CN112394272A

CN112394272A - Micro LED defect detection flexible probe and manufacturing method thereof

Info

Publication number: CN112394272A
Application number: CN202110071396.9A
Authority: CN
Inventors: 黄显; 杨晴
Original assignee: Institute of Flexible Electronics Technology of THU Zhejiang
Current assignee: Institute of Flexible Electronics Technology of THU Zhejiang
Priority date: 2021-01-19
Filing date: 2021-01-19
Publication date: 2021-02-23
Anticipated expiration: 2041-01-19
Also published as: CN112394272B

Abstract

The application relates to a flexible probe for detecting micro LED defects and a manufacturing method thereof, the probe comprises a flexible substrate, a flexible circuit film layer and a control unit, the flexible substrate comprises a flexible substrate and a flexible bulge part positioned on the flexible substrate, a circuit used for lighting the micro LED to be detected is arranged in the flexible circuit film layer, the flexible circuit film layer is attached to the surface of the flexible substrate on the side provided with the flexible bulge part, at least one part of the circuit of the flexible circuit film layer is positioned on the flexible bulge part, when the flexible micro LED defect detection probe is placed on a micro LED, the circuit on the flexible lug boss abuts against the pins of the micro LED to be detected, and is electrically connected with the pins, the control unit is electrically connected with the flexible circuit film layer, the control unit controls the flexible circuit film layer to light the MicroLED to be detected. The probe can detect the MicroLED before completing the electrical connection of the MicroLED.

Description

Micro LED defect detection flexible probe and manufacturing method thereof

Technical Field

The invention relates to the technical field of micro LED defect detection, in particular to a micro LED defect detection flexible probe and a manufacturing method thereof.

Background

The micro LED display technology is famous for the characteristics of high brightness, high contrast, high luminous efficiency, low power consumption, difficult aging phenomenon and the like, and is the key point of research and development of a new generation of display technology in China at present. Although the micro LED display device has a plurality of advantages, the problems of high manufacturing cost, low yield and the like still exist in mass production of the micro LED, and one of the difficulties lies in how to realize high-precision defect detection of the large-area micro LED.

The electroluminescence detection technology is a commonly used detection means, and in the prior art, the electroluminescence detection technology directly drives the micro led to emit light through voltage, so that information such as brightness, wavelength and the like of the micro led during operation is obtained. Therefore, the defective LED can be found more intuitively and accurately, and the method has higher accuracy. However, contact-based electroluminescence measurements have the potential to damage the wafer. Meanwhile, as the volume of the MicroLED is too small, the MicroLED is difficult to be electrically connected by using the traditional electrical test equipment, and the self interconnection circuit of the MicroLED display device is mostly utilized. Therefore, the contact type electroluminescence detection technology can be used as a quality control means only after the interconnection of the micro leds is completed, and the difficulty of performing electroluminescence detection before the electrical connection of the micro leds is completed is very high.

Disclosure of Invention

In view of the above, the invention provides a micro LED defect detection flexible probe and a manufacturing method thereof, and the micro LED defect detection flexible probe can detect a micro LED before the micro LED is electrically connected.

The invention provides a micro LED defect detection flexible probe, which comprises a flexible substrate, a flexible circuit film layer and a control unit, wherein the flexible substrate comprises a flexible substrate and a flexible bulge part positioned on the flexible substrate, a circuit used for lighting a micro LED to be detected is arranged in the flexible circuit film layer, the flexible circuit film layer is attached to the surface of one side, provided with the flexible bulge part, of the flexible substrate, at least one part of the circuit of the flexible circuit film layer is positioned on the flexible bulge part, when the micro LED defect detection flexible probe is placed on the micro LED, the circuit on the flexible bulge part is abutted against pins of the micro LED to be detected and is electrically connected with the pins, the control unit is electrically connected with the flexible circuit film layer, and the control unit controls the flexible circuit film layer to light the micro LED to be detected.

Furthermore, a circuit used for collecting electrical parameters in the micro LED to be detected is further arranged in the flexible circuit film layer, and after the control unit lights the micro LED to be detected, the control unit collects the electrical parameters in the micro LED to be detected.

Further, the control unit detects the MicroLED to be detected according to the electrical parameter information and outputs a KGD file containing the position of the qualified MicroLED.

Further, the flexible protruding portions are arranged on the flexible substrate in an array mode and are matched with the positions of the pins in the micro LED to be detected.

Furthermore, the flexible circuit film layer comprises a first packaging layer, a first electrode layer, an insulating layer, a second electrode layer and a second packaging layer, wherein the first packaging layer, the first electrode layer, the insulating layer, the second electrode layer and the second packaging layer are sequentially arranged from one side of the flexible substrate to the direction far away from the flexible substrate, a through hole exposing the second electrode layer is formed in the second packaging layer, a through hole exposing the first electrode layer is formed in the second electrode layer, the second packaging layer and the insulating layer, the position of the through hole corresponds to the position of the flexible protruding portion, and a circuit in the flexible circuit film layer is arranged in the first electrode layer and the second electrode layer.

Furthermore, the first electrode layer comprises a plurality of first electrode wires, the second electrode layer comprises a plurality of second electrode wires, the first electrode wires and the second electrode wires both comprise baselines and a plurality of extension wires arranged on the baselines at intervals, a connecting unit corresponding to a to-be-detected micro led is formed between each extension wire on the first electrode wire and the corresponding extension wire on the second electrode wire, the connecting unit is used for being connected with two pins on the to-be-detected micro led, the baselines on the first electrode wires and the second electrode wires are arranged between the flexible protrusions, and the extension wires on the first electrode wires and the second electrode wires are arranged on the corresponding flexible protrusions.

Furthermore, the first electrode lines extend along a first direction, the second electrode lines extend along a second direction, and the first electrode lines and the second electrode lines are arranged in a staggered mode.

Furthermore, hollow-out areas are formed in areas of the first packaging layer, which are opposite to the areas except the first electrode lines, in areas of the insulating layer, which are opposite to the areas except the first electrode lines and the second electrode lines, and/or in areas of the second packaging layer, which are opposite to the areas except the second electrode lines.

Furthermore, the first packaging layer, the second packaging layer and the insulating layer are all in a mesh shape, the positions of the first electrode wires correspond to the positions of the mesh lines of the mesh-shaped first packaging layer, and the positions of the first electrode wires and the second electrode wires correspond to the positions of the mesh lines of the mesh-shaped insulating layer; the positions of the second electrode wires correspond to the positions of the grid lines of the second mesh-shaped packaging layer.

Furthermore, the flexible probe for detecting the defects of the MicroLED further comprises a photoelectric detector, the photoelectric detector is electrically connected with the control unit, the photoelectric detector detects light rays emitted by the MicroLED to be detected and transmits a detection result to the control unit, and the control unit judges the quality of the MicroLED to be detected according to the light ray information.

Further, the flexible substrate is a transparent flexible substrate, and the photodetector is disposed on a side of the flexible substrate away from the flexible protruding portion.

Furthermore, the flexible probe for detecting the defects of the MicroLED further comprises a pressurizing device for applying pressure to the flexible substrate and a pressure sensor for detecting the applied pressure, wherein the pressurizing device and the pressure sensor are electrically connected with the control unit, and the control unit performs pressure compensation on a detection result according to the pressure detected by the pressure sensor.

Further, the flexible protrusions have a pyramidal shape, a hemispherical shape, or a cylindrical shape.

The invention also provides a manufacturing method of the micro LED defect detection flexible probe, which comprises the following steps:

s1: providing a flexible substrate, wherein the flexible substrate comprises a flexible substrate and a flexible bulge part arranged on the flexible substrate, the position of the flexible bulge part corresponds to the position of a pin of the micro LED to be detected, and providing a flexible circuit film layer, and a circuit used for lighting the micro LED to be detected is arranged in the flexible circuit film layer;

s2: and attaching the flexible circuit film layer to the flexible substrate, and enabling at least one part of the circuit in the flexible circuit film layer to be positioned on the flexible bulge.

Further, the flexible substrate is made of PDMS or Ecoflex material, and when the step S2 is performed, the method includes:

sequentially forming a Ti metal layer and a silicon dioxide layer on one side of the flexible circuit film layer, which is used for being attached to the flexible substrate;

aligning the flexible circuit film layer with the flexible substrate to enable the circuit in the flexible circuit film layer to be located on the flexible protruding part;

bonding the silicon dioxide layer to the flexible substrate by a bonding process.

In summary, the height difference of the micro led is made up by the external flexible substrate, and the micro led is detected by the external flexible circuit film layer, so that the micro led does not need to be arranged on a circuit when the probe is used for detection. In the production process, the micro LED can be detected directly when the micro LED is still positioned on the wafer, and the detection process is convenient and simple.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described in detail with reference to the accompanying drawings.

Drawings

Fig. 1 is a schematic cross-sectional structural view of a flexible micro led defect detection probe according to a first embodiment of the present invention.

Fig. 2 is a schematic structural diagram of the micro led defect detection flexible probe in fig. 1 for detecting defects of the micro led.

FIG. 3 is a system block diagram of a flexible probe for detecting defects of a MicroLED.

Fig. 4 is a schematic cross-sectional view of the flexible detection electrode film layer in the first direction.

Fig. 5 is a schematic cross-sectional structure view of the flexible detection electrode film layer in the second direction.

FIG. 6 is a schematic diagram illustrating a positional relationship between the first electrode layer and the second electrode layer.

Fig. 7 is a schematic structural diagram of the first electrode line.

Fig. 8 is a schematic structural view of a flexible substrate.

Fig. 9 is an exploded view of a flexible detection electrode film according to a second embodiment of the present invention.

Fig. 10 is a schematic structural diagram of the insulating layer in fig. 9.

Fig. 11 is a schematic structural view of a flexible substrate according to a third embodiment of the present invention.

Fig. 12 is a schematic structural view of a flexible substrate according to a fourth embodiment of the present invention.

Detailed Description

To further explain the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description is given with reference to the accompanying drawings and preferred embodiments.

The invention provides a micro LED defect detection flexible probe and a manufacturing method thereof, and the micro LED defect detection flexible probe can detect a micro LED before the manufacturing process of electrical connection of the micro LED is completed.

Fig. 1 is a schematic cross-sectional structural view of a micro led defect detection flexible probe according to a first embodiment of the present invention, fig. 2 is a schematic structural view of a micro led defect detection flexible probe in fig. 1 when the micro led defect detection flexible probe detects a defect, and fig. 3 is a system block diagram of the micro led defect detection flexible probe. As shown in fig. 1 to 3, a flexible probe for detecting a micro led defect provided in a first embodiment of the present invention includes a flexible substrate 10, a flexible circuit film 20 and a control unit 30, where the flexible substrate 10 includes a flexible substrate 11 and a flexible protrusion 12 located on the flexible substrate 11, a circuit for lighting the micro led is disposed in the flexible circuit film 20, the flexible circuit film 20 is attached to a surface of the flexible substrate 10 on a side where the flexible protrusion 12 is located, and at least a portion of the circuit of the flexible circuit film 20 is located on the flexible protrusion 12, and when the flexible probe for detecting a micro led defect is placed on the micro led40, the circuit on the flexible protrusion 12 abuts against a pin 41 of the micro led40 and is electrically connected to the pin 41. The control unit 30 is electrically connected to the flexible circuit film 20, and the control unit 30 controls the flexible circuit film 20 to light the micro led 40.

In this embodiment, by forming the flexible protruding portion 12 on the flexible substrate 10 and disposing the flexible circuit film 20 on the side of the flexible protruding portion 12 of the flexible substrate 10, when performing detection, every two flexible protruding portions 12 are connected to two pins 41 of one micro led40, because the flexible protruding portion 12 has flexibility, when placing the flexible detection probe on the array of micro leds 40, at the pin 41 with a higher micro led40, the flexible protruding portion 12 is subjected to a higher pressure and has a larger deformation, and at the pin 41 with a lower micro led, the flexible protruding portion 12 is subjected to a lower pressure and has a smaller deformation. Through the different deformation in different positions of flexible bellying 12 for flexible circuit rete 20 on the flexible bellying 12 all can contact with MicroLED 40's pin 41, just can light MicroLED40 through external flexible circuit rete 20, after lighting MicroLED40, can detect the electrical parameter of the MicroLED40 after lighting, like electric current or voltage, with the detection of accomplishing MicroLED 40's electroluminescence.

In the embodiment, the height difference of the micro led40 is compensated by the elasticity of the external flexible substrate 10, and the micro led40 is lighted by the external flexible circuit film layer 20, so that the micro led40 does not need to be arranged on a line when the probe is used for detection. In the production process, the huge number of micro leds 40 can be detected directly when the micro leds 40 are still on the wafer 42, and the detection process is convenient and simple.

Further, in order to facilitate direct detection of the micro led40, a circuit for collecting electrical parameters in the to-be-detected micro led40 after lighting the micro led40 is further arranged in the flexible circuit film layer, and the control unit 30 collects the electrical parameters in the to-be-detected micro led40 after lighting the to-be-detected micro led40, so as to facilitate detection of the micro led40 according to the electrical parameters. In the present embodiment, the electrical parameter may be current.

Further, the flexible protrusions 12 are arranged on the flexible substrate 11 in an array and are adapted to the positions of the pins in the micro led to be tested.

Further, after the detection, the control unit 30 can output a KGD (innown Good Die Good chip) file containing a position of the qualified micro led40 according to the detection result, and in a subsequent micro led40 process, only the qualified micro led40 can be selectively released on the wafer according to the file, so that the production cost is reduced, and the production flow is simplified.

Fig. 4 is a schematic cross-sectional structure view of the flexible circuit film layer in a first direction, fig. 5 is a schematic cross-sectional structure view of the flexible circuit film layer in a second direction, and fig. 6 is a schematic positional relationship view of the first electrode layer and the second electrode layer. In fig. 4 and 5, the first direction is hereinafter an extending direction of the first electrode lines 221, and the second direction is hereinafter an extending direction of the second electrode lines 241. As shown in fig. 4 to 6, in the present embodiment, the flexible circuit film 20 includes a first package layer 21, a first electrode layer 22, an insulating layer 23, a second electrode layer 24 and a second package layer 25, the first package layer 21, the first electrode layer 22, the insulating layer 23, the second electrode layer 24 and the second package layer 25 are disposed layer by layer, that is, the insulating layer 23 is disposed between the first electrode layer 22 and the second electrode layer 24, the first electrode layer 22 is disposed between the first package layer 21 and the insulating layer 23, the second electrode layer 24 is disposed between the second package layer 25 and the insulating layer 23, the first package layer 21 is disposed on one side of the flexible circuit film 20 facing the flexible protrusion 12, as shown in fig. 4, a through hole 26 exposing the second electrode layer 24 is disposed on the second package layer 25, as shown in fig. 5, a through hole 26 exposing the first electrode layer 22 is formed on the second electrode layer 24, the second package layer 25 and the insulating layer 23, the through holes 26 correspond to the flexible bumps 12, and on two flexible bumps 12 connected to the leads 41 on one micro led40, the first electrode layer 22 is exposed through the through holes 26 at the top end of one flexible bump 12, and the second electrode layer 24 is exposed through the through holes 26 at the top end of the other flexible bump 12. That is, the circuits in the flexible circuit film 20 are disposed in the first electrode layer 22 and the second electrode layer 24.

In the present embodiment, as shown in fig. 6, the first electrode layer 22 includes a plurality of first electrode lines 221 extending in a first direction shown in fig. 4, and the second electrode layer 24 includes a plurality of second electrode lines 241 extending in a second direction shown in fig. 5. It should be noted that, for the sake of illustration, fig. 6 only shows the positional relationship between the first electrode lines 221 and the second electrode lines 241, and the first encapsulation layer 21, the insulating layer 23, and the second encapsulation layer 25 are omitted.

In this embodiment, by arranging the plurality of first electrode lines 221 and the plurality of second electrode lines 241 so as to form the array electrodes in the flexible circuit film layer 20, the control unit 30 may perform a lighting operation on the micro leds 40 arranged in the array by using a passive matrix driving method.

In this embodiment, when a specific first electrode line 221 and a specific second electrode line 241 are selected to be energized, the micro led40 connected to the first electrode line 221 and the second electrode line 241 is turned on to detect the micro led 40. The mode can realize the rapid detection of the MicroLED40 array in a multi-unit parallel measurement mode.

Fig. 7 is a schematic structural diagram of the first electrode line. Referring to fig. 6 and 7, in the present embodiment, each of the first electrode lines 221 and the second electrode lines 241 includes a base line 2211 and a plurality of extension lines 2212 disposed on the base line 2211 at intervals, an included angle is formed between the extension line 2212 and the base line 2211, each extension line 2212 on the first electrode line 221 and the corresponding extension line 2212 on the second electrode form a connection unit (such as the structure indicated by the circle in fig. 6) corresponding to one micro led40, and the connection unit is used for connecting two pins 41 on one micro led 40. In the present embodiment, the first electrode lines 221 and the second electrode lines 241 are disposed alternately, such as 90 ° alternately.

That is, at this time, the extension line 2212 on the first electrode line 221 passes through the insulating layer 23, the second electrode layer 24 and the through hole 26 of the second packaging layer 25 in sequence to be connected to one lead 41 of the micro led40, and the extension line 2212 on the second electrode line 241 passes through the through hole 26 of the second packaging layer 25 to be connected to the other lead 41 of the micro led 40. It should be noted that fig. 6 only shows the structure of the first electrode lines 221, and the structure of the second electrode lines 241 may be the same as the first electrode lines 221, and is not further shown here.

In this embodiment, the base line 2211 of the first electrode line 221 and the second electrode line 241 may be disposed between the flexible protrusions 12, and the extension line 2212 on the first electrode line 221 and the second electrode line 241 is disposed on the corresponding flexible protrusions 12, so that the first electrode layer 22 and the second electrode layer 24 are more easily deformed, and the flexible circuit film layer 20 is more easily attached to the flexible protrusions 12 on the substrate.

Further, in this embodiment, the first electrode line 221 and the second electrode line 241 sequentially include a Ti metal layer, a Cu metal layer, a Ti metal layer, and an Au metal layer from the direction close to the insulating layer 23 to the direction away from the insulating layer 23, and the connection between the Cu metal layer and the Au metal layer and the connection between the Cu metal layer and the insulating layer 23 are stable through the arrangement of the Ti metal layer.

It is understood that, in other embodiments, the first electrode lines 221 and the second electrode lines 241 may be a single metal wire, such as a nano silver wire, a nano copper wire, or the like.

Referring to fig. 1 and fig. 3, in this embodiment, the flexible probe for detecting a defect of a micro led further includes a photodetector 51, such as an area array CMOS photodetector 51, the photodetector 51 is electrically connected to the control unit 30, the photodetector 51 detects light emitted by the micro led40 and transmits a detection result to the control unit 30, and the control unit 30 determines the quality of the micro led40 according to the information to assist in detecting an electrical parameter, such as a current.

In this embodiment, the flexible substrate 10 may be a transparent flexible substrate 10, the photodetector 51 is disposed on a side of the flexible substrate 11 away from the flexible protrusion 12, and light emitted by the micro led40 passes through the flexible substrate 11 and then enters the photodetector 51, so that the photodetector 51 detects the light.

Further, the flexible probe for detecting the micro led defect further includes a pressure device 52, the pressure device 52 can apply pressure on the flexible substrate 10 to ensure the connection between the flexible circuit film 20 and the micro led40 on the flexible substrate 10, for example, a pressure sensor 53, such as a piezoresistive or capacitive film pressure sensor 53, can be further disposed on one side of the photodetector 51 away from the flexible substrate 11 on the flexible probe for detecting the pressure applied to the flexible probe, the pressure sensor 53 is electrically connected to the control unit 30, the pressure sensor 53 transmits the detected pressure information to the control unit 30, and the control unit 30 performs pressure compensation on the detection results of the electrical parameters, the light rays and the like according to the pressure information transmitted by the pressure sensor 53.

Because the difference of the manufacture of the flexible protrusions 12 on the flexible substrate 11 and the pressure distribution can affect the contact condition of the flexible circuit film 20 and the pins 41 of the micro led40 and the resistance of the lap joint, and further affect the uniformity of the measured data, the detection of the electrical parameters and the light can be compensated by the arrangement of the pressure sensor 53, so as to more accurately judge the quality of the micro led 40.

Further, the flexible probe for detecting the micro led defects further comprises a moving device 54 for moving the flexible substrate 11 so as to detect the micro leds 40 on the wafer 42 by regions.

Fig. 8 is a schematic structural view of a flexible substrate. As shown in fig. 8, in the present embodiment, the flexible protrusions 12 may have a pyramidal shape (see fig. 8), a hemispherical shape (see fig. 11), or a cylindrical shape (see fig. 12). The three different shapes may be adapted to different needs, such as a pyramid shape may enable the extension on the first electrode lines 221 and the second electrode lines 241 to have a sufficiently large wiring area; the semicircular shape is more beneficial to ensuring the uniform deformation of the flexible convex part 12 after the flexible probe is pressed; and the column shape enables the base lines 2211 of the first electrode lines 221 and the second electrode lines 241 to be more easily laid. It is to be understood that other geometries are possible, and not limited.

In this embodiment, the flexible substrate 10 may be a flexible substrate 10 made of PDMS, Ecoflex, etc., and the first encapsulation layer 21, the insulating layer 23, and the second encapsulation layer 25 may be a first encapsulation layer 21, an insulating layer 23, and a second encapsulation layer 25 made of polyimide, parylene, etc.

In order to facilitate connection between the first encapsulation layer 21 and the flexible substrate 11, a silicon dioxide layer and a Ti layer are sequentially disposed between the flexible substrate 11 and the first encapsulation layer 21 from a direction close to the flexible substrate 11 to a direction away from the flexible substrate 11.

In summary, in the invention, the external flexible substrate 10 compensates for the height difference of the micro led40, and the external flexible circuit film layer 20 lights up the micro led40, so that the micro led40 does not need to be wired when the probe is used for detection. In the production process, the micro leds 40 can be detected directly when the micro leds 40 are still on the wafer 42, and the detection process is convenient and simple.

Fig. 9 is an exploded view of a flexible circuit film according to a second embodiment of the invention, and fig. 10 is a structural view of an insulating layer shown in fig. 9. As shown in fig. 9 and 10, the flexible micro led defect inspection probe according to the second embodiment of the present invention is substantially the same as the first embodiment, except that a hollow region 27 is formed on the first encapsulation layer 21, on the insulating layer 23, in a region other than the first electrode lines 221 and the second electrode lines 241, and/or on the second encapsulation layer 25, in a region other than the second electrode lines 241. In other words, the first encapsulating layer 21, the second encapsulating layer 25 and the insulating layer 23 are in a mesh shape. Taking the insulating layer 23 in fig. 10 as an example, the insulating layer 23 is in a mesh shape as in the combined pattern of the first electrode lines 221 and the second electrode lines 241, and the first electrode lines 221 and the second electrode lines 241 are disposed on the mesh lines of the mesh-shaped insulating layer 23 from the upper and lower sides of the insulating layer 23. Similarly, the first electrode lines 221 correspond to the grid lines of the mesh-shaped first encapsulation layer 21, and the second electrode lines 241 correspond to the grid lines of the second encapsulation layer 25.

Through the arrangement of the hollow area 27, the area where the extending portions of the first electrode line 221 and the second electrode line 241 are located can be tilted under the action of the flexible protruding portion 12, so that the flexible circuit film layer 20 can be better attached to the flexible substrate 11, and the extending lines 2212 of the first electrode line 221 and the second electrode line 241 are fixed to the top of the flexible protruding portion 12.

It should be noted that, since the first electrode line 221 needs to cross over the insulating layer 23 and contact the pin 41 of the micor led40, in the present embodiment, the hollow portion includes the through hole 26 provided on the insulating layer 23 and used for contacting the extension line 2212 of the first electrode line 221 with the pin 41 of the micoled 40.

s1: providing a flexible substrate 10, wherein the flexible substrate 10 comprises a flexible substrate 11 and a flexible protruding portion 12 arranged on the flexible substrate 11, and the position of the flexible protruding portion 12 corresponds to the position of the pin 41 of the micro led40 to be detected; a flexible circuit film 20 is provided, with traces disposed within the flexible circuit film 20 for illuminating the micro leds 40.

In this embodiment, when the flexible substrate 10 is manufactured, a mold may be provided, and then the flexible substrate 10 may be manufactured on the mold by a spin coating process through a spin coater.

When the flexible circuit film 20 is prepared, the flexible circuit film 20 may be prepared by photolithography, sputtering, oxygen plasma etching, and the like, so that the flexible circuit film 20 sequentially includes a first encapsulation layer 21, a first electrode layer 22, an insulation layer 23, a second electrode layer 24, and a second encapsulation layer 25.

S2: the flexible circuit film layer 20 is attached to the flexible substrate 10 with at least some of the traces in the flexible circuit film layer 20 on the flexible bumps 12.

In this embodiment, the flexible substrate 10 may be a flexible substrate 10 made of PDMS, Ecoflex, etc., and when the bonding is performed, the method includes the following steps:

sequentially forming a Ti metal layer and a silicon dioxide layer on one side of the flexible circuit film layer 20, which is used for being attached to the flexible substrate 10, by processes such as electron beam evaporation and evaporation;

transferring the flexible circuit film layer 20 onto the flexible substrate 10 by using a water-soluble adhesive tape, and aligning so that the circuit in the flexible circuit film layer 20 is located on the flexible bump 12; removing the water-soluble adhesive tape;

the bonding of the silicon dioxide layer and the flexible substrate 10 is realized through a bonding process such as ultraviolet ozone treatment, so as to realize the permanent binding of the flexible circuit film layer 20 and the flexible substrate 10.

In this embodiment, the template may be a silicon template. When the template is manufactured, different manufacturing methods may be adopted depending on the shape of the flexible protrusion 12.

For example, when the flexible protrusions 12 have a pyramidal shape, they may be fabricated by a silicon alkaline wet etching process. The silicon alkaline wet etching generates various etching due to the problem of crystalline phase, the atomic density of 111 crystalline phase is greater than that of 110 crystalline phase, and is also greater than that of 100 crystalline phase, and the etching speed of 100 crystalline phase is about 100 times of that of 111 crystalline phase. The reaction time of anisotropic silicon etching and the size of an etching opening are regulated, so that the regulation of the pyramid top form from a platform to a sharp top is realized, and the contact area between the flexible protruding part 12 and the micro LED pin is regulated and controlled when the flexible substrate 10 is manufactured. Using a 100-crystal-phase silicon wafer, using a photoetching process to expose square patterns corresponding to the micro LED pins and protect other parts, using potassium hydroxide or tetramethyl ammonium hydroxide to perform silicon wet etching and heating to obtain a pyramid microstructure template, using silica gel to spin, heating at 120 ℃ and demolding to obtain the flexible substrate 10 with the pyramid flexible protrusions 12.

When the flexible protruding part 12 is hemispherical, the flexible protruding part is etched by a silicic acid wet method, a silicon wafer is firstly exposed out of a circular pattern corresponding to the micro LED pin by using a photoetching process to protect other parts, and is etched by a silicon wet method by using nitric acid and hydrofluoric acid, wherein firstly, silicon is oxidized into silicon dioxide by the nitric acid and then reacts with the hydrofluoric acid to generate fluosilicic acid, and then the template with the hemispherical microstructure is obtained. Spin coating with silicone and heating at 120 deg.C to release the mold, to obtain the flexible substrate 10 with hemispherical flexible protrusions 12.

When the flexible convex part 12 is in a cylindrical shape, the flexible convex part is manufactured by adopting a deep silicon etching process through dry etching, passivation gas and etching gas are introduced into a plasma etching machine, the passivation gas is decomposed under the action of plasma to generate a protective layer, and the protective layer on the side wall is not removed due to the directional property of the plasma etching and the low etching speed. Firstly, exposing a circular pattern corresponding to a micro LED pin by using a photoetching process, protecting other parts, and repeating the passivation step and the etching step to cause the etching to be continuously carried out in the vertical direction, thereby obtaining the columnar microstructure template. The flexible substrate 10 with the pillar-shaped flexible protrusions 12 was obtained using a silicone spin coating and heating for mold release at 120 ℃.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. The utility model provides a flexible probe of micro LED defect detection which characterized in that: the flexible substrate comprises a flexible substrate, a flexible circuit film layer and a control unit, the flexible substrate comprises a flexible substrate and a flexible protruding portion located on the flexible substrate, a circuit used for lighting a micro LED to be detected is arranged in the flexible circuit film layer, the flexible circuit film layer is attached to the surface of one side, provided with the flexible protruding portion, of the flexible substrate, at least one part of the circuit of the flexible circuit film layer is located on the flexible protruding portion, when the micro LED defect detection flexible probe is placed on the micro LED, the circuit on the flexible protruding portion abuts against pins of the micro LED to be detected and is electrically connected with the pins, the control unit is electrically connected with the flexible circuit film layer, and the control unit controls the flexible circuit film layer to light the micro LED to be detected.

2. A micro led defect detection flexible probe according to claim 1, wherein: the flexible circuit film layer is also internally provided with a circuit for collecting the electrical parameters in the MicroLED to be detected, and the control unit collects the electrical parameters in the MicroLED to be detected after lighting the MicroLED to be detected.

3. A micro led defect inspection flexible probe according to claim 2, wherein: and the control unit detects the MicroLED to be detected according to the electrical parameter information and outputs a KGD file containing the position of the qualified MicroLED.

4. A micro led defect detection flexible probe according to claim 1, wherein: the flexible protruding parts are arranged on the flexible substrate in an array mode and are matched with the positions of pins in the micro LED to be detected.

5. A micro led defect detection flexible probe according to claim 1, wherein: the flexible circuit film layer comprises a first packaging layer, a first electrode layer, an insulating layer, a second electrode layer and a second packaging layer, the flexible substrate is located at one side and far away from the direction of the flexible substrate, the first packaging layer, the first electrode layer, the insulating layer, the second electrode layer and the second packaging layer are sequentially arranged, a through hole exposed out of the second electrode layer is formed in the second packaging layer, the through hole exposed out of the first electrode layer is formed in the second electrode layer, the position of the through hole corresponds to the position of the flexible protruding portion, and a circuit in the flexible circuit film layer is arranged in the first electrode layer and the second electrode layer.

6. A MicroLED defect detection flexible probe according to claim 5, wherein: the first electrode layer comprises a plurality of first electrode wires, the second electrode layer comprises a plurality of second electrode wires, the first electrode wires and the second electrode wires respectively comprise baselines and a plurality of extension wires arranged on the baselines at intervals, a connecting unit corresponding to a to-be-detected micro LED is formed between each extension wire on the first electrode wire and the corresponding extension wire on the second electrode wire, the connecting unit is used for being connected with two pins on the to-be-detected micro LED, the baselines on the first electrode wires and the second electrode wires are arranged between the flexible protrusions, and the extension wires on the first electrode wires and the second electrode wires are arranged on the corresponding flexible protrusions.

7. A MicroLED defect detection flexible probe according to claim 6, wherein: the first electrode wires extend along a first direction, the second electrode wires extend along a second direction, and the first electrode wires and the second electrode wires are arranged in a staggered mode.

8. A MicroLED defect detection flexible probe according to claim 6, wherein: and hollow areas are formed in the areas of the first packaging layer, which are opposite to the first electrode wires, in the areas of the insulating layer, which are opposite to the first electrode wires and the second electrode wires, and/or in the areas of the second packaging layer, which are opposite to the second electrode wires.

9. A MicroLED defect detection flexible probe according to claim 8, wherein: the first packaging layer, the second packaging layer and the insulating layer are all in a mesh shape, the positions of the first electrode wires correspond to the positions of mesh lines of the mesh-shaped first packaging layer, and the positions of the first electrode wires and the second electrode wires correspond to the positions of mesh lines of the mesh-shaped insulating layer; the positions of the second electrode wires correspond to the positions of the grid lines of the second mesh-shaped packaging layer.

10. A micro led defect detection flexible probe according to claim 1, wherein: the flexible probe for detecting the micro LED defects further comprises a photoelectric detector, the photoelectric detector is electrically connected with the control unit, the photoelectric detector detects light emitted by the micro LED to be detected and transmits a detection result to the control unit, and the control unit judges the quality of the micro LED to be detected according to light information.

11. A micro led defect inspection flexible probe according to claim 10, wherein: the flexible substrate is a transparent flexible substrate, and the photoelectric detector is arranged on one side of the flexible substrate, which is far away from the flexible bulge.

12. A micro led defect inspection flexible probe according to claim 10, wherein: the flexible probe for detecting the defects of the MicroLED further comprises a pressurizing device for applying pressure to the flexible substrate and a pressure sensor for detecting the applied pressure, wherein the pressurizing device and the pressure sensor are electrically connected with the control unit, and the control unit performs pressure compensation on a detection result according to the pressure detected by the pressure sensor.

13. A micro led defect detection flexible probe according to claim 1, wherein: the flexible convex part is pyramid-shaped, hemispherical or cylindrical.

14. A manufacturing method of a micro LED defect detection flexible probe is characterized by comprising the following steps: the method comprises the following steps:

15. The method for manufacturing a micro LED defect inspection flexible probe according to claim 14, wherein: the flexible substrate is made of PDMS or Ecoflex material, and when the step S2 is performed, the method comprises the following steps: