Mini LED chip detection method based on three-dimensional light deflection effect

Abstract

The present invention provides a Mini LED chip detection method based on the three-dimensional light deflection effect, S0. Preset the refraction angle of the laser when it passes through the normal position of the Mini LED chip; S1. Set the positions of the refraction plate group one and the refraction plate group two on the light guide plate according to the position of the Mini LED chip on the lamp board; S2. Align the light guide plate and the lamp board through the alignment slots at both ends of the light guide plate, so that the Mini LED chip on the lamp board is stuck in the distance between the refraction plate group one and the refraction plate group two; S3. Place the light guide plate and the lamp board in a dark room, and then start the laser transmitter to emit laser, so that the laser passes through the laser channel in sequence and is finally received by the laser receiver; S4. Analyze the refraction angle of the laser received by the laser receiver, and then judge whether the position of the Mini LED chip on the lamp board is offset. The position of the Mini LED chip can be detected more quickly, and the method is reliable.

Description

Technical Field

[0001] The present invention relates to the field of chip detection technology, and in particular to a Mini LED chip inspection method based on a three-dimensional light deflection effect. Background Art

[0002] During the Mini LED chip placement process, a chip placement machine is typically used to assemble the LED chips. During the assembly process, a motor drives a negative pressure suction nozzle to reciprocate between the wafer and the substrate, sucking the chip from the wafer and transporting it to the top of the substrate. Solder paste is pre-applied near the contacts on the substrate, and the chip is attached to the outside of the solder paste for fixation. During chip placement, since the chip is moved by the negative pressure suction nozzle, deviations (such as chip offset) are inevitable. This requires chip inspection. For example, Chinese patent application No. 202310587192.X, published on August 29, 2023, discloses a Mini or Micro LED chip inspection method and system, including collecting a first image set of a target display area of ​​the chip under a first image drive signal; performing a first analysis on the first image set to obtain image quality information; performing a second analysis on the first image set to obtain a mura compensation value; and performing optical correction based on the mura compensation value. The first image drive signal includes an AOI drive signal for lighting inspection after die bonding; and the first image set includes brightness and chromaticity value information.

[0003] The above method obtains a chip module image set by taking photos, then outputs different abnormality information through AOI inspection. Then, it performs demura optical correction analysis and extracts brightness and colorimetry information using a brightness and colorimeter to extract and repair mura. However, this process requires processing a high density of abnormal information detected by AOI inspection, which reduces the inspection efficiency of mini chips and slows down the inspection speed. Summary of the Invention

[0004] The present invention aims to provide a Mini chip detection method based on the three-dimensional light deflection effect, which can detect the position of the Mini chip more quickly, is reliable and has high detection efficiency.

[0005] To achieve the above objectives, a Mini LED chip detection method based on the three-dimensional light deflection effect is provided. The detection is achieved through a laser detection device. The laser detection device includes a laser emitter, a light guide plate, and a laser receiver. The laser receiver is connected to a processor.

[0006] The following steps are involved:

[0007] S0. Preset the refraction angle of the laser when it passes through the normal position of the Mini LED chip;

[0008] S1. Arrange the positions of refraction plate group 1 and refraction plate group 2 on the light guide plate based on the position of the Mini LED chips on the light board, so that refraction plate group 1 and refraction plate group 2 are staggered along the length of the light guide plate. The light guide plate is provided with two or more laser channels, and each laser channel is provided with a refraction plate group 1 and a refraction plate group 2. The number of laser channels is the same as the number of Mini LED chips, and the spacing between refraction plate group 1 and refraction plate group 2 matches the Mini LED chips on the light board.

[0009] S2. Align the light guide plate with the light board using the alignment slots at both ends of the light guide plate so that the Mini LED chip on the light board fits within the gap between refractive plate group 1 and refractive plate group 2.

[0010] S3. Place the light guide plate and light board in a dark test environment. Then activate the laser transmitter to emit laser light. The laser light passes through the laser channel and the Mini LED chip in sequence, and finally the laser receiver receives the laser light emitted from the light guide plate.

[0011] S4. The processor analyzes the refraction angle of the laser light received by the laser receiver, and then determines whether the position of the Mini chip on the light board is offset.

[0012] The above setting sets the position of the refraction plate group 1 and the refraction plate group 2 on the light guide plate by the position of the Mini LED chip on the light board, so as to ensure that the distance between the refraction plate group 1 and the refraction plate group 2 matches the Mini LED chip on the light board; by setting alignment slots at both ends of the light guide plate, the light guide plate and the light board can be accurately aligned, so that the Mini LED chip on the light board can be accurately inserted into the distance between the refraction plate group 1 and the refraction plate group 2, so that the laser can be refracted through the Mini LED chip after entering the light guide plate; and the light guide plate and the light board are placed in a dark room and then the laser transmitter is started to emit laser, so as to avoid other light interfering with the laser refraction process. Finally, the laser receiver is connected to the processor, and the light emitted by the laser transmitter passes through a laser channel and then passes through the distance position between the refraction plate group 1 and the refraction plate group 2. If a Mini LED chip is set between the refraction plate group 1 and the refraction plate group 2, the Mini LED chip refracts the laser and then compares it with the light after the preset normal refraction angle to determine the Mini Whether the LED chip is offset, this test method is simple and only needs to determine whether the emitted light is abnormal, which makes the detection efficiency high.

[0013] Furthermore, step S4 includes:

[0014] S4.1 If the laser refraction angle received by the laser receiver matches the predetermined refraction angle of the laser when passing through the Mini LED chip at its normal position, it is determined that the position of the Mini LED chip on the light board has not shifted;

[0015] S4.2 If the laser refraction angle received by the laser receiver does not match the preset refraction angle when the laser passes through the normal position of the Mini LED chip, it is determined that the position of the Mini LED chip on the light board has shifted;

[0016] S4.3 If the laser light received by the laser receiver has no refraction angle, it is determined that there is no Mini LED chip on the lamp board.

[0017] The above methods can determine whether there is a chip according to different situations, and can also easily determine whether the chip is placed correctly.

[0018] Furthermore, the laser emitter is arranged on one side of the light guide plate, and the laser receiver is arranged on the other side of the light guide plate. The light guide plate includes an upper light shading layer, an upper light guide layer, a middle light shading layer, a lower light guide layer and a lower light shading layer arranged in sequence from top to bottom. The upper light guide layer is provided with more than two refractive plate groups 1 arranged at intervals, and the lower light guide layer is provided with more than two refractive plate groups 2 arranged at intervals.

[0019] The above setting is to set the laser emitter on one side of the light guide plate and the laser receiver on the other side of the light guide plate. In this way, after the light guide plate and the light board are placed in a dark room, the laser emitter can emit laser light through the light guide plate and finally be received by the laser receiver; by arranging the refractive plate group 1 at intervals in the upper light guide layer and the refractive plate group 2 at intervals in the lower light guide layer, the propagation path of the laser can be changed by the refractive plate group 1 and refracted through the Mini LED chip, so that the refracted laser can then change the propagation path through the refractive plate group 2 and be emitted from the lower light guide layer, and the upper shading layer, the middle shading layer and the lower shading layer respectively block the light on the upper light guide layer and the lower light guide layer except for the light on the laser channel, thereby preventing the laser on the laser channel from affecting the upper and lower light guides.

[0020] Furthermore, one end of the refractive plate group 1 is fixed on the upper light guide layer, and the other end of the refractive plate group 1 extends downward and sequentially penetrates the middle light shielding layer, the lower light guide layer and the lower light shielding layer to protrude.

[0021] The above arrangement can change the propagation path of the laser after entering the upper light guide layer through the refraction plate group 1, and the refraction plate group 1 can extend to one side of the MiniLED chip.

[0022] Furthermore, one end of the second refractive plate group is fixed on the lower light guide layer, and the other end of the second refractive plate group extends downward and passes through the lower light shielding layer to protrude.

[0023] The above arrangement can change the propagation path of the refracted laser light through the second refraction plate group, so that the laser light enters the lower light guide layer and is emitted from the lower light guide layer.

[0024] Furthermore, the refractive plate group includes a box body and at least two refractive lenses, the refractive lenses are arranged on both sides of the box body and opposite to the refractive lenses on both sides of the box body, an opening is provided on both sides of the box body and opposite to the refractive lenses, and the angle between the refractive lenses and the vertical direction of the box body is set to 45°~60°.

[0025] The above arrangement makes it easy for the laser to enter the upper light guide layer, then pass through the opening at one end of the box body and hit the refractive lens to change the propagation path of the laser, and then pass through the opening at the other end of the box body and hit the MiniLED chip.

[0026] Furthermore, the refractive plate group 2 includes a box body 2 and at least two refractive lenses 2, the refractive lenses 2 are arranged on both sides of the box body 2 and the refractive lenses 2 on both sides of the box body 2 are arranged opposite to each other, and openings 2 are provided on both sides of the box body 2 and the refractive lenses 2, and the angle between the refractive lenses 2 and the vertical direction of the box body 2 is set to 45°~60°.

[0027] The above arrangement facilitates the laser light refracted by the MiniLED chip to pass through the second opening at one end of the second box body and be incident on the second refractive lens to change the propagation path of the laser light, and then pass through the second opening at the other end of the second box body and be emitted from the lower light guide layer.

[0028] Furthermore, alignment slots are fixed at both ends of the lower light-shielding layer.

[0029] The above setting avoids deviation when the light guide plate is placed on the light board.

[0030] Furthermore, the wavelength of the laser emitted by the laser emitter is set to 720nm ~ 760nm.

[0031] The above setting enables the laser to be refracted after passing through the light guide plate and the MiniLED chip.

[0032] Furthermore, the laser channel includes a first light guide groove arranged on the upper light guide plate and a second light guide groove arranged on the lower light guide plate. One end of the first light guide groove is arranged corresponding to the laser emitter, and the other end of the second light guide groove is fixed with one end of the refraction plate group one, and one end of the second light guide groove is fixed with one end of the refraction plate group two, and the other end of the second light guide groove is arranged corresponding to the laser receiver.

[0033] The above arrangement can be achieved by providing light guide grooves on the upper and lower light guide plates so that the laser enters the channel of the light guide plate through the light guide grooves and then passes through the first and second refractive plate groups and then is emitted from the second light guide channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the planar structure of the present invention.

[0035] Figure 2 Schematic diagram of the explosion of the light guide plate in the present invention.

[0036] Figure 3 for Figure 1 Enlarged view of point A in the middle.

[0037] Figure 4 for Figure 1 Enlarged view of point B in the middle.

[0038] Figure 5 for Figure 1 Enlarged view of point C in the middle.

[0039] Figure 6 It is the workflow diagram of the present invention.

[0040] Figure 7 This is a schematic diagram of the structure of the laser channel in the upper light guide layer in the present invention.

[0041] Figure 8 This is a schematic diagram of the structure of the laser channel in the lower light guide layer in the present invention. DETAILED DESCRIPTION

[0042] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] like Figure 1-5 As shown in Figures 7 and 8, the present invention provides a Mini LED chip detection method based on the three-dimensional light deflection effect, which is detected by a detection device. The detection device includes a laser emitter 1, a light guide plate and a laser receiver 3. The laser emitter 1 is arranged on one side of the light guide plate, and the laser receiver 3 is arranged on the other side of the light guide plate. The light guide plate includes an upper light-shielding layer 21, an upper light guide layer 22, a middle light-shielding layer 23, a lower light guide layer 24 and a lower light-shielding layer 25 arranged in sequence from top to bottom. The upper light guide layer 21 is provided with two or more refractive plate groups 1 that are spaced apart, and the lower light guide layer 24 is provided with two or more refractive plate groups 2 that are spaced apart. The refractive plate group 1 and the refractive plate group 2 are staggered along the length direction of the light guide plate. The light guide plate is provided with two or more laser channels, and each laser channel is provided with a refractive plate group 1 and a refractive plate group 2. The number of laser channels is the same as the number of Mini LED chips. In this embodiment, the laser receiver 3 is connected to a processor (not shown in the figure).

[0044] like Figure 1 As shown, one end of the refractive plate group 1 is fixed on the upper light guide layer 22, and the middle light shading layer 23, the lower light guide layer 24 and the lower light shading layer 25 are respectively provided with through holes (not marked in the figure) that match the refractive plate group 1. The other end of the refractive plate group 1 extends downward through the through hole and sequentially penetrates the middle light shading layer 23, the lower light guide layer 24 and the lower light shading layer 25 to protrude. In this way, the refractive plate group 1 can change the propagation path of the laser after entering the upper light guide layer 22; one end of the refractive plate group 2 is fixed on the lower light guide layer 24, and the lower light shading layer 25 is provided with a through hole that matches the refractive plate group 2. The other end of the refractive plate group 2 extends downward through the through hole and penetrates the lower light shading layer 25 to protrude. In this way, the refractive plate group 2 can change the propagation path of the laser after refracting the Mini LED chip 6 to enter the lower light guide layer 25 and emit from the lower light guide layer 25; the spacing between the refractive plate group 1 and the refractive plate group 2 matches the Mini LED chip 6 on the light board.

[0045] like Figure 1 As shown, the refractive sheet group 1 includes a box body 41 and at least two refractive lenses 42. In this embodiment, two refractive lenses 42 are provided in one box body 41, and the two refractive lenses 42 are respectively provided at both ends of the box body 41. The angle between the refractive lens 42 located in the upper light guide layer 22 of the box body 41 and the vertical direction of the box body 41 is set to 45°, and the angle between the refractive lens 42 at the other end of the box body 41 and the vertical direction of the box body 41 is set to 60°. Openings 43 are provided at positions corresponding to the refractive lenses 42 on both sides of the box body 41.

[0046] like Figure 1 As shown, the refractive plate group 2 includes a box body 2 51 and at least two refractive lenses 2 52. In this embodiment, two refractive lenses 2 52 are provided in one box body 2 51, and the two refractive lenses 2 52 are respectively provided at both ends of the box body 2 51. The angle between the refractive lens 2 52 located in the lower light guide layer 24 of the box body 2 51 and the vertical direction of the box body 2 51 is set to 45°, and the angle between the refractive lens 2 52 at the other end of the box body 2 51 and the vertical direction of the box body 2 51 is set to 60°. Openings 2 53 are provided at positions corresponding to the refractive lenses 2 52 on both sides of the box body 51.

[0047] like Figure 1 As shown, two alignment slots 7 are fixed at both ends of the lower light-shielding layer 25, which can prevent deviation during the process of placing the light guide plate on the lamp board 8; the laser wavelength emitted by the laser emitter 1 is set to 730nm, so that the laser can be refracted after passing through the light guide plate and the Mini LED chip.

[0048] In this embodiment, if Figure 3 、 4 As shown in FIG5 , the laser passes through the light guide plate and is emitted from the refraction plate group 1, and is refracted after passing through the MiniLED chip 6 . The refracted laser then enters the refraction plate group 2 and is emitted from the light guide plate, and is finally received by the laser receiver 3 .

[0049] In this embodiment, the laser channel includes a first light guide groove 01 arranged on the upper light guide layer 22 and a second light guide groove 02 arranged on the lower light guide layer 24. One end of the first light guide groove 01 is arranged corresponding to the laser emitter 1, and the other end of the first light guide groove 01 is fixed with one end of the refractive plate group 1, and one end of the second light guide groove 02 is fixed with one end of the refractive plate group 2, and the other end of the second light guide groove 02 is arranged corresponding to the laser receiver 3. The number of laser channels corresponds to the number of Mini LED chips 6 to be tested. In this embodiment, a row has three Mini LED chips 6, and three corresponding transverse laser channels are set along the length direction of the upper light guide layer 22. If there are multiple columns of Mini LED chips 6, laser channels can be set along the width direction of the upper light guide layer 22. The laser channels on the upper light guide layer 22 can only pass light within the first light guide groove 01. In this embodiment, each row has three first light guide grooves 01 and three second light guide grooves 02. A first light guide groove 01 on each row transmits light downward through refraction plate group 1, then passes through the LED chip and refraction plate group 2, and then is emitted through a second light guide groove 02.

[0050] In this embodiment, if Figure 8 As shown, the Mini LED chip detection method based on the three-dimensional light deflection effect also includes the following specific steps:

[0051] S0. Connect the laser receiver to the processor and preset the refraction angle of the laser when it passes through the normal position of the Mini LED chip;

[0052] S1. Set the positions of refractive plate group 1 and refractive plate group 2 on the light guide plate according to the position of the Mini LED chip on the light board, so that the refractive plate group 1 and the refractive plate group 2 are staggered, and the spacing between the refractive plate group 1 and the refractive plate group 2 matches the Mini LED chip on the light board;

[0053] S2. Use the alignment slots at both ends of the light guide plate to precisely align the light guide plate with the light board, ensuring that the MiniLED chip on the light board fits within the gap between refractive plate group 1 and refractive plate group 2.

[0054] S3. Place the light guide plate and light board in a dark room, then start the laser emitter to emit laser light, so that the laser light passes through the laser channel refraction plate group 1 and refraction plate group 2 in sequence, and finally receives the laser light emitted from the light guide plate through the laser receiver;

[0055] S4. The processor analyzes the refraction angle of the laser light received by the laser receiver and determines whether the position of the Mini LED chip on the light board has shifted.

[0056] S4.1 If the laser refraction angle received by the laser receiver is equal to the predetermined refraction angle of the laser when passing through the Mini LED chip at its normal position, it is determined that the position of the Mini LED chip on the light board has not shifted;

[0057] S4.2 If the laser refraction angle received by the laser receiver is not equal to the preset refraction angle of the laser when passing through the normal position of the Mini LED chip, it is determined that the position of the Mini LED chip on the light board has shifted;

[0058] S4.3 If the laser light received by the laser receiver has no refraction angle, it is determined that there is no Mini LED chip on the lamp board.

[0059] In this embodiment, the processor analyzes the refraction angle received by the laser, which is a prior art and will not be repeated here. It can be determined by the angle at which the received light deviates from the center. Then, in the process of confirming whether it matches, the processor can use the refraction angle when passing through the normal position of the Mini LED chip 6 ± the preset angle value, such as 2 degrees. If the obtained laser refraction angle is within this range, it is a match, otherwise it is a mismatch setting.

Claims

1. A Mini LED chip inspection method based on the three-dimensional light deflection effect, characterized by: Detection is achieved by a laser detection device, which includes a laser emitter, a light guide plate, and a laser receiver, and the laser receiver is connected to the processor; the laser emitter is arranged on one side of the light guide plate, and the laser receiver is arranged on the other side of the light guide plate, and the light guide plate includes, from top to bottom, an upper light-shielding layer, an upper light-guiding layer, a middle light-shielding layer, a lower light-guiding layer, and a lower light-shielding layer, the upper light-guiding layer is provided with two or more refractive plate groups 1 and spaced apart, and the lower light-guiding layer is provided with two or more refractive plate groups 2 and spaced apart; The following steps are involved: S0. Preset the refraction angle of the laser when it passes through the normal position of the Mini LED chip; S1. Arrange the positions of refraction plate group 1 and refraction plate group 2 on the light guide plate based on the position of the Mini LED chips on the light board, so that refraction plate group 1 and refraction plate group 2 are staggered along the length of the light guide plate. The light guide plate is provided with two or more laser channels, and each laser channel is provided with a refraction plate group 1 and a refraction plate group 2. The number of laser channels is the same as the number of Mini LED chips, and the spacing between refraction plate group 1 and refraction plate group 2 matches the Mini LED chips on the light board. S2. Align the light guide plate with the light board using the alignment slots at both ends of the light guide plate so that the Mini LED chip on the light board fits within the gap between refractive plate group 1 and refractive plate group 2. S3. Place the light guide plate and light board in a dark test environment. Then activate the laser transmitter to emit laser light. The laser light passes through the laser channel and the Mini LED chip in sequence, and finally the laser receiver receives the laser light emitted from the light guide plate. S4. The processor analyzes the refraction angle of the laser light received by the laser receiver, and then determines whether the position of the Mini chip on the light board is offset.

2. The Mini LED chip detection method based on the three-dimensional light deflection effect according to claim 1, characterized in that: Step S4 includes: S4.1 If the laser refraction angle received by the laser receiver matches the preset refraction angle of the laser when passing through the normal position of the Mini LED chip, it is determined that the position of the Mini LED chip on the light board has not shifted; S4.2 If the laser refraction angle received by the laser receiver does not match the preset refraction angle when the laser passes through the normal position of the Mini LED chip, it is determined that the position of the Mini LED chip on the light board has shifted; S4.3 If the laser light received by the laser receiver has no refraction angle, it is determined that there is no MiniLED chip on the lamp board.

3. The Mini LED chip detection method based on the three-dimensional light deflection effect according to claim 1, wherein: One end of the refractive plate group 1 is fixed on the upper light guide layer, and the other end of the refractive plate group 1 extends downward and sequentially penetrates the middle light shielding layer, the lower light guide layer and the lower light shielding layer to protrude.

4. The Mini LED chip detection method based on the three-dimensional light deflection effect according to claim 1, wherein: One end of the second refractive plate group is fixed on the lower light guide layer, and the other end of the second refractive plate group extends downward and penetrates the lower light shielding layer to protrude.

5. The Mini LED chip detection method based on the three-dimensional light deflection effect according to claim 1, wherein: The refractive sheet group includes a box body and at least two refractive lenses. The refractive lenses are arranged on both sides of the box body and the refractive lenses on both sides of the box body are arranged opposite to each other. Openings are provided at positions on both sides of the box body corresponding to the refractive lenses. The angle between the refractive lenses and the vertical direction of the box body is set to 45°~60°.

6. The Mini LED chip detection method based on the three-dimensional light deflection effect according to claim 1, wherein: The second refractive plate group includes a second box body and at least two second refractive lenses. The second refractive lenses are arranged on both sides of the second box body and the second refractive lenses on both sides of the second box body are arranged opposite to each other. Openings are provided at positions on both sides of the second box body corresponding to the second refractive lenses. The angle between the second refractive lenses and the vertical direction of the second box body is set to 45°~60°.

7. The Mini LED chip detection method based on the three-dimensional light deflection effect according to claim 1, wherein: Alignment slots are fixed at both ends of the lower light-shielding layer.

8. The Mini LED chip detection method based on the three-dimensional light deflection effect according to claim 1, wherein: The wavelength of the laser emitted by the laser transmitter is set to 720nm ~ 760nm.

9. The Mini LED chip detection method based on the three-dimensional light deflection effect according to claim 1, wherein: The laser channel includes a first light guide groove arranged on the upper light guide plate and a second light guide groove arranged on the lower light guide plate. One end of the first light guide groove is arranged corresponding to the laser emitter, and the other end of the first light guide groove is fixed with one end of the refractive plate group one, and one end of the second light guide groove is fixed with one end of the refractive plate group two, and the other end of the second light guide groove is arranged corresponding to the laser receiver.

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