The core equipmemt of SMT production line

The three core production equipment of the SMT production line include: solder paste printing machine, placement machine, reflow soldering equipment; among which the placement machine is the core equipment: used to achieve high-speed, high-precision, fully automatic placement of components, which is related to the SMT production line The high efficiency and precision are key and complex equipment, which usually account for more than 60% of the investment in the entire SMT production line.
1. Solder paste printing machine: Its function is to leak solder paste or patch glue to the pads of the PCB to prepare for the welding of components. The equipment used is a solder paste printer, located at the front end of the SMT production line
2. Conveyor: The direct bridge between the two devices plays the role of conveying the PCB board, and can also be used to manually detect the printing and patching conditions, acting as a testing table. Working principle: The circuit board is placed on two conveyor belts for transportation. The existing conveyor belts are generally fixed on the frame, so that the width of the circuit boards conveyed on the two conveyor belts is limited, which is not conducive to different sizes of circuit boards. The circuit boards are transported, making the docking station less suitable.
3. Pick and place machine: Its function is to accurately install the patch components on the fixed position of the PCB. The equipment used is a placement machine, which is located behind the screen printing machine in the SMT production line;
Machine structure: It is mainly composed of seven major structures including rack, transmission mechanism and support table, X, Y positioning system, optical centering system, placement head, feeder and sensor.
4. Reflow soldering: also known as reflow soldering machine or "reflow oven", it provides a heating environment to melt the solder paste by heat, so that surface mount components and PCB pads are firmly bonded through the solder paste alloy together. The equipment used is a reflow oven, which is located behind the placement machine in the SMT production line;
Working principle: Apply an appropriate amount and appropriate form of solder paste on the pads of the circuit board in advance, and then paste the SMT components into the corresponding positions; the solder paste has a certain viscosity to fix the components; The circuit board of the device enters the reflow equipment. The conveying system drives the circuit board through each set temperature area in the equipment. The solder paste is dried, preheated, melted, wetted and cooled to solder the components to the printed board. The core link of reflow soldering is to use an external heat source to heat, so that the solder melts and flows and infiltrates again to complete the soldering process of the circuit board.