What’s ahead for antennas, heaters and inks.

In the 39 years I’ve been in the printed electronics industry, I’ve had the privilege of witnessing, influencing and playing a part in life-changing innovations such as the SonoCine ultrasonic breast imaging device and printed wearable therapeutics. As brilliant as these breakthroughs were back in the day, however, they don’t hold a candle to today’s conductive transparent thin films that are enabling limitless design and engineering possibilities.

Different types of nickel corrosion and potential mitigation strategies.

Electroless nickel immersion gold (ENIG) chemistries were introduced in the mid-1990s to replace electrolytic nickel and gold for high-density circuits. In the mid-1990s, nickel corrosion, soon to be known as the ubiquitous “black pad,” was discovered. Chemical suppliers and board manufacturers took steps to reduce the occurrence of black pad. To that end, in 2002, IPC released IPC-4552, “Performance Specification for Electroless Nickel/Immersion Gold (ENIG) Plating for Printed Boards.”

In the late 1990s, electroless nickel electroless palladium immersion gold (ENEPIG) chemistries were introduced as a universal finish for gold, aluminum and copper wire bonding, with perceived protection from black pad. In 2013, IPC released IPC-4556, “Specification for Electroless Nickel/Electroless Palladium/Immersion Gold (ENEPIG) Plating for Printed Boards.” Today, black pad is still a reality with ENIG and ENEPIG plating.