Micro-hole PCBs Making HDI Interconnects More Reliable
Micro-hole design involves more than just reducing the hole diameter. It is necessary to simultaneously consider the medium thickness, target pads, laser processing, copper plating, and interconnect structures—especially for multi-layer stacked holes.
To understand the process, start by clarifying these key points
Single-layer microporous
Commonly used for interconnections between adjacent layers. First, determine the dielectric material, the dimensions of the via and its bottom, the target pads, and the fabrication method.
Misaligned Microporous Structures
The microvias in adjacent layers are staggered on the plane and connected via copper traces, so space must be reserved for the pads and connecting traces.
Stacked Microporous Structures
Since the microvia are stacked vertically, it is essential to thoroughly evaluate copper filling, interface bonding, alignment, and thermal cycling reliability; support for any number of stacked via layers cannot be assumed.
Design Boundaries and Manufacturing Reviews
- Laser Aperture
- In-house processing capabilities range from 0.075 to 0.15 mm; the applicable materials and media thicknesses must be confirmed on a project-by-project basis.
- HDI Order
- The current range lists orders 1–3; the order does not correspond directly to the number of stacked microporous layers that can be guaranteed.
- Hole Shape and Depth
- The drawings must specify the diameter of the hole opening, the bottom of the hole, and the thickness of the medium; providing only a single diameter is not sufficient.
- Hole-Filling Requirements
- Micro-hole copper filling and resin filling are not the same process; the objectives and acceptance criteria should be clearly defined.
- Stacked Hole Verification
- Confirm the manufacturing plan after submitting the layer pairs, stacked via structures, target pads, and reliability requirements.
The manufacturing values cited are based on this site’s existing process capabilities. The listed limit values do not imply that all can be achieved simultaneously; the manufacturing plan will be finalized after the complete stack-up, hole layout, and materials have been confirmed.
View Full Manufacturing CapabilitiesBefore requesting a quote, prepare these three sets of documents
Production and Layer Files
Gerber or ODB++ files, drill files, stack-up diagrams, and layer-to-hole mapping tables; ensure that file versions are consistent.
Key Process Requirements
Specify the hole diameter, plating material, copper-clad area, surface treatment, and required tolerances.
Quantity and Inspection Requirements
Please provide the quantity for prototypes and production runs, the desired delivery date, inspection reports, and reliability verification requirements.
Frequently Asked Questions
Is a 10:1 thickness-to-diameter ratio for machined holes suitable for microholes?
This cannot be applied directly. Laser micropores are subject to limitations imposed by the thickness of the substrate, pore shape, cleaning, and plating conditions, and should be evaluated on a case-by-case basis.
Are offset holes always cheaper than stacked holes?
You can't generalize. The cost also depends on the laminate structure, area, via filling, lamination, and inspection requirements; you should compare comprehensive proposals.
Submit the via design for engineering review
Shenzhen Jingpeng Electronics | We provide stack-up and via tables to help you assess manufacturability, cost implications, and delivery requirements.
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