1. Cleaning and Decontamination
Use plasma cleaning or isopropanol wiping to remove oxides, fingerprints, or residues from the positioning hole surface, ensuring surface cleanliness meets high-precision requirements (e.g., IPC-6012 Class 3 standard).
Check the through-hole status: Ensure the positioning hole is unblocked, the hole diameter tolerance is controlled within ±0.05mm, and the hole wall roughness is ≤5μm.
2. Surface Active Treatment (Optional)
For positioning holes intended for long-term storage or made of special materials, a small amount of flux can be applied or a tinning treatment can be performed to enhance wettability and bonding strength during welding.
Precautions
Avoid secondary contamination after pretreatment. Wear anti-static gloves during operation.
If the positioning hole is made of cast iron or steel, pay attention to rust prevention treatment to avoid oxidation affecting subsequent use.
