Abstract: A solid state amplifier includes at least one junction field effect transistor and an impedance network coupled between a signal input terminal of the amplifier and a gate terminal of the transistor. The network includes a p-n junction device having a region of conductivity opposite to that of the gate of the transistor coupled to the gate terminal, the p-n junction being shunted by a resistor coupled in parallel therewith. The network minimizes signal distortion which would otherwise be introduced to the signal output of the amplifier when an inductive load is present in the output circuit of the amplifier.
April 28, 1975
Date of Patent:
April 27, 1976
Bell Telephone Laboratories, Incorporated, Western Electric Co., Inc.
Charles W. Clark, Edwin G. Morton, Robert L. Voss
Abstract: Discrete semiconductor chips, such as sheet-diffused diodes are mass-tested after separation from a wafer. A carrier for retaining the chips in a predetermined array for testing has a plurality of cavities located in a planar surface and arranged in accordance with the predetermined array. The devices are loaded into the cavities and retained therein by a vacuum connected to each of the cavities. Electrical contact is made through the bases of the cavities to the bottom surfaces of the chips, while insulating walls of the cavities prevent leakage paths around the chips. The carrier is indexed in steps corresponding to the increments of the array to permit the top surface of each of the loaded chips to be contacted in sequence by a probe to establish electrical connection through such chip to a test set to test the chip.
Abstract: A bonder for attaching in succession small articles such as electronic devices to substrates has eight stations located along the path of a rotary member. The rotary member supports eight holders for substrates which are moved in sequence from station to station. At a first station a substrate is loaded onto one of the holders. The holder is then moved to an alignment station and transferred from the support member to a planar manipulator. An optical alignment control system recognizes a position of the substrate on the holder and controls the manipulation of the holder to align a substrate to a predetermined reference axis. The holder is then transferred back to the support member to fix the position of the substrate with respect to the support member. At the next station an article is also aligned to a corresponding reference axis and then tack-bonded or preliminarily attached to a bond site on the substrate.
November 27, 1974
Date of Patent:
March 30, 1976
Western Electric Company, Inc.
Norman Bahnck, Raymond H. Booth, John A. Boyer, Jack J. Monahan