A flux according to the present invention includes a phosphine oxide. It is thereby possible to provide a flux capable of improving solder wettability, a resin flux cored solder including the flux, and a solder paste including the flux.

Provided is a flux containing not less than 11.0 degrees and not more than 17.0 of a contact angle between the flux and a resist substrate on which the flux has been printed to have 1.0 mm of a diameter and 0.15 mm of a thickness when heating the resist substrate at 150 degrees C. for 30 seconds and cooling the resist substrate to a room temperature. The flux also contains more than zero seconds and not more than 2.0 seconds of a zero-cross time when heating a Cu plate at 150 degrees C. in a thermostat oven for 12 hours, applying the flux onto the baked Cu plate, and dipping the baked Cu plate onto which the flux is applied into a Sn-3.0Ag-0.5Cu alloy at a dipping speed of 15 mm/sec and by 2.0 mm of a dipped depth.

The present invention provides a solder paste free of reducing agents and activators, and a method for producing a soldered product in which the solder paste is used to achieve solder bonding. The solder paste for reducing gas of the present invention is a solder paste for reducing gas used together a reducing gas. The solder paste contains a solder powder; a thixotropic agent that is solid at normal temperature; and a solvent, and is free of reducing agents for removal of oxide films and free of activators for improvement of reducibility.

A self-heating solder flux material includes a solder flux material and a multi-compartment microcapsule. The solder flux material includes a solvent carrier, and the multi-compartment microcapsule includes a first compartment, a second compartment, and an isolating structure. The first compartment contains a first reactant, and the second compartment contains a second reactant. The isolating structure separates the first compartment from the second compartment. The isolating structure is adapted to rupture in response to a stimulus.

Provided is a flux that is able to suppress any solder bridges even when it is applied to the narrow pitched electrodes such that the bridge occurs when using the past flux. The flux is characterized by containing 15% by mass or more and 35% by mass or less of polyoxyalkylene ethylenediamine, 2% by mass or more and 15% by mass or less of an organic acid, 10% by mass or more and 30% by mass or less of a base material, 3% by mass or more and 30% by mass or less of an amine and 20% by mass or more and 40% by mass or less of a solvent.

A flux containing 0.1 to 20 wt % of 2-hydroxyisobutyric acid as an activator, 10 to 60 wt % of a cationic surfactant and 5 to 60 wt % of a nonionic surfactant. A solder paste contains a flux containing 0.1 to 20 wt % of 2-hydroxyisobutyric acid as an activator, 10 to 60 wt % of a cationic surfactant, and 5 to 60 wt % of a nonionic surfactant and a metal powder.

An object of the present invention is to provide a flux which does not precipitate a crystal and can improve solder wettability.

A flux comprising 0.4 to 10.0 mass % of ditolylguanidine and 1.0 to 10.0 mass % of an organic acid, and not comprising diphenylguanidine as an amine compound.

The disclosure describes techniques for eliminating or reducing non-wet open (NWO) defect formation by using a low activity flux to prevent a solder paste from sticking to ball grid array (BGA) solder balls during reflow soldering. The low activity flux may be configured such that: i) it creates a barrier that prevents the solder paste from sticking to the solder balls of the BGA; and ii) it does not impede the formation of solder joints during reflow. In implementations, a solid coating of the low activity flux may be formed over balls of the BGA, and the BGA may then be bonded to a PCB during reflow. In implementations, the balls of a BGA may be dipped in a low-activity creamy or liquid flux prior to reflow. In some implementations, the flux may applied on a solder paste printed on pads of the PCB, followed by placement of a BGA.

A self-heating solder flux material includes a solder flux material and a multi-compartment microcapsule. The solder flux material includes a solvent carrier, and the multi-compartment microcapsule includes a first compartment, a second compartment, and an isolating structure. The first compartment contains a first reactant, and the second compartment contains a second reactant. The isolating structure separates the first compartment from the second compartment. The isolating structure is adapted to rupture in response to a stimulus.

Provided is a flux that is able to suppress any solder bridges even when it is applied to the narrow pitched electrodes such that the bridge occurs when using the past flux. The flux is characterized by containing 15% by mass or more and 35% by mass or less of polyoxyalkylene ethylenediamine, 2% by mass or more and 15% by mass or less of an organic acid, 10% by mass or more and 30% by mass or less of a base material, 3% by mass or more and 30% by mass or less of an amine and 20% by mass or more and 40% by mass or less of a solvent.