Back to results
US 6,887,319 B2Granted
Residue-free solder paste
AssigneeSenju Metal Industry Co., Ltd.
InventorsTadatomo Suga, Keisuke Saito, Rikiya Kato, Sakie Yamagata
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeSenju Metal Industry Co., Ltd.
InventorsTadatomo Suga, Keisuke Saito, Rikiya Kato, Sakie Yamagata
Estimating the term…
A residue-free solder paste which leaves little or no flux residue after reflow soldering and which have good printability, storage stability, retainability of parts, and wettability, comprises a solder powder mixed with a rosin-free pasty flux. The flux comprises at least one solid solvent and at least one highly viscous solvent in a total amount of 30-90 mass %, in addition to at least one liquid solvent, all the solvents vaporizing at a reflow soldering temperature. The flux may further contain 0.5-12% of a thixotropic agent such as a fatty acid amide and 1-15% of an activator selected from organic acids and their amine salts, the thixotropic agent and activator vaporizing in the presence of the solvents while the solvents are vaporizing.
A residue-free solder paste for use in reflow soldering comprising a solder powder mixed with a pasty flux, the flux comprising at least one solid solvent which is solid at room temperature and which vaporizes at a reflow soldering temperature, at least one highly viscous solvent which is a highly viscous fluid at room temperature and which vaporizes at the reflow soldering temperature, and at least one liquid solvent which is liquid at room temperature and which vaporizes at the reflow soldering temperature.
A residue-free solder paste for use in reflow soldering comprising a solder powder mixed with a pasty flux, the flux comprising the following constituents, in mass %:
Dependencies are inferred from the claim text.