I am a firm believer that virtually anything can be accomplished if you have the expertise, time, and the right equipment and/or materials. Aspirations that seem difficult or unattainable are usually lacking one of these crucial elements. While the necessity of these essentials are not always realized simultaneously, when they do come together, great achievements can occur. Notable examples are Apollo 11, the Hubble Telescope, and the GPS constellation.
More often than not, the development of equipment or the discovery of materials is the last piece of the essentials puzzle. This is fitting, as having the right materials can be critical, especially when the target is the harsh environment of space. Aerospace vehicles, their electronics systems, and the PCBs that comprise them must be designed and built to withstand hardships that include extreme temperatures, shock, vibrations, and radiation due to launch, orbital deployment, or interplanetary travel conditions.
Meeting these challenges necessitates that PCB material selection is done with a good understanding of material properties and how they impact board quality and reliability for space aeronautics. Thus, we should look at the attributes that aerospace electronics need for aerospace deployment; only then can we align these with the appropriate PCB material properties such that proper selections can be made.
Requirements for Aerospace Electronics
Electronics and circuit boards are pervasive in practically all equipment, machinery, devices, and vehicles that are in use today. Broadly, we can classify these systems as either commercial or critical. Commercial systems include cellular phones, computers, televisions and appliances. Critical systems are those that have more stringent requirements as failure may produce dire results up to and including loss of life. The PCBs that comprise these critical systems are typically subjected to a higher performance criterion as defined in IPC-6011 Class 3 High-Reliability Electronic Product requirements where uninterrupted service is mandated.
Boards that will be used in avionics systems, such as military aircraft, satellites, and other space platforms, must meet the standards stipulated in IPC-6012DS Space And Military Avionics Applications Addendum To IPC-6012D, Qualification And Performance Specification For Rigid Printed Boards or IPC-6013D Qualification and Performance Specification for Flexible/Rigid-Flexible Printed Boards. In addition to these regulations and standards, aerospace electronics systems development must be carried out within a quality control process framework that includes a documented AS9100D compliant quality management system (QMS) and risk analysis. This level of oversight is warranted due to the hardships that aerospace electronics may encounter aboard orbital or interplanetary aeronautical platforms.
In order to adequately counter the types of adversity that boards may be subject to internally and externally, PCB materials should have the following attributes:
- Vibration and shock resistance
The energy required to launch vehicles into space is immense. Therefore, virtually all boards will undergo vibrations and/shock forces that may place stress on the board or its connectors. This is more of a threat for rigid boards, as their range of bendability is much tighter than flex boards.
- Temperature cycling resistance
Whether internal or external to the aerospace platform, extreme temperature swings may be a part of normal operation. PCB material selection must take this into consideration and ensure that board critical temperature parameters, such as the glass transition temperature (Tg), are not breached.
- Humidity resistance
Generally, the temperature is inversely proportional to humidity. However, in a closed environment like a space, vehicle humidity may become an issue. If so, electronics and circuit boards are subject to failure due to moisture. Thus, moisture resistance is a desirable attribute for PCB materials.
- Radiation resistance
Depending upon where the space vehicle is located in the earth’s atmosphere, it may have to weather radiation or unwanted RF. As these types of interference can wreak havoc on communications and other circuit operations, boards need to be able to resist them.
When selecting PCB materials for use in aerospace systems, the above attributes should be targeted.
PCBA Manufacturing for Extreme Environments - Part 1
Aligning PCB Material Selection With the Requirements Of Aerospace Electronics
The attributes listed above should be considered when choosing materials for your PCBs. This is true whether your boards are destined for orbital deployment in space or for interplanetary travel. This can be done by following the guidelines below, which will help to ensure that your aerospace electronics can survive the internal and external environment of your aerospace vehicle.
Be aware of and follow applicable regulations and standards
The first requirement for any aerospace system development is to ensure that you satisfy all applicable regulatory requirements for board design and PCB manufacturing.
Know the environment in which your boards will be required to operate
In order to choose materials whose properties exhibit acceptable attributes for your aeronautical vehicle requirements, it is mandatory that you know the environmental conditions in which your PCB will need to function. For example, for internal concerns, proximity to the engine or other locations that may exhibit extreme temperatures is pertinent. For external exposure, it is helpful to know the atmospheric level your platform will orbit.
Partner with a qualified contract manufacturer (CM)
Finally, it is imperative that you select a CM that is qualified to produce boards that meet the stringent requirements for aerospace electronics.
One of the most important aspects of developing boards for the aerospace industry is PCB material selection. If your boards are unable to withstand the external and internal conditions for space deployment, then your PCBs will be grounded.
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And to help you get started on the best path, we furnish information for your DFM checks and enable you to easily view and download DRC files. If you’re an Altium user, you can simply add these files to your PCB design software.
If you are ready to have your design manufactured, try our quote tool to upload your CAD and BOM files. If you want more information on PCB material selection that meets the demands of aerospace electronics, contact us.