How to Design a Printed Circuit Board for Aerospace Applications?
Printed Circuit Boards (PCBs) are integral components of almost all electrical, electronic, and electromechanical devices and gadgets. PCBs consist of multilayer laminated structures used to support and connect electronic components through the use of conductive pathways, tracks, or signals. Circuit boards that are specially designed for aerospace and aviation applications are made to withstand extreme environmental conditions, radiation, chemicals, contaminants, and more. With this in mind, this blog will cover the design and construction of circuit boards made for such applications.
There are some core values established by the aerospace and avionics industries when it comes to the design of circuit boards. The first includes making the circuit boards as reliable as possible. To extend the service life of circuit boards and increase their reliability, selecting high quality materials is a key factor. Circuit boards are expected to operate continuously for long periods of time -- sometimes being anywhere between 5 to 15 years without interruption, thus using materials of the highest caliber is paramount.
Heavy copper technology is often the material of choice, as it allows for increased heat dissipation without the need for additional cooling systems, even in the presence of high intensity circuits. However, with the use of copper, circuit boards lose the lightweight characteristics necessary for a myriad of applications. As an alternative to copper, anodized aluminum is a lightweight material that solves problems associated with heat dissipation. More than that, anodized aluminum offers great thermal conductivity as compared to other traditional materials like FR-4 and can minimize the effects of heat-induced oxidation.
PCB finishing materials are another additive that can enhance the structure’s performance even under harsh operating conditions. Conformal coating materials are one such type that consist of a thin polymeric film used to protect the board’s components. Some of these materials include electrolytic nickel gold, chemical silver, Hot Air Solder Leveling (HASL), and various others. This kind of coating can provide added protection against heat, humidity, water, and vibrations. Following the application of conformal coating, an acrylic-based spray should be applied to safeguard the final PCB from contamination or unprecedented short circuits.
Protective coatings can be especially important for electronics within an aircraft as they are often exposed to environmental extremes. For instance, the engine, fuselage, and cockpit are often encapsulated in order to protect such aircraft components from external wear and damage. PCBs are no exception, as they are typically contained within hermetically-sealed boxes that protect them from being exposed to outside stressors.
Routing guidelines are also incredibly important to consider when designing a circuit board due to the fact that they determine how much current load the board can handle and their ability to dissipate heat. Circuits with high frequency signals require angles on the traces that are less than 45 degrees, thus supporting normal signal transmission throughout a circuit. Electronic components that operate at low frequencies should be separated from those operating at high frequencies. The latter often generate waveforms and disturbances that can result in the degradation of signal quality, which is an integral feature of these applications.
Another important factor that should be taken into consideration when building these devices is adherence to reference standards. One of these standards includes IPC-6012DS, an addendum to the IPC-6012D standard that provides qualification and performance requirements for rigid printed circuit boards used in aerospace applications. This standard ensures that the circuit boards can withstand vibration, ground testing, and thermal cyclic environments present in the aerospace industry. Other standards include AS/EN 9100 which consists of a series of standards developed by the International Aerospace Quality Group (IAQG).
If you find yourself in need of circuit board components like conformal coating materials, transistors, capacitors, resistors, or other various parts, rely on One Click Aviation. One Click Aviation is a leading supplier of top-quality parts and components for aerospace, defense, and civil aviation markets. We operate with AS9120B, ISO 9001:2015, and FAA AC 00-56B certification and accreditation, ensuring you always receive superior quality items. Peruse our expansive catalogs, and fill out an RFQ form. Provide as many details about the parts you wish to acquire including target prices, desired quantities, and expected shipping time frames. In as little as 15 minutes, a dedicated representative will reach out to you with a quote for your comparisons. Alternatively, you may call or email us at sales@oneclickaviation.us. We are available to our customers 24/7x365.
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