LCP Laminate Is Well Suited To Handsets

In RF-intensive applications, liquid-crystalline-polymer (LCP) laminates are known for providing superior dielectric material. These thin-film, flexible, adhesiveless laminates are often used as a core for single-layer constructions. Or they can build up multi-layer constructions in high-frequency, micro-miniaturization applications; sensors; antennas; and high-speed flip-chip designs. To realize this potential, Rogers Corp. has introduced a product for the R/flex 3000 family of LCP-based circuit materials. To complement the R/flex 3600 LCP single-clad laminate that was introduced last year, the new R/flex 3850 double-clad laminate offers a low dielectric constant (Dk = 2.9) for controlled impedance. This feature combines with high dimensional stability for dense fine-line applications. Like the single-clad laminate, the R/flex 3850 laminate is produced in a range of copper and LCP thicknesses. It is available in standard panel formats.

The need for products like the R/flex 3000 LCP is being driven by the demand for high-speed microprocessors above 5 GHz and ASICs at 10 Gbps. (For high-end routers and servers, that number is 40 Gbps.) Because it is based on a thermotropic LCP polymer, the family includes laminates with CTEs that are matched to copper dielectric variants with high or low neumatic melt points. The result is an advanced circuit materials system that is suited for the fabrication of high-speed, high-density, environmentally friendly flex, multi-layer, rigid-flex, and mixed-dielectric circuit designs.

In addition, the R/flex 3000 family of materials now includes a single-clad lower melt point and a double-clad high-melt-temperature laminate. The materials offer a combination of mechanical, electrical, thermal, and environmental properties. These features make the materials well suited to tightly controlled impedance flex interconnections, next-generation wireless handsets, high-density flip-chip packages, and moisture-resistant sensors.

The performance benefits include excellent electrical properties. For example, applications that design high-frequency/high-speed circuits could have a dielectric constant of 2.9, dissipation factor of 0.002 at 10 GHz, and low moisture absorption (0.04%). Other benefits include dimensional stability. Here, fine line features are defined and reliable performance is critical. Chemical resistance also is provided when exposure to corrosive chemicals is required. LCP is a halogen-free material.