When people refer to JEDEC tray standards or carrier standards, unless a specific JEDEC Standard or Outline number is given such as CS-123 or CO-123, they usually mean the general outline defined in a JEDEC Publication 95 design guide.

The most important elements are the JEDEC tray dimensions, some specific features, and the tolerances, especially flatness. The external dimensions need to be compatible with automation equipment. The features that give orientation information, and are used by tray feeders, include end tabs, corner chamfer, and side cut-outs. The sidewall radius notch allows simple, quick verification that trays are properly stacked.

Flatness is important because it puts all the parts on a common plane for pickup and it minimizes the risk of bouncing parts out of the tray when parts are being picked up. Not only is it important that the trays are flat, but any bow should be in a direction that keeps the trays from rocking. Lack of flatness increases the profile height of a tray and can jam tray feeders.

JEDEC identifies two tray thicknesses and many trays default to one of them. But JEDEC trays are used for many parts that are too tall for JEDEC “thick” trays therefore many special thickness trays exist. Most all automation equipment can accept taller trays as long as the other dimensions and features follow the design standard.

In the early days of JEDEC tray standards, it was hoped that pocket locations would be standardized. Several BGA tray, QFP tray, Flat Pack tray, and PGA tray outlines were registered, as well as for other package types. But it was soon discovered that there were benefits to customizing pocket layouts. Automation equipment is easily programmed for pocket locations as long as they are in a regular matrix. It is rare that a specific JEDEC Outline Registration is specified or required.

Similar to JEDEC trays, JEDEC carrier outlines have been registered and standardized. And just like JEDEC tray dimensions, the carrier dimensions that matter most are the outline size and the reference features, particularly the notches that help with alignment to sockets and shipping tubes. Carrier specifications are more variable than JEDEC tray specifications because the carriers must match both the component and the mating sockets.

Your application requirements are the most important constraints for trays and carriers. But when RH Murphy Co. describes your trays or carriers as “JEDEC”, you can be confident that they incorporate the details and meet the tolerances necessary to work properly with industry standard automation equipment, feeders, and accessories.

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