Emerging Trends In Laminate Materials for Printed Circuit Boards
Laminate materials are used in the fabrication of Printed Circuit Boards especially for advanced electronic applications. These materials mainly have a low dissipation factor, a range of dielectric constants and manageable mechanical prices. Some of the commonly used laminate materials are FR4, modified epoxy, polyimide, PTFE/Cer and phenolic. However, with the rapid changes in the electronics world have led to numerous changes in the laminate materials’ properties and their applicability in different PCBs. PCBs with larger bandwidths and transmission speeds to increase data traffic rates and enhance the performance of the boards have been developed to aid in satisfying the ever changing demands. All this depends on the application of the PCB which the laminate is used. If you have any problems choosing the right laminate material for your PCB, please feel free to contact us and our team of experts will guide you. This article shall discuss the emerging trends in laminate materials for PCBs.
To begin with, laminate materials with a better cost and higher efficiency are being introduced in the market. The numbers of companies producing these materials have constantly increased with countries like Taiwan, Korea and China joining Japan in this market. However, the materials used to manufacture the laminate materials are different though the application is still the same. Luckily, they provide a variety of materials with limited background and data with the sampling rate approaching S20 at a frequency of 10GHz.
Current trends in FR4 Class laminate materials
In PCB laminate materials, FR4 is used as the standard for comparing the behavior of other laminate materials and their processability. As a laminate, FR4 is usually preferred due to its low cost and a high thermal-mechanical strength which is associated with HDI fans. Moreover, FR4 has to operate within some electrical performance limits so as to oversee a high transmission rate. Equally important, FR4 materials with around 5 to 6 gigabytes per seconds (Gbps) whose signal depends on the routing lengths and trace widths have been introduced into the market. However, the major inventions and changes related to FR4s came up when the international standard requiring the use of lead-free solder excursions was enforced. This led to the creation of a sub-class in the FR4 class.
As if that is not enough, FR4 resins have been recently modified in a way that there is a third reduction of the rated Df compared to the traditional ones. The quality of Df continues to improve thus more modified FR4s have been introduced into the market at a cheaper cost. Moreover, the effect of halogen-free Dfs on FR4s has led to the introduction of non-brominated replacements requiring lower resin contents for their effectiveness. Consequently, such FR4s can conform to UL9540 flame and have DF ratings of 0.01 to 0.016 at a cheaper price.
The use of over-engineered materials for design is often the case when new cheaper off-springs offspring are introduced. As the market for FR4s continues to expand, the use of such laminate materials becomes unnecessary. This has led to the mitigation of the Z-differential timing skew. The lower profile copper options which are smoother than RTF are yet to be introduced in the market because greater trace loss benefit can be achieved by the use of other lower DF resin systems. Recently, lead-free FR4s are being used in high speed applications for reducing power cost, stack up hybridization and other non-critical layers to improve the thermal-mechanical performances.
Low Df/Dk laminates class
Low Df/Dk laminates class have a Dk values less than or equal 3.7 and Df ratings below 0.005. With technological advancement, m id Df/Dk laminates materials can achieve this Dk range if they are enhanced with low Dk glass. The current standardizers of these laminates materials are Panasonic’s Megatron-6 and the Rodgers 4000 series of ceramic hydrocarbons. The thermal-mechanical characteristics of these materials are vital since they are used for complex HDI-type designs and they should endure a couple of lamination cycles at a lead-free temperature. The materials used in this class gave a proprietary resin formulations thus it’s not possible to determine their content. However, the modern ones like Taconic and Rogers have a measurable content of PTFE.
Since cost is a major consideration in the design of laminates, the PTFE laden materials are rarely used in the market. However, they are sometimes used for the sake of mitigating attenuation over traces over a distance of about a meter. Lower loss materials are also being used to increase the transmission rates to about 20 to 25 Gigabytes per second.
Mid Df/Dk laminates class
Mid Df/Dk laminates materials have a lower dielectric constant that that of FR4 and a DF rating ranging between 0.007 to 0.013. However, with the introduction of RoHS where highly modified epoxy materials are used (blended with cyanate), the mid Df/Dk laminate material have been modified to provide excellent performance even at higher temperatures. However, HDI has become more complicated with the plated over via and BGA pitches getting smaller hence the laminated board designs are most common today. As a result, most of the laminate suppliers have introduced more robust and new systems which not only address the thermal-mechanical problems but also chip away at better DF values thus more expansive options of copper smoothness offerings and spread weaves. Consequently, a new class within a class (of mid Df/Dk materials) has been introduced. This class performs at a cheap cost and has a performance better that of the ultra-premium low class Df/Dk laminates.
As a leading producer of PCBs products and services, we are dedicated to overseeing the introduction of better laminate materials in the market. This is because we appreciate the role of technology to humanity. In the event that you have problems choosing the best laminates materials for your PCB, please don’t hesitate to visit us at https://www.rushpcb.co.uk/and interact with our team of experts. Equally important, we offer services like Printed Circuit Board assembly, design and fabrication. Our products are of high quality and unique so we assure you of a perfect experience when you work with us.