阅读说明：本技术 一种碳化硅籽晶粘贴剂的制备方法 (Preparation method of silicon carbide seed crystal adhesive ) 是由 不公告发明人 于 2021-08-26 设计创作，主要内容包括：本发明属于碳化硅晶体领域,公开了一种碳化硅籽晶粘贴剂的制备方法,所述方法包括以下步骤：(1)以重量份计,取氮化硅粉料90-100份,二氧化硅粉20-30份,研磨、混合均匀；加入聚乙二醇80-100份；(2)以重量份计,向步骤(1)得到的混合物中加入硼酸10-20份,淀粉20-40份,并搅拌；(3)对步骤(2)中得到的混合物进行超声处理；(4)加入蒸馏水后加热并搅拌,得到碳化硅籽晶粘贴剂。本发明解决了物理气相传输法生长碳化硅单晶晶体,所使用的粘结剂造价昂贵,使用范围单一、操作困难的问题。(The invention belongs to the field of silicon carbide crystals, and discloses a preparation method of a silicon carbide seed crystal adhesive, which comprises the following steps: (1) taking 90-100 parts of silicon nitride powder and 20-30 parts of silicon dioxide powder by weight, grinding and uniformly mixing; adding 80-100 parts of polyethylene glycol; (2) adding 10-20 parts of boric acid and 20-40 parts of starch into the mixture obtained in the step (1) in parts by weight, and stirring; (3) carrying out ultrasonic treatment on the mixture obtained in the step (2); (4) adding distilled water, heating and stirring to obtain the silicon carbide seed crystal adhesive. The invention solves the problems of high cost of the used binder, single use range and difficult operation in the physical vapor transport method for growing the silicon carbide single crystal.)

1. The preparation method of the silicon carbide seed crystal adhesive is characterized by comprising the following steps of:

(1) taking 90-100 parts of silicon nitride powder and 20-30 parts of silicon dioxide powder by weight, grinding and uniformly mixing; adding 80-100 parts of polyethylene glycol;

(2) adding 10-20 parts by weight of boric acid and 20-40 parts by weight of starch into the mixture obtained in the step (1), and stirring to obtain a mixture;

(3) carrying out ultrasonic treatment on the mixture obtained in the step (2);

(4) adding distilled water, heating and stirring to obtain the silicon carbide seed crystal adhesive.

2. The method for preparing the silicon carbide seed crystal adhesive according to claim 1, wherein the time of the ultrasonic treatment in the step (3) is 1 to 1.5 hours.

3. The method for preparing the silicon carbide seed crystal adhesive according to claim 2, wherein the particle sizes of the silicon nitride powder and the silicon dioxide powder ground in the step (1) are less than 80 meshes.

4. A method for preparing a seed crystal paste of silicon carbide according to claim 3, wherein the heating temperature in the step (4) is 50-60 ℃.

5. The method for preparing the silicon carbide seed crystal adhesive according to claim 4, wherein the stirring condition in the step (4) is 800-1000 rpm for 30-45 minutes.

Technical Field

The invention belongs to the field of silicon carbide crystal preparation, and particularly relates to a preparation method of a silicon carbide seed crystal adhesive.

Background

The silicon carbide belongs to the third-generation semiconductor material and has the characteristics of high forbidden band width, high thermal conductivity, high electron drift rate, high chemical stability and the like. Due to good physical properties, the novel photovoltaic inverter has wide application prospects in the aspects of 5G communication, new energy automobile photovoltaic inverters and the like.

A commonly used method for producing a silicon carbide single crystal is a physical vapor transport method. When certain conditions such as high temperature and certain air pressure of inert gas atmosphere are reached, the silicon carbide raw material in the crucible can decompose and sublimate to form gaseous components, and under the action of the temperature gradient, the gaseous components are transferred to the surface of the silicon carbide seed crystal with lower temperature and are deposited and arranged in order, and the silicon carbide single crystal is formed after continuous growth.

When a silicon carbide single crystal is grown by a physical vapor transport method, a seed crystal is usually stuck to a crucible cover. The choice of binder used here is very important, not only for very high viscosity and strength, but also for withstanding high temperatures of around 1900 ℃. During the operation of adhering the seed crystal, the adhesive is properly applied to uniformly coat the space between the crucible cover and the seed crystal, if too small, the seed crystal or crystal will fall off. The factors cause the defects of high cost, single use range, easy solidification, need of using in time, occupation of a large amount of experimental time, difficult operation and the like of the adhesive used for adhering the seed crystal.

Disclosure of Invention

In order to solve the problems of high cost of the used adhesive, single use range and difficult operation in the physical vapor transport method for growing the silicon carbide single crystal in the prior art, the invention provides a preparation method of a silicon carbide seed crystal adhesive.

The invention adopts the specific scheme that: a preparation method of a silicon carbide seed crystal adhesive comprises the following steps:

(1) taking 90-100 parts of silicon nitride powder and 20-30 parts of silicon dioxide powder by weight, grinding and uniformly mixing; adding 80-100 parts of polyethylene glycol;

(2) adding 10-20 parts of boric acid and 20-40 parts of starch into the mixture obtained in the step (1) in parts by weight, and stirring;

(3) carrying out ultrasonic treatment on the mixture obtained in the step (2);

(4) adding distilled water, heating and stirring to obtain the silicon carbide seed crystal adhesive.

The ultrasonic treatment time in the step (3) is 1-1.5 hours.

The particle sizes of the silicon nitride powder and the silicon dioxide powder ground in the step (1) are smaller than 80 meshes.

The heating temperature in the step (4) is 50-60 ℃.

The stirring condition in the step (4) is 800-1000 revolutions, and the time is 30-45 minutes.

Compared with the prior art, the invention has the following beneficial effects:

according to the invention, silicon nitride powder is selected as a main body of the binder, silicon dioxide powder can be melted at high temperature, and other components are bound after polyethylene glycol is completely decomposed and evaporated; starch and silicon dioxide powder can be decomposed at high temperature to generate carbon and silicon, and are easily connected with silicon carbide seed crystals to form a stable bonding structure; the polyethylene glycol and the boric acid bond various powder materials in the process of preparing the bonding agent, and increase the viscosity. The silicon carbide seed crystal binder prepared by the invention has the characteristics of excellent high temperature resistance, small shrinkage, high hardness, high wear resistance coefficient, excellent chemical stability and the like.

Drawings

Fig. 1 shows a silicon carbide small wafer prepared by using the adhesive of the present invention.

Detailed Description

The present invention will be further described with reference to the following embodiments.

Example 1

The invention provides a preparation method of a silicon carbide seed crystal adhesive, which comprises the following steps:

(1) taking 90g of silicon nitride powder, 20g of silicon dioxide powder and 80g of polyethylene glycol;

(2) grinding silicon nitride powder and silicon dioxide powder and then uniformly mixing; the particle diameters of the silicon nitride powder and the silicon dioxide powder after grinding are less than 80 meshes; (3) adding the polyethylene glycol into the uniformly mixed powder;

(4) adding 10g of boric acid and 20g of starch into the mixture obtained in the step (3), and stirring;

(5) carrying out ultrasonic treatment on the mixture obtained in the step (4), wherein the ultrasonic treatment time is 1 hour;

(6) adding distilled water, heating at 50 deg.C and rotating at 800 rpm, and stirring for 30min to obtain silicon carbide seed crystal adhesive.

Example 2

A preparation method of a silicon carbide seed crystal adhesive comprises the following steps:

(1) taking 100g of silicon nitride powder, 30g of silicon dioxide powder and 100g of polyethylene glycol;

(2) grinding silicon nitride powder and silicon dioxide powder and then uniformly mixing; the particle diameters of the silicon nitride powder and the silicon dioxide powder after grinding are less than 80 meshes; (3) adding the polyethylene glycol into the uniformly mixed powder;

(4) adding 20g of boric acid and 40g of starch into the mixture obtained in the step (3), and stirring;

(5) carrying out ultrasonic treatment on the mixture obtained in the step (4), wherein the ultrasonic treatment time is 1.5 hours;

(6) adding distilled water, heating at 50 deg.C and 1000 rpm, and stirring for 45min to obtain silicon carbide seed crystal adhesive.

Example 3

A preparation method of a silicon carbide seed crystal adhesive comprises the following steps:

(1) taking 95g of silicon nitride powder, 25g of silicon dioxide powder and 90g of polyethylene glycol;

(2) grinding silicon nitride powder and silicon dioxide powder and then uniformly mixing; the particle diameters of the silicon nitride powder and the silicon dioxide powder after grinding are less than 80 meshes; (3) adding the polyethylene glycol into the uniformly mixed powder;

(4) adding 15g of boric acid and 30g of starch into the mixture obtained in the step (3), and stirring;

(5) carrying out ultrasonic treatment on the mixture obtained in the step (4), wherein the ultrasonic treatment time is 1.5 hours;

(6) adding distilled water, heating at 50 deg.C and 900 rpm, and stirring for 40min to obtain silicon carbide seed crystal adhesive.

The adhesive prepared by the invention is suitable for growing the silicon carbide single crystal by a physical vapor transport method, has extremely high viscosity and strength, can bear high temperature of about 1900 ℃, does not influence the growth of the silicon carbide single crystal, and has stable chemical property.

According to the invention, silicon nitride powder is selected as a main body of the binder, silicon dioxide powder can be melted at high temperature, and other components are bound after polyethylene glycol is completely decomposed and evaporated; starch and silicon dioxide powder can be decomposed at high temperature to generate carbon and silicon, and are easily connected with silicon carbide seed crystals to form a stable bonding structure; the polyethylene glycol and the boric acid bond various powder materials in the process of preparing the bonding agent, and increase the viscosity. The silicon carbide seed crystal binder prepared by the invention has the characteristics of excellent high temperature resistance, small shrinkage, high hardness, high wear resistance coefficient and the like.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications may be made to the above-described embodiments, and it is not necessary, nor is it intended to be exhaustive of all the embodiments. And obvious variations or modifications therefrom are intended to be within the scope of the invention.