A method for positioning and selecting LED chips

Abstract

A method for positioning and selecting LED chips includes: 101. Fabricating LED semiconductor dies using a photomask with a fixed spacing, and performing parameter point measurements on the fabricated LED semiconductor dies to obtain their point measurement data; 102. Determining the actual BIN segment interval to which each LED semiconductor die belongs based on the point measurement data; 103. Recording the grid layout of each LED semiconductor die to obtain layout data; 104. Sorting; the sorting device, based on the layout data, picks out LED semiconductor dies belonging to the same actual BIN segment interval from their original positions on the wafer and moves them to the corresponding blue film; wherein, the sorting device includes multiple individually controllable picking devices, and the spacing between each picking device is the same as the grid spacing, so that the sorting device can selectively pick up the corresponding LED semiconductor dies according to the layout data, which can improve the sorting efficiency of LED semiconductor dies in chip production, ensure chip quality, and help reduce production costs and improve automation level.

Description

Technical Field

[0001] This invention relates to the field of display technology, and more particularly to a method for positioning and selecting LED chips. Background Technology

[0002] In recent years, with continuous technological development, the LED industry has experienced rapid growth. While the LED industry is developing rapidly, the market is also placing increasingly stringent demands on the quality of LED chips. High-quality LED chips rely heavily on high-precision sorting. The LED chip production process typically includes key stages such as wafer fabrication, sorting, and chip packaging. Each die undergoes testing to ensure its electrical characteristics meet requirements; qualified dies are then selected, packaged, and ultimately formed into chips. In the sorting stage, current technology primarily utilizes automated LED chip sorting machines. These machines can sort LED chips according to different standards, improving production efficiency, ensuring chip quality, and helping to reduce production costs and increase automation. However, existing LED chip sorting methods suffer from poor stability and low production efficiency. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for LED chip positioning and selection.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A method for locating and selecting LED chips, characterized by comprising the following steps

[0006] 101. LED semiconductor chips are fabricated on a wafer using a photomask with a fixed spacing, and the fabricated LED semiconductor chips are subjected to parameter point measurements to obtain their point measurement data.

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

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

[0009] 104. Sorting: Based on the layout data, the sorting device picks out the LED semiconductor chips belonging to the same actual BIN segment interval from their original positions on the wafer and moves them to the corresponding blue film.

[0010] The sorting device has multiple suction devices, and the spacing between each suction device is the same as the spacing of the grid in the photomask, so that the sorting device can simultaneously suction multiple LED semiconductor chips 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: The blue membrane is divided into several virtual BIN intervals, and the virtual BIN intervals corresponding to each blue membrane are different;

[0014] 202. Actual sorting: After comparing the layout data and the virtual BIN interval, the sorting device described in 104 moves the LED semiconductor chips 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] Furthermore, step 202 includes:

[0017] 2021. Initial sorting: The first sorting device is moved to the corresponding position so that each of the picking devices corresponds to each of the LED semiconductor chips. Then, based on the layout data and the virtual BIN interval, the corresponding controllers are controlled so that the corresponding picking devices move and pick out the LED semiconductor chips 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. Sub-sorting: Move the second sorting device to the corresponding position, and move the corresponding picking devices through the controller to pick out the remaining LED semiconductor chips 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 for recording the layout data carrying position information of the LED semiconductor chips.

[0021] Furthermore, the photomask is designed with a fixed spacing, and the absorption devices are distributed in an equidistant array.

[0022] Furthermore, the sorting device is composed of several modular suction devices.

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

[0024] The beneficial effects of this invention are:

[0025] 1. The present invention proposes an LED chip positioning and selection method, which uses a fixed-interval photomask to fabricate LED chips. After fabrication, the photomask is removed, thereby obtaining neatly arranged LED semiconductor chips, which facilitates the sorting of LED semiconductor chips in subsequent steps.

[0026] 2. The LED chip positioning and selection method proposed in this invention utilizes a virtual BIN method for pre-sorting classification. After obtaining relevant parameters by performing parameter point measurements on the LED semiconductor dies of the wafer, the LED semiconductor dies are virtually classified using BIN, enabling the fabricated LED chips to flexibly adapt to complex manufacturing and testing requirements.

[0027] 3. The LED chip positioning and selection method proposed in this invention proposes to use multiple picking devices for picking at one time. Multiple picking devices can pick up multiple LED semiconductor chips at the same time, improving the picking efficiency; and by using a module to replace a single picking device, the replacement efficiency of the sorting device can be improved.

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

[0029] 5. The LED chip positioning and selection method proposed in this invention uses a sorting device to pick up LED semiconductor chips. The sorting device includes multiple picking devices, each connected to a corresponding controller. By controlling the controller of the corresponding picking device, the required LED semiconductor chips can be picked up arbitrarily, ensuring that all required LED semiconductor chips can be selected, improving the flexibility of chip sorting and reducing losses in production. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, 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 invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is an example diagram of virtual BIN classification in an LED chip positioning and selection method according to the present invention;

[0032] Figure 2 This is a schematic diagram of a sorting device for an LED chip positioning and selection method according to the present invention;

[0033] Figure 3 This is an example diagram of the position information marking in an LED chip positioning and selection method according to the present invention;

[0034] Figure 4 This is a schematic diagram of a sorting device for selecting LED chips in an LED chip positioning and selection method according to the present invention. Detailed Implementation

[0035] The following is combined Figure 1-4 The present invention will be described in detail below.

[0036] This invention relates to a method for locating and selecting LED chips, comprising the following steps:

[0037] A method for locating and selecting LED chips, characterized by comprising the following steps

[0038] 101. LED semiconductor chips are fabricated on wafers using photomasks with fixed spacing, and parameter point measurements are performed on the fabricated LED semiconductor chips to obtain their point measurement data.

[0039] 102. Determine the actual BIN segment range to which each LED semiconductor chip belongs based on the spot measurement data;

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

[0041] 104. Sorting: Based on the layout data, the sorting device picks out LED semiconductor chips belonging to the same actual BIN segment from their original positions on the wafer and moves them to the corresponding blue film.

[0042] The sorting device has multiple suction devices, and the spacing between each suction device is the same as the grid spacing, allowing the sorting device to simultaneously pick up multiple LED semiconductor chips belonging to the same actual BIN segment. In this embodiment, LED semiconductor chips are first fabricated on the wafer using a fixed-space photomask. After fabrication, the photomask is removed, resulting in several LED semiconductor chips with the same spacing and neatly arranged. The obtained LED semiconductor chips are then sorted.

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

[0044] 201. Virtual BIN Classification: Divide all blue membranes into several virtual BIN intervals, and the virtual BIN intervals corresponding to each blue membrane are different;

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

[0046] Specifically, the point-measurement data includes voltage parameters, brightness parameters, and wavelength parameters. In practice, the BIN segment range to which each LED semiconductor chip belongs is first determined based on the point-measurement data, then sorted according to the point-measurement data, and finally physically replaced. This implementation example... Figure 1 As shown, during the LED chip binning process, the original wafer contains LED semiconductor chips of different specifications with actual binning ranges from 1 to 25. This embodiment requires moving these chips to 45 blue films, performing virtual sorting on all blue films, with each blue film corresponding to a virtual binning interval. Since the maximum actual LED binning is currently 150, this embodiment uses a virtual binning value above 150, assigning the 45 blue films to 45 virtual binning intervals from 151 to 195, thus avoiding conflicts and confusion between virtual and actual binning. In actual production, the division of virtual binning can be determined by the number of blue films to which the chips need to be transferred. After completing the virtual binning classification, this embodiment calculates and determines the target blue film position for each type of LED semiconductor chip in the wafer, and then performs the actual sorting in step 202. LED semiconductor chips of the same specification may go to multiple positions on multiple blue films. This embodiment also records bin frame barcodes during virtual binning classification and compares them before selection to ensure accurate sorting.

[0047] In this embodiment, each suction device is a sorting nozzle, which can pick up the required LED semiconductor chips by controlling the sorting nozzle. This embodiment uses a fixed-gap photomask. In actual production, the process of etching LEDs on a complete, unprocessed wafer uses a photomask with a fixed gap. The LED semiconductor chips are then placed in the corresponding grids within the photomask. After the LED semiconductor chips are obtained, the photomask is removed, and the LED semiconductor chips are spaced at the same interval and arranged neatly. Moreover, LED semiconductor chips of the same specification 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 nozzles, and the spacing between each sorting nozzle is the same as the grid spacing. Multiple adjacent LED semiconductor chips of the same specification can be selected at once. Using multiple sorting nozzles to pick up multiple chips can improve the picking efficiency and reduce the cost of chip production.

[0048] In this embodiment, the photomask is designed with equal spacing, and correspondingly, 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, DCS controller, microcontroller, or other device capable of individual circuit control. The controller allows for the control of individual sorting nozzles, thereby selectively selecting target LED semiconductor chips. Figure 4 As shown in the figure, there are four LED semiconductor chips and four sorting nozzles at positions 1, 2, 3, and 4. In this embodiment, the target LED semiconductor chips are those at positions 1 and 3. During the picking process, the sorting nozzles at positions 1 and 3 are energized to control their movement and pick up the LED semiconductor chips at those positions. This embodiment allows the sorting nozzles to pick up single or multiple LED semiconductor chips, significantly improving the flexibility of the sorting process. Preferably, each sorting nozzle can be an electromagnetic nozzle, with its operation controlled electromagnetically. 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. Initial sorting: Move the first sorting device to the corresponding position so that each pick-up device corresponds to each LED semiconductor chip. Then, based on the layout data, power on each pick-up device corresponding to the LED semiconductor chips belonging to the same BIN segment. Each pick-up device moves and picks up the corresponding LED semiconductor chip from the original position of the wafer and moves it to the corresponding blue film.

[0051] Preferably, step 202 further includes:

[0052] 2022, Sub-sorting: The second sorting device is moved to the corresponding position, and the corresponding picking devices are moved by circuit control to pick out the remaining LED semiconductor chips 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 substantive sorting is the initial sorting, which first completes the selection of the concentrated LED semiconductor chips, and the second substantive sorting is performed again on the remaining LED semiconductor chips on the wafer. Through two sorting and picking processes, production efficiency is improved.

[0053] In this embodiment, each suction device is detachably connected to the sorting device. The structure of multiple sorting nozzles combined can be designed according to actual needs, and the sorting device consists of several modular suction devices. Figure 2As shown, the sorting nozzle in this embodiment has a square structure, which can save gripping time and cost. Since the sorting nozzle is a consumable, it often needs to be replaced during production. When wear and tear occurs, it is preferable to use a modular approach for replacement to reduce the difficulty of replacing the sorting nozzle.

[0054] In this embodiment, the layout of each LED semiconductor chip is recorded using an image sensor to obtain layout data. Preferably, the image sensor in this embodiment is a camera. Before selecting LED semiconductor chips, it is often necessary to obtain precise positions of the LED semiconductor chips. In this embodiment, a photomask is fabricated with a fixed spacing to ensure that the manufactured LED chips are uniformly arranged on the wafer. Then, a camera is used to record the positions of the LED semiconductor chips, and the position information of each LED semiconductor chip is marked with special symbols such as letters or symbols. Figure 3 As shown, in this embodiment, position information is marked with 1, 2, 3... and A, B, C... During use, the stored position information of the LED semiconductor chips is identified, and the corresponding LED semiconductor chips are selected based on the identified information. During the selection process, as long as the absolute position of the chip is not affected by film deformation, the correct selection of the chip's position can be achieved.

[0055] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand and implement the present invention. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for positioning and selecting LED chips, characterized in that, Includes the following steps 101. LED semiconductor chips are fabricated on a wafer using a photomask with a fixed spacing, and the fabricated LED semiconductor chips are subjected to parameter point measurement to obtain their point measurement data.

102. Determine the actual BIN segment interval to which each LED semiconductor chip belongs based on the point measurement data; 103. Record the layout of each LED semiconductor chip to obtain layout data; 104. Sorting: Based on the layout data, the sorting device picks out the LED semiconductor chips belonging to the same actual BIN segment interval from their original positions on the wafer and moves them to the corresponding blue film. The sorting device has multiple suction devices, each of which is an electromagnetically controlled sorting nozzle. The spacing between each suction device is the same as the spacing of the grid inside the photomask, allowing the sorting device to simultaneously pick up multiple LED semiconductor chips belonging to the same actual BIN segment. The sorting device includes a first sorting device and a second sorting device. Each suction device is electrically connected to a controller. Step 104 also includes:

201. Virtual BIN Classification: The blue membrane is divided into several virtual BIN intervals, and the virtual BIN intervals corresponding to each blue membrane are different; 202. Actual sorting: After comparing the layout data and the virtual BIN interval, the sorting device described in 104 moves the LED semiconductor chips belonging to the same actual BIN segment interval to the blue film of the corresponding virtual BIN interval; Step 202 includes: 2021. Initial sorting: Move the first sorting device to the corresponding position so that each of the picking devices corresponds to each of the LED semiconductor chips. Then, based on the layout data and the virtual BIN interval, control the corresponding controllers so that the corresponding picking devices move and pick out the LED semiconductor chips belonging to the same actual BIN segment interval from the original position of the wafer and move them to the corresponding blue film. 2022. Sub-sorting: Move the second sorting device to the corresponding position, and move the corresponding picking devices through the controller to pick out the remaining LED semiconductor chips belonging to the same actual BIN segment from the original position of the wafer and move them to the corresponding blue film.

2. The LED chip positioning and selection method as described in claim 1, characterized in that, The BIN value of the virtual BIN interval is greater than 150.

3. The LED chip positioning and selection method as described in claim 2, characterized in that, It also includes an image sensor for recording the layout data carrying position information of the LED semiconductor chips.

4. The LED chip positioning and selection method as described in claim 1, characterized in that, The photomask is designed with a fixed spacing, and the absorption devices are distributed in an equidistant array.

5. The LED chip positioning and selection method as described in claim 3, characterized in that, The sorting device consists of several modular suction devices.

6. The LED chip positioning and selection method as described in claim 5, characterized in that, Each of the aforementioned suction devices is detachably connected to the sorting device.

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