Most products today require special attention to signal intergrity. Hemeixin offers customers a large variety of base materials to cover their needs in the high speed/low loss arena. In addition, we can assist our customers with various advanced high frequency measurement techniques to verify compliance to specifications.
An RF PCB design is a bit different from a conventional board. What makes it distinct are parameters like impedance matching,type of traces (preferably co-planar), elimination of via stubs(to avoid refl ection), ground planes, vias, and power supply decoupling. Other aspects such as stack-up and material selection also play crucial roles in these boards.
With all these factors in mind, the complexity of an RF design process increases due to elements like EMI interference, high-frequency signal channeling, etc. we will discuss all these things in detail. For starters, let’s take up impedance matching.
In a controlled impedance RF circuit, maximum power transfer without distortion occurs from source to load when the impedance remains the same throughout the trace. This impedance is known as the characteristic impedance of the trace(Z0).The characteristic impedance depends on the geometry of the traces, such as trace width, the dielectric constant of the PCB material, trace thickness, and height from the reference ground plane. In order to match these impedances, matching circuits are also designed.
Choosing the right material is an essential part of a high-speed PCB design and fabrication process. PCB materials with the necessary performance characteristics contribute to the optimal performance of high-speed circuit assemblies. Maintaining the signal integrity of high-speed digital signals necessitates the use of PCB material capable of this.
Generally, PCB materials with greater stability (low and stable Dk values at high frequencies and temperatures) will support high-speed boards with low distortion of the higher-order harmonic signal components.
PCB material characteristics such as low loss and dissipation factor (Df) at higher frequencies are key criteria to look for in materials for high-speed digital circuits.
When you’re designing a PCB for a high-speed or RF application PCB, a careful comparison of the electrical and mechanical characteristics of PCB materials can help you select the right base material for your PCB.
These two table provides you with quick access to important information you need for your design.
RF PCBs are manufactured with certain materials that fulfill high-frequency operation requirements. These materials should have low signal losses, be stable over high-frequency operation, and should be able to absorb high amounts of heat. The dielectric constant (DK), loss tangent (tan δ), and coefficient of thermal expansion (CTE) values also require consistency over wide frequency ranges. Typical values of dielectric constant range from 3 to 3.5 for these boards. Loss tangent values are in the range of 0.0022 to 0.0095 for the frequency range of 10-30GHz.
Apart from all these specific necessities, the material cost and ease of manufacturing are also considered.
Materials that are made of Polytetrafluoroethylene (PTFE), ceramics, and hydrocarbons mixed with one another or with a form of glass are commonly used. Rogers material is a common choice for RF circuit boards. There are different variants of Rogers material available. A few of them are listed below:
In order to meet increasing demands for Microwave & RF Printed Circuit Boards for our customers all around the world, we have increased our investment over the last few years so that we have become a world-class manufacturer of PCBs using high frequency laminates.
The definition of RF and microwave PCBs is that they contain components that carry RF or microwave signals. These signals vary in frequency from, 50MHz to above 2 GHz, and these frequencies define the differences in components between RF and microwave PCBs and other PCB types.
These applications typically require laminates with specialized electrical, thermal, mechanical, or other performance characteristics that exceed those of traditional standard FR-4 materials. With our many years of experience with PTFE-based microwave laminate, we understand the high reliability and tight tolerance requirements of most applications.
High frequencies require high precision. And extensive expertise. In cooperation with our customers from the automotive and telecommunications industries, we at Hemeixin have developed to become one of the leading manufacturers of printed circuit boards for high-frequency applications in the range from 24 to 77 GHz.
In order to achieve more reasonable design and better anti-interference ability for high frequency PCB (Microwave RF PCB), design engineer should consider the tips as following:
RF PCBs handle low MHz frequencies to high GHz. The material selection for a PCB is important to ensure signal integrity, reliable operation, and consistency at high frequencies. The factors to consider while selecting PCB material are:
Some common materials are RO3000, RO4000, RT/Duroid, etc. The copper material selection for an RF PCB stack-up is also essential, as it influences the skin effect on signal propagation.
Special care needs to be given in RF PCB design stack-ups. Some of the areas to focus on are:
In RF PCBs, the RF traces are routed on the top layer; the immediate layers are ground and power planes. The immediate ground plane ensures a minimum ground current return path. The non-RF traces are laid on the bottom layer to minimize interference between RF and non-RF components.
RF PCB traces are vulnerable to transmission losses and signal interference issues. The main concern in RF trace design is characteristic impedance. The most commonly used RF traces are coplanar waveguides, striplines, and microstrips. Some of the best practices to follow while designing RF PCB traces are:
RF PCB design guidelines start with PCB substrate material selection to develop excellent RF PCB boards. Hemeixin can help you design PCB boards that handle RF and non-RF components and devices.
RF microwave PCBs are a specialized type of PCBs designed to handle high-frequency signals in the RF and microwave frequency range with minimal signal loss and maximum signal integrity. They are used in a wide range of electronic applications such as wireless communication systems, satellite communication systems, radar systems, and other high-frequency electronic systems. Their design and production require specialized knowledge and experience to ensure the expected performance.
Radio Frequency and Microwave PCBs are a special and innovative type of PCB, designed to operate on signals in the Megahertz to Gigahertz frequency ranges for communication signals in everything from smartphones to military radars. Very specific materials and technology that are not available in many factories are required to build the PCB equipment.
PTFE and FR4 are two of the most used PCB design materials, and it’s important to understand the difference between them. FR4 is a standard defined by National Electrical Manufacturers Association (NEMA), referring to glass-reinforced epoxy laminate material. The "FR" in FR4 stands for "flame retardant." While FR4 materials are common and they cost less, PTFE is a better choice for RF/microwave PCBs operating well above WiFi frequencies. PTFE materials have some important advantages:
One strategy for using PTFE materials alongside standard epoxy resin/fiberglass FR4 materials is to build a hybrid PCB stackup. In this type of design, one or more outer layers can be designed with a low-loss PTFE material to support RF routing. The other layers can then be chosen from standard FR4 materials with higher dielectric constant. This is a useful approach in mixed-signal systems that also have some digital interfaces, but they do not have the low-loss requirements of a typical RF interconnect.
A high frequency printed circuit board, whether it’s rigid or flex, offers faster signal flow rates and a frequency range of up to 100 GHz. It’s important to note that there are numerous materials designed to operate at high frequency levels. high frequency PCBs are defined by lower dielectric constant (Dk), lower dissipation factor (Df), and low levels of thermal expansion. They are used regularly for HDI technology. They are also used extensively in high speed communications, telecommunications, and RF microwave technology.
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 (high frequency) technology to view conductor widths as an electronic component.
Depending on various parameters, high frequency 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.
Special materials are required to achieve the high frequency provided by this type of PCB. There are a variety of substrate materials that will support your design and may differ based on signal speeds required and the application/environment of the circuit board.
In terms of price, FR4 is the least expensive compared to dedicated high speed materials and Teflon, with Teflon being the most expensive. Though, FR-4 starts to drop off in performance when signal speed edges above 1.6ghz
Newer generation substrates, Teflon, and flex circuits are the best options when it comes to Dk, Df, water absorption, and survivability in the environment
If a printed circuit board requires a frequency above 10GHz, newer generation substrates, Teflon, and Flex substrates are your best option since they are far superior to traditional FR-4 material.
The most common suppliers of high speed substrates are Rogers, Isola, Taconic, Dupont, and Megtron materials by Panasonic. All of these materials typically are lower Dk and lower loss.
High frequency rigid and flex PCBs are used in many products and across many industries, including:
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.
Hemeixin supports you starting immediately in the design phase. We help you to find appropriate substrates, dimensioning the conductor width and spacing, as well as with calculating the impedances.
Our offer for high frequency circuit boards:
When it comes to the cost of FR4, PPO, and Teflon laminates, FR4 is the least expensive, while Teflon is the most costly. Teflon is the best in terms of DK, DF, water absorption, and frequency characteristics. Only Teflon PCB substrate can be used to produce products that require frequencies more than 10GHz. Teflon’s performance is significantly superior to that of other substrates, yet, Teflon has the disadvantage of great heat resistance.
PTFE or polytetrafluoroethylene is a synthetic thermoplastic fluoropolymer and is the second most commonly used PCB laminate material. It offers consistent dielectric properties at a higher coefficient expansion than standard FR4. These two laminates, FR4 and PTFE, quickly became the 2 options for all PCBs coming to market.
The PTFE is commonly used in a higher-speed, higher-frequency technology. One example is microwave technology: the PTFE has a higher coefficient of thermal expansion (CTE). This makes it a good choice where the PCB could see changes in temperature.
The base PTFE had its challenges to overcome with the addition of woven glass assisted in the stability or size changes of the laminate due to fluctuating temperature. Later, ceramic fillers and microfiber glass were introduced to increase the dielectric constant (Dk) values. PTFE with additives such as glass or ceramic improved and stabilize the DK, allowing for a better signal between parts to be had.
The additional cost for this type of material is significant from FR4. It is more costly to produce and typically the quantity of PCBs is smaller for the purchase. This, compiled with the part’s physical size, is also typically smaller in the X,Y, driving up the cost to manufacture.
The supplier imposes a MOQ on laminate purchase to multiple sheets, leaving stock on the shelf for an undetermined amount of time. This cost is passed on to the consumer in the piece price or laminate cost so as to encourage consumption and ease the pain of purchasing and having stock for long periods of time. Introducing multiple parts on one panel has become more common to aid the customer in keeping costs down; we have seen 8 or 12 different PCBs on a single array for a one-time buy versus buying 5 pieces of 8 or 12 different parts in a single purchase each. This saves the customer on NRE passing as 1 instead of 8 or 12, but it also assists production on the consumption of panels where the physical size is small, so it is allowed.
This is a fair question and it relates to some important tasks in systems analysis. There are a few different considerations a designer should examine when qualifying an alternative PCB substrate material should be used. Here’s a short list of some dimensions you might look at when selecting an RF PCB substrate material.
Many years of experience in processing special high-frequency materials have made us the perfect partner for you and your RF PCB project.
We use special materials for achieving the high frequency operations of our HF PCBs. Depending on the range of signal speeds of the application, we use a variety of substrate materials that are the best suitable.
Ceramic-filled PTFE composites, which have exceptional electrical and mechanical stability. Rogers RO3000 series circuit materials have consistent mechanical properties, regardless of the dielectric constant (Dk) selected, which allows multi-layer board designs that use different dielectric constant materials without encountering war-page or reliability problems. The Taconic RF series of products has a low dissipation factor with high thermal conductivity possible so it will not oxidize, yellow, or show upward drift in dielectric constant and dissipation factor like its hydrocarbon-based competitors.
Ultra-low Loss, Highly Heat-Resistant, Halogen Free Megtron 6 circuit board material. With high glass transition temperature (Tg) and the low expansion ratio of hydrocarbon resin-based MEGTRON 6 - makes it ideal for High-Density Interconnect (HDI) and high speed (above 3 GHz) constructions.
Woven Glass Reinforced PTFE laminates are manufactured with very lightweight woven fiberglass and are more dimensionally stable than chopped fiber reinforced PTFE composites. Materials such as the Taconic TL family of products have a low dissipation factor, and this is perfect for radar applications designed at 77 GHz as well as other antennas in millimeter-wave frequencies.
Hydrocarbon ceramic laminates are used in microwave and millimeter-wave frequency designs as this low loss material offers easier use in circuit fabrication and streamlined properties over traditional PTFE materials. Rogers RO4000 series of products come in a wide range of DK values (2.55-6.15) and have above average thermal conductivity (.6-.8).
Filled PTFE (random glass or ceramic) composite laminates such as the Rogers RT/duroid® high frequency circuit materials have low electrical loss, low moisture absorption, and low outgassing properties that are preferred in space applications.
Thermoset microwave laminates combine low thermal coefficient of dielectric constant (Dk), a copper matched coefficient of thermal expansion and excellent mechanical reliability. Rogers TMM materials are high-frequency laminates ideal for high-reliability strip-line and micro-strip applications.
RF PCB boards come with a wide variety of benefits for MHz and GHz applications:
RF boards have a multitude of different applications, including wireless technologies, smart phones, sensors, robotics and security. With the advent of new technologies that are pushing the limits of electronics, the demand for RF boards is on the rise.
Finding a capable RF PCB manufacturer is critical to make sure the boards are fabricated to high quality standards and on-time. Our reputation speaks for itself. We pride ourselves on bringing the most demanding layout concepts to reality.
As high frequency PCB manufacturer, Hemeixin makes both rigid and flexible types of boards. Our high frequency PCBs offer faster signal flow for frequencies up to 100 GHz. Although numerous materials are available for high frequency operation, Hemeixin uses materials for HF PCBs that exhibit a few common features like low dielectric constant or Dk, low dissipation factor or Df, and low coefficient of thermal expansion or CTE. We use the materials for high frequency PCBs also for our boards using HDI technology. Industries using our high frequency PCBs include RF microwave, telecommunications, high speed communications, and more.
RO4000 hydrocarbon ceramic laminates are designed to offer superior high frequency performance and low cost circuit fabrication. The result is a low loss material which can be fabricated using standard epoxy/glass (FR-4) processes offered at competitive prices.
The selection of laminates typically available to designers is signifi cantly reduced once operational frequencies increase to 500 MHz and above. RO4000 material possesses the properties needed by designers of RF microwave circuits and matching networks and controlled impedance transmission lines. Low dielectric loss allows RO4000 series material to be used in many applications where higher operating frequencies limit the use of conventional circuit board laminates. The temperature coeffi cient of dielectric constant is among the lowest of any circuit board material , and the dielectric constant is stable over a broad frequency range . For reduced insertion loss, LoPro® foil is available. This makes it an ideal substrate for broadband applications.
RO4000 material’s thermal coeffi cient of expansion (CTE) provides several key benefi ts to the circuit designer. The expansion coeffi cient of RO4000 material is similar to that of copper which allows the material to exhibit excellent dimensional stability, a property needed for mixed dielectric multi-layer boards constructions. The low Z-axis CTE of RO4000 laminates provides reliable plated through-hole quality, even in severe thermal shock applications. RO4000 series material has a Tg of >280°C (536°F) so its expansion characteristics remain stable over the entire range of circuit processing temperatures.
RO4000 series laminates can easily be fabricated into printed circuit boards using standard FR-4 circuit board processing techniques. Unlike PTFE based high performance materials, RO4000 series laminates do not require specialized via preparation processes such as sodium etch. This material is a rigid, thermoset laminate that is capable of being processed by automated handling systems and scrubbing equipment used for copper surface preparation.
RO4003C™ laminates are currently offered in various confi gurations utilizing both 1080 and 1674 glass fabric styles, with all confi gurations meeting the same laminate electrical performance specifi cation. Specifi cally designed as a drop-in replacement for the RO4003C™ material, RO4350B™ laminates utilize RoHS compliant fl ame-retardant technology for applications requiring UL 94V-0 certifi cation. These materials conform to the requirements of IPC- 4103.
Although Rogers laminates are a bit more expensive than other materials, they perform well in challenging conditions. Here are the reasons to go for Rogers materials:
RO4350B laminates provide tight control on dielectric constant (Dk) and maintain low loss while utilizing the same processing method as standard epoxy/glass. Available at a fraction of the cost of conventional microwave laminates, RO4350B laminates do not require the special through-hole treatments or handling procedures as PTFE based materials. These materials are UL 94 V-0 rated for active devices and high power RF designs.
A glass-fi ber reinforced hydrocarbon ceramic laminate is used to manufacture the Rogers 4350B. You can fabricate Rogers 4350B boards using conventional FR-4 processing methods. Some of the signifi cant features of Rogers 4350B are:
Offered in various configurations, RO4003C laminates utilize both 1080 and 1674 glass fabric styles with all configurations meeting the same laminate electrical performance specification. RO4003C laminates provide tight control on dielectric constant (Dk) and low loss while utilizing the same processing method as standard epoxy/glass but at a fraction of the cost of conventional microwave laminates. Unlike PTFE based microwave materials, no special through-hole treatments or handling procedures are required.
RO4003C materials are non-brominated and are not UL 94 V-0 rated. For applications or designs requiring a UL 94 V-0 flame rating, RO4835™ and RO4350B™ laminates do meet this requirement.
With the advancements in electronic devices, circuit board materials such as Rogers are a must to ensure minimum signal losses in high-frequency applications such as aerospace, defense, and communication systems.
The use of high frequency rogers printed circuit board material is imperative when it comes to creating PCBs for critical applications that particularly need low signal loss as well as low dielectric loss. Such material is also the need of the hour when signal integrity and impedance matching are of utmost importance.
At Hemeixinpcb, we provide Rogers printed circuit boards, one of the well-known names, when it comes to Rogers PCB manufacturing:
Their high-quality materials, are especially known for their ability to withstand harsh environmental conditions.
As a Rogers PCB Manufacturer, we are fully equipped to manufacture eponymous printed circuit boards created from material sourced from Rogers that is known for their durability and reliability. We provide high mix printed circuit boards, high frequency rogers PCB, RF rogers printed circuit boards, SMT rogers circuit boards, Rogers PCB prototype and more. The range of manufacturing printed circuit boards are reliable, efficient and high performance for any type of specialty applications.