WO2012058678A2

WO2012058678A2 - Substrate shipper

Info

Publication number: WO2012058678A2
Application number: PCT/US2011/058622
Authority: WO
Inventors: Gary Gallagher; John Burns; Mark V. Smith; Paul Rosenfeld; Eric S. Olson; Russ V. Raschke
Original assignee: Entegris Inc
Current assignee: Entegris Inc
Priority date: 2010-10-29
Filing date: 2011-10-31
Publication date: 2012-05-03
Anticipated expiration: 2013-04-29
Also published as: WO2012058678A3; TW201233602A

Abstract

A substrate shipping container suitable for shipping solar cells, substrate wafers, or other suitable media. In some embodiments, the readily constructed container is made up of two identical container portions, each container portion having a horizontally-disposed base member and two adjacent vertically-disposed side members constructed of impact- absorbing double walls. The two container portions are shaped to be coupled using integrally formed tabs and slots located about the perimeter of the container portions. The horizontally-disposed base member of each container portion is equipped with a matrix of integrally formed pads. These pads serve as cushions to provide shock absorption in the vertical (i.e. "z") direction to substrates that are stacked between these members. Embodiments may further be comprised of molded pulp or bulrush fibers.

Description

SUBSTRATE SHIPPER

PRIORITY CLAIM

This application claims priority to U.S. Provisional Application No. 61/41 1,473, filed November 8, 2010 and to U.S. Provisional Application No. 61/408,448 filed October 29, 2010, and incorporates both herein by reference.

This application is also related to PCT application no. PCT/US2011/058615 filed on October 31 , 201 1, which claims priority to U.S. Provisional Application No. 61,408,448 filed October 29, 2010. Said application is incorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to a substrate shipping device. More particularly, the present invention relates to a multiple piece container for packaging substrates such as solar cell wafers.

BACKGROUND OF THE INVENTION

Solar cells are manufactured from substrates and accordingly are fragile, requiring significant protection and care when being transferred from one location to another. Containers and packaging for such devices need to be well suited for the task. Clean and largely contamination free environments during their transport and in between manufacturing process steps are important. Additional required or desirable characteristics of containers to transport and/or store substrates like solar cells include light weight, rigidity, cleanliness, and cost effective manufacturability. Such containers need to keep the wafers clean, uncontaminated, and undamaged. Improvements to these shipping containers are desired.

Wafers and cells require protection before, during, and after shipping. To enhance the protection of these items it is desirable to reduce the number of transfers these wafers and cells make. It is further advisable to reduce the number of carriers that are required to be managed and to reduce any cell damage that might occur during the transfer or handling process. Also, a container or packaging providing cost reduction is desired.

A further desire is for waste and scrap costs to be reduced and to minimize the environmental impact of the shipping materials. The industry further is realizing a need for low cost, super green, high volume, just-in-time, high density with solid cushioning performance to protect cells during shipment. Solar cell shipping volumes call for environmentally responsible, sustainable packaging solutions. Limiting the use of restricted materials ozone-depleting substances is desired. Accordingly, it is desirable to move away from using materials such as plastics or foam which can be harmful to the environment. Further it is desirable to maximize the use of post-consumer recycled content when possible.

SUMMARY OF THE INVENTION

The invention generally comprises a multiple piece substrate shipping container suitable for shipping solar cells, substrate wafers, or other media. In some embodiments, the readily constructed container is generally made up of two identical container portions, each container portion having a horizontally-disposed base member equipped with cushioning pads and two adjacent, vertically-disposed side members constructed of impact-absorbing double walls. The two container portions are shaped to be readily coupled with one another using integrally formed tabs and slots located about the perimeter of the container portions. The container portions are adapted to couple with one another when the container portions are placed in reversed and inverted orientations with respect to one another. The horizontally-disposed base member of each container portion is equipped with a matrix of integrally formed pads. These pads serve as cushions to provide shock absorption in the vertical (i.e. "z") direction to substrates that are stacked on and beneath these members.

The container portions are suitably formed of pulp materials such as bulrush or other organic materials, also the containers may be formed of polymers.

In an embodiment of the invention, first and second container portions may each have edge and groove features located about their perimeters that partially cooperate and engage with each other.

In an embodiment of the invention, the two piece container is adapted for shipping solar cells and is made of molded pulp.

In an embodiment of the invention, the two piece container is adapted for shipping solar cells and is made of bulrush fiber.

In an embodiment of the invention the container is formed by an injection molding process from polymers. In an embodiment the container is made from molded pulp. In an embodiment the container is formed from polymer sheets by vacuum molding. In an embodiment of the invention, the impact absorbing double walls of the side members have an outer wall to absorb impacts and an inner wall to prevent flexing against substrates in the interior of the container.

In an embodiment of the invention, the base of the container is equipped with a matrix of spaced-apart shock absorbing cushions to absorb shocks in the vertical direction. These cushions may be equipped with access holes for allowing easy cell removal assistance of the packaging.

DESCRIPTION OF THE DRAWINGS

Figure 1 is an exploded view of a substrate shipping container according to an embodiment of the invention.

Figure 2 is an exploded view of a substrate shipping container and media for shipping according to an embodiment of the invention.

Figure 3 is a perspective view of a closed substrate shipping container according to an embodiment of the invention.

Figure 4 is a top view of one container portion of a substrate shipping container according to an embodiment of the invention herein.

Figure 4A is a cross-sectional view of the container portion of the substrate shipping container in Figure 4 along line A-A according to an embodiment of the invention herein.

Figure 5 is a top view of an assembled substrate shipping container according to an embodiment of the invention herein.

Figure 5A is a cross-sectional view of the substrate shipping container of Figure 5 along line A-A according to an embodiment of the invention herein.

Figure 6 is a perspective view of a closed substrate shipping container that has been shrink wrapped with a corrugated pad on top and bottom according to the invention herein.

Figure 7A is a perspective view of a dampening spacer design for use in connection with the substrate shipping container according to an embodiment of the invention. Figure 7B is a perspective view of an alternative dampening spacer design for use in connection with the substrate shipping container according to an embodiment of the invention.

Figures 8A-D are perspective views of the packaging process for assembling a pallet of substrate shipping containers according to an embodiment of the invention herein.

Figure 9 is an exploded view of a substrate shipping container according to an embodiment of the invention.

Figure 10 is an exploded view of a substrate shipping container and media according to an embodiment of the invention.

Figure 1 1 is a perspective view of a closed substrate shipping container according to an embodiment of the invention.

Figure 12 is an exploded view of an alternative substrate shipping container and media for shipping according to an embodiment of the invention.

Figure 13 is a cross-sectional view of the closed substrate shipping container of Figure 12 according to an embodiment of the invention.

Figure 14 is a cross-sectional view of one portion of a substrate shipping container of Figure 12 according to an embodiment of the invention.

Figure 14A is a close up view of Section A of Figure 14.

Figure 15 is an example of the packaging for substrate shipping containers of Figure 12 according to an embodiment of the invention.

Figure 16 is an exploded perspective view of an embodiment.

DETAILED DESCRIPTION

Referring to Figures 1-6, embodiments of a substrate shipping container 20 are illustrated. The shipping container 20 generally comprises two portions 22, namely, a first container portion 22A and a generally identical second container portion 22B. Each container portion 22 has a base 24 and a pair of side walls 26 and 28. The container portions 22 are preferably made of a molded pulp, molded bulrush fiber or polypropylene material. Polypropylene materials, other plastics, bulrush and molded pulp materials are believed to be suitable materials to sensitive shipping applications. The base 24 is generally horizontally-disposed and serves as the bottom or top of the container shipping container. Various media 30, including square or pseudo square wafers or substrates, such as solar cells, may be horizontally stacked in a coin stacked disposition on the base 24. The surface of the base 24 is generally a horizontal plane, however, it is molded to include a matrix of pads 32 for cushion control in the vertical (i.e. "z") direction. The pads 32 provide uniform projections into the interior side of the container having flat projected surfaces 31 for contacting substrates or other packaged media 30. Accordingly, opposite each of the interior pad projections in the base 24 are recesses 33. These recesses 33 form a uniform pattern of depressions along top and bottom surfaces of a closed container. Surrounding the base 24 is an integrally formed shallow locking groove 34. This groove 34 extends along the two sides of the container portion 22 which do not contain side walls. At the base of the locking groove 34 are a plurality of spaced apart slots 35. These slots 35 are sized for coupled engagement with tab features in the corresponding oppositely-disposed container portion.

The side walls 26 and 28 are generally adjacent one another and vertically- disposed with respect to the horizontal plane of the base. The walls 26 and 28 are impact- absorbing double walls. This means that the walls each have an outer wall 36 to absorb and dampen impacts. Just inside each outer wall 36 is an inner wall 38 disposed in a generally parallel direction thereto. The inner walls 38 prevent flexing against the wafers or solar cell substrates 30. Accordingly, the side walls 26 and 28 provide cushioning from the side (i.e. the x-y direction). Moreover, the inwardly disposed surfaces of the inner walls 38 are typically relatively smooth for minimal friction near the edges of the wafer or solar cells 30. In some embodiments, walls 36 and 38 have differing properties from one another in terms of flexibility and rigidity.

The outer walls 36 and inner walls 38 join one another at an elongate top edge 40.

This top edge 40 extends the length of the two walls 26 and 28 and bends at their adjoining corner 42 to form an "L" shape protrusion. The top edge 40 further has a first inner rounded edge 44, a second outer rounded edge 46, and a groove 48 centrally- disposed between the edges 44 and 46. Further, locking tabs 50 extend from locations disposed along the groove 48 such that they extend beyond the height of the edges 44 and 46. The locking tabs 50 of the container portion 22A are spaced apart and correspond to the spacing of the slots 35 of the corresponding, oppositely-disposed, container portion 22B. In some embodiments, the inner rounded edge 44 contains recessed features 52 at the corners provide addition room for movement to protect the fragile corners of the wafers or solar cells 30 being shipped. This can be seen in Figure 4A and 4B, for example.

Figure 3 illustrates the assembled container 20. When the container is ready for assembly a first container portion 22A may be releasably engaged with a second container portion 22B to complete the shipping container. First, a second container portion 22B that is similarly oriented to container portion 22A would need to be inverted and rotated 180 degrees with respect to the first container portion 22A. The top edge 40 of the first (lower) container portion 22A is fit into the groove portion 34 of the second container portion 22B. Likewise, the tabs 50 of the first container portion 22A are fit into the corresponding slots 35 of the second container portion. Further the top edge 40 of the second container portion 22B is fit into the groove portion 34 of the first container portion 22A. Likewise, the tabs 50 of the second container portion 22A are fit into the corresponding slots 35 of the first container portion. The top edges 40 and groove portions 34 are fit together in an interference fit with one another in a tongue and groove fashion. The resulting assembled container 20 is the rectangular box shaped package shown in Figure 3.

Referring to Figure 4, an embodiment showing a top view of one portion 22A of the container 20 is illustrated. A uniform matrix pattern of pads 32 is shown as well as spaced apart locations of slots 35 and tab projections 50. The pads 32 generally have rounded edges and a flat plateau surface 31 which provides a level surface for contact with the media 30 being shipped. Various alternative spacing and patterns for the pads 32, slots 35 and tab projections 50 are possible as well without departing from the scope of the invention. Access holes 51 are shown in each of the pads 32 located in the corners of the matrix pattern. Access holes 51 are simply openings in the raised pads 32 which allow a person to insert his or her finger or an object to better grip or manipulate the container pieces during assembly or disassembly. Another feature that can be seen in the top view of Figure 4 is the perpendicular corner openings 54 found at opposite corners of the container portion 22 A.

Figure 4A shows a cross-sectional view of Figure 4 taken through a row of pads of the container portion in Figure 4 along line A-A. From this view, the general shape of the base 24 including plateau shaped pads 32, slots 35 and groove 34 may be better understood. Further, the shape of the walls 26 and 28 including inner walls 38, outer walls 36, projection tabs 50, first and second rounded edges 44 and 46, and prove portion 48 can be better understood.

Referring to Figure 5, an embodiment showing a top view of the combined portions 22A and 22B of the container 20 is illustrated. The recesses 33 formed from the uniform matrix pattern of pads 32 is shown as well as spaced apart tabs 50 extending through slots 35 on two sides of the container. The outer and inner walls 36 and 38 can be seen on two sides of the container 20. The open corners 54 of both container portions 22A and 22B can be seen to be aligned such that the assembled container is missing two opposing corners. This arrangement provides additional capabilities in terms of assembling and packaging groups of such containers.

Figure 5A shows a cross-sectional view of Figure 5 taken adjacent a row of pads 32 of the container in Figure 5 along line A-A. From this view, the manner in which the tabs 50 and slots 35 are coupled with one another can be seen. Figure 5A shows a cross- sectional view of the interlocking engagement of the first portion 22 A of the container and the second portion 22B of the container. Specifically, the groove 34 and slots 35 of the first container portion 22A is seen engaging in an interference fit with the tabs 50 and top edge 40 of the second container portion 22B on the bottom of the figure, and vice versa on the top of the figure. Further, the secure shipping arrangement can be better understood in Figure 5A. Specifically, in this figure a centrally located pocket of space is surrounded by pads 32 on two sides and sets of double walls 26 and 28 on the remaining sides.

In the various embodiments, further packing material such as corrugated pads, cardboard, or foam may be stacked between the container and wafers or solar cells 30 for additional protection. Further, similar materials may be placed around the outside of the container 20 and tape or shrink wrap may be placed around the outer periphery of the container and/or packaging material for a further seal. For example, in Figure 6, corrugated pads 56 are placed around the periphery of the container 20 and the exterior of the container and packaging is surrounded by shrink wrap 58.

Figure 7A illustrates a design for a dampening spacer 60A for use in connection with the substrate shipping container according to an embodiment of the invention. This type of dampening spacer can be placed between pad members 32 in the base 24 of a container 20 to provide additional shock protection in the vertical (i.e. "z") direction. The spacers 60A are generally strips of material in an overlapping, accordion-shaped disposition. Figure 7B illustrates an alternative dampening spacer 60B for use in connection with the substrate shipping container according to an embodiment of the invention. This spacer 60B has strips of material with fewer overlapping layers than Figure 7A. In general, spacer 60B forms an "S" shaped structure. In both embodiments in Figures 7 A and 7B the width " W" and length "L" are generally based on the size of the cells being shipped. The height dimension "H" is generally based on shipper quantity. These spacers allow for a reduced amount of cells in a standard container without a reduction in dampening in the vertical (i.e. " z ") direction.

Figures 8A-D illustrate the packaging process for assembling a pallet of substrate shipping containers according to an embodiment of the invention. The shipper containers 20 are generally first loaded with a predetermined number of wafers or cells 30 in each container 20. The containers are then vertically stacked in master cartons 70, with five shipper containers 20 per carton for example. Next, master cartons 70 are loaded on pallets 72 and a pallet sleeve 74 is placed over the pallet contents for shipping. Note that the substrate shipping containers can be vertically stacked as necessary during the shipping and storage process. First, due to the configuration of the containers, these containers can replace existing sort bins without equipment modifications. The containers work in both flat-mounted and angle-mounted sorting operations and the mold design generally allows for custom interface features in some embodiments. The containers also have built in locating features to align the shipping containers with the center of the wafer cells. Finally, stacking features for incoming wafer/cell storage are included. A removable insert in the mold can permit manufacturers' logos. Also, the containers are capable of handling many types of RFID tags, barcodes, and stickers for customer requirements. Further, a grid may be molded into the base for tracking, cleaning, reuse or other cycles. The outer surface of the container can provide external stacking features and a tapeable perimeter.

Figures 9-1 1 illustrate various embodiments of the shipping container corresponding to those disclosed in Figures 1-3 but represented with shaded surface depictions.

The components may generally be injected molded, molded from pulp, vacuum formed or otherwise manufactured from polymers or pulp, suitable for semiconductor wafers. In some embodiments, a container of the type described may have a capacity of 150, 130, 125, or 100 stacked wafers or solar cells, for example. For example, shipping media having total dimensions of 6.19" x 6.19" x 1.75" and weighing 63 oz could be readily accomplished with such a container. The shipper may further serve as a shipper, sorting bin, finished cell shipper, or finished cell sorting bin, in various embodiments.

Various methods and processes for forming conventional pulp containers are known and many same or similar methods and processes are contemplated for use in producing the designs disclosed in this application. For example, U.S. Patent Nos. 7449087 to Odajima et al.; 7288196 to Jensen et al; 6752910 to Sato et al; 6582562 to Gale et al; 6576089 to Sato et al; 6521096 to Jurvanen; 6361659 to Yang; 6287428 to Gale et al; 5826726 to Yang; 5431784 to Miyamoto et al; and U.S. Patent Publication No. 2009/0139678 to Nilsson et al, each hereby incorporated by reference, disclose methods of producing or forming molded pulp and pulp products.

An alternative shipping container 120 is shown in Figures 12-15. The shipping container is generally made up of two pieces, a first portion 122A and a second portion 122B which are used to package and protect various substrates, solar cells, wafers or other media 130 being shipped. The first and second portions are generally identical. When the portions are placed around media 130 for shipping, the first and second portions 122 A and 122B are placed on top and bottom of the stacked cells or wafers in inverted dispositions with respect to one another, for example. Each portion 122 provides a centrally located square recessed base 124 which is surrounded by walls 125 on four sides. The substrates may be for example, a stack of 150 solar cell wafers shrink wrapped.

The base 124 is generally flat and is suitable for placing a stack of cells, wafers, substrates 130. The walls 125 are each double sided and contain an exterior wall 136 and an interior wall 138. The interior and exterior walls 138 and 136 generally meet at a rounded edge 140. The height of the walls 125 from the base 124 to the rounded edge 140 is approximately half of the height of the media 130. Further an additional recess 142 is located around the interior base 124 of the walls 125. Accordingly, the resulting container portions are surrounded by overlapping wall structures to provide dampening from side impacts.

Each of the corners 146 of the container portions 122 do not meet at right angles but instead provide a set back area in order to prevent potentially harmful contact with the corners of the shipped media 130. The exterior end 150 of the container portions 122, opposite the media 130, contains an outwardly extending lip 152 surrounding its perimeter. Large notches 154 are cut from the center of each side of this lip 152.

As shown in Figure 14A, the height of the container portions "H" may be changed, as well as its geometry, to adjust the spring rate provided by the container. The width "W" of the entire wall portion may be changed, as well as its geometry, to adjust the spring rate provided by the container. Also, the container 120 may be made of molded pulp, molded bulrush or other suitable material.

Figure 15 discloses the vertical stacking method by which cartons 170 of containers can be readily assembled for further shipping. As shown, the exterior features of the containers are able to match with one another so as to cooperate to form a well- protected package for shipment.

Another alternative shipping container 220 is shown in Figure 16 as well. The shipping container 220 is generally made up of two pieces, namely, a first base portion 222 and a second top cover portion 224. Similar to the previous embodiments, this container 220 is used to package and protect various substrates, solar cells, wafers or other media 230 being shipped (not shown). Accordingly, the portions 222 and 224 are placed around the media 230 for protected and damage-free shipping.

The base 222 generally has a rectangular box shape with two elongate side walls 226 and two shorter end walls 228. The base 222 further has an open top and a bottom 230 that contains a matrix of upwardly projecting shock absorbing pads 232 on which media 230 can be stacked. Some of these pads 232 are further equipped with access holes 234 to aid in container manipulation and assembly. Further, the four corners 236 of the base 222 have been inwardly recessed. Accordingly, due to the shape of the corners 236, each of the side walls 226 and end walls 228 form outwardly projecting pockets along each side of the container base 222.

The top cover member 224 is largely a rectangular box-shaped component which has four sidewalls 240, a top surface 242 (equipped with pads on its unseen downwardly projected surface) and an open bottom surface. Further, each of the four corners 244 is slightly rounded at the top and is bordered by elongate slots 246 on both sides of the corners 244. These elongate slots 246 allow for interlocking of the top cover portion 224 and the walls 250 defining the corners 236 of the base portion 222. Specifically, when assembled, cover 224 is vertically placed over the base portion 222 such that the side members 240 of the cover slide inside the pockets defined by the walls 226 and 228 of the base 222. Moreover, the elongate slots 246 interlock with the corner walls 250 at the comers of the base 222, such that the comer portions 244 of the cover 224 are the located outside the walls of the base. In this arrangement, a secure container for shipping wafers or solar cells is provided, with multiple reinforced walls and padded base and top cover to prevent damage to the shipped media.

As with the other designs disclosed in this application, the container shown in Figure 16 can be made of molded pulp or bulrush fiber among other suitable materials.

Claims

1. A substrate shipping container in combination with a stack of substrates, the shipping container formed of pulp material, the container comprising a pair of structurally identical container portions, the container portions combinable to form an enclosure with the top portion being a mirror image of the bottom portion, the container having a top, a bottom and four sides and having therein a substrate receiving region.

2. The substrate shipping container in combination with a stack of substrates wherein the container has four double walls extending on each of four sides of the container.

3. The substrate shipping container in combination with a stack of substrates of claim

2 wherein each container portion comprises a base with a pair of double walls extending from the base.

4. The substrate shipping container in combination with a stack of substrates of claim

3 wherein the two double walls of each container portion are connected to each other at a corner and opposite from the two double walls are two open sides.

5. The substrate shipping container in combination with a stack of substrates of claim

4 wherein each double wall has a plurality of tabs extending therefrom and the base has at each of the two open sides, a plurality of receivers for each of the plurality of tabs.

6. The substrate shipping container in combination with a stack of substrates of claim 1 wherein each container portion has four double walls extending upwardly from a base portion.

7. The substrate shipping container in combination with a stack of substrates of any of the above claims wherein the container comprises bulrush.

8. A method of manufacturing shipping containers for substrates, the method comprising molding pulp into a plurality of like container portions, each container portion having a base and a plurality of sides, one of the container portions combinable with a like inverted second of the container portions to define therein a substrate receiving region.

9. The method of claim 8 further comprising using bulrush for the pulp.

10. The method of claim 8 further comprising configuring the container portions to be stackable with features nesting.

11.

1 1. A container for shipping substrates, the container comprising a base portion and a top cover portion, each or the base portion and cover portion formed of pulp, the base portion having a bottom with a plurality of pads for supporting a stack of substrates and four side walls extending upwardly from the base, each wall connected to an adjoining wall at a corner inset inwardly, the top cover having four walls four corner portions with gaps extending between each wall and the adjacent corner portions whereby the top cover may be joined with the base portion by inserted the four walls of the top cover inside of the base portion and the four corners of the top cover exterior of the four corners of the base portion.

12. A container for shipping substrates comprises a first container portion and a second container portion structurally the same as the first container portion, each container portion having a top, a bottom, and four sides, each container portion being a unitarily formed component formed of pulp and comprising a base portion with a substantially square footprint and a pair of double wall side walls extending upwardly from the base portion at two adjacent sides of the four sides, each double side wall having a proximal portion adjacent to the base and a distal portion, the other two of the four sides not having double side walls extending upwardly from the base portion, the two double side walls and the two sides not having double side walls defining a substrate stack receiving region, the container portion being open above the substrate stack receiving region, the first and second container portions cooperating to engage one another whereby an enclosure having a box shape with a top side, parallel bottom side, and four sides and an enclosed substrate receiving region is defined.

13. A container for shipping rectangular substrates, the container comprising a first container portion unitarily formed of pulp and a cooperating second container portion unitarily formed of pulp that when assembled form an enclosure with a substrate stack receiving region defined therein, the substrate stack receiving region defined by a planar bottom surface, a planar top surface, four side wall portions arranged in a rectangular configuration, each of the side wall surfaces jutting outwardly at the corners to provide four corner recesses whereby when the stack of substrates are in the substrate stack receiving region there is additional separation between the side walls and corners of the stack of substrates.

14. A container for shipping rectangular substrates, the container comprising a first container portion and a cooperating second container portion that when assembled form an enclosure with a top, a bottom, and four sides, a substrate stack receiving region defined therein, the substrate stack receiving region defined by a planar bottom surface, a planar top surface, four side wall portions arranged in a rectangular configuration, the container having an upwardly extending top peripheral edge and a downwardly extending bottom peripheral edge, the container having at least on U-shaped shock absorbing structure intermediate each of the peripheral edges and the substrate stack receiving region, the U- shaped structures each having an axis, each of the axis positioned parallel to one of the sides, the container portions comprising dried pulp.

15. A single container portion combinable with another structurally identical single container portion inverted and engaged therewith for forming a container for shipping substrates, the container portion having a top, a bottom, and four sides, the container portion being a unitarily formed from pulp and comprising a base portion with a substantially square footprint and a plurality of double wall side walls extending upwardly from the base portion at a plurality of the four sides, each double side wall.

16. The single container portion of claim 15 wherein the container portion has two double sidewalls at two of the four sides and the other two of the four sides not having double side walls.

17. The single container portion of claim 16 wherein the container portion has engagement structures for connecting to the another structurally identical single container portion.

18. The single container portion of claim 16 wherein the engagement structures comprise a tongue portion and groove structure defining a groove for receiving a tongue.

19. The single container portion of claim 16 wherein the two double sidewalls are adjacent to each other.

20. The single container portion of claim 16 , wherein the base portion has a plurality of pad portions defined by planar base wall portions surrounded by recessed regions.

21 The single container portion of claim 16 wherein each of the container portions has a lower peripheral edge portion that extends entirely around the base portion and defines the outer footprint of the container portion.

22. The single container portion of claim 21 , wherein the lower peripheral edge portion flares outwardly.

23. The single container portion of claim 16, wherein the container portion is nestable within another like container portion wherein the double wall portions each define a recess that configured for receiving the double wall portion of said another like container portion.

24 The container of claim 1 , wherein each of the base portions has an outer peripheral edge portion extending around the peripheral edge of the base portion at each side, and wherein intermediate the peripheral edge portion at each side and the substrate stack receiving region there is U shaped wall portion.

25. A stack of structurally the same nested container portions, each container portion having a top, a bottom, and four sides and being a unitarily formed component, each container portion comprising a base portion with a substantially square footprint, and a double wall side wall extending upwardly from the base portion, the double wall side wall having a recess therein receiving a double wall of an adjacent container portion, each container portion having a flared lower skirt with a recess extending continuously and uninterrupted inwardly of the flared lower skirt, each container portion comprising pulp material.