PCB News - What matters should be paid attention to in pcba processing workshop

What matters should be paid attention to in Shenzhen PCBA processing workshop
At present, the country has higher and higher requirements for environmental protection and greater efforts in link governance. This is a challenge but also an opportunity for PCB factories. If PCB factories are determined to solve the problem of environmental pollution, then FPC flexible circuit board products can be at the forefront of the market, and PCB factories can get opportunities for further development.
PCBA processing equipment is fully automatic, high-precision, high-speed, etc. The geometric dimensions of some mounted components and plug-ins are very small, and the assembly density is very high. In addition, some materials, such as solder paste, have higher requirements for ambient temperature and a moderate range, and are prone to changes in viscosity and thixotropy, which affect the yield and quality of PCBA products. Therefore, PCBA production equipment and PCBA processing technology have certain requirements on the electricity, air, ventilation, temperature, humidity, air cleanliness, and anti-static of the workshop.

The basic environmental requirements of Shenzhen PCBA processing workshop are as follows

Power requirements

The power supply voltage and power meet the requirements of PCBA processing equipment. The voltage is stable, and generally requires single-phase AC220V (220±10%, 50/60Hz), three-phase AC380V (380±10%, 50/60Hz). If it fails to meet the requirements, a regulated power supply must be configured. The power supply is greater than the power consumption of the device.

The power supply of the placement machine requires independent grounding. Generally, a three-phase five-wire connection method should be adopted. It is thought that the operation speed of the placement machine is high, and it is easy to cause electromagnetic interference when connected with other equipment, which affects the normal operation and placement accuracy of the placement machine.

Gas source requirements

The pressure of the air source is configured according to the requirements of the equipment. The air source of the factory can be used, or the worry-free compressed air machine can be configured separately. Generally, the pressure is greater than 7kgf/cm. Clean and dry air is required, and compressed air needs to be purified to remove oil, dust, and water. It is best to use stainless steel or pressure-resistant plastic pipes for air ducts, instead of iron pipes for air ducts.

Both reflow soldering and wave soldering equipment have exhaust and flue gas emission requirements, and the exhaust fan should be configured according to the equipment requirements. For all hot blast stoves, the minimum flow rate of the exhaust duct is generally required to be 14-15m/min.

Working environment requirements

PCBA processing equipment and process materials have certain requirements for environmental cleanliness, humidity, and temperature. In order to ensure the normal operation and assembly quality of the equipment, there are strict requirements on the working environment. The workplace must be clean and sanitary, dust-free, and non-corrosive. The environment temperature should be controlled at 23±3 degrees Celsius, and the relative humidity is 45%. -70%RH. According to the above conditions, due to the dry climate in the north and heavy sandstorms, double-glazed factory buildings and air-conditioning are required.

Electrostatic protection requirements

Precision electronic components such as ICs involved in PCBA processing are often easily damaged by static electricity, so static protection is also very important.

Anti-static workbench

1. Set up an electrostatic safety workbench. The static safety workbench consists of a workbench, an anti-static table mat, a wrist strap connector and a grounding wire.
2. There should be more than two wrist strap joints on the anti-static table mat, one for operators and one for technicians and inspectors.
3. Plastic boxes, rubber, cardboard, glass and other debris that are prone to static electricity are not allowed to be stacked on the static safety workbench. The drawings and materials should be placed in an anti-static document bag.
4. People who directly touch electrostatic sensitive devices must wear an anti-static wrist strap. The wrist strap should be in good contact with the human skin.
5. The component holding bags, turnover boxes, and PCB loading and unloading racks in the production site should have electrostatic protection. Metal and ordinary containers are not allowed, and all containers must be grounded.
6. People who enter the electrostatic work area and those who come into contact with SMD components must wear anti-static work clothes, especially in a dry environment with a relative humidity of less than 50%. Work clothes fabrics should meet the relevant national standards.
7. People entering the work area must wear anti-static work shoes, and those wearing ordinary shoes should use conductive shoe bundles or anti-static shoe covers.
8. The conveyor belts and drive shafts used on the production line should be equipped with anti-static grounding brushes.
9. All assembly fixtures, testing fixtures, welding tools, testing instruments, etc. used in production should be equipped with a good grounding wire
10. Install an anti-static test bench at the entrance of the production site, and enter the site only if the test meets the standard.