ESD Electrostatic Discharge Testing Laboratory

Electrostatic Discharge (ESD) is a common electromagnetic phenomenon, particularly in electronic components, integrated circuits, and other electrical devices. ESD events can cause device damage or failure. Therefore, understanding and applying ESD Testing methods and standards is crucial to ensure the reliability and safety of electronic products.

China's JJR Laboratory is a professional third-party ESD testing organization. The laboratory is qualified for and capable of conducting ESD testing on electronic and electrical products such as integrated circuits, passive components, semiconductor discrete devices, optoelectronic semiconductors, multi-chip modules, filters, household appliances, IT/AV products, etc. It holds CNAS certification and can issue internationally recognized third-party ESD test reports in both Chinese and English.

Purpose of ESD Testing

The primary purpose of ESD testing is to simulate electrostatic discharge events in real life to assess the tolerance of electronic components and systems to ESD incidents. These tests help determine the product’s ESD resistance and allow for necessary improvements during the design and manufacturing process to enhance the product's reliability.

Types of ESD Testing

ESD testing includes two parts: direct discharge and indirect discharge.

- Direct Discharge: This includes contact discharge and air discharge.

  1. Contact Discharge: This mainly targets the exposed metal parts on the device surface.

  2. Air Discharge: This mainly targets areas covered with insulating materials, such as those sprayed with insulating paint.

  Direct discharge simulates the phenomenon where a charged body, such as a human or other charged sources, directly discharges onto the device.

- Indirect Discharge: This only includes contact discharge.

This involves discharging on horizontal and vertical coupling boards. The coupling board is placed at a specific distance from the device, and the board is grounded through two 470k ohm resistors. Therefore, when discharging onto the coupling board, the static charge on the board does not immediately discharge to the ground but forms an electrostatic field to interfere with the device, simulating the device’s ability to withstand electrostatic field interference.

Test Levels

- Level 1: Contact Discharge 2kV, Air Discharge 2kV

- Level 2: Contact Discharge 4kV, Air Discharge 4kV

- Level 3: Contact Discharge 6kV, Air Discharge 8kV

- Level 4: Contact Discharge 8kV, Air Discharge 15kV

Common ESD Testing Methods

01 Human Body Model (HBM)

The HBM test method simulates the electrostatic discharge that may occur when a human contacts electronic devices. The test process is as follows:

- Use a standardized circuit, typically a 100 pF capacitor and a 1500-ohm resistor.

- Connect the device under test to the circuit, then charge the capacitor to the specified voltage.

- Discharge through the resistor onto the device under test and measure its response.

HBM test voltages usually range from 2 kV to 15 kV, depending on the product application and standard requirements.

02 Machine Model (MM)

The MM test method simulates electrostatic discharge that may occur when a machine or tool contacts electronic devices. Similar to HBM, but the MM test uses a 200 pF capacitor and has no series resistor. This method produces higher current transients, typically used to evaluate the ESD resistance of devices in industrial environments.

03 Charged Device Model (CDM)

The CDM test method simulates the discharge when a device itself is charged and then comes into contact with a grounded object. The test steps are as follows:

- First, charge the device under test to the required voltage.

- Then, allow the device to contact the grounded object and measure the discharge current.

CDM testing is closer to actual application scenarios, especially for high-density integrated circuits.

ESD Testing Process

1. Test Setup

The ESD generator, discharge loop cables, 470k ohm discharge resistors, grounded reference planes, and all connections forming the discharge path.

For compliance testing, the device under test should be subjected to continuous or cyclic tests in the most sensitive mode as determined by preliminary tests.

2. Test Plan

① Define the typical operational state of the device under test;

② Specify whether the device is a desktop or floor-standing unit for testing;

③ Identify the areas where static discharge will be applied;

④ For each application area, determine whether to use contact discharge or air discharge;

⑤ Choose the appropriate test level (1 to 4, and open levels can also be selected);

⑥ For compliance testing, define the number of discharges for each application area.

Note: For samples with pure plastic housings and no metallic parts, only air discharge is applied.

For devices with metallic housings, such as coaxial connectors and multi-core connectors, only the connector housing should be subjected to contact discharge.

3. Test Result Evaluation (Test Conclusion)

- Grade A: Performance is normal within the limits specified by the manufacturer, client, or purchaser.

- Grade B: Functionality or performance is temporarily lost or reduced but can recover automatically once the disturbance stops, without operator intervention.

- Grade C: Functionality or performance is temporarily lost or reduced and requires operator intervention for recovery.

- Grade D: Irrecoverable loss of function or performance due to hardware or software damage.

4. Test Report Content

The test report includes the device name, model, quantity, serial number, trademark, company name, address, test standards, test items, testing conditions, general product description, product usage, auxiliary equipment information, failure criteria, test level, test setup, and layout images of the device under test, test conclusion, and laboratory test equipment information.

5. Precautions Before ESD Testing

① Ensure the product has proper grounding. For static charges that cannot be dissipated, isolation should be done to prevent interference with critical circuits.

② Ensure the protection of the casing, panels, displays, and cables.

③ Keep PCB trace lengths as short as possible, as they function like coupled antennas.

Major ESD Testing Standards

1. IEC 61000-4-2

IEC 61000-4-2 is a standard issued by the International Electrotechnical Commission (IEC) and is widely applied in ESD testing for various electronic products. This standard defines test voltage levels, discharge current waveforms, and testing methods. Typical test voltage levels include 2 kV, 4 kV, 6 kV, and 8 kV.

2. ANSI/ESDA/JEDEC JS-001

The JS-001 standard is jointly issued by the Electrostatic Discharge Association (ESDA) and Semiconductor Equipment and Materials International (SEMI). It focuses on HBM testing and specifies the equipment, methods, and pass/fail criteria for HBM tests, typically used for ESD evaluation of semiconductor devices.

3. JESD22-C101

The JESD22-C101 standard is issued by JEDEC and is primarily used for CDM testing. It defines the test equipment, methods, and pass/fail criteria, suitable for ESD evaluation of integrated circuits and semiconductor devices.

4. AEC-Q100

The AEC-Q100 standard is issued by the Automotive Electronics Council (AEC) and is used for ESD testing of automotive electronic components. This standard includes HBM, MM, and CDM tests to ensure the reliability and safety of automotive electronics in harsh environments.

ESD Testing Equipment

ESD testing requires specialized equipment, including ESD generators, electrostatic discharge guns, test fixtures, and data recording devices. These devices must strictly comply with the test standards to ensure the accuracy and reliability of the test results.

ESD testing is a key step in ensuring the reliability and safety of electronic products. By understanding and applying the relevant testing methods and standards, products' ESD resistance can be effectively evaluated and improved, preventing equipment failures and damage due to electrostatic discharge. Companies should select appropriate ESD testing methods and standards based on their product characteristics and application environments to ensure high quality and reliability.

China's JJR Laboratory is a professional third-party ESD testing institution. The laboratory is qualified for ESD testing on various electronic products such as integrated circuits, passive components, semiconductor discrete devices, optoelectronic semiconductors, multi-chip modules, filters, household appliances, IT/AV products, etc. It holds CNAS certification and can issue internationally recognized third-party ESD test reports in both Chinese and English.

1. Trusted Brand: Established in 1998, a high-tech enterprise accredited by CNAS and CMA, a specialized small and medium-sized enterprise in Guangdong, and a national public technology service platform for SMEs.

2. Multiple Certifications: Recognized by various domestic and international organizations, with CNCA certification capability. Comprehensive qualifications, with test reports recognized internationally.

3. International Standards: The laboratory operates according to the international standard ISO/IEC 17025 and complies with over 10 international and domestic standards.

4. Service Guarantee: Efficient one-stop testing and certification services, complete experimental plans, trusted by many well-known domestic and international enterprises.