Abstract: A flux containing: a rosin; a solvent (S); a thixotropic agent; and an activator is disclosed. The rosin contains a rosin amine. The solvent (S) contains a first solvent (S1) having a boiling point of 250° C. or less, and the amount of the first solvent (S1) relative to the total amount of the solvent (S) is 50% by mass or more and 100% by mass or less.

Abstract: A solder paste includes a solder powder and a flux. The flux includes a rosin, an activator, a solvent, and a thixotropic agent containing a polyethylene glycol. A content of the polyethylene glycol is 10 mass % to 20 mass % with respect to a total mass of the flux, a content of the thixotropic agent excluding the polyethylene glycol is 5 mass % or less with respect to the total mass of the flux, and a content of the rosin is more than 15 mass % and 50 mass % or less with respect to the total mass of the flux.

Abstract: Provided is flux containing rosin-based resin, a solvent, a thixotropic agent and an activator. The thixotropic agent includes any or both of hardened castor oil and bisamide-based thixotropic agent. The contents of the hardened castor oil and the bisamide-based thixotropic agent are respectively within the range of 4 wt. % or more and 10 wt. % or less and the range of 1 wt. % or more and 5 wt. % or less based on the total weight of the flux. The contents of the thixotropic agent are within the range of 5 wt. % or more and 15 wt. % or less based on the total weight of the flux. The activator includes hydrohalide, a halogenated aliphatic compound and an imidazole compound. The contents of the halogen in the flux are within the range of 9000 ppm or more and 50000 ppm or less.

Abstract: Provided is flux containing rosin-based resin, a solvent, a thixotropic agent and an activator. The thixotropic agent includes any or both of hardened caster oil and bisamide-based thixotropic agent. The contents of the hardened caster oil and the bisamide-based thixotropic agent are respectively within the range of 4 wt. % or more and 10 wt. % or less and the range of 1 wt. % or more and 5 wt. % or less based on the total weight of the flux. The contents of the thixotropic agent are within the range of 5 wt. % or more and 15 wt. % or less based on the total weight of the flux. The activator includes hydrohalide, a halogenated aliphatic compound and an imidazole compound. The contents of the halogen in the flux are within the range of 9000 ppm or more and 50000 ppm or less.

Abstract: Provided is flux used for soldering and solder paste using the same. The flux used for an air-dispensing method contains a solvent, a high viscosity solvent of 1, 2, 6-hexantriol and isobornyl cyclohexanol, and a thixotropic agent but does not contain rosin. The flux used for the air-dispensing method and a jet-dispensing method contains a solvent, a high viscosity solvent of 1, 2, 6-hexantriol and isobornyl cyclohexanol, a thixotropic agent and rosin.

Abstract: A solder paste whereby metal does not flow out of a joint during a second or subsequent reflow heating stage. The solder paste exhibits high joint strength at room temperature and at high temperatures, excels in terms of temporal stability, exhibits minimal void formation, and can form highly cohesive joints. The solder paste comprises a powdered metal component and a flux component, the powdered metal component comprising: a powdered intermetallic compound that comprises copper and tin and has metal barrier layers covering the surfaces thereof and a solder powder including tin as a main component. Neither the powdered intermetallic compound nor the solder powder contains a copper-only phase, inhibiting the elution of copper ions into the flux.

Abstract: A method of printing solder paste on a substrate through minute apertures in a mask member, in which the solder paste is supplied to the apertures of the mask member under less than atmospheric pressure and has a viscosity so that the solder paste is filled in the apertures under atmospheric pressure. It is preferable that the solder paste has a viscosity of 50 through 150 Pa·s and a thixotropic ratio of 0.3 through 0.5. Further, the solder paste is obtained by mixing a flux containing solvent having a boiling point such that volatilization thereof is suppressed under the less than atmospheric pressure and solder powders. It is preferable that in the flux, the solvent having the boiling point of 240° C. or more is used and the solvent is octanediol.

Abstract: A solder paste whereby metal does not flow out of a joint during a second or subsequent reflow heating stage. The solder paste excels in terms of temporal stability and exhibits high joint strength at room temperature and at high temperatures. The solder paste comprises a powdered metal component and a flux component, the powdered metal component comprising: 10-70 mass % of a powdered intermetallic compound comprising copper and tin and 30-90 mass % of a solder powder including tin as a main component. Neither the powdered intermetallic compound nor the solder powder contains a copper-only phase, inhibiting the elution of copper ions into the flux.

Abstract: A method of printing solder paste on a substrate through minute apertures in a mask member, in which the solder paste is supplied to the apertures of the mask member under less than atmospheric pressure and has a viscosity so that the solder paste is filled in the apertures under atmospheric pressure. It is preferable that the solder paste has a viscosity of 50 through 150 Pa·s and a thixotropic ratio of 0.3 through 0.5. Further, the solder paste is obtained by mixing a flux containing solvent having a boiling point such that volatilization thereof is suppressed under the less than atmospheric pressure and solder powders. It is preferable that in the flux, the solvent having the boiling point of 240° C. or more is used and the solvent is octanediol.

Abstract: A method of preventing variation of the viscosity of a solder paste, and flux for producing solder paste, viscosity of which is prevented from varying. In the flux, which is suitable to be mixed with solder powder to produce the solder paste, an amount of methacrylate polymer which reduces a thixotropic index of the solder paste and enhances viscosity thereof is contained. As the methacrylate polymer, polyalkyl methacrylate having an alkyl group is preferable, and it is preferable that an addition amount of polyalkyl methacrylate is 05.-5.0 mass % of the flux. Further, as a thixotropic agent, hardened castor oil is preferably added.

Abstract: A solder paste whereby metal does not flow out of a joint during a second or subsequent reflow heating stage. The solder paste excels in terms of temporal stability and exhibits high joint strength at room temperature and at high temperatures. The solder paste comprises a powdered metal component and a flux component, the powdered metal component comprising: 10-70 mass % of a powdered intermetallic compound comprising copper and tin and 30-90 mass % of a solder powder including tin as a main component. Neither the powdered intermetallic compound nor the solder powder contains a copper-only phase, inhibiting the elution of copper ions into the flux.

Abstract: A solder paste whereby metal does not flow out of a joint during a second or subsequent reflow heating stage. The solder paste excels in terms of temporal stability and exhibits high joint strength at room temperature and at high temperatures. The solder paste comprises a powdered metal component and a flux component, the powdered metal component comprising the following: 10-70 mass % of a powdered intermetallic compound comprising copper and tin and 30-90 mass % of a solder powder including tin as a main component. Neither the powdered intermetallic compound nor the solder powder contains a copper-only phase, inhibiting the elution of copper ions into the flux.

Abstract: A solder paste whereby metal does not flow out of a joint during a second or subsequent reflow heating stage. The solder paste exhibits high joint strength at room temperature and at high temperatures, excels in terms of temporal stability, exhibits minimal void formation, and can form highly cohesive joints. The solder paste comprises a powdered metal component and a flux component, the powdered metal component comprising: a powdered intermetallic compound that comprises copper and tin and has metal barrier layers covering the surfaces thereof and a solder powder including tin as a main component. Neither the powdered intermetallic compound nor the solder powder contains a copper-only phase, inhibiting the elution of copper ions into the flux.

Abstract: A solder paste which solves any nozzle clogging that suddenly occurs in a case of being used in a discharging method and which also realizes residue-free because flux is decomposed by heating during soldering. In the solder paste produced by mixing solder powders with the flux, the flux is flux containing polyalkyl-methacrylate of not less than 1.0 mass % and less than 2.0 mass % as methacrylate polymer of an amount such that it prevents the solder powders from being sedimented at ordinary temperature and it is decomposed or evaporated in the process of heating during the soldering, and containing stearic acid amide of not less than 5.0 mass % and less than 15.0 mass %, as viscosity modifier, wherein viscosity is 50 through 150 Pa·s. It is preferable that the content of flux in the solder paste is not less than 11 mass % and less than 13 mass %.

Abstract: To provide solder paste that can be filled in minute apertures. The solder paste that is printed on a substrate through a mask member in which apertures are formed is supplied to the apertures of the mask member under decompression pressure and has a viscosity so that the solder paste is filled in the apertures under atmospheric pressure. It is preferable that the solder paste has a viscosity of 50 through 150 Pa·s and a thixotropic ratio of 0.3 through 0.5. Further, the solder paste is obtained by mixing a flux containing solvent having a boiling point such that volatilization thereof is suppressed under the decompression pressure and solder powders. It is preferable that in the flux, the solvent having the boiling point of 240° C. or more is used and the solvent is octanediol.

Abstract: To provide flux which has a property of suppression of sedimentation of the solder powder, dissolves by heating at the time of the soldering to remain no residue and does not block any wettability of the solder. In the flux which is mixed with solder powder to produce the solder paste, an amount of methacrylate polymer which suppresses of sedimentation of the solder powder at a normal temperature range and dissolves or vaporizes during a heating course at the time of the soldering. As the methacrylate polymer, polyalkyl methacrylate having an alkyl group is preferable and it is preferable that an addition amount of polyalkyl methacrylate is not less than 0.1 mass % through less than 1.0 mass %. It is also preferable to contain further a solvent having at least three OH groups.

Abstract: To provide flux for producing solder paste, viscosity of which is prevented from varying. In the flux which is mixed with solder powder to produce the solder paste, an amount of methacrylate polymer which reduces a thixotropic index of the solder paste and enhances viscosity thereof is contained. As the methacrylate polymer, polyalkyl methacrylate having an alkyl group is preferable and it is preferable that an addition amount of polyalkyl methacrylate is 0.5-5.0 mass % thereof. Further, as the thixotropic agent, hardened castor oil is preferably added.