Electronic component

Abstract

An electronic component 1 includes: an element body 10 containing an inorganic material; and an external electrode 21 provided on an end surface 10c of the element body 10. Carbon is dispersed in the inorganic material of the element body 10. The electronic component 1 has a mark region 30 enabling identification of the orientation of the element body 10 by observation from a principal surface 10a of the element body.

Description

Electronic components

[0001] This invention relates to electronic components.

[0002] In electronic components, marks are sometimes placed on the component surface to specify the orientation during mounting and to avoid mounting errors or manufacturing defects. Metal marking materials are widely used as the material for marking electronic components.

[0003] However, if a mark made of such metal material is used, it is necessary to consider short circuits with electrodes on electronic components, which limits the shape and position of the mark.

[0004] In recent years, the demand for miniaturization of products has been strong, and this problem has become more pronounced. Specifically, when the mark is made of metal, the smaller the product becomes, the narrower the distance between the electrode and the mark becomes, making it easier for a short circuit to occur due to contact between the electrode and the mark. To solve this problem, a technology for forming the mark using a material other than metal has been proposed in Patent Document 1.

[0005] Japanese Patent Publication No. 2010-40717

[0006] In the technology described in Patent Document 1, a ZnO-based material is used as the base material, and ZnO and ZrO are used as marks. ２ The material used consists of the following components. Because the base material and the marking material are different, they may react with each other. In addition, because the optimal firing temperatures are different, it is difficult to achieve good sinterability at the same time.

[0007] Therefore, problems arose such as defects like cracks, chips, and fissures in electronic components originating from the marked area and the interface between the marked area and the base material, as well as the densification of the electrical circuit formation layer near the marked area being inhibited, and the material of the marked area reacting with other materials to degrade its properties.

[0008] This invention was made to solve the above problems and aims to provide an electronic component with a mark that prevents defects such as cracking caused by the mark and has good visibility.

[0009] The electronic component of the present invention comprises a base body containing an inorganic material, and an external electrode provided on the end face of the base body, wherein carbon is dispersed in the inorganic material of the base body, and a mark region is provided that allows the orientation of the base body to be identified by observation from the main surface of the base body.

[0010] According to the present invention, defects such as cracking caused by the marked portion are prevented, and an electronic component with a mark that has good visibility can be provided.

[0011] Figure 1 is a schematic perspective view showing an example of an electronic component of the present invention. Figure 2 is a schematic exploded perspective view showing an example of the layer configuration of the base body. Figure 3 is a schematic perspective view showing the base body with the layer configuration shown in Figure 2. Figure 4 is a schematic perspective view showing another example of an electronic component of the present invention. Figure 5 is a schematic exploded perspective view showing another example of the layer configuration of the base body. Figure 6 is a schematic perspective view showing the base body with the layer configuration shown in Figure 5.

[0012] The electronic components of the present invention will be described below. However, the present invention is not limited to the following configurations, and can be modified and applied as appropriate without altering the essence of the invention. Furthermore, a combination of two or more desirable configurations of each embodiment of the present invention described below also constitutes the present invention.

[0013] Figure 1 is a schematic perspective view showing an example of an electronic component of the present invention. The electronic component 1 shown in Figure 1 comprises a base body 10 containing an inorganic material, and an external electrode provided on the end face of the base body 10.

[0014] The base body 10 is a laminate in which multiple inorganic material layers are stacked, and includes a first main surface 10a and a second main surface 10b facing the stacking direction T, a first side surface 10e and a second side surface 10f facing the width direction W perpendicular to the stacking direction T, and a first end surface 10c and a second end surface 10d facing the length direction L perpendicular to the stacking direction T and the width direction W.

[0015] As external electrodes, a first external electrode 21 is connected to a first end surface 10c of the element body 10, and a second external electrode 22 is connected to a second end surface 10d of the element body 10. The first external electrode 21 and the second external electrode 22 are end surface external electrodes. The end surface external electrodes are formed on the end surface of the element body, and further extend from the end surface to the side surfaces and the main surface of the element body.

[0016] Further, as external electrodes, a third external electrode 23 is connected to a first side surface 10e of the element body 10, and a fourth external electrode 24 is connected to a second side surface 10f of the element body 10. The third external electrode 23 and the fourth external electrode 24 are side surface external electrodes. The side surface external electrodes are formed on the side surface of the element body, and further extend from the side surface to the main surface of the element body.

[0017] The element body is a laminate formed by laminating a plurality of inorganic material layers. As the inorganic material, an inorganic material that can be co-fired with the metal constituting the internal electrodes is preferably used. A glass-ceramic composition is preferably used as the inorganic material. Examples of the glass-ceramic composition include a composition containing ceramic and glass.

[0018] Examples of the ceramic include MgAl ２ O ４ , Mg ２ SiO ４ , BaO, RE ２ O ３ (RE is a rare earth element), ZrO ２ , TiO ２ and at least one selected from the group consisting of MnO. The ceramic may further contain CuO, Mg ２ Al ４ Si ５ O １８ and BaAl ２ Si ２ O ８ may contain at least one selected from the group consisting of

[0019] Examples of the glass include those having a composition containing RO (R is at least one alkaline earth metal selected from Ba, Ca and Sr), SiO ２ , B ２ O ３ and Al ２ O ３ The glass contains Li２ may contain at least one selected from the group consisting of O and MgO.

[0020] The thickness per inorganic material layer is preferably 0.1 µm or more and 5.0 µm or less. In particular, when a mark region is provided in an inorganic material layer that is inner than the outermost inorganic material layer as in an embodiment described later, the thickness of the inorganic material layer is preferably thin so that the mark region can be visually recognized.

[0021] Examples of the metal constituting the internal electrode include Cu, Ag, Ni and the like.

[0022] The external electrode is preferably an electrode provided by printing or transferring an external electrode paste containing Cu or an alloy containing Cu as a main component and then firing, and may have a plating layer provided on the electrode surface.

[0023] The electronic component of the present invention has a mark region that enables identification of the orientation of the element body when observed from the main surface of the element body. In the electronic component 1 shown in FIG. 1, a mark region 30 exposed on the surface of the first main surface 10a of the element body 10 is provided, such that the mark region 30 can be observed (visually recognized) from the first main surface 10a of the element body 10. Like the electronic component 1 shown in FIG. 1, a configuration in which the mark region 30 is provided in the outermost inorganic material layer of the element body is one of the preferred embodiments of the electronic component of the present invention.

[0024] The electronic component 1 shown in FIG. 1 has a symmetrical external shape excluding the mark region 30, and it is difficult to distinguish the first external electrode 21 and the second external electrode 22 from the appearance of the electronic component 1. Further, it is difficult to distinguish the third external electrode 23 and the fourth external electrode 24.

[0025] When characteristics of the electronic component vary depending on the connection direction of the first external electrode 21 and the second external electrode 22 during mounting of the electronic component, that is, when the electronic component has polarity, a mark region for indicating the orientation of the electronic component is required. In the electronic component 1, the mark region 30 is provided on the first main surface 10a at a side deviated from the center in the length direction L and close to the first external electrode 21. Since an electrode close to the mark region 30 can be determined as the first external electrode 21, wrong orientation during mounting of the electronic component is prevented.

[0026] The mark region is a region where carbon is dispersed in the inorganic material of the element body. Regarding the composition of the mark region, the composition other than carbon is the same as that of the inorganic material surrounding the mark region. It can be said that the composition of the mark region is a composition obtained by adding carbon to the inorganic material composition surrounding the mark region. In the composition described in Patent Document 1, the material of the element body is a ZnO-based material, and the material of the mark is ZnO and ZrO ２ , and the material of the mark has a composition system different from that of the material of the element body. Therefore, the sinterability of the mark is different from that of the surrounding area, and it is difficult to obtain good sinterability. On the other hand, in the configuration of the present invention, the composition of the inorganic material affecting sinterability is the same in the mark region and the surrounding region, so the sinterability of the mark region and the surrounding region is the same, and defects such as cracks caused by the mark are prevented.

[0027] The mark region is not a region where only carbon exists, and most of the composition of the mark region is an inorganic material having the same composition as the inorganic material surrounding the mark region. The mark region is a non-metallic insulating mark, which is different from a conductive mark such as a mark formed by applying metal paste or metal plating.

[0028] When the mark is an insulating mark, no stray capacitance is generated even if an electrode pattern is arranged near the mark. In addition, no short circuit occurs even when the external electrode is in contact with the mark. Therefore, with the mark region defined in the present invention, the shape and formation position of the mark, as well as the shape of the external electrodes can be freely set, enabling miniaturization of electronic components.

[0029] The amount of carbon in the marked region should be observable; the guideline (residual carbon amount) is between 1,000 ppm and 10,000 ppm. Too much carbon can result in insufficient insulation in the marked region. The amount of carbon in the marked region can be quantified using XRF (X-ray fluorescence analysis).

[0030] The base material outside the marked area is usually white, but depending on the composition, it may have a brownish tint. The marked area contains carbon, and since carbon itself is black, the color of the marked area will be gray if the amount of carbon is small, and black if the amount is large. The difference between the white or brown of the base material and the gray or black of the marked area allows for identification of the marked area.

[0031] There are no limitations on how the marked area can be identified from its surroundings; visual inspection by an operator or mechanical observation using an image measuring machine are both possible. In the case of mechanical observation, for example, an optical image of the main surface of the object can be captured using an image measuring machine, and when the image is multi-leveled into 256 grayscale divisions, a criterion such as "the marked area is black with a grayscale difference of 64 or more levels compared to other areas" can be established to distinguish it. The degree of multi-leveling and the method of determining the grayscale difference are arbitrary.

[0032] There are no particular restrictions on the shape of the marking area; rectangles, triangles, circles, etc., can be selected as appropriate. There are also no particular restrictions on the area of ​​the marking area; it should be an appropriate size depending on the application. Furthermore, there are no particular restrictions on the thickness of the marking area.

[0033] Figure 2 is a schematic exploded perspective view showing an example of the layer structure of a basic component. Figure 2 shows the layer structure of an LC filter as an example of an electronic component.

[0034] The base body 10 is made up of stacked inorganic material layers 102, 103, 104, 111, 112, 113, 114, 115, 109, 110, 108, 107, 106, 105, 116, and 117, and includes a helical coil L and a capacitor C. The helical coil L is constructed by electrically connecting coil conductors 131a, 131b, 131c, and 131d via via hole conductors 125. However, the lead portion of coil conductor 131a is exposed on the left side of inorganic material layer 105, and the lead portion of coil conductor 131d is exposed on the right side of inorganic material layer 108.

[0035] Capacitor C is constructed by connecting in parallel a capacitor consisting of capacitor conductors 141 and 142 facing each other with an inorganic material layer 111 in between, a capacitor consisting of capacitor conductors 142 and 143 facing each other with an inorganic material layer 112 in between, a capacitor consisting of capacitor conductors 143 and 144 facing each other with an inorganic material layer 113 in between, and a capacitor consisting of capacitor conductors 144 and 145 facing each other with an inorganic material layer 114 in between.

[0036] The lead-out portions of capacitor conductors 141, 143, and 145 are exposed on the front and back edges of inorganic material layers 111, 113, and 115, respectively, while the lead-out portions of capacitor conductors 142 and 144 are exposed on the right-hand edges of inorganic material layers 112 and 114, respectively.

[0037] A marking area 30 is provided in the outermost inorganic material layer 102.

[0038] Figure 3 is a schematic perspective view showing the base structure with the layer configuration shown in Figure 2. The lead portion of the coil conductor 131a is exposed on the first end face 10c of the base structure. In Figure 3, the position of the lead portion of the coil conductor exposed on the first end face 10c of the base structure is indicated by a dotted line. The lead portion of the coil conductor 131d is exposed on the second end face 10d of the base structure.

[0039] The leads of capacitor conductors 141, 143, and 145 are exposed on the second side surface 10f and the first side surface 10e of the main body. Figure 3 shows the positions of the capacitor conductor leads exposed on the first side surface 10e of the main body with dotted lines. The leads of capacitor conductors 142 and 144 are exposed on the second end surface 10d of the main body.

[0040] The lead-out portions of the capacitor conductors 142 and 144 are not drawn out from the first end face 10c of the base body, but they are drawn out from the second end face 10d of the base body. Therefore, the configuration on the first end face side and the configuration on the second end face side of the base body are not equivalent, and it is necessary to identify the orientation of the base body. The mark area 30 is provided on the surface of the outermost inorganic material layer 102, and the presence of the mark area 30 makes it possible to identify the orientation of the base body.

[0041] Next, an example of a method for manufacturing an electronic component that can be obtained according to the present invention will be described.

[0042] (Preparation of paste for the base body) A paste for the base body containing the inorganic materials that constitute the base body is prepared. The glass ceramic composition described above can be used as the inorganic material. In addition to the inorganic materials, the paste for the base body contains a solvent, an organic vehicle containing a binder resin, etc. These components are made into a paste to form the paste for the base body. In addition to the components described above, various oxides, organometallic compounds, or resinates may also be included. Examples of binder resins to be included in the paste for the base body include ethyl cellulose and polyvinyl butyral, but ethyl cellulose is preferred.

[0043] (Preparation of marking paste) The marking paste includes the inorganic materials contained in the base paste, and further includes marking raw materials. The marking raw materials include the inorganic materials contained in the base paste and organic materials that serve as a carbon source. A specific example of the marking raw materials is SiO containing resin beads. ２ Particles can be used. When using these particles, the inorganic material SiO contained in the base paste is used. ２ A portion of SiO ２The marking particles containing are replaced. In this way, the SiO in the inorganic material contained in the base paste is replaced. ２ The content and SiO contained in the marking paste ２ The content will be the same, and the inorganic material composition in the paste for the base body and the inorganic material composition in the paste for marking will be the same.

[0044] As a raw material for marking, Al contains resin beads. ２ O ３ particles, TiO ２ Particle, ZrO ２ One or more oxides selected from the group consisting of particles may be used. These particles are added to the paste for the base material. ２ O ３ , TiO ２ , ZrO ２ It can be used when each of the following is included, and the Al included in the paste for the base body ２ O ３ , TiO ２ , ZrO ２ It can be used by substituting a part of it. SiO containing resin beads ２ particles, Al ２ O ３ particles, TiO ２ Particle, ZrO ２ Only one type of particle may be used, or multiple types may be used in combination.

[0045] The proportion of inorganic materials in the base paste that are replaced by marking materials is preferably 1% by weight or more and 10% by weight or less of the inorganic materials in the base paste. This replacement ratio is preferable because it allows for the formation of a mark area sufficient for identification, and prevents the proportion of carbon in the mark area from becoming too high.

[0046] As the material for the resin beads, a resin material that decomposes at temperatures between 300°C and 400°C is preferably used. Divinylbenzene can be used as an example of a resin material. Other resin materials such as polystyrene, epoxy, and phenol may also be used. The average particle size of the resin beads is, for example, 3 μm, and the resin beads are coated with SiO ２The coating thickness is, for example, 100 nm. The shape of the marking material is not particularly limited, and can be spherical, flake-shaped, etc., or a mixture of these shapes may be used. Furthermore, the average particle size of the inorganic material powder other than the marking material contained in the marking paste can be about the same as the average particle size of the inorganic material powder contained in the base paste.

[0047] The binder resin included in the marking paste is the same as the binder resin included in the base material paste. Preferably, the binder resin is included in the marking paste in an amount of 5 to 15 parts by weight per 100 parts by weight of the total amount of inorganic material and marking raw materials. Preferably, the solvent used in the marking paste is a solvent that is incompatible with the base material paste. Examples of solvents used in the marking paste include terpineol and dihydroterpineol. Preferably, dihydroterpineol is used. The solvent content of the marking paste is preferably 20% by weight or more, and preferably 60% by weight or less, based on the total weight of the marking paste. The marking paste may optionally contain dispersants, plasticizers, adhesives, and other additive powders.

[0048] (Preparation of base green sheet) After forming the base paste into a sheet using, for example, the doctor blade method and drying it, a ceramic green sheet is obtained by punching it out to the predetermined dimensions. For the ceramic green sheet to be placed in the position where the internal electrodes will be installed, the paste for the internal electrodes is printed on it, and a ceramic green sheet with an internal electrode paste layer formed is prepared. The internal electrode paste layer is the part that will become the internal electrode after firing. The base green sheet is obtained by the above process.

[0049] (Preparation of marking green sheet) Marking paste is applied to the base green sheet at the positions to be marked. The method of applying the marking paste is not particularly limited as long as it can uniformly form the marking area, and examples include screen printing, gravure printing, offset printing, and other methods for forming a thick film. Among these, screen printing is preferred. A marking green sheet is obtained by the above process.

[0050] (Lamination and firing) A laminate is obtained by laminating a green sheet for the base material and a green sheet for marking, and then a green chip is obtained by cutting the laminate into a predetermined shape. When laminating, the green sheet for marking is placed on top so that the side with the marking paste applied becomes the surface. Alternatively, the green sheets for the base material may be laminated and the marking paste applied to the surface of the laminate may be applied. The laminate is cut into green chips of the desired shape. Next, a debinder treatment and firing treatment are performed. These conditions are general conditions. After the debinder treatment and firing as described above, the base material is obtained.

[0051] During firing, the resin beads (organic components) contained in the marking material carbonize into carbon, which remains in the marked area. Since the remaining carbon turns black, a marking area is formed where the color of this carbon is visible. The inorganic material contained in the marking paste co-sintersects with the inorganic material of the base paste surrounding the marking paste, so there is no difference in sinterability between the marked area and its surroundings, preventing defects such as cracks caused by the marking.

[0052] Firing is preferably carried out under a reducing atmosphere. Firing in a reducing atmosphere makes it easier for organic components to remain as carbon rather than being completely decomposed and eliminated. Furthermore, if the marking material is a resin bead with an inorganic coating on its surface, the resin beads are prevented from completely disappearing during firing, making them more likely to remain as carbon. Organic components such as solvents and binder resins contained in the base green sheet and the marking green sheet, other than the marking material, disappear during firing, so no carbon derived from the solvents or binder resins remains. Therefore, only the area where the marking material was present becomes the marked area.

[0053] Next, external electrodes are formed on the base body. External electrodes can be formed by printing or transferring an external electrode paste onto the base body and then firing it. Then, if necessary, a plating layer is formed on the surface of the external electrodes.

[0054] If the layer configuration of the external electrodes provided on the base body is the same regardless of position, then when forming the external electrodes, the orientation of the base body does not need to be considered, and the external electrodes can be provided at the predetermined positions.

[0055] When external electrodes with different layer configurations are provided depending on the internal electrodes exposed on the surface of the base body, taking into account the polarity of the base body, it is preferable to determine the orientation of the electronic component based on the position of the marked area. In this case, the marked area is used as an indicator of the orientation of the base body when forming the external electrodes.

[0056] By the method described above, an electronic component of the present invention having a marked area on the first main surface of the base material can be obtained. This electronic component allows for the identification of the orientation of the base material by observation from the first main surface of the base material, and prevents defects such as cracking caused by the marked area.

[0057] Electronic components are mounted on printed circuit boards or other surfaces by soldering or other means and used in various electronic devices. For example, if the electronic component is an LC filter (high-frequency filter), it can be suitably used in communication devices such as PCs, smartphones, and mobile communication terminals.

[0058] Next, we will describe examples of electronic components in which the position of the mark area differs. Figure 4 is a schematic perspective view showing another example of an electronic component of the present invention. In the electronic component 2 shown in Figure 4, the mark area 30 provided on the base body 10 is provided in an inorganic material layer that is inside the outermost inorganic material layer. Figure 4 shows the mark area 30 that is visible by passing through the outermost inorganic material layer that constitutes the first main surface 10a of the base body 10.

[0059] Figure 5 is a schematic exploded perspective view showing another example of the layer structure of the base material. Figure 6 is a schematic perspective view showing the base material with the layer structure shown in Figure 5. The layer structure of the base material shown in Figures 5 and 6 is the same as the layer structure of the base material shown in Figure 2, except for the position of the marked area. In the layer structure shown in Figures 5 and 6, the marked area 30 is provided on the third inorganic material layer 104 from the outside. That is, when observed from the first main surface 10a of the base material 10, the marked area 30 is visible below the inorganic material layers 102 and 103.

[0060] If the inorganic material layer is thin and the number of inorganic material layers stacked on top of the marked area is small, the marked area can be visually identified by observation from the main surface of the base object, even if the marked area is located in an inorganic material layer inside the outermost inorganic material layer, making it possible to identify the orientation of the base object.

[0061] From the viewpoint of making the marked area visible from the main surface of the base material, it is preferable that the thickness of the inorganic material layer located outside the marked area is 50 μm or less. Furthermore, it is preferable that the total number of inorganic material layers located outside the marked area is two or less.

[0062] When fabricating the base body shown in Figures 5 and 6, the marking green sheet is placed in a layer inside the outermost layer (the third layer from the top in the layer configuration of Figure 5) to obtain a laminate. In this example, the total number of inorganic material layers located outside the marking area is two. The electronic component of the present invention can be obtained by performing the other steps in the same manner as described above.

[0063] 1, 2 Electronic components 10 Body 10a First main surface 10b Second main surface 10c First end surface 10d Second end surface 10e First side surface 10f Second side surface 21 First external electrode 22 Second external electrode 23 Third external electrode 24 Fourth external electrode 30 Marked area 102-117 Inorganic material layer 125 Via hole conductors 131a, 131b, 131c, 131d Coil conductors 141, 142, 143, 144, 145 Capacitor conductors

Claims

1. An electronic component comprising a body containing an inorganic material, and an external electrode provided on the end face of the body, wherein carbon is dispersed in the inorganic material of the body, and a mark region is provided that allows identification of the orientation of the body by observation from the main surface of the body.

2. The electronic component according to claim 1, wherein the base body is a laminate in which multiple inorganic material layers are stacked, and the mark region is provided on the outermost inorganic material layer.

3. The electronic component according to claim 1, wherein the base body is a laminate in which multiple inorganic material layers are stacked, and the marked area is provided in an inorganic material layer that is inside the outermost inorganic material layer.

4. An electronic component according to any one of claims 1 to 3, wherein when an optical image of the main surface of the element is captured by an image measuring machine and multi-level imager is performed by dividing it into 256 grayscale sections, the marked area has a grayscale difference of 64 or more levels of black compared to other areas.

5. The electronic component according to any one of claims 1 to 4, wherein the mark area is located off-center from the main surface and close to one of the external electrodes.

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