Abstract: A bond quality monitor and method for monitoring and analyzing the relative quality of bonding operations performed by ultrasonic bonding machines is disclosed. The bond quality monitor (40) includes an analog bond monitoring circuit (42) and a digital microcomputer (44). The bond monitoring circuit, which is placed in series between an ultrasonic signal generator (26) and its corresponding ultrasonic transducer (18), monitors the transducer power signal generated by the ultrasonic signal generator and performs a series of analog computations based on the logarithm of the impedance of the transducer in order to create a measure of bond quality. The microcomputer controls the operation of the bond monitoring circuit and performs comparisons to determine bond quality relative to previously monitored good quality bonds.

Abstract: A dryer in which fabrics are dryed quickly and at low temperature by subjecting them to microwave energy in an atmosphere of reduced pressure. The microwave energy elevates the temperature of the water within the fabric to its boiling point, which is quite low because of the reduced pressure, and the water vapor which is released from the fabric is condensed external to the microwave field at the same reduced pressure. In one embodiment the dryer is formed as a clothes dryer wherein the drying chamber is a spherical metallic vacuum vessel; the microwave energy is supplied by a solid state microwave array within the drying chamber; water vapor is condensed by a spray condenser external to the drying chamber; and reduced pressure is obtained by a water jet exhauster, which functions in part as a condenser. Drying time is accelerated by warming the lower surface of the drying chamber with hot water, and a jet of air fluffs the fabric after drying.