramic green block at the time of cutting is brought close to the temperature of the surface of the ceramic green block before cutting, so the ceramic green block corresponds to the size of the ceramic green block before cutting. Will be disconnected in the state. Therefore, this multilayer ceramic capacitor manufacturing method is also less susceptible to cutting water when the ceramic green block is cut, and is less likely to be displaced when the ceramic green block is cut with a dicer.

  Further, in this method for manufacturing a multilayer ceramic capacitor, the temperature of the cutting water is brought close to the temperature of the surface of the ceramic green block before cutting, so it is not necessary to adjust the temperature of the surface of the ceramic green block before cutting. Therefore, it is not necessary to apply water such as cutting water to the ceramic green block before cutting.

  In the above-described embodiment, the manufacturing method of the multilayer ceramic capacitor has been described as an example. However, in addition to the multilayer ceramic capacitor, the present invention particularly includes an internal electrode such as a multilayer LC composite component, a multilayer piezoelectric actuator, and a multilayer substrate. The present invention can also be applied to a method for manufacturing a multilayer ceramic electronic component for manufacturing other multilayer ceramic electronic components.

  The method for manufacturing a multilayer ceramic electronic component according to the present invention is suitably used for manufacturing a multilayer ceramic electronic component having internal electrodes, such as a multilayer ceramic capacitor, a multilayer LC composite component, a multilayer piezoelectric actuator, and a multilayer substrate.

DESCRIPTION OF SYMBOLS 10 Multilayer ceramic capacitor 12 Ceramic body 14 Ceramic layer 16a 1st main surface 16b 2nd main surface 18a 1st side surface 18b 2nd side surface 20a 1st end surface 20b 2nd end surface 22 Corner 24 Ridge 26a 1st internal electrode 26b 2nd internal electrode 28a 1st opposing part 28b 2nd opposing part 30a 1st drawer | drawing-out part 30b 2nd drawer | drawing-out part 32a 1st exposed part 32b 2nd exposed part 34a 1st External electrode 34b Second external electrode

Claims (4)

Preparing a ceramic green block including a plurality of laminated ceramic green sheets and having a cut mark on the surface;
Placing the ceramic green block on a table;
In the method of manufacturing a multilayer ceramic electronic component comprising a step of cutting the ceramic green block into a predetermined size by a dicer while applying cutting water to the ceramic green block with reference to the cut mark,
A method for producing a multilayer ceramic electronic component, wherein the temperature of the surface of the ceramic green block before cutting is made closer to the temperature of the surface of the ceramic green block at the time of cutting.   By cooling or warming the ceramic green block by applying the cutting water to the ceramic green block before cutting, the surface temperature of the ceramic green block before cutting is set to the temperature of the surface of the ceramic green block at the time of cutting. The method for producing a multilayer ceramic electronic component according to claim 1, wherein   The ceramic green block and the table before cutting are sprayed with the cutting water to cool or warm the ceramic green block and the table, so that the surface temperature of the ceramic green block before cutting is changed to the ceramic at the time of cutting. The method for producing a multilayer ceramic electronic component according to claim 1, wherein the temperature is close to the temperature of the surface of the green block.   By bringing the temperature of the cutting water close to the surface temperature of the ceramic green block before cutting, the surface temperature of the ceramic green block at the time of cutting is made close to the temperature of the surface of the ceramic green block before cutting. The method for producing a multilayer ceramic electronic component according to claim 1, wherein the method is characterized in that:

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