详情
Tape and Reel is a process of packing surface mount devices
(SMDs) by loading them into individual pockets comprising what is
known as a pocket tape or carrier tape. The units are sealed in the
carrier tape with a cover tape, usually by heat or pressure. The
carrier tape is wound around a reel for convenient handling and
transport. The reel is enclosed in a reel box before it is
finally shipped to the customer.
Packing units by Tape and Reel also facilitates automated
retrieval and mounting of the components on the application board
during customer manufacturing. Taping and reeling of SMDs is
the counterpart of packing non-SMDs in tubes.
Fig. 1. Photos of Carrier Tapes
Tape and reel is a relatively simple process but nonetheless
has certain requirements that need to be met to ensure successful
packing of the units. The physical and electrical properties
of the tape and reel materials used are important to prevent
loading/unloading problems and ESD failures. For instance,
the materials used in the carrier tape, cover tape, and even reels
should be antistatic, if not static dissipative. The ability of
these materials to withstand severe environmental conditions
(temperature and humidity) for a predefined duration must also be
considered.
Fig. 2. Photos of Cover Tapes
Peel back strength, which is the force needed to peel open the
cover tape, must also meet a lower and an upper limit. Depending on
the width of the carrier tape, the peel back strength requirement
may be as low as a few grams to more than a hundred grams.
Peel back strength testing is often done at room temperature,
with the pulling action performed at a predefined angle and
peel-off speed.
Fig. 3. Photos of Reels
Another critical parameter is the direction of feed, which is
defined as the direction in which the end customer unreels the
carrier tape. Aside from the direction of feed, the pin 1
orientation of the units with respect to the carrier tape is also
critical as any error may result in units being mounted improperly
on the boards.
The leader is an extra length of empty pockets run after the
reel has been filled with the correct number of parts. The leader
must meet a minimum length. The trailer, on the other hand, is an
extra length of empty pockets run prior to filling any pockets with
components. This must also meet a minimum length. One end of the
trailer is attached to the reel hub.
