Besi Switzerland Ag

Esec Ag

Heinrich Berchtold

Christoffer Stroemberg

Charles Galea

Rene Betschart

A device for dispensing and distributing flux-free solder on a substrate comprises an elongated tool, a tool mount, an ultrasonic generator, a wire guide tube, and optionally a heat sink and a housing. The tool can be fixed to the tool mount and has a longitudinal borehole which opens into an opening on the tip of the tool. The wire guide tube extends along a central longitudinal axis through the ultrasonic generator and the tool mount, protrudes into the longitudinal borehole of the tool and reaches up to a position above the tip of the tool. The wire guide tube does not touch the tool. The ultrasonic generator is fixed to the tool mount. Advantageously, a cooling chamber which can actively be cooled is formed between an inner wall of the housing and the ultrasonic generator.

Device for dispensing and distributing flux-free solder on a substrate

An apparatus for dispensing flux-free solder comprises a dispenser head with a stamp to which ultrasound can be applied. Solder is dispensed by:

Method and apparatus for dispensing flux-free solder on a substrate

The invention relates to a method for dispensing solder and a method for mounting a semiconductor chip on the dispensed solder. The substrate is heated to a temperature which lies above the melting temperature of the solder and a solder portion is applied. A pin is thereafter immersed in the solder portion until it touches the solder portion and presses against the substrate. The pin is subjected to ultrasonic sound in such a way that ultrasonic waves are generated in the pin, which are directed perpendicularly or angularly in relation to the surface of the substrate, and is then moved along a predetermined path in order to distribute the solder. The treatment with ultrasonic sound locally improves the wettability of the substrate. The temperature of the pin is preferably lower than the melting temperature of the solder.

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Luzern, Switzerland

Heinrich Berchtold