| 摘要 |
The present invention relates to controls for a multi-zone reflow oven. In the present invention a plurality of infra red thermal scanners are located at critical points along the path which a substrate passes in a reflow oven so as to generate an actual solder paste time/temperature profile as a substrate passes through the zones of the reflow oven. The actual temperature of the solder paste is determined at critical zones for generating feedback control signals. The time/temperature profile is stored for transfer to a different reflow oven so as to effect the identical solder paste time/temperature curve on the same or a different oven. Temperature deviations from the points on the solder paste time/temperature curve are calculated and control signals are generated for producing feedback signals that are applied to the controllers of the belt drive motor, the convection fan motors as well as the heating elements in the heating blocks of the vertical zone heaters to control and effect an actual and desired optimum solder paste time/temperature profile.
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