HDI High-Density Interconnect

Micro Vias for High-Density Attributes  HDI

HDI PCBs are characterized by high-density attributes including laser micro vias, fine lines, and high-performance thin materials. This increased density enables more functions per unit area. Higher technology HDI PCBs have multiple layers of copper filled stacked micro vias which creates a structure that enables even more complex interconnections. These very complex structures provide the necessary routing solutions for today’s large pin-count chips utilized in mobile devices and other high technology products.

HDI Structures

1+N+1 – PCBs contain 1 “build-up” of high-density interconnection layers.

i+N+i (i≥2) – PCBs contain 2 or more “build-up” of high density interconnection layers. Micro vias on different layers can be staggered or stacked. Copper filled stacked micro via structures are commonly seen in challenging designs.

Any Layer HDI – All the layers of a PCB are high-density interconnection layers which allow the conductors on any layer of the PCB to be interconnected freely with copper filled stacked micro-via structures (“any layer via”). This provides a reliable interconnect solution for highly complex large pin-count devices, such as CPU and GPU chips utilized on handheld and mobile devices.

Advanced Capabilities: Micro Vias  HDI

A micro via maintains a laser-drilled diameter of typically 0.006″ (150µm), 0.005″ (125µm), or 0.004″ (100µm), which are optically aligned and require a pad diameter typically 0.012″ (300µm), 0.010″ (250µm), or 0.008″ (200µm), allowing additional routing density. Micro vias can be via-in-pad, offset, staggered or stacked, non-conductive filled and copper-plated over the top, or solid copper filled or plated. Micro vias add value when routing out of fine pitch BGAs such as 0.8 mm pitch devices and below.

Micro vias HDI add value when routing out of a 0.5 mm pitch device where staggered micro vias can be used, however, routing micro-BGAs such as 0.4 mm, 0.3 mm, or 0.25 mm pitch device, requires using an inverted pyramid routing technique.

Highfive maintains years of experience with HDI products and was a pioneer of second-generation micro vias that offers solid copper stacked micro vias providing rout-out solutions for micro HDI BGAs.

Standard or First Generation Micro vias HDI

Create routing density (eliminate through vias)

Reduce layer count

Enhance electrical characteristics

Standard Microvias limited to layers 1 – 2 & 1 – 3

Second Generation Micro vias HDI

Allows increased routing on multiple layers

Provides routing solutions for next generation applications

1 mm – 0.8 mm – 0.65 mm – 0.5 mm – 0.4 mm – 0.3 mm & 0.25 mm

Provides solid copper plate eliminating potential solder voiding

Provides a Thermal Management Solution

Improves Current Carrying Capability

Improves Current Carrying Capability

Provides a Planar surface for BGA (Via-in-Pad)

Allows any layer via technology

Deep Stacked Micro Vias HDI

Provides additional dielectric for RF applications

Maintains small geometries on multiple layers

Improved signal integrity

Provides a solid copper plate

Improves Current Carrying Capability & Thermal Management

Provides a Planar surface for BGA (Via-in-Pad)

Any layer HDI

Multilayer copper filled stacked micro via structure

1.2/1.2 mil line/space

4/8 mil laser via capture pad size

Material options:

High temperature FR4

Halogen – Free

High Speed (low loss)

Please contact us for more details or visit our HIEDESIGN for some updating info about us.

Highfive PCBAE developed and now offers generation microvias which offers stacked microvia fabrication in a timely manner (5-7 days). And allows for a quick-turn of PCB designs with complex via structures and requires only one lamination cycle reducing thermal excursions (thermal degradation of material) and cycle time.

It eliminates the copper plating cycle of inner layers, improving impedance tolerance, reducing overall thickness and improving electrical characteristics. Additionally, it can provides designer flexibility to have any-layer-via connectivity using a metallurgical bond between conductive paste and copper on the inner layers. It can also be utilized for the surface or external microvias to create a solid copper via if required.

Additionally, HDI allows interconnecting of multiple subs containing high technology or standard technology. Also, this technology allows the use of high performance materials only where they are needed or required.