Name: High Frequency High Speed PCB Design
Plate: TG170 /TG180, F4BM, FR4, FR1-4, etc.
Designable layers: 1-32 layers
Minimum line width and line spacing: 3mil
Minimum laser aperture: 4mil
Minimum mechanical aperture: 8mil
Copper foil thickness: 18-175цm (standard: 18цm35цm70цm)
Peel strength: 1.25N/mm
Minimum punching hole diameter: single side: 0.9mm/35mil
Minimum hole diameter: 0.25mm/10mil
Aperture tolerance: ≤φ0.8mm±0.05mm
Hole tolerance: ±0.05mm
Hole wall copper thickness: double-sided/multi-layer: ≥2um/0.8mil
Hole resistance: double-sided/multi-layer: ≤300цΩ
Minimum line width: 0.127mm/5mil
Minimum pitch: 0.127mm/5mil
Screen printing color: black, white, red, green, etc.
Surface treatment: lead/lead-free tin spray, ENIG, silver, OSP
Service: Provide OEM service
Certificate: ISO9001.ROSH.UL
The high-frequency, High-Speed PCB design is vital in developing high-performance electronic devices that run at extremely high frequencies and send away high-speed signals. The use of HF/HS PCBs in designing the devices has become more instrumental in applications that require high-speed data transmission and high-frequency operation.
These applications incorporate high-speed data transmission, wireless communication, and radar systems. However, designing the HF/HS PCBs is more challenging due to three primary difficulties: signal integrity, EMI, and heat removal. Therefore, the guide will present definitions, basic principles, and the critical issues in designing HF/HS PCBs.
Design Principles And Considerations
High-frequency, high-speed PCB design is complex and difficult to master as a designer, but one must know the basics of design and use them to ensure that the circuit board will work at its peak performance under challenging conditions. Let us discuss 5 basic principles of effective HF or HS PCB design.
1. Signal Integrity:
Signal integrity must be maintained. It measures how well signal quality and strength are preserved while the signal moves through and around the PCB. Signal loss can be minimised using the highest-quality PCB materials with the lowest dielectric constants and loss factors.
The associated crosstalk resulting from the proper routing and trace spacing is continued, as it is a good ground plane design. Reflections generated by eliminating impedance discontinuities and a well-formed via stub ensure a uniformly matching impedance over the extent of the transmission.
2. Controlled Impedance:
Impedance control is also a critical element of signal quality in HF/HS PCB design. This is when the transmission lines are designed with the materials and size so the impedance stays uniform. This results in no signal reflections and keeps the signal spread as initially. Hence, thanks to how the impedance is controlled in the PCB, the signal is not distorted, and the signal loss is diminished.
3. Layer Stackup:
The ideal layer stack-up for high-frequency/high-speed PCB design performance should be selected. The selected material should have high-frequency dielectric properties to minimise loss’s impact on signal degradations. The thickness of the active signal layers and the ground planes should have low impedance. Using directed materials for signal paths between layers will also minimise signal degradation and interference when sending high-frequency signals.
4. Grounding and Power Distribution:
Adequate grounding and power distribution are key to minimal noise and voltage instability. Ground planes help provide low-inductance return paths for high-frequency signals, mainly when fed. Similarly, in cases where power planes are entirely solid, they offer first-rate means of distributing power.
Most importantly, decoupling capacitors close to IC power pins is crucial in solving the voltage problem by filtering the noise. The listed criteria would greenlight the PCB to perform job execution at high frequencies and speeds; otherwise, the board would be unable to conduct its operations.
5. EMI Mitigation Techniques:
It is essential to minimise electromagnetic interference in HF/HS PCB design. Several techniques can help the PCB run with minimum EMI, and proper component placement can reduce the H2 of the HS/HS PCB design.
Key sensitive components should be placed at a distance from high-frequency sources to reduce interferer. Shielding to enclose and grounded planes is instrumental in protecting the firm from EMI. Filters may also attenuate the undesired high-frequency noise to ensure that only the desired signals are transmitted or received.
Signal Integrity Issues And Mitigation Techniques
Maintaining signal integrity in high-frequency, high-speed PCB design might be difficult. Let’s examine typical problems and workable solutions to ensure PCB performance at its best.
1. Signal Loss:
Signal loss may be created due to the impedance mismatch, including the skin impact and dissipation within the dielectric. As a result, preventative measures include the following:
- Impedance Matching:Ensure that the transmission resistance is equal to the resistance between any two elements.
- Quality Materials: Using materials that exhibit minimal dielectric reduction could be employed to lower signal degradation.
2. Crosstalk:
Crosstalk is the undesired coupling of signals between neighbouring traces. To eliminate crosstalk:
- Proper Routing:Maintaining adequate spacing reduces the electromagnetic field generated by the conductor loop, decreasing the coupling probability.
- Ground Plane Design:A ground layer in a PCB offers electromagnetic isolation from the radiated signal field and the received noise field due to the area under the impedance loop. Overall, the ground plane reduces the signal planes.
3. Reflections:
Signal reflections mainly result from impedance discontinuities. The possible solutions to the above problem include:
- Consistent Impedance:In this case, impedance is consistently maintained throughout the transmission line.
- Via Stubs:Through minimising the use of vias and ensuring that they are well terminated.
Conclusion
In conclusion, high-frequency, high-speed PCB design is a vital yet intricate part of modern electronics. Designers know basic principles, including signal integrity, controlled impedance, optimal layer stack up, correct grounding, and EMI reduction, to make PCBs that meet the high-speed and high-frequency performance demands. They take into account these various factors to uphold peak performance and robustness.
