Flexible and HDI PCBs – Why they are integral to IoT Devices

Flexible and HDI PCBs – Why they are integral to IoT Devices

Apr 12,2019
The Internet of Things (IoT) has been around for a while and is gaining more prominence with time. According to Gartner, by 2020, more than 26 billion devices will be connected to the Internet. Many of these devices will require unique PCBs for operation. For instance, a wearable device such as a fitness tracker may require a PCB with a dense component placement to resist regular flexing and dynamic stress. Considering all these factors, PCB manufacturers are responding to specific demands by designing HDI PCBs and flexible PCBs. Do you want to know how these PCBs are driving IoT devices? Stay tuned to know more.

IoT and Flexible PCBs

Nowadays, flexible printed circuit boards are becoming a favored solution for all those applications, where traditional solutions do not work. Is that all? No. There are several features that make flexible PCBs perfect for IoT applications. They are discussed here in detail:
  • Compact Size and Flexibility: Most IoT devices have eye-catching contours and curves, and they combine superior electrical and mechanical characteristics, too. These eye-catching devices have complex designs due to their irregular shapes. These irregular shapes demand small PCB packages, and this is where a flexible circuit board can actually help. A flexible circuit board can easily fit in confined spaces, and be easily folded around the corners of irregular designs to create a tight packaging. However, rigid PCBs require more space which also hampers the design freedom, and may not be desirable for a product designer. Flexible PCBs are ideal for fitness trackers, microphones, and batteries, because they enable components to fit into a small package, and also improve their performance capabilities.
  • Light Weight: Flexibility and small space occupancy comes with light weight. It is seen that a flexible PCB reduces the weight of an application by almost 95%. This is because flexible circuits are made of thinnest substrates, which reduce the weight of the package. Such lightweight designs make the IoT devices perfect for all types of environments and applications such as wearable hearing aids and surgical equipment.
  • Reliability and Durability: A flexible PCB can easily flex up to 500 million times in IoT applications, which have several moving parts. The demand for PCB-driven IoT devices is increasing in industrial settings, as flexible PCBs can easily withstand harsh conditions. Most times, these PCBs are made of polyimide, which is well-known for its excellent thermal stability. Also, this thermal stability of the material assures a strong base for surface mounting components. Nowadays, flexible PCBs are largely used in fitness trackers because they can easily resist humidity, body heat, and regular movements.
  • Simplifies Wiring: Flexible circuit boards were initially designed as replacements for bulky wire harnesses. These circuit boards use no mechanical connectors and also eliminate the costs associated with routing, soldering, and wrapping wires. In these PCBs, the interconnection systems are installed as a complete unit. Also, whenever a replacement is needed, the entire system is replaced rather than individual components. This helps minimize wiring errors.
  • High-Density Designs: Thinnest substrates used in these circuit boards allow narrow lines, so more components can be mounted on the circuit board. This helps IoT PCB designers meet the requirements of high-density designs. The streamlined design of a flexible PCB helps improve the airflow through the circuit board.

HDI PCBs and Their Role in IoT Devices

Nowadays, IoT OEMs are exploiting the following aspects of HDI PCBs to their benefit:
  • Dense Circuitry: As their name suggests, these printed circuit boards are known for their dense component placements. Stacked microvias, tinier trace widths, and excellent wiring density help save space on the circuit board. These compact-sized denser circuit boards are finding applications in a large number of miniaturized IoT devices.
  • Excellent Electrical Performance: HDI PCBs make use of via-in-pad and blind vias, which can be placed close to each other. As these components require shorter wire lengths, their transmission range is reduced. This decreases crossing delays and transmission times and increases the signal strength. These PCBs have extremely low power requirements which makes them perfect for smaller end use wearable products.
  • Design Flexibility: HDI PCBs allow designers to utilize small components and parts on smaller boards, and perhaps they can use both sides of these boards.
  • Simplified Circuit Routes: Buried and blind microvias and vias used on the printed circuit boards offer brilliant and cleaner routing options. Nowadays, designers use microvias in the place of through-holes to augment the signal integrity of these PCBs. These microvias also help reduce the number of signal layers and their corresponding reference planes. The reliable performance offered by these HDI PCBs in compact spaces has made them a perfect choice for IoT devices.
  • Improved Channel Routing Width: Microvias used in the HDI PCBs have a small pad size, and this helps improve the routing width of channels.
  • Improved Service Life: As the components are placed closer to each other, the distance heat has to travel reduces, and there is a faster dissipation. This means, HDI PCBs is not subjected to high stress thermal expansion, and this helps improve their service life.
  • Excellent Cost Effectiveness: This is a combination of all the above-discussed factors. Denser circuit board designs, high energy efficiency, and reduced layering are a few features that allow PCB manufacturers to achieve cost effectiveness while designing these PCBs.
All the above-discussed factors will help you understand how HDI boards allow IoT device manufacturers to improve their reliability, profitability, and market reach. As said earlier, these circuits have denser configurations, which are not easy to achieve, unless and until you are approaching a trusted and experienced HDI manufacturer. Sierra Assembly Technology is one of the leading providers of HDI PCBs and flexible PCBs for IoT devices. Specializing in custom PCB designs, the company has been serving its clients across various industries such as aerospace and satellite, medical, computer and business electronics, and more, from past many years.