Agglomerated grinding fluid processing method for back reduction process of sapphire LED (light-emitting diode) chip

Abstract

The invention provides an agglomeration grinding fluid processing method for a sapphire LED chip back reduction process. The method comprises the following steps: S1, preparing a formula; s2, mixing; s3, precipitating and clarifying; s4, filtering and purifying; s5, performance testing; and S6, applying to grinding. The agglomerated grinding fluid has the following advantages in the sapphire LED chip back reduction process: the suspension property and the viscosity are improved: by adding the thickening agent (such as carbomer, CMC and the like), the suspension property of the liquid is enhanced, the precipitation of the grinding material in the grinding process is reduced, and the uniform distribution of the grinding material is ensured; according to the process, the resin honeycomb pad is matched with the agglomerated suspension liquid, a traditional copper disc process is replaced, the copper disc correction period is shortened, the time cost is reduced, and the production efficiency is improved; due to the use of the thickening agent, the grinding material is not easy to throw out in the grinding process, so that the utilization rate of the agglomerated powder is improved, and a more effective processing effect is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of grinding liquid, and more specifically to a method for processing agglomerated grinding liquid used in a back-reduction process of a sapphire LED chip. Background Art

[0002] The back-reduction process of sapphire LED chips refers to a process for processing the back side of sapphire-based LED chips during production. The main purpose of this process is to reduce the thickness of the sapphire substrate by thinning it, thereby improving light extraction efficiency and reducing material costs. Agglomerated grinding fluid is a liquid used for grinding and polishing materials, especially in semiconductors, optoelectronics and other high-precision manufacturing fields. Its main function is to achieve fine processing of the material surface by suspending abrasive particles. In the back-reduction process of sapphire LED chips, polycrystalline-like grinding fluid and agglomerated grinding fluid are usually used.

[0003] The conventional process for thinning sapphire substrates is single-sided grinding with a copper disk and a polycrystalline-like grinding liquid. However, copper disks have problems such as large deformation due to heat, rapid wear, and a dressing time that is impossible to produce. As a result, the cost of sapphire substrate processing cannot be further reduced, and the increase in production capacity can only rely on the addition of equipment and space.

[0004] The resin honeycomb mat of the present invention is combined with the agglomerated suspension liquid to perfectly replace the copper plate process. The process is convenient and the time for replacing the mat is short, which helps customers improve the time utilization rate of copper plate repair and increase production capacity. In particular, carbomer, CMC and other thickeners are added to the single-sided grinding agglomeration liquid to improve the suspension and viscosity of the liquid, ensure that the agglomerated abrasive is not thrown out during the double-sided grinding process, and improve the removal rate. Summary of the invention

[0005] The present invention aims to solve the technical problems raised by the above-mentioned background technology. The present invention provides the following technical solutions: a method for processing agglomerated polishing liquid for a sapphire LED chip back reduction process, comprising the following steps: S1. Formulation preparation: Select appropriate abrasive and pre-treat it, and add thickener to improve the suspension and viscosity of the liquid; S2. Mixing: Mix the abrasive, thickener and other additives in a certain proportion, use a stirring device to ensure uniform dispersion and avoid agglomeration to obtain a mixed liquid; S3, precipitation and clarification: let the mixed solution stand for a period of time to remove bubbles and insoluble matter and ensure that the liquid is clear; S4, filtration and purification: filtering the mixed solution after precipitation and clarification to remove the remaining insoluble matter and impurities to ensure that the agglomerated grinding liquid with sufficient purity and uniformity is obtained; S5. Performance test: Perform performance test on the grinding fluid, including abrasive distribution, viscosity, pH value and other indicators to ensure that it meets the process requirements; S6. Application in grinding: The prepared agglomerated grinding liquid is applied to the back reduction process of sapphire LED chips, and a resin honeycomb pad is used with agglomerated suspension to perfectly replace the copper disk process. This process is convenient and the time for replacing the pad is short, which helps customers improve the time utilization of copper disk repair and increase production capacity.

[0006] In one embodiment of the present invention, in S1, the abrasive is selected from one or more of aluminum oxide, silicon carbide, cubic boron nitride and diamond agglomerated powder.

[0007] In one embodiment of the present invention, in S1, the thickener is selected from one or more of carbomer, sodium carboxymethyl cellulose, xanthan gum and polyvinyl alcohol.

[0008] In one embodiment of the present invention, in S1, the preparation steps are specifically as follows: S1. Dry and sieve the selected abrasive according to its properties to ensure that the particles are uniform and free of moisture or impurities, and weigh the pre-treated abrasive according to the required proportion for later use; S2. Weigh the required amount of thickener and slowly add it to the pre-prepared water phase. Use a stirrer to keep stirring evenly to prevent caking. Continue stirring until the thickener is completely dissolved to form a uniform viscous liquid.

[0009] In one embodiment of the present invention, in S2, the additive is selected from one or more of a dispersant, a preservative and an antioxidant.

[0010] In one embodiment of the present invention, in S2, the mixing step is specifically as follows: S1. Gradually add the pretreated abrasive to the thickener solution, stirring while adding to ensure that the abrasive is completely dispersed. Adjust the viscosity as needed, increase the amount of thickener appropriately, or add water to achieve ideal fluidity; S2. Use a pH meter to test the pH value of the grinding liquid. Add a small amount of acid or alkali to adjust it as needed to obtain the best stability and performance; S3. Final mixing: The mixture is stirred carefully to ensure that all ingredients are evenly distributed to obtain a mixed solution.

[0011] In one embodiment of the present invention, in S3, the precipitation step is specifically as follows: S1. Pour the mixture into a transparent container and place it in a temperature-stable, vibration-free environment. The recommended standing time is usually 30 minutes to several hours. S2. During the standing process, regularly check whether bubbles disappear from the upper layer of the mixed liquid and whether sediment forms at the bottom.

[0012] In one embodiment of the present invention, in S3, the clarification step is specifically as follows: S1. After standing, use a transparent container to observe whether the upper layer of the mixed solution has become clear. If there are still suspended matter, consider extending the standing time; S2. If the upper layer of the mixed liquid is clear but there is sediment at the bottom, gently tilt the container and try to avoid stirring the sediment. You can carefully pour out the clear part and leave the sediment.

[0013] In one embodiment of the present invention, in S4, the filtration and purification step is specifically as follows: S1. Slowly pour the precipitated and clarified mixed liquid into the filtration equipment to ensure that the liquid flows evenly to improve the filtration efficiency; S2. You can use filter cloth, filter paper, or a dedicated filter to filter the mixture through the filter to ensure that all insoluble matter is removed; S3. Collect the filtered liquid and ensure that no impurities remain on the filter medium. Check the filtrate to ensure that it is clear and free of impurities. If necessary, repeat the filtration to further improve the purity.

[0014] In one embodiment of the present invention, in S5, the performance test uses a laser particle size analyzer to detect particle size distribution, a viscometer to measure viscosity, and a pH meter to monitor pH. Beneficial Effects

[0015] The agglomerated polishing liquid of the present invention has the following advantages when used in the back reduction process of sapphire LED chips: Improve suspension and viscosity: By adding thickeners (such as carbomer, CMC, etc.), the suspension of the liquid is enhanced, the precipitation of the abrasive during the grinding process is reduced, and the uniform distribution of the abrasive is ensured; Convenient process replacement: This process uses a resin honeycomb mat with agglomerated suspension to replace the traditional copper disc process, reducing the time cost of replacing the mat and improving production efficiency; Improve removal rate: Due to the use of thickener, the abrasive is not easily thrown out during the grinding process, thereby improving the removal rate and ensuring more effective processing results; High purity and uniformity: After the steps of precipitation, clarification and filtration, the high purity and uniformity of the agglomerated grinding fluid are ensured, and the influence of impurities on the grinding effect is reduced; Controllable performance: By testing and adjusting performance indicators such as viscosity and pH value, the performance of the grinding fluid can be optimized according to different needs to ensure that it meets specific process requirements; Reduce bubbles and precipitation: The standing and clarification steps can effectively remove bubbles and insoluble matter to ensure the quality of the final product; Environmentally friendly: The ingredients of the grinding fluid can be made of environmentally friendly materials, which helps to reduce the impact on the environment. DETAILED DESCRIPTION

[0016] The present invention provides a method for processing agglomerated polishing liquid for a sapphire LED chip back reduction process. The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Embodiment 1

[0017] The present embodiment provides a method for processing agglomerated polishing liquid for a sapphire LED chip back reduction process, comprising the following steps: S1. Formula preparation: Dry and sieve the selected agglomerated diamond powder according to its properties to ensure that the particles are uniform and free of moisture or impurities. Weigh the pre-treated agglomerated diamond powder according to the required proportion for use. Then weigh the required amount of carbomer and sodium carboxymethyl cellulose. Slowly add the carbomer and sodium carboxymethyl cellulose to the pre-prepared aqueous phase. Use a stirrer to keep stirring evenly to prevent caking. Continue stirring until the thickener is completely dissolved to form a uniform viscous liquid. S2, mixing: gradually add the pretreated agglomerated diamond powder to the carbomer and sodium carboxymethyl cellulose solution, stirring while adding to ensure that the alumina is completely dispersed, adjust the viscosity as needed, increase the amount of carbomer and sodium carboxymethyl cellulose appropriately to achieve ideal fluidity, and add dispersants and preservatives to improve solution performance. Then use a pH meter to detect the pH value of the grinding liquid, and add a small amount of acid to adjust as needed to obtain the best stability and performance. Finally, stir the mixture carefully to ensure that all ingredients are evenly distributed to obtain a mixed solution; S3, precipitation and clarification: Pour the mixed solution into a transparent container and place it in a temperature-stable, vibration-free environment. The recommended standing time is usually 30 minutes to several hours. During the standing process, regularly check whether bubbles disappear from the upper layer of the mixed solution and whether sediment forms at the bottom. After standing, use a transparent container to observe whether the upper layer of the mixed solution has become clear. If there are still suspended matter, consider extending the standing time. If the upper layer of the mixed solution is clear but there is sediment at the bottom, gently tilt the container to avoid stirring the sediment as much as possible. You can carefully pour out the clear part and leave the sediment. S4. Filtration purification: slowly pour the precipitated and clarified mixed liquid into the filtration equipment to ensure that the liquid flows evenly to improve the filtration efficiency. You can use filter cloth, filter paper, or a special filter to filter. Pass the mixed liquid through the filter to ensure that all insoluble matter is removed. Collect the filtered liquid to ensure that no impurities remain on the filter medium. Then check the filtrate to ensure that it is clear and free of impurities. If necessary, repeat the filtration to further improve the purity. S5. Performance test: The grinding fluid is tested for performance. The performance test uses a laser particle size analyzer to detect particle size distribution, a viscometer to measure viscosity, and a pH meter to monitor pH to ensure that it meets the process requirements; S6. Application in grinding: The prepared agglomerated grinding liquid is applied to the back reduction process of sapphire LED chips, and a resin honeycomb pad is used with agglomerated suspension to perfectly replace the copper disk process. This process is convenient and the time for replacing the pad is short, which helps customers improve the time utilization of copper disk repair and increase production capacity. Embodiment 2

[0018] The method is basically the same as Example 1, except that the reaction conditions of S1 are as follows: drying and sieving are performed according to the properties of the selected silicon carbide to ensure that the particles are uniform and free of moisture or impurities, the pretreated silicon carbide is weighed in the required proportion for use, and then the required amounts of carbomer and sodium carboxymethyl cellulose are weighed, and the carbomer and sodium carboxymethyl cellulose are slowly added to the pre-prepared aqueous phase, and a stirrer is used to maintain uniform stirring to prevent caking, and stirring is continued until the thickener is completely dissolved to form a uniform viscous liquid. Embodiment 3

[0019] The method is basically the same as Example 1, except that the reaction conditions of S1 are as follows: drying and sieving are performed according to the properties of the selected cubic boron nitride to ensure that the particles are uniform and free of moisture or impurities, the pretreated cubic boron nitride is weighed in the required proportion for use, and then the required amounts of carbomer and sodium carboxymethyl cellulose are weighed, and the carbomer and sodium carboxymethyl cellulose are slowly added to the pre-prepared aqueous phase, and a stirrer is used to maintain uniform stirring to prevent caking, and stirring is continued until the thickener is completely dissolved to form a uniform viscous liquid. Embodiment 4

[0020] The method is basically the same as Example 1, except that the reaction conditions of S1 are as follows: drying and sieving are performed according to the properties of the selected alumina to ensure that the particles are uniform and free of moisture or impurities, the pretreated alumina is weighed in the required proportion for use, and then the required amounts of carbomer and sodium carboxymethyl cellulose are weighed, and the carbomer and sodium carboxymethyl cellulose are slowly added to the pre-prepared aqueous phase, and a stirrer is used to maintain uniform stirring to prevent caking, and stirring is continued until the thickener is completely dissolved to form a uniform viscous liquid. Embodiment 5

[0021] The method is basically the same as Example 1, except that sodium carboxymethyl cellulose is not introduced into S2. Embodiment 6

[0022] The method is basically the same as Example 1, except that no dispersant is introduced into S2. Embodiment 7

[0023] The method is basically the same as Example 1, except that no preservative is introduced into S2. Embodiment 8

[0024] The method is basically the same as Example 1, except that the reaction conditions of S3 are as follows: the mixed solution is poured into a transparent container and placed in a temperature-stable, vibration-free environment. The recommended standing time is usually 30 minutes. During the standing process, regularly check whether bubbles disappear from the upper layer of the mixed solution and whether sediment is formed at the bottom. After standing, use a transparent container to observe whether the upper layer of the mixed solution has become clear. If suspended matter is still found, consider extending the standing time. If the upper layer of the mixed solution is clear and there is sediment at the bottom, gently tilt the container to avoid stirring the sediment as much as possible. The clear part can be carefully poured out, leaving the sediment. Embodiment 9

[0025] The method is basically the same as Example 1, except that the reaction conditions of S3 are as follows: the mixed solution is poured into a transparent container and placed in a temperature-stable, vibration-free environment. The recommended standing time is usually 60 minutes. During the standing process, regularly check whether bubbles disappear from the upper layer of the mixed solution and whether sediment is formed at the bottom. After standing, use a transparent container to observe whether the upper layer of the mixed solution has become clear. If suspended matter is still found, consider extending the standing time. If the upper layer of the mixed solution is clear and there is sediment at the bottom, gently tilt the container to avoid stirring the sediment as much as possible. The clear part can be carefully poured out, leaving the sediment. Embodiment 10

[0026] The method is basically the same as Example 1, except that: instead of using a resin honeycomb pad with a coagulation suspension in S6, a conventional copper disk with a polycrystalline-like grinding liquid is used for single-sided grinding. However, the copper disk has problems such as large deformation due to heat, rapid wear, and a dressing time that cannot be used for production. As a result, the cost of sapphire substrate processing cannot be further reduced, and the increase in production capacity can only rely on the addition of equipment and space.

[0027] In summary, the agglomerated polishing liquid of the present invention has the following advantages when used in the back reduction process of sapphire LED chips: 1. Improve suspension and viscosity: By adding thickeners (such as carbomer, CMC, etc.), the suspension of the liquid is enhanced, the precipitation of the abrasive during the grinding process is reduced, and the uniform distribution of the abrasive is ensured; 2. Convenient process replacement: This process uses resin honeycomb mats with agglomeration suspension to replace the traditional copper disc process, reducing the time cost of replacing mats and improving production efficiency; 3. Improve removal rate: Due to the use of thickener, the abrasive is not easily thrown out during the grinding process, thereby improving the removal rate and ensuring more effective processing results; 4. High purity and uniformity: After the steps of precipitation, clarification and filtration, the high purity and uniformity of the agglomerated grinding liquid are ensured, and the influence of impurities on the grinding effect is reduced; 5. Controllable performance: By testing and adjusting performance indicators such as viscosity and pH value, the performance of the grinding fluid can be optimized according to different needs to ensure that it meets specific process requirements; 6. Reduce bubbles and precipitation: The standing and clarification steps can effectively remove bubbles and insoluble matter to ensure the quality of the final product; 7. Environmentally friendly: The ingredients of the grinding fluid can be selected from environmentally friendly materials, which helps to reduce the impact on the environment.

[0028] This agglomerated grinding liquid not only improves the processing efficiency but also ensures product quality in the back-reduction process of sapphire LED chips, and has obvious technical advantages.

Claims

1. A method for processing agglomerated polishing liquid for a sapphire LED chip back reduction process, characterized in that: The following steps are involved: S1. Formulation preparation: Select appropriate abrasive and pre-treat it, and add thickener to improve the suspension and viscosity of the liquid; S2. Mixing: Mix the abrasive, thickener and other additives in a certain proportion, use a stirring device to ensure uniform dispersion and avoid agglomeration to obtain a mixed liquid; S3, precipitation and clarification: let the mixed solution stand for a period of time to remove bubbles and insoluble matter and ensure that the liquid is clear; S4, filtration and purification: filtering the mixed solution after precipitation and clarification to remove the remaining insoluble matter and impurities to ensure that the agglomerated grinding liquid with sufficient purity and uniformity is obtained; S5. Performance test: Perform performance test on the grinding fluid, including abrasive distribution, viscosity, pH value and other indicators to ensure that it meets the process requirements; S6. Application in grinding: The prepared agglomerated grinding liquid is applied to the back reduction process of sapphire LED chips, and a resin honeycomb pad is used with agglomerated suspension to perfectly replace the copper disk process. This process is convenient and the time for replacing the pad is short, which helps customers improve the time utilization of copper disk repair and increase production capacity.

2. The method for processing agglomerated grinding liquid for back-reduction process of sapphire LED chips according to claim 1, characterized in that: In S1, the abrasive is selected from one or more of aluminum oxide, silicon carbide, cubic boron nitride and diamond agglomerated powder.

3. The method for processing agglomerated grinding liquid for back-reduction process of sapphire LED chips according to claim 1, characterized in that: In S1, the thickener is selected from one or more of carbomer, sodium carboxymethyl cellulose, xanthan gum and polyvinyl alcohol.

4. The method for processing agglomerated grinding liquid for back-reduction process of sapphire LED chips according to claim 1, characterized in that: In S1, the preparation steps are as follows: S1. Dry and sieve the selected abrasive according to its properties to ensure that the particles are uniform and free of moisture or impurities, and weigh the pre-treated abrasive according to the required proportion for later use; S2. Weigh the required amount of thickener and slowly add it to the pre-prepared water phase. Use a stirrer to keep stirring evenly to prevent caking. Continue stirring until the thickener is completely dissolved to form a uniform viscous liquid.

5. The method for processing agglomerated grinding liquid for back-reduction process of sapphire LED chips according to claim 1, characterized in that: In S2, the additive is selected from one or more of a dispersant, a preservative and an antioxidant.

6. The method for processing agglomerated polishing liquid for back-reduction process of sapphire LED chips according to claim 1, characterized in that: In S2, the mixing steps are as follows: S1. Gradually add the pretreated abrasive to the thickener solution, stirring while adding to ensure that the abrasive is completely dispersed. Adjust the viscosity as needed, increase the amount of thickener appropriately, or add water to achieve ideal fluidity; S2. Use a pH meter to test the pH value of the grinding liquid. Add a small amount of acid or alkali to adjust it as needed to obtain the best stability and performance; S3. Final mixing: The mixture is stirred carefully to ensure that all ingredients are evenly distributed to obtain a mixed solution.

7. The method for processing agglomerated grinding liquid for back-reduction process of sapphire LED chips according to claim 1, characterized in that: In S3, the precipitation steps are as follows: S1. Pour the mixture into a transparent container and place it in a temperature-stable, vibration-free environment. The recommended standing time is usually 30 minutes to several hours. S2. During the standing process, regularly check whether bubbles disappear from the upper layer of the mixed liquid and whether sediment forms at the bottom.

8. The method for processing agglomerated grinding liquid for back-reduction process of sapphire LED chips according to claim 1, characterized in that: In S3, the clarification steps are as follows: S1. After standing, use a transparent container to observe whether the upper layer of the mixed solution has become clear. If there are still suspended matter, consider extending the standing time; S2. If the upper layer of the mixed liquid is clear but there is sediment at the bottom, gently tilt the container and try to avoid stirring the sediment. You can carefully pour out the clear part and leave the sediment.

9. The method for processing agglomerated grinding liquid for back-reduction process of sapphire LED chips according to claim 1, characterized in that: In S4, the filtration purification step is as follows: S1. Slowly pour the precipitated and clarified mixed liquid into the filtration equipment to ensure that the liquid flows evenly to improve the filtration efficiency; S2. You can use filter cloth, filter paper, or a dedicated filter to filter the mixture through the filter to ensure that all insoluble matter is removed; S3. Collect the filtered liquid and ensure that no impurities remain on the filter medium. Check the filtrate to ensure that it is clear and free of impurities. If necessary, repeat the filtration to further improve the purity.

10. The method for processing agglomerated polishing liquid for back-reduction process of sapphire LED chips according to claim 1, characterized in that: In S5, the performance test uses a laser particle size analyzer to detect particle size distribution, a viscometer to measure viscosity, and a pH meter to monitor acidity and alkalinity.