SMT surface mount processing factories indicate that there are many equipment required for SMT surface mount processing, such as solder paste printing machines, surface mount machines, reflow soldering, AOI detectors, and so on; In addition, if touching the touchpad with bare hands or causing a decrease in the adhesion of green oil, bubble detachment, and other effects; So now let me introduce the relevant content in detail for you.

1、 Equipment required for SMT surface mount processing

1. Solder paste printing machine

Modern solder paste printing machines generally consist of mechanisms such as plate mounting, solder paste addition, embossing, and transmission substrates. The working principle is to first fix the printed circuit board on the printing positioning table, and then use the left and right scrapers of the printing machine to leak the solder paste and red glue through the steel mesh to the corresponding solder pads. The leaked PCB is then input into the SMT machine through the transfer table for automatic SMT.

2. SMT machine

Surface Mount System: also known as a surface mount machine or surface mount system, it is a production equipment that is installed after the cream printing machine on the production line and is correctly configured by moving the surface mount machine. According to installation accuracy and installation speed, it is usually divided into high speed and normal speed.

3. Reflow soldering

There is a heating circuit inside reflow soldering, which heats the air and nitrogen to a sufficiently high temperature and blows it towards the PCB board where the parts have already been attached, causing the solder on both sides of the parts to melt and bond with the motherboard. The advantage of this process is that the temperature is easy to control, oxidation can be avoided during welding, and production and processing costs are also easy to control.

4. AOI detector

AOI stands for AutomaticOptic principle detection equipment for common defects in welding production. AOI is an emerging testing technology, but it is developing rapidly, and many manufacturers have launched AOI testing equipment. During automatic detection, the machine automatically scans the PCB through a camera, collects images, compares the tested solder joints with qualified parameters in the database, detects defects in the PCB through image processing, displays the defects on the monitor or automatically, and repairs them by maintenance personnel.

5. Parts cutting machine

Used for cutting feet and deforming pin components.

6. Wave soldering

Peak welding is achieved by directly contacting the welding surface of the plug-in board with high-temperature liquid welding to achieve the welding purpose. The high-temperature liquid welding maintains a sloping surface. Due to the special device that causes the liquid welding to form a wave like phenomenon, it is called peak welding, and its main material is the welding rod.

2、 The impact of bare handed operation on SMT surface mount processing

1. The bare touch panel before resistance welding can cause a decrease in the adhesion of the green oil, resulting in bubbles and detachment from the hot air during resistance welding.

2. The bare object in contact with the board causes a chemical reaction on the copper surface in a very short period of time, resulting in oxidation of the copper surface. After a slightly longer period of time, obvious fingerprints appeared after electroplating, the coating was uneven, and the appearance of the product was seriously poor.

3. Printing wet film and screen printing lines, as well as the surface of the board before laminating, have fingerprint grease, which can easily reduce the adhesion of dry/wet film. During electroplating, the plating layer separates from the plating layer, and the gold plate can easily cause patterns on the board surface. After resistance welding, the board surface oxidizes and appears in a positive and negative color.

4. During the process from solder mask to packaging, bare hand contact with the surface of the gold plate can result in unclean surface, poor weldability, or poor bonding.