There is provided a flux applying apparatus configured to jet and apply a flux to a target, whereby the flux applying apparatus is capable of rapidly collecting a surplus flux in a sub-tank and returning the same to the main tank for further jetting and applying. In particular, the flux applying apparatus is coupled to a control unit capable of estimating a flux amount trapped in the sub-tank on the basis of a time period for which the flux is to be jetted from the nozzle.

A flux transfer tool includes a flux tray, a baseplate, a flux transfer head and a flexible member. The baseplate is disposed on the flux tray. The baseplate has a plurality of holes formed thereon. The flux transfer head is arranged corresponding to the flux tray and configured to move with respect to the flux tray. The flexible member is disposed on the flux transfer head. The flexible member faces the baseplate when the flux transfer head is located above the flux tray. When the holes are filled with a flux, the flux transfer head moves towards the flux tray, such that the flexible member adsorbs the flux from the holes.

A flux transfer tool includes a heater, a flux supplier, an ejector and a baseplate. The heater has a nozzle. The flux supplier is connected to the heater and contains a flux. The ejector is connected to the heater. The baseplate has a plurality of first holes formed thereon. The flux supplier supplies the flux to the heater, the heater heats the flux, and the ejector ejects the flux from the nozzle to spray the flux on the baseplate.

In a die-substrate assembly, a copper inter-component joint is formed by bonding corresponding copper interconnect structures together directly, without using solder. The copper interconnect structures have distal layers of (111) crystalline copper that enable them to bond together at a relatively low temperature (e.g., below 300 C.) compared to the relatively high melting point (about 1085 C.) for the bulk copper of the rest of the interconnect structures. By avoiding the use of solder, the resulting inter-component joint will not suffer from the adverse IMC/EM effects of conventional, solder-based joints. The distal surfaces of the interconnect structures may be curved (e.g., one concave and the other convex) to facilitate mating the two structures and improve the reliability of the physical contact between the two interconnect structures. The bonding may be achieved using directed microwave radiation and microwave-sensitive flux, instead of uniform heating.

A flux transfer tool includes a frame, a plunger, a baseplate, a flux supplier and a driving mechanism. The frame has a chamber. The plunger is movably disposed in the chamber. The baseplate is mounted on the frame. The baseplate has a plurality of holes formed thereon. The flux supplier is connected to the frame and contains a flux. The flux supplier supplies the flux to the chamber between the plunger and the baseplate. The driving mechanism is disposed on the frame. The driving mechanism drives the plunger to move towards the baseplate to squeeze the flux out of the holes of the baseplate. The driving mechanism drives the plunger to move away from the baseplate to keep the flux in the chamber.

In component mounting for mounting a pin connecting component having a pin on a board having a through-hole electrode, a solder paste is printed on the through-hole electrode through a screen mask having an opening corresponding to the through-hole electrode, a flux is transferred onto the pin by holding the pin connecting component and immersing the pin into a flux tank filled with the flux, and the pin onto which the flux is transferred is inserted into the through-hole electrode on which the solder paste is printed to mount the pin connecting component on the board.

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 herein is a solder paste having low viscosity and easy coatability, and that provides high reinforcement for electronic components while satisfying both high room-temperature adhesion and high repairability, and forming a cured product of excellent properties, for example, high insulation against humidity. Amount structure including an electronic component mounted with the solder paste is also provided. The solder paste contains a solder powder and a flux. The flux contains an epoxy resin, a reactive diluent, a curing agent, an organic acid, and a rubber modified epoxy resin. The reactive diluent contains a compound having two or more epoxy groups, and has a viscosity of 150 mPa.Math.s or more and 700 mPa.Math.s or less. The reactive diluent has a total chlorine content of 0.5 weight % or less, and is contained in a proportion of 5 weight % or more and 45 weight % or less with respect to a total weight of the flux.

In a die-substrate assembly, a copper inter-component joint is formed by bonding corresponding copper interconnect structures together directly, without using solder. The copper interconnect structures have distal layers of (111) crystalline copper that enable them to bond together at a relatively low temperature (e.g., below 300 C.) compared to the relatively high melting point (about 1085 C.) for the bulk copper of the rest of the interconnect structures. By avoiding the use of solder, the resulting inter-component joint will not suffer from the adverse IMC/EM effects of conventional, solder-based joints. The distal surfaces of the interconnect structures may be curved (e.g., one concave and the other convex) to facilitate mating the two structures and improve the reliability of the physical contact between the two interconnect structures. The bonding may be achieved using directed microwave radiation and microwave-sensitive flux, instead of uniform heating.

A method for curing solder paste on a thermally fragile substrate is disclosed. An optically reflective layer and an optically absorptive layer are printed on a thermally fragile substrate. Multiple conductive traces are selectively deposited on the optically reflective layer and on the optically absorptive layer. Solder paste is then applied on selective locations that are corresponding to locations of the optically absorptive layer. After a component has been placed on the solder paste, the substrate is irradiated from one side with uniform pulsed light. The optically absorptive layer absorbs the pulsed light and becomes heated, and the heat is subsequently transferred to the solder paste and the cornponent via thermal conduction in order to heat and melt the solder paste.