Taking twelve zones reflow oven as an example:
1.Preheating zone: preheating of PCB and material (components). The reflow furnace says the heating effect of the first to two heating intervals. Higher preheating makes the welded material heat balance, the solder paste begins to move, the flux and other components are raised by the temperature.
The proper amount of evaporation is the heating action of the third to four heating zones for reflow furnace.
2. Constant zone: removing the surface oxide, some airflow begins to evaporate (start welding) to reach the solder paste melting point (at this time the solder paste will dissolve in the undissolved state), which is the heating effect of the reflow furnace for the 5673 heating zone.
3. Soldering zone: from solder paste melting to peak to dissolve melting point, solder paste melting process, PAD and solder formation welding, this is the reflow furnace for eighth, ninth, tenth or three adding interval heating.
4.Cooling zone: from the soldering point of solder to about 50 degrees, the forming process of the alloy solder joint, which is the cooling effect of the reflow furnace for both the eleventh and the twelfth cooling zones.
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