Issue link: https://iconnect007.uberflip.com/i/1473479
98 PCB007 MAGAZINE I JULY 2022 Introduction If one thought that electroless copper and other metallization systems were complex and the deep dark secrets of these systems shrouded in black magic, the discussions on electroplat- ing will seem like brain surgery. In this next series of columns, the intricacies of electrodeposition technology and its func- tion of building up the thickness of copper in the holes and on the surface will be presented in detail. Function of the active ingredients in the copper plating solutions will be presented. Process control limits for the various plat- ing solution components and the effects on deposit integrity will be discussed. Electrodeposition In contrast to the classic initial through- hole metallization with electroless copper, the buildup of the conductive layer in the through- hole to the desired thickness is being achieved by the electrodeposition of copper. It is under- stood that these technologies overlap, i.e., some initial metallization processes use direct electroplating and, conversely, fully additive processes build up copper solely with the elec- troless process. e historic preference for building up the copper deposit by electroplating has to do with the lower cost, faster deposition rate, and in general, better metallurgical properties of the electroplated copper. Improvements concen- trated on the "throwing copper" of the elec- trolytes, i.e., their ability to deposit a relatively uniform deposit of copper on the board surface and in the through-holes. A shi to higher acid and lower copper concentrations, as well as improved organic additives systems (brighten- Electrodeposition of Copper, Part 2 Trouble in Your Tank by Michael Carano, RBP CHEMICAL TECHNOLOGY