Ipc-sm-840 Pdf

The IPC-SM-840 standard evaluates several critical properties of the solder mask material:

The transition to lead-free soldering (RoHS compliance) drastically increased the thermal stress placed on solder masks. Standard solder paste reflow temperatures jumped from roughly 183°C (tin-lead) to upwards of 235°C-260°C (lead-free). If you are referencing an older version of the standard found in a random search, you might miss the specific thermal shock requirements added in Revision D and E to account for these higher temperatures. ipc-sm-840 pdf

Many engineering universities maintain subscriptions to industry standards. If you are a student, check your university’s electronic library database for access to ASTM, ISO, or IPC standards. or IPC standards.