Method for automatically correcting removal rate of LED chip grinding

Abstract

The application provides a kind of LED chip grinding automatic correction removal rate method, the method comprises: arranging wax on LED chip;Thin work is carried out to LED chip, and its thickness average is measured;The required removal amount of the LED chip is calculated;The required time of grinding of LED chip is calculated, and the current thickness average is measured to each tray the grinding work of LED chip;The actual removal rate of each tray the LED chip is calculated with actual removal rate average;Actual removal rate average is imported into the grinder table, and actual removal rate average is used as the next set removal rate of the grinder table, and steps two to five are repeated to realize automatic correction removal rate, in the process of realizing correction removal rate, manual intervention is not required, labor cost is reduced and work efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the technical field of LED chips, and specifically relates to a method for automatically correcting the removal rate during LED chip grinding. Background Technology

[0002] Light-emitting diodes, or LEDs for short, are made of compounds containing gallium (Ga), arsenic (As), phosphorus (P), and nitrogen (N). When electrons and holes recombine, they emit visible light, making them suitable for LED manufacturing. In circuits and instruments, they serve as indicator lights or form text or number displays. Depending on the substrate, they can be categorized as gallium arsenide diodes (red light), gallium phosphide diodes (green light), silicon carbide diodes (yellow light), and gallium nitride diodes (blue light). Based on their chemical properties, they are further classified as organic light-emitting diodes (OLEDs) and inorganic light-emitting diodes (LEDs).

[0003] With the rapid rise of the LED chip industry in recent years, chip factories are producing full-color gamut LED chips to increase market share. This requires a wide variety of product models and equipment, as well as more front-line operators. In the process of correcting the LED grinding and removal rate, manual intervention is prone to errors, and the labor costs are high, resulting in low efficiency. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides an automatic correction method for the removal rate of LED chip grinding, which solves the technical problems of easy errors, high labor costs, and low efficiency in the prior art due to manual intervention adjustments.

[0005] This invention provides the following technical solution: an automatic correction method for removal rate during LED chip grinding, characterized in that the method includes the following steps:

[0006] Step 1: Apply wax to the predetermined number of LED chips in each tray in sequence, accumulating a number of ceramic trays with LED chips already loaded;

[0007] Step 2: Thin the LED chips in each of the waxed trays and measure the average thickness of the LED chips in each tray after thinning using an automatic measuring machine;

[0008] Step 3: Calculate the required amount of LED chips to be removed from each plate according to the first preset formula;

[0009] Step 4: Grind the LED chips on each tray using a grinding machine, and then send the ground LED chips on each tray into the automatic measuring machine to measure the current average thickness.

[0010] Step 5: Calculate the actual removal rate and the average actual removal rate of the LED chips in each panel according to the second preset formula;

[0011] Step 6: The average actual removal rate is transmitted to the grinding machine through the MES system, and the average actual removal rate is used as the set removal rate for the next round of LED chips in the grinding machine. The next round of LED chips repeats steps 2 to 5 in sequence according to the set removal rate. The average actual removal rate is calculated again through the MES system and transmitted to the grinding machine for correction, so as to realize automatic correction of the removal rate.

[0012] Compared with the prior art, the beneficial effects of this application are as follows: This application obtains the average actual removal rate of LED chips in each disk, and uses the average actual removal rate as the set removal rate for the next round of the grinding machine. It also iteratively calculates and inputs the average actual removal rate to achieve automatic replacement and correction of the removal rate. The entire process does not require manual intervention, which reduces labor costs and improves work efficiency.

[0013] Preferably, in step one, after waxing each LED chip, it is allowed to cool to 25°C~35°C.

[0014] Preferably, in step two, the step of thinning the waxed LED chips on each tray includes:

[0015] The waxed LED chips are fed into a thinning machine, where they are thinned by a grinding wheel for 2 to 10 minutes.

[0016] Preferably, in step two, after the LED chip is thinned, a damage layer is formed on one side of the LED chip, and the damage layer is removed by the grinding machine.

[0017] Preferably, the thickness of the damaged layer is in the range of 15µm-20µm.

[0018] Preferably, in step two, after measuring the average thickness of the LED chips in each tray after thinning using an automatic measuring machine, the method further includes:

[0019] The MES system automatically generates a work document for the grinding machine, which includes the average thickness of the LED chips in each tray after thinning, as measured by the measuring machine.

[0020] Preferably, step three includes:

[0021] Based on the average thickness of the LED chips in each tray after thinning and the target thickness of the product, and according to the first preset formula L=HK, the required amount of LED chips to be removed from each tray is calculated, where L is the required amount of removal, H is the average thickness of the LED chips in each tray after thinning, and K is the target thickness of the product.

[0022] Preferably, the required removal amount L is greater than the thickness of the damaged layer.

[0023] Preferably, step four includes:

[0024] Based on the required removal amount and the set removal rate, the grinding time required for each tray of LED chips is T=L / S, where L is the required removal amount and S is the preset removal rate. The grinding machine performs grinding operations on each tray of LED chips according to the time T and the set removal rate S, and sends the ground LED chips of each tray into the automatic measuring machine to measure the current average thickness.

[0025] Preferably, step five includes:

[0026] Based on the current average thickness, the required removal amount, and the target thickness of the product, the actual removal rate of the LED chips in each tray is calculated according to the second preset formula S′={L-(H′-K)} / T, where S′ is the actual removal rate, L is the required removal amount, H′ is the current average thickness, K is the target thickness of the product, and T is the grinding time. The average actual removal rate S″ of the LED chips in each tray is obtained by the ratio of the sum of the actual removal rates S′ of the LED chips in each tray to the number of ceramic trays. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A flowchart of an automatic correction removal rate method for LED chip grinding provided in an embodiment of the present invention.

[0029] The present invention will now be described in detail with reference to the accompanying drawings. Detailed Implementation

[0030] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain embodiments of the present invention, and should not be construed as limiting the present invention.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] In one embodiment of the present invention, such as Figure 1 As shown, an automatic correction method for removal rate in LED chip grinding is described, the sorting method comprising the following steps:

[0033] Step 1: Apply wax to the predetermined number of LED chips in each tray in sequence, accumulating a number of ceramic trays with LED chips already loaded;

[0034] Specifically, in the actual production process, each ceramic plate contains seven LED chips, and generally eight ceramic plates are required. The ceramic plates are numbered N1, N2...N8.

[0035] Meanwhile, the waxing process is as follows: solid wax is evenly applied to a ceramic disc heated to about 90℃~110℃, and then the front of the LED chip is placed on the disc. After pressure is applied, the LED chip is fixed on the surface of the ceramic disc. The purpose of waxing is to facilitate the subsequent thinning and grinding process.

[0036] During the waxing process, the wax thickness must be controlled between 2 and 3 μm. This is directly affected by the selection of solid wax, the pressure method and conditions, and directly related to the uniformity of the finished thickness after grinding. When waxing, attention should be paid to the air bubbles generated during chip waxing. Air bubbles will prevent the chip from adhering completely to the ceramic disk, which will cause small cracks in the subsequent grinding process and increase the scrap rate of LED chips.

[0037] In this embodiment, after waxing each LED chip, it is allowed to cool to 25°C~35°C.

[0038] Because the ceramic disc is at a high temperature during the waxing process, if the LED chip is directly thinned, the solid wax may not completely fix the LED chip to the ceramic disc due to the high temperature. Therefore, it is necessary to cool it down to 35°C to ensure that the LED chip is completely fixed to the ceramic disc and that the LED chip will not easily fall off the ceramic disc during the subsequent thinning and grinding process.

[0039] Step 2: Thin the LED chips in each of the waxed trays and measure the average thickness of the LED chips in each tray after thinning using an automatic measuring machine;

[0040] In this embodiment, the waxed LED chips are fed into a thinning machine, where the LED chips are thinned by a grinding wheel for 2 to 10 minutes.

[0041] Specifically, a ceramic disc containing LED chips is placed in a thinning machine with the LED chips facing the grinding wheel. The grinding wheel is used to grind and thin the sides of the LED chips to achieve the required thickness. The specific thinning time depends on the actual specifications, model, and factory requirements of the LED chips.

[0042] In the specific thinning process, the waxed LED chips on each tray are fed into the thinning machine. Since the LED chips are small, the ceramic trays are not very large in size to save space. After the LED chips are fed into the thinning machine, the side of the ceramic tray containing the LED chips faces the grinding wheel. The grinding wheel is moved to gradually bring it into contact with the side of the LED chips. During the thinning process, thinning liquid needs to be sprayed onto the contact area between the LED chips and the grinding wheel. This can prevent the heat generated when the grinding wheel contacts the LED chips from affecting the thinning process and the quality of the LED chips. It also makes it easier to control the thickness of the thinning. In the actual thinning process, the automatic measuring machine needs to measure the current thickness of the LED chips in real time to ensure that the thickness of the thinning is within a safe range. This is to ensure that the LED chips can be successfully polished in the subsequent grinding process.

[0043] In this embodiment, after the waxed LED chip is fed into the thinning machine for thinning, since the thinning machine is a grinding wheel and its speed is relatively fast, a damage layer with a thickness of 15um-20um will be left on the surface of the LED chip after thinning. At this time, according to the target thickness requirement of the product, 28-35um can be reserved in the LED chip production process. Moreover, this damage layer will affect the subsequent grinding process, so it needs to be removed by the grinding machine.

[0044] Furthermore, following step two, the method further includes:

[0045] The MES system automatically generates a work document for the grinding machine, which includes the average thickness H of the LED chips on each disc as measured by the measuring machine.

[0046] Specifically, the job documents generated by the MES system also include the target thickness of the product, the ceramic disc number, the actual thickness of the LED chips in each disc, and the maximum and minimum thickness of the LED chips in each disc.

[0047] Step 3: Calculate the required amount of LED chips to be removed from each plate according to the first preset formula;

[0048] In this embodiment, based on the average thickness of the LED chips in each tray after thinning and the target thickness of the product, and according to the first preset formula L=HK, the required amount of LED chips to be removed from each tray is calculated, where L is the required amount of removal, H is the average thickness of the LED chips in each tray after thinning, and K is the target thickness of the product.

[0049] Wherein, the target thickness K of the product refers to the thickness required for the LED chip to leave the factory, and the average thickness H of the LED chips in each tray refers to the average thickness of all LED chips on each ceramic tray, denoted as H1, H2...H8. Subtracting the target thickness K from the average thickness H of the LED chips in each tray will yield the specific amount L to be removed from the LED chips in each tray, i.e., L=HK, and the required removal rate of the LED chips in each tray will be denoted as L1, L2...L8.

[0050] It is worth noting that the required removal amount L of the LED chips in each disc calculated in this step is an ideal required removal amount. In the actual processing, grinding is required according to the preset removal rate. The actual removal amount may not be equal to the calculated required removal amount. Therefore, in subsequent steps, the actual removal rate needs to be calculated based on the actual removal amount.

[0051] Meanwhile, the amount L to be removed in this step is greater than the thickness of the damaged layer. This is to ensure that the damaged layer can be completely removed by the grinding machine during the grinding process of the LED chip, and to avoid the situation where the damaged layer is not completely removed, which may lead to quality problems of the LED.

[0052] Step 4: Grind the LED chips on each tray using a grinding machine, and then send the ground LED chips on each tray into the automatic measuring machine to measure the current average thickness.

[0053] Specifically, the purpose of this step is to determine the actual remaining average thickness of the LED chip after the grinding operation. At the same time, the remaining average thickness, i.e. the current average thickness, can reflect the actual removal amount and actual removal rate of the grinding machine.

[0054] Similar to the thinning process, the waxed LED chips on each tray are fed into a grinding machine. Because the LED chips are small, the ceramic trays are not very large to save space. After the LED chips are fed into the grinding machine, the side of the ceramic tray containing the LED chips faces the grinding equipment. The grinding equipment is moved to gradually bring the tray into contact with the LED chips. During the grinding process, grinding fluid is constantly sprayed onto the contact area between the LED chips and the grinding equipment. This prevents the heat generated when the grinding equipment contacts the LED chips from affecting the thinning process and the quality of the LED chips, and also facilitates control of the grinding thickness. In the actual grinding process, an automatic measuring machine needs to measure the current thickness of the LED chips in real time to ensure that the grinding thickness is within a safe range, thus ensuring that the LED chips can proceed smoothly to the subsequent packaging process.

[0055] In this embodiment, based on the required removal amount L and the set removal rate S, the grinding time T = L / S for each tray of LED chips is obtained. The grinding machine performs grinding operations on each tray of LED chips according to the time T and the set removal rate S, and sends the ground LED chips of each tray into the automatic measuring machine to measure the current average thickness H′, which is recorded as H1′, H2′...H8′. The grinding time is recorded as T1, T2...T8.

[0056] It is worth mentioning that the grinding process in step four requires data transmission, and the data transmission principle is as follows: The thickness data is measured by an automatic measuring machine with a photosensitive device, and the thickness data is transmitted to an A / D converter. The A / D converter converts the digital signal into an analog signal, which is transmitted to a PLC. The PLC transmits the analog signal to a PC to calculate the average thickness H. Based on the required removal amount L and the set removal rate S, the grinding time T = L / S required for each tray of LED chips is obtained. The PC transmits the average value back to the grinding industrial control computer, which transmits it back to the grinding machine PC. The PC transmits it back to the grinding machine PLC to write the required removal amount L, the set removal rate S, and the grinding time T. The PLC controls the grinding machine to perform grinding operations on each tray of LED chips according to the time T and the set removal rate S.

[0057] The grinding time refers to the time required for the LED chip to be ground by the grinding machine. This time can be calculated by the ratio of the required removal amount L to the set removal rate S. After calculating the grinding time required for the LED chip, the grinding time is transmitted to the grinding machine to control the grinding time. The set removal rate S is pre-specified by the system or manually before LED processing. Since the removal rate of the first LED chip processing cannot be directly obtained in the previous processing, a preset removal rate needs to be specified here. Generally, the specific value of the set removal rate S is based on the removal rate of the grinding machine itself, and is generally 2.0-4.0. It is recommended to set it as high as possible to avoid quality abnormalities.

[0058] For example, in the preceding steps, the average thickness H of the eight ceramic discs was measured as H1=199 μm, H2=198 μm, H3=202 μm, H4=200 μm, H5=198 μm, H6=198 μm, H7=202 μm, and H8=195 μm. Discs N1 to N8 were then placed in the thinning process, with N1 to N4 fed into the grinding machine. Based on a product thickness of 170 μm and a set removal rate of 3.0, the required removal amounts L1=29 μm, L2=28 μm, L3=32 μm, and L4=30 μm were calculated. Therefore, the required grinding times for each disc were T1=9.67 min, T2=9.33 min, T3=10.67 min, and T4=10 min. The grinding machine was then used to complete the grinding of the LED chip according to the required grinding times, and the current average thickness after grinding was measured as H1′=176 μm. Given H2′=177 um, H3′=180 um, and H4′=179 um, the actual removal rates S1′=2.38, S2′=2.58, S3′=2.06, and S4′=2.10 can be calculated. The average actual removal rate S″=2.28. Therefore, the calculated average actual removal rate S″ of 2.28 is used to replace the set removal rate of 3.0 for the next round of N5~N8. The above operation is repeated and the actual removal rate and the average actual removal rate are recalculated. The LED chips in the next round are replaced, and the above operation is repeated to achieve the correction process of the removal rate.

[0059] Step 5: Calculate the actual removal rate and the average actual removal rate of the LED chips in each panel according to the second preset formula;

[0060] In this embodiment, based on the current average thickness, the required removal amount, and the target thickness of the product, and according to the second preset formula S′={L-(H′-K)} / T, the actual removal rate of the LED chips in each tray is calculated, where S′ is the actual removal rate, L is the required removal amount, H′ is the current average thickness, K is the target thickness of the product, and T is the grinding time. The average actual removal rate S″ of the LED chips in each tray is obtained by the ratio of the sum of the actual removal rates S′ of the LED chips in each tray to the number of ceramic trays.

[0061] The actual removal rate is the difference between the current average thickness H′ and the required removal amount L and the target thickness K of the product. The actual removal rate S′ can be obtained by subtracting the required removal amount L from the current average thickness H′ and the corresponding grinding time. This removal rate is the actual removal rate of the LED chip in the disk.

[0062] It is worth mentioning that in the second preset formula, {L-(H′-K)} represents the actual amount of LED chips removed by grinding in each tray. Due to the inherent error in the operation of the grinding machine and the error in controlling the grinding time, specifically, the calculated grinding time may be accurate to several decimal places. Regardless of whether the grinding machine is started and stopped manually or by software, it is impossible to ensure that the working time of the grinding machine matches the required grinding time T. Therefore, combined with the grinding machine's own grinding error and the grinding time error, there is a certain error between the actual amount of LED chips removed by the grinding machine and the required amount. Thus, according to the second preset formula S′={L-(H′-K)} / T, there is a certain error between the calculated actual removal rate of LED chips in each tray and the set removal rate. Therefore, by replacing the average of the calculated actual removal rate with the set removal rate of the grinding machine in the next round, the removal rate can be corrected.

[0063] Meanwhile, since there will be a certain difference between the actual removal rates S′ calculated for each LED chip, it is necessary to calculate the average value of the LED chips in each tray. That is, based on the ratio of the sum of the actual removal rates S′ of the LED chips in each tray to the number of ceramic trays n, the average value of the actual removal rate S″ of the LED chips in each tray is determined.

[0064] Step 6: The average actual removal rate is transmitted to the grinding machine through the MES system, and the average actual removal rate is used as the set removal rate for the next round of LED chips in the grinding machine. The next round of LED chips repeats steps 2 to 5 in sequence according to the set removal rate. The average actual removal rate is calculated again through the MES system and transmitted to the grinding machine through the MES system for correction, so as to realize automatic correction of the removal rate.

[0065] Specifically, in this step, the purpose of calculating the average actual removal rate S″ is to provide a reference for the removal rate of subsequent LED chip grinding. That is, the average actual removal rate S″ calculated after grinding the previous several batches of LED chips is used as the set removal rate in the grinding process of the subsequent batches of LED chips. In the grinding process of the subsequent batches of LED chips, the above steps are repeated. Each time the average actual removal rate S″ is input, the removal rate can be corrected. By repeating the above process, the removal rate can be automatically corrected.

[0066] With each correction process, that is, after each grinding, according to the second preset formula S′={L-(H′-K)} / T, an actual removal rate and an average actual removal rate will be calculated. The average actual removal rate is replaced with the set removal rate of the grinding machine for the next round. After repeating this several times, the calculated actual removal rate will gradually stabilize and approach a fixed value. The above calculation process can realize the correction of the removal rate.

[0067] It is worth mentioning that the process of calculating the actual removal rate S′ and the average actual removal rate S″ of the LED chip after obtaining the current average thickness H′ requires data transmission. The principle of data transmission is as follows: the current average thickness H′ is measured by an automatic measuring machine with a photosensitive device, and the current average thickness H′ is transmitted to an A / D converter. The A / D converter then converts the digital signal into an analog signal and transmits it to the PLC. The PLC transmits it to the PC to calculate the actual removal rate S′ and the average actual removal rate S″ of the LED chip. The PC sends the calculated actual removal rate S′ and the average actual removal rate S″ of the LED chip back to the grinding industrial control computer. The grinding industrial control computer sends it back to the grinding machine PC, and the PC sends it back to the grinding PLC to write the actual removal rate S′ and the average actual removal rate S″ of the LED chip.

[0068] In summary, the LED chip grinding automatic correction removal rate method in the above embodiments of the present invention obtains the average actual removal rate of LED chips in each tray, uses the average actual removal rate as the set removal rate for the next round of the grinding machine, and iteratively calculates and inputs the average actual removal rate to achieve automatic replacement and correction of the removal rate. The entire process requires no manual intervention, reducing labor costs while improving work efficiency.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for automatically correcting the removal rate during LED chip grinding, characterized in that, The method includes the following steps: Step 1: Apply wax to the predetermined number of LED chips in each tray in sequence, accumulating a number of ceramic trays with LED chips already loaded; Step 2: Thin the LED chips in each of the waxed trays and measure the average thickness of the LED chips in each tray after thinning using an automatic measuring machine; Step 3: Calculate the required amount of LED chips to be removed from each plate according to the first preset formula; Step 4: Grind the LED chips on each tray using a grinding machine, and then send the ground LED chips on each tray into the automatic measuring machine to measure the current average thickness. Step 5: Calculate the actual removal rate and the average actual removal rate of the LED chips in each panel according to the second preset formula; Step 6: The average actual removal rate is transmitted to the grinding machine through the MES system, and the average actual removal rate is used as the set removal rate for the next round of LED chips in the grinding machine. The next round of LED chips repeats steps 2 to 5 in sequence according to the set removal rate. The average actual removal rate is calculated again through the MES system and transmitted to the grinding machine through the MES system for correction, so as to realize automatic correction of the removal rate. In step two, after measuring the average thickness of the LED chips in each tray after thinning using an automatic measuring machine, the method further includes: The MES system automatically generates a work document for the grinding machine, which includes the average thickness of the LED chips in each tray after thinning, as measured by the measuring machine. Step three includes: Based on the average thickness of the LED chips in each tray after thinning and the target thickness of the product, and according to the first preset formula L=HK, the required amount of LED chips to be removed from each tray is calculated, where L is the required amount of removal, H is the average thickness of the LED chips in each tray after thinning, and K is the target thickness of the product. Step four includes: Based on the required removal amount and the set removal rate, the grinding time required for each tray of LED chips is T=L / S, where L is the required removal amount and S is the preset removal rate. The grinding machine performs grinding operations on each tray of LED chips according to the time T and the set removal rate S, and sends the ground LED chips of each tray into the automatic measuring machine to measure the current average thickness. Step five includes: Based on the current average thickness, the required removal amount, and the target thickness of the product, the actual removal rate of the LED chips in each tray is calculated according to the second preset formula S′={L-(H′-K)} / T, where S′ is the actual removal rate, L is the required removal amount, H′ is the current average thickness, K is the target thickness of the product, and T is the grinding time. The average actual removal rate S″ of the LED chips in each tray is obtained by the ratio of the sum of the actual removal rates S′ of the LED chips in each tray to the number of ceramic trays.

2. The method for automatically correcting the removal rate during LED chip grinding according to claim 1, characterized in that, In step one, after waxing each LED chip, it is left to cool to 25°C~35°C.

3. The method for automatically correcting the removal rate during LED chip grinding according to claim 1, characterized in that, In step two, the step of thinning the LED chips on each waxed tray includes: The waxed LED chips are fed into a thinning machine, where they are thinned by a grinding wheel for 2 to 10 minutes.

4. The method for automatically correcting the removal rate during LED chip grinding according to claim 1, characterized in that, In step two, after the LED chip is thinned, a damage layer is formed on one side of the LED chip, and the damage layer is removed by the grinding machine.

5. The method for automatically correcting the removal rate during LED chip grinding according to claim 4, characterized in that, The thickness of the damaged layer ranges from 15µm to 20µm.

6. The method for automatically correcting the removal rate during LED chip grinding according to claim 4, characterized in that, The required removal amount L is greater than the thickness of the damaged layer.

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