For rough vacuum application of PCB board lamination, Roots water ring vacuum system can be used for high pumping speed, the faster the pumping speed, the higher the vacuum degree, the better the pressing effect, the simple composition and the few accessories, and the installation is simple.
The core technology of electronic circuit board vacuum pressing technology lies in high temperature and high pressure evenly distributed on the entire surface of the workpiece, as well as temperature and pressure control accuracy, heat preservation and heat insulation effect; vacuum pump is one of the key components of the laminator, vacuum pressing Technology has high requirements on parameters such as vacuum pump quality and vacuum degree.
Which vacuum system should I choose for the vacuum pressing of the circuit board laminator in the electronic industry?
According to different vacuum degrees, select the corresponding vacuum pump or vacuum system; vacuum is used for circuit board lamination. The vacuum pump plays a role in pumping out bubbles. The faster the pumping speed, the higher the vacuum degree and the better the pressing effect.
Lamination is a rough vacuum application. According to actual production requirements, a roots water ring vacuum system consisting of a roots vacuum pump + a water ring vacuum pump can be selected, and many accessories can be omitted.
Is the use of Roots water ring vacuum system related to the external environment?
Roots vacuum system refers to a vacuum process without special requirements. The environmental requirements of this type of roots vacuum system are: any roots vacuum system requires no accumulated pollution sources, no dust, no iron filings, and no rust on the surface. The surface of the vacuum chamber of the Roots vacuum system should be smooth, free of soft structures, pores, internal welds and other defects that affect the vacuum.
In the Roots water ring vacuum system, the moving parts in the vacuum chamber should not use engine oil as a lubricant, but should use diffusion pump oil and low saturated vapor pressure silicone oil as lubricants. The flanges and the sealing parts of the observation window should be coated with High vacuum grease. Roots water ring vacuum systems should generally work in a clean air circulation environment with a temperature of 15 ~ 30 ℃ and a relative humidity of not higher than 70%, and the cooling water inlet temperature should not be higher than 25 ℃.
Roots water ring vacuum system not only has good mechanical properties and processing performance, but also meets other performance requirements, such as easy degassing, low saturated vapor pressure, certain chemical stability, certain purity and cleanliness, and suitable radiation Ability etc. Therefore, the roots vacuum system is relatively special and has strict requirements for cleaning treatment, so the pollution of the parts must be removed or reduced to a large extent.
How to do the anti-corrosion work of Roots water ring vacuum system ?
The Roots water ring vacuum system is equipped with an eccentric rotor with fixed blades, which throws water (liquid) onto the stator wall, and the water (liquid) forms a concentric liquid ring with the stator. The liquid ring and rotor blades form a variable volume rotary variable volume vacuum pump.
At present, in some large-scale chemical plants and industries with strong corrosiveness, the material requirements of Roots water ring vacuum systems are getting higher and higher. In order to reduce costs, some factories will require stainless steel impellers or stainless steel overflow parts. However, in actual use, the pump will be severely corroded within a few months, which actually greatly increases the production cost. The main solution is to armour the chemical stoneware in the pump body of the Roots water ring vacuum system and the cast iron shell with overflow parts on both sides, fill the adhesive between the cast iron shell and the chemical stoneware, and seal the end face of the joint with resin . The Borui steel impeller is fixed on the main shaft with steel keys, and Borui steel shaft sleeves are installed on both sides of the impeller to protect the main shaft from corrosive media. The shaft seals at both ends are mechanical seals.
The application of the water ring vacuum pump manufactured by the above-mentioned anti-corrosion measures in the selenium production process of the Roots water ring vacuum system shows that its service life is more than 8 times longer than that of ordinary cast iron pumps. The latter cannot resist the corrosion of sulfur dioxide and selenium dioxide gas. The pump will be damaged after 1-2 months, which will seriously affect the continuous industrial production and increase the cost of spare parts and maintenance. If the water ring pump is made of stainless steel, the manufacturing cost of the pump will increase more than three times. Some manufacturers have tried to spray corrosion-resistant materials on the overflow part of the water ring pump by thermal spraying, but they failed due to the weak bonding strength between the sprayed material and the body.
Copyright: EVP Vacuum Solutions