Relation between Dielectric Characteristics at Low Frequency and Degradation of Printed Wiring Board by Ionic Migration

Optical interconnect on printed wiring board

Integration of high-speed parallel optical interconnects into printed wiring boards (PWB) is studied. The aim is a hybrid optical–electrical board including both electrical wiring and embedded polymer waveguides. Robust optical coupling between the waveguide and the emitter/detector should be achieved by the use of automated pick-and-place assembly. Different coupling schemes were analyzed by c...

The state of the art in printed wiring board inspection

Automated visual inspection of printed wiring is providing research opportunities in completely utomated optical systems technology. This paper addresses device design considerations, articularly the important problem of turning an optical inspection device into a tool for lanufacturing process analysis and control.

Pull-off test in the assessment of adhesion at printed wiring board metallisation/epoxy interface

It is shown that the value of adhesion strength at the metallisation/polymer interface can be determined directly from a printed wiring board (PWB) by a pull-off method. However, careful optimisation of the test geometry is required. In particular, the mechanical properties of the substrate are important. The use of flexible substrate in the test results in severe underestimation of the adhesio...

Relation between dielectric and low-frequency Raman spectra of hydrogen-bond liquids.

We analyzed the complex dielectric and Raman spectra of hydrogen-bond liquids in the microwave to terahertz frequency range. As for water and methanol, the high-frequency component of the dielectric spectrum, i.e., the small deviation from the principal Debye relaxation, clearly corresponds to the Raman spectrum. This indicates that the cooperative relaxation, accompanied by huge polarization f...

Printed Wiring Board Pollution Prevention and Control Technology: Analysis of Updated Survey Results