Test Method for Anti-static System in Electronic Product Manufacturing
1. Scope
This standard specifies the test methods for anti-static systems in the manufacturing process of electronic products.
This standard applies to anti-static systems during the manufacturing process of electronic equipment, components and other products (including: floors, walls, workbenches, work chairs, workstation appliances, logistics transmission equipment, packaging bags, anti-static wrist straps, ion fans, personnel , Clothing, etc.).
2. Reference standards
The main texts contained in the following standards constitute the provisions of this standard through quotation in this standard. At the time of publication of the standard, the edition indicated was valid. All standards will be revised, and all parties using this standard should explore the possibility of using the latest version of the following standards.
GB2828-87 batch-by-batch inspection by attributes sampling procedure and sampling table (applicable to continuous batch inspection)
SJ/T10533-1994 Electronic equipment manufacturing anti-static technical requirements
SJ/T10630-1995 Technical requirements for anti-static in the manufacture of electronic components
Three, definition
This standard uses the following definitions
3.1 resistance of grouvding system
In an anti-static grounding system, the sum of grounding resistance. The current limiting resistance to ground is specified as 1MΩ
3.2 test point
During the test, the selected place to place the test electrode (or test lead)
Four, general requirements
4.1 Test basis
Press SJ/T 10533 and SJ/T 10630
4.2 Test conditions
All tests are carried out in the production site, the ambient temperature is 20-25℃, and the relative humidity is 40%-60%.
4.3 Test equipment
Testing instruments include: non-contact electrostatic voltmeter, ground resistance measuring instrument, 500VDC megohmmeter, multimeter, wrist strap tester, human body resistance tester, ion fan testing device, etc.
The accuracy of the instruments used is not less than 2.5, and they should all be within the validity period of the metrological verification. Allow the use of similar instruments that meet the test requirements
4.4 Test technical indicators
Test technical index
Item Surface resistance value Ω Product resistance value Ω Resistance value Ω Friction voltage V
Anti-static grounding resistance ＜10
Ground 105~1010 ＜100
Ground to ground bus resistance 5×104~109
Wall ＜400
Curtain ＜400
Floor mat 105~109 105~108 ＜100
Workbench pad 105~109 105~108 ＜100
Work surface 106~109 ＜100
Workbench facing wrist strap jack resistance 105~108
The resistance of the worktable to the ground system 106~108
The resistance of the work chair facing the casters 106~108
Chair surface and backrest resistance 108~1010 ＜100
Work clothes, work caps, gloves ＜100
Working shoe sole 0.5×105~108 ＜100
Station equipment and logistics delivery equipment 103~108 103~107 ＜100
Packing box (bag) ＜100
Logistics vehicle platform facing wheel system resistance 106~109
Wrist strap connection cable resistance ＜20K
System resistance when wearing a wrist strap 10M-10M
Wrist strap connection cable resistance 1M
Heel strap (shoe harness) system resistance 0.5×105~108
Human body comprehensive resistance 106~108
5. Frictional electrification voltage test
5.1 Use non-contact electrostatic voltmeter to measure
5.2 During the test, hold a dry cloth (pure cotton or anti-static fabric), use a frequency of about 120 times/min, apply pressure to the palm of the hand appropriately, and rub a certain part of the test piece 20 times in one direction. Yearly friction part, observe the value displayed on the meter.
Repeat the test 5 times and take the average value.
5.3 Test the overall effect of frictional electrification voltage on the anti-static facilities of the production site, including: ground (floor mats), walls, curtains, workbenches (bench mats), work chairs, shelves, workstation appliances, logistics delivery appliances, packaging bags (Box), work clothes (work caps, gloves), work shoes, etc.
Six, resistance test
6.1 Anti-static floor
6.1.1 Use a grounding resistance measuring instrument to test the grounding resistance of the anti-static ground electrode.
6.1.2 Test procedure: A. Connect the ground electrode to be measured to the terminal of the instrument. B. Insert a potential probe and a current probe in the same straight line direction at 20M and 40M wet ground, and connect each to the terminal of the instrument. C. Set the multiplier of the "magnification plate", D. Shake the handle of the instrument from slow to fast, to reach about 120r/min, adjust the "measurement dial", the pointer points to the zero position, and the reading is multiplied by the magnification scale, which is the grounding resistance Value; E. According to test steps C and D, repeat the test 3 to 5 times, and take the average value.
6.2 Ground
6.2.1 Divide the test grid
6.2.2 Randomly select test points
6.2.3 According to the sampling procedure specified in 4.8 of GB2828-87, regard all the grids on the ground to be tested as the sample size (batch range), and determine the sample size code at the general inspection level II; then use the "normal inspection once sampling plan" ".
6.2.4 Take the qualified quality level as 6.5, decide to sample the size of the code, look up the table to get Ac and RC. Test the ground surface resistance.
6.2.5 Take the qualified quality level as 6.5, decide to sample the size of the code, look up the table to get Ac and RC. The resistance of the test site to the ground bus bar.
6.3 Floor mat (workbench mat)
6.3.1 Test surface resistance
6.3.2 Test volume resistance
6.4 Workbench
Randomly select test points, each workbench shall not be less than 3 points
6.4.1 Test the surface resistance of the working table
6.4.2 Test the resistance of the workbench facing the wrist strap jack
6.4.3 Test the resistance of the ground system on the workbench
6.5 Work chair
Randomly select test points, and each work chair shall not be less than 5 points.
6.5.1 Test the resistance of the chair facing the casters
6.5.2 Test the resistance between the chair surface and the backrest
6.6 Work shoes
Measure the volume resistance of shoe soles
6.7 Work station equipment and logistics delivery equipment
Test container surface resistance and volume resistance
6.8 Logistics vehicles
The resistance of the test car platform facing the wheel system
6.9 Wristband
6.9.1 Test the resistance of the inner surface of the wrist strap to the cable buckle
6.9.2 Test the resistance of the connecting cable system
6.9.3 Use a wristband tester to test the system resistance when wearing a wristband
6.10 Heel strap (shoe harness)
Test the resistance of the heel strap system
6.11 Comprehensive resistance of the human body
The tested person should wear work clothes, work shoes, and test the comprehensive resistance of the human body.
Seven, other tests
Use a special instrument to test the neutralizing electrostatic performance of the ion fan.