-
- News
- Books
Featured Books
- pcb007 Magazine
Latest Issues
Current IssueThe Essential Guide to Surface Finishes
We go back to basics this month with a recount of a little history, and look forward to addressing the many challenges that high density, high frequency, adhesion, SI, and corrosion concerns for harsh environments bring to the fore. We compare and contrast surface finishes by type and application, take a hard look at the many iterations of gold plating, and address palladium as a surface finish.
It's Show Time!
In this month’s issue of PCB007 Magazine we reimagine the possibilities featuring stories all about IPC APEX EXPO 2025—covering what to look forward to, and what you don’t want to miss.
Fueling the Workforce Pipeline
We take a hard look at fueling the workforce pipeline, specifically at the early introduction of manufacturing concepts and business to young people in this issue of PCB007 Magazine.
- Articles
- Columns
Search Console
- Links
- Media kit
||| MENU - pcb007 Magazine
Estimated reading time: 1 minute

Contact Columnist Form
Lead-free Compatible OSPs: What Does This Really Mean?
Introduction
The setting: Early 2008. Many fabricators and EMS providers are continuing to push programs for RoHs compliance. This, of course, requires electronic assemblies to be, among other things, free of lead-bearing materials. To adopt such a program, the surface finish, component finish and the solder used in assembly must be lead-free. While the questions surrounding these issues are many, one in particular appears more frequently: How do we know that a particular finish is truly lead-free soldering compatible? This particular question is being addressed by one of the IPC standards writing committees responsible for developing an industry standard specification of organic solderability preservatives (OSP).
The Nature of the Beast
The IPC committee made up of a cross-section of suppliers, PWB fabricators, OEMs and EMS companies is working to complete the development of IPC-4555 (standard for OSP). This committee is developing a protocol to test OSP coatings for lead-free (high-temperature) compatibility. The protocol requires that copper coupons coated with the OSP would be subjected to three lead-free reflows, then tested for wettability with an appropriate wetting balance instrument. It should be noted that after the coupons are processed through the OSP solution, the coupons shall be rinsed with DI water and dried at 105°C. Following the protocol of the ANSI-JSTD-003B, the samples shall be fluxed using the standard 0.5% activated flux and immersed in SAC305 at a temperature of 255°C for 10 seconds. Further:
- Ten samples per test shall be run.
- The mean and standard deviation of the maximum force achieved shall be documented.
Interestingly, the committee has also recommended that a second set of test coupons be processed under the same pretreatment conditions. This time, however, without the drying step. Again, the ANSI-JSTD-003B, wetting balance procedure to measure wettability, will be utilized.
Read the full column here.
Editor's Note: This column originally appeared in the November 2014 issue of The PCB Magazine.
More Columns from Trouble in Your Tank
Trouble in Your Tank: Interconnect Defect—The Three Degrees of SeparationTrouble in Your Tank: Things You Can Do for Better Wet Process Control
Trouble in Your Tank: Processes to Support IC Substrates and Advanced Packaging, Part 5
Trouble in Your Tank: Materials for PWB Fabrication—Drillability and Metallization
Trouble in Your Tank: Supporting IC Substrates and Advanced Packaging, Part 5
Trouble in Your Tank: Electrodeposition of Copper, Part 6
Trouble in Your Tank: Electrolytic Copper Plating, Part 5
Trouble in Your Tank: Processes to Support IC Substrates and Advanced Packaging, Part 4