Dusting off the memory cells, I believe the maximum 150C topside board temperature relates to the nominal glass transition temperature of FR4. References may include IPC TM-650 or NEMA. This temperature was established prior to the implementation of lead-free soldering and the use of laminates accommodating higher temperatures.
Al Cabral
Regional Sales Manager
Finetech
Al Cabral is Regional Sales Manager for Finetech and Martin rework products. His expertise includes through-hole, surface mount and semiconductor packaging with an emphasis on soldering and heat transfer. Al has been a significant contributor to the development and optimization of reflow and rework processes and systems, particularly lead-free transitions and microelectronic applications.
S.M. should check J-STD-020D, section 4, tables 4-1 and 4-1.
Lee Wilmot
Director, EHS
TTM Technologies
Lee Wilmot has 20+ years doing EHS work in the PCB/PCBA industries, including environmental compliance, OSHA compliance, workers compensation, material content declarations, RoHS & REACH compliance. Active on IPC EHS committee and c-chaired committees on IPC-1331, J-STD-609A on labeling & marking, IPC-1758 on packaging and others.
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