High density interconnects (HDI) PCB, represent one of the fastest-growing technologies in PCBs. Because of its higher circuitry density than traditional circuit boards, the HDI PCB design can incorporate smaller vias and capture pads, and higher connection pad densities. HDI Boards contain blind and buried vias and often contain micro vias of 0.006inch or less in diameter.
By using HDI technology, designers now can place more components on both sides of the raw PCB if desired. Now as the development of via in pad and blind via technology, it allows designers to place smaller components closer together. This means faster transmission of signals and a significant reduction in signal loss and crossing delays. HDI PCB is frequently found in mobile phones, touch-screen devices, laptop computers, digital cameras, 4G network communications, also prominently featured in medical devices.
6Layer HDI pcb microsection
Compare to standard Rigid PCB, HDI PCB request much higher wiring density with finer trace and spacing, smaller vias and higher connection pad density. Blind and buried vias' design is one of their marked feature. HDI PCB are widely used for Cell Phone, tablet computer, digital camera, GPS, LCD module and other different area.
The advantages of HDI PCB include:
Reduce the cost
Better reliability
Increase the wiring density
Increase design efficiency
Can improve the thermal properties
In favor of the use of advanced packaging technology
Has better electrical performance and signal correctness
Can improve the radio frequency interference, electromagnetic interference and electrostatic discharge
Currently the advanced HDI technology we used include: "Copper Filled" for special stack microvia, "Laser Direct Imaging"(LDI) is specifically designed for fine line technology, to eliminate dimensional stability problem of artwork caused by environmental and material issues. "Direct Laser Drill"(DLD) is drilling of copper layer by direct CO2 laser irradiation, compare to additional laser drilling with conformal mask, the copper direct laser drilling is capable of providing higher accuracy, better hole quality and better efficiency for HDI projects
General Specification for HDI PCB
Layer Count: 4-20Layers
Type of stack up: 1+N+1, 2+N+2
Stand Process Flow for 1+4+1 HDI PCB: /uploadfile/upload/file/20210401/20210401090238_50253.pdf
Material Available: FR4, High Tg FR4, Halogen Free FR4
Board thickness: 0.4-3.2mm
Finished copper thickness: 1/3oz – 3oz
Min trace width/spacing: 3/3mil
Min through hole: 0.2mm
Min blind via: 0.1mm
Surface treatment: Immersion Gold, ENIG + OSP
----------- 
6 Layer HDI PCB for SSD Memory 8 Layer HDI PCB board
Material: FR4 S1000-2 Material: FR4 TU-768
Layer count: 6 Layer count: 8
Board thickness: 1.6mm Board thickness: 2.0mm
Copper thickness: 1oz Copper thickness: inner 0.5oz/outer 1oz
Surface finish: ENIG Surface finish: ENIG
Min. hole: 6mil Min. Hole: 0.2mm
Min. Line/space: 3.9/3.9mil Min Line/space: 4.1/4.1mil
Usage: SSD Memory Card Usage: Data collection
