Method for correcting rows of photoelectric data of LED chips

Abstract

The application provides a LED chip photoelectric data row-by-row correction method, comprising the following steps: selecting a certain die in a wafer as an origin and establishing an orthogonal coordinate system, measuring photoelectric data of the wafer by a testing machine, extracting dies with the same horizontal coordinate in a column of the wafer as samples, measuring standard photoelectric data of the samples by a standard machine, and selecting the photoelectric data of the corresponding dies measured by the testing machine as non-standard photoelectric data; dividing the whole wafer into rows along the vertical coordinates of the dies in the samples, obtaining error sets of all rows through the standard photoelectric data and the non-standard photoelectric data of the dies in the samples, and correcting the photoelectric data of the whole wafer measured by the testing machine through the error sets. The row-by-row correction method provided by the application solves the problem of test difference between different testing machines, improves the accuracy of the photoelectric data of the LED chip, and improves the product control of the chip.

Description

Technical Field

[0001] This invention relates to the field of chip data correction technology, and more specifically to a method for row correction of photoelectric data of LED chips. Background Technology

[0002] After LED chips (wafers) undergo COW and COT processes, they need to be tested using a testing machine to obtain photoelectric data before they can be shipped to customers or proceed to the next step of the BIN process. Therefore, the accuracy and consistency of the photoelectric data are key indicators for measuring the quality of chip products.

[0003] Currently, different chip manufacturers use different brands of testing machines, or different models within the same brand. The photoelectric data (mainly voltage, wavelength, and brightness) of the same wafer are not completely consistent between different models and different machines within the same model. For example, the average brightness values ​​of WAFER1 tested by testing machines MAC_1, MAC_2, and MAC_3 are 100mw, 105mw, and 95mw, respectively. If the test result of MAC_1 is taken as the standard, the test error of MAC_2, MAC_3 and MAC_1 all reach 5%, while the brightness value error of most chip manufacturers' shipments cannot exceed ±3%.

[0004] To address the aforementioned error issues, traditionally, chip manufacturers calibrate their testing machines daily using standard machines during production to ensure they operate at the same testing standard. However, testing machine performance fluctuates over time, leading to changes in test results. Furthermore, considering production costs, factories typically don't allocate sufficient personnel to increase calibration frequency; in most cases, a single machine's calibration cycle is one day. Significant machine fluctuations or other anomalies within a calibration cycle can easily cause the final test results to deviate from the error control range.

[0005] Therefore, resolving the issue of testing variability between different testing machines at any given time is of great significance for improving the accuracy of LED chip photoelectric parameters.

[0006] In summary, there is an urgent need for a method to correct the row-by-row data of LED chips in order to solve the problems existing in the current technology. Summary of the Invention

[0007] The purpose of this invention is to provide a method for correcting row spacing of photoelectric data in LED chips. The specific technical solution is as follows:

[0008] The method for correcting row-by-row data of LED chip optoelectronic data includes the following steps:

[0009] S1: Select a certain grain in the wafer as the origin and establish a rectangular coordinate system. Measure the photoelectric data of the wafer using a testing machine. Extract the grains in the same column of the wafer with the same horizontal coordinate as samples. Measure the standard photoelectric data of the samples using a standard machine. Select the photoelectric data of the corresponding grains measured by the testing machine as non-standard photoelectric data.

[0010] S2: Divide the entire wafer into rows along the ordinate of the grains in the sample. Using the standard photoelectric data and non-standard photoelectric data of the grains in the sample, obtain the error set K = (K1, K2, ..., K...). m ), where m represents the total number of rows;

[0011] S3: Photoelectric data of the entire wafer obtained by the error set K-line correction tester.

[0012] Preferably, step S1 further includes data removal, specifically as follows: setting data removal conditions, traversing all non-standard photoelectric data, and removing non-standard photoelectric data that meets the data removal conditions as well as the corresponding standard photoelectric data.

[0013] Preferably, the photoelectric data includes brightness value, voltage, and wavelength.

[0014] Preferably, the expression for the data removal condition is as follows: (VF cn >VF a orVF cn <VF b )or(LOP cn LOP a or LOP cn <LOP b )or(WD cn >WD a or WD cn <WD b )or(IR cn >IR a ); where n represents the row number of the grain in the sample, LOP cn This indicates that the brightness value of the sample in the nth row is non-standard photoelectric data, VF cn This indicates that the sample voltage in the nth row is non-standard photoelectric data, WD cn This indicates that the wavelength of the sample in the nth row is non-standard photoelectric data, VF a VF represents the upper voltage threshold. b LOP represents the voltage threshold. a LOP represents the upper threshold of the brightness value. b Indicates the threshold value for brightness, WD a Indicates the threshold wavelength, WD b Indicates the threshold wavelength, IR cnThis represents non-standard photoelectric data of current, IR. a This indicates the breakdown current.

[0015] Preferably, the error set K n =(K n1 K n2 K n3 ),

[0016] K n1 The expression is as follows:

[0017] K n2 The expression is as follows: K n2 =VF sn -VF cn ;

[0018] K n3 The expression is as follows: K n3 =WD sn -WD cn ;

[0019] Wherein, K n1 This represents the corrected mean brightness value of the sample in the nth row, 1 ≤ n ≤ m, K n2 K represents the corrected mean voltage of the sample in the nth row. n3 LOP represents the corrected mean wavelength of the sample in the nth row. sn VF represents the standard photoelectric data of the brightness value of the sample in the nth row. sn This represents the standard photoelectric data of the sample voltage in the nth row, WD. sn This represents the standard photoelectric data of the wavelength of the sample in the nth row.

[0020] Preferably, the correction expression for the brightness value is as follows: LOP* cn =LOP cn ×K n1 The corrected expression for the voltage is as follows: VF* cn =VF cn +K n2 The correction expression for the wavelength is as follows: WD* cn =WD cn +K n3 Among them, LOP* cn This indicates that the corrected brightness value is not standard photoelectric data, VF* cn This indicates that the corrected voltage is non-standard photoelectric data, WD* sn This indicates that the corrected wavelength is not standard data.

[0021] The application of the technical solution of the present invention has the following beneficial effects:

[0022] (1) The row correction method provided by the present invention uses the same column of dies in the wafer as a sample. By measuring its standard photoelectric data and non-standard photoelectric data, an error set for correction is calculated. The photoelectric data of all dies in the entire wafer measured by the non-standard machine is corrected by row correction of the error set, thereby solving the problem of test differences between different test machines, improving the accuracy of LED chip photoelectric data, and improving chip quality control at the factory.

[0023] (2) The present invention also includes a data rejection step. By setting data rejection conditions, non-standard optoelectronic data that meets the data rejection conditions and corresponding standard optoelectronic data are rejected, thereby enhancing the reliability of the error set used for correction, eliminating abnormal data, and improving the consistency of the corrected wafer optoelectronic data.

[0024] (3) The grains selected as samples in this invention come from the same column of the same wafer, which facilitates the selection of the photoelectric data of the corresponding grains measured by the testing machine as non-standard photoelectric data while the standard photoelectric data of the sample is measured by the standard machine.

[0025] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0026] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0027] Figure 1 This is a flowchart illustrating the line correction method in the preferred embodiment 1 of the present invention.

[0028] Figure 2 This is a line graph comparing the brightness values ​​of the sample before and after correction in the preferred embodiment of the present invention;

[0029] Figure 3 This is a line graph comparing the voltage correction of the sample before and after the preferred embodiment of the present invention;

[0030] Figure 4 This is a line graph comparing the wavelength of the sample before and after correction in the preferred embodiment of the present invention;

[0031] Figure 5 This is a color comparison image of the sample before and after brightness value correction in the preferred embodiment 1 of the present invention;

[0032] Figure 6 This is a color comparison image of the sample before and after voltage correction in the preferred embodiment 1 of the present invention;

[0033] Figure 7This is a color comparison image of the sample before and after wavelength correction in the preferred embodiment 1 of the present invention;

[0034] Figure 8 This is a color comparison image of the entire wafer before and after brightness value correction in preferred embodiment 1 of the present invention;

[0035] Figure 9 This is a color comparison image of the entire wafer before and after voltage correction in the preferred embodiment of the present invention.

[0036] Figure 10 This is a color comparison image of the entire wafer before and after wavelength correction in the preferred embodiment 1 of the present invention. Detailed Implementation

[0037] To facilitate understanding of the present invention, a more comprehensive description is provided below, along with preferred embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0039] Example 1:

[0040] See Figure 1 The method for correcting the row spacing of LED chip photoelectric data includes the following steps:

[0041] S1: Select a specific grain in the wafer as the origin and establish a rectangular coordinate system. Measure the photoelectric data of the wafer using a testing machine. Extract grains from the same column of the wafer with the same horizontal coordinate as samples (from the same column of the same wafer, facilitating subsequent selection of photoelectric data from the corresponding grains as non-standard photoelectric data). Measure the standard photoelectric data of the samples using a standard testing machine. Select the photoelectric data of the corresponding grains measured by the testing machine as non-standard photoelectric data. Through data rejection, remove some standard photoelectric data and corresponding non-standard photoelectric data, specifically as follows: Set data rejection conditions, traverse all non-standard photoelectric data, and reject non-standard photoelectric data that meets the data rejection conditions, as well as the corresponding standard photoelectric data.

[0042] The expression for the data removal condition is as follows: (VF cn >VF a or VF cn <VF b )or(LOP cn LOP aor LOP cn <LOP b )or(WD cn >WD a or WD cn <WD b )or(IR cn >IR a ); where n represents the total number of samples, LOP cn This indicates that the brightness value is non-standard photoelectric data, VF cn This indicates non-standard photoelectric data for voltage, WD cn This indicates non-standard photoelectric data, VF. a VF represents the upper voltage threshold. b LOP represents the voltage threshold. a LOP represents the upper threshold of the brightness value. b Indicates the threshold value for brightness, WD a Indicates the threshold wavelength, WD b Indicates the threshold wavelength, IR cn Indicates the test current, IR a VF represents the breakdown current. a VF b LOP a LOP b WD a and WD b The specific value is set according to the actual work requirements.

[0043] S2: Divide the entire wafer into rows along the ordinate of the grains in the sample. Using the standard photoelectric data and non-standard photoelectric data of the grains in the sample, obtain the error set K = (K1, K2, ..., K...). m ), m represents the total number of rows; the error set K n =(K n1 K n2 K n3 ),

[0044] The expression for K1 is as follows:

[0045] The expression for K2 is as follows: K n2 =VF sn -VF cn ;

[0046] The expression for K3 is as follows: K n3 =WD sn -WD cn ;

[0047] Wherein, K n1 This represents the corrected mean brightness value of the sample in the nth row, 1 ≤ n ≤ m, Kn2 K represents the corrected mean voltage of the sample in the nth row. n3 LOP represents the corrected mean wavelength of the sample in the nth row. sn VF represents the standard photoelectric data of the brightness value of the sample in the nth row. sn This represents the standard photoelectric data of the sample voltage in the nth row, WD. sn This represents the standard photoelectric data of the wavelength of the sample in the nth row.

[0048] The specific values ​​for standard photoelectric data, non-standard photoelectric data, and error sets are shown in Table 1:

[0049] Table 1. Standard photoelectric data, non-standard photoelectric data, and specific numerical values ​​of error sets (X and Y represent the x and y coordinates of the grain, respectively).

[0050]

[0051]

[0052]

[0053] S3: See Table 1 for the photoelectric data of the entire wafer measured by the error set K-line correction tester.

[0054] The correction expression for the brightness value is as follows: LOP* cn =LOP cn ×K n1 ;

[0055] The corrected expression for the voltage is as follows: VF* cn =VF cn +K n2 ;

[0056] The correction expression for the wavelength is as follows: WD* cn =WD cn +K n3 ;

[0057] Among them, LOP* cn This indicates that the corrected brightness value is not standard photoelectric data, VF* cn This indicates that the corrected voltage is non-standard photoelectric data, WD* sn This indicates that the corrected wavelength is not standard data.

[0058] See the standard photoelectric data, non-standard photoelectric data, and corrected non-standard photoelectric data for the sample. Figure 2-7As shown in Table 2, the corrected non-standard photoelectric data has the same line distribution and color distribution as the standard photoelectric data. According to the row correction method provided in this application, the non-standard photoelectric data measured by the non-standard machine can be effectively corrected to make it consistent with the standard photoelectric data measured by the standard machine, thereby solving the problem of test differences between different test machines, improving the accuracy of LED chip photoelectric data, and improving chip factory quality control.

[0059] Table 2 shows the specific values ​​for non-standard optoelectronic data, standard optoelectronic data, and error sets.

[0060]

[0061]

[0062]

[0063]

[0064] See the comparison chart of the entire wafer after photoelectric data correction. Figure 8 , Figure 9 as well as Figure 10 After the photoelectric data (such as brightness value, voltage and wavelength) of the wafer measured by the test machine is corrected by the row correction method provided by the present invention, it is basically consistent with the standard data of the standard machine measurement point. Since the standard machine sets the relevant parameters according to the shipping standard, the data of each test machine after this process will meet the shipping standard.

[0065] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for correcting row spacing of photoelectric data in LED chips, characterized in that, Includes the following steps: S1: Select a certain grain in the wafer as the origin and establish a rectangular coordinate system. Measure the photoelectric data of the wafer using a testing machine. Extract the grains in the same column of the wafer with the same horizontal coordinate as samples. Measure the standard photoelectric data of the samples using a standard machine. Select the photoelectric data of the corresponding grains measured by the testing machine as non-standard photoelectric data. S2: Divide the entire wafer into rows along the ordinate of the grains in the sample. Using the standard photoelectric data and non-standard photoelectric data of the grains in the sample, obtain the error set K = (K1, K2, ..., K...). m ), m represents the total number of rows; The error set K n =(K n1 K n2 K n3 ), K n1 The expression is as follows: ; K n2 The expression is as follows: ; K n3 The expression is as follows: ; Wherein, K n1 This represents the corrected mean brightness value of the sample in the nth row, 1 ≤ n ≤ m, K n2 K represents the corrected mean voltage of the sample in the nth row. n3 LOP represents the corrected mean wavelength of the sample in the nth row. sn VF represents the standard photoelectric data of the brightness value of the sample in the nth row. sn This represents the standard photoelectric data of the sample voltage in the nth row, WD. sn This represents the standard photoelectric data of the wavelength of the sample in the nth row; S3: Photoelectric data of the entire wafer obtained by the error set K-line correction tester.

2. The line break correction method according to claim 1, characterized in that, Step S1 further includes data removal, specifically as follows: setting data removal conditions, traversing all non-standard photoelectric data, and removing non-standard photoelectric data that meets the data removal conditions as well as the corresponding standard photoelectric data.

3. The line break correction method according to claim 2, characterized in that, The photoelectric data includes brightness value, voltage, and wavelength.

4. The line break correction method according to claim 3, characterized in that, The expression for the data removal condition is as follows: (VF cn >VF a or VF cn <VF b ) or (LOP cn LOP a or LOP cn <LOP b ) or (WD cn >WD a or WD cn <WD b )or (IR cn >IR a ); where n represents the row number of the grain in the sample, LOP cn This indicates that the brightness value of the sample in the nth row is non-standard photoelectric data, VF cn This indicates that the sample voltage in the nth row is non-standard photoelectric data, WD cn This indicates that the wavelength of the sample in the nth row is non-standard photoelectric data, VF a VF represents the upper voltage threshold. b LOP represents the voltage threshold. a LOP represents the upper threshold of the brightness value. b Indicates the threshold value for brightness, WD a Indicates the threshold wavelength, WD b Indicates the threshold wavelength, IR cn This represents non-standard photoelectric data of current, IR. a This indicates the breakdown current.

5. The line break correction method according to claim 4, characterized in that, The correction expression for the brightness value is as follows: LOP* cn =LOP cn ×K n1 The corrected expression for the voltage is as follows: VF* cn =VF cn +K n2 The correction expression for the wavelength is as follows: WD* cn =WD cn +K n3 ; Among them, LOP* cn This indicates that the corrected brightness value is not standard photoelectric data, VF* cn This indicates that the corrected voltage is non-standard photoelectric data, WD* sn This indicates that the corrected wavelength is not standard data.

Images