Is ESD Control a Waste of Time (and Money)?
Today’s post is going to be a bit shorter than usual. BUT: that doesn’t mean it’s going to be any less interesting. Quite the opposite! So, let’s jump right in.
A little while ago we were approached by a customer with the following statement:
“Generally speaking, most IC’s these days already have adequate protection on their pins, the notable exception being discrete J-FETs, and MOSFETs, especially for RF applications.
It’s difficult to advise when these might be in use on an assembly without giving everyone in-depth training on circuit design, so to avoid trouble in the 1% of cases that matter, it’s a good idea to play safe and keep applying our procedures for the other 99% of parts too.
I am of the opinion that a PCCU in its housing does not need special treatment though. It has ESD protection, and has passed testing for this, so I am not worried about someone touching its pins without wearing a grounded wristband, etc …"
So, is this statement true? Is ESD Control obsolete? Let’s find out!
Types of ESD Damage
Remember that there are two types of ESD damage:
1) catastrophic failure and
2) latent defects.
While catastrophic failures cause an ESD sensitive item to be damaged permanently, latent defects only partially degrade an ESD sensitive item that is exposed to an ESD event. It may continue to perform its intended function and may not be detected by normal inspection. However, intermittent or permanent failures may occur later.
Bottom line: Even if an ESD sensitive component has quite a high withstand voltage and no catastrophic failure has been caused, latent defects may still make your life miserable.
Continued Requirement for ESD Control
Here is a link to the ESD Association’s ESD Technology Roadmap. The document illustrates what future thresholds are expected for ESD sensitive devices and how they impact on ESD Control. The thresholds are determined by current trends in the semiconductor industry and are displayed as “roadmaps”. The aim is to predict future limitations of device protection which are driven by performance requirements and technology scaling.
You should head-over now and read through the document. But in case you haven’t got time, here are the main take-away notes:
- “Finally, these trends point to the need for continued improvements in ESD control procedures and compliance.” [section 1.0 Synopsis]
- “Therefore, the prevailing trend will be circuit performance at the expense of ESD protection levels.” [section 2.1 Overview]
- “Therefore, implementation of advanced HBM controls using the limits and qualifications requirements in ANSI/ESD S20.20, IEC 61340-5-1, or JESD625, would become necessary within the next 3 years.” [section 2.2 Device ESD Threshold Roadmaps]
Bottom line: As electronic technology advances, electronic circuitry gets progressively smaller. As the size of components is reduced, so is the microscopic spacing of insulators and circuits within them, increasing their sensitivity to ESD. Therefore, the need for proper ESD protection increases every day.
ESD control procedures and compliance continue to be required
For more information on the ESD damage and the costly effects of ESD, check-out this post.
Protect your sensitive devices from ESD Damage
Every company should document the most ESD sensitive device that they are handling.
A prerequisite of ESD control is the accurate and consistent identification of ESD susceptible items. Some companies assume that all electronic components are ESD susceptible. However, others write their ESD control plan based on the device and item susceptibility or withstand voltage of the most sensitive components used in the facility. A general rule is to treat any device or component that is received in ESD packaging as an ESD susceptible item.
This post provides further information on how to set-up an ESD Control Plan.
So, tell us: are there instances in your company where you forego standard ESD Control practices? If so, let us know in the comments – we’d like to hear from you.