Showing papers by "Motorola published in 1970"

Intermetallic formation in gold-aluminum systems

Abstract: Intermetallic formation in gold-aluminum systems has been studied at 200°C–460°C using butt-welded diffusion couples. The predominant intermetallic phase was found to be Au5Al2, but all five equilibrium phases of the system were present in the couples after annealing at long times. The kinetics of the process were measured and the activation energy for overall intermetallic formation was found to be 15.9 kcal/mol. The effect of silicon on intermetallic formation was also investigated. It was found that while silicon had little effect on the growth rate of AuAl, Au2Al, Au5Al2, and Au4Al, it substantially increased the amount of purple phase in the couples. An electron microprobe traverse indicated that this purple phase contained 6 wt.% Si. The relative tensile strengths of the intermetallics were determined indirectly by measuring the tensile properties of the diffused couples. It was found that all the intermetallics were stronger than gold or aluminum. However, appreciable voiding occurred in Au5Al2 after long times above 300°C and in AuAl2 after long times above 400°C weakening these phases catastrophically. The voiding was greatly accelerated by intermittent aging.

Selective calling system providing an increased number of calling codes or auxiliary information transfer

Abstract: The selective calling system includes a transmitter having first and second signal generators providing sinusoidal and rectangular signals which are combined to form a modulated calling signal. Each receiver of the system includes a first demodulator which demodulates the modulated calling signal and a second demodulator which demodulates the rectangular signal. A frequency selective device connects the first demodulator to a first input of an AND gate and a repetition rate selective device connects the second demodulator to a second input of the AND gate. If the demodulated frequency and repetition rate are within the passbands of the devices, the AND gate provides a turn-on signal which allows primary information to be reproduced by the receiver. The system can be modified so that auxiliary information is transferred to the receivers by the calling signal.

Support for carrying case

Abstract: A support for a carrying case for apparatus to be carried by a person supports the case on a belt, or the like, and permits the same to pivot with respect to the belt and to be easily and quickly connected thereto and detached therefrom. This support can be used for apparatus such as a personal radio paging receiver, or any other device which is to be carried by a person. The support includes a receptacle secured to the belt having a nonsymmetrical opening therein. The carrying case has a plate thereon with a button projecting therefrom having the same shape as the opening in the receptacle. The button can be inserted into the opening when the carrying case is in a position it will not assume during normal use, and will be retained when pivoted to other positions which it may assume during use.

Phase comparator using logic gates

Abstract: A digital frequency/phase detector employs a plurality of NAND gates interconnected to respond to changes in logic level of two input signals, the frequency/phase of which is to be compared. The detector is responsive to changes in the trailing edges of the input waveforms and produces outputs that are related to the repetition rate and relative phase of the inputs. The duty cycle of the input waveforms is unimportant since the circuit responds only to the trailing edge transitions in the input signal; and when the input signals are of the same frequency and are in phase, the output of the phase detector is a constant DC level.

Contact bonding and packaging of integrated circuits

Abstract: Wire bonding is eliminated in the assembly of microelectronic devices, by a process involving the direct bonding of circuit electrodes to a metallic sheet-frame member having a plurality of inwardly extending leads. A single-step bonding technique is employed for the simultaneous bonding of all leads to a semiconductor integrated circuit chip. Lateral confinement of the lead frame member during the bonding steps causes a buckling action in the lead fingers, to introduce a small but critical loop in each lead to ensure clearance between the lead fingers and the perimeter of the semiconductor chip, whereby electrical shorting is avoided. The loop also provides a structural flexibility in the leads, which tends to protect the bonding sites from excessive stresses. Subsequently, the first frame member including the bonded circuit is attached, preferably by resistance welding, to a second lead frame member of heavier gage and increased dimensions, suitable for connection with external circuitry. Excess portions of the first frame member are then removed, providing a completed assembly for packaging; e.g., plastic encapsulation or heremetic sealing, as in a ceramic-glass flat package.

Vehicle control system and equipment

Abstract: A vehicle warning and control system and equipment is disclosed utilizing radio frequencies and the Doppler principle wherein one of the vehicle lights acts as the R.F. radiator, reflector, receiving antenna as well as an illuminator, and through standard circuitry supplies a warning signal or a brake activating signal.

Stabilized complementary micro-power square wave oscillator

Abstract: A square wave oscillator is shown utilizing a P channel and an N channel Metal-Oxide-Silicon Field Effect Transistor (MOSFET) in combination with a quartz crystal for generating a frequency stabilized square wave signal suitable for use in a wristwatch.

Gain controlled differential amplifier circuit

Abstract: A two-stage monolithic differential amplifier circuit employs electronic gain control of both of the stages in order to improve the signal-to-noise ratio of the circuit and to reduce signal distortion and cross-modulation at high-signal levels. The input differential stage operates with current-division gain control. The output signals of the input stage are applied to the second or output differential amplifier stage, in which the transistors each have emitter resistors connected to a common terminal. The emitter resistors each are shunted by the collector-emitter path of a shunt transistor which is rendered nonconductive for maximum gain reduction of the output stage and which is saturated for minimum gain reduction of the output stage. The DC level of the output stage is maintained substantially constant throughout the AC gain control range.

Microstrip impedance matching circuit with harmonic terminations

Abstract: A microstrip impedance matching circuit has fixed harmonic terminations in the form of a pair of open-circuited stubs, each having a length equal to a quarter wavelength of a different harmonic frequency, connected to the main transmission line to cause the impedance at the harmonic frequencies to be made constant irrespective of the nature of the load impedance at the harmonic frequencies.

Amplifier protection circuit

Abstract: A protection circuit for a transmitter amplifier is provided which senses the forward power level and develops a first voltage which is compared with a reference voltage to provide a control voltage which controls the power developed by the transmitter amplifier. Increase in the forward power level is detected changing the control voltage to cause a reduction in the forward power developed by the transmitter amplifier. Decrease in forward power level is detected changing the control voltage to cause an increase in forward power developed by the transmitter amplifier. Reflected power is sensed developing a second voltage which causes a reduction in reference voltage when reflected power exceeds a predetermined level. Reduction of the reference voltage also changes the control voltage to reduce the forward power of the transmitter amplifier to a safe level. An increase in transmitter amplifier temperature beyond a predetermined level is sensed causing a reduction in the reference voltage to change the control voltage thereby reducing the power of the transmitter amplifier to a safe level.

Purple Plague Revisited

Abstract: Intermetallic formation in gold-aluminum systems has been studied at 200°C to 460°C using butt-welded diffusion couples. The predominant intermetallic phase was found to be Au5Al2, but all five equilibrium phases of the system were present in the couples after annealing at long times. The kinetics of the process were measured and the activation energy for overall intermetallic formation was found to be 15.9 kcal/mol. The effect of silicon on intermetallic formation was also investigated. It was found that while silicon had little effect on the growth rate of AuAl, Au2Al, Au5Al2, and Au4Al, it substantially increased the amount of purple phase in the couples. An electron microprobe traverse indicated that this purple phase contained 6 wt% Si. The relative tensile strengths of the intermetallics were determined indirectly by measuring the tensile properties of the diffused couples. It was found that all the intermetallics were stronger than gold or aluminum. However, appreciable voiding occurred in Au5Al2 after long times above 300°C and in AuAl2 after long times above 400°C weakening these phases catastrophically. The voiding was greatly accelerated by intermittent aging.

Automatic temperature responsive battery charging circuit

Abstract: A charger for charging a battery at a first predetermined rate and automatically terminating said charge rate when the battery temperature rises, in response to the charging current, to a point indicating full charge. The battery has a thermistor mounted therein which changes resistance as the battery temperature changes. The charger includes a charging circuit and silicon controlled rectifier in series with the battery. A sensing circuit, coupled to the thermistor, senses a thermistor resistance indicative of less than a full charge and changes from a first to a second state. If the thermistor resistance indicates a full charge, the sensing circuit changes from the second to the first state. A switch circuit connected to the sensing circuit and the rectifier gate electrode is responsive to changes from the first to the second state to trigger the rectifier into conduction and allow charging of the battery at the predetermined rate. A latch circuit connected to the sensing circuit and rectifier gate electrode operates in response to the sensing circuit changing from the second to the first state to inhibit further conduction of the silicon controlled rectifier. The latch circuit is deenergized, allowing further conduction of the silicon controlled rectifier, by removal of the battery from the battery charger.

Constant current source

Abstract: An improved constant current source, which may provide very small current without requiring the construction of a large resistor, is disclosed. This constant current source includes a transistor having a bias source comprising a second transistor that is biased to low current conduction, the biasing resistor for the biased transistor being advantageously small.

Epitaxial method for the fabrication of a distributed semiconductor power supply containing a decoupling capacitor

Abstract: A monolithic semiconductor structure and method of making same and in which structure supply voltages are distributed through adjacent P and N type layers to surface regions of the structure. These voltages are available for integrated circuits and other devices which are constructed in the surface regions of the structure. Good capacitive decoupling is provided between the P and N layers used to distribute voltages and a relatively high capacitive reactance at the surface region prevents AC short circuits at high frequencies.

Method of fabricating a plastic encapsulated semiconductor assembly

Abstract: A METHOD OF PLASTIC ENCAPSULATION INCLUDING THE USE OF A CORE PIN IN A PRESSURE-TYPE MOLD WHICH FORCES A NONPLASTIC PLATE-LIKE MEMBER AGAINST A DIE FACE FOR PREVENTING PLASTIC ENCAPSULATING MATERIAL FROM FLOWING BETWEEN THE DIE FACE AND THE NONPLASTIC PLATE-LIKE MEMBER TO FORM AND EXPOSED NONPLASTIC SURFACE ON A PLASTIC ENCAPSULATED ASSEMBLY

Diffusion guarded metal-oxide-silicon field effect transistors

Abstract: Metal-oxide-silicon field effect transistors (MOSFET) are shown utilizing diffusion guarding of the gate electrode of a MOSFET device and utilizing the drain of one MOSFET device as the source of the next integrally formed MOSFET device. Other types of isolation shown include the surrounding of a functional unit with a source diffusion area, and/or permanently connecting a gate electrode to a potential level for preventing signal flow past such a gate.

Vacuum-actuated chuck

Abstract: A vacuum-actuated chuck is disclosed for a delicate ceramic package, such as those used for an integrated circuit, in which the package is held firmly in position while the package leads are electrically connected to the bonding pads on the integrated circuit or chip, without, however, distorting the leads extending from the package and without injuring or damaging the package. The chuck comprises a base member having a cavity including support pads for positioning the package and a space for receiving the package leads as well as an additional space for holding a support plate in position. A resilient mat which is impervious to air and which has a hole through the middle portion thereof, fits over the plate and the edge portions of the base member and the edge portions of the package. The hole in the mat exposes the inner ends of the package leads and the bonding pads on the chip so that work may be done thereon.

A high-gain 15-W monolithic power amplifier with internal fault protection

Abstract: A combination of circuit and device innovations has resulted in the development of a 15-W integrated-circuit power amplifier that incorporates a preamplifier on the same chip to give an overall closed-loop gain of 60 dB. Two novel devices used are a new high-frequency drift-lateral p-n-p to improve stability and a new 3-A n-p-n power transistor design with individual emitter ballasting to achieve a larger safe-operating area. Other interesting features are an externally adjustable short-circuit current limit, a built-in thermal shutdown circuit that automatically limits the junction temperature to 175/spl deg/C, an electronic shutdown control to mute the amplifier; a supply voltage range of 10-40 V, excellent power-supply rejection (55 dB), and a unique biasing technique that ensures that the output quiescent point remains at one-half the supply voltage with the total bias current changing only 3 mA over the complete supply voltage range (10-40 V).

Complementary metal oxide semiconductor gate protection diode

Abstract: Gate protection is given to a complementary metal oxide semiconductor (CMOS) devices against excessive input voltage transients. An input diode which has a lower breakdown voltage than the gate oxide is attached to the input terminal to protect the gate oxide. The input protect diode is formed by diffusing an N+ region which overlaps both a P tube and an N substrate. The diffusion concentrations between the various regions determine the breakdown voltage of the protection diode. The overlapping relationship of the N+ diffusion over the P- tub and N substrate creates a structure which prevents parasitic NPN action.

Dual band stripline antenna

Abstract: A dual band antenna is disclosed in which the radiating elements for each band are slots in a conductive sheet and in which the slots are fed by wave guides and stripline distribution means. The conductive sheet is an outside layer of a sandwich comprising two outside conductive layers and two sheets of dielectric between said outside layers and said stripline distribution means or transmission line, between the dielectric sheets. Two additional similar sandwiches are used having therein transmission lines and couplings thereto for the two waves to be radiated. The outside layer of a middle sandwich is in close contact with an outside layer of the two other sandwiches, whereby there is no radiation from between the sandwiches. To make this close contact possible, the sandwiches are made with flat smooth outside surfaces and the sandwiches are not held together in a manner that may cause a bumpy surface.

Integrated circuit amplifier having an improved gain-versus-frequency characteristic

Abstract: Disclosed is an operational amplifier including an input differential amplifier stage and an output driver stage, with each of the input and output stages having pole compensating capacitance means therein for improving the gain-versus-frequency characteristic of the amplifier. The output pole compensating capacitance means is a high voltage MOS capacitor which splits two of the poles of the amplifier''s transfer function, broadbanding one of the poles and narrowbanding the other of the poles to improve the gain-versus-frequency characteristic of the amplifier. The input pole compensating capacitance means is a low voltage PN junction capacitor which relocates one of the poles of the amplifier''s transfer function to thereby further improve the gain-versus-frequency characteristic of the amplifier while at the same time minimizing the total monolithic integrated circuit die area required for the fabrication of the input and output pole compensating capacitance means.

Evaporation emission control device for fuel tanks

Abstract: An evaporation control device consists of two spherical balls which float in a housing defining a cavity so that the balls move up and down in accordance with the fuel level in the tank to allow the top ball to engage a conical seat to seal the vented passageway from the fuel tank to the engine. The spherical contact surfaces between the two balls allow quick and easy movement of the top ball to seal the opening at once where gasoline moves toward the opening.

Adaptive filter wherein opposite conductivity transistors are operative in response to signals in excess of predetermined amplitude

Abstract: An adaptive filter circuit for filtering and attenuating signals coupled thereto which includes first and second opposite conductivity transistors having base electrodes coupled together and emitter electrodes coupled together. The first and second transistors are operative to conduct in response to portions of the signal coupled thereto in excess of a predetermined amplitude. A filter network is coupled to the first and second transistors and has a first predetermined attenuation characteristic when the transistors are non-conductive and a second predetermined attenuation characteristic when the transistors are conductive.

High power gate-controlled switch

Abstract: The ratings of GCS's have remained around 10 amperes and 600 volts since the early 1960's. The problem of increasing the device's capability is therefore reviewed. Experimental results show that turn-off is governed by the diversion of the anode current through the gate,the sequence of junction recovery, the optimum gate drive timing, and the condition of a low impedance drive voltage below the gate avalanche point. Furthermore, the scaling-up for high current assumes that the total current is shared by each elemental area at all times, Tests revealed that nonuiformity leads to shifting of load current during turn-off into on area which causes failure. With due consideration of these factors, a practical design and process for the high power GCS were developed. Data on developmental 50-ampere GCS's are presented.

Monolithic coupling device including light emitter and light sensor

Abstract: A solid state monolithic optical coupling device including a light emitting PN junction, a light sensor and an insulating body. The light emitting PN junction is formed by a body of Ptype semiconductor and a body of N-type semiconductor. The insulating body is formed on the body of N-type semiconductor and the light sensor includes a body of photoconductive material formed on the insulating body. Electrical contacts are provided on the P-type and on the N-type semiconductor, respectively for biasing the light emitting PN junction, and spaced contacts are provided on the body of photoconductive material for applying a voltage thereto. When the light emitting junction is forward biased, light emitted thereat is transmitted through the insulating body and is absorbed by the photoconductive material, causing the conductivity thereof to change and thereby changing the current through the spaced electrodes thereon.

Data transferring system utilizing a monitor channel and logic circuitry to assure secure data communication

Abstract: The transmitter-encoder of the data transferring system utilizes polybinary, correlative encoding to develop an information carrying signal, which includes a monitor signal having a known data code, and data from a plurality of sources. The encoding techniques facilitates redundant bit transmission in a constrained bandwidth. The receiver-decoder includes monitor channel logic circuitry which determines whether the decoded signal is free from error. Moreover, each of the data decoding channels utilizes majority logic to verify that a particular control initiating signal is being received before the control signal is applied to data utilization devices associated therewith. If one error is detected in the monitor signal, the data channels are squelched for a first predetermined period of time thus preventing erroneous control signals from being applied to the utilization devices. If more than one error is detected in the monitor signal within a second predetermined period of time the data channels are squelched for a third predetermined period of time and an alarm is activated by the monitor channel-logic circuitry. As a result, the system provides security against abnormal transmission characteristics.

Process for soldering printed board assemblies utilizing paste solder and infrared radiation

Abstract: PROCESS FOR SOLDERING COMPONENTS ON PRINTED CIRCUIT BOARDS, WHEREIN SOLDER IS APPLIED IN PASTE FORM TO CONDUCTORS ON THE BOARD AND PASSED THROUGH AN OVEN TO CURE THE SAME THE BOARDS WITH THE SOLDER THEREON CAN BE STORED, OR CAN BE IMMEDIATELY USED, IN WHICH CASE COMPONENTS ARE PLACED ON THE BOARDS WITH LEADS INSERTED IN OPENINGS IN THE CONDUCTORS AND BOARDS THE BOARDS WITH THE SOLDER AND COMPONENTS THEREON ARE GRADUALLY PREHEATED, AND THE SOLDER IS THEN HEATED BY INFRARED RADIATION FOCUSED THEREON TO CAUSE THE SOLDER TO FLOW ABOUT THE LEADS CAUSING AN ELECTRICAL AND MECHANICAL CONNECTION THE PREHEATING MAY BE PROVIDED BY DIFFUSED INFRARED RADIATION, BY PULSING A HEAT SOURCE, OR BY OTHER MEANS

Single crystal silicon contact for integrated circuits and method for making same

Abstract: The method for making a single crystal silicon contact for integrated circuits is described. The epitaxial contact is selfpatterning and is formed by coherent growth on a surface of monocrystalline silicon for protecting and contacting said surface.

Hyperfine geometry devices and method for their fabrication

Abstract: A hyperfine geometry device and the method for the making thereof is disclosed which method employs the combination of a patterned oxide layer having apertures designating all the regions to be diffused into a substrate body. A layer of amorphous silicon is formed over the upper surface of the substrate body including the surface of the substrate exposed through the apertures as well as the oxide formed on said upper surface. A third layer of silicon dioxide is formed over the amorphous silicon layer and is patterned to expose selected apertures within the initial or first oxide layer. The patterning of this third layer need not be precise. A diffusion is performed through such exposed amorphous silicon areas into the substrate body. After such diffusion, the amorphous silicon is chemically changed into an oxide for protecting the diffusion aperture from additional diffusions or alternatively, a new passivating layer is formed over such previously diffused areas. In this manner apertures in the first oxide layer are selectively exposed as required in the sequence for manufacturing the desired semiconductor device.