Expanded PTFE Tape

Dielectric science has enjoyed a long and illustrious history. In addition, this long-standing branch of physics has had close links to chemistry and electrical engineering.

Over 130 years ago, Faraday coined the term ‘dielectric’ to suggest that something analogous to current flow occurs through a capacitor structure during the charging process when current introduced at one plate ‘flows’ through the insulator to charge the other plate.

It is generally accepted that a dielectric material interacts with an electric field differently than free space because the dielectric contains charges that can be displaced. Since nearly all materials contain charges, essentially every material can be broadly classified as a dielectric.

The quest for the industry has over the last 40 years been trying to approach the ultimate goal of 100% velocity of propagation, by introducing air into mechanical structures supporting the copper center conductor.

LOROM’s Latest Technology of Dielectrics

LOROM has been committed to excelling and will always be at the forefront of the technology curve in offering the latest technology of dielectrics used in differential as well as single ended transmission structures.

We take pride in being at the forefront offering solutions to the industry’s challenging signal integrity opportunities and system requirements.

From the early days of the “bamboo” style of cabling to the latest physical gas injection extrusion technologies we now offer the revolutionary ePTFE tape wrap tape and process technology.

LOROM’s ePTFE Tape Display

LOROM ePTFE tape display the lowest dielectric constant of any high-speed dielectric material.

By our unique process we expand solid PTFE resin into ePTFE precision tapes, increasing the air volume up to 70% air. Lowering the overall dielectric constant from 2.1 for PTFE to 1.3.

Our ePTFE dielectric tape, has a tightly and precisely controlled thickness, density and dielectric constant.

Choosing our ePTFE tapes as dielectric materials by applying the tape wrapping individual conductors enables. Lower interference, noise, and cross-talk and signal attenuation. As well as creating more phase stable limiting phase shift to 4.3° and signal attenuation to 0.05 dB at 110 GHz.

Additionally, ePTFE tape wrapped dielectric and insulation systems can be up to 50% thinner than other materials, increasing I/O packaging.

LR ePTFE technology

The Process

Heating the polymer to about 300°C below its 327°C melting point and then rapidly applying controlled force in one axis, expands the polymer’s microstructure to create air voids due to fibrillation in the PTFE.

The expanded polymer appears under atomic force microscopy as a network of densely coiled nodes connected by fibrils.

Controlling the expansion temperature, force, rate and direction allow us to dictate many microstructural attributes of ePTFE, including the network’s openness, density of the fibrils and distance between nodes. Each microstructural configuration, combined with the final product performance, provides us the ePTFE products unique characteristics.

Every good signal integrity high speed transmission line whether its single ended or differential is limited in the ability to maintain tight control of the Ke (dielectric constant) in:

• Homogenous cell size in the dielectric.
• Even dispersion of cells throughout the entire length of the cable