IPC 4552-Rev A/B presents challenges for PCB manufacturers that apply ENIG coatings to their boards. In particular, the new specification puts an upper limit on the amount of gold that is applied for optimum product performance. This gold thickness must be closely monitored, and the accepted measurement method is XRF thickness testing. To accurately measure the gold thickness in this newly defined range requires specific XRF hardware, software, and calibration standards.
Most PCB manufacturers already have XRF equipment in place as part of their QC process, but they are finding that many of the older instruments struggle to meet the new IPC specification demands, and may require upgrading to the latest in XRF technology. Bowman is the only company that guarantees that all of their XRF systems meet the new IPC 4552-Rev A/B requirements.
Specifically, the IPC requires a gage performance study to be run by measuring standards of known thickness >30 times and reporting the statistical results. If the XRF doesn’t meet the accuracy and precision requirements, guard bands must be applied to further lower the thickness tolerance range, putting more burden on the plating process operators.
All Bowman systems have been proven and guaranteed to meet and exceed the gage study requirements, so there is no concern about changes in the plating process. This high level of performance is made possible by Bowman’s exclusive use of silicon drift detector (SDD) technology, the best available for XRF instruments. SDDs also provide direct measurement of %P in electroless nickel deposits, which provides more up-to-date information about the plating bath and provides even greater consistency in monitoring plating thickness.
Bowman offers two types of SDDs. The standard SDD comes with every Bowman system, and offers significantly better performance compared to proportional counter (“prop counter”) detectors or PIN detectors. We also offer a large-window graphene SDD upgrade option which improves overall performance, minimizes test times (i.e. <10s with 24mil collimator to pass gage requirements), and provides even greater “light” element sensitivity for elements such as phos. These exclusive features, and our best-in-class local support network make a powerful case for choosing Bowman for your next XRF instrument purchase.