CUSHIONING MATERIAL, PACKING BODY, AND PACKING METHOD

There is provided a cushioning material, the cushioning material including a lower cushioning material that supports a lower portion of each of two rows of containers on a lower tier, middle cushioning materials that are interposed between the containers on an upper tier and the containers on the lower tier, and upper cushioning materials that are disposed in each of the two rows of the containers on the upper tier and that hold each of an upper portion of the containers on the upper tier, in which the lower cushioning material is formed without a space between the lower cushioning material and side plates of a packing case and the middle cushioning materials and the upper cushioning materials are formed with a predetermined space between the middle cushioning materials and the upper cushioning materials and the side plates of the packing case.

TECHNICAL FIELD

The present invention relates to a cushioning material to be used as a cushioning material for wafer containers and the like, a packing body, and a packing method.

BACKGROUND ART

In general transport of semiconductor wafers, a plurality of containers in each of which a plurality of semiconductor wafers are stored are prepared, and, after the plurality of containers are packed in a packing case, the packing case is transported by a carrying device.

During transport, external force such as impact of, for example, falling of the packing case from the carrying device may act on the containers. Thus, there is a demand for a structure with which semiconductor wafers are not deformed or damaged by external force. As such a structure, a structure in which a cushioning material is provided between containers and a packing case is known.

Patent Literature 1 describes a cushioning material to be used for packing a plurality of containers on two tiers including an upper tier and a lower tier in a packing case, the cushioning material including a lower cushioning material that supports the containers on the lower tier, a middle cushioning material interposed between the containers on the upper tier and the containers on the lower tier, and an upper cushioning material that holds an upper portion of each of the containers on the upper tier.

CITATION LIST

Patent Literature

SUMMARY OF THE INVENTION

Problem(s) to be Solved by the Invention

The cushioning material described in Patent Literature 1 has no space between the upper cushioning material and an inner surface of the packing case and a lateral surface of the upper cushioning material is in contact with the inner surface of the packing case. Thus, in Patent Literature 1, stability in removal of the cushioning material by a work robot or the like after a cover of a packing case is detached is impaired.

An object of the invention is to provide a cushioning material, a packing body, and a packing method with which the cushioning material disposed between a plurality of containers in a packing case can be stably removed.

Means for Solving the Problem(s)

A cushioning material according to an aspect of the invention is a cushioning material that is disposed, in a case where a plurality of containers each capable of storing a semiconductor wafer are packed in a box-shaped packing case including a bottom plate, side plates, and a cover, between the packing case and the plurality of containers, the containers being disposed such that two rows in each of which a plurality of the containers are arranged are disposed on each of two tiers including an upper tier and a lower tier, the cushioning material including, for cushioning storage of the containers in the two rows on each of the two tiers, a lower cushioning material that supports a lower portion of each of the two rows of the containers on the lower tier, middle cushioning materials that are interposed one each between the containers on the upper tier and the containers on the lower tier in each of the rows of the containers, and upper cushioning materials that are disposed one each in each of the two rows of the containers on the upper tier and that hold an upper portion of each of the containers on the upper tier, in which the lower cushioning material is formed without a space between the lower cushioning material and the side plates of the packing case, and the middle cushioning materials and the upper cushioning materials are formed with a predetermined space between the middle cushioning materials and the side plates of the packing case and between the upper cushioning materials and the side plates of the packing case.

In the aforementioned cushioning material, at least the upper cushioning materials or the middle cushioning materials may each have, at a lateral surface extending along an inner surface of the packing case, a recess that is formed to be recessed in a direction away from the inner surface of the packing case.

In the aforementioned cushioning material, the predetermined space may be in a range from 5 mm to 20 mm.

In the aforementioned cushioning material, a predetermined cushioning-material interval may be provided between the upper cushioning materials that are two upper cushioning materials.

In the aforementioned cushioning material, a predetermined cushioning-material interval may be provided between the middle cushioning materials that are two middle cushioning materials.

In the aforementioned cushioning material, the cushioning-material interval may be in a range from 5 mm to 20 mm.

A packing body according to another aspect of the invention is a packing body including any one of the aforementioned cushioning materials, the packing body including the plurality of containers, the packing case, and the cushioning material that is disposed with a predetermined space between the middle cushioning materials and the side plates of the packing case and between the upper cushioning materials and the side plates of the packing case.

A packing method according to a still another aspect of the invention is a packing method using any one of the aforementioned cushioning materials, the packing method including disposing the cushioning material inside the packing case with a predetermined space between the middle cushioning materials and the side plates of the packing case and between the upper cushioning materials and the side plates of the packing case, and packing the containers.

According to the aspects of the invention, the predetermined space is provided between the middle cushioning materials and the side plates of the packing case and between the upper cushioning materials and the side plates of the packing case, which makes it possible to stably remove the cushioning material.

DESCRIPTION OF EMBODIMENT

Hereinafter, a suitable exemplary embodiment of the invention will be described in detail with reference to the accompanying drawings.

A cushioning material according to the invention is disposed, when a plurality of containers each capable of storing a semiconductor wafer(s) are packed in a packing case, between the packing case and the plurality of containers. A packing body includes a plurality of containers, a packing case, and a cushioning material disposed between the packing case and the plurality of containers.

First, the packing case in which the plurality of containers are to be packed will be described. As illustrated inFIG.1, a packing case200is a case having an accommodation space in a rectangular cuboid shape and in which a plurality (twelve in the exemplary embodiment) of containers80are to be packed together with a cushioning material100. The number of the containers80to be packed is not limited to twelve.

The packing case200includes a case body201that has a rectangular cuboid shape whose one face, which is an upper face inFIG.1, is open and a case cover204that closes the upper face of the case body201, the case body201and the case cover204forming a box shape as a whole. The case body201is constituted by four side plates203that are connected to each other and form a quadrangular tubular shape, and a bottom plate202that closes a bottom thereof. The packing case200can be formed from a material, for example, card board, plastic, metal such as aluminum, or wood that is able to withstand transport by a truck or the like.

Next, arrangement of the cushioning material100and the containers80will be described.

As illustrated inFIG.1toFIG.3, twelve containers80in total are disposed inside the packing case200in the exemplary embodiment such that two rows in each of which three containers80are arranged are disposed in a horizontal (lateral) direction on each of two tiers including an upper tier and a lower tier. The number of the containers80in each row of the containers80is not limited thereto, and, for example, two rows in each of which two containers80are arranged may be disposed on each of two tiers including an upper tier and a lower tier.

For cushioning storage of the containers80in the two rows on each of the two tiers, the cushioning material100includes a lower cushioning material1that supports a lower portion of each of the containers80in the two rows on the lower tier, middle cushioning materials3that are interposed one each between each of the rows of the containers80on the upper tier and each of the rows of the containers80on the lower tier, and upper cushioning materials5that are disposed one each in each of the two rows of the containers80on the upper tier and that hold an upper portion of each of the containers80on the upper tier.

The cushioning material100further includes a vibration absorber9that is disposed between the lower cushioning material1and the bottom plate202of the packing case200.

In other words, a packing body10is the packing case200in which the twelve containers80, the two upper cushioning materials5, the two middle cushioning materials3, and the lower cushioning material1are disposed.

Next, the containers80will be described. The containers80are containers for storing semiconductor wafers W and are each, for example, a front opening shipping box (FOSB). As illustrated inFIG.5, each of the containers80includes a container body81whose upper side is open, and a container cover82that closes the upper side of the container body81.

The container body81integrally includes a pair of first walls83that face each other, a pair of second walls84that face each other and that form, together with the pair of first walls83, lateral surfaces of the container body81, and a bottom85that closes a lower side of the container body81. The container body81is formed to have a rectangular opening on the upper side.

The container body81includes, at the bottom85, a plurality of legs86, which are provided one each at four corners in the exemplary embodiment. The legs86protrude downward from the bottom85.

As illustrated inFIG.2, a comb-shaped wafer holder87that has holding grooves for holding the semiconductor wafers W with a space therebetween is provided inside the container body81of each of the containers80.

The wafer holder87is constituted by side holders87A that are to be in contact with an outer edge side portion of each of the semiconductor wafers W, and bottom holders87B that are provided on an inner side of the bottom85and that are to be in contact with an outer edge bottom portion of each of the semiconductor wafers W.

One row of the side holder87A is provided on an inner side of each of the second walls84facing each other. Two bottom holders87B are provided directly on the bottom85. The two side holders87A are disposed at a corresponding one of the second walls84to be parallel to each other in a groove arrangement direction, in other words, a direction orthogonal to the sheet ofFIG.2.

The container cover82is a plate-shaped member whose planar shape is rectangular and, as illustrated inFIG.5,FIG.6A, andFIG.6B, includes a pair of locks89on a surface side and a retainer91on a rear surface (inner surface) side.

The locks89are members that fix the container cover82to the container body81and, as illustrated inFIG.6A, each include lock bars89A and89B and a latch mechanism89C.

The lock bars89A and89B are members that are provided along sides of the container cover82facing each other and are movable in a direction D1or D2inFIG.6A.

By rotationally moving the latch mechanism89C, the lock bar89A and the lock bar89B can be moved by a cam mechanism in the direction D1and the direction D2, respectively. Consequently, respective ends of the lock bars89A and89B engage with corresponding recesses81A of the container body81and fix the container cover82to the container body81. The fixation of the container body81is cancelled by, in the state where the container cover82is fixed to the container body81, returning the position of the latch mechanism89C to an original position thereof to thereby pull and return the lock bars89A and89B to an inner side of the container cover82.

As illustrated inFIG.6B, the retainer91is a vertically elongated comb-shaped member that is provided on a rear surface side of the container cover82and is provided between the locks89. The retainer91allows respective upper peripheral edges of the semiconductor wafers W stored in the container body81to be inserted between comb teeth and to come into contact with the retainer91, thereby restricting the movement of the semiconductor wafers W in an axial direction or the turning of the semiconductor wafers W in a radial direction and retaining the semiconductor wafers W not to come into contact with each other.

As with a general wafer container, the comb shape of each of the side holders87A and the bottom holders87B of the wafer holder87is similar to the comb shape of the retainer91.

InFIG.6B, the retainer91is provided at a central portion of the container cover82to be parallel to an arrangement direction (vertical direction) of the semiconductor wafers W such that the retainer91is parallel to one of sides that constitute the rectangular shape of the container cover82.

The container body81has an option attachment hole (not illustrated) for attaching an option92(refer toFIG.5) to the container80. The option92can be attached to the option attachment hole of the container80. The option92to be attached is selectable from options having various shapes, and the type and the like of the container80can be distinguished on the basis of the shape of the option92.

Next, a structure of the lower cushioning material1constituting the cushioning material100will be described.

FIG.7is a top perspective view of the lower cushioning material1, andFIG.8is a bottom perspective view of the lower cushioning material1.FIG.9is a plan view of the lower cushioning material1, andFIG.10is a bottom view of the lower cushioning material1.FIG.11Ais a view (a front view of the lower cushioning material1) in a direction of an arrow A3inFIG.7, andFIG.11Bis a view (a side view of the lower cushioning material1) in a direction of an arrow A4inFIG.7.FIG.12Ais a sectional view taken along a line A5-A5inFIG.10, andFIG.12Bis a sectional view taken along a line A6-A6inFIG.10.

The lower cushioning material1is a cushioning material that supports the lower portion of each of the containers80in the rows of the containers80on the lower tier.

As illustrated inFIG.7and other figures, the lower cushioning material1has a rectangular shape. The lower cushioning material1is formed to cover substantially the entire surface of the bottom plate202of the packing case200. InFIG.7, the lower cushioning material1includes six lower receivers11that are formed as recesses between ribs that extend in two vertical rows and one lateral row and at an outer peripheral portion of the lower cushioning material1. The lower portions of the containers80are each received by a corresponding one of the lower receivers11.

As illustrated inFIG.2andFIG.3, the lower cushioning material1is formed without a space between the lower cushioning material1and inner surfaces of the side plates203of the packing case200. In other words, the lower cushioning material1is formed to be unable to move horizontally when being disposed on the bottom plate202of the packing case200with the vibration absorber9interposed therebetween.

The lower cushioning material1has four lateral surfaces, which are four lateral surfaces12and13in total including the lateral surfaces12at the front and the rear and the lateral surfaces13at the left and the right inFIG.7, to be in surface contact with the inner surfaces of the side plates203of the packing case200. Here, the lateral surfaces12at the front and the rear inFIG.7are lateral surfaces extending in a direction D3in which the rows of the containers80extend, and the lateral surfaces13at the left and the right are lateral surfaces orthogonal to the lateral surfaces12.

The lateral surfaces12and13of the lower cushioning material1are provided with a plurality of recesses14and15, as necessary. In other words, the lateral surfaces12and13of the lower cushioning material1are not required to be in surface contact at the entirety thereof with an inner surface of the packing case200. In the lower cushioning material1of the exemplary embodiment, the lateral surfaces12each have three recesses14, and the lateral surfaces13each have two recesses15. The position of each of the recesses14and15corresponds to a central position at the lower receiver11corresponding thereto.

Each lower receiver11is a portion having a shape to which a lower portion of the container80is fitted. The lower receiver11includes a lower facing surface16, a lower opening17, two sets of first lower ribs18, and two sets of second lower ribs19.

The lower opening17is a rectangular hole that is formed, at a central portion of the lower receiver11, in the bottom surface of the lower cushioning material1, that is, the lower facing surface16.

The first lower ribs18and the second lower ribs19are protrusions that support the four lateral surfaces (the first walls83and the second walls84) of the container from sides, that position the container80received at the lower receiver11in the horizontal direction, and that restrict the movement of the container80.

The first lower ribs18and the second lower ribs19are disposed such that the two sets of the first lower ribs18support lateral surfaces of the container80from directions opposite to each other and the two sets of the second lower ribs19support, from directions opposite to each other, lateral surfaces that differ from the lateral surfaces supported by the first lower ribs18.

The two first lower ribs18constituting one set of the first lower ribs18are disposed to be spaced from each other at predetermined intervals in a direction along a lateral surface of the container80.

Each of the first lower ribs18has a tapered surface18A that supports a lateral surface of the container80. The tapered surface18A is inclined such that, when the container80is received at the lower receiver11, an upper portion of the tapered surface18A is spaced from the lateral surface of the container body81and a lower portion of the tapered surface18A is in contact with the lateral surface of the container body81.

The two second lower ribs19constituting one set of the second lower ribs19are disposed to be spaced from each other predetermined intervals in a direction along a lateral surface of the container80differing from the lateral surface supported by the first lower ribs18. These second lower ribs19restrict the movement of the container80in the direction D3.

As illustrated inFIG.7,FIG.9,FIG.12A, andFIG.12B, each of the lower receivers11has a hollow20for receiving the option92when the container80to which the option92(refer toFIG.5) is attached is received. The hollow20is formed between one set of the second lower ribs19that are spaced from each other. The hollow20is a recessed portion formed in the lower facing surface16of the lower receiver11.

Next, a structure of each upper cushioning material5constituting the cushioning material100will be described.

FIG.13is a bottom perspective view of the upper cushioning material5, andFIG.14is a top perspective view of the upper cushioning material5.FIG.15Ais a plan view of the upper cushioning material5, andFIG.15Bis a bottom view of the upper cushioning material5.FIG.16Ais a view (a front view of the upper cushioning material5) in a direction of an arrow A7inFIG.13, andFIG.16Bis a view (a side view of the upper cushioning material5) in a direction of an arrow A8inFIG.13.FIG.17Ais a sectional view taken along a line A9-A9inFIG.15A, andFIG.17Bis a sectional view taken along a line A10-A10inFIG.15A.

The upper cushioning materials5are cushioning materials that hold upper portions of the containers80in the rows of the containers80on the upper tier. As illustrated inFIG.13,FIG.14,FIG.15A, andFIG.15B, each of the upper cushioning materials5has a rectangular shape. As illustrated inFIG.4, two upper cushioning materials5are used as one set in the packing body10, and each of the upper cushioning materials5is formed to cover substantially half of an opening of the packing case200.

As illustrated inFIG.13andFIG.15B, the upper cushioning materials5each include three upper receivers51. Each of the upper receivers51holds the container cover82of the container80corresponding thereto. The upper receivers51each have an upper facing surface56and an upper opening57.

The upper cushioning materials5each have four lateral surfaces, which are four lateral surfaces52and53in total including the lateral surfaces52at the front and the rear and the lateral surfaces53at the left and the right inFIG.13. Among the four lateral surfaces52and53, the lateral surfaces52are lateral surfaces extending in the direction D3in which the rows of the containers80extend, and the lateral surfaces53are lateral surfaces orthogonal to the lateral surfaces52.

As illustrated inFIG.2toFIG.4, the upper cushioning materials5are formed such that two upper cushioning materials5are accommodated in the packing body10to be adjacent to each other inside the case body201with a space G1provided between an inner surface of the case body201and an outer peripheral surface of these two upper cushioning materials5as a whole, that is, each of the three lateral surfaces52and53facing the inner surface of the case body201. The case body201and the upper cushioning materials5are formed such that the space G1has a dimension in a range from 5 mm to 20 mm.

The upper cushioning materials5are also formed such that a cushioning-material interval G2is provided between the upper cushioning materials5adjacent to each other in the packing body10. The upper cushioning materials5are formed such that the cushioning-material interval G2has a dimension in a range from 5 mm to 20 mm.

The lateral surfaces52and53of the upper cushioning materials5are provided, as necessary, with a plurality of recesses54and55that are formed to be recessed in a direction away from the inner surface of the packing case200in the packing body10. In other words, the lateral surfaces of the upper cushioning materials5may be not flat. In the upper cushioning materials5of the exemplary embodiment, each of the lateral surfaces52has three recesses54, and each of the lateral surfaces53has one recess55. The position of each of the recesses54and55corresponds to a central position at the upper receiver51corresponding thereto.

The upper opening57is a rectangular hole that is formed, at a central portion of the upper receiver51, in an upper surface of the upper cushioning material5, in other words, the upper facing surface56and that extends through the upper cushioning material5between the upper surface and a lower surface of the upper cushioning material5.

As illustrated inFIG.17AandFIG.17B, each upper opening57has four principal surfaces57A extending in the vertical direction and a finger rest57B formed at a lower end of the principal surfaces57A. The finger rest57B is an inclined surface having a shape formed by slantingly shaving a corner of a ridge between the upper facing surface56and the principal surfaces57A of the upper opening57.

The finger rest57B is not necessarily formed to be an inclined surface such as that described above as long as the finger rest57B has a shape that allows a worker to insert his/her fingers between the container cover82of the container80and the principal surfaces57A to detach the upper cushioning materials5. For example, a stepped shape recessed with respect to the principal surfaces57A may be employed. The finger rest57B is also not necessarily formed to extend over the total length of the ridge between the upper facing surface56and the principal surfaces57A and may be formed at a portion of the ridge.

Next, a structure of each middle cushioning material3will be described.

FIG.18is a top perspective view of the middle cushioning material3, andFIG.19is a bottom perspective view of the middle cushioning material3.FIG.20Ais a plan view of the middle cushioning material3, andFIG.20Bis a bottom view of the middle cushioning material3.FIG.21Ais a view (a front view of the middle cushioning material3) in a direction of an arrow A11inFIG.18, andFIG.21Bis a view (a side view of the middle cushioning material3) in a direction of an arrow A12inFIG.18.FIG.22Ais a sectional view of the middle cushioning material3taken along a line A13-A13, andFIG.22Bis a sectional view of the middle cushioning material3taken along a line A14-A14.

The middle cushioning materials3are cushioning materials that hold upper portions of the containers80in the rows of the containers80on the lower tier and that support lower portions of the containers80in the rows of the containers80on the upper tier.

As illustrated inFIG.18,FIG.19,FIG.20A, andFIG.20B, each of the middle cushioning materials3has a rectangular shape. Similarly to the upper cushioning materials5, two middle cushioning materials3are used as one set in the packing body10.

As illustrated inFIG.18andFIG.20A, three middle body receivers31similar to the lower receivers11of the lower cushioning material1are formed at an upper surface (a surface facing upward in the packing body10) of each of the middle cushioning materials3.

As illustrated inFIG.19andFIG.20B, middle cover receivers41similar to the upper receivers51of the upper cushioning materials5are formed at a lower surface (a surface facing downward in the packing body10) of each of the middle cushioning materials3.

Each middle cushioning material3has four lateral surfaces, which are four lateral surfaces32and33in total including the lateral surfaces32at the front and the rear and the lateral surfaces33at the left and the right inFIG.18. Among the four lateral surfaces32and33, the lateral surfaces32are lateral surfaces extending in the direction D3in which the rows of the containers80extend, and the lateral surfaces33are lateral surfaces orthogonal to the lateral surfaces32.

Similarly to the upper cushioning materials5, the middle cushioning materials3are formed such that two middle cushioning materials3are accommodated in the packing body10to be adjacent to each other inside the case body201with the space G1provided between the inner surface of the case body201and an outer peripheral surface of these two middle cushioning materials3as a whole, that is, each of the three lateral surfaces32and33facing the inner surface of the case body201. The case body201and the middle cushioning materials3are formed such that the space G1has a dimension in a range from 5 mm to 20 mm.

In addition, similarly to the upper cushioning materials5, the middle cushioning materials3are formed such that the cushioning-material interval G2is provided between the middle cushioning materials3adjacent to each other in the packing body10. The middle cushioning materials3are formed such that the cushioning-material interval G2has a dimension in a range from 5 mm to 20 mm.

The lateral surfaces32and33of the middle cushioning materials3are provided, as necessary, with a plurality of recesses34and35formed to be recessed in the direction away from the inner surface of the packing case200in the packing body10. In other words, the lateral surfaces of the middle cushioning materials3may be not flat. In the middle cushioning materials3of the exemplary embodiment, each of the lateral surfaces32has three recesses34, and each of the lateral surfaces33has one recess35. The position of each of the recesses34and35corresponds to a central position at the middle body receiver31or the middle cover receiver41corresponding thereto.

As illustrated inFIG.18, each of the middle body receivers31has a middle body facing surface36, a middle opening37, two sets of first middle ribs38, two sets of second middle ribs39, and a hollow40. Each of the first middle ribs38has a tapered surface38A having a shape and a function that are similar to those of the tapered surface18A of the lower cushioning material1.

Each of the first middle ribs38has a shape and a function that are similar to those of the first lower ribs18of the lower cushioning material1, and each of the second middle ribs39has a shape and a function that are similar to those of the second lower ribs19of the lower cushioning material1.

The hollow40has a shape and a function that are similar to those of the hollow20of the lower cushioning material1.

As illustrated inFIG.19, the middle cover receivers41each include a middle cover facing surface42.

Similarly to the upper opening57of each of the upper cushioning materials5, the middle opening37includes a finger rest37B formed at a lower end of principal surfaces37A. The finger rest37B has a shape and a function that are similar to those of the finger rest37B of the upper cushioning material5.

Next, a structure of the vibration absorber9will be described with reference toFIG.2andFIG.3.

The vibration absorber9is a member that absorbs vibration generated during packing of the containers80and includes plates9A and9B and elastic bodies9C.

The plates9A and9B are each a plate-shaped member having a rectangular shape substantially similar to the shape of the bottom plate202of the packing case200. In packing, the plate9B is first disposed on the bottom plate202of the packing case200, and the plate9A is then disposed on the plate9B with the elastic bodies9C interposed therebetween. The plates9A and9B are each constituted by, for example, a plastic plate.

Each elastic body9C is a member that elastically deforms in response to vibration and thereby absorbs the vibration. The elastic bodies9C, which are provided between the plates9A and9B, are formed from, for example, polyurethane, synthetic rubber, or polyurethane.

In a packing method using the aforementioned cushioning material100, the cushioning material100is disposed such that, in a state where the vibration absorber9is disposed inside the packing case200, the lower cushioning material1supports the lower portions of the two rows of the containers80on the lower tier, the middle cushioning materials3are interposed one each between the containers80on the upper tier and the containers80on the lower tier in each of the rows of the containers80, and the upper cushioning materials5are disposed one each in each of the two rows of the containers80on the upper tier. The middle cushioning materials3and the upper cushioning materials5are disposed with a predetermined space between each of the middle cushioning materials3and the side plates203of the packing case200and between each of the upper cushioning materials5and the side plates203of the packing case200.

According to the aforementioned exemplary embodiment, the middle cushioning materials3and the upper cushioning materials5are formed with the predetermined space G1between each of the middle cushioning materials3and the side plates203of the packing case200and between each of the upper cushioning materials5and the side plates203of the packing case200. It is thus possible to stably perform work to detach or attach the cushioning material100(the upper cushioning materials5and the middle cushioning materials3) by a work robot or the like after detaching the case cover204of the packing case200.

In addition, with the lower cushioning material1being formed without a space between the lower cushioning material1and the side plates203of the packing case200, the horizontal movement of the lower cushioning material1supporting the containers80from below inside the packing case200can be inhibited.

Further, with the finger rests57B and37B being respectively formed at the upper opening57of each upper cushioning material5and the middle opening37of each middle cushioning material3, a worker is enabled to remove the upper cushioning materials5and the middle cushioning materials3easily by placing his/her fingers on the inner side of the openings.

In addition, a contact area where each upper cushioning material5or each middle cushioning material3is brought into contact with the inner surface of the packing case200is reduced by the recesses54and55being formed at the lateral surfaces52and53of the upper cushioning materials5and the recesses34and35being formed at the lateral surfaces32and33of the middle cushioning materials3. It is thus possible to reduce contact resistance when each upper cushioning material5or each middle cushioning material3is brought into contact with the packing case200, improving stability in removal of the cushioning materials.

Further, with the ribs18and19being provided at the lower receivers11of the lower cushioning material1and the ribs38and39being provided at the middle body receivers31of the middle cushioning materials3, wobbling of the containers80during transport can be inhibited by these ribs that are in contact with the lateral surfaces of the containers80.

Moreover, the hollows20and40provided at the lower receivers11of the lower cushioning material1and the middle body receivers31of the middle cushioning materials3can prevent a packaging bag for a semiconductor storage case from being damaged that may otherwise be caused by contact between the option92and the cushioning material100during packing of the container80to which the option92is attached.

According to the exemplary embodiment, the cushioning material100is constituted by a foam body whose expansion ratio is in a range from 20 times to 40 times. It is thus possible to achieve both the hardness for withstanding impact from outside and softness for absorbing the impact.

In addition, according to the exemplary embodiment, the cushioning material100is formed from polyurethane foam, polyethylene foam, polypropylene foam, or polystyrene foam.

Therefore, the cushioning material100can be easily formed as a foam body whose expansion ratio is in a range from 20 times to 40 times.

While the invention has been described above on the basis of an exemplary embodiment, the invention is not limited to the aforementioned exemplary embodiment. It is natural for a person skilled in the art to arrive at various modifications and improved examples within the scope of the idea of the invention, and these are also included in the scope of the invention.

EXPLANATION OF CODES