A motion path setting method for transferring LEDs

Abstract

The present invention provides a method for setting a motion path for transferring LEDs, wherein an acupuncture device is used to transfer LED chips to a PCB carrier board. The PCB carrier board is provided with two or more single pixel fixed positions, each pixel fixed position is arranged in an array on the PCB carrier board, and each pixel point includes one or more LED chips. The LED chips are divided into two or more groups according to chip characteristics. A group of LED chips is transferred to the PCB board according to the motion path. The motion path includes: an alternate column path and / or an alternate row path. Another group of LED chips is supplemented at the alternate positions of the LED chips according to the motion path. The chip characteristic values ​​of the another group of LED chips are between the chip characteristic values ​​of the two adjacent LED chips. The present invention improves the display effect by setting different motion paths to achieve a mixed bin method of acupuncture-type transfer of LEDs, while also ensuring that the acupuncture method does not significantly reduce work efficiency.

Description

Technical Field

[0001] The present invention relates to the field of LED chip transfer, and in particular to a method for setting a motion path for transferring LEDs. Background Art

[0002] The process chain for Mini / Micro LED display panel production is long and complex, mainly including chip preparation, chip transfer, and defect detection and repair, among which chip transfer is a key step in the process chain.

[0003] LED chips are typically bonded together by suppliers onto a blue film to form wafers. After wafer fabrication, the LED chips often have a wide range of specifications (wavelength, brightness, and voltage). Directly transferring them to the driver circuit board without sorting can produce color patches and uneven brightness. Therefore, chip manufacturers re-sort the LED chips according to specific specifications to narrow the specification range and achieve greater consistency. However, this still does not meet the requirements for high-quality Mini / MicroLED display panels.

[0004] For this reason, the packaging factory will perform secondary bin mixing. Generally, bin mixing is achieved through a crystal bonding machine. The crystal bonding machine in the prior art includes: a wafer disc for carrying wafers, a carrier for carrying substrates, a needling device and a suction nozzle, wherein the wafer disc and the carrier are on the same horizontal plane, and the needling device is arranged below the wafer disc. When working, the needling head in the needling device is first used to lift the LED chip in the wafer to separate the LED chip from the blue film. At this time, the suction nozzle is used to transfer the LED chip to the substrate, such as the Chinese patent application number 202110750360.3, published on October 22, 2021. This structure discloses a needling type crystal bonding machine. The above-mentioned transfer process usually requires the LED chips to be lifted one by one by the needling device, resulting in low efficiency in LED chip transfer.

[0005] At the same time, in the bin mixing process, there are currently two methods, the swing arm method and the needle puncture method. The swing arm method adopts a one-by-one method, which uses a swinging device to adsorb the LED chips that have been pushed open on the wafer, and then swings the swing arm to rotate the LED chips to the driver circuit board. Its bin mixing movement path has a high degree of freedom and can achieve a random and extremely dispersed path. However, since it needs to use the swing arm movement in the process of transferring the LED chips, the transfer speed is slow, and the accuracy is low due to the swing arm movement. The other is through the needle puncture method. The needle puncture movement feature is continuous crystal puncture. If the needle puncture method uses the same random crystal fixing path as the swing arm method, it will violate the movement feature of the needle puncture and cause a great drop in efficiency (more than 50%). If the crystal is fixed in sequence, since the LED chips are arranged in sequence on the blue film, for example, arranged according to brightness, if these regular LED chips are transferred to the PCB, then the PCB will still maintain this pattern, and the PCB will show that some areas are bright and some areas are dark, thereby causing color blocks and uneven brightness.

[0006] Therefore, it is necessary to find a path setting method that has high transfer efficiency and can improve display effects. Summary of the Invention

[0007] The present invention aims to provide a method for setting a motion path for transferring LEDs, which can improve the display effect by setting a mixed bin motion path according to a needle-piercing method for transferring LEDs, and the mixed bin method is simple to set. In order to achieve the above-mentioned purpose, a method for setting a motion path for transferring LEDs is provided, wherein a needle-piercing device is used to transfer LED chips to a PCB carrier, wherein the PCB carrier is provided with two or more single pixel fixed positions, each pixel fixed position is arranged in an array on the PCB carrier, each pixel includes one or more LED chips, and the LED chips are divided into two or more groups according to chip characteristics. A group of LED chips is transferred to the PCB carrier according to the motion path, wherein the motion path includes: an alternate column path and / or an alternate row path, and another group of LED chips is supplemented at the alternate positions of the LED chips according to the motion path, and the chip characteristic values ​​of the other group of LED chips are between the chip characteristic values ​​of the two adjacent LED chips.

[0008] The above setting is to sort out LED chips of different specifications by setting the chip characteristic values ​​of the LED chips, and to set the LED chips on the PCB carrier according to the movement path by a needle-piercing method, and to set different paths by alternating columns, rows, or both rows and columns for each pixel point, so that LED chips with different characteristics are arranged on the PCB carrier in an alternating row or column manner, and then another LED chip located between the chip characteristic values ​​is added at the interval position, thereby preventing the situation where the characteristics of the LED chips moved after the LED chips are different by needle-piercing, and one piece is bright and the other is dark. This setting allows LED chips with similar characteristics removed from the wafer to be arranged at intervals, thereby achieving the LED chips removed from the same wafer to be shuffled, and then another group of LED chips located between adjacent LED chips are added at the interval position, thereby increasing the utilization rate of the PCB carrier and compensating for the characteristic differences at the interval position. Moreover, this setting is not a random setting, so that the existing needle-piercing device cannot achieve random operation. At the same time, the existing needle-piercing device can achieve the efficiency of mixed bin operation, and the mixed bin operation is simple.

[0009] Furthermore, the LED chips are divided into two or more groups according to the wavelength and / or brightness and / or voltage of the LED chips.

[0010] The above settings, by classifying by wavelength range, can ensure color uniformity after binning, and by classifying by brightness can ensure brightness consistency.

[0011] Furthermore, the fixed position of a single pixel point includes a fixed position for a red LED chip, a fixed position for a green LED chip, and a fixed position for a blue LED chip. The wavelength range of the red LED chip is 620 to 760 nm; the wavelength range of the green LED chip is 492 to 577; the wavelength range of the blue LED chip is 400 nm to 450 nm, and the screening voltage range of the LED chip is 0-5 V.

[0012] The above setting forms a pixel by combining the three colors of LED chips, making it easy to form a pixel point by mixing the red, green and blue chips to achieve mixed bin.

[0013] Furthermore, a group of LED chips on a single pixel point on the PCB carrier board are arranged at intervals according to the arrangement of LED chips on a wafer, and there is more than one interval position.

[0014] The above arrangement arranges the LED chips on a wafer in an intermittent manner, thereby spacing out the LED chips arranged sequentially on the wafer, thereby eliminating the color block problem caused by the same characteristics.

[0015] Furthermore, the greater the difference in chip characteristics between adjacent LED chips on a wafer, the more spacing positions are set.

[0016] The above arrangement results in a large difference in characteristics between adjacent LED chips on a wafer, and the characteristic difference can be adjusted with a larger spacing, so that more supplementary LED chips can be inserted to make up for it.

[0017] Furthermore, there are more than two spacing positions, and different groups of LED chips are arranged on the more than two spacing positions. The characteristic value of the LED chip on one spacing position and the characteristic value of the LED chip on another spacing position are between the characteristic values ​​of the LED chip fixed on the PCB carrier board through the motion path for the first time.

[0018] The above setting can achieve a disruptive effect by inserting LED chips with different characteristics from different wafers at the intervals, and can also supplement the difference in chip characteristics at the intervals to further improve the display effect.

[0019] Furthermore, there are more than two spacing positions, and a group of LED chips are added to the two spacing positions. The characteristic value of the LED chip on one spacing position and the characteristic value of the LED chip on another spacing position are between the characteristic values ​​of the LED chip fixed on the PCB carrier board through the motion path for the first time.

[0020] The above arrangement can improve efficiency while also facilitating improvement of display effects by supplementing LED chips on the same wafer at intervals.

[0021] Furthermore, the motion path also includes adding a starting point every other row or / and adding a starting point every other column.

[0022] The above settings further change the starting point position on an alternate line basis, thereby further disrupting the path and individual pixels. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the structure after the LED chip is fixed on the PCB carrier board of the present invention.

[0024] Figure 2 A diagram showing the composition of a single pixel in an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of the moving path of Example 1 of the present invention.

[0026] Figure 4 This is a schematic diagram of the moving path of Example 2 of the present invention.

[0027] Figure 5 This is a schematic diagram of the moving path of Example 3 of the present invention.

[0028] Figure 6 This is a schematic diagram of the moving path of Example 4 of the present invention.

[0029] Figure 7 This is a schematic diagram of the moving path of Example 5 of the present invention.

[0030] Figure 8 This is a schematic diagram of the moving path of Example 6 of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figures 1 to 7 A method for setting a motion path for transferring LEDs is shown, in which an acupuncture device (not shown) is used to transfer an LED chip 2 onto a PCB carrier board 1. The PCB carrier board 1 is provided with two or more single pixel fixed positions, each pixel fixed position is arranged in an array on the PCB carrier board 1, and each pixel point includes one or more LED chips. The LED chips are divided into two or more groups according to chip characteristics. A group of LED chips is transferred to the PCB carrier board 1 according to the motion path. The motion path includes: an alternate column path and / or an alternate row path, alternate rows with an additional starting point, and / or alternate columns with an additional starting point. Another group of LED chips is added to the alternate positions of the LED chips according to the motion path, and the chip characteristic values ​​of the LED chips in the other group are between the chip characteristic values ​​of the two adjacent LED chips.

[0033] In one embodiment, the fixed position of a single pixel point includes a fixed position for a red LED chip 21, a green LED chip 22, and a blue LED chip 23. The wavelength range of the red LED chip is 620-760nm; the wavelength range of the green LED chip is 492-577; the wavelength range of the blue LED chip is 400nm-450nm, and the screening voltage range of the LED chip is 0-5V.

[0034] In another embodiment, the single pixel fixed position includes a blue LED chip, and a yellow fluorescent adhesive layer is provided on the blue LED chip to form a single pixel.

[0035] LED chips are divided into two or more groups based on chip characteristics, which can be wavelength, brightness, and / or voltage. For example, if red, green, and blue LED chips are binned together, and green and blue LED chips are not binned together, then the red LED chips on a wafer have a wavelength range of 620-760nm. These chips can be grouped in 5nm increments, the 620-625nm group in another, and the 625-630nm group in another. These chips can then be fixed to different wafers based on their wavelengths.

[0036] The following will be specifically described using different embodiments according to different motion paths. In this embodiment, only the motion paths are different, and other implementation methods are the same.

[0037] At the same time, the number of alternate rows and columns cannot exceed a preset value, such as 10 rows or 10 columns, which is determined based on the number of rows and columns that the acupuncture device can cross. If the preset value is exceeded, the acupuncture device will quit working.

[0038] Example 1.

[0039] like Figure 3 As shown, the alternate-column path involves a group of LED chips being positioned in fixed positions within a single pixel in each row, with the chips spaced apart within the columns of the fixed pixel positions within each row. In the figure, 1-1, 1-2, ..., 1-10, ... represent the first group of LED chips, which originate from one wafer. Then, 2-1, 2-2, ..., 2-5, ... represent the second group of LED chips, which originate from another wafer. During movement, the first group of LED chips is fixed in alternate columns in the order 1-1, 1-2, ..., 1-10. The second group of LED chips is then added in alternate columns in the order 2-1, 2-2, ..., 2-5, and so on. The chip characteristic value of LED chip 2-1 lies between the chip characteristic values ​​of adjacent LED chips 1-1 and 1-2. For example, in this embodiment, the red LED chip in the red, green, and blue LED chips can be grouped according to the chip characteristic of wavelength, with the wavelength of LED chip 2-1 lying between LED chips 1-1 and 1-2. In this embodiment, the number of alternate columns is one.

[0040] Example 2.

[0041] like Figure 4 As shown, both this embodiment and the first embodiment use alternate rows for movement. However, in this embodiment, there are two alternate rows, one of which is supplemented by a group of LED chips, such as 2-1, 2-2, and 2-3, and the other is supplemented by another group of LED chips, such as 3-1, 3-2, and 3-3. The wavelengths of LED chips 2-1 and 3-1 are between those of LED chips 1-1 and 1-2. The greater the wavelength gap between LED chips 1-1 and 1-2, the more alternate rows are used for movement.

[0042] Example 3.

[0043] like Figure 5As shown, the interlaced path involves a group of LED chips being positioned in a single fixed pixel position in each column, with the chips spaced apart along the rows of fixed pixel positions in each column. In the figure, 1-1, 1-2, ..., 1-10, 1-11, 1-12, ... represent the first group of LED chips, which originate from one wafer. Then, 2-1, 2-2, ..., 2-5, ... represent the second group of LED chips, which originate from another wafer. During movement, the first group of LED chips is first fixed in alternate rows in the order 1-1, 1-2, ..., 1-10, 1-11, 1-12, .... , and then the second group of LED chips is added in alternate rows in the order 2-1, 2-2, ..., 2-5, etc. The chip characteristic value of LED chip 2-1 lies between the chip characteristic values ​​of the adjacent two LED chips 1-1 and 1-11. For example, in this embodiment, the red LED chip in the red, green, and blue LED chips can be grouped according to the chip characteristic of wavelength, where the wavelength of LED chip 2-1 lies between LED chips 1-1 and 1-11. In this embodiment, the number of alternate rows is 1 row. If the number of alternate rows is 2 rows, one group of LED chips is provided at one alternate position, and another group of LED chips is provided at another alternate position for supplementation.

[0044] Example 4.

[0045] like Figure 6 As shown, the alternate row and column path is a group of LED chips that are alternately set in a single pixel fixed position in each row and column. In the figure, 1-1, 1-2...1-10... represent the first group of LED chips, which come from one wafer, and then 2-1, 2-2...2-5... represent the second group of LED chips, which come from another wafer, and 3-1, 3-2...3-5... represent another group of LED chips. When they move, the first group of LED chips are first fixed in the order of 1-1, 1-2...1-10... in alternate columns and rows, and then the second group of LED chips are added in the order of 2-1, 2-2...2-5, etc., and then the adjacent rows are moved in the order of 3-1, 3-2...3-5, etc. A third group of LED chips is added in alternate rows. The chip characteristic value of LED chip 2-1 is between the chip characteristic values ​​of the adjacent two LED chips 1-1 and 1-2, and the chip characteristic value of LED chip 3-1 is between the chip characteristic values ​​of the adjacent two LED chips 1-1 and 1-6. For example, in this embodiment, the red LED chips in the red, green, and blue LED chips can be grouped according to the chip characteristics of wavelength, with the wavelength of LED chip 2-1 being between the wavelengths of LED chips 1-1 and 1-2, and the wavelength of LED chip 3-1 being between the wavelengths of LED chips 1-1 and 1-6. In this embodiment, the number of alternate rows is one. If the number of alternate rows is two, the supplementary LED chips are added by placing one group of LED chips in one alternate position and another group of LED chips in the other alternate position.

[0046] Example 5.

[0047] like Figure 7 As shown, the movement path of alternate rows and columns with added starting points is that a group of LED chips are alternately set in the fixed positions of single pixels in each row and column, and the starting points of the fixed positions of the single pixels in alternate rows are moved. In the figure, 1-1, 1-2...1-10... represent the first group of LED chips, which come from one wafer, and then 2-1, 2-2...2-5... represent the second group of LED chips, which come from another wafer, and 3-1, 3-2...3-5... represent another group of LED chips, among which 1-6 is the starting point position after being moved and set. When it moves, the first group of LED chips is first fixed in the order of 1-1, 1-2, 1-3, 1-4, 1-5, 1-6, 1-7, 1-8, 1-9, 1-10, 1-11, 1-12, 1-13, 1-14... in an alternate column and alternate row manner. Among them, the first position after the alternate row is moved backward by a fixed position, and the row located at 1-6 is then arranged in alternate columns starting from 1-6, and then arranged in alternate columns according to 2-1, 2-2, 2-3, 2-4, 2-5, 2-6, 2-7 , 2-8, 2-9, 2-10, 2-11... and so on, the second group of LED chips are supplemented in alternate columns, and then the third group of LED chips are supplemented in alternate columns in the order of 3-1, 3-2, 3-3, 3-4, 3-5, 3-6, 3-7... and so on, in the adjacent rows. The chip characteristic value of LED chip 2-1 is between the chip characteristic values ​​of the two adjacent LED chips 1-1 and 1-2, and the chip characteristic value of LED chip 3-1 is between the chip characteristic values ​​of the two adjacent LED chips 1-1 and 2-11. For example, in this embodiment, the red light LED chip among the red, green and blue LED chips can be grouped according to the chip characteristics of the wavelength, wherein the wavelength of LED chip 2-1 is between the LED chips 1-1 and 1-2, and the wavelength of LED chip 3-1 is between the wavelengths of LED chips 1-1 and 2-11. In this embodiment, the number of alternate rows is 1 row and the number of alternate columns is 1 column, and the number of starting points increased is to move backward one column. If the number of alternate rows is 2 rows and the number of alternate columns is 2 columns, then a group of LED chips is set on one separated position and another group of LED chips is set on another separated position for supplementation.

[0048] Example 6.

[0049] like Figure 8As shown, the movement path of alternate columns and increased starting points is that a group of LED chips are respectively set in a single pixel fixed position of each row, and the columns of the pixel fixed positions of each row are spaced apart, and the starting points of adjacent rows are increased. At the same time, the number of columns separated by adjacent rows is different, the first row is separated by two columns, and the second row is separated by one column, such as 1-5 are the starting points after the increase. In the figure, 1-1, 1-2, 1-3, 1-4, 1-5, 1-6, 1-7, 1-8, 1-9, 1-10, 1-11, 1-12, 1-13... represent the first group of LED chips, which come from one wafer. Then 2-1, 2-2, 2-3, 2-4, 2-5, 2-6, 2-7, 2-8, 2-9, 2-10, 2-11, 2-12, 2-13.. represent the second group of LED chips, which come from another wafer. Then, according to the order of 3-1, 3-2, 3-3, 3-4, 3-5, 3-6, 3-7..., the third group of LED chips are added in alternate columns of alternate rows, and the fourth group of LED chips are added in the starting position of alternate rows according to 4-1, 4-2... When moving, first press Fix the first group of LED chips in the order of 1-1, 1-2, 1-3, 1-4, 1-5, 1-6, 1-7, 1-8, 1-9, 1-10, 1-11, 1-12, 1-13..., and then add the second group of LED chips in the order of 2-1, 2-2, 2-3, 2-4, 2-5, 2-6, 2-7, 2-8, 2-9, 2-10, 2-11, 2-12, 2-13, 2-14, 2-15..., and then add the third group of LED chips in the order of 3-1, 3-2, 3-3, 3-4, 3-5, 3-6... at the separated column positions and the position shifted behind the starting point, and at the same time, add the fourth group of LED chips in the order of 4-1, 4-2... at the position shifted behind the starting point. The chip characteristic values ​​of LED chips 2-1 and 3-1 are between those of adjacent LED chips 1-1 and 1-2. The chip characteristic values ​​of LED chips 2-4 and 2-9 are between those of adjacent LED chips 1-1 and 2-13. In this embodiment, the number of alternate columns in the first row is two, the number of alternate columns in the second row is one, the number of alternate columns in the third row is two, and the number of alternate columns in the fourth row is three. The starting point of each row is shifted back by one position from the starting point of the previous row. Furthermore, the number of intervals between rows after the shifted starting point is equal to the number of fixed pixel positions before the starting point.

[0050] The working principle of the present invention is as follows: by setting the chip characteristic values ​​of the LED chip 2, LED chips of different specifications are sorted out, and the LED chips are set on the PCB carrier according to the movement path by a needle-piercing method, and different paths are set by each pixel point in an alternate column or row or both row and column manner, and the LED chips with different characteristics are arranged on the PCB carrier 1 in an alternate row or column manner, and then another LED chip located between the chip characteristic values ​​is added at the interval position, thereby preventing the situation where the characteristics of the LED chips moved after the LED chips are different by needle-piercing, and one is bright and the other is dark. This setting allows LED chips with similar characteristics removed from the wafer to be arranged at intervals, thereby realizing the LED chips removed from the same wafer and scrambling them, and then another group of LED chips located between adjacent LED chips are added at the interval position, thereby making the utilization rate of the PCB carrier higher, and at the same time, the characteristic difference at the interval position can be compensated. Moreover, such a setting is not a random setting, so that the existing needle-piercing device cannot achieve random operation, and at the same time, the existing needle-piercing device can achieve the operation efficiency of mixed bins, and the mixed bin operation is simple.

Claims

1. A method for setting a motion path for transferring LED chips to a PCB carrier using a needle-piercing device, characterized in that: The PCB carrier is provided with two or more single pixel fixed positions, each pixel fixed position is arranged in an array on the PCB carrier, each pixel includes one or more LED chips, and the LED chips are divided into two or more groups according to the wavelength and / or brightness and / or voltage of the LED chips. A group of LED chips is transferred to the PCB carrier according to the movement path, and the movement path includes: an alternate column path and / or an alternate row path. Another group of LED chips is added to the alternate positions of the LED chips according to the movement path, and the chip characteristic values ​​of the LED chips of the other group are between the chip characteristic values ​​of the two adjacent LED chips.

2. The method for setting a motion path for transferring LEDs according to claim 1, wherein: The fixed position of a single pixel point includes a fixed position for a red LED chip, a fixed position for a green LED chip, and a fixed position for a blue LED chip. The wavelength range of the red LED chip is 620-760nm; the wavelength range of the green LED chip is 492-577; the wavelength range of the blue LED chip is 400nm-450nm, and the LED chip screening voltage range is 0-5V.

3. The method for setting a motion path for transferring LEDs according to claim 1, wherein: A group of LED chips on a single pixel point on the PCB carrier board are arranged at intervals according to the arrangement method of LED chips on a wafer, and there is more than one interval position.

4. The method for setting a motion path for transferring LEDs according to claim 3, wherein: The greater the difference in chip characteristics between adjacent LED chips on a wafer, the more spacing positions are set.

5. The method for setting a motion path for transferring LEDs according to claim 3, wherein: There are more than two spacing positions, and different groups of LED chips are set on the more than two spacing positions. The characteristic value of the LED chip on one spacing position and the characteristic value of the LED chip on another spacing position are between the characteristic values ​​of the LED chip fixed on the PCB carrier board through the motion path for the first time.

6. The method for setting a motion path for transferring LEDs according to claim 3, wherein: There are more than two spacing positions, and a group of LED chips are added to the two spacing positions. The characteristic value of the LED chip on one spacing position and the characteristic value of the LED chip on the other spacing position are between the characteristic values ​​of the LED chip fixed on the PCB carrier board through the motion path for the first time.

7. The method for setting a motion path for transferring LEDs according to claim 1, wherein: The motion path further includes adding a starting point every other row or adding a starting point every other column.

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