US-12625176-B2 - Testing apparatus, testing method, and computer-readable storage medium

US12625176B2US 12625176 B2US12625176 B2US 12625176B2US-12625176-B2

Abstract

Provided is a testing apparatus including: a light emission control unit which causes a plurality of light emitting elements to be tested to emit light; a light measurement unit which receives the light emitted from the plurality of light emitting elements and measures wavelengths of the received light; and a determination unit which determines whether there is an abnormality in at least one light emitting element on the basis of intensity distributions of the wavelengths of the light, which is emitted from the plurality of light emitting elements, measured by the light measurement unit. The testing apparatus may further include: a light source; an optical system which irradiates the plurality of light emitting elements with light emitted from the light source; and an electrical measurement unit which measures a photoelectric signal obtained by each of the plurality of light emitting elements photoelectrically converting the light radiated by the optical system.

Inventors

Kotaro HASEGAWA
Koji Miyauchi

Assignees

ADVANTEST CORPORATION

Dates

Publication Date: 20260512
Application Date: 20231214
Priority Date: 20210908

Claims (15)

1 . A testing apparatus comprising: at least one processor; a light emission control unit which uses the at least one processor to cause a plurality of light emitting elements to be tested to emit light; a light measurement unit which uses the at least one processor to receive the light emitted from the plurality of light emitting elements and measures wavelengths of the received light; a determination unit which uses the at least one processor to determine whether there is an abnormality in at least one light emitting element among the plurality of light emitting elements on a basis of intensity distributions of the wavelengths of the light, which is emitted from the plurality of light emitting elements, measured by the light measurement unit; a light source; an optical system which irradiates the plurality of light emitting elements with light emitted from the light source; and an electrical measurement unit which measures a photoelectric signal obtained by each of the plurality of light emitting elements photoelectrically converting the light radiated by the optical system, wherein the light measurement unit receives the light emitted from the plurality of light emitting elements via the optical system; wherein the optical system has a branched fiber having end portions on a branched side connected to the light source and the light measurement unit, and a lens unit including one or more lenses.
2 . The testing apparatus according to claim 1 , wherein the determination unit uses the at least one processor to: determine quality of each of the plurality of light emitting elements on a basis of the photoelectric signals, which are output from the plurality of light emitting elements, measured by the electrical measurement unit, and exclude a light emitting element determined to be defective from a target to be caused to emit light by the light emission control unit.
3 . The testing apparatus according to claim 1 , wherein the optical system diffuses light emitted from the light source to collectively irradiate the plurality of light emitting elements with the light emitted from the light source, and condenses the diffused light emitted from the plurality of light emitting elements to guide the light to the light measurement unit.
4 . The testing apparatus according to claim 2 , wherein the optical system diffuses light emitted from the light source to collectively irradiate the plurality of light emitting elements with the light emitted from the light source, and condenses the diffused light emitted from the plurality of light emitting elements to guide the light to the light measurement unit.
5 . The testing apparatus according to claim 4 , wherein the optical system has a branched fiber having end portions on a branched side connected to the light source and the light measurement unit, and a lens unit including one or more lenses.
6 . The testing apparatus according to claim 1 , wherein the optical system combines light emitted from a plurality of light sources, each light source being identical to the light source, which emit light in wavelength bands different from each other to irradiate the plurality of light emitting elements.
7 . The testing apparatus according to claim 2 , wherein the optical system combines light emitted from a plurality of light sources, each light source being identical to the light source, which emit light in wavelength bands different from each other to irradiate the plurality of light emitting elements.
8 . The testing apparatus according to claim 3 , wherein the optical system combines light emitted from a plurality of light sources, each light source being identical to the light source, which emit light in wavelength bands different from each other to irradiate the plurality of light emitting elements.
9 . The testing apparatus according to claim 1 , wherein the determination unit uses the at least one processor to determine whether there is the abnormality on a basis of a result of comparing the intensity distributions with a reference intensity distribution corresponding to the number of the light emitting elements.
10 . The testing apparatus according to claim 1 , further comprising a group division unit which divides the plurality of light emitting elements into a plurality of groups in response to determination that there is the abnormality, wherein the light emission control unit and the light measurement unit use the at least one processor to cause all light emitting elements of each of the plurality of groups to emit light, and measure wavelengths of the light, and the determination unit uses the at least one processor to determine whether there is an abnormality in at least one light emitting element included in each of the plurality of groups on a basis of intensity distributions of the wavelengths of the light emitted from all the light emitting elements included in each of the plurality of groups.
11 . A testing apparatus comprising: a light source; an optical system which irradiates a plurality of light emitting elements to be tested with light emitted from the light source; an electrical measurement unit which measures a photoelectric signal obtained by each of the plurality of light emitting elements photoelectrically converting the light radiated by the optical system; at least one processor; a light emission control unit which uses the at least one processor to cause the plurality of light emitting elements to emit light; a light measurement unit which uses the at least one processor to receive the light emitted from the plurality of light emitting elements via the optical system and measures wavelengths of the received light; and a determination unit which uses the at least one processor to determine quality of the plurality of light emitting elements on a basis of a measurement result of at least one of the electrical measurement unit and the light measurement unit; wherein the optical system has a branched fiber having end portions on a branched side connected to the light source and the light measurement unit, and a lens unit including one or more lenses.
12 . The testing apparatus according to claim 11 , wherein the determination unit uses the at least one processor to determine quality of each of the plurality of light emitting elements on a basis of the photoelectric signals, which are output from the plurality of light emitting elements, measured by the electrical measurement unit, and exclude a light emitting element determined to be defective from a target to be caused to emit light by the light emission control unit.
13 . The testing apparatus according to claim 11 , wherein the optical system diffuses light emitted from the light source to collectively irradiate the plurality of light emitting elements with the light emitted from the light source, and condenses the diffused light emitted from the plurality of light emitting elements to guide the light to the light measurement unit.
14 . A testing method comprising: causing a plurality of light emitting elements to be tested to emit light; receiving the light emitted from the plurality of light emitting elements and measuring wavelengths of the received light; determining whether there is an abnormality in at least one light emitting element among the plurality of light emitting elements on a basis of intensity distributions of the wavelengths of the light, which is emitted from the plurality of light emitting elements, measured by measuring the wavelengths of the light; irradiating, by an optical system, a plurality of light emitting elements to be tested with light emitted from a light source; measuring a photoelectric signal obtained by each of the plurality of light emitting elements photoelectrically converting the light radiated by the optical system; causing the plurality of light emitting elements to emit light; receiving the light emitted from the plurality of light emitting elements via the optical system and measuring wavelengths of the received light; and determining quality of the plurality of light emitting elements on a basis of a measurement result of at least one of the measuring the photoelectric signal and the measuring the wavelengths of the light; wherein a branched fiber is provided to facilitate separate paths for the light emitted from the plurality of light emitting elements for measuring of the wavelengths and the irradiating of the plurality of light emitting elements from the light source.
15 . A computer-readable storage medium having stored thereon a program that, when executed by a computer, causes the computer to perform operations comprising: radiating light by an optical system irradiating a plurality of light emitting elements to be tested with light emitted from a light source; performing electrical measurement by measuring a photoelectric signal obtained by each of the plurality of light emitting elements photoelectrically converting the light radiated by the optical system; controlling light emission by causing the plurality of light emitting elements to emit light; measuring light by receiving the light emitted from the plurality of light emitting elements via the optical system and measuring wavelengths of the received light; and determining quality of the plurality of light emitting elements on a basis of a measurement result of at least one of the performing the electrical measurement and the measuring the light; wherein a branched fiber is provided to facilitate separate paths for the light emitted from the plurality of light emitting elements for measuring of the wavelengths and the irradiating of the plurality of light emitting elements from the light source.

Description

The contents of the following patent application(s) are incorporated herein by reference: NO. 2021-145919 filed in JP on Sep. 8, 2021NO. PCT/JP2022/020674 filed in WO on May 18, 2022 BACKGROUND 1. Technical Field The present invention relates to a testing apparatus, a testing method, and a computer-readable storage medium. 2. Related Art A method is known in which one of a pair of LEDs to be inspected is caused to emit light and the other is caused to receive the light, and a current value of a current output by a photoelectric effect is used to inspect optical characteristics of the LEDs (see, for example, Patent Documents 1 and 2). CITATION LIST Patent Document Patent Document 1: Japanese translation publication of a PCT rout patent application No. 2019-507953Patent Document 2: Japanese Patent Application Publication No. 2010-230568 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an example of a general view showing a schematic of a testing apparatus 100 for testing a plurality of LEDs 10. FIG. 2 is an example of a general view showing a schematic of the testing apparatus 100 for testing the plurality of LEDs 10. FIG. 3 is an example of a flow diagram for explaining a flow of a testing method by the testing apparatus 100. FIG. 4 is an example of a graph showing intensity distributions of wavelengths of light emitted from the plurality of LEDs 10 included in a measurement target area. FIG. 5 is an example of a graph showing intensity distributions of wavelengths of light emitted from the plurality of LEDs 10 included in the measurement target area. FIG. 6 is an example of a graph showing intensity distributions of wavelengths of light emitted from the plurality of LEDs 10 included in the measurement target area. FIG. 7 illustrates an example of a computer 1200 in which a plurality of aspects of the present invention may be embodied in whole or in part. DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the present invention will be described through embodiments of the present invention, but the following embodiments do not limit the present invention according to claims. In addition, not all combinations of features described in the embodiment are essential to the solution of the invention. FIGS. 1 and 2 are examples of a general view showing a schematic of a testing apparatus 100 for testing a plurality of LEDs 10. In FIGS. 1 and 2, an X axis, which is a +X direction in a rightward direction with respect to a paper surface, a Z axis, which is a +Z direction in an upward direction with respect to the paper surface, and a Y axis, which is a +Y direction in a depth direction with respect to the paper surface, are illustrated so as to be orthogonal to each other. Hereinafter, description may be given by using these three axes. In FIGS. 1 and 2, a flow of a control signal is indicated by a black arrow. In addition, in FIGS. 1 and 2, a moving direction of an electrical connection unit 150 is indicated by a white arrow. In addition, in FIG. 1, the light emitted from the plurality of LEDs 10 is indicated by hatching, and similarly, in FIG. 2, the light emitted from the light source 130 is indicated by hatching. In FIGS. 1 and 2, a through hole 161 of a placement unit 160 is indicated by a broken line. The testing apparatus 100 collectively tests the optical characteristics, such as wavelengths, of the plurality of LEDs 10 on the basis of the intensity distributions of the wavelengths of the light emitted from the plurality of LEDs 10. The testing apparatus 100 according to the present embodiment further uses the photoelectric effect of the LED 10 to collectively test the luminance characteristics or the luminosity characteristics of the plurality of LEDs 10 on the basis of the photoelectric signal output from the LED 10 irradiated with light. The testing apparatus 100 according to the present embodiment bidirectionally performs wavelength measurement and photoelectric signal measurement for the plurality of LEDs 10 by using the same optical system. When the testing apparatus 100 according to the present embodiment ends one of the wavelength measurement and the photoelectric signal measurement and starts the other, there is no need to change an apparatus configuration or move the LED 10 to be tested. The testing apparatus 100 according to the present embodiment collectively tests the optical characteristics, such as wavelengths, and the luminance characteristics or the luminosity characteristics of the plurality of LEDs 10, for example, in a state where an LED group in which the plurality of LEDs 10 are formed on a wafer 15 which is an LED wafer is placed on the placement unit 160. Note that in the following description, the optical characteristics, such as wavelength, of the LED 10 may be simply referred to as wavelength characteristics. The LED 10 in the present embodiment is a micro LED having a dimension of 100 μm or less. Note that instead of the micro LED, the LED 10 may be a mini LED having a dimension larger th