A soldering device for soldering a printed circuit board includes at least one heating appliance melting solder situated between electrical or electronic components being soldered onto a printed circuit board and the printed circuit board. At least one actuator mechanically oscillates the printed circuit board at a variable frequency of oscillation in a direction of a plane defioned by the printed circuit board. A second lateral edge of the printed circuit board, the second lateral edge being opposite to the first lateral edge of the printed circuit board, rests against iand supported by a fixed stop.

An electronic device may have housing structures, electrical components, and other electronic device structures. Adhesive may be used to join electronic device structures. Adhesive may be dispensed as liquid adhesive and cured to form adhesive joints. Adhesive joints may be debonded. Chain reactions may be initiated by applying a localized initiator such as a chemical or localized energy to the adhesive. Once initiated, the chain reaction may spread throughout the adhesive to cure the adhesive, to globally change adhesive viscosity, or to weaken the adhesive to facilitate debonding. Local changes to adhesive may also be made such as local increases and decreases to adhesive viscosity. Chain reaction curing may be used to cure adhesive or debond adhesive that is hidden from view within gaps in the electronic device structures. Viscosity changes may be used to control where adhesive flows.