Surface mount technology breakaway self regulating temperature heater

Abstract

Soldering of surface mount connector terminals to contact pads on a circuit board is facilitated by configuring the terminals and their solder tails as spaced integrally-formed projections of a selectively actuable heater. Thermal energy developed in the heater is conducted along the projections to the solder tails to melt fusible conductive material (e.g., solder, at the connection sites). After cooling, the projections are severed from the heater. The terminals, which are formed at the distal ends of the projections, are typically supplied partially inserted in respective terminal-receiving passages of the connector housing. After the soldering operation, the terminals are fully inserted into the passages. The heater is preferably a self-regulating heater in the form of a copper substrate having a skin layer of magnetically permeable, high resistance material. An alternating current of constant amplitude and high frequency is passed through the heater and concentrated in the skin layer at temperatures below the Curie temperature of the skin layer material. At higher temperatures the current is distributed through the lower resistance substrate to limit further heating. During the time interval required for the surface layer to reach its Curie temperature, the resistive power dissipation creates thermal energy that is conducted to the solder tails.