LED chip positioning and selecting method

Abstract

The invention relates to an LED chip positioning and selecting method, which comprises the following steps of: 101, manufacturing LED semiconductor crystal grains by using a photomask plate with a fixed interval, and carrying out parameter spot measurement on the manufactured LED semiconductor crystal grains to obtain spot measurement data of the LED semiconductor crystal grains; 102, determining an actual BIN section interval to which each LED semiconductor crystal grain belongs according to spot measurement data; 103, recording the grid layout condition of each LED semiconductor crystal grain to obtain layout data; 104, sorting is carried out; the sorting device picks out the LED semiconductor crystal grains belonging to the actually same BIN section interval from the original position of the wafer and moves the LED semiconductor crystal grains to the corresponding blue film based on the layout data; wherein the sorting device comprises a plurality of sucking devices which can be independently controlled, and the spacing distance between the sucking devices is the same as the spacing distance between grids, so that the sorting device can selectively suck the corresponding LED semiconductor crystal grains according to layout data, the sorting efficiency of the LED semiconductor crystal grains in chip production can be improved, and the quality of chips is ensured; and the production cost can be reduced, and the automation level can be improved.

Description

Technical Field

[0001] The invention relates to the field of display technology, and in particular to a method for positioning and selecting LED chips. Background Art

[0002] In recent years, with the continuous development of technology, the LED industry has ushered in rapid growth. While the LED industry is developing rapidly, the market has become more and more stringent on the quality of LED chips. High-quality LED chips are inseparable from high-precision sorting. The production process of LED chips usually includes key links such as wafer manufacturing, selection and sorting, and chip packaging. After each grain is tested to ensure that its electrical characteristics meet the requirements, qualified grains will be selected, packaged, and finally formed into chips. In the selection link, the existing technology mainly realizes sorting through automated LED chip sorting machines. LED chip sorting machines can sort LED chips according to different standards, which can not only improve production efficiency and ensure chip quality, but also help reduce production costs and improve the level of automation. However, in the existing LED chip sorting, there are problems of poor stability and low production efficiency. Summary of the invention

[0003] In view of the shortcomings of the background technology, the present invention aims to provide a method for positioning and selecting LED chips.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A method for positioning and selecting LED chips, characterized in that it includes the following steps

[0006] 101. Using a mask plate with a fixed spacing to manufacture LED semiconductor grains on a wafer, and performing point measurement on parameters of the manufactured LED semiconductor grains to obtain point measurement data thereof;

[0007] 102. Determine the actual BIN segment interval to which each LED semiconductor die belongs according to the point measurement data;

[0008] 103. Record the layout of each LED semiconductor grain to obtain layout data;

[0009] 104. Sorting: A sorting device picks out the LED semiconductor dies belonging to the same actual BIN segment from the original position of the wafer and moves them to the corresponding blue film based on the layout data;

[0010] The sorting device has a plurality of suction devices, and the spacing between the suction devices is the same as the spacing of the grids in the mask plate, so that the sorting device can simultaneously suck a plurality of LED semiconductor grains belonging to the same actual BIN segment.

[0011] Furthermore, the sorting device includes a first sorting device and a second sorting device; each of the suction devices is electrically connected to a controller.

[0012] Furthermore, step 104 also includes:

[0013] 201. Virtual BIN classification: dividing the blue film into a number of virtual BIN intervals, and the virtual BIN intervals corresponding to the blue films are different;

[0014] 202. Actual sorting: After comparing the layout data with the virtual BIN interval, the sorting device in 104 moves the LED semiconductor grains belonging to the same actual BIN segment interval to the blue film of the corresponding virtual BIN interval.

[0015] Furthermore, the BIN value of the virtual BIN interval is greater than 150.

[0016] Further, step 202 includes:

[0017] 2021. Preliminary sorting: Move the first sorting device to a corresponding position so that each of the suction devices corresponds to each of the LED semiconductor grains, and then control the corresponding controllers based on the layout data and the virtual BIN interval so that the corresponding suction devices move and pick out the LED semiconductor grains belonging to the same actual BIN segment interval from the original position of the wafer and move them to the corresponding blue film.

[0018] Furthermore, step 202 also includes:

[0019] 2022. Segment sorting: Move the second sorting device to a corresponding position, and move the corresponding suction devices through the controller to pick out the remaining LED semiconductor grains belonging to the same actual BIN segment from the original position of the wafer and move them to the corresponding blue film.

[0020] Furthermore, it also includes an image sensor, which is used to record the layout data carrying the position information of the LED semiconductor grains.

[0021] Furthermore, the mask plates are designed with fixed spacing, and the suction devices are distributed in an equidistant array.

[0022] Furthermore, the sorting device is composed of the suction devices of a plurality of module structures.

[0023] Furthermore, each of the suction devices can be detachably connected to the sorting device.

[0024] The beneficial effects of the present invention are:

[0025] 1. The present invention proposes a method for positioning and selecting LED chips. LED grains are made by using a fixed-interval mask plate. After the production is completed, the mask plate is removed to obtain neatly arranged LED semiconductor grains, which is convenient for sorting the LED semiconductor grains in subsequent steps.

[0026] 2. The present invention proposes a method for positioning and selecting LED chips, and proposes a method for using virtual BIN to perform classification before sorting. After performing parameter point measurement on the LED semiconductor grains of the wafer to obtain their relevant parameters, the LED semiconductor grains are subjected to BIN virtual classification, so that the prepared LED chips can flexibly adapt to complex manufacturing and testing requirements.

[0027] 3. The LED chip positioning and selection method proposed in the present invention proposes to use multiple suction devices for suction at one time. Multiple suction devices can suck multiple LED semiconductor grains at one time, which improves the suction efficiency; and the use of a module to replace a single suction device can improve the replacement efficiency of the sorting device.

[0028] 4. The LED chip positioning and selection method proposed in the present invention records the position information of LED semiconductor grains before selection through an image sensor, thereby improving the chip sorting accuracy and ensuring that each LED semiconductor grain can be accurately identified and processed in the subsequent sorting process.

[0029] 5. The LED chip positioning and selection method proposed by the present invention uses a sorting device to complete the absorption of LED semiconductor grains. The sorting device includes multiple absorption devices, each of which is connected to a corresponding controller. By controlling the controller of the corresponding absorption device, the required LED semiconductor grains can be arbitrarily absorbed to ensure that the required LED semiconductor grains can be selected, thereby improving the flexibility of chip sorting and reducing losses in production. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 An example diagram of virtual BIN classification of a method for positioning and selecting LED chips of the present invention;

[0032] Figure 2 A schematic diagram of a sorting device for a method for positioning and selecting LED chips of the present invention;

[0033] Figure 3 An example diagram of a position information mark of a method for positioning and selecting an LED chip according to the present invention;

[0034] Figure 4 The present invention is a schematic diagram of a sorting device selecting grains in a method for positioning and selecting LED chips. DETAILED DESCRIPTION

[0035] Combine the following Figure 1-4 The present invention is described in detail.

[0036] The present invention is a method for positioning and selecting LED chips, comprising the following steps:

[0037] A method for positioning and selecting LED chips, characterized in that it includes the following steps

[0038] 101. Using a mask plate with a fixed spacing to manufacture LED semiconductor grains on a wafer, and performing point measurement of parameters on the manufactured LED semiconductor grains to obtain point measurement data thereof;

[0039] 102. Determine the actual BIN segment interval to which each LED semiconductor die belongs based on the point measurement data;

[0040] 103. Record the layout of each LED semiconductor grain to obtain layout data;

[0041] 104. Sorting: The sorting device picks out LED semiconductor dies belonging to the same actual BIN segment from the original position of the wafer and moves them to the corresponding blue film based on the layout data;

[0042] The sorting device has a plurality of suction devices, and the spacing between the suction devices is the same as the grid spacing, so that the sorting device can simultaneously absorb a plurality of LED semiconductor grains belonging to the same actual BIN segment interval. In this embodiment, a fixed-interval mask plate is first used to process and manufacture LED semiconductor grains on a wafer, and after the manufacture is completed, the mask plate is removed, and at this time, a plurality of LED semiconductor grains with the same spacing and neat arrangement can be obtained, and then the obtained LED semiconductor grains are sorted.

[0043] In this embodiment, step 104 further includes:

[0044] 201. Virtual BIN classification: All blue films are divided into several virtual BIN intervals, and the virtual BIN intervals corresponding to each blue film are different;

[0045] 202. Actual sorting: After comparing the layout data and the virtual BIN interval, the sorting device calculates the moving path of the LED semiconductor grains, and moves the LED semiconductor grains belonging to the same actual BIN segment from the original position of the wafer to the blue film of the corresponding virtual BIN interval.

[0046] Specifically, the point measurement data includes voltage parameters, brightness parameters, wavelength parameters, etc. In practice, the BIN segment interval to which each LED semiconductor die belongs is first determined based on the point measurement data, and then sorted based on the point measurement data, and finally replaced in kind. Figure 1 As shown, in the process of LED chip BIN classification, there are LED semiconductor grains of different specifications with actual BIN in the range of 1 to 25 on the original wafer. In this embodiment, it is necessary to move them to 45 blue films, and perform virtual sorting on all blue films, and each blue film corresponds to a virtual BIN interval; since the maximum BIN of LED is 150 in practice, the virtual BIN in this embodiment takes a value above 150, and 45 blue films correspond to 45 virtual BIN intervals of 151 to 195, thereby avoiding conflicts between virtual BIN and actual BIN and confusion. The division of virtual BIN during specific production can be determined by the number of blue films that need to be transferred to in actual situations. After completing the virtual BIN classification, this embodiment calculates and determines the target blue film position to which each type of LED semiconductor grain in the wafer will go, and then performs the actual sorting of step 202. LED semiconductor grains of the same specification may go to multiple positions of multiple blue films. In this embodiment, bin fram barcodes are also recorded during virtual BIN classification, and are compared before selection to ensure the accuracy of sorting.

[0047] In this embodiment, each suction device is a sorting suction nozzle, and the required LED semiconductor grains can be sucked by controlling the sorting suction nozzle. This embodiment adopts a fixed spacing to make a mask plate. In actual production, the process of etching and making LEDs on a complete unprocessed wafer uses a fixed spacing mask plate, and then the LED semiconductor grains made will be in the corresponding grid in the mask plate. After the LED semiconductor grains are made, the mask plate is removed, and the LED semiconductor grains are spaced at the same interval and arranged neatly, and LED semiconductor grains of the same specifications are often in the same area, and most of them will go to the adjacent position of the same blue film. Preferably, in this embodiment, there are multiple sorting suction nozzles, and the spacing between each sorting suction nozzle is the same as the grid spacing, so that multiple adjacent LED semiconductor grains of the same specification can be selected at one time. The suction of multiple grains by multiple sorting suction nozzles can improve the suction efficiency and reduce the cost of chip production.

[0048] In this embodiment, the mask plate is designed with equidistant spacing, and accordingly, the suction device is an equidistant array of sorting nozzles. In this embodiment, each sorting nozzle is also electrically connected to a corresponding controller. Specifically, the controller can be a PLC controller, a DCS controller, a microcontroller, or other device that can realize independent circuit control. The controller can realize the control of a single sorting nozzle, thereby selectively selecting the target LED semiconductor grains. Figure 4 As shown in the figure, there are four LED semiconductor grains and four sorting nozzles at positions 1, 2, 3, and 4. The target LED semiconductor grains in this embodiment are the LED semiconductor grains at positions 1 and 3. During the suction process, the sorting nozzles at positions 1 and 3 are powered on to control the movement of the sorting nozzles at positions 1 and 3 and to grab the LED semiconductor grains at positions 1 and 3. In this embodiment, the sorting nozzle can arbitrarily absorb a single or multiple LED semiconductor grains, which significantly improves the flexibility of the sorting process. Preferably, each sorting nozzle can also be an electromagnetic nozzle, and the operation of each sorting nozzle is controlled by electromagnetic. In this embodiment, the sorting device also includes a first sorting device and a second sorting device.

[0049] In this embodiment, step 202 includes:

[0050] 2021. Preliminary sorting: Move the first sorting device to the corresponding position so that each suction device corresponds to each LED semiconductor chip. Then, based on the layout data, energize each suction device corresponding to the LED semiconductor chip belonging to the same BIN segment. Each suction device moves and picks out the corresponding LED semiconductor chip from the original position on the wafer and moves it to the corresponding blue film.

[0051] Preferably, step 202 further includes:

[0052] 2022. Segment sorting: Move the second sorting device to the corresponding position, move the corresponding suction devices through circuit control, pick out the remaining LED semiconductor grains belonging to the same BIN segment from the original position of the wafer and move them to the corresponding blue film; wherein step 2022 is after step 2021. In this embodiment, the first substantial sorting is the initial sorting, which first completes the selection of concentrated LED semiconductor grains, and the second substantial sorting is to select the remaining LED semiconductor grains on the wafer again, and the production efficiency is improved through two sorting and grabbing.

[0053] In this embodiment, each suction device can be detachably connected to the sorting device. The structure of the combination of multiple sorting nozzles can be designed according to actual needs, and the sorting device is composed of a plurality of suction devices of modular structure. Figure 2As shown, the sorting nozzle in this embodiment is a square structure, which can save grasping time and cost. Since the sorting nozzle is a consumable, it often needs to be replaced during production. When it is worn out, it is preferably replaced in a module to reduce the difficulty of replacing the sorting nozzle.

[0054] In this embodiment, the layout of each LED semiconductor grain is recorded by an image sensor to obtain layout data. Preferably, the image sensor in this embodiment is a camera. Before selecting LED semiconductor grains, it is often necessary to obtain the precise position of the LED semiconductor grains. In this embodiment, a fixed spacing is used to make a mask plate to ensure that the manufactured LED grains are evenly arranged on the wafer, and then the position of the LED semiconductor grains is recorded by a camera, and the position information of each LED semiconductor grain is marked with special symbols such as letters or symbols. Figure 3 As shown, this embodiment uses 1, 2, 3 ... and A, B, C ... to mark its position information. When in use, the stored position information of LED semiconductor crystal grains is identified, and the corresponding LED semiconductor crystal grains are selected according to the identified information. In the selection process, the absolute position of the crystal grain can be correctly selected as long as it is ensured that it is not affected by the deformation of the film.

[0055] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for positioning and selecting LED chips, characterized in that: The following steps are included 101. Using a mask plate with a fixed spacing to manufacture LED semiconductor grains on a wafer, and performing point measurement on parameters of the manufactured LED semiconductor grains to obtain point measurement data thereof; 102. Determine the actual BIN segment interval to which each LED semiconductor die belongs according to the point measurement data; 103. Record the layout of each LED semiconductor grain to obtain layout data; 104. Sorting: A sorting device picks out the LED semiconductor dies belonging to the same actual BIN segment from the original position of the wafer and moves them to the corresponding blue film based on the layout data; The sorting device has a plurality of suction devices, and the spacing between the suction devices is the same as the spacing of the grids in the mask plate, so that the sorting device can simultaneously suck a plurality of LED semiconductor grains belonging to the same actual BIN segment.

2. A method for positioning and selecting LED chips as claimed in claim 1, characterized in that: The sorting device comprises a first sorting device and a second sorting device; each of the suction devices is electrically connected to a controller.

3. A method for positioning and selecting LED chips as claimed in claim 2, characterized in that: Step 104 also includes:

201. Virtual BIN classification: dividing the blue film into a number of virtual BIN intervals, and the virtual BIN intervals corresponding to the blue films are different; 202. Actual sorting: After comparing the layout data with the virtual BIN interval, the sorting device in 104 moves the LED semiconductor grains belonging to the same actual BIN segment interval to the blue film of the corresponding virtual BIN interval.

4. A method for positioning and selecting LED chips as claimed in claim 3, characterized in that: The BIN value of the virtual BIN interval is greater than 150.

5. A method for positioning and selecting LED chips as claimed in claim 4, characterized in that: Step 202 includes: 2021. Preliminary sorting: Move the first sorting device to a corresponding position so that each of the suction devices corresponds to each of the LED semiconductor grains, and then control the corresponding controllers based on the layout data and the virtual BIN interval so that the corresponding suction devices move and pick out the LED semiconductor grains belonging to the same actual BIN segment interval from the original position of the wafer and move them to the corresponding blue film.

6. A method for positioning and selecting LED chips as claimed in claim 5, characterized in that: Step 202 also includes: 2022. Segment sorting: Move the second sorting device to a corresponding position, and move the corresponding suction devices through the controller to pick out the remaining LED semiconductor grains belonging to the same actual BIN segment from the original position of the wafer and move them to the corresponding blue film.

7. A method for positioning and selecting LED chips as claimed in claim 6, characterized in that: It also includes an image sensor, which is used to record the layout data carrying the position information of the LED semiconductor grains.

8. The method for positioning and selecting LED chips according to claim 1, characterized in that: The photomask plates are designed with fixed spacing, and the suction devices are distributed in an equidistant array.

9. A method for positioning and selecting LED chips as claimed in claim 8, characterized in that: The sorting device is composed of the suction devices of a plurality of module structures.

10. A method for positioning and selecting LED chips as claimed in claim 9, characterized in that: Each of the suction devices can be detachably connected to the sorting device.

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