Welcome to Qinsun Instruments Co., Limited.
- +86-21-6780 0179 |
- info@qinsun-lab.com |
- Customer Services
ESD electrostatic discharge gun is an important equipment in the electrostatic discharge immunity test in the electromagnetic compatibility measurement and test. You've come across electrostatic energy in your everyday life, but probably didn't know it. For example, you experience an ESD event when you are electrocuted by a doorknob after walking across a carpet during a dry period. Clothes stick together when you take them out of the dryer, often called static cling, which is caused by a static charge. The most dramatic form is lightning in thunderstorms, which are huge static discharges.
The working principle of ESD electrostatic discharge gun:
The principle of ESD discharge: In a certain electric field, there is an unbalanced or uneven charge distribution, or a voltage difference, and one of the two must exist before charge transfer or discharge occurs. ESD phenomenon simulation: the approach of pointed objects and round objects destroys the balance of the electrostatic system of the entire environment, resulting in energy or charge transfer or conversion.
ESD electrostatic discharge test:
1. Contact discharge
In the contact discharge method, stress can be applied directly to the EUT or to the coupling plane adjacent to the EUT. Before each test pulse, the capacitor is charged to the required level, but its voltage is maintained at the probe of the generator via a vacuum relay. Apply the probes to appropriately selected points on the EUT or coupling plane. The generator is then triggered, closing the relay contacts, and the capacitor voltage is applied to the EUT through the probe. This produces a current pulse as the voltage discharges through the combined series impedance of the generator, EUT and ground plane. Repeat the movement as many times as needed in each position with the appropriate polarity and level.
2. Air discharge
The same generator is used for the air discharge method, but with rounded rather than pointed probe tips. The capacitor is charged to the required level as before, but the voltage is now continuously applied to the probe, which is kept away from the EUT. For each test pulse, the tip is subtly lifted to a selected point on the EUT until it makes contact. Just before that, the air gap between the tip and the EUT will be broken down and the discharge current will flow, limited as before by the combined series impedance of the generator, air gap, EUT and return path. Again, repeat the movement as many times as needed in each position with proper polarity and level.
Layout of ESD electrostatic discharge test:
ESD pulses have sub-nanosecond rise times, so RF layout precautions are critical.
1. The test must recreate the fast rise time actually found, since this is the path that determines the discharge through the EUTand the important parameters of the EUT's own response. The Ground Reference Plane (GRP) is an integral part of the setup to which the return lead of the generator must be well connected, as this connection forms part of the current return path.
2. The indirect discharge part of the test uses two other planes different from the GRP, called the horizontal coupling plane (HCP) and the vertical coupling plane (VCP). The electrical discharges from these planes simulate the stresses that would arise from real-life radiation fields emanating onto nearby objects.
3. Each coupling plane is connected to the GRP through resistive leads to ensure that any charge flows out within a few microseconds. The construction of these leads is critical: each end should be close to a resistor so that the length of lead between them is isolated from the connection and stray coupling to it is neutralized.
4. While the power rating is not important, the resistor itself should be able to withstand high pulse dV/dt without damage, so the carbon composition type is suitable.
5. For an ESD event of tens of nanoseconds, the plane carries the full stress voltage, which is capacitively coupled to the EUT. Any stray capacitance from the plane to objects other than the EUT will modify the voltage and current waveforms at the plane and thus the applied stress.
6. Therefore, it is important to maintain a clear space of at least 1 meter around the EUT, which means some separation of the table setup from walls or other objects.
7. Likewise, the separation from the VCP to the EUT is specified as 10cm; even small changes in this distance can cause large changes in the coupling to the EUT, so a convenient method of controlling it, such as a plastic 10cm spacer on a flat surface, is helpful.
What harm can ESD cause?
There are not many around you. If you get an electric shock while touching your home computer, stereo, or other electronic equipment, it is possible, but unlikely, to cause some damage. Most likely, your computer will reset, or your stereo will erase all stations you have recorded. Most companies design protection against ESD into their products.
Of course, if you've taken your computer or stereo apart and had an ESD event while touching the internal components, there's a good chance you've damaged or destroyed electronic circuitry. The protections designed into these products are no longer effective when you touch the internal parts and components, as individual components often have little or no built-in ESD protection. With this in mind, consider the factory where your computer or stereo is manufactured, where the people and machines that work there are in constant contact with the inner workings and components of those products. The cost of ESD in such plants can be prohibitively high. Electrostatic discharge in manufacturing facilities can cause various defects and problems in products assembled there, and it can also damage sensitive equipment and machinery used in the manufacturing process. ESD is a huge problem in factories that produce everything from computers and stereos to electronic components.
ESD simulator (electrostatic discharge generator or electrostatic gun) complies with IEC 61000-4-2, EN61000-4-2, ISO10605, IOS17626.2, IOS17215.301 and IOS17215.322 and other standards Require.
ESD generators are designed to evaluate the immunity performance of electrical and electronic equipment when subjected to electrostatic discharge. ESD61000-2/ESD61000-2A adopts LCD display that can be switched between Chinese and English (note: additional costs are required for metal brackets).
ESD61000-2_ Electrostatic Discharge Generator
