Printed Circuit Board which interconnect the conductors and circuit components on a electric board is widely used in almost all electronic devices. Ingress of moisture during PCB assembly can increase the number of failures during assembly, and decrease the circuit assemblies and its life.
In addition to the above, PCB assembly areas may experience significant impact from untreated external air or the release of acid vapours, corrosive substances, and toxic gases. These unaddressed contaminants have the potential to induce various consequences within the manufacturing environment.
Effects of Uncontrolled Moisture
Exposure to high moisture during Printed Circuit Board (PCB) assembly and manufacturing, leads to:
- Microscopic corrosion
- Adhesion failures
- Surface defects
- Decreased performance of the circuit board.
- Increase electrical resistance
- Decrease capacitance
Causes of Uncontrolled Moisture
The electronic compounds are mounted and interconnected to form a circuit. These compounds are hygroscopic and absorb moisture and make cuts in the bridging of microscopic circuit lines, resulting in circuit failures.
Effects of Corrosive Gases
Ingress of corrosive gases into Printed Circuit Board (PCB) assembly area leads to:
- Corrosion of silver contacts by strong oxidising properties of S compounds, especially H₂S
- Corrosion of Cu/Al by SO42-
- Crystal formation by neutralisation with SO42 and NO3 with NH4+
General Recommendations
Relative Humidity in PCB Assembly Clean Rooms should be maintained at 20%-35% RH at 20°C temperature. Additionally, it is important to remove any corrosive gases to protect electronic equipment and devices from the threat of abrupt failures.
Bry-Air Solution
Desiccant Dehumidifiers from Bry-Air provide the ideal low humidity environment in the manufacturing, assembly and storage of these precision, high quality electronic Printed Circuit Boards. These dehumidifiers can maintain the required relative humidity at a constant level, regardless of ambient conditions.
To avoid abrupt failures due to corrosive gases, Bry-Air Gas Phase Filtration (GPF) Systems are the ideal solution. They remove corrosive gases through the process of adsorption and chemisorption. Besides, the GPF systems neutralise odourous gases and make the environment comfortable for humans.
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