LED chip transfer method, device manufacturing method, device, module and display

Abstract

The present invention discloses a method for transferring an LED chip. First, the LED chip on the substrate is transferred to a first temporary carrier. The first temporary carrier adheres the LED chip through a first adhesive, and the first adhesive is reduced in viscosity when irradiated by a first light; then the LED chip on the first temporary carrier is aligned with the corresponding pad on the target substrate and welded; then the first adhesive of the first temporary carrier is irradiated with a first light, so that the adhesive force between the first adhesive and the LED chip is less than the fixing force between the target substrate and the LED chip, and then the first temporary carrier is removed, so that the LED chip cannot be adhered from the substrate or another temporary carrier due to the small adhesive force between the first temporary carrier and the LED chip, or the LED chip fails to be transferred to the target substrate due to the large adhesive force between the first temporary carrier and the LED chip. In addition, the present invention also discloses a method for manufacturing an LED device, an LED device manufactured by the manufacturing method, and a display module and a display including the LED device.

Description

Technical Field

[0001] The present invention relates to the technical field of LED display, and in particular to an LED chip transfer method, a device manufacturing method, a device, a module and a display. Background Art

[0002] The luminescent materials of traditional display devices are usually organic molecular materials, which have defects such as poor stability, resulting in a low service life of the display devices. In order to solve the problems of traditional display devices, it is proposed to use mini light-emitting diode chips (Mini LED) or micro light-emitting diode chips (Micro LED) to make display devices.

[0003] After the Mini / Micro LED chips are manufactured, they need to be transferred to the target substrate by mass transfer to form an LED array, and then further processed to obtain the required LED devices. In the process of transferring LED chips using a temporary carrier, the LED chips are usually adhered using adhesive on the temporary carrier. However, the adhesive force of the adhesive is prone to fluctuations, making it difficult to control the adhesion between the LED chip and the temporary carrier. Low adhesion may cause the temporary carrier to be unable to adhere the LED chip from the substrate / another temporary carrier, while high adhesion may cause the LED to fail to transfer to the target substrate, resulting in low LED chip transfer efficiency and low yield, which in turn leads to low production efficiency and low yield of LED devices. Summary of the invention

[0004] The object of the present invention is to provide an LED chip transfer method, a device manufacturing method, a device, a module and a display method to improve the manufacturing efficiency and the yield rate.

[0005] To achieve the above object, the present invention provides a method for transferring an LED chip, comprising the steps of:

[0006] S1, adhering the LED chip to a first adhesive of a first temporary carrier, wherein the first temporary carrier comprises a first substrate and the first adhesive adhered to the first substrate, wherein the viscosity of the first adhesive decreases when the first adhesive is irradiated by a first light;

[0007] S2, aligning the LED chip on the first temporary carrier with the corresponding pad on the target substrate, and welding and fixing the electrodes of the LED chip to the corresponding pad;

[0008] S3, using the first light to irradiate the first adhesive, so that the adhesion between the first adhesive and the LED chip is smaller than the fixing force between the target substrate and the LED chip, and then removing the first temporary carrier.

[0009] In some embodiments, in step S3, the first light is used to irradiate the first adhesive, so that the adhesion of the first adhesive to the LED chip is smaller than the adhesion of the first adhesive to the first substrate.

[0010] In some embodiments, the adhesion between the first adhesive and the LED chip, and the fixing force between the target substrate and the LED chip are measured; the first light is used to irradiate the first adhesive until the adhesion between the first adhesive and the LED chip is less than the fixing force between the target substrate and the LED chip, and the difference reaches a first preset value.

[0011] In some embodiments, in step S1, before adhering the LED chip to the first adhesive of the first temporary carrier, it also includes: fixing the LED chip on the substrate to the second temporary carrier; removing the substrate; adhering the LED chip on the second temporary carrier to the first adhesive of the first temporary carrier; and removing the second temporary carrier.

[0012] In some embodiments, the LED chip on the substrate is adhered and fixed to the second adhesive of the second temporary carrier, the second temporary carrier includes a second base and the second adhesive adhered to the second base, the viscosity of the second adhesive decreases when irradiated by a second light; the second adhesive is irradiated with the second light to make the adhesion between the second adhesive and the LED chip smaller than the adhesion between the first adhesive and the LED chip, and the adhesion between the second adhesive and the LED chip smaller than the adhesion between the second adhesive and the second base; the second temporary carrier and the LED chip are peeled off.

[0013] In some embodiments, the viscosity of the second adhesive and the viscosity of the first adhesive are measured; the second adhesive is irradiated with the second light until the viscosity of the second adhesive is less than the viscosity of the first adhesive and the difference reaches a second preset value.

[0014] To achieve the above object, the present invention further provides a method for manufacturing an LED device, comprising:

[0015] Transferring the LED chip to the target substrate using the transfer method described above;

[0016] Covering the surface of the LED chip of the target substrate with packaging glue;

[0017] The packaged target substrate is cut based on the number and / or type of LED chips that each LED device needs to include.

[0018] To achieve the above object, the present invention further provides an LED device, which is manufactured using the manufacturing method described above.

[0019] To achieve the above object, the present invention further provides an LED display module, which includes the LED device described above.

[0020] To achieve the above object, the present invention further provides an LED display, which includes the LED display module as described above.

[0021] Compared with the prior art, the LED chip transfer method provided by the present invention allows the first temporary carrier to adhere the LED chip through the first adhesive, and then aligns the electrodes of the LED chip on the first temporary carrier with the corresponding pads on the target substrate and welds them to fix; then uses the first light to irradiate the first adhesive of the first temporary carrier, so that the adhesion between the first adhesive of the first temporary carrier and the LED chip is smaller than the fixing force between the target substrate and the LED chip, and then removes the first temporary carrier, which can avoid the failure of transferring the LED chip to the target substrate due to excessive adhesion between the first temporary carrier and the LED chip, thereby improving the transfer efficiency and yield of the LED chip, and thus improving the manufacturing efficiency and yield of LED devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a flow chart of a method for manufacturing an LED device according to an embodiment of the present invention;

[0023] Figures 2 to 10 It is a schematic diagram of the process of a method for manufacturing an LED device according to an embodiment of the present invention;

[0024] Fig.11 is a three-dimensional structural diagram of an LED device manufactured according to an embodiment of the present invention;

[0025] Fig.12 It is a schematic diagram of the process of transferring LED chips from the second temporary carrier to the first temporary carrier according to one embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to explain the content, structural features, achieved purposes and effects of the present invention in detail, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In the description of the invention, it should be understood that the directions or positional relationships indicated by the terms "upper" and "lower" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and therefore cannot be understood as limiting the protection content of the invention.

[0028] The technical solution of the embodiment of the present invention is described in detail below with reference to the accompanying drawings:

[0029] In the process of manufacturing LED chips, such as Mini / Micro LED chips, the main body of the LED chip is grown on a substrate (such as a sapphire substrate), and then electrodes are made on the side of the main body of the LED chip that is away from the substrate, and finally the LED chip is obtained. In the process of using LED chips to manufacture LED devices, multiple chip transfers are required. That is, the LED chip must first be transferred from the substrate to a temporary carrier. At this time, the electrodes of the LED chip are fixed to the temporary carrier. However, the electrodes of the LED chip ultimately need to be welded and fixed to the target substrate. Therefore, the LED chip must be transferred from the temporary carrier to another temporary carrier for a second time to achieve the purpose of flipping the electrodes of the LED chip. At this time, the electrodes of the LED chip are away from the other temporary carrier. In the subsequent process of transferring the LED chip from the other temporary carrier to the target substrate, the electrodes of the LED chip face the target substrate, and can be welded to the target substrate.

[0030] The manufactured LED device may include only at least one LED chip, which can be fixed to other circuit substrates for use. The manufactured LED device may also include an array of LED chips emitting multiple different colors, which can be used to make displays.

[0031] See also Figures 1 to 10 , an LED device manufacturing method provided by an embodiment of the present invention includes the following steps S101 to S108.

[0032] S101, fix the LED chip 2 on the substrate 1 to the second temporary carrier 3. Specifically, the LED chip 2 and the second temporary carrier 3 can be fixed by lamination bonding, which can be achieved by pressing with a bonding machine. The LED chip 2 and the second temporary carrier 3 can also be fixed by bonding or other methods.

[0033] S102, removing the substrate 1. Specifically, the substrate 1 can be peeled off from the LED chip 2 by irradiating the bonding interface of the substrate 1 and the LED chip 2 or the area near the bonding interface with a peeling light, leaving the LED chip 2 and the second temporary carrier 3, such as Figure 2 The stripping light may be a laser with a wavelength of 355nm, 266nm, etc.

[0034] S103, bringing the LED chip 2 on the second temporary carrier 3 and the first adhesive 42 on the first temporary carrier 4 close to each other, such as Figure 3As shown, and pasted together. Among them, the first temporary carrier 4 used includes a first base 41 and a first adhesive 42 adhered to the first base 41, and the viscosity of the first adhesive 42 decreases when it is irradiated by the first light. The first base 41 of the first temporary carrier 4 is preferably transparent glass to avoid obstructing the first light. Before the first adhesive 42 of the first temporary carrier 4 or the bonding surface of the second temporary carrier 3 and the LED chip 2 is processed, the adhesion between the first adhesive 42 of the first temporary carrier 4 and the LED chip 2 can be greater than the adhesion between the second temporary carrier 3 and the LED chip 2, or it can be less than or equal to the adhesion between the second temporary carrier 3 and the LED chip 2.

[0035] In some embodiments, the second temporary carrier 3 used includes a second base 31 and a second adhesive 32 adhered to the second base 31, and the viscosity of the second adhesive 32 is reduced when the second light is irradiated. The second light is used to irradiate the second adhesive 32 of the second temporary carrier 3, so that the adhesion between the second adhesive 32 of the second temporary carrier 3 and the LED chip 2 is smaller than the adhesion between the second adhesive 32 of the second temporary carrier 3 and the second base 31, so as to avoid the second adhesive 32 from falling off the second temporary carrier 3 when the chip is transferred, thereby facilitating the LED chip 2 to be detached from the second temporary carrier 3.

[0036] In some embodiments, the first temporary carrier 4 is further improved, including: before the first adhesive 42 is adhered to the first substrate 41, the surface of the first substrate 41 for adhering the first adhesive 42 is roughened to increase the roughness of the surface of the first substrate 41, thereby increasing the bonding force between the first adhesive 42 and the first substrate 41, and then the adhesion between the first adhesive 42 and the first substrate 41 can be greater than the adhesion of the first adhesive 42 to the LED chip 2; and then, the first adhesive 42 is adhered to the roughened first substrate 41. With this design, it can be prevented that the entire piece of the first adhesive 42 is separated from the first substrate 41 along with the LED chip 2 when the first light is used to irradiate the first adhesive 42 in step S106.

[0037] In some embodiments, the roughening treatment of the first substrate 41 is achieved by opening a plurality of grooves on the surface of the first substrate 41 at positions other than the positions corresponding to the positions for attaching the LED chips 2. When the first adhesive 42 is attached to the roughened first substrate 41, the first adhesive 42 is attached to the side of the first substrate 41 where the grooves are exposed, and the first adhesive 42 is squeezed into the grooves. When the first adhesive 42 is dried, the groove walls can further fix the first adhesive 42.

[0038] When the first substrate 41 is grooved, the position of the first substrate 41 corresponding to the pasting of the LED chip 2 can be avoided to prevent the grooved portion of the first substrate 41 from blocking the light transmission when the first light is used to irradiate the first adhesive 42 in step S106; at the same time, it can also avoid the LED chip 2 being difficult to peel off from the first temporary carrier 4 due to the thick first adhesive 42 at the groove affecting the light transmission.

[0039] The adhesive force of the first adhesive 42 adhering to the side (front) of the LED chip 2 is Fpositive, and the adhesive force of the first adhesive 42 adhering to the side of the first substrate 41 is Fback. When the first adhesive 42 is illuminated with light from the side of the first substrate 41 away from the first adhesive 42, the side (back) of the first adhesive 42 combined with the first substrate 41 will be affected by the light first, and the light effect is negative. If no light is irradiated, the viscosity of the front and back of the first adhesive 42 is the same. Under the same light illumination conditions, Fback < Fpositive. At this time, the back of the first adhesive 42 may be separated from the first substrate 41, while the LED chip 2 on the front of the first adhesive 42 does not fall off.

[0040] To avoid this problem, in some embodiments, the friction between the first substrate 41 and the first adhesive 42 is increased so that Fpositive <= Fback is maintained after light irradiation. Finally, the volume of the adhesive in each slot is Vglue>=f(t, l, p)s / a*n, where Vglue represents the volume of the adhesive in each slot, t represents the light intensity, l represents the thickness of the adhesive, p represents the light transmittance of the adhesive, s represents the slot wall area of ​​the slot, a represents the coefficient, n represents the number of slots, and f(t, l, p) represents the effect of the first light on the adhesive force.

[0041] The derivation process of V glue>=f(t, l, p)s / a*n is as follows:

[0042] The friction force between the rubber and the slot is Fslot = a*Vslot*n / s, where a represents the coefficient, Vslot represents the volume of rubber in each slot, s represents the slot wall area, and n represents the number of slots. The following must be met:

[0043] Fslot>=f(t,l,p), therefore, a*Vglue*n / s>=f(t,l,p), and finally, the volume of glue in each slot is obtained: Vglue≥f(t,l,p)s / (a*n).

[0044] In this embodiment, the size of the opening end of the groove may be smaller than the size of the groove bottom. Each groove may penetrate at least one side surface of the first substrate 41, and after the first adhesive 42 is cured by the first light, the cured first adhesive 42 can be slid out from one side of the first substrate 41, and the first substrate 41 can be reused.

[0045] In some embodiments, the roughening of the first substrate 41 is achieved by frosting the surface of the first substrate 41 for pasting the first adhesive 42. When frosting the first substrate 41, the position of the first substrate 41 corresponding to the LED chip 2 can be avoided to prevent the frosted portion of the first substrate 41 from blocking the first light from passing through when the first light is irradiated on the first adhesive 42 in step S106.

[0046] Furthermore, in some embodiments, after the first adhesive 42 is adhered to the roughened first substrate 41 , a press with a release film is used to press the first adhesive 42 and the first substrate 41 to further increase the bonding force between the first adhesive 42 and the first substrate 41 .

[0047] In some embodiments, before "sticking the LED chip 2 on the second temporary carrier 3 and the first adhesive 42 of the first temporary carrier 4 together", the surface of the first adhesive 42 used for sticking to the LED chip 2 can also be treated to reduce the viscosity. The corresponding first light can be used to first illuminate the side of the first adhesive 42 away from the first substrate 41 to slightly reduce the viscosity of the side of the first adhesive 42 away from the first substrate 41, so that the adhesion of the first adhesive 42 to the LED chip 2 is less than the adhesion of the first adhesive 42 to the first substrate 41, but the LED chip 2 can still be adhered to the second temporary carrier 3.

[0048] In some embodiments, before "sticking the LED chip 2 on the second temporary carrier 3 to the first adhesive 42 of the first temporary carrier 4" in step S103, the surface of the LED chip 2 for sticking to the first adhesive 42 is also smoothed. For example, a transparent resin or other material capable of increasing smoothness is sprayed on the surface of the LED chip 2 for sticking to the first adhesive 42.

[0049] S104, removing the second temporary carrier 3. Specifically, if the adhesion between the first adhesive 42 of the first temporary carrier 4 and the LED chip 2 is much greater than the fixing force between the second temporary carrier 3 and the LED chip 2, the second temporary carrier 3 can be directly peeled off from the LED chip 2 by mechanical force, leaving the first temporary carrier 4 and the LED chip 2. Figure 4 If the adhesion between the first adhesive 42 of the first temporary carrier 4 and the LED chip 2 is less than or equal to the fixing force between the second temporary carrier 3 and the LED chip 2, some auxiliary methods can be used to cancel or reduce the fixing force between the second temporary carrier 3 and the LED chip 2, and then the second temporary carrier 3 can be peeled off from the LED chip 2.

[0050] For example, in an embodiment where the LED chip 2 and the second temporary carrier 3 are adhered together by the second adhesive 32, the second adhesive 32 of the second temporary carrier 3 is less viscous when irradiated with a second light. The second light may be ultraviolet (UV) light. In step S104, the second light is firstly used to irradiate the second adhesive 32 of the second temporary carrier 3, so that the adhesion between the second adhesive 32 of the second temporary carrier 3 and the LED chip 2 is less than the adhesion between the first adhesive 42 of the first temporary carrier 4 and the LED chip 2, and the difference reaches a second preset value. Then, the second temporary carrier 3 and the LED chip 2 are peeled off, leaving the first temporary carrier 4 and the LED chip 2.

[0051] In some embodiments, when the second light is used to illuminate the second adhesive 32 of the second temporary carrier 3, only the portion where the second adhesive 32 is fixed to the LED chip 2 may be illuminated, and other portions of the second adhesive 32 may not be illuminated. In other embodiments, both the portion where the second adhesive 32 is fixed to the LED chip 2 and other portions of the second adhesive 32 may be illuminated.

[0052] In some embodiments, before the second light is used to irradiate the second adhesive 32 of the second temporary carrier 3, the viscosity of the second adhesive 32 of the second temporary carrier 3 and the viscosity of the first adhesive 42 of the first temporary carrier 4 are measured. Then, the viscosity of the second adhesive 32 of the second temporary carrier 3 and the viscosity of the first adhesive 42 of the first temporary carrier 4 are compared. If the viscosity of the first adhesive 42 of the first temporary carrier 4 does not exceed the second preset value of the second adhesive 32 of the second temporary carrier 3, the second light is used to irradiate the second adhesive 32 of the second temporary carrier 3 until the viscosity of the second adhesive 32 of the second temporary carrier 3 is less than the viscosity of the first adhesive 42 of the first temporary carrier 4, and the viscosity difference reaches the second preset value. Then, the second temporary carrier 3 is peeled off from the LED chip 2.

[0053] In some embodiments, a viscosity test area may be set on the reverse side of the side of the first adhesive 42 / second adhesive 32 used to adhere the LED chip 2, and a through hole is provided to connect the viscosity test area and the side of the first adhesive 42 / second adhesive 32 used to adhere the LED chip 2, and the cross-sectional size of the through hole is smaller than the size of the bonding area between the LED chip 2 and the first adhesive 42 / second adhesive 32. By setting the viscosity test area on the reverse side of the first adhesive 42 / second adhesive 32, it is possible to avoid interfering with the fixation between the first adhesive 42 / second adhesive 32 and the LED chip 2. The viscosity sensor for viscosity testing may be set in the viscosity test area, or the glue may be obtained from the viscosity test area through an external viscosity sensor for viscosity testing. Of course, in other embodiments, a viscosity test area may also be set on the side of the first adhesive 42 / second adhesive 32 used to adhere the LED chip 2.

[0054] In some embodiments, there may be one or more viscosity testing areas, and the viscosity testing areas may be as close to the LED chip 2 as possible, or may be between multiple LED chips 2, so as to obtain more accurate viscosity data.

[0055] In some embodiments, when the second light is used to irradiate the second adhesive 32 of the second temporary carrier 3, the irradiation power, irradiation time, and various wavelength components in the light, etc., are adjusted according to the viscosity difference between the second adhesive 32 of the second temporary carrier 3 and the first adhesive 42 of the first temporary carrier 4. The relationship between the viscosity and the various illumination factors can be set in advance. When adjusting the illumination factors, the gravity of the LED chip 2 itself can be taken into account. For example, Figure 3 As shown, the LED chip 2 is adhered to the bottom of the second temporary carrier 3, and the LED chip 2 is adhered to the first temporary carrier 4. When the second adhesive 32 of the second temporary carrier 3 has the same viscosity as the first adhesive 42 of the first temporary carrier 4, due to the influence of the gravity of the LED chip 2 itself, the adhesion between the LED chip 2 and the first temporary carrier 4 will be greater than the adhesion between the LED chip 2 and the second temporary carrier 3. Therefore, when adjusting the lighting factor, the gravity of the LED chip 2 itself can be taken into consideration.

[0056] In some embodiments, before using the second light to irradiate the second adhesive 32 of the second temporary carrier 3, the adhesion between the second adhesive 32 of the second temporary carrier 3 and the LED chip 2, and the adhesion between the first adhesive 42 of the first temporary carrier 4 and the LED chip 2 can be measured first, and the second light is used to irradiate the second adhesive of the second temporary carrier until the adhesion between the second adhesive of the second temporary carrier and the LED chip is less than the adhesion between the first adhesive of the first temporary carrier and the LED chip, and the difference reaches a second preset value.

[0057] S105, aligning the LED chip 2 on the first temporary carrier 4 with the corresponding pad 51 on the target substrate 5, such as Figure 5 As shown, the electrodes of the LED chip 2 are fixedly welded to the corresponding pads 51. Specifically, the electrodes of the LED chip 2 can be fixedly welded to the corresponding pads 51 by laser, and the laser can be, for example, a laser with a wavelength of 1064 nm. The solder (such as solder paste, etc.) on the corresponding pads 51 can also be melted by reflow soldering, etc., to achieve the welding and fixing of the electrodes of the LED chip 2 to the corresponding pads 51.

[0058] S106, irradiating the first adhesive 42 of the first temporary carrier 4 with the first light, so that the adhesive force of the first adhesive 42 of the first temporary carrier 4 on the LED chip 2 is smaller than the fixing force of the target substrate 5 on the LED chip 2, and then removing the first temporary carrier 4, leaving the target substrate 5 and the LED chip 2, as shown in FIG. Figure 6 shown.

[0059] In some embodiments, a first light can be used to irradiate the first adhesive glue 42 of the first temporary carrier 4 so that the adhesion of the first adhesive glue 42 to the LED chip 3 is smaller than the adhesion of the first adhesive glue 42 to the first substrate 31, so as to prevent the first adhesive glue 42 from falling off the first temporary carrier 4, thereby facilitating the LED chip to detach from the first temporary carrier 4.

[0060] In some embodiments, when the first light is used to illuminate the first adhesive 42 of the first temporary carrier 4, only the portion where the first adhesive 42 is fixed to the LED chip 2 may be illuminated, and other portions of the first adhesive 42 may not be illuminated. In other embodiments, both the portion where the first adhesive 42 is fixed to the LED chip 2 and other portions of the first adhesive 42 may be illuminated.

[0061] In some embodiments, when the first light is used to illuminate the first adhesive glue 42 of the first temporary carrier 4, only the portion where the first adhesive glue 42 is fixed to the LED chip 2 is illuminated, and other portions of the first adhesive glue 42 are not illuminated. At this time, the groove may be at a position on the first substrate 41 corresponding to the position where the LED chip 2 is pasted.

[0062] In some embodiments, before the first adhesive glue 42 of the first temporary carrier 4 is irradiated with the first light, the viscosity of the first adhesive glue 42 of the first temporary carrier 4 is first measured to determine the adhesive force between the first adhesive glue 42 and the LED chip 2, and the fixing force between the target substrate 5 and the LED chip 2 is also measured. Then, the adhesive force between the first adhesive glue 42 of the first temporary carrier 4 and the LED chip 2 and the fixing force between the target substrate 5 and the LED chip 2 are compared. If the adhesive force between the first adhesive glue 42 of the first temporary carrier 4 and the LED chip 2 exceeds the fixing force between the target substrate 5 and the LED chip 2, the first light is irradiated with the first adhesive glue 42 of the first temporary carrier 4 until the adhesive force between the first adhesive glue 42 of the first temporary carrier 4 and the LED chip 2 is less than the fixing force between the target substrate 5 and the LED chip 2, and the difference reaches a first preset value. Then, the first temporary carrier 4 is peeled off from the LED chip 2.

[0063] S107, the surface of the LED chip 2 of the target substrate 5 is covered with a packaging glue 6, such as Figure 7 shown.

[0064] S108, based on the number and / or type of LED chips 2 required to be included in each LED device, cut the packaged target substrate 5 to obtain individual LED devices 7, such as Fig.10 shown.

[0065] In some embodiments, before cutting the target substrate 5, first remove part of the packaging glue between the individual LED devices to be obtained, such as Figure 8 , Fig. 9 As shown, the excess packaging glue is removed and the target substrate 5 is cut to facilitate cutting.

[0066] It is understandable that, in some embodiments, the second temporary carrier 3 may be subjected to the same treatment as the first temporary carrier 4, for example, the second base 31 of the second temporary carrier 3 may be roughened, and corresponding light may be used to illuminate the side of the second adhesive 32 of the second temporary carrier 3 facing away from the second base 31, etc., which will not be elaborated here.

[0067] In some embodiments, the LED chip 2 may include a red LED chip, a green LED chip, and a blue LED chip, which are labeled 2a, 2b, and 2c, respectively. In steps S101 and S102, three second temporary carriers may be used, which are labeled 3a, 3b, and 3c, respectively. The substrates on which the red LED chip 2a, the green LED chip 2b, and the blue LED chip 2c are grown may be matched with the second temporary carriers 3a, 3b, and 3c, respectively, and the red LED chip 2a, the green LED chip 2b, and the blue LED chip 2c may be transferred to the three second temporary carriers 3a, 3b, and 3c in sequence, that is, each second temporary carrier corresponds to one LED chip. The chip spacing on the second temporary carriers 3a, 3b, 3c is a set value. When the LED chip 2a on the second temporary carrier 3a is transferred to the first temporary carrier 4, the chip spacing on the first temporary carrier 4 can just accommodate the LED chips 2b, 2c on the other two second temporary carriers 3b, 3c. The process of transferring the LED chips from the three second temporary carriers to the first temporary carrier 4 is as follows. Fig.12 By sequentially transferring the LED chips 2a, 2b, 2c on the three second temporary carriers 3a, 3b, 3c to the first temporary carrier 4, the LED chips on the first temporary carrier 4 are arranged in order of red LED chips 2a, green LED chips 2b, and blue LED chips 2c. Finally, the three-dimensional structure diagram of the single LED device 7 is obtained as shown in FIG. Fig.11 shown.

[0068] In steps S101 and S102, the LED chips 2 on the substrate 1 may be selectively peeled off, and the LED chips 2 on the second temporary carrier 3 may be arranged in order of red LED chips, green LED chips, and blue LED chips, and then transferred to the first temporary carrier 4 at one time.

[0069] S109, fixing a plurality of LED devices 7 on the substrate at a certain interval to form an LED display module.

[0070] S110, assembling a plurality of LED display modules into an LED display.

[0071] In summary, the LED chip transfer method provided by the present invention is to first transfer the LED chip 2 on the substrate 1 to the second temporary carrier 3, at which time, the electrode of the LED chip 2 is fixed together with the second temporary carrier 3; then transfer the LED chip 2 on the second temporary carrier 3 to the first temporary carrier 4, so that the electrode of the LED chip 2 is away from the first temporary carrier 4, and the first temporary carrier 4 adheres to the LED chip 2 through the first adhesive 42, and the viscosity of the first adhesive 42 is reduced when it is irradiated by the first light; then the electrode of the LED chip 2 on the first temporary carrier 4 is connected to the corresponding pad on the target substrate 5. 51 is aligned and welded to fix; and then a first light is used to irradiate the first adhesive 42 of the first temporary carrier 4, so that the adhesion between the first adhesive 42 of the first temporary carrier 4 and the LED chip 2 is smaller than the fixing force between the target substrate 5 and the LED chip 2, and then the first temporary carrier 4 is removed. This can avoid the failure of adhering the LED chip 2 from the second temporary carrier 3 due to too small adhesion between the first temporary carrier 4 and the LED chip 2, or the failure of transferring the LED chip 2 to the target substrate 5 due to too large adhesion between the first temporary carrier 4 and the LED chip 2, thereby improving the manufacturing efficiency and yield rate of LED devices.

[0072] Compared with the prior art, the LED chip transfer method provided by the present invention allows the first temporary carrier 4 to adhere to the LED chip 2 through the first adhesive glue 42, and then aligns the electrode of the LED chip 2 on the first temporary carrier 4 with the corresponding pad 51 on the target substrate 5 and welds and fixes it; then, the first light is used to irradiate the first adhesive glue 42 of the first temporary carrier 4, so that the adhesion between the first adhesive glue 42 of the first temporary carrier 4 and the LED chip 2 is less than the fixing force between the target substrate 5 and the LED chip 2, and then the first temporary carrier 4 is removed, which can avoid the failure of the LED chip 2 to be transferred to the target substrate 5 due to the excessive adhesion between the first temporary carrier 4 and the LED chip 2, thereby improving the transfer efficiency and yield of the LED chip 2, and thus improving the manufacturing efficiency and yield of LED devices.

[0073] The LED chip transfer method provided by the present invention can effectively ensure the success rate of LED chip transfer by measuring the viscosity between the first adhesive 42, the second adhesive 32 and the LED chip 2, the first substrate 41, and the second substrate 31 in advance, so that the viscosity difference reaches a preset value, and then transfers the chip, thereby improving the production efficiency and yield rate of LED devices.

[0074] The above disclosure is only a preferred embodiment of the present invention, which cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are all within the scope of the present invention.

Claims

1. A method for transferring an LED chip, characterized in that: Includes steps: S1, adhering the LED chip to the first adhesive of the first temporary carrier, wherein the first temporary carrier comprises a first substrate and the first adhesive adhered to the first substrate, wherein the viscosity of the first adhesive decreases when irradiated by a first light; wherein before adhering the first adhesive to the first substrate, roughening the surface of the first substrate for adhering to the first adhesive, wherein the roughening position avoids the position of the first substrate corresponding to the position of the LED chip for adhering; S2, aligning the LED chip on the first temporary carrier with the corresponding pad on the target substrate, and welding and fixing the electrodes of the LED chip to the corresponding pad; S3, using the first light to irradiate the first adhesive, so that the adhesion between the first adhesive and the LED chip is smaller than the fixing force between the target substrate and the LED chip, and then removing the first temporary carrier; In step S3, "using the first light to irradiate the first adhesive so that the adhesive force between the first adhesive and the LED chip is smaller than the fixing force between the target substrate and the LED chip, and then removing the first temporary carrier" includes: Measuring the adhesion between the first adhesive and the LED chip, and the fixing force between the target substrate and the LED chip, setting a viscosity test area on the reverse side of the first adhesive used to adhere the LED chip, and testing the adhesion of the adhesive in the viscosity test area by a viscosity sensor to measure the adhesion between the first adhesive and the LED chip; The first light is used to irradiate the first adhesive until the adhesive force between the first adhesive and the LED chip is less than the fixing force between the target substrate and the LED chip, and the difference reaches a first preset value.

2. The transfer method according to claim 1, characterized in that: In step S3, the first light is used to irradiate the first adhesive, so that the adhesive force of the first adhesive to the LED chip is smaller than the adhesive force of the first adhesive to the first substrate.

3. The transfer method according to claim 1, characterized in that: In step S1, before the LED chip is bonded to the first temporary carrier by the first adhesive, the method further includes: Fixing the LED chip on the substrate to the second temporary carrier; removing the substrate; The method of bonding the LED chip to the first temporary carrier with a first adhesive comprises: Adhere the LED chip on the second temporary carrier to the first adhesive of the first temporary carrier; The second temporary carrier is removed.

4. The transfer method according to claim 3, characterized in that: “Fixing the LED chip on the substrate to the second temporary carrier” includes: The LED chip on the substrate is fixed to the second adhesive of the second temporary carrier; the second temporary carrier comprises a second base and the second adhesive adhered to the second base, and the viscosity of the second adhesive is reduced when the second adhesive is irradiated by the second light; “Removing the second temporary carrier” includes: Using the second light to irradiate the second adhesive, so that the adhesion between the second adhesive and the LED chip is smaller than the adhesion between the first adhesive and the LED chip, and the adhesion between the second adhesive and the LED chip is smaller than the adhesion between the second adhesive and the second substrate; The second temporary carrier is peeled off from the LED chip.

5. The transfer method according to claim 4, characterized in that: “Using the second light to irradiate the second adhesive, so that the adhesion between the second adhesive and the LED chip is smaller than the adhesion between the first adhesive and the LED chip, and the adhesion between the second adhesive and the LED chip is smaller than the adhesion between the second adhesive and the second substrate” includes: measuring the viscosity of the second adhesive and the viscosity of the first adhesive; The second adhesive is irradiated with the second light until the viscosity of the second adhesive is less than the viscosity of the first adhesive, and the difference reaches a second preset value.

6. A method for manufacturing an LED device, characterized in that: include: Transferring the LED chip to a target substrate using the transfer method described in any one of claims 1 to 5; Covering the surface of the LED chip of the target substrate with packaging glue; The packaged target substrate is cut based on the number and / or type of LED chips that each LED device needs to include.

7. An LED device, characterized in that: The LED device is manufactured by the manufacturing method as claimed in claim 6.

8. An LED display module, characterized in that: The LED display module comprises the LED device according to claim 7.

9. An LED display, characterized in that: The LED display comprises the LED display module as claimed in claim 8.

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