Hybrid / Mixed-Material PCB Fabrication

Hybrid PCB manufacturing — PTFE+FR4 · 20 layers · 5.7 mm · 4-step blind via · Blind slot · Embedded resistors · Back drill · Build-to-print from Gerber files

Capabilities

Hybrid Lamination Process

Mixed-Material Single-Press

• Multiple materials (PTFE, ceramic-filled, FR-4) laminated in a single press cycle

• Material stack-up design with CTE matching across dissimilar substrates

• Dk range from 2.2 (PTFE) to 4.5 (FR-4) on the same board

• Bonding film selection: Rogers 3001, Speedboard C, FR-4 prepreg by zone

4-Step Blind Via

• Sequential build-up: four lamination + drill + plate cycles

• Laser-drilled microvias through PTFE layers — plasma desmear activation

• Stacked and staggered via configurations across all four steps

• Copper-filled blind vias (via-in-pad) for high-density BGA routing

Blind Slot

• Slot routed to controlled depth, stopping on a copper plane

• Slot sidewall plated — copper continuity to inner layers

• Used for RF cavity integration, waveguide coupling, and mechanical interlock

Embedded Resistors

• Multi-level inner-layer planar resistors: 8 discrete resistance values

• OhmegaPly® or Ticer® thin-film resistor foil, patterned with trace layers

• Laser trim to ± 5% tolerance per resistor value

• Eliminates discrete SMD resistors — saves board area, improves reliability

Back Drill

• Blind via back drill — removes unused via stub in blind hole stack

• Through-hole back drill — stub length controlled to < 0.25 mm

• Depth-controlled drilling with conductive inner-layer target pad

Step Features

• Milled steps with internal surface finish, trace routing, solder mask, and silkscreen

• Multiple step heights on a single board — 3D topography for connector mating and heatsink seating

Applications

• Phased-array antenna — RF beamforming on PTFE + digital beam-control on FR-4 · One board

• Aerospace transceiver — Ku/Ka-band front-end + IF/baseband in a single hybrid stack

• 5G base station filter — cavity filter integrated into PCB via blind slot + step

• Satellite payload — low-Dk PTFE for LNA + FR-4 for power distribution

• Defense electronics — mixed-signal, high-reliability, single-board LRU replacement

• Medical imaging — ultrasound front-end (PTFE) + digital back-end (FR-4) hybrid

Why Hybrid Lamination

• One board replaces two or more assembled PCBs — eliminates inter-board connectors and cables

• RF and digital circuits on a single substrate — reduced latency, improved phase coherence

• Each zone uses the optimal material — low-Dk PTFE for RF, cost-effective FR-4 for digital

• Fewer mechanical interfaces — better vibration and thermal cycling reliability

• Single DFM review, single fabrication run — shorter lead time than multiple boards