Advanced Circuits, Inc. (ACI)


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Microvias in Advanced PCB Designs

Advanced Circuits offers expanded PCB manufacturing capabilities including laser-drilled microvias for high-tech requirements.  Microvias and stacked microvias can be found in High Density Interconnect circuit boards, also known as HDI PCBs, to enable complex interconnections in advanced designs. 

Microvias, stacked microvias, and via-in-pad features allow miniaturization for higher functionality in less space and can accommodate large pin-count chips such as the ones used in cell phones and tablets.  Microvias help reduce layer count in printed circuit board designs while enabling higher routing density and eliminating the need for through vias.

Standard Microvia PCB Microsection

Standard Microvia

Microsections of Microvias Exhibiting Uniformity of Plating

No occlusions, voids, or skips

Microvia example 1  Microvia example 2  Microvia PCB example 3  

Microvia printed circuit board 4  Microvia example 5

Copper-Filled Microvia Microsection

Copper-Filled Microvia PCB

Stacked Microvia Microsection

stacked microvia

Advanced Circuits Microvia Capabilities

Refer to the chart below for Advanced Circuit's HDI / Laser Drilled Microvia (μVia) Capabilities
  Smallest (as ablated) Laser Microvia   0.003"
  Largest (as ablated) Laser Via   0.010"
  Microvia Aspect Ratio (Depth to Diameter)

  0.75:1 Standar / 1:1 Advanced

  Capture Pad Size   μVia +0.008" Std. / μVia +0.006" Adv.
  Landing Pad Size   μVia +0.008" Std. / μVia +0.006" Adv.
  Stacked Microvia   Yes
  Type I Capabilities   Yes
  Type II Capabilities   Yes
  Type III Capabilities   Design Dependent
  Copper Filled Microvias   Yes
The information provided in the chart above is subject to change without prior notice.

High-density interconnects are categorized by six design types in IPC-2226. They are grouped by stackup characteristics in the following categories:  Type I, Type II, Type III, Type IV, Type V, and Type VI

  • TYPE I 1 [C] 0 or 1 [C] 1, with through-vias from surface to surface.
  • TYPE II 1 [C] 0 or 1 [C] 1, with buried vias in the core and may have through-vias connecting the outer layers from surface to surface.
  • TYPE III 2 [C] 0, two or more HDI layers added to through-vias in the core or from surface to surface.
  • TYPE IV 1[P] 0 where P is a passive substrate with no electrical connecting functions.
  • TYPE V Coreless constructions using layer pairs.
  • TYPE VI Alternate constructions of coreless construction using layer pairs.

For more information about Microvias and other advanced PCB capabilities, Click here to contact us or download our full capability sheet.