ABSTRACTThe predominate substrate for multilayer printed wiring boards is laminate constructed from epoxy resin reinforced with fiber glass fabrics. This combination of materials dominates the segment of the electronics market where dimensional stability of the substrate is critical. The rapid development of high speed digital and analog electronic systems has challenged the predominance of fiber glass as the reinforcement of choice. As systems move to the GHz frequency range, there is a need for lower dielectric constant of the substrate to insure integrity and speed of signals. A lower dissipation factor of the substrate is desired for the wireless communication applications of printed wiring boards. A review is presented of materials competing as substrates for the high speed application of the printed wiring board market.
Recently, printed wiring boards (PWBs) employed in electronic devices have been miniaturized, lightened, and made multifunctional. Therefore, a new technology is required to improve the mounting density of PWBs. In the present report, we study high-quality, high-speed drilling of through-holes in PWBs. Particularly, we investigate the tool path for drilling grid-pattern holes. We estimate the drill temperature and PWB temperature while drilling the PWBs. On the basis of the results, we propose a tool path decision method that considers heat damage on the PWBs for a drilling CAM system.
AbstractHigh speed, high density packaging requirements have made multichip modules (MCM) one of the most active areas of research in the electronic industry.High density printed wiring board (PWB) have low production cost and good electrical performance. However, the most questioned issue in application is the reliability. As a result, a thermal and mechanical analysis on a MCM has been conducted to understand its feasibility. The results indicate that with proper design, the components can operate under satisfactory conditions on PWB laminates.
Factors Controlling the Surface Morphology of Copper Foil for Printed Wiring Board Electrodeposited at High Speed.
