A method includes applying a first flux onto an electrode provided on a substrate and placing a solder material on the electrode, heating the substrate to form a solder bump on the electrode, deforming the solder bump to provide a flat surface or a depressed portion on the solder bump, applying a second flux to the solder bump; placing a core material on the solder bump, the core material including a core portion and a solder layer that covers a surface of the core portion, and heating the substrate to join the core material to the electrode by the solder bump and the solder layer.

The object of the present invention is to provide a flux composition and a solder paste composition in which scattering of flux is suppressed. A flux composition comprising an anti-scattering agent represented by formula (1) below, ##STR00001##
wherein Z is optionally substituted alkylene, R.sup.1 and R.sup.2 are each independently optionally substituted alkyl, optionally substituted aralkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted cycloalkyl, or optionally substituted heterocycloalkyl, R.sup.3 and R.sup.4 are each independently optionally substituted alkyl.

An electric component includes: a semiconductor component including a heat radiating portion, a semiconductor element, a lead terminal, and a coating resin coating a part of each of the above; a wiring board including a first mounting portion, a second mounting portion, and an insulating substrate; a first solder connecting the first mounting portion and the heat radiating portion; and a second solder connecting the second mounting portion and the lead terminal. The first solder includes (a) a solder connecting portion connecting the heat radiating portion and the first mounting portion and (b) a flux provided around the solder connecting portion, and a third space which is provided as a space after excluding a second space that is an overlap of the heat radiating portion and the first mounting portion from a first space.

A flux resin composition contains: 60-80% by weight of an epoxy resin; 0.01-2% by weight of an imidazole compound; 1-5% by weight of a thixo agent; 4-20% by weight of an activator; and 7-30% by weight of a phenolic compound. The epoxy resin contains at least one resin selected from the group consisting of naphthalene type epoxy resins, biphenyl aralkyl type epoxy resins, trisphenol methane type epoxy resins, biphenyl type epoxy resins, and dicyclopentadiene type epoxy resins. Content of the at least one resin falls within a range from 15% by weight to 40% by weight with respect to a total weight of the flux resin composition. The phenolic resin is liquid and contains a phenol novolac.

A laser soldering system is disclosed. The laser soldering system has a moving system, a gripper mounted on the moving system, a presser mounted on the moving system and having a transparent member, and a laser. The gripper grips an object and places the object at a target location on a product to be soldered. The transparent member presses the object against the product. The laser emits a laser beam through the transparent member to solder the object to the target location while the object is pressed against the product.

A flux for soldering contains 10 to 40 wt % of coumarin, 5 to 30 wt % of a monoamide-based thixotropic agent and 40 to 80 wt % of a solvent. A solder paste contains the flux and a solder powder. A method for producing a soldered product includes supplying the solder paste to a soldering portion of an electronic circuit board, mounting an electronic component onto the soldering portion and heating the soldering portion up to a temperature at which the solder powder melts in a reducing atmosphere containing a reducing gas to join the electronic component and the electronic circuit board.

A method for assembling components implementing includes a pre-treatment of the solder bumps allowing an assembly by fluxless and residue-free soldering. A first component carrying solder bumps is assembled with a second component carrying connectors. Beforehand, a pre-treatment of the components carrying solder bumps is carried out by contacting them with a pre-treatment liquid which makes their subsequent fluxless and residue-free soldering possible.

A solder member mounting method includes providing a substrate having bonding pads formed thereon, detecting a pattern interval of the bonding pads, selecting one of solder member attachers having different pattern intervals from each other, such that the one selected solder member attacher of the solder member attachers has a pattern interval corresponding to the detected pattern interval of the bonding pads, and attaching solder members on the bonding pads of the substrate, respectively, using the one selected solder member attacher.

A multilayer ceramic capacitor includes a laminate including dielectric layers and internal electrode layers, and external electrodes on surfaces of the laminate. A silane coupling agent layer is on at least a mounting surface among surfaces of the laminate. The silane coupling agent layer is made of a fluorine-based silane coupling agent, and a silane coupling agent concentration on the mounting surface is about 0.1 or higher and about 365 or lower and is higher than a silane coupling agent concentration on a counter surface opposing the mounting surface, or the silane coupling agent layer is made of a carbon-based silane coupling agent, and a silane coupling agent concentration on the mounting surface is about 0.91 or higher and about 38.10 or lower and is higher than a silane coupling agent concentration on a counter surface opposing the mounting surface.

Provided is a flux which is rosin-free and contains 50% by mass or more and 90% by mass or less of 2,4-diethyl-1,5-pentanediol, more than 0% by mass and less than 50% by mass of a solvent, 1% by mass or more and 15% by mass or less of an organic acid, wherein the total amount of the 2,4-diethyl-1,5-pentanediol and the solvent is 83% by mass or more and 99% by mass or less. This flux does not require washing with an organic detergent when transferred to solder balls is provided.