Shenzhen Bicheng Electronics Technology Co., Ltd
| Model Number | F4BM255 |
| Brand Name | Wangling |
View Detail Information
Explore similar products
F4BME220 High Frequency PCB PTFE DK2.2 Dual Layer Cheap RF PWB for Couplers
F4BME265 High Frequency PCB DK2.65 PTFE Double Sided With OSP and Green Mask
F4BTM298 High Frequency PCB 3.0mm Substrates RF PCB Board With Immersion Tin
F4BTM350 High Frequency PCB Board 1.5mm PTFE Plate with 3oz Copper and Immersion
Product Specification
| Model Number | F4BM255 | Brand Name | Wangling |
Material Overview – F4BM255 (Wangling)
F4BM255 is a PTFE (polytetrafluoroethylene) woven glass fabric copper-clad laminate produced by Taizhou Wangling Insulation Materials Factory. It is engineered for microwave and RF applications requiring low dielectric loss, stable dielectric constant across temperature, and excellent dimensional stability .
The material is manufactured by scientifically formulating PTFE resin with woven glass fabric and laminating under strict process control.
This construction provides:
Glass reinforcement – improves dimensional stability and reduces thermal expansion
PTFE dielectric – delivers ultra-low loss and stable Dk
ED copper foil – standard electrodeposited copper (F4BM series)
Key Material Characteristics
| Feature | Benefit |
| Dk = 2.55 ± 0.05 @ 10 GHz | Low and stable dielectric constant – consistent impedance across frequency . |
| Df = 0.0013 @ 10 GHz | Very low dissipation factor – minimizes insertion loss . |
| Dk temperature coefficient = -110 ppm/°C | Stable Dk across -55°C to +150°C – essential for outdoor/automotive applications . |
| Tg > 280°C (DSC) | High thermal stability – supports lead-free assembly . |
| Td = 360°C | Excellent thermal decomposition resistance – robust for harsh environments . |
| XY CTE = 16–21 ppm/°C | Good dimensional stability – matches copper for reliable PTHs . |
| Z-axis CTE = 173 ppm/°C | Low Z-axis expansion – reduces PTH stress during thermal cycling . |
| Moisture Absorption ≤ 0.08% | Maintains electrical stability in humid environments . |
| Thermal Conductivity = 0.33 W/m·K | Adequate heat dissipation for RF power circuits . |
| UL 94 V-0 | Meets safety requirements . |
Typical Applications
Material Datasheet – Consolidated Properties (F4BM255)
| Property Category | Property | Test Condition | Typical Value | Unit |
| Electrical | Dielectric Constant (Dk) | 10 GHz | 2.55 ± 0.05 | – |
| Dissipation Factor (Df) | 10 GHz | 0.0013 | – | |
| Dissipation Factor (Df) | 20 GHz | 0.0018 | – | |
| Dk Temperature Coefficient | -55°C to +150°C | -110 | ppm/°C | |
| Volume Resistivity | Normal | ≥ 6 × 10⁶ | MΩ·cm | |
| Surface Resistivity | Normal | ≥ 1 × 10⁶ | MΩ | |
| Dielectric Strength (Z-axis) | 5kV, 500V/s | > 25 | kV/mm | |
| Breakdown Voltage (XY-axis) | 5kV, 500V/s | > 34 | kV | |
| Thermal | Thermal Stress (260°C, 10s × 3) | Solder float | No delamination | – |
| CTE – XY direction | -55°C to 288°C | 16–21 | ppm/°C | |
| CTE – Z direction | -55°C to 288°C | 173 | ppm/°C | |
| Thermal Conductivity (Z-axis) | – | 0.33 | W/(m·K) | |
| Continuous Operating Temp | – | -55 to +260 | °C | |
| Flammability | UL 94 | V-0 | Rating | |
| Mechanical | Peel Strength (1oz ED copper) | Normal | > 1.8 | N/mm |
| Peel Strength (1oz RTF copper) | Normal | > 1.6 | N/mm | |
| Density | Normal | 2.25 | g/cm³ | |
| Physical | Water Absorption | 24h @ 20±2°C | ≤ 0.08 | % |
| Composition | Core Material | – | PTFE + Woven Glass | – |
| Copper Foil (F4BM) | – | ED Copper | – |
Standard Availability
| Parameter | Options |
| Copper Foil (F4BM) | 0.5oz (18µm), 1oz (35µm), 1.5oz (50µm), 2oz (70µm) |
| Standard Panel Sizes | 460×610mm, 500×600mm, 850×1200mm, 914×1220mm, 1000×1200mm |
| Custom Sizes | 300×250mm, 350×380mm, 500×500mm, 840×840mm, 1000×1500mm |
| Thickness Range | 0.1mm (min for Dk ≤ 2.65) to 12.0mm |
| Size Restriction | For thickness ≤0.2mm or ≥4.0mm: max panel 500×610mm |
Custom PCB – Double-Sided F4BM255 with 2oz Copper & ENIG Finish
This double-sided board demonstrates our capability to handle long-format F4BM255 PCBs with heavy copper and tight dimensional tolerances .
Basic Specifications
| Item | Specification |
| Layer Count | 2 layers |
| Base Material | Wangling F4BM255 – 3.0mm dielectric thickness |
| Finished Board Thickness | 3.1mm (3.0mm dielectric + 2 × 0.035mm copper) |
| Finished Copper Weight | 2oz / 2oz (70µm) – both sides |
| Copper Foil Type | ED copper (F4BM series) |
| Surface Finish | ENIG (Immersion Gold) |
| Solder Mask (Top) | Green |
| Silkscreen (Top) | White |
| Solder Mask (Bottom) | None (bare copper) |
| Silkscreen (Bottom) | None |
| Board Dimensions | 521mm × 59mm (1 piece, ±0.15mm tolerance) |
| Minimum Trace/Space | 7/7 mils |
| Minimum Hole Size | 0.4mm |
| Via Plating Thickness | 20µm |
| Via Structure | No blind vias – through-hole only |
| Components | 28 |
| Total Pads | 194 (148 through-hole, 46 top SMT) |
| Nets | 2 |
| Quality Standard | IPC-6012 Class 2 |
| Artwork Format | Gerber RS-274-X |
Why F4BM255 for This Design?
| Requirement | How F4BM255 Addresses It |
| Microwave frequency operation | Df = 0.0013 @ 10 GHz, Df = 0.0018 @ 20 GHz – minimal insertion loss for RF signal integrity . |
| Stable dielectric constant | Dk = 2.55 ± 0.05 – consistent impedance across the long 521mm format . |
| High-power RF handling | 2oz copper (70µm) reduces DC resistance and improves thermal dissipation . |
| Temperature stability | Dk TC = -110 ppm/°C – stable performance across -55°C to +260°C . |
| Long-format linear array | 3.0mm thick F4BM255 with warp ≤0.010 mm/mm ensures flatness across 521mm length . |
| Cost-effective PTFE alternative | F4BM255 offers comparable performance to imported PTFE at competitive pricing . |
| Solderable surface | ENIG finish provides excellent solderability for component attachment and wire bonding . |
Q1: What does F4BM255 mean?
A: F4B = Wangling's PTFE woven glass laminate series; M = ED copper foil; 255 = dielectric constant 2.55 .
Q2: What is the difference between F4BM and F4BME?
A: F4BM uses standard ED copper (general RF applications). F4BME uses reverse-treated RTF copper for ultra-low PIM (≤-159 dBc) – ideal for carrier-grade base station antennas .
Q3: Does F4BM255 require special processing like imported PTFE?
A: F4BM255 does not require sodium etch for standard ED copper. However, for PTH metallization, plasma treatment or sodium-naphthalene solution is recommended .
Q4: Why choose 2oz copper for this design?
A: 2oz (70µm) copper provides lower DC resistance and better thermal dissipation for high-power RF circuits. It also supports the high-current requirements of large antenna feed networks .
Q5: What is the maximum warp for 3.0mm F4BM255?
A: For 3.0–5.0mm thick boards, maximum warp is ≤0.010 mm/mm – ensuring flatness across the 521mm length .
Q6: What is the minimum hole size for F4BM255?
A: Minimum mechanical drill size is 0.4mm (as specified in this design). Drilling parameters require standard carbide tooling with controlled feed rates .
Q7: Is ENIG the only surface finish available?
A: No. ENIG is specified for this design. Other options include OSP, HASL, immersion silver, immersion tin – depending on your application requirements .
Q8: Can F4BM255 be used for millimeter-wave (mmWave) applications?
A: Yes. F4BM255 has been used in microwave and millimeter-wave bands (cmWave, mmWave) for antennas and feed networks. The Df of 0.0018 @ 20 GHz demonstrates suitability up to 20 GHz+ .
Q9: What is the lead time for this 521mm × 59mm board?
A: Typical prototype lead time is 7–10 working days for double-sided boards with ENIG and 2oz copper. Large-format production may require additional time for panel optimization.
Q10: Can you provide impedance control for this long-format board?
A: Yes. With stable Dk = 2.55 ± 0.05, we can design and control impedance across the entire 521mm length. Final impedance values are verified by TDR testing.
Contact Us
As a specialized PCB supplier based in China, we have extensive experience with Wangling F4BM255 PTFE laminates, heavy copper (2oz+) PCBs, and long-format microwave substrates .
We provide:
For technical inquiries, stack-up review, or quotation requests, please contact our sales team directly. We are ready to support your microwave antenna, RF distribution, and high-power RF projects.
Company Details
Business Type:
Manufacturer,Distributor/Wholesaler,Exporter,Seller
Year Established:
2003
Total Annual:
10 million-18 million
Employee Number:
350~450
Ecer Certification：
Site Member
Founded in 2003, Shenzhen Bicheng Electronics Technology Co., Ltd. has established itself as a reliable high-frequency PCB supplier and exporter based in Shenzhen, China. For over 24 years, we have served industries worldwide, including cellular base station antennas, satellite communi... Founded in 2003, Shenzhen Bicheng Electronics Technology Co., Ltd. has established itself as a reliable high-frequency PCB supplier and exporter based in Shenzhen, China. For over 24 years, we have served industries worldwide, including cellular base station antennas, satellite communi...
Get in touch with us
Leave a Message, we will call you back quickly!