Military and aerospace are two industry sectors that utilize most advanced electronic applications. The systems used in these sectors demand precision and superiority in terms of performance. Most military and aerospace systems are required to adhere to IPC –A-610E Class 3 for high performance products as per the IPC guidelines. This is why PCBs must be made with utmost precision and attention. There are several factors that influence the design of these PCBs. Do you wish to know about these factors? Well, read this post. It will discuss important factors affecting their design.
Factors to be Considered During the Design and Fabrication of Military and Aerospace PCBs
During the PCB assembly process, various factors must be taken into consideration. They are mentioned below:
Material of Construction: PCB assemblies used in military and aerospace applications must be strong enough to withstand high temperatures. Typically, high temperature laminates like aluminum and copper substrates are used in PCBs for aerospace and military applications. Nowadays, anodized aluminum is used to minimize the effects of heat induced oxidation. Various aluminum substrates combined with thermally conductive pre-pegs are known to offer weight advantages.
Reduction of Electromagnetic Induction and Attenuation: During the PCB assembly for military and aerospace applications, a stranded wire is dipped into the hot melted solder, dried, and left to solidify. Dried soldering achieves strength on drying. It helps improve transform a stranded wire into a solid wire, and eliminate air gaps, as well as allow a stable air flow. This helps reduce effects of electromagnetic interference (EMI), as well as attenuation. Also, it improves the reliability of aerospace/military PCBs by about 2-5%.
Thermal Dissipation: Many times, it is seen that certain components on a PCB start dissipating heat more than 1 watt. It becomes important to control this heat dissipation to avoid PCB damage. This is the reason why components are usually mounted about 20.00 MILS from the board surface or a spacer is used between a component and a heat sink. Both these strategies help control heat dissipation in military or aerospace PCBs. This spacing also helps avoid stress, as there is a sufficient clearance to protect the PCB surface, and components. This adds to the reliability of aerospace PCBs.
Conformal Coating and Surface Finishes: Most aerospace and defense applications are subjected to extreme environment conditions, such as continuous exposure to moisture, water, extreme temperature, and humidity. Hence, application of an appropriate conformal coating becomes important. Generally, acid based sprays are considered for conformal coating. Other types of surface finishing and coating include ENIG, HASL, immersion silver, etc.
PCB driven Aerospace and Military Applications
The following are some advanced aerospace and military applications that utilize high quality PCBs:
- Cryptanalysis systems
- Cyber counterintelligence systems
- Command and control systems
- Automatic search jamming systems
- AMRAAM – Advanced Medium Range Air to Air Missiles
- ECCM – Electronic Counter-Countermeasure
- IADS – Integrated Air Defense System
- AEW&C – Airborne Early Warning & Control
- AWACS – Airborne Warning and Control System
- ASRAAM – Advanced Short Range Air to Air Missiles
All the above-mentioned examples will help you understand the rising importance of PCBs in aerospace and military industry. It is important that you source these PCBs from an ITAR certified manufacturer. Accelerated Assemblies provides PCB assemblies military industry. All PCBs are subjected to intensive testing and inspection before delivering to the client, which helps ensure high quality and long term performance.
