April 20, 2024
Flexible Hybrid Electronics

Flexible Hybrid Electronics: The Future of Printed Circuit Boards

Flexible Hybrid Circuits Enable Novel Form Factors
Flexible hybrid electronics leverages the flexibility and form factor of polymer substrates along with the functionality of integrated electronic components. By printing or depositing conductive traces, dielectrics and other materials onto thin polymer sheets, flexible hybrid circuits can take novel shapes and conform to irregular surfaces. This enables applications not possible with traditional rigid printed circuit boards. Wearables, implantables and conformal medical sensors are areas primed to benefit from these flexible hybrid technologies.

Printed Circuit Board Manufacturing Goes Additive

Rather than traditional subtractive circuit manufacturing which involves etching away copper cladding, Flexible Hybrid Electronics relies on additive processes such as printing, deposition and bonding of materials. Conductive inks made from silver, copper or carbon nanotubes replace copper traces and can be directly patterned onto thin plastic or polymer sheets using inkjet or gravure printing. Dielectric and passivation layers are also additively fabricated using similar wet deposition techniques. Discreet electronic components such as processors, memory, sensors and batteries are mounted to the substrate through methods like anisotropic conductive film bonding or solder paste printing. This additive layer-by-layer construction allows for designing circuits in non-traditional layouts.

Enabling Novel Form Factors in Wearables and Implantables

One key application for flexible hybrid circuits is wearable electronics and medical devices. By taking advantages of their flexibility and thin film form factor, these circuits can comfortably contour and flex with the body. Wearables like smartwatches, virtual/augmented reality headsets and health monitors can have hybrid circuits laminated directly onto their frames or embedded within soft, flexible materials. Implantable devices leveraging these technologies include glucose monitors, hearing aids, pacemakers and nerve stimulators that don’t require surgery for implantation. These flexible hybrid circuits don’t displace rigid electronics but rather enable an entirely new class of applications through novel form factors.

Reliability and Lifespan Challenges

While offering new possibilities, flexible hybrid circuits also present challenges compared to traditional rigid printed circuit boards. The addition process is more sensitive to defects and environmental factors. Bendability can cause fatigue failure of conductive traces over time. Moisture/liquid exposure poses risk of delamination between layers. Thermal cycling during use may lead to conductive pathway cracks. Improving the durability, adhesion and reliability of printed dielectrics/conductors along with encapsulation/passivation strategies is an active area of research. Lifespan expectations also need to match application needs, whether months for removable wearables or years for implanted devices. Overcoming these reliability obstacles will unlock the full potential of flexible hybrid circuits.

Mass Manufacturing Processes Mature

Flexible hybrid technologies have typically been limited to low-volume prototyping and proof-of-concept products due to immature, expensive manufacturing capabilities. However, continuous improvements and scaling up of printing, deposition and bonding equipment used to fabricate these circuits provides a clear path towards mass manufacturing. Gravure, flexography and inkjet web-scale printing processes developed in other industries are increasingly capable of producing flexible hybrid circuits at high throughput and reduced costs. Automated component placement and bonding further increases manufacturing speed. Likewise, supply chain maturation leads to lower materials costs. These developments presage the wider real-world proliferation of flexible hybrid circuit applications across diverse sectors.

In summary, flexible hybrid electronics leverages additive manufacturing techniques and novel form factors to open up new possibilities for wearables, medical devices and beyond. While reliability challenges remain, ongoing adoption by industry and maturation of mass production methods move this technology closer to enabling its full transformative potential. Flexible hybrid circuits represent a new paradigm that goes beyond mere component-level flexibility to rethink the very nature of how electronics are designed and integrated.

1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it.