This standard specifies the test method for the bending strength of silicon single crystal cutting, grinding and polishing wafers. This standard is applicable to the measurement of the bending strength of CZ and FZ silicon single crystal wafers with crystal orientation of <111> and <100> at room temperature. The thickness of silicon wafer is 250～900μm. GB/T 15615-1995 Test method for bending strength of silicon wafer GB/T15615-1995 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Test method for measuring
flexure strength of silicon slicesSubject content and scope of application
GB/T15615-1995
This standard specifies the test method for the flexure strength of silicon single crystal cutting, grinding and polishing slices (referred to as silicon slices). This standard is applicable to the measurement of the flexure strength of CZ and FZ silicon single crystals with crystal orientations <111> and <100 at room temperature. The silicon thickness is 250~900μm.
2 Reference standards
GB12964 Silicon single crystal polishing slices
GB12965 Silicon single crystal cutting and grinding slices
3 Terminology
3.1 Flexure strength
The maximum bending stress when the sample is broken, usually the maximum radial tensile stress on the convex surface for brittle materials, characterizes the performance of anti-breaking. 3.2 Little deflection
When a disc is bent by a central load, the maximum displacement of the disc center surface before and after bending is a small amount compared to the disc thickness. 4 Method principle
This standard uses the simply supported disc concentrated load impact method to measure the bending strength of silicon wafers. A steel ball rolls down from a 1/4 circular track and impacts the silicon wafer sample placed vertically at the end of the track, and the height of the steel ball is continuously increased until the silicon wafer is broken. The bending strength of the sample α is calculated according to formula (1) derived from the thin plate theory and elastic mechanics theory. : a. = 9. 806 7X
Wherein: a. Silicon wafer bending strength test value N/mm\p-steel ball mass.kg;
A--sample simply supported radius, mm;
B-sample thickness, mm;
PH11/2
H-vertical height of the steel ball rolling down when breaking the sample, mm; -(Yln
. (1)
X(kg·mm-2)1/2,Y,Z: coefficients related to the elastic modulus and Poisson's ratio of silicon material, for (111) silicon single crystal wafer, they are 182.0.621 and 1.146 respectively; for <100) silicon single crystal wafer, they are 207, 0.621 and 1.146 respectively. Formula (1) is derived under the condition of small deflection of thin plate, that is, the maximum deflection of the wafer when it is broken is required to be less than 1/5 of the thickness of the sample. Therefore, corrections should be made for test results that do not meet the small deflection conditions. Approved by the State Administration of Technical Supervision on July 12, 1995, 69.1
Implementation on February 1, 1996
GB/T15615-1995
The correction coefficient K for testing silicon wafers of different thicknesses and strengths is obtained through a large number of experiments (see Appendix A), and the relationship between K and thickness B and strength is listed (see Table A1). The error of K is ≤0.01. The test value of the silicon wafer. Multiplying it by the corresponding K gives the true bending strength of the silicon wafer. That is:
The true bending strength value of the silicon wafer, N/mm2;
Where: o—
K——correction coefficient;
g. — Silicon wafer strength test value, N/mm
5 Apparatus and instruments
5.1 Brittle material bending strength tester (see Figure 1) Schematic diagram of the tester
1-frame; 2-drawing plate; 3 support plate; 4-sample; 5-height adjustment screw; 6-slide rail: steel ball 5.1.1 Bracket: a square frame supporting a 1/4 round slide rail. 5.1.2 Slide rail: radius 260mm, with grooves on the front, polished and chrome-plated surface, and vertical height scale on the side, accurate to 1mm. 5.1.3 Sample support plate: for vertical placement of round sample. 5.1.4 Steel ball bracket: can be moved on the slide rail and fixed at the required height. 5.1.5 Steel ball: bearing ball with a mass range of 1~10g. 5.2 Micrometer screw: measurement accuracy 0.01mm. 6 Sample preparation
(2)
6.1 The bending strength of silicon wafers is related to the intrinsic quality and surface damage of silicon wafers. Generally, mechanical parameters have a certain degree of dispersion. Therefore, about 10 pieces are required for each group of samples for research. The sampling inspection can be carried out according to the relevant sampling standards or agreed upon by the supply and demand parties. 6.2 The surface of the sample should meet the requirements of GB12964 or GB12965. 6.3 The sample is adhered to the glass plate with an adhesive made of paraffin wax and rosin = 2:1, and cut into 40mm diameter discs on a bench drill with a 40mm diameter cutting sleeve. The cutting position is stipulated as follows: silicon wafers with a diameter less than 80mm are in the concentric circle position; silicon wafers with a diameter of more than 80tmm are cut at a position 45° away from the main reference surface. 6.4 The sample is dewaxed with an appropriate solvent, cleaned with detergent, rinsed with deionized water, dried and placed in a lower desiccator for use. 695
7 Measurement procedure
7.1 Instrument calibration
GB/T15615—1995
7.1.1 Adjust the height of the rail so that the rolling steel ball hits the center of the sample. 7.1.2 Calibrate the screw micrometer to zero.
7.2 Measurement
7.2.1 Place the sample on the sample support plate.
7.2.2 Select an appropriate steel ball, fix the steel ball bracket at a certain height, pull out the baffle to make the steel ball roll down along the slide rail and hit the center of the sample. Gradually increase the height of the steel ball at a certain interval (usually 5mm) until the sample is broken. 7.3 Record the following data after the sample is broken
7.3.1H: The height of the steel ball rolling down (measured by the center of the ball) minus 1/2 of the interval value, and the reading is accurate to 1mm. 7.3.2B Use a screw micrometer to measure the thickness B of the sample at the broken part, accurate to 5×103mm, and take the average value of the two fragments. 7.3.3P: Mass of steel ball, accurate to 1mg. 7.3.4A: Radius of simple support, accurate to 0.05mm. 7.4 Factors affecting the test
7.4.1 The steel ball is too large and the initial drop height is too high, which will cause the sample to break at the first impact, making the result incorrect. The sample is not placed firmly in the support plate, which will cause the test result to be smaller. 7.4.2
7.4.3 The uneven thickness of the sample does not affect the measurement result; the bending of the sample will cause measurement error. The bending of 10μm will cause an error of 0%~~1%. 7.4.4
The sample surface is damaged during the sample preparation and operation process, and foreign matter (such as fine silicon particles) on the surface of the sample or steel ball will cause errors. 8 Calculation of measurement results
8.1 Calculate the test value 0c of each sample by formula (1). 8.2 According to the test value. And the thickness B of the sample, find the correction factor K in Table A2, and use formula (2) to calculate the bending strength α of the sample. 8.3 Find the average bending strength of a group of samples, which is the bending strength of this group of samples. 9 Precision
The measurement precision of this method in a single laboratory is ±25% (R3S), and this precision value is obtained by measuring 8 groups of different samples. 10 Test report
10.1 The test report should include the following: sample number, brand and production unit;
sample diameter, thickness and quantity;
average bending strength:
this standard number;
measurer;
measurement date.
GB/T 15615-1995
Appendix A
Method for obtaining the correction coefficient
(Supplement)
The calculation formula for the bending strength used in this method is derived under the assumption of small deflection. When the silicon wafer is thin and the strength value is large, the deflection deviates from the small deflection when the sample is broken. The correction coefficient is obtained through experiments. 15 sections of various single crystals are taken, and each section is cut into 5 silicon wafers of different thicknesses at intervals. They are divided into 5 groups according to thickness. Each group is surface processed strictly according to the specified grinding or grinding and polishing conditions. The bending strength value of each group is measured, and the average value is calculated as the measured value of the group. The average thickness of the group is B. Table A1 lists the . and B values ​​of each group of 12\ single crystals. Table A1
c, N·mm\
Plot . and B to obtain the -B curve, as shown in Figure A1. It can be seen from the figure that as B increases, 0. decreases and approaches constants α, α. is the true bending strength of this section of single crystal. Let the ratio of the curve with different thickness B is %: K, K is the correction coefficient of a when the thickness of this section of single crystal is B and the strength is. The -B curves of other sections of single crystals can also be made on Figure A1. Take the values ​​on each curve when B0.3 and the corresponding K values ​​to draw curves, and get the K-. curve when B=0.30mm (Figure A2). Similarly, the Ko. curves when B0.35, 0.40, *0.90mm can be obtained. The relationship between K and B and a. is read from each curve and listed in Table A2. 50 × 9.8067
10×9.8067
30 ×9.8067H
Figure A112 and other single crystal aB relationship diagrams
GB/T 15615-1995
Correction coefficient and B, o.Relationship
147.10196.13245.17294.20343.23392.27/441.30490.34539.37588.40637.44|686. 47735.50784.54833.57882.60931.64080.670.900.820.75
0.690.660.650.64
0. 900. 83
0.730.700. 67
0. 730. 700. 68
0.840.780.740.71
0.920.840.7910.740.71
0.920.840.790.750.72
10.93/0.85
0. 75 | | tt | 610. 610. 61 | | tt | 630. 630. 630. 630. 63
0. 63 1 0. 630. 630. 63
0. 630. 63
10. 640. 640. 63
10.650.64
0. 660. 650. 65
0.690.680.670.660.650.65
0. 690. 680. 670. 66
0.700. 690. 680. 67
0. 700. 690. 68
0.750.730.710.69
0.750.740. 72
0. 650.65
0.660.660.650.65
0. 680. 67
0.740.720.71
0. 810. 780. 76
0. 900. 860. 820. 79
0.980.910.860.820.790.77
0.750.730.720.70
0. 980. 91 0. 87 0. 830. 800. 77|0. 75|0. 74 | 67
0. 690. 680. 670. 67
0.730.720.700.690.680.68
0.63/0.63
GB/T15615-1995
Continued Table A2
147.10196. 13245. 17294.20343. 23392. 27/411.30490.34539. 37588. 40637. 44j686.17735. 50784. 54833. 57882. 60|931. 61980. 570.850.810.790.77
1. 000. 92
1. 000. 92
1. 000. 93
0. 860.830. 80
1. 00 0. 94 1
1. 000. 94
0. 950. 91
1. 00 /0. 95 / 0. 91
0. 86 0. 84
0.750.730.720.71
0. 760. 74 |0. 73 0. 71 | | tt | 800. 79
0. 860. 840. 82
0. 900.87
0.960.930.900.88
10. 930. 91
1. 000. 970. 94
1.000.970.9410.91
1. 000. 97 0. 94
1. 000.99
1. 00 1. 00
1. 001. 001. 00
0. 7110.69
0. 69 0. 68
0. 700. 690. 68
0. 700. 700. 69
0. 730. 72 10. 71
0.700.690.69
0.813 0. 80 | |tt | 75
10.870. 85
0. 92 /0. 910. 89
0. 990. 970. 960. 940. 93
Additional notes:
20 × 9. 8067
GB/T15615—1995
413 × 9. 8067
60 × 9. 8167
80 × 9. 8067
101×9.8067
Ue,N.mm-!
When B=0.3mm,Ka. Relationship diagram
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Central South University of Technology. The main drafters of this standard are Xie Shuyin and Shi Zhiyi. 700620. 620. 620. 62
0. 620. 620. 62
0. 630. 630. 630. 630. 63
0. 63 1 0. 630. 630. 63
0. 630. 63 | | tt | 66
0.700. 690. 680. 67
0. 700. 690. 68
0.750.730.710.69
0.750.740. 72
0. 650.65
0.660.660.650.65
0. 680. 67
0.740.720.71
0. 810. 780. 76www.bzxz.net
0. 900. 860. 820. 79
0.980.910.860.820.790.77
0.750.730.720.70
0. 980. 91 0. 87 0. 830. 800. 77|0. 75|0. 74 | 67
0. 690. 680. 670. 67 | | tt | | 0.730.720.700.690.680.68 | 23392. 27/411.30490.34539. 37588. 40637. 44j686.17735. 50784. 54833. 57882. 60|931. 61980. 570.850.810.790.77
1. 000. 92 | /0. 95 / 0. 91
0. 86 0. 84
0.750.730.720.71
0. 760. 74 |0. 73 0. 71
0.760.740.730.72
0.750.730.72
0. 75↓ 0. 74
0. 790. 770. 76
0. 790.780.760. 75
0. 800. 79
0. 860. 840. 82
0. 900.87
0.960.930.900.88
10. 930. 91
1. 000. 970. 94
1.000.970.9410.91
1. 000. 97 0. 94
1. 000.99
1. 00 1. 00 | | tt | | 1. 001. 001. 00 | 10. 71
0.700.690.69
0.813 0. 80
0.7910.77
0. 730.72
0.750.740.73
0. 750.740.73
0. 760.750.73
0. 790. 780. 760. 75
10.870. 85
0. 92 /0. 910. 89
0. 990. 970. 960. 940. 93
Additional notes:
20 × 9. 8067
GB/T15615—1995
413 × 9. 8067
60 × 9. 8167
80 × 9. 8067
101×9.8067
Ue,N.mm-!
When B=0.3mm,Ka. Relationship diagram
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Central South University of Technology. The main drafters of this standard were Xie Shuyin and Shi Zhiyi. 700620. 620. 620. 62
0. 620. 620. 62
0. 630. 630. 630. 630. 63
0. 63 1 0. 630. 630. 63
0. 630. 63 | | tt | 66
0.700. 690. 680. 67
0. 700. 690. 68
0.750.730.710.69
0.750.740. 72
0. 650.65
0.660.660.650.65
0. 680. 67
0.740.720.71
0. 810. 780. 76
0. 900. 860. 820. 79
0.980.910.860.820.790.77
0.750.730.720.70
0. 980. 91 0. 87 0. 830. 800. 77|0. 75|0. 74 | 67
0. 690. 680. 670. 67 | | tt | | 0.730.720.700.690.680.68 | 23392. 27/411.30490.34539. 37588. 40637. 44j686.17735. 50784. 54833. 57882. 60|931. 61980. 570.850.810.790.77
1. 000. 92 | /0. 95 / 0. 91
0. 86 0. 84
0.750.730.720.71
0. 760. 74 |0. 73 0. 71
0.760.740.730.72
0.750.730.72
0. 75↓ 0. 74
0. 790. 770. 76
0. 790.780.760. 75
0. 800. 79
0. 860. 840. 82
0. 900.87
0.960.930.900.88
10. 930. 91
1. 000. 970. 94
1.000.970.9410.91
1. 000. 97 0. 94
1. 000.99
1. 00 1. 00 | | tt | | 1. 001. 001. 00 | 10. 71
0.700.690.69
0.813 0. 80
0.7910.77
0. 730.72
0.750.740.73
0. 750.740.73
0. 760.750.73
0. 790. 780. 760. 75
10.870. 85
0. 92 /0. 910. 89
0. 990. 970. 960. 940. 93
Additional notes:
20 × 9. 8067
GB/T15615—1995
413 × 9. 8067
60 × 9. 8167
80 × 9. 8067
101×9.8067
Ue,N.mm-!
When B=0.3mm,Ka. Relationship diagram
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Central South University of Technology. The main drafters of this standard were Xie Shuyin and Shi Zhiyi. 70095 / 0. 91
0. 86 0. 84
0.750.730.720.71
0. 760. 74 |0. 73 0. 71 | | tt | 800. 79
0. 860. 840. 82
0. 900.87
0.960.930.900.88
10. 930. 91
1. 000. 970. 94
1.000.970.9410.91
1. 000. 97 0. 94 | | tt | 700. 700. 69 | |tt | 750.740.73
0. 760.750.73
0. 790. 780. 760. 75
10.870. 85
0. 92 /0. 910. 89
0. 990. 970. 960. 940. 93
Additional Notes:
20 × 9. 8067
GB/T15615—1995
413 × 9. 8067
60 × 9. 8167
80 × 9. 8067
101×9.8067
Ue,N.mm-!
When B=0.3mm,Ka. Relationship Diagram
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Central South University of Technology. The main drafters of this standard are Xie Shuyin and Shi Zhiyi. 70095 / 0. 91
0. 86 0. 84
0.750.730.720.71
0. 760. 74 |0. 73 0. 71 | | tt | 800. 79
0. 860. 840. 82
0. 900.87
0.960.930.900.88
10. 930. 91
1. 000. 970. 94
1.000.970.9410.91
1. 000. 97 0. 94 | | tt | 700. 700. 69 | | tt | 750.740.73
0. 760.750.73
0. 790. 780. 760. 75
10.870. 85
0. 92 /0. 910. 89
0. 990. 970. 960. 940. 93
Additional Notes:
20 × 9. 8067
GB/T15615—1995
413 × 9. 8067
60 × 9. 8167
80 × 9. 8067
101×9.8067
Ue,N.mm-!
When B=0.3mm,Ka. Relationship Diagram
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Central South University of Technology. The main drafters of this standard are Xie Shuyin and Shi Zhiyi. 700
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.