General Information

PCL-CF-471 is a halogen-free, high glass transition temperature (Tg), FR-4 epoxy resin coated foil designed for microvia and high-density applications. The epoxy resin is based on the same system used in Polyclad's high performance halogen-free 571 laminates and prepregs. It consists of electro-deposited copper foil coated with two layers of epoxy resin. The first resin layer adjacent to the copper foil is a fully cured, C-stage layer providing consistent dielectric thickness control. The second resin layer is a B-staged layer, manufactured to precise rheological properties to provide optimal flow and fill during the lamination process. Because the resin is based on the 571 system of laminate and prepregs, processability and performance are consistent with other Polyclad FR-4 systems with the exception of a lower dielectric constant because there is no woven glass reinforcement. The 471 system is also laser fluorescing and UV blocking for maximum compatibility with automated optical inspection systems (AOI), optical positioning systems and photoimagable soldermask imaging.

AVAILABLITY
PCL-CF-471 resin coated foils are available with a variety of copper foil weights and thicknesses. 5 micron (1/8 ounce) with a copper carrier, 12-micron (3/8 ounce) and 18 micron (1/2 ounce) unsupported are standard copper thicknesses. High temperature elongation (HTE), low profile copper foils are standard. PCL-CF-471 with other copper foil types and thicknesses can be custom made to meet specific requirements.

The thickness of each of the two resin layers can be controlled between 25 microns (.001 inches) and 50 microns (.002 inches). The standard thickness tolerance for each of the individual resin layers is ± 2.5 microns (.0001 inches). Other custom thickness combinations may be available to meet specific designs and applications. For more detailed availability, please see Standard Product Availability Bulletin: Resin Coated Foil.

PROCESSING AND STORAGE
Storage of PCL-CF-471 resin coated foils is the same as for FR-4 prepregs. They should be stored below 68° F (20°C) and 30-50% relative humidity. Resin coated foils stored below recommended temperatures should be allowed to equilibrate to the above specified conditions for A minimum of eight hours prior to use. More detailed storage recommendation technical bulletins are available from Polyclad.

APPLICABLE SPECIFICATIONS AND RECOGNITIONS
Polyclad's UL file number is E45456. PCL-CF-471 is UL listed under the generic designation PCL-CF-471. PCL-CF-471 resin coated foil and PWBs constructed using it are capable of achieving a UL 94-V0 flammability rating. Certain other more specific parts of Polyclad's UL listing may be applicable in some cases. PCL-CF-471 can be certified to IPC/JPCA-4104, Specification for High Density Interconnect (HDI) and Microvia Materials, specification sheet IPC/JPCA-4104/12, Designation CI C 1 N 1 CF 1 Epoxy Coated Foil, and IPC-CF-148A, Resin Coated Foil for Printed Boards, specification sheet IPC-CF-148A/02. Other industry or customer specific specifications, recognitions or designations may be applicable or certifiable to in certain cases. If you need additional information or have questions, please contact Polyclad Technical Services.