WL-CT hydrocarbon ceramic PCB laminate from Wangling delivers Rogers RO4000-class RF performance with FR4-compatible processing. Complete guide covering WL-CT300 through WL-CT615 specs, Dk/Df data, Rogers comparison, and design tips for 5G, radar, and aerospace applications.
If you’ve ever quoted a board in Rogers RO4350B and watched your customer’s face drop, you already know the problem. Standard FR4 collapses past a few GHz. PTFE laminates behave beautifully at 10 GHz and 24 GHz, but they fight your fabricator at every drill, via, and lamination cycle. Somewhere between those two extremes sits a quieter option: the WL-CT hydrocarbon ceramic PCB laminate from Taizhou Wangling. It runs on a standard FR4 process line, costs less than the US-branded equivalents, and delivers Dk and Df numbers that let your 5 GHz to 25 GHz designs actually close. This guide walks through the WL-CT family the way a PCB engineer thinks about it — data sheets, trade-offs, and fab-floor realities.
What the WL-CT Series Actually Is
The WL-CT series is a family of organic polymer copper-clad laminates built on a thermosetting hydrocarbon resin system, loaded with ceramic filler and reinforced with woven fiberglass cloth. That construction should sound familiar. It is the same material chemistry that Rogers popularized with its RO4000 line — hydrocarbon/ceramic composites designed to behave like PTFE electrically and like epoxy/glass mechanically.
Wangling’s factory in Taizhou, Jiangsu has been building high-frequency substrates since 1982, so this isn’t a newcomer brand. The WL-CT line specifically targets engineers who want sub-0.005 loss tangent performance without the PTFE fabrication penalty. The dielectric stack is hydrocarbon resin + ceramics + glass cloth, giving it a high Tg (>280 °C), low Z-axis CTE, and dielectric constant options from 3.00 all the way up to 6.15.
Why Hydrocarbon Ceramic Matters for RF Engineers
Three reasons, in the order a designer tends to hit them:
- FR4’s Df climbs fast with frequency. By the time you’re north of 3 GHz, you’re burning real dB per inch in the dielectric. A WL-CT hydrocarbon ceramic PCB laminate holds its loss tangent flat out to roughly 25 GHz.
- PTFE processing is expensive. Sodium etch, specialized drill parameters, plasma desmear — every one of these adds cost and lead time. Hydrocarbon ceramic materials run on a regular epoxy/glass line.
- Dimensional stability matches copper. With X/Y CTE sitting around 13–17 ppm/°C, the laminate expands the same way the traces do. Plated through-holes stay reliable through thermal cycling.
WL-CT Model Breakdown: Picking the Right Dk
The WL-CT series doesn’t offer one dielectric constant — it offers six, plus variants. That matters because Dk is the single biggest factor in trace width, propagation velocity, and ultimately whether your antenna radiates where you expected.
| Model | Dielectric Constant (10 GHz) | Dissipation Factor (10 GHz) | Typical Use Case |
| WL-CT300 | 3.00 ± 0.05 | 0.0028 | Low-Dk RF, wideband antennas, satellite front-ends |
| WL-CT330 | 3.30 ± 0.05 | 0.0030 | 5G base station, general microwave |
| WL-CT338 | 3.38 ± 0.05 | 0.0034 | RO4003C drop-in replacement, mm-wave |
| WL-CT350 | 3.48 ± 0.05 | 0.0040 | RO4350B drop-in, UL 94 V-0 designs |
| WL-CT410 | 4.10 ± 0.05 | 0.0050 | Mixed-signal, digital/RF hybrid stacks |
| WL-CT615 | 6.15 ± 0.10 | 0.0045 | Miniaturized antennas, high-Dk filters |
The WL-CT350 is the workhorse of the line, and it’s the one most engineers end up comparing to Rogers. With a Dk of 3.48 and a Df around 0.004 at 10 GHz, it hits essentially the same target as RO4350B, and several fabricators explicitly market it as a cross-reference part.
Thickness and Copper Options
Stack-up planning lives or dies on available thicknesses. Here’s what the WL-CT line gives you:
| Parameter | Specification |
| Dielectric thickness range | 0.102 mm (4 mil) to 3.05 mm (120 mil), custom beyond |
| Copper foil weight | 0.5 oz (17.5 µm), 1 oz (35 µm), 2 oz (70 µm) available |
| Foil types | ED (electrodeposited) standard; RTF (reverse-treated) for low-loss |
| Panel sizes | 610 × 460 mm, 600 × 500 mm, 915 × 1224 mm |
| Thickness tolerance | ±0.01 mm for thin cores, ±0.08 mm for thick |
Note that when you spec reverse-treated foil (RTF), the dielectric thickness increases by about 0.018 mm (0.7 mil). That matters for impedance control — don’t ignore it in your stack-up calculator.
Technical Specifications That Actually Drive Design Decisions
A PCB engineer doesn’t design off marketing bullets. These are the numbers I pull up before I commit to a material.
Electrical Properties (WL-CT350 Reference)
| Property | Value | Test Method |
| Dk @ 10 GHz | 3.48 ± 0.05 | IPC-TM-650 2.5.5.5 stripline |
| Df @ 10 GHz | 0.0040 | IPC-TM-650 2.5.5.5 |
| Df @ 2.5 GHz | 0.0032 | Stripline |
| TCDk (-50 to 150 °C) | ~43 ppm/°C (CT350), ~27 ppm/°C (CT300) | — |
| Volume resistivity | ≥1 × 10⁹ MΩ·cm | IPC-TM-650 |
| Surface resistivity | ≥4 × 10⁸ MΩ | IPC-TM-650 |
| Dielectric strength | 94V-0 flame rated | UL 94 |
Thermal and Mechanical Properties
| Property | Value |
| Glass transition (Tg) | >280 °C |
| CTE X-axis | 11 ppm/°C |
| CTE Y-axis | 14 ppm/°C |
| CTE Z-axis | 34 ppm/°C |
| Thermal conductivity | 0.70 W/m·K (approx.) |
| Operating temperature | -50 °C to +260 °C |
| Water absorption (24 hr) | 0.05% |
| Copper peel strength (1 oz) | 9 N/cm |
| Thermal stress (288 °C solder) | ≥3× no delamination |
| Specific gravity | 1.9 |
The 280 °C Tg is the number to notice. Most mid-tier FR4 taps out around 170 °C Tg. Megtron-class materials reach roughly 185 °C. When the WL-CT resin clears 280 °C, plated through-hole reliability through reflow cycles becomes a non-issue even for lead-free assembly.
The FR4 Processing Advantage — Why Your Fabricator Will Thank You
This is the single biggest reason the WL-CT hydrocarbon ceramic PCB laminate earns its keep in production. PTFE boards (think Rogers RT/duroid or Taconic TLY) demand sodium-etch or plasma hole prep because nothing sticks to Teflon. That’s a specialty process. Fabs that don’t run it either outsource or refuse the job outright.
WL-CT processes like FR4. Drill with carbide bits at standard parameters. Desmear with conventional alkaline permanganate. Plate with normal electroless copper chemistry. Laminate with standard vacuum press cycles. I’ve seen fabricators quote WL-CT at roughly the same NRE as a mid-Tg FR4 run, which is almost unheard of for a material hitting 0.004 Df.
What This Looks Like on the Fab Floor
- Drilling: Same bits, same feeds and speeds as high-Tg FR4. Hole wall quality holds up through 2,000+ hits without the smear problems PTFE throws at you.
- Desmear: Standard permanganate chemistry works. No plasma cycle required.
- Lamination: Conventional vacuum press at normal FR4 temperatures and pressures. WL-PP prepreg (Wangling’s companion bonding film) mates with WL-CT cores and with FR4 cores — useful for hybrid stack-ups.
- Solder mask and surface finish: Drop in your normal LPI solder mask and any standard finish (HASL, ENIG, immersion silver). No chemistry changes.
If you’re building a hybrid RF+digital board where the top layer is WL-CT350 and the inner digital layers are FR4, the WL-PP prepreg glues those together in a single lamination cycle. That’s a design freedom PTFE users don’t have without a lot of pain.
WL-CT vs. Rogers RO4000: The Comparison Engineers Actually Care About
Rogers’ RO4000 series is the benchmark. The RO4003C at Dk 3.38 and RO4350B at Dk 3.48 are the two most-specified hydrocarbon ceramic laminates in North America. Here’s how WL-CT stacks up against them.
| Parameter | WL-CT338 | Rogers RO4003C | WL-CT350 | Rogers RO4350B |
| Dk @ 10 GHz | 3.38 ± 0.05 | 3.38 ± 0.05 | 3.48 ± 0.05 | 3.48 ± 0.05 |
| Df @ 10 GHz | ~0.0034 | 0.0027 | 0.0040 | 0.0037 |
| Tg | >280 °C | >280 °C | >280 °C | >280 °C |
| CTE X/Y | 11–14 ppm/°C | 11/14 ppm/°C | 11–14 ppm/°C | 10/12 ppm/°C |
| UL 94 V-0 | Yes | No | Yes | Yes |
| FR4-compatible process | Yes | Yes | Yes | Yes |
| Typical cost (relative) | 0.6–0.7× | 1.0× | 0.6–0.7× | 1.0× |
The honest engineer’s read: Rogers still edges out WL-CT on loss tangent by a small margin — roughly 0.0003 to 0.0013 depending on grade. Whether that matters depends on your link budget. For a 5G small-cell antenna at 3.5 GHz running 10-inch microstrip traces, the difference is negligible. For a 77 GHz automotive radar where every 0.001 of Df matters, Rogers or a high-end PTFE may still be the right call. For everything in between — and that’s most commercial RF work — the WL-CT hydrocarbon ceramic PCB laminate closes the gap cleanly.
When to Pick WL-CT Over Rogers
- Cost-driven production runs where margins are thin and volumes are real (5G infrastructure, automotive aftermarket, consumer IoT).
- Asia-Pacific supply chains where Wangling has shorter lead times than importing Rogers stock.
- Mil-spec applications needing UL 94 V-0 plus hydrocarbon-ceramic electrical performance at a national-industry price point.
When to Stick With Rogers
- Flight-critical aerospace where the design was already qualified to RO4350B — requalifying costs more than the material savings.
- mm-wave radar above 40 GHz where the Df delta starts compounding into measurable insertion loss.
- Low-PIM applications where specific Rogers foil treatments are part of the spec.
Application Spaces Where WL-CT Shines
5G and Base Station Antennas
Sub-6 GHz 5G equipment — the massive-MIMO antenna arrays, the baseband-to-RF interconnect boards — is exactly the volume/performance sweet spot WL-CT was built for. WL-CT350 is used widely in 3.5 GHz and 4.9 GHz base-station radios. The Dk stability across temperature matters here, because outdoor radios see -40 °C to +85 °C and you can’t afford your antenna pattern drifting with the weather.
Automotive Radar (24 GHz and 77 GHz)
For 24 GHz short-range radar, WL-CT338 and WL-CT350 both work well. At 77 GHz the story gets tighter — you’re into mm-wave territory where loss tangent matters more, and most designers reach for PTFE-based material there. But the 24 GHz lane-change, blind-spot, and parking sensor modules are well-served by hydrocarbon ceramic.
Satellite and Aerospace
The Wangling data sheet calls out low outgassing performance per NASA’s vacuum volatility standards, plus irradiation resistance. Those aren’t trivial specs. For LEO satellite payloads — think GNSS correction services, earth observation downlinks — a PCB laminate that doesn’t outgas or shift Dk under ionizing radiation is worth its weight.
Power Amplifier and RF Front-Ends
The 0.70 W/m·K thermal conductivity isn’t going to compete with an aluminum-clad board, but it’s noticeably better than standard FR4 (~0.25 W/m·K) and better than most PTFE/glass composites. For a Doherty amplifier running 100 W average at a 5G site, WL-CT350 as the RF layer with aggressive thermal vias to a metal backplate makes engineering sense.
Design Guidelines for Engineers New to WL-CT
A few practical tips from the trenches:
Run your Dk at the frequency of use, not just at 10 GHz. Wangling’s Dk is specified at 10 GHz stripline, but your design might operate at 2.4 GHz or 28 GHz. Ask for frequency-dependent data; the manufacturer publishes TCDk curves that make this straightforward.
Account for the 50-ohm microstrip “design Dk” bump. Like Rogers, Wangling specifies a slightly higher “design Dk” for microstrip geometries versus the stripline value (roughly 0.1 higher for WL-CT350). Use the design value in your trace-width calculator, not the bare material spec.
Plan your hybrid stack-ups. WL-PP prepreg bonds to both WL-CT cores and standard FR4 cores. A typical 6-layer RF+digital hybrid puts the RF on top with WL-CT350 cores and bonds down to FR4 for the digital signals. One lamination cycle, no special press program.
Order samples before you commit. Even with published data sheets, every RF designer has been burned once. Order a small run, measure the dielectric constant with a resonator fixture on your specific stack-up, and verify before you commit to 500 boards.
Useful Resources and Downloads
For engineers specifying the WL-CT hydrocarbon ceramic PCB laminate, here are the references worth bookmarking:
- Wangling manufacturer site: wang-ling.com.cn — the source data sheets, in English, straight from Taizhou.
- Wangling PCB fabrication services: Wangling PCB — full-service prototyping and production on WL-CT materials with FR4-compatible processing.
- WL-CT series data sheet (PDF): Available from most authorized distributors and fabricators who stock the material.
- IPC-TM-650 test methods: The 2.5.5.5 stripline test method is the industry reference for Dk/Df — worth reading to understand how the numbers on the data sheet were measured.
- IPC-4103 specifications: The slash sheets (/10 for Dk 3.38 class, /11 for Dk 3.48 class) that Rogers RO4003C and RO4350B conform to. WL-CT338 and WL-CT350 target the same categories.
- Sierra Circuits PCB Material Selector: protoexpress.com/tools/pcb-material-selector — useful online tool for cross-referencing Dk/Df across dozens of materials.
- San Francisco Circuits Material Reference Guide: Good primer on Dk, Df, TC, and CTE if you’re new to high-frequency material selection.
Frequently Asked Questions
Is WL-CT350 a direct replacement for Rogers RO4350B?
Electrically and dimensionally, yes — in most commercial applications WL-CT350 is specified as an RO4350B cross-reference with matching Dk (3.48 ± 0.05), matching Tg (>280 °C), and UL 94 V-0 flame rating. The loss tangent runs marginally higher (0.0040 vs. 0.0037). For qualified aerospace or mil-spec programs already locked to a specific Rogers slash sheet, requalification is required regardless of how close the specs match.
Can my existing FR4 fabricator process WL-CT without new equipment?
In most cases, yes. The material processes on the same drilling, desmear, plating, lamination, and solder-mask lines as high-Tg FR4. No sodium etch, no plasma cycle, no special drill chemistry. That said, any fabricator running a new material for the first time should do a process qualification run before a production job — it’s standard practice, not a WL-CT problem.
What’s the difference between WL-CT and WL-PP?
WL-CT is the copper-clad laminate (the rigid core with dielectric and copper foil). WL-PP is the matching prepreg bonding film — uncured hydrocarbon ceramic resin on glass cloth, used to bond WL-CT cores together or to bond WL-CT cores to FR4 cores in hybrid multilayer stack-ups. Both share the same base chemistry, so dielectric properties are consistent across the laminated structure.
How does WL-CT perform at mm-wave frequencies (above 40 GHz)?
The material holds stable Dk and low loss up to about 25 GHz according to the published spec. Above that, the ceramic-glass-resin composite starts showing the limitations of any hydrocarbon system — loss tangent creeps up. For 77 GHz automotive radar or 5G FR2 mm-wave (24, 28, 39 GHz), designers typically move to PTFE-based materials (Wangling’s F4BXW or F4BTMS, or Rogers RT/duroid) for lowest loss. WL-CT sits firmly in the sub-25 GHz zone.
What copper foil options come with WL-CT material?
Standard is ED (electrodeposited) copper, available in 0.5 oz, 1 oz, and 2 oz weights. For lower-loss designs where conductor roughness matters — millimeter-wave, long microstrip runs, or PIM-sensitive antenna feeds — reverse-treated foil (RTF) is available on most WL-CT grades except WL-CT440 and WL-CT615, which are ED-only. RTF adds about 0.7 mil to the dielectric thickness, which your impedance calculator needs to see.
Closing Thoughts
The WL-CT hydrocarbon ceramic PCB laminate doesn’t reinvent high-frequency PCB materials. It takes the hydrocarbon/ceramic formula that Rogers pioneered, matches the electricals within a few thousandths of Df, adds FR4-compatible processing that keeps your fabricator happy, and lands at a price point that makes commercial volume production viable. For 5G infrastructure, automotive radar up to 24 GHz, satellite payloads, and RF power amplifier designs, it earns its spot on the BOM. It won’t replace Rogers in every design — loss-budget-critical millimeter-wave applications still tip toward the premium brands — but for the broad middle of the RF market, WL-CT deserves a serious look before the next project goes to layout.
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WL-CT hydrocarbon ceramic PCB laminate from Wangling delivers Rogers RO4000-class RF performance with FR4-compatible processing. Complete guide covering WL-CT300 through WL-CT615 specs, Dk/Df data, Rogers comparison, and design tips for 5G, radar, and aerospace applications.
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