Specifications to Create Reliable Military Printed Circuit Boards

Printed Circuit Boards (PCBs) used in the military are designed in a manner to withstand extreme conditions. Military PCBs are designed in a manner so that they can perform in these conditions, work for extensive periods, and still last a long time.

Steps Taken To Enhance PCB Performance in Military Applications

Some very important specifications need to be kept in mind when fabricating heavy duty PCBs for military operations.

1. Use of Thermal Compound: A thermal compound acts as an insulator by reducing the heat transfer. Application of which, also reduces the vibrations, reducing the formation of cracks on the soldering. Thus, it reinforces the structure by preventing the solder from cracking.
2. Soldering Flange Mounts: Generally, flange mounts are hand pressed onto PCBs. Flanges in military specific PCBs are press-fit and then hand soldered to reduce vibrations and increase reliability.
3. Pre-tinning of Wires:Pre-tinning is conducted to improve the reliability of wires. Stranded wires are dipped in hot melted solder to form a single consistent piece of wire. This makes the wire resistant to electromagnetic interference and increases its life.
4. Resolving Heat Dissipation Issues: If some components dissipate more than one watt of heat, a spacer can be installed or the component can be mounted 20.00 mils away from the board.
5. Application of Conformal Coating: An acrylic based conformal coating keeps dust, water, moisture and other contaminants away from the surface of the board.
6. Increasing Volume of Solder Paste: The solder paste applied to the military PCBs must be 25% higher than the amount applied on commercial PCBs. This increases the reliability of the PCB as well.

Other than the above-mentioned steps, rigorous military level quality checks must be conducted. All divisions of the military use these PCBs. The applications range from land operations to aviation and marine activities. Some specific examples of such applications include temperature sensors, cyber counterintelligence systems, and radio communication systems. The boards designed for the military need to be reliable and have the ability to sustain rigorous applications and environments.