Disclosed is a product carrier having a desiccant incorporated
therein and a method for making the same. The inventive carrier
reduces the number of steps required to package a semiconductor
What is claimed:
1. A carrier for a semiconductor device, the carrier comprising:
a material containing a desiccant embedded therein; and a holding
region for the semiconductor device.
2. The carrier of claim 1 wherein the desiccant is montmorillonite
3. The carrier of claim 1 wherein the material can withstand temperatures
from about -125.degree. C. to about 150.degree. C.
4. The carrier of claim 1 comprising: at least two layers of material.
5. The carrier of claim 1 wherein the material comprises about
5% to about 30% recycled materials.
6. The carrier of claim 1 wherein the carrier is selected from
the group consisting of a tube, a tray, a reel, and a jewel box.
7. The carrier of claim 1 wherein the carrier is configured to
accommodate a single semiconductor device.
8. A method for manufacturing a carrier for a semiconductor device,
the method comprising the steps of: mixing a desiccant with molten
plastic; molding the mixture into a product carrier. loading a device
into the product carrier; and dry packing the loaded product carrier
in a bag.
9. The method of claim 8 comprising: mixing sufficient desiccant
with the molten plastic such that the dry packed product carrier
comprises from about 32 grams of desiccant to about 64 grams of
10. The method of claim 8 comprising: mixing sufficient desiccant
with the molten plastic such that an environment within the dry
packed bag is maintained at no greater than about 20 percent relative
humidity for about 12 months.
11. The method of claim 8 comprising: molding the product carrier
into a form selected from the group consisting of a tube, a tray,
a reel and a jewel box.
12. The method of claim 8 comprising: molding the product carrier
into a form configured for holding one semiconductor device.
13. The method of claim 8 comprising: molding the product carrier
into a form configured for holding a plurality of semiconductor
14. The method of claim 8 further comprising the step of: including
a card comprising a humidity sensitive element in the dry packed
15. The method of claim 8 further comprising: labeling an outside
of the dry pack bag; packing the dry pack bag in a box; and labeling
an outside of the box with a moisture-sensitivity caution label.
 The present invention relates to a product carrier that
has a desiccant incorporated therein. The present invention is particularly
applicable in reducing the steps required to package a semiconductor
 The world of shipping and handling is a hostile one in which
product can encounter stress from moisture, temperature changes,
and rough handling. Carefully designed packaging methodologies that
ensure the preservation of product quality from the factory floor
to the customer are required.
 Some IC packages are susceptible to moisture induced damage.
The risk of this is highest when plastic encapsulation materials
are used, as plastic is naturally permeable to moisture. The moisture
in the package will increase or decrease to reach the Relative Humidity
(RH) of the surrounding environment.
 Therefore, controlling the moisture level in the package
body is critical to reducing the risk of moisture-induced damage.
Such damage may include delamination between the die and the plastic
encapsulation material, which may result in open connections due
to broken wirebonds. Package cracking may also occur when the components
are exposed to the high temperatures and steep temperature gradients
used in reflow board assembly techniques. Moisture in the package
rapidly heats and vaporizes and, if there is sufficient steam due
to the moisture in the package having reached a critical level,
it will fracture the package to escape. This phenomenon is known
as the "popcorn effect."
 Thus, plastic semiconductor devices are susceptible to moisture
due to the permeable nature of their plastic components. It is well
known that integrated circuits which are contaminated by high levels
of moisture may not be useful. Mechanical failure of such contaminated
integrated circuits often leads to the subsequent electrical failure
of the device which contains the integrated circuit due to thermal
and mechanical stresses. Accordingly, exposure of integrated circuits
to moisture should be limited.
 This concern about limiting the exposure of integrated circuits
to moisture has been addressed in the design of shipping packaging
for integrated circuits. Currently the preferred method to form
a packaging system for integrated circuits includes baking the integrated
circuit devices until dry, placing them into a water and humidity
proof packaging bag which contains desiccant packets and a humidity
indicator card, sealing the bag immediately, and then shipping the
device to the customer in these packaging bags.
 Once it is determined that a product is moisture sensitive,
the product is typically dry packed for storage and shipment. This
is done for all types of product carrier (e.g., tubes, trays, reels,
etc.). Dry packing protects product from environmental moisture
by maintaining the interior of the dry pack bag at (less than or
equal to) 20 percent RH. Included in the dry pack bag are a prescribed
number of desiccant pouches. The desiccant pouches greatly reduce
the presence of moisture.
SUMMARY OF THE INVENTION
 There exists a need for an efficient cost-effective carrier
for a semiconductor device which eliminates unnecessary product
 There is also a need for a method for manufacturing such
a carrier in an efficient, cost-effective manner.
 According to one aspect of the invention, a carrier for
a semiconductor device is provided. The carrier includes a material
containing desiccant particles embedded therein and a holding region
for the semiconductor device.
 Another aspect of the present invention provides a method
for manufacturing such a semiconductor carrier. The method includes
the steps of mixing a desiccant with molten plastic and molding
the mixture into a product carrier.
 Other objects and advantages of the present invention will
become readily apparent to those skilled in this art from the following
detailed description. The embodiments shown and described provide
illustration of the best mode contemplated for carrying out the
invention. The invention is capable of modifications in various
obvious respects, all without departing from the invention. Accordingly,
the drawings are to be regarded as illustrative in nature, and not
BRIEF DESCRIPTION OF THE DRAWINGS
 Reference is made to the attached drawings, wherein elements
having the same reference numeral designations represent like elements
 FIG. 1 illustrates an embodiment of the present invention.
 FIG. 2 illustrates a flow chart for practicing a method
of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
 An embodiment of the present invention is illustrated in
FIG. 1 wherein the product carrier is a tray 20 formed from a material,
e.g., plastic. It will be appreciated that other materials suitable
for forming relatively thin, sturdy structures can be used to form
tray 20. Exemplary materials include, for example, conductive thermoplastic,
non-conductive and insulated plastic, antistatically coated PVC,
antistatically coated polysulfone (to provide protection from ESD
damage and to eliminate the potential for low leakage between component
leads), conductive carbon-filled polypropylene, and black dissipative
BPI-10 plastic. In certain embodiments, the carrier material can
withstand temperatures up to about 40.degree. C. to about 60.degree.
C., for example, temperatures of -125.degree. C. to 150.degree.
C. The material can also include a carbon-based material or be antistatically
coated to provide ESD protection.
 With continued reference to FIG. 1. desiccant particles
25 are embedded within tray 20. A preferred desiccant is montmorillonite
(bentonite) clay. Tray 20 includes a notched corner 25 a flat or
open bottom 27 two sets of opposing vertical sides 23a, 23b, and
an open top 29. Together, the flat bottom and two sets of opposing
vertical sides form a holding region in which a semiconductor device
may be placed. Multiple trays of product can be stacked for shipment
with an additional tray serving as a cover. All devices can be uniformly
oriented so pin one is aligned with the notched corner 25 of tray
 Though the embodiment depicted in FIG. 1 comprises a single
material, it should be emphasized that the product carrier of the
present invention may comprise one or more materials and/or may
comprise one or more layers of material. Further, the inventive
product carriers may comprise a recycled material, such as about
5% to 30% recycled materials In this exemplary embodiment, the product
carrier is a tray. However, given the guidance and objectives disclosed
herein, the particular product carrier, e.g., tube, tray, reel,
and jewel box, can be readily selected and optimized based on a
particular semiconductor device to achieve the goals of the present
 Moreover, one having ordinary skill in the art will appreciate
that the present invention is not limited to product carriers for
any particular IC package style. Rather, the product carriers of
the present invention may be configured to accommodate, for example,
Pin Grid Arrays (PGAs), ceramic flat packs, non-quad flat packs,
quad flat packs, and Dual-In-Line packages.
 In the embodiment illustrated in FIG. 1 the tray is configured
to accommodate multiple semiconductor devices. However, the inventive
product carrier may be configured to accommodate a single device
and/or product carriers may be configured to accommodate a plurality
of devices, each of which is already being held in a carrier.
 The inventive product carriers are uniformly sized, in compliance
with standard JEDEC outlines. The inventive product carriers are
also sized to ensure that there is no excessive movement of product
in the tube during shipping and handling. This protects the mechanical
integrity of the package and, if present, leads; it also ensures
an unimpaired dispensing of product for manufacturing operations.
 For shipment, a stack of trays, for example, six trays,
can be secured with straps; five containing parts and the sixth
serving as a cover. Bound trays may then be loaded into an antistatic
bubble pack bag, for extra cushioning protection, and then packed
in a tray box for shipment. Because a desiccant is incorporated
directly into the product carrier, it is unnecessary to include
separate desiccant packets in the packaging bag.
 FIG. 2 is a flow diagram illustrating the method for forming
a product carrier in accordance with an embodiment of the present
invention. Referring to FIG. 2 at step 200 desiccant particles,
such as montmorillonite (bentonite) clay, are mixed with molten
plastic. At step 210 the molten plastic with desiccant particles
mixed therein is molded into the product carrier, as with conventional
techniques. One of ordinary skill in the art will appreciate that
the amount of desiccant mixed with the molten plastic will be sufficient
to greatly reduce the presence of moisture in a dry pack bag (i.e.,
moisture barrier bag). For example, the amount of desiccant mixed
with the molten plastic can be optimized such that there are about
32 grams of clay to about 64 grams of clay per dry pack bag. Alternatively,
the amount of desiccant mixed with the molten plastic can be optimized
such that the environment in the bag is maintained at no greater
than 20 percent RH, thus protecting the devices during shipment
and storage for at least 12 months. If this 12-month shelf life
is exceeded, the devices need to be dry baked again only if the
RH in the bag has exceeded 30 percent, as evidenced by a humidity
 Upon determination that a product is moisture sensitive,
the product is dry packed for storage and shipment. This is done
regardless of the type of product carrier (e.g., tubes, trays, reels,
etc.). The first step in the dry pack process is to remove any moisture
buildup in the package by baking the finished product for 5 to 15.5
hours, depending on the package type, at 125.degree. C.+/-5.degree.
C. While baking, the product is contained in the product carriers
(provided the carrier is made of material that can withstand the
high temperature) or aluminum trays or tubes. Within 50 hours after
baking, the product is sealed in a dry pack bag under a partial
 An exemplary dry pack bag (i.e., moisture barrier bag) is
designed with three layers. The inner layer is a low-density polyethylene,
which has a static-dissipative coating. A second layer is 400 angstroms
aluminum metallized to 92-guage polyester. The third layer is 400
angstrom aluminum metallized to 92-guage polyester, which has a
static-dissipative coating. ESD protection is provided by the inner
layer of antistatic polyethylene and the second layer of aluminum
 The bag is sealed using an impulse heat sealer at a seal
time of about 1.0 to about 1.5 seconds; and a seal pressure of about
40 to about 50 psi; and a temperature range of about 191 to about
 Included in each dry pack bag is a card that has humidity
sensitive elements which turn from blue to pink whenever the specific
RH level is exceeded.
 Labels may also be applied to the outside of the dry pack
bag. For example, a standard product label, which identifies the
contents by manufacturing lot number, product part number, and the
product date code(s) and quantity per date code. Also, a dry pack
caution label, which identifies the date the bag was sealed, the
dry pack expiration date (which is 12 months later)), as well as
product handling guidelines. A small moisture-sensitivity caution
label may also be applied to the outside of the box in which the
dry packed parts are packed.
 Described has been an apparatus and method for manufacturing
an apparatus that is a carrier for semiconductor devices. An advantage
of the invention is that it can easily be implemented and is both
efficient and cost-effective in reducing the number of steps required
to package and ship a semiconductor device. Another advantage of
the invention is that it is readily fabricated and customized to
various semiconductor devices. In this disclosure, there is shown
and described only certain preferred embodiments of the invention,
but, as aforementioned, it is to be understood that the invention
is capable of use in various other combinations and environments
and is capable of changes or modifications within the scope of the
inventive concept as expressed herein.