OSP and Selective Electroless Nickel for Mixed-Metal Finish PWBs and BGA Substrates

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The documentation relating to the requirements for alternative surface finishes have been well publicized at many industry forums. Pressure to eliminate lead in electronics assemblies is forcing fabricators and OEMs to reevaluate their surface finish and joint attachment procedures. Many of the requirements, in fact, are obvious. Regardless, the PWB fabrication industry needs to work closely with contract manufacturers and end users to fully appreciate the true impact of technology trends. These trends are significant and include:

• Surface mount continues to increase at the expense of through-hole with finer and finer features.
• The use of non-tin/lead coatings and surface finishes will increase. Surface finishes such as electroless nickel/immersion gold, OSP and immersion tin will be utilized.
• With political movements toward banning lead in all electronic assemblies gaining significant  momentum, lead-free solder pastes and wave solder materials will be adopted.
• The need for more robust solderable finishes under extreme environmental conditions including corrosive atmospheres.
• The alternative surface finishes must perform through multiple thermal cycles with less active pastes and fluxes.
• The use of multiple metal finishes on the same bare board will place new emphasis on the compatibility of coating with each other, and the actual assembly module.
• Increased I/O demand and reduced lead pitch will require much tighter controls over the processes used to fabricate the bare board.

Read the full article here.

Editor’s Note: This article originally appeared in the February 2015 issue of The PCB Magazine

11/25/2020 | Dan Beaulieu, D.B. Management Group

Founded in 2007, QCMS is one of the more interesting EMS companies on the East Coast. They are actually a sister company to Niche Electronics located in Pennsylvania. Dan Beaulieu interviews QCMS General Manager Rick McAnally.

11/25/2020 | Pete Starkey, I-Connect007

With its regular program of physical seminars and symposia on hold, the Institute of Circuit Technology went virtual and presented a webinar of three technical papers, organized by Technical Director Bill Wilkie and introduced by IPC Chair Emma Hudson. Pete Starkey brings you all the details.

11/19/2020 | I-Connect007 Editorial Team

We asked for you to send in your questions for Joe Fjelstad, and you took us up on it! We know you all enjoyed reading these questions and answers, so we’ve compiled all of them into one article for easy reference. We hope you enjoy having another bite at the apple. And if you’d like to hear more from Joe, view his column series “Flexible Thinking.”