A method for processing agglomerated grinding liquid for sapphire LED chip back reduction process

Abstract

The present invention provides a method for processing an agglomerated grinding liquid for use in a sapphire LED chip back-reduction process, comprising the following steps: S1, formula preparation; S2, mixing; S3, precipitation and clarification; S4, filtration and purification; S5, performance testing; and S6, application to grinding. The agglomerated grinding liquid of the present invention has the following advantages when used in a sapphire LED chip back-reduction process: improved suspension and viscosity: by adding a thickener (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: the process uses a resin honeycomb pad with an agglomerated suspension, replacing the traditional copper disk process, reducing the copper disk correction cycle and time cost, and improving production efficiency; improved removal rate: due to the use of a thickener, the abrasive is not easily thrown out during the grinding process, thereby improving the utilization rate of the agglomerated powder and ensuring a more effective processing effect.

Description

Technical Field

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

[0002] The sapphire LED chip back-reduction process refers to a process for processing the back side of sapphire-based LED chips during production. The main purpose of this process is to improve light extraction efficiency and reduce material costs by thinning the sapphire substrate and reducing its thickness. 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 using a copper disk and a polycrystalline-like grinding fluid. However, copper disks suffer from large deformation due to heat, rapid wear, and unsustainable finishing time. As a result, the cost of sapphire substrate processing cannot be further reduced, and increasing production capacity can only rely on increasing equipment and space.

[0004] The resin honeycomb mat, combined with the agglomerated suspension, is a perfect alternative to copper plate processing. This process is convenient and reduces mat replacement time, helping customers improve copper plate repair time and increase production capacity. Specifically, the addition of thickeners such as carbomer and CMC to the agglomerated suspension for single-side grinding enhances the suspension and viscosity of the liquid, preventing agglomerated abrasive from being thrown out during double-side grinding, thereby improving removal efficiency. Summary of the Invention

[0005] The present invention aims to solve the technical problems raised by the above background technology, and provides the following technical solutions: a method for processing agglomerated polishing liquid for a sapphire LED chip back reduction process, comprising the following steps:

[0006] S1. Formulation preparation: Select appropriate abrasive and pre-treat it, and add thickener to improve the suspension and viscosity of the liquid;

[0007] S2. Mixing: Mix the abrasive, thickener and other additives in a certain proportion, use a stirring device to ensure uniform dispersion and avoid agglomeration, and obtain a mixed liquid;

[0008] S3, precipitation and clarification: let the mixed solution stand for a period of time to remove bubbles and insoluble matter and ensure the liquid is clear;

[0009] S4, filtration and purification: filtering the mixture after precipitation and clarification to remove the remaining insoluble matter and impurities to ensure that the agglomerated grinding liquid of sufficient purity and uniformity is obtained;

[0010] 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;

[0011] 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 the 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.

[0012] 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 agglomerate powder.

[0013] 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.

[0014] In one embodiment of the present invention, in S1, the preparation steps are specifically as follows:

[0015] S1. Dry and sieve the selected abrasive according to its properties to ensure that the particles are uniform and free of moisture or impurities. Weigh the pre-treated abrasive according to the required proportion for later use.

[0016] 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 lumps. Continue stirring until the thickener is completely dissolved to form a uniform viscous liquid.

[0017] 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.

[0018] In one embodiment of the present invention, in S2, the mixing step is specifically as follows:

[0019] 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 the desired fluidity;

[0020] S2. Use a pH meter to test the pH value of the grinding liquid. If necessary, add a small amount of acid or base to adjust it to obtain the best stability and performance;

[0021] S3. Final mixing: The mixture is stirred carefully to ensure that all ingredients are evenly distributed to obtain a mixed solution.

[0022] In one embodiment of the present invention, in S3, the precipitation step is specifically as follows:

[0023] 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.

[0024] 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.

[0025] In one embodiment of the present invention, in S3, the clarification step is specifically as follows:

[0026] S1. 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.

[0027] S2. If the upper layer of the mixture is clear but there is sediment at the bottom, gently tilt the container to avoid stirring the sediment. Carefully pour out the clear portion and leave the sediment.

[0028] In one embodiment of the present invention, in S4, the filtration and purification step is specifically as follows:

[0029] S1. Slowly pour the precipitated and clarified mixed liquid into the filtration equipment to ensure uniform liquid flow to improve filtration efficiency;

[0030] 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;

[0031] 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.

[0032] 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

[0033] The agglomerated polishing liquid of the present invention has the following advantages when used in the back-reduction process of sapphire LED chips:

[0034] 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;

[0035] Convenient process replacement: This process uses a resin honeycomb mat with agglomerated suspension, replacing the traditional copper disc process, reducing the time cost of mat replacement and improving production efficiency;

[0036] Improved removal rate: Due to the use of thickeners, the abrasive is not easily thrown out during the grinding process, thereby improving the removal rate and ensuring more effective processing results;

[0037] High purity and uniformity: After the steps of precipitation, clarification and filtration, the high purity and uniformity of the agglomerated grinding fluid are ensured, reducing the impact of impurities on the grinding effect;

[0038] 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;

[0039] Reduce bubbles and precipitation: The standing and clarification steps can effectively remove bubbles and insoluble matter to ensure the quality of the final product;

[0040] 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

[0041] The present invention proposes a method for processing agglomerated polishing liquid for a back-reduction process of a sapphire LED chip. The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Example 1

[0042] The present embodiment provides a method for processing agglomerated polishing liquid for a sapphire LED chip back-reduction process, comprising the following steps:

[0043] S1. Formula preparation: Dry and sieve the selected agglomerated diamond powder according to its properties to ensure uniform particles and free of moisture or impurities. Weigh the pre-treated agglomerated diamond powder according to the required proportions and set aside. Then weigh the required amounts of carbomer and sodium carboxymethyl cellulose. Slowly add the carbomer and sodium carboxymethyl cellulose to the pre-prepared aqueous phase. Use a stirrer to maintain uniform stirring to prevent lumps. Continue stirring until the thickener is completely dissolved to form a uniform viscous liquid.

[0044] 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. The amount of carbomer and sodium carboxymethyl cellulose can be increased appropriately to achieve ideal fluidity. Dispersants and preservatives can also be added to improve solution performance. Then, use a pH meter to test the pH value of the grinding liquid. A small amount of acid can be added as needed to adjust for optimal stability and performance. Finally, the mixture is carefully stirred to ensure that all ingredients are evenly distributed to obtain a mixed solution.

[0045] S3. Sedimentation and clarification: 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. During the standing process, regularly check whether bubbles appear in the upper layer of the mixture and whether there is sediment at the bottom. After standing, use a transparent container to observe whether the upper layer of the mixture has become clear. If suspended matter is still found, consider extending the standing time. If the upper layer of the mixture is clear but there is sediment at the bottom, gently tilt the container to avoid stirring the sediment. Carefully pour out the clear portion and retain the sediment.

[0046] S4. Filtration and purification: Slowly pour the precipitated and clarified mixture into the filtration equipment to ensure uniform flow of the liquid to improve filtration efficiency. 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. 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.

[0047] S5. Performance test: The performance test of the grinding fluid is carried out by using a laser particle size analyzer to detect the particle size distribution, a viscometer to measure the viscosity and a pH meter to monitor the pH to ensure that it meets the process requirements;

[0048] 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 the 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. Example 2

[0049] Basically the same as Example 1, except for the reaction conditions of S1: drying and sieving according to the properties of the selected silicon carbide to ensure that the particles are uniform and free of moisture or impurities, weighing the pretreated silicon carbide according to the required proportion for use, then weighing the required amount of carbomer and sodium carboxymethyl cellulose, slowly adding the carbomer and sodium carboxymethyl cellulose to the pre-prepared aqueous phase, using a stirrer to maintain uniform stirring to prevent agglomeration, and continuing stirring until the thickener is completely dissolved to form a uniform viscous liquid. Example 3

[0050] The reaction conditions of S1 are basically the same as those in Example 1, except that the selected cubic boron nitride is dried and sieved 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. Then, the required amounts of carbomer and sodium carboxymethyl cellulose are weighed and slowly added to the pre-prepared aqueous phase. A stirrer is used to maintain uniform stirring to prevent agglomeration. Stirring is continued until the thickener is completely dissolved to form a uniform viscous liquid. Example 4

[0051] The reaction conditions of S1 are basically the same as those in Example 1, except that: the selected alumina is dried and sieved 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. Then, the required amounts of carbomer and sodium carboxymethyl cellulose are weighed and slowly added to the pre-prepared aqueous phase. A stirrer is used to maintain uniform stirring to prevent agglomeration. Stirring is continued until the thickener is completely dissolved to form a uniform viscous liquid. Example 5

[0052] The process is basically the same as Example 1, except that sodium carboxymethyl cellulose is not introduced into S2. Example 6

[0053] The process is basically the same as Example 1, except that no dispersant is introduced into S2. Example 7

[0054] The process is basically the same as Example 1, except that no preservative is introduced into S2. Example 8

[0055] The reaction conditions of S3 are basically the same as those in Example 1, except that 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 appear in the upper layer of the mixed solution and whether there is precipitation 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 precipitation at the bottom, gently tilt the container to avoid stirring the precipitation as much as possible. You can carefully pour out the clear portion and leave the precipitation. Example 9

[0056] The reaction conditions of S3 are basically the same as those in Example 1, except that 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 appear in the upper layer of the mixed solution and whether there is precipitation 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 precipitation at the bottom, gently tilt the container to avoid stirring the precipitation as much as possible. The clear portion can be carefully poured out, leaving the precipitation. Example 10

[0057] The process is basically the same as Example 1, except that a resin honeycomb pad is not used in combination with an agglomerated suspension. Instead, a conventional copper disk is used in combination with a polycrystalline-like polishing liquid for single-sided polishing. However, the copper disk has problems such as large deformation due to heat, rapid wear, and unsustainable repair time. 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.

[0058] 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:

[0059] 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;

[0060] 2. Convenient process replacement: This process uses a resin honeycomb mat with agglomerated suspension, replacing the traditional copper disc process, reducing the time cost of mat replacement and improving production efficiency;

[0061] 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;

[0062] 4. High purity and uniformity: After the steps of precipitation, clarification and filtration, the high purity and uniformity of the agglomerated grinding fluid are ensured, reducing the impact of impurities on the grinding effect;

[0063] 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;

[0064] 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;

[0065] 7. Environmentally friendly: The ingredients of the grinding fluid can be made of environmentally friendly materials, which helps to reduce the impact on the environment.

[0066] This agglomerated grinding liquid not only improves 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, and 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 the liquid is clear; S4, filtration and purification: filtering the mixture after precipitation and clarification to remove the remaining insoluble matter and impurities to ensure that the agglomerated grinding liquid of 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 fluid is applied to the back-reduction process of sapphire LED chips. A resin honeycomb pad is used in combination with the agglomerated suspension to perfectly replace the copper plate process. This process is convenient and requires only a short time to replace the pad, helping customers improve the time utilization of copper plate repair and increase production capacity. In S1, the abrasive is selected from one or more of aluminum oxide, silicon carbide, cubic boron nitride and diamond agglomerated powder; In S1, the thickener is selected from one or more of carbomer, sodium carboxymethyl cellulose, xanthan gum and polyvinyl alcohol; 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. 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 prepared aqueous phase. Use a stirrer to keep it evenly stirred to prevent lumps. Continue stirring until the thickener is completely dissolved to form a uniform viscous liquid. In S2, the additive is selected from one or more of a dispersant, a preservative and an antioxidant; 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 the desired fluidity; S2. Use a pH meter to test the pH value of the grinding liquid. If necessary, add a small amount of acid or base to adjust it 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; In S3, the precipitation step is 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 solution and whether sediment forms at the bottom. 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 suspended matter is still found, consider extending the standing time. S2. If the upper layer of the mixture is clear but there is sediment at the bottom, gently tilt the container to avoid disturbing the sediment. Carefully pour out the clear portion and leave the sediment. In S4, the filtration purification step is as follows: S1. Slowly pour the precipitated and clarified mixed liquid into the filtration equipment to ensure uniform liquid flow to improve 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 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. 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.