Wavelength measuring device and wavelength measuring method

Abstract

The wavelength measuring device includes a light splitting unit (3) that splits light emitted from a plurality of light emitting element chips (101) included in a measurement target object (100) when the light emitting element chips are excited, a light receiving unit (5) that has a plurality of pixels (51) that receive the light split by the light splitting unit in a plurality of regions, a separation unit (6) that separates measurement data obtained based on a light receiving result for each of the light emitting element chips (101), and a calculation unit (6) that calculates a representative wavelength from measurement data for each wavelength for a plurality of regions in a light emitting surface for each of the light emitting element chips (101) separated by the separation unit.

Description

Technical Field

[0001] The present invention relates to a wavelength measuring apparatus and a wavelength measuring method for measuring representative wavelengths of light-emitting element chips, such as multiple LED chips, contained in an object to be measured. Background Technology

[0002] For example, regarding LEDs used in backlights of displays such as televisions, color deviations cause uneven color distribution and reduced image quality, thus requiring strict management of the emitted color. Therefore, a so-called merging process has been previously performed, measuring the wavelength of each LED chip and classifying them according to each color.

[0003] As a method for measuring the wavelength of LED chips in such a merger, Non-Patent Document 1 discloses the method of measuring the wavelength of each LED chip individually using a point spectrometer.

[0004] Non-Patent Document 1: Otsuka Electronics Co., Ltd. Homepage, Example "LED Color Classification (LEseries) in LED Manufacturing Process" URL: https: / / www.otsukael.jp / appcase / detail / caseid / 116

[0005] However, the following issues exist in the method of measuring the representative wavelength of each LED chip individually using a point spectrometer, as described in Non-Patent Document 1.

[0006] That is, for example, for micro LED chips with a diameter of less than 100μm on each side, the smaller the size of the LED chip, the larger the number of LED chips that need to be measured. Measuring each chip individually is time-consuming and inefficient.

[0007] Furthermore, when measurements are performed on a wafer, if the LED chip is small, multiple LED chips will be included in the measurement area of ​​the spot spectrometer, which may result in the inability to perform measurements with high accuracy. Summary of the Invention

[0008] This invention was made in view of the following technical background, and its purpose is to provide a wavelength measuring device and a wavelength measuring method that can efficiently and accurately measure the representative wavelengths of multiple LED chips.

[0009] The above objectives are achieved in the following ways.

[0010] (1) A wavelength measuring device, comprising:

[0011] The spectrometer unit disperses the light emitted by multiple light-emitting element chips contained in the object being measured when they are excited.

[0012] The light-receiving unit has multiple pixels, which receive light emitted from each light-emitting surface of the multiple light-emitting element chips and then split by the light-splitting unit in multiple regions.

[0013] The separation unit separates the measurement data obtained based on the light-receiving results of the light-receiving unit for each of the aforementioned light-emitting element chips; and

[0014] The processing unit calculates the representative wavelength for each light-emitting element chip separated by the separation unit, based on the measurement data of each wavelength for multiple regions within the light-emitting surface.

[0015] (2) According to the wavelength measuring device described in the preceding paragraph (1), the above-mentioned calculation unit averages the measurement data of the region in the above-mentioned light-emitting surface that has the maximum value for a specified wavelength and the measurement data of one or more regions adjacent to that region, and calculates the representative wavelength based on the averaged measurement data of each wavelength.

[0016] (3) According to the wavelength measuring device described in the preceding paragraph (2), the wavelength specified above is any one of the following: the wavelength with the greatest brightness in the data of a pixel group containing measurement data of a suitable area of ​​multiple light-emitting element chips, the wavelength with the greatest brightness in the measurement data of a data area of ​​a light-emitting element chip, and the design wavelength of the light-emitting element chip.

[0017] (4) According to the wavelength measuring device described in any one of the preceding items (1) to (3), the above-mentioned light receiving unit is a region sensor.

[0018] Each pixel in one pixel column of the aforementioned region sensor corresponds to multiple regions in one-dimensional direction of the aforementioned object to be measured, and each pixel in another pixel column orthogonal to the aforementioned pixel column receives light emitted from the multiple regions in the aforementioned one-dimensional direction and after it has been split.

[0019] (5) According to the wavelength measuring device described in the preceding paragraph (4), the wavelength measuring device includes a moving unit, which moves at least one of the measured object and the wavelength measuring device relative to each other in a direction orthogonal to both the one pixel column and the other pixel column.

[0020] By performing measurements while moving at least one of the measured object and the wavelength measuring device using the aforementioned moving unit, the region sensor receives the dispersed light from each region in the two-dimensional direction of the measured object.

[0021] (6) The wavelength measuring device described in any one of the preceding items (1) to (5) is the wavelength of the emission peak.

[0022] (7) The wavelength measuring device described in any one of the preceding items (1) to (5) is the centroid wavelength.

[0023] (8) The wavelength measuring device described in any one of the preceding items (1) to (5) is the center wavelength.

[0024] (9) According to the wavelength measuring device described in any one of the preceding items (1) to (8), the above-mentioned light-emitting element chip is an LED chip.

[0025] (10) The wavelength measuring device described in any one of the preceding items (1) to (9) includes a light source unit, which excites the plurality of light-emitting element chips and causes the plurality of light-emitting element chips to emit light.

[0026] (11) A wavelength measurement method, comprising:

[0027] The spectral separation step involves using a spectral separation unit to separate the light emitted by multiple light-emitting element chips contained in the object being measured when they are excited.

[0028] In the light-receiving step, the light emitted from each light-emitting surface of the multiple light-emitting element chips and then split by the light-splitting step is received by the multiple pixels of the light-receiving unit in multiple regions.

[0029] The separation step involves separating the measurement data obtained from the light-receiving results of the light-receiving step for each of the aforementioned light-emitting element chips; and

[0030] The calculation steps involve calculating the representative wavelength for each light-emitting element chip separated by the above separation steps, based on measurement data for multiple regions within the light-emitting surface.

[0031] (12) According to the wavelength measurement method described in the preceding paragraph (11), in the above calculation step, the measurement data of the region in the above luminescent surface that has the maximum value for the specified wavelength and the measurement data of one or more regions adjacent to the region are averaged, and the representative wavelength is calculated based on the averaged measurement data of each wavelength.

[0032] (13) According to the wavelength measuring device described in the preceding paragraph (1), the wavelength specified above is any one of the following: the wavelength with the greatest brightness in the data of a pixel group containing measurement data of a suitable area of ​​multiple light-emitting element chips, the wavelength with the greatest brightness in the measurement data of a data area of ​​a light-emitting element chip, and the design wavelength of the light-emitting element chip.

[0033] (14) According to the wavelength measurement method described in any one of the preceding items (11) to (13), the above-mentioned light-receiving unit is a region sensor.

[0034] One pixel column of the aforementioned regional sensor receives light from each region in a one-dimensional direction of the aforementioned object being measured, while another pixel column orthogonal to the aforementioned pixel column receives light after it has been split, corresponding to each region in the aforementioned one-dimensional direction.

[0035] (15) According to the wavelength measurement method described in the preceding paragraph (14), the wavelength measurement method includes a moving step, in which at least one of the area sensor and the object to be measured is moved relative to each other in the direction of the other pixel column.

[0036] By moving at least one of the aforementioned area sensors and the object being measured based on the above-described moving steps, the area sensors receive light from each region of the object being measured in a two-dimensional direction.

[0037] (16) The wavelength described above is the peak emission wavelength according to the wavelength measurement method described in any one of the preceding items (11) to (15).

[0038] (17) The wavelength described above is the centroid wavelength, according to the wavelength measurement method described in any one of the preceding items (11) to (15).

[0039] (18) The wavelength described above is the center wavelength, according to the wavelength measurement method described in any one of the preceding items (11) to (15).

[0040] (19) The above-mentioned light-emitting element chip is an LED chip according to the wavelength measurement method described in any one of the preceding items (11) to (18).

[0041] According to the invention described in paragraphs (1) and (11) above, a plurality of light-emitting element chips contained in the object to be measured are excited to emit light. The light emitted from the light-emitting surface of each light-emitting element chip and split by the beam-splitting unit is received by a plurality of pixels of the light-receiving unit in multiple regions. The measurement data obtained based on the light-receiving results is separated according to each light-emitting element chip, and a representative wavelength is calculated according to the measurement data for each wavelength in multiple regions within the light-emitting surface of each separated light-emitting element chip.

[0042] In this way, by using measurement data from multiple light-emitting element chips emitted light at once, and calculating the representative wavelength for each light-emitting element chip, the measurement time can be shortened and the measurement efficiency improved compared to measuring the representative wavelength of each light-emitting element chip individually using a point spectrometer. Furthermore, by calculating the representative wavelength based on measurement data from multiple regions within the emitting surface of the light-emitting element chip, highly accurate measurement results can be obtained, eliminating biases.

[0043] According to the invention described in paragraphs (2) and (12), the measurement data of the region in the luminescent surface that has the maximum value for a specified wavelength and the measurement data of one or more regions adjacent to that region are averaged, and the representative wavelength is calculated based on the measurement data of each wavelength after averaging, so that a representative wavelength with high accuracy can be easily obtained.

[0044] According to the invention described in paragraphs (3) and (13) above, the measurement data of any one of the following wavelengths that has the highest brightness in the data of a pixel group containing measurement data of a suitable region containing multiple light-emitting element chips, the wavelength that has the highest brightness in the measurement data of a data region of a light-emitting element chip, and the region where the design wavelength of the light-emitting element chip is maximized, and the measurement data of one or more regions adjacent to that region are averaged.

[0045] According to the invention described in the preceding paragraphs (4) and (14), it is possible to receive light from each region of the object to be measured in a one-dimensional direction through a pixel column of a region sensor, and to receive the light after spectral dispersion corresponding to each region in the one-dimensional direction through another pixel column orthogonal to the pixel column.

[0046] According to the invention described in paragraphs (5) and (15), by moving at least one of the object to be measured and the wavelength measuring device, the area sensor can receive the spectral light from each region of the object to be measured in a two-dimensional direction.

[0047] According to the invention described in paragraphs (6) and (16), it is possible to determine the peak wavelength of emission as a representative wavelength.

[0048] According to the invention described in the preceding paragraphs (7) and (17), it is possible to determine the centroid wavelength as a representative wavelength.

[0049] According to the invention described in the preceding paragraphs (8) and (18), it is possible to determine the center wavelength as a representative wavelength.

[0050] According to the invention described in paragraphs (9) and (19), it is possible to calculate the representative wavelength of each LED chip using measurement data when multiple LED chips are excited and emit light at one time.

[0051] According to the invention described in the preceding paragraph (10), it is possible to excite multiple light-emitting element chips and make the multiple light-emitting element chips emit light through the light source section. Attached Figure Description

[0052] Figure 1 This is a block diagram illustrating the structure of a wavelength measuring device according to one embodiment of the present invention.

[0053] Figure 2 It means Figure 1A three-dimensional view of a specific part of the wavelength measuring device.

[0054] Figure 3 It is a diagram used to illustrate the relationship between the size of multiple LED chips and the pixel size of the light-receiving unit on the object being measured.

[0055] Figure 4 This schematically illustrates the light-receiving state of each pixel when light of any wavelength received from the surface of the object being measured is received by the light-receiving unit.

[0056] Figure 5 (A) is a diagram showing the state after separating the measurement data of each pixel according to each light-emitting element chip. Figure 5 (B) is a diagram used to illustrate the method for calculating the representative wavelength. Figure 5 (C) is Figure 5 Enlarged view of (B).

[0057] Figure 6 It is a spectral map depicting the average value of nine pixels for each wavelength of the data area of ​​multiple light-emitting element chips.

[0058] Figure 7 It is a spectral map depicting the value of one pixel for each wavelength of the data area of ​​multiple light-emitting element chips.

[0059] Figure 8 It is a graph that calculates the average value of 9 pixels for each wavelength for the data area of ​​a light-emitting element chip, and plots the average value and the fitted curve based on the average value.

[0060] Figure 9 It is a diagram used to illustrate the measurement method for a wide range of test objects. Detailed Implementation

[0061] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0062] Figure 1 This is a block diagram illustrating the structure of a wavelength measuring apparatus according to one embodiment of the present invention. In this embodiment, the case where the light-emitting element chip is an LED chip and the measuring object 100 is a wafer on which multiple LED chips are formed will be described.

[0063] Figure 1 The wavelength measuring device shown includes: a light source 1 for excitation, an objective lens 2 with adjustable magnification, a beam splitter 3, an imaging lens 4, a two-dimensional imaging element, i.e., a region sensor, composed of a CCD sensor or the like 5, a calculation unit 6, and a measurement result display unit 7 composed of a liquid crystal display device or the like.

[0064] The excitation light source 1 illuminates multiple LED chips on the test object 100 with excitation light, exciting the multiple LED chips and causing them to emit light.

[0065] The beam splitter 3 splits the light from each LED chip that has passed through the objective lens 2 according to each wavelength, and the imaging lens 4 images the light of each wavelength after being split by the beam splitter 3 onto the area sensor 5. In this embodiment, the structure splits the light of each wavelength at a wavelength interval of 5 nm.

[0066] Area sensor 5 is equivalent to the light-receiving part, and has the capability to detect light. Figure 2 As shown, multiple pixels 51 are arranged horizontally and vertically. The horizontal direction of the area sensor 5 ( Figure 2 The Y direction represents the horizontal direction of physical space, and each pixel 51 in the horizontal direction corresponds to the horizontal region of the object being measured. On the other hand, the vertical direction of the region sensor 5 ( Figure 2 The Z-direction corresponds to the brightness (luminance) of each wavelength of light. That is, each pixel 51 in the horizontal pixel column corresponds to multiple regions in the one-dimensional direction of the object to be measured 100, and the light emitted from each region and after wavelength decomposition is received by each pixel 51 in the vertical pixel column. Therefore, in order to perform spectroscopic measurement on each region in the two-dimensional direction (plane) of the object to be measured 100, it is necessary to make the object to be measured 100 in a certain position. Figure 2 Spectroscopic measurements can be performed while the object being measured (100) moves in the Z direction. Alternatively, the wavelength measuring device can be moved without moving the object being measured (100). Figure 2 The object 100 can move in the Z direction, or the wavelength measuring device can move with a speed difference between them. In short, as long as at least one of the object 100 and the wavelength measuring device moves relative to the other... Figure 2 The object can be moved relative to the target in the Z direction. In this embodiment, the object being measured 100 is moved, such as... Figure 1 As shown, a moving device 300 is provided that enables the worktable 200 on which the measuring object 100 is placed to move in the Z direction.

[0067] Furthermore, the technique of dividing the plane of the object to be measured 100 into regions of the same size as each pixel 51 of the region sensor 5, and then splitting the light from each region and receiving it by each pixel 51 of the region sensor 5, is known, for example, as in a hyperspectral camera.

[0068] As needed, the measurement data, which are electrical signals output from each pixel 51 of the area sensor 5, are converted into digital signals by a current / voltage (IV) conversion circuit (not shown) and an analog / digital (AD) conversion circuit, and then sent to the arithmetic unit 6. The arithmetic unit 6 uses the received measurement data to calculate the representative wavelength for each of the multiple LED chips on the object being measured, using a CPU or similar device. Details of the method for calculating the representative wavelength will be explained later.

[0069] The measurement result display unit 7 displays the calculation results based on the calculation unit 6. Furthermore, the conversion of the measurement data output from the area sensor 5 into a digital signal can also be performed by the calculation unit 6.

[0070] The arithmetic unit 6 can be a dedicated device or a personal computer. Furthermore, the measurement data output from the area sensor 5 and processed into digital signals can also be transmitted to the arithmetic unit 6 via a network. In this case, even if the arithmetic unit 6 is located far from the measurement site, it is possible to measure the representative wavelength of the LED chip.

[0071] Next, regarding the passage Figure 1 The method for measuring the representative wavelength of each LED chip on the wafer of the object to be measured 100 using the wavelength measuring device shown will be explained.

[0072] Figure 3 This is a diagram used to illustrate the relationship between the size of multiple LED chips 101 on the object to be measured 100 and the size of the pixel 51 of the area sensor 5. Figure 3 The horizontal axis of the small grid is Figure 2 The Y-axis represents space, and the X-axis represents space generated by scanning the LED chip 101 in the Z-wavelength direction. The size of one grid cell is the measurement area, corresponding to the size of pixel 51.

[0073] The LED chips 101 are represented by rectangles and are arranged horizontally and vertically on the object being measured 100. In addition, the rectangular areas directly become the light-emitting surfaces of each LED chip 101.

[0074] The arrangement spacing of the LED chips 101, the pixel spacing of the area sensor 5, and the magnification of the objective lens 2 are set to enable data acquisition from the light-emitting surface of one LED chip 101 using multiple pixels 51. This means that light emitted from multiple areas of the light-emitting surface of one LED chip 101, each corresponding to a pixel 51, can be received using these multiple corresponding pixels 51. In this embodiment, the system is configured to receive light from the light-emitting surface of one LED chip 101 in a pixel arrangement of 3×3=9 pixels or more.

[0075] Next, excitation light is irradiated onto the object 100 to be measured, which is placed on the worktable 200, from the excitation light source 1. The worktable 200 is then moved by the moving device 300. Figure 2 While moving in the Z direction, the area sensor 5 uses each pixel 51 to receive light emitted from multiple LED chips 101 on the object to be measured 100. The light emitted from the LED chips 101 is split by the beam splitter 3 according to a predetermined wavelength, and each wavelength of light after splitting is received by each pixel 51. The value (brightness value) of each pixel 51 after receiving the light is sent as measurement data to the arithmetic unit 6 and stored in a memory (not shown) within the arithmetic unit 6. In addition, the object to be measured 100 on the worktable 200 is moved by the moving device 300. Figure 2 Measurements are performed while the object moves in the Z direction, thus obtaining measurement data for each wavelength after spectral dispersion for each region corresponding to the pixel in the two-dimensional direction of the object 100, in other words, in the plane.

[0076] Based on the measurement data obtained in this way, the arithmetic unit 6 calculates the representative wavelength of each LED chip 101 through calculation.

[0077] Figure 4 The schematic representation illustrates the light reception state in each pixel 51 when light of any wavelength received from the surface of the object being measured 100, such as light of wavelength λ with the highest brightness in the data of a pixel group in an appropriate area containing measurement data of multiple LED chips 101, is received by the area sensor 5. Figure 4 The horizontal direction is Figure 2 The spatial Y direction is represented by the vertical direction, and the spatial X direction is represented by the data obtained by scanning the LED chip 101 in the Z direction. Figure 4 The black box 8 shown represents the area corresponding to the light-emitting surface of an LED chip 101. Additionally, the denser area 9 indicates greater brightness, showing that the brightness decreases towards the periphery.

[0078] Next, the measurement data received by each pixel 51 of the area sensor 5 is separated according to each LED chip 10. This separation can be performed, for example, as follows: Based on the data of a group of pixels in an appropriate region containing the measurement data of multiple LED chips 101, the wavelength λ with the maximum brightness is determined. Then, within the wavelength λ, each pixel 51 is classified according to brightness, and a certain brightness level is used as a threshold for image processing, thereby separating the data according to each LED chip 101. Figure 5 (A) represents the state after separating the measurement data from each pixel 51 according to each LED chip 101. Figure 5 In (A), it is separated into 9 data regions 10a to 10i, represented by black boxes.

[0079] Next, based on the measurement data of each separated LED chip 101, the pixel of interest with the maximum brightness (luminance value) is determined. For example, as... Figure 5 As shown in (B), in the measurement data for a data area (e.g., data area 10b) of an LED chip 101, if the maximum value is obtained by pixel 51a at a certain wavelength, then pixel 51a is identified as the pixel of interest.

[0080] Here, a certain wavelength is only used to discover the brightness level of the pixel and the pixel of interest. For example, as mentioned above, it is possible to list the wavelength with the highest brightness in the data of a pixel group that includes the measurement data of multiple LED chips 101, or the wavelength with the highest brightness in the measurement data of a data area of ​​an LED chip, the design wavelength of the light-emitting element chip, etc.

[0081] After identifying the pixel of interest 51a, the value of pixel 51a is averaged with the values ​​of one or more surrounding pixels to obtain the spectral data for that wavelength (brightness data at that wavelength). Figure 5 In example (B), such as Figure 5 As shown in (C) magnification, the values ​​of the eight pixels 51b to 51i surrounding the pixel of interest 51a and the pixel of interest 51a, totaling nine pixels 51, are averaged.

[0082] By averaging the data of multiple pixels containing the pixel of interest 51a in this way, a reduction in measurement noise can be achieved. This is explained below.

[0083] In other words, the emission wavelength of a self-emissive element is a crucial factor determining its characteristics. The main self-emissive elements are LEDs and OLEDs (Organic Light Emitting Diodes). Compared to OLEDs, LEDs, in principle, exhibit a more uniform emission wavelength across any part of their emitting surface. Therefore, in the case of LEDs, the representative wavelength can be measured at any location within the emitting surface, and by averaging the data from area segmentation, measurement noise can be reduced. However, the light-emitting element chip is not limited to LED chip 101; it can also be an OLED.

[0084] Furthermore, setting the averaged pixels to the pixels surrounding the focus pixel 51a is to converge the measurement area of ​​the LED chip 101's wavelength within the light-emitting surface, thereby obtaining values ​​with less bias using a smaller amount of data. Specifically, if values ​​including the values ​​of the nine pixels surrounding the focus pixel 51a, which represents the maximum brightness, are used, values ​​with sufficiently low bias can be obtained.

[0085] Furthermore, compared to OLED, LEDs, in principle, emit a more uniform wavelength at any point within their light-emitting surface, for the following reasons.

[0086] That is, the emission wavelength of an LED is determined by the band gap (Eg) of the compound semiconductor material, as expressed by the following formula.

[0087] λ(nm) = 1240 / Eg(eV)

[0088] For example, since GaAs (gallium arsenide) has an Eg of 1.4 eV (at 300 K), its emission wavelength λ is 885 nm. Eg is determined by the composition of the compound semiconductor material constituting the LED, so deviations in material composition can be considered a factor in the deviation of the emission wavelength. On the other hand, the basic principle of OLEDs is the same as that of LEDs, so deviations in material composition can also be considered a factor in the deviation of the emission wavelength. Furthermore, in the case of OLEDs, due to their relatively broad emission spectrum, color purity is improved by using a microcavity structure to steepen the spectrum. Since the microcavity structure utilizes the resonance effect of light between the upper and lower electrodes of the organic light-emitting layer, deviations in the thickness of the organic light-emitting layer can be considered a factor in the deviation of the emission wavelength.

[0089] In other words, LEDs have fewer deviation factors compared to OLEDs, resulting in smaller deviations in the emission wavelength within the emitting surface of the chip.

[0090] Figure 6 It is aimed at Figure 5 (A) shows four data regions 10b, 10d, 10f, and 10h within the data regions 10a to 10i of the multiple LED chips 101. A spectral diagram depicting the average values ​​of nine pixels for each wavelength is provided. On the other hand, Figure 7 This involves plotting the spectral graphs of the values ​​of pixel 51a, calculated for each of the four data regions 10b, 10d, 10f, and 10h, based on their respective wavelengths. In each graph, the horizontal axis represents wavelength, and the vertical axis represents brightness. Comparing the two graphs reveals... Figure 7 The spectral shape shown, which focuses only on the value of pixel 51a, is corrupted.

[0091] For each wavelength, the brightness values ​​of the pixel of interest 51a and its surrounding pixels 51b to 51i are averaged, and the representative wavelength is determined based on the average value of each wavelength. Specifically, as follows... Figure 8 As shown, based on the average value of each wavelength, a fitting curve is obtained through Gaussian fitting, and the wavelength of the peak value of the fitting curve is taken as the representative wavelength. Alternatively, when the wavelength spacing is small, fitting may not be performed, and the wavelength of the largest average value among the average values ​​of each wavelength may be taken as the representative wavelength.

[0092] Thus, for all LED chips 101 of the object being measured 100, representative wavelengths are calculated based on the measurement data. In this embodiment, the calculated representative wavelength is the emission peak wavelength, but it can also be the centroid wavelength, center wavelength, etc. The centroid wavelength refers to the weighted average of wavelengths with the emission spectrum as weights. In other words, the centroid wavelength is the value obtained by integrating the product of each wavelength and the intensity of light over the entire emission wavelength region, divided by the value obtained by integrating the light intensity over the entire emission wavelength region. In addition, the center wavelength refers to the average of the two half-value wavelengths that are 3dB lower than the maximum amplitude on both sides of the peak wavelength.

[0093] Next, regarding the measurement repeatability accuracy of the representative wavelengths obtained as described above, a comparison is made between the case where the wavelength is calculated based on the average value of 9 pixels including the pixel of interest 51a, and the case where the wavelength is calculated based solely on the value of the pixel of interest 51a. The measurement of the LED chip 101 was repeated 10 times. For a data area of ​​the LED chip 101, the average value of 9 pixels was calculated for each wavelength. The representative wavelengths calculated based on the peak positions of each fitted curve are shown in Table 1(A). Alternatively, the process of calculating the value of the pixel of interest 51a only for each wavelength was performed. The representative wavelengths calculated based on the peak positions of each fitted curve are shown in Table 1(B).

[0094] [Table 1]

[0095] (A) 9-pixel average

[0096] Maximum value 226.94 234.56 235.64 228.35 232.78 235.86 238.17 238.17 227.7 220.52 238.17 220.52 17.65 5.78 231.87 peak position 626.7 626.6 626.6 626.82 626.43 626.52 626.81 626.81 626.62 626.79 626.82 626.43 0.39 0.14 626.67

[0097] (B) 1 pixel

[0098] Maximum value 269.27 226.12 208.94 243.7 205.14 255.96 226.66 230.73 212.58 227.14 269.27 205.14 64.13 20.55 230.62 peak position 626.61 626.94 626.18 626.78 626.19 627.29 626.74 627.33 627.16 627.12 627.33 626.18 1.15 0.42 626.83

[0099] In Table 1, "maximum value" refers to the maximum value of the fitted curve, and "peak position" refers to the peak wavelength at the maximum value of the fitted curve, i.e., the representative wavelength. In Table 1(B), the method of calculating the representative wavelength by focusing on only one pixel, the difference (Δ) between the maximum (max) and minimum (min) values ​​of the representative wavelength is 1.15, the standard deviation based on the STDEV function is 0.42, and the average (ave) is 626.83. In contrast, in Table 1(A), the method of calculating the representative wavelength based on the average of nine pixels, the difference (Δ) between the maximum (max) and minimum (min) values ​​of the representative wavelength is 0.39, the standard deviation based on the STDEV function is 0.14, and the average (ave) is 626.67. The deviation is smaller, converging to less than approximately 0.5 nm in 3σ.

[0100] Furthermore, the measurement range of the object 100 is greater than... Figure 9 If the measurement area 11, represented by a rectangle, is too wide to complete in a single measurement, and the entire measurement range cannot be measured in one measurement, then after measuring the representative wavelength of each LED chip 101 within the measurement area 11, at least one of the measurement symmetry object 100 and the measurement device is moved. This moves the measurement area 11 to the next measurement location for measurement, and the measurement is repeated sequentially. Figure 9 In the diagram, solid and dashed arrows indicate the direction of movement of the measurement area 11, so that the measurement area 11 moves sequentially from left to right and from top to bottom.

[0101] As described above, in this embodiment, the plurality of LED chips 101 included in the object to be measured 100 are excited to emit light at once. The light emitted from the light-emitting surface of each LED chip 101 and split by the beam splitter 3 is received by the plurality of pixels 51 of the area sensor 5 in multiple regions. The measurement data obtained based on the light reception results is separated according to each LED chip 101, and a representative wavelength is calculated according to the measurement data of each wavelength for each region within the light-emitting surface of each separated LED chip 101.

[0102] In this way, by using the measurement data of multiple LED chips 101 emitting light at once, and calculating the representative wavelength for each LED chip 101, the measurement time can be shortened and the measurement efficiency improved compared to measuring the representative wavelength of each LED chip 101 individually using a point spectrometer. Furthermore, by averaging the measurement data of the region where the maximum value is obtained within the emitting surface of the LED chip 101 and the measurement data of one or more adjacent regions, and calculating the representative wavelength based on the averaged measurement data for each wavelength, bias can be eliminated and a highly accurate representative wavelength can be easily obtained.

[0103] This application is accompanied by a priority claim in Japanese Patent Application No. 2020-186652, filed on November 9, 2020, the disclosure of which forms a direct part of this application.

[0104] Industrial availability

[0105] The present invention can be used as a wavelength measuring device for measuring representative wavelengths of light-emitting element chips, such as multiple LED chips, contained in the object to be measured.

[0106] Explanation of reference numerals in the attached figures: 1…Light source for excitation; 2…Objective lens; 3…Beam splitter; 4…Imaging lens; 5…Area sensor; 51…Pixel; 51a…Pixel of interest; 51b~51i…Surrounding pixels; 6…Arithmetic unit; 7…Measurement result display unit; 10a~10i…Data area; 100…Object to be measured; 101…Light-emitting element chip (LED chip); 200…Stage; 300…Moving device.

Claims

1. A wavelength measuring device, comprising: A light source irradiates multiple light-emitting element chips formed on a wafer that is the object being measured with excitation light; Objective lens; The beam-splitting unit separates the light emitted by the multiple light-emitting element chips when they are excited once and passes through the objective lens. The light-receiving unit has multiple pixels, which receive light emitted from each light-emitting surface of the multiple light-emitting element chips and then split by the beam-splitting unit; The acquisition unit, based on the light-receiving result of the light-receiving unit, acquires measurement data for each wavelength according to each region of size corresponding to the pixel in the surface of the object to be measured, which includes multiple light-emitting surfaces; The separation unit separates the measurement data of multiple light-emitting element chips when they are excited and emit light at one time, by classifying each pixel according to its brightness in the first predetermined wavelength of the data of the pixel group in the region containing the measurement data of multiple light-emitting element chips, and performing image processing with the predetermined brightness level as a threshold. as well as The processing unit calculates the representative wavelength for each light-emitting element chip separated by the separation unit, based on measurement data for each wavelength in multiple regions within the light-emitting surface.

2. The wavelength measuring device according to claim 1, wherein, The calculation unit averages the measurement data of the region in the light-emitting surface that has the maximum value for the second specified wavelength and the measurement data of one or more regions adjacent to that region, and calculates the representative wavelength based on the averaged measurement data of each wavelength.

3. The wavelength measuring device according to claim 2, wherein, At least one of the first specified wavelength and the second specified wavelength is any one of the wavelength with the highest brightness in the data of a pixel group containing measurement data of a suitable region of multiple light-emitting element chips, the wavelength with the highest brightness in the measurement data of a data region of a light-emitting element chip, and the design wavelength of the light-emitting element chip.

4. The wavelength measuring device according to any one of claims 1 to 3, wherein, The light-receiving unit is a region sensor. Each pixel in one pixel column of the region sensor corresponds to multiple regions in one-dimensional direction of the object being measured, and each pixel in another pixel column orthogonal to the one pixel column receives light emitted from the multiple regions in one-dimensional direction and then split.

5. The wavelength measuring device according to claim 4, wherein, The wavelength measuring device includes a moving unit that moves at least one of the object being measured and the wavelength measuring device relative to each other in the direction of another pixel column. By performing measurements while moving at least one of the object to be measured and the wavelength measuring device by the moving unit, the area sensor receives the dispersed light from each region in the two-dimensional direction of the object to be measured.

6. The wavelength measuring device according to any one of claims 1 to 3, wherein, The representative wavelength is the peak wavelength of emission.

7. The wavelength measuring device according to any one of claims 1 to 3, wherein, The representative wavelength is the centroid wavelength.

8. The wavelength measuring device according to any one of claims 1 to 3, wherein, The representative wavelength is the center wavelength.

9. The wavelength measuring device according to any one of claims 1 to 3, wherein, The light-emitting element chip is an LED chip.

10. The wavelength measuring device according to any one of claims 1 to 3, wherein, The wavelength measuring device includes a light source section, which excites the plurality of light-emitting element chips and causes the plurality of light-emitting element chips to emit light.

11. A wavelength measurement method, comprising: In the spectral separation step, a spectral separation unit is used to separate the light emitted by multiple light-emitting element chips formed on the wafer that is being measured, which are excited by excitation light from the light source and pass through the objective lens. In the light-receiving step, multiple pixels of the light-receiving unit receive light emitted from each light-emitting surface of the multiple light-emitting element chips and then split by the light-splitting step. The acquisition step involves acquiring measurement data for each wavelength based on the light reception result of the light reception step, according to each region of size corresponding to the pixel in the surface of the measurement object containing multiple light-emitting surfaces. The separation step involves classifying each pixel according to its brightness in the first predetermined wavelength of the pixel group data in the region containing the measurement data of multiple light-emitting element chips, and performing image processing using the predetermined brightness level as a threshold, thereby separating the measurement data of multiple light-emitting element chips when they are excited and emit light at one time according to each of the light-emitting element chips. as well as The calculation steps involve calculating a representative wavelength for each light-emitting element chip separated by the separation steps, based on measurement data for each wavelength in multiple regions within the light-emitting surface.

12. The wavelength measurement method according to claim 11, wherein, In the calculation step, the measurement data of the region in the light-emitting surface that has the maximum value for the second specified wavelength and the measurement data of one or more regions adjacent to the region are averaged, and the representative wavelength is calculated based on the measurement data of each averaged wavelength.

13. The wavelength measurement method according to claim 12, wherein, At least one of the first specified wavelength and the second specified wavelength is any one of the wavelength with the highest brightness in the data of a pixel group containing measurement data of a suitable region of multiple light-emitting element chips, the wavelength with the highest brightness in the measurement data of a data region of a light-emitting element chip, and the design wavelength of the light-emitting element chip.

14. The wavelength measurement method according to any one of claims 11 to 13, wherein, The light-receiving unit is a region sensor. One pixel column of the region sensor receives light from each region in a one-dimensional direction of the object being measured, and another pixel column orthogonal to the first pixel column receives light after it has been split, corresponding to each region in the one-dimensional direction.

15. The wavelength measurement method according to claim 14, wherein, The wavelength measurement method includes a movement step, in which at least one of the region sensor and the object being measured is moved relative to each other in the direction of another pixel column. By moving at least one of the area sensor and the object being measured based on the moving step, the area sensor receives light from each area of ​​the object being measured in a two-dimensional direction.

16. The wavelength measurement method according to any one of claims 11 to 13, wherein, The representative wavelength is the peak wavelength of emission.

17. The wavelength measurement method according to any one of claims 11 to 13, wherein, The representative wavelength is the centroid wavelength.

18. The wavelength measurement method according to any one of claims 11 to 13, wherein, The representative wavelength is the center wavelength.

19. The wavelength measurement method according to any one of claims 11 to 13, wherein, The light-emitting element chip is an LED chip.

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