| 摘要 |
A reflow soldering apparatus has a preheating zone, a soldering zone and a cooling zone through which the workpiece to be soldered is conveyed. Preheater units (2) are located in the preheating zone to heat the workpiece. In the soldering zone, the workpiece is heated up at least to the soldering temperature using heater units (1). The workpiece is cooled in the cooling zone before removal. The apparatus is novel in that there are at least four heater units (1), two acting from below and two from above, in the soldering zone sequentially arranged in the conveyance direction. The first heater units (1a), which are located in the conveyance direction after the preheater zone, produce a higher temperature than the subsequent other two heater units (1b). The heater units (1) are convection heaters, pref. giving off radiation. The first heater units (1a) produce a temperature greater than 210 degrees C, pref. 270-300 degrees C. The second heater units (1b) produce a temperature of greater than 190 degrees C, pref. ca. 230 degrees C. The heater units (1) can be individually controlled. The different zones are arranged linearly or crosswise. The conveyance direction is horizontal or, in parts, vertical. |
