Polyamides enable USB Type-C connectors

USB is the industry bus standard used for transferring data and power to and from digital devices. Device charging over USB has become a major consumer feature in recent years. USB is by far the most popular and successful means of connecting peripherals, with some 5bn ports being produced every year.The introduction of the USB Type-C connector is the result of the need to reduce electronic waste. Legislation in Europe, for example, is enforcing the use of a standardised charging interface, so that one charger and its associated cable can be used for multiple devices. As a result, the USB Type-C connector will be obligatory from 2017. Some electronics OEMs, including Apple and Google, have already launched equipment that incorporates Type-C ports.

The Type-C connector overcomes an important draw-back that has traditionally been associated with USB. Until now, numerous different types of plugs and sockets have been available, therefore, charging two different mobile phones often requires two different sets of chargers and cables. In addition, ‘in’ and ‘out’ connectors have different shapes. The new USB type-C standard is the first USB connector with reversible design, allowing it to function whether you plug it in right-side up or upside down. Moreover, with wall thicknesses at only 25% of previous generation connectors, the connector is much smaller.

Stanyl (polyamide 46) and Stanyl ForTii (polyamide 4T) have high Comparative Tracking Index ratings well above 400V, which are a measure of their ability to provide electrical insulation. Alternative materials show a short break during CTI testing, resulting in a serious performance and safety issue for the complete device when in use and exposed to particles, moisture, sweat or other pollution due to electrical tracking. DSM high performance polyamides offer a suitable balance of toughness and stiffness. Furthermore, the flame retardant additive systems that they incorporate to provide a UL 94 V-0 rating contain no halogens.

In addition to ensuring high output rates, the processability of Stanyl and Stanyl ForTii also provides connector designers with flexibility in component structure and tooling design. Stanyl and Stanyl ForTii can be used to produce connectors with wall thicknesses as thin as 0.12mm but retain the required high mechanical properties. Their high flow in combination with high weld-line strength ensure the required high pin pull-out strength parts successfully pass durability tests that involve mating and unmating plugs and sockets more than 10,000 times.

Further important advantages for DSM high performance polyamides in this application include their ability to withstand the very high temperatures used in lead-free reflow soldering processes used to assemble components on PCBs, as well as their compatibility with ultrasonic welding. The materials also have very good wear resistance, which is essential to meet the high mating/unmating cycles of manufacturers.

“We are getting great performance from DSM materials, and DSM also provides excellent technical support and service, as well as strong application expertise, all of which together have helped us develop and put into production high performance USB Type-C connectors in a very short time. In specific, we value the high CTI of DSM materials, which allows us to provide OEMs with higher end product safety against potential fire hazards caused by electrical tracking. We have now started mass production and are winning new business from many OEMs,” commented a spokesperson at Acon.