Chip transfer method, transient substrate, and display panel

Abstract

The application discloses a chip transfer method, a temporary substrate and a display panel. The chip transfer method comprises the following steps: a growth substrate is attached to a temporary substrate, so that the chips arranged in an array on the growth substrate are fixed to the pyrolytic glue blocks arranged in an array on the temporary substrate one by one; a transfer substrate is connected to the chips arranged in an array from a side away from the temporary substrate; one of the pyrolytic glue groups on the temporary substrate is heated and completely debonded, so that the chips corresponding to the pyrolytic glue group are separated from the temporary substrate and transferred to the transfer substrate; the chips on the transfer substrate are transferred to a driving backboard; the connecting step, the debonding step and the transferring step are cyclically executed n times, the transfer of the chips corresponding to the n pyrolytic glue groups is completed, and all the chips are transferred to the driving backboard in batches. Through the above method, the selective transfer of the chips is realized, and the release cost of the chips in specific positions is saved.

Description

Technical Field

[0001] This application relates to the display field, and more particularly to a chip transfer method, a transient substrate, and a display panel. Background Technology

[0002] During the manufacturing process of Micro LED panels, the necessary chips are fabricated as densely as possible on the growth substrate to minimize the spacing A between any two chips. However, the spacing B between any two pixels on the driving backplane is determined by the resolution and display size, and is often greater than A (to facilitate transfer, B is generally an integer multiple of A). This results in a mismatch between the spacing between any two chips on the growth substrate and the spacing between any two pixels on the final driving backplane. During mass transfer, not all chips on the growth substrate can be transferred to the driving backplane at once. Instead, chips with spacing that matches the pixel spacing on the backplane must be selected from the growth substrate for transfer.

[0003] However, at present, photodegradable adhesive is used in conjunction with special laser equipment. The laser can selectively irradiate specific locations to de-adhede the photodegradable adhesive and release the chip from the specific location for selective transfer. However, this method is more expensive than thermal degradable adhesive, and the laser equipment is not mature and has high equipment costs.

[0004] Therefore, how to achieve selective chip transfer while saving the cost of releasing chips in specific locations has become an urgent problem to be solved in this field. Summary of the Invention

[0005] This application discloses a chip transfer method, a transient substrate, and a display panel, with the aim of achieving selective chip transfer while saving the cost of releasing chips at specific locations.

[0006] This application discloses a chip transfer method, which includes the following steps: a fixing step: a growth substrate is attached to a transient substrate so that the chips arranged in an array on the growth substrate and the pyrolytic adhesive blocks arranged in an array on the transient substrate are fixed one by one.

[0007] Stripping step: Strip the growth substrate, leaving the chip on the transient substrate;

[0008] Connection step: Connect the transfer substrate to the arrayed chips from the side away from the transient substrate;

[0009] Debonding step: Heating and completely debonding one of the thermally debonded groups on the transient substrate, so that the chip corresponding to the thermally debonded group detaches from the transient substrate and is transferred to the transfer substrate;

[0010] Transfer step: Provide a driving backplane to transfer the chip on the transfer substrate to the driving backplane;

[0011] Returning to the connection step, the connection step, the debonding step, and the transfer step are executed n times in a loop to complete the transfer of the chips corresponding to the n thermal adhesive groups, so as to transfer all the chips to the driving backplane in batches.

[0012] The array of pyrolytic adhesive blocks is divided into multiple pyrolytic adhesive groups, each of which includes multiple pyrolytic adhesive blocks. The spacing between the multiple pyrolytic adhesive blocks matches the spacing between the target pixels; n is an integer greater than or equal to 2.

[0013] Optionally, the unbonding step, which involves heating and completely unbonding one of the thermally debonded adhesive groups on the transient substrate, so that the chip corresponding to the thermally debonded adhesive group detaches from the transient substrate and is transferred to the transfer substrate, further includes:

[0014] The transient substrate is heated, and the n thermally conductive components corresponding to the multiple thermally conductive components are completely debonded in order of decreasing thermal conductivity, so that the chips corresponding to the n thermally conductive components are separated from the transient substrate in batches.

[0015] The chips, which are detached in batches, are sequentially transferred onto the transfer substrate;

[0016] The transient substrate includes a first substrate, a second substrate, and a plurality of heat-conducting components. The first substrate and the second substrate are disposed opposite each other, and the plurality of heat-conducting components are arranged in an array between the first substrate and the second substrate.

[0017] The multiple heat-conducting components are divided into n heat-conducting component groups. The multiple heat-conducting components in each heat-conducting component group have the same thermal conductivity, while the multiple heat-conducting components in different heat-conducting component groups have different thermal conductivity.

[0018] Optionally, all of the multiple heat-conducting elements are made of the same material, and among the multiple heat-conducting elements, the cross-sectional area of ​​the multiple heat-conducting elements decreases sequentially from high to low thermal conductivity.

[0019] Optionally, the multiple heat-conducting elements are made of different materials, and among the multiple heat-conducting elements, the thermal conductivity of the multiple heat-conducting elements decreases sequentially from high to low.

[0020] Optionally, the multiple heat-conducting elements are made of the same material, and among the multiple heat-conducting elements, the spacing between the multiple heat-conducting elements with thermal conductivity decreasing from high to low gradually increases with the first substrate.

[0021] Optionally, the same-side edge spacing between two adjacent pixels on the driving backplane is N times the same-side edge spacing between two adjacent chips on the growth substrate. The connection step, the de-adhesion step, and the transfer step are executed n times in a loop, where n is equal to N times, and N is an integer and N≥2.

[0022] Optionally, an adhesive layer is provided on the side of the transfer substrate close to the chip. The adhesive layer is used to attach the chip, and the adhesive force of the adhesive layer is less than the adhesive force when the pyrolytic adhesive block is not completely debonded, but greater than the adhesive force when the pyrolytic adhesive block is completely debonded.

[0023] Optionally, the fixing step: bonding a growth substrate to a transient substrate so that the chips arranged in an array on the growth substrate and the pyrolytic adhesive blocks arranged in an array on the transient substrate are respectively fixed, includes:

[0024] A pyrolytic adhesive material is laid on the transient substrate and cured to form a pyrolytic adhesive layer.

[0025] Connect the plurality of chips on the growth substrate to the pyrolytic adhesive layer;

[0026] Plasma etching is performed on a portion of the pyrolytic adhesive layer between two adjacent chips to remove the portion of the pyrolytic adhesive layer not covered by the chips, forming the pyrolytic adhesive block.

[0027] This application also discloses a transient substrate, which is applied in the chip transfer method described above;

[0028] The transient substrate includes a first substrate, a second substrate, and a plurality of heat-conducting components. The first substrate and the second substrate are disposed opposite each other, and the plurality of heat-conducting components are arranged in an array between the first substrate and the second substrate.

[0029] The multiple heat-conducting components are divided into n heat-conducting component groups. The multiple heat-conducting components in each heat-conducting component group have the same thermal conductivity, while the multiple heat-conducting components in different heat-conducting component groups have different thermal conductivity.

[0030] This application also discloses a display panel, including a driving backplane and multiple chips, wherein the multiple chips are connected to the driving backplane through the chip transfer method described above.

[0031] This application improves upon traditional chip transfer methods by bonding a growth substrate to a transient substrate, thereby fixing the chips arrayed on the growth substrate to the arrayed pyrolytic adhesive blocks on the transient substrate. The growth substrate is then peeled off, leaving the chips on the pyrolytic adhesive blocks of the transient substrate. A transfer substrate is then connected to the arrayed chips from the side furthest from the transient substrate, facilitating the subsequent pickup of chips detached from the pyrolytic adhesive blocks on the transient substrate. During the transfer of chips from the pyrolytic adhesive blocks to the driving backplane, the transient substrate is first heated until one group of pyrolytic adhesive blocks on the transient substrate is completely debonded. This allows the chips, originally fixed to the pyrolytic adhesive blocks, to be "released" after the pyrolytic adhesive blocks are completely debonded. This allows the transfer substrate to pick up multiple "released" chips and transfer them to the driving backplane. Other locations on the transient substrate, where the pyrolysis adhesive is not yet fully detached, cannot be picked up by the transfer substrate. Since the spacing between the pyrolysis adhesive blocks within each pyrolysis adhesive group matches the target pixel spacing, the spacing between the chips connected to the pyrolysis adhesive blocks in each group also matches the target pixel spacing. This ensures that the chips transferred to the driving backplane accurately correspond to the target pixel positions, achieving accurate chip transfer. After the first transfer, the transient substrate is heated again to completely detach the next batch of partially detached pyrolysis adhesive groups, which are then transferred to the driving backplane in the same way. This process of connecting, debonding, and transferring is repeated n times until all chips are transferred to the driving backplane. This achieves selective chip transfer while saving on the cost of releasing chips at specific locations. Attached Figure Description

[0032] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They serve to demonstrate implementation methods of this application and, together with the textual description, explain the principles of this application. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort. In the drawings:

[0033] Figure 1 This is a step diagram of the first embodiment of the chip transfer method of this application;

[0034] Figure 2 This diagram illustrates the steps of unbinding the pyrolytic adhesive assembly and transferring the chip in the first embodiment of the chip transfer method of this application.

[0035] Figure 3 This is a schematic diagram showing the alignment of the growth substrate and the driving backplane in the first embodiment of the chip transfer method of this application;

[0036] Figure 4 This is a schematic diagram of the formation of a pyrolytic adhesive layer on a transient substrate in the first embodiment of the chip transfer method of this application;

[0037] Figure 5 This is a schematic diagram of the chip transfer method of this application after the pyrolytic adhesive layer is cut into pyrolytic adhesive blocks;

[0038] Figure 6 This is a schematic diagram illustrating the transfer of a chip from a growth substrate to a transient substrate in the first embodiment of the chip transfer method of this application.

[0039] Figure 7 This is a schematic diagram of the chip transfer method of this application after the growth substrate has been peeled off;

[0040] Figure 8 This is a schematic diagram showing the connection between the transfer substrate and the transient substrate in the first embodiment of the chip transfer method of this application;

[0041] Figure 9 This is a schematic diagram of the transfer substrate picking up the chip in the first embodiment of the chip transfer method of this application;

[0042] Figure 10 This is a schematic diagram of a transfer substrate transferring a chip to a driving substrate in the first embodiment of the chip transfer method of this application;

[0043] Figure 11 This is a schematic diagram of the transient substrate in the second embodiment of the chip transfer method of this application;

[0044] Figure 12 This is a schematic diagram of the transient substrate in the third embodiment of the chip transfer method of this application;

[0045] Figure 13 This is a step diagram illustrating the process of fixing the chip to the pyrolysis adhesive block in the fourth embodiment of the chip transfer method of this application;

[0046] Figure 14 This is a schematic diagram of chip insertion into a pyrolytic adhesive layer in the fourth embodiment of the chip transfer method of this application;

[0047] Figure 15 This is a schematic diagram of the pyrolytic adhesive block after being formed in the fourth embodiment of the chip transfer method of this application;

[0048] Figure 16 This is a schematic diagram of an embodiment of the transient substrate of this application;

[0049] Figure 17 This is a schematic diagram of one embodiment of the display panel of this application.

[0050] Among them, 10 is a display panel; 100 is a growth substrate; 110 is a chip; 200 is a transient substrate; 210 is a pyrolytic adhesive layer; 211 is a pyrolytic adhesive block; 212 is a pyrolytic adhesive group; 220 is a first substrate; 230 is a second substrate; 240 is a thermally conductive component; 250 is a thermally conductive component group; 300 is a transfer substrate; 310 is an adhesive layer; 400 is a driving backplate; and 410 is a pixel. Detailed Implementation

[0051] Figure 1 This is a step diagram of the first embodiment of the chip transfer method of this application. Figure 2 This diagram illustrates the steps of unbinding the pyrolytic adhesive assembly and transferring the chip in the first embodiment of the chip transfer method of this application. Figure 3 This is a schematic diagram showing the alignment of the growth substrate and the driving backplane in the first embodiment of the chip transfer method of this application; Figure 4 This is a schematic diagram of the formation of a pyrolytic adhesive layer on a transient substrate in the first embodiment of the chip transfer method of this application; Figure 5 This is a schematic diagram of the chip transfer method of this application after the pyrolytic adhesive layer is cut into pyrolytic adhesive blocks; Figure 6 This is a schematic diagram illustrating the transfer of a chip from a growth substrate to a transient substrate in the first embodiment of the chip transfer method of this application. Figure 7 This is a schematic diagram of the chip transfer method of this application after the growth substrate has been peeled off; Figure 8 This is a schematic diagram showing the connection between the transfer substrate and the transient substrate in the first embodiment of the chip transfer method of this application; Figure 9 This is a schematic diagram of the transfer substrate picking up the chip in the first embodiment of the chip transfer method of this application; Figure 10 This is a schematic diagram of a transfer substrate transferring a chip to a driving substrate in the first embodiment of the chip transfer method of this application;

[0052] like Figures 1 to 10 As shown in the figure, this application discloses a chip 110 transfer method, which includes the following steps:

[0053] S1: Fixing step: A growth substrate 100 is attached to a transient substrate 200 so that the chips 110 arranged in an array on the growth substrate 100 and the pyrolytic adhesive blocks 211 arranged in an array on the transient substrate 200 are fixed one by one.

[0054] S2: Stripping step: Strip the growth substrate 100 so that the chip 110 remains on the transient substrate 200;

[0055] S3: Connection step: Connect the transfer substrate 300 to the arrayed chips 110 from the side away from the transient substrate 200;

[0056] S4: Debonding step: Heat one of the pyrolytic adhesive blocks 211 groups on the transient substrate 200 and completely debond it, so that the chip 110 corresponding to the pyrolytic adhesive block 211 group is detached from the transient substrate 200 and transferred to the transfer substrate 300.

[0057] S5: Transfer step: Provide a driving backplane 400 to transfer the chip 110 on the transfer substrate 300 to the driving backplane 400;

[0058] Return to connection step S3, and repeat connection step S3, de-adhesion step S4 and transfer step S5 n times to complete the transfer of chips 110 corresponding to n pyrolysis adhesive blocks 211 groups, so as to transfer all chips 110 to the drive backplane 400 in batches.

[0059] The array of pyrolytic adhesive blocks 211 is divided into multiple groups of pyrolytic adhesive blocks 211, and each group of pyrolytic adhesive blocks 211 includes multiple pyrolytic adhesive blocks 211. The spacing between the multiple pyrolytic adhesive blocks 211 matches the spacing between the target pixels 410; n is an integer greater than or equal to 2.

[0060] This application improves upon the conventional chip 110 transfer method by bonding the growth substrate 100 to the transient substrate 200, thereby fixing the arrayed chips 110 on the growth substrate 100 to the arrayed pyrolytic adhesive blocks 211 on the transient substrate 200. Then, the growth substrate 100 is peeled off, leaving the chips 110 on the pyrolytic adhesive blocks 211 of the transient substrate 200. Finally, the transfer substrate 300 is connected to the arrayed chips 110 from the side furthest from the transient substrate 200, facilitating the transfer process. The substrate 300 picks up the chips 110 that subsequently detach from the pyrolytic adhesive blocks 211 on the transient substrate 200. During the transfer of the chips 110 from the pyrolytic adhesive blocks 211 to the drive backplane 400, the transient substrate 200 is first heated, causing one group of pyrolytic adhesive blocks 211 on the transient substrate 200 to completely de-adhere. This allows the multiple chips 110 originally fixed to the pyrolytic adhesive blocks 211 to be "loosened" after the pyrolytic adhesive blocks 211 are completely de-adheded. The transfer substrate 300 is in an "open" state, allowing it to pick up the multiple "released" chips 110 and transfer them to the driving backplane 400. Other locations on the transient substrate 200 cannot be picked up by the transfer substrate 300 because the pyrolysis adhesive blocks 211 are not completely detached. Furthermore, since the spacing between the pyrolysis adhesive blocks 211 within each group matches the spacing of the target pixels 410, the spacing of the chips 110 connected to the pyrolysis adhesive blocks 211 within each group also matches the spacing of the target pixels 410. The pixel spacing of the 410 pixels is matched, allowing the chip 110 transferred to the driving backplane 400 to accurately correspond to the target pixel 410 position, thus achieving accurate transfer of the chip 110. After the first transfer is completed, the transient substrate 200 is heated again to completely de-adhere the next batch of incompletely debonded thermal adhesive blocks 211, which are then transferred to the driving backplane 400 in the same way. By repeating the connection step, debonding step, and transfer step n times in the above manner, all chips 110 are transferred to the driving backplane 400. In this way, selective transfer of chips 110 can be achieved while saving the release cost of chips 110 at specific positions.

[0061] The array of pyrolytic adhesive blocks 211 is divided into multiple groups of pyrolytic adhesive blocks 211, and each group of pyrolytic adhesive blocks 211 includes multiple pyrolytic adhesive blocks 211. The spacing between the multiple pyrolytic adhesive blocks 211 matches the spacing between the target pixels 410; n is an integer greater than or equal to 2.

[0062] It should be noted that, in this embodiment, the target pixel 410 can be understood as a pixel 410 pre-set on the driving backplane 400 according to preset resolution, clarity, and other specifications; the spacing between the multiple pyrolytic adhesive blocks 211 in each pyrolytic adhesive group 212 matches the spacing between the target pixels 410, which can be understood as: the spacing between two adjacent pyrolytic adhesive blocks 211 is equal to the spacing between two adjacent target pixels 410, or the spacing between two adjacent pyrolytic adhesive blocks 211 is equal to the spacing between one or more pixels 410, for example; when adjacent The spacing between two pyrolysis adhesive blocks 211 is equal to the spacing between the first and third pixels 410 in three consecutive pixels 410. That is, as long as the multiple pyrolysis adhesive blocks 211 in each pyrolysis adhesive group 212 are aligned with the positions of the pixels 410 on the driving backplate 400, it can be guaranteed that the chips 110 on the corresponding multiple pyrolysis adhesive blocks 211 can be transferred to the driving backplate 400 and correspond to the positions of the multiple target pixels 410. It is not required that the spacing between two adjacent pyrolysis adhesive blocks 211 must be equal to the spacing between two adjacent pixels 410.

[0063] Since more chips 110 need to be fabricated on the growth substrate 100, the spacing between chips 110 on the growth substrate 100 should be as small as possible. Therefore, the spacing between multiple chips 110 cannot be equal to the spacing between multiple pixels 410 on the driving backplane 400. Therefore, the number of transfers n is at least two. It takes at least two transfers to transfer all the chips 110 to the driving backplane 400.

[0064] Specifically, the same-side edge spacing between two adjacent pixels 410 on the driving backplane 400 is N times the same-side edge spacing between two adjacent chips 110 on the growth substrate 100, and the number of cycles n is equal to N times, where N is an integer and N≥2.

[0065] In the manufacturing process of a Micro LED panel, the required chips 110 are fabricated as densely as possible on the growth substrate 100 to minimize the edge spacing A between adjacent chips 110 on the same side. However, the edge spacing B between adjacent pixels 410 on the same side on the driving backplane 400 is determined by the resolution and display size and is often greater than A. To facilitate transfer, B is generally an integer multiple of A, i.e., N times. In reality, the number of transfers required is the same as the multiple of the spacing between the two. Thus, the number of transfers can be determined by the multiple of the spacing, thereby improving transfer efficiency.

[0066] Specifically, the S4 debonding step: heating and completely debonding one of the pyrolytic adhesive blocks 211 groups on the transient substrate 200, so that the chip 110 corresponding to the pyrolytic adhesive block 211 group is detached from the transient substrate 200 and transferred to the transfer substrate 300, also includes the following steps;

[0067] S41: Heat the transient substrate 200, and sequentially and completely de-adhere the n pyrolysis adhesive blocks 211 groups corresponding to the multiple heat-conducting components 240 in order of decreasing thermal conductivity, so that the chips 110 corresponding to the n pyrolysis adhesive blocks 211 groups are separated from the transient substrate 200 in batches.

[0068] S42: The chips 110 that are detached in batches are sequentially transferred to the transfer substrate 300;

[0069] The transient substrate 200 includes a first substrate 220, a second substrate 230 and a plurality of heat-conducting components 240. The first substrate 220 and the second substrate 230 are disposed in a box, and the plurality of heat-conducting components 240 are arranged in an array between the first substrate 220 and the second substrate 230.

[0070] Multiple heat-conducting components 240 are divided into n heat-conducting component groups 250. The heat-conducting components 240 in each heat-conducting component group 250 have the same heat conduction performance, while the heat-conducting components 240 in different heat-conducting component groups 250 have different heat conduction performance.

[0071] In this embodiment, a transient substrate 200 is prepared. The transient substrate 200 has two layers, namely a first substrate 220 and a second substrate 230. The materials can be glass, quartz, sapphire, etc. A pyrolytic adhesive material is coated on the first substrate 220 and cured to form a pyrolytic adhesive layer 210. Then, by photolithography and etching, the pyrolytic adhesive layer 210 is separated from the position where the subsequent chip 110 is transferred to form a pyrolytic adhesive block 211. This can effectively avoid the thermal conductivity influence between the pyrolytic adhesive blocks 211 under the two adjacent chips 110 after the chips 110 are transferred to the transient substrate 200.

[0072] According to the existing method, the chip 110 on the growth substrate 100 is transferred to the pyrolytic adhesive block 211 of the transient substrate 200 by means of LLO (laser lift-off), each chip 110 is fixed by each pyrolytic adhesive block 211, and the growth substrate 100 is peeled off from the chip 110.

[0073] During the transfer process, a transfer substrate 300 is first attached to multiple chips 110 to facilitate the subsequent picking up and transfer of any chips 110 that have become "loose".

[0074] In this embodiment of the application, the transient substrate 200 is improved by forming a plurality of spaced heat-conducting elements 240 between the first substrate 220 and the second substrate 230, and the plurality of heat-conducting elements 240 are correspondingly disposed below the plurality of pyrolytic adhesive blocks 211.

[0075] Multiple thermal conductive elements 240 are divided into multiple thermal conductive element groups 250. Each thermal conductive element group 250 corresponds to a pyrolytic adhesive group 212. The multiple thermal conductive elements 240 in each thermal conductive element group 250 have the same thermal conductivity, while the multiple thermal conductive elements 240 in different thermal conductive element groups 250 have different thermal conductivity.

[0076] The second substrate 230 is heated (e.g., using a heating plate), and the heat is transferred to the first substrate 220 through multiple heat-conducting elements 240, and then further transferred to the pyrolytic adhesive block 211, causing the pyrolytic adhesive block 211 to be heated and thus producing a change in viscosity.

[0077] When n equals 3, that is, 3 transfers are required, the thermal conductivity of the multiple thermal conductive components 240 should be sorted from high to low into three groups: the best thermal conductivity, the medium thermal conductivity, and the worst thermal conductivity. These three groups of thermal conductive components 250 with different thermal conductivity correspond to three different groups of pyrolytic adhesive 212. In these three different groups of pyrolytic adhesive 212, each pyrolytic adhesive block 211 has a chip 110 fixed on it. The three groups of pyrolytic adhesive 212 fix all the chips 110.

[0078] At this time, due to the different thermal conductivity of the different thermal conductive components 250 corresponding to different pyrolytic adhesive groups 212, the heating of different positions of the first substrate 220 is different, resulting in different decomposition degrees of the pyrolytic adhesive blocks 211 in different pyrolytic adhesive groups 212. The pyrolytic adhesive blocks 211 in the pyrolytic adhesive group 212 with the best thermal conductivity are completely debonded first, and then the heating is stopped. The chip 110 on the completely debonded pyrolytic adhesive block 211 is picked up by the transfer substrate 300 and transferred to the driving backplane 400.

[0079] Then, following the existing method, the electrodes on the chip 110 are fixed by the Sn / In metal at the die-bonding point of the drive backplate 400, thereby bonding the chip 110 on the transfer substrate 300 to the drive backplate 400 and completing the first transfer.

[0080] Repeat the above steps, heat the second substrate 230 again to completely debond the pyrolytic adhesive in the medium thermal conductivity area, and then transfer it to the drive backplate 400 in the same way to complete the second transfer.

[0081] Repeat the above steps, heat the second substrate 230 again to completely debond the thermally conductive adhesive at the worst location, pick it up and transfer it to the drive backplate 400 in the same way, and complete the third transfer.

[0082] This process involves sequentially and completely unbinding the n pyrolytic adhesive blocks 211 groups corresponding to multiple thermally conductive components 240 in descending order of thermal conductivity. This allows the chips 110 corresponding to the n pyrolytic adhesive blocks 211 groups to be detached from the transient substrate 200 in batches, thereby completing the transfer of all performance. This achieves selective transfer of the chips 110 while saving the cost of releasing the chips 110 at specific locations.

[0083] It is important to understand that the number of thermal conductive component groups 250 with different thermal conductivity levels is the same as the number of transfers n. That is, if n transfers are required, n different thermal conductive component groups 250 with different thermal conductivity levels need to be prepared for the transfers. Taking 3 transfers as an example, there are 3 corresponding thermal conductive component groups 250 with the best, medium and worst thermal conductivity. This application only uses n equal to 3 as an example. In fact, depending on the manufacturing requirements of the display panel 10, the number of transfers may not necessarily be 3. The number of transfers can also be adjusted according to the actual situation.

[0084] Furthermore, all the heat-conducting components 240 are made of the same material, and among the multiple heat-conducting components 240, the cross-sectional area of ​​the multiple heat-conducting components 240 decreases sequentially from high to low thermal conductivity.

[0085] In this embodiment, the materials of the multiple heat-conducting elements 240 are all the same, so that the thermal conductivity of the multiple heat-conducting elements 240 is the same. In order to ensure that the thermal conductivity of the different heat-conducting element groups 250 are different, this embodiment changes the cross-sectional area of ​​the heat-conducting elements 240 in the different heat-conducting element groups 250, so that the contact area between the heat-conducting elements 240 in the different heat-conducting element groups 250 and the first substrate 220 is different, thereby obtaining different thermal conductivity effects.

[0086] Taking the requirement of three transfers as an example, the multiple heat-conducting components 240 are divided into three groups of heat-conducting components 250. The cross-sectional areas of the heat-conducting components 240 in the three groups of heat-conducting components 250 are the largest, medium, and smallest, respectively, thus corresponding to the highest, medium, and worst thermal conductivity. In this embodiment, by controlling the cross-sectional area of ​​the heat-conducting components 240, the thermal conductivity of the heat-conducting components 240 in different groups of heat-conducting components 250 is made different, thereby achieving different degrees of heating effect on different pyrolytic adhesive groups 212, so as to achieve complete debonding of different pyrolytic adhesive groups 212 in batches, and provide a guarantee for subsequent successful transfer.

[0087] Furthermore, the shape of the heat-conducting element 240 can be columnar, cuboid, etc., and this application does not limit the specific shape of the heat-conducting element 240.

[0088] In this embodiment, an adhesive layer 310 is provided on the side of the transfer substrate 300 near the chip 110. The adhesive layer 310 is used to attach the chip 110, and the adhesive force of the adhesive layer 310 is less than the adhesive force when the pyrolytic adhesive block 211 is not completely debonded, and greater than the adhesive force when the pyrolytic adhesive block 211 is completely debonded.

[0089] The adhesive layer 310 can be made of PDMS (polydimethylsiloxane), a material with weak adhesion.

[0090] When transferring the chip 110 on the transient substrate 200 using the transfer substrate 300, since the adhesive force of the adhesive layer 310 is greater than the adhesive force when the pyrolytic adhesive block 211 is completely unbonded, the adhesive layer 310 on the transfer substrate 300 can be used to pick up the chip 110 on the pyrolytic adhesive block 211 that has been completely unbonded, thereby transferring the picked-up chip 110 to the driving backplane 400. However, since the adhesive force of the adhesive layer 310 is less than the adhesive force when the pyrolytic adhesive block 211 is not completely unbonded, the chip 110 is not completely unbonded. The chip 110 on the pyrolytic adhesive block 211 will not be picked up by the adhesive layer 310 on the transfer substrate 300, but will remain temporarily on the transient substrate 200 until the next transfer process. After the pyrolytic adhesive block 211, which was not completely debonded in the previous transfer, is completely debonded, the chip 110 on it will be picked up by the adhesive layer 310 on the transfer substrate 300. This is beneficial for transferring multiple chips 110 to the driving backplane 400 in batches according to specific positions, which can improve the manufacturing efficiency and save costs.

[0091] Figure 11 This is a schematic diagram of the transient substrate in the second embodiment of the chip transfer method of this application, as shown below. Figure 11 As shown, the multiple heat-conducting components 240 are made of different materials, and among the multiple heat-conducting components 240, the thermal conductivity of the multiple heat-conducting components 240 decreases sequentially from high to low.

[0092] The difference between this embodiment and the previous embodiment is that, in order to achieve different thermal conductivity of the thermal conductive elements 240 in different thermal conductive element groups 250, different materials are used to make the thermal conductive elements 240 in different thermal conductive element groups 250.

[0093] For example, taking the requirement of three transfers as an example, the multiple heat-conducting components 240 are divided into three groups of heat-conducting components 250. The materials of the heat-conducting components 240 in the three groups of heat-conducting components 250 are Ag, Cu, and Al, respectively. That is, the heat-conducting components 240 with the best thermal conductivity are made of metal Ag, the medium thermal conductivity is made of metal Cu, and the worst thermal conductivity is made of metal Al. Thus, the corresponding thermal conductivity is the highest, medium, and worst. In this embodiment, by controlling the material of the heat-conducting components 240, the thermal conductivity of the heat-conducting components 240 in different groups of heat-conducting components 250 is different, thereby achieving different degrees of heating effect on different pyrolytic adhesive groups 212, so as to achieve complete debonding of different pyrolytic adhesive groups 212 in batches, and provide a guarantee for subsequent successful transfer.

[0094] In addition, thermally conductive materials can also include thermally conductive graphite, etc. This application only uses the thermally conductive component 240 made of thermally conductive metal material as an example.

[0095] Figure 12 This is a schematic diagram of the transient substrate in the third embodiment of the chip transfer method of this application, as shown below. Figure 12 As shown, the multiple heat-conducting elements 240 are made of the same material, and among the multiple heat-conducting elements 240, the spacing between the multiple heat-conducting elements 240 with thermal conductivity decreasing from high to low gradually increases with the first substrate 220.

[0096] The difference between this embodiment and the previous embodiment is that, in order to achieve different thermal conductivity of the thermal conductive elements 240 in different thermal conductive element groups 250, when using thermal conductive elements 240 of the same material and the same thermal conductivity, the distance between the thermal conductive elements 240 in different thermal conductive element groups 250 and the first substrate 220 is controlled so that different thermal conductive element groups 250 produce different thermal conductivity effects.

[0097] For example, taking the requirement of three transfers as an example, the multiple heat-conducting components 240 are divided into three groups of heat-conducting components 250. The heat-conducting components 240 in the three groups of heat-conducting components 250 are made of the same material, but the distance between the heat-conducting components 240 in the three groups of heat-conducting components 250 and the first substrate 220 is respectively the closest (can be directly abutting the first substrate 220), medium, and farthest, thus corresponding to the highest, medium, and worst thermal conductivity. That is, this embodiment achieves different thermal conductivity of the heat-conducting components 240 in different groups of heat-conducting components 250 by controlling the distance between the heat-conducting components 240 of the same material and the first substrate 220, thereby achieving different degrees of heating effect on different pyrolytic adhesive groups 212, so as to achieve complete debonding of different pyrolytic adhesive groups 212 in batches, and provide a guarantee for subsequent successful transfer.

[0098] Of course, in order to improve the support for the first substrate 220, a shim 260 made of the same material as the first substrate 220 (such as organic PI) can be added above the heat-conducting component 240 that has a gap with the first substrate 220 to raise it, thereby keeping the contact ends of multiple heat-conducting components 240 with different gaps at the same height with the first substrate 220, thereby providing better support and enhancing the structural stability of the transient substrate 200.

[0099] In addition, one or more of the methods of changing the thermal conductivity of the heat-conducting component 240 with different cross-sectional areas, different materials, and different distances from the first substrate 220 can be combined to form different thermal conductivity and further enhance the difference in thermal conductivity. For example, the heat-conducting component 240 made of Ag has the largest cross-sectional area and is closest to the first substrate 220; the heat-conducting component 240 made of Cu has a medium cross-sectional area and is at a medium distance from the first substrate 220; and the heat-conducting component 240 made of Al has the smallest cross-sectional area and is farthest from the first substrate 220. This further amplifies the difference in thermal conductivity between the three different types of heat-conducting components 240 and improves process reliability.

[0100] Figure 13 This diagram illustrates the steps of fixing the chip to the pyrolysis adhesive block in the fourth embodiment of the chip transfer method of this application. Figure 14 This is a schematic diagram of chip insertion into a pyrolytic adhesive layer in the fourth embodiment of the chip transfer method of this application; Figure 15 This is a schematic diagram of the pyrolytic adhesive block after being formed in the fourth embodiment of the chip transfer method of this application;

[0101] like Figures 13 to 15 As shown, S1: Fixing step: The step of bonding a growth substrate 100 with a transient substrate 200 so that the chips 110 arranged in an array on the growth substrate 100 and the pyrolytic adhesive blocks 211 arranged in an array on the transient substrate 200 are respectively fixed includes:

[0102] S11: Pyrolytic adhesive block 211 material is laid on transient substrate 200 and cured to form pyrolytic adhesive block 211 layer;

[0103] S12: Connect the multiple chips 110 on the growth substrate 100 to the pyrolysis adhesive block 211 layer;

[0104] S13: Perform plasma etching on a portion of the pyrolytic adhesive block 211 layer between two adjacent chips 110 to remove the portion of the pyrolytic adhesive block 211 layer not covered by the chip 110, forming the pyrolytic adhesive block 211.

[0105] The difference between this embodiment and the above embodiment is that this embodiment improves the fixing step. Specifically, in the step of fixing the chips 110 arranged in an array on the growth substrate 100 to the pyrolytic adhesive blocks 211 arranged in an array on the transient substrate 200:

[0106] First, a pyrolytic adhesive block 211 material is laid on the transient substrate 200 and cured in a conventional manner to form a pyrolytic adhesive block 211 layer. Then, instead of photolithography and etching the pyrolytic adhesive block 211 layer to form the pyrolytic adhesive block 211, the chip 110 on the growth substrate 100 is directly connected to the pyrolytic adhesive block 211 layer.

[0107] After multiple chips 110 are transferred to the pyrolytic adhesive block 211 layer of the transient substrate 200, the pyrolytic adhesive block 211 layer on the transient substrate 200 is then divided according to the spacing between two adjacent chips 110. Plasma etching can be used, for example, etching with oxygen or carbon tetrachloride. These gases will not etch the chips 110, but will etch the organic pyrolytic adhesive block 211 material, thereby etching away the part of the pyrolytic adhesive block 211 layer that is not covered by the chips 110. The pyrolytic adhesive block 211 layer located under the chips 110 is divided into individual pyrolytic adhesive blocks 211, thus forming each individual pyrolytic adhesive block 211 connected and fixed to each individual chip 110. In this way, it is not necessary to perform photolithography and etching on the entire pyrolytic adhesive block 211 layer before forming the pyrolytic adhesive block 211, thus saving one photolithography process and helping to save manufacturing costs.

[0108] Figure 16 This is a schematic diagram of an embodiment of the transient substrate of this application, as shown below. Figure 16 As shown, this application embodiment also discloses a transient substrate 200, which is applied in the chip 110 transfer method described above;

[0109] The transient substrate 200 includes a first substrate 220, a second substrate 230 and a plurality of heat-conducting components 240. The first substrate 220 and the second substrate 230 are disposed opposite each other, and the plurality of heat-conducting components 240 are arranged in an array between the first substrate 220 and the second substrate 230.

[0110] Multiple heat-conducting components 240 are divided into n heat-conducting component groups 250. The heat conduction performance of multiple heat-conducting components 240 in each heat-conducting component group 250 is the same, while the heat conduction performance of multiple heat-conducting components 240 in different heat-conducting component groups 250 is different.

[0111] In this embodiment, the transient substrate 200 is improved by forming a plurality of spaced heat-conducting elements 240 between the first substrate 220 and the second substrate 230, and the plurality of heat-conducting elements 240 are correspondingly disposed below the plurality of pyrolytic adhesive blocks 211.

[0112] Multiple thermal conductive elements 240 are divided into multiple thermal conductive element groups 250. Each thermal conductive element group 250 corresponds to a pyrolytic adhesive group 212. The multiple thermal conductive elements 240 in each thermal conductive element group 250 have the same thermal conductivity, while the multiple thermal conductive elements 240 in different thermal conductive element groups 250 have different thermal conductivity.

[0113] The second substrate 230 is heated (e.g., using a heating plate), and the heat is transferred to the first substrate 220 through multiple heat-conducting elements 240, and then further transferred to the pyrolytic adhesive block 211, causing the pyrolytic adhesive block 211 to be heated and thus producing a change in viscosity.

[0114] When n equals 3, that is, 3 transfers are required, the thermal conductivity of the multiple thermal conductive components 240 should be sorted from high to low into three groups: the best thermal conductivity, the medium thermal conductivity, and the worst thermal conductivity. These three groups of thermal conductive components 250 with different thermal conductivity correspond to three different groups of pyrolytic adhesive 212. In these three different groups of pyrolytic adhesive 212, each pyrolytic adhesive block 211 has a chip 110 fixed on it. The three groups of pyrolytic adhesive 212 fix all the chips 110.

[0115] At this time, due to the different thermal conductivity of the different thermal conductive components 250 corresponding to different pyrolytic adhesive groups 212, the heating of different positions of the first substrate 220 is different, resulting in different decomposition degrees of the pyrolytic adhesive blocks 211 in different pyrolytic adhesive groups 212. The pyrolytic adhesive blocks 211 in the pyrolytic adhesive group 212 with the best thermal conductivity are completely debonded first, and then the heating is stopped. The chip 110 on the completely debonded pyrolytic adhesive block 211 is picked up by the transfer substrate 300 and transferred to the driving backplane 400.

[0116] Figure 17 This is a schematic diagram of one embodiment of the display panel of this application, as shown below. Figure 17 As shown in the illustration, this application also discloses a display panel 10, including a driving backplane 400 and a plurality of chips 110. The plurality of chips 110 are connected to the driving backplane 400 by the chip 110 transfer method described above. Mounting the plurality of chips 110 onto the driving backplane 400 using the chip 110 transfer method can, on the one hand, improve the speed of chip 110 mounting and accelerate the fabrication efficiency of the display panel 10; on the other hand, it can be used for the normal light emission of the display panel 10.

[0117] The display panel 10 in this application is mainly aimed at Micro LED (micro light-emitting diode) display panel 10, which has a high-density integrated LED array. The distance between the LED chips 110 in the array is generally on the order of micrometers, and each LED chip 110 can emit light on its own.

[0118] In contrast, when transferring multiple chips 110 to the driver backplane 400 using the chip 110 transfer method, traditional Micro LED display panels 10 employ laser equipment for transfer, which is costly.

[0119] Based on the aforementioned problems, this application improves the chip 110 transfer method in the display panel 10. By bonding the growth substrate 100 to the transient substrate 200, the chips 110 arranged in an array on the growth substrate 100 are fixed one-to-one with the pyrolytic adhesive blocks 211 arranged in an array on the transient substrate 200. Then, the growth substrate 100 is peeled off, leaving the chips 110 on the pyrolytic adhesive blocks 211 of the transient substrate 200. Finally, the transfer substrate 300 is moved from the side away from the transient substrate 200 to the side with the arrayed chips... The 110 connection facilitates the use of the transfer substrate 300 to pick up the chips 110 that have subsequently detached from the pyrolytic adhesive blocks 211 on the transient substrate 200. During the transfer of the chips 110 from the pyrolytic adhesive blocks 211 to the drive backplane 400, the transient substrate 200 is first heated, causing one group of pyrolytic adhesive blocks 211 on the transient substrate 200 to completely de-adhere. This allows the multiple chips 110 originally fixed to the pyrolytic adhesive blocks 211 to be released from their original state after the pyrolytic adhesive blocks 211 are completely de-adheded. The transfer substrate 300 can pick up the multiple "released" chips 110 from the fixed state and transfer them to the driving backplane 400. Other locations on the transient substrate 200 cannot be picked up by the transfer substrate 300 because the pyrolysis adhesive blocks 211 are not completely detached. Since the spacing between the pyrolysis adhesive blocks 211 in each group matches the spacing of the target pixels 410, the spacing between the chips 110 connected to the pyrolysis adhesive blocks 211 in each group also matches. The spacing of the chips 110 is matched with that of the target pixels 410, so that the chips 110 transferred to the driving backplate 400 can accurately correspond to the positions of the target pixels 410, achieving accurate transfer of the chips 110. After the first transfer is completed, the transient substrate 200 is heated again, so that the next batch of incompletely debonded thermal adhesive blocks 211 are completely debonded, and then transferred to the driving backplate 400 in the same way. By repeating the connection step, debonding step and transfer step n times in the above manner, until all chips 110 are transferred to the driving backplate 400. In this way, the selective transfer of chips 110 can be achieved while saving the release cost of chips 110 at specific positions, thereby improving the manufacturing efficiency of the display panel 10 and saving the cost of the display panel 10.

[0120] It should be noted that the inventive concept of this application can form many embodiments, but due to the limited space of the application documents, they cannot all be listed. Therefore, without conflict, the embodiments described above or the technical features can be arbitrarily combined to form new embodiments. After the embodiments or technical features are combined, the original technical effect will be enhanced.

[0121] The above description, in conjunction with specific optional embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of this application, and all such modifications or substitutions should be considered within the scope of protection of this application.

Claims

1. A chip transfer method characterized by, The chip transfer method comprises the steps of: a fixing step: a growth substrate is attached to a temporary substrate, so that the chips arranged in an array on the growth substrate are fixed to the pyrolytic glue blocks arranged in an array on the temporary substrate one by one; a peeling step: the growth substrate is peeled off, so that the chips remain on the temporary substrate; a connecting step: a transfer substrate is connected to the chips arranged in an array from a side away from the temporary substrate; a debonding step: one of the pyrolytic glue groups on the temporary substrate is heated and completely debonded, so that the chips corresponding to the pyrolytic glue group are transferred from the temporary substrate to the transfer substrate; a transferring step: a driving backplane is provided, and the chips on the transfer substrate are transferred to the driving backplane; returning to the connecting step, the connecting step, the debonding step and the transferring step are cyclically executed n times, the transfer of the chips corresponding to n pyrolytic glue groups is completed, and all the chips are transferred to the driving backplane in batches; wherein the pyrolytic glue blocks arranged in an array are divided into a plurality of pyrolytic glue groups, each pyrolytic glue group includes a plurality of pyrolytic glue blocks, and the spacing between the plurality of pyrolytic glue blocks matches the spacing between target pixels; n is an integer greater than or equal to 2; the debonding step: heating and completely debonding one of the pyrolytic glue groups on the temporary substrate, so that the chips corresponding to the pyrolytic glue group are transferred from the temporary substrate to the transfer substrate, further comprises: heating the temporary substrate, and sequentially completely debonding n pyrolytic glue groups corresponding to a plurality of heat conduction members in order from high to low in terms of heat conduction performance, so that the chips corresponding to the n pyrolytic glue groups are sequentially and batchwise separated from the temporary substrate; sequentially transferring the batchwise separated chips to the transfer substrate; wherein the temporary substrate comprises a first substrate, a second substrate and a plurality of heat conduction members, the first substrate and the second substrate are arranged in a box, and the plurality of heat conduction members are arranged in an array between the first substrate and the second substrate; the plurality of heat conduction members are divided into n heat conduction member groups, the plurality of heat conduction members in each heat conduction member group have the same heat conduction performance, and the plurality of heat conduction members in different heat conduction member groups have different heat conduction performances.

2. The chip transfer method according to claim 1, wherein The materials of the plurality of heat conduction members are the same, and the cross-sectional areas of the plurality of heat conduction members with high to low heat conduction performance gradually decrease in the plurality of heat conduction members.

3. The chip transfer method according to claim 1, wherein The materials of the plurality of heat conduction members are different, and the thermal conductivities of the plurality of heat conduction members with high to low heat conduction performance gradually decrease in the plurality of heat conduction members.

4. The chip transfer method according to claim 1, wherein The materials of the plurality of heat conduction members are the same, and the spacing between the plurality of heat conduction members with high to low heat conduction performance and the first substrate gradually increases in the plurality of heat conduction members.

5. The chip transfer method according to claim 1, wherein The same side edge spacing between two adjacent pixels on the driving backplane is N times the same side edge spacing between two adjacent chips on the growth substrate, and in the cyclic execution of the connecting step, the debonding step and the transferring step n times, n is equal to N times, wherein N is an integer and N≥2.

6. The chip transfer method according to claim 5, wherein The transfer substrate is provided with an adhesive layer on the side close to the chip, the adhesive layer is used to attach the chip, and the adhesive force of the adhesive layer is less than the adhesive force when the pyrolytic glue block is not completely debonded and greater than the adhesive force when the pyrolytic glue block is completely debonded.

7. The chip transfer method according to claim 6, wherein The fixing step: a growth substrate is attached to the temporary substrate, so that the array of chips on the growth substrate is fixed to the array of pyrolytic glue blocks on the temporary substrate, respectively, including: Laying a pyrolytic glue material on the temporary substrate and curing to form a pyrolytic glue layer; Connecting the plurality of chips on the growth substrate to the pyrolytic glue layer; Plasma etching part of the pyrolytic glue layer between two adjacent chips to remove the part of the pyrolytic glue layer not blocked by the chip, forming the pyrolytic glue block.

8. A transient substrate, characterized in that, The temporary substrate is applied to the chip transfer method of any one of claims 1 to 7; The temporary substrate includes a first substrate, a second substrate, and a plurality of heat-conducting elements, the first substrate and the second substrate are attached to each other, and the plurality of heat-conducting elements are arrayed between the first substrate and the second substrate; The plurality of heat-conducting elements are divided into n groups of heat-conducting elements, the plurality of heat-conducting elements in each group of heat-conducting elements have the same heat-conducting performance, and the plurality of heat-conducting elements in different groups of heat-conducting elements have different heat-conducting performances.

9. A display panel comprising a driving backplane and a plurality of chips, characterized in that, The plurality of chips are connected to the driving backboard by the chip transfer method of any one of claims 1 to 7.

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