As you no doubt already know, space is an unforgiving and brutal place – especially when it comes to technology. There are extremes in temperature, radiation, debris, a vacuum… and in an environment where the continuous operation of technology is vital, satellite tech must withstand anything that space throws at it – sometimes literally.
A major component in ensuring satellites remain operational through the incredibly harsh conditions of space is the performance of printed circuit boards (PCBs). Without high-performing and durable PCBs, satellites would soon become expensive paperweights and wouldn’t be fit for purpose. This would have a major impact on not only space exploration but global communication as well.
In this article, we’re going to explore the complex topic of PCBs in satellites, including the role they play, the materials used to make them so durable, and what standards must be met when designing satellite PCBs.
PCBs in satellite systems: an overview
PCBs are an integral part of satellite technology, contributing to almost every aspect of a satellite’s functionality. This includes signal processing and communication, data handling and processing and power distribution, as well as how it can reliably operate in some of the harshest conditions known to man.
Not only do PCBs in satellites have to be durable, but there are also other vital considerations as well, such as space and weight limitations, customisations for specific purposes, and fail-safes and fault tolerances should a component develop an issue.
PCB materials and design for space conditions
Because PCBs have to operate in harsh environments and must meet strict space and weight requirements, satellite PCB design must be done with specific materials and structure.
You wouldn’t necessarily use the same materials in a PCB bound for space as you would in one for use in the home, manufacturing or transportation. They have to withstand extreme polarising temperatures, immense pressure and vacuums, zero gravity, vibrations, impacts and more.
- High-performance substrates are frequently used such as ceramic or polyimide, which can withstand extremely harsh conditions.
- Copper is just as useful in space as it is on Earth thanks to its light weight and high conductivity.
- Fiberglass-reinforced epoxy is commonly used due to its durability and weight.
- The solder mask must have high thermal stability so it can endure hot and cold temperatures and not risk short circuits.
- Gold is often used on satellite PCBs as a durable surface finish due to it being corrosion-resistant and having great conductivity.
When it comes to space travel and specifically satellites, every last millimetre of space must be used conservatively so everything is as lightweight and small as possible. This involves structuring PCBs in a way that might not be used in other environments.
- PCBs are constructed in layers, with the number of layers depending on the complexity of the electronic systems.
- Miniaturisation techniques are used to save space while retaining complexity, which can include high-density interconnects and microvias.
- PCBs for satellites often have dedicated power planes and ground planes to distribute power and minimise electromagnetic interference respectively.
As well as material and structure, there are other aspects of satellite PCB design that must be considered.
- PCBs in satellites have to withstand shock and vibration, so solder joints must be strong to prevent damage.
- Components are often protected by hermetic sealing to increase protection while in the vacuum of space.
- Components must be resistant to high levels of radiation, including microprocessors, sensors, memory and power supplies.
- Satellites must have durability and longevity, and must be designed to operate in harsh conditions without degradation for long periods.
PCBs in satellite communication systems
Satellites are one of the most important pieces of global communication infrastructure, which means a problem with a satellite caused by a short circuit can have a major impact on an international scale.
PCBs host signal processing and communication components, such as amplifiers and transceivers, which affect how a satellite can send and receive data. There are also antenna interfaces to provide a reliable link between the satellite and ground stations. The data processed by the satellite is stored using microprocessors and memory modules. These PCBs are often small, so specific design techniques must be used to ensure the appropriate technology is included in the smallest possible space. Some satellites operate in high-frequency bands, and to prevent signal loss certain materials and layouts may be necessary.
PCBs in navigational and observational satellites
Both the public and private sectors heavily depend on navigational and observational satellites. This may be something simple like using Google to find your way to the shops, or something globally significant like military and defence industries monitoring for potential threats.
For navigational satellites, signal integrity and timing is critical, which allows for precision and accuracy, using components such as signal processors and atomic clocks. Microprocessors process incoming signals, which requires a high level of precision to pinpoint a location. This requires antennas that receive ground-based signals that are reliable and high quality.
For observational satellites, payload instruments, sensors and cameras capture data and process it so it can be communicated in real time.
Quality and reliability standards for space PCBs
Due to the importance of quality and reliability when it comes to PCBs used in satellites, there are strict standards in place that must be met. PCB manufacturers such as ourselves at ABL Circuits know how crucial meeting these standards is. We have the knowledge and skill required to design and manufacture of pace-grade PCBs that meet international standards, including:
- NASA standards, including NASA-STD-8739.3 and NASA-STD-8739.4
- IPC standards, including IPC-6012, J-STD-001 and IPC-A-600
- ECSS standards, including ECSS-Q-ST-70-02
- US Military standards, including MIL-PRF-31032
Manufacturers have a responsibility to use the materials, processes, designs and components needed so PCBs operate in the harsh conditions of space. This includes always meeting compliance requirements and undertaking stringent quality control and testing procedures. It’s also likely that ‘off-the-shelf’ designs won’t be compatible, so bespoke designs, customisations, prototyping and continuous improvements are needed.
PCBs are one of the key aspects of safe and reliable space exploration and communication, and without them, humanity wouldn’t be as interconnected as it is today. This is why PCBs used in space must be durable and dependable – and why a trusted PCB manufacturer like ABL Circuits should be used to provide an expert and bespoke end-to-end solution.
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