Connector Design for Wearables
Paper discusses contact physics, plating options, force requirements and trade-offs that occur when selecting a connector for an application.
Randy Schueller, Ph.D.
As electronics continue to shrink and their performance capabilities grow, these electronics are becoming more and more integrated into our daily lives. The next step is the internet of everything and wearable electronics. Communication between devices and providing power through the use of connectors is critical; connector sales are a $50 billion/year industry. As critical as they are, separable connectors are often times the first item to fail in electronics.
This problem is only expected to worsen as electronics are used in increasingly challenging environments. This paper will discuss contact physics, contact plating options, normal force requirements and general tradeoffs that frequently occur when designing or selecting a connector for an application. Physics of failure along with a number of connector failure examples will be presented as well.
Connectors are one of the most critical components in an electronic product and this is anticipated to be especially true with wearable products that will have to endure sweat, high humidity, elevated temperature, corrosive gasses, and various types of debris. In addition, those charged with a power connector should experience a high number of insertion withdrawal cycles.
Whenever possible, select connector systems with a long history of success. Use gold plated contacts when possible and be aware of the appropriate thickness of gold. There are a wide range of connector suppliers and it usually pays off to use those with a proven reputation. Be aware of the primary failure mechanisms and design to avoid them. Understand the environment that the connector will be placed in and make sure that sufficient reliability testing has been performed.
Initially Published in the SMTA Proceedings
Agreed on all points. There are however other interconnect design options that are outside the traditional approach to connector interface that could prove superior. My company came up with a HDMI D prototype connector using a unique approach that worked quite well first pass. (19 pin female about the size of a USB mini) Not being a connector company however, the interest has been limited. Perhaps when the problem becomes intractable using established methods.
Joseph Fjelstad, Verdant Electronics