MLCC structure for improving ESR of C0G product

Abstract

The invention relates to the technical field of MLCC design, in particular to an MLCC structure used for improving C0G product ESR, in the MLCC printing process, through design modification of the shape of a screen printing plate, a cross-shaped screen printing plate design different from a general design is adopted, the area of an inner electrode leading-out end and the connection proportion of an inner electrode and an outer electrode are increased, and the ESR of a C0G product is improved. The ESR level of the C0G first-class porcelain product is reduced; and the ESR stability of the C0G first-class porcelain product is improved. And meanwhile, the dielectric loss of the product is reduced, and the voltage resistance and capacitance stability of the product are improved to a certain extent. The design of the cross-shaped screen also increases the area of the leading-out end of the inner electrode, increases the connection proportion of the inner electrode and the outer electrode, and further increases the binding force of the inner electrode and the outer electrode, thereby improving the plate bending resistance, push-pull resistance and other mechanical properties of C0G porcelain products. And the internal deformation proportion in the MLCC cutting process is reduced, so that the product yield is improved, the inspection mode after the product cutting is completed is simplified, and the working efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of MLCC design, in particular to a MLCC structure for improving ESR of C0G product. BACKGROUND

[0002] The multilayer ceramic capacitor (MLCC) is made by ceramic dielectric film with printed electrodes (internal electrodes) stacked with a certain offset, sintered at high temperature, and then sealed with metal layers (external electrodes) at both ends. The basic working principle is based on the energy storage characteristics of the capacitor, which uses the polarization phenomenon of ceramic dielectric under the action of electric field to store and release electric charge. When a voltage is applied to both ends of the MLCC, the ceramic dielectric is polarized, and the electric charge accumulates on the electrode, thereby storing electric energy; when the voltage changes, the electric charge is released, completing the energy storage and discharge process.

[0003] Among the many process links, screen printing design plays a key role. As a carrier for transferring internal electrode patterns, it deeply affects the electrical performance parameters, structural integrity and long-term reliability of MLCC by precisely controlling the deposition form of metal paste.

[0004] With the development of electronic devices towards miniaturization, high frequency and high reliability, the number of layers of MLCC is increasing (modern high-end products have reached more than 1000 layers), and the size is continuously shrinking (008004 specification is only 0.25x0.125mm), which poses unprecedented challenges to screen printing technology. Screen printing design has developed from a simple pattern transfer tool to a comprehensive technology integrating material science, fluid mechanics and structural optimization, and has become a key breakthrough in promoting the development of MLCC technology.

[0005] Currently, the traditional screen printing design is mainly rectangular, and its performance needs to be further improved. SUMMARY

[0006] Therefore, the present application aims to provide a MLCC structure for improving ESR of C0G product to solve the technical problem of improving the ESR of a type of ceramic C0G product.

[0007] To achieve the above purpose, the present application provides a MLCC structure for improving ESR of C0G product, which comprises a ceramic film and an electrode arranged on the surface of the ceramic film, wherein the electrode comprises a rectangular part and an extension part. The extension part is arranged on the long side of the rectangular part, and one extension part is arranged on each long side of the rectangular part, and the two extension parts and the rectangular part are directly connected and integrally formed. The extension part is rectangular. The electrode is arranged on the ceramic film surface in a uniform manner, and the extension parts of the upper and lower adjacent electrodes are staggered.

[0008] Further, the extension part can also be arranged in an isosceles triangle shape.

[0009] Further, the extension part can also be arranged in a T shape.

[0010] Further, the extension part is arranged at the middle position of the long side of the rectangular part.

[0011] Further, the long side of the rectangular extension part is parallel to the long side of the rectangular part, and the length of the rectangular extension part is less than the length of the rectangular part.

[0012] Further, the length of the rectangular part is 1.96 mm, and the width of the rectangular part is 0.3 mm.

[0013] Further, the length of the rectangular extension part is between 0.2 mm and 0.8 mm, and the width of the rectangular extension part is between 0.1 mm and 0.2 mm.

[0014] Further, a part of the rectangular part of the electrode is embedded in the ceramic film, and the extension part is attached to the surface of the ceramic film.

[0015] Further, the outer surfaces of the rectangular part and the extension part of the electrode are flush.

[0016] Further, the upper extension part of the electrode is opposite to the upper electrode gap, and the lower extension part of the electrode is opposite to the lower electrode gap.

[0017] The beneficial effects of the present application are as follows: 1. In the printing process of the MLCC, the shape of the screen is modified, thereby changing the structure design of the MLCC, increasing the area of the inner electrode lead-out end, and increasing the proportion of the connection between the inner and outer electrodes, thereby increasing the connection between the inner and outer electrodes of the C0G ceramic product, and further reducing the ESR level of the C0G ceramic product; 2. The present application improves the ESR stability of the C0G ceramic product by simple design change, while reducing the dielectric loss of the product, and to some extent, increasing the voltage resistance and capacitance stability of the product; 3. The present application modifies the shape of the screen, increases the area of the inner electrode lead-out end, increases the proportion of the connection between the inner and outer electrodes, and further increases the bonding force between the inner and outer electrodes, thereby increasing the mechanical properties such as bending resistance and push-pull resistance of the C0G ceramic product.

[0018] 4. The present application modifies the shape of the screen, reduces the internal deformation ratio in the cutting process of the MLCC, thereby improving the product yield, simplifying the inspection method after the cutting of the product, and improving the work efficiency BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the present application or the prior art, the drawings required to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only a part of the present application, and other drawings can also be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0020] Figure 1 It is a schematic diagram of the principle of the device of the present application.

[0021] Figure 2 It is a schematic diagram of the mainstream design of the traditional screen in the industry.

[0022] Figure 3 It is a schematic diagram of the screen extension shape of experimental examples 1-3.

[0023] Figure 4 It is a schematic diagram of the screen design size of experimental examples 4-6.

[0024] The marks in the figure are: 11, porcelain film, 12, extension, 101, rectangular part, 102, extension. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present application more clear and obvious, the present application will be further described in detail below in combination with specific embodiments.

[0026] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present application should be understood as the usual meaning understood by those skilled in the art to which the present application belongs. The words "first", "second" and similar words used in the present application do not represent any order, quantity or importance, but are only used to distinguish different components. The words "include" or "contain" and similar words mean that the elements or objects before the word cover the elements or objects listed after the word and their equivalents, and do not exclude other elements or objects. The words "connect" or "connected" and similar words are not limited to physical or mechanical connection, but can include electrical connection, whether direct or indirect. The words "up", "down", "left", "right" and the like are only used to represent relative positional relationship, and when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0027] The present application mainly aims at the problem that the equivalent series resistance ESR measurement level of C0G ceramic products in the full frequency range (especially in the low frequency range) cannot be further reduced and the level stability is poor, and proposes a new screen shape design method to change the internal and external electrode connectivity. On the basis of a C0G ceramic material with high temperature stability, a coating machine is used to coat it to obtain a ceramic film 11 with a corresponding thickness, and then a specific screen shape internal electrode is printed on the ceramic film 11, and then a ceramic capacitor green body is obtained through the staggered stacking design of the internal electrode and the ceramic film 11, and then a corresponding ceramic capacitor MLCC is obtained through processes such as sintering, copper plating of the external electrode, etc. Compared with the ceramic capacitors prepared by the general design, the MLCC prepared by the screen design not only meets the general C0G MLCC requirements for ESR, but also meets the requirements of high Q value special frequency application and better ESR stability.

[0028] In the MLCC industry, the rectangular screen design is the mainstream design, and its shape structure is as shown in the following figure Figure 2 The present application adopts a cross-shaped screen design different from the general design, and its shape structure is as shown in the following figure Figure 1 The ESR level of the C0G ceramic product produced by the screen design provided by the present application can be reduced by 200-500 mΩ, and the finished MLCC is obtained through the related preparation process of the applicant.

[0029] Preferably, triangular and T-shaped extension designs can also be used. Specific embodiment 1:

[0030] A C0G ceramic powder of SrTiO3-CaTiO3 as the main powder is used in normal production of the applicant, 2.5% by mass percentage (dispersant), 20% by mass percentage of toluene / ethanol mixed solvent, to obtain a mixed ceramic slurry, 25% by mass percentage of PVB binder is added to the slurry, a coating machine is used to coat it to obtain a ceramic film 11 with a corresponding thickness, and different shapes of screen designs (the overall shape of the screen is different, and the specific shape is shown in the following table) are used to print on the ceramic film 11, and then the same conditions are used for stacking, water pressure, cutting, degassing, sintering, tumbling, immersion plating, end burning, and electroplating to produce MLCC products.

[0031] As shown in the following table, the performance of the products produced by different screen designs is tested, and the test results are listed in the following table. Figure 3

[0032] Table 1 Experimental examples 1-3

[0033] ​As shown in Table 1, when the screen extension 102 is changed to a triangular shape, the ESR level of the same size product increases by 60 mΩ, and the tensile force also decreases by 0.14 kgw. When the screen extension 102 is changed to a T shape, the ESR and tensile force increase levels are not large, but due to the increase in the area of the inner electrode metal nickel paste, the difference between the shrinkage of the metal nickel paste and the ceramic body increases, which also causes cracking. Therefore, according to all the experimental data, the screen shape design of Example 1 is still the best. Specific embodiment 2:

[0034] A SrTiO3-CaTiO3-based powder of a C0G type ceramic powder produced by the company was used, 2.5% by mass of a dispersant, 20% by mass of a toluene / ethanol mixed solvent, and a mixed ceramic slurry was obtained. 25% by mass of PVB binder was added to the slurry, and a coating machine was used to coat it to obtain a ceramic film 11 of a corresponding thickness, and different shapes of screen designs (X1 has size differences, and the specific sizes are shown in the table below) were used for printing on the basis of the ceramic film 11. Subsequently, 0402 MLCC products were produced through the same conditions of stacking, water pressure, cutting, degassing, sintering, rolling, plating, burning, and electroplating. As shown in Figure 4 The performance of the products produced by different screen designs was tested, and the test results are shown in the table below.

[0035] Table 2 Experimental examples 4-6

[0036] As shown in Table 2, when the screen shape is changed to a cross-shaped screen, i.e. the extension 102 is rectangular, the ESR level of the same size product decreases by nearly 400 mΩ, and the tensile force also increases by 0.4 kgw. However, when the X1 size is further expanded, due to the increase in the area of the inner electrode metal nickel paste, the local shrinkage stress of the product after sintering increases sharply, which leads to the increase in the difference between the shrinkage of the metal nickel paste and the ceramic body, thereby causing cracking. Therefore, according to all the experimental data, the screen design of Example 5 is the best, which can not only meet the requirements of ESR and tensile force, but also meet the negative effects of reducing shrinkage.

[0037] In summary, based on the C0G characteristic ceramic powder material with temperature stability, different MLCC products were produced by ball milling, slurry mixing, coating, printing, stacking, water pressure, cutting, degassing, sintering, rolling, plating, burning, and electroplating, and the performance was tested and compared. Finally, a screen design and structure design that can reduce the ESR level by 200-500 mΩ is obtained, which also improves the end tensile force, capacitance level, and stability of the product.

[0038] Those skilled in the art should understand that the above discussion of any embodiment is only intended to be illustrative and is not intended to be in any way limiting as to the scope of the present application, including the claims that follow it; the above embodiments or technical features among different embodiments can also be combined, steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above, which are not provided in details for the sake of brevity.

[0039] The present application is intended to cover all such alternatives, modifications, and variations as fall within the broad scope of the appended claims. Accordingly, any one of the above-described embodiments of the present application can be further modified than or combined with another in addition to the changes discussed in the above description.

Claims

1. An MLCC structure for improving ESR of a C0G product, comprising a ceramic film (11) and an extension (12) provided on a surface of the ceramic film (11), characterized in that, The extension (12) comprises a rectangular part (101) and an extension part (102); The extension part (102) is arranged on the long side of the rectangular part (101), and each of the two long sides of the rectangular part (101) is provided with one extension part (102), and the two extension parts (102) and the rectangular part (101) are directly connected and integrally formed; The extension part (102) is rectangular. The ceramic film (11) is provided with a plurality of uniformly arranged extension parts (12) on the surface, and the positions of the extension parts (102) of the upper and lower adjacent extension parts (12) are staggered.

2. The MLCC structure for improving ESR of C0G products according to claim 1, wherein, The extension part (102) can also be arranged in an isosceles triangular shape.

3. The MLCC structure for improving ESR of C0G products according to claim 1, wherein, The extension part (102) can also be arranged in a T shape.

4. The MLCC structure for improving ESR of C0G products according to claim 1, 2 or 3, wherein, The extension part (102) is arranged at the middle position of the long side of the rectangular part (101).

5. The MLCC structure for improving ESR of C0G products according to claim 1, wherein, The long side of the rectangular extension part (102) is parallel to the long side of the rectangular part (101), and the length of the rectangular extension part (102) is less than the length of the rectangular part (101).

6. The MLCC structure for improving ESR of C0G products according to claim 1 or 5, wherein, The length of the rectangular part (101) is 1.96 mm, and the width of the rectangular part (101) is 0.3 mm.

7. The MLCC structure for improving ESR of C0G products according to claim 6, wherein, The length of the rectangular extension part (102) is between 0.2 mm and 0.8 mm, and the width of the rectangular extension part (102) is between 0.1 mm and 0.2 mm.

8. The MLCC structure for improving ESR of C0G products according to claim 1, wherein, The rectangular part (101) of the extension part (12) is embedded in the ceramic film (11), and the extension part (102) is attached to the surface of the ceramic film (11).

9. The MLCC structure for improving ESR of C0G products according to claim 1 or 9, wherein, The outer surfaces of the rectangular part (101) and the extension part (102) of the extension part (12) are flush.

10. The MLCC structure for improving ESR of C0G products according to claim 1, wherein, The upper extension part (102) of the extension part (12) faces the gap between the upper extension part (12), and the lower extension part (102) of the extension part (12) faces the gap between the lower extension part (12).

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