Method for improving rubber discharge rate of high-purity alumina electrostatic chuck

Abstract

The invention discloses a method for improving the glue discharging rate of a high-purity aluminum oxide electrostatic chuck, and belongs to the technical field of electrostatic chucks. The method comprises the steps that S1, an electrostatic chuck green body is put into a glue discharging furnace; s2, setting process parameters in the rubber removal furnace, and heating to a first preset temperature within a first preset time period, the range of the first preset time period being 10-15 hours, and the range of the first preset temperature being 300-350 DEG C; s3, the temperature is increased to a second preset temperature within a second preset time period, the range of the second preset time period is 20-25 h, and the range of the second preset temperature is 350-450 DEG C; s4, a section of heat preservation curve is set in a third preset time period, the range of the third preset time period is 2-5 h, and the range of the third preset temperature is 350-450 DEG C; and S5, a section of cooling curve is set in a fourth preset time period, the range of the fourth preset time period is 10-12 h, and the range of the fourth preset temperature is 150-200 DEG C.

Description

Technical Field

[0001] The invention relates to the technical field of electrostatic chucks, and in particular to a method for improving the debinding rate of a high-purity alumina electrostatic chuck. Background Art

[0002] In the prior art, during the preparation of multilayer ceramic electrostatic chucks (ESCs), a variety of organic additives are added to the dielectric diaphragm and the metal inner electrode. Before the product is fired, most of the organic substances in the green embryo are slowly removed through the debinding process to prevent the various organic additives remaining in the ceramic material to be sintered from decomposing during high-temperature sintering to cause defects such as holes and splitting. During the manufacturing process of the electrostatic chuck, it is also necessary to protect the metal inner electrode from oxidation and maintain its activity, complete its densification and particle growth process, and realize the characteristics of the electrostatic chuck. Therefore, nitrogen and water vapor are used to discharge organic substances during the debinding process. The manufacturing process of high-purity alumina electrostatic chucks often uses nano-scale powders and more organic substances to make green embryos. These organic substances exist not only between the dielectric layers, but also in the internal electrodes. These organic substances are more difficult to discharge during the debinding process. In the debinding process, problems such as excessive organic colloid residues and low debinding efficiency are prone to occur, which affects the quality of the fired products.

[0003] The main defects of the existing technology are: when the binder is not fully removed, organic matter will remain inside and on the surface of the product, which will cause uneven color of the debinding product, and inconsistent shrinkage during firing, resulting in holes or cracks inside. When the binder is removed too quickly, the organic matter will volatilize and remain on the surface of the product. The exhaust gas concentration in the debinding furnace is high, which will easily cause stratification or cracking inside the green body, greatly limiting production efficiency and increasing production costs. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for improving the debinding rate of a high-purity alumina electrostatic chuck, so as to solve the problem raised in the background technology.

[0005] In order to solve the above technical problems, the technical solution of the present invention is:

[0006] A method for improving the debinding rate of a high-purity alumina electrostatic chuck, the method comprising:

[0007] S1: preparing an electrostatic chuck green body, and evenly placing the electrostatic chuck green body on a firing plate, and stacking them into a debinding furnace;

[0008] S2: Introduce inert gas into the debinding furnace to exhaust oxygen in the debinding furnace, and set the process parameters in the debinding furnace to rise to a first preset temperature within a first preset time period, the first preset time period ranges from 10 to 15 hours, the first preset temperature ranges from 300 to 350°C, and the first preset gas introduced within the first preset time period is one of N2 and Ar, and the flow rate of the first preset gas, the power of the circulating fan in the debinding furnace, and the opening of the exhaust valve are set;

[0009] S3: Raise the temperature to the second preset temperature within the second preset time period, the second preset time period ranges from 20 to 25 hours, the second preset temperature ranges from 350 to 450°C, the second preset gas introduced within the second preset time period is one of N2 and Ar, water vapor is added within the second preset time period, the water vapor temperature is 25 to 30°C, and the flow rate of the second preset gas, the power of the circulating fan in the debinding furnace, and the opening of the exhaust valve are set;

[0010] S4: setting a heat preservation curve in a third preset time period, the third preset time period ranges from 2 to 5 hours, the third preset temperature ranges from 350 to 450°C, the third preset gas introduced in the third preset time period is one of N2 and Ar, water vapor is added in the third preset time period, the water vapor temperature is 25 to 30°C, and the flow rate of the third preset gas, the power of the circulating fan in the debinding furnace, and the opening of the exhaust valve are set;

[0011] S5: A cooling curve is set in the fourth preset time period, the fourth preset time period ranges from 10 to 12 hours, the fourth preset temperature ranges from 150 to 200°C, the fourth preset gas introduced in the fourth preset time period is one of N2 and Ar, water vapor is added in the fourth preset time period, the water vapor temperature is 25 to 30°C, and the flow rate of the fourth preset gas, the power of the circulating fan in the debinding furnace and the opening of the exhaust valve are set.

[0012] Preferably, in step S1, the gap between the setter plates when stacked is 5 to 7 cm, so that the gas flow rate between the setter plates in the debinding furnace is faster, so as to better discharge the organic matter.

[0013] Preferably, in the step S2, the inert gas introduced into the debinding furnace is N2 or Ar.

[0014] Preferably, the flow rate of the first preset gas set in step S2 is 60-80 L / min, the frequency of the circulating fan is 15-20 Hz, and the opening of the exhaust valve is 25-40%.

[0015] Preferably, in step S3, the second preset gas flow rate is set to 80-100 L / min, the circulating fan frequency is 25-30 Hz, and the exhaust valve opening is 40-50%; in step S4, the third preset gas flow rate is set to 80-100 L / min, the circulating fan frequency is 25-30 Hz, and the exhaust valve opening is 40-50%; in step S5, the fourth preset gas flow rate is set to 80-100 L / min, the circulating fan frequency is 25-30 Hz, and the exhaust valve opening is 40-50%.

[0016] The above technical solution has the following beneficial effects:

[0017] In the technical solution of the present application, the debinding efficiency of the high-purity alumina electrostatic chuck is improved by regulating the temperature, time, atmosphere, and air intake and exhaust during the debinding process;

[0018] In the first preset temperature range of 300-350°C, under the continuous introduction of nitrogen or Ar, part of the organic matter in the ceramic dielectric layer on the surface of the electrostatic chuck is discharged, which provides more colloid discharge channels for the debinding of the electrode layer and the ceramic dielectric layer inside the electrostatic chuck in the second preset temperature range of 350-450°C. At the same time, the debinding time is extended at the second preset temperature to make the debinding rate smoother and avoid the generation of cracks and holes inside the electrostatic chuck.

[0019] In the second preset temperature range and the third preset temperature range, increasing the nitrogen or Ar flow rate in the debinding furnace and adding water vapor introduction can take away more organic substances on the surface of the electrostatic chuck to improve the debinding efficiency at this stage. At this time, the amount of waste gas containing glue in the debinding furnace also increases. Therefore, the operating frequency of the circulating fan in the debinding furnace and the opening of the exhaust valve are increased to make the gas circulation frequency in the furnace faster and reduce the accumulation of waste gas in the furnace.

[0020] The present invention provides a process scheme for solving the problem of nano-level fine powder high-purity alumina electrostatic chuck debinding, which makes the internal organic matter removal rate higher and reduces the surface carbon residue. The product appearance color is uniform brown, and the organic matter loss rate is 92% as measured by experiments. DETAILED DESCRIPTION

[0021] The specific embodiments of the present invention are further described below. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] The main defects of the existing technology are: when the binder is not sufficient, organic matter will remain inside and on the surface of the product, which will cause uneven color of the debinding product, inconsistent shrinkage during firing, resulting in holes or cracks inside, and when the binder is debinded too quickly, the organic matter will evaporate and remain on the surface of the product. The exhaust gas concentration in the debinding furnace is high, which makes it easy for the inside of the green body to have stratification or cracking and other quality problems, greatly limiting production efficiency and increasing production costs.

[0023] The technical solution of the present application improves the debinding rate of the high-purity alumina electrostatic chuck by improving the debinding process, and provides a debinding method for the high-purity alumina electrostatic chuck, which solves the problem that the existing debinding process method does not remove organic matter cleanly, the carbon residue of the product after debinding is high, and it is easy to cause internal cracks in the product during firing.

[0024] The basic concept of the technical solution of this application is to improve the debinding efficiency of the high-purity alumina electrostatic chuck and increase the loss rate of organic matter by regulating the temperature, time, atmosphere, air intake and exhaust during the debinding process, as shown below:

[0025] A method for improving the debinding rate of a high-purity alumina electrostatic chuck comprises the following steps:

[0026] S1: preparing an electrostatic chuck green body, specifically a high-purity alumina electrostatic chuck ceramic green body, and then evenly placing the electrostatic chuck green body on a firing plate, stacking them in a debinding furnace, with a gap of 5 to 7 cm between the firing plates when stacking, so that the gas flow rate between the firing plates in the debinding furnace is faster, so as to better discharge organic matter; completing debinding in the debinding furnace, and improving the debinding efficiency of the high-purity alumina electrostatic chuck and the loss rate of organic matter by setting the debinding process parameters of the debinding furnace;

[0027] S2: Introduce inert gas into the debinding furnace. The inert gas introduced into the debinding furnace is N2 or Ar. The inert gas introduced is used to exhaust the oxygen in the debinding furnace, and the process parameters in the debinding furnace are set as follows: the temperature rises to the first preset temperature within the first preset time period. The first preset time period ranges from 10 to 15 hours, and the first preset temperature ranges from 300 to 350°C. The first preset gas introduced into the first preset time period is one of N2 and Ar, and the flow rate of the first preset gas, the power of the circulating fan in the debinding furnace, and the opening of the exhaust valve are set. The flow rate of the first preset gas is set to 60-80 L / min, the frequency of the circulating fan is 15-20 Hz, and the opening of the exhaust valve is 25-40%. In other implementations of this embodiment, the flow rate of the first preset gas is set to 60 L / min or 80 L / min, the flow rate of the first preset gas can also be 70 L / min, the frequency of the circulating fan is 15 Hz or 20 Hz, the frequency of the circulating fan can also be 17 Hz, the opening of the exhaust valve is 25% or 40%, and the opening of the exhaust valve can also be 32%;

[0028] S3: Raise to the second preset temperature within the second preset time period, the second preset time period ranges from 20 to 25h, the second preset temperature ranges from 350 to 450°C, the second preset gas introduced within the second preset time period is one of N2 and Ar, water vapor is introduced within the second preset time period, the water vapor temperature is 25°C or 30°C, the water vapor temperature can also be 27°C, and the flow rate of the second preset gas, the power of the circulating fan in the debinding furnace and the opening of the exhaust valve are set, the set second preset gas flow rate is 80L / min or 100L / min, the second preset gas flow rate can also be 90L / min, the circulating fan frequency is 25Hz or 30Hz, the circulating fan frequency can be 27Hz, the exhaust valve opening is 40% or 50%, and the exhaust valve opening can also be 45%;

[0029] S4: setting a heat preservation curve in a third preset time period, the third preset time period ranges from 2 to 5 hours, the third preset temperature ranges from 350 to 450°C, the third preset gas introduced in the third preset time period is one of N2 and Ar, water vapor is introduced in the third preset time period, the water vapor temperature is 25 to 30°C, and the flow rate of the third preset gas, the power of the circulating fan in the debinding furnace and the opening of the exhaust valve are set, the set third preset gas flow rate is 80L / min or 100L / min, the third preset gas flow rate can also be 90L / min, the circulating fan frequency is 25Hz or 30Hz, the circulating fan frequency can be 27Hz, the exhaust valve opening is 40% or 50%, and the exhaust valve opening can also be 45%;

[0030] In the second preset temperature range and the third preset temperature range, increasing the nitrogen or Ar flow rate in the debinding furnace and adding water vapor introduction can take away more organic substances on the surface of the electrostatic chuck to improve the debinding efficiency at this stage. At this time, the amount of waste gas containing glue in the debinding furnace also increases. Therefore, the operating frequency of the circulating fan in the debinding furnace and the opening of the exhaust valve are increased to make the gas circulation frequency in the furnace faster and reduce the accumulation of waste gas in the furnace.

[0031] S5: Set a cooling curve in the fourth preset time period, the fourth preset time period ranges from 10 to 12 hours, the fourth preset temperature ranges from 150 to 200°C, the fourth preset gas introduced in the fourth preset time period is one of N2 and Ar, and water vapor is added in the fourth preset time period, the water vapor temperature is 25 to 30°C, and the flow rate of the fourth preset gas, the power of the circulating fan in the debinding furnace and the opening of the exhaust valve are set. The set fourth preset gas flow rate is 80L / min or 100L / min, the fourth preset gas flow rate can also be 90L / min, the circulating fan frequency is 25Hz or 30Hz, the circulating fan frequency can be 27Hz, the exhaust valve opening is 40% or 50%, and the exhaust valve opening can also be 45%.

[0032] In the technical solution of the present application, the debinding efficiency of the high-purity alumina electrostatic chuck is improved by regulating the temperature, time, atmosphere, and air intake and exhaust during the debinding process;

[0033] In the first preset temperature range of 300-350°C, under the continuous introduction of nitrogen or Ar, part of the organic matter in the ceramic dielectric layer on the surface of the electrostatic chuck is discharged, which provides more colloid discharge channels for the debinding of the electrode layer and the ceramic dielectric layer inside the electrostatic chuck in the second preset temperature range of 350-450°C. At the same time, the debinding time is extended at the second preset temperature to make the debinding rate smoother and avoid the generation of cracks and holes inside the electrostatic chuck.

[0034] In the second preset temperature range and the third preset temperature range, increasing the nitrogen or Ar flow rate in the debinding furnace and adding water vapor introduction can take away more organic substances on the surface of the electrostatic chuck to improve the debinding efficiency at this stage. At this time, the amount of waste gas containing glue in the debinding furnace also increases. Therefore, the operating frequency of the circulating fan in the debinding furnace and the opening of the exhaust valve are increased to make the gas circulation frequency in the furnace faster and reduce the accumulation of waste gas in the furnace.

[0035] The present invention provides a process scheme for solving the problem of nano-level fine powder high-purity alumina electrostatic chuck debinding, which makes the internal organic matter removal rate higher and reduces the surface carbon residue. The product appearance color is uniform brown and the organic matter removal rate is about 92%.

[0036] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the protection scope of the present invention.

Claims

1. A method for improving the debinding rate of a high-purity alumina electrostatic chuck, characterized in that: The method comprises: S1: preparing an electrostatic chuck green body, and evenly placing the electrostatic chuck green body on a firing plate, and stacking them into a debinding furnace; S2: Introduce inert gas into the debinding furnace to exhaust oxygen in the debinding furnace, and set the process parameters in the debinding furnace to rise to a first preset temperature within a first preset time period, the first preset time period ranges from 10 to 15 hours, the first preset temperature ranges from 300 to 350°C, and the first preset gas introduced within the first preset time period is one of N2 and Ar, and the flow rate of the first preset gas, the power of the circulating fan in the debinding furnace, and the opening of the exhaust valve are set; S3: Raise the temperature to the second preset temperature within the second preset time period, the second preset time period ranges from 20 to 25 hours, the second preset temperature ranges from 350 to 450°C, the second preset gas introduced within the second preset time period is one of N2 and Ar, water vapor is added within the second preset time period, the water vapor temperature is 25 to 30°C, and the flow rate of the second preset gas, the power of the circulating fan in the debinding furnace, and the opening of the exhaust valve are set; S4: setting a heat preservation curve in a third preset time period, the third preset time period ranges from 2 to 5 hours, the third preset temperature ranges from 350 to 450°C, the third preset gas introduced in the third preset time period is one of N2 and Ar, water vapor is added in the third preset time period, the water vapor temperature is 25 to 30°C, and the flow rate of the third preset gas, the power of the circulating fan in the debinding furnace, and the opening of the exhaust valve are set; S5: A cooling curve is set in the fourth preset time period, the fourth preset time period ranges from 10 to 12 hours, the fourth preset temperature ranges from 150 to 200°C, the fourth preset gas introduced in the fourth preset time period is one of N2 and Ar, water vapor is added in the fourth preset time period, the water vapor temperature is 25 to 30°C, and the flow rate of the fourth preset gas, the power of the circulating fan in the debinding furnace and the opening of the exhaust valve are set.

2. A method for improving the debinding rate of a high-purity alumina electrostatic chuck according to claim 1, characterized in that: In the step S1, the gap between the setter plates when stacked is 5 to 7 cm, so that the gas flow rate between the setter plates in the debinding furnace is faster, so as to better discharge the organic matter.

3. A method for improving the debinding rate of a high-purity alumina electrostatic chuck according to claim 1, characterized in that: In step S2, the inert gas introduced into the debinding furnace is N2 or Ar.

4. A method for improving the debinding rate of a high-purity alumina electrostatic chuck according to claim 1, characterized in that: The flow rate of the first preset gas set in step S2 is 60-80 L / min, the frequency of the circulating fan is 15-20 Hz, and the opening of the exhaust valve is 25-40%.

5. A method for improving the debinding rate of a high-purity alumina electrostatic chuck according to claim 1, characterized in that: In the step S3, the second preset gas flow rate is set to 80-100 L / min, the circulating fan frequency is 25-30 Hz, and the exhaust valve opening is 40-50%; in the step S4, the third preset gas flow rate is set to 80-100 L / min, the circulating fan frequency is 25-30 Hz, and the exhaust valve opening is 40-50%; in the step S5, the fourth preset gas flow rate is set to 80-100 L / min, the circulating fan frequency is 25-30 Hz, and the exhaust valve opening is 40-50%.