Ceramic construction

Abstract

The utility model provides a ceramic structure with an identification mark which is not easy to generate cracks. A ceramic structure (30) is provided with: a first ceramic layer (11) having a first main surface (11a) and a second main surface (11b) facing the first main surface (11a); and an identification mark (20) formed on the first main surface (11a) of the first ceramic layer (11) and made of a ceramic, the identification mark (20) having a plurality of continuous sections (21) and non-continuous sections (22) positioned between the plurality of continuous sections (21) in a cross-section of the identification mark (20) in a direction perpendicular to the first main surface (11a).

Description

Technical Field

[0001] The utility model relates to a ceramic structure. Background Art

[0002] Conventionally, in order to identify the orientation of LC composite components such as laminated filters, and ceramic laminates such as laminated ceramic capacitors and laminated inductors, identification marks have been formed on their surfaces.

[0003] For example, Patent Document 1 discloses a stacked inductor having a spiral coil conductor in a rectangular chip obtained by stacking and firing a plurality of sheet layers, and having marking layers for indicating the position of the lead-out portion of the coil conductor on the inner side of the upper surface side sheet layer and the inner side of the lower surface side sheet layer constituting the chip. The stacked inductor is characterized in that each of the marking layers is formed into a rectangular shape having the same width as the chip, two sides of each marking layer on the side surface of the chip are exposed at two side surfaces of the chip, and one side on the end surface side of the chip is located at a specified distance from the end surface of the chip.

[0004] In the laminated inductor described in Patent Document 1, the two edges of each marking layer, which are located near the chip side, are exposed on both sides of the chip, while the edge, which is located near the chip end face, is positioned a predetermined distance inward from the chip end face. This ensures that the upper and lower sheet layers sandwiching each marking layer maintain sufficient adhesion. This prevents peeling between the sheet layer covering each marking layer and each marking layer during the manufacturing process and when mounted on a substrate.

[0005] Furthermore, when manufacturing the stacked inductor described in Patent Document 1, even if air is introduced during the formation of the marking layer and remains in the form of bubbles, the air can be discharged from the two exposed edges of each marking layer on the side surfaces of the chip. This prevents the air from being scattered from the sheet layer covering each marking layer and each marking layer due to the expansion or rupture of the remaining bubbles during the manufacturing process or when the substrate is mounted.

[0006] In addition, Patent Document 2 discloses a method for manufacturing porous ceramics, wherein ceramic particles comprising at least one material selected from aluminum nitride, silicon carbide, and silicon nitride are mixed with carbonaceous particles in such a manner that the ceramic particles are uniformly attached to the surface of the carbonaceous particles, and then the mixture is sintered while or after being pressed to obtain a sintered body, and then the carbonaceous particles contained in the sintered body are oxidized and burned.

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2005-166745

[0008] Patent Document 2: International Publication No. 2015 / 025951

[0009] In the laminated inductor described in Patent Document 1, the marking layer has a different composition than the sheet layer, which serves as the other base ceramic layers. Consequently, the sintering properties differ. Consequently, there is a problem in that, when the marking layer and the sheet layer are sintered simultaneously, the shrinkage rates differ, making cracks more likely to form in the marking layer.

[0010] Patent Document 2 discloses a method for independently controlling the pore shape and porosity of porous ceramics, but does not disclose a method for preventing cracks from occurring when two layers having different sintering properties are stacked and fired simultaneously. Utility Model Content

[0011] The present invention is a utility model completed in order to solve the above-mentioned problem. The purpose of the present invention is to provide a ceramic structure having an identification mark that is not prone to cracking.

[0012] The ceramic structure of the present invention comprises: a first ceramic layer having a first main surface and a second main surface opposite to the first main surface; and an identification mark formed on the first main surface of the first ceramic layer and composed of ceramic, wherein in a cross section of the identification mark in a direction perpendicular to the first main surface, the identification mark has a plurality of continuous portions and a non-continuous portion located between the plurality of continuous portions.

[0013] According to the present invention, a ceramic structure having an identification mark that is less likely to crack can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1A This is a cross-sectional view schematically showing an example of a ceramic laminate including the ceramic structure according to the first embodiment of the present invention.

[0015] Figure 1B yes Figure 1A An enlarged view of the dotted line portion.

[0016] Figure 2 This is a process diagram schematically showing a step of preparing a ceramic green sheet laminate in a method of manufacturing a ceramic laminate.

[0017] Figure 3 This is a process diagram schematically showing a step of preparing an identification mark slurry in a method of manufacturing a ceramic laminate.

[0018] Figure 4 This is a process diagram schematically showing the identification mark paste printing step in the method for producing a ceramic laminate.

[0019] Figure 5 This is a process diagram schematically showing a lamination step in a method for producing a ceramic laminate.

[0020] Figure 6 This is a process diagram schematically showing a firing step in a method for producing a ceramic laminate.

[0021] Figure 7 It is a cross-sectional view schematically showing an example of a ceramic laminate including a ceramic structure according to a second embodiment of the present invention.

[0022] Figure 8 This is a cross-sectional view schematically showing an example of another embodiment of a ceramic laminate including the ceramic structure according to the second embodiment of the present invention.

[0023] Figure 9 It is a cross-sectional view schematically showing an example of a ceramic laminate including a ceramic structure according to a third embodiment of the present invention.

[0024] Figure 10 It is a cross-sectional view schematically showing an example of another embodiment of the ceramic laminate including the ceramic structure according to the third embodiment of the present invention. DETAILED DESCRIPTION

[0025] Hereinafter, the ceramic structure of the present invention will be described.

[0026] However, the present invention is not limited to the following configurations, and can be appropriately modified and applied without changing the gist of the present invention. In addition, a combination of two or more of the preferred configurations of the present invention described below is also the present invention.

[0027] The ceramic structure of the present invention comprises: a first ceramic layer having a first main surface and a second main surface opposite to the first main surface; and an identification mark formed on the first main surface of the first ceramic layer and composed of ceramic, wherein in a cross section of the identification mark in a direction perpendicular to the first main surface, the identification mark has a plurality of continuous portions and a non-continuous portion located between the plurality of continuous portions.

[0028] That is, in the ceramic structure of the present invention, the identification mark has a discontinuous portion. Therefore, even if stress is generated, the stress is easily dispersed. Therefore, the ceramic structure of the present invention can be said to be a ceramic structure having an identification mark that is less likely to crack.

[0029] The ceramic structure of the present invention is useful as a local structure in ceramic laminates such as LC composite components such as laminated filters, laminated ceramic capacitors, and laminated inductors. Furthermore, in addition to being useful as a local structure in the aforementioned ceramic laminates, the ceramic structure of the present invention can also be used as a local structure in ceramic structures requiring identification.

[0030] Hereinafter, embodiments of the ceramic structure of the present invention will be described with reference to the drawings.

[0031] [First embodiment]

[0032] First, a ceramic laminate including a ceramic structure according to a first embodiment of the present invention will be described.

[0033] Figure 1A This is a cross-sectional view schematically showing an example of a ceramic laminate including the ceramic structure according to the first embodiment of the present invention.

[0034] Figure 1B yes Figure 1A An enlarged view of the dotted line portion.

[0035] Figure 1A The ceramic laminate 1 shown is formed by laminating a plurality of ceramic layers 10 .

[0036] The plurality of ceramic layers 10 include a first ceramic layer 11 ( Figure 1A The first ceramic layer 11 includes a first main surface 11 a and a second main surface 11 b opposite to the first main surface 11 a.

[0037] In the ceramic laminate 1 , the first principal surface 11 a of the first ceramic layer 11 is disposed so as to be exposed to the outside.

[0038] Furthermore, an identification mark 20 made of ceramic is formed on the first main surface 11 a of the first ceramic layer 11 .

[0039] The structure composed of the first ceramic layer 11 and the identification mark 20 is the ceramic structure 30 according to the first embodiment of the present invention.

[0040] like Figure 1B As shown, in a cross section of the identification mark 20 in a direction perpendicular to the first major surface 11 a , the identification mark 20 has a plurality of continuous portions 21 and a non-continuous portion 22 located between the plurality of continuous portions 21 .

[0041] In the ceramic structure 30, the identification mark 20 has a discontinuous portion. Therefore, even if stress is generated, the stress is easily dispersed. Therefore, the ceramic structure 30 can be said to be a ceramic structure having the identification mark 20 that is less likely to crack.

[0042] In addition, as will be described below, in particular, it is possible to prevent cracks from occurring in the identification mark 20 when the ceramic structure 30 is manufactured.

[0043] The first ceramic layer 11 and the identification mark 20 are formed by firing. During firing, the first ceramic layer 11 and the identification mark 20 shrink. If the shrinkage rate (sinterability) of the first ceramic layer 11 differs from the shrinkage rate (sinterability) of the identification mark 20, stress is likely to be generated in the identification mark 20. However, as described above, the identification mark 20 easily disperses stress, thereby preventing cracks from forming in the identification mark 20.

[0044] Hereinafter, preferred embodiments of the identification mark 20 will be described.

[0045] like Figure 1B As shown, in the ceramic structure 30 , the width W2 of the discontinuous portion 22 is preferably smaller than the width W1 of the continuous portion 21 adjacent to the discontinuous portion 22 .

[0046] With such a structure, the visibility of the identification mark 20 is improved.

[0047] Furthermore, the width W2 of the discontinuous portion 22 is preferably not less than 0.1 times and not more than 0.9 times the width W1 of the continuous portion 21 .

[0048] In this specification, the width W1 of the continuous portion 21 and the width W2 of the discontinuous portion 22 can be measured by the following method.

[0049] The ceramic structure 30 was cut perpendicularly to the first main surface 11a so as to pass through the identification mark 20, and the cross section was imaged using a scanning electron microscope (SEM) at a magnification of 1000 to 2000 times. Next, the continuous and discontinuous portions in the SEM image were binarized to clearly define their boundaries.

[0050] In this SEM image, the continuous portion 21 and the discontinuous portion 22 are aligned in the thickness direction ( Figure 1B direction indicated by the arrow Y in the middle) perpendicular to the direction ( Figure 1B The lengths in the direction indicated by the arrow X in the middle are respectively the width W1 of the continuous portion 21 and the width W2 of the discontinuous portion 22.

[0051] Furthermore, in the ceramic structure of the present invention, the width of the discontinuous portion may be the same as or larger than the width of the continuous portion adjacent to the discontinuous portion.

[0052] like Figure 1B As shown, in the ceramic structure 30 , the continuous portion 21 has a thin portion 21 a in the thickness direction Y and a thick portion 21 b in the thickness direction Y.

[0053] When the continuous portion 21 has the thin portion 21 a and the thick portion 21 b , even if a difference occurs between the shrinkage rates of the identification mark 20 and the first ceramic layer 11 during firing, the difference can be absorbed, and cracks can be prevented from occurring in the identification mark 20 .

[0054] The thin portion 21a and the thick portion 21b are formed with irregularities on the surface of the continuous portion 21. The surface roughness Rz of the continuous portion 21 is preferably 1 μm or more, more preferably 1 μm or more and 3 μm or less.

[0055] The surface roughness Rz (JIS B 0601-2001) of the surface of the continuous portion 21 can be measured using the above-mentioned SEM image and image analysis software.

[0056] Furthermore, in the ceramic structure of the present invention, the identification mark may also have a uniform thickness.

[0057] In the ceramic structure 30 , the area of ​​the discontinuous portion 22 accounts for preferably 20% to 50% of the total area of ​​the continuous portion 21 and the discontinuous portion 22 , and more preferably 30% to 40%.

[0058] If the above-mentioned ratio is less than 20%, the ratio of the continuous portion becomes too large, and cracks are likely to occur.

[0059] If the above-mentioned proportion exceeds 50%, the visibility of the entire identification mark tends to decrease.

[0060] The area of ​​the continuous portion 21 and the area of ​​the discontinuous portion 22 can be measured using the above-mentioned SEM image and image analysis software.

[0061] In the ceramic structure 30 , the thickness of the identification mark 20 is preferably not less than 4 μm and not more than 10 μm, and more preferably not less than 4 μm and not more than 9 μm.

[0062] When the thickness of the identification mark 20 is 4 μm or more and 10 μm or less, visibility can be ensured and structural defects can be suppressed.

[0063] In addition, the thickness of the identification mark 20 is a value obtained as follows.

[0064] In the SEM image, the portion of the identification mark 20 with the greatest distance in the thickness direction Y is defined as the identification mark center. The thickness of a first portion extending 10 μm to the right of the identification mark center in the X direction and the thickness of a second portion extending 10 μm further to the right from the first portion are measured.

[0065] The thickness of the third portion 10 μm further to the left in the X direction of the center portion of the identification mark and the thickness of the fourth portion 10 μm further to the left from the third portion were measured.

[0066] The average value of the thicknesses of the central portion, the first portion, the second portion, the third portion, and the fourth portion is defined as the "thickness of the identification mark."

[0067] In addition, when the first portion is located in the discontinuous portion 22, the thickness of the first portion is excluded when calculating the above-mentioned "thickness of the identification mark." The same applies to the second to fourth portions.

[0068] In the ceramic structure 30 , the information represented by the identification mark 20 is not particularly limited, and may be a direction mark indicating a direction, or a front and back identification mark indicating the front and back sides of the ceramic structure 30 .

[0069] In the ceramic structure 30, the identification mark 20 only needs to be formed so as to be visually distinguishable from the plurality of ceramic layers 10. For example, the identification mark 20 preferably includes at least one material selected from Mn, Co, Al2O3, TiO2, and ZrSiO4, and a glass material.

[0070] When the identification mark 20 contains Mn, the color of the identification mark 20 becomes black. When the identification mark 20 contains Mn, the identification mark 20 may further contain Cr.

[0071] When the identification mark 20 contains Co, the color of the identification mark 20 becomes blue.

[0072] When the identification mark 20 contains at least one material among Al 2 O 3 , TiO 2 , and ZrSiO 4 , the color of the identification mark 20 becomes white.

[0073] Examples of the glass material include lead glass and borosilicate glass.

[0074] Next, preferred embodiments of the first ceramic layer 11 and the other ceramic layers 10 will be described.

[0075] The first ceramic layer 11 and the ceramic layer 10 are preferably fired bodies of ceramic green sheets. The ceramic green sheets can be formed, for example, by applying a doctor blade method or the like to a ceramic slurry on a carrier film.

[0076] The ceramic slurry may include, for example, ceramic powder, a binder, and a plasticizer. As a ceramic material, for example, a low temperature sintered ceramic (LTCC) material can be used. A low temperature sintered ceramic material refers to a ceramic material that can be sintered at a temperature below 1000°C and can be fired simultaneously with Au, Ag, Cu, etc. having a low resistivity. As a low temperature sintered ceramic material, specifically, a glass composite low temperature sintered ceramic material in which borosilicate glass is mixed with ceramic powders such as alumina, zirconia, magnesia, and forsterite, a crystallized glass low temperature sintered ceramic material using a crystallized glass of a ZnO-MgO-Al2O3-SiO2 system, a non-glass low temperature sintered ceramic material using a BaO-Al2O3-SiO2 system ceramic powder or an Al2O3-CaO-SiO2-MgO-B2O3 system ceramic powder, etc.

[0077] The thickness of the first ceramic layer 11 and the other ceramic layers 10 is preferably, for example, not less than 5 μm and not more than 100 μm.

[0078] Next, a method for producing the ceramic laminate 1 will be described. The method for producing the ceramic laminate 1 includes (1) preparing a laminate of ceramic green sheets, (2) preparing an identification mark paste, (3) printing the identification mark paste, (4) laminating, and (5) firing.

[0079] (1) Ceramic green sheet laminate preparation process

[0080] Figure 2 This is a process diagram schematically showing a step of preparing a ceramic green sheet laminate in a method of manufacturing a ceramic laminate.

[0081] First, a ceramic material for LTCC green sheets, a binder, and a plasticizer are mixed in arbitrary amounts to prepare a slurry.

[0082] Next, the slurry is applied to a carrier film to form a sheet. The slurry can be applied using a lip coater or a doctor blade. The slurry is preferably formed into a sheet with a thickness of 5 μm to 100 μm.

[0083] Through the above method, it is possible to form Figure 2 The LTCC green sheet shown is made of a ceramic material (hereinafter referred to as a "first ceramic green sheet 41").

[0084] Furthermore, as needed, via holes and electrode patterns may be formed on the first ceramic green sheet 41 .

[0085] When forming a via hole, first, a via hole for vertical conduction is formed in the first ceramic green sheet 41 .

[0086] The through holes can be formed by a mechanical punch, a CO2 laser, a UV laser, etc. The diameter of the through holes is preferably 20 μm to 200 μm.

[0087] Then, conductive powder, a plasticizer, and a binder are mixed to prepare a conductive paste for through-hole filling, and the conductive paste for through-hole filling is filled into the through-holes.

[0088] The composition of the conductive paste for filling the via hole can be a composition known in the art.

[0089] Furthermore, a co-base (ceramic material) may be added to the conductive paste for adjusting the shrinkage.

[0090] Next, conductive powder, a plasticizer, and a binder are mixed to prepare a circuit-forming conductive paste, which is then printed on the surface of the first ceramic green sheet 41 to form an electrode pattern.

[0091] The electrode pattern may include a resonator-forming electrode or a capacitor-forming electrode.

[0092] Examples of the printing method include screen printing, inkjet printing, and gravure printing.

[0093] (2) Preparation of slurry for identification mark

[0094] Figure 3 This is a process diagram schematically showing a step of preparing an identification mark slurry in a method of manufacturing a ceramic laminate.

[0095] Next, if Figure 3 As shown, a ceramic material 51, an insoluble resin material 52, a binder, and a plasticizer are mixed in arbitrary amounts to prepare the identification mark slurry 50. The insoluble resin material 52 is insoluble in the identification mark slurry 50.

[0096] The identification mark slurry 50 is fired as described below to form the identification mark. The ceramic material 51 contained in the identification mark slurry 50 is not particularly limited, as long as it is a material that produces a different color between the fired ceramic layer and the identification mark. The ceramic material contained in the identification mark slurry is preferably a material containing at least one material selected from Mn, Co, Al2O3, TiO2, and ZrSiO4, and a glass material.

[0097] When the identification mark paste 50 contains Mn, the color of the identification mark after firing becomes black.

[0098] When the identification mark paste 50 contains Co, the color of the identification mark after firing becomes blue.

[0099] When the identification mark paste 50 contains at least one material among Al 2 O 3 , TiO 2 and ZrSiO 4 , the color of the identification mark after firing becomes white.

[0100] Examples of the glass material include lead glass and borosilicate glass.

[0101] The identification mark slurry 50 includes an insoluble resin material 52 .

[0102] The material of the insoluble resin material 52 is not particularly limited as long as it is a component that is thermally decomposed in the firing step described later, but acrylic resin, polyethylene resin, and polypropylene can be used.

[0103] The average particle size of the insoluble resin material 52 is not particularly limited, but is preferably 0.9 μm or more and 10 μm or less, and more preferably 1.5 μm or more and 5 μm or less.

[0104] The weight ratio of the insoluble resin material 52 in the identification mark slurry 50 is preferably 20% by weight or more and 40% by weight or less.

[0105] By adjusting the average particle size and weight ratio of the insoluble resin material 52 , the size and shape of the continuous and discontinuous portions of the identification mark formed through the firing step described later can be adjusted.

[0106] (3) Identification mark paste printing process

[0107] Figure 4 This is a process diagram schematically showing the identification mark paste printing step in the method for producing a ceramic laminate.

[0108] Next, if Figure 4 As shown, the identification mark paste 50 is placed on a mesh 61 provided on a printing plate, and the identification mark paste 50 is screen-printed on the first main surface 41 a of the first ceramic green sheet 41 by moving a squeegee 62 .

[0109] By adjusting the opening size of the mesh 61, the size and shape of the continuous and discontinuous portions of the identification mark formed in the firing process described below can be adjusted. Specifically, by reducing the opening size of the mesh 61 and forming more discontinuous portions, the width of each continuous portion can be narrowed. By increasing the opening size of the mesh 61 and forming fewer discontinuous portions, the width of each continuous portion can be widened.

[0110] In addition, by increasing the wire diameter of the mesh 61 , the width of each discontinuous portion can be increased.

[0111] (4) Lamination process

[0112] Figure 5 This is a process diagram schematically showing a lamination step in a method for producing a ceramic laminate.

[0113] Next, if Figure 5 As shown, on the second main surface 41b side (ie, Figure 5 Another ceramic green sheet 40 is stacked on the lower side of the ceramic green sheet 40 to produce a ceramic green sheet stack 45. In addition, via holes and electrode patterns may be formed on the ceramic green sheet 40.

[0114] Then, the ceramic green sheet stack 45 is placed in a mold and pressure-bonded. The pressure and temperature are preferably set arbitrarily according to the type and shape of the ceramic green sheet stack.

[0115] Next, the laminate of the pressure-bonded ceramic green sheets is cut into pieces.

[0116] Examples of the cutting method include methods using a microtome, a dicing cutter, a laser, and the like.

[0117] In addition, barrel grinding can be performed after cutting as needed.

[0118] (5) Firing process

[0119] Figure 6 This is a process diagram schematically showing a firing step in a method for producing a ceramic laminate.

[0120] Next, if Figure 6 As shown, the ceramic green sheet laminate 45 is fired. The firing conditions are not particularly limited and are preferably appropriately set according to the materials and shapes of the ceramic green sheet laminate 45 and the identification mark slurry 50.

[0121] As a firing furnace for firing, a batch furnace or a belt furnace can be used.

[0122] By going through this step, the ceramic green sheet laminate 45 is fired to form the ceramic laminate 1 , and the identification mark slurry 50 is fired to form the identification mark 20 .

[0123] At this time, the insoluble resin material 52 contained in the identification mark slurry 50 is burned off by pyrolysis, thereby forming the discontinuous portion 22 .

[0124] The first ceramic green sheet 41 and the other ceramic green sheets become the first ceramic layer 11 and the other ceramic layers 10 .

[0125] The width of the continuous portion, the width of the discontinuous portion, the thickness of the continuous portion (the thickness of the identification mark), the surface roughness Rz of the surface of the continuous portion, and the area ratio of the discontinuous portion can be controlled by adjusting the average particle size and weight ratio of the insoluble resin material contained in the identification mark slurry, the opening size of the mesh, and the amount of identification mark slurry arranged on the first main surface of the ceramic green sheet.

[0126] Through the above steps, the ceramic laminate 1 can be manufactured.

[0127] Furthermore, in the above-described method for producing the ceramic laminate 1 , the identification mark paste is printed by screen printing. However, the identification mark paste may be printed by inkjet printing or gravure printing instead of screen printing.

[0128] [Second embodiment]

[0129] Next, a ceramic laminate including a ceramic structure according to a second embodiment of the present invention will be described.

[0130] In the ceramic structure according to the second embodiment of the present invention, the identification mark is located inside the ceramic structure. Such a ceramic structure will be described using the drawings.

[0131] Figure 7 It is a cross-sectional view schematically showing an example of a ceramic laminate including a ceramic structure according to a second embodiment of the present invention.

[0132] Figure 7 The ceramic laminate 101 shown has the same structure as the ceramic laminate 1 described above, except that a second ceramic layer 12 is laminated on the first ceramic layer 11 of the ceramic laminate 1 described above.

[0133] That is, the second ceramic layer 12 is stacked so as to be in contact with the first main surface 11 a of the first ceramic layer 11 , and the identification mark 20 is located between the first ceramic layer 11 and the second ceramic layer 12 .

[0134] In the ceramic laminate 101 , the second ceramic layer 12 is located as the outermost layer, and the first ceramic layer 11 is located inside the second ceramic layer 12 .

[0135] In the ceramic laminate 101 , since the identification mark 20 is located between the first ceramic layer 11 and the second ceramic layer 12 , the identification mark 20 is not exposed to the outside.

[0136] Therefore, it is possible to prevent the identification mark 20 from being cracked due to friction or collision with an external member.

[0137] Furthermore, since both the first ceramic layer 11 and the second ceramic layer 12 support the identification mark 20 , even if stress is generated in the identification mark 20 , cracks are unlikely to occur in the identification mark 20 .

[0138] The identification mark 20 is preferably located at a distance of 10 μm to 50 μm from the surface of the ceramic laminate 101 in the thickness direction, and more preferably located at a distance of 25 μm to 50 μm from the surface of the ceramic laminate 101 in the thickness direction.

[0139] When the identification mark 20 is located in such a portion, it is possible to ensure sufficient visibility of the identification mark 20. In addition, since external force is less likely to be transmitted to the identification mark 20, it is possible to prevent cracks from being generated in the identification mark 20.

[0140] As a method for manufacturing the ceramic laminate 101, there can be cited a method of manufacturing a ceramic laminate 101, in which a layer of another ceramic green sheet serving as a second ceramic layer is stacked on the first main surface 41a side of the first ceramic green sheet 41 in the "(4) stacking step" described in the method for manufacturing the ceramic laminate involved in the first embodiment of the above-mentioned utility model to produce a ceramic green sheet stack.

[0141] Next, other aspects of the second embodiment of the present invention will be described.

[0142] Figure 8 This is a cross-sectional view schematically showing an example of another embodiment of a ceramic laminate including the ceramic structure according to the second embodiment of the present invention.

[0143] Figure 8 The ceramic laminate 201 shown has the same structure as the ceramic laminate 1 described above, except that the second ceramic layer 12 is laminated on the first main surface 11 a of the first ceramic layer 11 , and another ceramic layer 10 is further laminated on the second ceramic layer 12 .

[0144] That is, in Figure 8 In the embodiment, the first ceramic layer 11 is arranged so that the first principal surface 11 a of the first ceramic layer 11 faces downward, and the second ceramic layer 12 and the other ceramic layers 10 are sequentially stacked on the downward side of the first ceramic layer 11 .

[0145] Therefore, in the ceramic laminate 201 , the first ceramic layer 11 becomes the outermost layer, and the second main surface 11 b of the first ceramic layer 11 becomes the surface of the ceramic laminate 201 .

[0146] Furthermore, the identification mark 20 is located between the first ceramic layer 11 and the second ceramic layer 12 .

[0147] The identification mark 20 is preferably located at a portion that is more than 10 μm and less than 50 μm from the surface of the ceramic stack 201 (i.e., the second main surface 11b of the first ceramic layer 11) in the thickness direction, and more preferably located at a portion that is more than 25 μm and less than 50 μm from the surface of the ceramic stack 201 (i.e., the second main surface 11b of the first ceramic layer 11) in the thickness direction.

[0148] When the identification mark 20 is located in such a portion, it is possible to ensure sufficient visibility of the identification mark 20. In addition, since external force is less likely to be transmitted to the identification mark 20, it is possible to prevent cracks from being generated in the identification mark 20.

[0149] As a method for manufacturing the ceramic laminate 201, the method that can be cited is the "(4) stacking step" described in the method for manufacturing the ceramic laminate involved in the first embodiment of the above-mentioned utility model, in which a ceramic green sheet stacking to form a second ceramic layer is stacked on the first main surface 41a of the first ceramic green sheet 41, and other ceramic green sheets are further stacked on the ceramic green sheet to form the second ceramic layer to produce a ceramic green sheet stack.

[0150] That is, by placing the first main surface 41a of the first ceramic green sheet 41 upward and placing the first ceramic green sheet 41 at the bottom, a ceramic green sheet to be the second ceramic layer and other ceramic green sheets are sequentially stacked on the first main surface 41a of the first ceramic green sheet 41 to produce a ceramic green sheet laminate. After the subsequent steps, the obtained ceramic laminate 201 is turned over, thereby producing Figure 8 The ceramic laminate 201 is shown.

[0151] [Third embodiment]

[0152] Next, a ceramic laminate including a ceramic structure according to a third embodiment of the present invention will be described.

[0153] In the ceramic structure according to the third embodiment of the present invention, wiring such as a circuit pattern and electrodes is formed on the first main surface of the first ceramic layer along with the identification mark. That is, the wiring is formed on the same layer as the identification mark. This ceramic structure will be described using the accompanying drawings.

[0154] Figure 9 It is a cross-sectional view schematically showing an example of a ceramic laminate including a ceramic structure according to a third embodiment of the present invention.

[0155] exist Figure 9 The ceramic laminate 301 shown has the same structure as the ceramic laminate 1 described above, except that a circuit pattern and wiring 70 such as electrodes are formed on the first main surface 11 a of the first ceramic layer 11 together with the identification mark 20 .

[0156] By forming the wiring 70 on the first principal surface 11 a of the first ceramic layer 11 , the first principal surface 11 a can function as a wiring arrangement surface of a wiring substrate.

[0157] Furthermore, by forming the wiring 70 on the first main surface 11 a , the degree of freedom in designing the entire ceramic laminate can be increased.

[0158] As a method for manufacturing the ceramic laminate 301, there can be cited a method of printing a conductive paste for wiring formation on the first main surface 41a of the first ceramic raw sheet 41 between the "(3) identification mark slurry printing process" and the "(4) lamination process" described in the method for manufacturing the ceramic laminate involved in the first embodiment of the above-mentioned utility model.

[0159] Examples of printing methods for the conductive paste for forming wiring include screen printing, inkjet printing, and gravure printing.

[0160] The conductive paste for forming wiring can be prepared by mixing conductive powder, a plasticizer, and a binder. A co-base (ceramic material) for adjusting the shrinkage rate may also be added to the conductive paste for forming wiring.

[0161] Next, other aspects of the third embodiment of the present invention will be described.

[0162] Figure 10 It is a cross-sectional view schematically showing an example of another embodiment of the ceramic laminate including the ceramic structure according to the third embodiment of the present invention.

[0163] exist Figure 10 The ceramic laminate 401 shown has the same structure as the above-mentioned ceramic laminate 1, except that a wiring 70 of a circuit pattern, electrodes, etc. is formed together with the identification mark 20 on the first main surface 11a of the first ceramic layer 11, and the second ceramic layer 12 is stacked to contact the first main surface 11a of the first ceramic layer 11.

[0164] By forming the wiring 70 on the first principal surface 11 a of the first ceramic layer 11 , the first principal surface 11 a can function as a wiring arrangement surface of a wiring substrate.

[0165] Furthermore, by forming the wiring 70 on the first main surface 11 a , the degree of freedom in designing the entire ceramic laminate can be increased.

[0166] In addition, since the identification mark 20 and the wiring 70 are covered by the second ceramic layer 12 , the identification mark 20 and the wiring 70 are not exposed to the outside.

[0167] Therefore, it is possible to prevent the identification mark 20 and the wiring 70 from being damaged due to friction or collision with external components.

[0168] Furthermore, since both the first ceramic layer 11 and the second ceramic layer 12 support the identification mark 20 and the wiring 70 , even if stress is generated in the identification mark 20 , the identification mark 20 and the wiring 70 are unlikely to be damaged.

[0169] As a method for manufacturing the ceramic laminate 401, there can be cited a method in which a conductive paste for forming wiring is printed on the first main surface 41a of the first ceramic green sheet 41 between the "(3) identification mark slurry printing step" and the "(4) lamination step" described in the method for manufacturing the ceramic laminate involved in the first embodiment of the present invention, and in the "(4) lamination step", another ceramic green sheet serving as a second ceramic layer is laminated on the side of the first main surface 41a of the first ceramic green sheet 41 to produce a ceramic green sheet laminate.

[0170] Examples of printing methods for the conductive paste for forming wiring include screen printing, inkjet printing, and gravure printing.

[0171] The conductive paste for forming wiring can be prepared by mixing conductive powder, a plasticizer, and a binder. A co-base (ceramic material) for adjusting the shrinkage rate may also be added to the conductive paste for forming wiring.

[0172] [Disclosure in this specification]

[0173] The following contents are disclosed in this specification.

[0174] The present disclosure (1) is a ceramic structure comprising: a first ceramic layer having a first main surface and a second main surface opposite to the first main surface; and an identification mark formed on the first main surface of the first ceramic layer and composed of ceramic, wherein in a cross section of the identification mark in a direction perpendicular to the first main surface, the identification mark has a plurality of continuous portions and a discontinuous portion located between the plurality of continuous portions.

[0175] In the present disclosure (2), according to the ceramic structure described in the present disclosure (1), a second ceramic layer is stacked and brought into contact with the first main surface of the first ceramic layer, and the identification mark is located between the first ceramic layer and the second ceramic layer.

[0176] In the present disclosure (3), according to the ceramic structure described in the present disclosure (2), in the cross section of the above-mentioned identification mark in the direction perpendicular to the above-mentioned first main surface, the above-mentioned identification mark is located in a portion that is more than 10 μm and less than 50 μm away from the surface of the above-mentioned ceramic structure in the thickness direction.

[0177] In the present disclosure (4), according to the ceramic structure described in any one of the present disclosures (1) to (3), in the cross section of the above-mentioned identification mark in a direction perpendicular to the above-mentioned first main surface, the width of the above-mentioned discontinuous portion is smaller than the width of the above-mentioned continuous portion adjacent to the above-mentioned discontinuous portion.

[0178] In the present disclosure (5), according to the ceramic structure described in any one of the present disclosures (1) to (4), in the cross section of the above-mentioned identification mark in a direction perpendicular to the above-mentioned first main surface, the above-mentioned continuous portion has a thin portion in the thickness direction and a thick portion in the thickness direction.

[0179] In the present disclosure (6), according to the ceramic structure described in any one of the present disclosures (1) to (5), in the cross-section of the above-mentioned identification mark in a direction perpendicular to the above-mentioned first main surface, the area of ​​the above-mentioned discontinuous portion accounts for more than 20% and less than 50% of the total area of ​​the area of ​​the above-mentioned continuous portion and the area of ​​the above-mentioned discontinuous portion.

[0180] In the present disclosure (7), according to the ceramic structure described in any one of the present disclosures (1) to (6), the above-mentioned identification mark includes at least one material selected from Mn, Co, Al2O3, TiO2 and ZrSiO4 and a glass material.

[0181] In the present disclosure (8), according to the ceramic structure described in any one of the present disclosures (1) to (7), in a cross section of the identification mark in a direction perpendicular to the first main surface, the thickness of the identification mark is greater than or equal to 4 μm and less than or equal to 10 μm.

[0182] In the present disclosure (9), according to the ceramic structure described in any one of the present disclosures (1) to (8), wiring is formed on the first main surface of the first ceramic layer together with the identification mark.

[0183] Description of Reference Numerals

[0184] 1, 101, 201, 301, 401...ceramic laminate; 10...ceramic layer; 11...first ceramic layer; 11a...first principal surface; 11b...second principal surface; 12...second ceramic layer; 20...identification mark; 21...continuous portion; 21a...thin portion of the continuous portion; 21b...thick portion of the continuous portion; 22...discontinuous portion; 30...ceramic structure; 40...ceramic green sheet; 41...first ceramic green sheet; 41a...first principal surface; 41b...second principal surface; 45...ceramic green sheet laminate; 50...slurry for identification mark; 51...ceramic material; 52...insoluble resin material; 61...mesh; 62...scraper; 70...wiring.

Claims

1. A ceramic structure, characterized in that have: a first ceramic layer having a first main surface and a second main surface opposite to the first main surface; and an identification mark formed on the first main surface of the first ceramic layer and made of ceramic, In a cross section of the identification mark in a direction perpendicular to the first main surface, the identification mark has a plurality of continuous portions and a discontinuous portion located between the plurality of continuous portions. The surface roughness Rz of the surface of the continuous portion (21) is greater than 1 μm.

2. The ceramic structure according to claim 1, wherein A second ceramic layer is stacked so as to be in contact with the first main surface of the first ceramic layer, and the identification mark is located between the first ceramic layer and the second ceramic layer.

3. The ceramic structure according to claim 2, characterized in that In a cross section of the identification mark in a direction perpendicular to the first main surface, the identification mark is located at a portion that is 10 μm to 50 μm away from the surface of the ceramic structure in a thickness direction.

4. The ceramic structure according to any one of claims 1 to 3, characterized in that In a cross section of the identification mark in a direction perpendicular to the first main surface, a width of the discontinuous portion is smaller than a width of the continuous portion adjacent to the discontinuous portion.

5. The ceramic structure according to any one of claims 1 to 3, characterized in that In a cross section of the identification mark in a direction perpendicular to the first main surface, the continuous portion has a portion that is thin in the thickness direction and a portion that is thick in the thickness direction.

6. The ceramic structure according to any one of claims 1 to 3, characterized in that In a cross section of the identification mark in a direction perpendicular to the first main surface, the area of ​​the discontinuous portion accounts for 20% to 50% of the total area of ​​the continuous portion and the discontinuous portion.

7. The ceramic structure according to any one of claims 1 to 3, characterized in that In a cross section of the identification mark in a direction perpendicular to the first main surface, the thickness of the identification mark is 4 μm or more and 10 μm or less.

8. The ceramic structure according to any one of claims 1 to 3, characterized in that On the first main surface of the first ceramic layer, wiring is formed together with the identification mark.

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