Surface mount PCB assembly procedure differs from thru-hole assembly process in several aspects. Thru-hole technology uses solder wire or solder bar to mount electronic components onto the PCB board. However, Surface Mount Technology (SMT) utilizes solder paste to mount Surface Mount Devices (SMDs) on the board. SMT is a laborious process. However, it provides outstanding electrical conductivity and superior performance.
PCB manufacturers use several equipment to execute SMT assembly processes. They are different in terms of the machineries used in thru-hole soldering.
Introducing 5 Equipments Utilized in SMT
There are a number of equipment used in SMT. Following are the most common amongst them.
- Solder Paste Screen Printer – SMT solder paste screen printers are designed exclusively to screen solder paste onto PCB boards. Post this process, SMDs are placed according to the design specifications. Available in manual, semi-automatic, and fully automatic configurations, these machines can be customized as per the customers’ application requirements.
- Pick and Place Machine – The process of picking and placing SMDs onto PCB boards must be executed with utmost care and precision. There are several models of SMT pick and place machines available that can accurately place electronic components on the board. Depending on the application requirements, users can choose from stand-alone machines or bench top models.
- Reflow Soldering Equipment – There are several models of reflow soldering machines available to apply solder paste to desired locations/pads on the PCB board. Next to pick and place machines, these equipment largely contribute to streamlining an SMT line.
- Solvent Cleaning Equipment – PCBs are assembled utilizing fluxes and solder paste. After the soldering process, the assembly must be cleaned thoroughly to remove residues of flux and solder paste. Manual cleaning is not effective, and has some limitations. Hence, to remove excess solder flux from the SMT assembly services, manufacturers make use of automated solvent cleaning equipment. These equipment can perform the cleaning process quickly without affecting the components mounted on the PCBs.
- Inspection Equipment – SMT assembly must be comprehensively inspected throughout the manufacturing stages to detect errors and also to ensure the quality of solder joints. The two most commonly used SMT repair and inspection equipment are; x-ray and laser.
The aforementioned machines are integrated, scalable, and reliable solutions that contribute a great deal in producing SMT assemblies to the required specifications. Utilizing these machines in the SMT line not only helps streamline the production process, but also leads to producing boards in a short turnaround time.