What are the ESD models?
There are several ESD models including charged device model (CDM), machine model (MM), and human body model (HBM). Of these, the HBM is most commonly used to test and rate capacitors. The CDM is one of the most neglected models. This ESD event occurs when a device slides down a tube, bag, or similar source.
How do you conduct an ESD test?
The testing conducted consists of applying one positive and one negative pulse to the component, allowing a 0.3 second interval between pulses. A set of devices is exposed to these pulses at a given voltage level and pin grounding combinations; the device is tested for full static and dynamic parameters.
What is CDM ESD test?
The charged-device model (CDM) test is the most accurate component-level test as far as simulating real world events. CDM testing simulates ESD charging followed by a rapid discharge, similar to what is seen in the automated handling, manufacturing, and assembly of IC devices.
What is machine model ESD?
The Machine Model (MM) is the ESD model which is intended to simulate abrupt discharge events which are caused by contact with equipment and empty sockets (functional test, burn in, reliability testing, etc.). The model was developed in Japan and is widely used there.
What are the ESD failure methods?
ESD Failure Modes Basic failure mechanisms include oxide punchthrough, junction burnout, and metallization burnout. Some typical ESD damage phenomena are shown in Figure 1.
Why ESD test is required?
ESD testing simulates various electrostatic impacts that equipment might experience either during transit or operation. An electrostatic discharge test determines whether a product is in compliance with its ESD protective area and procedures. ESD can be transferred through the air or contact.
How is ESD voltage measured?
The amount of the electrostatic charge can be measured typically with an electrostatic voltmeter or a measurement construction of a Charge Plate Monitor. Resistance to ground measurement is one of the most important measurements in automated equipment.
What is ESD test?
ESD testing is an electromagnetic compatibility test (EMC test). ESD testing simulates various electrostatic impacts that equipment might experience either during transit or operation. An electrostatic discharge test determines whether a product is in compliance with its ESD protective area and procedures.
How do you check for ESD damage?
The trouble with ESD damage is that it can be very subtle. You can get anything between a slightly unusual behaviour (e.g. a small change in a MOSFET’s gate threshold voltage) and a complete failure of the entire device.
What is HBM CDM?
There are three main test models for ESD tests: the human body model (HBM), the charge device model (CDM), and the machine model (MM). HBM simulates ESD due to discharge from human beings. People are considered a principal source of ESD, and HBM is a commonly used model to describe an ESD event.
How are device-level ESD testing standards different?
These tests were designed to reproduce as many situations that cause ESD events as possible and are divided into different standards based on the ESD event that the test is simulating. These standards are further divided into sensitivity classification levels based on the amount of voltage that runs through the device being tested.
How does a CDM test for ESD work?
CDM testing simulates ESD charging followed by a rapid discharge, similar to what is seen in the automated handling, manufacturing, and assembly of IC devices. Unfortunately, this test also gives results that can differ from lab to lab and lot to lot.
Which is ESD test simulates real world events?
Of all of the component-level ESD tests available, the charged-device model (CDM) test is the closest to simulating real world events. CDM testing simulates ESD charging followed by a rapid discharge, similar to what is seen in the automated handling, manufacturing, and assembly of IC devices.
What is the IEC 61000-4-2 standard for ESD?
Since IEC 61000-4-2 is a test standard and not a product standard, you have to check ESD test levels from applicable product standard. For instance, for medical devices, IEC/EN 60601-1-2 standard defines test levels as -/+2kV, -/+4kV and -/+8kV for air discharges and -/+2kV, -/+4kV and -/+6kV for contact discharges.