阅读说明：本技术 一种蓝宝石晶片研磨抛光方法 (Sapphire wafer grinding and polishing method ) 是由 姚健 于 2019-10-17 设计创作，主要内容包括：本发明属于宝石晶片加工技术领域,具体涉及一种蓝宝石晶片研磨抛光方法。包括以下步骤：对切割获得的蓝宝石晶片按厚度分组,使得同一组中多片蓝宝石晶片的厚度差在0.001mm以内；研磨阶段:采用粒度为1-3um的高硬度微粉做为磨料,配合粗磨液,输入至研磨机进行研磨10-15分钟；粗抛阶段：研磨结束后对所述蓝宝石晶片进行粗抛光；精抛阶段：将粗抛光后的蓝宝石晶片通过薄片状固定装置放置在双面抛光机的下抛光盘上,注入抛光液,所述上抛光盘和下抛光盘对蓝宝石晶片的上表面和下表面同时进行精抛光,其中所述抛光温度为45-55℃,抛光时间为25-35min。本发明的方法简单有效,适合工业化生产,所得的蓝宝石晶片的粗糙度低于0.3nm。(The invention belongs to the technical field of sapphire wafer processing, and particularly relates to a sapphire wafer grinding and polishing method. The method comprises the following steps: dividing the sapphire wafers obtained by cutting into groups according to the thickness, so that the thickness difference of a plurality of sapphire wafers in the same group is within 0.001 mm; grinding stage, using high-hardness micropowder whose grain size is 1-3um as grinding material, matching with coarse grinding liquor, inputting into grinding machine and grinding for 10-15 min; a rough polishing stage: after grinding is finished, carrying out rough polishing on the sapphire wafer; and (3) a fine polishing stage: and placing the roughly polished sapphire wafer on a lower polishing disc of a double-sided polishing machine through a sheet-shaped fixing device, injecting polishing liquid, and simultaneously carrying out fine polishing on the upper surface and the lower surface of the sapphire wafer by using the upper polishing disc and the lower polishing disc, wherein the polishing temperature is 45-55 ℃, and the polishing time is 25-35 min. The method is simple and effective, is suitable for industrial production, and the roughness of the obtained sapphire wafer is lower than 0.3 nm.)

1. A sapphire wafer grinding and polishing method is characterized by comprising the following steps:

(1) dividing the sapphire wafers obtained by cutting into groups according to the thickness, so that the thickness difference of a plurality of sapphire wafers in the same group is within 0.001 mm;

(2) grinding stage, using high-hardness micropowder whose grain size is 1-3um as grinding material, matching with coarse grinding liquor, inputting into grinding machine and grinding for 10-15 min;

(3) a rough polishing stage: after grinding, carrying out rough polishing on the sapphire wafer, wherein the polishing temperature is 25-38 ℃, and the single surface is polished for 25-35 min;

(4) and (3) a fine polishing stage: and placing the roughly polished sapphire wafer on a lower polishing disc of a double-sided polishing machine through a sheet-shaped fixing device, injecting polishing liquid, and simultaneously carrying out fine polishing on the upper surface and the lower surface of the sapphire wafer by using the upper polishing disc and the lower polishing disc, wherein the polishing temperature is 45-55 ℃, and the polishing time is 25-35 min.

2. The method for grinding and polishing the sapphire wafer as claimed in claim 1, comprising the steps of: the coarse grinding fluid in the step (2) comprises the following components in parts by mass: 35-48 parts of silicon dioxide, 28-32 parts of silicon carbide, 18-25 parts of aluminum oxide, 14-21 parts of boron nitride, 8-15 parts of chitosan, 8-14 parts of titanium diboride, 12-18 parts of glycerol, 7-11 parts of polyethylene glycol, 6-9 parts of carbon black, 6-9 parts of vermiculite powder, 4-7 parts of surfactant, 3-5 parts of dispersant and 150 parts of deionized water.

3. The method for grinding and polishing the sapphire wafer as claimed in claim 1, comprising the steps of: the coarse grinding fluid in the step (2) comprises the following components in parts by mass: 38 parts of silicon dioxide, 30 parts of silicon carbide, 22 parts of aluminum oxide, 18 parts of boron nitride, 12 parts of chitosan, 11 parts of titanium diboride, 15 parts of glycerol, 9 parts of polyethylene glycol, 8 parts of carbon black, 8 parts of vermiculite powder, 6 parts of surfactant, 4 parts of dispersant and 160 parts of deionized water.

4. The method for grinding and polishing the sapphire wafer as claimed in claim 1, comprising the steps of: and (4) polishing the single surface for 33min at the polishing temperature of 32 ℃ in the step (3).

5. The method for grinding and polishing the sapphire wafer as claimed in claim 1, comprising the steps of: and (4) polishing at 50 ℃ for 32 min.

Technical Field

The invention belongs to the technical field of sapphire wafer processing, and particularly relates to a sapphire wafer grinding and polishing method.

Background

Sapphire is a single crystal material with good light transmission and heat conductivity, and meanwhile, because the sapphire has excellent temperature resistance (the melting point is as high as 2200 ℃) and ultrahigh hardness (the Mohs hardness is as high as 9.0, and is only next to the diamond with the hardness of 10), the sapphire single crystal is commonly used for a guide window of a missile in the war industry, a precise instrument plate surface, a high-grade watch surface and the like. Recently, sapphire single crystal is used as a screen of a high-end mobile phone, which attracts great attention of wide merchants and consumers, but because the polishing processing efficiency of the sapphire single crystal plane is very low and the cost is high, the low polishing efficiency is a root cause for restricting the development of the sapphire screen. The development of an efficient sapphire polishing technology has extremely high economic value. The polishing of sapphire wafers is divided into a-direction polishing and C-direction polishing. From the crystal plane properties of sapphire, the hardness of the A-direction crystal plane is higher than that of the C-direction crystal plane. The mobile phone screen surface belongs to an A-direction sapphire crystal face, and the polishing difficulty is the highest. The sapphire A-direction polishing is generally divided into three stages of grinding, copper polishing and fine polishing. The first grinding section has the effect of reducing the depth of stepped scratches on the surface of the sapphire raw material sheets generated in the cutting process, and more importantly, the thicknesses of the sapphire raw material sheets in batches are consistent as much as possible. The thickness difference of the incoming materials of the same sapphire wafer is as high as 10-20um, and the thickness difference of the ground sapphire wafer can be reduced to 1-3 um. The second copper polishing stage is intended to further reduce the Total Thickness Variation (TTV) and surface roughness (Ra) of the sapphire wafer. The sapphire crystal face after the copper polishing section begins to have light transmittance. And the third fine polishing section reduces the surface roughness of the crystal face to be less than 1nm, so that the surface of the sapphire is flat, and the sapphire flat sheet is transparent. Grinding, copper polishing and polishing, and the key aim is to gradually reduce the TTV and Ra values of the wafer. The quality of the surface of the crystal face manufactured by the previous process greatly influences the difficulty of subsequent processing.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a sapphire wafer grinding and polishing method which is simple and effective and is suitable for industrial production.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a sapphire wafer grinding and polishing method comprises the following steps:

(1) dividing the sapphire wafers obtained by cutting into groups according to the thickness, so that the thickness difference of a plurality of sapphire wafers in the same group is within 0.001 mm;

(2) grinding stage, using high-hardness micropowder whose grain size is 1-3um as grinding material, matching with coarse grinding liquor, inputting into grinding machine and grinding for 10-15 min;

(3) a rough polishing stage: after grinding, carrying out rough polishing on the sapphire wafer, wherein the polishing temperature is 25-38 ℃, and the single surface is polished for 25-35 min;

(4) and (3) a fine polishing stage: and placing the roughly polished sapphire wafer on a lower polishing disc of a double-sided polishing machine through a sheet-shaped fixing device, injecting polishing liquid, and simultaneously carrying out fine polishing on the upper surface and the lower surface of the sapphire wafer by using the upper polishing disc and the lower polishing disc, wherein the polishing temperature is 45-55 ℃, and the polishing time is 25-35 min.

Preferably, the coarse grinding fluid in the step (2) comprises the following components in parts by mass: 35-48 parts of silicon dioxide, 28-32 parts of silicon carbide, 18-25 parts of aluminum oxide, 14-21 parts of boron nitride, 8-15 parts of chitosan, 8-14 parts of titanium diboride, 12-18 parts of glycerol, 7-11 parts of polyethylene glycol, 6-9 parts of carbon black, 6-9 parts of vermiculite powder, 4-7 parts of surfactant, 3-5 parts of dispersant and 150 parts of deionized water.

Preferably, the coarse grinding fluid in the step (2) comprises the following components in parts by mass: 38 parts of silicon dioxide, 30 parts of silicon carbide, 22 parts of aluminum oxide, 18 parts of boron nitride, 12 parts of chitosan, 11 parts of titanium diboride, 15 parts of glycerol, 9 parts of polyethylene glycol, 8 parts of carbon black, 8 parts of vermiculite powder, 6 parts of surfactant, 4 parts of dispersant and 160 parts of deionized water.

Preferably, the polishing temperature in the step (3) is 32 ℃, and the single-side polishing is carried out for 33 min.

Preferably, the polishing temperature in the step (4) is 50 ℃ and the polishing time is 32 min.

Compared with the prior art, the invention has the following beneficial effects: the method is simple and effective, is suitable for industrial production, and the roughness of the obtained sapphire wafer is lower than 0.3 nm.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments. It will be understood by those skilled in the art that the following examples are illustrative of the present invention only and should not be taken as limiting the scope of the invention. The specific techniques or conditions are not indicated in the examples, and the techniques or conditions described in the literature in the art are performed in accordance with the instructions. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

1. Grinding conditions are as follows:

grinding equipment: 18B grinding machine;

grinding pressure: 88g/cm²；

The rotating speed of the machine head: at 22 rpm.

2. Detection device

Roughness: a roughness tester;

thickness: a knob type micrometer.