Abstract
A thin Zn filter (/spl sim/300 /spl mu/m) and relatively low X-ray tube voltage (/spl sim/45 kV) is recommended for X-ray inspection of surface-mounted device solder joints on printed wiring boards (PWBs). An optimal filter minimizes the Si dose that could result in cumulative damage to sensitive integrated circuit (IC) nodes, yet provides good contrast for metals such as Cu traces on PWBs and device solder balls. While we expect orders of magnitude Si dose reductions when effective filters are inserted, a properly chosen filter should not attenuate the portion of the white X-ray spectrum required to image Cu, Sn, and Pb (solder balls). Some X-ray inspection suppliers can achieve a Si dose of as little as 0.060 rads, while other X-ray inspection suppliers, not yet optimized for minimum dose, may use as much as four orders of magnitude more dose. We used thermo luminescent detectors (TLDs) to measure the X-ray dose that IC product shipments would encounter during a shipping process, for example, as personal baggage or cargo, as /spl les/0.050 rads.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: IEEE Transactions on Device and Materials Reliability
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
