A method and system for spot checking LED chips

Abstract

The present invention discloses a random inspection method and system for LED die. The random inspection method includes: testing LED wafers to obtain test data of the LED die; classifying the LED die into several classification levels based on the test data of the LED die, and selecting a mandatory classification level from the classification levels, wherein the LED die corresponding to the mandatory classification level are the mandatory die, and the LED die are from at least one wafer; arranging the LED die onto different square pieces according to the classification levels to obtain several finished square pieces; selecting square pieces to be inspected from the finished square pieces, wherein the LED die on the square pieces to be inspected are first-sampled die, and the first-sampled die include the mandatory die from any LED wafer; and testing the first-sampled die on the square pieces to be inspected to determine whether the first-sampled die meet the standard. The random inspection method of the present invention has high inspection efficiency and low missed detection rate.

Description

Technical Field

[0001] The present invention relates to the technical field of light emitting diodes, and in particular to a random inspection method and system for LED crystals. Background Art

[0002] After the LED dies have been classified by photoelectric parameters, they need to be sorted by grade. LED dies of the same grade are placed on the same finished product sheet. Figure 1 , Figure 1 There are 6 finished square pieces, including finished square piece 1, finished square piece 2, finished square piece 3, finished square piece 4, finished square piece 5 and finished square piece 6. Each finished square piece is arranged with multiple LED chips of the same grade. Figure 1 The LED dies on the six finished squares are of the same grade. The numbers on the finished squares indicate which wafer the LED dies come from. LED dies with the same numbers come from the same wafer, for example, 1 represents wafer 1, 2 represents wafer 2, and so on. The LED dies on some finished squares may all come from the same wafer, while the LED dies on some finished squares may come from different wafers.

[0003] After the LED dies are classified and sorted according to their optoelectronic parameters, spot testing equipment is required to ensure that the electrical and optical properties of each die are consistent with the classification and selection requirements, while also ensuring the quality of LED product shipments.

[0004] An existing random inspection method is to conduct random inspection on each finished square piece, for example Figure 1 All 6 finished square pieces are sampled. This method requires a lot of manpower and machines, and has high manufacturing costs.

[0005] Another existing random sampling inspection method is to select the finished product square pieces in proportion for random testing, for example Figure 1 The method of sampling 1 or 2 finished wafers from the 6 finished wafers for random testing is prone to missing wafers, resulting in quality abnormalities. Figure 1 Among the 6 finished square pieces, if finished square piece 1 and finished square piece 3 are randomly selected for sampling, the LED chips of wafer 3 will be missed because the LED chips of finished square piece 1 and finished square piece 3 do not come from wafer 3; if finished square piece 4 and finished square piece 5 are randomly selected for sampling, the LED chips of wafer 1 will be missed because the LED chips of finished square piece 4 and finished square piece 5 do not come from wafer 1; if finished square piece 1 and finished square piece 5 are randomly selected for sampling, the LED chips of wafer 2 will be missed because the LED chips of finished square piece 1 and finished square piece 5 do not come from wafer 2. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for spot-checking LED dies, which has high spot-checking efficiency and low missed detection rate, and the spot-checked dies include LED dies from any LED wafer.

[0007] The technical problem that the present invention also aims to solve is to provide a random inspection system for LED dies, which has a simple structure, high random inspection efficiency, and low missed inspection rate, and the randomly inspected dies include LED dies from any LED wafer.

[0008] In order to solve the above technical problems, the present invention provides a method for spot checking LED dies, comprising:

[0009] Test LED wafers to obtain test data of LED dies;

[0010] Classifying the LED dies into a plurality of classification levels according to the test data of the LED dies, and selecting a mandatory level from the classification levels, wherein LED dies corresponding to the mandatory level are mandatory dies, and the LED dies are from at least one wafer;

[0011] Arranging the LED chips onto different square pieces according to the classification levels to obtain a plurality of finished square pieces;

[0012] Selecting a square piece to be sampled from the finished square pieces, wherein the LED dies on the square piece to be sampled are first sampled dies, and the first sampled dies include the must-sample dies from any LED wafer;

[0013] Testing the first sampled dies on the sample to be inspected to determine whether the first sampled dies meet the standard;

[0014] If the first sampled grains on the square piece to be sampled meet the standards, the remaining finished square pieces do not need to be tested and are transferred to the next process;

[0015] If the first sampled grains on the square piece to be sampled do not meet the standard, all the finished square pieces will be detained.

[0016] As an improvement to the above solution, mandatory square pieces are selected from the square pieces to be inspected according to the inspection ratio, the number of the mandatory square pieces is less than the number of the substitute inspection square pieces, the LED dies on the mandatory square pieces are second inspection dies, and the second inspection dies include mandatory dies from any LED wafer;

[0017] Testing the second sampled dies on the mandatory square sheet to determine whether the second sampled dies meet the standard;

[0018] If the second random inspection grains on the required square pieces meet the standards, the remaining finished square pieces do not need to be inspected and are transferred to the next process;

[0019] If the second sampling of the required square pieces does not meet the standards, all finished square pieces will be detained.

[0020] As an improvement to the above solution, in the LED wafer, the classification level with the largest number of LED chips is the mandatory level, and the LED wafer contains at least one mandatory level.

[0021] As an improvement to the above solution, the sampling ratio refers to the ratio of the number of the second sampled dies from any LED wafer to the total number of the second sampled dies from the LED wafer;

[0022] The number of must-sample dies in the second random inspection die from any LED wafer is a, the inspection ratio is k, and the total number of must-sample dies in the LED wafer is b. If a≥b*k, the square piece to be inspected is selected as the must-sample square piece.

[0023] As an improvement to the above solution, the test data of the LED die includes electrical data, optical data and appearance data.

[0024] As an improvement to the above solution, the method of selecting the square pieces to be sampled from the finished square pieces includes:

[0025] The square piece to be inspected is selected based on the required grade and required dies. If the LED dies on the finished square piece include required dies from at least one LED wafer, the finished square piece is selected as the square piece to be inspected.

[0026] Accordingly, the present invention also provides a random inspection system for LED dies, comprising:

[0027] A testing module, configured to test LED dies on an LED wafer to obtain test data of the LED dies;

[0028] a processing module for analyzing the test data to classify the LED dies into a plurality of classification levels, and selecting a required level from the classification levels;

[0029] A sorting module is used to sort and arrange the LED dies, and the LED dies are arranged on different square pieces according to the classification level to obtain a plurality of finished square pieces;

[0030] A sampling module is used to select a square piece to be sampled from the finished square piece, wherein the LED dies on the square piece to be sampled are first sampled dies, and the first sampled dies include the must-sample dies from any LED wafer;

[0031] The detection module is used to detect the first sampled dies to determine whether the first sampled dies meet the standard.

[0032] As an improvement to the above scheme, the selection module is also used to select the must-select square pieces from the square pieces to be inspected, the number of the must-select square pieces is less than the number of the substitute inspection square pieces, the LED grains on the must-select square pieces are the second inspection grains, and the second inspection grains include the must-select grains from any LED wafer.

[0033] As an improvement to the above solution, the detection module is further configured to detect the second sampled die to determine whether the second sampled die meet the standards.

[0034] As an improvement to the above solution, in the LED wafer, the classification level with the largest number of LED chips is the mandatory level, and the LED wafer contains at least one mandatory level.

[0035] The implementation of the present invention has the following beneficial effects:

[0036] The sampling inspection method of this application is a new sampling inspection method, which breaks away from the sampling inspection ideas of random sampling and full sampling. While effectively improving the sampling inspection efficiency, it ensures the accuracy of the sampling inspection and reduces the probability of missed inspection.

[0037] The LED grain sampling inspection system provided in this embodiment only needs to inspect the sample to be inspected, which effectively improves the sampling efficiency and reduces manufacturing costs and labor costs. In addition, since the first sampled grains on the sample to be inspected include the required grains from any LED wafer, the probability of missed inspection is greatly reduced and the accuracy of sampling is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the arrangement of existing LED chips on the finished square wafer;

[0039] Figure 2 Schematic diagram of the arrangement of LED dies from wafers 1 to 3 on the finished wafer in Example 1 of the present invention;

[0040] Figure 3 Schematic diagram of the arrangement of LED dies from wafers 4 to 6 on the finished wafer in Example 2 of the present invention;

[0041] Figure 4 It is a structural diagram of a random inspection system for LED dies provided by another embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below with reference to the accompanying drawings.

[0043] The present application provides a method for spot checking LED dies, comprising the following steps:

[0044] S1. Test the LED wafer;

[0045] Specifically, an LED wafer contains multiple LED dies. In this application, the LED wafer is placed in a test device for in-and-out testing to obtain test data of the LED dies.

[0046] The test data of the LED die includes electrical data, optical data and appearance data, but is not limited thereto.

[0047] S2. Classify the LED dies into a plurality of classification levels based on the test data of the LED dies, and select a mandatory level from the classification levels, wherein LED dies corresponding to the mandatory level are mandatory dies, and the LED dies are from at least one wafer;

[0048] In the LED wafer, the classification level with the largest number of LED chips is the mandatory level, and the LED wafer contains at least one mandatory level.

[0049] Figure 1 The LED dies in the 6 finished square pieces come from 3 LED wafers and have the same classification grade. In actual production, one LED wafer generally contains 30,000 LED dies. The specific number of LED dies is determined by the size of the LED wafer and the size of the dies. The LED dies in 3 LED wafers will be divided into 100 grades, which means that 3 LED wafers will produce at least 100 finished square pieces. Figure 1 The three finished square pieces in the figure are just one grade of LED die among 100 grades.

[0050] In Example 1 of the present application, wafers 1 to 3 are taken as an example. After wafers 1 to 3 are tested, wafers 1 to 3 are classified into the following categories based on the test data of the wafers, as shown in Table 1:

[0051] Table 1

[0052] project Wafer 1 Wafer 2 Wafer 3 Total number of particles 100 100 100 Number of levels 10 levels 11 levels 9 levels Level 1 (piece) 5 - - Level 2 (pieces) 10 2 5 Level 3 (pieces) 12 4 9 Level 4 (pieces) 13 8 10 Level 5 (pieces) 20 10 15 Level 6 (pieces) 10 15 29 Level 7 (pieces) 10 25 10 Level 8 (pieces) 10 10 9 Level 9 (pieces) 7 8 7 Level 10 (pieces) 3 7 6 Level 11 (pieces) - 6 - Level 12 (pieces) - 5 -

[0053] Among them, wafers 1 to 3 each have 100 LED dies. For the convenience of statistics, the number of dies on the wafers is reduced in this embodiment. The LED wafers actually produced generally contain more than 30,000 LED dies. In this embodiment, wafer 1 is divided into 10 grades, among which grade 5 has the largest number of LED dies. Therefore, grade 5 is the required grade for wafer 1, and grade 5 LED dies are the required dies for wafer 1; wafer 2 is divided into 11 grades, among which grade 7 has the largest number of LED dies. Therefore, grade 7 is the required grade for wafer 2, and grade 7 LED dies are the required dies for wafer 2; wafer 3 is divided into 9 grades, among which grade 6 has the largest number of LED dies. Therefore, grade 6 is the required grade for wafer 3, and grade 6 LED dies are the required dies for wafer 3.

[0054] In Example 2 of the present application, wafers 4 to 6 are taken as an example. After wafers 4 to 6 are tested, wafers 4 to 6 are classified into the following categories based on the test data of the wafers, as shown in Table 2:

[0055] Table 2

[0056]

[0057]

[0058] Among them, wafers 4 to 6 each have 100 LED dies. For the convenience of statistics, the number of dies on the wafers is reduced in this embodiment. The LED wafers actually produced generally contain more than 30,000 LED dies. In this embodiment, wafer 4 is divided into 10 grades, among which grade 5 has the largest number of LED dies. Therefore, grade 5 is the required grade for wafer 4, and the LED dies of grade 5 are the required dies for wafer 4. Wafer 5 is divided into 11 grades, among which grade 7 has the largest number of LED dies. Therefore, grade 7 is the required grade for wafer 5, and the LED dies of grade 7 are the required dies for wafer 5. Wafer 6 is divided into 9 grades, among which grade 5 has the largest number of LED dies. Therefore, grade 5 is the required grade for wafer 6, and the LED dies of grade 5 are the required dies for wafer 6.

[0059] S3, arranging the LED chips onto different square pieces according to the classification levels to obtain a plurality of finished square pieces;

[0060] After the LED chips are graded and classified, the sorting equipment will arrange the LED chips onto different square pieces according to the set method to obtain finished square pieces.

[0061] like Figure 1 As shown, the LED chips are arranged in a matrix of M rows and N columns, where M and N are positive integers, and the specific values ​​of M and N are determined by the actual number of LED chips, wherein the LED chips from the same wafer are arranged in the direction of rows, and the LED chips from different wafers are arranged in the direction of columns.

[0062] Specifically, when arranging the LED dies to be tested, the LED dies from wafer 1 are first arranged from left to right to fill the first row, then from right to left to fill the second row, and so on. The odd rows are arranged in sequence from left to right, and the even rows are arranged in sequence from right to left. When the LED dies from wafer 1 are arranged, the LED dies from wafer 2 are arranged in this order, and so on, until all the LED dies from 10 wafers are arranged. Of course, in other embodiments, the LED dies can also be arranged from right to left in odd rows and from left to right in even rows, and the present invention is not limited to this.

[0063] Wafers 1 to 3 provided in Example 1 of the present application are arranged according to the classification levels in Table 1. The LED dies of wafer 1 are arranged on 10 square pieces, the LED dies of wafer 2 are arranged on 11 square pieces, and the LED dies of wafer 3 are arranged on 9 square pieces. Since some levels of wafers 1 to 3 are repeated, the final number of finished square pieces is 12. Figure 2 As shown. Among them,

[0064] The five LED dies on finished wafer 1-1 belong to grade 1 and all come from wafer 1.

[0065] The 17 LED dies on finished wafers 1-2 belong to grade 2 and come from wafers 1, 2, and 3.

[0066] The 25 LED dies on finished wafers 1-3 belong to grade 3 and come from wafers 1, 2, and 3.

[0067] The 31 LED dies on finished wafers 1-4 are grade 4 and come from wafers 1, 2, and 3.

[0068] The 45 LED dies on finished wafers 1-5 are grade 5 and come from wafers 1, 2, and 3.

[0069] The 54 LED dies on finished wafers 1-6 belong to grade 6 and come from wafers 1, 2, and 3.

[0070] The 45 LED dies on finished wafers 1-7 are grade 7 and come from wafers 1, 2, and 3.

[0071] The 29 LED dies on finished wafers 1-8 are grade 8 and come from wafers 1, 2, and 3.

[0072] The 22 LED dies on finished wafers 1-9 are grade 9 and come from wafers 1, 2, and 3.

[0073] The 16 LED dies on finished wafers 1-10 are grade 10 and come from wafers 1, 2, and 3.

[0074] The six LED dies on finished wafers 1-11 belong to grade 11 and all come from wafer 3;

[0075] The five LED dies on finished wafers 1-12 are grade 12 and all come from wafer 3.

[0076] Wafers 4 to 6 provided in Example 2 of the present application are arranged according to the classification levels in Table 2. The LED dies of wafer 4 are arranged on 10 square pieces, the LED dies of wafer 5 are arranged on 11 square pieces, and the LED dies of wafer 6 are arranged on 9 square pieces. Since some levels of wafers 4 to 6 are repeated, the final number of finished square pieces is 12. Figure 3 As shown. Among them,

[0077] The five LED dies on finished wafer 2-1 belong to grade 1 and all come from wafer 4;

[0078] The 17 LED dies on finished wafer 2-2 belong to grade 2 and come from wafers 4, 5, and 6.

[0079] The 25 LED dies on finished wafers 2-3 belong to grade 3 and come from wafers 4, 5, and 6.

[0080] The 31 LED dies on finished wafers 2-4 belong to grade 4 and come from wafers 4, 5, and 6.

[0081] The 53 LED dies on finished wafers 2-5 are grade 5 and come from wafers 4, 5, and 6.

[0082] The 46 LED dies on finished wafers 2-6 are grade 6 and come from wafers 4, 5, and 6.

[0083] The 45 LED dies on finished wafers 2-7 are grade 7 and come from wafers 4, 5, and 6.

[0084] The 29 LED dies on finished wafers 2-8 are grade 8 and come from wafers 4, 5, and 6.

[0085] The 22 LED dies on finished wafers 2-9 are grade 9 and come from wafers 4, 5, and 6.

[0086] The 16 LED dies on finished wafers 2-10 are grade 10 and come from wafers 4, 5, and 6.

[0087] The six LED dies on finished wafers 2-11 are grade 11 and all come from wafer 6.

[0088] The five LED dies on finished wafers 2-12 are grade 12 and all come from wafer 6.

[0089] S4. Select a square piece to be sampled from the finished square pieces, where the LED dies on the square piece to be sampled are first sampled dies, and the first sampled dies include the required dies from any LED wafer;

[0090] Specifically, the method of selecting the square pieces to be sampled from the finished square pieces includes:

[0091] The square piece to be inspected is selected based on the required grade and required dies. If the LED dies on the finished square piece include required dies from at least one LED wafer, the finished square piece is selected as the square piece to be inspected.

[0092] like Figure 2 As shown, wafers 1 to 3 provided in Example 1 of the present application are sorted to form 12 finished wafers. An existing sampling inspection method is to perform sampling inspection on each finished wafer, that is, sampling inspection on finished wafers 1-1 to 1-12. This method requires a lot of manpower and equipment, and has high manufacturing costs.

[0093] Another existing random sampling inspection method is: selecting finished squares for random testing in proportion, that is, selecting one or two finished squares from finished squares 1-1 to finished squares 1-12 for random testing in proportion. If finished squares 1-1 and finished squares 1-11 are randomly selected for random testing, since the LED chips in finished squares 1-1 and finished squares 1-11 do not come from wafer 3, the LED chips in wafer 3 will be missed; if finished squares 1-11 and finished squares 1-12 are randomly selected for random testing, since the LED chips in finished squares 1-11 and finished squares 1-12 do not come from wafer 1 and wafer 3, the LED chips in wafer 1 and wafer 3 will be missed.

[0094] In order to improve the efficiency of random inspection, reduce manpower and equipment costs, and solve the problem of missed inspection, this embodiment selects a number of squares to be inspected from the 12 finished squares.

[0095] The classification level of the LED chips on the finished square pieces 1-5 belongs to level 5 (mandatory level). Since the LED chips corresponding to the mandatory level are mandatory chips, the LED chips on the finished square pieces 1-5 are mandatory chips; similarly, the classification level of the LED chips on the finished square pieces 1-6 belongs to level 6 (mandatory level). Since the LED chips corresponding to the mandatory level are mandatory chips, the LED chips on the finished square pieces 1-6 are mandatory chips; similarly, the classification level of the LED chips on the finished square pieces 1-7 belongs to level 7 (mandatory level). Since the LED chips corresponding to the mandatory level are mandatory chips, the LED chips on the finished square pieces 1-7 are mandatory chips. Therefore, in this embodiment, finished square pieces 1-5, finished square pieces 1-6, and finished square pieces 1-7 are selected as square pieces to be inspected, among which the LED chips on finished square pieces 1-5, finished square pieces 1-6, and finished square pieces 1-7 are all first-sampled chips, that is, the first-sampled chips in this embodiment include the necessary chips from wafers 1 to 3.

[0096] like Figure 3 As shown, wafers 4 to 6 provided in Example 2 of the present application are finally formed into 12 finished square wafers after sorting.

[0097] The LED dies on finished wafer 2-5 are classified as level 5 (mandatory sampling). Since the LED dies corresponding to the mandatory sampling level are mandatory sampling dies, the LED dies on finished wafer 2-5 are mandatory sampling dies. Similarly, the LED dies on finished wafer 2-7 are classified as level 7 (mandatory sampling). Since the LED dies corresponding to the mandatory sampling level are mandatory sampling dies, the LED dies on finished wafer 2-7 are mandatory sampling dies. Therefore, in this embodiment, finished wafers 2-5 and 2-7 are selected as wafers to be sampled. The LED dies on finished wafers 2-5 and 2-7 are both the first sampled dies. That is, the first sampled dies in this embodiment 2 include the mandatory dies from wafers 4 to 6.

[0098] It should be noted that in actual production, 3 LED wafers produce at least 100 finished square pieces. Among the 100 finished square pieces, generally more than a dozen square pieces are selected for random inspection. If the number of wafers is greater, the number of square pieces selected for random inspection will be greater. In order to further improve the efficiency of random inspection, the present application can also select more square pieces from the square pieces to be inspected.

[0099] Specifically, the must-be-sampled square pieces are selected from the square pieces to be sampled according to the sampling ratio, the number of the must-be-sampled square pieces is less than the number of the substitute sampling square pieces, the LED grains on the must-be-sampled square pieces are the second sampling grains, and the second sampling grains include the must-be-sampled grains from any LED wafer.

[0100] The sampling ratio refers to the ratio of the number of required sampling dies from any LED wafer in the second sampling dies to the total number of required sampling dies of the LED wafer.

[0101] The number of must-sample dies in the second random inspection die from any LED wafer is a, the inspection ratio is k, and the total number of must-sample dies in the LED wafer is b. If a≥b*k, the square piece to be inspected is selected as the must-sample square piece.

[0102] Among the 12 finished square pieces provided in Example 1 of the present application, the square pieces to be sampled are finished square piece 1-5, finished square piece 1-6, and finished square piece 1-7.

[0103] If the sampling ratio is set to 40%, the number of grade 5 grains that must be sampled in wafer 1 is 20, the number of grade 7 grains that must be sampled in wafer 2 is 25, and the number of grade 6 grains that must be sampled in wafer 3 is 29. Then, the number of grade 5 grains in the second sampling that come from wafer 1 is at least 8, the number of grade 7 grains in the second sampling that come from wafer 2 is at least 10, and the number of grade 6 grains in the second sampling that come from wafer 3 is at least 12.

[0104] The number of must-drawn grains from wafer 1 in finished square pieces 1-5, finished square pieces 1-6, and finished square pieces 1-7 is greater than 8, the number of must-drawn grains from wafer 2 in finished square pieces 1-5, finished square pieces 1-6, and finished square pieces 1-7 is greater than or equal to 10, and the number of must-drawn grains from wafer 3 in finished square pieces 1-5, finished square pieces 1-6, and finished square pieces 1-7 is greater than or equal to 10. Therefore, any one or several finished square pieces from finished square pieces 1-5, finished square pieces 1-6, and finished square pieces 1-7 can be selected as must-drawn square pieces.

[0105] The number of squares that must be drawn is set according to actual needs and is not specifically limited in this application.

[0106] If the sampling ratio is set to 50%, then at least 10 grade 5 die from wafer 1 must be included in the second sampling, at least 13 grade 7 die from wafer 2 must be included in the second sampling, and at least 15 grade 6 die from wafer 3 must be included in the second sampling. If the number of required slices is set to 1, then finished slices 1-5 are selected as the required slices. If the number of required slices is set to 2, then finished slices 1-5 and 1-6, or finished slices 1-5 and 1-7, or finished slices 1-6 and 1-7 must be selected as the required slices.

[0107] S5. Testing the first sampled die on the sample to be inspected to determine whether the first sampled die meets the standard;

[0108] If the first sampled grains on the square piece to be sampled meet the standards, the remaining finished square pieces do not need to be tested and are transferred to the next process;

[0109] If the first sampled grains on the square piece to be sampled do not meet the standard, all the finished square pieces will be detained.

[0110] After sorting, wafers 1 to 3 provided in Example 1 of the present application ultimately form 12 finished wafers, among which the wafers selected for random inspection are finished wafers 1-5, finished wafers 1-6, and finished wafers 1-7. In this step, the first random inspection dies on the finished wafers 1-5, finished wafers 1-6, and finished wafers 1-7 are tested. If the first random inspection dies on the three finished wafers all meet the standards, the remaining finished wafers (finished wafers 1-1 to finished wafers 1-4, finished wafers 1-8 to finished wafers 1-12) do not need to be tested and are transferred to the next process.

[0111] If any first sampled grain on any of the finished squares 1-5, 1-6, and 1-7 does not meet the standard, all the finished squares will be detained.

[0112] If the sampling inspection method of the present application selects a mandatory sample from the sample to be inspected, then in this step, only the second sampled die on the mandatory sample is tested to determine whether the second sampled die meets the standard;

[0113] If the second random inspection grains on the required square pieces meet the standards, the remaining finished square pieces do not need to be inspected and are transferred to the next process;

[0114] If the second sampling of the required square pieces does not meet the standards, all finished square pieces will be detained.

[0115] The sampling inspection method of this application is a new sampling inspection method, which breaks away from the sampling inspection ideas of random sampling and full sampling. While effectively improving the sampling inspection efficiency, it ensures the accuracy of the sampling inspection and reduces the probability of missed inspection.

[0116] The randomly inspected grains in the random inspection method of the present application include grains from any wafer, and the missed inspection rate can be reduced to zero.

[0117] The sampling inspection method of this application is highly efficient and effectively saves equipment and labor costs.

[0118] See also Figure 4The present application also provides a sampling inspection system for LED chips, including: a testing module 101, a processing module 102, a sorting module 103, a sampling module 104 and a detection module 105, wherein the testing module 101 is used to test the LED chips on the LED wafer to obtain test data of the LED chips; the processing module 102 is used to analyze the test data to classify the LED chips into several classification levels, and select the required sampling levels from the classification levels; the sorting module 103 is used to sort and arrange the LED chips, and the LED chips are arranged on different square pieces according to the classification levels to obtain several finished square pieces; the sampling module 104 is used to select square pieces to be sampled from the finished square pieces, and the LED chips on the square pieces to be sampled are first sampled chips, and the first sampled chips include the required sampling chips from any LED wafer; the detection module 05 is used to detect the first sampled chips to determine whether the first sampled chips meet the standards.

[0119] Preferably, the processing module 102 is further configured to collect classification level information and transmit the classification level information to the sorting module 103 , so that the sorting module 103 arranges the LED dies onto different squares according to the classification level information to obtain a plurality of finished squares.

[0120] Preferably, the processing module 102 is further configured to collect data on required grades and required grains, and transmit the data on required grades and required grains to the selection module 104 so that the selection module 104 selects the wafers to be inspected from the finished wafers.

[0121] Preferably, the processing module 102 is further configured to collect information of the wafer to be sampled and transmit the information of the wafer to be sampled to the detection module 105 so that the detection module 105 can test the first sampled die on the wafer to be sampled.

[0122] Preferably, the selection module 104 is also used to select the must-select square pieces from the square pieces to be inspected, the number of the must-select square pieces is less than the number of the substitute inspection square pieces, the LED grains on the must-select square pieces are the second inspection grains, and the second inspection grains include the must-select grains from any LED wafer.

[0123] Preferably, the detection module 105 is further configured to detect the second sampled die to determine whether the second sampled die meet the standards.

[0124] Specifically, in the LED wafer, the classification level with the largest number of LED chips is the mandatory level, and the LED wafer contains at least one mandatory level.

[0125] The LED grain sampling inspection system provided in this embodiment only needs to inspect the sample to be inspected, which effectively improves the sampling efficiency and reduces manufacturing costs and labor costs. In addition, since the first sampled grains on the sample to be inspected include the required grains from any LED wafer, the probability of missed inspection is greatly reduced and the accuracy of sampling is improved.

[0126] The above disclosure is only a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for spot checking LED dies, characterized in that: include: Test LED wafers to obtain test data of LED dies; According to the test data of the LED dies, the LED dies are classified into a plurality of classification levels, and a mandatory level is selected from the classification levels, wherein LED dies corresponding to the mandatory level are mandatory levels, and the LED dies are from at least one wafer; in the LED wafer, the classification level with the largest number of LED dies is the mandatory level, and the LED wafer contains at least one mandatory level; Arranging the LED chips onto different square pieces according to classification levels to obtain a plurality of finished square pieces; Selecting a square piece to be sampled from the finished square pieces, wherein the LED dies on the square piece to be sampled are first sampled dies, and the first sampled dies include the must-sample dies from any LED wafer; Testing the first sampled dies on the sample to be inspected to determine whether the first sampled dies meet the standard; If the first sampled grains on the square piece to be sampled meet the standards, the remaining finished square pieces do not need to be tested and are transferred to the next process; If the first sampled grains on the square piece to be sampled do not meet the standard, all the finished square pieces will be detained.

2. The method for spot checking LED dies according to claim 1, wherein: Selecting mandatory square pieces from the square pieces to be inspected according to the sampling ratio, wherein the number of the mandatory square pieces is less than the number of the square pieces to be inspected, and the LED dies on the mandatory square pieces are second-sampled inspection dies, and the second-sampled inspection dies include mandatory dies from any LED wafer; Testing the second sampled dies on the mandatory square sheet to determine whether the second sampled dies meet the standard; If the second random inspection grains on the required square pieces meet the standards, the remaining finished square pieces do not need to be inspected and are transferred to the next process; If the second sampling of the required square pieces does not meet the standards, all finished square pieces will be detained.

3. The method for spot checking LED dies according to claim 2, wherein: The sampling ratio refers to the ratio of the number of the second sampling die from any LED wafer to the total number of the required die from the LED wafer; The number of must-sample dies in the second random inspection die from any LED wafer is a, the inspection ratio is k, and the total number of must-sample dies in the LED wafer is b. If a≥b*k, the square piece to be inspected is selected as the must-sample square piece.

4. The method for spot checking LED dies according to claim 1, wherein: The test data of the LED die includes electrical data, optical data and appearance data.

5. The method for spot checking LED dies according to claim 1, wherein: The method for selecting the square pieces to be sampled from the finished square pieces includes: The square piece to be inspected is selected based on the required grade and required dies. If the LED dies on the finished square piece include required dies from at least one LED wafer, the finished square piece is selected as the square piece to be inspected.

6. A random inspection system for LED dies, characterized in that: include: A testing module, configured to test LED dies on an LED wafer to obtain test data of the LED dies; a processing module for analyzing the test data to classify the LED dies into a plurality of classification levels, and selecting a required level from the classification levels; In the LED wafer, the classification grade with the largest number of LED dies is the mandatory grade, and the LED wafer contains at least one mandatory grade; A sorting module is used to sort and arrange the LED dies, and the LED dies are arranged on different square pieces according to the classification level to obtain a plurality of finished square pieces; A sampling module is used to select a square piece to be sampled from the finished square piece, wherein the LED dies on the square piece to be sampled are first sampled dies, and the first sampled dies include the must-sample dies from any LED wafer; The detection module is used to detect the first sampled dies to determine whether the first sampled dies meet the standard.

7. The LED die sampling inspection system according to claim 6, wherein: The selection module is also used to select the must-select square pieces from the square pieces to be inspected, the number of the must-select square pieces is less than the number of the square pieces to be inspected, the LED chips on the must-select square pieces are the second-sampled chips, and the second-sampled chips include the must-selected chips from any LED wafer.

8. The LED die sampling inspection system according to claim 7, wherein: The detection module is further configured to detect the second sampled dies to determine whether the second sampled dies meet the standard.

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