Electrolytic Polishing of Steel Meshes: Technical Specifications

I. Process Principle

Electrolytic polishing of steel meshes is a technology that achieves micro-levelling through selective dissolution in an electrolyte, with the steel mesh serving as the anode. Its core mechanisms are:

• Tip discharge effect: The current density is higher at the convex parts of the hole walls, resulting in preferential dissolution.
• Mucus membrane theory: A phosphate film forms a thicker protective layer in concave areas, while convex areas dissolve rapidly to achieve smoothness.
• Dynamic equilibrium: Controllable dissolution is realized by controlling the current (10-25A/dm²) and voltage (8-10V).

II. Process Flow

Pretreatment stage

• Chemical degreasing and oil removal (residual moisture must be completely removed).
• Acid pickling for rust removal (for steel meshes with severe oxidation).

Electrolytic polishing stage

• Electrolyte configuration: Phosphoric acid-based solution (temperature 60-70℃).
• Parameter control: Time 5-8 minutes, with lead plates used as cathodes.
• Real-time monitoring: The optimal state is when the electrolyte is slightly green.

Post-treatment stage

• Three-stage water washing (to remove residual electrolyte).
• Nitric acid film stripping (concentration ≥20%).
• Neutralization with sodium hydroxide (1-3% solution).

III. Technical Advantages

IV. Industrial Applications

• High-precision SMT stencils: Used for printing micro-pitch components such as 01005.
• Semiconductor packaging: Processing of ball-planting steel meshes for BGA/CSP devices.
• Special scenarios:
  • Steel meshes for medical equipment (requiring Ra ≤ 0.4μm).
  • Automotive electronics (printing of high-temperature-resistant solder paste).

V. Key Points of Process Control

• Electrolyte management: 12-15L of stock solution needs to be replenished for every 100㎡ of steel mesh.
• Defect prevention:
  • Pitting: Control moisture content to <3%.
  • Striations: Maintain electrolyte flow rate at 0.8-1.2m/s.
• Equipment selection:
  • High-frequency pulse power supply is recommended (accuracy ±0.5V).
  • Titanium alloy fixtures ensure uniform current distribution.