JP6442881B2 - Manufacturing method of ceramic electronic component - Google Patents

Description

  The present invention relates to a method for manufacturing a ceramic electronic component, and more particularly to a method for manufacturing a ceramic electronic component such as a multilayer ceramic capacitor.

  For example, a multilayer ceramic capacitor, which is one of typical ceramic electronic components, is usually arranged such that a plurality of internal electrodes face each other through a ceramic layer, and are alternately drawn out to the opposite end face. The external electrode is disposed on both end faces of the ceramic body having the above structure so as to be electrically connected to the internal electrode.

  By the way, in manufacturing the multilayer ceramic capacitor as described above, the end face of the ceramic body is polished so that the internal electrode is reliably exposed to the end face, and the contact between the internal electrode and the external electrode is strengthened, or The ceramic body is polished to round the ridgeline (including corners) of the ceramic body to prevent cracking and chipping at the ridgeline of the ceramic body and cutting at the ridgeline of the external electrode. To be done.

  As such a ceramic body polishing method, for example, as in Patent Document 1, a raw ceramic body and an abrasive are put into a barrel, and the raw ceramic body is polished by rotating the barrel. There are a dry barrel polishing method and a wet barrel polishing method in which water, a raw ceramic body and an abrasive are put into the barrel and the raw ceramic body is polished by rotating the barrel.

JP-A-8-69943

  However, as in the method of manufacturing a ceramic electronic component described in Patent Document 1, when the ridge line portion of the raw ceramic body is polished by dry barrel polishing, the temperature in the barrel pot increases during polishing. In some cases, the raw ceramic body may undergo thermoplastic deformation. As a result, the appearance failure of the multilayer ceramic capacitor occurs or the internal electrode is exposed at the end face, resulting in deterioration of the continuity of the external electrode, such as a contact failure between the external electrode and the internal electrode. May lead to a decrease in reliability.

  Also, when the ridge line portion of the raw ceramic body is polished by wet barrel polishing, the ridge line portion is polished without causing thermoplastic deformation due to temperature rise because barrel polishing is performed in water. However, since the additive component of the dielectric material of the raw ceramic body is eluted in water, the reliability of the multilayer ceramic capacitor may be deteriorated.

  Specifically, Ba, which is an additive component of the dielectric, elutes in water, so that the amount of Ba contained in the raw ceramic body is reduced and the molar ratio (Ba / Ti) of the ceramic dielectric is reduced. Since the ceramic dielectric is sintered as the molar ratio is reduced, the ceramic is excessively sintered when the raw ceramic body is fired. At this time, excessive growth of the ceramic grains may change the solid solution state of the additive or deteriorate the ceramic body (ideal ceramic body should be smooth, but abnormal grain growth during firing) As a result, the insulation resistance decreases, leading to a decrease in the reliability of the multilayer ceramic capacitor.

  Therefore, the main object of the present invention is to suppress the thermoplastic deformation of the raw ceramic body caused by barrel polishing on the raw ceramic body and the change in the electrical characteristics of the ceramic electronic component. It is to provide high ceramic electronic components.

A method of manufacturing a ceramic electronic component according to the present invention includes a ceramic body in which a plurality of ceramic layers and a plurality of internal electrodes are alternately stacked, and an exposed portion of the internal electrode exposed on both end faces of the ceramic body. In a method for manufacturing a ceramic electronic component comprising an external electrode that is electrically connected, a step of obtaining a raw ceramic body having a ceramic layer and an internal electrode and polishing a ridge line portion of the raw ceramic body And polishing the ridges of the raw ceramic body by rotating the raw ceramic body in a barrel containing a mixture of a solvent and an additive component of the ceramic body. There line wet barrel polishing of by the raw ceramic body after the wet barrel polishing, and further comprising the step of drying under 35 ° C. less environment, Ceramic is a method of manufacturing an electronic component.
In the method for manufacturing a ceramic electronic component according to the present invention, it is preferable to perform suction drying.
Furthermore , in the method for manufacturing a ceramic electronic component according to the present invention, the additive components of the ceramic body are preferably Ba and Mg.

According to the method of manufacturing a ceramic electronic component according to the present invention, in the step of polishing the ridge line portion of the raw ceramic body, since the polishing is performed by the wet barrel polishing method, the ridge line is generated without causing the thermoplastic deformation due to the temperature rise. Due to poor external appearance of the external electrode, such as poor external appearance of the resulting ceramic electronic component and the exposed internal electrode at the end face. A decrease in the reliability of the ceramic electronic component can be suppressed.
In the method for manufacturing a ceramic electronic component according to the present invention, when polishing is performed by a wet barrel polishing method, for example, Ba and Mg, which are additive components of a dielectric (ceramic body), are dissolved in a solvent in advance. By setting (ie, creating a saturated state), elution of additive components during polishing by the wet barrel polishing method can be suppressed, and the molar ratio (Ba / Ti) of the ceramic dielectric can be maintained. Therefore, oversintering can be prevented, and as a result, changes in electrical characteristics such as a decrease in insulation resistance of the ceramic electronic component can be prevented.
Furthermore, in the step of polishing the raw ceramic body, it comprises a drying step of drying the raw ceramic body after washing, and in the drying step, by performing suction drying in an environment at a temperature of 35 ° C. or less, The binder flow is reduced by drying at a temperature lower than the glass transition point of the binder contained in the ceramic green sheet, which is lowered by the action of the plasticizer contained in the ceramic green sheet produced to form the ceramic body. Therefore, the sticking failure between the raw ceramic bodies can be suppressed.

  According to the present invention, it is possible to suppress the thermoplastic deformation of the raw ceramic body caused by barrel polishing of the raw ceramic body and the change in the electrical characteristics of the ceramic electronic part, and to provide a highly reliable ceramic electronic part. Can be provided.

  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 an external appearance perspective view which shows an example of the ceramic electronic component to which this invention is applied. It is a side view which shows an example of the ceramic electronic component to which this invention is applied. FIG. 2 is an illustrative sectional view showing a section taken along line AA in FIG. 1. It is an external appearance perspective view which shows the other example of the ceramic electronic component to which this invention is applied. It is a side view which shows the other example of the ceramic electronic component to which this invention is applied. FIG. 5 is a cross sectional view showing a cross section taken along line BB in FIG. 4.

(Ceramic electronic components)
An example of a ceramic electronic component to which the present invention is applied will be described. FIG. 1 is an external perspective view showing an example of a ceramic electronic component to which the present invention is applied, and FIG. 2 is a side view showing an example of a ceramic electronic component to which the present invention is applied. FIG. 3 is an illustrative sectional view showing a section taken along line AA of FIG. This ceramic electronic component shows a multilayer ceramic capacitor as an example.

  The ceramic electronic component 1 according to this embodiment includes a ceramic body 10 (laminated body) and first and second external electrodes 12 a and 12 b formed on the surface of the ceramic body 10.

  The ceramic body 10 includes a plurality of laminated ceramic layers 14a and 14b. The ceramic body 10 is formed in a rectangular parallelepiped shape, and extends in the length direction (L direction) and the width direction (W direction). The first main surface 16a and the second main surface 16b, and the length direction (L Direction) and the first side surface 18a and the second side surface 18b extending along the height direction (T direction), and the first end surface 20a and the second side surface extending along the width direction (W direction) and the height direction (T direction). And an end face 20b. In the ceramic body 10, the first main surface 16a and the second main surface 16b face each other, the first side surface 18a and the second side surface 18b face each other, and the first end surface 20a and the second end surface 20b opposite. Further, the ceramic body 10 has a rounded ridgeline portion 22.

As the ceramic layers 14a and 14b, for example, a dielectric ceramic made of a main component such as BaTiO ₃ , CaTiO ₃ , SrTiO ₃ , CaZrO ₃ is used. Moreover, you may use what added subcomponents, such as a Mn compound, Fe compound, Cr compound, Co compound, Ni compound, to these main components. The dielectric ceramic is preferably made of a ferroelectric ceramic in order to obtain a large capacitance. The thickness of the ceramic layers 14a and 14b is preferably 0.2 μm or more and 10 μm or less.

  As the ceramic layers 14a and 14b, piezoelectric ceramics such as PZT ceramics, semiconductor ceramics such as spinel ceramics, and magnetic ceramics such as ferrite can be used.

  The ceramic body 10 has a plurality of first internal electrodes 24a and second internal electrodes 24b so as to be sandwiched between the plurality of ceramic layers 14a and the ceramic layers 14b. Therefore, the plurality of ceramic layers 14a and 14b and the plurality of internal electrodes 24a and 24b are alternately stacked. The first and second internal electrodes 24a and 24b are opposed to each other with the ceramic layers 14a and 14b interposed therebetween, and electrical characteristics (for example, electrostatic capacity) are generated by the opposed portions. For example, Ni, Cu, Ag, Pd, an Ag—Pd alloy, Au, or the like can be used as the material of the first and second internal electrodes 24a and 24b. The thickness of the first and second internal electrodes 24a, 24b is preferably 0.3 μm or more and 2.0 μm or less.

  The first internal electrode 24a has a facing portion 26a and an exposed portion 28a. The facing portion 26a faces the second internal electrode 24b. The exposed portion 28a is formed so as to extend from the facing portion 26a to the first end surface 20a of the ceramic body 10 and be exposed.

  Similarly to the first internal electrode 24a, the second internal electrode 24b has a facing portion 26b and an exposed portion 28b. The facing portion 26b faces the first internal electrode 24a. The exposed portion 28b is formed to extend from the facing portion 26b to the second end face 20b of the ceramic body 10 and be exposed.

  Thus, in the ceramic body 10 according to this embodiment, as described above, the capacitance is formed by the internal electrodes facing each other with the dielectric ceramic layer interposed therebetween. Thereby, this multilayer ceramic electronic component functions as a capacitor.

  On the other hand, the piezoelectric ceramic functions as a piezoelectric component, the semiconductor ceramic functions as a thermistor, and the magnetic ceramic functions as an inductor. However, in the case of an inductor, the internal electrode is a coiled conductor.

  The first external electrode 12a is electrically connected to the first internal electrode 24a on the first end surface 20a of the ceramic body 10 so as to cover the first end surface 20a and the first internal electrode 24a. . The first external electrode 12a is formed so as to cover a part of the first main surface 16a and the second main surface 16b and a part of the first side surface 18a and the second side surface 18b. Similarly, the second external electrode 12b is electrically connected to the second internal electrode 24b on the second end surface 20b of the ceramic body 10 so as to cover the second end surface 20b and the second internal electrode 24b. It is formed. The second external electrode 12b is formed so as to cover a part of the first main surface 16a and the second main surface 16b and a part of the first side surface 18a and the second side surface 18b.

  The first external electrode 12a includes a base layer 30a and a plating layer 32a formed on the surface of the base layer 30a. The second external electrode 12b includes a base layer 30b and a plating layer 32b formed on the surface of the base layer 30b.

  For example, Cu, Ni, Ag, Pd, Ag—Pd alloy, Au, or the like can be used as the material of the base layers 30a and 30b. The underlying layers 30a and 30b may be a cofire that is fired simultaneously with the internal electrodes 24a and 24b, or may be a postfire that is applied and baked with a conductive paste. Moreover, it may be formed by direct plating or may be formed by curing a conductive resin including a thermosetting resin.

  In the case where the underlayers 30a and 30b are formed by baking the conductive paste for external electrodes, it is preferable to use a paste containing conductive metal and glass for the underlayers 30a and 30b. As the glass component, glass containing B, Si, Ba, Mg, Al, Li, Zn, or the like can be used. Further, for example, Cu, Ni, Ag, Pd, an Ag—Pd alloy, Au, or the like can be used as the base layers 30a and 30b. The underlying layers 30a and 30b may be a cofire that is fired simultaneously with the internal electrodes 24a and 24b, or may be a postfire that is applied and baked with a conductive paste for external electrodes. Moreover, it may be formed by direct plating or may be formed by curing a conductive resin including a thermosetting resin. The thickness of the foundation layers 30a and 30b is preferably 10 μm or more and 50 μm or less at the thickest portion.

  On the other hand, Cu, Ni, Ag, Pd, Ag-Pb alloy, Au, etc. can be used for the material of the plating layers 32a and 32b, for example. The plating layers 32a and 32b may be formed in a plurality of layers. A two-layer structure of Ni plating and Sn plating is preferable. For example, when Ni is used as the internal electrodes 24a and 24b, it is preferable to use Cu having good bonding properties with Ni as the base layers 38a and 38b. When the plating layers 32a and 32b have a two-layer structure, the second layer formed on the surface of the first layer of the plating layers 32a and 32b is preferably made of Sn or Au having good solder wettability. The first layer formed on the surface of the ground layers 38a and 38b is preferably made of Ni having solder barrier performance. The thickness per layer of the plating layers 32a and 32b is preferably 1 μm or more and 10 μm or less. Moreover, a conductive resin layer for stress relaxation may be formed between the base layers 30a and 30b and the plating layers 32a and 32b.

  Further, when the underlayers 30a and 30b are formed by plating, the underlayers 30a and 30b are, for example, one type selected from the group consisting of Cu, Ni, Sn, Pb, Au, Ag, Pd, Bi, and Zn. These metals or alloys containing the metals can be used. When the underlayers 30a and 30b are formed by plating, the underlayers 30a and 30b preferably do not contain a glass component, and the metal ratio per unit volume of the underlayers 30a and 30b is 99% by volume or more. preferable. When Ni is used as the internal electrodes 24a and 24b, it is preferable to use Cu having good bonding properties with Ni as the base layers 30a and 30b. In this case, the thickness of the foundation layers 30a and 30b is preferably 1 μm or more and 15 μm or less.

  Next, another example of the ceramic electronic component to which the present invention is applied will be described. 4 is an external perspective view showing another example of the ceramic electronic component to which the present invention is applied, and FIG. 5 is a side view showing another example of the ceramic electronic component to which the present invention is applied. FIG. 6 is an illustrative sectional view showing a section taken along line B-B in FIG. 4. This ceramic electronic component also shows a multilayer ceramic capacitor as an example. 4 to 6, the same parts as those of the ceramic electronic component 1 shown in FIGS. 1 to 3 are denoted by the same reference numerals, and the description thereof is omitted.

  The ceramic electronic component 1 ′ is configured by a substantially prismatic ceramic body 10 by increasing the number of laminated ceramic layers 14 a and 14 b as compared with the ceramic electronic component 1. Even when such a ceramic electronic component 1 ′ is manufactured, the method for manufacturing a ceramic electronic component according to the present invention can be used.

(Method for manufacturing ceramic electronic components)
Next, an embodiment of a method for producing a ceramic electronic component having the above configuration will be described by taking the ceramic electronic component 1 as an example.

  First, a ceramic green sheet, an internal electrode conductive paste for forming the first and second internal electrodes 24a, 24b, and an external electrode conductivity for forming the first and second external electrodes 12a, 12b A paste is prepared. The ceramic green sheet, the internal electrode conductive paste, and the external electrode conductive paste include an organic binder and a solvent, and a known organic binder or organic solvent can be used.

  Then, for example, the internal electrode conductive paste is printed in a predetermined pattern on the ceramic green sheet, and the internal electrode pattern is formed on the ceramic green sheet. The internal electrode conductive paste can be printed by a known method such as a screen printing method.

  Next, a predetermined number of outer layer ceramic green sheets on which internal electrode patterns are not printed are laminated, and ceramic green sheets on which internal electrode patterns are printed are sequentially laminated on the outer layer ceramic green sheets. A predetermined number of sheets are laminated to produce a mother laminate.

  And this mother laminated body is crimped | bonded to a lamination direction by means, such as an isostatic press.

  Thereafter, the mother laminate is cut into a predetermined shape and a raw ceramic body is cut out (step of obtaining a raw ceramic body having a ceramic layer and internal electrodes).

  Next, the ridge line portion of the cut out raw ceramic body is polished and rounded (step of polishing the raw ceramic body). In the step of polishing the ridge line portion of the raw ceramic body, a mixture of a solvent and an additive component of a dielectric (ceramic body) is injected into the barrel, and the raw ceramic body cut into the mixture is injected into the barrel. It is thrown in and polishing is performed by rotating the barrel (wet barrel polishing method). Here, for example, Ba and Mg are used as additive components of the dielectric (ceramic body) dissolved in the solvent. The addition amount of Ba and Mg is adjusted in proportion to the amount of the solvent. For example, water is used as the solvent.

  Subsequently, by cutting the raw ceramic body, the cut raw ceramic body having the ridge line polished and rounded is cleaned (cleaning step). In the cleaning step, the raw ceramic body is washed with water for a predetermined time to wash away the raw ceramic body shavings and additive components adhering to the raw ceramic body during barrel polishing.

  Then, the raw ceramic body after washing is dried (drying process for drying the raw ceramic body after wet barrel polishing). In the drying step, the raw ceramic body after washing is placed in an environment maintained at a constant temperature, sucked and dried, and dried while gradually decreasing the temperature. The drying temperature is preferably dried at a temperature not higher than the glass transition point of the binder contained in the ceramic green sheet, and specifically, drying is preferably performed in an environment of 35 ° C. or lower. In this embodiment, the raw ceramic body after washing is placed in an environment maintained at 35 ° C., sucked and dried, and dried while the temperature is lowered to 20 ° C. Thereby, it can dry at temperature lower than it with respect to the glass transition point of the binder contained in the ceramic green sheet reduced by the effect | action of the plasticizer contained in a ceramic green sheet. Therefore, since the flow of the binder contained in the ceramic green sheet can be suppressed, the sticking failure between the raw ceramic bodies can be suppressed.

Subsequently, the polished raw ceramic body is fired to produce a ceramic body 10 that is a laminate. The firing temperature when firing the raw ceramic body depends on the ceramic material and the material of the internal electrode conductive paste, but is preferably 900 ° C. or higher and 1300 ° C. or lower. The firing of the conductive paste for external electrodes and the firing of the raw ceramic body are performed, for example, in the air, in an N ₂ atmosphere, in a steam + N ₂ atmosphere.

  Next, a process for forming a base layer on the ceramic body will be described.

First, the case where the base layer is formed by baking the conductive paste for external electrodes will be described.
The conductive paste for external electrodes is applied to the first end face 20a and the second end face 20b of the fired ceramic body 10, and the base layers 30a, 30b of the first and second external electrodes 12a, 12b are formed by baking. It is formed. The baking temperature is preferably 700 ° C. or higher and 900 ° C. or lower. If necessary, one or more plating layers 32a and 32b are formed on the surfaces of the base layers 30a and 30b.

Next, a case where the base layer is formed by plating will be described.
The first end face 20a and the second end face 20b of the fired ceramic body 10 are plated to form the base layers 30a and 30b on the exposed portions 28a and 28b of the first and second internal electrodes 24a and 24b. To do. Either electroplating or electroless plating may be used for the plating process, but electroless plating requires pretreatment with a catalyst or the like to improve the plating deposition rate, making the process complicated. There is a disadvantage of doing. Therefore, it is usually preferable to employ electrolytic plating. As the plating method, barrel plating is preferably used. Further, if necessary, after forming the base layers 30a and 30b by plating, heat treatment is performed to alloy the joints between the first and second internal electrodes 24a and 24b and the base layers 30a and 30b. Measures that increase the bonding strength may be introduced. In this case, it is preferable that the temperature of heat processing is 750 degreeC or more and 1000 degrees C or less, for example. Furthermore, if necessary, one or more plating layers 32a and 32b are formed on the surfaces of the base layers 30a and 30b.

  The desired ceramic electronic component 1 is obtained by the above manufacturing method.

  According to the method for manufacturing a ceramic electronic component according to the present embodiment, in the step of polishing the ridge line portion of the raw ceramic body, since polishing is performed by a wet barrel polishing method, without causing thermoplastic deformation due to temperature rise, It becomes possible to polish the ridge portion, and external appearance such as defective contact between the external electrode and the internal electrode is caused by the appearance failure of the obtained ceramic electronic component 1 and the internal electrode exposed in the end face of the ceramic body 10. A decrease in the reliability of the ceramic electronic component 1 due to the deterioration of the continuity of the electrodes can be suppressed.

  Further, in the method for manufacturing a ceramic electronic component according to the present invention, Ba and Mg, which are additive components of a dielectric (ceramic body), are dissolved in advance in water as a solvent when polishing by a wet barrel polishing method. By setting (ie, creating a saturated state), elution of additive components during polishing by the wet barrel polishing method can be suppressed, and the molar ratio (Ba / Ti) of the ceramic dielectric can be maintained. Therefore, oversintering can be prevented. As a result, changes in electrical characteristics such as a decrease in insulation resistance of the ceramic electronic component 1 manufactured by the method for manufacturing a ceramic electronic component according to the present embodiment can be prevented.

(Experimental example)
In the experimental example, the ceramic electronic component 1 is manufactured by the above-described method, the presence or absence of thermoplastic deformation is confirmed, the reliability test change (IR deterioration) by HALT (Highly Accelerated Life Test) is confirmed, and the sticking failure is confirmed. It was.

(Example)
In Example 1, a multilayer ceramic capacitor as the ceramic electronic component 1 shown in FIG. 1 was manufactured by the method for manufacturing a ceramic electronic component according to the above-described embodiment. The conditions for polishing the raw ceramic body by the wet barrel polishing method were as follows. That is, the barrel conditions were such that 1 cc of Mg and 70 cc of Ba were added into 300 cc of water as a dielectric (ceramic body) additive component. Then, 100000 raw ceramic bodies were put into the barrel, the polishing time by barrel polishing was set to 60 minutes, and polishing was performed by rotating at a rotation speed of 180 rpm.
Thereafter, the raw ceramic body after barrel polishing was washed and dried in a drying step. In the drying step, the raw ceramic body after washing was put in an environment maintained at 25 ° C., sucked and dried, and dried for 20 minutes while the temperature was lowered to 20 ° C.

In Example 2, the multilayer ceramic capacitor as the ceramic electronic component 1 shown in FIG. 1 was manufactured by the method for manufacturing a ceramic electronic component according to the above-described embodiment. The conditions for polishing the raw ceramic body by the wet barrel polishing method were as follows. That is, the barrel conditions were such that 1 cc of Mg and 70 cc of Ba were added into 300 cc of water as a dielectric (ceramic body) additive component. Then, 100000 raw ceramic bodies were put into the barrel, the polishing time by barrel polishing was set to 60 minutes, and polishing was performed by rotating at a rotation speed of 180 rpm.
Thereafter, the raw ceramic body after barrel polishing was washed and dried in a drying step. In the drying step, the raw ceramic body after washing was placed in an environment maintained at 30 ° C., sucked and dried, and dried for 20 minutes while the temperature was lowered to 25 ° C.

Moreover, in Example 3, the multilayer ceramic capacitor which is the ceramic electronic component 1 shown in FIG. 1 was manufactured by the method for manufacturing a ceramic electronic component according to the above-described embodiment. The conditions for polishing the raw ceramic body by the wet barrel polishing method were as follows. That is, the barrel conditions were such that 1 cc of Mg and 70 cc of Ba were added into 300 cc of water as a dielectric (ceramic body) additive component. Then, 100000 raw ceramic bodies were put into the barrel, the polishing time by barrel polishing was set to 60 minutes, and polishing was performed by rotating at a rotation speed of 180 rpm.
Thereafter, the raw ceramic body after barrel polishing was washed and dried in a drying step. In the drying step, the raw ceramic body after washing was put in an environment maintained at 35 ° C., sucked and dried, and dried for 20 minutes while the temperature was lowered to 20 ° C.

  The outer dimensions of the manufactured multilayer ceramic capacitor were 0.6 mm in length, 0.3 mm in width, and 0.15 mm in height. Further, barium titanate-based dielectric ceramic was used as the ceramic layers 14a and 14b (dielectric ceramic). Furthermore, Ni was used as a material for the internal electrodes 24a and 24b. Further, for the external electrodes 12a and 12b, the base layers 30a and 30b are made of Cu, and the plating layers 32a and 32b are formed on the second layer formed on the first layer by forming the Ni plating film on the first layer. It was formed by a two-layer structure in which a Sn plating film is formed.

(Comparative example)
In Comparative Example 1, the raw ceramic body was polished using the conventional wet barrel polishing method as in the example, but Mg and Ba were not added as additive components of the dielectric to the water used for polishing. It was. The barrel conditions were the same as in the examples except that Mg and Ba were not added. Further, the external electrodes of the manufactured ceramic electronic component were also formed in the same structure as in the examples.

  Further, in Comparative Example 2, unlike the example, polishing was performed using a conventional dry barrel polishing method. That is, Mg and Ba were not added as water and dielectric additive components. The barrel conditions were the same as those in the example except that water, Mg and Ba were not added and the polishing time by barrel polishing was 180 minutes. Further, the external electrodes of the manufactured ceramic electronic component were also formed in the same structure as in the examples. The barrel time is longer than the wet barrel polishing method. The dry barrel polishing method is inferior in polishing power compared to the wet barrel polishing method, so in order to obtain a similar structure, the polishing time by barrel polishing is lengthened. This is necessary.

  In Comparative Example 3, the raw ceramic body was polished using the wet barrel polishing method in the same manner as in the example. However, in the subsequent drying process, suction drying was not performed, and a constant temperature of 50 ° C. was used. Drying was performed for 20 minutes under the environment. The barrel conditions were the same as in the example. In addition, the external electrode of the manufactured ceramic electronic component was also formed in the same structure as the example.

  Furthermore, in Comparative Example 4, the raw ceramic body was polished using the wet barrel polishing method as in the example, but in the subsequent drying process, suction drying was not performed, and a constant temperature of 60 ° C. was used. Drying was performed for 20 minutes under the environment. The barrel conditions were the same as in the example. In addition, the external electrode of the manufactured ceramic electronic component was also formed in the same structure as the example.

(Confirmation method of thermoplastic deformation)
The laminated ceramic capacitors according to the samples of Examples 1 to 3 and Comparative Examples 1 and 2 obtained above were subjected to cross-sectional polishing along the L direction to a position of 1/2 W, and one side ceramic At the end of the element body 10, along the L direction from the most protruding part of the end face of the ceramic element body 10 to the most recessed part of the end face of the ceramic element body 10, with reference to the perpendicular along the end face. The distance was measured with a microscope (magnification × 1000 times). At that time, those having a distance of 3 μm or more were counted as thermoplastically deformed. The confirmation of the thermoplastic deformation was performed by preparing 100 pieces in each of Examples 1 to 3 and Comparative Examples 1 and 2.

(Confirmation method of IR degradation by HALT)
About the multilayer ceramic capacitor concerning each sample of Example 1 thru | or Example 3 obtained above, and the comparative example 1 and the comparative example 2, HALT (super acceleration life test which applies the voltage of 8V at the temperature of 150 degreeC ) In this super-acceleration test, it was evaluated that the time until the IR value was 10 kΩ or less was less than 10 hours was inferior in reliability. Confirmation of IR deterioration by HALT was carried out by preparing 18 pieces in each of Examples 1 to 3 and Comparative Examples 1 and 2.

(Check for sticking defects)
The raw ceramic body according to each of the samples of Examples 1 to 3 and Comparative Examples 3 and 4 obtained after the drying step is passed through a mesh having a size through which one raw ceramic body passes. The raw ceramic body, which was put into a sieve having a mesh and did not pass through the mesh due to vibration, was considered to be stuck.

Table 1 shows the results of confirming the presence or absence of thermoplastic deformation of each of the multilayer ceramic capacitors of Examples 1 to 3 and Comparative Examples 1 and 2, and confirming the change in reliability test (IR degradation) by HALT. Indicates.
Table 2 shows the results of confirming the sticking failure performed on the raw ceramic bodies obtained after the drying steps of Examples 1 to 3 and Comparative Examples 3 and 4. .

  As described above, by using the method for manufacturing a ceramic electronic component according to the present invention, it becomes possible to polish the ridge line portion without causing thermoplastic deformation due to temperature rise, and the appearance defect of the multilayer ceramic capacitor or the ceramic Since the internal electrode is exposed at the end face of the element body 10, it is possible to suppress a decrease in reliability (IR decrease) due to deterioration of the continuity of the external electrode such as a contact failure between the external electrode and the internal electrode. confirmed.

  In addition, when barrel polishing is performed in water, the additive component of the dielectric (ceramic body) is dissolved in water in advance (to create a saturated state), so that the additive component during polishing is eluted. It can be suppressed and the molar ratio (Ba / Ti) of the ceramic dielectric can be maintained, preventing oversintering and preventing changes in electrical characteristics such as a decrease in insulation resistance of the multilayer ceramic capacitor. It was confirmed that

  Furthermore, in the drying process after barrel polishing, by performing drying at a temperature of 35 ° C. or less while performing suction drying, it is possible to suppress the sticking failure between the raw ceramic bodies and suppress the decrease in the yield of the product. It was confirmed that it was possible.

  Therefore, by using the method for manufacturing a ceramic electronic component according to the present invention, the thermoplastic deformation of the raw ceramic body caused by barrel polishing of the raw ceramic body, and the change in electrical characteristics of the ceramic electronic component (insulation resistance) Can be suppressed, and a highly reliable ceramic electronic component can be provided.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is carried out within the range of the summary. In addition, the thickness, the number of layers, the counter electrode area, and the external dimensions of the ceramic layers of the ceramic electronic component are not limited thereto.

DESCRIPTION OF SYMBOLS 1 Ceramic electronic component 10 Ceramic body 12a 1st external electrode 12b 2nd external electrode 14a, 14b 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 face 22 Ridge line portion 24a First internal electrode 24b Second internal electrode 26a, 26b Opposing portion 28a, 28b Exposed portion 30a, 30b Underlayer 32a, 32b Plating layer

Claims (3)

A ceramic body in which a plurality of ceramic layers and a plurality of internal electrodes are alternately laminated;
An external electrode electrically connected to an exposed portion of the internal electrode exposed at both end faces of the ceramic body;
In a method for manufacturing a ceramic electronic component comprising:
Obtaining a raw ceramic body having the ceramic layer and the internal electrodes;
Polishing the ridge portion of the raw ceramic body;
With
The step of polishing the ridge line portion of the raw ceramic body comprises polishing the raw ceramic body by rotating the barrel in a barrel containing a mixture of a solvent and an additive component of the ceramic body. wet barrel have rows polishing, the raw ceramic body after the wet barrel polishing, characterized in that it comprises a step of drying under 35 ° C. the following environmental, manufacturing method of a ceramic electronic component. The method for manufacturing a ceramic electronic component according to claim 1, wherein the drying step performs suction drying . 3. The method of manufacturing a ceramic electronic component according to claim 1, wherein additive components of the ceramic body are Ba and Mg . 4.

Images