Surface mounting process of printed circuit board

Abstract

The invention discloses a surface mounting process of a printed circuit board, relates to the technical field of processing of a printed circuit board, and solves the problem that insufficient solventvolatilization is likely to cause the solder paste to splash. The surface mounting process includes the following steps of: a, printing the solder paste; b, mounting components on a front surface; c,performing soldering in a reflow furnace; d, overturning the printed circuit board; e, printing the solder paste; f, mounting components on a rear surface; g, performing soldering in the reflow furnace; and h, performing visual inspection. By using ultrasonic vibration, the solvent and the moisture in the solder paste are fully volatilized without reducing the soldering quality, thereby preventing the problem of solder splashing.

Description

technical field [0001] The invention relates to the technical field of printed circuit board processing, more specifically, it relates to a printed circuit board surface mounting process. Background technique [0002] When surface mounting printed circuit boards, most of the components are soldered on the surface of the printed circuit board by reflow soldering; when soldering, most of the solder is pre-coated on the surface of the printed circuit board, and then the components are placed To the printed circuit board, and finally send the printed circuit board with components into the reflow oven for reflow soldering. [0003] In the reflow soldering process, the workpiece coated with solder paste needs to pass through the preheating zone, heat preservation zone, reflow soldering zone and cooling zone in sequence in the reflow soldering furnace. The existing preheating zone is mainly through heating. Force the solvent and water in the solder paste to be fully volatilized, s...

AI Technical Summary

Problems solved by technology

[0003] In the reflow soldering process, the workpiece coated with solder paste needs to pass through the preheating zone, heat preservation zone, reflow soldering zone and cooling zone in sequence in the reflow soldering furnace. The existing preheating zone is mainly through heating. Force the solvent and water in the solder paste to be fully volatilized, so as to avoid the solvent and water in the solder paste volatilizing during the reflow soldering process and cause the solder paste to splash. At the same time, preheating can be used to make the solder fully Wet the workpiece to be welded. In the setting of the preheating zone, if the preheating temperature rises too fast or the preheating temperature is too high, it is easy to cause uneven heating of the workpiece to be welded and be damaged. If the preheating temperature is too low or the preheating The temperature rise is slow, and it is difficult to make the solder fully wet the workpiece to be soldered, and the solvent and moisture in the solder paste cannot be fully volatilized; the range of the existing preheating temperature mainly depends on the components of the solder and the components of each group. It is difficult to find a balance between preventing solder spatter and not reducing soldering quality through temperature control alone.