Like many others, I gravitated to engineering, particularly synthesis and design, in order to exercise my creativity and ingenuity. The prospect of bringing a novel idea or product to life is quite compelling. I have even heard electronics design spoken of as an art. Although I like the comparison and can even see some similarities between the two, I am hesitant to accept that description. Art, at least in its purest and best form, involves no restrictions. This is not true of electronics design. The best designs are, in fact, those that can closely accept and incorporate restrictions or boundaries.
Designing PCBs requires designers to operate within limitations on available components, material types, equipment capabilities, board fabrication and PCB assembly methods. “Creating” with restrictions is challenging and requires the designer to incorporate their design intent while adhering to manufacturing restrictions. This is known as design for manufacturing (DFM), and it is essential to optimize the design and development of PCBs.
When designing PCBs for critical systems, like those used in aerospace technology, DFM is even more essential and includes additional requirements that are not necessary for other boards, such as those for consumer electronics. However, before exploring DFM for aerospace technology PCBs, let’s briefly review DFM in general so we can draw a distinct contrast between the two.
Design for Manufacturing (DFM) for PCBs
Today, virtually all PCB software design packages include the ability to set rules and guidelines for board layout. These design rule checks (DRCs) help the designer stay within preset restrictions and tolerances for manufacturing. For your board to be built, simply utilizing this feature is not sufficient. Instead, it is necessary to implement true DFM, which includes tolerances tailored to your contract manufacturer’s (CM’s) equipment capabilities. This also encompasses rules and guidelines for PCB assembly and testing, as described below.
Design for Assembly (DFA) is the incorporation of specific rules and guidelines that impact the PCB assembly stage of manufacturing. This includes confirming that component footprints are accurate, ensuring your board is capable of withstanding the thermal and physical stresses of assembly and considering your board’s depanelization.
Design for Testing (DFT) is the inclusion of test points and required testing regimens in your design, if necessary. Testing is usually implemented to ensure your board adheres to special requirements; it can be done offline or automatically during manufacturing runs.
DFM for Aerospace Technology PCBs
All good PCB layouts should include DFM as described above. However, more advanced DFM for aerospace technology is required when designing space flight vehicles, such as satellites. To be maximally effective, this more advanced DFM requires a good understanding of the steps of PCB manufacturing and how these are impacted by additional regulatory restrictions and standards and performance requirements as well as the component management, material durability and board reliability measures necessary for space deployment. This knowledge can be encapsulated into the following list of essentials to guide your aerospace technology PCB design.
- Research and familiarize yourself with applicable standards and regulations.
Supplying parts and systems to aerospace industry organizations is heavily regulated and failing to adhere to these requirements can prevent your products from being used.
- Select components with a traceable supply chain.
The proliferation of counterfeit components has resulted in strict requirements for component supply chain management. If you are supplying agencies such as NASA, there is a multitiered component approval process in place that you must follow.
- Choose materials that can withstand the environmental rigors of space flight and deployment.
Your design should account for environmental concerns like vibration and extreme temperatures. It is recommended that software simulations, and perhaps physical testing, be performed to verify your board’s ability to withstand these stresses.
- Ensure that your CM meets your quality management system (QMS) requirements.
For aerospace systems, having a QMS that adheres to AS9100D is mandatory. The breadth of this standard requires that your CM’s quality control processes and documentation are supportive.
|Tempo‘s Custom Avionics for PCB Manufacturing Service
Tempo Automation, the industry leader in fast, precise PCB prototyping and low volume production, is experienced in building critical system boards and can assist you in implementing DFM for aerospace technology to ensure you meet the rigid requirements of the industry.
And to help you get started on the best path, we furnish information for your DFM 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 DFM for aerospace technology PCBs or how to incorporate it into your design, contact us.