The types of HDI PCB

1.through vias from surface to surface,
2.with buried vias and through vias,
3.two or more HDI layer with through vias,
4.passive substrate with no electrical connection,
5.coreless construction using layer pairs
6.alternate constructions of coreless constructions using layer pairs.

HDI (High Density Interconnection) circuit boards usually include laser blind vias and mechanical blind vias; general through buried vias, blind vias, stacked vias, staggered vias, cross blind buried, through vias, blind via filling plating, fine line small gaps, The technology of realizing the conduction between the inner and outer layers by processes such as micro-holes in the disk, usually the diameter of the blind buried is not more than 6 mils.

Work flow for HDI

Board Cut - Inner Wet film -DES - AOI - Brown Oxido - Outer Layer Press - Out Layer Lamination - X-RAY & Rounting - Copper reduce & brown oxide - Laser Drilling - Drilling - Desmear PTH - Panel plating - Outer Layer dry film - Etching - AOI- Impedance Testing - S/M Pluged hole - Solder Mask - Component Mark - Impedance testing - Immersion Gold -V-cut - Routing - Electrical Test - FQC - FQA -Package -Shipment