Abstract:
In a wiring board having a mounting region on which an integrated circuit having a plurality of terminals is mounted, and having a plurality of substrate-side wiring lines to be connected to the integrated circuit formed thereon, a conductor pattern is formed to extend in a substantially radial form from a prescribed, point in the mounting region to reach two or more of the substrate-side wiring lines to be grounded.
Abstract:
In a multi-layered printed circuit board on which an LSI having a plurality of power supply pins and a plurality of signal pins is mounted, and a grid array package which adopts the printed circuit board, some or all of the plurality of power supply pins are connected to a power supply pattern via an inductance pattern, thereby reducing generation of radiation noise.
Abstract:
A resistor of SMD (Surface Mounted Device) construction includes a film of a resistive alloy as a resistive track on two electrically separated carrier plate elements of copper, which are constructed as contact elements solderable to the terminals of a printed circuit board to thereby ensure good heat dissipation into a printed circuit board. In order to manufacture such resistors, a resistive film sufficient for a plurality of individual resistors is adhered to but electrically isolated from a large copper plate and the laminate formed thereby is split into the individual resistors after producing the individual resistive tracks and their electrical connections to the copper plate and after producing gaps between the plate elements for each track.
Abstract:
Electromagnetic filtering for a VLSI device having multiple power input leads is realized by employing a sub-power plane which is physically separate from a main power distribution system on a circuit board. The sub-power plane is placed directly under a corresponding VLSI device. Decoupling capacitors are connected to the sub-power plane and, in turn, to each of the power input leads on the VLSI device. Power is supplied from the main power distribution system to the sub-power plane via a ferrite bead type filter.
Abstract:
A fiber optic to electrical conversion unit includes front and rear modular design with rear card modules conditioning signals to be passed to front modules. A frame synchronization method transmits a stream of multiplexing frames and periodically inserts a synchronization word in the stream. Prediction of the next synchronizing word in the receiving unit reduces the need to search for a synchronization word in the stream. Loop current regulation in a two-wire loop between a central office and a PBX uses a transformer serially connected in the two-wire circuit with a regulation circuit which holds the current in the loop within a predetermined range to permit the transformer to be held to a relatively small size. High frequency noise bypassing is accomplished by forming capacitor loops from the power connection to the ground connection of the component near to the component.
Abstract:
Apparatus and method for bypassing high frequency noise from a component mounted to a circuit board provides that the component be connected to the power and signal ground planes of the PC board with respective signal traces and that bypass capacitors be connected between these signal traces between the component and the signal and ground planes.
Abstract:
A high density memory module in which memory chips are mounted in an array of rows and columns on a printed circuit board. The circuit board includes groups of serpentine parallel conductors which extend along adjacent columns for connecting corresponding power, ground, control, address and data pins between the adjacent columns to one another. Adjacent groups of serpentine parallel conductors are nested within one another. According to the invention, high density packaging is provided for large chip arrays, using a minimum number to vias to interior board layers, and minimum interchip spacing.
Abstract:
A multilayer printed circuit memory board is designed and constructed so that the top and bottom layers contain repetitive integrated circuit (IC) chip component hole/pad and interconnection line patterns which are mirror images of one another. The board uses surface mounted techniques in which the integrated chip components of the memory array are mounted and soldered to both sides of the board thereby doubling the density or capacity of the memory board. The integrated circuit memory chips, mounted on the top and bottom of the board, are aligned with each other for sharing common holes or vias in which logically equivalent input signal connections are exchanged in a manner for reducing the number of holes and length of connective wiring.
Abstract:
A circuit package, or other device, (10) is mounted on a printed circuit board, or other substrate, (14) with an electrically conductive sinuous resistor wire structure 30 therebetween to define a space filled with adhesive. When the adhesive is set the package is held in place. When removal is desired, current is passed through the sinuous wire structure to soften the adhesive to permit removal of the package without damage to the package or the board.
Abstract:
In an electronic circuit arrangement mounted on a printed circuit board in which leadless circuit parts are attached to the printed circuit board with adhesive. A white paint is applied onto a region to which adhesive is applied, and an adhesive containing pigment contrastable to the white paint is applied onto the paint.