CN110911436B - A transfer device and transfer method for driving backplane and light-emitting diodes - Google Patents

Abstract

The invention discloses a driving backplane, a transfer device for light-emitting diodes, and a transfer method, wherein the transfer device for light-emitting diodes includes: a transfer substrate, a plurality of transfer head structures located on the transfer substrate, a plurality of photosensitive sensors and a plurality of The transfer head structure is provided with a photosensitive sensor and two detection probes on the side away from the transfer substrate; the transfer head structure has an accommodating area for accommodating light-emitting diodes, and the two detection probes are respectively located in the accommodating area. The opposite sides of the area; the detection probes are used to electrically connect with the contact electrodes at the corresponding positions on the driving backplane after the transfer device is pressed together with the driving backplane, and provide driving voltages to the contact electrodes; the photosensitive sensor is used for After the detection probe provides a driving voltage to the contact electrode, it detects whether the light-emitting diode at the corresponding position emits light, and outputs a photosensitive detection signal. The transfer device provided by the embodiment of the present invention realizes the detection of the light-emitting diode during the transfer process.

Description

A transfer device and transfer method for driving backplane and light-emitting diodes

technical field

The present invention relates to the field of display technology, in particular to a transfer device and transfer method for driving a backplane and light emitting diodes.

Background technique

Micro light-emitting diodes (μLEDs) have the characteristics of self-illumination without a backlight, which is similar to organic light-emitting diodes (OLEDs), but compared to organic light-emitting diodes, the color of micro-light-emitting diodes is easier and more accurate. It has the advantages of simple structure, almost no light consumption, very long service life, high brightness, low power consumption, ultra-high resolution and color saturation. The biggest advantage of micro light-emitting diodes comes from its biggest feature, that is, the micron-level pitch, each pixel can be addressed and controlled and driven to emit light at a single point. Therefore, compared with other display modes, the luminous efficiency is the highest.

At present, the application fields of micro-LEDs are very wide, spanning wearable devices, large indoor display screens, head-mounted displays, head-up displays (HUDs), taillights, wireless optical communication (Li-Fi), projectors, etc.

However, due to the extremely small size of micro-LEDs and the need for refined operating techniques, micro-LEDs are more fragile than conventional LEDs. Therefore, the success rate of the transfer process for micro-LEDs is related to the overall display effect. However, , the current transfer method cannot detect the micro-LEDs during the transfer process.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a driving backplane, a transfer device for light-emitting diodes, and a transfer method, so as to solve the problem in the prior art that micro-LEDs cannot be detected during the transfer process.

In a first aspect, an embodiment of the present invention provides a light-emitting diode transfer device, including: a transfer substrate, a plurality of transfer head structures located on the transfer substrate, a plurality of photosensitive sensors, and a plurality of detection probes;

The transfer head structure is provided with the photosensitive sensor and the two detection probes on the side away from the transfer substrate;

The transfer head structure has an accommodating area for accommodating light-emitting diodes, and the two detection probes are respectively located on opposite sides of the accommodating area;

The detection probe is used to electrically connect with the contact electrode at the corresponding position on the drive backplane after the transfer device is pressed together with the drive backplane, and provide a drive voltage to the contact electrode;

The photosensitive sensor is used for detecting whether the light emitting diode at the corresponding position emits light after the detection probe provides a driving voltage to the contact electrode, and outputs a photosensitive detection signal.

In a possible implementation manner, in the above-mentioned transfer device provided by the embodiment of the present invention, the detection probe is retractable in a direction perpendicular to the transfer substrate.

In a possible implementation manner, in the above-mentioned transfer device provided by the embodiment of the present invention, the detection probe includes: an elastic conductive structure and a conductive probe that are electrically connected to each other.

In a possible implementation manner, in the above-mentioned transfer device provided by the embodiment of the present invention, the transfer head structure has a groove at a position corresponding to the detection probe;

the elastic conductive structure is located inside the groove;

The conductive probe has an engaging portion at one end close to the elastic conductive structure; the engaging portion is located inside the groove, and the engaging portion cannot pass through the opening of the groove, and the conductive The part of the probe other than the engaging part can pass through the opening of the groove.

In a possible implementation manner, in the above-mentioned transfer device provided by the embodiment of the present invention, the elastic conductive structure includes: a plurality of elastic conductive microspheres;

A plurality of the elastic conductive microspheres are filled in the grooves on the side of the engaging portion close to the transfer substrate.

In a possible implementation manner, in the above-mentioned transfer device provided by the embodiment of the present invention, the material of the conductive probe is one of copper, aluminum, silver, and gold, or an alloy composed of at least two of them.

In a second aspect, an embodiment of the present invention further provides a driving backplane, including: a base substrate, a plurality of contact electrode groups and a plurality of conductive structures located on the base substrate;

The contact electrode group is used for electrical connection with one light-emitting diode, and the contact electrode group includes two oppositely arranged contact electrodes;

The contact electrode group corresponds to the two oppositely arranged conductive structures, and the two contact electrodes in the contact electrode group are located between the corresponding two conductive structures; the conductive structures and the corresponding contact the electrodes are in contact;

the conductive structure corresponds to the position of the detection probe in the transfer device;

The conductive structure is used for contacting the detection probe in the transfer device after the transfer device is pressed against the driving backplane.

In a possible implementation manner, in the above-mentioned driving backplane provided by the embodiment of the present invention, the contact electrode is an elastic conductive glue.

In a possible implementation manner, in the above-mentioned driving backplane provided by the embodiment of the present invention, the height of the conductive structure is lower than the height of the corresponding contact electrode.

In a third aspect, an embodiment of the present invention also provides a method for transferring a light emitting diode, including:

Adopt the above-mentioned transfer device to adsorb a plurality of light emitting diodes;

moving the transfer device to the top of the driving backplane, and the side on which the light-emitting diode is adsorbed by the transfer device is opposite to the side with the contact electrodes of the driving backplane;

aligning and pressing the transfer device and the driving backplane, so that the detection probes in the transfer device are in contact with the corresponding conductive structures on the driving backplane;

applying a driving voltage to each of the detection probes;

According to the photosensitive detection signals output by each photosensitive sensor in the transfer device, it is determined whether each of the light-emitting diodes is successfully transferred.

The beneficial effects of the present invention are as follows:

Embodiments of the present invention provide a driving backplane, a light-emitting diode transfer device, and a transfer method, wherein the light-emitting diode transfer device includes: a transfer substrate, a plurality of transfer head structures located on the transfer substrate, a plurality of photosensitive sensors, and a plurality of The transfer head structure is provided with a photosensitive sensor and two detection probes on the side away from the transfer substrate; the transfer head structure has an accommodating area for accommodating light-emitting diodes, and the two detection probes are respectively located in the accommodating area. The two opposite sides of the area; the detection probes are used to electrically connect with the contact electrodes at the corresponding positions on the driving backplane after the transfer device is pressed together with the driving backplane, and provide driving voltages to the contact electrodes; the photosensitive sensor is used for After the detection probe provides a driving voltage to the contact electrode, it detects whether the light-emitting diode at the corresponding position emits light, and outputs a photosensitive detection signal. In the light-emitting diode transfer device provided by the embodiment of the present invention, by arranging a photosensitive sensor and a detection probe on the side of the transfer head structure away from the transfer substrate, after the transfer device and the driving backplane are pressed together, the detection probe can be connected with the driving backplane. The contact electrodes at the corresponding positions are electrically connected, and a driving voltage is provided to the contact electrodes, and then a photosensitive sensor can be used to detect whether the light-emitting diodes at the corresponding positions emit light, thereby realizing the detection of the light-emitting diodes during the process of transferring the light-emitting diodes.

Description of drawings

FIG. 1 is a schematic structural diagram of a light-emitting diode transfer device provided by an implementation of the present invention;

FIG. 2 is a schematic structural diagram of a transfer device after picking up a light-emitting diode according to an embodiment of the present invention;

3 is a schematic view of the transfer device viewed from the side of the detection probe toward the side of the transfer substrate;

4 is a schematic structural diagram of a transfer head structure picking up light-emitting diodes in an embodiment of the present invention;

5 is a schematic structural diagram of a detection probe in an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a drive backplane provided by an embodiment of the present invention;

7 is a schematic top-view structural diagram of a driving backplane in an embodiment of the present invention;

8 is a schematic structural diagram of a transfer device in the prior art after being pressed with a driving backplane;

9 is a schematic structural diagram of the transfer device and the driving backplane after being pressed together in an embodiment of the present invention;

10 is a flowchart of a method for transferring a light emitting diode according to an embodiment of the present invention;

11 to 13 are schematic structural diagrams corresponding to each step in the above-mentioned transfer method according to an embodiment of the present invention;

FIG. 14 to FIG. 16 are respectively schematic structural diagrams of the case where the transfer of the light emitting diode fails in the embodiment of the present invention.

Detailed ways

Aiming at the problem in the prior art that the micro-LEDs cannot be detected during the transfer process, embodiments of the present invention provide a driving backplane, a transfer device for light-emitting diodes, and a transfer method.

The specific implementations of the driving backplane, the light-emitting diode transfer device and the transfer method provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The thickness and shape of each film layer in the drawings do not reflect the actual scale, and are only intended to illustrate the content of the present invention.

In a first aspect, an embodiment of the present invention provides a transfer device for light emitting diodes, as shown in FIG. 1 , including: a transfer substrate 10 , a plurality of transfer head structures 11 located on the transfer substrate 10 , a plurality of photosensitive sensors 12 , and a plurality of detection probes 13;

The transfer head structure 11 is provided with a photosensitive sensor 12 and two detection probes 13 on the side away from the transfer substrate 10;

The transfer head structure 11 has an accommodating area D for accommodating the light-emitting diodes, and the two detection probes 13 are respectively located on opposite sides of the accommodating area D;

The detection probe 13 is used for electrically connecting with the contact electrode at the corresponding position on the driving backplane after the transfer device is pressed together with the driving backplane, and providing a driving voltage to the contacting electrode;

The photosensitive sensor 12 is used to detect whether the light emitting diode at the corresponding position emits light after the detection probe 13 provides the driving voltage to the contact electrode, and output a photosensitive detection signal.

In the light-emitting diode transfer device provided by the embodiment of the present invention, by arranging a photosensitive sensor and a detection probe on the side of the transfer head structure away from the transfer substrate, after the transfer device and the driving backplane are pressed together, the detection probe can be connected with the driving backplane. The contact electrode at the corresponding position is electrically connected, and a driving voltage is provided to the contact electrode, and then the photosensitive sensor can be used to detect whether the light-emitting diode at the corresponding position emits light. The photosensitive detection signal output by the photosensitive sensor can feedback the effect of fixed-point transfer in real time. Thus, the detection of the light-emitting diode is realized during the process of transferring the light-emitting diode.

The transfer device provided by the embodiment of the present invention can be used to transfer micro-light-emitting diodes (μLEDs) with a size in the order of micrometers, and can transfer and mount a large number of micro-LEDs on the corresponding driving backplane. In addition, the above-mentioned transfer device can also It is applied to the process of transferring light-emitting diodes with larger size, and the application scenarios of the above-mentioned transfer device are not limited here.

In order to be able to pick up multiple light-emitting diodes at the same time, the above-mentioned transfer device includes a plurality of transfer head structures 11. In the drawings in the embodiments of the present invention, in order to illustrate the structure of the transfer device more clearly, only one of the transfer devices is used for transferring The head structure 11 is taken as an example for illustration. During the specific implementation, the number and distribution of the transfer head structure 11 can be set according to actual needs, which is not limited here.

In the embodiment of the present invention, the above-mentioned transfer head structure 11 may be an electrostatic adsorption type or an electromagnetic adsorption type transfer head, and the light-emitting diodes are adsorbed to the accommodating area through the adsorption force. Therefore, the transfer head structure 11 is disposed on the side away from the transfer substrate 10 . The photosensitive sensor 12 will not affect the adsorption of the light emitting diodes by the transfer head structure 11 . Specifically, the electrostatic adsorption transfer head includes periodically arranged electrostatic units. By controlling the on-off of the electrostatic units, electrostatic loading and unloading can be realized, so that the electrostatic units at the transfer part can be selectively turned on to absorb the light-emitting diodes, and the transfer head After the structure moves to the corresponding position, the electrostatic unit is disconnected to release the light-emitting diode, thereby realizing the transfer of the light-emitting diode. The electromagnetic adsorption transfer head includes a conductive coil, and the presence or absence of magnetism is controlled by controlling the current to realize the pickup and release of the light-emitting diode.

The above-mentioned photosensitive sensor 12 can use any device with the function of detecting light, for example, a photosensitive diode can be used, and it can also be other photosensitive devices, which is not limited here. The photosensitive sensor 12 is located on the side of the transfer head structure 11 away from the transfer substrate 10, so that the light emitted by the light-emitting diode can be more easily detected. 12 is embedded in the corresponding accommodating groove, or the photodiode 12 can also be directly fixed to the surface of the transfer head structure 11, which is not limited here.

In order to ensure that the light emitted by the light emitting diodes can be detected, at least one photosensitive sensor 12 is provided on the side of the transfer head structure 11 away from the transfer substrate 10, and more photosensitive sensors 12 can also be provided, which is not limited here. The detection probes 13 are provided to subsequently provide driving voltages to the contact electrodes on the driving backplane. Since each light-emitting diode corresponds to two contact electrodes, generally two detection probes are provided on the side of the transfer head structure 11 away from the transfer substrate 10 . Probe 13. In order to provide driving voltages to the contact electrodes on the driving backplane, the detection probes 13 are also electrically connected to the internal circuit of the transfer device, and the internal circuits provide corresponding driving voltages for the detection probes 13 respectively. The probes 13 are respectively connected to the positive voltage and the negative voltage, and the voltage difference between the positive voltage and the negative voltage can be set according to the excitation threshold voltage of the corresponding light-emitting diode.

FIG. 2 is a schematic view of the structure of the above-mentioned transfer device after picking up the light-emitting diode, and FIG. 3 is a schematic view of the transfer device viewed from the side of the detection probe 13 toward the side of the transfer substrate 10. As shown in FIGS. 2 and 3, the light-emitting diode 20 includes an epitaxy The structure 201 and the two lead electrodes 202 on the same side of the epitaxial structure 201 are mainly used for transferring and detecting the light emitting diodes 20 with the lead electrodes 202 on the same side of the epitaxial structure 201 as shown in FIG. 2 and FIG. 3 . In order to facilitate the electrical connection between the subsequent detection probe and the contact electrode at the corresponding position, the light emitting diode 20 needs to be located in the accommodating area D, and the arrangement of the lead electrode 202 of the transferred light emitting diode 20 needs to be consistent with the arrangement of the detection probe 13 . That is, the arrangement is as shown in FIG. 3 , that is, the arrangement is in the manner of the detection probe 13 , the extraction electrode 202 , the extraction electrode 202 , and the detection probe 13 .

In the actual transfer process, the transfer device shown in FIG. 2 after picking up the light-emitting diodes 20 is moved to the top of the corresponding driving backplane, and the positions of the plurality of transfer head structures 11 in the transfer device are respectively the same as those of the plurality of transfer head structures 11 on the driving backplane. The positions of the contact electrode groups correspond to each other. After the transfer device and the driving backplane are aligned and pressed together, the detection probes are respectively electrically connected to the contact electrodes at the corresponding positions on the driving backplane, and then the detection probes are respectively connected to the corresponding contact electrodes through the detection probes. The contact electrode provides the driving voltage, so that the successfully transferred light-emitting diode can emit light, while the failed light-emitting diode cannot emit light. The photosensitive sensor can detect whether the light-emitting diode at the corresponding position emits light. By detecting the photosensitive detection signal output by the photosensitive sensor, it can be judged Whether the light-emitting diode at the corresponding position emits light, so as to detect whether the light-emitting diode is transferred successfully, and realize the real-time detection of the light-emitting diode in the transfer process. If it is found that the transfer fails at a certain point, the light-emitting diode can be replaced before the contact electrode is completely cured, which greatly reduces the cost of replacing the bad point after the overall transfer is completed.

Further, in the above-mentioned transfer device provided by the embodiment of the present invention, in order to ensure that after the transfer device and the driving backplane are pressed together, the detection probe can be electrically connected to the contact electrode at the corresponding position on the driving backplane. Referring to FIG. The probes 13 are retractable in a direction perpendicular to the transfer substrate 10 .

In specific implementation, a conductive structure can be set in the driving backplane, the conductive structure is in contact with the corresponding contact electrode, and the detection probe can be electrically connected with the corresponding contact electrode line by contacting the conductive structure. The specific setting of the conductive structure The manner will be described in detail in the second manner, and will not be repeated here.

If the lengths of the detection probe and the conductive structure in the direction perpendicular to the transfer substrate are fixed, it is difficult to ensure that the light-emitting diode is in contact with the corresponding contact electrode, and the detection probe is in contact with the corresponding The conductive structures are in contact with each other, and the cost and process of large-scale production of scalable conductive structures on the driving backplane are very difficult. Therefore, setting the detection probes to be stretchable in the direction perpendicular to the transfer substrate can be cost-effective and On the basis of easy realization of the process, it is ensured that the detection probe can be electrically connected with the corresponding contact electrode, and the contact between the light emitting diode and the corresponding contact electrode is not affected.

In practical applications, as shown in FIG. 4 , in order to ensure that the detection probe 13 can be in contact with the corresponding conductive structure, the lower end of the detection probe 13 in the extended state, that is, the position of the dotted line H2 in the figure, can be set lower than the The lower edge of the transferred light-emitting diode 20 is the position where the dotted line H1 is in the figure.

Specifically, in the above-mentioned transfer device provided by the embodiment of the present invention, as shown in FIG. 5 , the detection probe 13 includes: an elastic conductive structure 131 and a conductive probe 132 that are electrically connected to each other.

The detection probe 13 is composed of an elastic conductive structure 131 and a conductive probe 132 that are electrically connected to each other, which can not only ensure that the detection probe 13 can be stretched in a direction perpendicular to the transfer substrate, but also ensure that the detection probe 13 has a certain hardness , thereby ensuring the stability of the detection probe 13 .

More specifically, in the above-mentioned transfer device provided by the embodiment of the present invention, as shown in FIG. 5 , the transfer head structure 11 has a groove U at a position corresponding to the detection probe 13;

The elastic conductive structure 131 is located inside the groove U;

The conductive probe 132 has an engaging portion K at one end close to the elastic conductive structure 131; the engaging portion K is located inside the groove U, and the engaging portion K cannot pass through the opening of the groove U, and the conductive probe 132 removes the engaging portion A portion of K can pass through the opening of groove U.

Placing the elastic conductive structure 131 inside the groove U can ensure that the elastic conductive structure 131 expands and contracts in a direction perpendicular to the transfer substrate, and avoids deviation of the stretchable direction of the elastic conductive structure 131 . By providing the engaging portion K at one end of the conductive probe 132 close to the elastic conductive structure 131, and the engaging portion K is located inside the groove U, the engaging portion K cannot pass through the opening of the groove U, thereby fixing the detection probe 13 at the corresponding position of the transfer head structure 11 . When the detection probe 13 is in an extended state, the opening and closing portion K can be stuck to the opening of the groove U, so as to ensure that the conductive probe 132 will not be separated from the transfer head structure 11. When the detection probe 13 is compressed and shortened, due to the The other parts of the conductive probe 132 except the engaging portion K can pass through the opening of the groove U, so that the conductive probe 132 can squeeze the elastic conductive structure 131 and shorten the detection probe 13 .

In order to ensure that the engaging portion K cannot pass through the opening of the groove U, the width of the engaging portion K can be set to be larger than the opening size of the groove U at least in one direction parallel to the transfer substrate. Other parts other than the engaging part K can pass through the opening of the groove U, and other parts of the conductive probes 132 need to be set so that the width in any direction parallel to the transfer substrate is smaller than the opening size of the groove U, such as in FIG. 5 . The conductive probes 132 are arranged to be "T" shaped in cross section.

In addition, a connection structure 14 may also be provided at the bottom of the groove U in the transfer head structure 11, and the detection probe 13 may be electrically connected to the internal circuit of the transfer device through the connection structure.

During specific implementation, in the above-mentioned transfer device provided by the embodiment of the present invention, as shown in FIG. 5 , the elastic conductive structure 131 includes: a plurality of elastic conductive microspheres Q;

A plurality of elastic conductive microspheres Q are filled in the grooves U on the side of the engaging portion K close to the transfer substrate.

When the detection probe 13 is in an extended state, the interaction force between the elastic conductive microspheres Q is small, and when the detection probe 13 is squeezed and shortened, the elastic conductive microspheres Q squeeze each other, so that the detection probe 13 is compressed. Needle 13 is shortened.

In addition, in order to prevent the elastic conductive microspheres Q from falling, the distance between the engaging portion K and the inside of the groove U can be set to be smaller than the size of the elastic conductive microspheres Q. Specifically, the elastic conductive microspheres Q can be directly made of elastic conductive materials, or the microspheres can be made of elastic insulating materials, and then a layer of conductive material is wrapped on the surface of the microspheres to form the elastic conductive microspheres Q, here only For example, the specific implementation of the elastic conductive microspheres Q is not limited.

In practical applications, in the above-mentioned transfer device provided by the embodiment of the present invention, the material of the conductive probe is one of copper, aluminum, silver, and gold, or an alloy composed of at least two of them. The conductive probe is made of a metal material or an alloy material composed of a metal material, which can make the conductive probe have a certain hardness on the basis of ensuring that the conductive probe has good conductivity, thereby ensuring the stability of the conductive probe.

In the second aspect, based on the same inventive concept, an embodiment of the present invention further provides a driving backplane. Since the principle of the driving backplane for solving the problem is similar to that of the above-mentioned transfer device, the implementation of the driving backplane can refer to the implementation of the above-mentioned transfer device, and the repetition will not be repeated.

FIG. 6 is a schematic structural diagram of a driving backplane provided by an embodiment of the present invention, and FIG. 7 is a top-view structural schematic diagram of the structure shown in FIG. 6 . The driving backplane provided by the embodiment of the present invention, as shown in FIGS. 6 and 7 , includes: a lining a base substrate 30, a plurality of contact electrode groups 31 and a plurality of conductive structures 32 located on the base substrate 30;

The contact electrode group 31 is used for electrical connection with one light-emitting diode, and the contact electrode group 31 includes two oppositely arranged contact electrodes 311;

The contact electrode group 31 corresponds to two oppositely arranged conductive structures 32, and the two contact electrodes 311 in the contact electrode group 31 are located between the corresponding two conductive structures 32; the conductive structures 32 are in contact with the corresponding contact electrodes 311;

The conductive structure 32 corresponds to the position of the detection probe in the transfer device;

The conductive structure 32 is used for contacting the detection probes in the transfer device after the transfer device is pressed with the driving backplane.

In the driving backplane provided by the embodiment of the present invention, a plurality of conductive structures are arranged on the base substrate, and the conductive structures are in contact with the corresponding contact electrodes. The detection probe is in contact to realize the electrical connection between the detection probe and the corresponding contact electrode, so that after the detection probe provides a driving voltage to the corresponding contact electrode, the photosensitive sensor can detect whether the light emitting diode at the corresponding position is successfully transferred.

The embodiment of the present invention is mainly used for transferring and detecting the light-emitting diodes 20 whose lead-out electrodes 202 are located on the same side of the epitaxial structure 201 as shown in FIG. 2 and FIG. 3 . Therefore, one contact electrode group 31 in the driving backplane corresponds to one light-emitting diode, And the contact electrode group 31 includes two oppositely arranged contact electrodes 311 .

In order to make the conductive structures 32 easier to contact and electrically connect with the corresponding contact electrodes 311, and the contact area is large enough, the two contact electrodes 311 in the contact electrode group 31 are arranged between the corresponding two conductive structures 32. The two conductive structures 32 are arranged on both sides of the two contact electrodes 311, so that the conductive structures 32 correspond to the positions of the detection probes in the transfer device, so that the detection probes can be realized after the transfer device and the driving backplane are pressed together. Electrical connections to conductive structures.

In addition, as shown in FIG. 6 and FIG. 7 , an insulating layer 33 is further provided between the base substrate 30 and the conductive structure 32, and the orthographic projection of each conductive structure 32 on the base substrate is located on the pattern of the insulating layer 33 on the substrate. In the range of the orthographic projection on the substrate 30, each conductive structure 32 is insulated from other circuits in the driving backplane.

In a specific implementation, in the above-mentioned driving backplane provided by the embodiment of the present invention, the above-mentioned contact electrode is an elastic conductive adhesive. In this way, the contact electrodes can have a certain elasticity, and after the transfer device and the driving backplane are pressed together, it is easier to ensure that the light emitting diodes are in contact with the corresponding contact electrodes and the detection probes are in contact with the corresponding conductive structures.

In addition, because the contact electrode has a certain elasticity, the stability of the contact electrode is poor. During the pressing process of the transfer device and the driving backplane, the contact electrode is easily squeezed and deformed. When the direction or size of the pressure is not uniform, the The contact electrodes are prone to incline, which leads to the inclination of the corresponding light-emitting diodes, resulting in a phenomenon of decreased collimation, which affects the overall display effect of the display device.

8 is a schematic diagram of the structure of the prior art after the transfer device and the driving backplane are pressed together, as shown in FIG. The pressure of F will deviate from the direction perpendicular to the driving backplane. For example, the LED 20 shown in FIG. 8 is subjected to the pressure F, so that the pressure on the two contact electrodes is not uniform, resulting in serious tilting of the LED 20 .

FIG. 9 is a schematic structural diagram of the transfer device and the driving backplane after being pressed together in the embodiment of the present invention. As shown in FIG. 9 , in the embodiment of the present invention, conductive electrodes 311 are arranged on both sides of the two oppositely disposed contact electrodes 311 respectively. In the structure 32, under the action of the pressure F, the contact electrode 311 will also be subjected to the reaction force f of the conductive structure 32, so the conductive structure 32 blocks the deformation of the contact electrode 311, thereby alleviating the tilting of the light emitting diode 20. Compared with the light-emitting diode 20 on the right side in FIG. 8 and the light-emitting diode 20 on the right side in FIG. 9, it can be clearly seen that the tilt phenomenon of the light-emitting diode 20 in FIG. Straightness is better.

During specific implementation, in the above-mentioned driving backplane provided by the embodiment of the present invention, as shown in FIG. 6 , the height of the above-mentioned conductive structure 32 is lower than the height of the corresponding contact electrode 311 .

If the conductive structure 32 is too high, when the transfer device and the driving backplane are pressed together, the light emitting diode is easily supported by the conductive structure 32, that is, it is easy to cause poor contact between the light emitting diode and the contact electrode. Therefore, in the embodiment of the present invention, the conductive structure 32 The height of the contact electrode 311 is set to be lower than the height of the corresponding contact electrode 311 , which can prevent the conductive structure 32 from affecting the fixing effect of the contact electrode 311 on the light emitting diode.

Specifically, the height of the contact electrode 311 is generally in the range of 2-4 μm, and the height of the conductive structure 32 can be set in the range of 1-3 μm. In addition, the width of the conductive structure 32 can be set in combination with the space on the driving backplane. Generally, the width of the conductive structure 32 can be set in the range of 3-20 μm.

In the actual process, the above-mentioned driving backplane provided by the embodiment of the present invention can be manufactured according to the following manufacturing method:

forming an insulating layer on the base substrate, and patterning the insulating layer;

A conductive layer is deposited on the insulating layer, for example, a sputtering process can be used to form a metal layer, and the material of the metal layer can be metals such as copper and aluminum;

A layer of photoresist is coated on the conductive layer, and the photoresist layer is exposed and developed;

The conductive layer is processed by an etching process (for example, wet etching may be used) to obtain each conductive structure.

In the actual process, in order to improve the efficiency and save the manufacturing cost of the driver backplane, multiple driver backplanes will be fabricated on one motherboard. Due to the process requirements such as subsequent packaging, the driver backplane must be kept intact during the LED transfer process. However, in the case of maintaining the integrity of the driving backplane, the light-emitting diodes cannot be detected by the driving backplane. In the embodiment of the present invention, by arranging a detection probe and a photosensitive sensor in the transfer device, and arranging a conductive structure in the driving backplane, a driving voltage can be applied to the light-emitting diode through a structure other than the driving backplane, so as to realize the transmission of the light-emitting diode. Detection, without cutting and other processing of the drive backplane, the process control and production difficulty is small.

In a third aspect, based on the same inventive concept, an embodiment of the present invention further provides a method for transferring a light emitting diode. Since the principle of the transfer method to solve the problem is similar to the above-mentioned transfer device and driving backplane, the implementation of the transfer method can refer to the implementation of the above-mentioned transfer device and driving backplane, and the repetition will not be repeated.

The transfer method of the light emitting diode provided by the embodiment of the present invention, as shown in FIG. 10 , includes:

S401. Referring to FIG. 2 at the same time, the above-mentioned transfer device 1 is used to adsorb a plurality of light-emitting diodes 20;

S402, referring to FIG. 11 at the same time, move the transfer device 1 to the top of the above-mentioned driving backplane 3, and the side of the transfer device 1 on which the light-emitting diodes 20 are adsorbed is opposite to the side of the driving backplane 3 with the contact electrodes 311;

S403. Referring to FIG. 12 at the same time, the transfer device 1 and the driving backplane 3 are aligned and pressed together, so that the detection probes 13 in the transfer device 1 are in contact with the corresponding conductive structures 32 on the driving backplane 3; While the detection probe 13 is in contact with the conductive structure 32 , the lead-out electrode of the light emitting diode 20 is also in contact with the corresponding contact electrode 311 .

S404, referring to FIG. 13 at the same time, apply a driving voltage to each detection probe 13; as shown in the figure, apply a positive voltage to the detection probe 13 on the left side, and the positive voltage is applied to an outlet of the light emitting diode 20 through the conductive structure 32 and the contact electrode 311 On the electrode, a negative voltage is applied to the detection probe 13 on the right side, and the negative voltage is applied to the other lead-out electrode of the light-emitting diode 20 through the conductive structure 32 and the contact electrode 311, so that the light-emitting diode 20 is turned on. If the transfer is successful , the light emitting diode 20 can emit light, and if the transfer fails, the light emitting diode 20 cannot emit light.

S405 , according to the photosensitive detection signals output by each photosensitive sensor 12 in the transfer device 1 , determine whether each light-emitting diode 20 is successfully transferred.

In the above-mentioned transfer method provided by the embodiment of the present invention, after the transfer device and the driving backplane are aligned and pressed together, the detection probes are brought into contact with the corresponding conductive structures, so that the driving voltage can be applied to each detection probe subsequently. If the light-emitting diode is successfully transferred, the photosensitive sensor at the corresponding position can detect the light, otherwise the photosensitive sensor cannot detect the light. Therefore, the photosensitive detection signal output by the photosensitive sensor can be used to determine each light-emitting Whether the diode is transferred successfully, so as to realize the real-time detection of the light-emitting diode during the transfer process.

In addition, if the light-emitting diode does not detect light, the transfer of the light-emitting diode at the corresponding position fails, and the following situations may occur: as shown in Figure 14, it may occur that the transfer device 1 fails to pick up the light-emitting diode; Figure 15 As shown in Fig. 16, it is possible that the alignment accuracy during the transfer process exceeds the space where the light-emitting diodes 20 are located, resulting in that the light-emitting diodes 20 are not electrically connected to the corresponding contact electrodes 311; as shown in Fig. 16, the light-emitting diodes 20 may be damaged. , such as LEDs lacking therefore electrodes.

In the driving backplane, the light-emitting diode transfer device, and the transfer method provided by the embodiments of the present invention, by arranging a photosensitive sensor and a detection probe on the side of the transfer head structure away from the transfer substrate, after the transfer device and the driving backplane are pressed together, detection is performed. The probe can be electrically connected to the contact electrode at the corresponding position on the driving backplane, and provide a driving voltage to the contact electrode, and then the photosensitive sensor can be used to detect whether the light-emitting diode at the corresponding position emits light, so as to realize the process of transferring the light-emitting diode. Check the light-emitting diodes. In addition, the conductive structure on the driving backplane can also block the deformation of the contact electrode and prevent the contact electrode from tilting, thereby alleviating the tilting phenomenon of the light emitting diode and improving the collimation degree of the light emitting diode.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Thus, provided that these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims (7)

1. A transfer device for light emitting diodes, comprising: a transfer substrate, a plurality of transfer head structures located on the transfer substrate, a plurality of photosensors and a plurality of detection probes; The transfer head structure is provided with the photosensitive sensor and the two detection probes on the side away from the transfer substrate; The transfer head structure has an accommodating area for accommodating light-emitting diodes, and the two detection probes are respectively located on opposite sides of the accommodating area; The detection probe is used to electrically connect with the contact electrode at the corresponding position on the drive backplane after the transfer device is pressed together with the drive backplane, and provide a drive voltage to the contact electrode; The photosensitive sensor is used to detect whether the light-emitting diode at the corresponding position emits light after the detection probe provides a driving voltage to the contact electrode, and output a photosensitive detection signal; The detection probe is retractable in a direction perpendicular to the transfer substrate; The detection probe includes: an elastic conductive structure and a conductive probe electrically connected to each other; The transfer head structure has a groove at a position corresponding to the detection probe, and the sidewall of the groove is perpendicular to the transfer substrate; the elastic conductive structure is located inside the groove; The conductive probe has an engaging portion at one end close to the elastic conductive structure; the engaging portion is located inside the groove, and the engaging portion cannot pass through the opening of the groove, and the conductive The part of the probe other than the engaging part can pass through the opening of the groove. 2. The transfer device according to claim 1, wherein the elastic conductive structure comprises: a plurality of elastic conductive microspheres; A plurality of the elastic conductive microspheres are filled in the grooves on the side of the engaging portion close to the transfer substrate. 3 . The transfer device according to claim 1 , wherein the material of the conductive probe is one of copper, aluminum, silver, and gold, or an alloy composed of at least two of them. 4 . 4. A driving backplane, comprising: a base substrate, a plurality of contact electrode groups and a plurality of conductive structures located on the base substrate; The contact electrode group is used for electrical connection with one light emitting diode, and the contact electrode group includes two oppositely arranged contact electrodes; The contact electrode group corresponds to the two oppositely arranged conductive structures, and the two contact electrodes in the contact electrode group are located between the corresponding two conductive structures; the conductive structures and the corresponding contact the electrodes are in contact; The conductive structure is used for contacting the detection probe in the transfer device after the transfer device is pressed against the driving backplane; The conductive structures correspond to the positions of the detection probes in the transfer device. 5 . The driving backplane of claim 4 , wherein the contact electrodes are elastic conductive glue. 6 . 6 . The driving backplane of claim 4 , wherein the height of the conductive structure is lower than that of the corresponding contact electrode. 7 . 7. A method for transferring light-emitting diodes, comprising: Adopt the transfer device according to any one of claims 1 to 3 to adsorb a plurality of light emitting diodes; The transfer device is moved to the top of the driving backplane according to any one of claims 4 to 6, and the side of the transfer device on which the light-emitting diodes are adsorbed is opposite to the side of the driving backplane with contact electrodes ; aligning and pressing the transfer device and the driving backplane, so that the detection probes in the transfer device are in contact with the corresponding conductive structures on the driving backplane; applying a driving voltage to each of the detection probes; According to the photosensitive detection signals output by each photosensitive sensor in the transfer device, it is determined whether each of the light emitting diodes is successfully transferred.

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