Dielectric paste composition, dielectric ceramic sheet, and method for manufacturing multilayer electronic component

Abstract

The present disclosure provides a dielectric paste composition, a dielectric ceramic sheet, and a method of manufacturing a multilayer electronic component. The dielectric slurry composition comprises dielectric particles, a solvent, a dispersant and an adhesive, the dielectric particles comprise BaTiO3, the solvent comprises ethanol and toluene, the dispersant comprises polyvinylpyrrolidone, and the mass ratio of the ethanol to the toluene is greater than 1.0 and less than 2.3.

Description

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0111254, filed on August 20, 2024, and Korean Patent Application No. 10-2024-0199167, filed on December 27, 2024, both filed with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] This disclosure relates to a dielectric paste composition, a dielectric ceramic sheet, and a method for manufacturing multilayer electronic components. Background Technology

[0003] Multilayer ceramic capacitors (MLCCs, a type of multilayer electronic component) are chip capacitors mounted on printed circuit boards of various electronic products, such as image display devices (including liquid crystal displays (LCDs) and plasma display panels (PDPs)), computers, smartphones, cellular phones, on-board chargers (OBCs), DC-DC converters, etc., to be able to charge and discharge them.

[0004] To miniaturize and increase the capacitance of multilayer ceramic capacitors, it is necessary to increase the number of layers by thinning the dielectric ceramic sheet forming the dielectric layer. In this case, compared to cases where the dielectric sheet is formed thicker, the thickness variation, roughness distribution, and stiffness of the dielectric ceramic sheet may have a greater impact on the electrical characteristics of the multilayer ceramic capacitor. Therefore, to achieve miniaturization and increased capacitance of multilayer ceramic capacitors, ensuring the dispersibility of the dielectric paste composition forming the dielectric layer, as well as the strength and chemical resistance of the dielectric ceramic sheet, may be important.

[0005] To ensure the uniformity of the dielectric paste composition, a method can be used to improve dispersion stability by adding a dispersant during the weighing stage, and polyvinyl butyral has been tried as a dispersant in related technologies.

[0006] However, since the content of functional groups that can be used as hydrogen bond donors in the dispersants of related technologies is less than about 40 mol% in the whole polymer, there may be limitations in improving the interfacial bonding between the adhesive and the dielectric particles and the mechanical strength of the dielectric ceramic sheet.

[0007] Therefore, a method is needed to form a dielectric paste composition that enhances the steric hindrance effect between dispersants and the dispersion stability of dielectric particles by increasing the number of hydrogen bonds between the binder and dielectric particles or controlling the molecular weight of the dispersant, and to improve the mechanical properties of dielectric ceramic sheets by using the dielectric paste composition. Summary of the Invention

[0008] One aspect of this disclosure is to provide a dielectric paste composition in which the dispersibility of dielectric particles is improved.

[0009] Another aspect of this disclosure is to improve the mechanical strength of the dielectric ceramic sheet.

[0010] However, the purpose of this disclosure is not limited to the foregoing, and will be more readily understood in the process of describing specific embodiments of this disclosure.

[0011] According to one aspect of this disclosure, a dielectric paste composition includes dielectric particles, a solvent, a dispersant, and a binder, wherein the dielectric particles include BaTiO3, the solvent includes ethanol and toluene, and the dispersant includes polyvinylpyrrolidone, wherein the mass ratio of ethanol to toluene is greater than 1.0 and less than 2.3.

[0012] According to another aspect of this disclosure, a dielectric ceramic sheet includes dielectric particles, a dispersant, a binder, and a plasticizer, wherein the dielectric particles include BaTiO3, the dispersant includes polyvinylpyrrolidone, and the plasticizer has a negative charge.

[0013] According to another aspect of this disclosure, a method of manufacturing a multilayer electronic component includes forming the body of the multilayer electronic component from a dielectric ceramic sheet as described above. Attached Figure Description

[0014] The above and other aspects, features and advantages of this disclosure will become clearer from the following detailed embodiments, taken in conjunction with the accompanying drawings, in which: Figure 1 This is a perspective view schematically illustrating a multilayer electronic assembly according to an embodiment of the present disclosure; Figure 2 It is along Figure 1 A cross-sectional view taken from line I-I'; Figure 3 The structural formula of polyvinyl butyral (PVB) is shown; Figure 4 The structural formula of polyvinylpyrrolidone (PVP) is shown; Figures 5A to 5C The state of BaTiO3 particles in dielectric paste according to different molecular weights of PVP dispersant is shown; Figure 6 These are images of samples of dielectric paste compositions with different types of dispersants analyzed using Fourier transform infrared spectroscopy. Figure 7 This is a graph comparing the dispersion stability and viscosity of a sample of dielectric paste composition with PVB as a dispersant and a sample of dielectric paste composition with PVP dispersants of different molecular weights. Figure 8This is a graph comparing the particle size distribution of a sample of dielectric paste composition with PVB as a dispersant and a sample of dielectric paste composition with PVP dispersants of different molecular weights. Figure 9 The images show samples of dielectric paste compositions with PVB as a binder and samples of dielectric paste compositions with PVB binder and PVP dispersants of different molecular weights analyzed by Fourier transform infrared spectroscopy. Figure 10 This is a graph showing the stress-strain curves of samples of dielectric ceramic sheets with different types of dispersants; Figure 11A This is a graph showing the short-circuit rate of a multilayer electronic assembly comprising dielectric layers with different types of dispersants; and Figure 11B This is a graph showing the breakdown voltage (BDV) distribution of a multilayer electronic assembly that includes dielectric layers with different types of dispersants. Detailed Implementation

[0015] In the following, exemplary embodiments of the inventive concept will be described in detail with reference to the accompanying drawings. However, the inventive concept can be exemplified in many different forms and should not be construed as limited to the specific embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be exhaustive and complete, and will fully convey the scope of the inventive concept to those skilled in the art. In the drawings, for clarity, the shape and size of elements (such as layers, films, components, regions, etc.) may be exaggerated, and the same reference numerals will always be used to denote the same or similar elements.

[0016] For the purpose of clarifying this disclosure, portions irrelevant to the description have been omitted. Throughout the specification, unless expressly stated otherwise, the word "comprising" and variations such as "including" or "containing" shall be understood to imply inclusion of the stated elements but not exclusion of any other elements.

[0017] In the accompanying drawings, the first direction can be defined as the direction or thickness (T) direction in which the first inner electrode and the second inner electrode are arranged alternately and the dielectric layer is located between them. In the second direction and the third direction (the direction perpendicular to the first direction), the second direction can be defined as the length (L) direction and the third direction can be defined as the width (W) direction.

[0018] Dielectric paste composition Figure 3 The structural formula of polyvinyl butyral (PVB) is shown.

[0019] Figure 4 The structural formula of polyvinylpyrrolidone (PVP) is shown.

[0020] Figures 5A to 5C The state of BaTiO3 particles in dielectric paste according to different molecular weights of PVP dispersant is shown.

[0021] In the following text, reference will be made to Figures 3 to 5C The dielectric paste compositions according to embodiments of the present disclosure and various examples thereof are described in detail.

[0022] The dielectric paste composition according to embodiments of the present disclosure may include dielectric particles 11, solvent 21, dispersant 12 and binder 22, wherein the dielectric particles 11 include BaTiO3, the solvent 21 includes ethanol and toluene, and the dispersant 12 includes polyvinylpyrrolidone.

[0023] The dielectric particles 11 may include BaTiO3 and may be a major component of the dielectric layer of a multilayer electronic component. The dielectric particles 11 may include not only BaTiO3, but also elements such as Ca (calcium) or Zr (zirconium) partially dissolved in BaTiO3. 1- x Ca x TiO3 (0 < x < 1), Ba(Ti 1-y Ca y O3 (0 < y < 1), (Ba 1-x Ca x (Ti) 1-y Zr y O3 (0 < x < 1, 0 < y < 1) or Ba(Ti) 1-y Zr y )O3 (0 < y < 1).

[0024] The dielectric particles 11 included in the dielectric paste composition need to be uniformly and stably dispersed in the dielectric paste composition and need to interact sufficiently with other components in the dielectric paste composition to form a dielectric ceramic sheet. Therefore, the dielectric paste composition may include ceramic additives, solvents 21, dispersants 12, binders 22, etc. In addition, the dielectric particles 11 can be very small microparticles.

[0025] Reference Figure 4 Polyvinylpyrrolidone has functional groups that act as hydrogen bond acceptors, and each of its monomers can have such functional groups. Therefore, polyvinylpyrrolidone is a dispersant with excellent miscibility with dielectric particles (including BaTiO3), binders and solvents used in slurry preparation.

[0026] Additionally, refer to Figure 3 Conventional dispersants, including polyvinyl butyral (PVB), have repeating units containing a carbonyl group (C=O) as a hydrogen bond acceptor and repeating units containing a hydroxyl group (-OH), while reference Figure 4All functional groups in the polymer chain of polyvinylpyrrolidone can form hydrogen bonds. Figure 3 The characters “x”, “y”, and “z” in the text refer to the number of each repeating unit.

[0027] Therefore, in embodiments of this disclosure, when the dielectric paste composition includes a dispersant comprising polyvinylpyrrolidone, the interfacial bond strength between the adhesive and the dielectric particles can be increased, and thus, mechanical strength (such as the strength of the dielectric ceramic sheet) can be improved.

[0028] Dispersants including polyvinylpyrrolidone exhibit excellent miscibility with ethanol-rich solvents. Therefore, in embodiments of this disclosure, in solvent 21 comprising ethanol and toluene (also referred to as ethanol-toluene solvent 21), the mass ratio of ethanol to toluene may be greater than 1.0.

[0029] Furthermore, when the mass ratio of ethanol to toluene is 2.3 or greater, the proportion of toluene, a nonpolar solvent, in the total solvent is too low, which may cause dielectric particles to precipitate. Therefore, in the embodiments of this disclosure, the mass ratio of ethanol to toluene may be less than 2.3.

[0030] In an example of a method for measuring the mass ratio of ethanol to toluene in a dielectric paste composition, the dielectric paste composition can be filtered to obtain only the solvent, and the toluene and ethanol contents in the solvent can then be analyzed by gas chromatography-mass spectrometry (GC-MS), and the mass ratio can be calculated from the toluene and ethanol contents.

[0031] In an embodiment, a dispersant 12 comprising polyvinylpyrrolidone (also referred to as polyvinylpyrrolidone dispersant 12) may be disposed on the surface of the dielectric particles 11, and the presence of the dispersant 12 comprising polyvinylpyrrolidone may be confirmed by detecting the nitrogen (N) element on the surface of the dielectric particles 11 through transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDS) analysis or Fourier transform infrared spectroscopy (FT-IR) analysis.

[0032] When the dispersant 12, including polyvinylpyrrolidone, is disposed on the surface of the dielectric particles 11, the dielectric particles 11 can be uniformly dispersed in the ethanol-toluene solvent 21.

[0033] In dielectric paste compositions, the molecular weight of the dispersant 12, including polyvinylpyrrolidone, can be another factor affecting the dispersibility of dielectric particles. When the molecular weight of the dispersant 12, including polyvinylpyrrolidone, is less than 6300 g / mol, it may not be able to form a repulsive force sufficient to overcome the attractive forces between dielectric particles 11. Therefore, the dielectric particles 11 may exist in an aggregated state in the solvent (e.g., ...). Figure 5A(As shown in the diagram). When the molecular weight of the dispersant 12, including polyvinylpyrrolidone, is greater than 309,000 g / mol, the dispersant chains extending from the surface of the dielectric particles 11 into the solvent may become entangled with the dispersant chains formed on the surface of adjacent dielectric particles, and thus the dielectric particles 11 may exist in an aggregated form (as shown in the diagram). Figure 5C (As shown in the figure). In an embodiment, by controlling the molecular weight of the dispersant 12, which includes polyvinylpyrrolidone, to be greater than or equal to 6300 g / mol and less than or equal to 309000 g / mol, the dielectric particles can be uniformly dispersed in the solvent (e.g. Figure 5B (as shown in the image).

[0034] The molecular weight of the dispersant 12, including polyvinylpyrrolidone, can be measured by gel permeation chromatography (GPC) under the following conditions: a PL Aquagel-OH hybrid column (300 mm × 7.5 mm) × 2 / 40 °C, a flow rate of 0.8 mL / min, a mobile phase solvent of deionized water (DI water) (30% MeOH) with buffer (0.2 M NaNO3 + 0.01 M Na2HPO4), and an injection volume of 100 μL, but this disclosure is not limited thereto.

[0035] In embodiments, the Hansen solubility parameter (Ra) of the dispersant 12 included in the dielectric paste composition may be greater than 13 and less than 16. If the solubility parameter (Ra) is 13 or less, the dispersant 12 may be relatively more soluble in the solvent than on the surface of the dielectric particles 11, potentially resulting in insufficient increase in the interfacial bonding force between the dielectric particles 11 and the binder 22. Furthermore, when the Hansen solubility parameter (Ra) of the dispersant including PVP is 16 or greater, the binder may clump when the dispersant is mixed with the binder. Additionally, in embodiments, when the solubility parameter of the dispersant 12 in the ethanol-toluene solvent 21 is greater than 13 and less than 16, the dispersant 12 is more likely to be disposed on the surface of the dielectric particles 11 than dissolved in the solvent 21, thus sufficiently increasing the interfacial bonding force between the dielectric particles 11 and the binder 22 and preventing the aggregation or precipitation of the dielectric particles 11, thereby improving the dispersibility of the dielectric paste composition.

[0036] Furthermore, Hansen solubility parameters are values ​​used to predict the solubility of a substance. Knowing the Hansen solubility parameters (HSPs) for various solvents, the solubility of organic compounds in solvents with a range of HSPs can be measured to determine affinity. The best fit can be analyzed and calculated from solubility test results using a program called HSPiP (Hansen Solubility Parameters in Practice), developed by Dr. Hansen's group, and the Ra value can be controlled by adjusting the ratio of ethanol to toluene content in the solvent. Other methods and / or tools understood by those skilled in the art can be used, even if not described in this disclosure.

[0037] In an embodiment, the binder 22 of the dielectric paste composition may include polyvinyl butyral.

[0038] Each monomer of the polyvinylpyrrolidone dispersant 12 has a carbonyl group (C=O), which, in addition to hydrophobic interactions, also acts as a hydrogen bond acceptor group and forms hydrogen bonds with the hydroxyl group (-OH) of the polyvinyl butyral (PVB) adhesive 22 (i.e., adhesive 22 comprising polyvinyl butyral (PVB)) as a hydrogen bond donor group. Furthermore, in the case where both the dispersant and the adhesive comprise polyvinyl butyral, complex interactions may occur because both hydrogen bond acceptors and hydrogen bond donors are included.

[0039] Therefore, in the embodiments where the dispersant 12 of the dielectric paste composition comprises polyvinylpyrrolidone and the adhesive 22 comprises polyvinyl butyral, the interaction between the dispersant 12 and the adhesive 22 on the surface of the dielectric particles 11 can be increased. Thus, dispersion stability can be improved compared to the case where both the dispersant and the adhesive comprise polyvinyl butyral.

[0040] Furthermore, when the dielectric paste composition includes polyvinylpyrrolidone as a dispersant 12 and polyvinyl butyral as a binder 22, if the number of monomers or repeating units of polyvinylpyrrolidone is n, and the number of hydroxyl-containing monomers or repeating units included in polyvinyl butyral (PVB) is y, then n / y can satisfy a value greater than or equal to 0.67 and less than 3.7. Therefore, the interaction between the dispersant and the binder can be improved. However, if n / y is 3.7 or greater, the aggregation of dielectric particles may become severe, and it may be difficult to control the performance of the dielectric sheet. Additionally, when the molar ratio of PVP dispersant to PVB binder multiplied by the number of PVP monomers multiplied by the number of hydroxyl monomers in the PVB binder is C, the n / y value can be adjusted along with the C value. Specifically, when the average size of the dielectric particles is 70 nm, the C value can be 8.5 or greater, and when the average size of the dielectric particles is 100 nm, the C value can be 5.7 or greater.

[0041] Dielectric ceramic sheet The dielectric paste compositions according to various embodiments of this disclosure can be manufactured into dielectric ceramic sheets by additional processes.

[0042] There are no particular limitations on the method of manufacturing dielectric ceramic sheets from dielectric paste compositions, and after adding adhesive solutions and plasticizers to dielectric paste compositions, the corresponding mixture can be coated onto polyethylene terephthalate (PET) films by a doctor blade method, and a drying operation can be performed to remove solvents from the dielectric paste compositions.

[0043] Apart from solvents and plasticizers, the dielectric ceramic sheets according to embodiments of the present disclosure may include substantially the same components as those in the dielectric paste compositions according to various embodiments of the present disclosure.

[0044] Specifically, the dielectric ceramic sheet may include dielectric particles, a dispersant, a binder, and a plasticizer. The dielectric particles include BaTiO3, and the dispersant includes polyvinylpyrrolidone. Because the dielectric ceramic sheet includes polyvinylpyrrolidone as a dispersant, its mechanical properties can be improved.

[0045] Furthermore, the dielectric ceramic sheet including polyvinylpyrrolidone as a dispersant may include a plasticizer, and when the plasticizer has a negative charge, the absolute magnitude of static electricity generated during peeling can be reduced, thereby reducing defects occurring during the stacking of the dielectric ceramic sheets. When the plasticizer has a negative charge, the effect of reducing the absolute magnitude of static electricity generated during peeling is better when polyvinylpyrrolidone is used as a dispersant compared to when polyvinyl butyral is used. Therefore, in the embodiments of this disclosure, when forming the dielectric layer of a multilayer electronic component using a dielectric ceramic sheet including dielectric particles (including BaTiO3), a dispersant (including polyvinylpyrrolidone), a binder, and a negatively charged plasticizer, the short-circuit rate can be reduced, the breakdown voltage (BDV) distribution can be improved, i.e., the electrical characteristics of the multilayer electronic component can be improved.

[0046] Additionally, examples of negatively charged plasticizers include plasticizers such as triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and polyethylene glycol dimethyl ether. That is, in the embodiments, the plasticizer may include one or more of triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and polyethylene glycol dimethyl ether. Furthermore, the plasticizer does not contain dioctyl adipate.

[0047] In the embodiments, by controlling the molecular weight of the dispersant, including polyvinylpyrrolidone, to be greater than or equal to 6300 g / mol and less than or equal to 309000 g / mol, the dielectric particles can be uniformly dispersed in the dielectric paste composition, thereby improving the mechanical properties of the dielectric ceramic sheet.

[0048] In this embodiment, the binder for the dielectric ceramic sheet may include polyvinyl butyral. Therefore, compared to cases where both the dispersant and binder comprise polyvinyl butyral, the interaction between the dispersant and binder on the surface of the dielectric particles can be increased, and the mechanical properties of the dielectric ceramic sheet can be improved.

[0049] In an embodiment, when the dielectric ceramic sheet comprises polyvinylpyrrolidone as a dispersant and polyvinyl butyral as a binder, if the number of monomers or repeating units in polyvinylpyrrolidone is n, and the number of hydroxyl-containing monomers or repeating units in polyvinyl butyral (PVB) is y, then n / y can satisfy a value greater than or equal to 0.67 and less than 3.7. Therefore, the interaction between the dispersant and the binder can be improved, thereby improving the mechanical properties of the dielectric ceramic sheet. If n / y is 3.7 or greater, the aggregation of dielectric particles may become severe, and it may be difficult to control the performance of the dielectric sheet. Furthermore, when the molar ratio of PVP dispersant to PVB binder multiplied by the number of PVP monomers multiplied by the number of hydroxyl monomers in the PVB binder is C, the n / y value can be adjusted together with the C value. Specifically, when the average size of the dielectric particles is 70 nm, the C value can be 8.5 or greater, and when the average size of the dielectric particles is 100 nm, the C value can be 5.7 or greater.

[0050] Figure 6 This is a graph showing samples of dielectric paste compositions with different types of dispersants analyzed using Fourier transform infrared spectroscopy.

[0051] Figure 7 This is a graph comparing the dispersion stability and viscosity of a sample of dielectric paste composition with PVB as a dispersant and a sample of dielectric paste composition with PVP dispersants of different molecular weights.

[0052] Figure 8 This is a graph comparing the particle size distribution of a sample of dielectric paste composition with PVB as a dispersant and a sample of dielectric paste composition with PVP dispersants of different molecular weights.

[0053] Figure 9 The images show samples of dielectric paste compositions with PVB as a binder and samples of dielectric paste compositions with PVB binder and PVP dispersants of different molecular weights analyzed by Fourier transform infrared spectroscopy.

[0054] Figure 10 This is a graph showing the stress-strain curves of samples of dielectric ceramic sheets with different types of dispersants.

[0055] Figure 11A It is a graph showing the short-circuit rate of a multilayer electronic assembly including dielectric layers with different types of dispersants, and Figure 11B This is a graph showing the breakdown voltage (BDV) distribution of a multilayer electronic assembly that includes dielectric layers with different types of dispersants.

[0056] In the following text, reference will be made to Figures 6 to 11BDetailed description of experimental examples of dielectric paste compositions and dielectric ceramic sheets according to embodiments.

[0057] In each experimental example, a dielectric paste composition sample was formed by introducing a PVP or PVB dispersant solution (10% by weight in ethanol), BaTiO3 (70 nm) powder, and zirconia beads into an ethanol / toluene (EtOH / Tol) mixed solvent in a vial and milling it. Prior to the milling process, the PVB resin was dissolved in the ethanol and toluene mixture by ultrasonic treatment until the target viscosity was reached (approximately 2 hours) to prepare an adhesive solution. The adhesive solution and plasticizer were added to the dielectric paste composition, and dielectric ceramic sheet samples with a thickness of 0.8 μm or less were fabricated on a polyethylene terephthalate (PET) film using a doctor blade.

[0058] (Experimental Example 1) Figure 6 This is a graph showing samples of dielectric paste compositions with different types of dispersants analyzed using Fourier transform infrared spectroscopy.

[0059] Comparative Example 1-1 is the case where dielectric particles including BaTiO3 are added and no dispersant is added; Comparative Example 1-2 is the case where dielectric particles including BaTiO3 are added and polyvinyl butyral (PVB) is used as a dispersant; and Example 1-3 is the case where dielectric particles including BaTiO3 are added and polyvinylpyrrolidone is used as a dispersant.

[0060] Reference Figure 6 It can be seen that Comparative Examples 1-2 have peaks in wavenumber region a corresponding to the acetal group of PVB and wavenumber region c corresponding to the methylene group (-CH2), and Examples 1-3 have a strong peak in wavenumber region b corresponding to the carbonyl group (C=O).

[0061] (Experimental Example 2) Figure 7 This is a graph comparing the dispersion stability and viscosity of a sample of dielectric paste composition with PVB as a dispersant and a sample of dielectric paste composition with PVP dispersants of different molecular weights.

[0062] Figure 8 This is a graph comparing the particle size distribution of a sample of dielectric paste composition with PVB as a dispersant and a sample of dielectric paste composition with PVP dispersants of different molecular weights.

[0063] Figure 7 and Figure 8The characteristics of the comparative and example samples are as follows, and the solubility parameter (Ra) of the dispersant in ethanol-toluene solvent is 14. Dispersion stability was measured by instability index using a disk centrifugation photosedimentometer (DCP; DC24000 UHR, CPS Instruments, USA) and a LUMiSizer (a stability analyzer, LUM GmbH, Germany) at a rotation speed of 4000 RPM and a measurement temperature of 25°C, and viscosity was measured using a micro-sample volume viscometer (m-VROC, Rheosense Inc., USA) at a measurement temperature of 25°C.

[0064] (1) Comparative Example 2-1: Dielectric particles including BaTiO3 were added and polyvinyl butyral (PVB) was used as a dispersant.

[0065] (2) Example 2-4: Add dielectric particles including BaTiO3, use polyvinylpyrrolidone as a dispersant, and the molecular weight of the polyvinylpyrrolidone dispersant is 6320 g / mol.

[0066] (3) Example 2-5: Add dielectric particles including BaTiO3, use polyvinylpyrrolidone as a dispersant, and the molecular weight of the polyvinylpyrrolidone dispersant is 17700 g / mol.

[0067] (4) Example 2-6: Add dielectric particles including BaTiO3, use polyvinylpyrrolidone as a dispersant, and the molecular weight of the polyvinylpyrrolidone dispersant is 27000 g / mol.

[0068] (5) Example 2-7: Add dielectric particles including BaTiO3, use polyvinylpyrrolidone as a dispersant, and the molecular weight of the polyvinylpyrrolidone dispersant is 34100 g / mol.

[0069] (6) Example 2-8: Add dielectric particles including BaTiO3, use polyvinylpyrrolidone as a dispersant, and the molecular weight of the polyvinylpyrrolidone dispersant is 309000 g / mol.

[0070] Reference Figure 7As can be seen, Comparative Example 2-1 has an instability index of 0.175, and Examples 2-4, 2-5, 2-6, 2-7, and 2-8 have instability indices of 0.168 or less. Furthermore, the viscosity of Comparative Example 2-1 and all examples except Example 2-8 is less than 1.8 mPa·s, and the viscosity of Comparative Example 2-1, as well as Examples 2-5, 2-6, and 2-7, is between approximately 1.7 mPa·s and 1.8 mPa·s. It can be seen that, excluding the effect of viscosity on improving dispersion stability, the effect of using polyvinylpyrrolidone as a dispersant on improving dispersion stability is better than that of using polyvinyl butyral (PVB) as a dispersant.

[0071] Additionally, refer to Figure 8 Compared to Comparative Example 2-1, in the case of Example 2-4, the D of the dielectric particles in the dielectric paste composition is... 50 The thickness was reduced by approximately 2.5 nm, but in the cases of examples 2-6 with high molecular weights, it can be seen that the thickness of the dispersant layer disposed on the surface of the dielectric particles increased, resulting in D 50 The value is in the range of D in Comparative Example 2-1 50 The same level of value.

[0072] (Experimental Example 3) Figure 9 The images show samples of dielectric paste compositions with PVB as a binder and samples of dielectric paste compositions with PVB binder and PVP dispersants of different molecular weights analyzed by Fourier transform infrared spectroscopy.

[0073] Figure 10 This is a graph showing the stress-strain curves of samples of dielectric ceramic sheets with different types of dispersants.

[0074] exist Figure 9 and Figure 10 The characteristics of each comparative example and example are as follows, and the solubility parameter (Ra) of the dispersant in ethanol-toluene solvent is 14.

[0075] In addition, the comparative examples and examples include dielectric particles containing BaTiO3 and use polyvinyl butyral (PVB) as a binder.

[0076] To remove excess dispersant from the dielectric paste composition used for Fourier transform infrared spectroscopy analysis, a total of three processes were performed, involving centrifugation (10,000 rpm, 10 min) to settle the dielectric particles followed by redispersion with ethanol (EtOH). Subsequently, the dielectric particles were completely dried to remove any residual solvent, and measurements were performed using a light source with a beam size of 70 μm (depth: 3 μm to 5 μm).

[0077] To analyze the tensile strength of dielectric ceramic sheets using a dynamic mechanical analyzer (DMA), each dispersant was mixed with the binder solution in equal proportions, and the resulting dielectric paste composition was coated onto a PET film to fabricate sheets. For DMA measurements, dumbbell-shaped specimens were cut from the dielectric sheets in the casting direction using a sample cutter, and strain and stress were measured. Tensile tests were performed at a rate of 0.1 mm / s, and at least four specimens were tested to calculate the average tensile properties of these sheets.

[0078] (1) Comparative Example 3-1: No dispersant used.

[0079] (2) Example 3-1: Using polyvinyl butyral as a dispersant.

[0080] (3) Example 3-2: Use polyvinylpyrrolidone dispersant with a molecular weight of 6320 g / mol.

[0081] (4) Example 3-3: Use polyvinylpyrrolidone dispersant with a molecular weight of 27000 g / mol.

[0082] Reference Figure 9 As the molecular weight of polyvinylpyrrolidone dispersant increases, the concentration at 3100 cm⁻¹ corresponds to the hydroxyl group (-OH) of the adhesive. -1 Up to 3700cm -1 The peaks in the range shifted to lower wavenumbers, confirming that the interaction between the dispersant and the binder increases with the molecular weight of the polyvinylpyrrolidone dispersant.

[0083] Reference Figure 10 It can be seen that the yield strength of the dielectric ceramic sheet is higher when using polyvinylpyrrolidone dispersant than when not using a dispersant or when using polyvinyl butyral as a dispersant. Furthermore, it can be seen that the yield strength of the dielectric ceramic sheet tends to increase with the increase of the molecular weight of the polyvinylpyrrolidone dispersant.

[0084] (Experimental Example 4) Figure 11A It is a graph showing the short-circuit rate of a multilayer electronic assembly including dielectric layers with different types of dispersants, and Figure 11B This is a graph showing the breakdown voltage (BDV) distribution of a multilayer electronic assembly that includes dielectric layers with different types of dispersants.

[0085] The characteristics of the comparative and example examples are as follows. A multilayer electronic component is manufactured by the following steps: printing internal electrode paste on a dielectric ceramic sheet, stacking the individual sheets to manufacture a multilayer sheet, sintering the manufactured multilayer sheet at a temperature used to achieve the same electrostatic capacitance, and forming external electrodes through a capping process.

[0086] The short-circuit rate was measured by applying a 120Hz, 500mV voltage to a sample of a total of 30 multilayer electronic components, resulting in a short circuit. The dielectric breakdown voltage (BDV) was measured by applying a voltage increase rate of 50V / sec from 0V until the chip breaks using an HV BDV tester (PR12PF).

[0087] (1) Comparative Example 4-1: Multilayer electronic components were manufactured using a dielectric paste composition comprising dielectric particles containing BaTiO3 and polyvinyl butyral as a dispersant.

[0088] (2) Example 4-1: Using a dielectric paste composition comprising dielectric particles containing BaTiO3 and using polyvinylpyrrolidone (PVP) with a molecular weight of 27000 g / mol as a dispersant to manufacture multilayer electronic components.

[0089] (Experimental Example 5) Table 1 below shows the results of measurements of the peel force and static electricity generated during peeling for each dispersant, according to the type of plasticizer.

[0090] After forming a dielectric ceramic sheet on a substrate using dispersants and plasticizers classified as follows, the peel force and electrostatics were measured using a peel force measuring device (90º peel test) and an electrostatic measuring device at a measurement temperature of 25°C and a peel rate of 300 mm / min.

[0091] Dioctyl adipate (DOA) was used as a positively charged (+) plasticizer, and tetraethylene glycol dimethyl ether was used as a negatively charged (-) plasticizer.

[0092] [Table 1]

[0093] Referring to Table 1, it can be seen that when the plasticizer applied to the dielectric ceramic sheet has a negative charge (-), the absolute magnitude of static electricity generated during peeling is reduced compared to the case where a PVB dispersant is used, thus reducing defects occurring during stacking. Conversely, when the plasticizer applied to the dielectric ceramic sheet has a negative charge (-), the absolute magnitude of static electricity generated during peeling is significantly reduced compared to the case where the plasticizer applied to the dielectric ceramic sheet has a positive charge (+), thus reducing defects occurring during stacking.

[0094] (Experimental Example 6) Table 2 below shows the dispersibility of the dielectric paste composition and the mechanical properties of the dielectric ceramic sheet as measured by varying the molecular weight of the PVP dispersant.

[0095] [Table 2]

[0096] Referring to Table 2, it can be seen that when the molecular weight of the PVP dispersant is greater than or equal to 6300 g / mol and less than or equal to 309000 g / mol, no aggregation occurs in the dielectric paste composition. Furthermore, it can be seen that when the molecular weight of the PVP dispersant is greater than or equal to 6320 g / mol and less than or equal to 309000 g / mol, no aggregation occurs in the entire paste composition, and the dispersion stability is excellent due to an instability index value of 0.168 or less. Additionally, it can be seen that when the molecular weight of the PVP dispersant is greater than or equal to 17700 g / mol and less than or equal to 34100 g / mol, the mechanical properties of the dielectric ceramic sheet are improved. In Table 2, an instability index value greater than 1.7 is indicated as NG, and the mechanical property evaluation is rated OK when the elastic modulus is 15 MPa or greater and the strain value is 10% or greater; otherwise, it is rated as NG.

[0097] Multilayer electronic components Figure 1 It is a schematic three-dimensional view of a multi-layered electronic assembly.

[0098] Figure 2 It is along Figure 1 The cross-sectional view taken from line I-I'.

[0099] In the following text, reference will be made to Figure 1 and Figure 2 This disclosure describes in detail a multilayer electronic component manufactured using a method for manufacturing a multilayer electronic component according to embodiments of the present disclosure. However, while a multilayer ceramic capacitor is described as an example of a multilayer electronic component, this disclosure is also applicable to various electronic products (such as inductors, piezoelectric devices, varistors, or thermistors) that use dielectric paste compositions.

[0100] The body 110 includes alternating stacked dielectric layers 111 and internal electrodes 121 and 122.

[0101] More specifically, the body 110 may include a capacitor forming portion in which a first inner electrode 121 and a second inner electrode 122 are alternately arranged facing each other and a dielectric layer 111 is disposed between the first inner electrode 121 and the second inner electrode 122 to form a capacitor.

[0102] There are no particular restrictions on the specific shape of the main body 110, but as Figure 1 and Figure 2As shown, the main body 110 can be formed into a hexahedron shape or a similar shape. Due to the shrinkage of the ceramic powder included in the main body 110 during the sintering process, the main body 110 may not have a perfect straight hexahedron shape but may have a generally hexahedron shape.

[0103] The main body 110 may have a first surface 1 and a second surface 2 that are opposite to each other in a first direction, a third surface 3 and a fourth surface 4 that are connected to the first surface 1 and the second surface 2 and are opposite to each other in a second direction, and a fifth surface 5 and a sixth surface 6 that are connected to the first surface 1, the second surface 2, the third surface 3, and the fourth surface 4 and are opposite to each other in a third direction.

[0104] The multiple dielectric layers 111 forming the main body 110 are in a sintered state, and adjacent dielectric layers 111 may be integrated such that it is difficult to distinguish the boundary between them without using a scanning electron microscope (SEM).

[0105] The raw material for forming the dielectric layer 111 is not limited as long as sufficient capacitance can be obtained. Generally, perovskite (ABO3)-based materials can be used, and, for example, barium titanate-based materials, lead composite perovskite-based materials, or strontium titanate-based materials can be used. The barium titanate-based material may include BaTiO3-based ceramic powder, and examples of the BaTiO3-based ceramic powder include BaTiO3 and (Ba 1-x Ca x )TiO3 (0 < x < 1), Ba(Ti 1-y Ca y )O3 (0 < y < 1), (Ba 1-x Ca x )(Ti 1-y Zr y )O3 (0 < x < 1, 0 < y < 1) or Ba(Ti 1-y Zr y )O3 (0 < y < 1).

[0106] In addition, the raw material for forming the dielectric layer 111 can be a powder such as barium titanate (BaTiO3), to which various ceramic additives, organic solvents, binders, dispersants, etc. can be added according to the purpose of the present disclosure.

[0107] The inner electrodes 121 and 122 can be stacked alternately with the dielectric layers 111.

[0108] The inner electrodes 121 and 122 may include a first inner electrode 121 and a second inner electrode 122, and the first inner electrode 121 and the second inner electrode 122 may be alternately arranged facing each other with a dielectric layer 111 between the first inner electrode 121 and the second inner electrode 122, and the first inner electrode 121 and the second inner electrode 122 may be exposed on the third surface 3 and the fourth surface 4 of the body 110, respectively.

[0109] More specifically, the first inner electrode 121 may be spaced apart from the fourth surface 4 and exposed through the third surface 3, and the second inner electrode 122 may be spaced apart from the third surface 3 and exposed through the fourth surface 4. The first outer electrode 131 may be disposed on the third surface 3 of the body 110 and connected to the first inner electrode 121, and the second outer electrode 132 may be disposed on the fourth surface 4 of the body 110 and connected to the second inner electrode 122.

[0110] That is, the first inner electrode 121 can be connected to the first outer electrode 131 but not to the second outer electrode 132, and the second inner electrode 122 can be connected to the second outer electrode 132 but not to the first outer electrode 131. Here, the first inner electrode 121 and the second inner electrode 122 can be electrically separated from each other by a dielectric layer 111 disposed between them.

[0111] Alternatively, the body 110 can be formed by alternately stacking ceramic green sheets on which conductive paste for the first internal electrode 121 is printed and ceramic green sheets on which conductive paste for the second internal electrode 122 is printed, and then sintering them.

[0112] There are no particular limitations on the materials used to form the internal electrodes 121 and 122, and materials with excellent electrical conductivity can be used. For example, the internal electrodes 121 and 122 may include one or more of nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), and alloys thereof.

[0113] Furthermore, the internal electrodes 121 and 122 can be formed by printing an internal electrode conductive paste, including one or more of nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), and alloys thereof, onto a ceramic green sheet. The printing method for the internal electrode conductive paste may include screen printing or gravure printing, but this disclosure is not limited thereto.

[0114] Additionally, the main body 110 may include cover portions 112 and 113 arranged on two surfaces of the capacitor forming portion in a first direction.

[0115] More specifically, the main body 110 may include an upper cover portion 112 disposed above the capacitor forming portion in a first direction and a lower cover portion 113 disposed below the capacitor forming portion in a first direction.

[0116] The upper cover portion 112 and the lower cover portion 113 can be formed by stacking a single dielectric layer 111 or two or more dielectric layers 111 on the upper and lower surfaces of the capacitor forming portion in the first direction, respectively, and can substantially prevent damage to the inner electrodes 121 and 122 due to physical stress and / or chemical stress.

[0117] The upper cover 112 and the lower cover 113 do not include the inner electrodes 121 and 122, and may include the same material as the dielectric layer 111. That is, the upper cover 112 and the lower cover 113 may include ceramic materials (e.g., barium titanate (BaTiO3) based ceramic materials).

[0118] In addition, the edge portion may be provided on the third-direction surface of the capacitor forming portion.

[0119] More specifically, the edge portion may include a first edge portion disposed on one surface of the capacitor forming portion in the third direction (corresponding to the fifth surface 5 of the body 110) and a second edge portion disposed on another surface of the capacitor forming portion in the third direction (corresponding to the sixth surface 6 of the body 110). That is, the edge portions may be disposed on the surfaces of the capacitor forming portion that are opposite to each other in the third direction.

[0120] The edge portion may refer to the area between the two ends of the first inner electrode 121 and the second inner electrode 122 in the third direction and the outer surface of the body 110, based on the cross-section of the body 110 in the second direction and the third direction.

[0121] The edges can essentially prevent damage to the inner electrodes 121 and 122 due to physical and / or chemical stress.

[0122] The edge portion can be formed by applying conductive paste to a ceramic green sheet (excluding the area where the edge portion is to be formed) to form the inner electrodes 121 and 122. As another example, to suppress the step difference caused by the inner electrodes 121 and 122, the edge portion can be formed by stacking ceramic green sheets on which conductive paste for the inner electrodes is printed to obtain a stack, cutting the stack such that the stacked inner electrodes 121 and 122 are exposed on the two third-side surfaces of the capacitor forming portion, and then stacking a single dielectric layer or two or more dielectric layers on the two third-side surfaces of the capacitor forming portion.

[0123] In embodiments of this disclosure, the ceramic electronic component 100 is described as having a structure including two external electrodes 131 and 132, but the number or shape of the external electrodes 131 and 132 may be changed depending on the shape of the internal electrodes 121 and 122 or for other purposes.

[0124] External electrodes 131 and 132 may be arranged on the body 110 and connected to internal electrodes 121 and 122.

[0125] More specifically, the external electrodes 131 and 132 may include a first external electrode 131 and a second external electrode 132 respectively disposed on the third surface 3 and the fourth surface 4 of the body 110 and connected to the first internal electrode 121 and the second internal electrode 122 respectively. That is, the first external electrode 131 may be disposed on the third surface 3 of the body 110 and connected to the first internal electrode 121, and the second external electrode 132 may be disposed on the fourth surface 4 of the body 110 and connected to the second internal electrode 122.

[0126] The external electrodes 131 and 132 can be formed of any conductive material (such as metal), and the specific material can be determined by taking into account electrical properties, structural stability, etc. In addition, the external electrodes 131 and 132 can have a multilayer structure.

[0127] For example, the external electrodes 131 and 132 may include electrode layers 131a and 132a disposed on the body 110 and plating layers 131b and 132b disposed on the electrode layers 131a and 132a.

[0128] For a more specific example of electrode layers 131a and 132a, electrode layers 131a and 132a may be sintered electrodes comprising conductive metal and glass or resin-based electrodes comprising conductive metal and resin.

[0129] In addition, electrode layers 131a and 132a may be in the form of sintered electrodes and resin-based electrodes sequentially formed on the body 110.

[0130] Alternatively, electrode layers 131a and 132a can be formed by transferring a sheet including conductive metal onto the body 110, or by transferring a sheet including conductive metal onto a sintered electrode.

[0131] The conductive metal used in electrode layers 131a and 132a is not particularly limited, as long as it is a material that can be electrically connected to the inner electrodes 121 and 122 to form a capacitor, and may include one or more of, for example, nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), and alloys thereof. Electrode layers 131a and 132a can be formed by coating a conductive paste and then sintering it, the conductive paste being prepared by adding a glass frit to conductive metal powder.

[0132] The 131b and 132b coatings improve mounting characteristics.

[0133] There are no particular limitations on the type of plating layers 131b and 132b, and they can be single-layer plating layers 131b and 132b including at least one of nickel (Ni), tin (Sn), palladium (Pd) and alloys thereof, or they can include multiple layers.

[0134] For a more specific example of plating layers 131b and 132b, plating layers 131b and 132b may be Ni plating layers or Sn plating layers, or they may be in the form of Ni plating layers and Sn plating layers sequentially formed on electrode layers 131a and 132a, or they may be in the form of Sn plating layers, Ni plating layers, and Sn plating layers sequentially formed. Additionally, plating layers 131b and 132b may include multiple Ni plating layers and / or multiple Sn plating layers.

[0135] One of the various effects of this disclosure is to provide a dielectric paste composition in which the dispersibility of dielectric particles is improved.

[0136] One of the various effects of this disclosure is to improve the mechanical strength of the dielectric ceramic sheet.

[0137] Although embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the embodiments and drawings described above, but is intended to be defined by the appended claims. Therefore, those skilled in the art can make various substitutions, modifications and variations without departing from the technical spirit of the present disclosure described in the claims, and these will also be considered to fall within the scope of the present disclosure.

[0138] The expression "an exemplary embodiment or an example" as used in this disclosure does not refer to an exact same example and is provided to emphasize the distinct features that distinguish the various examples. However, the examples provided in the above description do not preclude the association with and implementation of features of other examples. For example, unless otherwise stated in its description, even if something described in a particular example is not described in another example that is different from it, such content may be understood to be related to that other example.

[0139] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well.

Claims

1. A dielectric paste composition comprising: Dielectric particles, including BaTiO3; Solvents, including ethanol and toluene; Dispersants, including polyvinylpyrrolidone; and Adhesive, The mass ratio of ethanol to toluene is greater than 1.0 and less than 2.

3.

2. The dielectric paste composition according to claim 1, wherein, The molecular weight of the polyvinylpyrrolidone is greater than or equal to 6300 g / mol and less than or equal to 309000 g / mol.

3. The dielectric paste composition according to claim 1, wherein, The Hansen solubility parameter of the dispersant is greater than 13 and less than 16.

4. The dielectric paste composition according to claim 1, wherein, The dispersant is disposed on the surface of the dielectric particles.

5. The dielectric paste composition according to claim 1, wherein, The polyvinylpyrrolidone includes nitrogen elements disposed on the surface of the dielectric particles.

6. The dielectric paste composition according to claim 1, wherein, The adhesive comprises polyvinyl butyral.

7. The dielectric paste composition according to claim 6, wherein, The number of repeating units in the polyvinylpyrrolidone is n, and the number of repeating units containing hydroxyl groups in the polyvinyl butyral is y, where n / y satisfies greater than or equal to 0.67 and less than 3.

7.

8. A dielectric ceramic sheet, comprising: Dielectric particles, including BaTiO3; Dispersants, including polyvinylpyrrolidone; Adhesives; as well as Plasticizer, The plasticizer has a negative charge.

9. The dielectric ceramic sheet according to claim 8, wherein, The plasticizer includes at least one selected from triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and polyethylene glycol dimethyl ether.

10. The dielectric ceramic sheet according to claim 8, wherein, The molecular weight of the polyvinylpyrrolidone is greater than or equal to 6300 g / mol and less than or equal to 309000 g / mol.

11. The dielectric ceramic sheet according to claim 8, wherein, The dispersant is disposed on the surface of the dielectric particles.

12. The dielectric ceramic sheet according to claim 8, wherein, The polyvinylpyrrolidone includes nitrogen elements disposed on the surface of the dielectric particles.

13. The dielectric ceramic sheet according to claim 8, wherein, The adhesive comprises polyvinyl butyral.

14. The dielectric ceramic sheet according to claim 13, wherein, The number of repeating units in the polyvinylpyrrolidone is n, and the number of repeating units containing hydroxyl groups in the polyvinyl butyral is y, where n / y satisfies greater than or equal to 0.67 and less than 3.

7.

15. The dielectric ceramic sheet according to claim 8, wherein, The plasticizer includes tetraethylene glycol dimethyl ether.

16. The dielectric ceramic sheet according to claim 8, wherein, The plasticizer does not contain dioctyl adipate.

17. A method for manufacturing a multilayer electronic component, comprising: The body of the multilayer electronic assembly is formed from a dielectric ceramic sheet according to any one of claims 8-16.

Images