TW202123270A - Multilayer ceramic capacitor and manufacturing method thereof - Google Patents

Abstract

A multilayer ceramic capacitor and a manufacturing method thereof are disclosed. The multilayer ceramic capacitor includes a base part including ceramic dielectrics, and inner electrodes formed in the ceramic dielectrics and arranged in interval by a staggered manner; two first outer electrodes of outer electrode layers are sintered and formed on two sides of the base part, and in electrical contact with the inner electrode terminals of the inner electrodes. Second outer electrodes are formed on outer parts of the two first outer electrodes. The inner electrodes and the first outer electrodes have barium titanate powder and nickel powder with average particle diameters in range of 0.2 [mu]m to 0.4 [mu]m, so that the inner electrodes are in good electrical contact with the first outer electrodes, to improve binding strength and reduce peeling of the first outer electrodes from the inner electrodes.

Description

Multilayer ceramic capacitor and its manufacturing method

The present invention relates to a multilayer ceramic capacitor and its manufacturing method. In particular, the internal electrodes of the multilayer ceramic capacitor and the first external electrodes on both sides both contain nickel powder and barium titanate powder with a particle size of 0.2~0.4μm. In this way, the internal electrode and the first external electrode have good electrical contact, and the mutual bonding strength is improved, thereby reducing the peeling.

According to, today's electronic products and related electronic equipment need to use active components and passive components. Among them, active components (such as IC or CPU) can perform arithmetic processing functions independently, while passive components perform relative to active components. When the current or voltage changes, the resistance or impedance of the components will not change accordingly. Generally, capacitors, resistors and inductors are collectively called the three passive components. However, they are based on functions. In other words, capacitors store charges in electrostatic mode, which can release electrical energy within a predetermined period of time, and can even be used as a filter or side wave coordinated use; while resistors can be used to adjust the voltage and current in the circuit; inductance is used to filter noise in the current , The main function is to prevent electromagnetic interference.

At present, various information, communications, consumer electronics or other cutting-edge electronic products are used in conjunction with each other to achieve the purpose of electronic circuit control, and because the types of electronic products have no boundaries, the capacitors in the passive components Requirements have been raised, for example: capacitors The size of capacitors is getting smaller or the requirements for dielectric stability of capacitors are getting higher and higher. However, capacitors can be divided into aluminum electrolytic capacitors, ceramic capacitors, plastic film capacitors, tantalum capacitors and mica capacitors according to their materials. Among them, ceramic capacitors Because it has the characteristics of high dielectric coefficient, good insulation, good heat resistance, small size, suitable for mass production, and good stability and reliability, and because of the advantages of ceramic capacitors with high voltage and high heat resistance and wide operating temperature range, plus the chip The ceramic capacitors can be directly welded through surface mount technology (SMT), and the speed and quantity of manufacturing are also much better than other capacitors such as electrolytic capacitors and assembled capacitors.

In addition, there are many types of ceramic capacitors. For example, disc ceramic capacitors, ingot ceramic capacitors and multilayer ceramic capacitors (Multi-Layer Ceramic Capacitor, MLCC) are typical ceramic capacitors commonly used in the market. Among them, multilayer ceramic capacitors are mainly composed of It is composed of barium titanate with high dielectric properties, and its capacitance content is usually proportional to the surface area of the product and the number of ceramic film stacks. The interior is composed of an internal electrode layer, a ceramic dielectric layer, and an internal electrode layer. Stacked at intervals to form capacitors connected in parallel, that is, each ceramic dielectric layer is sandwiched by the upper and lower internal electrode layers to form a flat capacitor, and then combined with the external electrode layers for electrical conduction. In this way, multilayer ceramic capacitors It can be used as a container for storing electricity.

Furthermore, multilayer ceramic capacitors are the most popular and most widely used ceramic capacitors in electronic products because of the large number of stacks of ceramic dielectric layers and internal electrode layers in staggered intervals. They are especially common in portable high-end electronics and Communication products, such as PCs, mobile phones or automotive electronic components, etc.

Conventional techniques such as the patent of Japanese Patent Application Laid-Open No. 5-3131, which discloses a multilayer ceramic capacitor with internal electrodes and ceramic dielectrics alternately stacked The internal electrode of the multilayer ceramic capacitor is composed of nickel, and the external electrode layer on the two sides of the ceramic dielectric includes the first external electrode, and the two first external electrodes are located outside the two first external electrodes and are bonded by glass The second external electrode formed by silver (or silver alloy), and the third external electrode formed by electroplating metal film formed on the outside of the two second external electrodes.

Among them, the ceramic dielectric body and the first external electrode made of nickel are around the adjacent bonding position. Due to the high sintering temperature, it is easy to form a diffusion layer of nickel oxide, which improves the bonding strength. However, when the second external electrode is made, the glass material The powder has the characteristics of very high sintering temperature and lengthy sintering time, so it is easy for the glass component to invade the first external electrode and the ceramic dielectric body by thermal diffusion, and ultimately cause the structural strength of the multilayer ceramic capacitor or dielectric body to decrease.

In addition, because the second external electrode includes glass powder and silver (or silver alloy) materials at the same time, uneven distribution of the glass powder is prone to occur. When the glass powder accumulates around or is densely distributed, it will be placed outside the second external electrode. When the third external electrode is electroplated, it is easy to cause the electroplating solution (such as nickel electroplating solution) to penetrate into the ceramic dielectric body through the diffusion path of the second and first external electrodes, resulting in a serious poor density and quality of the multilayer ceramic capacitor. Due to deterioration, fragile texture, and easy cracking, if applied to electronic products, the multilayer ceramic capacitor cannot perform the expected normal function, so there are many shortcomings that need to be improved.

In addition, conventional multilayer ceramic capacitors generally use multiple heating or sintering processes to fabricate the layered structure of the external electrodes. However, frequent sintering or excessively high temperature heating will damage the capacitors, especially the internal electrodes and the first For external electrodes, in order to produce high-capacity multilayer ceramic capacitors and increase the number of internal electrodes stacked, many internal electrodes are gradually becoming thinner, so that the contact area between each layer of internal electrodes and the first external electrode is much reduced. The formed first external electrode is affected by the temperature of the subsequent process and undergoes thermal expansion Phenomenon, the position where the first external electrode and the internal electrode were in contact with each other will peel off, or even break or break, which will affect the electrical characteristics of the capacitor.

In addition, the conventional multilayer ceramic capacitor may choose copper-containing metal or copper metal when making the external electrode or the first external electrode. However, the external electrode and the internal electrode have different thermal expansion coefficients due to the different materials. If the volume changes, the original contact position of the first external electrode and the internal electrode is also prone to damage.

As mentioned above, the conventional technology has many of the above-mentioned problems of multilayer ceramic capacitors. In particular, the uneven presence of glass will cause the plating solution to invade the ceramic dielectric body during the molding process of the external electrodes and cause reliability cracking. Therefore, how to solve the problem of multilayer ceramic capacitors Diffusion invaded by glass powder materials or other impurity elements, this is where the relevant manufacturers in the field urgently want to study and improve the direction.

Therefore, in view of the above-mentioned deficiencies, the inventor collected relevant information, evaluated and considered from many parties, and based on years of experience in this industry, through continuous trials and modifications, he began to design this type of multilayer ceramic capacitor and its manufacturing method. Invention patentee.

The main purpose of the present invention is that the base of the ceramic capacitor includes a ceramic dielectric body and a plurality of internal electrodes formed in the ceramic dielectric body and arranged in staggered intervals, and each side of the plurality of internal electrodes is provided with the internal electrodes exposing the ceramic dielectric body. The extreme part, and the internal electrode contains nickel powder and barium titanate powder with a particle size of 0.2μm~0.4μm, and two first external electrodes of external electrode layers are sintered on both sides of the base, and the two first The external electrode is in electrical contact with the inner electrode ends of the plurality of internal electrodes, and the first external electrode contains nickel powder and barium titanate powder with a particle size of 0.2μm~0.4μm, and is connected to the two first external electrodes. External molding There is a second external electrode made of metal powder and resin. Both the internal electrode and the first external electrode contain nickel powder and barium titanate powder with a particle size of 0.2μm~0.4μm, so the internal electrode can be The first external electrode has good electrical contact and can increase the mutual bonding strength, thereby reducing the occurrence of peeling of the first external electrode from the internal electrode, thereby preventing the intrusion of electroplating solution, so as to achieve the improvement of product yield and increase market competitiveness. purpose.

The secondary objective of the present invention is that the volume percentage of nickel powder to barium titanate powder in the second nickel electrode paste is preferably the same as the volume percentage of nickel powder to barium titanate powder in the first nickel electrode paste, so that the multilayer ceramic capacitor When swelling occurs due to heat, the volume change will tend to be the same or similar, thereby avoiding damage caused by thermal expansion, and the first nickel electrode paste can be used as the second nickel electrode paste, thereby reducing material manufacturing time, waste and inventory purpose.

Another object of the present invention is that the base and the first external electrode of the external electrode layer are made by a co-sintering method, which can effectively reduce the number of subsequent heating or temperature caused by the capacitor itself or the internal electrode end of the plurality of internal electrodes. The structure is destroyed, so that the texture of the first external electrode will not be fragile or cracked, thereby increasing the density, thereby achieving the purpose of improving the electrical contact between the two first external electrodes and the plurality of internal electrodes.

Another object of the present invention is that the metal powder in the metal electrode paste can be silver powder, silver and nickel mixed powder, copper powder, copper powder covered with silver or other conductive powder, and the resin contains epoxy Resin and thermosetting resin, and because the second external electrode is cured and molded in a temperature range of about 250°C, it can be ensured that when the second external electrode is molded, the metal powder will not diffuse or invade the two first external electrodes, The position of the ceramic dielectric body or the internal electrode can achieve the purpose of not affecting the structural strength or electrical conductivity of the first external electrode, the ceramic dielectric body or the internal electrode.

1‧‧‧Base

11‧‧‧Ceramic dielectric

12‧‧‧Internal electrode

121‧‧‧Inner electrode end

2‧‧‧External electrode layer

21‧‧‧First external electrode

22‧‧‧Second external electrode

23‧‧‧Third external electrode

The first figure is a cross-sectional side view of the present invention.

The second figure is a flowchart of the present invention.

The third figure is the test result figure (1) of the electrostatic capacity and insulation resistance cracking rate of the present invention.

The fourth figure is the test result figure (2) of the electrostatic capacity and insulation resistance cracking rate of the present invention.

In order to achieve the above-mentioned purpose and effect, the technical means and structure adopted by the present invention are illustrated below in detail to illustrate the features and functions of the preferred embodiments of the present invention, so as to fully understand.

Please refer to the first figure, which is a side sectional view of the present invention. It can be clearly seen from the figure that the multilayer ceramic capacitor includes a base 1 and an external electrode layer 2 formed on both sides of the base 1, in which:

The base 1 includes a ceramic dielectric body 11 and a plurality of internal electrodes 12 formed in the ceramic dielectric body 11 and arranged in staggered intervals, wherein one side of the plurality of internal electrodes 12 is respectively provided with internal electrode ends exposing the ceramic dielectric body 11 121, and the inner electrode ends 121 of the plurality of inner electrodes 12 are respectively exposed at two opposite sides of the ceramic dielectric body 11 in a staggered manner, and the inner electrodes 12 contain nickel powder with a particle size of 0.2μm~0.4μm And barium titanate powder.

The external electrode layer 2 includes a first external electrode 21 formed on both sides of the ceramic dielectric body 11 of the base 1, a second external electrode 22 formed on the outside of the two first external electrodes 21, and two second external electrodes formed on 22 external third external electrode 23, where the The two first external electrodes 21 are in electrical contact with the inner electrode ends 121 of the plurality of internal electrodes 12, and the first external electrodes 21 contain nickel powder and barium titanate powder with a particle size ranging from 0.2 μm to 0.4 μm, The second external electrode 22 is formed by curing and forming components such as metal powder and resin.

The composition of the ceramic dielectric body 11 of the base 1 includes barium titanate powder, manganese oxide powder, yttrium oxide powder, silicon oxide powder, resin and the like.

Furthermore, the particle size of the barium titanate powder contained in the internal electrode 12 of the base 1 and the first external electrode 21 of the external electrode layer 2 is between 0.05 μm and 0.1 μm, and the barium titanate in the internal electrode 12 The volume percentage of the powder to the nickel powder may be 25 vol%, and the volume percentage of the barium titanate powder to the nickel powder in the first external electrode 21 is between 15 vol% and 50 vol%.

And the second external electrode 22 of the external electrode layer 2 is composed of metal powder, resin and other components, and the metal powder can be silver powder, silver and nickel mixed powder, copper powder, copper powder covered with silver or other conductive materials The powder, and the resin contains epoxy resin and thermosetting resin (such as: urea formaldehyde or phenolic resin, etc.).

However, the third external electrode 23 of the external electrode layer 2 is an electroplated layer whose main components are nickel, tin, etc., which are electroplated.

Please refer to the second figure again, which is the flow chart of the present invention. From the figure, it can be clearly seen that the manufacturing method of the multilayer ceramic capacitor of the present invention includes the following steps:

(A) The ceramic slurry can be processed into a ceramic thin strip by a thin strip forming machine.

(B) The first nickel electrode paste is processed and formed on the ceramic thin tape to make the ceramic A nickel electrode paste layer is formed on the ceramic thin belt, and is allowed to dry. The first nickel electrode paste contains nickel powder and barium titanate powder, and the nickel powder has a particle size ranging from 0.2 μm to 0.4 μm.

(C) Then stack a plurality of ceramic thin strips in a staggered manner, so that the plurality of nickel electrode paste layers are stacked in a staggered pattern, and are laminated and combined under pressure, and then cut, that is, the production of a multilayer ceramic capacitor is formed Embryos, and one side of the plurality of nickel electrode paste layers are respectively exposed on two opposite sides of the green embryo in a staggered manner.

(D) The two opposite sides of the green embryo can be immersed in the second nickel electrode paste, and then coated with a predetermined thickness and then dried. The second nickel electrode paste contains nickel powder and barium titanate powder, And the nickel powder has a particle size ranging from 0.2 μm to 0.4 μm.

(E) Then the green blank and the second nickel electrode paste on the two end faces are sintered by a common sintering method, so that the green blank is sintered and formed into the base 1 of the multilayer ceramic capacitor, and the plurality of ceramic ribbons are sintered and formed into the base 1 A plurality of ceramic dielectric bodies 11, and the plurality of nickel electrode paste layers are sintered to form the plurality of internal electrodes 12 of the base 1, and the second nickel electrode paste is sintered to form the first external electrodes 21 of the external electrode layer 2, and the plurality of internal electrodes 12 The end 121 of the inner electrode exposed on the two opposite sides of the base 1 is in electrical contact with the first outer electrode 21.

(F) Then, the metal electrode paste is formed on the opposite outer sides of the two first external electrodes 21, and the first external electrode 21 is solidified and formed into the second external electrode 22.

(G) Electroplating is performed on the outside of the two second external electrodes 22 to form the third external electrode 23 to complete the manufacture of the multilayer ceramic capacitor.

Step (A01) can be performed first before the above step (A):

(A01) Take a predetermined weight of the main component (based on barium titanate, and then add other components (such as: manganese oxide powder, yttrium oxide powder or silica powder, etc.)), solvent (ie ethanol and Toluene) and plasticizer, etc., and processed and mixed through a ball mill to make ceramic slurry.

In addition, the ceramic slurry in the above step (A) can be used to produce a ceramic ribbon with a width of about 150mm and a thickness of about 10μm on a plastic film (such as PET film) through the scraper of the ribbon forming machine. A ceramic ribbon with a width of about 150mm and a thickness of about 6μm is used to make a 3225 size 10μF capacitor.

Furthermore, the first nickel electrode paste in the above step (B) is a nickel electrode paste layer that can be formed on a ceramic thin belt through a screen printing process, and the first nickel electrode paste includes nickel powder and barium titanate. Powder, binder, solvent and other ingredients, and the barium titanate powder has a particle size ranging from 0.05 μm to 0.1 μm, and the volume percentage of nickel powder to barium titanate powder is about 25 vol%.

The ceramic thin strip in the above step (C) can be cut into a size of about 150mm*150mm.

However, the step (D01) can be further executed before the above step (D) is executed:

(D01) Fill the container with the raw embryo and food powder, and rotate the container to grind the corners of the raw embryo.

In the above step (D), the second nickel electrode paste includes nickel powder, barium titanate powder, binder and solvent, etc. The particle size of the barium titanate powder is between 0.05μm and 0.1μm, and the nickel The volume percentage of barium titanate powder to barium titanate powder is 15vol%~50vol%, and the volume percentage of nickel powder to barium titanate powder in the second nickel electrode paste is preferably the same as that in the first nickel electrode paste. The powder volume percentage is the same, so that when the multilayer ceramic capacitor is heated and swelled, the volume change will tend to be the same or similar, so as to avoid damage caused by thermal expansion, and the first nickel electrode paste can be used as the second nickel electrode paste. This reduces material manufacturing time, waste and in stock.

In addition, the thickness of the second nickel electrode paste in the above step (D) is between 5μm~50μm to maintain the stable electrical characteristics of the multilayer ceramic capacitor. When the thickness of the second nickel electrode paste exceeds 50μm, the external electrode layer 2bis. After the first external electrode 21 is sintered and formed, the first external electrode 21 may be peeled off. When the thickness of the second nickel electrode paste is less than 5μm, two first external electrodes 21 and a plurality of Insufficient electrical connection between the internal electrode ends 121 of the internal electrode 12 may result in a lack of stable electrical characteristics for the sintered product.

And after the second nickel electrode paste is formed on the opposite sides of the green embryo in the above step (E), the green embryo and the second nickel electrode paste on the two end faces can be placed in a nitrogen environment and heated to a temperature of about 400°C. The temperature is degreasing treatment, and the hydrogen/water vapor content is controlled so that the green embryo and the second nickel electrode paste are sintered at about 1300°C under a low reducing atmosphere that is one digit lower than the equilibrium oxygen partial pressure of nickel. Sintering operation; however, when the first external electrode 21 of the external electrode layer 2 is sintered on both sides of the base 1 at a temperature of about 1300°C, the texture of the first external electrode 21 will not be fragile or cracked, and after sintering The density of the first external electrodes 21 is excellent, so that the two first external electrodes 21 and the inner electrode ends 121 of the plurality of internal electrodes 12 can be fully connected electrically, thereby improving the stability of electrical conduction and using The co-sintering method can effectively reduce the number of subsequent heating or the structural damage caused by the temperature to the capacitor itself or the inner electrode end 121 of the plurality of internal electrodes 12; in addition, the degreasing conditions can be adjusted according to the types of binders and plasticizers used The conditions are determined. As for the maximum sintering temperature, it can be determined according to the type of ceramic material at which sufficient compactness can be obtained. However, as for the atmosphere, if the sintering operation is performed in an atmosphere in which nickel can be oxidized, the second external electrode layer 2 First outside The partial electrode 21 will be acidified, and therefore, cannot be fully conducted, so care must be taken.

The metal electrode paste in the above step (F) can be directly applied to the two opposite sides of the two first external electrodes 21, or the two first external electrodes 21 can be immersed in the metal electrode paste to make the metal electrode paste It is formed at the opposite outer sides of the two first external electrodes 21, and the metal electrode paste on the two sides can be heated or placed in an environment with a temperature of about 250° C. to solidify the metal electrode paste into the second external electrode 22.

And the metal electrode paste in the above step (F) includes metal powder and resin and other components, and can be dried at about 100℃~150℃/30 minutes in an atmospheric environment, and then heated at 220℃~ The metal electrode paste is solidified and formed at 270°C, thereby solidifying and forming the second external electrode 22, and the temperature at which the metal electrode paste is solidified and formed is preferably between 240°C and 270°C, so that the base 1 and the external electrode layer 2bis. The first external electrode 21 has sufficient fixation, bonding strength and good electrical conduction state; in addition, the metal powder in the metal electrode paste can be silver powder, mixed powder of silver and nickel, copper powder, and silver coated on the surface. Copper powder or other conductive powder, and the resin contains epoxy resin and thermosetting resin (such as: urea formaldehyde or phenolic resin, etc.), and because the second external electrode 22 is cured in the temperature range of about 250 ℃ Therefore, it can be ensured that when the second external electrode 22 is formed, the metal powder will not diffuse or invade into the two first external electrodes 21, the ceramic dielectric body 11 or the internal electrode 12, etc., and will not affect the first external electrode 21, The ceramic dielectric body 11 or the internal electrode 12 has such properties as structural strength or electrical conductivity.

The second external electrode 22 in the above step (G) is a third external electrode 23 that can be formed through nickel and tin electroplating, so that the first external electrode 21 and the second external electrode layer 2 of the external electrode layer 2 are respectively formed on both sides of the base 1 Two external electrodes 22 and a third external electrode 23 to make Multilayer ceramic capacitors can be produced, and the structural strength and reliability of the multilayer ceramic capacitors can be improved. In addition, because the resin material in the second external electrode 22 has the special property of blocking the diffusion of metal elements, it can be used as the second side of the base 1 When the external electrode 22 is electroplated to form the third external electrode 23, the plating solution of the third external electrode 23 will not penetrate into the second external electrode 22, the first external electrode 21, the ceramic dielectric 11 or the internal electrode 12, etc. In order to maintain the existing structural strength of multilayer ceramic capacitors, and thus have good capacitor performance.

In addition, in order to verify the capacitance strength and reliability of the multilayer ceramic capacitor produced by the present invention, the nickel powder and barium titanate powder in the internal electrode 12 of the base 1 and the first external electrode 21 of the external electrode layer 2 of the present invention are selected Three kinds of different particle sizes are matched, and the nickel powder and barium titanate powder in the first external electrode 21 are tested according to different volume percentage ratios. After firing, the difference of the thickness of the first external electrode on the electrostatic capacity and insulation resistance cracking rate is compared. As a result, all the test results are shown in the third and fourth figures.

The first combination: the particle size of the nickel powder in the internal electrode 12 is 0.4μm and the particle size of the barium titanate powder is 0.1μm, and the volume percentage ratio of the barium titanate powder to the nickel powder is 25vol%, and the first external The particle size of the nickel powder in the electrode 21 is 0.4 μm and the particle size of the barium titanate powder is 0.1 μm.

The second combination: the particle size of the nickel powder in the internal electrode 12 is 0.2μm and the particle size of the barium titanate powder is 0.05μm, and the volume percentage ratio of the barium titanate powder to the nickel powder is 25vol%, and the first external The particle size of the nickel powder in the electrode 21 is 0.4 μm and the particle size of the barium titanate powder is 0.1 μm.

The third combination: the particle size of the nickel powder in the internal electrode 12 is 0.2μm and the particle size of the barium titanate powder is 0.05μm, and the volume percentage ratio of the barium titanate powder to the nickel powder is 25 vol%, and the particle size of the nickel powder in the first external electrode 21 is 0.2 μm and the particle size of the barium titanate powder is 0.05 μm.

It can be clearly seen from the above three combinations that the internal electrode 12 uses nickel powder with a particle size of 0.2 to 0.4 μm and barium titanate powder with a particle size of 0.05 to 0.1 μm, and the first external electrode 21 uses a particle size of 0.2 to 0.4 μm. In the case of nickel powder and barium titanate powder with a particle size of 0.05 to 0.1 μm, the average thickness of the first external electrode 21 after sintering is within the range of 5 to 50 μm without peeling, and the electrostatic capacitance can reach more than 10 μF. The composition range of the volume ratio of barium titanate powder to nickel powder in an external electrode 21 is 15 vol% ~ 50 vol%, and the reliability test results for 1000 hours show that none of the 80 test products is defective. Or insulation resistance cracking.

The present invention has the following advantages:

(1) The internal electrode and the first external electrode both contain nickel powder and barium titanate powder with a particle size of 0.2μm~0.4μm, so the internal electrode and the first external electrode have good electrical contact and can be The mutual bonding strength is improved, thereby reducing the occurrence of peeling of the first external electrode from the internal electrode, thereby preventing the intrusion of electroplating solution, so as to achieve the effect of improving product yield and increasing market competitiveness.

(2) The volume percentage of nickel powder to barium titanate powder in the second nickel electrode paste is preferably the same as the volume percentage of nickel powder to barium titanate powder in the first nickel electrode paste, so that the multilayer ceramic capacitor will swell when heated , The volume changes tend to be the same or similar, thereby avoiding structural damage caused by thermal expansion, and the first nickel electrode paste can be used as the second nickel electrode paste, thereby achieving the effect of reducing material manufacturing time, waste and inventory.

(3) The base 1 and the first external electrode 21 of the external electrode layer 2 are transparent The joint sintering method can effectively reduce the number of subsequent heating or the structural damage caused by the temperature to the capacitor itself or the inner electrode end 121 of the plurality of inner electrodes 12, so that the texture of the first outer electrode 21 will not be fragile or generated. Cracks and other conditions can further increase the density, thereby achieving the effect of improving the electrical contact between the two first external electrodes 21 and the plurality of internal electrodes 12.

(4) The metal powder in the metal electrode paste can be silver powder, silver and nickel mixed powder, copper powder, copper powder covered with silver or other conductive powder, and the resin contains epoxy resin and thermosetting Resin, and because the second external electrode 22 is cured and molded in a temperature range of about 250°C, it can be ensured that when the second external electrode 22 is molded, the metal powder will not diffuse or invade the second external electrode 21 and the ceramic dielectric The position of the body 11 or the internal electrode 12 will not affect the structural strength or electrical conductivity of the first external electrode 21, the ceramic dielectric body 11 or the internal electrode 12, etc.

The above are only the preferred embodiments of the present invention, which does not limit the patent scope of the present invention. Therefore, all simple modifications and equivalent structural changes made by using the description and drawings of the present invention should be included in the same reasoning. Within the scope of the patent of the present invention, it should be Chen Ming.

In summary, the multilayer ceramic capacitor and its manufacturing method of the present invention can indeed achieve its effects and purposes during actual application and implementation. Therefore, the present invention is a research and development with excellent practicality and meets the requirements of an invention patent application. , Yan filed an application in accordance with the law, and I hope that the review committee will grant this case as soon as possible to ensure the inventor’s hard research and development and creation. If the review committee of the Bureau has any doubts, please feel free to write instructions, and the inventor will do his best to cooperate and feel good.

Claims (10)

A multilayer ceramic capacitor includes a base and external electrode layers formed on two sides of the base, wherein: The base includes a ceramic dielectric body and a plurality of internal electrodes formed in the ceramic dielectric body and arranged in staggered intervals, and one side of the plurality of internal electrodes is respectively provided with internal electrode ends exposing the ceramic dielectric body, and the internal electrode contains a particle size Nickel powder and barium titanate powder between 0.2μm~0.4μm; The external electrode layer includes a first external electrode sintered and molded on the two sides of the ceramic dielectric body at the base and a second external electrode molded on the outside of the two first external electrodes, wherein the two first external electrodes are the same as the plurality of internal The inner electrode end of the electrode is in electrical contact, and the first outer electrode contains nickel powder and barium titanate powder with a particle size of 0.2μm~0.4μm, and the second outer electrode is made of metal powder and resin. forming. In the multilayer ceramic capacitor described in the first item of the patent application, the two first external electrodes of the base portion and the external electrode layer are sintered by a common sintering method. In the multilayer ceramic capacitor described in the first item of the patent application, the particle size of the barium titanate powder contained in the inner electrode of the base and the first outer electrode of the outer electrode layer is between 0.05 μm and 0.1 μm. In the multilayer ceramic capacitor described in the first item of the patent application, the volume percentage of the barium titanate powder to the nickel powder in the inner electrode of the base part and the first outer electrode of the outer electrode layer are the same. The multilayer ceramic capacitor described in the first item of the scope of patent application, wherein the volume percentage of barium titanate powder to nickel powder in the first external electrode of the external electrode layer is between 15vol%~ 50vol%. The multilayer ceramic capacitor described in the first item of the scope of patent application, wherein the average thickness of the first external electrode is between 5 and 50 μm. The multilayer ceramic capacitor described in claim 1, wherein the metal powder of the second external electrode is silver powder, mixed powder of silver and nickel, copper powder or copper powder covered with silver, and the resin contains epoxy resin And thermosetting resin. A method for manufacturing multilayer ceramic capacitors includes the following steps: (A) First, the ceramic slurry is processed into a ceramic thin strip by a thin strip forming machine; (B) The first nickel electrode paste is processed and formed on the ceramic thin strip, so that a nickel electrode paste layer is formed on the ceramic thin strip, and is allowed to dry, and the first nickel electrode paste contains nickel powder and titanium Barium acid powder, and the nickel powder has a particle size of 0.2μm~0.4μm; (C) Then stack a plurality of ceramic thin strips in a staggered manner, so that the plurality of nickel electrode paste layers are stacked in a staggered pattern, and are laminated and combined under pressure, and then cut, that is, the production of a multilayer ceramic capacitor is formed Embryos, and one side of the plurality of nickel electrode paste layers are respectively exposed on two opposite sides of the green embryo in a staggered manner; (D) The two opposite sides of the green embryo can be immersed in the second nickel electrode paste, and then coated with a predetermined thickness and then dried. The second nickel electrode paste contains nickel powder and barium titanate powder, And the nickel powder has a particle size of 0.2μm~0.4μm; (E) Then the green embryo and the second nickel electrode paste on the two end faces are sintered by a common sintering method, so that the green embryo is sintered and formed into the base of the multilayer ceramic capacitor, and the plural ceramic ribbons are sintered and formed into the plural ceramics of the base Dielectric body, and the plural nickel The electrode paste layer is sintered to form a plurality of internal electrodes of the base, and the second nickel electrode paste is sintered to form the first external electrode of the external electrode layer, and the plurality of internal electrodes are exposed on the opposite sides of the base. The first external electrode forms electrical contact; (F) The resin containing the metal electrode paste is formed on the opposite outer sides of the two first external electrodes, and cured to form the second external electrode. The manufacturing method of the multilayer ceramic capacitor as described in item 8 of the scope of patent application, wherein the volume of the barium titanate powder in the step (B) the first nickel electrode paste and the step (D) the second nickel electrode paste to the nickel powder The percentage is the same and is between 15vol%~50vol%. The manufacturing method of the multilayer ceramic capacitor as described in the scope of patent application, wherein the step (D) the second nickel electrode paste is sintered and formed into the first external electrode of the external electrode layer, and the thickness of the first external electrode is 5μm ~50μm.

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