KR102485363B1 - Apparatus for Micro LED Inspection and Method for The Same - Google Patents

Abstract

A micro LED inspection apparatus according to the present invention includes a light emitter generating and irradiating a first light to be used for inspecting a micro LED, an optical system processing the first light to direct the micro LED to be inspected, and each micro LED by the first light. and a detection unit that obtains inspection information based on the second light generated from , and the irradiation of the first light and the acquisition of inspection information by the detection unit are performed in an 'inspection area unit' that is a plurality of micro LED units forming a straight line. The inspection information may include spatial information indicating the location of each micro LED, spectral information indicating the size of each wavelength band, image information, and the like. According to the present invention, it is possible to inspect the chip state (whether defective, contaminated, etc.) and check its characteristics without applying a voltage to the electrode of each micro LED chip. Therefore, the state of the chip can be inspected anywhere during the chip processing process as well as after the plurality of micro LED chips are arranged on the substrate.

Description

Micro LED inspection device and its method { Apparatus for Micro LED Inspection and Method for The Same }

The present invention relates to an apparatus and method for inspecting a micro LED, enabling a plurality of micro LEDs to be quickly and accurately inspected.

Micro LED refers to an LED (Light Emitting Diode) with a size of about 1 to 100 μm, and if it is realized as a display by configuring pixels made of RGB, it can be used in all existing displays, from small displays to large TVs. The micro LED display uses the micro LED chip itself as a light emitting material.

1 schematically shows a manufacturing process of a micro LED display panel, and FIG. 2 schematically shows a manufacturing process from an Epi wafer to display panel manufacturing.

The production process of the micro LED display panel consists of Epi wafer fabrication step (Step 1), precise cutting and separation of chips (or pixels) (Step 2), and precision arranging and bonding of chips on a CMOS substrate (Step 3). can

These Steps 1 to 3 may be referred to as LED chip processing steps.

Since the micro LED chips are to be used in a display, after each micro LED chip emits light, a spectral spectrum inspection and an external inspection are necessarily performed.

As a specific example, assuming a 4K UHD TV, the number of micro LED chips to be inspected is approximately 24,800,000, and these chips need to be inspected at each stage of the manufacturing process shown in FIG. 2 .

Regarding the problem of defective micro LED, Korean Patent Publication No. 10-2019-0114334 discloses a micro LED inspection and repair method that inspects whether the micro LED is good or bad and replaces the defective micro LED with a good micro LED. are doing

However, in the conventional LED inspection, after the LED chips are arranged on the substrate through the chip processing process, voltage is applied to the electrodes to individually inspect each chip (pixel), so there is a problem in that the inspection time is very long. .

In addition, in the conventional micro LED inspection, since the size of the chip is very small, tens of micrometers, only some micro LED chips are partially sampled and inspected to determine whether the corresponding panel itself is defective. For this reason, there was a problem that an accurate determination could not be made.

That is, although an electrical signal must be applied to emit light from the micro LED, the electrical signal cannot be applied unless the final panel is manufactured, making it difficult to inspect the micro LED in each necessary process.

In addition, since it is difficult to perform smooth inspection due to the small size of the micro LED chip and the large number of inspections, current technology has limitations in effectively inspecting the micro LED.

Korean Patent Publication No. 10-2019-0114334 (Name: Micro LED inspection and repair method, publication date: 2019.10.10)

Accordingly, the present invention has been made to solve the above problems, and the state of the micro LED chips can be inspected (confirmed) in any process, not only after the micro LED chips are placed on the substrate, but also before they are placed. , Its purpose is to provide a micro LED inspection device and method.

Another object of the present invention is to be able to inspect the state of the micro LED chip without applying a voltage to the electrode.

However, the technical problem to be achieved by each embodiment of the present invention is not limited to the above technical problems, and other technical problems may exist.

In order to achieve the above object, a micro LED inspection device according to the present invention includes a light irradiation unit generating and irradiating first light to be used for micro LED inspection; an optical system for processing the first light emitted from the light irradiation unit to direct the plurality of micro LEDs to be inspected; and a detector configured to obtain test information based on second light emitted from the plurality of micro LEDs by the first light.

At this time, the irradiation of the first light to the micro LED and the acquisition of inspection information in the detection unit may be performed in an 'inspection area unit' that is a unit of a plurality of micro LEDs forming a straight line.

The inspection information may include spatial information indicating the position of each micro LED and spectral information indicating the size of each wavelength band.

The irradiation of the first light to each micro LED belonging to the inspection area unit may be sequentially performed for each micro LED.

In this case, sequential light irradiation to each micro LED belonging to the inspection area unit may be performed by adjusting the rotation angle of the mirror.

In addition, the irradiation of light to all micro LEDs belonging to the inspection area unit may be configured to be faster than the speed at which inspection information is acquired by the detection unit.

The irradiation of the first light to each micro LED belonging to the inspection area unit may be configured to be performed simultaneously with line light.

The light irradiation unit may include a plurality of light generating units each generating light of different wavelengths; a plurality of expander units corresponding to each of the light generating units and expanding the light generated by each light generating unit in a line shape; a mux filter unit for receiving the light expanded through each of the expander units through a mirror and combining them into one optical signal; an ND filter unit adjusting optical output power of the mux filter unit; and a wavelength selection control unit selectively controlling the operation of each light generating unit.

The light generating unit includes a first light generating unit generating light having a wavelength of 375 nm or 405 nm; and a second light generating unit generating light having any wavelength of 532 nm or more and 610 nm or less.

The wavelength selection control unit determines whether the arrayed micro LEDs to be inspected include green micro LEDs, blue micro LEDs, or red micro LEDs, and the first light generating unit and The second light generator may be selectively operated.

The optical system may include a beam generator that processes the light emitted from the light irradiator to have a line light form; a beam splitter unit disposed obliquely with respect to the forward and backward directions and into which the light processed by the beam generator is incident; and an objective lens for transmitting light incident from the beam splitter to the micro-LED, and the detector may include a spectrometer for obtaining spectral information of the second light.

The first light is incident toward the beam splitter in a direction orthogonal to the forward and backward directions, and the beam splitter reflects the incident first light toward each of the micro LEDs located in the front, from each of the micro LEDs. The generated second light may pass through and be transmitted to the spectrometer located at the rear.

Here, the front-back direction may be a direction connecting a front where the micro LED is disposed and a rear where the spectrometer is disposed.

The beam generator may adjust the rotation angle of the mirror so that light is sequentially irradiated to each micro LED in the inspection area unit.

The beam generator may be configured to convert light emitted from the light emitter into line light.

The micro LED inspection apparatus according to the present invention may further include a tube lens for determining magnification according to the focal length of the objective lens.

The detection unit may further include an imaging unit that forms an image of the second light. In addition, the optical system may further include a detection path selector configured to transmit all of the second light to the imaging unit, all of the second light to the spectrometer, or pass the second light to the imaging unit and the spectrometer at a predetermined ratio.

The micro LED inspection method according to the present invention is a method of inspecting a plurality of micro LEDs to be inspected through the micro LED inspection device of each embodiment, wherein the light irradiation unit irradiates the first light to each micro LED in the current inspection order. and controlling the optical system; and acquiring inspection information based on second light generated in each micro LED by irradiation of the first light through the detector for all micro LEDs to be inspected.

At this time, the irradiation of the first light and acquisition of inspection information may be performed in an 'inspection area unit' that is a unit of a plurality of micro LEDs forming a straight line.

Light irradiation to each micro LED in the inspection area unit may be sequentially performed for each micro LED or simultaneously with line light.

The micro LED inspection device of the present invention can inspect the state (whether defective, contaminated, etc.) of each micro LED chip and check its characteristics without applying a voltage to the electrode of each micro LED chip.

Therefore, the state of the micro LED chips can be inspected (confirmed) anywhere during the chip processing process, not only after the plurality of micro LED chips are arranged (placed) on the substrate but also before the arrangement.

Accordingly, unlike the conventional vision inspection that performs inspection at the final stage, it is possible to directly intervene in the process to improve yield and reduce loss.

However, the effects obtainable through the present invention are not limited to the above effects, and other effects may exist.

1 schematically shows the production process of a micro LED display panel,
Figure 2 schematically shows the manufacturing process from Epi wafer to display panel manufacturing,
3 is an embodiment of a micro LED inspection device according to the present invention;
Figure 4 is a specific embodiment of the light irradiation unit,
5 schematically shows an example of an optical system structure that can be applied to the micro LED inspection device of the present invention;
6 schematically shows another example of an optical system structure that can be applied to the micro LED inspection device of the present invention;
7 is an embodiment of a micro LED inspection method according to the present invention;
8 is an example of image information of each micro LED acquired through an imaging unit;
9 is an example of a GUI screen on which various inspection information such as light emission status and spectral information of each micro LED is output;
10 is an example comparing performance of the present invention and a conventional micro LED inspection device.

Since the present invention can apply various transformations and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, it should be understood that this is not intended to limit the present invention to specific embodiments, and includes all transformations, equivalents, and substitutes included in the spirit and scope of the present invention.

In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

3 shows an embodiment of the micro LED inspection device 100 according to the present invention, the light irradiation unit 110 generating and irradiating the first light used for micro LED inspection, and the light irradiation unit 110 irradiates the light. Inspection based on the second light generated from each micro LED by the first light incident through the optical system 120 that processes the first light toward a plurality of arrayed micro LEDs to be inspected, and the optical system 120 It includes a detection unit 130 that obtains information.

A plurality of micro LEDs to be inspected may be arranged horizontally and vertically on a member such as a substrate and placed on the sample holder 71, and the first light generated by the light irradiation unit 110 is irradiated to each micro LED, thereby Inspection information on each micro LED is obtained through the second light generated from each micro LED.

At this time, the irradiation of light to the micro LED and the detection of inspection information by the detector 130 are performed in units of inspection areas.

The inspection area unit refers to a plurality of micro LED units forming a straight line. Therefore, each inspection is performed with some micro LED units forming a straight line among a plurality of micro LEDs arrayed.

For example, a line corresponding to one row (horizontal line) or a line corresponding to one column (vertical line) of a plurality of arrayed micro LED chips may be inspected in units of a specific number of micro LEDs.

The second light generated by each micro LED by the first light may be various types of light. For example, it may be PL light or fluorescence.

The micro LED inspection device 100 according to the present invention may emit light from the micro LED to be inspected based on a light-emitting technique called PL (Photoluminescence). That is, the micro LED may emit light by using the first light emitted from the light emitter 110 as an excitation light. Through this, processing may be performed so that a light emitting effect identical to or corresponding to that of light emitting with electrodes is achieved without applying a voltage to the electrodes of each micro LED.

The inspection information obtained by the detection unit 130 through the second light may be configured in various ways and is not particularly limited.

As a specific example, the detection unit 130 may include a spectroscopic unit 131 that obtains spectral information. In this case, the inspection information obtained by the spectrometer 131 through the second light may include spatial information of each micro LED constituting a unit of inspection area and spectral information indicating the size of each wavelength band.

In the course of inspecting the arrayed micro LEDs in units of inspection areas, since each micro LED belonging to each inspection area unit forms a straight line, light irradiation to each micro LED may be performed in a line shape.

As a specific embodiment of performing light irradiation on each micro LED in a unit of inspection area in a line form, light irradiation on each micro LED in unit of inspection area may be sequentially performed on each micro LED (point scan method).

For example, assuming that the inspection area unit is n micro LED units forming a straight line, light is irradiated to one of them, and then light is irradiated to the next one.

A method for sequential light irradiation may be configured in various ways.

As a specific example, sequential light irradiation to each micro LED in units of inspection area may be performed by adjusting a rotation angle of a mirror constituting the optical system 120 .

At this time, the light can be configured in an arbitrary form through mechanical movement of the mirror using a Galvano mirror scanner, mems mirror scanner, or the like.

The irradiation of light to all the micro LEDs belonging to the inspection area unit may be configured to be faster than the speed at which inspection information is acquired by the detection unit 130 . Then, even if the light irradiation to each micro LED belonging to the inspection area unit is sequentially performed, the process may be performed as if the light irradiation was performed at once.

As another embodiment of performing light irradiation on each micro LED in a unit of inspection area in the form of a line, light irradiation on each micro LED in unit of inspection area may be performed simultaneously through line light (line scan method). ).

This line scan method uses a lens optical element such as a cylindrical lens, a DOE, or a powell lens, and can configure light in a line form without mechanical movement and irradiate it in batches.

The light emitter 110 may be configured in various ways to generate and emit first light used for micro LED inspection.

4 shows an embodiment of the light irradiator 110, a plurality of light generators 111 and 114 generating light of different wavelengths, and the light generated by each light generator 111 and 114. A plurality of expander units (112, 115) extending in a line form, receiving the expanded light from each expander unit (112, 115) through mirrors (113, 116) and integrating them into one optical signal A laser mux filter 117, an ND filter 118 that adjusts the light output of the mux filter 117, and a wavelength selection controller that selectively controls the operation of each light generating unit 111, 114 ( 119) may be included.

Although FIG. 4 shows two light generators 111 and 114 generating light of different wavelengths, the number of light generators may be configured in various ways as needed, but is not limited thereto.

In FIG. 4, the light generating unit includes a first light generating unit 111 generating light (beam, laser beam) having a wavelength of 375 nm or 405 nm, and a second light generating unit generating light having a wavelength of 532 nm or more and 610 nm or less ( 114) may be included.

The micro LED chips arranged as inspection objects may include three types of micro LEDs: red micro LED, green micro LED, and blue micro LED.

At this time, the first light generating unit 111 may generate laser light used to measure the light emission of the green micro LED and the blue micro LED among the three types of micro LEDs (RGB micro LEDs). Also, the second light generating unit 114 may generate laser light used to measure light emission of the red micro LED among the three types of micro LEDs. The first light generating unit 111 may be referred to as a green/blue LED light emitting laser, an A laser, or the like, and the second light generating unit 114 may be referred to as a red LED light emitting laser, a B laser, or the like.

Each of the expander units 112 and 115 is provided to correspond to each of the light generators 111 and 114 and can expand the light generated by each of the light generators 111 and 114 in a line shape.

The ND filter unit 118 may be used to adjust the output of light emitted from the light irradiator 110, and may adjust the output power of light.

The wavelength selection control unit 119 selectively controls the operation of each of the light generating units 111 and 114 and may be in charge of overall control of the light irradiation unit 110 .

In particular, the wavelength selection control unit 119 controls the first light generation unit 111 according to whether the arrayed micro LEDs to be inspected are green micro LEDs, blue micro LEDs, or red micro LEDs. ) or the second light generating unit 114 may be selectively controlled to operate.

That is, if an inspection target to be inspected is one of a red micro LED wafer, a green micro LED wafer, and a blue micro LED wafer, the wavelength selection control unit 119 controls the first light generating unit 111 and the first light generator 111 according to the type of the inspection target wafer. The second light generating unit 114 may be selectively operated.

Specifically, the wavelength selection control unit 119 controls the first light generating unit 111 to operate to generate laser light of a corresponding wavelength when the inspection target is a green micro LED wafer or a blue micro LED wafer, and In the case of a red micro LED wafer, the second light generating unit 114 may operate and control to generate laser light of a corresponding wavelength.

The mux filter unit 117 receives the expanded light generated from the first light generation unit 111 and the second light generation unit 114 and integrates them into one optical signal, and the integrated light into one is the ND filter unit 118 ), the light output power can be adjusted. Then, the first light whose output power is adjusted by the ND filter unit 118 may be irradiated from the light irradiation unit 110 .

The optical system 120 processes the first light emitted from the light emitter 110 toward a plurality of arrayed micro LEDs to be inspected.

5 and 6 schematically show an example of an optical system structure that can be applied to the micro LED inspection device of the present invention, and with reference to FIG. 3, the optical system 120 constituting the micro LED inspection device of the present invention An embodiment is described.

The optical system 120 may include a beam generator 121 that processes the first light emitted from the light emitter 110 into a line light type.

In this case, a method in which the beam generator 121 processes the first light in the form of line light may be configured in various ways.

As an example, the beam generator 121 may adjust the rotation angle of the mirror so that light is sequentially irradiated to each micro LED in each inspection area (point scan method). As another example, the beam generator 121 uses a galvano scanner, a Powell lens, a cylindrical lens, etc. to transmit the first light emitted from the light irradiator 110, It can also be converted into line light (line scan method).

That is, the first light emitted from the light irradiator 110 may be incident to the beam splitter 123 in the form of line light of a point scan method or a line scan method by the beam generator 121 .

The optical system 120 includes a beam generator 121, a beam splitter unit 123 disposed at an angle with respect to the forward and backward directions, an objective lens 125 that transmits light incident from the beam splitter unit 123 to the micro LED to be inspected, and the like. It can be configured to include.

In this case, the first light may be incident toward the beam splitter in a direction orthogonal to the forward and backward directions. Here, the forward-backward direction may mean a direction connecting a front where the microLEDs to be inspected are disposed and a rear where the spectrometer 131 is disposed.

That is, the front-back direction may mean a direction perpendicular to the upper surface of the substrate on which a plurality of micro LED chips to be inspected are arranged.

The front-back direction means the 4 o'clock-10 o'clock direction in the example of FIG. 5 and the 6 o'clock-12 o'clock direction in the example of FIG. In the example of 3, it may mean the direction from 3 o'clock to 9 o'clock, but this direction setting is only an example to help understanding of the description, but is not limited thereto.

The beam splitter unit 123 reflects line-shaped light incident from the light irradiator 110 through the beam generator 121 toward each micro LED located in front of the beam splitter unit 123, and also each micro LED. The second light generated from may pass through and be transmitted to the rear of the beam splitter unit 123 .

For example, if a fluorescence or PL signal of a 450 nm band is generated from a sample (micro LED) by irradiating a first light having a wavelength of 405 nm, the beam splitter unit 123 reflects the first light having a wavelength of 405 nm toward the sample. The second light in the 450 nm band generated from the sample may be transmitted toward the spectrometer 131 .

A beam splitter may be otherwise referred to as an entrance slit, a dichroic mirror, or the like.

The objective lens 125 is disposed in front of the beam splitter unit 123 and may be otherwise referred to as an objective lens or a front lens.

The detector 130 may include a spectrometer 131 that detects spectral information of the second light, and the spectrometer 131 may be disposed behind the beam splitter 123 .

In addition, a second lens may be disposed between the beam splitter unit 123 and the splitter 131, and the second lens may be otherwise referred to as an A-lens or a collimator.

The beam splitter unit 123 may reflect incident light in the form of a line to be transmitted to the micro LED chip to be inspected located in front of the objective lens 125 . Accordingly, light in the form of a line reflected by the beam splitter unit 123 may be irradiated to the focal plane of the sample, and second light in the form of a line may be generated from a plurality of micro LEDs belonging to an inspection area unit forming a straight line.

This second light may return to the beam splitter unit 123 as reflected light, and the beam splitter unit 123 passes the light reflected from the micro LED and is located behind the beam splitter unit 123. It can be transmitted to the spectroscopy unit 131.

The spectrometer 131 diffracts and passes the light transmitted through the beam splitter unit 123 to obtain inspection information on each microLED to be inspected to which line-shaped light is irradiated. Here, the inspection information may include spatial information and spectral information of each micro LED belonging to the inspection area unit.

In particular, the spectrometer 131 may obtain size information for each wavelength band as spectral information.

In addition, a tube lens 124 may be disposed between the beam splitter unit 123 and the objective lens 125 . The tube lens 124 is used together with the objective lens 125, so that the magnification can be determined according to the focal length of the objective lens 125.

Meanwhile, the detection unit 130 may further include an imaging unit 132 that forms an image of the second light. In addition, the optical system 120 may further include a detection path selector 126 that distributes the second light to the imaging unit 132 and the spectrometer 131 .

At this time, the detection path selection unit 126 transfers all of the second light to the image pickup unit 132, transfers all of the second light to the spectrometer 131, or transmits all of the second light to the image pickup unit 132 and the spectrograph 131 at a predetermined ratio. It can be configured to deliver to.

Second light (e.g., PL or fluorescence signal) is generated by the light reaching the micro LED to be inspected, and this signal is again transmitted through the objective lens 125, the tube lens 124, and the beam splitter unit 123 (dike). It is transferred to the path determined by the detection path selection unit 126 after passing through the gain filter).

The detection path selection unit 126 may distribute the second light to the imaging unit 132 and the spectroscopic unit 131 by performing a mirror/beam splitter/black mode selection function.

The imaging unit 132 may be configured in various ways. As a specific example, the imaging unit 132 may be configured using a charge-coupled device (CCD). Through the imaging unit 132, not only the spectral information but also the external information of the pixel may be simultaneously acquired.

The second light (fluorescence, PL light) generated from the sample may form a distinct image on the spectrometer 131 or the imaging unit 132 by the tube lens 124 .

The detection path selector 126 may be configured in various ways, and as an example, may be configured using a beam splitter.

When the detection path selector 126 selects the mirror mode, all of the second light is reflected and sent to the imaging unit 132 to form an image on the CCD. When the beam splitter mode is selected, some of the transmitted light is ), and some of them go into the imaging unit 132.

Since the beam splitter has optical characteristics (e.g., 50:50) of distributing transmission and reflection at a constant ratio, the second light can be measured simultaneously.

If the detection path selector 126 selects the blank mode, all of the second light enters the spectrometer 131 .

The positions of the plurality of micro LEDs to be inspected located in front of the objective lens 125 may be varied.

That is, when inspection information based on the irradiation of the first light to each micro LED belonging to the inspection area unit in the current order and the second light emitted from each micro LED is acquired, the micro LED belonging to the inspection area unit in the next order is obtained. Irradiation of the first light must be performed. To this end, the sample holder 71 on which a plurality of micro LEDs to be inspected are placed may be configured to be movable.

In addition, the micro LED inspection device 100 may include a sample movement control unit 151 that moves the sample holder 71 on which a plurality of micro LEDs to be tested are placed.

The sample movement control unit 151 may move the sample holder 71 according to a predetermined time period. Here, the predetermined time period may be related to a period (cycle) from when the first light is irradiated from the light emitter 110 to when the acquisition of inspection information by the detector 130 ends.

Under the control of the sample movement control unit 151 , acquisition of inspection information in units of inspection areas for a plurality of micro LEDs to be inspected may be continuously performed.

The micro LED inspection method according to the present invention is a method of inspecting a plurality of inspection target micro LEDs using the micro LED inspection device 100 of the present invention.

Referring to FIG. 7 , as the inspection starts (S211), controlling the light emitter 110 and the optical system 120 to radiate a first light to each micro LED in the current inspection sequence (S213), and Acquiring inspection information based on the second light generated from each micro LED by light irradiation through the detector 130 (S214) is performed.

The irradiation of light to each micro LED in step S213 and the acquisition of inspection information through the detection unit 130 in step S214 may be performed in units of inspection areas.

Steps S213 and S214 are continuously performed in units of inspection areas for all micro LEDs to be inspected (S212, S215, and S216).

Then, when steps S213 and step S214 are executed for all micro LEDs to be inspected, the inspection ends (S217).

The inspection information obtained in step S214 may include spatial information and spectral information indicating the size of each micro LED constituting each inspection area unit and the size of each wavelength band, and may include an image obtained by capturing a light emitting state of each micro LED. there is.

An embodiment of performing light irradiation on each micro LED in a unit of inspection area in the form of a line is a method of sequentially performing light irradiation on each micro LED (point scan method).

A method for sequential light irradiation may be configured in various ways, and as a specific example, it may be performed by adjusting a rotation angle of a mirror.

At this time, it is preferable to configure the light irradiation to all micro LEDs belonging to the inspection area unit to be faster than the speed at which inspection information is acquired by the detection unit 130 .

Then, even if the light irradiation to each micro LED belonging to the inspection area unit is sequentially performed, the process may be performed as if the light irradiation was performed at once.

Another embodiment in which light is irradiated to each micro LED in a unit of inspection area in a line form is to simultaneously irradiate light to each micro LED in unit of inspection area with line light (line scan method).

For example, a lens optical element such as a cylindrical lens, a DOE, or a powell lens may be used to configure line light without a mechanical movement and collectively irradiate the line light.

The micro LED inspection method according to the present invention may be implemented in the form of a program that can be executed through various computer means and recorded on a computer readable recording medium. Here, the computer means is not particularly limited as it can be configured in various ways.

For example, the computer means interworks with the micro LED inspection device 100, provides a graphical user interface (GUI), allows control commands to be issued to the micro LED inspection device 100, and is related to various micro LED inspections. It may be a computer device providing functions.

Computer-readable recording media includes all types of recording devices in which data readable by computer means is stored, and may include program instructions, data files, data structures, etc. alone or in combination. The programs recorded on the medium may be specially designed and configured for the present invention, or may be known and usable to those skilled in computer software.

Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. - includes hardware devices specially configured to store and execute program instructions, such as magneto-optical media, and ROM, RAM, flash memory, and the like.

Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter, as well as machine language codes such as those produced by a compiler.

According to the present invention, through the image information of each micro LED element obtained through the imaging unit 132 (CCD) and the spectroscopic characteristic information of each micro LED element obtained through the spectrometer 131, a plurality of micro LEDs You can check the status of

8 shows an example of image information of each micro LED device acquired through the imaging unit 132 (CCD), and FIG. 9 shows a GUI screen on which various inspection information such as image information and spectral information of each micro LED is output example is shown.

Area A of FIG. 9 shows image information of each micro LED, and area B and C show the brightness intensity of each micro LED of area A in a graph form. In addition, in area D, the spectral information of the individual micro LEDs of the currently selected part (cross-hair) in area A is shown in the form of a graph, and in area E, the emission information calculated through the spectral information (eg, center wavelength, full width at half maximum, color purity, color coordinates, etc.) are shown in numerical form.

As in this example, when the present invention is used, all characteristics of LED emission, such as Peak, FWHM, Integration value, color coordinates (x, y), luminance, color information, and defect, are accurately and quickly inspected for a plurality of micro LEDs can do.

10 is a comparison of the performance of the micro LED inspection device 100 according to the present invention and the performance of the conventional inspection device, and 'existing PL mapper' shows a case of performing an inspection in an Rθ rotation method, for example, and 'our company' PL mapper' represents an example of performing an inspection by the micro LED inspection apparatus 100 of the present invention.

The micro LED inspection apparatus 100 of the present invention performs an inspection by the PL method, does not require voltage application to electrodes, and can simultaneously acquire pixel shape information as well as spectral information.

In the inspection method using the micro LED inspection device 100 according to the present invention, it can be confirmed that the data acquisition speed has changed significantly from minutes (min) to seconds (s) compared to the conventional technology. It can be seen that the data acquisition speed for the wafer also changed remarkably short.

Compared to the prior art, the micro LED inspection apparatus 100 according to the present invention can accurately inspect the state or characteristics of a plurality of micro LEDs while reducing the total inspection time.

In the above, the present invention has been shown and described in relation to specific preferred embodiments, but the present invention can be variously modified and changed without departing from the technical features or fields of the present invention provided by the claims below. It is clear to those skilled in the art that it can be.

71: sample holder
100: micro LED inspection device
110: light irradiation unit
111, 114: light generating unit
112, 115: expander part
113, 116: mirror
117: mux filter unit
118: ND filter unit
119: wavelength selection controller
120: optical system
121: beam generator
123: beam splitter unit
124: tube lens
125: objective lens
126: detection path selection unit
130: detection unit
131: spectrometer
132: imaging unit
151: sample movement control unit

Claims (17)

a light emitter generating and irradiating first light to be used for micro LED inspection;
an optical system for processing the first light emitted from the light irradiation unit to direct a plurality of arrayed micro LEDs to be inspected; and
A detector configured to obtain inspection information based on second light generated by the plurality of micro LEDs by the first light;
The irradiation of the first light to the micro LED and the acquisition of inspection information in the detection unit are performed in an 'inspection area unit', which is a unit of a plurality of micro LEDs forming a straight line,
The irradiation of the first light to each micro LED belonging to the inspection area unit is sequentially performed for each micro LED;
Light irradiation to all micro LEDs belonging to the inspection area unit is faster than the speed of obtaining inspection information from the detection unit, micro LED inspection device. According to claim 1,
The inspection information includes spatial information, which is the location of each micro-LED, and spectral information indicating the size of each wavelength band. delete According to claim 1,
The micro LED inspection device, wherein the sequential light irradiation to each micro LED belonging to the inspection area unit is performed by adjusting the rotation angle of the mirror. delete delete According to claim 1,
The light irradiator,
a plurality of light generators each generating light of different wavelengths;
a plurality of expander units corresponding to each of the light generating units and expanding the light generated by each light generating unit in a line shape;
a mux filter unit for receiving the light expanded through each of the expander units through a mirror and combining them into one optical signal;
an ND filter unit adjusting optical output power of the mux filter unit; and
Micro LED inspection device comprising a wavelength selection control unit for selectively controlling the operation of each light generating unit. According to claim 7,
The light generating unit includes a first light generating unit generating light having a wavelength of 375 nm or 405 nm; and a second light generating unit generating light having any wavelength of 532 nm or more and 610 nm or less. According to claim 8,
The wavelength selection controller
Whether the arrayed micro LEDs to be inspected include green micro LEDs or blue micro LEDs,
Or depending on whether it includes a red micro LED,
Characterized in that the first light generating unit and the second light generating unit selectively operate, the micro LED inspection device. According to claim 1,
The optical system,
a beam generator that processes the light emitted from the light irradiator to have a line light;
a beam splitter unit disposed obliquely with respect to the forward and backward directions and into which the light processed by the beam generator is incident; and
An objective lens for transmitting light incident from the beam splitter to the micro LED,
The detection unit includes a spectroscopic unit for obtaining spectral information of the second light,
The first light is incident toward the beam splitter in a direction orthogonal to the forward and backward directions, and the beam splitter reflects the incident first light toward each of the micro LEDs located in the front, from each of the micro LEDs. The generated second light passes through and is transmitted to the spectrometer located at the rear,
The front-back direction is a direction connecting a front where the micro LED is disposed and a rear where the spectrometer is disposed. According to claim 10,
The beam generator controls the rotation angle of the mirror to sequentially irradiate light to each micro LED in the unit of inspection area. delete According to claim 10,
Further comprising a tube lens to determine the magnification according to the focal length of the objective lens, the micro LED inspection device. According to claim 10,
The detection unit further includes an imaging unit for forming an image of the second light,
The optical system further includes a detection path selector configured to transmit all of the second light to the imaging unit, to all of the spectroscopy unit, or to each of the imaging unit and the spectroscopy unit at a predetermined ratio. A micro LED inspection method for inspecting a plurality of micro LEDs to be inspected using the micro LED inspection device according to claim 1,
controlling the light irradiation unit and the optical system to radiate the first light to each micro LED in a current inspection sequence; and
Obtaining inspection information based on second light generated in each micro LED by irradiation of the first light through the detector,
It is performed on all micro LEDs to be inspected,
The irradiation of the first light and the acquisition of inspection information are performed in an 'inspection area unit' that is a plurality of micro LED units forming a straight line. According to claim 15,
The micro LED inspection method, characterized in that the irradiation of light to each micro LED in units of the inspection area is sequentially performed for each micro LED. A computer-readable recording medium in which a program for executing the micro LED inspection method according to claim 15 in a computer is recorded.

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