Materials Used for European Automotive Printed Circuit Boards

by Kate Han

The European Printed Circuit Board (PCB) market services a variety of end markets such as industrial equipment, aerospace, medical and automotive. All these markets have some special requirements to fulfill. Some would say that automotive is the most demanding but I’m not here to debate that subject. However, I want to review what some of the special demands and requirements are for solder mask in automotive PCBs and what type of solder masks and materials can be found in vehicles.

Extreme Environment – Solder Mask and Via Fill

  • These solder masks and via fill products meet the requirement of High-Low temperature cycle, High-temperature Storage, and Electromigration resistance.
  • These properties allow the solder mask to survive in the extreme environments.
  • Two of the most popular tests for extreme environment is the Thermal Cycle Test (TCT) that generally ranges from (-40°C ↔ 160°C) for 1000 hours and Hot Storage that is normally run at 160°C for 2000 hours. Taiyo America is working on a new ink that will blow past both of those requirements with extreme temperature capabilities of 200°C. Keep an eye out for it.


Thermal Management – Coatings and Via Fill

  • Most thermal management for printed circuit boards is relied upon by the substrate/laminate used in manufacturing. Some printed circuit boards will require higher Tg laminates for boards that are in the extreme temperature areas of an automotive.
  • Batteries, LED lights, and EV batteries all utilize thermal management materials to improve reliability of their parts.
  • Taiyo America is developing thermal management inks that can be used in the manufacturing of LED lights and as a coating to dissipate heat out of the printed circuit board. Please explore Taiyo America's Thermo Cool 10.2W heat dissipating ink.


Application in LED Technology – White Solder Mask

  • The LED white solder mask market is really divided into two areas. There are the needs for white solder mask that has extremely high reflectivity and there is also the market for high white color stability. Generally, for automotive, the key is color stability. This is mainly due to the fact that if one was to replace a LED headlamp, they would like the replacement lamp to match the color of the older lamp.
  • Beyond the need for white color stability and reflectivity there is also the need for crack resistance. Since the LEDs in the automobiles are placed by high temperature areas, crack resistance is important. Taiyo America developed a white solder mask specifically for this crack resistance application; it’s called PSR-4000 CR01MW. It is the Ferrari of LED white solder mask and continues to outperform the competition.


Flexible Solder Mask

  • There are many applications within the vehicle that requires flexibility and space in its printed circuit boards. The properties for this flexible solder mask are that it is free bending and light weight. It also has great heat dissipation and weldability.
  • Components in ECU controllers, motor controller, sensors, navigation systems, and other similar tech items generally use flexible solder mask. For the latest in flexible solder mask check out Taiyo’s FLEXFINER.


To summarize, the electronics in any automobile have a variety of characteristics; it all depends on where the electronics are and what type of environment they are put into. Taiyo America is dedicated to the automotive electronics market from various types of solder mask from flexible solder mask to extreme temperature requirements to thermal management. We encourage you to reach out to Taiyo America to learn more about our various solder mask products, thermal management inks and via fill products that we have that will meet your automotive needs.