An electronic component mounting substrate 10A is configured of an electronic component 20, and a mounting substrate 10 mounting the electronic component 20 thereon, in which concave parts 24 are formed on a mounting surface 23 of the electronic component 20 opposite to the mounting substrate 10, a connection part 39 is exposed at the bottom of the concave part 24, and electronic component attachment parts 12 provided on the mounting substrate 10 are soldered to the connection parts 39 provided in the electronic component 20.

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.

The present invention provides a method for manufacturing a backlight source. The method for manufacturing a backlight source according to the present invention forms a plurality of tin soldering pattern groups on a substrate. Each tin soldering pattern group includes tin soldering patterns spaced from one another, and the tin soldering patterns are in a closed ring shape. The Mini-LEDs are disposed on the tin soldering pattern groups respectively. The substrate is placed in the space having a varying magnetic field. The circuit of the tin soldering patterns in the tin soldering pattern groups generates the induced current for rapid heating and melting, to solder the Mini-LEDs on the substrate. The soldering speed is improved, the process efficiency is high, the process cost is low, and the light effect of the backlight source is effectively ensured.

A flux includes: at least one liquid solvent that has one or more hydroxy groups and is liquid at ordinary temperature; and at least two solid solvents that respectively have one or more hydroxy groups and are solid at normal temperature, in which the content of each of the solid solvents is less than 40 mass % based on the total content of the liquid solvent and the solid solvents.

A system for flux residue detection is provided. The system includes a flux heater, where the flux heater controls a temperature of a flux spray applied to a printed circuit board, and an infrared camera, wherein the infrared camera provides a thermal image of the flux on the printed circuit board. A method, a computer system, and a computer program product for flux residue detection is provided, including setting flux application parameters, applying flux to a printed circuit board, and capturing an infrared image of the flux applied to the printed circuit board. A method, a computer system, and a computer program product for flux residue detection is provided, including setting flux application parameters, applying flux to a printed circuit board, capturing an infrared image of the flux applied to the printed circuit board, and determining there is excess flux residue on the printed circuit board.

A bonding member that includes a base material that has a spiral shape when viewing a cross section thereof orthogonal to a longitudinal direction thereof, and contains a low melting point metal; and a coating film in a gap between opposed surfaces of the base material when the base material is in the spiral shape. The coating film contains metal particles of a high melting point metal that forms an intermetallic compound having a melting point higher than that of the low melting point metal by reaction of the high melting point metal with a melt of the low melting point metal. The low melting point metal is, for example, Sn or a Sn alloy. The high melting point metal is, for example, a CuNi alloy, a CuMn alloy, a CuCr alloy, or a CuAl alloy.

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.

A multilayer wiring board includes first and second insulating layers, a first conductive wiring layer on the first insulating layer, a second conductive wiring layer on a surface the second insulating layer facing the first insulating layer, an interlayer connection conductor including an intermetallic compound and penetrating through the first insulating layer to interconnect the first and second conductive wiring layers, a first intermetallic compound layer between the first conductive wiring layer and the interlayer connection conductor, and a second intermetallic compound layer between the second conductive wiring layer and the interlayer connection conductor, wherein the intermetallic compounds in the first and second intermetallic compound layers have a composition different from that of the intermetallic compound in the interlayer connection conductor, and the first intermetallic compound layer at a level different from a level of an interface between the first conductive wiring layer and the first insulating layer.

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.

An ejector for jetting droplets of viscous media onto a substrate is disclosed. The ejector comprises a jetting nozzle having a nozzle space and a nozzle outlet, and an impacting device for impacting a volume of the viscous medium in the nozzle space such that droplets of viscous medium is jetted from the nozzle space through the nozzle outlet towards the substrate. The ejector also comprise a sensor arrangement arranged after the jetting nozzle in the jetting direction, wherein the sensor arrangement is adapted to detect a jetted droplet of viscous medium passing thereby.