2UUL JOINT X Solder Paste 50g (FS158 / FS183 / FS200)

Imagine a sandwich board where the top layer has to come off without the bottom reflowing. Or a chip that has to stay put while you work on the parts around it. Choosing solder with different melting points lets you control which joints melt and which hold.

The 2UUL JOINT X solder paste comes in 50 g jars in three versions: FS158 melts at 158 °C, FS183 at 183 °C and FS200 at 200 °C. According to the listing, it wets pads well and doesn't separate. It suits both stencil and manual use, and leaves little residue and smoke.

Which version for which job

• FS158: heat-sensitive chips, or stacked boards where lower layers mustn't reflow.

• FS183: everyday BGA reballing and general soldering.

• FS200: joints that need to hold while nearby work is done at a lower temperature.

• Cold or dry joints, or a weak joint that has failed and needs reworking.

Use

Stir the paste first. Spread it thinly over the stencil or pads, then reflow with hot air until the joints are fully formed. Clean off any residue if necessary.

Seal the jar after use. Don't mix the three versions, because their melting points won't match.