A Photoimageable Dielectric for Sequential PWB Fabrication

Abstract

As printed wiring boards move to thin laminate structures, there is growing interest in the use of photoimageable coatings to serve as dielectric. Shipley has developed a liquid photoimageable dielectric which combines liquid coating, imaging and plateability. This paper presents work using this material to produce electrolessly plated lines and blind vias, along with initial adhesion data. Some of the interesting properties of this material are: low dielectric constant, low moisture absorption and good compliance to stress. The material can be processed to provide a high Tg and high plated adhesion can be obtained using conventional swell and etch techniques. It can be imaged and processed using conventional printed circuit coating and imaging techniques. This material will offer a relatively low cost alternative to thin clad laminates and may find use for adding one or two layers to a conventional multilayer board or in providing surface topography for surface mount devices. The paper describes recent developments related to this dielectric and its use.

Citation

Knudsen, P.D., Brainard, R.L. and Schell, K.T. (1995), "A Photoimageable Dielectric for Sequential PWB Fabrication", Circuit World, Vol. 21 No. 3, pp. 5-9. https://doi.org/10.1108/eb044030