-
- News
- Books
Featured Books
- pcb007 Magazine
Latest Issues
Current IssueThe Growing Industry
In this issue of PCB007 Magazine, we talk with leading economic experts, advocacy specialists in Washington, D.C., and PCB company leadership to get a well-rounded picture of what’s happening in the industry today. Don’t miss it.
The Sustainability Issue
Sustainability is one of the most widely used terms in business today, especially for electronics and manufacturing but what does it mean to you? We explore the environmental, business, and economic impacts.
The Fabricator’s Guide to IPC APEX EXPO
This issue previews many of the important events taking place at this year's show and highlights some changes and opportunities. So, buckle up. We are counting down to IPC APEX EXPO 2024.
- Articles
Article Highlights
- Columns
Search Console
- Links
- Events
||| 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: Supporting IC Substrates and Advanced Packaging, Part 5Trouble 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
Trouble in Your Tank: Processes to Support IC Substrates and Advanced Packaging, Part 3
Trouble in Your Tank: Electrodeposition of Copper, Part 4—Addition Agents
Trouble in Your Tank: Lead-free and the Fabrication Challenge, Part 1
Trouble in Your Tank: Processes to Support IC Substrates and Advanced Packaging, Part 2