Electronic component

Abstract

The present invention provides an electronic component having a glass layer with plating solution resistance. The electronic component has a ceramic unit body, an external electrode provided on a part of a surface of the ceramic unit body, and a glass layer covering at least a part of the surface of the ceramic unit body; the glass layer contains silicon atoms, titanium atoms, and zirconium atoms, the titanium dispersion ratio of the glass layer is 90% or more, and the zirconium dispersion ratio is 60% or more.

Description

Technical Field

[0001] This invention relates to electronic components, and more specifically, to an electronic component having a ceramic unit and a glass layer covering a portion of the surface of the ceramic unit. Background Technology

[0002] In electronic components that include ceramic units, external electrodes for mounting on circuit boards or the like can be provided on both sides of the ceramic unit. For example, in Patent Document 1, terminal electrodes are provided at both ends of the ceramic unit (thermistor chip), and a metal plating layer is formed on the surface of the terminal electrodes by electroplating. During electroplating, in order to prevent the formation of a coating on the sides of the ceramic unit, a high-resistivity layer such as a glass layer is used to cover the sides of the ceramic unit.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 8-236306 Summary of the Invention

[0006] In Patent Document 1, since the glass layer is formed on the side of the ceramic unit and then electroplated, the glass layer is in contact with the plating solution.

[0007] However, sometimes glass has low resistance to plating solutions, and the glass layer may peel off from the ceramic unit during the plating process. If the glass layer peels off, a coating will form on the side of the ceramic unit, so it is necessary to prevent the glass layer from peeling off.

[0008] Therefore, the object of the present invention is to provide an electronic component having a glass layer that is resistant to plating solutions.

[0009] According to one aspect of the present invention, an electronic component is provided, comprising a ceramic unit, an external electrode disposed on a portion of the surface of the ceramic unit, and a glass layer covering at least a portion of the surface of the ceramic unit; wherein the glass layer contains silicon atoms, titanium atoms, and zirconium atoms, and the titanium dispersion ratio of the glass layer is 90% or more, and the zirconium dispersion ratio is 60% or more.

[0010] According to the present invention, an electronic component is provided that can suppress the peeling of the glass layer during electroplating by forming a glass layer that is resistant to plating solution. Attached Figure Description

[0011] Figure 1 This is a schematic cross-sectional view of an example electronic component in an embodiment of the present invention.

[0012] Figure 2The TEM image shows a cross-sectional view of the glass layer in an embodiment of the present invention, and the results of investigating the distribution of Ti and Zr from the TEM image by EDX analysis.

[0013] Figure 3 The TEM image shows a cross-sectional view of the glass layer in an embodiment of the present invention, and the results of investigating the distribution of Ti and Zr from the TEM image by EDX analysis.

[0014] Figure 4 This is a schematic perspective view of the ceramic unit body in an embodiment of the present invention. Detailed Implementation

[0015] The electronic component of this embodiment has a ceramic unit, an external electrode disposed on a portion of the surface of the ceramic unit, and a glass layer covering at least a portion of the surface of the ceramic unit. The glass layer contains silicon atoms, titanium atoms, and zirconium atoms, and the titanium dispersion ratio of the glass layer is 90% or more, and the zirconium dispersion ratio is 60% or more.

[0016] The inventors conducted in-depth research, and as a result, they defined the concepts of "titanium dispersion ratio" and "zirconium dispersion ratio" as indicators of the properties of the glass layer, and discovered that they are related to the resistance of the glass layer to plating solutions, thus completing this invention.

[0017] The electronic components of the present invention will now be described.

[0018] If the electronic component has a ceramic unit, external electrodes disposed on the surface of the ceramic unit, and a glass layer, there are no particular limitations on the shape, size, and material of the ceramic unit, or the number, arrangement, and shape of the external electrodes. The ceramic unit may or may not have internal electrodes embedded in it; if so, the internal electrodes are electrically connected to the external electrodes in an appropriate manner.

[0019] Electronic components that can be used in this embodiment may be, for example, surface-mount type, especially chip components; more specifically, capacitors such as multilayer ceramic capacitors; inductors (coils) such as winding inductors, thin-film inductors, and multilayer inductors; resistors such as chip resistors; transistors; LC composite components, etc.

[0020] For example, the electronic component 10 in this embodiment may be as follows: Figure 1The stacked ceramic capacitor shown includes: a ceramic unit 1 comprising a ceramic portion 3 made of ceramic material and internal electrodes 5a and 5b facing each other with respect to the ceramic portion 3, and external electrodes 9a and 9b disposed on the surface of the ceramic unit 1 and electrically connected to the internal electrodes 5a and 5b, respectively. More specifically, the internal electrodes 5a and 5b are embedded in the ceramic unit 1 and are stacked in such a way that they are alternately exposed from opposite end faces of the ceramic unit 1 and electrically connected to the external electrodes 9a and 9b, respectively. However, the electronic component 10 of this embodiment is not limited to... Figure 1 The electronic components shown can be any of the electronic components described above.

[0021] In the electronic component 10 of this embodiment, such as Figure 1 As shown, a glass layer 6 is included that contacts the surface of the ceramic unit 1. The glass layer 6 covers at least a portion of the surface of the ceramic unit 1. Preferably, the glass layer 6 covers at least a portion of the surface of the ceramic unit 1 where external electrodes 9a and 9b are not provided, and more preferably covers all of it. Furthermore, as... Figure 1 As shown, a portion of the glass layer 6 can also be disposed on the surface of the ceramic unit 1 covered by the external electrodes 9a and 9b.

[0022] Since the glass layer 6 is insulating, it is formed at a location that avoids the internal electrodes 5a and 5b. If it is an electronic component without internal electrodes (e.g., a winding inductor), the glass layer 6 can also be formed on the entire surface of the ceramic unit 1.

[0023] It should be noted that, as a variation of the glass layer of the present invention containing Ti and Zr, a glass layer that imparts conductivity by containing metal can also be used. If it is a conductive glass layer, it can also be provided on the internal electrodes 5a and 5b.

[0024] Regarding the resistivity of the conductive glass layer, to ensure conduction with the internal electrodes, the resistivity is preferably less than 1.0 × 10⁻⁶. －2 Ω·cm.

[0025] By constructing the glass layer 6 as described above, the surface of the ceramic unit 1 not covered by the external electrodes 9a and 9b can be protected during the formation of the coating.

[0026] Glass layer 6 contains titanium atoms and zirconium atoms. Their content and dispersion can be determined using the "titanium dispersion ratio" and "zirconium dispersion ratio".

[0027] "Titanium dispersion ratio" is equivalent to the area fraction of the cross-section of the glass layer where titanium (Ti) is identified as present. Similarly, "zirconium dispersion ratio" is equivalent to the area fraction of the cross-section of the glass layer where zirconium (Zr) is identified as present.

[0028] For example, if the entire observation area of ​​the cross section (100% of the area of ​​the observation area) is determined to contain titanium, then the titanium dispersion ratio is 100%.

[0029] Additionally, for example, if 80% of the area of ​​the cross-section under observation is determined to contain zirconium, then the zirconium dispersion ratio is 80%.

[0030] If the titanium dispersion ratio and zirconium oxide dispersion ratio in glass layer 6 are high, the resistance of glass layer 6 to plating solution can be improved. The mechanism is not yet clear, but it is speculated as follows.

[0031] First, if glass layer 6 comes into contact with the plating solution, its surface dissolves, reducing its thickness. When the pH of the plating solution is alkaline, the mesh structure of the glass layer will be disrupted. Furthermore, the components of the plating solution and the stability constant of the metal oxides constituting glass layer 6 also have an impact; a high stability constant will cause the dissolution of the metal oxides constituting glass layer 6. As glass layer 6 gradually dissolves, the bond between glass layer 6 and the ceramic unit 1 becomes weak, leading to delamination between them.

[0032] In this embodiment, since the glass layer 6 is formed using the sol-gel method, it is presumed that oxides such as SiO2, TiO2, and ZrO2 do not exist individually in the glass layer 6, but rather form a network such as Si-O-Ti and Si-O-Zr. Besides their high chemical stability, TiO2 and ZrO2 are also firmly bonded as Si-O-Ti and Si-O-Zr. Therefore, by containing a large amount of Ti and Zr within the glass layer 6 (i.e., a high titanium dispersion ratio and a high zirconium oxide dispersion ratio), the dissolution of the glass layer 6 can be suppressed, improving its resistance to plating solutions. Furthermore, the ionic radius is larger than that of Si... 4+ Ti ions, and also have a strong binding strength with oxygen ions. 4+ Zr 4+ Entering the space of the mesh structure should also be one of the reasons.

[0033] In this invention, the titanium dispersion ratio in the glass layer is more than 90%, and the zirconium dispersion ratio is more than 60%, thereby obtaining a glass layer with excellent coating resistance.

[0034] The titanium dispersion ratio is preferably 95% or more, more preferably 99%, even more preferably 99.9%, and the upper limit is 100%.

[0035] The zirconium dispersion ratio is preferably 75% or more, more preferably 78%, even more preferably 99.9%, and the upper limit is 100%.

[0036] It should be noted that if both the titanium dispersion ratio and the zirconium dispersion ratio are at high levels, for example, a titanium dispersion ratio of 90% or higher and a zirconium dispersion ratio of 60% or higher, the plating solution resistance of the glass layer 6 can be significantly improved. However, since both titanium and zirconium improve plating solution resistance through the same effect, a glass layer 6 that satisfies either a titanium dispersion ratio of 90% or higher or a zirconium dispersion ratio of 60% or higher can also improve plating solution resistance compared to conventional glass layers.

[0037] The “titanium dispersion ratio” and “zirconium dispersion ratio” are obtained using intensity data from EDX images according to the following steps 1) to 7).

[0038] First, let's take "titanium dispersion ratio" as an example.

[0039] 1) The cross-section of glass layer 6 was observed using TEM-EDX at a magnification of approximately 200,000x, and TEM images and EDX mapping images of Ti were acquired for the same observation area. Preferably, the images were acquired with the interface between glass layer 6 and ceramic unit 1 horizontally aligned on the image (see reference). Figure 2 These interfaces can be tilted slightly (see reference). Figure 3 For example, the tilt angle (the angle between the horizontal direction on the screen and the interface) should be within 20°. When the tilt angle exceeds 20°, it should be corrected to within 20° through image processing, or the image should be changed to another part of the glass layer 6.

[0040] 2) Using a TEM-EDX device (FE-TEM / EDX (JEOL JEM-F200 (manufactured by JEOL Ltd.) / Analysis System Noran system 7 (manufactured by Thermo Fisher Scientific))), intensity data is extracted from the EDX image of Ti as a CVS file. The CVS file contains matrix-like numerical data. For example, a matrix of 256 rows × 256 columns can be used. Each of these numerical data corresponds to the intensity of the TEM and EDX images in each small region divided into 256 vertical × 256 horizontal sections. The matrix-like numerical data, if output in the form of spreadsheet software, facilitates subsequent processing.

[0041] 3) Standardize the numerical data in the CVS file. Determine the maximum value (Vmax) in the numerical data contained in the CVS file, and determine the coefficient (100 / Vmax) to use this maximum value.

[0042] 4) Multiply the determined coefficients by all the numerical data in the CVS file. This standardizes all the numerical data, making the maximum value of the numerical data 100.

[0043] 5) The extent of glass layer 6 was determined using TEM images. Figure 2 In the diagram, draw a horizontal line (the lower dashed line) that passes through the interface between the glass layer 6 and the ceramic unit 1, and a horizontal line (the upper dashed line) that passes through the interface between the glass layer 6 and the protective film used for sample cutting. The area enclosed by these two dashed lines is the "measurement area". The "measurement area" must be rectangular (either a rectangle or a square).

[0044] It should be explained that, for example Figure 3 As shown, when these interfaces are tilted from the horizontal direction, the lower dashed line is drawn horizontally through the highest point of the interface between the glass layer 6 and the ceramic unit 1, and the upper dashed line is drawn horizontally through the lowest point of the interface between the glass layer 6 and the protective film. By drawing the dashed lines in this way, the "measurement area" enclosed by the two dashed lines contains only the glass layer 6.

[0045] 6) The EDX image of Ti is arranged next to the TEM image, and the upper and lower dashed lines are extended to the EDX image ( Figure 2 In each CVS file, determine the positions where the dashed lines intersect the left and right edges of each EDX image (the positions of the four corners of glass layer 6) on the matrix data. For example, the position of the lower right corner can be considered as the rightmost column in the matrix-like numerical data, and when observing the change in values ​​from bottom to top, the position can be considered as the position of a valid value (e.g., a value greater than 10). The numerical data within the range enclosed by the specified "four corners" on the matrix-like numerical data corresponds to the intensity data contained in the "measurement area" sandwiched by two dashed lines in the EDX image. It should be noted that instead of specifying the positions of all four corners on the matrix-like numerical data, the positions of the two corners located on the diagonal are specified, and the numerical data enclosed by the rectangular range having these two corners corresponds to the intensity data contained in the specified "measurement area" in the EDX image.

[0046] In addition, when Figure 3 When the interface of glass layer 6 is tilted, focus on the two corners adjacent to the interfaces of glass layer 6 and other layers (ceramic unit 1 or protective film) among the four locations where the dashed lines intersect with the left and right edges of each EDX image. Figure 3 In the image, two corners are located: the upper left corner near the interface between glass layer 6 and the protective film, and the lower right corner near the interface between glass layer 6 and ceramic unit 1. These two corners lie on the diagonal of the rectangular "measurement area". The positions of these two corners are specified on the matrix-like numerical data within the CVS file using the method described above. The numerical data enclosed within the rectangular area containing these two corners corresponds to the intensity data contained in the "measurement area" specified in the EDX image.

[0047] It should be noted that gaps may sometimes occur at the interface between glass layer 6 and ceramic unit 1, or at the interface between glass layer 6 and protective film. When a gap is located at any of the four corners, the surface of glass layer 6 facing the gap is used as the "interface" to determine the two corners. This allows for a clear definition of the "measurement area".

[0048] 7) Calculate the total number of numerical data points (denoted as "Ntitotal") within the specified rectangular range corresponding to the "Measurement Object Area" in the matrix-shaped numerical data, and the number of numerical data points with a value of 20 or more within that rectangular range (denoted as "Nti20").

[0049] 8) Substitute Ntitotal and Nti20 into equation (1) to calculate the "titanium dispersion ratio".

[0050] Titanium dispersion ratio (%) = Nti20 / Ntitotal × 100···(1)

[0051] The zirconium dispersion ratio is also determined by obtaining a TEM image of the cross-section of glass layer 6 and an EDX mapping image of Zr. Using the same steps, the total number of numerical data points (denoted as "Nzrtotal") located within the specified rectangular range corresponding to the "measurement object area" in the matrix numerical data is calculated, as well as the number of numerical data points greater than 20 within that rectangular range (denoted as "Nzr20"). These values ​​are then substituted into the following formula (2) to obtain the "zirconium dispersion ratio".

[0052] Zirconium dispersion ratio (%) = Nzr20 / Nzrtotal × 100···(2)

[0053] A titanium dispersion ratio of 100% means Nti20 = Ntitotal. That is, it implies that titanium was observed throughout the entire "measurement area" defined on the Ti EDX image. In this case, titanium can be considered uniformly dispersed within the "measurement area." Thus, a high titanium dispersion ratio suggests that titanium is relatively uniformly dispersed within the "measurement area."

[0054] Similarly, when the zirconium dispersion ratio is high, it can be inferred that the zirconium is relatively uniformly dispersed within the "test area".

[0055] Furthermore, to improve the titanium and zirconium dispersion ratios, glass layer 6 is preferably low in porosity. If voids are present, titanium and zirconium cannot exist in that region. Therefore, if voids exist in the "measurement area," the values ​​of Nti20 and Nzr20 decrease, resulting in lower titanium and zirconium dispersion ratios. Therefore, glass layer 6 is preferably dense.

[0056] The thickness of the glass layer 6 is preferably 0.01 μm to 2 μm. Such a thin glass layer 6 can be formed, for example, by using the sol-gel method.

[0057] The external electrode 9 may include a base electrode layer and a plating layer disposed on the base electrode layer. The base electrode layer includes at least one sintered layer, a resin layer, and a thin film layer. The thickness of the base electrode layer is preferably 10 μm to 50 μm.

[0058] The sintered layer contains glass and metal. The metallic material constituting the sintered layer is composed of one metal selected from Ni, Cu, Ag, Pd, and Au, or an alloy containing that metal; for example, an alloy of Ag and Pd can be used. The glass contains Si and Zn. The sintered layer can be composed of multiple stacked layers. The sintered layer can be a layer on which a conductive paste is coated and sintered, or a layer sintered simultaneously with the internal electrodes 5a and 5b.

[0059] The resin layer contains conductive particles and thermosetting resin. When the resin layer is provided, a sintering layer can be omitted, and the resin layer can be directly placed on the ceramic unit. The resin layer can be composed of multiple stacked layers. The maximum thickness of the resin layer is preferably 5 μm to 20 μm.

[0060] The thin film layer is formed by thin film formation methods such as sputtering or evaporation. The thin film layer is a layer less than 1 μm thick with deposited metal particles.

[0061] The material constituting the coating is composed of one metal selected from Ni, Cu, Ag, Pd, and Au, or an alloy containing that metal. For example, an alloy of Ag and Pd can be used.

[0062] The plating layer can also consist of multiple stacked layers. In this case, a two-layer structure of forming a Sn plating layer on a Ni plating layer is preferred. The Ni plating layer has the function of preventing the base electrode layer from being eroded by solder during the mounting of electronic components. The Sn plating layer has the function of improving the wettability with solder during the mounting of electronic components, making the mounting of electronic components easier.

[0063] The average thickness of the Ni coating is preferably 0.5 μm to 10 μm. The average thickness of the Sn coating is preferably 0.5 μm to 10 μm.

[0064] [Manufacturing Method]

[0065] The electronic component 10 of this embodiment can be manufactured, for example, by the following method.

[0066] 1) Preparation of ceramic unit 1

[0067] First, prepare ceramic unit 1. Ceramic unit 1 can be manufactured by any suitable method.

[0068] For example, the ceramic material constituting the ceramic unit 1 (more specifically, the ceramic part 3) is not particularly limited; any ceramic material used in electronic components is not particularly limited. Because Figure 1 The electronic component 10 is a multilayer capacitor, therefore the ceramic material is a dielectric material, such as BaTiO3, CaTiO3, SrTiO3, CaZrO3, (BaSr)TiO3, Ba(ZrTi)O3, and (BiZn)Nb2O7. When internal electrodes are present, the materials constituting the internal electrodes 5a and 5b only need to be conductive and are not particularly limited, such as Ag, Cu, Pt, Ni, Al, Pd, and Au. The preferred materials constituting the internal electrodes 5a and 5b are Ag, Cu, and Ni.

[0069] It should be noted that the ceramic material used in this embodiment is not limited to the materials described above, and can be appropriately selected according to the type and structure of the electronic component. For example, when the electronic component is a ferrite coil component, the ceramic material can also be a ferrite material containing Fe, Ni, Zn, Mn, Cu, etc. In this case, the ceramic unit can have a coil instead of an internal electrode. Such a coil only needs to be electrically connected to an external electrode in the end; for example, it can be pre-embedded in the ceramic unit, or it can be wound around the ceramic unit before or after the external electrode is formed.

[0070] 2) Formation of glass layer 6

[0071] Next, a glass layer 6 is formed in the area on the surface of the ceramic unit 1 other than the internal electrodes 5a and 5b.

[0072] In this embodiment, the glass layer 6 can be formed using a solution-based thin-film fabrication method. As a thin-film fabrication method, sol-gel method, MOD (organic metal decomposition) method, CSD (chemical solution deposition) method, etc., can be utilized. It should be noted that these methods are often considered synonymous. Unless otherwise stated, the term "sol-gel method" as used in this specification includes the narrow definition of "sol-gel method," MOD, and CSD.

[0073] By using the sol-gel method to deposit TiO2 and ZrO2 precursors to form a glass layer 6, a dense glass layer 6 with few pores can be formed. Furthermore, by slowing down the sol-gel reaction, the formation of voids within the glass layer 6 can be suppressed. Methods for slowing down the sol-gel reaction include using a solvent with a high boiling point as the solvent in the raw material composition and reducing the rate of temperature rise during heat treatment.

[0074] When forming glass layer 6 using the sol-gel method, a raw material composition for forming glass layer 6 is prepared. The raw material composition may also be a liquid (paste) obtained by dissolving or dispersing glass raw materials (glass precursors) and organic polymers in a solvent.

[0075] [Glass precursor]

[0076] The precursors for glass are glass raw materials, which can be any starting material capable of forming the glass matrix (glass region 13). As glass precursors, in addition to SiO2 precursors which form the main framework of glass, they must contain precursors of TiO2 and ZrO2, and can be appropriately mixed with other components. Examples of glass precursors include metal alkoxides, acetylacetone complexes, and acetates. Furthermore, these raw materials can be modified with functional groups such as long-chain alkyl groups and epoxy groups. The following describes compounds that can be used as glass precursors.

[0077] (Metal alkoxides)

[0078] Elements that can form metal alkoxides include Li, Be, B, C, Na, Mg, Al, Si, P, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Rb, Sr, Y, Zr, Nb, Mo, Cd, In, Sn, Sb, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Hg, Tl, Pb, Bi, Th, Pa, U, and Pu. Alkoxides of these elements can be used as glass precursors.

[0079] The specific metal alkoxides that can be used as glass precursors are shown below.

[0080] Sodium methoxide, sodium ethoxide, calcium diethanoloxide, lithium isopropoxide, lithium ethoxide, lithium tert-butoxide, lithium methoxide, boronol, potassium tert-butoxide, tetraethyl orthosilicate, allyltrimethoxysilane, isobutyl(trimethoxy)silane, tetrapropyl orthosilicate, tetramethyl orthosilicate, [3-(diethylamino)propyl]trimethoxysilane, triethoxy(octyl)silane, triethoxyvinylsilane, triethoxyphenylsilane, trimethoxyphenylsilane, trimethoxymethylsilane, butyltrichlorosilane, n-propyltriethoxysilane, methyltrichlorosilane, dimethoxy(methyl)octylsilane, dimethoxydimethylsilane, tris(tert-butoxy)silanol, tris(tert-pentoxy)silanol, hexadecyltrimethoxysilane, dipotassium tris(1,2-phthalate-O,O′)silicate tris(1,2-benzenediolato-O,O′)silicate), tetrabutyl orthosilicate, aluminum silicate, calcium silicate, tetramethylammonium silicate solution, aluminum triisopropoxy titanium (IV), titanium isopropoxide (IV), titanium 2-ethylhexyl oxide (IV), titanium ethoxide (IV), titanium butoxide (IV), titanium tert-butoxide (IV), titanium propoxide (IV), titanium methanol (IV), bis(diethylcitrate) dipropoxide zirconium (IV), zirconium dibutoxide (IV), bis-2,4-pentanedionate (IV), 2-ethylhexanoate zirconium (IV), zirconium isopropoxide (IV) isopropanol complex, zirconium ethoxide (IV), zirconium butoxide (IV), zirconium tert-butoxide (IV), zirconium propoxide (IV), aluminum tert-butoxide (Aluminum) Metal alkoxides such as tert-butoxide, aluminum isopropoxide, aluminum ethoxide, aluminum trisec-butoxide, and aluminum phenolate.

[0081] (Acetylacetone complex)

[0082] Specific acetylacetone complexes that can be used as glass precursors are shown below.

[0083] Metal complexes of acetylacetone, including lithium acetylacetone, titanium oxyacetylacetone (IV), titanium diisopropoxide bis(acetylacetone), zirconium trifluoroacetylacetonate (IV), zirconium acetylacetonate (IV), aluminum acetylacetonate, aluminum acetylacetone (III), calcium acetylacetone (II), and lead acetylacetone (II).

[0084] (acetate)

[0085] The specific acetates that can be used as glass precursors are shown below.

[0086] Acetates such as zirconium acetate, zirconium acetate(IV) hydroxide, and basic aluminum acetate.

[0087] (Additives for glass)

[0088] The glass contained in glass layer 6 may also include additives as shown below (these will be referred to as "glass additives"). The additives may be mixed in the form of powder, microparticles or nanoparticles.

[0089] Sodium carbonate (Na₂CO₃), sodium bicarbonate (NaHCO₃), sodium percarbonate (2Na₂CO₃·3H₂O₂), sodium sulfite (Na₂SO₃), sodium bisulfite (NaHSO₃), sodium sulfate (Na₂SO₄), sodium thiosulfate (Na₂S₂O₃), sodium nitrate (NaNO₃), sodium nitrite (NaNO₂), and other oxyacids; sodium fluoride (NaF), sodium chloride (NaCl), sodium bromide (NaBr), sodium iodide (NaI), and other halides; peroxides Oxides such as sodium (Na2O2) and sodium hydroxide (NaOH); inorganic salts such as hydroxides, sodium hydride (NaH), sodium sulfide (Na2S), sodium hydrogen sulfide (NaHS), sodium silicate (Na2SiO3), trisodium phosphate (Na3PO4), sodium borate (Na3BO3), sodium borohydride (NaBH4), sodium cyanide (NaCN), sodium cyanate (NaOCN), and sodium tetrachloroaurate (Na[AuCl4]); and organic acid salts such as sodium acetate (CH3COONa) and sodium citrate.

[0090] Inorganic salts such as calcium peroxide (CaO2), calcium hydroxide (Ca(OH)2), calcium fluoride (CaF2), calcium chloride (CaCl2·2H2O), calcium bromide (CaBr2·2H2O), calcium iodide (CaI2·3H2O), calcium hydride (CaH2), calcium carbide (CaC2), and calcium phosphide (Ca3P2); and calcium carbonate (CaCO3), calcium bicarbonate (Ca(HCO3)2), calcium nitrate (Ca(NO3)2·4H2O), calcium sulfate (CaSO4·2H2O), calcium sulfite (CaSO3), and calcium silicate (CaSiO3 or Ca2). SiO4), calcium phosphate (Ca3(PO4)2), calcium pyrophosphate (Ca2O7P2), calcium hypochlorite (Ca[ClO]2), calcium chlorate (Ca(ClO3)2), calcium perchlorate (Ca(ClO4)2), calcium bromate (Ca(BrO3)2), calcium iodate (Ca(IO3)2, H2O), calcium arsenite (Ca3(AsO4)2), calcium chromate (CaCrO4), calcium tungstate (CaWO4), calcium molybdate (CaMoO4), calcium magnesium carbonate (CaMg(CO3)2), hydroxyapatite (Ca5(PO4)3(OH) or Ca 10 Oxyacid salts such as (PO4)6(OH)2); calcium acetate (Ca(CH3COO)2), calcium gluconate (C 12 H 22 CaO 14 ), calcium citrate (Ca3(C6H5O7)2), calcium malate (Ca(C2H4O(COO)2), calcium lactate (C6H 10 CaO6), calcium benzoate (C 14 H 10 CaO4), calcium stearate (Ca(C) 17 H 35 Organic salts such as COO2 and calcium aspartate (Ca(C4H6NO4)2).

[0091] Lithium carbonate (Li₂CO₃), lithium chloride (LiCl), lithium titanate (Li₂TiO₃), lithium nitride (Li₃N), lithium peroxide (Li₂O₂), lithium citrate (Li₃C₆H₅O₇), lithium fluoride (LiF), lithium hexafluorophosphate (LiPF₆), lithium acetate (C₂H₃LiO₂), lithium iodide (LiI), lithium hypochlorite (ClLiO), lithium tetraborate (Li₂B₄O₇), lithium bromide (LiBr), lithium nitrate (LiNO₃), lithium hydroxide (LiOH), lithium aluminum hydride (LiAlH₄), lithium triethylborohydride (Li(C₂H₅)₃BH), lithium hydride (LiH), lithium amino (LiNH₂), lithium imino (Li₂NH), lithium diisopropylamino (C₆H₅) 14 LiN or LiN(C3H7)2), lithium tetramethylpiperidine (C9H)18 LiN, lithium sulfide (Li2S), lithium sulfate (Li2SO4), lithium thiophene (C6H5LiS), and lithium phenol (C6H5LiO).

[0092] Boron triiodide (BI3), sodium cyanoborohydride (NaBH3CN), sodium borohydride (NaBH4), tetrafluoroboric acid (HBF4), triethylborane ((CH3CH2)3B), borax (Na2B4O5(OH)4·8H2O), boric acid (B(OH)3).

[0093] Potassium arsenide (K3As), potassium bromide (KBr), potassium carbide (K2C2), potassium chloride (KCl), potassium fluoride (KF), potassium hydride (KH), potassium iodide (KI), potassium triiodide (KI3), potassium azide (KN3), potassium nitride (K3N), potassium superoxide (KO2), potassium ozonide (KO3), potassium peroxide (K2O2), potassium phosphide (K3P), potassium sulfide (K2S), potassium selenide (K2Se), potassium telluride (K2Te), potassium tetrafluoroaluminate (KAlF4), potassium tetrafluoroborate (KBF4), potassium tetrahydroborate (KBH4), potassium methanide (KCH3), potassium cyanide (KCN), potassium formate (KHCOO), potassium hydrogen fluoride (KHF2), tetraiodomercuric(II) acid Potassium (K2[HgI4]), potassium hydrogen sulfide (KHS), potassium octachlorodimolybdate (K4[Mo2Cl8]), potassium amino (KNH2), potassium hydroxide (KOH), potassium hexafluorophosphate (KPF6), potassium carbonate (K2CO3), potassium tetrachloroplatinate (K2[PtCl4]), potassium hexachloroplatinate (K2[PtCl6]), potassium nonahydrorhenium (K2[ReH9]), potassium sulfate (K2SO4), potassium acetate (CH3COOK), potassium gold (I) cyanide (K[Au(CN)2]), potassium hexanitrocobalt (III) cyanide (K3[Co(NO2)6]), potassium hexacyanoferric (III) cyanide (K3[Fe(CN)6]), potassium hexacyanophosphate ... Potassium ferrate (K4[Fe(CN)6]), potassium methoxide (KOCH3), potassium ethoxide (KOCH2CH3), potassium tert-butoxide (KOC(CH3)3), potassium cyanate (KOCN), potassium fulminate (KONC), potassium thiocyanate (KSCN), potassium aluminum sulfate (AlK(SO4)2), potassium aluminate (KAlO2), potassium arsenate (K3AsO4), potassium bromate (KBrO3), potassium hypochlorite (KClO), potassium chlorite (KClO2), potassium chlorate (KClO3), potassium perchlorate (KClO4), potassium carbonate (K2CO3), potassium chromate (K2CrO4), potassium dichromate (K2Cr2O7), potassium tetra(peroxy)chromate (K3Cr(O2)4) Potassium copper(III) (KCuO2), potassium ferrate (K2FeO4), potassium iodate (KIO3), potassium periodate (KIO4), potassium permanganate (KMnO4), potassium manganate (K2MnO4), potassium hypomanganate (K3MnO4), potassium molybdate (K2MoO4), potassium nitrite (KNO2), potassium nitrate (KNO3), tripotassium phosphate (K3PO4), potassium perrhenate (KReO4), potassium selenate (K2SeO4), potassium silicate (K2SiO3), potassium sulfite (K2SO3), potassium sulfate (K2SO4), potassium thiosulfate (K2S2O3), potassium metabisulfite (K2S2O5), potassium dithionite (K2S2O6), potassium pyrosulfite (K2S2O7).Potassium persulfate (K₂S₂O₈), potassium dihydrogen arsenate (KH₂AsO₄), dipotassium hydrogen arsenate (K₂HAsO₄), potassium bicarbonate (KHCO₃), potassium dihydrogen phosphate (KH₂PO₄), dipotassium hydrogen phosphate (K₂HPO₄), potassium hydrogen selenate (KHSeO₄), potassium bisulfite (KHSO₃), potassium bisulfate (KHSO₄), and potassium persulfate (KHSO₅).

[0094] Barium sulfite (BaSO3), barium chloride (BaCl2), barium chlorate (Ba(ClO3)2), barium perchlorate (Ba(ClO4)2), barium peroxide (BaO2), barium chromate (BaCrO4), barium acetate (C4H6O4Ba), barium cyanide (Ba(CN)2), barium bromide (BaBr2), barium oxalate (BaC2O4), barium nitrate (BaN2O6), barium hydroxide (Ba(OH)2), barium hydride (H2Ba), barium carbonate (BaCO3), barium iodide (BaI2), barium sulfide (BaS), and barium sulfate (BaSO4).

[0095] Metal oxides such as sodium oxide (Na2O), calcium oxide (CaO), lithium oxide (Li2O), boron oxide (B2O3), potassium oxide (K2O), barium oxide (BaO), silicon oxide (SiO2), titanium oxide (TiO2), zirconium oxide (ZrO2), aluminum oxide (Al2O3), zinc oxide (ZnO), and magnesium oxide (MgO).

[0096] [Organic polymers]

[0097] Organic polymers are used to increase the viscosity of raw material compositions to make them into a paste. Examples of organic polymers include acrylic polymers (homomers or copolymers of acrylic acid, methacrylic acid, or their esters; specifically, acrylate copolymers, methacrylate copolymers, acrylate-methacrylate copolymers, etc.); polyvinyl acetal polymers (specifically, polyvinyl acetal, polyvinyl butyral, etc.); cellulose polymers (specifically, hydroxypropyl cellulose, cellulose ether, carboxymethyl cellulose, acetyl cellulose, acetyl nitrocellulose, etc.); polyvinyl alcohol polymers; polyvinyl acetate polymers; polyvinyl chloride polymers; polycarbonate polymers; homopolymers or copolymers of polyvinylpyrrolidone, etc., containing at least one selected from these.

[0098] [solvent]

[0099] The preferred solvents are alcohols (specifically, 2-ethylhexanol (185℃), benzyl alcohol (205℃), 1,3-butanediol (207℃), 1,4-butanediol (228℃), etc.); ketones (specifically, cyclohexanone (156℃), diacetone alcohol (166℃), diisobutyl ketone (168℃), etc.); and glycol ethers (specifically, butyl carbitol acetate (247℃), ethyl carbitol (202℃), diethylene glycol monoethyl ether (202℃), diethylene glycol monomethyl ether (194℃), ethylene glycol monomethyl ether acetate (144℃), ethylene glycol monoethyl ether (135℃), ethylene glycol monomethyl ether (124℃), 2-methoxyethanol (124℃), propylene glycol monomethyl ether (121℃), etc.). Because these solvents have high boiling points, they enable the sol-gel reaction to proceed slowly, making it difficult to create voids inside glass layer 6, thereby increasing the titanium dispersion ratio and zirconium dispersion ratio.

[0100] [Other components (reactants, additives)]

[0101] The raw material composition may include glass raw materials (and any glass additives) and any suitable reactants and additives other than solvents. Examples of reactants used to react metal alkoxides and produce compounds with a main framework represented by the formula –O-M-O- (where M is a metal atom) include water, alkoxy groups of metal alkoxides converted to hydroxyl groups, and substituted hydroxyl-containing compounds. Examples of additives include catalysts, viscosity modifiers, pH adjusters, and stabilizers that promote the reaction.

[0102] Next, the raw material composition is coated onto a designated area of ​​the ceramic unit 1 and dried appropriately to form a coating film from the raw material composition. The coating method is not particularly limited; dipping, spraying, screen printing, brushing, inkjet printing, etc., can be used. Drying is performed to remove most, preferably substantially all, of the solvent from the raw material composition. More specifically, drying can be performed by heating the ceramic unit coated with the raw material composition at, for example, 25–200°C for 5–60 minutes.

[0103] Next, the ceramic unit with the coating is heated to obtain a glass layer 6 from the coating. The temperature and time of the heating treatment can be, for example, 300°C to 1100°C for 10 to 60 minutes. The temperature of the heating treatment is particularly preferably 400°C to 1000°C.

[0104] During the heat treatment process (in this case, during both drying and heat treatment), the raw material composition is gelled to form a glass layer 6 as a sol-gel sintered film.

[0105] Thus, the glass layer 6 formed by the sol-gel method becomes a dense glass layer with few pores.

[0106] 3) Formation of external electrode 9 and coated phase

[0107] An external electrode is formed on the obtained ceramic unit with a glass layer.

[0108] A base electrode layer is formed on the surface of a ceramic unit with a glass layer. Specifically, the base electrode layer of the external electrode 9 is formed by various thin film formation methods, various printing methods, or impregnation methods. For example, when the base electrode layer is formed by impregnation, a conductive paste is applied to both ends of the ceramic unit and then sintered. The conductive paste includes organic solvents, metal particles, and glass. The sintering temperature is, for example, 840°C.

[0109] Next, a plating process is performed to form a coating that covers the base electrode layer. The outer electrode 9 is formed by forming the plating.

[0110] Electroplating is carried out by immersing a ceramic unit with a base electrode layer in a plating solution (plating bath) and subjecting it to plating treatment under specified conditions. The plating solution and plating treatment conditions can be appropriately selected based on the type of metal to be plated, the thickness of the coating, and other factors.

[0111] Therefore, the electronic component 10 of this embodiment can be manufactured.

[0112] The above describes one embodiment of the present invention, but the present invention is not limited to this embodiment and various modifications can be made.

[0113] Example 1

[0114] In the following embodiments and comparative examples, although it is assumed that the electronic component is a winding inductor and a ceramic unit cell for winding inductors is used, these results are equally applicable to other electronic components.

[0115] (Example 1)

[0116] 1) Preparation of ceramic unit 1'

[0117] First, prepare the ceramic unit 1' for the winding inductor. This ceramic unit 1' is made of ferrite material and has… Figure 4 The shape is schematically represented in the diagram. The dimensions of the ceramic unit 1' are as follows: L = 0.70 mm, W = 0.30 mm, T = 0.50 mm, E = 0.30 mm, F = 0.32 mm, G = 0.29 mm.

[0118] 2) Formation of the glass layer

[0119] The raw materials (components) shown in Table 1 are mixed according to the specified mass to prepare the raw material composition (paste). It should be noted that the paste includes Si alkoxide (TEOS: tetraethyl orthosilicate), Ti alkoxide (TiBu: titanium butoxide), and Zr alkoxide (ZrPr: zirconium propoxide) as glass precursors. 0.01N-HCl (0.01 equivalent hydrochloric acid aqueous solution) acts as the acid as a catalyst and water for hydrolysis, while HPC (hydroxypropyl cellulose) acts as a viscosity modifier and stabilizer.

[0120] Next, on the LW surface on the lower side of the aforementioned ceramic unit 1' (refer to...) Figure 4 The raw material composition and its outer coating are dried at 150°C for 30 minutes in an air atmosphere (normal pressure) to form a coating film from the raw material composition.

[0121] [Table 1]

[0122] Diethylene glycol monomethyl ether 13.15 Aluminum acetylacetonate (III) 0.37 Tetraethyl orthosilicate 1.53 Titanium butoxide (IV) 0.24 Zirconium propoxide solution 70% in 1-propanol 0.21 0.01 equivalent hydrochloric acid aqueous solution 0.26 Hydroxypropyl cellulose 4.24 total 20.00

[0123] Then, the ceramic unit 1' with the coating is heated at 815°C for 30 minutes in an air atmosphere (at normal pressure) to form a glass layer from the coating, which is used as a sample for measurement.

[0124] (Examples 2-5, Comparative Examples 1-2)

[0125] The solvents used were those shown in Table 2. Otherwise, a glass layer was formed on the surface of the ceramic unit as in Example 1 (Examples 2-5, Comparative Examples 1-2). The results of the titanium dispersion ratio and zirconium dispersion ratio for each sample are shown in Table 2. It should be noted that Example 1 is also recorded in Table 2.

[0126] The samples obtained according to Examples 1-5 and Comparative Examples 1-2 were tested for their resistance to plating solutions. The results are recorded in Table 2.

[0127] The plating solution resistance is assessed according to the following guidelines.

[0128] 1. In each embodiment and comparative example, at least N = 10 samples of glass layers prepared under the same conditions are prepared.

[0129] 2. Using SEM-EDX, EDX images and atomic ratios of the glass layer surface were obtained at a magnification of approximately 1000x, with a sample number N=5.

[0130] 3. Add up the atomic percentages of all glass components (Si, Ti, Zr, and Al). Divide this sum by the main component of the ceramic unit (Fe), using N=5, and calculate the average value. Use this average value as the initial glass content.

[0131] 4. Immerse the remaining sample that has not been measured by SEM-EDX in Cu plating solution at 60°C for 24 hours, and then wash and dry it with water.

[0132] 5. Use sample 4 to perform 2-3 tests, and use this value as the amount of glass after impregnation.

[0133] 6. Calculate the reduction rate due to immersion in the plating solution based on the glass amount obtained in steps 3 and 5.

[0134] [Table 2]

[0135]

[0136] The results in Table 2 were investigated.

[0137] In Examples 1-5, the high boiling point of the solvents used resulted in a high dispersion ratio of Ti and Zr in the glass, leading to a low reduction rate of the glass layer. Conversely, Comparative Example 1, lacking a mixture of Ti and Zr in the glass, exhibited a high reduction rate of the glass layer. Comparative Example 2, with its low boiling point of the solvent, resulted in a low dispersion ratio of Ti and Zr in the glass, thus exhibiting a high reduction rate of the glass layer.

[0138] This application claims priority based on Japanese Patent Application No. 2021-054078 filed on March 26, 2021, the entire contents of which are incorporated herein by reference. Attached Figure Description

[0140] 1. Ceramic unit

[0141] 3. Ceramics Department

[0142] Internal electrodes of 5a and 5b

[0143] 6 glass layers

[0144] 9, 9a, 9b External electrodes

[0145] 10 Electronic components

Claims

1. An electronic component comprising a ceramic unit, an external electrode disposed on a portion of the surface of the ceramic unit, and a glass layer covering at least a portion of the surface of the ceramic unit. The glass layer contains silicon atoms, titanium atoms, and zirconium atoms, with a titanium dispersion ratio of over 90% and a zirconium dispersion ratio of over 60%. The titanium dispersion ratio is equivalent to the area ratio of the regions in the cross section of the glass layer where titanium is identified. By acquiring the TEM image of the cross section of the glass layer and the EDX mapping image of Ti, the total number of numerical data Ntitotal and the number of numerical data Nti20 located within the specified rectangular range corresponding to the "measurement object area" in the obtained matrix of numerical data are calculated. Substituting Ntitotal and Nti20 into the following formula (1), the titanium dispersion ratio is obtained. The zirconium dispersion ratio is equivalent to the area ratio of the regions in the cross section of the glass layer where zirconium is determined to exist. By acquiring the TEM image of the cross section of the glass layer and the EDX mapping image of Zr, the total number of numerical data Nzrtotal and the number of numerical data Nzr20 located within the specified rectangular range corresponding to the "measurement object area" in the obtained matrix of numerical data are calculated. Substituting Nzrtotal and Nzr20 into the following formula (2), the zirconium dispersion ratio is obtained. Titanium dispersion ratio (%) = Nti20 / Ntitotal × 100 (1) Zirconium dispersion ratio (%) = Nzr20 / Nzrtotal × 100 (2).

2. The electronic component according to claim 1, wherein, The titanium dispersion ratio is above 95%, and the zirconium dispersion ratio is above 75%.

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