Method and apparatus for testing encapsulated circuits

A method for evaluating an encapsulated electrical circuit for use in a service environment, the service environment being characterized by pressure cycling between a minimum service pressure and a maximum service pressure, the method comprising:

• immersing the circuit in an electrically-conductive evaluating fluid;
• subjecting the immersed circuit to a first evaluating pressure for a first predetermined time period;
• increasing the immersed circuit to a second evaluating pressure over a second predetermined time period;
• subjecting the immersed circuit to a second evaluating pressure for a third predetermined time period;
• removing the circuit from the fluid;
• applying an input signal to the circuit after the circuit is removed from the fluid;
• and
• monitoring the response of the circuit to the input signal for a fourth predetermined time period.

An apparatus for evaluating an encapsulated electrical circuit for use in a service environment, the service environment being characterized by pressure cycling between a minimum service pressure and a maximum service pressure, the apparatus comprising:

• a pressure-tight chamber containing a quantity of an electrically-conductive evaluating fluid sufficient to immerse the circuit in the fluid;
• a pump and a pressure control valve in fluid communication with the chamber, wherein the pump and the valve selectively operate to bring the pressure within the chamber to a first evaluating pressure and a second evaluating pressure;
• a signal generator for applying an input signal to the circuit when the circuit is removed from the fluid;
• and
• a tester for monitoring circuit response to the input signal.