8 Layer 2nd Order HDI OSP Black Solder Mask PCB Via ≤25μM Registration Control

Product Description

• Stacked Laser Via Alignment: Two-stage laser drilling process: first stage to L2, second stage to L3. Cumulative offset controlled within ≤25μm. Cross-section measurement of via center distance performed every shift for continuous process monitoring.
• Black Solder Mask Optimization: Exposure energy increased by 6-10% versus green oil to compensate for low light transmittance. Developing point narrowed by 15 seconds compared to green oil, effectively preventing residue and ensuring clean via openings.
• OSP Film Thickness Control: OSP coating thickness precisely maintained at 0.2-0.4μm with micro-etch rate controlled at 1.0-1.5μm/min, ensuring uniform film coverage and optimal solderability.
• 24-Hour Soldering Window: Boards must be soldered within 24 hours after vacuum packaging is opened. Beyond this window, solderability degradation may occur due to OSP film oxidation.
• Black Oil Residue Prevention: Enhanced developing parameters prevent black oil residue inside vias, which is critical for uniform OSP coating. Residue-free surface ensures consistent OSP film formation across all copper pads.
• 2nd-Order HDI Stack-Up: 2+N+2 construction with blind vias connecting L1-L2, L1-L3, L6-L8, and L5-L8, enabling maximum routing density for complex high-speed digital designs.