Bale wrapping unit and transport container

Abstract

This invention provides a bundling unit (10) for bundling stored objects (80A) in a box-type container (200) in a manner that is divided into two columns spaced apart in the width direction and two layers in the vertical direction. The bundling unit includes: a lower buffer (1) supporting the two columns of stored objects (80A) in the lower layer; a middle buffer (3) clamping one between each of the upper and lower stored objects; an upper buffer (5) holding the upper part of the stored objects; and a vibration absorption unit (20) provided with... At the bottom of the container, the vibration absorption unit (20) has a first plate (21), a second plate (22), and an elastic body (23) disposed between the first plate (21) and the second plate (22). The center of the elastic body (23) is located further outward than the center of gravity of the stored objects relative to the middle of the two rows of stored objects. The distance (D) in the width direction between the center of the elastic body (23) and the center of gravity of the stored objects is more than 2% and less than 8% of the maximum outer diameter of the elastic body (23).

Description

Technical Field

[0001] This invention relates to a bundling unit for bundling stored objects in a container and a transport container. Background Technology

[0002] In recent years, the quality requirements for semiconductor wafers have become more stringent, and issues such as damage to semiconductor wafers caused by vibration / impact during transport and the adhesion of resin materials used for wafer fixing have become problems.

[0003] As a method for transporting semiconductor wafers, there is a known method of preparing multiple storage containers for storing semiconductor wafers, bundling these multiple storage containers inside a shipping container, and then transporting them using a conveying device.

[0004] Therefore, it is known that a component (called a bundling unit) is provided for bundling a storage container in a shipping container, comprising a cushioning element between the shipping container and the storage container, and a vibration absorbing unit disposed below the cushioning element. It is known that the cushioning element is mainly formed of polyurethane foam or the like, and the vibration absorbing unit has a structure having a pair of plastic plates and multiple elastomers sandwiched between the pair of plastic plates.

[0005] The vibration absorption unit is a unit that suppresses the vibration of the storage container during transportation by means of an elastomer. For example, Patent Document 1 describes a unit consisting of a pair of corrugated sheets made of synthetic resin and an elastomer sandwiched between the pair of corrugated sheets made of synthetic resin.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2011-16549 Summary of the Invention

[0009] The technical problem that the invention aims to solve

[0010] The elastomer that constitutes the vibration absorption unit has the function of absorbing vibration / impact through elastic deformation. However, depending on the position of the elastomer, sometimes the plastic sheet deflects significantly, which may cause the container to tilt or the buffer components to come into contact with each other.

[0011] Furthermore, regarding the number of elastomers, multiple elastomers can be configured to suppress the deflection of the plastic sheet, but on the other hand, since the effect of absorbing vibration / shock is reduced, they need to be configured to the necessary minimum.

[0012] In particular, in the case of a structure in which the storage containers are arranged in two overlapping layers inside the container, there is a problem that the storage containers arranged on the upper layer are tilted more significantly than the storage containers arranged on the lower layer.

[0013] Furthermore, this also leads to a wider gap between the buffer and the container, resulting in a decrease in the buffering effect when impacts occur during transportation.

[0014] The purpose of this invention is to suppress the tilting of the stored object in a bundling unit used to bundle the stored object in a container, and in a transport container in which the bundling unit is housed, and to stably remove the stored object or a buffer.

[0015] Solutions for solving technical problems

[0016] The bundling unit of the present invention is for bundling containers containing semiconductor wafers into a box-type shipping container in a manner that divides them into two columns spaced apart in the width direction and into two layers in the vertical direction. It is characterized by comprising: a lower buffer member supporting the lower part of the two lower columns of the containers; a middle buffer member, one of which is sandwiched between the upper and lower columns of the containers; an upper buffer member, one of which is disposed in each of the two upper columns of the containers to hold the upper part of the containers; and a vibration absorption unit for absorbing vibrations from the lower buffer member. The vibration-absorbing unit, supported below and located at the bottom of the container, comprises: a first plate; a second plate parallel to the first plate and disposed below the first plate; and an elastomer disposed between the first plate and the second plate, the number of which is the same as the number of the stored objects in each layer. When viewed from above, the center of the elastomer is located further outward than the center of gravity of the stored objects relative to the middle of the two rows of stored objects. The distance in the width direction between the center of the elastomer and the center of gravity of the stored objects is more than 2% and less than 8% of the maximum outer diameter of the elastomer.

[0017] In the above-mentioned bundling unit, if the interval between the centers of adjacent elastic bodies in the column direction is taken as Gx, and the interval between the centers of adjacent elastic bodies in the width direction is taken as Gy, then the ratio of Gy to Gx, Gy / Gx, can be greater than 1 and less than 1.3.

[0018] In the above-mentioned bundling unit, the bending strength of the first plate can be more than 2 times and less than 3 times the bending strength of the second plate.

[0019] In the above-mentioned bundling unit, at least the first plate has a groove formed in the first plate.

[0020] The transport container of the present invention is characterized by comprising: the above-mentioned bundling unit; and a box-type container for accommodating the bundling unit. Attached Figure Description

[0021] Figure 1 It is a 3D view showing the bundled state of a container with storage containers and cushioning components inside.

[0022] Figure 2 It is along Figure 1 A sectional view cut along line A1-A1.

[0023] Figure 3 It is along Figure 1 A sectional view cut along line A2-A2.

[0024] Figure 4 It is a 3D diagram of the storage container.

[0025] Figure 5A This is a top view of the storage container.

[0026] Figure 5B This is a rear view of the container lid.

[0027] Figure 6 This is a cross-sectional view of the vibration absorption unit according to an embodiment of the present invention.

[0028] Figure 7 yes Figure 6 View VII-VII is a top view of the vibration absorption unit according to an embodiment of the present invention.

[0029] Figure 8 This is a cross-sectional view of the vibration absorption unit according to an embodiment of the present invention, showing the configuration of eight elastomers.

[0030] Figure 9 It is a graph showing the displacement of the first plate when the position of the elastic body changes in the Y direction.

[0031] Figure 10 This is a graph showing the displacement of the first plate when the position of the elastomer in the Y direction changes when there are 8 elastomers.

[0032] Figure 11 It is a graph representing the results of a vibration test.

[0033] Figure 12 It is a graph representing the results of a vibration test.

[0034] Figure 13 It is a graph representing the results of a vibration test.

[0035] Figure 14 It is a graph showing the correlation between Gy / Gx and RMS. Detailed Implementation

[0036] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0037] The bundling unit 10 of the present invention is a unit for bundling multiple storage containers 80 inside a container 200. The structure having the bundling unit 10 and the box-type container 200 containing the bundling unit 10 is referred to as a transport container 200A.

[0038] Multiple semiconductor wafers W are stored in a storage container 80. Hereinafter, the storage container 80 containing the semiconductor wafers W will be referred to as the storage object 80A.

[0039] The bundling unit 10 has a buffer assembly 100 and a vibration absorption unit 20. The buffer assembly 100 includes an upper buffer 5, a middle buffer 3, and a lower buffer 1. The vibration absorption unit 20 supports the lower buffer 1 from below and is located at the bottom of the container 200.

[0040] When the stored objects 80A are bundled in the container 200, the buffer assembly 100 is positioned between multiple stored objects 80A and the container 200.

[0041] First, let's describe container 200, which contains multiple stored items 80A. For example... Figure 1 As shown, the container 200 is a rectangular storage space and together with the buffer assembly 100, it bundles multiple (12 in this embodiment) boxes for storing objects 80A.

[0042] The container 200 comprises a container body 201 with an open upper surface and a container cover 204 that closes the upper surface of the container body 201, forming a box shape as a whole. The container body 201 is composed of four interconnected, four-cornered cylindrical side panels 203 and a closed bottom panel 202. The container 200 is made of materials capable of withstanding transport by trucks, such as corrugated board, plastic, metals such as aluminum, or wood.

[0043] Next, the configuration of the buffer assembly 100 and the object 80A to be stored will be explained.

[0044] like Figures 1 to 3 As shown, the storage objects 80A, configured as 3 items, are arranged in 2 columns horizontally and 2 layers vertically, totaling 12 items 80A, within the container 200. That is, the bundling unit 10 bundles the storage objects 80A into the container 200 in a manner that is divided into 2 columns with a spacing in the width direction and 2 layers vertically.

[0045] The number of storage objects 80A in the column is not limited to this. For example, it can also be configured so that the columns with 2 storage objects 80A are arranged as 2 columns and 2 layers above and below.

[0046] In the following explanation, the direction in which the column of the stored object 80A extends is called the X direction (column direction), the direction orthogonal to the X direction is called the Y direction (width direction), and the vertical direction is called the Z direction.

[0047] The buffer assembly 100 buffers and stores the two rows and two layers of stored objects 80A. The buffer assembly 100 includes: a lower buffer 1 that supports the lower part of the two rows of stored objects 80A in the lower layer; a middle buffer 3, one of which is sandwiched between the upper and lower rows of stored objects 80A in each row of stored objects 80A; and an upper buffer 5, one of which is arranged in each of the two upper rows of stored objects 80A to hold the upper part of the stored objects 80A.

[0048] In the following description, the state in which 12 stored objects 80A, 2 upper buffers 5, 2 middle buffers 3, and 1 lower buffer 1 are configured inside container 200 is referred to as the bundled state.

[0049] Next, the storage container 80 constituting the stored object 80A will be described. The storage container 80 is a container for storing semiconductor wafers W, such as a FOSB (Front Opening Shipping Box). Figure 4 As shown, the storage container 80 has an open container body 81 and a container lid 82 that closes the container body 81.

[0050] The container body 81 integrally comprises a pair of first wall portions 83, a pair of second wall portions 84 forming the side of the container body 81 together with the pair of first wall portions 83, and a bottom 85 that closes the lower part of the container body 81.

[0051] The container body 81 has multiple feet 86. The feet 86 are feet that protrude downwards from the bottom 85.

[0052] like Figure 2 As shown, a comb-shaped wafer storage section 87 is provided inside the container body 81 of the storage container 80. The wafer storage section 87 has storage slots for storing multiple semiconductor wafers W at intervals.

[0053] The wafer storage section 87 is composed of a side storage section 87A that contacts the outer edge of the semiconductor wafer W and a bottom storage section 87B that contacts the bottom of the outer edge of the semiconductor wafer W.

[0054] Side storage sections 87A are arranged in one row on the inner side of each opposing second wall section 84. Two bottom storage sections 87B are arranged immediately above the bottom 85. In each second wall section 84, the two side storage sections 87A are arranged in the direction of the slot... Figure 2 They are arranged parallel to each other in the orthogonal direction on the paper.

[0055] The container lid 82 is a plate-shaped component with a rectangular planar shape, such as... Figure 4 , Figure 5A ,as well as Figure 5B As shown, it has a pair of locking parts 89 on the front side and a retaining part 91 on the back (inner) side.

[0056] Locking part 89 is a component that fixes the container lid 82 to the container body 81, such as... Figure 5A As shown, it has locking bars 89A and 89B and a latching mechanism 89C.

[0057] Locking rods 89A and 89B are components provided along opposite edges of the container lid 82, capable of moving along... Figure 5A The orientation of L1 and L2 moves.

[0058] By rotating the latching mechanism 89C, the locking bar 89A moves along the L1 direction and the locking bar 89B moves along the L2 direction via the cam mechanism. This engages the front ends of the locking bars 89A and 89B with the recess 81A of the container body 81, fixing the container lid 82 to the container body 81. With the container lid 82 fixed to the container body 81, returning the latching mechanism 89C to its original position pulls the locking bars 89A and 89B back to the inside of the container lid 82, releasing the container body 81 from its fixed position.

[0059] like Figure 5B As shown, the retaining part 91 is a longitudinally elongated comb-shaped member provided on the back side of the container cover 82, and is disposed between the locking parts 89. The retaining part 91 retains the semiconductor wafer W in such a way that by inserting the upper periphery of the semiconductor wafer W housed in the container body 81 into the teeth of the comb to make it abut, the axial movement or circumferential rotation of the semiconductor wafer W is restricted, so that the semiconductor wafers W do not come into contact with each other.

[0060] exist Figure 5B In the middle, the holding part 91 is disposed in the center of the container cover 82 in a manner parallel to one side of the rectangle constituting the container cover 82 and parallel to the arrangement direction of the semiconductor wafer W.

[0061] Next, the buffer components 1, 3, and 5 that constitute the buffer assembly 100 will be described.

[0062] Buffer components 1, 3, and 5 are made of any one of expanded polyurethane, expanded polyethylene, expanded polypropylene, or expanded polystyrene.

[0063] The lower buffer 1 constituting the buffer assembly 100 is a buffer that supports the lower part of the stored object 80A in the lower layer of the stored object 80A column.

[0064] The lower buffer 1 is rectangular. The lower buffer 1 is formed to cover almost the entire surface of the bottom plate 202 of the container 200. The lower buffer 1 has six lower storage sections 11 for accommodating the lower part of the storage container 80. Three lower storage sections 11 are formed in the X direction and two are formed in the Y direction.

[0065] The lower storage section 11 is a part shaped to fit the lower part of the storage container 80. In the lower storage section 11, a rectangular hole, namely the lower opening 12, is formed in the center of the lower storage section 11 and is formed on the bottom surface of the lower buffer member 1.

[0066] The upper buffer 5 constituting the buffer assembly 100 is a buffer that holds the upper part of the stored object 80A in the upper column of stored object 80A.

[0067] The upper buffer 5 is rectangular. The upper buffer 5 is configured to be used in groups of two in the bundled state, and each upper buffer 5 covers almost half of the opening of the container 200.

[0068] The upper buffer 5 has three upper storage sections 51. Each upper storage section 51 holds the container lid 82 of the storage container 80.

[0069] like Figure 1 as well as Figure 2 As shown, the upper buffer 5 is stored side by side inside the container body 201 in a bundled state.

[0070] In the upper storage section 51, a rectangular hole, namely the upper opening section 52, is formed in the center of the upper storage section 51, which penetrates between the upper surface and the lower surface of the upper buffer member 5.

[0071] The middle buffer 3 is a buffer that holds the upper part of the stored object 80A in the lower layer of the stored object 80A column and supports the lower part of the stored object 80A in the upper layer of the stored object 80A column.

[0072] The middle buffer 3 is rectangular. Similar to the upper buffer 5, the middle buffer 3 is used in sets of two when bundled.

[0073] Three central body storage portions 31, identical to the lower storage portion 11 of the lower cushioning member 1, are formed on the upper surface of the central cushioning member 3 (the surface facing upwards in the bundled state). A central cover storage portion 41, identical to the upper storage portion 51 of the upper cushioning member 5, is formed on the lower surface of the central cushioning member 3 (the surface facing downwards in the bundled state).

[0074] The position of the stored item 80A in its bundled state is determined by the shape of the cushioning element. The stored item 80A is symmetrically arranged with respect to the center CL in the Y direction.

[0075] Next, refer to Figure 2 and Figure 3 The structure of the vibration absorption unit 20 will be described.

[0076] The vibration absorption unit 20 is a unit that absorbs vibrations generated when the object 80A is bundled and stored, and includes a first plate 21, a second plate 22, and a plurality of elastic bodies 23. The vibration absorption unit 20 is disposed between the lower buffer 1 and the bottom plate 202 of the container 200.

[0077] The first plate 21 and the second plate 22 are rectangular plate-shaped components that are slightly smaller than the bottom plate 202 of the container 200. The second plate 22 is disposed on the bottom plate 202 of the container 200, and the first plate 21 is disposed on the second plate 22 through a plurality of elastic bodies 23.

[0078] The second plate 22 is parallel to the first plate 21 and is disposed below the first plate 21. The elastomer 23 is configured to be sandwiched between the first plate 21 and the second plate 22.

[0079] The first plate 21 and the second plate 22 are preferably plastic sheets with a thickness of 3 mm or more and 25 mm or less, more preferably plastic sheets with a thickness of 8 mm or more and 20 mm or less. The first plate 21 and the second plate 22 are preferably formed of hollow-structured plates made of plastic, such as plastic corrugated sheets. The first plate 21 and the second plate 22 are not limited to plastic sheets, and other plate-shaped components that are lightweight and have excellent vibration absorption can also be used.

[0080] like Figure 7 As shown, grooves 24 are formed in the first plate 21 and the second plate 22. In this embodiment, the grooves 24 are formed approximately at the center of the long side in the X direction of the plates 21 and 22. The grooves 24 may also be formed on the short side of the plates 21 and 22. The shape of the grooves 24 is preferably semi-circular, but may also be rectangular or the like.

[0081] In addition, although grooves 24 are formed in the first plate 21 and the second plate 22 in this embodiment, it is not limited to this. As long as grooves 24 are formed in at least the first plate 21, it is sufficient.

[0082] The bending strength of the first plate 21 is more than twice and less than three times the bending strength of the second plate 22.

[0083] The first plate 21 of this embodiment can be formed from a plastic sheet with a bending strength of 2 MPa or more and 8 MPa or less. The second plate 22 of this embodiment can be formed from a plastic sheet with a bending strength of 1 MPa or more and 4 MPa or less.

[0084] The thickness of the first plate 21 is the same as that of the second plate 22, and different bending strengths are formed by using different materials for the plastic plates.

[0085] Alternatively, the first plate 21 and the second plate 22 can be made of the same plastic plate, and the thickness of the first plate 21 can be made greater than the thickness of the second plate 22, thereby setting the bending strength of the first plate 21 to be more than twice and less than three times the bending strength of the second plate 22.

[0086] The elastomer 23 is cylindrical and absorbs vibrations through elastic deformation relative to vibration. The diameter of the elastomer 23 is 45 mm or more and 85 mm or less. The height of the elastomer 23 is 25 mm or more and 35 mm or less. The elastomer 23 can be formed from, for example, polyurethane resin, synthetic rubber, polyethylene, etc., but is preferably formed from polyurethane resin.

[0087] The upper and lower surfaces of the elastomer 23 are bonded to the plates 21 and 22.

[0088] The number of elastomers 23 is the same as the number of objects 80A stored in each layer (6).

[0089] Next, the details of the location of the elastomer 23 will be explained.

[0090] Figure 6 This is a cross-sectional view of the vibration absorption unit 20. Figure 7 This is a top view of the vibration absorption unit. (Example) Figure 6 as well as Figure 7 As shown, each elastic body 23 is positioned between a pair of plates 21 and 22 at a location corresponding to the object being stored 80A (approximately the same position as the object being stored 80A when viewed from above). That is, similar to the object being stored 80A, the elastic bodies 23 are symmetrically arranged with respect to their center CL in the Y direction. The position of the center C1 of the elastic body 23 in the X direction is approximately the same as the position of the center of gravity C2 of the object being stored 80A in the X direction.

[0091] Viewed from above, the position of the center C1 of the elastic body 23 in the Y direction differs from the position of the center of gravity C2 of the stored object 80A. The center C1 of the elastic body 23, relative to the middle of the two rows of stored objects 80A, is located further outward than the center of gravity C2 of the stored object 80A. This "further outward than the center of gravity C2" means that the distance D1 between the center CL in the Y direction and the center C1 of the elastic body 23 is greater than the distance D2 between the center CL in the Y direction and the center of gravity C2 of the stored object 80A.

[0092] When viewed from the column direction (X direction), the distance D in the Y direction (horizontal direction) between the center C1 of the elastic body 23 and the center of gravity C2 of the object 80A is more than 2% and less than 8% of the diameter of the elastic body 23. If the diameter of the elastic body 23 is 65mm, then the horizontal distance between the center of the elastic body 23 and the center of gravity of the object 80A is approximately more than 1.3mm and less than 5.2mm. When the elastic body 23 is cylindrical, the diameter of the elastic body 23 is its maximum outer diameter.

[0093] Furthermore, when the elastic body 23 is a polygonal cross-section rather than a cylinder, the horizontal distance between the center of the elastic body 23 and the center of gravity of the object 80A being housed is more than 2% and less than 8% of the maximum outer diameter of the elastic body 23. The maximum outer diameter is the diameter of the circumcircle of the polygon.

[0094] Furthermore, if the interval between adjacent elastic bodies in the X direction is set as Gx and the interval between adjacent elastic bodies in the Y direction is set as Gy, then the ratio of Gy to Gx, Gy / Gx, is in the range of 1 or more and 1.3 or less.

[0095] [Optimization of the location and number of elastomers, bending strength of the plate, etc.]

[0096] Next, the analysis performed to optimize the position and number of elastic bodies 23, the bending strength of plates 21 and 22, and the ratio Gy / Gx of the spacing Gy between adjacent elastic bodies in the Y direction and the spacing Gx between adjacent elastic bodies in the X direction will be explained.

[0097] [Study on the location and number of elastomers]

[0098] The inventors believe that the position of the elastic body 23 affects the deflection of the first plate 21 and the tilt of the object 80A. In particular, since the upper buffer 5 and the middle buffer 3 are divided in the Y direction, it is believed that the position of the elastic body 23 in the Y direction has a significant impact on the deflection of the first plate 21 and the tilt of the object 80A. The displacement (deflection) of the first plate 21 was analyzed by changing the position of the elastic body 23 in the Y direction.

[0099] The position of the elastic body 23 is based on the center of gravity C2 of the object being stored 80A, causing the center C1 of the elastic body 23 to change in the Y direction. The position of the elastic body 23 in the X direction is the same as the position of the object being stored 80A in the X direction and remains unchanged. Furthermore, the diameter of the elastic body 23 is 65mm.

[0100] And, as Figure 8 As shown, in order to study the number of elastic bodies 23, the case of adding two elastic bodies 23 to the center CL in the Y direction, thus setting the number of elastic bodies 23 to 8, was also analyzed.

[0101] Figure 9 It means in such Figure 7 The graph shows the displacement of the first plate 21 when the position of the elastic body 23 in the Y direction changes when the six elastic bodies 23 are configured. Figure 9 The horizontal axis represents the position (mm) in the Y direction of the first plate 21, and the vertical axis represents the vertical displacement of the first plate 21. Additionally, 0mm in the Y direction is... Figure 7 The left end LS, 950mm in the Y direction is Figure 7 RS on the right side.

[0102] like Figure 9 As shown, when the distance D between the center C1 of the elastic body 23 and the center of gravity C2 of the object 80A is 5mm, the displacement of the first plate 21 becomes minimal. That is, when the position of the center C1 of the elastic body 23 is 5mm further outward than the position of the center of gravity C2 of the object 80A, the deflection of the first plate 21 is minimal.

[0103] Since the diameter of the elastic body 23 is 65mm, even if the position of the center C1 of the elastic body 23 is set 5mm further outward than the position of the center of gravity C2 of the object 80A, the elastic body 23 is present directly below the center of gravity C2 of the object 80A. Therefore, it is considered that the first plate 21 is stably supported.

[0104] On the other hand, the first plate 21 deflects the most when the distance D is 44.5 mm. Since the diameter of the elastic body 23 is 65 mm, there is no elastic body 23 directly below the center of gravity C2 of the object 80A, so the first plate 21 is considered to be prone to deflection.

[0105] Specifically, as the distance D increases to 9.9 mm, 19.9 mm, 23.9 mm, and 44.5 mm, the deflection of the first plate 21 increases.

[0106] Furthermore, regarding the case where the center C1 of the elastomer 23 is positioned further inward than the center of gravity C2 of the object being housed 80A, even at a distance D of -0.1 mm (i.e., when the elastomer 23 is located directly below the center of gravity C2 of the object being housed 80A), the deflection increases compared to the case where the distance D is 5 mm. At distances of -2.5 mm and -5.1 mm, the deflection increases further.

[0107] Figure 10 It means in such Figure 8 The graph shows the displacement of the first plate 21 when the position of the elastic body 23 in the Y direction changes when the configuration of 8 elastic bodies 23 is shown. Figure 10 The horizontal axis represents the position (mm) in the Y direction of the first plate 21, and the vertical axis represents the displacement of the first plate 21 in the vertical direction.

[0108] like Figure 10 As shown, when the distance D between the center C1 of the elastic body 23 and the center of gravity C2 of the object 80A is 53mm, the displacement of the first plate 21 becomes minimal. This can be attributed to the following result: by arranging two elastic bodies 23 at the center CL in the Y direction, the first plate 21 is difficult to bend even if there is no elastic body 23 directly below the center of gravity C2 of the object 80A.

[0109] Based on the above analysis, the following results are obtained: When 6 elastic bodies 23 are configured, the distance D between the center C1 of the elastic body 23 and the center of gravity C2 of the object to be stored 80A is preferably 5mm, and when 8 elastic bodies 23 are configured, the distance D is preferably 53mm.

[0110] Next, to investigate the quantity of elastomers 23, a container 200 containing the object 80A and the bundling unit 10 was fixed on a vibration testing machine. Vibration sensors were installed at specified positions on the container, pallet, and vibration table, and a vibration test was conducted. The vibration frequency was 5–500 Hz, the excitation condition was 0.5G, and the excitation time was 5 minutes.

[0111] Figure 11 The results of the vibration tests are presented in graphs, showing the results under conditions 1 (6 elastomers 23 with a distance D of 44.5 mm), 2 (6 elastomers 23 with a distance D of 5 mm), and 3 (8 elastomers 23 with a distance D of 53 mm). In the vibration tests, the container was excited in the Z-direction, and the vibration intensity in the Z-direction was compared. Figure 11 The “lower layer” refers to the vibration intensity detected in the lower layer of the storage container, and the “upper layer” refers to the vibration intensity detected in the upper layer of the storage container.

[0112] like Figure 11 As shown, even with an arrangement of eight elastic bodies 23, which reduces the displacement of the first plate 21, the vibration excitation velocity in the Z direction still increases. This is believed to be mainly because increasing the number of elastic bodies 23 results in excessively high overall stiffness of the vibration absorption unit 20 and reduced vibration absorption capacity. The conclusion is that six elastic bodies are the preferred number.

[0113] Additionally, although condition 1 becomes... Figure 9 The graph showing the displacement of the first plate 21 shows a large displacement, but it also confirms that even with a large displacement, the vibration excitation velocity in the Z direction is not significantly affected, while the magnitude of the displacement has a greater impact.

[0114] and, Figure 12 It is a graph showing the results of vibration tests under conditions 1, 2, and 3, and comparing the vibration intensity of the container in the X direction with that of the container under Z-direction excitation.

[0115] like Figure 12 As shown, even with an arrangement of eight elastic bodies 23, which reduces the displacement of the first plate 21, the vibration excitation velocity, especially in the upper X direction, increases. This is believed to be primarily because increasing the number of elastic bodies 23 leads to excessively high overall stiffness of the vibration absorption unit 20 and reduced vibration absorption capacity. Based on these results, it is concluded that six elastic bodies are preferable.

[0116] Regarding condition 1, it can also be confirmed that the vibration excitation velocity in the X direction is not significantly affected, while the quantity is greatly affected.

[0117] With six elastomers 23 configured, if the distance D is expressed as a ratio to the diameter of the elastomer 23, then the distance D is most preferably 8% (≈5mm / 65mm) of the diameter of the elastomer 23, and this is taken as the upper limit. Figure 9 It can be seen that since the deflection increases when the distance D is 9.9 mm, an upper limit was set to exclude this.

[0118] On the other hand, the lower limit of the distance D is set to 2% of the diameter of the elastomer 23. The position of the center C1 of the elastomer 23 is preferably further outward than the position of the center of gravity C2 of the object being housed 80A. This is to eliminate the possibility that, due to manufacturing errors, the position of the center C1 of the elastomer 23 may become further inward than the position of the center of gravity C2 of the object being housed 80A. Figure 9 It can be seen that since the deflection increases when the distance D is -0.1mm, a lower limit was set to exclude this.

[0119] [Study on the Bending Strength of Flat Plates]

[0120] Next, in order to study the strength of the plate, vibration tests were conducted using two types of first plates 21 with different bending strengths.

[0121] Figure 13 The results of the vibration tests are presented in graphs showing the results under condition 2 (where the number of elastic bodies 23 is set to 6, the distance D is set to 5 mm, and the bending strength of the first plate is set to 1.5 MPa (the same as the bending strength of the second plate)) and condition 4 (where the number of elastic bodies 23 is set to 6, the distance D is set to 5 mm, and the bending strength of the first plate is set to 3 MPa (twice the bending strength of the second plate)). In the vibration test, the container was excited in the Z direction, and the vibration intensity in the X direction was compared.

[0122] like Figure 13 As shown, when the bending strength of the first plate is set to twice that of the second plate, although the vibration intensity of the upper layer increases slightly, the vibration intensity of the lower layer is improved while the deflection is also improved. Based on this result, it is concluded that the bending strength of the first plate 21 is preferably twice that of the second plate.

[0123] [Optimization of the ratio Gy / Gx of the spacing between adjacent elastic bodies in the Y direction and the spacing between adjacent elastic bodies in the X direction]

[0124] The ratio Gy / Gx, which is the spacing between adjacent elastic bodies in the Y direction and the spacing between adjacent elastic bodies in the X direction, is optimized by constructing a vibration analysis model for containers, bundled units, stored objects, and pallets supporting them from below, and performing frequency response analysis using finite element analysis software.

[0125] Specifically, in the frequency response analysis, a sinusoidal wave with an amplitude of ±0.5G is applied to the pallet supporting the container from below. The acceleration is calculated, and the response of each component to external vibration is evaluated. The frequency range is set to 10Hz to 200Hz, and the frequency interval is set to 1Hz.

[0126] The evaluation index is the effective value RMS (Root Mean Square) calculated by the following formula (1).

[0127] RMS = √(the average of the sum of squares of accelerations at each frequency) ... (1)

[0128] In other words, RMS is the root mean square of acceleration at each frequency.

[0129] Furthermore, analysis of past vibration experiments on the objects being stored reveals a correlation between the amount of resin adhering to the wafer tip due to vibration during transport and the RMS (Resin Surface Mass).

[0130] Figure 14 This is a graph showing the correlation between Gy / Gx and RMS. For example... Figure 14 As shown, it was confirmed that RMS tends to decrease when the ratio Gy / Gx is above 1 and below 1.3.

[0131] According to the above embodiment, by setting the distance D between the center C1 of the elastomer 23 and the center of gravity C2 of the object 80A to be 2% or more and 8% or less of the diameter of the elastomer 23, the deflection of the first plate 21 can be reduced. Therefore, in the bundling unit 10 for bundling the object 80A in the container 200, tilting of the object 80A can be suppressed, and the object 80A or the buffer can be removed stably.

[0132] Furthermore, if the spacing between adjacent elastomers in the X direction is set to Gx and the spacing between adjacent elastomers in the Y direction is set to Gy, the ratio of Gy to Gx, Gy / Gx, is in the range of 1 or more and 1.3 or less. This can suppress vibration of the object 80A during transport and reduce the amount of resin adhering to the wafer end.

[0133] Furthermore, by setting the bending strength of the first plate 21 to be more than twice and less than three times the bending strength of the second plate 22, it is possible to reduce the vibration intensity during excitation.

[0134] Furthermore, by forming grooves 24 on the first plate 21 and the second plate 22, the vibration absorption unit 20 can be removed using the grooves 24. Thus, the vibration absorption unit 20 can be easily removed.

[0135] Furthermore, in the above embodiment, the elastomer 23 is cylindrical, but it is not limited to this. For example, it can be a prism shape such as a cuboid or a cone shape.

[0136] Furthermore, in the above embodiment, although the position of the elastic body 23 in the X direction is approximately the same as the position of the center of gravity C2 of the object being stored 80A in the X direction, it is not limited to this and may also be offset from the X direction. Among them, the elastic body 23 at the center in the X direction is preferably approximately the same as the position of the center of gravity C2 of the object being stored 80A in the X direction.

[0137] Furthermore, in the above embodiment, the bending strength of the first plate 21 is set to be more than twice and less than three times the bending strength of the second plate 22, but it is not limited to this. As long as the deflection of the first plate 21 can be suppressed by optimizing the position of the elastic body 23, for example, the bending strength of the first plate 21 can be the same as that of the second plate 22.

[0138] Furthermore, the lower buffer is formed as a single piece, but it can also be divided in the width direction, just like the upper and middle buffers.

[0139] Furthermore, the central buffer can also be divided in the vertical direction.

[0140] Explanation of reference numerals in the attached figures

[0141] 1-Lower buffer, 3-Middle buffer, 5-Upper buffer, 10-Bundling unit, 20-Vibration absorption unit, 21-First plate, 22-Second plate, 23-Elastomer, 80-Storage container, 80A-Storage object, 81-Container body, 100-Buffer assembly, 200-Container, 200A-Transport container, 201-Container body, 202-Base plate, C1-Center, C2-Center of gravity, D-Distance, W-Semiconductor wafer.

Claims

1. A bundling unit for bundling an object containing semiconductor wafers, which is a container for storing semiconductor wafers, in a container-type shipping container in a manner that is divided into two rows spaced apart in the width direction and in two layers in the vertical direction, the bundling unit comprising: The lower buffer supports the lower part of the two rows of stored objects in the lower layer; A central buffer is installed between the upper and lower layers of the stored objects in each column of the stored objects; The upper buffer is provided with one in each of the two columns of stored objects in the upper layer to hold the upper part of the stored objects; and The vibration absorption unit supports the lower buffer from below and is located at the very bottom of the container. The vibration absorption unit has: First tablet; A second plate, parallel to the first plate, and positioned below the first plate; and An elastomer is disposed between the first plate and the second plate, and the number of elastomers is the same as the number of objects stored in each layer. When viewed from above, the center of the elastomer is located further outward than the center of gravity of the two rows of stored objects relative to the middle of the stored objects. The distance in the width direction between the center of the elastomer and the center of gravity of the stored objects is more than 2% and less than 8% of the maximum outer diameter of the elastomer.

2. The bundling unit according to claim 1, wherein, If the interval between the centers of adjacent elastic bodies in the column direction is defined as Gx, and the interval between the centers of adjacent elastic bodies in the width direction is defined as Gy, then the ratio of Gy to Gx, Gy / Gx, is greater than or equal to 1 and less than or equal to 1.

3.

3. The bundling unit according to claim 1 or 2, wherein, The bending strength of the first plate is more than twice and less than three times that of the bending strength of the second plate.

4. The bundling unit according to claim 1 or 2, wherein, In the first plate and the second plate, at least the first plate has a groove formed.

5. A transport container, comprising: The bundling unit as described in claim 1 or 2; and A box-type container that houses the bundled units.

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