Best Practice for PCB Moisture Protection in Outdoor Environments

In this era of technological innovation at its best, all the manufacturing unit, OEM, SME, large size company and giant business are completely penetrated by electronic equipments and instrumentation that even an hour of downtime or electronic malfunction can cost to a tidy sum. Also, one of the root component in any of the device or machinery is the printed circuit board, be it a simple or a complex pcb layout or PCB assembly. When a PCB is placed in the external environment, the chances of a malfunction increases due to pollution, moisture or any type of thermal conditions. This can end up to a financial repercussions due to need of a PCB repair, PCB rework, depreciation of machine/equipment, low estimated life of the asset that indirectly affect the work productivity, quick turnaround, delay in delivery of orders, high defect in batch of production and many more production issues. There are simple remedies that one can practice by themselves to toughen the PCB as an advanced level of defense to malfunction when placed in the external environment. Read on further content to know which solution proves to be the best for your PCB assignment.

One of the general sources of circuit board malfunction in the external environment is majorly due to moisture/humidity on the boards. Printed Circuit Boards when deployed, now has different types of solution to protect the boards from moisture. Be it PCB assembly for an outdoor sensor system, high energy motor controller, high power battery chargers, industrial load testers, ultrasonic technologies, water treatment plants, robotic cable assemblies, aerospace, electronic equipment, marine technologies, extreme outdoor PCB application in telecom projects or Military & Defense instrumentation, the condensation and other uncertainties due to hazardous climatic reactions breaks down the circuitry when PCB is exposed to humidity.

These types of issues are faced by metalworking foundry, motor industry, Glassworks, microprocessor industry, agricultural sector, airline operations, electronic banking operations and telecommunication industry in addition to chemical, industrial, medical, robotic, renewable, marine water treatment and power plants at large.

The simplest measures for PCB Moisture Protection:

• PCB should be equipped with tight enclosures and a strong sealing system. In some cases, there needs a tough and customized enclosure for taking a step ahead in protecting the PCB from humidity. These include the situation where enclosures need to be opened on a regular basis; holes are drilled in the enclosure due to wiring the circuit or in case of other environmental conditions.
• Placing the PCB in a case or a box. Case should have round shaped sides to allow quick flowing away of condensation from the PCB. In addition, corral it with a desiccant that can easily absorb moisture in the box.
• Apply a suitable conformal coating on the printed circuit boards. At the time of choosing a coating material, the properties that should be brought to concern includes moisture resistance, chemical resistance or temperature range coating that is highly protective against humidity, air gaps on the circuit board, rain, corrosive chemicals, salt water, pesticides, rapid thermal changes or any other uncertain external climate.
• It is recommended to consult an expert PCB manufacturer for the required flow and viscosity of conformal coatings for your PCB that proves to give high flexibility when the circuit board has many solder joints, sharp edges and irregular topography on the printed circuit board.
• Embedding the entire PCB with safeguarding material like silicone or epoxy to make a smooth headway for advance protection to the PCB from external bodies. The PCB manufacturing trends has now got several options for low thermal expansion and high thermal conductivity to get rid of issues pertaining to temperature control and strain to the solder joints.
• Using effective pcb layout software that can help incorporate the component specs into an embedded design. Moreover, it also helps to verify and track the appropriate component for a particular material or a coating.

PCB malfunctions in outdoor environment due to thermal conditions:

A good many cases wherein the outdoor electric device or installation that dwell in the control enclosure ends up with a malfunction or a shutdown due to thermal conditions. Excessively low or high temperature with heaps of fluctuation causes the PCB for a rework or a repair. Overheating of an electrical device or stretching the service life of internal electronics are few more thermal issues that are sincere point of concern when installed in the external environment. On the other hand, the harsh or difficult thermal climate includes the risk from the presence of solvents, oil, aggressive substance, sugary, corrosive, saline, fibers or dusty atmosphere. For this, one can opt for simple practices to avoid PCB malfunction at the time of thermal issues. These include:

• Regular calculation of the internal heat of the circuit board that needs to be balanced.
• According to the type of harsh environment, take more efforts in choosing the right IP.
• As per the purpose of installation and type of climatic reaction in the installed location, take efforts to decide better thermal solution and suitable type of installation process.
• For an early detection of condensation and to avoid over-or- under sizing errors in PCB components, one needs to regularly keep track and measuring the humidity level (dry, humid or very humid) and air temperature (maxi- mini mean temperature).
• A strict inspection of the installation area helps to derive actual constraints to which the electrical equipment will be exposed.
• Regularly analyze and measure the air quality in the installation site.

Technotronix is one of the kingpins in providing PCB layout, PCB assembly, PCB manufacturing, PCB engineering and PCB rework services. Our team of expert engineers provides a top notch solution to prevent breakdown and malfunction, especially for the PCB installed in the outdoor environments. Furthermore, to get support for best PCB software to be used, preferable measuring devices required for keeping track on temperature, pollution, air quality and humidity, consultation on choosing a suitable conformal coating for your PCB installation, expert recommendation on selecting the right enclosure and sealing technique for your PCB assignment adds value to our services offered. Please feel free to give us a call or drop a mail at sales@technotronix.us to solve your queries.