Start SensorReproduction of all relevant process parameters is imperative for consistantly perfect results. The FINEPLACER® COMISS reflow module with PC control allows well-tried preprogrammed top heating profiles to be run, using its outstanding control accuracy. In case of large area multilayers, heating of the underside is necessary. However, the temperature course of the board cannot be controlled exactly by a standard configuration, because its true value is not used for feedback. In practice, the temperature of a board might vary under different factors of influence.
For example, if a chip has just been desoldered, the temperature will be much higher than the temperature of a board coming out of the repository. To carry out bottom heating processes based on different initial temperatures would have an influence on the results if the starting point of the top heat process was not adapted. To do so, the use of a start sensor measuring the board temperature is inevitable.
The Start Sensor is measuring a temperature of a defined point on the board surface. After activating the bottom heater, the temperature of the board will rise, beginning from the initial value. As soon as the board surface reaches an adjustable threshold, the upper hot gas nozzle reflow programme will be started automatically. This way, an accurate process is guaranteed, independent of the board's starting temperature. The PCB is only exposed to as much heat as necessary to reduce thermal stress significantly. Of course, existing placer control boxes can also be retrofitted with the Infrared Start Sensor.
FINETECH offers two models: |
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