The TLX-9 PCB – 10 mil, EPIG (Nickel-Free) for High-Frequency Dominance

The TLX-9 PCB – 10 mil, EPIG (Nickel-Free) for High-Frequency Dominance

In the world of RF and microwave engineering, the substrate is not just a physical holder for copper—it is the heart of the signal integrity game. When you need tight dielectric control, minimal signal loss, and a surface finish that won't ruin your impedance, you stop looking at standard FR-4.

Enter the TLX-9 PCB (10mil, EPIG Nickle-Free) . This is a 2-layer rigid board designed for applications where moisture absorption and dielectric constant (DK) stability are non-negotiable.

Let’s break down the specs, the stackup, and why this matters for your next LNA, antenna, or high-power amplifier.

The Foundation: Taconic TLX-9

The star of this build is the TLX-9 laminate. This is a PTFE/woven glass composite. Unlike standard RF materials that drift with temperature or humidity, TLX-9 is a workhorse.

• Dielectric Constant (DK): 2.5 @ 10 GHz (tightly controlled across frequency/temp)
• Dissipation Factor (Df): 0.0019 @ 10 GHz
• Moisture Absorption: <0.02% (virtually zero during fabrication)

Why does this matter? A Df of 0.0019 means incredibly low insertion loss. The <0.02% moisture absorption means your phase shift won't change next week because the weather changed. This material also holds a UL 94 V-0 flammability rating, so safety isn't sacrificed for performance.

The Construction: Minimalist but Mighty

This is a no-frills, high-performance 2-layer rigid design. Check out the stackup:

• Top Layer: 35 µm Copper (1 oz)
• Core: Taconic TLX-9 – 0.254 mm (10 mils)
• Bottom Layer: 35 µm Copper (1 oz)

Board Details:

• Dimensions: 91.6mm x 45.3mm (±0.15mm)
• Thickness: 0.3mm finished (This is very thin—ideal for tight enclosures or flex-to-fit applications).
• Trace/Space: 5/6 mils (tight enough for dense RF routing).
• Minimum Hole Size: 0.3mm (standard mechanical drill).
• Via Plating: 20 µm (robust enough for reliability).

Notably Absent: There is no solder mask on top or bottom, and no silkscreen. This is intentional. For high-frequency designs, solder mask adds unpredictable loss and phase variation. A bare copper and PTFE surface is often superior.

The Finish: Why EPIG (Nickel-Free)?

This board uses EPIG (Electroless Palladium Immersion Gold) , specifically the Nickel-free variant.

Standard ENIG uses a Nickel barrier layer. Nickel is ferromagnetic and lossy at high frequencies. By removing the Nickel and using EPIG, you get:

• Gold (for solderability and corrosion resistance)
• Palladium (as the diffusion barrier)
• No magnetic losses in your RF paths.

This is the gold standard (pun intended) for RF boards where every 0.1dB of loss matters.

PCB Statistics: Simple but Functional

Looking at the netlist and pad count confirms this is a targeted RF circuit, not a complex digital motherboard.

• Components: 29
• Total Pads: 45
• Thru Hole Pads: 24 (likely for connectors or through-hole RF components)
• Top SMT Pads: 21
• Bottom SMT Pads: 0 (All components on top side)
• Vias: 19
• Nets: 2 (Essentially a single RF path plus ground. Very clean).

Thermal & Mechanical Performance

RF components get hot. TLX-9 handles it well:

• Thermal Conductivity: 0.19 W/m/K (Respectable for PTFE).
• CTE (x-y): 9-12 ppm/°C (Matches copper well—good reliability during thermal cycling).
• CTE (z-axis): 130-145 ppm/°C (Standard for PTFE; ensure your plated through holes are robust).
• Peel Strength: 12 lbs/linear inch (1oz copper). You won't lift pads easily.

Who is this for? (Typical Applications)

Based on the TLX-9 properties, this board is engineered for:

1. LNAs, LNBs, LNCs (Low Noise Blocks/Converters) – Where low noise figure and stable gain are critical.

2. PCS/PCN Large Format Antennas (Personal Communications Service/Network) – The 2.5 DK allows for predictable antenna tuning.

3. High Power Amplifiers – The high dielectric breakdown (>60kV) and low loss keep things efficient.

4. Passive Components (Couplers, Filters, Dividers) – The tightly controlled DK ensures your center frequency doesn't wander.

Quality & Availability

• Quality Standard: IPC-Class-2 (Standard for commercial RF hardware; allows for minor cosmetic imperfections but ensures electrical functionality).
• Testing: 100% Electrical test prior to shipment.
• Artwork: Gerber RS-274-X (Industry standard).
• Availability: Worldwide.

The Verdict

If you are designing a sensitive receiver front-end or a high-power transmit chain in the GHz range, the TLX-9 10mil EPIG board eliminates three major headaches: moisture drift, nickel-induced loss, and DK tolerance.

It is a minimalist board (2-layer, no mask, no silk) built for maximal RF performance. Just be aware: with 0.3mm total thickness and no solder mask, you will need a careful assembly process. But for the signal integrity purist? This is a dream.

Specification Snapshot:

• Material: Taconic TLX-9 (PTFE/Woven Glass)
• Finish: EPIG (Nickel-free)
• DK/Df: 2.5 / 0.0019 @ 10GHz
• Thickness: 0.3mm
• Cu Weight: 1 oz outer layers

Ready to move past FR-4? This is your board.