High-temp PPA ousts nylon in 190-pin connector

A 190-pin connector used in automotive underhood applications must meet USCAR Class 3 requirements and be capable of operating in ambient temperatures ranging from -40C to 125C, with the added ability to withstand a peak of 145C. Engineers at Tyco Electronics picked a grade of AMODEL polyhthalamide (PPA) from Solvay for this demanding application. The specific grade, AMODEL AS-4133 HS, is one of a series heat stabilized, glass-reinforced resins that are designed to exhibit strength and stiffness over a broad temperature range.

The critical temperature dictating the choice of this resin, however, is not experienced during normal automotive operation, but during the assembly process, when much higher heat is generated. The connector is attached to the module’s circuit board by a process known as “IR-reflow”. During the reflow process, the connector’s 190 pins are soldered to a printed circuit board at a temperature of 250C. The heat-deflection temperature (HDT) of the connector’s material must be sufficient to withstand this heat without charring or melting. The HDT value for this grade of AMODEL PPA is measured at 300C at 264 psi, which is much higher than conventional nylons specified for this type of application.

Solvay Engineered Polymers 905-738-6433