Everyone has their own needs and every lab is different. Home chemists must have a frigde and a ton of glassware. No metalworking shop is complete without a hammer. And no one can think about an electronics lab without a soldering iron. However, the available tools vary based on the user’s experience and interests. Not everyone needs BGA reballing tools (yet), but we will cover the essential tools for your shop. Like proper ESD protection.
If you are working with electronic devices, chances are high that the components are sensitive to electrostatic discharge (ESD). Microcontrollers, sensors, and everything on a PCB usually operates with extra low voltage (ELV). Officially less than 120V DC, usually way below 12V DC. The new, fancy silicon carbide (SiC) semiconductors promise to switch over 1 kV, but your usual components rarely survive double-digit voltage! Just as our example, the mighty ATmega328p microcontroller, the heart of millions of Arduinos. Apply 12 V to sign a death wish.
Of course, you may go over the limits for a brief time. Transients are still harmful, but at least won’t take long! Just a little spark, lasting for a fraction of a second, how bad it can be? Well, it can still kill a sensitive component, because sparks are usually in the kV range – and that’s waaay over 6-8 V! A human body (just like anything) acts as a capacitor, and we can collect some extra charge. Next time you zap something with your hand, take note of the size of your spark. Each mm means about 2 kV of voltage. (that’s the insulation of the air) Every time you touch something with your bare hands, you risk killing it.
It’s always cheaper to prevent the problem. “Just don’t wear synthetic clothes bro!” It is actually useful to wear “compatible” stuff for work, but that’s not enough. Sure, everyone has their own story, me too. I have zapped PCBs literally hundreds of times before, even super expensive ones, and they turned out just fine! (I am not bragging, once I worked with terrible conditions) But once you kill something vital, you will regret every zap. So collect the tools to prevent expensive disasters.
After posting the initial version of this, I found @zh1nu’s post about his shocking experience, similar to a regular ESD, just on steroids. You can find some nice videos too in the Twitter thread but beware: some of them are pretty painful to watch! Oh, there is a lesson too! Capacitors can store charge for surprisingly long, and high voltage means potentially lethal high voltage. ALWAYS discharge capacitors and similar components!
ESD sparks happen because you and something else are on a different potential, resulting in a voltage. Touch it, and current can flow. I heard that in some schools the kids must touch an exposed metal pipe before working with micro:bits. (every piece of metal must be grounded in theory, heating, water and other pipes, faucets, and even computers) No voltage means no spark. But kids rarely sit still, so they can still generate some charge after letting go the extra electrons.
And not just kids! Every little movement can help to charge You too. The solution: connect yourself to the ground! These are dirt cheap. Really, just a few bucks. It’s a crime against electronic devices not to use one. Meanwhile a good question can arise: where should I connect it? Other grounded things are usually a good idea. Even if you are just repairing a computer, connect it to the case. (I always forget to use one, sadly)
ESD is still a potential danger if only You are grounded! We want ourselves and the devices on the same potential. ESD mats like this have a pretty high, but not infinite resistance. You can place a working PCB on it and won’t cause a short circuit, while you can be connected with your wristband to this mat. Any charge building up gets constantly equalized. It prevents practically all ESD related accidents! Of course, walking away while being attached is another story.
Meanwhile you can have the fancy blue silicone mat too, like me. Just ensure the proper proper grounding, because they usually don’t have a contact point like the previous mat. I prefer these, because they can be easily cleaned. Also silicone mats handle the hot soldering iron and hot air way better. The small holes for screws look useful first, but they are not. It’s a nightmare to get thermal paste and other dirt from the little holes, get one as flat and clear as possible.
Is this enough?
Using an ESD mat and a wristband is usually a good start and enough for most home labs. I really recommend to invest in safety, even before buying your first soldering iron! It’s really inexpensive to get the basic tools and you can use them forever! Of course don’t get overboard, don’t spend a fortune on making a cleanroom.