20mil IsoClad 917 Substrates High Frequency PCB Non Woven Fiberglass / PTFE Composites

Today, we are going to discuss an innovative technology that is transforming the field of printed circuit board substrates - Rogers IsoClad 917 laminates. These laminates are composed of non-woven fiberglass and PTFE composites in a low ratio, allowing them to achieve the lowest dielectric constant and dissipation factor in their class.

The non-woven fiberglass reinforcement of these laminates makes them suitable for applications where flexibility and shaping of the printed circuit board are required, such as in conformal or wrap-around antennas. Moreover, the laminates' longer random fibers and unique manufacturing process ensure enhanced dimensional stability and uniformity of the dielectric constant, surpassing similar laminates available in the market.

Let's begin by providing an overview of the typical properties of IsoClad 917.

Typical Properties of IsoClad 917

One notable feature is its dielectric constant, which measures either 2.17 or 2.20 depending on the specific formulation.

IsoClad 917 also boasts an impressively low dissipation factor of 0.0013 at 10 GHz, indicating minimal energy loss during signal transmission.

It exhibits high volume resistivity of 1.5 x 10^10 MΩ-cm and high surface resistivity of 1.0 x 10^9 MΩ.

With a long arc resistance of over 180 seconds and a high dielectric breakdown voltage exceeding 45 kV, IsoClad 917 demonstrates excellent electrical properties.

Regarding thermal characteristics, IsoClad 917 has a thermal coefficient of Er of -157 ppm/°C, implying that its dielectric constant can change by that magnitude for every degree Celsius of temperature variation. However, in some cases, a lower coefficient may be preferred.

It features a low coefficient of thermal expansion of 46 ppm/°C in the X-axis, 47 ppm/°C in the Y-axis, and 236 ppm/°C in the Z-axis.

However, its thermal conductivity is relatively low at only 0.263 W/mK at 100°C.

IsoClad 917 also offers favorable mechanical properties, including a peel strength of 10 lbs. per inch after thermal testing, a tensile modulus of 133-120 kpsi, a tensile strength of 4.3-3.8 kpsi, a compressive modulus of 182 kpsi, and a flexural modulus of 213 kpsi.

The density of IsoClad 917 is 2.23 g/cm3 at 23°C, as measured by ASTM D-792 Method A. This results in a relatively high weight-to-volume ratio, which can be advantageous in specific applications.

In terms of water absorption, it has a relatively low rate of 0.04% as measured by E1/105 + D24/23, making it less susceptible to moisture-related damage.

Let's move on to discuss its outgassing properties.

IsoClad 917 exhibits minimal total mass loss at 0.02%, well below the maximum allowance of 1.00% under the condition of ≤10-6 torr at 125°C.

Similarly, the collected volatile condensable material is 0.00%, with a maximum permissible value of 0.10%. There is no condensable material present.

Moreover, the water vapor regain is only 0.02%, and visible condensate is absent.

Lastly, IsoClad 917 meets the flammability requirements of UL94-V0.

Now, let's delve into our PCB capability using IsoClad 917 substrates.

Our PCB capability for IsoClad 917 includes various options for layer count, such as single-sided boards, double-sided boards, multi-layer boards, and hybrid designs.

We offer copper weights on tracks and pads with 1oz (35µm) and 2oz (70µm).

Dielectric thicknesses are available in 20mil (0.508mm), 31mil (0.787mm), and 62mil (1.575mm) options.

The maximum size of circuit boards is 400mm by 500mm, allowing for single large boards or multiple designs within this sheet.

To meet your design requirements, we provide different solder mask options, including green, black, blue, yellow, and red.

We also offer a variety of surface finishes, such as immersion gold, HASL, immersion silver, immersion tin, ENEPIG, OSP, bare copper, and pure gold plating.

IsoClad 917 is widely used in various electronic systems, including conformal antennas, stripline and microstrip circuits, guidance systems, and radar systems, among others.

In terms of manufacturing, IsoClad 917 material is compatible with a range of tooling systems. The specific choice of using round or slotted pins, external or internal pinning, standard or multiline tooling, and pre- or post-etch punching will depend on the capabilities and preferences of the circuit manufacturing facility, as well as the desired registration requirements. In most cases, utilizing slotted pins, a multiline tooling format, and post-etch punching will be sufficient. It is advisable to maintain copper around tooling holes, regardless of the chosen approach.

To enhance layer registration, it is recommended to apply a flow pattern compatible with the selected adhesive system between circuits and around the perimeter of the panel. However, in general, preserving as much copper as possible will contribute to improved layer registration.