Check Out the PCMI Online Library!

online library

The PCMI Library contains hundreds of publications that cover a broad range of subjects from process information and latest equipment technology through to market applications of the PCM process. These publications include electronic copies of journal archives and general PCM-related informational articles.

For PCMI members the publications are free, but everyone can download a sample for FREE!

Emeritus Professor David Allen, well-known PCM authority, consultant and specialist, has offered to share a few publications to illustrate the wide selection of industry-related publications available for download in the PCMI Online Library.

Free Publication Abstract

Characterization of aqueous ferric chloride etchants used in industrial photochemical machining
David M. Allen* and Heather J.A. Almond

Ferric chloride (FeCl3) is the most commonly used etchant for photochemical machining (PCM) but there is a great variety in the grades of the commercial product. This paper aims at defining standards for industrial etchants (that are not chemically pure) and methods by which they are analyzed and monitored.

In an ideal world, to maintain a constant rate of etching and hence control of part dimensions dependent on etch time, the etchant composition would be constant. Unfortunately, in the real world, the etchant composition changes continuously. As an n-valent metal (M) is dissolved into solution, etchant is consumed and the by-products of ferrous chloride (FeCl2) and metal chlorides (MCln) are generated, i.e.  Read More…

Click here to download the free publication.