It is recommended to tightly strap the stack of trays with ESD quality VelcroŽ straps, heavy-duty conductive rubber bands, or other means. During dry packing, the trays and contents are baked in industrial ovens for several hours at 125°C to get the moisture out of the components, and then sealed in moisture barrier vacuum bags (look for the dewdrop icon on the outside of the bag). Do not use standard bags to vacuum seal the tray stack. Desiccant and humidity indicators are typically packed inside the bag. The trays and contents are vacuum-sealed in the moisture barrier vacuum bag for safe packing, storage and transport.
The maximum baking temperature is stamped into JEDEC trays. Exceeding the stated maximum baking temperature will cause the dimensions of the tray to alter; thus, potentially damaging the contents. The type of molding compound used during the tray's manufacture determines the tray's maximum temperature rating. Multiple compounds and/or powders are mixed together during the molding process to add specific features such as color, ESD properties, dimensional stability and maximum temperature ratings.
Typical temperature ratings for bakeable JEDEC trays are: 140°C, 150°C and 180°C. Higher temperature trays cost more. Normally baking is done at 125°C. Typically, 140°C trays are sufficient to maintain dimensional stability during baking. Non-bakeable trays rated at 50~75°C are also available.
JEDEC trays are also known as "matrix" trays since the components are nested into pockets in fixed position rows and columns. The spacing (pitch) of each component pocket (cells) is defined by JEDEC standards. This allows automated pick and place machines to dimensionally locate and pick up the components from the tray and place onto a PC board. JEDEC trays are also required by industries outside of traditional electronics. The solar photovoltaic industry as well as the medical industry is enjoying benefits by using JEDEC trays during storage, handling and transport of devices specific to their industries.
JEDEC trays are available in a variety of colors, though black is the most popular color for microelectronics and IC devices. Carbon fibers or carbon powder is combined into the molding compounds to make ESD safe trays (conductive or dissipative). Anti-static, non-bakeable trays are constructed from ABS (Acrylonitrile Butadiene Styrene) in multiple colors, such as blue, red, green, yellow, cream and white.