High-Throw DC Acid Copper Formulation for Vertical Continuous Electroplating Processes


Reading time ( words)

Abstract

The electronics industry has grown immensely over the last few decades owing to the rapid growth of consumer electronics in the modern world. New formulations are essential to fit the needs of manufacturing printed circuit boards and semiconductors. Copper electrolytes for high throwing power applications with high thermal reliability and high throughput are becoming extremely important for manufacturing high aspect ratio circuit boards.

Here we discuss innovative DC copper metallization formulations for hoist lines and vertical continuous plating (VCP) applications with high thermal reliability and throughput for high aspect ratio PCB manufacturing. The formula has a wide range of operation for current density. Most importantly, plating at high current density using this DC high-throw acid copper process offers high throughput, excellent thermal reliability, and improved properties for present-day PCB manufacturing. The operating CD range is 10–30 ASF where micro distribution of ≥ 85% for AR 8:1 is achievable. This formulation offers bright ductile deposits where plating parameters are optimized for improved micro-distribution and the properties of the plated copper deposit such as tensile strength and elongation. The thermal reliability and properties of the deposits were examined at different bath ages. Measured properties are: Elongation ≥ 18% and tensile strength ≥ 40,000 psi. All the additives can be easily controlled by cyclic voltammetry stripping (CVS) analysis.

Introduction

Copper has a high electrical conductivity and is relatively inexpensive compared to other high conductive metals such as silver. Therefore, the use of copper in the mass production of PCBs and semiconductors grew exponentially in the last few decades[1]. With today’s complex circuit board designs an even deposition with specific physical properties is necessary to meet the standards. Especially with high aspect ratios, through-hole plating to obtain desired plating distribution is much more challenging. During the quality control inspection, a board can be rejected if there is insufficient copper on the center walls of the through-holes. Moreover, plated copper should meet the minimum requirements of physical properties such as tensile strength and elongation (T&E) to withstand the high temperature applications[2].

To read the full version of this article which appeared in the August 2017 issue of The PCB Magazine, click here.

Share


Suggested Items

Walt Custer’s Annual Update from productronica 2017

11/21/2017 | Patty Goldman, I-Connect007
Industry consultant Walt Custer of Custer Consulting sat down with me at productronica 2017 to once again inform our readers with his yearly update and perspective on what’s happening in the industry. And guess what? It’s good news! Pertinent charts referenced in our conversation are included, but if you want more, Walt invites you to click the link at the end of this conversation and email him directly.

New I-Connect007 Team Members Tour American Standard Circuits

11/06/2017 | Kiersten Rohde and Jonathan Zinski, I-Connect007
Recently, Anaya Vardya, CEO of American Standard Circuits, invited two of I-Connect007’s newest team members, IT coordinator Jonathan Zinski and Editor Kiersten Rohde, to tour his facility in West Chicago, Illinois. Happy Holden, resident PCB expert, also joined the newbies on their field trip to ASC. In the following articles, Jonathan and Kiersten describe their experience touring ASC. Special thanks to Anaya for hosting the I-Connect007 team.

Catching up with…Brigitflex

11/02/2017 | Dan Beaulieu
Today, Brigitflex is building unique custom-made boards for companies all over the world, from large defense and aerospace companies to small incubator companies inventing new products. They have become well-known as the shop to go to when nobody else can solve your problems.



Copyright © 2017 I-Connect007. All rights reserved.