Three key processes of SMT patch processing

Three key processes of SMT patch processing

SMT patch processing belongs to the category of electronic processing. Most people hear the most words such as OEM or ODM, or SMT patch. SMT patch processing includes multiple processes, and finally a piece of electronic products in our daily life can be produced. Main board, most people are familiar with the main board of computer or mobile phone. The main board inside is full of various electronic components, some of which are very small and can hardly be seen with the naked eye. So how are these electronic components mounted on the circuit board? Yes, this is done by SMT chip processing.

The three key processes of SMT patch processing are solder paste printing, patch, and reflow soldering.

Solder paste printing

Solder paste printing is literally printing solder paste. Solder paste is similar to our toothpaste. It is made of a mixture of various rare metals such as tin powder and flux. Solder paste printing is mainly for bonding components in the placement process. Stick to the PCB board, after high-temperature heat melting in reflow soldering, let the electronic components climb tin, then cool and solidify, and then firmly fixed on the PCB board to form a PCBA board. The main equipment for solder paste printing is a solder paste printing machine, also known as a stencil printing machine.

2. SMD

Chip placement is the highlight of SMT chip processing. Chip placement is the main factor to determine the capacity of a production line. The configuration of an SMT production line is mainly based on the placement speed of the placement machine. The placement machine has a high-speed placement machine. Different from the multi-function placement machine, the high-speed placement machine is mainly for sticking CHIP parts, and the multi-function placement machine is also called a useless placement machine or a medium-speed machine, mainly for placement of special-shaped parts (such as: all kinds of pins) IC or BGA, etc.), most of the placement machines in China still use imported brands, such as Siemens, Panasonic, Fuji and other brands of placement machines

3. Reflow soldering

The main purpose of reflow soldering is to melt the solder paste, so that electronic components can be fixed on the PCB board. Reflow soldering basically has a temperature zone, which is a preheating zone, a constant temperature zone, a reflow zone, and a cooling zone. The functions of each zone are different. The preheating zone is to slowly increase the temperature of the PCB and various electronic components at room temperature. If the electronic components after placement directly enter the high-temperature zone, it may burn or burst, etc. Therefore, the temperature needs to be raised slowly in the preheating zone. The constant temperature zone is to let all kinds of electronic components basically reach a certain temperature. The reflow zone is the highest temperature zone, basically between 200-230 degrees, so that the solder paste can be heated. Melting, the cooling zone is the area that cools down the board. Therefore, the most important thing for reflow soldering is temperature curve control. Different types of electronic product processing have different temperature curves, and different products have different requirements for reliability. Therefore, reflow soldering also extends beyond nitrogen reflow soldering and vacuum reflow soldering.