esd testing Archives | All-Spec's Official Blog

Latex Gloves – Are You Allergic?


Many industrial manufacturing environments require workers to wear protective gloves, including during electronics and medical device production and assembly. Latex gloves not only protect workers from harmful chemicals but also protect products from worker contact and contamination during manufacturing Read more

ST 925 SMT Rework System–Three favorites combined into one nice savings


Save a few steps--and some money--with the Pace 925 SMT Rework System Pace has introduced a new low-cost “combination” system ideal for surface mount technology (SMT) rework. It’s worth adding up the savings by comparing the a la carte prices Read more

Metcal’s CV-5200 Connection Validation Soldering Station Changes Everything


You may or may not have heard about Metcal’s new soldering station, the CV-5200. The evolutionary tool removes much of the reliance on visual inspection of hand-soldered joints and adds a second, more technology-driven method for validating a successful Read more

Putting Your Components to the ESD Test

Posted on by Andy in ESD News, ESD Testing, Static Control Tips and Tricks Leave a comment

Testing ESD Sensitivity 

Testing the sensitivity of components to ESD can be done in a couple of different ways. Either way, you’re determining what it takes to make a device fail when subjected to an electrostatic discharge (ESD). The two primary models for ESD testing include Human Body Model (HBM) and Charged Device Model (CDM) testing.

The models can simulate events; though they can’t completely mimic the entire range of potential ESD events. These two tests, HBM and CDM however have proven to be successful at reproducing more than 99% of ESD field failure signatures. Through these tests industries can –

  • Create and quantify suitable on-chip protection
  • Make comparisons between devices
  • Form a classification system for ESD sensitivity to help ESD design and monitoring requirements of manufacturing and assembly settings
  • Access documented test procedures to substantiate reliable and repeatable results

Human Body Model (HBM) Testing

Kid with hair standing up ESD

Human Body Model (HBM) testing

It doesn’t take much to cause a discharge. Walk across the floor in your socks and you’ you add an electrostatic charge to your body. After doing so, if you were to touch your finger to a lead on a ESDS device or assembly, the body could discharge and possibly cause damage to the device.

The oldest and most common form of testing to classify ESD sensitivity–using an ESD simulator with a special output circuit called the Human Body Model (HBM). The device is placed in a test system and contact is made through a relay matrix and the device is zapped with ESDs.

The device is considered to have failed if it doesn’t meet the datasheet parameters using parametric and functional testing. Failures usually include junction damage, metal penetration, melting of metal layers, contact spiking and damaged gate oxides.

Charged Device Model (CDM) Testing

charged device model testing

Charged Device Model (CDM) testing

A charge can also come from an ESDS device and cause an ESD event. For instance, if a device slides down a feeder in an automated assembler, the device can become charged. If it were to touch the insertion head or another conductive device, a quick discharge may take place. This represents a Charged Device Model (CDM) event and is potentially more destructive than an HBM event. Damage can take place in as little as a nanosecond.

This type of event generally happens in automated-manufacturing environments where machines may always stay turned on and cause electronic integrated circuits (ICs) to become charged. If the part touches a grounded conductor, the built-up storage of energy discharges. CDM discharge depends mostly on the parasitic parameters of the discharge as well as the size and type of component package.

To test, the device is placed on a field plate with the leads pointing up; then the device is charged and discharged.

 

All-Spec EOS/ESD Audit Kit

All-Spec EOS/ESD Audit Kit

All-Spec carries a large selection of quality ESD testing and measurement equipment such as EOS/ESD audit kits, electrostatic field meters and static locators; surface resistivity meters; and ESD event, EMI field and RF signal detectors.

All-Spec also carries a comprehensive range of ESD-safe, static control grounding supplies and partners with industry leaders like  SCS, Desco, Simco-Ion and more to offer the best static control products on the market.