Reflow Soldering & Solder Alloys for China PCBA
1 resources tagged with "Solder"
Solder choice drives both reliability and compliance in China PCB assembly: SAC305 (Sn96.5/Ag3.0/Cu0.5) is the standard lead-free alloy with a melting point near 217°C, while legacy Sn63Pb37 leaded solder melts at 183°C and is still used for cost-sensitive non-RoHS builds. The reflow profile — preheat, soak, reflow, and cooling zones — must match the alloy and the J-STD-020 moisture sensitivity level of the components. A wrong ramp rate or peak temperature causes tombstoning, voids, or popcorning on moisture-sensitive parts.
When specifying assembly, the pitfall is leaving alloy and profile to the factory's default. We confirm SAC305 vs leaded in the work order, require RoHS-compliant solder for EU/US-bound product, and ask for the actual oven profile used on your board.
Wiki (1)
FAQ
Should I use lead-free or leaded solder for my PCB?
Lead-free SAC305 is required for RoHS markets like the EU. Leaded Sn63Pb37 is only acceptable for products exempt from RoHS, and it melts lower at 183°C.
What goes wrong with a bad reflow profile?
An incorrect ramp or peak temperature causes tombstoning, solder voids, cold joints, or popcorning on moisture-sensitive components rated under J-STD-020.
Related Topics
Have a sourcing project in mind?
Tell us what you need. We respond within 24 hours, including weekends.