Vacuum base

Vacuum bases are core components in vacuum systems, used for load-bearing, positioning, sealing, and connection. They are widely used in semiconductor manufacturing, vacuum coating, aerospace, and scientific instruments. Their performance directly determines the sealing, stability, and operational accuracy of the vacuum system, adapting to low to ultra-high vacuum environments ranging from 10⁻¹Pa to 10⁻⁹Pa. The following section introduces their structure, function, material selection, manufacturing process, quality control, and application scenarios.

Structure and Core Functions

Vacuum bases typically include a positioning platform, sealing groove, evacuation channel, and flange interface. Their core functions are threefold: 1. Sealing and isolation: using O-rings and metal gaskets to isolate the vacuum chamber from the external environment, preventing gas leakage; 2. Precise positioning: providing a high-precision reference surface to ensure that the installation tolerances of components such as vacuum gauges, valves, and wafer carriers are controlled within ±0.01mm; 3. Stable load-bearing capacity: adapting to different load-bearing requirements, from gram-level precision components to hundreds-ton fusion device Dewar bases. Some bases also integrate airflow regulation and quick-connect couplings to improve system adaptability.

Material Selection

Mainstream materials fall into three categories: 304/316L stainless steel, suitable for high vacuum and corrosion-resistant applications, undergoes vacuum heat treatment to enhance strength; aluminum alloy is used for lightweight applications, and anodizing enhances wear resistance and sealing performance; ceramic materials are suitable for semiconductor wafer processing, possessing anti-static and low dust generation properties. Material impurities and porosity must be controlled to comply with RoHS standards and prevent gas release that could affect vacuum levels.

Manufacturing Process

Precision bases utilize precision stamping and CNC machining as core processes. Molds are made of wear-resistant materials such as Cr12MoV, and hardened through vacuum quenching. Large bases, such as fusion dewar bases, require mastering high-precision welding and millimeter-level deformation control technologies. After stamping, deburring, surface grinding (Ra≤0.4μm), and vacuum leak testing are required. Key parameters such as stamping pressure and welding temperature must be precisely controlled to prevent warping and sealing defects.

Quality Control

Key performance indicators include vacuum sealing (leakage rate ≤10⁻¹² Pa·m³/s), dimensional accuracy (IT6-IT8 grade), surface roughness, and mechanical strength. Helium mass spectrometry leak detection, coordinate measuring machine (CMM) measurement, and metallographic analysis are employed to ensure long-term stable operation.

Application Scenarios

In the semiconductor field, it is used for positioning wafer transport devices; in vacuum testing, it is used to fix vacuum gauges to ensure measurement accuracy; in aerospace, it is used for vacuum environment testing of satellite components; in fusion devices, the Dewar pedestal supports the main system and is a core support component under extreme conditions.