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Power transistor is provided with an integral flat plate aluminum heat sink which mounts directly on a printed circuit board containing associated circuitry. Standoff spacers are used to attach the heat sink to the printed circuit board containing the remainder of the circuitry.
A multi-board module provides high density electronic packaging in which multiple printed circuit boards are stacked. Electrical power, or signals, are conducted between the boards through a resilient contact. One end of the contact is located at a via in the lower circuit board and soldered to a pad near the via. The top surface of the contact rests against a via of the facing printed circuit board.
Array of tiny probes tests complex printed circuit boards prior to mounting of microcircuit chips and other active and passive components. Insertion and alignment of board, performance of entire computer-controlled test, and printing of results requires about a minute; performed manually same tests require as much as 30 hours.
Topographic simulation scheme used to program path layout of conductors in printed circuit board design
Printed circuit boards retaining as much copper as possible provide electromagnetic shielding between stages of the high frequency amplifiers and transmitters. Oscillation is prevented, spurious output signals are reduced, and multiple stages are kept isolated from each other, both thermally and electrically.
Environmental testing and material characteristics of multilayer printed circuit boards
Mentor's DxDesigner and Expedition schematic capture and printed circuit board tools were chosen to implement a custom high speed signal processing board containing many high pin count Field Programmable Gate Arrays and many high speed serial connections with data rates over 2 Gigasamples/sec. The methodology used to place the parts and route the board involved the interaction of both the DxDesigner and Expedition tools. The basic design philosophy was to specify as much as possible through design constraints at the schematic level. This paper will explore implementing that philosophy in both tools to facilitate part placement and trace routing.
Techniques for preparing printed circuit boards are used to provide an alternate method for producing panel symbology for ground computer test trap. After processing, the panel unit is either solder or gold plated.
Investigation of soldered component failure in plated printed circuit boards consisting of tinned laminate copper, plated copper, and gold overplate
Compatibility standards for printed circuits and component wire materials
Cold testing method prevents formation of frost on printed circuit boards and part holders during testing at sub-zero temperatures. Freon permits rapid attainment of the required testing temperature.
Electrical connection for printed circuits on common board, using bellows principle in rivet
Program assists in solving spacing problems encountered in printed circuit /PC/ design. It is intended to have maximum use for two-sided PC boards carrying integrated circuits, and also aids design of discrete component circuits.
Materials compatibility study for improved multilayer printed circuit board
A Solder Committee designated to investigate a solder cracking phenomena occurring on the SATURN electrical/electronic hardware found the cause to be induced stress in the soldered connections rather than faulty soldering techniques. The design of the printed circuit (PC) board assemblies did not allow for thermal expansion of the boards that occurred during normal operation. The difference between the thermal expansion properties of the boards and component lead materials caused stress and cracking in the soldered connections. The failure mechanism and various PC boards component mounting configurations are examined in this report. Effective rework techniques using flanged tubelets, copper tubelets, and soft copper wiring are detailed. Future design considerations to provide adequate strain relief in mounting configurations are included to ensure successful solder terminations.
Nondestructive measurement of elastic and plastic deformation in soldered joints and printed circuit boards by holographic interferometry
Highly reliable soldered joints for printed circuit boards
Ferric chloride in an aqueous medium etches copper from the surface of printed-circuit boards. Ferric ions are reduced to ferrous ions resulting in a reduced etching rate.