Precision solder paste,
engineered for every bench.

Both are lead-free tin-silver-copper alloys. SAC305 (Sn96.5/Ag3.0/Cu0.5) is near-eutectic: it melts over a narrow 217–220°C range and has better thermal-fatigue resistance, which makes it the default for general and fine-pitch SMT work. SAC0307 (Sn99.0/Ag0.3/Cu0.7) cuts silver to 0.3% to lower metal cost, but melts over a wider 217–227°C range and is not fully liquid until 227°C. Reflow it at a 240–250°C peak (target 245°C) with 60–90 s above 227°C — never profile it to 217°C. Compare SAC305 and SAC0307.

Type 4 (20–38 µm) and Type 5 (15–25 µm) are IPC J-STD-005 powder-size classes. Type 4 suits standard pads and stencil apertures down to roughly 0.4–0.5 mm pitch and is the more economical choice. Type 5 releases more cleanly through small apertures and deposits consistent volumes on micro-pads — choose it for 0201/01005 passives, fine-pitch QFN/BGA and pitches down to roughly 0.3 mm. A common rule of thumb is that at least five particles should fit across the narrowest aperture. tinvoa SAC305 comes in both Type 4 and Type 5, in 15 g syringes.

Sn42/Bi58 — the standard low-temperature alloy for LED strips and arrays, flexible circuits (FPC), heat-sensitive components and second-stage reflow. It is eutectic at 138°C; reflow at a 160–170°C peak with 30–60 s above 138°C, and keep the peak at or below 170°C, because excess heat oxidizes the bismuth. The trade-offs: bismuth joints are more brittle than SAC under drop, shock and vibration, and they soften well before 138°C, so avoid parts that run hot. Don't use it on tin-lead finishes — lead contamination forms a low-melting phase near 96°C that weakens the joint. See tinvoa Sn42/Bi58.

Yes. For prototypes and rework, dispense a small dot from the syringe onto each pad, place the part, then melt the paste with a hot-air station or a hot plate. Preheat the board first, heat evenly until the paste turns bright and the part self-aligns, then let the joint cool undisturbed. Match the heat to the alloy: a joint temperature of 160–170°C for Sn42/Bi58; for SAC305 or SAC0307 the joint itself must pass the liquidus (220°C or 227°C), so aim for the alloy's normal 240–250°C peak. tinvoa's no-clean ROL0 flux leaves a non-conductive, non-corrosive residue, so cleaning is optional.

Unopened, tinvoa solder paste keeps 6 months from the manufacturing date printed on the syringe when refrigerated at 2–10°C (36–50°F). Do not freeze it. Before use, let the sealed syringe reach room temperature (20–25°C) for at least 4 hours — opening it cold condenses moisture into the paste and causes spattering and solder balls. After opening, recap the syringe, store it upright in the refrigerator, and use it within about three weeks. For rework without paste, our No-Clean Soldering Flux stores at room temperature; to hold parts in place, use our No-Clean Tacky Flux.