TO DESIGN PCBS FOR HARSH ENVIRONMENTS

In today's technology-focused world,printed circuit boards have many different applications. Depending on your industry,you may need printed circuit boards that can operate in harsh environments. However,even if you have not needed printed circuit boards for harsh environments in the past,it may benefit you to know how they are created and how your industry could potentially benefit from them.

WHAT ARE HARSH ENVIRONMENTS?
The first question you may be asking is what exactly are harsh environments? Harsh environments are environments where your printed circuit board may be surrounded by hazardous conditions that could damage sensitive electronic parts.
This includes areas where there can be an extreme buildup of moisture,where temperature extremes may exist,where aggressive chemicals may be present or where toxic vapors might be found in the atmosphere. Elements like fungus,salt spray or even intense mechanical vibration are also among the environments that could be considered harsh.
These harsh environments can often be found in the aerospace industry,the automotive industry and defense applications,among others.
When we talk about designing PCBs for harsh environments,we typically would like to know what type of harsh environmental conditions we can expect this product to be used in. The steps we will take to protect the PCB against high temperatures may be different from the ones to protect against very low temperatures,while conditions of high moisture or where significant impacts are likely can call for a completely different set of considerations.

WHAT ARE RUGGED ELECTRONICS?
Rugged is the designation for the type of laptop,tablet,smartphone or other device that is conditioned for harsh environments. Your PCB that is designed for harsh environments is one that you can expect will end up in a rugged electronic device.
Rugged electronic devices are graded on levels:

• Nearly indestructible electronics,defined as fully-rugged,slightly less but still incredibly durable electronics as semi-rugged.

• Durable electronics,which can probably stand up to anything you would be likely to throw at it in a commercial environment.

• Commercial grade,which are likely to stand up to any hazards that might befall a home-use electronic device as well as most commercial electronic devices.

HOW DOES DESIGNING ELECTRONICS FOR HARSH ENVIRONMENTS WORK?
If you expect your electronics to meet tough environmental conditions,the material you make the PCB and the rest of the device out of will be crucial. For example,some rugged computers come in a magnesium alloy case that allows you to drop them from heights as great as six feet without concerns about damaging the delicate electronic components inside.
Another ruggedizing step may be to solder the CPU onto the PCB and enclose and shock mount the hard drive to make sure nothing moves if the device is dropped or subjected to some other kind of impact or vibration.

PCBS FOR HARSH ENVIRONMENTS:DESIGN CONSIDERATIONS
When designing a PCB for harsh environments,you will have to consider what materials you will need to use to design the board. Your determination may be based on factors such as time,cost and how crucial your environmental protections will be.
Another important design element when it comes to PCB for harsh environments will often be your methods of heat transfer. Cooling slots,fans and heat sinks are all important design elements for PCBs that may find themselves in applications where they will regularly be subjected to very high temperatures. Keeping a PCB from overheating even in normal conditions is challenging,so proper cooling is vital for high-temperature conditions.