Abstract: A solder composition is provided comprising from about 5.5 to 7.0 percent by weight of bismuth, from about 2.0 to 2.5 percent by weight of silver, from about 0.5 to 0.7 percent by weight of copper, and the remainder of the composition being tin. The use of the solder composition and an electronic device comprising the solder composition are also provided.

Abstract: There is disclosed a mass storage device (such as a hard disk drive) comprising an input connector for electrically receiving both a first set of data signals and a second set of data signals. The first set of data signals are used to store or retrieve information on the mass storage device, whereas the second set of data signals are electrically conducted to an output connector on the mass storage device. When an adjacent mass storage device is connected to the output connector, the second set of data signals are used to store or retrieve information on this adjacent mass storage device.

Abstract: A flat panel display structure is disclosed that can support significant loads on the viewing surface without fracturing or permanently damaging the video display. A rigid body is fitted in a peripheral frame and situated behind the viewing surface. When a load is applied to the video display, the load is transferred to the rigid body, which absorbs and distributes the load to the peripheral frame.

Abstract: It has been observed that turbulent solder flow, particularly at the opening of a conventional flow well, correlates to a greater degree of Cu dissolution of the PTH barrels of a PCB, especially those that are aligned with the opening. A more laminar solder flow is created to more evenly distribute the solder flow and thus reduce the rate of Cu dissolution near the flow well opening, particularly during a PTH rework process. In one aspect, a flow well for a soldering machine is provided comprising a flow distribution element, wherein solder flowing into the flow well is distributed by the flow distribution element to provide a more laminar flow.

Abstract: It has been observed that turbulent solder flow, particularly at the opening of a conventional flow well, correlates to a greater degree of Cu dissolution of the PTH barrels of a PCB, especially those that are aligned with the opening. A more laminar solder flow is created to more evenly distribute the solder flow and thus reduce the rate of Cu dissolution near the flow well opening, particularly during a PTH rework process. In one aspect, a flow well for a soldering machine is provided comprising a flow distribution element, wherein solder flowing into the flow well is distributed by the flow distribution element to provide a more laminar flow.

Abstract: The invention provides a heat sink assembly having a positionable heat sink permitting the heat sink to be mounted to a substrate in more than one configuration. Various features are described for permitting multiple degrees of freedom in the arrangement of the heat sink assembly. Such features permit the heat sink assembly to be adapted to different environments. The heat sink assembly also has features such as a vane for directing air flow relative to the heat sink. Features for varying and maintaining pressure between the heat sink and a component to be cooled are also included.

Abstract: A thermo-electro sub-assembly comprises a gas supply, a first duct, a first heatsink adjacent a first device, a second duct, and a second heat sink adjacent a second device. The gas supply may be realized as a fan, a blower, or a compressed gas source. The first duct provides a passageway for delivering pressurized gas from the gas supply to the first heat sink. The duct may include a plurality of vanes for reducing the turbulence and air boundary separation within the duct. The first heatsink is in thermal communication with a first heat-producing device such as a microprocessor. In a preferred embodiment the heatsink comprises an axial shaped folded fin heatsink. The second duct is used to provide a pathway for the air leaving the first heatsink and delivers the air to the second heatsink. The second duct may also include a plurality of vanes for reducing turbulence and boundary flow separation within the second duct.

Abstract: For an asynchronous memory control system, a system and method of interfacing the system with a synchronous memory device is provided. A first set of signals indicating an asynchronous memory operation from the control system and a first memory address associated with the asynchronous memory operation from the control system are received. Next, a second set of signals, a second memory address and at least one asynchronous clock pulse are generated, wherein the generated signals allowing processing of a comparable synchronous operation to the asynchronous operation by the synchronous memory device at the second memory address. The second set of signals and initiation, duration and frequency of the asynchronous clock pulse comply with requirements of the synchronous memory device to process the synchronous operation.

Abstract: The invention provides a heat sink assembly having a positionable heat sink permitting the heat sink to be mounted to a substrate in more than one configuration. Various features are described for permitting multiple degrees of freedom in the arrangement of the heat sink assembly. Such features permit the heat sink assembly to be adapted to different environments. The heat sink assembly also has features such as a vane for directing air flow relative to the heat sink. Features for varying and maintaining pressure between the heat sink and a component to be cooled are also included.

Abstract: A heat removal system comprising a gas supply, a duct, and a heatsink is presented. The gas supply may be realized as a fan, a blower, or a compressed gas source and is located remotely from the heatsink. The duct provides a passageway for delivering high velocity gas from the gas supply to the first heat sink. The duct includes a plurality of vanes for reducing the turbulence and air boundary separation within the duct. The heatsink is in thermal communication with a heat-producing device such as a microprocessor.

Abstract: A control system for selectively isolating a power supply from a common bus is provided. The control system comprises a connection to an output path of an output signal of the power supply and a resistive element providing a variable resistance between an input terminal and an output terminal. The input terminal is connected to the connection and the output terminal is connected to the common bus. The resistive element further comprises a control terminal allowing adjustment of the variable resistance. A control element provides a control signal to the control terminal; the control element is responsive to current flowing between the output path and the common bus.

Abstract: A control system for selectively isolating a power supply from a common bus is provided. The control system comprises a connection to an output path of an output signal of the power supply and a resistive element providing a variable resistance between an input terminal and an output terminal. The input terminal is connected to the connection and the output terminal is connected to the common bus. The resistive element further comprises a control terminal allowing adjustment of the variable resistance. A control element provides a control signal to the control terminal; the control element is responsive to current flowing between the output path and the common bus.

Abstract: A power loss reduction circuit and method for use in an output stage of a voltage converter is provided. The circuit has one transistor associated with a first output terminal of the output stage and ground. There is also a clamping circuit associated with the first output terminal. There is also a second transistor with a second conduction path associated with a second output terminal of the output stage and ground. The second transistor has a second control terminal controlled by a second control signal. Each of the first and second transistors has a lower voltage drop than a voltage drop for a Schottky diode. There is also a second clamping circuit associated with the second output terminal. There is also an energy storage device associated with the first and second clamping circuits to store energy from the first and second ringing signals.

Abstract: A Printed Circuit Board (PCB) has a cut-out that permits a monolithic copper or aluminum heatsink to be mounted flush with the surface of the PCB. Electrical devices can be mounted to the monolithic heat sink. The heat sink is bent to extend out of the plane of the PCB. The heatsink can have parts mounted to connect with either face of the PCB, and can extend from either side of the PCB. The heatsink is stepped to present one surface flush with the PCB and another surface that lies along the face of the PCB.

Abstract: The printed circuit board (PCB) header attachment station mounts a header (PCB) onto a PCB having pre-existing solder joints, such as underneath a direct mount IC chip. The apparatus applies a soldering paste to PCB lands configured to receive the pins of the header; nests the header component in stacked alignment with the PCB in order to bring the header pins into contact with the respective PCB lands; heats the PCB to a temperature approaching the reflow temperature of the solder in the pre-existing PCB solder joints; and actuates a compliant heating block or bar to heat the header pins to an extent sufficient for the pins to conduct enough heat to locally reflow the solder on the corresponding PCB lands without reflowing the solder in the pre-existing solder joints. The local reflow of the solder precludes solder reflow in the surrounding pre-existing joints which may coalesce under the direct mount IC chip and render the PCB defective.

Abstract: A central processing unit having at least one memory for storing instructions and data includes a program counter for storing program counter values. An execution unit retrieves and processes instructions located in the memory at addresses corresponding to the contents of the program counter. Multiple stacks independent of the memory are provided for storing program counter values. A multiplexer connects the program counter to each stack. A stack select register connected to a control input of the multiplexer enables the transfer of program counter values between the program counter and one of the stacks indicated by the contents of the stack select register. The central processing unit provides an efficient multi-tasking capability since the program counter state of each task can be stored in one of the multiple stacks.

Abstract: There is provided a detector for detecting conductive contaminants entrained in an airflow. The detector comprises first and second electrically conductive meshes mounted in a spaced apart relationship to provide an operational gap. Each of the meshes is sized to provide a relatively large surface for substantially intersecting the airflow and is sufficiently porous so as not to substantially attenuate the airflow. The meshes form part of an energizable electric circuit wherein the operational gap constitutes a discontinuity of the circuit. The detector includes a capacitor connected in parallel to the portion of the circuit containing the operational gap for releasing a charge stored in the capacitor through the circuit discontinuity when one of the conductive contaminants simultaneously contacts the first and second meshes. The detector further provides for indication of a discharge of the capacitor and thereby the presence of one of the airborne conductive contaminants entrained in the airflow.

Abstract: A printed antenna structure for transmission of radio frequency energy in the gigahertz range that provides good dispersion characteristics and a relatively wide bandwidth using a thin substrate material. The antenna includes a thin printed circuit board having top and bottom surfaces. The bottom surface features an electrically conductive ground plane layer. The top surface features a microstrip feed line structure which is connected to a radiating element. The microstrip feedline extends over the ground plane but the radiating element does not. The radiating element has a main V-shaped segment for coupling radio energy over a wide spatial region, and a tuning stub is sequentially connected to the V-shaped segment. Overall, the printed antenna has an overall shape which resembles a hook in oder to minimize the space occupied on the printed circuit board.