Why HDI flex circuitry?

HDI flex circuit - via in pad

HDI flex circuit – via in pad

In the pursuit of continuous miniaturization, the properties of flex based materials enable smaller application form factors with the benefit of reduced weight and optimized packaging utilization.

The goal and driving force is to facilitate new designs that require smaller footprints and ultra-dense and precise conductor geometries.

Why PFC?

  • PFC has been a leader in HDI flex circuit technology for more than 9 years
  • PFC has been building 50 micron trace and space, in production, since
    HDI flex circuit showing cross section of via filled with conductive material

    HDI flex circuit showing cross section of via filled with conductive material

    2008

  • Currently, PFC has provided 37.5 micron trace and space flex circuits in prototype quantities
  • PFC’s technology roadmap is driving flex circuit technology to below 25 micron trace and space
  • PFC’s competitors call 75 micron trace and space HDI technology
  • PFC’s understanding of key materials, etching processes and design allow PFC to continue to improve on HDI flex circuitry technology

PFC recommended design guidelines

Advances in materials and etching technologies have made HDI – high density flex geometries attainable. Standard copper clad-foil for HDI flex circuitry has 18 microns thick copper and in some cases thinner.

Material choices play a big factor in PFC’s ability to provide high density circuits cost effectively.

Micro vias

High density via fabrication dramatically increases the I/O count. Mechanical drilling of vias is now being done as small as 0.004” (100 micron) diameter. Laser drilling can be done at 0.002” diameter (50 micron) on thin substrates. While PFC offers laser capabilities, the cost to laser each hole one by one becomes expensive.

  • Blind and/or buried vias
  • Via fill
  • Via-in-pad
  • 20 µm circuit geometries
  • 25 µm dielectric layers
  • 50 µm laser via

Our high-yield manufacturing of HDI flex applications and professional, hands-on consulting services are compelling reasons to make PFC your flex circuit partner of choice.

Description HDI flex circuit
Lines 50/50 µm
Microvias/pads diameter 50/200 µm
Thinnest copper 25 µm
Thinnest dielectric thickness 12 µm
Conductor width tolerance +/- 20%
Artwork to soldermask tolerance +/- 25 µm
Layer count 4
Description Ultra-high HDI flex circuit
Lines 37.5/37.5 µm
Microvias/pads diameter 40/100 µm
Thinnest copper 9 µm
Thinnest dielectric thickness 12 µm
Conductor width tolerance +/- 15%
Artwork to soldermask tolerance +/- 25 µm
Layer count 8
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