CERAMIC ELECTRONIC COMPONENT

A ceramic electronic component that includes: an element body containing ceramic as main material thereof; and an identification mark on a surface of element body, wherein the element body includes: a first layer containing a specific compound containing barium and silicon; and a second layer that contains the specific compound, is interposed between the identification mark and the first layer, and has a proportion of the specific compound lower than a proportion of the specific compound in the first layer.

TECHNICAL FIELD

The present description relates to a ceramic electronic component including an element body mainly made of ceramic and an identification mark formed on the element body.

BACKGROUND ART

A multilayer ceramic substrate as an example of a ceramic electronic component mainly made of ceramic is disclosed in Patent Document 1. In the multilayer ceramic substrate, first ceramic layers and second ceramic layers thinner than the first ceramic layers are alternately laminated. Each of the first ceramic layers and the second ceramic layers contains celsian (BaAl2Si2O8). The celsian improves mechanical properties, electrical insulation, and the like of the ceramic electronic component. Usually, celsian crystals are randomly scattered inside the ceramic electronic component.

Patent Document 2 discloses an example of a ceramic electronic component in which an identification mark is formed on a surface of an element body mainly made of ceramic. The identification mark is for identifying a direction of the ceramic electronic component. The identification mark of the ceramic electronic component disclosed in Patent Document 2 is made of a porcelain material.Patent Document 1: JP-B2-5263226Patent Document 2: JP-A-S60-170922

SUMMARY OF THE DESCRIPTION

A ceramic electronic component in which an identification mark is formed on an element body containing celsian has the following problems.

Usually, a ceramic electronic component is manufactured by singulating a wafer in which a plurality of element bodies are arranged. As described above, the celsian crystals are randomly scattered inside the ceramic electronic component. When the celsian is unevenly scattered in the wafer, the density of the celsian included in each of the plurality of element bodies varies.

The identification mark formed on the element body is sintered to the element body by being fired together with the element body. At this time, the sinterability of the identification mark with respect to the element body decreases as the density of celsian included in the element body increases. When the sinterability of the identification mark with respect to the element body decreases, the visibility of the identification mark with respect to the element body may decrease. Here, in a case where the density of the celsian varies as described above, sinterability of the identification mark with respect to the element body varies in the plurality of element bodies arranged on the wafer. That is, sinterability and visibility of the identification mark formed on the element body having a low density of celsian are high with respect to the element body, while sinterability and visibility of the identification mark formed on the element body having a high density of celsian are low with respect to the element body.

Therefore, an object of the present description is to solve the above problems, and to provide a ceramic electronic component capable of maintaining high sinterability of an identification mark with respect to an element body.

In order to achieve the above object, the present description is configured as follows. A ceramic electronic component according to an aspect of the present description includes: an element body containing ceramic as a main material thereof; and an identification mark on a surface of the element body, in which the element body includes: a first layer containing a specific compound containing barium and silicon; and a second layer that contains the specific compound, is interposed between the identification mark and the first layer, and has a proportion of the specific compound lower than a proportion of the specific compound in the first layer.

According to the present description, the sinterability of the identification mark with respect to the element body can be maintained at a high level.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A ceramic electronic component according to an aspect of the present description includes: an element body containing ceramic as a main material thereof; and an identification mark on a surface of the element body, in which the element body includes: a first layer containing a specific compound containing barium and silicon; and a second layer that contains the specific compound, is interposed between the identification mark and the first layer, and has a proportion of the specific compound lower than a proportion of the specific compound in the first layer.

According to this configuration, a proportion of the specific compound contained in the second layer close to the identification mark is lower than a proportion of the specific compound contained in the first layer away from the identification mark. The specific compound contains barium and silicon, and is, for example, celsian (Alumina (aluminum oxide) is contained in addition to barium and silicon.) or fresnoite (Titanium oxide is contained in addition to barium and silicon.). As a result, in this configuration, the sinterability of the identification mark with respect to the element body can be maintained at a high level as compared with the configuration in which the element body does not include the second layer. Furthermore, since the sinterability of the identification mark with respect to the element body is maintained at a high level, the visibility of the identification mark with respect to the element body is improved.

In the ceramic electronic component, the element body may contain celsian as the main material thereof, and the identification mark may contain alumina as a main material thereof.

According to this configuration, the identification mark contains alumina as a main material. Here, at an interface with alumina in the element body and a peripheral portion thereof, celsian is less likely to be crystallized. Therefore, when the identification mark containing alumina as a main material is formed on a surface of the element body containing celsian and the element body is fired together with the identification mark, a density of celsian in the peripheral portion of the identification mark in the element body is lower than a density of celsian in other portions other than the peripheral portion in the element body. The peripheral portion corresponds to the second layer, and the other portions correspond to the first layer. That is, according to this configuration, the element body including the first layer and the second layer can be easily manufactured.

In the ceramic electronic component, a thickness of the second layer may be the same as or substantially the same as a maximum thickness of the identification mark.

In a case where the thickness of the second layer is smaller than the maximum thickness of the identification mark, that is, in a case where a portion of the identification mark contributing to the improvement of the sinterability with respect to the second layer is thin, there is a possibility that the sinterability of the identification mark with respect to the second layer is deteriorated. In a case where the thickness of the second layer is larger than the maximum thickness of the identification mark, that is, in a case where a volume of the portion where a proportion of the specific compound is low is large, a proportion of the specific compound in the entire element body may decrease, leading to deterioration of the mechanical properties, electrical insulation, and the like of the ceramic electronic component. According to this configuration, the thickness of the first layer is the same as or substantially the same as the maximum thickness of the identification mark. This makes it possible to suppress a decrease in the proportion of the specific compound in the entire element body while suppressing a decrease in the sinterability of the identification mark with respect to the second layer.

In the ceramic electronic component, the element body may include an electrode interposed between the first layer and the second layer.

According to this configuration, in a case where the second layer is formed in a manufacturing process of the element body, excessive expansion of a formation range of the second layer can be prevented by the electrode.

Embodiment

FIG.1is a plan view of a ceramic electronic component according to an embodiment of the present description.FIG.2is a cross-sectional view illustrating an A-A cross section ofFIG.1.FIG.3is an enlarged view of an alternate long and short dash line portion inFIG.2. The ceramic electronic component includes an element body provided with an identification mark. In the ceramic electronic component according to the present embodiment, for example, an interlayer connection conductor, an internal electrode, an external electrode, and a plating layer are provided on the element body in addition to the identification mark. The ceramic electronic component can be mounted on a mother substrate or the like via the external electrode.

As illustrated inFIGS.1and2, a ceramic electronic component10according to the present embodiment includes an element body20, an interlayer connection conductor30, an internal electrode40, an external electrode50, an identification mark70, and a plating layer80.

The element body20has a rectangular parallelepiped shape as a whole. The shape of the element body20is not limited to a rectangular parallelepiped shape. In the present embodiment, the element body20is formed by integrating base materials21to29laminated in a thickness direction100. That is, in the present embodiment, the element body20is formed by integrating nine base materials. The number of base materials constituting the element body20is not limited to nine. Each of the base materials21to29is insulating and has a plate shape.

The element body20contains ceramic as a main material. The main material of the element body20is a material having the highest proportion among a plurality of types of materials included in the element body20. In a case where the element body20includes one kind of material, the one kind of material constituting the element body20is the main material of the element body20. The definition of the main material is the same for other than the element body20. For example, the main material of the identification mark70is a material having the highest proportion among a plurality of types of materials included in the identification mark70.

In the present embodiment, the element body20(each of the base materials21to29) contains a filler that is a main material and determines dielectric properties, a glass material, and an additive for adjusting physical properties such as a shrinkage factor. The proportion of each material contained in the element body20is, for example, about 60% for the filler, about 10% for the glass material, and about 30% for the additive. The filler and the additive contain aluminum (Al) (for example, alumina), magnesium (Mg), silicon (Si), barium (Ba), titanium (Ti), zirconium (Zr) (for example, zirconia), and the like. In the present embodiment, the element body20contains celsian (BaAl2Si2O8). The celsian contains barium and silicon. The celsian is an example of the specific compound.

Note that, as long as a condition that the main material is ceramic is satisfied, the material contained in the element body20is not limited to the above-described one, and the proportion of each material contained in the element body20is not limited to the above-described proportion. Furthermore, the filler and the additive may contain substances other than the above-mentioned substances. Furthermore, in the present embodiment, the element body20contains celsian crystals, but may contain other crystals. For example, the element body20may contain fresnoite (for example, Ba2TiSi2O8or Ba2TiGe2O8) instead of celsian. In this case, the fresnoite corresponds to a specific compound containing barium and silicon.

As illustrated inFIG.2, the element body20includes a pair of principal surfaces20A and20B and a side surface20C. The principal surface20A is a principal surface of the base material21and faces the outside of the element body20. The principal surface20B is a principal surface of the base material29and faces the outside of the element body20. The principal surface20B faces opposite to the principal surface20A. The principal surface20B is an example of a surface of the element body20. The side surface20C is configured by a side surface of the base materials21to29. The side surface20C connects the principal surfaces20A and20B.

In the present embodiment, the pair of principal surfaces20A and20B is orthogonal to the thickness direction100. The plan view ofFIG.1is a view of the ceramic electronic component10as viewed in the thickness direction100(seeFIG.2). Furthermore, in the present embodiment, a length in a longitudinal direction of the principal surfaces20A and20B is 2 to 4 mm, a length in a lateral direction of the principal surfaces20A and20B is 1 to 2 mm, and a length in the thickness direction100of the element body20is 45 to 1000 μm. Note that each of the lengths is not limited to the length described above.

As illustrated inFIGS.1and2, the element body20includes a first portion61and a second portion62. Furthermore, as illustrated inFIG.3, a diffusion layer90is formed in the element body20. Furthermore, as illustrated inFIG.3, the base material29of the element body20includes a first layer291and a second layer292. The first portion61, the second portion62, the diffusion layer90, the first layer291, and the second layer292will be described later.

As illustrated inFIG.2, the interlayer connection conductor30is formed inside the element body20. The interlayer connection conductor30can be formed on at least one of the base materials21to29. In the present embodiment, the interlayer connection conductor30is formed on the base materials21to27.

The interlayer connection conductor30is formed by filling a through hole20D penetrating at least one of the plurality of base materials21to29in the thickness direction100with a conductive paste, and co-firing the conductive paste with the element body20containing ceramic as a main material. The conductive paste contains, for example, a conductive powder such as copper. The conductive powder contained in the conductive paste is not limited to copper, and may be, for example, silver. In the present embodiment, since the through hole20D has a cylindrical shape, the interlayer connection conductor30has a cylindrical shape. The shape of the through hole20D is not limited to the cylindrical shape, and may be, for example, a shape such as a quadrangular prism.

InFIG.2, the interlayer connection conductor30includes four interlayer connection conductors31to34. The interlayer connection conductor31is filled in the through hole20D penetrating the base materials23to27. Each of the interlayer connection conductors32to34is filled in the through hole20D penetrating the base materials21and22. The length of each of the interlayer connection conductors31to34in the thickness direction100(the number of base materials penetrating therethrough) is not limited to the length described above.

The internal electrode40is formed inside the element body20and is not exposed to the outside of the element body20. The internal electrode40can be formed on at least one of the base materials21to29. In the present embodiment, the internal electrode40is formed on the base materials22,24,25,27, and28.

In a case where the main material of the element body20is ceramic as in the present embodiment, the internal electrode40is obtained by printing a conductive paste on the principal surface of the base material (each of the base materials22,24,25,27, and28in the present embodiment) and co-firing the paste with the base material. The conductive paste contains, for example, copper or silver.

In the present embodiment, the internal electrode40includes nine internal electrodes41to49. The internal electrode41is formed on the base material27. The internal electrodes42to44are formed on the base material22(seeFIG.3). The internal electrodes45and47are formed on the base material25. The internal electrodes46and48are formed on the base material24. The internal electrode49is formed on the base material28. The internal electrode49is an example of an electrode.

Each of the internal electrodes40is electrically connected to another internal electrode40or the external electrode50. In the present embodiment, as illustrated inFIG.2, the internal electrode41is electrically connected to the internal electrode44via the interlayer connection conductor31. The internal electrode42is electrically connected to an external electrode51via the interlayer connection conductor32. The internal electrode43is electrically connected to an external electrode52via the interlayer connection conductor33. The internal electrode44is connected to the internal electrode41via the interlayer connection conductor31, and is electrically connected to an external electrode53via the interlayer connection conductor34.

The external electrode50is formed outside the element body20. That is, the external electrode50is exposed to the outside of the element body20. In the present embodiment, the external electrode50is formed on the principal surface of the base material21(principal surface20A of the element body20). Note that the external electrode50may be formed on at least one of the principal surface20B of the element body20and the side surface20C of the element body20instead of the principal surface20A of the element body20or in addition to the principal surface20A of the element body20.

The external electrode50is configured in the same manner as the internal electrode40. That is, in the present embodiment, the external electrode50is obtained by printing a conductive paste on the principal surface20A of the element body20and co-firing the paste with the base materials21to29. In the present embodiment, the external electrode50includes three external electrodes51to53.

As described above, the external electrode51is electrically connected to the internal electrode42via the interlayer connection conductor32, the external electrode52is electrically connected to the internal electrode43via the interlayer connection conductor33, and the external electrode53is electrically connected to the internal electrode44via the interlayer connection conductor34.

The identification mark70is formed on the principal surface20B of the element body20. The identification mark70is for indicating an attitude and a direction of the ceramic electronic component10.

In the present embodiment, the ceramic electronic component10includes one identification mark70, but may include a plurality of the identification marks70.

In the present embodiment, as illustrated inFIG.1, the identification mark70has a circular shape when viewed in the thickness direction100, but is not limited to a circular shape. Furthermore, in the present embodiment, a diameter of the identification mark70viewed from the thickness direction100is 100 to 150 μm, but the diameter is not limited to 100 to 150 μm.

As illustrated inFIGS.2and3, a part of the identification mark70is embedded in the base material29of the element body20. On the other hand, the remaining portion (in other words, the portion excluding the part) of the identification mark70protrudes from the principal surface20B of the element body20.

Note that the identification mark70may not be embedded in the element body20. In this case, the entire identification mark70protrudes from the principal surface20B of the element body20. That is, it is sufficient that at least a part of the identification mark70protrudes from the principal surface20B of the element body20.

In each drawing, the color of the identification mark70is indicated by white or hatching, but the color of the identification mark70is not limited to white, and may be other colors such as black, gray, and red. The color of the identification mark70is preferably a color different from that around the identification mark70(the base material29in the present embodiment).

In the present embodiment, the identification mark70contains ceramic as a main material, and contains alumina as a main material and a glass material. The proportion of each material contained in the identification mark70is about 75% for alumina and about 25% for the glass material. In the present embodiment, the proportion of the glass material contained in the identification mark70is larger than the proportion of the glass material contained in the element body20. Furthermore, in the present embodiment, a thermal shrinkage rate of the identification mark70is lower than a thermal shrinkage rate of the element body20. For example, the element body20is adjusted so that the thermal shrinkage rate is lower than that of the identification mark70by the above-described additive. Furthermore, for example, the element body20contains as a main material a material (for example, zirconia (ZrO2)) having a thermal shrinkage rate lower than that of alumina, which is a main material of the identification mark70. The identification mark70may be non-shrunk at least at a temperature when fired.

Note that the material of the identification mark70is arbitrary on condition that the material has high distinguishability (high visibility) from those around the identification mark70(the base material29in the present embodiment). For example, the identification mark70may contain resin, metal, or the like as a main material. That is, the main material of the identification mark70may be other than ceramic. Furthermore, a proportion of the glass material contained in the identification mark70may be less than or equal to a proportion of the glass material contained in the element body20. Furthermore, the identification mark70may not contain the glass material. Furthermore, the identification mark70may contain a coloring material for making the identification mark70different in color from the base material29.

As illustrated inFIGS.1and3, the element body20includes the first portion61and the second portion62.

The first portion61is a portion of the element body20that surrounds the identification mark70and is in contact with an outer edge portion70A of the identification mark70as viewed in the thickness direction100. The outer edge portion70A of the identification mark70is a portion including an outer edge of the identification mark70and the vicinity of the outer edge when viewed from the thickness direction100. In the present embodiment, as viewed in the thickness direction100, the first portion61is an annular portion formed in the vicinity of the identification mark70(seeFIG.1).

The second portion62is a portion of the element body20surrounding the first portion61as viewed in the thickness direction100. That is, the second portion62is a portion outside the first portion61as viewed in the thickness direction100. In the present embodiment, the second portion62is in contact with an outer edge portion of the first portion61. The outer edge portion of the first portion61is a portion including an outer edge of the first portion61and the vicinity of the outer edge as viewed in the thickness direction100. As described above, when viewed from the thickness direction100, the first portion61is sandwiched between the second portion62and the identification mark70.

As illustrated inFIG.3, the first portion61is raised with respect to the second portion62. In the present embodiment, a height of the ridge of the first portion61with respect to the second portion62, in other words, a protrusion length of the first portion61from the second portion62in the thickness direction100is 4 μm. Note that the height of the ridge of the first portion61with respect to the second portion62is not limited to 4 μm.

In the present embodiment, the height of the ridge of the first portion61is the same as or substantially the same as a height of a protruding distal end portion of the identification mark70. In other words, in a protruding direction of the identification mark70with respect to the element body20, the ridge distal end portion of the first portion61and the protruding distal end portion of the identification mark70are at the same position or substantially the same position.

Note that the height of the ridge of the first portion61may be lower than the height of the protruding distal end portion of the identification mark70or may be higher than the height of the protruding distal end portion of the identification mark70.

As illustrated inFIG.3, the element body20includes the diffusion layer90. Note that, inFIG.2, the diffusion layer90is not illustrated. The diffusion layer90is formed at an interface portion of the base material29of the element body20with the identification mark70. The interface portion of the base material29of the element body20with the identification mark70is a portion including an interface with the identification mark70of the base material29and the vicinity of the interface in the base material29.

The diffusion layer90is a layer in which the composition of the element body20is changed by a substance diffused from the identification mark70(substance constituting the identification mark70). For example, in a firing step in a manufacturing process of the ceramic electronic component10, alumina, which is a substance constituting the identification mark70, diffuses into the base material29of the element body20. The composition of the material constituting the base material29is changed by the diffused alumina. Specifically, a proportion of alumina at the interface portion between the base material29and the identification mark70is higher than a proportion of alumina at a portion other than the interface portion of the base material29. A portion where the proportion of alumina is higher (an interface portion of the base material29with the identification mark70) is the diffusion layer90. Note that, inFIG.3, the diffusion layer90is illustrated to have a constant thickness, but a thickness of the diffusion layer90may vary.

As illustrated inFIG.3, the base material29of the element body20includes the first layer291and the second layer292.

The second layer292is formed on an opposite side of the identification mark70with respect to the diffusion layer90, and is in contact with the diffusion layer90. That is, the diffusion layer90is interposed between the second layer292and the identification mark70.

The first layer291is formed on an opposite side of the diffusion layer90and the identification mark70with respect to the second layer292, and is in contact with the second layer292. That is, the second layer292is interposed between the identification mark70and the first layer291.

As described above, the element body20contains celsian. That is, each of the first layer291and the second layer292provided on the base material29of the element body20contains celsian. A proportion of celsian contained in the second layer292is lower than a proportion of celsian contained in the first layer291.

In the present embodiment, a proportion of celsian contained in the base materials21to28other than the base material29is lower than the proportion of celsian contained in the first layer291. In the present embodiment, the base materials21to28correspond to the first layer similarly to the first layer291. Here, the internal electrode49is interposed between the base materials28and29. The internal electrode49restricts the second layer292of the base material29(that is, a region having a lower proportion of celsian than that of the first layer291) from reaching the base material28corresponding to the first layer. In other words, the internal electrode49functions as a barrier that restricts excessive expansion of the second layer292.

A thickness T1of the second layer292is the same as a maximum thickness T2of the identification mark70. Here, the thickness T1of the second layer292is, for example, a maximum thickness of the second layer292or an average thickness of the second layer292. In the present embodiment, the thickness T1of the second layer292is the same regardless of the position as illustrated inFIG.3. In the present embodiment, the identification mark70becomes deeper in the thickness direction100from the outer edge portion70A toward the central portion as viewed in the thickness direction100. That is, in the present embodiment, the maximum thickness T2of the identification mark70is the thickness of the central portion of the identification mark70. A position corresponding to the maximum thickness T2of the identification mark70is different depending on the shape and configuration of the identification mark70.

The thickness T1of the second layer292and the maximum thickness T2of the identification mark70may not be completely the same. For example, in the process of manufacturing the ceramic electronic component10, in a case where the thickness of the second layer292has a slight variation for each position, a difference of the variation is generated between the thickness T1and the maximum thickness T2. In this case, the thickness T1is substantially the same as the maximum thickness T2.

As illustrated inFIG.2, the plating layer80covers the external electrode50. The plating layer80suppresses the influence of atmosphere, moisture, and the like on the external electrode50. The plating layer80is a film containing, for example, Ni (nickel)-Sn (tin), Ni (nickel)-electroless Au (gold), or the like. In the present embodiment, the plating layer80includes an inner layer81containing nickel and an outer layer82containing gold. The inner layer81is formed on the surface of the external electrode50. The outer layer82is formed on the inner layer81on a side opposite to the external electrode50.

In the present embodiment, the plating layer80includes the two layers (the inner layer81and the outer layer82), but the plating layer80may include one layer or three or more layers.

According to the present embodiment, the proportion of celsian contained in the second layer292close to the identification mark70is lower than the proportion of celsian contained in the first layer291away from the identification mark70. As a result, in the present embodiment, the sinterability of the identification mark70with respect to the element body20can be maintained at a high level as compared with an embodiment in which the element body20does not have the second layer292. Furthermore, since the sinterability of the identification mark70with respect to the element body20is maintained at a high level, the visibility of the identification mark70with respect to the element body20is improved.

According to the present embodiment, the identification mark70contains alumina as a main material. Here, at the interface with alumina in the element body20and the peripheral portion thereof, celsian is less likely to be crystallized. Therefore, when the identification mark70containing alumina as a main material is formed on the surface of the element body20containing celsian, and the element body20is fired together with the identification mark70, the density of celsian in the peripheral portion of the identification mark70in the element body20is lower than the density of celsian in other portions other than the peripheral portion in the element body20. The peripheral portion corresponds to the second layer292, and the other portions correspond to the first layer291. That is, according to the present embodiment, the element body20including the first layer291and the second layer292can be easily manufactured.

In a case where the thickness of the second layer292is smaller than the maximum thickness T2of the identification mark70, that is, in a case where a portion of the identification mark70contributing to the improvement of the sinterability with respect to the second layer292is thin, there is a possibility that the sinterability of the identification mark70with respect to the second layer292is deteriorated. In a case where the thickness of the second layer292is larger than the maximum thickness T2of the identification mark70, that is, in a case where the volume of the portion where the proportion of celsian is low is large, the proportion of celsian in the entire element body20decreases, and there is a possibility that the mechanical properties, electrical insulation, and the like of the ceramic electronic component10decrease. According to the present embodiment, the thickness of the first layer291is the same as or substantially the same as the maximum thickness T2of the identification mark70. As a result, it is possible to suppress a decrease in the proportion of celsian in the entire element body20while suppressing a decrease in the sinterability of the identification mark70with respect to the second layer292.

According to the present embodiment, in a case where the second layer292is formed in the manufacturing process of the element body20, excessive expansion of the formation range of the second layer292can be prevented by the internal electrode49.

<Method of Manufacturing Ceramic Electronic Component According to Present Embodiment>

Hereinafter, an example of a method of manufacturing the ceramic electronic component10according to the present embodiment will be described with reference toFIGS.4to8.FIG.4is a cross-sectional view when an interlayer connection conductor is formed on a base material in a process of manufacturing the ceramic electronic component according to the embodiment of the present description.FIG.5is a cross-sectional view when an internal electrode is printed on the base material in the process of manufacturing the ceramic electronic component according to the embodiment of the present description.FIG.6is a cross-sectional view when an identification mark is printed on the base material in the process of manufacturing the ceramic electronic component according to the embodiment of the present description.FIG.7is a cross-sectional view when a plurality of the base materials are laminated to form an element body in the process of manufacturing the ceramic electronic component according to the embodiment of the present description.FIG.8is a cross-sectional view when the element body is crimped in the process of manufacturing the ceramic electronic component according to the embodiment of the present description.

The ceramic electronic component10is manufactured by segmenting a laminate into a plurality of element bodies20. The laminate is formed by integrating the plurality of element bodies20in an arranged state. InFIGS.4to8, for convenience of description, only a portion corresponding to one element body20of the laminate is illustrated. A method of manufacturing the ceramic electronic component10according to the present embodiment includes a sheet forming step, an interlayer connection conductor forming step, an electrode forming step, an identification mark forming step, an element body forming step, a crimping step, a segmenting step, a firing step, and a plating layer laminating step.

First, the sheet forming step is executed. In the sheet forming step, the base materials21to29illustrated inFIG.2are individually formed. In the base materials21to29formed in the sheet forming step, raw materials including a main agent, a plasticizer, a binder, and the like corresponding to each of the base materials21to29are mixed to prepare a slurry constituting each of the base materials21to29. Each of the base materials21to29at this stage is a green sheet including the slurry.

For each of the base materials21to29, for example, a sinterable ceramic powder or the like is used as the main agent. As the plasticizer, for example, phthalic acid ester, di-n-butyl phthalate, or the like is used. As the binder, for example, an acrylic resin, polyvinyl butyral, or the like is used.

The slurry constituting each of the base materials21to29is formed into a sheet shape on a carrier film101illustrated inFIG.4using, for example, a lip coater, a doctor blade, or the like. That is, each of the nine base materials21to29is formed on each of the nine carrier films101. As the carrier film101, for example, a polyethylene terephthalate (PET) film or the like is used. A thickness of each of the base materials21to29is, for example, 5 to 100 (μm).

FIG.4illustrates the carrier film101and the base material26formed on the carrier film101.

Next, the through hole20D penetrating each of the base materials21to29and the carrier film101in the thickness direction is formed.

Note that, inFIG.4, one through hole20D is formed in the base material27and the carrier film101, but the number of through holes20D formed in each of the base materials21to29is not limited to one. Furthermore, the number of through holes20D formed in the base materials21to29and the number of through holes20D formed in the carrier film101corresponding to each of the base materials21to29may be the same or different. Furthermore, the positions of the through holes20D formed in the base materials21to29and the carrier film101corresponding to each of the base materials21to29may be the same position or different positions.

In the method of manufacturing the ceramic electronic component10according to the present embodiment, the number and positions of the through holes20D formed in the nine base materials21to29and carrier films101are determined so that the element body20as illustrated inFIG.2is finally formed.

Next, the interlayer connection conductor forming step is executed. In the interlayer connection conductor forming step, the conductive paste102is filled in the through hole20D formed in each of the base materials21to29and the carrier films101in the sheet forming step (seeFIG.4). The paste102filled in the through hole20D corresponds to the interlayer connection conductor30.

The paste102is prepared, for example, by mixing raw materials containing a conductive powder, a plasticizer, and a binder.

Next, the electrode forming step is executed. In the electrode forming step, the internal electrode40and the external electrode50are formed.

In the method of manufacturing the ceramic electronic component10according to the present embodiment, for example, as illustrated inFIG.5, a paste corresponding to the internal electrode49is formed on the principal surface of the base material28. The paste is formed by, for example, screen printing, inkjet printing, gravure printing, or the like. Note that other internal electrodes40(internal electrodes42to48) and external electrodes50are also formed on each of the base materials21to29in the same manner as the internal electrode41.

The paste corresponding to the internal electrodes40and the external electrodes50is prepared by mainly mixing raw materials containing a conductive powder, a plasticizer, and a binder, similarly to the paste102described above. Note that the paste corresponding to the internal electrodes40and the external electrodes50may be constituted of the same raw material as the paste102, or may be constituted of a raw material different from the paste102.

Next, the identification mark forming step is executed. In the identification mark formation step, the identification mark70is formed.

In the method of manufacturing the ceramic electronic component10according to the present embodiment, as illustrated inFIG.6, a paste corresponding to the identification mark70is formed on the principal surface of the base material29. The paste corresponding to the identification mark70is formed by, for example, screen printing, inkjet printing, gravure printing, a transfer method described later, or the like. The paste corresponding to the identification mark70contains a material (alumina and glass material in the present manufacturing method) constituting the identification mark70described above. As described above, the material of the identification mark70is arbitrary. For example, in a case where the identification mark70includes a conductive material, the paste corresponding to the identification mark70is a conductive paste, and in a case where the identification mark70does not include a conductive material, the paste corresponding to the identification mark70is a non-conductive paste. In the present manufacturing process, a thermal shrinkage rate of the material constituting the identification mark70is lower than a thermal shrinkage rate of the material constituting at least the base material29among the base materials21to29.

Next, the element body forming step is executed. In the element body forming step, as illustrated inFIG.7, the base materials21to29excluding the carrier films101are laminated. As a result, the element body20is obtained.

In the element body forming step, the nine base materials21to29are laminated in the order from a base material having a small numerical value to a base material having a large numerical value, specifically, in the order of base materials21,22,23,24,25,26,27,28, and29. As a result, the principal surface of the base material21becomes the principal surface20A of the element body20, and the principal surface of the base material29becomes the principal surface20B of the element body20. Furthermore, the side surface of the base materials21to29becomes the side surface20C of the element body20.

In the present embodiment, some of the nine base materials21to29are inverted and laminated with respect to base materials other than the some of the nine base materials21to29. In the example illustrated inFIG.7, the base materials22to29are laminated with the surface on a side of the carrier film101facing downward in the drawing, while the base material21is laminated with the surface on the side of the carrier film101facing upward in the drawing. As a result, as illustrated inFIG.7, each of the internal electrodes40and the identification mark70formed on the base materials22,24,25,27,28, and29is located above each of the base materials22,24,25,27,28, and29, and the external electrodes50formed on the base material21is located below the base material21.

Next, the crimping step is executed. In the crimping step, the laminated base materials21to29are crimped in a mold.

As illustrated inFIG.8, when each of the base materials21to29is crimped, the internal electrodes40enter the base materials22,24,25,27, and28, the external electrodes50enter the base material21, and the identification mark70enters the base material29. As a result, the identification mark70is embedded in the element body20.

Note that the crimping step may not be executed. In this case, the identification mark70is not embedded in the element body20.

Next, the segmenting step is performed. In the segmenting step, the laminate in which the plurality of element bodies20are arranged is cut into the plurality of element bodies20. For cutting the laminate, for example, a dicing saw, a guillotine cutter, a laser, or the like is used. After the laminate is cut, a corner portion and an edge portion of the element body20may be polished by, for example, barrel processing or the like (seeFIG.2). The polishing may be performed after the firing step.

Next, the firing step is executed. In the firing step, the element body20is fired. As a result, each of the base materials21to29constituting the element body20is cured. That is, each of the base materials21to29, which is a flexible green sheet, is cured and transformed into a substrate (seeFIG.2).

As described above, the thermal shrinkage rate of the material constituting the identification mark70is lower than the thermal shrinkage rate of the material constituting the base material29. Therefore, in the firing step, an amount of shrinkage of the identification mark70is smaller than an amount of shrinkage of the base material29. Therefore, shrinkage of the base material29toward the identification mark70is inhibited by the outer edge portion70A (seeFIG.8) of the identification mark70. As a result, the base material29rises in the vicinity of the outer edge portion70A. A portion where the base material29is raised is the first portion61(seeFIGS.1and3).

Furthermore, in the firing step, the alumina contained in the identification mark70is diffused into the base material29to form the diffusion layer90.

Furthermore, in the firing step, the celsian is less likely to be crystallized in the peripheral portion of the identification mark70in the element body20(specifically, in the element body20, a side opposite to the identification mark70with respect to the diffusion layer90) than in portions other than the peripheral portion in the element body20. As a result, in the element body20, the proportion of celsian contained in the peripheral portion is lower than the proportion of celsian contained in portions other than the peripheral portion. The peripheral portion of the element body20corresponds to the second layer292. The portions other than the peripheral portion in the element body20correspond to the first layer291.

Next, the plating layer laminating step is executed. In the plating layer laminating step, the external electrode50is subjected to a known plating treatment. As a result, as illustrated inFIG.2, the plating layer80is laminated so as to cover the external electrode50.

FIG.9is a cross-sectional view illustrating a plurality of base materials laminated in a modification of the process of manufacturing the ceramic electronic component according to the embodiment of the present description and a film on which an identification mark is printed. The identification mark70may be formed on the base material29by a transfer method.

In the case of the transfer method, as illustrated inFIG.9, the identification mark70is printed on a principal surface103A of a transfer sheet103. Thereafter, in the element body forming step, the transfer sheet103is laminated on the base material29such that the principal surface103A of the transfer sheet103is on a side of the base material29. As a result, the identification mark70is transferred from the transfer sheet103to the base material29(seeFIG.7).

In the method of manufacturing the ceramic electronic component10described above, the first portion61is formed in the element body20by firing the element body20and the identification mark70having different thermal shrinkage rates. However, the manufacturing method of forming the first portion61is not limited thereto.

For example, before the crimping step, a paste containing a material that burns out by heat is formed in a region excluding the identification mark70on the principal surface of the base material29and the vicinity of the outer periphery thereof (in other words, a region corresponding to the second portion62). In the subsequent crimping step, the paste is embedded in the base material29. In the subsequent firing step, the paste is burned out. As a result, the second portion62recessed with respect to a region where the paste is not formed is formed in a region where the paste is formed. That is, in the region where the paste is not formed, the first portion61that is raised with respect to the region where the paste is formed is formed.

Note that, by appropriately combining arbitrary embodiments among the various embodiments described above, the effects of the respective embodiments can be achieved.

Although the present description has been fully set forth in connection with the preferred embodiment thereof with reference to the drawings as appropriate, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.

EXPLANATION OF REFERENCES