ESD Safe Jigs and Fixtures
3D printed jigs and fixtures are becoming common in the manufacturing and assembly space. With this comes challenges in preventing static build up from damaging sensitive electronics, especially when assembling notoriously sensitive devices like lasers.
Thankfully there are an increasing number of ESD safe materials that are available. The first step to choosing the right material is understanding what Anti-Static, Static Dissipative and Conductive means.
Materials
There are three MAIN categories when it comes to eSD materials - anti-static, static dissipative, and conductive. These are all classified by their surface resistivity. Generally speaking, plastics are insulative and metals are conductive.
Anti-static materials are conductive enough to prevent static charge build-up, but not enough to discharge quickly and prevent external sources of static from damaging components.
The best regime to operate in when designing jigs and fixtures for sensitive components is the static dissipative or conductive regime.
For simple ESD safe fixtures, we use 3DXTech’s ESD ABS. This is a high quality ESD ABS made in the US with carbon nanotube technology. This material falls into the Static Dissipative regime, but interestingly can enter the Conductive regime with increasing extrusion temperature.
3DXTech ESD ABS
Taken from 3DXTech’s website, this graph shows how increasing EXTRUSION temperature can decrease surface resistance of a part. At Ember, we print all our materials very hot to promote the best layer adhesion for functional prototypes, which means that we can also achieve Plastic ESD Safe jigs and fixtures that start entering the conductive regime.
The fixture above is designed to hold a set of PCBAs which require some additional manual work after SMT assembly at a contract manufacturer. You can see how conductive the material is with a crude resistance measurement (there are better ways to measure surface resistance - for further reading on measuring surface resistance, read this document).
Since originally writing this post - Formlabs has come out with an ESD safe SLA resin. This resin is also categorized as static dissipative and allows high resolution jigs & fixtures that are fully isotropic.
To learn more about this resin and to see some case studies that Ember Prototypes was involved in - check out this webinar and blog post on the Formlabs website. In the meantime, below are some examples of ESD parts we’ve printed with this resin!
