Lighting test device for super small light emitting diode

Abstract

The present invention relates to a lighting test device for super small light emitting diodes. The lighting test device for super small light emitting diodes of the present invention includes a face contact probe which makes face contact with the front of a light emitting diode assembly in which a plurality of super small light emitting diodes are arranged in a forward direction through a resistivity member, thereby making both end electrodes of the plurality of super small light emitting diodes contact each other, a probe electrode which makes line contact on one side and the other side of the face contact probe and supplies power, a photographing unit which photographs the light emitting diode assembly on the opposite side of the face contact probe in contact, and a control unit which supplies power in the forward direction to the probe electrode in the arrangement direction of the plurality of super small light emitting diodes and tests the lighting state of the plurality of super small light emitting diodes based on the images of the light emitting diode assembly photographed by the photographing unit before and after the power is supplied.

Description

[0001] Cross-reference to related applications

[0002] This application is based on and claims priority to Korean patent applications No. 10-2021-0071184, filed on June 2, 2021, and No. 10-2021-0177181, filed on February 13, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to a lighting test device for ultra-small light-emitting diodes (LEDs), and more specifically, to a lighting test device for ultra-small LEDs. After a surface contact probe contacts the front of an assembly composed of multiple ultra-small LEDs arranged in a square, a power supply for lighting is applied to both sides to uniformly test the lighting state of the ultra-small LEDs. Background Technology

[0004] Typically, a light-emitting diode (LED) is a semiconductor light-emitting element that uses compound semiconductor materials to convert electric current into light. Based on the types of compound semiconductor materials used, LEDs can produce light sources in various wavelengths, from ultraviolet to infrared. Compared to existing light sources, they have characteristics such as fast response speed, extremely small structure, and long lifespan, thus finding applications in various fields such as lighting, electronic displays, televisions, mobile phones, and automobiles.

[0005] In order to ensure greater market competitiveness, related industries are actively conducting research on the diversity of application products that can be integrated with fields such as communications, medical, biochemistry, or fiber, in addition to displays.

[0006] Therefore, technologies related to improving the flexibility and size control of light-emitting diodes are needed. Recently, ultra-small light-emitting diodes that can achieve improved flexibility and size control are attracting attention as the next generation of displays.

[0007] Micro light-emitting diodes (LEDs) are light-emitting elements composed of multiple light-emitting structures manufactured at a level of approximately 5μm to 100μm. The light-emitting structures themselves can be used as pixels, and they are easily bent, thus overcoming the problem of existing LEDs frequently breaking due to external impacts.

[0008] These ultra-small light-emitting diodes can be widely used in optical applications that require low power consumption, miniaturization, and lightweight design, including implantable medical devices such as flexible displays, or the development of smart fibers incorporating light-emitting diodes.

[0009] The background technology of this invention has been disclosed in Korean Patent Publication No. 10-2019-0106655 (LED testing apparatus and transfer apparatus published on September 18, 2019). Summary of the Invention

[0010] Technical issues

[0011] As mentioned above, in order to use ultra-small light-emitting diodes (LEDs) in a display, the completed LEDs must be identified and tested to ensure they are electrically sound before being transferred from the wafer to the target substrate. However, due to the extremely small size of the LEDs, there is no suitable transfer and testing method. Using existing methods can lead to breakage or damage, or manual operation can increase costs.

[0012] Furthermore, if the electrical goodness of multiple miniature light-emitting diodes is not tested directly on the wafer before being transferred to the target substrate, there is a risk that the target substrate itself may become defective if a defective miniature light-emitting diode subsequently occurs on the target substrate.

[0013] The present invention is proposed to improve the problems mentioned above. According to one aspect, the object of the present invention is to provide a lighting test device for ultra-small light-emitting diodes, which applies power for lighting on both sides after the surface contact probe contacts the front of an assembly composed of multiple ultra-small light-emitting diodes arranged in a positive direction, thereby uniformly testing the lighting state of the ultra-small light-emitting diodes.

[0014] Technical solution

[0015] According to one aspect of the present invention, a lighting test apparatus for ultra-small light-emitting diodes (LEDs) includes: a surface contact probe that contacts the front surface of an LED assembly composed of a plurality of ultra-small LEDs arranged in a positive direction via a resistivity component, thereby causing the two end electrodes of the plurality of ultra-small LEDs to contact each other; a probe electrode that makes line contact with one side and the other side of the surface contact probe and provides power; an imaging unit that takes an image of the LED assembly on the opposite side of the surface contact probe; and a control unit that provides positive power to the probe electrode along the arrangement direction of the plurality of ultra-small LEDs, and tests the lighting state of the plurality of ultra-small LEDs based on images of the LED assembly taken by the imaging unit before and after providing power.

[0016] In this invention, the surface contact probe is any one of the following: a resistivity thin film, a resistivity PDMS (Polydimethylsiloxane), a resistivity liquid, and a resistivity gel.

[0017] In this invention, when the surface contact probe is a thin film with resistivity, it further includes a pressurizing device for pressurizing the surface contact probe.

[0018] In this invention, the pressurizing device is a buffer component that uses elasticity to pressurize a resistivity film.

[0019] In this invention, the pressurizing device consists of a pressurizing chamber. In order to create an empty space inside the pressurizing chamber and arrange the resistivity film in the empty space, the probe electrode is pressurized, and pressurized fluid is injected into the empty space through the injection port to pressurize the resistivity film.

[0020] In this invention, the pressurized fluid includes a non-conductive gas or liquid.

[0021] In this invention, when the surface contact probe is a resistive liquid or a resistive colloid, it further includes a guide partition, which corresponds to the area of ​​the light-emitting diode assembly that restricts the resistive liquid or resistive colloid.

[0022] The present invention further includes a transparent substrate for fixing a light-emitting diode assembly.

[0023] The present invention further includes an output section for outputting test results of the lighting state of an ultra-small light-emitting diode.

[0024] Beneficial effects

[0025] According to one aspect of the present invention, a lighting test device for ultra-small light-emitting diodes (LEDs) applies a power supply for lighting on both sides after the surface contact probe contacts the front of an assembly composed of multiple ultra-small LEDs arranged in a positive direction. This enables a unified test of the lighting state of the ultra-small LEDs, which not only reduces the time and cost required for light-emitting tests but also avoids direct contact with the contact pins of the ultra-small LEDs, thereby reducing physical damage to the components during the test. Attached Figure Description

[0026] Figure 1 This is a structural block diagram of a lighting test device for an ultra-small light-emitting diode according to an embodiment of the present invention.

[0027] Figure 2 This is an example diagram of a lighting test device for an ultra-small light-emitting diode according to an embodiment of the present invention.

[0028] Figure 3This is an equivalent circuit diagram of a lighting test device for an ultra-small light-emitting diode according to an embodiment of the present invention.

[0029] Figure 4 yes Figure 2 The diagram shows a cross-sectional view of the surface contact probe of a lighting test apparatus for an ultra-small light-emitting diode according to an embodiment of the present invention.

[0030] Figure 5 yes Figure 2 The diagram shows a cross-sectional view of the pressure device of the lighting test apparatus for an ultra-small light-emitting diode according to an embodiment of the present invention. Detailed Implementation

[0031] The lighting test apparatus for the ultra-miniature light-emitting diode according to the present invention will now be described with reference to the accompanying drawings. During this process, for clarity and convenience, the thickness of lines or the dimensions of constituent elements illustrated in the drawings may be exaggerated. Furthermore, the terminology used below is defined in consideration of the function of the present invention and may vary based on the intentions or habits of different users or operators. Therefore, the definitions of these terms will depend on the entire contents of this specification.

[0032] Figure 1 This is a structural block diagram of a lighting test device for an ultra-small light-emitting diode according to an embodiment of the present invention. Figure 2 This is an example diagram of a lighting test device for an ultra-small light-emitting diode according to an embodiment of the present invention. Figure 3 This is an equivalent circuit diagram of a lighting test device for an ultra-small light-emitting diode according to an embodiment of the present invention. Figure 4 yes Figure 2 The diagram shown is a cross-sectional view of the surface contact probe of a lighting test apparatus for an ultra-small light-emitting diode according to an embodiment of the present invention. Figure 5 yes Figure 2 The diagram shows a cross-sectional view of the pressure device of the lighting test apparatus for an ultra-small light-emitting diode according to an embodiment of the present invention.

[0033] like Figure 1 As shown, the lighting test device for an ultra-small light-emitting diode according to an embodiment of the present invention includes a surface contact probe 20, a probe electrode 10, an imaging unit 30, a control unit 40, an output unit 50, and a power supply unit 60.

[0034] The surface contact probe 20 contacts the front surface of the light-emitting diode assembly 70 through a resistivity component. The light-emitting diode assembly 70 is composed of multiple miniature light-emitting diodes 75 arranged in the forward direction, thereby enabling the two end electrodes of the multiple miniature light-emitting diodes 75 to contact each other.

[0035] The surface contact probe 20 contacts the front surface of the light-emitting diode assembly 70, and based on the resistance determined by the length, area and volume of the resistivity component, a current path can be formed through multiple miniature light-emitting diodes 75 to illuminate the assembly.

[0036] That is, such as Figure 3 As shown, by determining the resistivity, length, area, and volume of the resistivity component, when the miniature light-emitting diodes 75 of the light-emitting diode assembly 70 are arranged in the resistive grid at each intersection, the resistive grid not only connects in series and parallel with each miniature light-emitting diode 75 of the light-emitting diode assembly 70, but also forms a current path and illuminates the miniature light-emitting diodes 75.

[0037] At this time, the surface contact probe 20 can be made of any one of the following: a resistivity thin film, a resistivity PDMS (Polydimethylsiloxane), a resistivity liquid, and a resistivity gel.

[0038] The resistivity of the thin film may include a thin film with resistivity or a stretchable soft film.

[0039] Therefore, as Figure 2 As shown, when the surface contact probe 20 with resistivity contacts the front surface of the light-emitting diode assembly 70, which is composed of multiple miniature light-emitting diodes 75, and power is supplied through the probe electrodes 10 formed on both sides, the multiple miniature light-emitting diodes 75 forming the light-emitting diode assembly 70 can be lit.

[0040] Further details are as follows, such as Figure 2 As shown, when the resistivity material surface contact probe 20 contacts the front surface of the light-emitting diode assembly 70, it can behave as follows: Figure 3 The equivalent circuit shown.

[0041] That is, the surface contact probe 20 can be in the form of a resistor grid, and the miniature light-emitting diodes 75 of the light-emitting diode assembly 70 can be arranged at each intersection. Therefore, if the power supply section 60 is powered by the probe electrodes 10 formed on both sides in a positive direction, each miniature light-emitting diode 75 constituting the light-emitting diode assembly 70 can be lit simultaneously.

[0042] The surface contact probe 20 may be composed of a resistivity thin film 22, and may further include a pressure-applying device for applying pressure to the resistivity thin film 22.

[0043] That is, such as Figure 4 shown Figure 2 The cross-sectional view of the AA line shows that after the miniature light-emitting diodes 75 are arranged along the positive direction on the transparent substrate 72 used to fix the light-emitting diode assembly 70, the light-emitting diode assembly 70 is covered by the surface contact probe 20 of the resistivity film 22 to make surface contact with the miniature light-emitting diodes 75.

[0044] The transparent substrate 72 may include the wafer substrate used in the manufacturing process of the ultra-small light-emitting diode 75.

[0045] At this time, in order to make the resistivity film 22, which serves as the surface contact probe 20, come into close contact with the ultra-small light-emitting diode 75, pressure can be applied by the buffer component 82, which serves as the pressure application device.

[0046] like Figure 4 As shown, the buffer component 24 applies pressure to the resistivity film 22, which serves as the surface contact probe 20, using elastic force, thereby enabling the resistivity film 22 to make surface contact with all the miniature light-emitting diodes 75 of the light-emitting diode assembly 70.

[0047] In addition, such as Figure 5 As shown, as a pressurizing device, in order to form an empty space inside and arrange the resistivity film 22, which is the surface contact probe 20, in the space, the probe electrode 10 is pressurized and sealed, pressurizing fluid 88 is injected into the empty space inside through the injection port 84, and a pressurizing chamber 84 is formed for pressurizing the resistivity film 22.

[0048] The pressurized fluid 88 may include a non-conductive gas or liquid.

[0049] Furthermore, in the process of manufacturing a panel by transferring an ultra-small light-emitting diode 75, when the ultra-small light-emitting diode 75 is transferred to a resistivity PDMS, the resistivity PDMS can also be used as a surface contact probe 20.

[0050] Additionally, when the surface contact probe 20 is a resistive liquid or a resistive gel, such as Figure 2 As shown, it preferably further includes a guide partition 26 that corresponds to the size of the light-emitting diode assembly 70 and restricts the area of ​​the resistivity liquid or resistivity colloid, thereby maintaining the shaped form, and forming a current path between the miniature light-emitting diodes 75 to maintain the resistance that allows lighting.

[0051] The probe electrode 10 can supply power to the surface contact probe 20 by making line contact between one side and the other side of the surface contact probe 20.

[0052] The imaging unit 30 takes a picture of the light-emitting diode assembly 70 on the opposite side of the surface contact probe 20 and provides the captured image to the control unit 40.

[0053] The control unit 40 provides a positive illumination power supply to the probe electrode 10 along the arrangement direction of the miniature light-emitting diodes 75, and tests the illumination state of the miniature light-emitting diodes 75 by comparing the images of the light-emitting diode assembly 70 captured by the imaging unit 30 before and after the power supply is provided.

[0054] The output section 50 can output the test results of the lighting status of the ultra-small light-emitting diode 75.

[0055] As described above, the ultra-small light-emitting diode lighting test device according to the present invention, after contacting the front of the component composed of multiple ultra-small light-emitting diodes arranged in the positive direction by a surface contact probe, applies power for lighting on both sides, thereby enabling unified testing of the lighting state of the ultra-small light-emitting diodes. This not only reduces the time and cost required for light emission testing, but also reduces physical damage to the components during the testing process because the pins do not directly contact the ultra-small light-emitting diodes.

[0056] The description herein can be implemented, for example, as a method or step, an apparatus, a software program, a data stream, or a signal. Even if discussed only in a single form (e.g., only a method is discussed), the features discussed can also be implemented in other forms (e.g., an apparatus or a program). An apparatus can be implemented, for example, as suitable hardware, software, and firmware. A method can be implemented, for example, as an apparatus such as a processor, which refers to a general processing device including, for example, a computer, a microprocessor, an integrated circuit, or a programmable logic device. Processors also include communication devices, such as computers, cellular phones, tablet computers, portable / personal digital assistants (“PDAs”), and other devices that facilitate the transfer of information between end users.

[0057] The present invention has been described with reference to the embodiments shown in the accompanying drawings. This is merely an illustrative example, and those skilled in the art should understand that various modifications and other equivalent embodiments can be made based on the above description.

[0058] Therefore, the true scope of protection of this invention should be determined by the appended claims.

[0059] Explanation of reference numerals in the attached figures

[0060] 10: Probe electrode; 20: Surface contact probe

[0061] 22: Thin film with resistivity 26: Guided septum

[0062] 30: Filming Department 40: Control Department

[0063] 50: Output section 60: Power supply section

[0064] 70: Light Emitting Diode Components 75: Ultra-Miniature Light Emitting Diodes

[0065] 82: Buffer component; 84: Injection port

[0066] 86: Pressurized fluid 88: Pressurized chamber

Claims

1. A lighting test device for an ultra-small light-emitting diode, comprising: A surface contact probe is used to make contact with the front surface of a light-emitting diode assembly composed of multiple ultra-small light-emitting diodes arranged in a forward direction through a resistivity material, thereby making contact between the two electrodes of the multiple ultra-small light-emitting diodes. The probe electrode makes line contact with one side and the other side of the probe and provides power. The imaging unit takes an image of the light-emitting diode assembly from the opposite side of the surface contact probe; and The control unit provides positive power to the probe electrodes along the arrangement direction of the plurality of miniature light-emitting diodes (LEDs), and tests the illumination status of the plurality of miniature LEDs based on images of the LED assembly captured by the imaging unit before and after the power is supplied. The surface contact probe is any one of resistivity thin film, resistivity PDMS, resistivity liquid, and resistivity colloid.

2. The lighting test device for ultra-small light-emitting diodes as described in claim 1, characterized in that, When the surface contact probe is a thin film of the resistivity, it further includes a pressure device for pressurizing the surface contact probe.

3. The lighting test device for ultra-small light-emitting diodes as described in claim 2, characterized in that, The pressurizing device is a buffer component that uses elasticity to pressurize the resistivity film.

4. The lighting test device for ultra-small light-emitting diodes as described in claim 2, characterized in that, The pressurizing device consists of a pressurizing chamber. In order to create an empty space inside the pressurizing chamber and arrange the resistivity film in the empty space, the probe electrode is pressurized. Pressurized fluid is injected into the empty space inside the chamber through the injection port to pressurize the resistivity film.

5. The lighting test device for ultra-small light-emitting diodes as described in claim 4, characterized in that, The pressurized fluid includes non-conductive gas or liquid.

6. The lighting test device for ultra-small light-emitting diodes as described in claim 1, characterized in that, When the surface contact probe is a liquid or a colloid of the resistivity, it further includes a guide partition corresponding to the area of ​​the light-emitting diode assembly that restricts the liquid or colloid of the resistivity.

7. The lighting test device for ultra-small light-emitting diodes as described in claim 1, characterized in that, It further includes a transparent substrate for fixing the light-emitting diode assembly.

8. The lighting test device for ultra-small light-emitting diodes as described in claim 1, characterized in that, It further includes an output section for outputting test results of the lighting state of the ultra-small light-emitting diode.

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