Glue discharging jig and glue discharging method for ceramic green body
By setting the gradient aperture on the disk-shaped burning plate of the green ceramic body, uniform glue distribution of the ceramic body is achieved, the uneven performance problem caused by carbon residue is solved, and the density and thermal conductivity of the ceramic body is improved. performance.
Patent Information
- Application Number
- CN202411059586.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-05
- Publication Date
- 2025-01-03
AI Technical Summary
During the preparation of semiconductor structural parts, especially in large-sized green ceramic bodies, carbon residues are difficult to completely evaporate, resulting in uneven grain distribution, poor density, color spots, low thermal conductivity and mechanical properties during sintering. The problem of poor quality is particularly obvious in large-size solid wall thickness products.
A disc-shaped burning plate is used as a glue discharge fixture. By setting the central through hole and the inner and outer area through holes with gradient distribution on the burning plate, the glue discharge process from room temperature to 500℃ is carried out to ensure the heat. Exchange uniformly to volatile additives and plasticizers to reduce carbon residue.
The consistency of carbon content in the upper and lower areas of the ceramic body is achieved, the carbon residue is reduced, and the yield and thermal conductivity are improved.
Smart Images
Figure CN119238702A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of ceramic debinding, and in particular to a debinding jig and a debinding method for ceramic green bodies. Background Art
[0002] In the process of preparing semiconductor structural parts, especially large-sized green billets, electrostatic chuck molding is generally achieved through dry pressing, isostatic pressing, and tape casting. Due to the large size of the product, dry pressing is prone to poor density of the green body, isostatic pressing requires a large investment in equipment, and tape casting can be adjusted arbitrarily according to the size of the product for easy storage. However, a large amount of additives and plasticizers must be added during the tape casting process to ensure the formability of the green body. These additives must be removed through a certain period of temperature and atmosphere to evaporate and completely eliminate them. Even if the debinding temperature is increased or the debinding time is extended under the atmosphere, there will still be residual carbon that has not been completely volatilized in different parts of the green body. Although the carbon residue reduces the oxygen (carbon) content of the aluminum nitride grains through carbon thermal reaction, these residual carbon will participate in the reaction during the sintering process, change the distribution between the grains, and leave pores to promote abnormal grain growth, resulting in poor microstructure density, color spots, and thermal conductivity. Low and poor mechanical properties are particularly obvious for large-size solid wall thick products. Through the monitoring and analysis of the product debinding rate and the bottom carbon-sulfur tester, the carbon content in the bottom center is higher than that in the upper and side measurements. Even if the debinding temperature is increased to 600°C or higher and the debinding time is extended to 40h, the carbon content in the upper area is 540ppm and the carbon content in the center of the lower area is 6300ppm, and the carbon content is still exceeded. In order to discharge the carbon residue to a trace level, that is, the carbon content of semiconductor ceramics is usually less than 500ppm, a debinding fixture and debinding method for large-size thick wall products are needed. Summary of the invention
[0003] The technical problem to be solved by the present invention is to provide a binder removal jig and a binder removal method for ceramic green bodies, so as to reduce the carbon content of the ceramic green bodies and make the upper and lower performances of the ceramic green bodies consistent.
[0004] In order to solve the above technical problems, the technical solution of the present invention is:
[0005] On the one hand, the present invention discloses a binder removal jig for ceramic green bodies, the binder removal jig comprises a disc-shaped supporting plate for placing the ceramic green bodies, a central through hole is provided at the center of the disc-shaped supporting plate, the disc-shaped supporting plate comprises an inner area and an outer area, the inner area is between the central through hole and the outer area, a plurality of circles of through holes are provided on the inner area, and an outer through hole is provided on the outer area, the diameters of all the through holes on the inner area are smaller than the diameter of the central through hole, and the diameters of all the outer through holes on the outer area are smaller than any through hole on the inner area.
[0006] Preferably, the diameters of the plurality of circles of through holes on the inner area are the same or decrease in size from the center of the circle to the outside.
[0007] Preferably, the outer area includes a plurality of sector-shaped partitions spliced along the circumferential direction, and the apertures of the outer through holes on the sector-shaped partitions gradually decrease from the center of the circle to the outside or remain the same.
[0008] Preferably, the diameter of the ceramic green body is less than or equal to the diameter of the disc-shaped support plate.
[0009] Another aspect of the present invention discloses a debinding method using the above-mentioned debinding jig for ceramic green bodies, the method comprising:
[0010] S1: preparing an aluminum nitride disc-shaped setter plate, the size of the aluminum nitride disc-shaped setter plate is: a diameter greater than or equal to φ500 mm, and a height greater than or equal to 12 mm;
[0011] S2: Sintered, ground and polished to ensure flatness, with surface roughness controlled at 0.4;
[0012] S3: First, drill a φ4mm center hole at the center of the disc-shaped setter according to the designed size, and then drill holes in the inner and outer areas and polish them;
[0013] S4: warm-pressing the cut alumina blank made by tape-casting, wherein the diameter of the alumina blank is greater than or equal to φ500 mm and the thickness h is greater than or equal to 22 mm, and weighing its loss on ignition rate;
[0014] S5: Place the alumina blank with marked pore sizes in different areas on a perforated disc-shaped setter plate and perform debinding in air at a rate of 0.3°C / min from room temperature to 500°C according to the debinding curve. After reaching the highest temperature, the holding time is greater than or equal to 400 minutes, and the temperature is naturally lowered after the holding period ends.
[0015] S6: The binder removal rate of the alumina blank after binder removal is tested, and then a carbon-sulfur analyzer is used to perform destructive carbon content analysis at the marked points of the alumina blank. After testing the central through hole, inner area and outer area, the experimental results fully meet the performance requirements, proving that the carbon content of the blank meets the technical requirements by opening holes in different areas.
[0016] The above technical solution has the following beneficial effects:
[0017] Reduce energy consumption and improve yield rate;
[0018] Through experiments, it was found that under the same debinding conditions, by changing the gradient aperture of the disc-shaped support plate, the heat will pass through the aperture to exchange heat with the green body at the bottom, which is more conducive to the uniform volatilization of additives and plasticizers, making the green body performance consistent from top to bottom. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a structural schematic diagram of a binder removal jig for ceramic green body of the present invention;
[0020] Figure 2 Another structural schematic diagram of a binder removal jig for ceramic green body according to the present invention;
[0021] Figure 3 for Figure 2 Schematic diagram of the structure of the middle sector area. DETAILED DESCRIPTION
[0022] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. 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 the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0023] Example 1
[0024] By measuring the carbon content at the center point of the bottom of a large-sized ceramic body with a diameter of φ500mm and a thickness of h22mm, the measurement was performed from the inner point of the center point to the outer measuring point. The center point was 6300ppm, the middle point was 2200ppm, and the outer point was 700ppm. It was found that the carbon content of the center point decreased from the inside to the outside. This is because the heat in the debinding process is directly exchanged with the body from the top and the outside of the body to achieve the debinding effect, and the bottom of the large-sized body on the solid disc-shaped sintering plate 1 is difficult to directly react with the hot air, but is achieved through heat conduction. Due to the high porosity and poor density during the body forming process, the corresponding low thermal conductivity results in a certain temperature gradient between the bottom of the center point of the body and the periphery of the body, resulting in less or no complete participation of the carbon content in the bottom center point and its vicinity in the reaction;
[0025] To solve the problem of too high carbon content at the bottom of large-size and thick-walled products, we select a disc-shaped setter 1 of homogeneous size and evenly distribute it, and make holes in gradient sizes to achieve debinding of the green body. The experimental test shows that the effect is obvious, and the carbon residue in each part is less than 500ppm.
[0026] The original solid firing method is changed to uniformly distribute gradient holes at the center point to achieve balanced heat exchange between the center point at the bottom of the green body, the middle part of the center point and the outer circle with the hot air flow, thus reducing the difference in carbon content in different areas.
[0027] Choose a disc-shaped setter plate 1 made of AIN material with good thermal conductivity to reduce the temperature difference caused by temperature gradient;
[0028] refer to Figure 1On one hand, the present invention discloses a binder removal jig for ceramic green body, the binder removal jig comprises a disc-shaped setter 1 for placing the ceramic green body, a central through hole 2 is arranged at the center of the disc-shaped setter 1, the disc-shaped setter 1 comprises an inner region 4 and an outer region 5, the inner region 4 is between the central through hole 2 and the outer region 5, a plurality of circles of through holes 6 are arranged on the inner region 4, an outer through hole 7 is arranged on the outer region 5, the diameters of all the through holes on the inner region 4 are smaller than the diameter of the central through hole 2, and the diameters of all the outer through holes 7 on the outer region 5 are smaller than any through hole on the inner region 4;
[0029] According to the above test on carbon content, the diameter of the central through hole 2 to be set is the largest, and then from the central hole to the inside area 4, the apertures of the holes in this area can be the same, or can be gradually reduced outward, but the apertures of the holes in the inner area 4 are smaller than the apertures of the central through hole 2. The inner area 4 is provided with multiple circles of holes, which are arranged with the central through hole 2 as the center. At the same time, the central through hole 2 is also the center of the multiple circles of holes of the entire disc-shaped support plate 1. The outer through holes 7 on the outer area 5 can be several circles of holes, and then gradually decrease from the inside to the outside. The range of the inner area 4 and the range of the outer area 5 can be set according to actual needs. For example: if the diameter of the disc-shaped support plate 1 is 500mm, the dividing circle 3 with a diameter of 250mm can be used as a reference, and the diameter from the inside of the circle to the central through hole 2 is the inner area 4, and the area outside the circle is the outer area 5.
[0030] The diameters of the plurality of through holes on the inner area 4 are the same or gradually decrease from the center of the circle to the outside, preferably gradually decrease from the center of the circle to the outside, which can meet the carbon content of the ceramic after sintering. At the same time, the disc-shaped support plate 1 also needs to meet the basic support of the ceramic green body;
[0031] refer to Figure 2 , Figure 3 The outer area 5 includes 12 sector-shaped partitions 8 spliced along the circumferential direction. Figure 3 8 is a schematic diagram of the structure of the sector-shaped partition 8. The apertures of the outer through holes 7 on the sector-shaped partition 8 gradually decrease from the center of the circle to the outside or remain the same. In other implementations of the present embodiment, the outer region 5 may also be provided with a plurality of circle holes, in which case the apertures may be the same or may decrease from the inside to the outside.
[0032] The diameter of the ceramic green body is less than or equal to the diameter of the disc-shaped support plate 1, so as to facilitate the support of the ceramic green body to be sintered and meet the basic debinding support;
[0033] Through experiments, under the same binder removal conditions, by changing the gradient aperture of the disc-shaped support plate 1, the heat will pass through the aperture to exchange heat with the green body at the bottom, which is more conducive to the uniform volatilization of additives and plasticizers, making the green body performance consistent from top to bottom.
[0034] Example 2
[0035] Another aspect of the present invention discloses a debinding method using the debinding fixture for ceramic green body, comprising the following steps:
[0036] S1: preparing an aluminum nitride disc-shaped setter 1, the size of the aluminum nitride disc-shaped setter 1 is: a diameter greater than or equal to φ500 mm, and a height greater than or equal to 12 mm;
[0037] S2: Sintered, ground and polished to ensure flatness, with surface roughness controlled at 0.4;
[0038] S3: First, a φ4mm center hole is drilled at the center point of the disc-shaped setter 1 according to the designed size, and then holes are drilled and polished on the inner area 4 and the outer area 5;
[0039] S4: warm-pressing the cut alumina blank made by tape-casting, wherein the diameter of the alumina blank is greater than or equal to φ500 mm and the thickness h is greater than or equal to 22 mm, and weighing its loss on ignition rate;
[0040] S5: placing the alumina blank with marked pore sizes in different areas on a perforated disc-shaped setter 1 and debinding in air at a rate of 0.3°C / min from room temperature to 500°C according to the debinding curve. After reaching the highest temperature, the heat preservation time is greater than or equal to 400 minutes, and the temperature is naturally lowered after the heat preservation ends.
[0041] S6: The binder removal rate of the alumina body after binder removal is tested, and then a destructive carbon content analysis is performed at the marked points of the alumina body using a carbon-sulfur analyzer. After testing the central through hole 2, the inner area 4 and the outer area 5, the experimental results fully meet the performance requirements, proving that by opening holes in different areas, the carbon content of the ceramic body meets the technical requirements.
[0042] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, 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 scope of protection of the present invention.
Claims
1. A binder removal jig for ceramic greenware, characterized in that: The debinding jig includes a disc-shaped support plate for placing ceramic green bodies, a central through hole is provided at the center of the disc-shaped support plate, the disc-shaped support plate includes an inner area and an outer area, the inner area is between the central through hole and the outer area, a plurality of circles of through holes are provided on the inner area, and an outer through hole is provided on the outer area, the diameters of all the through holes on the inner area are smaller than the diameter of the central through hole, and the diameters of all the outer through holes on the outer area are smaller than any through hole on the inner area.
2. A binder removal jig for ceramic green body according to claim 1, characterized in that: The diameters of the plurality of circles of through holes on the inner area are the same or gradually decrease from the center of the circle to the outside.
3. A binder removal jig for ceramic green body according to claim 1, characterized in that: The outer area includes a plurality of sector-shaped partitions spliced along the circumferential direction, and the apertures of the outer through holes on the sector-shaped partitions gradually decrease from the center of the circle to the outside or remain the same.
4. A binder removal jig for ceramic green body according to claim 3, characterized in that: The diameter of the ceramic green body is smaller than or equal to the diameter of the disc-shaped support plate.
5. A debinding method using the debinding jig for ceramic green body according to any one of claims 1 to 4, characterized in that: The method comprises: S1: Prepare an aluminum nitride disc-shaped support plate. The size of the aluminum nitride disc-shaped support plate is: the diameter is greater than or equal to Height greater than or equal to 12mm; S2: Sintered, ground and polished to ensure flatness, with surface roughness controlled at 0.4; S3: First punch the center point of the disc-shaped support plate according to the designed size. The center hole is then drilled and polished on the inner and outer areas; S4: Warm press the cut alumina blank of the tape-cast laminate, wherein the diameter of the alumina blank is greater than or equal to If the thickness h is greater than or equal to 22 mm, weigh its loss on ignition rate; S5: Place the alumina blank with marked pore sizes in different areas on a perforated disc-shaped setter plate and perform debinding in air at a rate of 0.3°C / min from room temperature to 500°C according to the debinding curve. After reaching the highest temperature, the holding time is greater than or equal to 400 minutes, and the temperature is naturally lowered after the holding period ends. S6: The binder removal rate of the alumina blank after binder removal is tested, and then a carbon-sulfur analyzer is used to perform destructive carbon content analysis at the marked points of the alumina blank. After testing the central through hole, inner area and outer area, the experimental results fully meet the performance requirements, proving that the carbon content of the blank meets the technical requirements by opening holes in different areas.