Tape and
Reel
Tape and Reel
is a process of packing surface mount devices (SMD's) 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 SMD's is the counterpart of packing non-SMD's 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.
Figure
4. Examples of Tape and Reel Equipment
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