SuZhou Tonkida Electromechanical Technology Co., Ltd Professional SMT whole line supplier

SMT is the abbreviation of Surface Mounted Technology, which is a popular technology and process in the electronic assembly industry. Surface assembly technology is a kind of circuit assembly technology, which does not need to drill plug-in holes in the printed circuit board, and directly paste and weld the surface assembly components to the specified position on the printed circuit board surface.

Surface mount technology is a new generation of electronic assembly technology, it will compress the traditional electronic components into only a few tens of the volume of the device, so as to achieve the assembly of electronic products of high density, high reliability, miniaturization, low cost, and production automation. This miniaturized component is called: SMY device (or SMC, chip device). The process method of assembling components onto a printed substrate (or other substrate) is called the SMT process. The related assembly equipment is called SMT equipment.

At present, advanced electronic products, especially in computers and communication electronic products, have widely adopted SMT technology. The international output of SMD devices has increased year by year, while the output of traditional devices has decreased year by year, so with the passage of SMT technology will become more and more popular.

1. Introduction to traditional process (THT process)

The traditional perforated electronic assembly process is to insert the component pin into the pilot hole of the PCB after fixing, using the Wave Soldering (Wave Soldering) process, through the flux coating, preheating, solder coating, detection and cleaning steps to complete the entire welding process.

2, surface mount (smt) technology introduction

As the products of the electronic industry continue to design their products as short and lightweight with time and trend, relatively prompting the volume and weight of various components to become smaller and smaller, its functional density is also relatively improved, in line with the trend of The Times and customer needs, under the influence of this change, surface mount components become the main components on the PCB, its main feature is that it can greatly save space. To replace traditional dip welded components

The surface adhesion assembly process mainly includes the following main steps: solder paste printing, assembly mounting, reflow welding. The steps are outlined below:

Stencil Printing: The solder paste is the next material for connecting the surface adhesive component to the PCB. After the steel plate is first etched or laser cut, the solder paste is printed on the PCB solder pad by the squeegee through the opening on the steel plate to proceed to the next step.

Component Placement: Component placement is the main key technology and focus of the entire SMT process, the process uses high-precision automatic placement equipment, through computer programming to accurately place the surface mount components on the solder pad of the printed solder paste PCB. As the design of surface adhesive components becomes more sophisticated, the spacing of their pins becomes smaller, so the technical level of the placement operation becomes increasingly difficult.

Reflow Soldering: Reflow welding is to preheat the PCB which has been placed on the surface of the adhesive component through the reflow furnace to activate the flux, and then raise the temperature to 217℃ to melt the solder paste, the component foot is connected with the welding pad of the PCB, and then the cooling is done to solidify the solder, that is, to complete the joint of the surface adhesive component and the PCB.