High frequency circuit boards
We buy these materials from an agent at Rogers Materials and then process and produce blank circuit boards. We don’t produce core materials. The following information is for reference only.
High frequency PCB with Rogers material 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.
ALCANTA PCB provides you with know-how, all popular materials and qualified manufacturing processes – reliably even for complex requirements.
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.Materials used for HF circuit boards:
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. 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.
|Property||Typical Value(1)||Direction||Unit||Condition||Test Method|
|Dielectric Constant, r|
3.00 ± 0.04
3.50 ± 0.05
6.15 ± 0.15
10.2 ± 0.30
10 GHz 23°C
|(2) Dielectric Constant, r|
8 GHz – 40 GHz
|Differential Phase Length Method|
|Dissipation Factor, tan ||0.0010||0.0015||0.0020||0.0022||Z||–||10 GHz 23°C||IPC-TM-650 220.127.116.11|
|Thermal Coefficient of r||-3||-45||-262||-395||Z||ppm/°C||10 GHz|
-50 to 150°C
|X Y||mm/m||COND A||IPC TM-650 2.2.4|
|Volume Resistivity||107||107||105||105||M•cm||COND A||IPC 18.104.22.168|
|Surface Resistivity||107||107||105||105||M||COND A||IPC 22.214.171.124|
|X Y||MPa||23°C||ASTM D638|
|Moisture Absorption||0.04||0.04||0.02||0.05||–||%||D48/50||IPC-TM-650 126.96.36.199|
|Thermal Conductivity||0.50||0.50||0.79||0.95||–||W/m/K||50°C||ASTM D5470|
|Coefficient of Thermal Expansion (-55 to 288 °C)||17|
|X Y Z|| |
|Td||500||500||500||500||°C TGA||ASTM D3850|
Copper Peel Strength
|1 oz. EDC|
After Solder Float
|Lead Free Process Compatible||YES||YES||YES||YES|
RO3000® Series Circuit Materials
RO3003™, RO3006™, RO3010™ and RO3035™
High Frequency Laminates
RO3000® high frequency circuit materials are ceramic-filled PTFE composites intended for use in commercial microwave and RF applications. This family of products was designed to offer exceptional electrical and mechanical stability at competitive prices.
RO3000 series laminates are ceramic-filled PTFE based circuit materials with mechanical properties that are consistent regardless of the dielectric constant selected. This allows the designer to develop multi-layer board designs that use different dielectric constant materials for individual layers, without encountering warpage or reliability problems.
RO3000 materials exhibit a coefficient of thermal expansion (CTE) in the X and Y axis of 17 ppm/oC. This expansion coefficient is matched to that of copper, which allows the material to exhibit excellent dimensional stability, with typical etch shrinkage (after etch and bake) of less than 0.5 mils per inch. The Z-axis CTE is 24 ppm/ °C, which provides exceptional plated through-hole reliability, even in severe thermal environments. The dielectric constant versus temperature for RO3003™ and RO3035™ materials is very stable (Chart 1).
RO3000 series laminates can be fabricated into printed circuit boards using standard PTFE circuit board processing techniques, with minor modifications as described in the application note “Fabrication Guidelines for RO3000 Series High Frequency Circuit Materials.”