Aluminum nitride heating sheet and preparation method thereof

Abstract

The invention relates to the technical field of ceramic materials, in particular to an aluminum nitride heating sheet and a preparation method thereof.The preparation method of the aluminum nitride heating sheet comprises the following steps that S1, granulation is conducted, specifically, aluminum nitride, a sintering aid and an organic binder are mixed and granulated; s2, pre-pressing forming is conducted, specifically, a three-section pre-pressing process is adopted for green body forming; s3, glue discharging and sintering: performing glue discharging in a glue discharging furnace, and sintering in a graphite furnace with a nitrogen protective atmosphere and a flow rate of 25-40ml / min; the sintering temperature is 1300-1550 DEG C, and the temperature is kept for 50-60 And S4, cooling and grinding, wherein the sintered body is cooled to the normal temperature and ground to be flat. According to the preparation method disclosed by the invention, the obtained heating sheet has good mechanical strength and thermal conductivity.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic materials, and in particular to an aluminum nitride heating plate and a preparation method thereof. Background Art

[0002] As the semiconductor industry is booming, precise temperature control has become an indispensable key link in chip manufacturing, testing, and the operation of many precision electronic devices. As the core component that provides a stable heat source, the performance and quality of the heater are directly related to the reliability and stability of the entire system.

[0003] At present, the most common process for producing heaters is tape casting, which can achieve continuous production, has a relatively uniform product thickness, and is widely used. However, as semiconductor technology develops towards high integration and refinement, the shortcomings of tape casting are highlighted. Limited by the molding principle and parameters, the maximum thickness of the heater produced is about 1mm, which is difficult to meet the requirements of semiconductor chips for the diverse thickness of heaters.

[0004] When thicker heaters are needed, the industry often uses hot pressing, lamination and isostatic pressing. However, this process has many problems. The lamination operation is complicated, and the interface bonding between layers is difficult to control, which can easily cause internal stratification and destroy the structural integrity and uniformity of the product. The temperature and pressure are uneven during hot pressing, and the material flow is poor, resulting in flow marks inside and on the surface of the product, affecting the stability of electrical and thermal properties. Moreover, in the subsequent mechanical processing stage, due to the residual stress and fragile structure of the material, collapse often occurs, there are many white spots on the surface, and the yield is low. From the perspective of production economics, this process is complicated and requires high-end equipment such as high-precision hot presses and large isostatic presses, with high equipment purchase and maintenance costs. The long process is also accompanied by high energy consumption and a large amount of manpower investment, soaring production costs, and low production efficiency, which cannot adapt to the large-scale and high-efficiency production needs of the modern semiconductor industry. Summary of the invention

[0005] In view of this, the object of the present invention is to provide an aluminum nitride heating plate and a preparation method thereof, wherein the obtained heating plate has good mechanical strength and thermal conductivity.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: A method for preparing an aluminum nitride heating plate comprises the following steps: S1: Granulation: mixing aluminum nitride, sintering aid and organic binder to form granules; S2: Pre-pressing: Green billet is formed by three-stage pre-pressing process; S3: Debinding and sintering: After debinding in the debinding furnace, sintering is performed in a graphite furnace with a nitrogen protective atmosphere and a flow rate of 25-40ml / min; the sintering temperature is 1300-1550℃, and the heat preservation time is 50-60min; S4: Cooling and grinding: The sintered body is cooled to room temperature and ground.

[0007] Preferably, in step S1, the weight ratio of aluminum nitride, sintering aid and organic binder is 98:1:1.

[0008] Preferably, the sintering aid in step S1 is modified yttrium oxide.

[0009] Preferably, the preparation method of the modified yttrium oxide is specifically as follows: mixing didecyl dimethyl ammonium chloride, chitosan, yttrium oxide and a 50% by volume ethanol solution, stirring at 30-40° C. for 4-6 hours, and vacuum drying to obtain the modified yttrium oxide.

[0010] Preferably, the weight ratio of didecyldimethylammonium chloride, chitosan, yttrium oxide and ethanol solution is 1:1:2:4.

[0011] Preferably, the organic binder in step S1 is a modified bisacrylamide polymer.

[0012] Preferably, the preparation method of the modified bisacrylamide polymer is specifically as follows: N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate and 75% by volume tetramethylethylenediamine solution are mixed, stirred for 12-24 hours, polyvinyl alcohol and graphene are added, and stirring is continued for 12-24 hours to obtain the modified bisacrylamide polymer.

[0013] Preferably, the weight ratio of the N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine solution, polyvinyl alcohol and graphene is 1:1:2:4:1:1.

[0014] Preferably, the specific process of the three-stage pre-pressing process is: initially pre-pressing at a pressure of 0.3-0.5 t / cm² for 5-10 seconds, then increasing the pressure at a rate of 1.2-1.8 t / cm² for 20-30 seconds, and maintaining the pressure for 10-20 seconds.

[0015] An aluminum nitride heating plate is prepared by the above-mentioned preparation method.

[0016] The present invention can regulate the growth of aluminum nitride grains and grain boundary migration by modifying the sintering aid, effectively reduce the sintering temperature by about 50°C-100°C, promote uniform grain refinement, and improve product density and thermal conductivity; at the same time, it is matched with 1%-3% special organic binder, which has both flexibility and high-strength bonding. Through the adsorption and bonding of aluminum nitride particles, it is beneficial to the rearrangement and growth of aluminum nitride grains, ensures that the granulation powder particles are tightly combined during dry pressing, and can be completely decomposed and removed during debinding. Through the three-stage pre-pressing process airflow classification, the particle size of the granulation powder is regulated so that its particle size is concentrated in 10μm-50μm, and it has good fluidity and filling properties, making the sintering more dense, and the thermal conductivity and strength better. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. In addition, it is specifically stated that the raw materials and equipment of the present invention can be obtained from commercial sources, and no longer listed one by one. Among them, the raw materials of the present invention can be obtained from commercial sources and are well known to those skilled in the art. Example 1

[0018] A method for preparing an aluminum nitride heating plate comprises the following steps: S1: Granulation: Aluminum nitride, modified yttrium oxide and modified bisacrylamide polymer are mixed and granulated in a weight ratio of 98:1:1, and the particle size of the granulated powder is 15-30 μm; The preparation method of the modified yttrium oxide is specifically as follows: didecyl dimethyl ammonium chloride, chitosan, yttrium oxide and 50% by volume ethanol solution are mixed in a weight ratio of 1:1:2:4, stirred at 30° C. for 4 hours, and vacuum dried to obtain the modified yttrium oxide; The preparation method of the modified bisacrylamide polymer is specifically as follows: N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate and a tetramethylethylenediamine solution with a volume fraction of 75% are mixed, and after stirring for 12 hours, polyvinyl alcohol and graphene are added, and stirring is continued for 12 hours, and the weight ratio of N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine solution, polyvinyl alcohol and graphene is 1:1:2:4:1:1, so as to obtain the modified bisacrylamide polymer; S2: Pre-pressing: The green body is formed by a three-stage pre-pressing process: initially pre-pressing at 0.3t / cm² for 5s, then increasing the pressure at 1.2t / cm² for 20s, and maintaining the pressure for 10s; S3: Debinding sintering: After debinding in the debinding furnace, sintering is performed in a graphite furnace with a nitrogen protective atmosphere and a flow rate of 25 ml / min; the sintering temperature is 1300°C and the temperature is kept for 50 minutes; S4: Cooling and grinding: The sintered body is cooled to room temperature and ground by a surface grinder.

[0019] An aluminum nitride heating plate is prepared by the above-mentioned preparation method. Example 2

[0020] A method for preparing an aluminum nitride heating plate comprises the following steps: S1: Granulation: Aluminum nitride, modified yttrium oxide and modified bisacrylamide polymer are mixed and granulated in a weight ratio of 98:1:1, and the particle size of the granulated powder is 15-30 μm; The preparation method of the modified yttrium oxide is specifically as follows: didecyl dimethyl ammonium chloride, chitosan, yttrium oxide and 50% by volume ethanol solution are mixed in a weight ratio of 1:1:2:4, stirred at 40° C. for 6 hours, and vacuum dried to obtain the modified yttrium oxide; The preparation method of the modified bisacrylamide polymer is specifically as follows: N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate and a tetramethylethylenediamine solution with a volume fraction of 75% are mixed, and after stirring for 24 hours, polyvinyl alcohol and graphene are added, and stirring is continued for 24 hours, and the weight ratio of N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine solution, polyvinyl alcohol and graphene is 1:1:2:4:1:1, so as to obtain the modified bisacrylamide polymer; S2: Pre-pressing: The green body is formed by a three-stage pre-pressing process: initially pre-pressing at 0.5t / cm² for 10s, then increasing the pressure at 1.8t / cm² for 30s, and maintaining the pressure for 20s; S3: Debinding sintering: After debinding in the debinding furnace, sintering is performed in a graphite furnace with a nitrogen protective atmosphere and a flow rate of 40 ml / min; the sintering temperature is 1550°C and the temperature is kept for 60 minutes; S4: Cooling and grinding: The sintered body is cooled to room temperature and ground by a surface grinder.

[0021] An aluminum nitride heating plate is prepared by the above-mentioned preparation method. Example 3

[0022] A method for preparing an aluminum nitride heating plate comprises the following steps: S1: Granulation: Aluminum nitride, modified yttrium oxide and modified bisacrylamide polymer are mixed and granulated in a weight ratio of 98:1:1, and the particle size of the granulated powder is 15-30 μm; The preparation method of modified yttrium oxide is specifically as follows: didecyl dimethyl ammonium chloride, chitosan, yttrium oxide and 50% ethanol solution by volume are mixed in a weight ratio of 1:1:2:4, stirred at 35° C. for 5 hours, and vacuum dried to obtain modified yttrium oxide; The preparation method of the modified bisacrylamide polymer is specifically as follows: N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate and a tetramethylethylenediamine solution with a volume fraction of 75% are mixed, and after stirring for 20 hours, polyvinyl alcohol and graphene are added, and stirring is continued for 20 hours, and the weight ratio of N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine solution, polyvinyl alcohol and graphene is 1:1:2:4:1:1, so as to obtain the modified bisacrylamide polymer; S2: Pre-pressing: The green body is formed by a three-stage pre-pressing process: initially pre-pressing at 0.4t / cm² for 8s, then increasing the pressure at 1.6t / cm² for 25s, and maintaining the pressure for 15s; S3: Debinding sintering: After debinding in the debinding furnace, sintering is performed in a graphite furnace with a nitrogen protective atmosphere and a flow rate of 30 ml / min; the sintering temperature is 1400°C and the heat preservation time is 55 minutes; S4: Cooling and grinding: The sintered body is cooled to room temperature and ground by a surface grinder.

[0023] An aluminum nitride heating plate is prepared by the above-mentioned preparation method. Comparative Example 1:

[0024] The preparation method of Comparative Example 1 is basically the same as that of Example 1, except that aluminum nitride and yttrium oxide are directly mixed and dispersed, specifically: A method for preparing an aluminum nitride heating plate comprises the following steps: S1: Granulation: Aluminum nitride, yttrium oxide and modified bisacrylamide polymer are mixed and granulated in a weight ratio of 98:1:1, and the particle size of the granulated powder is 15-30 μm; The preparation method of the modified bisacrylamide polymer is specifically as follows: N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate and a tetramethylethylenediamine solution with a volume fraction of 75% are mixed, and after stirring for 12 hours, polyvinyl alcohol and graphene are added, and stirring is continued for 12 hours, and the weight ratio of N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine solution, polyvinyl alcohol and graphene is 1:1:2:4:1:1, so as to obtain the modified bisacrylamide polymer; S2: Pre-pressing: The green body is formed by a three-stage pre-pressing process: initially pre-pressing at 0.3t / cm² for 5s, then increasing the pressure at 1.2t / cm² for 20s, and maintaining the pressure for 10s; S3: Debinding sintering: After debinding in the debinding furnace, sintering is performed in a graphite furnace with a nitrogen protective atmosphere and a flow rate of 25 ml / min; the sintering temperature is 1300°C and the temperature is kept for 50 minutes; S4: Cooling and grinding: The sintered body is cooled to room temperature and ground by a surface grinder.

[0025] An aluminum nitride heating plate is prepared by the above-mentioned preparation method. Comparative Example 2:

[0026] The preparation method of Comparative Example 2 is basically the same as that of Example 1, except that aluminum nitride and yttrium oxide are directly mixed and dispersed, and polyethyl acrylate is directly used as the organic binder, specifically: A method for preparing an aluminum nitride heating plate comprises the following steps: S1: Granulation: Aluminum nitride, yttrium oxide and polyethyl acrylate are mixed in a weight ratio of 98:1:1 to form granules, and the particle size of the granulated powder is 15-30 μm; S2: Pre-pressing: The green body is formed by a three-stage pre-pressing process: initially pre-pressing at 0.3t / cm² for 5s, then increasing the pressure at 1.2t / cm² for 20s, and maintaining the pressure for 10s; S3: Debinding sintering: After debinding in the debinding furnace, sintering is performed in a graphite furnace with a nitrogen protective atmosphere and a flow rate of 25 ml / min; the sintering temperature is 1300°C and the temperature is kept for 50 minutes; S4: Cooling and grinding: The sintered body is cooled to room temperature and ground by a surface grinder.

[0027] An aluminum nitride heating plate is prepared by the above-mentioned preparation method. Comparative Example 3:

[0028] The preparation method of Comparative Example 3 is basically the same as that of Example 1, except that the three-stage pre-pressing process is not used, specifically: A method for preparing an aluminum nitride heating plate comprises the following steps: S1: Granulation: Aluminum nitride, modified yttrium oxide and modified bisacrylamide polymer are mixed and granulated in a weight ratio of 98:1:1, and the particle size of the granulated powder is 15-30 μm; The preparation method of the modified yttrium oxide is specifically as follows: didecyl dimethyl ammonium chloride, chitosan, yttrium oxide and 50% by volume ethanol solution are mixed in a weight ratio of 1:1:2:4, stirred at 30° C. for 4 hours, and vacuum dried to obtain the modified yttrium oxide; The preparation method of the modified bisacrylamide polymer is specifically as follows: N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate and a tetramethylethylenediamine solution with a volume fraction of 75% are mixed, and after stirring for 12 hours, polyvinyl alcohol and graphene are added, and stirring is continued for 12 hours, and the weight ratio of N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine solution, polyvinyl alcohol and graphene is 1:1:2:4:1:1, so as to obtain the modified bisacrylamide polymer; S2: Pre-pressing: pre-pressing for 30 seconds at a pressure of 0.3t / cm²; S3: Debinding sintering: After debinding in the debinding furnace, sintering is performed in a graphite furnace with a nitrogen protective atmosphere and a flow rate of 25 ml / min; the sintering temperature is 1300°C and the temperature is kept for 50 minutes; S4: Cooling and grinding: The sintered body is cooled to room temperature and ground by a surface grinder.

[0029] An aluminum nitride heating plate is prepared by the above-mentioned preparation method.

[0030] The following tests were conducted on the heating plates obtained from Examples 1-3, the commercially available heating plates from Shenzhen Supot Technology Co., Ltd., and Comparative Examples 1-3.

[0031] Performance Test: Strength: Take the heating plate with a specification of 24*24mm as a sample, and use a universal electronic material testing machine to test the substrate strength through fracture extrusion.

[0032] Thermal conductivity: Using LFA467 thermal conductivity tester (10mm*2.0mm specification sample), the qualified thermal conductivity range is ≥170W / (m·K).

[0033] The strength and thermal conductivity were tested by taking 100 heaters and taking the average value of the test results.

[0034] Table 1: Test data of heating sheets of Examples 1-3, commercially available heating sheets and comparative examples 1-3

[0035] It can be seen from the above table that the heating plates prepared in Examples 1-3 have relatively good strength and thermal conductivity.

[0036] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing an aluminum nitride heating plate, characterized in that: The following steps are involved: S1: Granulation: mixing aluminum nitride, sintering aid and organic binder to form granules; S2: Pre-pressing: Green billet is formed by three-stage pre-pressing process; S3: Debinding and sintering: After debinding in the debinding furnace, sintering is performed in a graphite furnace with a nitrogen protective atmosphere and a flow rate of 25-40ml / min; the sintering temperature is 1300-1550℃, and the heat preservation time is 50-60min; S4: Cooling and grinding: cooling the sintered body to room temperature and grinding it; The sintering aid in step S1 is modified yttrium oxide; the preparation method of the modified yttrium oxide is specifically as follows: mixing didecyl dimethyl ammonium chloride, chitosan, yttrium oxide and a 50% by volume ethanol solution, stirring at 30-40° C. for 4-6 hours, and vacuum drying to obtain the modified yttrium oxide; The organic binder in step S1 is a modified bisacrylamide polymer; the preparation method of the modified bisacrylamide polymer is specifically as follows: N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate and a 75% by volume tetramethylethylenediamine solution are mixed, stirred for 12-24 hours, polyvinyl alcohol and graphene are added, and stirring is continued for 12-24 hours to obtain the modified bisacrylamide polymer.

2. The method for preparing the aluminum nitride heating plate according to claim 1, characterized in that: In the step S1, the weight ratio of aluminum nitride, sintering aid and organic binder is 98:1:

1.

3. The method for preparing the aluminum nitride heating plate according to claim 1, characterized in that: The weight ratio of didecyldimethylammonium chloride, chitosan, yttrium oxide and ethanol solution is 1:1:2:

4.

4. The method for preparing the aluminum nitride heating plate according to claim 1, characterized in that: The weight ratio of the N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine solution, polyvinyl alcohol and graphene is 1:1:2:4:1:

1.

5. The method for preparing the aluminum nitride heating plate according to claim 1, characterized in that: The specific process of the three-stage pre-pressing process is: initially pre-pressing at a pressure of 0.3-0.5t / cm² for 5-10s, then increasing the pressure at a rate of 1.2-1.8t / cm² for 20-30s, and maintaining the pressure for 10-20s.

6. An aluminum nitride heating plate, characterized in that: The product is prepared by the preparation method described in claim 1.

Images