How to see the temperature curve of the reflow oven
Reflow oven temperature zone works when assembled PCB board in the metal mesh type or double track conveyor belt, through the reflow oven each temperature zone section of the hot and cold trip (such as 8 hot 2 cold large machine, the total length of 5-6m lead reflow oven), in order to achieve molten solder paste and cooling healing into the purpose of solder joints, its main temperature changes can be divided into four parts: 1.
1, reflow furnace start preheating section refers to the first two sections of the furnace area, starting from room temperature to reach 110-120 ℃ in terms of the saddle head (for example, 10 sections of the machine 1-2 temperature zone).
2, reflow oven temperature (thermostat) heat absorption section refers to the reflow oven curve of the slow rise and flatter saddle (for example, 10 reflow oven of 3-6 sections, time 60-90 seconds.) The temperature at the end of the saddle is 150-170°C. Hope to achieve the board and parts of the internal and external temperature, and drive away the solvent to avoid the purpose of spattering tin.
3, reflow oven peak temperature strong heat section (reflow oven melting zone) can be PCB board temperature quickly (3 ℃ / sec) to 235-245 ℃ between the high, in order to achieve the purpose of solder paste melting solder; this section takes no more than 20 seconds to appropriate (for example, 10 reflow oven of 7-8 two sections).
4, reflow oven fast cooling section followed by rapid cooling (3-5 ℃ / sec) so that reflow joints can be instantly cured to form solder joints, so that the surface roughness of the solder joints and micro-cracking can be reduced, and aging strength will be better (such as 10 reflow oven section 9-10).
