by Jared Rouleau, Go-To-Market Manager, Rogers Corp.
In today’s fast paced world, getting your designs off the drawing board and into reality is essential. Unfortunately, we’ve all known those great ideas that simply couldn’t get off the block. Getting to that first prototype quickly and being able to see and test how the product will perform are key to market success.
The ability to help a customer design, prototype, and test their designs is an important function of the XRD® Impact Institute. It’s here where we work with our customers to find the right XRD solution for their unique impact protection design. Part of this process involves helping to provide a protective padding prototype which is as close to the final product as possible.
Decision makers don’t want to imagine what a product “would look like;” they demand more finished products they can use. For this, we’ve developed a new line of XRD molded parts call the XRD 810 Series. The XRD 810 Series includes 5 unique tessellation patterns, each with varying functions and features:
- XRD 810 Hex
- XRD 810 Mini Hex
- XRD 810 Cones
- XRD 810 Delta
- XRD 810 Tear Drop
Each pattern offers designers and product developers the ability to easily die cut their unique shape from the 8” x 10” pad (hence the name 810) and quickly incorporate and test their protective padding design. We’ll dedicate our next few blogs to telling you more about the various XRD 810 Series patterns, their features and how you can benefit from using each design. If you have immediate questions or sample needs, please contact us for additional information. XRD 810 Hex The XRD 810 Hex size and thickness (about 7.1 mm) offers good coverage for larger zones requiring impact protection. Yet, the hex pattern still provides good movement and flexibility while being durable and abrasive resistant. The Hex pattern is a popular choice for designers of protective apparel and equipment. The convenient tessellation pattern allows for various protective padding designs for rib, chest, thigh and other areas. For example, our partners at Cliff Keen Athletic have used the XRD Hex design in their popular Xtreme Impact™ Kneepad.
The XRD 810 Hex is easy to work with, simply:
- Use scissors to cut a desired shape from your XRD 810 Hex sample.. For your use, a PDF pattern of the XRD 810 Hex can be downloaded for testing your initial shape ideas before you test them on physical samples.
- Arrange the XRD shapes on your application.
- Apply the XRD shapes using an acrylic or polyurethane adhesive, fusible web adhesive or insert it into a pocket. (Note: We have found that Pellon’s Heavy Duty Wonder Under paper backed fusible web tends to work well when bonding to apparel)
- Test, trial and wear your prototype. Make updates and cut new design ideas as they work for your project.
- If you are satisfied with your XRD Hex shape, you may order this directly from Rogers (we’ll die cut the final part for you) or work with the XRD Team to develop a custom XRD molded part based from your prototype.
The XRD 810 Hex dimensions (length x width x thickness): 10” x 8” x 0.280” (254 mm x 203 mm x 7.1 mm). It is available in two different densities: 12 lb/f³ (192 kg/m³) and 20 lb/f³ (kg/m³) and comes in the XRD Vivid Yellow color. Please contact us for additional PORON formulation requests.
High-frequency circuit designers have a number of different circuit types from which to provide solutions from radio frequency (RF) through millimeter-wave frequencies. Coplanar waveguide (CPW) might be an approach to consider as an option to popular microstrip techniques. Traditional CPW circuitry consists of a conductor separated by a pair of ground planes, on the same plane on top of a dielectric material. A variation on that circuit approach is grounded coplanar waveguide (GCPW), also known as conductor-backed coplanar waveguide (CBCPW). It adds a ground plane to the bottom of the basic CPW circuit structure, with plated through holes (PTHs) connecting the top and bottom ground planes.
The absence of PTH ground connections in CPW results in less radiation at discontinuities than GCPW, although both circuit types feature superb isolation of adjacent signal channels, resulting in low crosstalk for densely packed circuits. The placement of PTHs in GCPW circuits can be critical for achieving impedance and loss goals, but the use of these grounding PTHs can allow the use of a much thicker dielectric material for a given higher frequency than when using microstrip circuits. The added ground plane in GCPW circuits provides additional mechanical stability compared to CPW circuits, with improved thermal management for higher-power circuits and devices. Microstrip circuits typically suffer increased surface-wave leakage and radiation losses compared to GCPW circuits when using the same circuit materials and at higher microwave and millimeter-wave frequencies.
Both CPW and GCPW circuits are fairly straightforward to fabricate and provide consistent performance through millimeter-wave frequencies. The electromagnetic (EM) energy through the transmission lines, especially for GCPW, remains largely concentrated within the PCB’s dielectric material. Both CPW and GCPW circuits can suffer higher conductor losses than microstrip circuits, but the loss characteristics of CPW and GCPW circuits follow a constant slope with frequency, whereas microstrip undergoes loss transitions at the upper microwave frequencies associated with radiation losses. Such losses can be minimized in CPW and GCPW designs through proper spacing of PTHs and other circuit dimensions.
At higher frequencies, such as millimeter-wave frequencies, circuit dimensions become smaller and more critical as the lengths of circuits begin to approach the dimensions of the wavelengths of the signals propagating through those circuits. Selecting a suitable circuit technology can be critical at higher frequencies, as reflections and radiation losses can increase for microstrip and even stripline circuits at higher frequencies. When treated properly, CPW and especially GCPW can provide excellent results at higher frequencies, and are often even combined with microstrip. In many cases, GCPW provides practical, high-performance interfaces at connector interfaces before making a transition to microstrip transmission lines for the remainder of a high-frequency design.
A CPW circuit includes a conductor fabricated between two ground planes on the top surface of a dielectric layer, in a ground-signal-ground (GSG) configuration on the top of the circuit material. By using a ground conductor that is coplanar with the signal conductor, CPW circuits use the signal line width and gap between the ground and the conductor to control the impedance. The impedance can be kept constant as the width of the signal conductor is tapered to form a connection with a connector pin.
A GCPW circuit adds a ground plane to the bottom of the dielectric layer and a means of interconnecting the ground areas, such as PTHs. In a CPW circuit, the EM energy is mainly concentrated within the dielectric material. Leakage of CPW and GCPW EM energy into the air can be controlled by maintaining a substrate height that is at least twice the conductor width. The characteristic impedance is established essentially by the width of the center conductor and the spacing between the conductor and the ground planes. For CPW, the characteristic impedance can typically be set between 20 and 250 Ω, compared to about 20 to 120 Ω for microstrip circuits and 35 to 250 Ω for stripline circuits.
Coupling For CPW/GCPW
As with any circuit technology, CPW and GCPW have positive and negative aspects, and tradeoffs that must be weighed for different applications, for both analog and digital circuits. The top-layer ground strips in CPW and GCPW circuits can produce even- and odd-mode current flow that cause mode coupling in those circuits. When tight spacing is maintained between the GSG traces of CPW and GCPW circuits, those circuits deliver tight coupling with excellent mode suppression and low radiation losses at higher frequencies. Loss can be minimized when wider spacings are used between the signal trace and the two top-layer ground strips, especially when a wider signal trace (with lower conductor loss and insertion loss) is used. When the signal conductor is widely spaced from the ground traces, in a loosely coupled configuration, the tradeoff for lower conductor and insertion losses is a possible increase in radiation loss and spurious distortion. Finding the right level of coupling in a CPW or GCPW circuit will provide a balance between low loss and good spurious mode suppression.
In general, thinner circuits are better for minimizing radiation loss than thicker circuits. For millimeter-wave circuits of 30 GHz and higher, radiation losses can become a significant part of a circuit’s total loss. Radiation loss also depends on a PCB material’s Dk value, with circuit materials having higher Dk values suffering less radiation loss than circuit materials with lower Dk values. Since tradeoffs must always be considered, those materials with higher Dk values usually exhibit higher conductor losses than circuit materials with lower Dk values since narrower signal conductors are needed for a given impedance on circuit materials with higher Dk values.
Copper surface roughness affects the electric field and current flow for a PCB. The effective dielectric constant increases as the surface roughness of the copper conductor increases. Copper surface roughness can also impact a PCB’s insertion loss, although with less effect on a GCPW circuit than on a microstrip circuit. On the GCPW circuit, the electric field and current are tightly maintained within the GSG configuration of the PCB whereas on the microstrip circuit, the electric field and current move towards the bottom of the conductive metal, towards the roughness of the metal.
The use of CAE software tools, such as EM simulators, can help find the appropriate values for the various CPW and GCPW circuit parameters, such as conductor width, circuit material thickness, and separation between ground planes, which contribute to circuit performance goals. During a technical presentation at the 2009 Automatic RF Techniques Group (ARFTG) by Sonnet Software’s father and son team of James and Brian Rautio (“High Accuracy Broadband Measurement of Anisotropic Dielectric Constant Using a Shielded Planar Dual Mode Resonator”), methods were detailed for measuring the Dk values of different circuit materials, even for CPW and GCPW circuits across ranges of different key parameters. The presentation included measurements to 10 GHz on the anisotropic RO3010™ circuit material from Rogers Corp. with the capability to separate even- and odd-mode material resonances numerically. The measurements determined two dielectric constant values for a given material: one for the horizontal electric field (parallel to the substrate surface) and one for the vertical electric field. This report shows how different parameters could be analyzed when considering circuit materials for different frequencies and applications and provides valuable guidance for those specifying circuit materials for CPW and GCPW designs as well as for stripline and microstrip configurations.
Download the ROG Mobile appto access Rogers’ calculators, including the popular Microwave Impedance simulation tool, literature, technical papers, and the ability to order samples of the company’s high performance printed circuit board materials.
Ask an Engineer
Do you have a design or fabrication question? Rogers Corporation’s experts are available to help. Log in to the Rogers Technology Support Hub and “Ask an Engineer” today.
Sealing against debris and water, preventing leaks, and managing energy are just a few of the challenges faced by designers when selecting automotive materials for today’s advanced vehicles. The following videos (available in English, German, and Chinese) discuss these issues in more detail.
PORON® Urethane and BISCO® Silicone materials allow designers to have confidence in the materials they select. With excellent compression set, stress relaxation, and sealability, PORON Urethane and BISCO Silicone materials provide reliable, time-test options for solving the automotive challenges of today and tomorrow.
Today’s average high-end car runs roughly seven times more software code than a Boeing 787. But the typical in-car, embedded, onboard navigation applications in today’s connected car are way out of step with the actual needs of drivers, claims WIRED. “They are expensive and yet are woefully inferior in content and capabilities from what’s on a typical mobile phone. As a result, drivers have increasingly begun to simply use what’s on their smartphones in a cradle or in their hand.”
One of the most important developments is the introduction of an Open Computing Language (OpenCL)-based automotive development environment from Freescale. This will provide auto manufacturers and their suppliers with a faster way to implement a more sophisticated range of Advanced Driver Assistance Systems (ADAS) as soon as 2015. OpenCL is an open, royalty free standard for cross-platform, parallel programming. It is maintained by the non-profit technology consortium Khronos Group.
To get the most out of these safety systems, and to take the next step to autonomous vehicles, standards are required.
One of the more difficult challenges for the growing fleet of connected cars is in the area of cybersecurity and regulatory oversight. In the United States, for example, the National Highway Traffic Safety Administration (NHTSA) recently announced that it may make vehicle-to-vehicle communications mandatory. This could call into question whether OEMs can protect their driver-generated data and keep it proprietary. To deter government regulations, the Alliance of Automobile Manufacturers created a set of standard consumer privacy practices that will go into effect in the model year 2017.
The IEEE is active many key areas: connected vehicles, autonomous and automated vehicles, inter- and intra-vehicle communications, and transportation electrification. Some of the projects include:
The smart grid will allow utilities to integrate electric vehicles. IEEE standard 2030is the “Guide for Smart Grid Interoperability of Information Technology Operation with Energy Technology and the Electric Power System and End-Use Applications and Loads.” This standard provides guidelines in understanding and defining smart-grid interoperability of the electric power system with end-use applications and loads, such as electric vehicles.
Power-line communications are part of intelligent transportation; they allow data to be transmitted over existing power lines. IEEE standard 1901is the “Standard for Broadband over Power Line Networks: Medium Access Control and Physical Layer Specifications.” It’s for high-speed communication devices that use electric power lines, also known as broadband over power-line devices, which can be used in transportation platform applications. The standard also addresses security to ensure that the communications between users are private.
Networking and communications are obviously crucial to connected vehicles. The well-known IEEE 802 series, which includes the IEEE 802.3Ethernet and IEEE 802.11Wi-Fi standards, is an obvious choice for vehicle connectivity. These proven and broadly adopted standards are being used in ways that may very well go beyond the wildest imaginations of their inventors.
Wireless access in vehicular environments is another key to intelligent transportation. The IEEE 1609series of standards, known as the WAVE standards, addresses the lack of homogeneous communications interfaces between different automotive manufacturers. It also helps solve the lack of ubiquitous high-speed communications between vehicles and service providers.
ISO 15638 addresses “Telematics Applications for Regulated commercial Vehicles (TARV).” According to project leader Bob Williams, “This delivers standards based on the same secure communications that are used for cooperative intelligent transport systems (C-ITS) – harmonized and compatible with such systems. The advantage is that it can use the 2G/3G mobile phone already installed for today’s fleet management systems, it can use the 5.8 GHz technology currently used for electronic toll collection, and it can migrate to LTE/4G communications or use the new dedicated 5.9 GHz technology being developed for C-ITS.”
To ensure that the technologies being developed for vehicles around the world are reliable, IECQ (IEC Quality Assessment System for Electronic Components) has created a program that gives the automotive industry a standardized way of testing the components. IECQ AQP (Automotive Qualification Programme) helps automotive manufacturers avoid multiple tests and related costs. It can also be used by independent, third-party certification bodies to make sure that components meet automotive industry standards.
We are pleased to announce that Rogers Corporation has signed a definitive agreement to acquire Arlon, LLC, currently owned by Handy & Harman Ltd. (NASDAQ: HNH), for $157 million, subject to closing and post-closing adjustments. The transaction, which is subject to regulatory clearances, is expected to close in the first half of 2015. Rogers intends to finance the transaction through a combination of cash and borrowings under an existing bank credit facility.
Bruce Hoechner, President and Chief Executive Officer of Rogers said, “This transaction is truly a unique strategic fit for both Rogers and Arlon. We are energized by the opportunity to serve our customers with our complementary capabilities and technologies in circuit materials and engineered silicones and to enhance value for our shareholders. We look forward to closing this acquisition as another significant milestone in Rogers’ growth as a premier global engineered materials solutions company.”
Arlon: A Strong, Strategic Fit
The proposed acquisition of Arlon is consistent with Rogers’ strategy as it adds complementary solutions to its Printed Circuit Materials and High Performance Foams business segments and expands Rogers’ capabilities to serve a broader range of markets and application areas.
Arlon’s circuit materials product family positions Rogers for additional growth in the rapidly expanding telecommunications infrastructure sector, as well as in the automotive, aerospace and defense sectors. Arlon produces its circuit materials in Bear, Delaware; Rancho Cucamonga, California; and Suzhou, China.
The engineered silicones product family of Arlon will further diversify the Company’s solutions and market opportunities in sealing and insulation applications. Arlon will bring new capabilities in precision-calendered silicones, silicone-coated fabrics and specialty extruded silicone tapes. Used primarily for electrical insulation, these materials serve a wide range of high reliability applications across many market segments, including aviation, rail, power generation, semiconductor, foodservice, medical and general industrial. This product family is primarily manufactured in Bear, Delaware.
Revenue and operating income for the Arlon segment of Handy & Harman Ltd. were $100.4 million and $16.7 million, respectively, for the trailing twelve months ended September 30, 2014 (compiled based on amounts reported by Handy & Harman Ltd. in Forms 10-K and 10-Q filed with the Securities and Exchange Commission).