10L Thin Board With 2-Stage Laser

A 10-layer thin HDI PCB on S7439 high-speed laminate, 0.75±0.075mm thick, with two-stage stacked laser microvias at φ0.10mm and a buried via at φ0.20mm. The 2-stage laser construction lets the design route from layer 1 through to interior layers without going all the way through the board, freeing the inner stack for clean differential-pair routing while keeping the outer-layer escape from fine-pitch BGA balls extremely short. Stacking two laser steps also avoids the radial space penalty of staggered microvia patterns, so the BGA breakout footprint stays compact. The 0.75mm finished thickness fits inside slim handhelds and wearables, and the S7439 substrate keeps loss low across the high-frequency bands used in modern radios. Typical fits are smartphone main and sub-boards, smartwatch and AR headset main boards, 5G mmWave modules, optical-module daughter boards, and any thin device that needs HDI-grade routing under fine-pitch BGAs.