CN115625341A - Gold powder for LTCC (Low temperature Co-fired ceramic), preparation method and gold conductor slurry - Google Patents
Gold powder for LTCC (Low temperature Co-fired ceramic), preparation method and gold conductor slurry Download PDFInfo
- Publication number
- CN115625341A CN115625341A CN202211288238.XA CN202211288238A CN115625341A CN 115625341 A CN115625341 A CN 115625341A CN 202211288238 A CN202211288238 A CN 202211288238A CN 115625341 A CN115625341 A CN 115625341A
- Authority
- CN
- China
- Prior art keywords
- gold
- gold powder
- preparation
- acid solution
- solution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/16—Making metallic powder or suspensions thereof using chemical processes
- B22F9/18—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
- B22F9/24—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
- B22F1/107—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material containing organic material comprising solvents, e.g. for slip casting
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/20—Conductive material dispersed in non-conductive organic material
- H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
The invention relates to the technical field of materials, in particular to gold powder for LTCC (Low temperature Co-fired ceramic), a preparation method and gold conductor slurry, wherein the preparation method comprises the following steps: reducing chloroauric acid under the conditions of mechanical stirring and ultrasonic vibration by using D-isoascorbic acid as a reducing agent in a water bath environment to obtain a reaction solution; centrifuging the obtained reaction solution and taking a precipitate; and washing and drying the precipitate to obtain gold powder. The gold powder prepared by the preparation method has good dispersibility, high purity and narrow particle size distribution, and the gold conductor paste prepared by using the gold conductor paste as a raw material has compact structure, no air bubbles and no cracking of a substrate after being co-fired with the LTCC green tape, thereby greatly solving the problem of unmatched sintering of the gold conductor paste and the green tape and improving the stability of the product.
Description
Technical Field
The invention relates to the technical field of materials, in particular to gold powder for LTCC (low temperature co-fired ceramic), a preparation method and gold conductor slurry.
Background
Low temperature co-fired ceramic (LTCC) is one of the mainstream technologies of multilayer packaging and passive element packaging at present, conductor paste is printed on an interconnected multilayer green tape according to a required pattern, and then the multilayer green tape is laminated and sintered to form an interconnection structure. Meanwhile, the green ceramic tape and the noble metal conductor slurry can be co-fired at a lower sintering temperature, so that the process flow is simplified, and the stability of the product is ensured. At present, LTCC is widely applied in the fields of military, aerospace and the like due to excellent performance.
The LTCC mainly comprises a substrate material and conductor paste. In order to ensure the electrical property of the conductor paste, noble metals such as Au, ag and the like with good stability and low resistivity become the first choice, wherein the adaptability of Au is far better than that of silver. The gold conductor slurry is required to be compact and flat after sintering, and good co-firing matching with the substrate is ensured to prevent the substrate from cracking. The method has high requirements on the particle size uniformity, morphology, purity and the like of the gold powder used by the gold conductor slurry.
The wide particle size distribution of the gold powder easily causes the slurry to foam and expose porcelain after sintering, meanwhile, in order to ensure that the gold powder is fully dispersed and does not agglomerate in the preparation process, a large amount of dispersing agents are added into the reaction liquid, and the dispersing agents can be coated in gold powder particles in the nucleation process of the gold powder, so that cavities are left on the surface of the gold conductor slurry after sintering, and the compactness of the slurry is influenced. This nondeterministic encapsulation has a dramatic impact on LTCC device performance and batch stability.
Disclosure of Invention
The invention provides gold powder for LTCC (low temperature co-fired ceramic), a preparation method and gold conductor slurry, which are used for solving the problems that the existing gold powder for LTCC is easy to cause foaming, poor compactness, large sheet resistance and the like after sintering of the gold conductor slurry.
The invention provides a preparation method of gold powder for LTCC (low temperature co-fired ceramic), which comprises the following steps:
in a water bath environment, reducing chloroauric acid by using D-isoascorbic acid as a reducing agent under the conditions of mechanical stirring and ultrasonic vibration to obtain a reaction solution;
centrifuging the obtained reaction solution and taking a precipitate; and washing and drying the precipitate to obtain the gold powder.
In the scheme, the gold powder for the LTCC is prepared by adopting D-isoascorbic acid as a reducing agent and reacting with chloroauric acid under the conditions of mechanical stirring and ultrasonic vibration. The D-isoascorbic acid has weaker reducibility, can slow down the reaction speed and can ensure the uniformity of gold powder particles. The reaction is carried out under the conditions of mechanical stirring and ultrasonic vibration, so that reactants can be fully contacted and reacted, the reaction efficiency is improved, and the prepared gold powder meets the requirements of gold conductor slurry which is free from bubbling, good in compactness and small in sheet resistance after sintering. And the reaction is carried out in a water bath heating environment, so that the residue of organic matters in the gold powder can be greatly reduced, and the purity of the gold powder is improved. The gold powder prepared by the preparation method has good dispersibility, high purity and narrow particle size distribution, and the gold conductor slurry prepared by taking the gold conductor slurry as a raw material has compact structure, no air bubbles and no cracking of a substrate after being co-fired with the LTCC green tape, thereby greatly solving the problem that the gold conductor slurry is not matched with the green tape in sintering and improving the stability of the product.
The preparation method provided by the invention specifically comprises the following steps:
step S1: weighing a certain amount of D-isoascorbic acid, dissolving the D-isoascorbic acid by using a first solvent, and adding a certain amount of dispersant to obtain a D-isoascorbic acid solution; weighing a certain amount of chloroauric acid tetrahydrate, dissolving the chloroauric acid tetrahydrate in water, adding a certain amount of dispersant, and adjusting the pH value to 5-7 by using a pH regulator to obtain a chloroauric acid solution;
step S2: adding the obtained chloroauric acid solution into the D-isoascorbic acid solution, adjusting the temperature of a water bath to 20-30 ℃, and reacting for 40-80 min under the condition of mechanical stirring and ultrasonic vibration; after the reaction is finished, raising the temperature of the water bath to 60-80 ℃, and continuously reacting for 40-80 min under the condition of mechanical stirring to obtain the reaction solution;
and step S3: pouring the reaction solution into a centrifuge tube, placing the centrifuge tube in a centrifuge for centrifugation, and taking a precipitate; and fully washing the precipitate with deionized water, and then drying at the temperature of 60-80 ℃ to obtain the gold powder.
In the scheme, in the step S1, the D-isoascorbic acid solution is obtained by dissolving D-isoascorbic acid with a first solvent and adding a certain amount of dispersant, the chloroauric acid solution is obtained by dissolving chloroauric acid tetrahydrate with water and adding a certain amount of dispersant, and the pH value is adjusted to be 5-7 by adopting a pH regulator. The pH value of the chloroauric acid solution is 5-7, so that the reaction speed can be further slowed down, and the uniformity of gold powder particles can be further ensured. In the step S2, adding the obtained chloroauric acid solution into a D-isoascorbic acid solution, adjusting the temperature of a water bath to 20-30 ℃, and reacting for 40-80 min under the condition of mechanical stirring and ultrasonic vibration; after the reaction is finished, the temperature of the water bath is raised to 60-80 ℃, the reaction is continued for 40-80 min under the condition of mechanical stirring, reactants can be more fully contacted and reacted through controlling the reaction temperature, the reaction time and the stirring condition, the reaction efficiency is improved, meanwhile, the agglomeration of gold powder particles is reduced, the purity of the gold powder is improved, and the prepared gold powder can better meet the requirements of the gold conductor slurry which is free from foaming, good in compactness and small in sheet resistance after sintering. In step S3, the reaction solution is poured into a centrifuge tube, and after standing and settling, a precipitate is taken out, and the precipitate is sufficiently washed with deionized water to reduce the residue of impurities in the gold powder and improve the purity of the gold powder.
According to the preparation method provided by the invention, in the step S1, the concentration of the D-isoascorbic acid solution is 0.2-0.4 mol/L.
Alternatively, the concentration of the D-isoascorbic acid solution can be 0.2mol/L, 0.22mol/L, 0.25mol/L, 0.28mol/L, 0.30mol/L, 0.32mol/L, 0.35mol/L, 0.38mol/L, 0.4mol/L, or the like.
In the scheme, the concentration of the D-isoascorbic acid solution is limited within a reasonable range, so that the reduction reaction is facilitated, and the reaction efficiency is improved.
According to the preparation method provided by the invention, in the step S1, the first solvent is one or more of deionized water, ethylene glycol butyl ether, ethylene glycol methyl ether, diethylene glycol butyl ether and ethanol; preferably, the first solvent is one or more of deionized water, ethylene glycol methyl ether and diethylene glycol butyl ether.
In the scheme, the proper first solvent is selected, so that the D-erythorbic acid is dissolved favorably, and the reduction reaction is not influenced. The prepared gold powder can meet the requirements of the gold conductor slurry which is free from foaming, good in compactness and small in sheet resistance after sintering.
According to the preparation method provided by the invention, in the step S1, the mass fraction of the first solvent is 30wt% -50 wt%.
Alternatively, the mass fraction of the first solvent may be 30wt%, 32wt%, 35wt%, 38wt%, 40wt%, 42wt%, 45wt%, 48wt%, 50wt%, or the like.
In the scheme, the mass fraction of the first solvent is limited in a reasonable range, so that the dissolution of the D-erythorbic acid is facilitated, the reduction reaction is facilitated, and the reaction efficiency is improved.
According to the preparation method provided by the invention, in the step S1, the concentration of gold element in the chloroauric acid solution is 0.3-0.7 mol/L.
Alternatively, the gold element concentration in the chloroauric acid solution can be 0.3mol/L, 0.35mol/L, 0.4mol/L, 0.45mol/L, 0.5mol/L, 0.55mol/L, 0.6mol/L, 0.65mol/L, 0.7mol/L and the like.
In the scheme, the concentration of gold element in the chloroauric acid solution is limited in a reasonable range, so that the reduction reaction is facilitated, and the reaction efficiency is improved.
According to the preparation method provided by the invention, in the step S1, the molar ratio of the gold element in the chloroauric acid solution to the D-erythorbic acid is 1.7-1.
Alternatively, the molar ratio of gold element in the chloroauric acid solution to the D-erythorbic acid may be 1.7, 1.75, 1.8, 1.85, 1.9, 1.95 or 1.
In the scheme, the molar ratio of gold element to D-erythorbic acid in the chloroauric acid solution is limited within a reasonable range, so that the reduction reaction is facilitated, and the reaction efficiency is improved.
According to the preparation method provided by the invention, in the step S1, the dispersing agent is one or more of gum arabic, polyvinylpyrrolidone and polyvinyl alcohol.
In the scheme, the proper type of the dispersing agent is selected, so that the dispersibility of the gold powder is favorably provided, the agglomeration of gold powder particles can be effectively prevented, the control of the particle size of the gold powder is realized, and the gold powder has better compatibility in a resin system. The co-use of a plurality of dispersants can also improve the surface topography of the gold powder so that the gold powder has better fluidity after being prepared into gold conductor slurry.
According to the preparation method provided by the invention, in the step S1, the pH regulator comprises a strong base solution and/or a strong acid solution; preferably, the strong alkali solution is a 1mol/L NaOH solution, and the strong acid solution is 12mol/L concentrated hydrochloric acid.
In the scheme, the purpose of effectively adjusting the pH value of the chloroauric acid solution can be achieved by selecting the proper type of pH regulator.
According to the preparation method provided by the invention, in the step S2, the frequency of the ultrasonic vibration is 40 KHz-60 KHz.
Alternatively, the frequency of the ultrasonic vibration may be 40KHz, 42KHz, 45KHz, 48KHz, 50KHz, 52KHz, 55KHz, 58KHz, 60KHz, or the like.
In the scheme, the frequency of ultrasonic vibration is controlled within a reasonable range value, so that the reaction efficiency can be effectively improved, and the prepared gold powder meets the requirements of the gold conductor slurry which is not foamed after sintering, has good compactness and small sheet resistance.
According to the preparation method provided by the invention, in the step S3, the water consumption in the process of fully washing with deionized water is 60-80 times of the mass of the gold powder; and/or ultrasonic-assisted washing treatment is carried out in the process of fully washing with the deionized water. Preferably, the time of the ultrasonic-assisted washing treatment is 8min to 15min. More preferably, the time of the ultrasonic-assisted washing treatment is 10min.
Optionally, the amount of water used in the fully washing process with the deionized water can be 60 times, 65 times, 70 times, 75 times or 80 times of the mass of the gold powder.
In the scheme, the purpose of fully washing the precipitate can be achieved by limiting the water consumption in the process of fully washing with deionized water, so that the prepared gold powder has high purity. In order to accelerate the dissolution of the residual impurities on the gold powder into water and achieve better washing effect, ultrasonic wave is used for assisting washing treatment in the process of fully washing with deionized water.
According to the preparation method provided by the invention, the gold powder is spherical gold powder, the particle size is distributed between 0.8 mu m and 3 mu m, and the specific surface area is 0.3m 2 /g-0.5m 2 /g。
When the gold powder prepared by the preparation method is applied to the gold conductor slurry, the gold conductor slurry can be enabled not to foam after being sintered, and has good compactness and small sheet resistance.
The invention also provides the gold powder for the LTCC, which is prepared by the preparation method.
The invention also provides gold conductor slurry which comprises the following components in parts by weight: the gold powder prepared by the preparation method or 80-90 parts of the gold powder, 10-15 parts of organic carrier and 2-5 parts of glass powder.
In the scheme, the gold conductor paste is prepared by reasonably configuring the gold powder, the organic carrier and the glass powder, and after the gold conductor paste and the LTCC green tape are co-fired, the structure is compact, no bubble exists, the substrate is not cracked, the problem that the gold conductor paste and the green tape are not matched in sintering is solved to a great extent, and the stability of the product is improved.
According to the gold conductor paste, the organic carrier is composed of a second solvent, a tackifier and a surfactant; the second solvent accounts for 75-90% of the total weight of the organic carrier, the tackifier accounts for 10-25% of the total weight of the organic carrier, and the surfactant accounts for 1-2% of the total weight of the second solvent and the tackifier;
and/or the second solvent is one or more of terpineol, alcohol ester-12, ethylene glycol butyl ether acetate and triethylene glycol monobutyl ether; the tackifier is ethyl cellulose; the surfactant is one or more of behenate sorbitol ester, sodium dodecyl sulfate and triethanolamine.
In the scheme, the rheological property, the printing property, the adhesion strength with the base material and the like of the gold conductor paste can be improved by limiting the composition, the types and the dosage of the organic carrier in the gold conductor paste, and the improvement of the overall performance of the gold conductor paste is facilitated.
According to the gold conductor paste, the glass powder is calcium boron lanthanum glass powder;
and/or the particle size of the glass powder is 2-4 μm.
In the scheme, the preparation method of the glass powder in the gold conductor paste and the limitation of the particle size can effectively reduce the sintering temperature of the gold conductor paste and improve the adhesion of the gold conductor paste and the substrate.
The gold powder for LTCC provided by the invention is prepared by reacting D-isoascorbic acid serving as a reducing agent with chloroauric acid under the conditions of mechanical stirring and ultrasonic vibration. The D-isoascorbic acid has weaker reducibility, can slow down the reaction speed and can ensure the uniformity of gold powder particles. The reaction is carried out under the conditions of mechanical stirring and ultrasonic vibration, so that reactants can be fully contacted and reacted, the reaction efficiency is improved, and the prepared gold powder meets the requirements of the gold conductor slurry which is not foamed after sintering, has good compactness and small sheet resistance. And the reaction is carried out in a water bath heating environment, so that the residue of organic matters in the gold powder can be greatly reduced, and the purity of the gold powder is improved. The gold powder prepared by the preparation method has good dispersibility, high purity and narrow particle size distribution, and the gold conductor slurry prepared by taking the gold conductor slurry as a raw material has compact structure, no air bubbles and no cracking of a substrate after being co-fired with the LTCC green tape, thereby greatly solving the problem that the gold conductor slurry is not matched with the green tape in sintering and improving the stability of the product.
Drawings
In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
FIG. 1 is a scanning electron micrograph of gold powder obtained in example 2 of the present invention;
FIG. 2 is a scanning electron micrograph of gold powder obtained in example 3 of the present invention;
FIG. 3 is a microscope photograph of a gold conductive paste printed substrate prepared from the gold powder of example 1 of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
A preparation method of gold powder for LTCC uses D-isoascorbic acid as a reducing agent, gum arabic and PVP as dispersing agents, the pH value of a chloroauric acid solution is adjusted to be 5, and 60KHz ultrasonic vibration is assisted in a step S2, and the preparation method specifically comprises the following steps:
step S1: 28.83g of chloroauric acid tetrahydrate, 0.41g of gum arabic and 0.18g of PVP are weighed and placed in a 150mL beaker, deionized water is added for stirring and dissolution, the pH value is adjusted to 5 by using 1mol/L NaOH solution and 12mol/L concentrated hydrochloric acid, and finally, a chloroauric acid solution with the concentration of 0.7mol/L is prepared.
21.14g of D-isoascorbic acid, 2.23g of gum arabic and 0.90g of PVP are weighed and placed in a 500mL beaker, deionized water is added, and the mixture is stirred and dissolved to prepare a D-isoascorbic acid solution with the concentration of 0.4mol/L.
Step S2: pouring the prepared chloroauric acid solution into a D-isoascorbic acid solution, adjusting the temperature of a water bath to 25 ℃, and reacting for 1h under the condition of mechanical stirring and 60KHz ultrasonic vibration; after the reaction is finished, raising the temperature of the water bath to 80 ℃, and continuously reacting for 1 hour under the condition of mechanical stirring to obtain reaction liquid.
And step S3: pouring the reaction solution into a centrifuge tube, placing the centrifuge tube in a centrifuge for centrifugation, and taking a precipitate; and repeatedly washing the precipitate with deionized water 60 times the mass of the gold powder, treating for 10min with ultrasonic vibration, then centrifugally separating, and drying in a blast oven at 70 ℃ to obtain A1 gold powder.
Example 2
A preparation method of gold powder for LTCC uses D-isoascorbic acid as a reducing agent, gum arabic as a dispersing agent, the pH value of a chloroauric acid solution is adjusted to be 5, and 60KHz ultrasonic vibration is assisted in step S2, and the preparation method specifically comprises the following steps:
step S1: 28.83g of chloroauric acid tetrahydrate and 0.59g of gum arabic are weighed and placed in a 150mL beaker, deionized water is added for stirring and dissolution, the pH value is adjusted to 5 by using 1mol/L NaOH solution and 12mol/L concentrated hydrochloric acid, and a chloroauric acid solution with the concentration of 0.7mol/L is finally prepared.
21.14g of D-erythorbic acid and 3.13g of gum arabic are weighed and placed in a 500mL beaker, deionized water is added, and the mixture is stirred and dissolved to prepare a D-erythorbic acid solution with the D-erythorbic acid concentration of 0.4mol/L.
Step S2: pouring the prepared chloroauric acid solution into a D-isoascorbic acid solution, adjusting the temperature of a water bath to 25 ℃, and reacting for 1h under the condition of mechanical stirring and 60KHz ultrasonic vibration; after the reaction is finished, the temperature of the water bath is raised to 80 ℃, and the reaction is continued for 1h under the condition of mechanical stirring, so as to obtain reaction liquid.
And step S3: pouring the reaction solution into a centrifuge tube, placing the centrifuge tube in a centrifuge for centrifugation, and taking a precipitate; and (2) repeatedly cleaning the precipitate with deionized water with the mass 60 times that of the gold powder, treating for 10min with ultrasonic vibration, then centrifugally separating, and drying in a blast oven at 70 ℃ to obtain A2 gold powder, wherein a scanning electron microscope image of the A2 gold powder is shown in figure 1, and the obtained gold powder has uniform particle size distribution as can be seen from figure 1.
Example 3
A preparation method of gold powder for LTCC uses D-erythorbic acid as a reducing agent, gum arabic as a dispersing agent, a first solvent selects a 30wt% diethylene glycol monobutyl ether solution, the pH value of a chloroauric acid solution is adjusted to be 5, and 60KHz ultrasonic vibration is assisted in step S2, and the preparation method specifically comprises the following steps:
step S1: 28.83g of chloroauric acid tetrahydrate and 0.59g of gum arabic are weighed and placed in a 150mL beaker, deionized water is added for stirring and dissolution, the pH value is adjusted to 5 by using 1mol/L NaOH solution and 12mol/L concentrated hydrochloric acid, and a chloroauric acid solution with the concentration of 0.7mol/L is finally prepared.
21.14g of D-erythorbic acid and 3.13g of gum arabic are weighed and placed in a 500mL beaker, and a 30wt% diethylene glycol butyl ether solution is added, stirred and dissolved to prepare a D-erythorbic acid solution with a D-erythorbic acid concentration of 0.4mol/L.
Step S2: pouring the prepared chloroauric acid solution into a D-isoascorbic acid solution, adjusting the temperature of a water bath to 25 ℃, and reacting for 1h under the condition of mechanical stirring and 60KHz ultrasonic vibration; after the reaction is finished, the temperature of the water bath is raised to 80 ℃, and the reaction is continued for 1h under the condition of mechanical stirring, so as to obtain reaction liquid.
And step S3: pouring the reaction solution into a centrifuge tube, placing the centrifuge tube in a centrifuge for centrifugation, and taking a precipitate; and (3) repeatedly cleaning the precipitate with deionized water with the mass of 60 times that of the gold powder, treating for 10min with ultrasonic vibration, then centrifugally separating, and drying in a blast oven at 70 ℃ to obtain A3 gold powder, wherein a scanning electron microscope image of the A3 gold powder is shown in figure 2, and the obtained gold powder has uniform particle size distribution as can be seen from figure 2.
Example 4
A preparation method of gold powder for LTCC uses D-erythorbic acid as a reducing agent, gum arabic as a dispersing agent, a first solvent selects a 30wt% diethylene glycol monobutyl ether solution, the pH value of a chloroauric acid solution is adjusted to 7, and 60KHz ultrasonic vibration is assisted in step S2, and the preparation method specifically comprises the following steps:
step S1: 28.83g of chloroauric acid tetrahydrate and 0.59g of gum arabic are weighed and placed in a 150mL beaker, deionized water is added for stirring and dissolution, the pH value is adjusted to 7 by using 1mol/L NaOH solution and 12mol/L concentrated hydrochloric acid, and a chloroauric acid solution with the concentration of 0.7mol/L is prepared finally.
21.14g of D-erythorbic acid and 3.13g of gum arabic are weighed and placed in a 500mL beaker, and a 30wt% diethylene glycol butyl ether solution is added, stirred and dissolved to prepare a D-erythorbic acid solution with a D-erythorbic acid concentration of 0.4mol/L.
Step S2: pouring the prepared chloroauric acid solution into a D-isoascorbic acid solution, adjusting the temperature of a water bath to 25 ℃, and reacting for 1h under the condition of mechanical stirring and 60KHz ultrasonic vibration; after the reaction is finished, raising the temperature of the water bath to 80 ℃, and continuously reacting for 1 hour under the condition of mechanical stirring to obtain reaction liquid.
And step S3: pouring the reaction solution into a centrifuge tube, placing the centrifuge tube in a centrifuge for centrifugation, and taking a precipitate; and repeatedly washing the precipitate with deionized water with the mass of 60 times that of the gold powder, treating for 10min with ultrasonic vibration, then centrifugally separating, and drying in a blast oven at 70 ℃ to obtain A4 gold powder.
Example 5
A preparation method of gold powder for LTCC uses D-erythorbic acid as a reducing agent, gum arabic as a dispersing agent, a first solvent selects a 30wt% diethylene glycol monobutyl ether solution, the pH value of a chloroauric acid solution is adjusted to be 5, and 40KHz ultrasonic vibration is assisted in step S2, and the preparation method specifically comprises the following steps:
step S1: 28.83g of chloroauric acid tetrahydrate and 0.59g of gum arabic are weighed and placed in a 150mL beaker, deionized water is added for stirring and dissolution, the pH value is adjusted to 5 by using 1mol/L NaOH solution and 12mol/L concentrated hydrochloric acid, and a chloroauric acid solution with the concentration of 0.7mol/L is prepared finally.
21.14g of D-erythorbic acid and 3.13g of gum arabic are weighed and placed in a 500mL beaker, and a 30wt% diethylene glycol butyl ether solution is added and stirred to dissolve the mixture to prepare a D-erythorbic acid solution with a D-erythorbic acid concentration of 0.4mol/L.
Step S2: pouring the prepared chloroauric acid solution into a D-isoascorbic acid solution, adjusting the temperature of a water bath to 25 ℃, and reacting for 1h under the condition of mechanical stirring and 40KHz ultrasonic vibration; after the reaction is finished, raising the temperature of the water bath to 80 ℃, and continuously reacting for 1 hour under the condition of mechanical stirring to obtain reaction liquid.
And step S3: pouring the reaction solution into a centrifuge tube, placing the centrifuge tube in the centrifuge tube for centrifugation, and taking a precipitate; and repeatedly washing the precipitate with deionized water 60 times the mass of the gold powder, treating for 10min with ultrasonic vibration, then centrifugally separating, and drying in a blast oven at 70 ℃ to obtain A5 gold powder.
Comparative example 1
A preparation method of gold powder for LTCC uses L-ascorbic acid as a reducing agent, gum arabic as a dispersing agent, the pH value of a chloroauric acid solution is adjusted to be 5, and 60KHz ultrasonic vibration is assisted in step S2, and the preparation method specifically comprises the following steps:
step S1: 28.83g of chloroauric acid tetrahydrate and 0.59g of gum arabic are weighed and placed in a 150mL beaker, deionized water is added for stirring and dissolution, the pH value is adjusted to 5 by using 1mol/L NaOH solution and 12mol/L concentrated hydrochloric acid, and a chloroauric acid solution with the concentration of 0.7mol/L is prepared finally.
21.14g of L-ascorbic acid and 3.13g of gum arabic are weighed and placed in a 500mL beaker, deionized water is added, and the mixture is stirred and dissolved to prepare an L-ascorbic acid solution with the L-ascorbic acid concentration of 0.4mol/L.
Step S2: pouring the prepared chloroauric acid solution into an L-ascorbic acid solution, adjusting the temperature of a water bath to 25 ℃, and reacting for 1h under the condition of mechanical stirring and 60KHz ultrasonic vibration; after the reaction is finished, the temperature of the water bath is raised to 80 ℃, and the reaction is continued for 1h under the condition of mechanical stirring, so as to obtain reaction liquid.
And step S3: pouring the reaction solution into a centrifuge tube, placing the centrifuge tube in a centrifuge for centrifugation, and taking a precipitate; and repeatedly washing the precipitate with deionized water 60 times the mass of the gold powder, treating for 10min with ultrasonic vibration, then centrifugally separating, and drying in a blast oven at 70 ℃ to obtain B1 gold powder.
Comparative example 2
A preparation method of gold powder for LTCC uses D-erythorbic acid as a reducing agent, gum arabic and PVP as dispersing agents, and the pH value of a chloroauric acid solution is adjusted to be 5, and the method specifically comprises the following steps:
step S1: 28.83g of chloroauric acid tetrahydrate, 0.41g of gum arabic and 0.18g of PVP gum are weighed and placed in a 150mL beaker, deionized water is added for stirring and dissolution, the pH value is adjusted to 5 by using 1mol/L NaOH solution and 12mol/L concentrated hydrochloric acid, and the chloroauric acid solution with the concentration of 0.7mol/L is prepared finally.
21.14g of D-erythorbic acid, 2.23g of gum arabic and 0.90g of PVP are weighed and placed in a 500mL beaker, deionized water is added, and the mixture is stirred and dissolved to prepare a D-erythorbic acid solution with the concentration of the D-erythorbic acid of 0.4mol/L.
Step S2: pouring the prepared chloroauric acid solution into the D-isoascorbic acid solution, adjusting the water bath temperature to 25 ℃, and reacting for 1h under the condition of mechanical stirring; after the reaction is finished, the temperature of the water bath is raised to 80 ℃, and the reaction is continued for 1h under the condition of mechanical stirring, so as to obtain reaction liquid.
And step S3: pouring the reaction solution into a centrifuge tube, placing the centrifuge tube in a centrifuge for centrifugation, and taking a precipitate; and repeatedly washing the precipitate with deionized water with the mass of 60 times that of the gold powder, treating for 10min with ultrasonic vibration, then centrifugally separating, and drying in a blast oven at 70 ℃ to obtain B2 gold powder.
Comparative example 3
A preparation method of gold powder for LTCC uses D-erythorbic acid as a reducing agent and Arabic gum as a dispersing agent, and adjusts the pH value of a chloroauric acid solution to be 5, and specifically comprises the following steps:
step S1: 28.83g of chloroauric acid tetrahydrate and 0.59g of gum arabic are weighed and placed in a 150mL beaker, deionized water is added for stirring and dissolving, the pH value is adjusted to 5 by using 1mol/L NaOH solution and 12mol/L concentrated hydrochloric acid, and finally, a chloroauric acid solution with the concentration of 0.7mol/L is prepared.
21.14g of D-erythorbic acid and 3.13g of gum arabic are weighed and placed in a 500mL beaker, deionized water is added, and the mixture is stirred and dissolved to prepare a D-erythorbic acid solution with the D-erythorbic acid concentration of 0.4mol/L.
Step S2: pouring the prepared chloroauric acid solution into the D-isoascorbic acid solution, adjusting the water bath temperature to 25 ℃, and reacting for 1h under the condition of mechanical stirring; after the reaction is finished, the temperature of the water bath is raised to 80 ℃, and the reaction is continued for 1h under the condition of mechanical stirring, so as to obtain reaction liquid.
And step S3: pouring the reaction solution into a centrifuge tube, placing the centrifuge tube in a centrifuge for centrifugation, and taking a precipitate; and repeatedly washing the precipitate with deionized water 60 times the mass of the gold powder, treating for 10min with ultrasonic vibration, then centrifugally separating, and drying in a blast oven at 70 ℃ to obtain B3 gold powder.
Comparative example 4
A preparation method of gold powder for LTCC uses D-erythorbic acid as a reducing agent, gum arabic as a dispersing agent, a first solvent adopts 30wt% diethylene glycol butyl ether solution, and the pH value of chloroauric acid solution is adjusted to be 5, and the preparation method specifically comprises the following steps:
step S1: 28.83g of chloroauric acid tetrahydrate and 0.59g of gum arabic are weighed and placed in a 150mL beaker, deionized water is added for stirring and dissolving, the pH value is adjusted to 5 by using 1mol/L NaOH solution and 12mol/L concentrated hydrochloric acid, and finally, a chloroauric acid solution with the concentration of 0.7mol/L is prepared.
21.14g of D-erythorbic acid and 3.13g of gum arabic are weighed and placed in a 500mL beaker, and a 30wt% diethylene glycol butyl ether solution is added and stirred to dissolve the mixture to prepare a D-erythorbic acid solution with a D-erythorbic acid concentration of 0.4mol/L.
Step S2: pouring the prepared chloroauric acid solution into the D-isoascorbic acid solution, adjusting the water bath temperature to 25 ℃, and reacting for 1 hour under the mechanical stirring condition; after the reaction is finished, the temperature of the water bath is raised to 80 ℃, and the reaction is continued for 1h under the condition of mechanical stirring, so as to obtain reaction liquid.
And step S3: pouring the reaction liquid into a centrifugal tube, placing the centrifugal tube in the reaction liquid, standing and settling the reaction liquid, and taking a precipitate; and repeatedly washing the precipitate with deionized water 60 times the mass of the gold powder, treating for 10min with ultrasonic vibration, then centrifugally separating, and drying in a blast oven at 70 ℃ to obtain B4 gold powder.
Comparative example 5
A preparation method of gold powder for LTCC uses D-isoascorbic acid as a reducing agent, gum arabic as a dispersing agent, 50wt% diethylene glycol butyl ether solution as a first solvent, and the pH value of chloroauric acid solution is adjusted to be 5, and specifically comprises the following steps:
step S1: 28.83g of chloroauric acid tetrahydrate and 0.59g of gum arabic are weighed and placed in a 150mL beaker, deionized water is added for stirring and dissolution, the pH value is adjusted to 5 by using 1mol/L NaOH solution and 12mol/L concentrated hydrochloric acid, and a chloroauric acid solution with the concentration of 0.7mol/L is prepared finally.
21.14g of D-erythorbic acid and 3.13g of gum arabic are weighed and placed in a 500mL beaker, and a 50wt% diethylene glycol butyl ether solution is added and stirred to dissolve, so that a D-erythorbic acid solution with a D-erythorbic acid concentration of 0.4mol/L is prepared.
Step S2: pouring the prepared chloroauric acid solution into the D-isoascorbic acid solution, adjusting the water bath temperature to 25 ℃, and reacting for 1h under the condition of mechanical stirring; after the reaction is finished, raising the temperature of the water bath to 80 ℃, and continuously reacting for 1 hour under the condition of mechanical stirring to obtain reaction liquid.
And step S3: pouring the reaction liquid into a centrifugal tube, placing the centrifugal tube in the reaction liquid, standing and settling the reaction liquid, and taking a precipitate; and repeatedly washing the precipitate with deionized water 60 times the mass of the gold powder, treating for 10min with ultrasonic vibration, then centrifugally separating, and drying in a blast oven at 70 ℃ to obtain B5 gold powder.
The results of the performance tests of the gold powders prepared in the above examples and comparative examples are shown in table 1.
TABLE 1 gold powder Performance test for different preparation Processes
| Sample numbering | A1 | A2 | A3 | A4 | A5 | B1 | B2 | B3 | B4 | B5 |
| Specific surface area (g/m) 2 ) | 0.415 | 0.395 | 0.377 | 0.433 | 0.419 | 0.405 | 0.499 | 0.403 | 0.430 | 0.652 |
| Ignition loss (%) | 0.09 | 0.08 | 0.06 | 0.05 | 0.05 | 0.07 | 0.09 | 0.06 | 0.07 | 0.09 |
| Particle size (. Mu.m) | 1-1.4 | 1.9-2.7 | 2-3 | 1-2.5 | 0.8-1.4 | 1.9-3.2 | 0.5-2 | 1-1.2 | 2-2.6 | 0.3-1.5 |
The preparation method of the gold conductor paste printed substrate comprises the following steps:
(1) preparing an organic carrier containing 15% of ethyl cellulose, 45% of terpineol and 40% of triethylene glycol monobutyl ether according to the mass ratio, adding triethanolamine accounting for 1% of the total mass of the organic carrier, and stirring and dissolving under the condition of 90 ℃ water bath to obtain the gold conductor slurry organic carrier.
(2) Preparing gold conductor paste according to the proportion shown in Table 2, mixing gold powder, an organic carrier and glass powder by using a homogenizer, rolling by using a three-roll mill until the fineness is less than or equal to 10 mu m, and defoaming to obtain the gold conductor paste. Wherein the glass powder is commercial calcium boron lanthanum glass powder with the grain diameter of 2-4 μm.
TABLE 2 gold conductor paste ratio (% by mass)
(3) Printing the prepared gold conductor slurry on a green ceramic chip through screen printing, and then carrying out the procedures of cutting, laminating, hot pressing, sintering and the like, wherein the number of laminated layers is 6, the sintering temperature rise rate is 5 ℃/min, the temperature is raised to about 850 ℃, the temperature is kept for 2h, and then the temperature is reduced. After the sample is cooled to room temperature, the sample is taken out and the sheet resistance is tested by using a four-probe and the surface appearance is observed under a microscope, and as shown in fig. 3, a microscope picture of the gold conductor paste printed substrate prepared by the gold powder in the example 1 is obtained when the magnification is 45 times.
Table 3 comparison table of properties of gold conductor pastes prepared from gold powders of examples and comparative examples
| Gold powder type | Square resistance (m omega/sq) | Surface topography |
| Example 1 | 1.9 | Slight blistering |
| Example 2 | 1.8 | Good effect |
| Example 3 | 1.1 | Is good |
| Example 4 | 1.2 | Is good |
| Example 5 | 1.4 | Good effect |
| Comparative example 1 | 2.0 | Slight foaming |
| Comparative example 2 | 2.8 | Foaming |
| Comparative example 3 | 2.2 | Foaming |
| Comparative example 4 | 1.9 | Foaming |
| Comparative example 5 | 2.6 | Slight foaming |
As can be seen from table 3, the gold conductive paste prepared using the gold powder of the present invention has a small sheet resistance, and no or only slight blistering after sintering. As can be seen from the experimental comparison results of example 2 and comparative example 1, the particle size of the gold powder prepared by using L-ascorbic acid as a reducing agent is not much different from that of the gold powder prepared by D-erythorbic acid, but the performance of the prepared gold conductor paste is poor. As can be seen from the experimental comparison results of example 1 and example 2, the performance of the gold powder prepared using a single dispersant is superior to that of the gold powder prepared using a plurality of dispersants. As can be seen from the comparison results of example 1 and comparative example 2, example 2 and comparative example 3, and example 3 and comparative example 4, the gold conductor paste prepared by using a single reducing agent solvent and using the gold powder prepared without ultrasonic vibration treatment in step S2 has the disadvantages of foaming on the surface, poor densification degree, large sheet resistance and low adhesion. Further, as can be seen from the results of the comparative experiments between example 2 and examples 3 to 5, the sheet resistance of the gold conductor paste made of the gold powder prepared by using 30wt% diethylene glycol butyl ether solution as the reducing agent solvent and assisting the ultrasonic vibration treatment in step S2 was smaller than that of the gold conductor paste made of the gold powder prepared by using deionized water as the reducing agent solvent. In addition, the gold conductor slurry prepared from the gold powder prepared by using 30wt% of diethylene glycol butyl ether solution as a reducing agent solvent and assisting ultrasonic vibration treatment in the step S2 is sintered compactly, has no bubbles and obvious defects on the surface and small sheet resistance, and has good matching property with the ceramic substrate.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A preparation method of gold powder for LTCC is characterized by comprising the following steps:
reducing chloroauric acid under the conditions of mechanical stirring and ultrasonic vibration by using D-isoascorbic acid as a reducing agent in a water bath environment to obtain a reaction solution;
centrifuging the obtained reaction solution to obtain a precipitate; and washing and drying the precipitate to obtain the gold powder.
2. The preparation method according to claim 1, comprising the steps of:
step S1: weighing a certain amount of D-isoascorbic acid, dissolving the D-isoascorbic acid by using a first solvent, and adding a certain amount of dispersant to obtain a D-isoascorbic acid solution; weighing a certain amount of chloroauric acid tetrahydrate, dissolving the chloroauric acid tetrahydrate in water, adding a certain amount of dispersant, and adjusting the pH value to 5-7 by using a pH regulator to obtain a chloroauric acid solution;
step S2: adding the obtained chloroauric acid solution into the D-isoascorbic acid solution, adjusting the water bath temperature to 20-30 ℃, and reacting for 40-80 min under the condition of mechanical stirring and ultrasonic vibration; after the reaction is finished, raising the temperature of the water bath to 60-80 ℃, and continuously reacting for 40-80 min under the condition of mechanical stirring to obtain the reaction solution;
and step S3: pouring the reaction solution into a centrifuge tube, placing the centrifuge tube in a centrifuge for centrifugation, and taking a precipitate; and fully washing the precipitate with deionized water, and then drying at the temperature of 60-80 ℃ to obtain the gold powder.
3. The process according to claim 2, wherein in step S1, the concentration of the D-erythorbic acid solution is 0.2 to 0.4mol/L;
and/or the first solvent is one or more of deionized water, ethylene glycol butyl ether, ethylene glycol methyl ether, diethylene glycol butyl ether and ethanol;
and/or the mass fraction of the first solvent is 30wt% -50 wt%;
and/or the concentration of gold element in the chloroauric acid solution is 0.3-0.7 mol/L;
and/or the molar ratio of the gold element in the chloroauric acid solution to the D-erythorbic acid is 1.7-1;
and/or the dispersing agent is one or more of gum arabic, polyvinylpyrrolidone and polyvinyl alcohol;
and/or, the pH regulator comprises a strong base solution and/or a strong acid solution; preferably, the strong base solution is a 1mol/L NaOH solution, and the strong acid solution is 12mol/L concentrated hydrochloric acid.
4. The method according to claim 2, wherein in step S2, the frequency of the ultrasonic vibration is 40KHz to 60KHz.
5. The preparation method according to claim 2, wherein in step S3, the amount of water used in the process of fully washing with deionized water is 60 to 80 times of the mass of the gold powder; and/or ultrasonic-assisted washing treatment is carried out in the process of fully washing with the deionized water.
6. The method according to claim 2, wherein the gold powder is a spherical gold powder having a particle size distribution of 0.8 μm to 3 μm and a specific surface area of 0.3m 2 /g-0.5m 2 /g。
7. Gold powder for LTCC, characterized by being produced by the production method according to any one of claims 1 to 6.
8. The gold conductor paste is characterized by comprising the following components in parts by weight: 80-90 parts of gold powder prepared by the preparation method of any one of claims 1-6 or 7, 10-15 parts of organic carrier and 2-5 parts of glass powder.
9. The gold conductor paste of claim 8, wherein the organic vehicle is comprised of a second solvent, an adhesion promoter, a surfactant; the second solvent accounts for 75-90% of the total weight of the organic carrier, the tackifier accounts for 10-25% of the total weight of the organic carrier, and the surfactant accounts for 1-2% of the total weight of the second solvent and the tackifier;
and/or the second solvent is one or more of terpineol, alcohol ester-12, ethylene glycol butyl ether acetate and triethylene glycol monobutyl ether; the tackifier is ethyl cellulose; the surfactant is one or more of sorbitol ester of behenic acid, sodium dodecyl sulfate and triethanolamine.
10. The gold conductor paste of claim 8 wherein the glass frit is a calborlanthanum glass frit;
and/or the particle size of the glass powder is 2-4 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211288238.XA CN115625341A (en) | 2022-10-20 | 2022-10-20 | Gold powder for LTCC (Low temperature Co-fired ceramic), preparation method and gold conductor slurry |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211288238.XA CN115625341A (en) | 2022-10-20 | 2022-10-20 | Gold powder for LTCC (Low temperature Co-fired ceramic), preparation method and gold conductor slurry |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115625341A true CN115625341A (en) | 2023-01-20 |
Family
ID=84907579
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211288238.XA Pending CN115625341A (en) | 2022-10-20 | 2022-10-20 | Gold powder for LTCC (Low temperature Co-fired ceramic), preparation method and gold conductor slurry |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115625341A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117300147A (en) * | 2023-11-28 | 2023-12-29 | 长春黄金研究院有限公司 | Superfine gold powder and preparation method thereof |
-
2022
- 2022-10-20 CN CN202211288238.XA patent/CN115625341A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117300147A (en) * | 2023-11-28 | 2023-12-29 | 长春黄金研究院有限公司 | Superfine gold powder and preparation method thereof |
| CN117300147B (en) * | 2023-11-28 | 2024-03-01 | 长春黄金研究院有限公司 | Superfine gold powder and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104036842B (en) | A kind of leadless environment-friendly circuit board conductive silver slurry and preparation method thereof | |
| KR100895414B1 (en) | The conductive paste composition for electrode including powder coated with silver and the manufacturing method thereof | |
| CN115625341A (en) | Gold powder for LTCC (Low temperature Co-fired ceramic), preparation method and gold conductor slurry | |
| CN110227827A (en) | A kind of electronic ceramics electrode printing slurry silver powder and preparation method thereof | |
| CN104078093B (en) | A kind of high-strength PC B circuit board conductive silver slurry and preparation method thereof | |
| CN104078098B (en) | A kind of low silver content printed circuit board (PCB) silver slurry and preparation method thereof | |
| CN104003731A (en) | Dielectric paste for thick-film process and preparation method thereof | |
| CN105472881A (en) | 3D printed graphene circuit board | |
| CN112489850A (en) | Conductive silver paste for filtering and preparation method thereof | |
| CN113506648B (en) | Inner-layer gold conductor paste for Ca-B-Si system LTCC | |
| CN104961471A (en) | Cast film slurry of ultrathin lamination flaky inductor and manufacturing method for cast film of ultrathin lamination flaky inductor | |
| CN108962422B (en) | Conductive silver paste for LTCC ceramic substrate and preparation method thereof | |
| KR20190048316A (en) | Surface-treated silver powder and method for producing the same | |
| CN111054929A (en) | Low-temperature co-fired ceramic colloid and preparation method and application thereof | |
| CN114178523A (en) | Method for producing surface-treated copper fine particles | |
| CN111627590A (en) | Conductive silver paste for chip inductor and preparation method thereof | |
| KR102007856B1 (en) | The manufacturing method of silver powder with improved dispersibility | |
| WO2018070817A1 (en) | Silver powder for high temperature sintering, and preparation method therefor | |
| JPS622003B2 (en) | ||
| CN105081343B (en) | A kind of manufacture method of conductive silver powder for touch-screen UV type laser engraving silver pastes | |
| CN107799197A (en) | Realize LTCC conductive copper films of air dumping and preparation method thereof | |
| JP2022137855A (en) | platinum paste | |
| WO2020111903A1 (en) | Method for producing silver powder with adjustable shrinkage | |
| CN111875361B (en) | Preparation method of core-shell structure composite powder precursor and LTCC substrate | |
| CN107068237B (en) | The preparation method of lower Tc PTC heat sensitive electronic component electrode thick liquid without lead and silver |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |