ESD brush detection method
Plastic anti-static brush sold on the market can be divided into three types: large, medium, and small. They are suitable for cleaning various electronic components, PCB boards, etc., and can also scrub PCB boards.
Paint brush type brush is divided into: round handle, straight shank two, each of which has the size of the points, suitable for cleaning a variety of electronic components, PCB board and so on.
U-shaped brush is also divided into: large, medium and small three, suitable for cleaning a variety of electronic components, PCB board, etc., can also scrub the PCB board.
Shaped brushes are specially designed for certain processes, such as long aluminum alloy anti-static brushes made for plastic printing.
Anti-static brush bristles soft and hard selection, should be based on the PCB components to be cleaned to determine the requirements, for fear of being scratched on the use of soft hair brush selection, but the cleaning effect of hard brush dominant.
1) Bristle surface resistance and brush handle surface resistance:
6 Resistance test
6.1 Point to Point Resistance and System Resistance Test
Electrode structure used: column electrode diameter 63 mm ± 3 mm: electrode material is stainless steel or copper; electrode contact material conductive rubber, hardness 60 ± 10 (Shore A grade), thickness 6mm ± 1mm, the volume resistance is less than 500Ω: The electrode weight is 2.25 kg?2.5 kg.
When testing point-to-point resistance, the product (material) should be placed on an insulating surface or placed in an actual state of use. Mesa surface resistance and volume resistance are greater than 1x10^13Ω, respectively, and their geometrical perimeter dimensions are larger than the measured material 10 cm. The distance between the electrodes is 300 mm. In the ground test, the distance between electrodes is 900 mm to 1000 mm.
When testing the system resistance, the test sample (ground) should be tested for actual use. During the engineering test, the electrode is more than 10 cm away from the edge of the material under test.
2) Frictional electrification voltage test:
The friction motor was used for friction and the non-contact type electrostatic voltage meter was used to test the frictional electrification voltage. The friction electrode of the friction motor is in a shape of a circle, with a diameter of 50 mm to 60 mm, a weight of 1 kg, a volume resistance greater than 1x1O^13 ohms, and a high-insulation nylon cloth (surface resistance no less than 1x1O^13 ohm. Wrapped to increase friction The coefficient (see Fig. 1): During the test, the friction motor was started to rub the friction electrode against the measured object, and the unidirectional friction was stopped 20 times (time 20s), and the friction trajectory voltage was measured with a non-contact type electrostatic voltmeter within 10 s.