Gold Plated Conical Inductor Custom Metal Composite Inductor Micro Magnetic Shielding

Custom Conical Inductor Noble Metal Composite Plating Micro Magnetic Shielding Optimized Return Loss Impedance

HACC-CUSTOM-NM: Noble Metal Plated Magnetically Shielded Conical Inductor with Optimized Return Loss & Impedance Matching

Proprietary Multi-Layer Noble Metal Composite Plating

Standard gold-plated conical inductor wire uses a simple Au/Ni/Cu stack that is adequate for benign environments but degrades in high-humidity, high-temperature, or corrosive atmospheres. The Au-Ni interface is susceptible to Kirkendall voiding after extended high-temperature exposure, and the thin Au flash (<0.1 µm) provides limited corrosion protection. The HACC-CUSTOM-NM employs a proprietary multi-layer noble metal composite: a Ni adhesion layer (1–2 µm) over the Cu wire, a dense Pd barrier layer (0.5–1.0 µm) that prevents Ni diffusion into the Au surface, and an Au flash top layer (0.1 µm) for bondability. This Au/Pd/Ni/Cu stack eliminates intermetallic growth after 1,000 hours at 150°C — no Kirkendall voiding, wire bond pull strength maintained above 4.0 g. Customer-selectable variants include Au/Pt/Ni/Cu for extreme corrosion environments (>500 hours salt spray per ASTM B117) and Au/Ag/Ni/Cu for cost-sensitive applications — all RoHS compliant and ENIG-compatible with standard PCB surface finishes.

Integrated Micro-Magnetic Shielding Enclosures

Multi-coil RF modules — phased arrays, multi-channel bias-tee banks, simultaneous transmit-receive modules — suffer from near-field magnetic coupling between adjacent conical inductors. At 1 mm separation, the H-field coupling can exceed -10 dB, creating cross-channel interference that degrades beamforming accuracy and channel isolation. The HACC-CUSTOM-NM integrates a micro-magnetic shielding enclosure: a 0.1–0.3 mm thick Mumetal or nanocrystalline shield with relative permeability above 50,000 at 1 kHz, providing over 10 dB near-field H-field suppression from 1–10 GHz at 1 mm separation. The shield is laser-welded at the seam for continuous magnetic closure and can be configured as a full cylinder, a partial cap, or an open-sided directional shield depending on the module layout. In multi-coil arrays, adjacent channel isolation improves by over 8 dB — eliminating the need for additional inter-coil shielding structures that consume precious module area.

Optimized Return Loss & Perfect Impedance Matching Curves

Conical inductors are inherently broadband, but their impedance is not inherently matched to 50 Ω. S11 can dip to -5 dB or worse at certain frequencies, creating a reflective node that compromises the bias-tee insertion loss and system return loss budget. The HACC-CUSTOM-NM is tuned for return loss: S11 is optimized below -15 dB across the full specification band from 100 MHz to 40 GHz, with impedance matched to 50 Ω ±5%. Every device ships with a measured S11(f) plot and .s2p Touchstone file — verifying that the Smith chart trace stays within the VSWR <1.5 circle across the entire band. Custom impedance matching to 25 Ω or 75 Ω is available for non-standard system impedances.

Key Specifications

Applications

• Multi-Channel Phased Array Bias Networks — >8 dB adjacent channel isolation via micro-shielding, S11 <-15 dB per channel for beamforming accuracy
• Simultaneous Transmit-Receive (STAR) Modules — H-field shielding >10 dB for TX-RX isolation, noble metal plating for maritime/offshore corrosion resistance
• High-Density Multi-Coil Assemblies — 0.1–0.3 mm shield, 1 mm coil-to-coil pitch, laser-welded continuous magnetic closure
• Corrosion-Resistant Outdoor RF — Au/Pd/Ni/Cu or Au/Pt/Ni/Cu plating, >500h salt spray, mixed gas qualified for industrial deployment

Contact us with your plating stack, shielding geometry, and impedance matching requirements. Noble-metal plated magnetically-shielded conical inductors ship in 5–7 business days.