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CN-122016579-A - Method for detecting dispersibility of slurry particles

CN122016579ACN 122016579 ACN122016579 ACN 122016579ACN-122016579-A

Abstract

The invention belongs to the field of conductive paste, and particularly discloses a method for detecting the dispersibility of paste particles. The detection method comprises the steps of centrifuging slurry, sampling from the bottom of the slurry, forming a film of a sampled product to obtain a test sample film, spraying metal on the surface of the test sample film, and observing the particle size and the number of large particles in the test sample film by adopting a scanning electron microscope, wherein the centrifugation is that the slurry is centrifuged for 3-12 times by adopting a centrifugal force of 500-3000g, and each time is centrifuged for 10s-7min. According to the invention, large particles are actively enriched to the bottom of the slurry through centrifugation, and then are directly sampled and observed from the bottom, so that the large particles are easier to capture and analyze. The method fundamentally avoids misjudgment of the size and missed detection of the quantity caused by natural sinking of large particles during drying and film forming and difficulty in effective observation by an electron microscope in the traditional method, thereby realizing more accurate statistics and characterization of the large particles in the slurry.

Inventors

  • SHI FANGZHOU
  • MA YANHONG

Assignees

  • 潮州三环（集团）股份有限公司

Dates

Publication Date
20260512
Application Date
20260225

Claims (10)

  1. 1. A method for detecting the dispersibility of slurry particles is characterized by comprising the following steps: centrifuging the slurry, sampling from the bottom of the slurry, and forming a film of the sampled product to obtain a test sample film; Spraying metal on the surface of the test sample film, and observing the particle size and the number of large particles in the test sample film by adopting a scanning electron microscope; the centrifugation is to centrifuge the slurry for 3-12 times by adopting a centrifugal force of 500-3000g, and the centrifugation is carried out for 10s-7min each time.
  2. 2. The method for detecting the dispersibility of slurry particles according to claim 1, wherein said large particles are particles having a particle diameter of 1 μm or more.
  3. 3. The method for detecting the dispersibility of slurry particles according to claim 1, wherein the centrifugation is performed by first centrifuging with a centrifugal force of 500 to 700g, then centrifuging with a centrifugal force of 1000 to 1500g, and then centrifuging with a centrifugal force of 2000 to 3000 g.
  4. 4. The method for detecting the dispersibility of slurry particles according to claim 1 or 3, wherein the number of centrifugation times for the first centrifugation is 1 to 3 and each centrifugation time is 1 to 5 minutes; and/or the centrifugation times of the second centrifugation are 1-5 times, and each centrifugation is 30-45s; and/or the centrifugation times of the third centrifugation are 1-3 times, and each centrifugation is 15-30s.
  5. 5. The method for detecting the dispersibility of slurry particles according to claim 3, wherein the first centrifugation is performed for 2 to 3 times using a centrifugal force of 600 to 700g for 2 to 3 minutes each; and/or the second centrifugation is to use a centrifugal force of 1200-1300g for 4-5 times, and each time for 35-40s; and/or, the third centrifugation is to use a centrifugal force of 2000-2500g to centrifuge 1-2 times, each centrifugation for 20-30s.
  6. 6. The method for detecting the dispersibility of slurry particles according to claim 1, wherein said slurry has at least one of the following characteristics: (a1) The slurry is selected from any one of nickel slurry, silver slurry, copper slurry, palladium slurry and silver-palladium alloy slurry; (a2) The solid content of the slurry is 45% -65%; (a3) The viscosity of the slurry is less than or equal to 5000cps measured at 25 ℃.
  7. 7. The method for detecting the dispersibility of slurry particles according to claim 1, wherein the step of forming the film of the sample comprises transferring the sample to a substrate, scraping the sample, and drying the sample.
  8. 8. The method for detecting the dispersibility of slurry particles according to claim 1, wherein the step of observing by a scanning electron microscope comprises the step of observing the test sample film at a magnification of 5000 to 10000 times for 10 to 20 minutes by using a scanning electron microscope.
  9. 9. The method for detecting the dispersibility of slurry particles according to claim 1, wherein when the viscosity of the slurry measured at 25 ℃ is greater than 5000cps, the slurry is diluted with a solvent to a viscosity of 25 ℃ of 5000cps or less.
  10. 10. Use of the method for detecting the dispersibility of slurry particles according to any one of claims 1 to 9 in conducting slurry quality inspection.

Description

Method for detecting dispersibility of slurry particles Technical Field The invention belongs to the field of conductive slurry, and particularly relates to a method for detecting the dispersibility of slurry particles. Background The chip type Multi-layer ceramic capacitor (Multi-LAYER CERAMIC Capacitors, MLCC) integrates various advantages of small volume, compact structure, long service life, high reliability, and compatibility with Surface Mount Technology (SMT), thus being widely applied. In order to adapt to the development trend of chip, large capacity, low cost, miniaturization and high reliability, the performance requirements of key raw materials such as ceramic slurry and metal conductive slurry are also becoming strict in the industry. The ultra-fine powder is extremely easy to agglomerate due to the large specific surface area and high surface energy, and how to accurately evaluate the dispersibility of the slurry prepared by the ultra-fine powder is a great challenge. Taking nickel slurry as an example, the traditional method is to scrape a film from the slurry, dry the film, and observe large-particle nickel powder by a scanning electron microscope. However, the method has the inherent defects that nickel powder with larger specific gravity can be precipitated to the bottom when being dried, so that the observed large particle size is smaller and the quantity is smaller, and finally, the misjudgment on the dispersibility is caused. Disclosure of Invention In order to overcome at least one technical problem of the prior art, one of the purposes of the present invention is to provide a method for detecting dispersibility of slurry particles. The second objective of the present invention is to provide an application of the method for detecting the dispersibility of slurry particles in quality inspection of conductive slurry. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The first aspect of the present invention provides a method for detecting dispersibility of slurry particles, comprising the steps of: centrifuging the slurry, sampling from the bottom of the slurry, and forming a film of the sampled product to obtain a test sample film; Spraying metal on the surface of the test sample film, and observing the particle size and the number of large particles in the test sample film by adopting a scanning electron microscope; the centrifugation is to centrifuge the slurry for 3-12 times by adopting a centrifugal force of 500-3000g, and the centrifugation is carried out for 10s-7min each time. In some embodiments of the invention, the centrifugal force is any one or both of 500g、600g、700g、800g、900g、1000g、1100g、1200g、1300g、1400g、1500g、1600g、1700g、1800g、1900g、2000g、2100g、2200g、2300g、2400g、2500g、2600g、2700g、2800g、2900g、3000g. In some embodiments of the invention, the number of centrifugation is any one or any two of 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or range of values. In some embodiments of the invention, the centrifugation is for a period of time of 10s, 20s, 30s, 50s, 1min, 1.5min, 2min, 2.5min, 3min, 3.5min, 4min, 4.5min, 5min, 5.5min, 6min, 6.5min, 7min, or any range of values formed by any two or more of these values. In some embodiments of the invention, the large particles are particles having a particle size of 1 μm or more, in some embodiments of the invention, 1 to 10 μm, in some embodiments of the invention, 1 to 4 μm, and in some embodiments of the invention, 1 to 3.5 μm. In some embodiments of the invention, the centrifugation is performed first with a centrifugal force of 500-700g, then with a centrifugal force of 1000-1500g, and then with a centrifugal force of 2000-3000 g. In some embodiments of the invention, the centrifugal force of the first centrifugation is any one or any two of 500g, 550g, 600g, 650g, 700g or a range of values formed by any two. In some embodiments of the invention, the first centrifugation is performed for 1 to 3 times, each for 1 to 5 minutes. In some embodiments of the invention, the first centrifugation is performed for a period of time of any one or any two of 1min, 2min, 3min, 4min, 5min. In some embodiments of the invention, the first centrifugation is performed using a centrifugal force of 600-700g for 2-3 times, each for 2-3 minutes. The invention performs the first centrifugation under lower centrifugal force, so that the large particles at the central position of the slurry can gradually subside or migrate to the pipe wall in the force field, thereby realizing the effective screening of the large particles. In some embodiments of the invention, the centrifugal force of the second centrifugation is any one or any two of 1000g, 1100g, 1200g, 1300g, 1400g, 1500g or a range of values formed by any two. In some embodiments of the invention, the second centrifugation is performed for a number of centrifugation of from 1 to 5 and each centrifugation is performed for a period of from 30 to 45 seconds. In some