U.S. patent application number 11/430710 was filed with the patent office on 2006-09-14 for protective shipper.
This patent application is currently assigned to Entegris, Inc.. Invention is credited to James Nigg, Michael Zabka.
Application Number | 20060201847 11/430710 |
Document ID | / |
Family ID | 26890006 |
Filed Date | 2006-09-14 |
United States Patent
Application |
20060201847 |
Kind Code |
A1 |
Zabka; Michael ; et
al. |
September 14, 2006 |
Protective shipper
Abstract
A protective shipper comprises a cover and a base that are held
together by a latching member. The base is configurable to retain
and protect semiconductor wafers or film frames with wafers within
a storage pocket. The base comprises latching member and a support
wall that defines a storage pocket. The cover encloses the storage
pocket. One or both of the cover may receive recesses for
gripability. The cover may receive one or more latching apertures
configured to minimize unintended unlatching. The shipper of the
present invention may be manufactured in a mold capable of
producing film frame or wafer containing configurations of the
shipper by using an interchangeable mold insert.
Inventors: |
Zabka; Michael; (Eagan,
MN) ; Nigg; James; (Howard Lake, MN) |
Correspondence
Address: |
Patterson, Thuente, Skaar & Christensen, P.A.;4800 IDS Center
80 South 8th Street
Minneapolis
MN
55402-2100
US
|
Assignee: |
Entegris, Inc.
|
Family ID: |
26890006 |
Appl. No.: |
11/430710 |
Filed: |
May 9, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10194438 |
Jul 12, 2002 |
7040487 |
|
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11430710 |
May 9, 2006 |
|
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60305422 |
Jul 14, 2001 |
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Current U.S.
Class: |
206/710 |
Current CPC
Class: |
H01L 21/67386 20130101;
H01L 21/67373 20130101; H01L 21/67353 20130101; H01L 21/67379
20130101 |
Class at
Publication: |
206/710 |
International
Class: |
B65D 85/30 20060101
B65D085/30 |
Claims
1. A carrier for semiconductor wafers comprising: a base having a
perimeter with at least one support wall extending upwardly inside
the perimeter and defining a storage pocket inside the at least one
support wall, the base including at least one resilient latching
member positioned between the perimeter and the support wall and
having an upright portion extending upwardly with a hook portion
having an engagement surface, the at least one latching member
having a depth dimension d.sub.1, a depth dimension d.sub.2, a
depth dimension d.sub.3 and a width dimension w.sub.1, wherein the
dimension d.sub.2 is equal to dimension d.sub.1 plus dimension
d.sub.3; and a cover having a periphery with at least one sidewall
extending downwardly inside the periphery, the cover being
disposable on the base to enclose the storage pocket, the cover
including structure defining at least one latching aperture
positioned between the periphery and the at least one sidewall and
corresponding to one of the at least one latching members, the at
least one aperture having a width dimension w.sub.2, a width
dimension w.sub.3, a depth dimension a.sub.1, a depth dimension
a.sub.2 and a depth dimension a.sub.3, wherein the dimension
w.sub.2 is greater than dimension w.sub.3, wherein dimension
w.sub.3 is greater than dimension w.sub.1, wherein dimension
a.sub.2 is greater than dimension d.sub.2, wherein dimension
d.sub.2 is greater than dimension a.sub.1, and wherein dimension
d.sub.3 is less than dimension a.sub.1.
2. The carrier of claim 1, wherein the latching aperture is
generally T-shaped.
3. The carrier of claim 1, wherein the storage pocket is configured
to retain film frames, with wafers adhered thereto, therein.
4. The carrier of claim 1, wherein the storage pocket is configured
to retain semiconductor wafers therein without film frames.
5. The carrier of claim 1, wherein the at least one support wall
comprises an outer perimeter and an inner perimeter, the inner
perimeter and outer perimeter defined by a pattern of two distinct
radii alternating in a repeating pattern.
6. The carrier of claim 5, wherein the base further comprises one
or more wafer support segments, the one or more wafer support
segments defining an inner pocket.
7. The carrier of claim 6, wherein the support wall has a saw-tooth
configuration.
8. The carrier of claim 1, wherein the cover further comprises one
or more apertures defined in the periphery and extending inwardly
of the perimeter of the base, the one or more apertures aiding in
grasping of the carrier when stacked vertically upon an adjacent
carrier.
9. The carrier of claim 1, wherein the perimeter of the base
comprises four sides, and wherein a tab is disposed at a midpoint
of one or more of the four sides, the tabs for receiving
identification information.
10. A shipper for semiconductor wafers, the shipper comprising: a
base having a perimeter with at least one support wall extending
upwardly inside the perimeter and defining a storage pocket inside
the at least one support wall, the base including at least one
resilient latching member positioned between the perimeter and the
support wall and having an upright portion extending upwardly with
a hook portion having an engagement surface, the at least one
support wall comprising an outer perimeter and an inner perimeter,
the inner perimeter and outer perimeter defined by a pattern of two
distinct radii alternating in a repeating pattern; and a cover
having a periphery with at least one sidewall extending downwardly
inside the periphery, the cover being disposable on the base to
enclose the storage pocket, the cover including structure defining
at least one latching aperture positioned between the periphery and
the at least one sidewall and corresponding to one of the at least
one latching members.
11. The shipper of claim of claim 10, wherein, the cover further
comprises a latching aperture, the latching aperture defining a
first engagement width and a second engagement width, the first
engagement width being larger than the second engagement width.
12. The shipper of claim 10, wherein the at least one support wall
has a saw-tooth configuration.
13. A carrier for semiconductor wafers, the carrier comprising: a
base having a perimeter with at least one support wall extending
upwardly inside the perimeter and defining a storage pocket inside
the at least one support wall, the base including at least one
resilient latching member positioned between the perimeter and the
support wall and having an upright portion extending upwardly with
a hook portion having an engagement surface, the at least one
support wall comprising an outer perimeter and an inner perimeter,
the inner perimeter and outer perimeter defined by a pattern of two
distinct radii alternating in a repeating pattern; and a cover
having a periphery with at least one sidewall extending downwardly
inside the periphery, the cover being disposable on the base to
enclose the storage pocket, the cover including structure defining
at least one latching aperture positioned between the periphery and
the at least one sidewall and corresponding to one of the at least
one latching members, the cover including one or more apertures
defined in the periphery and extending inwardly of the perimeter of
the base, the one or more apertures aiding in grasping of the
carrier when stacked vertically upon an adjacent carrier.
14. The carrier of claim 13, wherein the at least one latching
member has a depth dimension d.sub.1, a depth dimension d.sub.2, a
depth dimension d.sub.3 and a width dimension w.sub.1, wherein the
dimension d.sub.2 is equal to dimension d.sub.1 plus dimension
d.sub.3, and the at least one aperture has a width dimension
w.sub.2, a width dimension w.sub.3, a depth dimension a.sub.1, a
depth dimension a.sub.2 and a depth dimension a.sub.3, wherein the
dimension w.sub.2 is greater than dimension w.sub.3, wherein
dimension w.sub.3 is greater than dimension w.sub.1, wherein
dimension a.sub.2 is greater than dimension d.sub.2, wherein
dimension d.sub.2 is greater than dimension a.sub.1, and wherein
dimension d.sub.3 is less than dimension a.sub.1.
15. A method for minimizing unintended unlatching of a wafer
carrier cover from a base containing a plurality of wafers in a
storage pocket, the method comprising the steps of: generally
aligning one or more latching members with a respective latching
aperture; abutting a cam surface of the latching member against the
respective latching apertures; urging an engaging portion of each
of the latching member through the respective latching aperture at
a portion of the aperture having a first width so that at least a
portion of the latching member passes through a second smaller
width; and contacting the cover to the base, thereby completing a
latching operation.
16. A method of manufacturing a film frame carrier in a mold
configured to manufacture a wafer carrier, the method comprising
the steps of: placing one or more blanks in a mold cavity of a
mold, the mold cavity including inner recesses for forming inner
walls and outer recesses for forming outer walls, the blanks placed
in the inner recesses; and injecting a hot molten plastic into the
mold cavity to form the film frame carrier, whereby the film frame
carrier may be molded in the same mold as the wafer carrier.
17. The carrier of claim 19, wherein the base further comprises one
or more wafer support segments for defining an inner pocket.
18. A carrier for semiconductor wafers comprising: a base having a
perimeter with means for defining a storage pocket and including at
least one resilient latching member positioned between the
perimeter and the means for defining a storage pocket; and a cover
having a periphery with at least one sidewall extending downwardly
inside the periphery, the cover being disposable on the base to
enclose the means for defining a storage pocket, the cover
including means for engaging the at least one latching member.
19. A carrier for semiconductor wafers comprising: a base having a
perimeter with means for defining a storage pocket and including at
least one resilient latching member positioned between the
perimeter and the means for defining a storage pocket; and a cover
having a periphery with at least one sidewall extending downwardly
inside the periphery, the cover being disposable on the base to
enclose the means for defining a storage pocket, the cover
including means for grasping an adjacent base of an adjacent
carrier stacked vertically upon the cover.
20. The carrier of claim 19, wherein the cover further comprises
means for engaging the at least one latching member.
Description
REFERENCES TO RELATED APPLICATIONS
[0001] This application is based upon U.S. Provisional Application
Ser. No. 60/305,422, which is hereby incorporated by reference
herein.
FIELD OF THE INVENTION
[0002] This invention relates to carriers for semiconductor wafers
and film frames, and more particularly relates to shippers for
same.
BACKGROUND OF THE INVENTION
[0003] Integrated circuits are manufactured from semiconductor
wafers that are conventionally round in shape and made of highly
brittle silicon. Such wafers are subjected to a variety of
processing steps in transforming the semiconductor wafer into
integrated circuit components. The various processing steps must be
performed under ultra-clean conditions to minimize the potential of
contamination of the wafers as they are being processed. Each wafer
may be subjected to dozens, if not hundreds of steps in its
processing cycle. The potential for contamination and destruction
of a wafer or reduction in yield is ever-present throughout the
various processing and packaging steps. Particularly during the
steps that take place at fabrication facilities, any minute
particulates can destroy the integrated circuit on which it falls.
Once the processing steps of the wafers are completed, they are
generally shipped while still in wafer form to a facility that will
dice and encapsulate, in integrated circuit packaging, each
individual circuit on the wafer.
[0004] The stringent particulate control that takes place during
the processing steps is generally not necessary in shipping the
completed wafers to the facility that dices and packages the
individual circuits.
[0005] Traditionally, during the processing, storage and shipping
of semiconductor wafers, the wafers are supported and constrained
at their edges to prevent any contact, possible damage and
contamination to the faces of the wafers having the circuits
thereon.
[0006] Even as semiconductor wafers are getting larger in scale,
now up to 300 millimeters in diameter, the density of components is
getting significantly greater. Moreover, disks are also are getting
thinner, providing much thinner completed integrated circuit
packages. This has been driven, at least in part, by the cellular
phone industry that has sought thinner cell phones.
[0007] Accompanying the trend towards larger, more dense and
thinner wafers, the wafers are becoming more valuable, more brittle
and more easily damaged during shipment. Although it is possible,
desirable, and common to ship thicker wafers in enclosed containers
that would support the wafers exclusively by their edges, using
such devices to ship the thinner wafers has proven problematic due
to breakage and damage of the wafers.
[0008] Thus, for the thinner more fragile wafers, enclosures are
utilized which have the wafers axially stacked on top of one
another and separated by layers of paper-like flexible sheet
material. Thus, the support of each wafer is by adjacent wafers and
the entire stack of wafers. Foam material, such as urethane, is
used to cushion the top and bottom of the stack.
[0009] Such shippers can also be configured to receive film frames.
The film frames are packaged similar to the wafers and protected
during transport.
[0010] One type of prior art wafer carrier is disclosed in U.S.
Pat. No. 5,553,711 to Lin. Lin discloses a container that has a
base, upright sidewalls defining a circular pocket, wafer dividers
and a cover that comes down and threadingly attaches to the
base.
[0011] FIG. 1 discloses a conventional wafer carrier in which the
enclosure is defined by a cookie tin-like plastic container having
a bottom 50, a top lid 52, and utilizing a circular urethane foam
bottom cushion 54, and sheet material 56 interspersed between the
wafer 58.
[0012] Referring to FIGS. 2 and 3, another wafer shipper is
disclosed for shipping the stacked wafers with dividers
therebetween. This wafer shipper has a base 60 and a top cover 62.
The base and top cover are injection molded and have circular
shaped and axially-extending structural members 64 in the base
component. Similarly, the top cover has axially-extending circular
structural members 64 and radially extending ribs 66 that also
project axially.
[0013] These stacking wafer shippers may be either manually
handled, robotically handled or both. Thus, means for opening and
closing such containers must be both manually and robotically
operable, and for manual purposes should be intuitive as well as
simple, and reliable and quick. Various means are known for
latching such wafer shippers. These include threads, such as shown
in prior art FIG. 1, or a snap-on seal as shown in prior art FIGS.
2-3. Other means for latching are a minimal rotation thread as
shown in the embodiment of prior art FIG. 4, and axially-projecting
spring latches as discussed hereinbelow.
[0014] Wafer shippers that use the threaded engagements are awkward
and subject to misalignment and improper attachment. These wafer
shippers visually appear symmetrical in at least two planes, and
therefore, there are typically four different options in assembling
a top cover to a bottom cover. However, conventional prior art
shippers generally require that the top cover be assembled in a
specific orientation for proper latching.
[0015] U.S. Pat. No. 6,193,068 to Lewis, et al., discloses another
type of conventional shipper featuring axially-extending spring
latches and utilizing a double wall to define the pocket for the
stack of wafer carriers. Said double wall thickness is defined by
two spaced thin wall sections which are not attached to one another
extending from the base. This configuration appears to allow the
individual unsupported thin walls supported only at the base to
take on and retain deformation. The concentric arrangement of the
thin walls makes any such deformation visibly apparent. The double
sidewall in this prior art embodiment may help to isolate direct
impact on the top cover from direct communication from top cover
structure to the wall defining the wafer pocket.
[0016] In the minimal rotation latch embodiment shown in FIG. 4,
any separation stress will occur as illustrated by gap G. Such
loading of the wafer shipper also can cause the deformation of the
otherwise planar corners of the base to be stressed out of
position, causing wobbling when placed on a planar surface and
error in seating when placed on a machine interface. Such
deformation can be caused in part by an overloading condition and
also in part by the structural configuration of the wafer
shipper.
[0017] It would be desirable to provide sufficient structure in the
base of such wafer shipper to prevent such distortion and bowing.
Moreover, it would be highly desirable to provide a wafer carrier
that has indicating means therein to prevent such an overloaded
condition.
[0018] Other minimal rotation latched shippers may use stunted
threads that allow the wafer carrier to be rotated less than
30.degree. to accomplish the latching. Such wafer carrier has the
difficultly of requiring relatively precise angular positioning for
initial placement of the top cover on the base before said
rotation.
[0019] Other embodiments may use axially-projecting double thin
walls. Such embodiments provide double sidewalls are connected at
the ends of each segment. Thus, four separate wall portions are
defined, all of which are distinct from one another and integral
with the base. Due to the connecting portions, which connect each
of the pairs of thin sidewall segments, a direct impact blow on the
top cover will transmit the force of such blow directly from the
top cover through said connecting portions to the wafers. This top
cover also has features configured as nubs, which may engage a
floppy disk.
[0020] Generally, all embodiments of the wafer carriers herein will
be injection molded of thermoplastic material such as
polypropylene. Such material requires structure such as ribs and
channels for rigidity.
[0021] In that these shippers do not have the severe particulate
control issues that are necessary for carriers in the fab
processing environment, it is not necessary to have hermetic
sealing. In fact, such hermetic sealing is inimical to robotic
handling and easy manual handling, specifically the opening and
closing of the shippers. Still, it is important to have the
interface between the top cover and the base to provide the best
sealing characteristics possible. Moreover, it is important to
eliminate or reduce any bowing that occurs along one of the
sidewalls intermediate the corners of the top cover or the
base.
[0022] These types of containers may be utilized once and thrown
away, or may be recycled and utilized multiple times. Although the
product shipped in such containers can be of immense value, it is
still important to reduce the manufacturing cost of the shippers to
as great as extent as possible, consistent with the other necessary
characteristics.
[0023] A most important characteristic of such wafer shippers for
stackable wafers is that the shippers provide protection from
damage due to shock during the transportation. This shock may
consist of direct impact with the shipper's top cover or base, or
consist of jarring of the entire shipper package. In either case,
it is important to provide protection from damage to the wafers
packed therein.
[0024] Moreover, it is important that such wafer shippers provide
latching means of high integrity that do not inadvertently open
during shipment or handling; for example, when a shipper is
inadvertently dropped.
[0025] Such shippers are typically drop tested to determine the
overall integrity of the shipper. Upon such dropping, unlatching,
breakage of the shipper or damage to the wafers constitutes a
failure. The impact during dropping, including drop testing,
creates shear, compressive and torsional forces on the shipper
components. The shipper, including the latches, must withstand
combinations of these forces when loaded.
[0026] These shippers rely heavily upon the separation of materials
between wafers or frames, which may be polyethylene sheet material
with carbon providing a static dissipative characteristic,
polyurethane foam, or other suitable, flexible thin sheet material.
Typically, the packing material placed on the bottom and top of the
stack will be the polyurethane foam that is compressible. The
compressibility of the foam facilitates packing a variable number
of wafers in a particular shipper, which can leave some undesirable
discretion to the packer as to how many wafers and/or how much
padding material is appropriate for a particular shipper. Moreover,
inserting excessive, or even a full load, of wafers and foam
padding can, in prior art wafer shippers, particularly those with
latches on the diagonal corners, cause distortion and/or bowing of
the top cover and/or base. This bowing may actually cause a gap
between the top cover and base. Such a gap is visually undesirable,
may provide a pathway to contamination of the contents, and may
further affect the integrity of the container during impact or
shock, causing breakage or unlatching.
[0027] If the shipper is underpacked with foam or other packing
material, breakage may occur at limits under normal impact limits.
Known prior art wafer carriers have provided no ready assistance in
identifying an appropriate range of foam and wafer stacked
thickness, which is optimal for providing security to the wafers.
Similarly, the stacked wafer shippers with the latches on the
diagonally opposite corners have provided no means to minimize the
visibility of the gap at the sides of the shipper when the shipper
is fully loaded or slightly overloaded. Moreover, these prior art
shippers have inadequately provided structural means to the base
and top cover to provide rigidity and minimize said bowing and gaps
at the interface.
SUMMARY OF THE INVENTION
[0028] A protective shipper comprises a cover and a base that are
held together by a latching member. The base is configurable to
retain and protect semiconductor wafers or film frames with wafers
within a storage pocket. The base comprises a latching member and a
support wall that defines a storage pocket. The cover encloses the
storage pocket. One or both of the cover may receive recesses for
gripability. The cover may receive one or more latching apertures
having a first engagement width and a second engagement width, the
first engagement width being larger than the second engagement
width. The shipper of the present invention may be manufactured in
a mold capable of producing film frame, wafer containing or
combination configurations of the shipper by using an
interchangeable mold insert.
[0029] A feature and advantage of particular embodiments of the
invention is to improve the handling and stacking of shippers by
providing recessed portions therein.
[0030] A further feature and advantage of particular embodiments of
the invention is that the shipper is less likely to release when
shock is introduced because the latches require a horizontal
component of movement within the substantially T-shaped aperture to
release.
[0031] A further feature and advantage of particular embodiments of
the invention is that the shipper can be configured to retain film
frames, semiconductor wafers or a combination thereof.
[0032] A further feature and advantage of particular embodiments of
the invention is that the shipper can be produced according to film
frame, wafer stack or combination configurations on the same
machinery.
[0033] A further feature and advantage of particular embodiments of
the present invention is to overcome disadvantages present in the
prior art.
[0034] Further features and advantages of particular embodiments of
the invention will become apparent to those skilled in the art
through the descriptions, claims and the figures herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 is a perspective view of a prior art wafer carrier
for carrying a stack of wafers.
[0036] FIG. 2 is a perspective view of a base of a prior art wafer
carrier.
[0037] FIG. 3 is a perspective view of a top cover of a prior art
wafer carrier.
[0038] FIG. 4 is a perspective view of a prior art wafer carrier
illustrating bowing stability issues.
[0039] FIG. 5 is a perspective view of the portions of two shippers
in stacking alignment according to an embodiment of the present
invention.
[0040] FIG. 6 is a perspective view of the base of a wafer shipper
according to an embodiment of the present invention.
[0041] FIG. 7A is a partial plan view of the film frame support
wall according to an embodiment of the present invention.
[0042] FIG. 7B is a partial plan view of the film frame support
wall according to an embodiment of the present invention.
[0043] FIG. 7C is a partial plan view of the film frame support
wall according to an embodiment of the present invention.
[0044] FIG. 7D is a partial plan view of the film frame support
wall according to an embodiment of the present invention.
[0045] FIG. 7E is a partial plan view of the film frame support
wall according to an embodiment of the present invention.
[0046] FIG. 7F is a partial plan view of the film frame support
wall according to an embodiment of the present invention.
[0047] FIG. 7G is a partial plan view of the film frame support
wall according to an embodiment of the present invention.
[0048] FIG. 8 is a plan view of the inside of the top of a cover
for a shipper according to an embodiment of the present
invention.
[0049] FIG. 9 is a side view of a cover for a shipper according to
an embodiment of the present invention.
[0050] FIG. 10 is a plan view of the outside top of a cover for a
shipper according to an embodiment of the present invention.
[0051] FIG. 11 is a side view of a cover for a shipper according to
an embodiment of the present invention.
[0052] FIG. 12 is a perspective edge view of a cover for a shipper
according to an embodiment of the present invention.
[0053] FIG. 13 is a top plan view of a base for a shipper according
to an embodiment of the present invention.
[0054] FIG. 14 is a side view of a base for a shipper according to
an embodiment of the present invention.
[0055] FIG. 15 is a bottom view of a base for a shipper according
to an embodiment of the present invention.
[0056] FIG. 16 is a side view of a base for a shipper according to
an embodiment of the present invention.
[0057] FIG. 17 is a perspective edge view of a base for a shipper
according to an embodiment of the present invention.
[0058] FIG. 18 is a diagram of a latching mechanism before
introduction of an impact force.
[0059] FIG. 19 is a diagram of a shipper in shearing movement.
[0060] FIG. 20 is a diagram of the latching mechanism of FIG. 43
after the shear movement.
[0061] FIG. 21 is a perspective view of a recess according to an
embodiment of the present invention.
[0062] FIG. 22 is a perspective view of a convertible mold with
inserts for converting the mold according to an embodiment of the
present invention.
[0063] FIG. 23 is a perspective view of the latching member of the
base according to an embodiment of the present invention.
[0064] FIG. 24 is a diagram of the latching member engaging the
latching aperture according to an embodiment of the present
invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0065] Copending U.S. application Ser. No. 09/851,499, filed on May
8, 2001, hereby incorporated by reference, discloses a shock
resistant variable load tolerant wafer shipper. Such wafer shipper
uses axially projecting spring latches to secure said shipper in
the closed position.
[0066] Referring to FIGS. 5-6, a shipper for protecting
semiconductor wafers or film frames according to embodiments of the
present invention is shown. The shipper 100 generally comprises two
cooperating portions, configured as a base 102 and a top cover 104.
The top cover 104 and base 102 meet at an interface 106 and are
secured by latch mechanisms 108.
[0067] The base 102 has a plurality of arcuate lateral wafer
support segments 110, which extend from a planar portion 114 of the
base and define the wafer stack pocket 112. A floor 116 is
positioned at the bottom of the pocket 112. The planar portion 114
constitutes a seat and bearing surface for the top cover edge. A
side wall 120 extends around the periphery 170 of the base. Nominal
wall structures 122 in the pocket floor 116 provide structural
rigidity to the base 102.
[0068] The planar surface 114, which constitutes a bearing surface
for the top cover edge, extends around the lateral wafer support
segments 110. Extending upwardly from the planar surface 114 is a
protruding structure configured as a shoulder 128. The shoulder 128
includes an upright surface 130, which operates as an outer
constraint to the top cover 104, primarily during impact or other
stressing.
[0069] Extending from two of the four corners of the base 102 are
latching members 132. Latching members 132 include a hook portion
134 with a cam surface 136 and an engagement surface 138. The cam
surface 136 deflects the latching member 132 when the top cover 104
is lowered into the latching position and snaps into place with the
surface 138 engaged with top surface of the top cover 104.
Significantly, the latching arm 132 has a horizontal extending
section 142 and a curved portion 144 extending into an elongated
upright portion 146. The horizontal portion 142 reduces the spring
constant of the latching member 132 in the vertical direction by
allowing up and down flex of said member 132. This compares to
conventional wafer carriers with latches that do not include said
horizontal member that have a spring constant in the vertical
direction that equates to the spring constant of the material and
any flex in the base where it is attached. This horizontal portion
effectively extends the positions where the top cover 102 may be
fixed in position. Moreover, it softens the downward pull of the
top cover toward the base, which allows greater shock absorption
during impact, such as dropping of the shipper. Said shock
absorption can prevent further damage to the wafers and prevent
damage to the shipper that would otherwise occur.
[0070] Referring to FIGS. 5, and 8-12, top cover 104 is depicted.
The significant features include a nominal wall 140 that comprises
the vast majority of said top cover, including various stiffening
structure 174. The nominal wall may be configured to provide a
pocket 176 for a 31/2 inch diskette or a CD case. The top cover has
a periphery 177 that includes an upwardly-extending lip 178 that
follows the periphery. Said lip 178 adds to the structural rigidity
and provides a stacking means.
[0071] Four planar sidewalls 175 extend downwardly from the upper
lip 178 and, along with inset corner portions 173, define a wafer
enclosure. The wafer enclosure perimeter 179 is generally square in
shape. At each corner 173 is a flange portion 171 with apertures
148 to receive the latch member 132. Top cover 104, in conjunction
with the sidewalls 175, provide a top cover 104 that is highly
rigid, even when formed with such soft plastics as
polypropylene.
[0072] The latching apertures 148 in cover 104 are formed in an
approximate T-shape. This shape comprises a first width or head 150
and a second narrower width or neck 152. The neck 152 is slightly
greater in width than the width of the latching member 132 where it
extends through the neck. The head 150 has a width greater than the
neck 152. The latching member 132 engages the head 150 of the
aperture 148 and is moved into the neck region 152 due to the
movement of cam surface 136 along the underside of the cover 104
corner portion 173 during the latching process.
[0073] Referring to FIGS. 23 and 24, the movement of latching
member 132 within the latching aperture 148 is illustrated. The
latching aperture has a depth dimensions d.sub.1, d.sub.2 and
d.sub.3 as shown. Dimension d.sub.2 is equal to d.sub.1 plus
d.sub.3. Dimension d.sub.3 is the depth of the engagement surface
138. Dimension d.sub.1 is the depth of the upright portion 146 of
the latching member 132. The latching member also defines a width
dimension w.sub.1. It should be appreciated that the dimensions of
portions of the latching member may vary when measured at different
points, due to tapering or irregular shape. Therefore, the
dimensions will be described with reference to a maximum value
taken at horizontal plane taken at the height of the engagement
surface 138.
[0074] The latching aperture 148 defines a head 150 having a depth
dimension a.sub.1 and a neck 152 having a depth dimension a.sub.3.
Dimension a.sub.2 is the sum of a.sub.1 plus a.sub.3. The head
defines a width w.sub.2 and the neck 152 defines a width w.sub.3.
Again, these dimensions are defined as maximum values. Dimension
w.sub.2 is greater than w.sub.3 and w.sub.3 is greater than w.sub.1
(w.sub.2>w.sub.3>w.sub.1). Moreover, a.sub.2 is greater than
d.sub.2, which is greater than a1 (a.sub.2>d.sub.2>a.sub.1).
Dimension d.sub.3 is also less than a.sub.1 (d.sub.3<a.sub.1)
and d.sub.2 is greater than d.sub.3 (d.sub.2>d.sub.3).
[0075] Referring to FIGS. 18, 19 and 20, an advantage of the
approximately T-shaped aperture 148 is illustrated. FIG. 18 shows
the latching member 132 in the engaged or latched position.
Latching member 132 must receive a purely perpendicular force L to
urge said member 132 into the neck region 152 to complete the
unlatching process. A force with any non-perpendicular component,
such as that received due to a drop or other strike, will not
unlatch the cover 104.
[0076] In FIG. 18, force F is introduced to the shipper. Force F
has both a lateral component and a perpendicular component with
respect to member 132. FIG. 19 illustrates how force F causes base
102 to shear in direction M1 with respect to cover 104, which moves
relatively in direction M2. Such relative movements of the cover
104 and base 102 cause latching member 132 to move in direction S,
as shown in FIG. 18. By moving to the position shown in FIG. 20,
the member 132 cannot move in perpendicular direction L so as to
unlatch the shipper 100. By preventing the shipper 100 from
unintentionally unlatching, the protection of the shipper contents
is enhanced.
[0077] A further feature of particular embodiments of the invention
is shown in the differences between FIG. 5 and FIG. 6. The shipper
100 may be configured to contain either film frames as shown in
FIG. 5, or semiconductor wafers as shown in FIG. 6, or a
combination thereof. In wafer shipping configuration, the base 102
of shipper 100 is provided with a wafer support wall 120 that
defines an inner pocket 154 and an outer region 156. The support
wall 120 in the preferred embodiment is a continuous ring having a
diameter only slightly greater than the diameter of the wafers
carried therein.
[0078] In film frame configuration, the base of shipper 100 is
provided with a frame support wall 158 that defines an inner frame
pocket 160 and outside region 162. The frame support wall 158
preferably forms an undulating surface that alternates between
forming an inner circumference 164 and outer circumference 166, as
shown in FIGS. 5 and 6. Other configurations of frame support walls
may be used without departing from the scope of the present
invention.
[0079] FIGS. 7A-7G show some of the potential alternative wall 160
configurations contemplated by the present invention. As
illustrated in FIGS. 7B, 7C and 7E, the support wall 158 comprises
an inner perimeter 165 and outer perimeter 167. Inner perimeter 165
has a radius r.sub.1 from a center point 194 of the base 102. Outer
perimeter 167 has a radius r.sub.2 from the center point 194.
Dimension r.sub.2 is greater than r.sub.1. The radius dimensions
r.sub.2 and r.sub.1 are varied in a repeating pattern to define the
respective outer 165 and inner 167 perimeters.
[0080] A further feature of particular embodiments of the present
invention is shown in FIGS. 8-17 and 21. The cover 104 is provided
with a plurality of recesses 168 about the perimeter 170. The
recesses 168 are disposed preferably at the approximate midpoint of
each side about the perimeter 170 of the cover 104. However, other
configurations of greater or fewer recesses and at other positions
are within the scope of the present invention. The base 102 may
also be recessed, as shown in FIGS. 16-21, in addition to, or
instead of, the recesses in the cover 104. The recesses 168 enable
the carriers 100 to be more easily grasped by either humans or
mechanical devices when vertically stacked with one or more
respective shippers 100.
[0081] The top surface of a first shipper is further configured to
cooperate with the bottom surface of a second carrier so that the
combination of stacked carriers resists shearing movement. FIG. 21
shows base 102 of a first carrier in alignment with a cover 102 of
a second carrier. Clearance is created by a recess 168 between the
bottom of base 102 of a first shipper and the top of cover 104 of a
second shipper in stacked configuration. The recess 168 is formed
by an aperture 169 formed in the cover 104 along the periphery
thereof. The aperture extends inwardly of at least a portion of the
perimeter 179 of the base 102. A second aperture 196 may also be
formed in the perimeter of the base 102.
[0082] A further feature of particular embodiments of the present
invention is shown in FIGS. 5, 6, 16 and 21. Tab 172 is provided on
one or more sides of base 102. Tab 172 may be used for mounting an
identification and/or information means, such as a bar code label,
on shipper 100. Additionally, the tab, when aligned with recess
168, serves as a guard for preventing forces from being introduced
to the cover 104 of a shipper 100 when the base 102 of said shipper
100 is grasped at recess 168.
[0083] A further aspect of the present invention is the method for
manufacturing a shipper wherein the mold is easily adapted to
produce shippers for both wafers and film frames. Referring to FIG.
22, a mold 180 is shown with a lower portion 184 and an upper
portion 182 that cooperate to form a mold cavity 186. Such a mold
180 is shown for molding the base portion having a mold cavity 186,
including a first set of slots 192 or recesses, which are for
forming the frame support wall, and a second set of slots 188 or
recesses, which are for forming the wafer support wall. Plugs or
blanks 190 sized to fill or cover the second set of slots 188 is
utilized for converting from, for example, a wafer shipper to a
film frame shipper. The methodology of accomplishing comprises
insertion of the blanks into the slots and performing the molding
operation.
[0084] Although the present invention has been described with
reference to preferred embodiments, workers skilled in the art will
recognize changes may be made in form and detail without departing
from the spirit and scope of the invention.
* * * * *