JP4367229B2 - Manufacturing method of multilayer ceramic electronic component - Google Patents

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 including a step of obtaining a plurality of chips by cutting a multilayer body of ceramic green sheets, for example.

  To manufacture a multilayer ceramic electronic component, a ceramic green sheet is first formed using a ceramic material. By printing a conductive paste on the ceramic green sheet, a conductor pattern to be an internal electrode of the multilayer ceramic electronic component is formed. For example, when manufacturing a multilayer ceramic capacitor, a plurality of rectangular conductor patterns are formed on a ceramic green sheet. A plurality of ceramic green sheets on which a conductor pattern is formed are laminated, and a laminate 1 is formed as shown in FIG. In the laminate 1, the conductor patterns 2 are laminated alternately in adjacent ceramic green sheets.

  The obtained laminated body 1 is placed on the cut stage 3 and cut by the cutting blade 4 to form a chip in which the conductor patterns 2 adjacent to the opposing end faces are alternately exposed. At this time, the laminated body 1 is heated by the heater 5 in the cut stage 3 to soften the laminated body 1 so that the laminated body 1 can be easily cut. By firing the obtained chip, a substrate having an internal electrode is formed. A multilayer ceramic capacitor is formed by forming an external electrode on the internal electrode exposed surface of the substrate (see, for example, Patent Document 1).

  However, for example, as shown in FIG. 10, when the heater 5 is arranged in a circle in the cut stage 3, the laminate 1 is sufficiently heated at the top of the heater 5, but at a portion away from the heater 5, It is not heated enough. Therefore, in the cut line shown in FIG. 10, a portion that is easy to cut such as a portion corresponding to the heater 5 of the laminated body 1 and a portion that is difficult to cut such as a corner portion or a central portion of the laminated body 1 are generated. Moreover, since the cut stage 3 is supported by the support part 3a as shown in FIG. 11, heat will escape from this support part 3a. Therefore, in the part corresponding to the support part 3a, there exists a tendency for heating temperature to become low.

  Thus, in the system in which the entire cut stage 3 is heated by the heater 5, it is difficult to make the temperature distribution of the laminated body 1 constant, and there is a possibility of causing a cut defect of the laminated body 1. Therefore, a technique is disclosed in which the cut blade 4 is heated and pressed against the laminated body 1 to obtain a uniform temperature distribution along the cut line of the laminated body 1 and accurately cut the laminated body 1 (for example, Patent Document 2).

JP 61-144810 A Japanese Patent Laid-Open No. 2-126621

  However, in the method of cutting the laminate by heating the cutting blade, when the amount of binder in the laminate is large and the laminate is hard, or when the number of ceramic green sheets is large and the thickness of the laminate is large. However, it is difficult to achieve a temperature at which the cut portion is softened in a short time only by heating from the cutting blade. Further, if the temperature of the cutting blade is raised too much, the laminated body becomes locally too hot, and problems such as delamination due to gasification of the plasticizer and moisture occur in the cross section of the laminated body.

  Therefore, a main object of the present invention is to provide a method for manufacturing a multilayer ceramic electronic component capable of accurately cutting a multilayer body in a short time and obtaining a multilayer ceramic electronic component free from defects such as layer peeling. Is to provide.

The present invention includes a step of preparing a laminated body in which a plurality of ceramic green sheets are laminated, a step of placing the laminated body on a cut stage for cutting the laminated body, and at least a line for cutting the laminated body A multilayer ceramic electronic component including a step of adjusting temperatures in a plurality of ranges of the cut stage so that the temperature distribution is substantially constant, and a step of cutting the laminate along a line in which the temperature distribution is substantially constant It is a manufacturing method.
In such a method for manufacturing a multilayer ceramic electronic component, the temperature may be adjusted so that the temperature distribution of the entire multilayer body is substantially constant.
Moreover, a temperature sensor is contact | abutted along the line which cuts a laminated body, and a laminated body can be cut when the temperature distribution detected by a temperature sensor becomes substantially constant.

The laminated body can be heated corresponding to the heat transfer state in each range by adjusting the temperature in a plurality of ranges of the cut stage instead of heating the entire cut stage at once. Thereby, it can be set as a substantially constant temperature distribution on the line which cuts a laminated body, and a laminated body can be cut, without raise | generating peeling of a layer. And since the whole surface of a laminated body is heated from a cut stage, the temperature adjustment of a laminated body can be performed in a short time.
Note that it is sufficient that the temperature distribution is substantially constant along at least a line for cutting the laminate, and the temperature of the plurality of ranges of the cut table may be controlled so that the temperature distribution of the entire laminate is substantially constant. .
Further, by contacting the temperature sensor along a line for cutting the laminate, the temperature distribution can be actually measured to cut the laminate. Therefore, the laminated body can be cut when the temperature distribution becomes substantially constant, and useless heating can be prevented.

  According to the present invention, since the laminate can be cut cleanly in a short time, a multilayer ceramic electronic component free from defects such as layer peeling can be efficiently produced.

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

  FIG. 1 is a perspective view showing a multilayer ceramic capacitor as an example of a multilayer ceramic electronic component. The multilayer ceramic capacitor 10 includes a base 12. As shown in FIG. 2, the base 12 has a structure in which a plurality of ceramic layers 14 and internal electrodes 16 are alternately stacked. In such a base body 12, adjacent internal electrodes 16 are alternately drawn out to the opposing end face of the base body 12. An external electrode 18 is formed on the end surface of the base 12 from which the internal electrode 16 is drawn. The external electrode 18 is formed, for example, by applying and baking a conductive paste on the end face of the substrate 12 where the internal electrode 16 is exposed. If necessary, a plating process may be performed on the baked electrode to form a Ni electrode layer for preventing solder erosion, a Sn electrode layer for improving solderability, and the like.

  In order to produce such a multilayer ceramic capacitor 10, a ceramic slurry is formed using a dielectric material. Using this ceramic slurry, a ceramic green sheet 20 is formed as shown in FIG. By printing a conductive paste on one surface of the ceramic green sheet 20, a plurality of rectangular conductor patterns 22 are formed side by side in the vertical and horizontal directions.

  A plurality of ceramic green sheets 20 on which conductor patterns 22 are formed are laminated, and ceramic green sheets 20 on which no conductor patterns are formed are laminated on the top and bottom thereof to form a laminate 24 as shown in FIG. The At this time, the conductor patterns 22 formed on the adjacent ceramic green sheets 20 are arranged alternately in the longitudinal direction.

  The laminate 24 thus obtained is placed on the cut stage 26. In the cut stage 26, for example, a plurality of heaters 28 are formed so that the temperature can be individually adjusted in a plurality of ranges. The laminate 24 on the cut stage 26 is heated by the heater 28 and is softened so as to be easily cut. At this time, each heater 28 is controlled so that the entire laminated body 24 has a substantially uniform temperature distribution. The laminated body 24 that has been heated and softened is cut by the cutting blade 30 at an intermediate portion in the longitudinal direction of the conductor pattern 22 and an intermediate portion between adjacent conductor patterns 22. Further, in the laminated body 24, the intermediate portion of the adjacent conductor pattern 22 is cut in the width direction of the conductor pattern 22. As a result, a chip is formed in which the conductor patterns 22 adjacent to the opposing end face are alternately exposed.

  In addition, when heating the laminated body 24, as shown, for example in FIG. 5, the laminated body 24 is divided | segmented into nine ranges of zone 1-zone 9, and the temperature of the cut stage 26 is individually corresponded to each zone. Adjusted to For example, when there is a support portion on the lower surface of the cut stage 26, heat escapes from the support portion, so that heat is less likely to be transmitted to the portion corresponding to the support portion of the laminate 24 than the other portions. Therefore, in the portion corresponding to the support portion, the amount of heat conducted to the laminate 24 is adjusted to be equal to that of the other portion by raising the heating temperature of the heater 28 from the other portion. Thus, by adjusting the temperature individually in the zones 1 to 9, the entire laminated body 24 is adjusted to have a substantially constant temperature distribution.

  By adjusting the temperature distribution of the entire laminated body 24 to be substantially constant, the laminated body 24 can be uniformly softened, and the laminated body 24 can be cut into a desired shape. Moreover, since the laminated body 24 does not become locally high temperature, when the laminated body 24 is cut, it is possible to prevent the occurrence of defects such as layer peeling.

  By firing the chip obtained by cutting the laminate 24, the substrate 12 on which the ceramic layer 14 and the internal electrode 16 are laminated is formed. A conductive paste for an external electrode is applied to the exposed surface of the internal electrode of the substrate 12, and the external electrode 18 is formed by baking this. Furthermore, if necessary, the Ni electrode layer and the Sn electrode layer are formed by performing a plating process on the external electrode 18, and the multilayer ceramic capacitor 10 is formed.

  Thus, by heating so that the temperature distribution of the entire laminated body 24 becomes substantially constant and cutting with the cutting blade 30, a chip having a clean sectional property and no layer peeling can be obtained. Therefore, the finally obtained multilayer ceramic capacitor 10 can have the characteristics as designed without defects.

  In the above example, the temperature distribution of the entire laminated body 24 is adjusted so as to be substantially constant. However, when the laminated body 24 is cut, the temperature distribution may be substantially constant along at least the cut line. In this case, the laminate 24 can be cut cleanly. Therefore, even if there is some variation in temperature distribution in the entire laminate 24, the laminate 24 can be cut cleanly as long as the temperature distribution is substantially constant along the cut line.

  In addition, a certain time is required from the time when the stacked body 24 is placed on the cut stage 26 until it is stabilized in a desired temperature range. The time to stabilization varies depending on the chip design (element thickness, number of layers, outer layer thickness, overall thickness, etc.), specific heat capacity of the layered product, storage state of the layered product (layer temperature before cutting), and the like. Therefore, it is very difficult to set the time until temperature stabilization for each laminate, and in order to cut the laminate 24 stably, a holding time with a considerable allowance must be set. There is a problem that the processing time becomes unnecessarily long. Therefore, as shown in FIG. 6, when the laminate 24 is cut, a pressing portion 32 for pressing the stacked body 24 is used, and a temperature sensor 34 is provided at a contact portion of the pressing portion 32 with the stacked body 24. Can do. By bringing such a temperature sensor 34 into contact with the surface of the laminated body 24, the temperature of the laminated body 24 can be constantly monitored, and whether or not cutting can be started can be determined. Therefore, it is possible to minimize the holding time from the time when the laminated body 24 is placed on the cut stage 26 to the start of cutting, thereby improving the processing efficiency.

  In addition, when the laminated body 24 is divided into a plurality of zones and temperature adjustment is performed, it is not necessary to divide into nine zones as described above, and the number of zones to be divided can be arbitrarily changed. By increasing the number of divided zones of the laminate 24 and adjusting the temperature of the cut stage 26 in the portions corresponding to these zones, finer temperature adjustment is possible, and the temperature distribution of the laminate 24 is made constant. The effect can be enhanced. The present invention is not limited to the manufacture of multilayer ceramic capacitors, but can be applied to the manufacture of all chip-type multilayer ceramic electronic components.

  A ceramic green sheet having a thickness of 4.2 μm printed with a conductor pattern was prepared, and the ceramic green sheets were laminated so that the number of laminated conductor patterns was 240, and a laminate (vertical × horizontal × thickness = 200 mm × 200 mm × 1.83 mm) was formed. This laminated body was heated and softened, and chips were cut out by pressing a cutting blade. Here, from the composition and addition amount of the organic binder contained in the ceramic green sheet, the temperature at which the laminate is softened and the optimum temperature at which no layer peeling occurs is set to 95 ° C. to 100 ° C., and the entire laminate is shown in FIG. As shown in FIG. 4, the heating section was controlled so that the temperature of the laminated body was within the set temperature range in all zones.

  In this way, the laminate was divided into nine zones, and the temperature distribution of each zone when the temperature was controlled for each zone was measured. The results are shown in FIG. As can be seen from FIG. 7, a substantially constant temperature distribution could be obtained in all zones of the laminate. Then, when the laminate was placed on the cut stage and cut while holding the laminate for 2 minutes while performing the temperature control as described above, the laminate could be accurately cut into a desired chip shape. . Furthermore, the properties of the cross section were clean, and the laminate could be cut without causing defects such as layer peeling.

  As a comparative example, the laminate was sufficiently heated (100 ° C., 3 minutes) from both upper and lower surfaces with a heat plate, then transported to a cut stage having a heat retaining function (100 ° C.), and pressed with a cutting blade. In this case, the entire laminate could be cut, but a cut surface defect (roughness) occurred with the chips cut from the end of the laminate.

  Therefore, on the cut stage, when the heater is arranged in the zone 5 and the entire laminated body is heated at once, the laminated body on the cut stage is divided into nine zones shown in FIG. The results are shown in FIG. As can be seen from FIG. 8, when the entire laminate is heated at once, the temperature distribution varies within the laminate, and the zones 1 and 7 where the cross-sectional defects occur are lower than the other zones. It was.

  Moreover, as another comparative example, the case where the laminated body was cut by heating the cutting blade without heating the laminated body was investigated. And the possibility of cutting | disconnection and the cross-sectional property were observed, and the result was shown in Table 1.

  As can be seen from Table 1, when the cutting blade temperature is less than 120 ° C., the laminate cannot be cut completely, and when the cutting blade temperature is 110 ° C. or more, defects such as layer peeling and roughening occur on the cut surface. . Therefore, it was confirmed that the laminate could not be cut normally only by heating the cutting blade.

  In this way, by dividing the laminate into a plurality of zones and individually adjusting the temperature in each zone, the temperature distribution of the entire laminate can be kept almost constant, and no defects occur in the cut cross section. Thus, the laminate can be cut cleanly.

1 is a perspective view showing a multilayer ceramic capacitor as an example of a multilayer ceramic electronic component to which the present invention is applied. FIG. 2 is an illustrative view showing an internal structure of the multilayer ceramic capacitor shown in FIG. 1. It is a top view which shows the ceramic green sheet and conductor pattern for producing the multilayer ceramic capacitor shown in FIG. It is an illustration figure which shows the state which mounted the laminated body which laminated | stacked the ceramic green sheet shown in FIG. 3 on the cut stage. It is an illustration for demonstrating the state which divided | segmented the laminated body into the several zone. It is an illustration figure which shows the state cut while measuring the temperature of a laminated body using a sensor. It is a graph which shows the temperature distribution of each zone at the time of the cut of the laminated body in the manufacturing method of this invention. It is a graph which shows the temperature distribution of each zone at the time of the cut of the laminated body in a comparative example. It is an illustration figure which shows the cutting process of the laminated body in the conventional manufacturing method. It is an illustration figure which shows a mode when a circular heater is provided in the cut stage. It is an illustration figure which shows the cut stage which has a support part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Multilayer ceramic capacitor 12 Base body 14 Ceramic layer 16 Internal electrode 18 External electrode 20 Ceramic green sheet 22 Conductive pattern 24 Laminated body 26 Cut stage 28 Heater 30 Cut blade 32 Holding part 34 Temperature sensor

Claims (3)

Preparing a laminate in which a plurality of ceramic green sheets are laminated,
Placing the laminate on a cut stage for cutting the laminate,
Adjusting the temperature in a plurality of ranges of the cut stage so that the temperature distribution is substantially constant along at least a line for cutting the laminate, and the lamination along the line in which the temperature distribution is substantially constant A method for producing a multilayer ceramic electronic component, comprising a step of cutting a body.   The method for manufacturing a multilayer ceramic electronic component according to claim 1, wherein the temperature is adjusted so that the temperature distribution of the entire multilayer body is substantially constant.   The temperature sensor is brought into contact with a line for cutting the laminate, and the laminate is cut when a temperature distribution detected by the temperature sensor becomes substantially constant. The manufacturing method of the multilayer ceramic electronic component of description.

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