Auxiliary material
Solder Paste (lead-free)
✓ Expert reviewed All content on this page has been reviewed by a senior motor engineer.
Process flow
Upstream manufacturing of this bought-in item is not covered yet; see the incoming inspection and approval tests.
Incoming inspection & approval tests
- Alloy composition (e.g. SAC305)J-STD-006
- Viscosity, slump and solder ballingJ-STD-005 / IPC-TM-650
- Flux residue reliability (SIR)J-STD-004; IPC-TM-650 2.6.3.7
- Storage and shelf lifeRefrigerated per data sheet; thaw and stir before use
Buyer FAQ
- Which alloy should I use?
- SAC305 (Sn96.5Ag3Cu0.5) is the standard lead-free alloy; low-silver alloys cut cost; SnBi low-temperature pastes protect heat-sensitive parts but have lower fatigue strength.
- How should solder paste be stored and handled?
- Refrigerate at 2–10 °C, warm to room temperature for several hours before opening, stir, and use within the stencil life stated by the maker; record open time per jar.
- How do I check paste printing?
- Use 3D SPI to measure paste volume, area and height on every board, and check X-ray voids under power MOSFETs after reflow.