Patents Assigned to Crestek, Inc.
  • Patent number: 5397397
    Abstract: The present invention relates to an aqueous composition and improved process useful for cleaning and facilitate drying of various metallic and non-metallic surfaces or components. According to the invention the water-immiscible hydrocarbon or non-halogenated organic solvent cleaning step is followed by an aqueous displacement solution (ADS) which contains a surfactant component and a pH modifier component in sufficient amounts to substantially displace the hydrophobic organic solvent residue from on the surface of the substrate and prevent its redeposition. The improved process is an alternative for replacing the ozone depleting chlorofluorocarbons and Halogenated solvents (ODS) or other volatile organic solvents (VOC) being commonly used in cleaning variety of industrially manufactured metallic and non-metallic components.
    Type: Grant
    Filed: February 17, 1993
    Date of Patent: March 14, 1995
    Assignee: Crestek, Inc.
    Inventor: Sami B. Awad
  • Patent number: 4864547
    Abstract: A regulated ultrasonic generator operable for supplying a driving signal to an ultrasonic transducer is disclosed. The generator includes: a power supply; a bridge inverter circuit for generating a power signal having two alternating components of opposite potential; a timing circuit for generating a timing signal equal in frequency to the desired frequency of the power signal; a bridge driver circuit for periodically generating base drive signals for switching on the bridge inverter circuit; a bridge modulating circuit for controlling the amount of time during each cycle that the bridge inverter circuit is on so as to regulate the power content of the power signal; and means for supplying the power signal to the ultrasonic transducer.
    Type: Grant
    Filed: May 20, 1986
    Date of Patent: September 5, 1989
    Assignee: Crestek, Inc.
    Inventor: Steve Krsna
  • Patent number: 4815001
    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.
    Type: Grant
    Filed: May 30, 1986
    Date of Patent: March 21, 1989
    Assignee: Crestek, Inc.
    Inventors: P. Michael Uthe, Paul S. Bamburak