CN117012768A - Chip assembly and preparation method thereof, and preparation method of display panel - Google Patents
Chip assembly and preparation method thereof, and preparation method of display panel Download PDFInfo
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- 238000012546 transfer Methods 0.000 abstract description 41
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- 229910052594 sapphire Inorganic materials 0.000 description 14
- 239000010980 sapphire Substances 0.000 description 14
- UMIVXZPTRXBADB-UHFFFAOYSA-N benzocyclobutene Chemical compound C1=CC=C2CCC2=C1 UMIVXZPTRXBADB-UHFFFAOYSA-N 0.000 description 13
- 239000000463 material Substances 0.000 description 11
- 238000010586 diagram Methods 0.000 description 7
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- 229910001218 Gallium arsenide Inorganic materials 0.000 description 6
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- 229910002601 GaN Inorganic materials 0.000 description 5
- JMASRVWKEDWRBT-UHFFFAOYSA-N Gallium nitride Chemical compound [Ga]#N JMASRVWKEDWRBT-UHFFFAOYSA-N 0.000 description 5
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Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L25/00—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof
- H01L25/03—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes
- H01L25/04—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes the devices not having separate containers
- H01L25/075—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes the devices not having separate containers the devices being of a type provided for in group H01L33/00
- H01L25/0753—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes the devices not having separate containers the devices being of a type provided for in group H01L33/00 the devices being arranged next to each other
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/15—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components having potential barriers, specially adapted for light emission
- H01L27/153—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components having potential barriers, specially adapted for light emission in a repetitive configuration, e.g. LED bars
- H01L27/156—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components having potential barriers, specially adapted for light emission in a repetitive configuration, e.g. LED bars two-dimensional arrays
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/005—Processes
- H01L33/0093—Wafer bonding; Removal of the growth substrate
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/005—Processes
- H01L33/0095—Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
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- Microelectronics & Electronic Packaging (AREA)
- Computer Hardware Design (AREA)
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- General Physics & Mathematics (AREA)
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Abstract
The application relates to a chip assembly, a preparation method thereof and a preparation method of a display panel. After the light emitting chip is bonded to the drive back plate, the connection between the carrier substrate and the light emitting chip can be released by simply breaking the weakened connection structure, and the transfer process of the light emitting chip from the carrier substrate to the drive back plate is completed. The transfer process is realized based on the weakened connection structure, so that the method is easy to realize, the damage to the light-emitting chip is low, and the transfer efficiency and yield of the light-emitting chip are improved.
Description
Technical Field
The application relates to the technical field of LEDs, in particular to a chip assembly, a preparation method of the chip assembly and a preparation method of a display panel.
Background
At present, red light, green light and blue light chips are not separated from each other in the LED high-definition display scheme. The LED chips with the three colors can be transferred to the driving backboard from the substrate after being prepared, the combination between the LED chips and the substrate needs to be released through laser in the transfer process, and the process is mature and simple for a blue light chip or a green light chip. However, for the red light chip, since the red light epitaxial layer is actually bonded to the substrate by BCB (benzocyclobutene) glue, the peeling of the substrate is actually to release the bonding of the red light LED chip to the substrate by laser decomposing the BCB glue layer. However, the absorption of the BCB adhesive to laser is poor, so that higher laser energy is often needed, the BCB adhesive is carbonized and decomposed by utilizing the physical impact action of laser, but the red light chip is easily damaged by the excessively high laser energy; if the laser energy is reduced to reduce the damage risk of the laser to the red light chip, the laser stripping process window of the red light chip is greatly reduced. Therefore, the existing process of transferring the red light chip to the driving backboard has the problems of high transfer difficulty and low transfer yield.
Therefore, how to reduce the difficulty of transferring the red light chip to the driving backboard and improve the transfer yield is a problem to be solved urgently.
Disclosure of Invention
In view of the shortcomings of the related art, the application aims to provide a chip assembly, a preparation method thereof and a preparation method of a display panel, and aims to solve the problems of high difficulty and low yield when a red light chip is transferred to a driving backboard at present.
The application provides a chip assembly, comprising:
a carrier substrate;
at least two light emitting chips on the carrier substrate; and
an adhesion layer and a space occupying sacrificial layer positioned between the bearing substrate and the light emitting chip;
the light emitting chip is provided with a driving backboard, a driving backboard and a bearing substrate, wherein one surface of the light emitting chip, which faces the driving backboard, is a near backboard surface, and the surface opposite to the near backboard surface is a far backboard surface; the adhesive layer simultaneously bonds the far back plate surface and the bearing substrate, and the contact area of the adhesive layer and the far back plate surface is smaller than the contact area of the adhesive layer and the bearing substrate; the occupation sacrificial layer is attached to the far back plate surface and comprises a first area in contact with the far back plate surface and a second area in a non-shielding state, and the first area is communicated with the second area.
In the chip assembly, at least two light emitting chips are adhered to the bearing substrate through the adhesive layer, a space occupying sacrificial layer is arranged between the light emitting chips and the bearing substrate, and the space occupying sacrificial layer is adhered to the far back plate surface of the light emitting chips. Because the occupation of the occupation sacrificial layer on the far back plate surface makes the adhesion layer impossible to adhere to the whole area of the far back plate surface of the light-emitting chip, the contact area between the adhesion layer and the light-emitting chip is reduced, and the adhesion capability of the adhesion layer to the light-emitting chip is also reduced. Meanwhile, because the occupied sacrificial layer comprises the first area contacted with the surface of the far backboard and the second area in the non-shielding state, when the occupied sacrificial layer is removed by wet etching, not only the second area in the non-shielding state in the occupied sacrificial layer can be removed, but also the first area can be removed because the first area is communicated with the second area. After the first area, which is in contact with the surface of the far back plate, in the space occupying sacrificial layer is removed, the adhesion layer forms a weakened connection structure between the bearing substrate and the light emitting chip. And because the contact area of the adhesive layer and the light-emitting chip is smaller than that of the adhesive layer and the bearing substrate, the combination between the adhesive layer and the bearing substrate is firmer than the combination between the adhesive layer and the light-emitting chip, so that after the connection between the bearing substrate and the light-emitting chip is destroyed, the adhesive layer is easier to fall off along with the bearing substrate. Therefore, after the light emitting chip is bonded to the driving back plate, the connection between the carrier substrate and the light emitting chip can be released by simply breaking the weakened connection structure, and the transfer process of the light emitting chip from the carrier substrate to the driving back plate is completed. The transfer process is realized based on the weakened connection structure, so that the method is easy to realize, the damage to the light-emitting chip is low, and the transfer efficiency and yield of the light-emitting chip are improved.
Alternatively, the space occupying sacrificial layer is formed of a growth substrate of the light emitting chip.
In the chip assembly, the occupying sacrificial layer can be directly formed by the growth substrate, so that the epitaxial layer of the light-emitting chip is grown from the growth substrate until the chip assembly is prepared, the epitaxial layer is not required to be transferred, the light-emitting chip is directly transferred from the growth substrate to the driving backboard, multiple transfer processes in the preparation process of the related display panel are avoided, the preparation difficulty of the display panel is reduced, and the growth efficiency is improved. Meanwhile, the growth substrate directly forms the occupied sacrificial layer, which further reduces the production cost.
Optionally, the thickness of the placeholder sacrificial layer is less than the thickness of the growth substrate.
In the chip assembly, the thickness of the occupied sacrificial layer is smaller than that of the growth substrate, so that the growth substrate undergoes thinning treatment when the occupied sacrificial layer is formed. Compared with the scheme of not thinning the growth substrate, the thickness of the occupied sacrificial layer is reduced in the scheme provided by the embodiment, so that the thickness of the whole chip assembly can be reduced, the thickness of the adhesive layer is reduced, the material consumption of the adhesive layer is reduced, and the cost can be saved.
Optionally, the contact area of the adhesion layer and the distal back plate surface is smaller than the contact area of the sacrificial layer and the distal back plate surface.
In the chip assembly, the contact area of the adhesion layer and the far back plate surface is smaller than the contact area of the occupying sacrificial layer and the far back plate surface, so that the adhesion capability of the adhesion layer to the light-emitting chip can be reduced as much as possible while the light-emitting chip and the bearing substrate are combined by the adhesion layer, and the convenience in separating the light-emitting chip from the adhesion layer and the bearing substrate is further enhanced.
Optionally, the distal back plate is rectangular, the rectangle includes four interior corner regions, and the adhesive layer is simultaneously attached to the four interior corner regions.
Based on the same inventive concept, the present application also provides another chip assembly, comprising:
a carrier substrate;
at least two light emitting chips on the carrier substrate; and
an adhesive layer between the carrier substrate and the light emitting chip and configured to adhere the two;
the light emitting chip is provided with a driving backboard, a driving backboard and a bearing substrate, wherein one surface of the light emitting chip, which faces the driving backboard, is a near backboard surface, and the surface opposite to the near backboard surface is a far backboard surface; the contact area of the adhesion layer and the far back plate surface is smaller than the contact area of the adhesion layer and the bearing substrate; an empty space exists between the light emitting chip and the bearing substrate, the empty space is contacted with the surface of the far backboard, and the empty space is communicated with the external space.
In the chip assembly, at least two light emitting chips are adhered to the bearing substrate through the adhesive layer, and an empty space exists between the light emitting chips and the bearing substrate and is in contact with the far back plate surface of the light emitting chips. Due to the existence of the empty space, the adhesive layer is not adhered to the whole area of the far back surface of the light-emitting chip, so that the contact area between the adhesive layer and the light-emitting chip is reduced, the adhesive capability of the adhesive layer to the light-emitting chip is reduced, and the adhesive layer exists as a weakened connection structure between the bearing substrate and the light-emitting chip. And because the contact area of the adhesive layer and the light-emitting chip is smaller than that of the adhesive layer and the bearing substrate, the combination between the adhesive layer and the bearing substrate is firmer than the combination between the adhesive layer and the light-emitting chip, so that after the connection between the bearing substrate and the light-emitting chip is destroyed, the adhesive layer is easier to fall off along with the bearing substrate. Therefore, after the light emitting chip in the chip assembly is bonded to the driving back plate, the connection between the carrier substrate and the light emitting chip can be released by simply breaking the weakened connection structure, and the transfer process of the light emitting chip from the carrier substrate to the driving back plate is completed. The transfer process is realized based on the weakened connection structure, so that the method is easy to realize, the damage to the light-emitting chip is low, and the transfer efficiency and yield of the light-emitting chip are improved.
Based on the same inventive concept, the application also provides a chip assembly preparation method, which is applied to the preparation of the first chip assembly, and comprises the following steps:
providing an epitaxial layer on the growth substrate, wherein the epitaxial layer comprises an N-type semiconductor layer, an active layer and a P-type semiconductor layer, and the distance between the N-type semiconductor layer, the active layer and the P-type semiconductor layer are sequentially increased from the growth substrate;
an N electrode and a P electrode which are electrically connected with the N-type semiconductor layer and the P-type semiconductor layer are respectively arranged to form at least two light emitting chips, and one surface of each light emitting chip facing the growth substrate is a far back plate surface;
arranging adhesive on one side of the growth substrate provided with the light-emitting chip, and adhering a temporary substrate opposite to the growth substrate through the adhesive;
patterning the growth substrate until part of the area of the far back plate surface is exposed out of the growth substrate, so that a space occupying sacrificial layer is formed by using the growth substrate;
an adhesive layer is arranged on one side of the light-emitting chip far away from the temporary substrate, a bearing substrate opposite to the temporary substrate is adhered through the adhesive layer, and the contact area of the adhesive layer and the far back plate surface is smaller than the contact area of the adhesive layer and the bearing substrate; after the adhesive layer is arranged, the occupying sacrificial layer comprises a first area contacted with the surface of the far backboard and a second area in a non-shielding state, and the first area is communicated with the second area;
And removing the adhesive and the temporary substrate to obtain the chip assembly.
In the above method for manufacturing a chip assembly, after the epitaxial layer with the growth substrate is obtained, the electrodes of the light emitting chips can be directly manufactured on the growth substrate, so that at least two light emitting chips are formed on the growth substrate. The temporary substrate is then bonded to the light emitting chip with an adhesive paste such that the temporary substrate is opposed to the growth substrate. And then carrying out patterning treatment on the growth substrate, directly forming a space occupying sacrificial layer by using the growth substrate, arranging an adhesive layer on one side of the light emitting chip far away from the temporary substrate, bonding the light emitting chip and the carrier substrate by using the adhesive layer, and then removing the bonding glue and the temporary substrate to obtain the chip assembly. In the preparation method of the chip component, the occupied sacrificial layer is formed by directly utilizing the growth substrate of the light-emitting chip, so that the epitaxial layer of the light-emitting chip is grown from the growth substrate until the preparation of the chip component is completed, the substrate transfer of the epitaxial layer is not needed, the light-emitting chip is directly transferred from the growth substrate to the driving backboard, the repeated transfer process in the preparation process of the related display panel is avoided, the preparation difficulty of the display panel is reduced, and the growth efficiency is improved. Meanwhile, the growth substrate directly forms the occupied sacrificial layer, which further reduces the production cost. Of course, the chip assembly manufactured by the chip assembly manufacturing method can also utilize the occupied sacrificial layer to enable the adhesion layer to form a weakened connection structure between the bearing substrate and the light-emitting chip, so that the efficiency and the yield of transferring the light-emitting chip on the chip assembly to the driving backboard are improved.
Optionally, before the patterning treatment is performed on the growth substrate, the method further includes:
and thinning the growth substrate.
In the above method for manufacturing a chip assembly, the space-occupying sacrificial layer is formed by thinning the growth substrate, and compared with the solution without thinning the growth substrate, the thickness of the space-occupying sacrificial layer in the solution provided by the embodiment is reduced, so that the thickness of the whole chip assembly can be reduced, and meanwhile, the thickness of the adhesive layer is reduced, and the material consumption of the adhesive layer is reduced, so that the cost can be saved.
Optionally, the adhesive is thermal adhesive, and removing the adhesive and the temporary substrate includes:
and heating the adhesive until the adhesive fails and the light-emitting chip falls off.
According to the preparation method of the chip assembly, the light-emitting chip and the temporary substrate are combined by using the pyrolysis glue as the bonding glue, so that when the bonding glue and the temporary substrate are required to be removed, the bonding glue is heated to be invalid, the bonding glue and the temporary substrate can fall off from the light-emitting chip together, the preparation method is convenient and rapid, the preparation efficiency of the chip assembly is improved, and the production difficulty is reduced.
Based on the same inventive concept, the application also provides a display panel preparation method, comprising the following steps:
Providing a first chip assembly;
immersing the occupied sacrificial layer in wet etching solution until the occupied sacrificial layer is corroded and removed;
bonding at least two light emitting chips in the chip assembly to a drive back plate;
and removing the adhesive layer and the bearing substrate to manufacture the display panel.
In the method for manufacturing the display panel, the first chip assembly with the space occupying sacrificial layer is provided, then the space occupying sacrificial layer in the chip assembly is removed through wet etching, so that the adhesion layer forms a weakened connection structure between the bearing substrate and the light emitting chip, after the light emitting chip in the chip assembly is bonded to the driving backboard, the connection between the bearing substrate and the light emitting chip can be relieved by simply damaging the weakened connection structure, and the transfer process of the light emitting chip from the bearing substrate to the driving backboard is completed, and the process does not damage the light emitting chip. In addition, the light-emitting chip can be directly transferred from the growth substrate to the driving backboard in the preparation method of the display panel, so that the process of transferring the light-emitting chip by adopting the transient substrate in the middle is omitted, the process flow is simplified, the production cost is reduced, and the production efficiency is improved.
Drawings
FIG. 1 is a schematic view of a manufacturing process of a display panel according to the related art;
FIG. 2 is a schematic diagram of a chip assembly according to an alternative embodiment of the present application;
FIG. 3 is a schematic top view of a chip assembly according to an alternative embodiment of the application;
FIG. 4a is a schematic illustration of an etched region on a growth substrate provided in an alternative embodiment of the present application;
FIG. 4b is a schematic illustration of an etched region on another growth substrate provided in an alternative embodiment of the present application;
FIG. 4c is a schematic illustration of an etched region on a growth substrate provided in an alternative embodiment of the present application;
FIG. 5 is a schematic diagram of a chip assembly according to another alternative embodiment of the present application;
FIG. 6 is a schematic flow chart of a method for manufacturing a chip assembly according to another alternative embodiment of the present application;
FIG. 7 is a schematic view of a process of a chip assembly according to another alternative embodiment of the present application;
FIG. 8 is a schematic flow chart of a method for manufacturing a display panel according to another alternative embodiment of the present application;
fig. 9 is a schematic process diagram of a display panel according to another alternative embodiment of the application.
Reference numerals illustrate:
10-red light chip; a 110-GaAs substrate; a 111-N type semiconductor layer; 112-an active layer; 113-P type semiconductor layer; 114-an ITO layer; 115-BCB gum layer; 116-sapphire substrate; 117—temporary substrate; 118-transferring the substrate; 119-driving the back plate; a 20-chip assembly; 21-a carrier substrate; 22-a light emitting chip; 220-an epitaxial layer; a 221-N type semiconductor layer; 222-an active layer; 223-P-type semiconductor layer; 224—a current spreading layer; 23-an adhesion layer; 24-occupying the sacrificial layer; 241-first region; 242-a second region; 25-empty space; 40 a-a growth substrate; 40 b-a growth substrate; 40 c-a growth substrate; a 50-chip assembly; 70-a growth substrate; 71-bonding glue; 72-temporary substrate; 90-driving a back plate; 100-display panel.
Detailed Description
In order that the application may be readily understood, a more complete description of the application will be rendered by reference to the appended drawings. The drawings illustrate preferred embodiments of the application. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
At present, in the preparation scheme of the LED high-definition display screen, red light, green light and blue light chips are bonded to a driving backboard, each pixel point at least consists of three light-emitting chips of red light, green light and blue light, the pixel points are arranged into a lattice structure, and the light-emitting chips in each pixel point can be independently driven and can support to respectively adjust the brightness of the light-emitting chips of the red light, the green light and the blue light.
When preparing red light, green light and blue light chips, the blue light and green light emitting chips can directly grow GaN (gallium nitride) base structures on the sapphire substrate, and the setting of chip electrodes is completed on the sapphire substrate, so that the blue light chips or the green light chips are prepared. However, the red light chip generally grows an AlGaInP (aluminum gallium indium phosphorus) -based structure on a GaAs (gallium arsenide) substrate 110, and in combination with (a) in fig. 1, an N-type semiconductor layer 111, an active layer 112, a P-type semiconductor layer 113 are grown stepwise, and an ITO (indium tin oxide) layer 114 is deposited. The red light epitaxial layer is then typically transferred to the sapphire substrate 116 and the preparation of the red light chip is continued: in the related art, BCB glue layer 115 is typically formed by spin-coating BCB glue on ITO layer 114, please refer to (b) in fig. 1, and then the red light epitaxial layer is transferred to sapphire substrate 116 by using the adhesiveness of BCB glue layer 115, as shown in (c) and (d) in fig. 1.
After the transfer of the red epitaxial layer to the sapphire substrate 116, chip electrodes respectively connected to the two semiconductor layers are provided, thereby producing the red chip 10, as shown in (e) of fig. 1. After the red light chip 10 is prepared, it needs to be peeled off from the sapphire substrate 116. The most common mode of Lift-Off today is Laser Lift-Off (LLO). The essence of laser lift-off is that the material absorbs the special band laser: the material absorbs photon energy, so that electrons transition to excited states and eventually decompose. In the blue light chip and the green light chip, the laser is directly adopted to decompose GaN, and GaN-Ga+N is utilized 2 The principle of (2) enables the sapphire substrate to be separated from the light-emitting chip. The GaN material has high absorptivity to laser, so that the blue light chip and the green light chip can be separated from the sapphire substrate more thoroughly. However, for the red light chip 10, the peeling of the sapphire substrate 116 is essentially to decompose the BCB adhesive layer 115, and the BCB adhesive is decomposed by carbonizing the BCB adhesive purely by physical impact, as shown in (g) of fig. 1, in this case, the problem of incomplete adhesive residue or adhesive removal is not easy to occur, and more importantly, the laser may damage the red light chip 10, thereby affecting the quality of the red light chip 10. In addition, in the related art, after the chip electrode is prepared on the sapphire substrate 116, the red light chip 10 needs to undergo a plurality of transfer processes to be transferred onto the driving back plate, for example, in fig. 1 (f), the chip electrode is prepared The red light chip 10 is bonded to the temporary substrate 117 by a temporary bonding paste, and then the BCB paste layer 115 is decomposed by a laser in fig. 1 (g), and the sapphire substrate 116 is peeled off. Subsequently, in fig. 1 (h), a transfer substrate 118 is bonded to the ITO layer 114 in the red light chip 10, and in fig. 1 (i), the temporary bonding paste and the temporary substrate 117 are peeled off, and the red light chip 10 is transferred onto the driving back plate 119 using the transfer substrate 118. In the above transfer scheme, the transfer frequency is too high, which results in low transfer efficiency and transfer yield of the red light chip 10, and in the transfer process, the red light chip 10 is also easily damaged, which affects the production efficiency.
Based on this, the present application is intended to provide a solution to the above technical problem, the details of which will be described in the following examples.
An alternative embodiment of the application:
the present embodiment provides a limited number of chip assemblies, please refer to a schematic structural diagram of the chip assembly shown in fig. 2: the chip assembly 20 includes a carrier substrate 21, at least two light emitting chips 22, an adhesive layer 23, and a sacrificial layer 24.
The light emitting chip 22 may be a red light chip, however, in other examples of the present embodiment, the light emitting chip 22 may be an LED chip of other colors. In addition, the Light Emitting chip 22 may be a Micro-LED (Micro Light Emitting Diode), a Mini-LED (Mini Light Emitting Diode), or an OLED (Organic Light-Emitting Diode) chip.
It will be appreciated that when the light emitting chip 22 is transferred to the drive backplate, it is necessary that one face be facing the drive backplate, which in this embodiment is referred to as the "near backplate face" of the light emitting chip 22 for ease of description, while the face of the light emitting chip 22 opposite the near backplate face is the "far backplate face". The light emitting chip 22 is exemplified as a flip-chip structure: referring to fig. 2, since the light emitting chip 22 is flip-chip, the side with the chip electrode is the near back surface, so in fig. 2, the far back surface of the light emitting chip 22 faces the carrier substrate 21.
The carrier substrate 21 is used to carry each light emitting chip 22 in the chip assembly 20, and in some examples of the present embodiment, the carrier substrate 21 may be a sapphire substrate, but in other examples of the present embodiment, the carrier substrate 21 may also be a silicon substrate, a silicon nitride substrate, or the like.
The adhesion layer 23 and the space occupying sacrificial layer 24 are both located between the carrier substrate 21 and the light emitting chip 22, and in this embodiment, the adhesion layer 23 has the function of adhering the carrier substrate 21 and the light emitting chip 22, and the adhesion layer 23 may be a glue material with viscosity. The space occupying sacrificial layer 24 is attached to the far back surface of the light emitting chip 22, and mainly plays a role of occupying and covering the far back surface, and the adhesion layer 23 is prevented from adhering to the whole area of the far back surface of the light emitting chip 22. The presence of the space-occupying sacrificial layer 24 can reduce the contact area of the adhesive layer 23 and the light-emitting chip 22 and reduce the adhesion capability of the adhesive layer 23 to the light-emitting chip 22, compared with the case where the space-occupying sacrificial layer 24 is not provided. In some examples of the present embodiment, the contact area between the adhesion layer 23 and the far back surface of the light emitting chip 22 is smaller than the contact area between the space-occupying sacrificial layer 24 and the far back surface, so that the difficulty in detachment of the subsequent light emitting chip from the adhesion layer 23 can be reduced as much as possible while ensuring that the adhesion layer 23 has sufficient adhesion capability to the light emitting chip 22. In this embodiment, the adhesion layer 23 may be adhered to the far back surface of the light emitting chip 22, the surface of the carrier substrate 21 facing the light emitting chip 22, and the surface of the space-occupying sacrificial layer 24 facing away from the light emitting chip 22, so that the contact area between the adhesion layer 23 and the far back surface of the light emitting chip 22 is smaller than the contact area between the adhesion layer 23 and the carrier substrate 21, and thus the reliability of the bonding between the adhesion layer 23 and the light emitting chip 22 is smaller than the reliability of the bonding between the adhesion layer 23 and the carrier substrate 21.
Although the adhesive layer 23 may be attached to the placeholder sacrificial layer 24, and may even cover at least a partial area of the side of the placeholder sacrificial layer 24 facing the carrier substrate 21, the adhesive layer 23 and the light emitting chip 22 do not form a complete package with the placeholder sacrificial layer 24. In this embodiment, a partial region on the sacrificial layer 24 is in an "unobstructed state", and such an area on the sacrificial layer 24 in an unobstructed state is referred to herein as a "second region". It will be appreciated that an area of the sacrificial placeholder layer 24 that is in an unobstructed state, i.e., belonging to a second area, will be in direct contact with a liquid if the chip assembly 20 is immersed in that liquid. Please refer to a top view schematic diagram of the chip assembly 20 shown in fig. 3: the area of the sacrificial layer 24 between the two light emitting chips 22 can be used as the second area 242 in the non-shielding state. The space-occupying sacrificial layer 24 includes, in addition to the second region, a first region 241 in contact with the distal plate surface of the light emitting chip 22. In this embodiment, each of the first regions 241 is in communication with the second region 242, which means that if the chip assembly 20 is immersed in a liquid that can etch the sacrificial placeholder layer 24 without damaging other structures in the chip assembly 20, the first regions 241 will also be progressively etched away after the second region 242 of the sacrificial placeholder layer 24 is etched.
It will be appreciated that after the sacrificial placeholder layer 24 in the chip assembly 20 is removed, the adhesion layer 23 will form a weakened connection between the carrier substrate 21 and the light emitting chip 22. In this case, the connection formed by the weakened connection structure can be broken in a relatively easy manner, so that the light emitting chip 22 is separated from the carrier substrate 21, the risk that the light emitting chip 22 is damaged due to transfer in the preparation process of the display panel is reduced, the transfer yield and the transfer efficiency of the light emitting chip 22 are improved, and the preparation cost of the display panel is reduced. In addition, since the reliability of the bonding between the adhesion layer 23 and the carrier substrate 21 is higher than the reliability of the bonding between the adhesion layer 23 and the light emitting chip 22, when the weakened connection structure is damaged, the adhesion layer 23 is removed along with the carrier substrate 21, so that the probability of the adhesion layer 23 remaining on the light emitting chip 22 is reduced, and the light emitting effect of the prepared display panel is improved.
In some examples of the present embodiment, the arrangement of the light emitting chips 22 on the chip assembly 20 is consistent with the arrangement of the corresponding chip receiving areas on the driving back plate, for example, the light emitting chips 22 in the chip assembly 20 are red light chips, the arrangement of the red light chips on the carrier substrate 21 is consistent with the arrangement of the respective red light chip receiving areas on the driving back plate, then the light emitting chips 22 in the chip assembly 20 may be bonded to the driving back plate first, so that the light emitting chips 22 are fixed in the corresponding chip receiving areas, and then the carrier substrate 21 is removed. Of course, the present embodiment does not exclude the steps of removing the light emitting chip 22 from the carrier substrate 21 and then transferring and bonding to the driving back plate.
In some examples of the present embodiment, the placeholder sacrificial layer 24 may be formed of a growth substrate of the light emitting chip 22, for example, if the light emitting chip 22 is a red light chip, the placeholder sacrificial layer 24 may be formed of a gallium arsenide substrate. Of course, if the light emitting chip 22 is a chip of another color, such as a blue light chip or a green light chip, the space occupying sacrificial layer 24 may be formed of any one of a sapphire substrate, a gallium nitride substrate, and a silicon substrate. It should be appreciated that if the placeholder sacrificial layer 24 is formed from the growth substrate of the light emitting chip 22 by processing, it is illustrated that the light emitting chip 22 may be directly fabricated into the chip assembly 20 after being fabricated from the growth substrate and directly bonded to the drive back plate after fabrication of the chip assembly 20 without other transfer processes. Therefore, the production cost is reduced because the occupation sacrificial layer 24 is not specially arranged, the transfer times of the light emitting chip 22 from the preparation completion to the whole process of transferring to the driving backboard are greatly reduced, the problem that the light emitting chip 22 is damaged due to excessive transfer is avoided, the quality of the display panel is improved, and the preparation cost of the display panel is further reduced.
When the growth substrate is used to form the space-occupying sacrificial layer, the growth substrate can be subjected to patterning treatment, and it is understood that the etched-out area of the growth substrate also immediately etches the exposed area on the far back surface of the light emitting chips 22, and then the exposed area is covered by the adhesive layer 23, so that when the growth substrate is subjected to patterning treatment, it is ensured that after the growth substrate is etched, a part of the far back surface of each light emitting chip 22 is exposed, and at the same time, a part of the far back surface is still covered by the growth substrate, so that each light emitting chip 22 can be ensured to be in contact with the adhesive layer 23, but the far back surface of each light emitting chip 22 is not completely covered by the adhesive layer 23. In some examples of this embodiment, the central area of the distal back surface of the light emitting chip 22 may be etched away, for example, please refer to a schematic diagram of an etched area of the growth substrate 40a shown in fig. 4a, in which in fig. 4a, the distal back surface of the light emitting chip 22 is rectangular, and the black area in the middle of the rectangle is the etched area of the growth substrate 40 a. It is clear that for a rectangular distal back plate surface having four inner corner regions, in other examples of this embodiment it is conceivable to remove the portion of the growth substrate that is located in the inner corner regions, for example, in fig. 4b the portion of the growth substrate 40b that covers two inner corner regions of the light emitting chip 22 is removed, and in fig. 4b the two exposed inner corner regions are located on the diagonal of the rectangular distal back plate surface after etching, in other examples the two exposed inner corner regions may also be located on the same side of the rectangular distal back plate surface. In still other examples, the portions of the growth substrate opposite the inner corner regions of all rectangular distal back plate faces may be removed, as shown in fig. 4c, with portions of the growth substrate 40c covering four inner corner regions of the light emitting chip 22 removed. In addition, in other examples of this embodiment, the exposed area on the far back surface of the light emitting chip after etching the growth substrate may be other areas, for example, the patterning scheme for the growth substrate may be determined according to the shape of the far back surface of the light emitting chip 22, the arrangement of the light emitting chip 22 on the growth substrate, and other factors.
In some examples of the present embodiment, the thickness of the space-occupying sacrificial layer 24 is smaller than the thickness of the growth substrate of the light-emitting chip 22, that is, the growth substrate is subjected to thinning treatment in the process of forming the space-occupying sacrificial layer 24 by using the growth substrate, for example, in some examples of the present embodiment, the growth substrate may be subjected to thinning treatment, such as polishing, before patterning treatment. The patterning of the growth substrate and then thinning of the growth substrate is not excluded in this embodiment. However, in comparison, after the thinning process is performed, the workload of patterning the growth substrate can be significantly reduced, and the efficiency of forming the occupied sacrificial layer 24 can be improved.
The chip assembly provided by the embodiment utilizes the occupation of the occupation sacrificial layer on the far back plate surface, reduces the contact area between the adhesive layer and the light-emitting chip, and reduces the adhesion capability of the adhesive layer to the light-emitting chip. Meanwhile, when the occupation sacrificial layer is removed by wet etching, a first area, which is in contact with the surface of the light-emitting chip far back plate, in the occupation sacrificial layer can be removed, so that the adhesion layer can form a weakened connection structure between the bearing substrate and the light-emitting chip. And because the bonding between the adhesive layer and the carrier substrate is more firm than the bonding between the adhesive layer and the light-emitting chip, the adhesive layer is easier to fall off along with the carrier substrate after the connection between the carrier substrate and the light-emitting chip is broken. Therefore, after the light emitting chip is bonded to the driving back plate, the connection between the carrier substrate and the light emitting chip can be released by simply breaking the weakened connection structure, and the transfer process of the light emitting chip from the carrier substrate to the driving back plate is completed. The transfer process is realized based on the weakened connection structure, so that the method is easy to realize, the damage to the light-emitting chip is low, and the transfer efficiency and yield of the light-emitting chip are improved.
Another alternative embodiment of the application:
with continued reference to fig. 2, it can be appreciated that the chip assembly 20 provided in the foregoing embodiment requires that the sacrificial layer 24 of the chip assembly 20 be removed during application, and then the light emitting chips 22 therein should be bonded to the back plate. In this embodiment, a chip assembly that does not include the space-occupying sacrificial layer 24 is also provided, for example, as shown in fig. 5. The chip assembly 50 shown in fig. 5 is different from the chip assembly 20 provided in the foregoing embodiment in that the space-occupying sacrificial layer 24 is included in the chip assembly 20, and the space-occupying sacrificial layer is not present in the chip assembly 50, and thus, the chip assembly 50 can be manufactured by removing the space-occupying sacrificial layer 24 in the chip assembly 20.
Referring to fig. 5, the chip assembly 50 includes a carrier substrate 21, at least two light emitting chips 22, and an adhesive layer 23. For the specific structure of the light emitting chip 22, the material of the carrier substrate 21, the positional relationship between the light emitting chip 22 and the carrier substrate 21, and the like, please refer to the description of the foregoing embodiments, and the details are not repeated here. The adhesive layer 23 simultaneously adheres the distal back surface of the light emitting chip 22 and the carrier substrate 21, and the contact area between the adhesive layer 23 and the light emitting chip 22 is smaller than the contact area between the light emitting chip 22 and the carrier substrate 21, so that in the case where the light emitting chip 22 is separated from the carrier substrate 21, the adhesive layer 23 is more easily attached to the carrier substrate 21, and is separated from the light emitting chip 22 together with the carrier substrate 21.
In the chip assembly 50, between the light emitting chip 22 and the carrier substrate 21, there is a space 25, the space 25 is in contact with the distal back surface of the light emitting chip 22, and the space 25 is in communication with an external space, that is, air in the space 25 can be circulated with the external air, and a portion of the distal back surface of the light emitting chip 22 in contact with the control space 25 can be directly in contact with the air. It will be appreciated that the empty space 25 is actually the space formed by removing the sacrificial layer.
In some examples of the present embodiment, the contact area between the adhesive layer 23 and the distal back surface of the light emitting chip 22 is smaller than the contact area between the empty space 25 and the distal back surface, so that the difficulty in detachment of the subsequent light emitting chip from the adhesive layer 23 can be reduced as much as possible while ensuring that the adhesive layer 23 has sufficient adhesion capability to the light emitting chip 22.
In some examples of the present embodiment, the adhesive layer 23 is attached only to a partial region of the edge of the back surface of the light emitting chip 22, for example, the adhesive layer 23 is attached to four inner corner regions of the back surface of the light emitting chip 22 at the same time, and in other examples, the adhesive layer 23 may be attached to only one, two or three inner corner regions of the four inner corner regions. It should be appreciated that the adhesive layer 23 will not typically adhere to all areas of the distal back plane edge at the same time, because if the adhesive layer 23 adheres to all areas of the distal back plane edge at the same time, the adhesive layer 23 will form a complete enclosure to the distal back plane center area, resulting in the empty space 25 between the distal back plane surface and the carrier substrate 21 will be in a closed state, which is difficult to achieve from the manufacturing process of the chip assembly 50. In still other examples, the adhesive layer 23 may be attached to a central region of the light emitting chip 22 away from the back surface, and the region other than the central region of the back surface is exposed.
It is needless to say that the process of removing the sacrificial layer after the chip assembly 50 is obtained and put into use may be omitted. In some examples of the present embodiment, the arrangement of the light emitting chips 22 on the chip assembly 50 is consistent with the arrangement of the corresponding chip receiving areas on the driving back plate, for example, the light emitting chips 22 in the chip assembly 50 are red light chips, the arrangement of the red light chips on the carrier substrate 21 is consistent with the arrangement of the respective red light chip receiving areas on the driving back plate, then the light emitting chips 22 in the chip assembly 50 may be bonded to the driving back plate first, so that the light emitting chips 22 are fixed in the corresponding chip receiving areas, and then the carrier substrate 21 is removed. Of course, the present embodiment does not exclude the steps of removing the light emitting chip 22 from the carrier substrate 21 and then transferring and bonding to the driving back plate.
In the chip assembly provided in this embodiment, the weakened connection structure between the carrier substrate and the light emitting chip is formed by using the adhesive layer, and after the light emitting chip in the chip assembly is bonded to the driving back plate, the connection between the carrier substrate and the light emitting chip can be released by simply breaking the weakened connection structure, so that the transfer process of the light emitting chip from the carrier substrate to the driving back plate is completed. The transfer process is realized based on the weakened connection structure, so that the method is easy to realize, the damage to the light-emitting chip is low, and the transfer efficiency and yield of the light-emitting chip are improved.
Yet another alternative embodiment of the present application:
in this embodiment, the method for manufacturing the chip assembly in the foregoing embodiment will be described, and please refer to a schematic flow chart of the method for manufacturing the chip assembly shown in fig. 6, and a schematic process diagram of the chip assembly shown in fig. 7:
s602: an epitaxial layer is provided on a growth substrate.
Referring to fig. 7 (a), the epitaxial layer 220 includes an N-type semiconductor layer 221, an active layer 222 and a P-type semiconductor layer 223, and the distances between the three layers and the growth substrate 70 are sequentially increased. It is understood that other layer structures may be included in the epitaxial layer 220, such as a buffer layer between the N-type semiconductor layer 221 and the growth substrate 70, an electron blocking layer between the active layer 222 and the P-type semiconductor layer 223, and the like. In an example of this embodiment, please continue to refer to (a) in fig. 7, the epitaxial layer 220 further includes a current spreading layer 224, where the current spreading layer 224 is located on a side of the P-type semiconductor layer 223 away from the growth substrate 70, and in some examples of this embodiment, the current spreading layer 224 may be a transparent conductive layer, such as an ITO (indium tin oxide) layer, etc., and of course, it will be understood by those skilled in the art that the current spreading layer 224 may also be other layer structures with good conductivity, such as a CNT (carbon nanotube layer) or a nano silver wire layer, etc.
S604: and respectively arranging an N electrode and a P electrode which are electrically connected with the N-type semiconductor layer and the P-type semiconductor layer to form at least two light emitting chips.
In the present embodiment, after the epitaxial layer 220 on the growth substrate 70 is obtained, the chip electrode may be directly disposed on the epitaxial layer 220 on the growth substrate 70 to form at least two light emitting chips 22 on the growth substrate 70. It will be appreciated that in the process of forming the light emitting chip 22 by using the epitaxial layer 220 on the growth substrate 70, the epitaxial layer 220 must be subjected to etching treatment, and the etching of the epitaxial layer 220 includes mesa etching and trench etching, by which the large-area epitaxial layer 220 is divided into at least two independent sub-epitaxial layers, and the electrode arrangement regions of the N electrode and the P electrode are exposed by using the mesa etching, as shown in (b) of fig. 7. Subsequently, an N electrode electrically connected to the N-type semiconductor layer 221 is provided in the N electrode setting region, and a P electrode electrically connected to the P-type semiconductor layer is provided in the P electrode setting region. Alternatively, in one example of the present embodiment, the chip electrode may be provided in any one of the ways including, but not limited to, evaporation, PVD (Physical Vapor Deposition ), CVD (Chemical Vapor Deposition, chemical vapor deposition), and the like. After the chip electrode is disposed, at least two light emitting chips 22 located on the growth substrate 70 can be obtained, as shown in fig. 7 (c), in this embodiment, the light emitting chips 22 are in a flip-chip structure, and one surface of the light emitting chips 22 provided with the chip electrode faces away from the growth substrate 70, that is, the near-back surface of the light emitting chips 22 faces away from the growth substrate 70, and the far-back surface faces toward the growth substrate 70.
S606: and arranging adhesive on one side of the growth substrate provided with the light-emitting chip, and adhering a temporary substrate opposite to the growth substrate through the adhesive.
In the present embodiment, after the preparation of the light emitting chip 22 is completed by the growth substrate 70, an adhesive 71 may be provided on the side of the growth substrate 70 provided with the light emitting chip 22, and the light emitting chip 22 and the temporary substrate 72 may be bonded together with the adhesive 71, and after the temporary substrate 72 is bonded, the temporary substrate 72 is opposed to the growth substrate 70 with the light emitting chip 22 and the adhesive 71 interposed therebetween, as in (d) of fig. 7. In the present embodiment, the adhesive 71 and the temporary substrate 71 are only temporarily attached to the light emitting chip 22 and then need to be removed, so the adhesive 71 used in the present embodiment is a relatively easy-to-remove adhesive material, for example, in one example, the adhesive 71 is a thermal decomposition adhesive.
S608: and patterning the growth substrate until part of the area of the far back plate surface is exposed out of the growth substrate, so that the growth substrate is utilized to form the occupied sacrificial layer.
After the temporary substrate 72 is provided, the growth substrate 70 may be processed to form the placeholder sacrificial layer 24 using the growth substrate 70. In some examples of this embodiment, the growth substrate 70 may be directly subjected to patterning treatment, so that a partial region on the distal back plate surface of the light emitting chip is exposed from under the growth substrate 70. In still other examples, the growth substrate 70 may be thinned by grinding or the like, as shown in fig. 7 (e). After the thinning process is completed, the growth substrate 70 is subjected to patterning process to form the sacrificial spacer layer 24, as shown in (f) of fig. 7, in some examples, the light emitting chip 22 is a red light chip, and thus, the sacrificial spacer layer 24 may be GaAs material, which is formed of a GaAs growth substrate of the red light chip. In this embodiment, when patterning the thinned growth substrate, it is necessary to ensure that a part of the distal back surface of each light emitting chip 22 is exposed, for example, in one example, four inner corner regions of the distal back surface are exposed to the growth substrate; in another example, a central region of the distal back plate surface is exposed to the growth substrate. It should be understood that in fig. 7 (f), not all of the growth substrate 70 in the edge region of the far back plate surface is removed, but only the growth substrate 70 in the middle region of the edge region of the far back plate surface is removed.
S610: an adhesive layer is provided on a side of the light emitting chip remote from the temporary substrate, and a carrier substrate opposite to the temporary substrate is adhered via the adhesive layer.
After the growth substrate 70 is processed to form the space-occupying sacrificial layer 24, an adhesive layer 23 may be disposed on a side of the space-occupying sacrificial layer 24 away from the temporary substrate 72, and a carrier substrate 21 may be bonded with the adhesive layer 23, the adhesive layer 23 being simultaneously attached to the exposed distal back plate surface of the light emitting chip 22, the side of the space-occupying sacrificial layer 24 away from the light emitting chip 22, and the side of the carrier substrate 21 facing the light emitting chip 22, as in (g) of fig. 7. It will be appreciated that the material of the adhesive layer 23 is generally different from that of the adhesive 71, otherwise, the means for removing the adhesive 71 will be effective for the adhesive layer 23 when the adhesive 71 is removed later, resulting in that the adhesive layer 23 is removed together with the adhesive 71. Thus, if the adhesive glue 71 is a pyrolytic glue, the adhesive layer 23 is typically a glue other than a pyrolytic glue, such as a BCB glue.
In this embodiment, after the adhesion layer 23 is disposed, the space-occupying sacrificial layer 24 includes a second area in an unobstructed state, and further includes first areas contacting the far back surface of the light emitting chip 22, and in this embodiment, each of the first areas is in communication with the second area, so if the space-occupying sacrificial layer 24 is immersed in the wet etching solution, after the second area in the unobstructed state in the space-occupying sacrificial layer 24 is etched by the wet etching solution, the wet etching solution may also contact the first area of the space-occupying sacrificial layer 24, thereby removing a portion in the first area of the space-occupying sacrificial layer 24.
In some examples of the present embodiment, the contact area between the adhesive layer 23 and the distal back surface of the light emitting chip 22 is smaller than the contact area between the adhesive layer 23 and the carrier substrate 21, so that it is ensured that the adhesive layer 23 does not fall off together with the light emitting chip 22 when the light emitting chip 22 falls off from the carrier substrate 21.
S612: and removing the adhesive and the temporary substrate to obtain the chip assembly.
In the present embodiment, the temporary substrate 72 is disposed on the side of the growth substrate 70 on which the light emitting chip 22 is disposed, mainly for carrying and supporting the light emitting chip 22 by the temporary substrate 72 during the patterning process of the growth substrate 70 and during the disposing of the carrier substrate 21, so as to avoid damage of the light emitting chip 22 during the patterning process of the growth substrate 70, so that the temporary substrate 72 is disposed for facilitating the processing of the growth substrate 70 and protecting the light emitting chip 22. After the space-occupying sacrificial layer 24 is formed and the placement of the carrier substrate 21 is completed, the adhesive tape 71 and the temporary substrate 72 may be removed, thereby obtaining the chip assembly 20, please refer to (h) in fig. 7.
In some examples of the present embodiment, the adhesive 71 is a thermal adhesive, so when the adhesive 71 and the temporary substrate 72 are removed, the adhesive 71 may be heated, so that the adhesive 71 gradually fails, and the adhesive force is lost, so that the temporary substrate 72 and the adhesive 71 are detached from the light emitting chip 22.
It will be appreciated that after the chip assembly 20 with the sacrificial placeholder layer 24 is fabricated, the sacrificial placeholder layer 24 may also be removed by wet etching, thereby fabricating the chip assembly 50 without the sacrificial placeholder layer 24.
The present embodiment also provides a method for manufacturing a display panel, please refer to fig. 8 and 9, which are shown as follows:
s802: a chip assembly with a sacrificial placeholder layer is provided.
In this embodiment, the chip assembly 20 is provided with the sacrificial layer 24, as shown in fig. 9 (a), and the chip assembly 20 may be directly purchased or prepared by itself.
S804: and immersing the occupied sacrificial layer in a wet etching solution until the occupied sacrificial layer is corroded and removed.
Subsequently, the placeholder sacrificial layer may be immersed in the wet etching solution until the placeholder sacrificial layer 24 is etched away by the wet etching solution, as shown in (b) of fig. 9. In some examples of this embodiment, the entire chip assembly 20 may be immersed in the wet etching solution, and in other examples, only the side of the chip assembly 20 provided with the space-occupying sacrificial layer 24 may be immersed in the wet etching solution, and a part of the area on the light emitting chip 22 may still be exposed to the liquid surface. It should be appreciated that the wet etching solution should not damage the light emitting chips 22, at least for a short time, the light emitting chips 22.
It is needless to say that the process in S804 may be omitted if the chip component provided is the chip component without the space occupying sacrificial layer in the foregoing embodiment.
S806: at least two light emitting chips in the chip assembly are bonded to the driving back plate.
In the present embodiment, after the removal of the space-occupying sacrificial layer 24, the light emitting chips in the chip assembly 20 may be bonded to the driving back plate, that is, the chip electrodes of the light emitting chips 22 and the pads on the driving back plate 90 are soldered together, as shown in (c) of fig. 9.
S808: and removing the adhesive layer and the bearing substrate to manufacture the display panel.
After the bonding of the light emitting chip 22 and the driving back plate is completed, the adhesive layer 23 and the carrier substrate 21 may be removed, resulting in the display panel 100, as shown in (d) of fig. 9. In some examples of the present embodiment, the adhesive layer 23 is formed of a thermal adhesive, and thus, removal of the adhesive layer 23 from the carrier substrate 21 may be achieved by heating the adhesive layer 23. In other examples of the present embodiment, the adhesion layer 23 may be removed by laser, and thus, the laser penetration of the carrier substrate 21 may also be controlled to decompose the adhesion layer 23, so that the carrier substrate 21 and the adhesion layer 23 are removed.
It will be appreciated that after the removal of the space-occupying sacrificial layer 24, there is an empty space between the carrier substrate 21 and the light emitting chip 22, and therefore, in some examples of this embodiment, if the adhesive layer 23 is a brittle material after curing is completed, the weakened connection structure between the carrier substrate 21 and the light emitting chip 22 may be broken by applying pressure toward each other to at least one of the carrier substrate 21 and the driving back plate, so that the carrier substrate 21 and the adhesive layer 23 are separated from the light emitting chip 22. For example, if, in the preparation of the chip assembly 20, the portions of the growth substrate corresponding to the four inner corner regions of the distal back surface of the light emitting chip 22 are removed, and the outer sides of the four inner corner regions of the distal back surface of the light emitting chip 22 are exposed to the space-occupying sacrificial layer 24, after the adhesive layer 23 is provided, the adhesive layer 23 is placed on the distal back surface of one light emitting chip 22 like a four-leg table, and the adhesive layer 23 and the light emitting chip 22 are connected by four "legs", so that when a pressure is applied to the table top through the carrier substrate 21 and exceeds the bearing limit of the "legs", the "legs" will break, thereby causing the "table top" and the carrier substrate 21 connected to the "table top" to come off together. If the portion of the growth substrate corresponding to the center region of the distal back surface of the light emitting chip 22 is removed during the fabrication of the chip assembly 20, after the adhesive layer 23 is provided, the adhesive layer 23 is placed on the distal back surface of one of the light emitting chips 22 like a single leg table, and the adhesive layer 23 is connected to the light emitting chip 22 by a "leg" so that when pressure is applied to the table surface through the carrier substrate 21 and exceeds the bearing limit of the "leg", the "leg" is also broken so that most of the adhesive layer 23 is removed together with the carrier substrate 21.
It will be appreciated that fig. 8 shows only one application of the chip assembly 20, and in other examples of this embodiment, the light emitting chip 22 may be picked up from the carrier substrate 21 and then the light emitting chip 22 may be transferred to the driving back plate to complete bonding.
According to the chip assembly preparation method and the display panel preparation method, the occupied sacrificial layer is formed by directly utilizing the growth substrate of the light-emitting chip, so that the epitaxial layer of the light-emitting chip grows from the growth substrate to the preparation of the chip assembly, the substrate transfer of the epitaxial layer is not required, the multiple transfer processes in the preparation process of the related display panel are avoided, the preparation difficulty of the display panel is reduced, meanwhile, the damage caused by the multiple transfer to the light-emitting chip is avoided, the preparation efficiency of the display panel is improved, and the production cost is reduced. Meanwhile, the adhesion layer forms a weakened connection structure between the bearing substrate and the light-emitting chip by utilizing the occupying sacrificial layer, so that the efficiency and the yield of transferring the light-emitting chip on the chip assembly to the driving backboard are improved.
It is to be understood that the application is not limited in its application to the examples described above, but is capable of modification and variation in light of the above teachings by those skilled in the art, and that all such modifications and variations are intended to be included within the scope of the appended claims.
Claims (10)
1. A chip assembly, comprising:
a carrier substrate;
at least two light emitting chips on the carrier substrate; and
an adhesion layer and a space occupying sacrificial layer positioned between the bearing substrate and the light emitting chip;
wherein, the surface of the light emitting chip configured to face the driving backboard is a near backboard surface, the surface opposite to the near backboard surface is a far backboard surface, and the far backboard surface faces the bearing substrate; the adhesive layer is used for simultaneously bonding the far back plate surface and the bearing substrate, and the contact area of the adhesive layer and the far back plate surface is smaller than that of the adhesive layer and the bearing substrate; the space occupying sacrificial layer is attached to the far back plate surface and comprises a first area in contact with the far back plate surface and a second area in an unoccluded state, and the first area is communicated with the second area.
2. The chip assembly of claim 1, wherein the placeholder sacrificial layer is formed from a growth substrate of the light emitting chip.
3. The chip assembly of claim 2, wherein the thickness of the placeholder sacrificial layer is less than the thickness of the growth substrate.
4. The chip assembly of claim 1, wherein a contact area of the adhesive layer with the distal back plate surface is less than a contact area of the placeholder sacrificial layer with the distal back plate surface.
5. The chip assembly of any one of claims 1-4, wherein the distal back plate is rectangular, the rectangle comprising four interior corner regions, the adhesive layer being attached to the four interior corner regions simultaneously.
6. A chip assembly, comprising:
a carrier substrate;
at least two light emitting chips on the carrier substrate; and
an adhesion layer between the carrier substrate and the light emitting chip and configured to adhere the two;
wherein, the surface of the light emitting chip configured to face the driving backboard is a near backboard surface, the surface opposite to the near backboard surface is a far backboard surface, and the far backboard surface faces the bearing substrate; the contact area of the adhesion layer and the far back plate surface is smaller than the contact area of the adhesion layer and the bearing substrate; an empty space exists between the light emitting chip and the bearing substrate, the empty space is in surface contact with the far backboard, and the empty space is communicated with an external space.
7. A method for manufacturing a chip assembly, characterized by being applied to the manufacturing of a chip assembly according to any one of claims 1 to 5, the method comprising:
providing an epitaxial layer on a growth substrate, wherein the epitaxial layer comprises an N-type semiconductor layer, an active layer and a P-type semiconductor layer, and the distance between the N-type semiconductor layer, the active layer and the P-type semiconductor layer are sequentially increased;
an N electrode and a P electrode which are electrically connected with the N-type semiconductor layer and the P-type semiconductor layer are respectively arranged to form at least two light emitting chips, and one surface of each light emitting chip facing the growth substrate is a far back plate surface;
arranging adhesive glue on one side of the growth substrate provided with the light-emitting chip, and adhering a temporary substrate opposite to the growth substrate through the adhesive glue;
patterning the growth substrate until a partial area of the far back plate surface is exposed out of the growth substrate, so as to form a space occupying sacrificial layer by using the growth substrate;
an adhesive layer is arranged on one side of the light-emitting chip far away from the temporary substrate, and a bearing substrate opposite to the temporary substrate is adhered through the adhesive layer, wherein the contact area of the adhesive layer and the far back plate surface is smaller than that of the adhesive layer and the bearing substrate; after the adhesive layer is arranged, the occupying sacrificial layer comprises a first area in contact with the far backboard surface and a second area in an unoccluded state, and the first area is communicated with the second area;
And removing the adhesive and the temporary substrate to obtain the chip assembly.
8. The method of manufacturing a chip assembly of claim 7, wherein prior to patterning the growth substrate, further comprising:
and thinning the growth substrate.
9. The method of manufacturing a chip assembly of claim 7, wherein the adhesive is a thermal adhesive, and the removing the adhesive and the temporary substrate comprises:
and heating the adhesive until the adhesive fails and the light-emitting chip falls off.
10. A method for manufacturing a display panel, comprising:
providing a chip assembly according to any one of claims 1-5;
immersing the occupied sacrificial layer in a wet etching solution until the occupied sacrificial layer is removed by corrosion;
bonding at least two of the light emitting chips in the chip assembly to a drive back plate;
and removing the adhesion layer and the bearing substrate to obtain the display panel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210455933.4A CN117012768A (en) | 2022-04-27 | 2022-04-27 | Chip assembly and preparation method thereof, and preparation method of display panel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210455933.4A CN117012768A (en) | 2022-04-27 | 2022-04-27 | Chip assembly and preparation method thereof, and preparation method of display panel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117012768A true CN117012768A (en) | 2023-11-07 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210455933.4A Pending CN117012768A (en) | 2022-04-27 | 2022-04-27 | Chip assembly and preparation method thereof, and preparation method of display panel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117012768A (en) |
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2022
- 2022-04-27 CN CN202210455933.4A patent/CN117012768A/en active Pending
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