Electronics Assembly Knowledge, Vision & Wisdom
Quantitative Analysis of Corrosion Resistance
Quantitative Analysis of Corrosion Resistance
An electrochemical method via sequential electrochemical reduction analysis instrument to quantify the corrosion resistance of the EN deposit is proposed.
Analysis Lab

Authored By:
Dr. Lei Jin, Dr. Jun Nable, Dr. Kesheng Feng, Lenora Toscano, Dr. Ernie Long
Electronics Solutions, MacDermid, Inc.
Waterbury, CT USA
,{url:'http://www.circuitinsight.com/videos/programs_final.mp4'}], clip:{autoBuffering:true, autoPlay:true, scaling:'scale' } }).ipad();
Summary
An electroless nickel (EN) layer is frequently used in various industrial applications. Commonly it is used as the barrier layer in electroless nickel/immersion gold (ENIG) as a solderability preservative for the electronics industry. The finish provides excellent corrosion resistance and good solderability. A shortcoming of this process is the potential for a hyperactive corrosion of the nickel surface during immersion gold plating. The resultant defect displays itself as a gray or black appearance at the nickel/gold interface, known as "Black Pad" or "Black Line Nickel".

It is important to determine and control the corrosion properties of an EN deposit during an ENIG process to obtain high quality products. Unfortunately, quantitative analysis of corrosion resistance of the EN layer has not been established in the field of PCB. In this paper, an electrochemical method via sequential electrochemical reduction analysis (SERA) instrument to quantify the corrosion resistance of the EN deposit is proposed. The data obtained via the electrochemical method was analyzed and correlated to the deposit properties of the EN. The method is easy to use and can be applied for quantitative analysis in industrial EN processes.
Conclusions
Results presented here show that the new SERA test method can be applied on a routine basis to assess the corrosion resistance behavior of EN deposit. This method is a relatively simple, fast, and quantitative analysis. Within the same EN bath, this method can even be used to determine P% at different points on a PCB boards. This proposed method can also been applied on other applications, such as EN quality control, product screening, and formulation comparisons on a simple and quantitative basis.
Initially Published in the IPC Proceedings
Submit A Comment

Comments are reviewed prior to posting. Please avoid discussion of pricing or recommendations for specific products. You must include your full name to have your comments posted. We will not post your email address.

Your Name


Company


E-mail


Country


Comments


Authentication

Please type the number displayed into the box. If you receive an error, you may need to refresh the page and resubmit the information.



Related Programs
bullet How To Verify Cleanliness After Rework and Prior to Re-coating?
bullet SMT Adhesive Inspection
bullet Signal Loss in a High Speed High Frequency Transmission Line
bullet Exposed Leads on Conformally Coated Boards
bullet Un-cleaned PCB Assemblies Potted
bullet Dewetting of Acrylic Conformal Coating
bullet Conformal Coating for Tin Whisker Management
bullet Conformal Coating over No Clean Flux
bullet Aerosol Jet Printing of Conductive Epoxy for 3D
bullet Hybrid Conformal Coatings for Mitigating Tin Whiskers
More Related Programs
About | Advertising | Contact | Directory | Directory Search | Directory Submit | Privacy | Programs | Program Search | Sponsorship | Subscribe | Terms

Circuit Insight
6 Liberty Square #2040, Boston MA 02109 USA

Jeff Ferry, Publisher | Ken Cavallaro, Editor/Business Manager

Copyright © Circuitnet LLC. All rights reserved.
A Circuitnet Media Publication