CN112542325A - Preparation method of high-frequency high-Q capacitor - Google Patents
Preparation method of high-frequency high-Q capacitor Download PDFInfo
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Abstract
The invention discloses a preparation method of a high-frequency high-Q capacitor, which comprises the steps of preparing high-activity composite powder with a shell-core structure in sequence, mixing the high-activity composite powder with an organic solvent, a dispersing agent, a plasticizer, a defoaming agent and a sizing agent to prepare high-rheological characteristic tape-casting slurry, then carrying out tape-casting treatment to prepare a dielectric film, carrying out printing and laminating treatment on the dielectric film to prepare a bar block, carrying out laminating treatment on the bar block to prepare a capacitance green sheet, carrying out high-temperature glue discharging and high-temperature sintering on the capacitance green sheet to prepare a capacitance ceramic sheet, finally carrying out sorting after a reliability test, and packaging qualified products.
Description
Technical Field
The invention relates to a preparation method of a high-frequency high-Q capacitor.
Background
The information technology is leading the revolution of our times at an unprecedented speed, the development of electromagnetic materials and devices in radio frequency, microwave and millimeter wave bands from analog to digital, fixed frequency to frequency conversion and connectors to planar chip is promoted, and new requirements are provided for the use frequency band, the synthesis process and means, the microstructure and force, the heat, the light, the electrical property and the like of electromagnetic functional materials. Components based on these materials must be developed with the goals of small size, thinness, lightness, low power consumption, high reliability and high stability, and novel high-performance core components and manufacturing materials thereof become the main research problems in the field of high-end passive electronic components in the world today. The development of hybrid integration of passive or active devices creates good conditions and rapidly finds wide application in stacked chip passive integrated components, of which multilayer chip capacitors are one.
The development trend of modern electronic equipment is miniaturization, integration and diversification, and the trend has requirements on electronic components such as small volume, low loss and high stability. The multilayer chip ceramic dielectric capacitor has the characteristics of small volume, excellent performance, high stability and the like, and the product conforms to the development trend of electronic equipment, so that most models are made into a home-made state at present. At present, the usage amount of multilayer chip ceramic dielectric capacitors accounts for 60% of the total amount of passive components, and is used in new electronic products (such as radars, cellular base stations, wireless communication, high frequency/microwave, radio frequency power amplifiers, mixers, oscillators, low noise amplifiers, and the like).
The market share of enterprises in China in the field of high-frequency high-Q multilayer chip capacitors is very small, mainly because the product performance cannot reach the level of products of foreign enterprises. The high-frequency and high-Q capacitor produced by enterprises in China has small capacity, is used under the radio frequency condition of 1MHz, has low Q value (generally lower than 1000), and can not meet the use requirement of modern mobile communication equipment.
Disclosure of Invention
In view of the above, the present invention provides a method for manufacturing a high-frequency high-Q capacitor having the characteristics of high Q value, low equivalent series resistance, and high self-resonant frequency, and ensuring extremely low loss transmission of microwave circuit signals.
In order to solve the technical problems, the technical scheme of the invention is as follows:
a preparation method of a high-frequency high-Q capacitor comprises the following steps:
step 1, preparing high-activity composite powder with a shell-core structure, which comprises the following steps:
c. firstly, preparing Ba6-3xNd8+2xTi18O54 powder by a hydrothermal method, placing titanium tetrachloride, barium acetate, neodymium chloride and doping element solution in an autoclave, and carrying out high pressure treatment at 175-275 DEG C
d. Carrying out hydrothermal reaction to obtain high-activity Ba6-3xNd8+2xTi18O54 powder uniformly doped with trace elements for later use;
c. b, increasing ultrasonic oscillation treatment on the powder prepared in the specific step a to reduce the agglomeration effect of the powder and further improve the dispersibility and the activity, then mixing the Ba6-3xNd8+2xTi18O54 powder prepared in the specific step b with a Mg (NO3)2 and TiCl4 solution, placing the mixture in a high-energy ball mill for high-energy ball milling, uniformly coating Mg and Ti elements on the surface of the Ba6-3xNd8+2xTi18O54 powder by high-energy ball milling, and simultaneously improving the dispersibility of the powder;
d. c, drying the powder subjected to ball milling in the step c in a drying furnace, taking out the powder, conveying the powder into a presintering furnace for presintering, systematically adjusting a presintering process, and adjusting the presintering temperature and time to synthesize MgTiO3 on the surface of Ba6-3xNd8+2xTi18O54 so as to finally prepare the high-activity composite powder with a shell-core structure, wherein the shell-core structure comprises Ba6-3xNd8+2xTi18O54 as a core and MgTiO3 as a shell;
step 2, slurry preparation: adding the high-activity composite powder prepared in the step 1, an organic solvent, a dispersing agent, a plasticizer and a defoaming agent into a ball milling tank filled with zirconium balls in proportion, rotating the ball milling tank to drive materials in the tank to move, so that the zirconium balls shear the high-activity composite powder, and grinding and dispersing effects on slurry are achieved; then adding the molding slurry, performing secondary ball milling, adjusting the rheological property of the slurry, and preparing the high-rheological-property casting slurry meeting the production requirement for later use;
step 3, casting treatment: adopting a high-precision casting machine to perform casting treatment on the casting slurry prepared in the step 2, firstly adjusting the distance between a scraper of the casting machine and a substrate to change the thickness of the film, then adjusting the displacement speed of the scraper to control the film forming speed and quality, and finally improving the thick film drying process, adjusting the temperature rise program and the heat preservation time in the drying process, specifically, controlling the belt speed to be 11mm/s, and correspondingly raising the temperature to 5 ℃ every time the drying process enters a temperature zone, namely, the temperature of a first temperature zone is 60 ℃, the temperature of a second temperature zone is 65 ℃, the temperature of a third temperature zone is 70 ℃, the temperature of a fourth temperature zone is 75 ℃, the temperature of a fifth temperature zone is 80 ℃, the temperature of a sixth temperature zone is 85 ℃, meanwhile, the wind speed of a fan corresponding to each temperature zone is 2Hz in the first temperature zone, the wind speed of the second temperature zone is 3Hz, the wind speed of the third temperature zone is 6Hz, and the wind speed of the fourth temperature zone is, the wind speed of the fifth temperature zone is 10Hz, the wind speed of the sixth temperature zone is 12Hz, and the cracking phenomenon of the dielectric film can be prevented by slowly raising the temperature and controlling the size of the air draft;
and 4, printing and laminating treatment, which comprises the following specific steps:
a. printing treatment: printing a layer of clear, uniform-size and uniform-thickness ultrathin conductive inner plasma material on the dielectric film prepared in the step (4) by using a high-precision format flat printing machine to form a printing film; standby;
b. laminating: b, placing the printed film sheets prepared in the step a into a high-precision stacking machine, regularly stacking the printed ceramic films one by one, ensuring that each layer is extremely accurate to the ceramic films, and forming green bodies of the capacitors into bars;
step 5, laminating treatment: putting the barblock prepared in the step 4 into a high-pressure hot press, setting process parameters, specifically, setting a first section pressure of 20MPa, a pressure maintaining time of 5min, a second section pressure of 40MPa, a pressure maintaining time of 10min, a third section pressure of 60MPa, a pressure maintaining time of 20min, a fourth section pressure of 40MPa, a pressure maintaining time of 5min, a fifth section pressure of 20MPa and a pressure maintaining time of 5min, and ensuring the compactness of the barblock under heavy pressure to prepare a capacitance green sheet for later use;
step 6, glue discharging treatment: placing the capacitor green sheet prepared in the step 5 into a glue discharging box with uniform temperature under large air volume, and regularly decomposing and discharging organic matters in the capacitor green sheet under the conditions that the rotating speed of a wind wheel is 800 revolutions per minute and the heating temperature is 200 ℃ to prepare a blank sheet for later use;
and 7, high-temperature sintering: firstly, feeding the blank sheet prepared in the step 6 into a sintering furnace, slowly heating the blank sheet at the temperature of 100-600 ℃ to remove a solvent and an adhesive, preserving heat for 2h at the temperature of 600 ℃ to remove organic matters such as the adhesive, after the organic matters are completely discharged, quickly heating the blank sheet to 980 ℃ and preserving heat for 2h to sinter a sample into porcelain, simultaneously preventing MgTiO3 coated on the surface of Ba6-3xNd8+2xTi18O54 from diffusing into crystal grains, then quickly cooling to a secondary sintering temperature to preserve heat for 10h at the temperature of 200 ℃, wherein in the stage, air holes can shrink until the air holes disappear, and meanwhile, the MgTiO3 coats the Ba6-3xNd8+2xTi18O54 to enable the crystal grains to form a shell-core structure with a core composed of Ba6-3xNd8+2xTi18O54 and a shell composed of MgTiO3, thereby preparing the capacitor;
step 9, reliability test: according to the product quality grade or technical protocol requirements provided by a client, completing a reliability test according to the requirements of a GJB 360A-96 test method of the national military standard, and removing unqualified products;
step 10, braiding: and (4) quickly filling the product qualified by the test in the step (9) or qualified by the reliability test into the paper tape/adhesive tape hole through a high-speed braider, winding the paper tape/adhesive tape into a disc to form a capacitor braid finished product, and attaching a factory inspection report.
Further, the organic solvent described in step 2 is one of ethanol, toluene and xylene, the dispersant is one of phosphate and an ethoxy compound, the plasticizer is dibutyl phthalate, the defoaming agent is silicone emulsion, and the forming slurry is one of PVB, polymethyl acrylate and ethyl cellulose.
Further, the high rheology casting slurry in the step 2 comprises the following materials in percentage by weight: 43% of high-activity composite powder, 38.69% of organic solvent, 0.1% of dispersing agent, 1.9% of plasticizer, 0.09% of defoaming agent and 16.3% of molding slurry.
Further, the high rheology casting slurry in the step 2 comprises the following materials in percentage by weight: 45.2% of high-activity composite powder, 35.5% of organic solvent, 0.1% of dispersing agent, 1.91% of plasticizer, 0.09% of defoaming agent and 17.2% of forming slurry.
Further, the high rheology casting slurry in the step 2 comprises the following materials in percentage by weight: 43.6% of high-activity composite powder, 36.95% of organic solvent, 0.1% of dispersant, 2.09% of plasticizer, 0.06% of defoaming agent and 17.2% of molding slurry.
The technical effects of the invention are mainly reflected in the following aspects: the preparation method comprises the steps of sequentially preparing high-activity composite powder with a shell-core structure, mixing the high-activity composite powder with an organic solvent, a dispersing agent, a plasticizer, a defoaming agent and a sizing agent to prepare high-rheological-property casting slurry, then carrying out casting treatment to prepare a dielectric film, carrying out printing and laminating treatment on the dielectric film to obtain a bar block, carrying out laminating treatment on the bar block to obtain a capacitance green sheet, carrying out high-temperature glue discharging and high-temperature sintering on the capacitance green sheet to obtain a capacitance ceramic sheet, finally covering a nickel layer and a tin layer on the surface, carrying out sorting after a reliability test, and packaging qualified products.
Drawings
FIG. 1 is a flow chart of the process for preparing Ba6-3xNd8+2xTi18O54 powder of the high-frequency high-Q capacitor of the present invention;
FIG. 2 is a schematic diagram illustrating the growth process of ceramic grains in the high-activity composite powder of the high-frequency high-Q capacitor according to the present invention;
FIG. 3 is a schematic view of the microstructure of a specific ceramic grain "shell-core" in the highly active composite powder of the high-frequency high-Q capacitor according to the present invention;
Detailed Description
The following detailed description of the embodiments of the present invention is provided in order to make the technical solution of the present invention easier to understand and understand.
Examples
A preparation method of a high-frequency high-Q capacitor comprises the following steps:
step 1, preparing high-activity composite powder with a shell-core structure, which comprises the following steps:
e. firstly, preparing Ba6-3xNd8+2xTi18O54 powder by a hydrothermal method, placing titanium tetrachloride, barium acetate, neodymium chloride and doping element solution in an autoclave, and carrying out high pressure treatment at 175-275 DEG C
f. Carrying out hydrothermal reaction to obtain high-activity Ba6-3xNd8+2xTi18O54 powder uniformly doped with trace elements for later use;
c. and c, performing additional ultrasonic oscillation treatment on the powder prepared in the specific step a to reduce the agglomeration effect of the powder and further improve the dispersibility and the activity, wherein a flow chart of a preparation process of the Ba6-3xNd8+2xTi18O54 powder is shown in figure 1. Then, mixing the Ba6-3xNd8+2xTi18O54 powder prepared in the step b with Mg (NO3)2 and TiCl4 solution, placing the mixture in a high-energy ball mill for high-energy ball milling, enabling Mg and Ti elements to be uniformly coated on the surface of the Ba6-3xNd8+2xTi18O54 powder through the high-energy ball milling, and improving the dispersibility of the powder;
d. c, drying the powder subjected to ball milling in the specific step c in a drying furnace, taking out the powder, conveying the powder into a presintering furnace for presintering, systematically adjusting a presintering process, and adjusting the presintering temperature and time to synthesize MgTiO3 on the surface of Ba6-3xNd8+2xTi18O54 to finally prepare the high-activity composite powder with a shell-core structure, wherein the shell-core structure is formed by taking Ba6-3xNd8+2xTi18O54 as a core and taking MgTiO3 as an outer shell, the growth process schematic diagram of ceramic crystal grains in the high-activity composite powder is shown in figure 2, and the microstructure schematic diagram of specific ceramic crystal grains in the high-activity composite powder is shown in figure 3; specifically, the shaded portion of the ceramic crystal grain in fig. 2 and 3 is a shell made of MgTiO3, and the structure coated by the shell is a core portion of the ceramic crystal grain made of Ba6-3xNd8+2xTi18O 54.
Step 2, slurry preparation: adding the high-activity composite powder prepared in the step 1, an organic solvent, a dispersing agent, a plasticizer and a defoaming agent into a ball milling tank filled with zirconium balls in proportion, rotating the ball milling tank to drive materials in the tank to move, so that the zirconium balls shear the high-activity composite powder, and grinding and dispersing effects on slurry are achieved; then adding the molding slurry, performing secondary ball milling, adjusting the rheological property of the slurry, and preparing the high-rheological-property casting slurry meeting the production requirement for later use;
step 3, casting treatment: adopting a high-precision casting machine to perform casting treatment on the casting slurry prepared in the step 2, firstly adjusting the distance between a scraper of the casting machine and a substrate to change the thickness of the film, then adjusting the displacement speed of the scraper to control the film forming speed and quality, and finally improving the thick film drying process, adjusting the temperature rise program and the heat preservation time in the drying process, specifically, controlling the belt speed to be 11mm/s, and correspondingly raising the temperature to 5 ℃ every time the drying process enters a temperature zone, namely, the temperature of a first temperature zone is 60 ℃, the temperature of a second temperature zone is 65 ℃, the temperature of a third temperature zone is 70 ℃, the temperature of a fourth temperature zone is 75 ℃, the temperature of a fifth temperature zone is 80 ℃, the temperature of a sixth temperature zone is 85 ℃, meanwhile, the wind speed of a fan corresponding to each temperature zone is 2Hz in the first temperature zone, the wind speed of the second temperature zone is 3Hz, the wind speed of the third temperature zone is 6Hz, and the wind speed of the fourth temperature zone is, the wind speed of the fifth temperature zone is 10Hz, the wind speed of the sixth temperature zone is 12Hz, and the cracking phenomenon of the dielectric film can be prevented by slowly raising the temperature and controlling the size of the air draft;
and 4, printing and laminating treatment, which comprises the following specific steps:
a. printing treatment: printing a layer of clear, uniform-size and uniform-thickness ultrathin conductive inner plasma material on the dielectric film prepared in the step (4) by using a high-precision format flat printing machine to form a printing film; standby;
b. laminating: b, placing the printed film sheets prepared in the step a into a high-precision stacking machine, regularly stacking the printed ceramic films one by one, ensuring that each layer is extremely accurate to the ceramic films, and forming green bodies of the capacitors into bars;
step 5, laminating treatment: putting the barblock prepared in the step 4 into a high-pressure hot press, setting process parameters, specifically, setting a first section pressure of 20MPa, a pressure maintaining time of 5min, a second section pressure of 40MPa, a pressure maintaining time of 10min, a third section pressure of 60MPa, a pressure maintaining time of 20min, a fourth section pressure of 40MPa, a pressure maintaining time of 5min, a fifth section pressure of 20MPa and a pressure maintaining time of 5min, and ensuring the compactness of the barblock under heavy pressure to prepare a capacitance green sheet for later use;
step 6, glue discharging treatment: placing the capacitor green sheet prepared in the step 5 into a glue discharging box with uniform temperature under large air volume, and regularly decomposing and discharging organic matters in the capacitor green sheet under the conditions that the rotating speed of a wind wheel is 800 revolutions per minute and the heating temperature is 200 ℃ to prepare a blank sheet for later use;
and 7, high-temperature sintering: firstly, feeding the blank sheet prepared in the step 6 into a sintering furnace, slowly heating the blank sheet at the temperature of 100-600 ℃ to remove a solvent and an adhesive, preserving heat for 2h at the temperature of 600 ℃ to remove organic matters such as the adhesive, after the organic matters are completely discharged, quickly heating the blank sheet to 980 ℃ and preserving heat for 2h to sinter a sample into porcelain, simultaneously preventing MgTiO3 coated on the surface of Ba6-3xNd8+2xTi18O54 from diffusing into crystal grains, then quickly cooling to a secondary sintering temperature to preserve heat for 10h at the temperature of 200 ℃, wherein in the stage, air holes can shrink until the air holes disappear, and meanwhile, the MgTiO3 coats the Ba6-3xNd8+2xTi18O54 to enable the crystal grains to form a shell-core structure with a core composed of Ba6-3xNd8+2xTi18O54 and a shell composed of MgTiO3, thereby preparing the capacitor;
step 9, reliability test: according to the product quality grade or technical protocol requirements provided by a client, completing a reliability test according to the requirements of a GJB 360A-96 test method of the national military standard, and removing unqualified products;
step 10, braiding: and (4) quickly filling the product qualified by the test in the step (9) or qualified by the reliability test into the paper tape/adhesive tape hole through a high-speed braider, winding the paper tape/adhesive tape into a disc to form a capacitor braid finished product, and attaching a factory inspection report.
In this embodiment, the organic solvent in step 2 is one of ethanol, toluene and xylene, the dispersant is one of phosphate and an ethoxy compound, the plasticizer is dibutyl phthalate, the defoaming agent is silicone emulsion, and the forming slurry is one of PVB, polymethyl acrylate and ethyl cellulose.
In the whole preparation flow, the high-activity composite powder, the organic solvent, the dispersing agent, the plasticizer, the defoaming agent and the forming slurry in the step 2 are provided with the following scheme:
in the first scheme, the high rheological property casting slurry in the step 2 comprises the following materials in percentage by weight: 43% of high-activity composite powder, 38.69% of organic solvent, 0.1% of dispersing agent, 1.9% of plasticizer, 0.09% of defoaming agent and 16.3% of molding slurry.
And the second scheme is that the high rheological property casting slurry in the step 2 comprises the following materials in percentage by weight: 45.2% of high-activity composite powder, 35.5% of organic solvent, 0.1% of dispersing agent, 1.91% of plasticizer, 0.09% of defoaming agent and 17.2% of forming slurry.
And the third scheme is that the high rheological property casting slurry in the step 2 comprises the following materials in percentage by weight: 43.6% of high-activity composite powder, 36.95% of organic solvent, 0.1% of dispersant, 2.09% of plasticizer, 0.06% of defoaming agent and 17.2% of molding slurry.
All three proportioning schemes in this embodiment are the preferred proportioning schemes obtained by long-term experiments of the skilled person.
Product application
Characteristics and execution standard
(1) High capacity stability;
(2) low equivalent series resistance, low equivalent series inductance;
(3) high self-resonance;
(4) low noise;
(5) the reliability is high;
(6) GJB 192B-2011 general Specification for non-encapsulated multilayer chip ceramic dielectric capacitors with failure rate grades; Q/FH 20001A.1-2011 CCK41 type no-encapsulation multilayer chip ceramic capacitor with failure rate grade detailed specification.
Applications of
Typical application functions are: bypass, coupling, tuning, feedback, impedance matching and dc blocking;
typical application circuits: microwave/radio frequency/intermediate frequency amplifier, mixer, oscillator, low noise amplifier, filter network, timing circuit and delay circuit.
③ the main performance indexes are shown in the following table:
the technical effects of the invention are mainly reflected in the following aspects: the preparation method comprises the steps of sequentially preparing high-activity composite powder with a shell-core structure, mixing the high-activity composite powder with an organic solvent, a dispersing agent, a plasticizer, a defoaming agent and a sizing agent to prepare high-rheological-property casting slurry, then carrying out casting treatment to prepare a dielectric film, carrying out printing and laminating treatment on the dielectric film to obtain a bar block, carrying out laminating treatment on the bar block to obtain a capacitance green sheet, carrying out high-temperature glue discharging and high-temperature sintering on the capacitance green sheet to obtain a capacitance ceramic sheet, finally covering a nickel layer and a tin layer on the surface, carrying out sorting after a reliability test, and packaging qualified products.
The above are only typical examples of the present invention, and besides, the present invention may have other embodiments, and all the technical solutions formed by equivalent substitutions or equivalent changes are within the scope of the present invention as claimed.
Claims (5)
1. A preparation method of a high-frequency high-Q capacitor is characterized by comprising the following steps:
step 1, preparing high-activity composite powder with a shell-core structure, which comprises the following steps:
a. firstly, preparing Ba6-3xNd8+2xTi18O54 powder by a hydrothermal method, placing titanium tetrachloride, barium acetate, neodymium chloride and doping element solution in an autoclave, and carrying out high pressure treatment at 175-275 DEG C
b. Carrying out hydrothermal reaction to obtain high-activity Ba6-3xNd8+2xTi18O54 powder uniformly doped with trace elements for later use;
c. b, increasing ultrasonic oscillation treatment on the powder prepared in the specific step a to reduce the agglomeration effect of the powder and further improve the dispersibility and the activity, then mixing the Ba6-3xNd8+2xTi18O54 powder prepared in the specific step b with a Mg (NO3)2 and TiCl4 solution, placing the mixture in a high-energy ball mill for high-energy ball milling, uniformly coating Mg and Ti elements on the surface of the Ba6-3xNd8+2xTi18O54 powder by high-energy ball milling, and simultaneously improving the dispersibility of the powder;
d. c, drying the powder subjected to ball milling in the step c in a drying furnace, taking out the powder, conveying the powder into a presintering furnace for presintering, systematically adjusting a presintering process, and adjusting the presintering temperature and time to synthesize MgTiO3 on the surface of Ba6-3xNd8+2xTi18O54 so as to finally prepare the high-activity composite powder with a shell-core structure, wherein the shell-core structure comprises Ba6-3xNd8+2xTi18O54 as a core and MgTiO3 as a shell;
step 2, slurry preparation: adding the high-activity composite powder prepared in the step 1, an organic solvent, a dispersing agent, a plasticizer and a defoaming agent into a ball milling tank filled with zirconium balls in proportion, rotating the ball milling tank to drive materials in the tank to move, so that the zirconium balls shear the high-activity composite powder, and grinding and dispersing effects on slurry are achieved; then adding the molding slurry, performing secondary ball milling, adjusting the rheological property of the slurry, and preparing the high-rheological-property casting slurry meeting the production requirement for later use;
step 3, casting treatment: adopting a high-precision casting machine to perform casting treatment on the casting slurry prepared in the step 2, firstly adjusting the distance between a scraper of the casting machine and a substrate to change the thickness of the film, then adjusting the displacement speed of the scraper to control the film forming speed and quality, and finally improving the thick film drying process, adjusting the temperature rise program and the heat preservation time in the drying process, specifically, controlling the belt speed to be 11mm/s, and correspondingly raising the temperature to 5 ℃ every time the drying process enters a temperature zone, namely, the temperature of a first temperature zone is 60 ℃, the temperature of a second temperature zone is 65 ℃, the temperature of a third temperature zone is 70 ℃, the temperature of a fourth temperature zone is 75 ℃, the temperature of a fifth temperature zone is 80 ℃, the temperature of a sixth temperature zone is 85 ℃, meanwhile, the wind speed of a fan corresponding to each temperature zone is 2Hz in the first temperature zone, the wind speed of the second temperature zone is 3Hz, the wind speed of the third temperature zone is 6Hz, and the wind speed of the fourth temperature zone is, the wind speed of the fifth temperature zone is 10Hz, the wind speed of the sixth temperature zone is 12Hz, and the cracking phenomenon of the dielectric film can be prevented by slowly raising the temperature and controlling the size of the air draft;
and 4, printing and laminating treatment, which comprises the following specific steps:
a. printing treatment: printing a layer of clear, uniform-size and uniform-thickness ultrathin conductive inner plasma material on the dielectric film prepared in the step (4) by using a high-precision format flat printing machine to form a printing film; standby;
b. laminating: b, placing the printed film sheets prepared in the step a into a high-precision stacking machine, regularly stacking the printed ceramic films one by one, ensuring that each layer is extremely accurate to the ceramic films, and forming green bodies of the capacitors into bars;
step 5, laminating treatment: putting the barblock prepared in the step 4 into a high-pressure hot press, setting process parameters, specifically, setting a first section pressure of 20MPa, a pressure maintaining time of 5min, a second section pressure of 40MPa, a pressure maintaining time of 10min, a third section pressure of 60MPa, a pressure maintaining time of 20min, a fourth section pressure of 40MPa, a pressure maintaining time of 5min, a fifth section pressure of 20MPa and a pressure maintaining time of 5min, and ensuring the compactness of the barblock under heavy pressure to prepare a capacitance green sheet for later use;
step 6, glue discharging treatment: placing the capacitor green sheet prepared in the step 5 into a glue discharging box with uniform temperature under large air volume, and regularly decomposing and discharging organic matters in the capacitor green sheet under the conditions that the rotating speed of a wind wheel is 800 revolutions per minute and the heating temperature is 200 ℃ to prepare a blank sheet for later use;
and 7, high-temperature sintering: firstly, feeding the blank sheet prepared in the step 6 into a sintering furnace, slowly heating the blank sheet at the temperature of 100-600 ℃ to remove a solvent and an adhesive, preserving heat for 2h at the temperature of 600 ℃ to remove organic matters such as the adhesive, after the organic matters are completely discharged, quickly heating the blank sheet to 980 ℃ and preserving heat for 2h to sinter a sample into porcelain, simultaneously preventing MgTiO3 coated on the surface of Ba6-3xNd8+2xTi18O54 from diffusing into crystal grains, then quickly cooling to a secondary sintering temperature to preserve heat for 10h at the temperature of 200 ℃, wherein in the stage, air holes can shrink until the air holes disappear, and meanwhile, the MgTiO3 coats the Ba6-3xNd8+2xTi18O54 to enable the crystal grains to form a shell-core structure with a core composed of Ba6-3xNd8+2xTi18O54 and a shell composed of MgTiO3, thereby preparing the capacitor;
step 8, surface treatment: covering a uniform nickel layer and a uniform tin layer on the outer electrode of the capacitor ceramic chip sintered in the step 7 in sequence, wherein the thickness of the nickel layer is generally 2-4um and is used as a thermal barrier layer to ensure the thermal shock resistance of the product, and the thickness of the tin layer is generally 4-7um and has good weldability to ensure that the product is in good contact with an external circuit;
step 9, reliability test: according to the product quality grade or technical protocol requirements provided by a client, completing a reliability test according to the requirements of a GJB 360A-96 test method of the national military standard, and removing unqualified products;
step 10, braiding: and (4) quickly filling the product qualified by the test in the step (9) or qualified by the reliability test into the paper tape/adhesive tape hole through a high-speed braider, winding the paper tape/adhesive tape into a disc to form a capacitor braid finished product, and attaching a factory inspection report.
2. The method for producing a high-frequency high-Q capacitor as claimed in claim 1, wherein: the organic solvent recorded in the step 2 is one of ethanol, toluene and xylene, the dispersant is one of phosphate and an ethoxy compound, the plasticizer is dibutyl phthalate, the defoaming agent is emulsified silicone oil, and the molding slurry is one of PVB, polymethyl acrylate and ethyl cellulose.
3. The method for producing a high-frequency high-Q capacitor as claimed in claim 1, wherein: the high rheological property casting slurry in the step 2 comprises the following materials in percentage by weight: 43% of high-activity composite powder, 38.69% of organic solvent, 0.1% of dispersing agent, 1.9% of plasticizer, 0.09% of defoaming agent and 16.3% of molding slurry.
4. The method for producing a high-frequency high-Q capacitor as claimed in claim 1, wherein: the high rheological property casting slurry in the step 2 comprises the following materials in percentage by weight: 45.2% of high-activity composite powder, 35.5% of organic solvent, 0.1% of dispersing agent, 1.91% of plasticizer, 0.09% of defoaming agent and 17.2% of forming slurry.
5. The method for producing a high-frequency high-Q capacitor as claimed in claim 1, wherein: the high rheological property casting slurry in the step 2 comprises the following materials in percentage by weight: 43.6% of high-activity composite powder, 36.95% of organic solvent, 0.1% of dispersant, 2.09% of plasticizer, 0.06% of defoaming agent and 17.2% of molding slurry.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113943155A (en) * | 2021-11-18 | 2022-01-18 | 广东风华邦科电子有限公司 | Preparation method of wide-temperature high-capacity chip ceramic dielectric capacitor |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05347228A (en) * | 1992-06-15 | 1993-12-27 | Tdk Corp | Manufacture of laminated ceramic electronic component |
| US20040112504A1 (en) * | 2001-03-20 | 2004-06-17 | Andreas Roosen | Method for joining ceramic green bodies using a transfer tape and conversion of bonded green body into a ceramic body |
| CN211373147U (en) * | 2019-12-20 | 2020-08-28 | 南充三环电子有限公司 | Curtain coating drying equipment |
-
2020
- 2020-12-08 CN CN202011426007.1A patent/CN112542325A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05347228A (en) * | 1992-06-15 | 1993-12-27 | Tdk Corp | Manufacture of laminated ceramic electronic component |
| US20040112504A1 (en) * | 2001-03-20 | 2004-06-17 | Andreas Roosen | Method for joining ceramic green bodies using a transfer tape and conversion of bonded green body into a ceramic body |
| CN211373147U (en) * | 2019-12-20 | 2020-08-28 | 南充三环电子有限公司 | Curtain coating drying equipment |
Non-Patent Citations (2)
| Title |
|---|
| 薛赵茹等: "小尺寸高容量MLCC切割侧裂问题的解决方法", 《电子工艺技术》 * |
| 高泮嵩: "军用高频高Q电容器设计及工艺", 《现代信息科技》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113943155A (en) * | 2021-11-18 | 2022-01-18 | 广东风华邦科电子有限公司 | Preparation method of wide-temperature high-capacity chip ceramic dielectric capacitor |
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