#Reflow pcb manual#

For the patch, the yield rate is determined by the machine’s PPM. Its core is the accuracy of the screen printing. The simplest process of reflow soldering is “screen printing solder paste-patch-reflow soldering.

#Reflow pcb manual#

B, double-sided placement: A side pre-coated solder paste → patch (divided into manual placement and machine automatic placement) → reflow soldering → B side pre-coated solder paste → placement (divided into manual placement and machine automatic placement) Mounting) → reflow soldering → inspection and electrical test.A, single-sided mounting: pre-coated solder paste → patch (divided into manual placement and machine automatic placement) → reflow soldering → inspection and electrical test.The reflow soldering process is a surface-mounted board, and its process is more complicated, which can be divided into two types: single-sided mounting and double-sided mounting.

So it is called reflow soldering because its working principle is to solder the components and the circuit board together by the reflow of hot air in the furnace and the reflow of liquid tin. Reflow soldering is also called reflow soldering, which relies on the continuous reflow of the heat in the furnace, so that the solder paste is dissolved into tin liquid to solder the smt chip components and the circuit board. Reflow soldering is an automated soldering process in the SMT production process of electronic products. The PCB enters the cooling zone, so that the solder joints are solidified and the reflow soldering is completed. When the PCB enters the soldering area, the temperature rises rapidly so that the solder paste reaches a molten state, and the liquid solder wets, diffuses, diffuses, or reflows to the PCB pads, component ends and pins to form solder joints. When the PCB enters the heat preservation area, make the PCB and components fully preheated to prevent the PCB from suddenly entering the welding high temperature area and damaging the PCB and components. When the PCB enters the heating zone, the solvent and gas in the solder paste evaporate, and at the same time, the flux in the solder paste wets the pads, component ends and pins, and the solder paste softens, collapses, and covers the solder The pad, isolate the pads and component pins from oxygen. Introduction to the principle and process of reflow soldering

The colloidal flux physically reacts under a certain high temperature airflow to achieve SMD soldering the reason why it is called “reflow soldering” is because the gas circulates in the soldering machine to generate high temperature to achieve soldering.

Reflow soldering relies on the effect of hot airflow on the solder joints. Reflow soldering is to solder the components to the PCB board, and reflow soldering is to mount the components on the surface. Reflow soldering is to remelt the solder paste pre-distributed on the printed board pads to realize the mechanical and electrical connection between the solder ends or pins of the surface mount components and the printed board pads.