APPLICABLE TO THE FOLLOWING POLYCLAD PRODUCT GRADES:

STORAGE
Laminates should be stored horizontally in their original packaging until use. Preferred environmental conditions are at a temperature of less than 74°F (23°C) and less than 50% relative humidity. Prepregs and resin coated foils should be should be stored horizontally in their original sealed packaging at a temperature of 65±3° F (18±2° C) and 30- 50% relative humidity.

SAFETY
Laminate, prepreg and resin coated foil for Printed Wiring Board applications are relatively safe materials. The laminate itself is a fully cured epoxy polymer reinforced with glass fabric. As such, it is regulated as an article or material and poses little or no risk. Dust generated by machining operations such as drilling or routing can be considered nuisance dust and reasonable dust minimization techniques should be used. Prepreg and resin coated foil are partially cured epoxy resin. They are essentially polymers with no free curing agent remaining but that have not reached full strength. Again, machining operations can generate dust and reasonable care should be taken. Since they are not fully cured, they are somewhat more prone to fracture and dust can also be generated in handling. A few individuals have developed skin rashes after repeated exposure to epoxy resins. Gloves are recommended when handling laminate, prepreg, coated foil, and normal hygiene procedures should be followed.

While laminate, prepreg and resin coated foil are made from fire resistant materials, at high temperatures they can decompose with the formation of hydrogen bromide. Hydrogen bromide can cause severe respiratory distress. The fire retarding components of the materials do not contain polybrominated biphenyls or polybrominated biphenylene oxides. Since prepreg and resin coated foils are partially cured polymers, there is a possibility of an exothermic reaction if large quantities of the material are raised above 420°F in a confined container or press. This exotherm can generate hydrogen bromide and other decomposition products. In normal multilayer constructions using Polyclad recommended or industry typical press cycles this is not a problem.

Additional safety and health information may be found in the Material Safety Data Sheets for the specific materials. You should contact your local or state environmental agencies to determine the proper methods of disposal in your area.

GENERAL PROCESS GUIDELINES
Industry best practices production techniques used for manufacturing and assembly of traditional FR-4 multilayer Printed Wiring Boards and resin coated foil build up structures are generally applicable and appropriate to all Polyclad products covered by this bulletin. The diversity of designs and production techniques used throughout the industry make specific recommendations for most process steps difficult if not impossible to provide. For specific recommendations not addressed in this bulletin, please contact Polyclad Technical Services.

INNER LAYER BONDING TREATMENTS
A variety of Inner layer bonding treatments can be used successfully with Polyclad laminate and prepreg materials. Traditional copper oxide treatments, “oxide” alternatives and double treat are all successful and capable of achieving excellent performance results. Care should be taken to ensure any of these products used achieve consistent performance and meet end product requirements. Please contact Polyclad Technical Service for assistance. Polyclad does not recommend the use of Tin based inner layer bonding treatments.

LAMINATION PROCESS GUIDELINES
The following multilayer lamination press cycle recommendations are designed to address most Printed Wiring Board designs, hydraulic lamination press techniques, panel sizes 21” x 24” (540 x 570 mm) or smaller and, artwork and tooling configurations. Unusual or non-typical designs and larger panel sizes are best addressed by requesting specific recommendations from Polyclad Technical Services.