Scratching method

Abstract

A scratching method is provided, belonging to the field of semiconductor manufacturing. The method comprises: attaching a first blue film to a side of a light-emitting diode chip away from a sapphire substrate, the thickness of the sapphire substrate being greater than 220 microns; when scribing the light-emitting diode chip, controlling the distance between the two focal points of the dual-focus laser in the light-emitting diode chip to be 35-45 μm, and at the same time controlling the distance from the focal point farther from the sapphire substrate to the surface of the sapphire substrate to be 105-115 μm, and the distance at the oblique crack surface of the sapphire substrate is 4-6 μm less than the distance at the non-oblique crack surface. Through the above design, it is avoided that the electrode is slightly lifted due to the poor scribing effect on the side away from the sapphire substrate due to the thick sapphire substrate on the front side during the cracking, thereby improving the yield of micro light-emitting diode products.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor manufacturing technology, and in particular to a cleaving method. Background Art

[0002] With the continuous development of science and technology, consumption is constantly upgrading, and the proportion of cultural entertainment in household consumption is gradually increasing. Under the increasingly rich demand for family entertainment, large-screen display technology has also ushered in breakthrough innovations, from cathode ray tube (Cathode Ray Tube, CRT) displays to liquid crystal displays (Liquid Crystal Display, LCD). LCD technology is also constantly innovating. Taking LCD backlight as an example, from using cold cathode fluorescent lamp (Cold Cathode Fluorescent Lamp, CCFL) backlight module to using light emitting diode (Light Emitting Diode, LED) as backlight module, the color effect is more realistic, the brightness is higher, and the energy efficiency ratio is higher.

[0003] LEDs are divided into flip-chip LEDs and face-up LEDs. Sapphire substrates are often used in the manufacturing process of flip-chip LED chips. Since the thickness of sapphire is relatively thick among current chips, the power of current dicing machines cannot effectively cut it completely, and the front electrode will slightly warp when the chip is cracked. Summary of the invention

[0004] The embodiment of the present disclosure provides a splitting method, which can avoid the electrode warping and improve the product yield. The technical solution is as follows:

[0005] At least one embodiment of the present disclosure provides a cleaving method, which is applicable to a flip-chip light-emitting diode chip having a sapphire substrate, and includes:

[0006] A first blue film is attached to a side of the light-emitting diode chip away from the sapphire substrate, and the thickness of the sapphire substrate is greater than 220 microns;

[0007] Using a dual-focus laser to perform scribing on the other side of the light-emitting diode chip, during the scribing process, the distance between the two focal points of the laser emitted by the dual-focus laser within the light-emitting diode chip is controlled to be 35-45 μm, and the distance between the focal point farther from the sapphire substrate and the surface of the sapphire substrate is 105-115 μm, and the distance at the oblique crack surface of the sapphire substrate is 4-6 μm less than the distance at the non-oblique crack surface;

[0008] The light emitting diode chip after dicing is split by using a cleaver with a cleaver angle of 70° to 80°.

[0009] Optionally, a blue film is attached to one side of the light emitting diode chip, comprising:

[0010] The light-emitting diode chip is placed on a base with nano vacuum holes, and adsorbed by vacuum, with an adsorption pressure less than or equal to -80 kPa;

[0011] In the adsorption state, the first blue film is attached to one side of the light emitting diode chip.

[0012] Optionally, the viscosity of the first blue film is less than or equal to 0.3N / 20mm, and the diameter of the first blue film is 255-260mm.

[0013] Optionally, during the scribing process, the laser frequency of the non-oblique crack surface is 45-55 Hz, and the scribing speed is 190-210 mm / s; the laser frequency of the oblique crack surface is 45-55 Hz, and the scribing speed is 290-310 mm / s.

[0014] Optionally, the power control of the dual-focus laser can make each scribing line be scribed within 1 to 3 seconds, so that the fluctuation range of the line irradiated by the laser on the light-emitting diode chip is -1 μm to 1 μm.

[0015] Optionally, during the chip splitting, the spacing between the light emitting diode chips is 2-3 μm under the chip splitting debugging condition.

[0016] Optionally, before splitting, the distance between the splitting knife and the light-emitting diode chip is 4-5 mm; during splitting, the time for which the splitting knife is pressed on the light-emitting diode chip is 380-420 ms.

[0017] Optionally, the method further comprises:

[0018] Stick the second blue film on the metal ring;

[0019] The light-emitting diode chip after splitting is attached to the second blue film of the metal ring for pressing;

[0020] Placing one side of the light-emitting diode chip on a nano vacuum plate for adsorption, and removing the first blue film;

[0021] The second blue film is expanded to separate the light-emitting diode chips after being split.

[0022] Optionally, during the tableting, the tableting time is 8 to 12 seconds, and the tableting pressure is less than or equal to -0.6 MPa.

[0023] Optionally, the method further comprises:

[0024] The light-emitting diode chip after film expansion is placed on an optical display mirror for inclined plate inspection to observe the electrode warping at the edge of the light-emitting diode chip.

[0025] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects:

[0026] In the scheme disclosed in the present invention, when the light-emitting diode chip is scribed, the distance between the two focal points of the dual-focus laser within the light-emitting diode chip is controlled to be 35-45 μm, and the distance from the focal point farther from the sapphire substrate to the surface of the sapphire substrate is controlled to be 105-115 μm, and the distance at the oblique crack surface of the sapphire substrate is less than the distance at the non-oblique crack surface by 4-6 μm. The dual-focus laser provides more energy, so that in the case of a thicker sapphire substrate, the two sides of the light-emitting diode chip can be cleaved; and by using different focal depths on the oblique crack surface and the non-oblique crack surface, it is ensured that the oblique crack surface and the non-oblique crack surface have a good scribing effect. Then, when the chip is split, a cleaver with a cleaving angle of 70° to 80° is selected, which is conducive to splitting a thicker sapphire substrate. Through the above design, it is avoided that the cleaving effect on the side away from the sapphire substrate is poor due to the thick sapphire substrate on the front side during the chip splitting, resulting in a slight warping of the electrode, thereby improving the yield of the micro light-emitting diode product. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 is a flow chart of a splitting method provided by some embodiments of the present disclosure;

[0029] Figure 2 is a flow chart of a splitting method provided by some embodiments of the present disclosure;

[0030] Figure 3 It is a comparative schematic diagram of the related technology provided by the embodiment of the present disclosure and the present disclosure. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0032] Figure 1 is a flow chart of a splitting method provided by some embodiments of the present disclosure. The method is applied to the splitting method of light-emitting diode chips, see Figure 1, the method comprising:

[0033] S11: attaching a first blue film to a side of the light emitting diode chip away from a sapphire substrate, wherein the thickness of the sapphire substrate is greater than 220 micrometers.

[0034] In the disclosed embodiment, the target is a flip-chip LED, and the thickness of the sapphire substrate is relatively thick, for example, 250 microns. Among them, the flip-chip LED refers to a LED with the light-emitting surface on one side of the substrate. Compared with the upright LED, the flip-chip LED needs to be provided with a metal reflection layer, a distributed Bragg reflector (DBR) and other structures on the side away from the substrate. Therefore, compared with the upright LED, the flip-chip LED is thicker and more difficult to be scratched.

[0035] After the LED is split, the size of a single core particle may be 660 microns by 1524 microns.

[0036] S12: Use a dual-focus laser to perform scribing on the other side of the LED chip. During the scribing process, the distance between the two focal points of the laser emitted by the dual-focus laser is controlled to be 35-45 μm within the LED chip, and the distance from the focal point farther from the sapphire substrate to the surface of the sapphire substrate is 105-115 μm, and the distance at the oblique crack surface of the sapphire substrate is 4-6 μm less than the distance at the non-oblique crack surface.

[0037] The other side of the light emitting diode chip may be the back side of the light emitting diode chip, that is, one side of the substrate.

[0038] In the disclosed embodiment, unidirectional slicing is used, that is, slicing is performed along the track from end A to end B, and then not slicing from end B to end A (laser locking light). Unidirectional slicing can avoid the problem of laser energy attenuation during the return journey during S-shaped slicing, so that this slicing method combined with the above-mentioned laser focal length can better scribe flip-chip LED chips with thicker sapphire substrates.

[0039] In the disclosed embodiment, the two focal points of the laser emitted by the dual-focus laser are arranged along the thickness direction of the substrate. The dual-focus laser allows greater energy to be injected into the chip, and the laser energy can more easily cause cracks on both the front and back sides of the light-emitting diode chip.

[0040] In the embodiments of the present disclosure, the oblique crack surface of the sapphire substrate, that is, the cleavage surface of the sapphire substrate, refers to a surface that will break along a certain crystal plane network under the action of external force.

[0041] For example, when scribing, the laser scribing follows a set track. If the actual scribing track deviates from the set track, this is an oblique crack surface, and the laser is controlled according to the focal depth of the oblique crack surface. If the actual scribing track is consistent with the set track, this is a non-oblique crack surface, and the laser is controlled according to the focal depth of the non-oblique crack surface.

[0042] Among them, the depth of the two focal points of the dual-focus laser and the distance between the two focal points can be controlled by the laser.

[0043] S13: using a cleaver with a cleaver angle of 70° to 80° to split the diced light emitting diode chip.

[0044] In the related art, the cleaving angle is 70°, but the embodiment of the present disclosure can adopt a larger angle, thereby facilitating the cleaving of large-sized LED chips.

[0045] It should be noted that the LED chip in the embodiment of the present disclosure is a wafer before dicing, and the wafer includes a plurality of LED chip units. After dicing, the wafer becomes a grain, and each grain is a LED chip unit.

[0046] In the scheme disclosed in the present invention, when the light-emitting diode chip is scribed, the distance between the two focal points of the dual-focus laser within the light-emitting diode chip is controlled to be 35-45 μm, and the distance from the focal point farther from the sapphire substrate to the surface of the sapphire substrate is controlled to be 105-115 μm, and the distance at the oblique crack surface of the sapphire substrate is less than the distance at the non-oblique crack surface by 4-6 μm. The dual-focus laser provides more energy, so that in the case of a thicker sapphire substrate, the two sides of the light-emitting diode chip can be cleaved; and by using different focal depths on the oblique crack surface and the non-oblique crack surface, it is ensured that the oblique crack surface and the non-oblique crack surface have a good scribing effect. Then, when the chip is split, a cleaver with a cleaving angle of 70° to 80° is selected, which is conducive to splitting a thicker sapphire substrate. Through the above design, it is avoided that the cleaving effect on the side away from the sapphire substrate is poor due to the thick sapphire substrate on the front side during the chip splitting, resulting in a slight warping of the electrode, thereby improving the yield of the micro light-emitting diode product.

[0047] Figure 2 is a flow chart of another method for splitting provided by some embodiments of the present disclosure. The method is applied to a method for splitting a light-emitting diode chip. Figure 2 , the method comprising:

[0048] S21: placing the light-emitting diode chip on a base with nano vacuum holes on the base, and performing vacuum adsorption, with an adsorption pressure less than or equal to -80 kPa.

[0049] S22: in the adsorption state, attaching the first blue film to one side of the light emitting diode chip.

[0050] The one side of the light emitting diode chip may be the front side of the light emitting diode chip, that is, the side away from the substrate.

[0051] In this implementation, the light emitting diode chip is first vacuum-adsorbed and then the blue film is attached, so the attachment quality can be guaranteed.

[0052] In the disclosed embodiment, the viscosity of the first blue film is less than or equal to 0.3N / 20mm, and the diameter of the first blue film is 255-260mm.

[0053] Exemplarily, the diameter of the first blue film is 258 mm.

[0054] For example, the first blue film can be first attached to an iron ring with a diameter of 210 mm, and then one side of the light emitting diode chip is attached to the first blue film.

[0055] In this implementation, the blue film with the above viscosity can ensure the adhesion to the light-emitting diode chip and ensure the normal subsequent dicing. The blue film with the above size can meet the processing requirements.

[0056] S23: Use a dual-focus laser to perform scribing on the other side of the LED chip. During the scribing process, the distance between the two focal points of the laser emitted by the dual-focus laser is controlled to be 35 to 45 μm within the LED chip, and the distance from the focal point farther from the sapphire substrate to the surface of the sapphire substrate is 105 to 115 μm, and the distance at the oblique crack surface of the sapphire substrate is 4 to 6 μm less than the distance at the non-oblique crack surface.

[0057] When scribing the LED chip, the distance between the two focal points of the dual-focus laser within the LED chip is controlled to be 35-45 μm, and the distance from the focal point farther from the sapphire substrate to the surface of the sapphire substrate is controlled to be 105-115 μm, and the distance at the oblique crack surface of the sapphire substrate is 4-6 μm less than the distance at the non-oblique crack surface. The dual-focus laser provides more energy, so that in the case of a thicker sapphire substrate, the two sides of the LED chip can be slashed; and by using different focal depths on the oblique crack surface and the non-oblique crack surface, it is ensured that both the oblique crack surface and the non-oblique crack surface have a good scratching effect. The above design avoids the problem of the electrode slightly warping due to the poor scribing effect on the side away from the sapphire substrate due to the thick sapphire substrate when slicing, thereby improving the yield of the micro LED product.

[0058] Exemplarily, during the scribing process, the distance between the two focal points of the laser emitted by the dual-focus laser within the LED chip is controlled to be 40 μm, the distance from the focal point farther from the sapphire substrate to the surface of the sapphire substrate is 110 μm, and the focal depth of the oblique crack surface is 5 μm lower than that of the non-oblique crack surface.

[0059] In the disclosed embodiment, during the scribing process, the laser frequency of the non-oblique crack surface is 45-55 Hz, and the scribing speed is 190-210 mm / s; the laser frequency of the oblique crack surface is 45-55 Hz, and the scribing speed is 290-310 mm / s.

[0060] In this implementation, the above-mentioned power and scribing speed are adopted, and compared with the related technology, the laser power is reduced and the scribing machine speed is lowered to ensure the scribing effect.

[0061] Exemplarily, during the scribing process, the laser frequency of the non-oblique crack surface is 50 Hz, and the scribing speed is 200 mm / s; the laser frequency of the oblique crack surface is 50 Hz, and the scribing speed is 300 mm / s.

[0062] In the disclosed embodiment, the power control of the dual-focus laser can make each scribing line be scribed within 1 to 3 seconds, so that the fluctuation range of the line irradiated by the laser on the light-emitting diode chip is -1 μm to 1 μm.

[0063] Exemplarily, the power control of the dual-focus laser enables each scribe line to be scribed within 2 seconds.

[0064] In this implementation, the dicing quality can be further guaranteed by controlling the dicing time and dicing line fluctuation.

[0065] The lines produced by scribing are usually straight lines, and the line fluctuation range is -1μm to 1μm, which means that the lines fluctuate 1μm to both sides on the originally designed straight line path. The fluctuation range of the lines produced by scribing in the conventional LED chip splitting scheme is too large for the light-emitting diode chip, so it is necessary to control the fluctuation range of the lines. The present disclosure controls the power of the laser to make the line fluctuation range -1μm to 1μm, avoiding the problems of back line misalignment, product size edge and so on, thereby solving the appearance abnormality problem mentioned above.

[0066] In addition, when dicing, it is necessary to ensure that the front and back sides of the slice are completely cut apart. When dicing, it is necessary to pay attention to the lines on the back of the product. Waves, misaligned lines, etc. are prohibited.

[0067] In the embodiment of the present disclosure, the laser may be a U-FAST dual-focus laser.

[0068] In the disclosed embodiment, under the premise of the above-mentioned laser focus, laser frequency and scribing speed design, the power of the laser is adjusted step by step with an adjustment step of 0.01W; after each adjustment, the appropriate power of the laser is determined by the effect after the slicing, and finally the appropriate power is determined.

[0069] In the disclosed embodiment, the dual-focus laser further comprises a beam expander arranged between the laser and the light-emitting diode chip, and the beam expander is used to control the spot of the laser to be between 5 mm and 7 mm.

[0070] By setting a beam expander to control the spot width (the width of the spot generated by laser irradiation on the chip surface), the laser is made more suitable for dicing light-emitting diode chips.

[0071] In the embodiment of the present disclosure, the beam expander may be a 1.5 to 2 times beam expander.

[0072] In the disclosed embodiment, the distance between the beam expander and the laser can be adjusted as needed, as long as the requirements of the line fluctuation range and the oblique split angle can be finally met.

[0073] S24: using a cleaver with a cleaver angle of 70° to 80° to split the diced light emitting diode chip.

[0074] When splitting, a splitter with a splitting angle of 70° to 80° is used, which is conducive to splitting thicker sapphire substrates. The above design avoids the poor slicing effect on the side away from the sapphire substrate due to the thick sapphire substrate during splitting, which causes the electrode to slightly warp, thereby improving the yield of micro-light-emitting diode products.

[0075] Exemplarily, a cleaver with a cleaver angle of 75° is used to break the diced light emitting diode chip.

[0076] In the embodiment of the present disclosure, when cracking, the distance between the light emitting diode chips is 2 to 3 μm under the cracking debugging condition.

[0077] The LED chip spacing here refers to the spacing between adjacent LED cores after being split by a splitting knife. Splitting debugging is performed before formal splitting.

[0078] In this implementation, the light emitting diode chips are split with a force of 2-3 μm in the chip splitting debugging condition, thereby ensuring the chipping quality and preventing the electrodes from warping.

[0079] Exemplarily, during the chip splitting, the force used is that the distance between the light emitting diode chips is 2.5 μm under the chip splitting debugging condition.

[0080] In the disclosed embodiment, before splitting, the distance between the splitting knife and the LED chip is 4-5 mm; during splitting, the time that the splitting knife is pressed on the LED chip is 380-420 ms.

[0081] Here, the distance between the splitting knife and the LED chip is set to 4-5 mm, which is not too large to affect the chip splitting efficiency, nor too small to easily cause chip damage, so as to achieve a balance between risk and efficiency.

[0082] In this implementation, the splitting knife is pressed on the LED chip for 380-420 ms, which is neither too long nor too short. The LED chip can be protected from damage while ensuring the splitting effect.

[0083] Exemplarily, before splitting, the distance between the splitting knife and the LED chip is 4.5 mm; during splitting, the time for the splitting knife to press on the LED chip is 400 ms.

[0084] In addition, in the above-mentioned splitting process, the splitting method uses front splitting, the splitting direction uses cleaving, and the oblique splitting surface is preferentially split. It is forbidden to use a hammer to knock during the splitting process.

[0085] Wherein, cleaving refers to cleaving from the front side of the light-emitting diode with electrodes. During cleaving, the cleaver cleaves down each time, then rises, and moves to the next position to repeat the above process. Therefore, the cleaving route can be planned. In the embodiment disclosed in the present invention, the oblique cleavage surface is cleaved first, and then the non-oblique cleavage surface is cleaved, which can make the non-oblique cleavage surface easier to cleave, and will not cause the uncleaved oblique cleavage surface to collapse and deform when cleaving the non-oblique cleavage surface, thereby affecting the cleaving effect.

[0086] S25: Stick the second blue film on the metal ring.

[0087] Exemplarily, the metal ring is an iron ring.

[0088] Among them, the size of the iron ring is 260mm.

[0089] In the embodiment of the present disclosure, the viscosity of the second blue film is greater than or equal to 0.4, and the diameter of the second blue film is 255-260 mm.

[0090] For example, the diameter of the second blue film is 258 mm. Although the blue film is smaller than the iron ring, it can be attached to most areas of the iron ring without affecting the use of the blue film.

[0091] S26: The light-emitting diode chip after splitting is attached to the second blue film of the metal ring for pressing.

[0092] The side of the light emitting diode chip that is not attached with the first blue film is attached here.

[0093] In the disclosed embodiment, during tableting, the tableting time is 8 to 12 seconds, and the tableting pressure is less than or equal to -0.6 MPa.

[0094] In this implementation, the above-mentioned tablet pressing time and pressure are adopted, which can ensure the tablet pressing effect and avoid damaging the light-emitting diode chip.

[0095] Exemplarily, during the tableting, the tableting time is 10 s and the tableting pressure is less than or equal to -0.6 MPa.

[0096] S27: placing one side of the light emitting diode chip on a nano vacuum plate for adsorption, and removing the first blue film.

[0097] What is adsorbed here is the side of the light-emitting diode chip attached to the second blue film.

[0098] After placing one side of the light emitting diode chip on the nano vacuum plate for adsorption, the first blue film can be torn off.

[0099] In the embodiment of the present disclosure, after the above step S27 is executed, the third blue film can be re-attached and torn off, and this can be repeated twice. By attaching and tearing off the blue film, it is easy to find problems such as electrode warping during scratching.

[0100] S28: Expanding the second blue film to separate the split light emitting diode chips.

[0101] In the above steps, the light emitting diode chips are separated after being split by pressing and expanding the films.

[0102] In the disclosed embodiment, the second blue film is expanded by 120±2 mm.

[0103] In the disclosed embodiment, the diameter of the entire light-emitting diode wafer before cleavage is 105 mm, and the diameter of the region formed by the multiple core particles after film expansion is 120±2 mm, so that the multiple core particles are fully separated.

[0104] S29: placing the expanded light-emitting diode chip on an optical display mirror for inclined plate inspection to observe the electrode warping at the edge of the light-emitting diode chip.

[0105] Inclined plate inspection refers to the use of an inclined plate to hold up the LED chip during observation, making it easier for an optical display lens to observe the electrode warping of the LED chip.

[0106] After each slicing procedure is completed, the technicians will place the expanded product on the optical display mirror for inclined plate inspection to observe whether the electrode on the edge of the product is warped. Once it is confirmed that there is no electrode warping, it can be delivered for mass production.

[0107] After the above improvements, the electrode hanging in the air and warping caused by sapphire defects on the side of the chip can be basically eliminated.

[0108] Figure 3 is a comparative diagram of the related technology provided by the embodiment of the present disclosure and the present disclosure. Figure 3 , the solid line is the Vfin (minimum turn-on voltage) electrical yield of the LED chip obtained by the cleaving solution provided by the embodiment of the present disclosure, and the dotted line is the Vfin electrical yield of the LED chip obtained by the cleaving solution provided by the related art. By comparison, it can be seen that the cleaving solution provided by the embodiment of the present disclosure increases the Vfin electrical yield of the LED chip by an average of 6.74%.

[0109] The above description is only an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A splitting method, characterized in that: The method is applicable to a flip-chip light-emitting diode chip having a sapphire substrate, and the method comprises: A first blue film is attached to a side of the light-emitting diode chip away from the sapphire substrate, and the thickness of the sapphire substrate is greater than 220 microns; Using a dual-focus laser to perform scribing on the other side of the light-emitting diode chip, during the scribing process, the distance between the two focal points of the laser emitted by the dual-focus laser within the light-emitting diode chip is controlled to be 35-45 μm, and the distance between the focal point farther from the sapphire substrate and the surface of the sapphire substrate is 105-115 μm, and the distance at the oblique crack surface of the sapphire substrate is 4-6 μm less than the distance at the non-oblique crack surface; The light emitting diode chip after dicing is split by using a cleaver with a cleaver angle of 70° to 80°.

2. The method according to claim 1, characterized in that A blue film is attached to one side of the light emitting diode chip, comprising: The light-emitting diode chip is placed on a base with nano vacuum holes, and adsorbed by vacuum, with an adsorption pressure less than or equal to -80 kPa; In the adsorption state, the first blue film is attached to one side of the light emitting diode chip.

3. The method according to claim 2, characterized in that The viscosity of the first blue film is less than or equal to 0.3N / 20mm, and the diameter of the first blue film is 255-260mm.

4. The method according to any one of claims 1 to 3, characterized in that: During the scribing process, the laser frequency of the non-oblique crack surface is 45-55 Hz, and the scribing speed is 190-210 mm / s; the laser frequency of the oblique crack surface is 45-55 Hz, and the scribing speed is 290-310 mm / s.

5. The method according to any one of claims 1 to 3, characterized in that: The power control of the dual-focus laser can make each scribing line be scribed within 1 to 3 seconds, so that the fluctuation range of the line irradiated by the laser on the light-emitting diode chip is -1 μm to 1 μm.

6. The method according to any one of claims 1 to 3, characterized in that: When cracking, the distance between the light emitting diode chips is 2-3 μm under the cracking debugging condition.

7. The method according to any one of claims 1 to 3, characterized in that: Before splitting, the distance between the splitting knife and the light emitting diode chip is 4-5 mm; during splitting, the time for the splitting knife to press on the light emitting diode chip is 380-420 ms.

8. The method according to any one of claims 1 to 3, characterized in that: The method further comprises: Stick the second blue film on the metal ring; The light-emitting diode chip after splitting is attached to the second blue film of the metal ring for pressing; Placing one side of the light-emitting diode chip on a nano vacuum plate for adsorption, and removing the first blue film; The second blue film is expanded to separate the light emitting diode chips after being split.

9. The method according to claim 8, characterized in that During the tableting, the tableting time is 8 to 12 seconds, and the tableting pressure is less than or equal to -0.6 MPa.

10. The method according to claim 8, characterized in that The method further comprises: The light-emitting diode chip after film expansion is placed on an optical display mirror for inclined plate inspection to observe the electrode warping at the edge of the light-emitting diode chip.

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