CN113745130A

CN113745130A - Transfer mechanism

Info

Publication number: CN113745130A
Application number: CN202110968534.3A
Authority: CN
Inventors: 胡琛; 卢马才
Original assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2021-08-23
Filing date: 2021-08-23
Publication date: 2021-12-03
Anticipated expiration: 2041-08-23
Also published as: CN113745130B

Abstract

The application provides a transfer mechanism for transferring micro light-emitting element, transfer mechanism includes switch base plate and transfer assembly, transfer assembly set up in on the switch base plate, transfer assembly includes: the dielectric layer is a flexible dielectric layer, and a cavity is formed inside the dielectric layer; the transfer assembly is arranged on the inner wall of one surface of the cavity facing the micro light-emitting element; the elastic filling layer is filled in the cavity. This application is through the setting of flexible dielectric layer and elasticity filling layer for the transfer assembly elasticity filling layer can provide sufficient buffer space when adsorbing miniature light-emitting component, makes the dielectric layer can be produced elastic deformation, thereby increases the area of contact of the contact surface of unevenness between miniature light-emitting component and the transfer mechanism, thereby be favorable to increasing the adsorption affinity between miniature light-emitting component and the transfer mechanism, and then improves the yield that the transfer mechanism shifted miniature light-emitting component in-process.

Description

Transfer mechanism

Technical Field

The application relates to the technical field of display devices, in particular to a transfer mechanism.

Background

The Micro LED (Micro-LED) or mini LED (mini LED) display technology uses a Micro light emitting element of 1 to 100 micrometers (μm) as a pixel unit of a display, and has the outstanding advantages of high quantum efficiency, high contrast, high viewing angle, high color gamut, extremely fast response time, easy transparent display, long service life and the like compared with the LCD and OLED display technologies, and will gradually become the mainstream technology of the next generation display.

In the manufacturing process of Micro or Mini LED display devices, the key process is to accurately and rapidly transfer the single or cut Micro light-emitting elements with Micro light-emitting elements in small size onto the display substrate. When a large number of micro-light-emitting elements can be transferred at one time, the process is called bulk transfer. At present, the bulk transfer process generally picks up the micro light-emitting devices by a transfer mechanism onto the transfer mechanism, and transfers the picked micro light-emitting devices to the TFT substrate by the transfer mechanism.

At present, when the micro light-emitting element is transferred to the display substrate, the situations of core leakage, crystal setting and micro light-emitting element deviation, poor contact between an electrode of the micro light-emitting element and a bonding pad, insufficient joint and the like are easy to occur due to the reasons of errors in manufacturing processes of an adapter of a transfer mechanism or the micro light-emitting element, and finally the conditions of abnormal pixel display and low yield of the micro light-emitting element transfer process are caused.

Disclosure of Invention

The application provides a transfer mechanism to solve the problem that transfer mechanism transfer process yield is low.

The present application provides a transfer mechanism for transferring a micro-light emitting element, the transfer mechanism comprising: switch base plate and transfer assembly, the transfer assembly set up in on the switch base plate, the transfer assembly includes:

the dielectric layer is arranged on the switch substrate, the dielectric layer is a flexible dielectric layer, and a cavity is formed in the dielectric layer;

the adsorption component is arranged on the inner wall of one surface of the cavity facing the switch substrate;

the elastic filling layer is filled in the cavity.

In this application a possible implementation, the dielectric layer includes bottom surface and side, the bottom surface is for the orientation switch substrate's one side, the side encloses to be located the border of bottom surface, the side with interior angle between the bottom surface is the obtuse angle setting.

In one possible implementation manner of the present application, a side of the dielectric layer facing the switch substrate is a plane.

In one possible implementation manner of the present application, the transfer mechanism further includes:

a piezoelectric layer disposed between the switch substrate and the transfer assembly.

the protective layer is arranged between the piezoelectric layer and the transfer component and is made of an insulating material.

In one possible implementation manner of the present application, the switch substrate includes a base, and a gate layer and a source drain layer sequentially disposed along a direction departing from the base.

In one possible implementation of the present application, the piezoelectric layer is disposed on a surface of the gate, and the piezoelectric layer is disposed between the gate and the protective layer.

In one possible implementation manner of the present application, the protection layer is disposed on the surface of the source electrode, the drain electrode, and the piezoelectric layer.

In one possible implementation manner of the present application, the transfer mechanism further includes: the detection control circuit and the adsorption control circuit are respectively electrically connected with the switch substrate.

In one possible implementation of the present application, the transfer assembly includes one of an electrostatic electrode, a coil, or an adhesive glue.

The application provides a pair of transfer mechanism, through will shift the subassembly set up in on the switch substrate, and shift the flexible dielectric layer of subassembly inside has seted up the cavity, will shift the subassembly set up in cavity inner wall, and fill elasticity filling layer in the cavity. Because the surface of the micro light-emitting element and the surface of the dielectric layer are both of uneven structures with concave-convex fluctuation, namely the contact surface between the micro light-emitting element and the transfer mechanism is uneven, through the arrangement of the flexible dielectric layer and the elastic filling layer, the elastic filling layer can provide enough buffer space when the transfer assembly adsorbs the micro light-emitting element, so that the dielectric layer can be elastically deformed, the contact area between the micro light-emitting element and the transfer mechanism is increased, the adsorption force between the micro light-emitting element and the transfer mechanism is increased, and the yield of the transfer mechanism in the process of transferring the micro light-emitting element is improved.

Drawings

The technical solution and other advantages of the present application will become apparent from the detailed description of the embodiments of the present application with reference to the accompanying drawings.

Fig. 1 is a schematic cross-sectional structural view of a transfer mechanism according to an embodiment of the present application.

Fig. 2 is a schematic structural diagram of a transfer assembly in a transfer mechanism according to an embodiment of the present application.

Fig. 3 is a schematic structural diagram of a switch substrate in a transfer mechanism according to an embodiment of the present application.

Fig. 4 is a schematic structural diagram of a transfer mechanism adsorbing a micro light-emitting device according to an embodiment of the present application.

Fig. 5 is a schematic circuit connection diagram of a transfer mechanism according to an embodiment of the present disclosure.

Fig. 6 is a schematic structural diagram of a display substrate according to an embodiment of the present application.

Fig. 7 is a schematic diagram illustrating a transfer mechanism for transferring micro light-emitting devices to a display substrate according to an embodiment of the present disclosure.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact of the first and second features, or may comprise contact of the first and second features not directly but through another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The following disclosure provides many different embodiments or examples for implementing different features of the application. In order to simplify the disclosure of the present application, specific example components and arrangements are described below. Of course, they are merely examples and are not intended to limit the present application.

Referring to fig. 1 to 7, an embodiment of the present application provides a transfer mechanism for transferring a micro light emitting device 210, the transfer mechanism includes a switch substrate 10 and a transfer assembly 20, and the transfer assembly 20 is disposed on the switch substrate 10.

The transfer member 20 includes a dielectric layer 21, an elastic filling layer 22, and an adsorption member 23.

The dielectric layer 21, the dielectric layer 21 is a flexible dielectric layer, and the dielectric layer 21 encloses a cavity 201. Specifically, the dielectric layer 21 is made of a flexible organic piezoelectric material, so that the dielectric layer 21 can be elastically deformed when being subjected to an external force.

Referring to fig. 1 and fig. 2, the adsorption component 23 is disposed on an inner wall of a surface of the cavity 201 facing the switch substrate 10, and the adsorption component 23 is used for adsorbing and picking up or releasing the micro light emitting device 210.

The elastic filling layer 22 is filled in the cavity 201. The elastic filling layer 22 is used to provide sufficient space for the formation of the dielectric layer 21. Specifically, the material of the elastic filling layer 22 may be a metal nanomaterial capable of conducting electricity, such as at least one of aluminum, tungsten, titanium oxide, hafnium oxide, tantalum oxide, zirconium oxide, and aluminum oxide.

According to the transfer mechanism provided by the embodiment of the application, the transfer component 20 is arranged on the switch substrate 10, the cavity 201 is formed in the flexible dielectric layer 21 of the transfer component 20, the transfer component 20 is arranged on the inner wall of the cavity 201, and the elastic filling layer 22 is filled in the cavity 201. Because the surface of the micro light-emitting element 210 and the surface of the dielectric layer 21 are both of uneven structures with concave-convex fluctuation, that is, the contact surface between the micro light-emitting element 210 and the transfer mechanism is uneven, the arrangement of the dielectric layer 21 and the elastic filling layer 22 enables the elastic filling layer 22 to provide enough buffer space when the transfer assembly 20 adsorbs the micro light-emitting element 210, so that the dielectric layer 21 can be elastically deformed, thereby increasing the contact area between the micro light-emitting element 210 and the transfer mechanism, increasing the adsorption force between the micro light-emitting element 210 and the transfer mechanism, and further improving the yield in the process of transferring the micro light-emitting element 210 by the transfer mechanism.

In some embodiments, the dielectric layer 21 includes a bottom surface 212 and a side surface 211, the bottom surface 212 is a surface facing away from the switch substrate 10, i.e., a surface facing the micro light emitting device 210, the side surface 211 surrounds an edge of the bottom surface 212, and an inner angle between the side surface 211 and the bottom surface 212 is an obtuse angle.

Illustratively, when the dielectric layer 21 is in a truncated cone structure, the radius thereof gradually decreases along a direction approaching the micro light-emitting element 210. Compared with an upper-lower equal-width structure such as a cylinder, the structure of the dielectric layer 21 can make the dielectric layer 21 not easily scratch other structures on the display substrate 200 when the micro light-emitting element 210 is transferred to the dielectric layer 21, especially when the micro light-emitting element 210 is placed on the display substrate 200 after the micro light-emitting element 210 is adsorbed, so that the display substrate 200 can be better protected.

In some embodiments, the surface of the dielectric layer 21 facing the micro light-emitting element 210 is a plane, that is, the bottom surface 212 of the dielectric layer 21 is a plane, and by disposing the ground surface as a plane, it is beneficial to further increase the contact area between the dielectric layer and the micro light-emitting element 210, so as to further enhance the suction force of the suction component 23 on the micro light-emitting element 210.

In some embodiments, the transfer mechanism further comprises a piezoelectric layer 30.

The piezoelectric layer 30 is made of a flexible organic piezoelectric material, and may specifically be at least one of quartz crystal, lithium gallate, lithium germanate, titanium germanate, iron transistor lithium niobate, lithium tantalate, barium titanate BT, lead zirconate titanate PZT, modified lead zirconate titanate, lead meta-niobate, lead barium lithium niobate PBLN, modified lead titanate PT, and an organic piezoelectric material such as polyvinylidene fluoride (PVDF).

Wherein the piezoelectric layer 30 is disposed between the switch substrate 10 and the transfer member 20. In the embodiment of the present invention, the dielectric layer 21 and the piezoelectric layer 30 are both made of insulating materials, and when pressure is applied, only the thickness of the film of the sensor changes, so that the sensor is a capacitive pressure sensor, and the transfer unit 20 can achieve a detection function, for example, whether the bonding of the micro light emitting device 210 is good or not can be detected by the capacitive pressure sensor.

Illustratively, when the metal nanomaterial of the elastic filling layer 22 is disposed in the dielectric layer 21, conductive particles are distributed in the dielectric layer 21, and no conductive particles are disposed in the piezoelectric layer 30, then when the pressure is low, only the thickness of the dielectric layer 21 changes, and when the pressure is high, the piezoelectric layer 30 deforms, and the conductive particles therein gradually gather and contact to generate a conductive action, so that the structure forms a capacitance-resistance type pressure sensor combining capacitance and resistance.

In some embodiments, the piezoelectric layer 30 is disposed on a surface of the gate layer 13, the gate layer 13 serves as a contact electrode layer of the piezoelectric layer 30, and the piezoelectric layer 30 is disposed between the gate layer 13 and the protection layer 40. The piezoelectric layer 30 is in contact with the gate layer 13, so that pressure generated between the piezoelectric layer 30 and the transferred micro light-emitting element 210 can be converted into an electrical signal of the gate layer 13, and then the signal is output through the switch substrate 10 controlled by the gate layer 13, thereby realizing signal detection.

In some embodiments, as shown in fig. 5, the transfer mechanism further includes a detection control circuit 102 and a suction control circuit 101, and the detection control circuit 102 and the suction control circuit 101 are electrically connected to the switch substrate 10, respectively.

The switch substrate 10 can control the piezoelectric layer 30 through the absorption control circuit 101 to realize real-time detection of the binding condition of the micro light emitting element 210 on the display substrate 200.

Specifically, as shown in fig. 6 and fig. 7, since the piezoelectric layer 30 is made of a piezoelectric material, during the transfer process, the binding condition of the micro light emitting device 210 may generate a tensile or compressive force on the piezoelectric material, and the piezoelectric material may form a voltage according to the tensile or compressive force, so as to change the electrical property of the thin film transistor in the switch substrate 10, and generate or change an electrical signal. Thus, when the transferring member 20 picks up the micro light emitting elements 210, the transferring mechanism can confirm whether the micro light emitting elements 210 are properly picked up by the transferring member 20 or whether the micro light emitting elements 210 themselves have a defect or flaw. The transfer mechanism can also detect the binding condition of the micro light-emitting elements 210 on the display substrate 200, so that the transfer mechanism contacts the display substrate 200, the point positions with the micro light-emitting elements 210 generate resistance, the point positions without the micro light-emitting elements 210 do not generate resistance, and the difference of the electric signals can be fed back to the system for repair.

When the transfer mechanism bound with the micro light-emitting element 210 is in contact with the display backboard, the transfer mechanism can detect the bonding condition of the micro light-emitting element 210 and the display backboard in real time through a piezoelectric signal, and then the transfer mechanism can be adjusted in real time to avoid the phenomenon that the bonding force bound with the micro light-emitting element 210 is too large or too small, so that the transfer failure or pressure injury is avoided. The transfer mechanism is also able to confirm that the micro-lighting elements 210 are properly positioned at the target location and that the micro-lighting elements 210 are picked up or otherwise defective when the transfer assembly 20 is removed.

In addition, the transfer mechanism can identify the bonding condition of the micro light-emitting elements 210 and then repair the micro light-emitting elements in a targeted manner, and if the bonding of the micro light-emitting elements 210 at a certain point fails, the transfer mechanism can locate the failed point and selectively pick up the corresponding micro light-emitting element 210 for repair when binding next time.

In some embodiments, the transfer mechanism further comprises a protective layer 40. A protective layer 40 is disposed between piezoelectric layer 30 and transfer member 20.

Specifically, the protection layer 40 is made of an insulating material. The protective layer 40 may be an inorganic insulating material, such as one of silicon compounds of SiOx, SiNx, SiOx, SiNOx, etc., or an organic insulating material, such as one of PS, PVP, PMMA, PVC, PP, PE, etc. A protective layer 40 is deposited on the piezoelectric layer 30 to increase the stability of the device.

Specifically, in some embodiments, the protection layer 40 is disposed on the surface of the source drain layer 14 and the piezoelectric layer 30.

In some embodiments, a plurality of Thin Film Transistors (TFTs) are disposed on the switch substrate 10 in an array. The TFT array may adopt different structures and materials, and the TFT may be specifically an oxide semiconductor TFT, a silicon-based TFT, and the like, which is not limited herein.

Specifically, the switch substrate 10 includes a substrate 11, and an active layer 12, a gate layer 13, and a source drain layer 14 sequentially disposed along a direction departing from the substrate 11, where the source drain layer 14 includes a source and a drain, and the source and the drain are disposed in the same layer.

In some embodiments, the adsorbent assembly 23 comprises one of an electrostatic electrode, a coil, or an adhesive glue.

Specifically, the absorption element 23 is disposed on the inner wall of the dielectric layer 21, and the absorption of the micro light emitting device 210 by the absorption element 23 can be achieved by a mechanical force (e.g., an adhesive force) or an electromagnetic force (e.g., an electrostatic force or an electrostatic force increased by an ac voltage of a bipolar electrode).

The adsorption component 23 is connected to the adsorption control circuit 101 through the piezoelectric layer 30 on the switch substrate 10, and the adsorption component 23 may be an electrostatic adsorption component 23 or an electromagnetic adsorption component 23, and adsorbs the micro light emitting device 210 by an adsorption force. The electrostatic adsorption type adsorption assembly 23 may be an electrostatic adsorption assembly 23 having a bipolar structure. Illustratively, the adsorption assembly 23 includes a pair of silicon electrodes. When transferring, positive and negative voltages are respectively applied to the silicon electrodes in the transferring process, when the micro light-emitting element 210 needs to be picked up from the source substrate, the adsorption assembly 23 contacts the micro light-emitting element 210 to be transferred, a positive voltage is applied to one silicon electrode of the adsorption assembly 23, the micro light-emitting element 210 is adsorbed on the adsorption assembly 23, when the micro light-emitting element 210 needs to be placed at the target position of the display substrate, a negative voltage is applied to the other silicon electrode, and the adsorbed micro light-emitting element 210 can be released, so that the transferring is completed.

The adsorption component 23 of the electromagnetic adsorption type transfer mechanism may include a conductive coil, and the current of the conductive coil is controlled to control the presence or absence of magnetism, so as to realize the picking up and releasing of the micro light-emitting element.

Wherein the viscous rubber material is selected from one of water glass, synthetic resin, synthetic rubber and the like.

In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

In a specific implementation, each unit or structure may be implemented as an independent entity, or may be combined arbitrarily to be implemented as one or several entities, and the specific implementation of each unit or structure may refer to the foregoing method embodiment, which is not described herein again.

The foregoing describes in detail a transfer mechanism provided in an embodiment of the present application, and a specific example is applied to describe the principle and implementation manner of the embodiment of the present application, and the description of the foregoing embodiment is only used to help understanding the technical solution and the core idea of the embodiment of the present application; those of ordinary skill in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications or substitutions do not depart from the spirit and scope of the present disclosure as defined by the appended claims.

Claims

1. A transfer mechanism for transferring a micro-light emitting element, the transfer mechanism comprising: switch base plate and transfer assembly, the transfer assembly set up in on the switch base plate, the transfer assembly includes:

the elastic filling layer is filled in the cavity.

2. The transfer mechanism of claim 1, wherein the dielectric layer comprises a bottom surface and a side surface, the bottom surface is a surface facing away from the switch substrate, the side surface is arranged around an edge of the bottom surface, and an inner angle between the side surface and the bottom surface is arranged in an obtuse angle.

3. The transfer mechanism of claim 2, wherein a bottom surface of the dielectric layer is planar.

4. The transfer mechanism of claim 1, further comprising:

5. The transfer mechanism of claim 4, further comprising:

6. The transfer mechanism of claim 5, wherein the switch substrate comprises a base and a gate and source drain layer sequentially disposed along a direction away from the base.

7. The transfer mechanism of claim 6, wherein the piezoelectric layer is disposed on a surface of the gate, the piezoelectric layer being disposed between the gate and the protective layer.

8. The transfer mechanism of claim 7, wherein said protective layer is disposed on a surface of said source drain layer and said piezoelectric layer.

9. The transfer mechanism of any one of claims 1-8, further comprising: the detection control circuit and the adsorption control circuit are respectively electrically connected with the switch substrate.

10. The transfer mechanism of any one of claims 1-8, wherein the adsorption component comprises one of an electrostatic electrode, a coil, or an adhesive glue.