The increasing complexity of electronic components and switches continually requires faster signal flow rates, and thus higher transmission frequencies. Because of short pulse rise times in electronic components, it has also become necessary for high frequency (HF) technology to view conductor widths as an electronic component.
Depending on various parameters, HF signals are reflected on circuit board, meaning that the impedance (dynamic resistance) varies with respect to the sending component. To prevent such capacitive effects, all parameters must be exactly specified, and implemented with the highest level of process control.
Critical for the impedances in high frequency circuit boards are principally the conductor trace geometry, the layer buildup, and the dielectric constant (εr) of the materials used.
Multi-CB provides you with know-how, all popular materials and qualified manufacturing processes - reliably even for complex requirements.
HIGH FREQUENCY PCBs
Inclusive
- 0.1mm tracks, annular ring
- 0.2mm drills, unlimited
- 0.4mm via pad
- 35µm copper
- 2x solder-stop green
- 1x legend print white
- Inner milling, PTH slits
- E-Test, Design-Rule-Check
Optional: add. Rogers thicknesses, multilayer build-up, impedance control, ENEPIG surface (for bonding), Filled & Capped Vias (IPC 4761 Type 7), ...
| e.g. 2 layers 80mm x 100mm | RO4350B 0.51mm chem. gold | RO4350B 1.52mm HAL lead-free | SAVING |
| 1 pc. | 139.20 € | 181.16 € | 12WD |
| 3 pcs. each | 61.61 € | 81.68 € | 12WD |
| 5 pcs. each | 42.05 € | 56.13 € | 12WD |
| 10 pcs. each | 25.53 € | 34.37 € | 12WD |
Materials used for HF circuit boards
High-frequency boards, e.g. for wireless applications and data rates in the upper GHz range have special demands on the material used:
- Adapted permittivity
- Low attenuation for efficient signal transmission
- Homogeneous construction with low tolerances in insulation thickness and dielectric constant
For many applications, it is sufficient to use FR4 material with an appropriate layer buildup. In addition, we process high-frequency materials with improved dielectric properties. These have a very low loss factor, a low dielectric constant, and are primarily temperature and frequency independent.
Additional favourable properties are high glass transition temperature, an excellent thermal durability, and very low hydrophilic rate.
We use (among others) Rogers or PTFE materials (for example, Teflon from DuPont) for impedance controlled high frequency circuit boards. Sandwich buildups for material combinations are also possible.
| Material for high frequency boards | Order Share | εr, Dk- Permittivity | Dk Loss Tangent | Tg | Td Value | Thermal Conductivity | CTE-z (T<TG) | Electric Strength | Surface Resistivity | Peel Strength |
|---|---|---|---|---|---|---|---|---|---|---|
| @10GHz | @10GHz | °C | °C | W/m*K | ppm/°C | KV/mm | MΩ | N/mm | ||
| Rogers 4350B HF Material | +++ | 3,5 | 0,0037 | 280° | 390° | 0,69 | 32 | 31 | 5,7 x 10^9 | 0,9 |
| Rogers 4003C PTFE HF Material | ++ | 3,4 | 0,0027 | 280° | 425° | 0,71 | 46 | 31 | 4,2 x 10^9 | 1,1 |
| Panasonic Megtron6 HF Material | + | 3,6 | 0,004 | 185° | 410° | - | 45 | - | 1 x 10^8 | 0,8 |
| Rogers RO3003 PTFE ceramic-filled | + | 3,0 | 0,0013 | - | 500° | 0,50 | 25 | - | 1 x 10^7 | 2,2 |
| Rogers RO3006 PTFE ceramic-filled | o | 6,2 | 0,002 | - | 500° | 0,79 | 24 | - | 1 x 10^5 | 1,2 |
| Rogers RO3010 PTFE ceramic-filled | o | 10 | 0,0022 | - | 500° | 0,95 | 16 | - | 1 x 10^5 | 1,6 |
| Taconic RF-35 Ceramic | o | 3,5** | 0,0018* | 315° | - | 0,24 | 64 | - | 1,5 x 10^8 | 1,8 |
| Taconic TLX PTFE | o | 2,5 | 0,0019 | - | - | 0,19 | 135 | - | 1 x 10^7 | 2,1 |
| Rogers RO3001 Bonding Film for PTFE | - | 2,3 | 0,003 | 160° | - | 0,22 | - | 98 | 1 x 10^9 | 2,1 |
| Taconic TLC PTFE | - | 3,2 | - | - | - | 0,24 | 70 | - | 1 x 10^7 | 2,1 |
Complete overview of available circuit board materials
Depending on the stock on hand, the materials listed may be replaced by technically equivalent or similar products. For critical tolerances, please discuss your requirements with our engineers.
Impedance Check
The impedance defined by the customer is tested by our CAM station engineers on manufacturability. Depending on the layer buildup, the PCB layout and the customer's requested impedances a calculation model is chosen. The result is any required modification of the layer builduo and the necessary adjustments to the relevant conductor geometries.
Please also refer to our pages for impedance control of printed circuit boards.
After the manufacture of high frequency circuit boards, the impedances are checked (with a precision of up to 5%), and the detailed results are recorded exactly in a test protocol.
Typical applications for high-frequency printed circuit boards
Our high-frequency PCBs are used wherever fast, low-loss signal transmission in the GHz range is required - from the automotive industry to telecommunications. The following overview shows you the most important industries and application examples:
- Advanced Driver-Assistance Systems (ADAS): For fast data processing using sensors and radars.
- Vehicle-to-X communication (V2X): For efficient networking.
Railway technology
- Train control systems (ETCS): For reliable wireless communication between train and signal box.
- Passenger information and entertainment systems: For stable WLAN and mobile phone connections on the train.
- Remote monitoring of running gear sensors: For wireless transmission of vibration and temperature data in real time.
Data technology
- High-speed routers and switches: For low-loss signal transmission in data centres and network infrastructures.
- Server backplanes: For connecting multiple high-speed slots on one board.
- Optical transceiver modules: For the conversion and transmission of signals between fibre optics and electronics in the GHz range.
Industrial electronics
- High-speed machine control systems: For fast data communication.
- Automation systems: For precise control and monitoring in production.
Aerospace & Defence
- Radar systems: For tracking and navigation in military and civilian applications.
- Avionics: For reliable communication and control systems in aeroplanes.
Medical technology
- Imaging systems: e.g. in MRI and ultrasound devices for detailed images.
- Wireless medical devices: For communication and data transmission.
Measuring technology
- High-frequency measuring devices (e.g. spectrum analysers, network analysers): For precise signal analysis up to the GHz range.
- Oscilloscopes with high bandwidth: For fast and distortion-free acquisition of high-frequency signals.
- Signal generators and measurement transmitters: For stable generation and output of defined RF signals for testing and calibration purposes.
Telecommunications
- Mobile radio base stations: For fast signal transmission.
- Satellite communication: For efficient data transmission over long distances.
- 5G technology: For faster data rates and improved network reliability.
Consumer electronics
- Wi-Fi routers & IoT devices: For high-speed data transmission.
- Smartphones & tablets: For compact, high-performance network functions.
High frequency (HF) printed circuit boards FAQ
At high frequencies, conductor tracks must be considered as components, as they influence the signal behaviour. Defined impedances (characteristic impedance), a homogeneous layer structure and specially matched materials with a constant dielectric constant (εr) and low losses are crucial. Standard FR4 is often only suitable for lower frequencies.
We process specially developed HF materials such as Rogers (RO4000, RO3000), PTFE or Megtron 6. These are characterised by a constant dielectric constant (εr), a very low dissipation factor (Df) , temperature stability and low water absorption - all of which are crucial for reliable signal transmission in the GHz range.
The impedance (characteristic impedance) must match the transmitter and receiver components exactly, otherwise signal reflections, losses and distortions will occur. We calculate the required parameters based on the layer structure, track geometry and material and check the manufactured PCBs with an accuracy of up to 5 % - documented in a test report (see impedance check). You can use our PCB impedance calculator for your own estimation.
Yes, in many cases a customised FR4 structure is sufficient for the outer layers. For higher demands hybrid buildups (also sandwich structures) with a combination of HF materials (e.g. Rogers) and FR4 are possible. This allows costs and performance to be optimised. Talk to us at an early stage.
You calculate and order directly via our circuit board calculator. Select the impedance check option there and send us your specifications regarding impedance and layer structure with the data. Every impedance ordered is measured and recorded. You will receive an impedance report on request.