The 1+N+1 HDI PCB architecture integrates laser-drilled microvias on external layers bonded to a central multi-layer core (N), achieving high component density and fine-line routing capabilities beyond standard through-hole limitations. This configuration accommodates fine-pitch BGAs down to 0.4 mm pitch while preserving internal power and ground planes. Fabrication utilizes laser direct imaging (LDI), controlled-depth laser drilling, and sequential lamination processes tailored for high-density signal distribution, fully compliant with RoHS and REACH environmental directives.

Technical Specifications

Parameter	Specification Limit
Layer Count	3 to 12 layers (1+N+1 stack-up)
Min. Trace Width / Spacing	3.0 / 3.0 mil (0.075 mm / 0.075 mm)
Min. Laser Microvia Diameter	4 mil (0.1 mm)
Board Thickness Range	0.6 mm - 2.4 mm
Aspect Ratio (Microvia)	Up to 1:1
Aspect Ratio (Through-Hole)	Up to 12:1
Core Material Options	FR-4 (Tg 170°C / 180°C), High-Frequency (Rogers, Taconic), Low-Loss (Panasonic Megtron 6/7)
Surface Finish	ENIG, Immersion Silver, OSP, HASL (Lead-Free), ENEPIG
Solder Mask Color	Green, Black, Blue, Red, White, Yellow (Matte/Glossy available)
Impedance Control Tolerance	±10% standard (±5% available upon request)

Key Features

Sequential Lamination Processing: Eliminates mechanical drill stub resonance by stacking laser microvias directly over buried vias (stacked-via technology).

Fine-Pitch BGA Routing: Supports component pitches down to 0.4 mm without sacrificing power delivery plane integrity.

Controlled Dielectric Spacing: Maintains precise distance between reference planes and signal traces to suppress electromagnetic interference (EMI).

High-Tg Material Substrates: Withstands multiple thermal excursions during lead-free assembly reflow profiles up to 260°C.

Applications

5G Infrastructure

Active antenna units (AAU) and baseband radio units requiring high-frequency signal routing.

Automotive Electronics

Advanced Driver Assistance Systems (ADAS) radar modules and camera control units.

Industrial Computing

High-speed data acquisition boards and embedded edge processors.

Medical Equipment

Ultrasound imaging probes and portable diagnostic monitors requiring compact footprints.

Customization

Stack-Up Engineering: Engineering review of customer Gerber and stack-up proposals to optimize impedance and reduce layer count.

Material Substitution: Cross-referencing alternative laminate materials (e.g., Isola, Shengyi) to meet target cost and dielectric constant (Dk) requirements.

Plugged Via Options: Resin plugging (IPC-4761 Type VII) and copper plating over filled vias for pad-in-via applications.

Profiling Tolerances: Routing, V-scoring, and laser routing tailored to complex chassis enclosures.

Quality Control

Automated Optical Inspection (AOI): 100% inspection of inner and outer layers for etch defects, shorts, and opens.

Automated X-Ray Inspection (AXI): Verifies alignment and void percentages in stacked microvia structures.

Flying Probe Testing: Electrical continuity and isolation testing executed on 100% of fabricated panels prior to shipment.

Microsection Analysis: Destructive physical analysis performed per lot to verify copper plating thickness, dielectric thickness, and barrel crack resistance.

Manufacturing & Certifications

Facility Equipment Base: Equipped with Orbotech LDI systems, Hitachi high-speed CNC drilling machines, Schmoll laser via drills, and automatic vacuum lamination presses.

Process Capability: Cleanroom class 10,000 environment for dry film imaging and solder mask application.

Compliance Standards: Manufactured in accordance with IPC-A-600 Class 2/3 and IPC-6012 standards, meeting global RoHS and REACH regulatory requirements.

System Certifications: ISO 9001:2015, IATF 16949 (Automotive), ISO 13485 (Medical Devices), and UL certified (E-number tracking available on request).

Packaging & Delivery

Packaging Details

Vacuum-sealed ESD-safe moisture barrier bags containing silica gel and humidity indicator cards (HIC), packed in rigid double-wall corrugated cartons.

Logistics Partners

Expedited air freight via DHL, FedEx, and UPS for prototypes; palletized ocean or air freight for volume production batches.

Lead Times & Scaling

Prototypes (1+N+1): 5 - 7 business days with optimized panel utilization for quick-turn validation.
Volume Production: 12 - 18 business days, featuring tooling continuity to ensure seamless scaling from prototype batches to mass-production lines.

FAQ

Q: What is the minimum blind via size supported in a 1+N+1 configuration?

A: The standard production capability supports a minimum laser-drilled microvia diameter of 4 mil (0.1 mm) with a target capture pad size of 10 mil.

Q: Can you process customer-specified impedance calculations?

A: Engineering performs a DFM review using Polar Instruments SI8000/9000 software based on your dielectric constants and trace geometry before production release.

Q: What is the maximum copper thickness achievable on microvia layers?

A: Outer layers standardly support 1 oz finished copper after plating, with 0.5 oz and 2 oz options available subject to line/space limitations.

Q: How do you handle stacked-via reliability during thermal shock?

A: Controlled copper plating parameters fill microvias completely, and resin filling is applied where flat pad-in-via surfaces are required to prevent dimpling and solder joint voids.

Q: What documentation is provided with each delivery shipment?

A: Every batch includes a standard Certificate of Compliance (CoC), microsection test reports, electrical test verification records, and material traceability logs confirming RoHS and REACH compliance.

Q: What file formats are required to initiate a DFM check?

A: Gerber RS-274X or ODB++ files along with an IPC-D-356 netlist and a fabrication drawing specifying stack-up requirements.