The impact of compressed air not up to the standard on the PCB industry

The impact of compressed air not up to the standard on the PCB industry

Example: A certain company uses an imported high-speed drilling machine, but the current drilling rate is only one-third of the rated rate. What is the reason? The company’s production department often complains about water in the gas equipment, which affects production. What is the reason?

　　 The most fundamental reason is that there is water in the compressed air!

　　PCB (Printed Circuit Board), the Chinese name is printed circuit board, is an important electronic component, a support for electronic components, and a provider of electrical connections for electronic components. Because it is made by electronic printing, it is called a "printed" circuit board.

　　PCB layers are generally divided into three types: single-sided, double-sided and multilayer. Single-sided board is a single-sided copper-clad, so it can only be used to design the welding of circuit wires and components on the copper-clad side; double-sided board is a circuit with copper coated on both sides including TOP (top) and Bottom (bottom) Both sides of the board can be wired and welded, with an insulating layer in the middle, which is a commonly used circuit board; a multilayer board is a double-sided board with other layers between the top and bottom layers, such as placing two power board layers The composition of the four-layer board and so on.

　　 Mounting machines, exposure machines, drilling machines, and inspection machines are the types of PCB industry that require more gas. The use of pneumatic drill bits is accepted by most companies because of its low energy consumption, fast response, and the required pressure and speed in a relatively short period of time. However, the pneumatic drill bit uses a large amount of air. If the compressed air does not meet the standard and the water content is too large, it will cause the drilling machine's rotational speed to be unstable, damage the pneumatic components, and have a greater impact on the position and speed control, resulting in poor product quality , The defective rate increases. At the same time, the poor quality of compressed air will damage other production equipment and affect all production links.

The compressed air process of the drilling machine in operation is: the compressed air after drying and filtering by the dryer is transported to the back cover through the pipeline-through the internal air pipe pipeline to the front and rear bearings and the spindle housing-in the spindle housing and the front and rear bearings There is a row of uniform air holes on the inner wall.

When the air enters, the surrounding air blows up the shaft and makes it suspend in the air. When the coil passes the current after the frequency conversion, a magnetic field force is generated, and the shaft rotates at the air pressure. The machine constantly supplements the pressure loss to ensure the normal suspension of the shaft (in this process, if the compressed air is not dry, a certain amount of water will directly contact the product, and it will affect the normal operation of the spindle, resulting in defective products) .

According to ISO8573/1 standard (typical compressed air quality classification) and industry standard (JBT5967-2007 pneumatic components and system air medium quality grade), the basic requirements for compressed air quality in the PCB industry are: water content -20°C (pressure dew point) , 0.1μ dust, 0.1 ㎎/m? oil. The pressure dew point is an index to measure the quality of compressed air. For PCB production with a large amount of air, the average pressure dew point reaches -20°C to ensure the good quality of the circuit board. However, as far as the current market is concerned, the quality of compressed air in the PCB industry is generally not up to standard, resulting in a high rate of defective products.

To sum up, the harm caused by the quality of compressed air to the PCB industry is as follows: 1. Damage to production equipment, such as electronic testing equipment, exposure machines, drilling machines, optical inspection equipment, etc.; 2. Directly affect the spindle Rotation speed, defective rate increase; 3. The quality of compressed gas is not up to standard, which will easily cause pollution to subsequent gas equipment, such as solenoid valves and cylinders.