M705-ULT369 is newly designed solder paste to be state-of-the-art. More user-friendly, achieving a high workability.
Low Void
The trend to high-capacity and high-speed communication puts heat radiation into focus.
In this connection, voiding became an important character in terms of soldering. ULT369 has a high flowability. Voids are easily discharged from solder. Even in case of subdivided pattern, ULT369 is able to decrease the voiding.
High Printability
ULT369 has a high printability. Especially the filling/releasing ability is increased. This contributes to the printability at small openings and narrow pitches. ULT369 has an excellent temporal stability to achieve high productivity.
High reflowability
・Electric parts become smaller and smaller, and require thus a smaller solder powder size. Smaller solder powder oxidizes easily, affecting the solderability. ULT369 can keep its solderability with high heat resistance. ・BGA Packages become thinner and thinner, bending more easily.
This can cause HiP (Head in Pillow) and NWO (Non-wet Open) issues. ULT369 overcomes those problems with its outstanding wettability. ・Its high wettability can help soldering difficult places like QFN edges.
Alloy Name M705
Alloy Composition (%): Sn-Ag3.0-Cu0.5
Specific Gravity: 7.4
Melting Temp. (°C) Solidus 217. Liquidus 220
Tensile Strength (MPa) 53.3
Elongation (%) 56
Young’s Module (GPa) 46.9
0.2 Yield Point (MPa) 39.4
CTE (ppm/ C) 21.7
Vickers Hardness (Hv) 17.9
Solder paste characteristics change corresponding to temperature. There is a tendency for viscosity to become lower (softer) at high temperature. Slumping and/or spreading in the printing stage and solder ball or bridging in reflow stage may potentially occur if the paste has lower viscosity. Conversely, sticking to squeegee and/or clogging to stencil aperture may occur if viscosity is higher. Therefore, suitable environmental conditions are preferred for this paste’s use. 25+/-3°C temperature is usually recommended for this product.
