Wafer temporary storage device

Abstract

The utility model provides a wafer temporary storage device, which comprises a temporary storage box, a first lifting plate, a second lifting plate, a temporary storage frame and a wafer adsorption arm, and is characterized in that the first lifting plate and the second lifting plate are respectively arranged in the temporary storage box along the vertical direction and can divide the temporary storage box into a water storage area, an immersion area and a drainage area which are arranged in sequence; the temporary storage rack is arranged in the immersion area, and the wafer adsorption arm is arranged on the outer side of the temporary storage box; water in the water storage area can flow into the immersion area to immerse the wafer when the first lifting plate moves upwards, and water in the immersion area can flow into the drainage area when the second lifting plate moves upwards. According to the wafer temporary storage device provided by the utility model, the effect of supplying water or draining water to the immersion area is realized through the lifting cooperation of the first lifting plate and the second lifting plate, so that the wafer can be fully immersed in deionized water in the temporary storage period, and the wafer is in a fully moisturizing state; the problem that a spraying area formed by a traditional nozzle cannot cover the wafer completely is solved, and the machining quality of the wafer is effectively guaranteed.

Description

Technical Field

[0001] The utility model belongs to the technical field of positioning tooling, and more specifically, relates to a wafer temporary storage device. Background Art

[0002] CMP (Chemical Mechanical Planarization) is a technology for planarizing wafers through chemical and mechanical actions. Before the wafer is transferred to the cleaning area after CMP, situations such as congestion in the cleaning area often occur, and the wafer needs to be temporarily stored at a certain station for waiting. However, the existing horizontal temporary storage method has strict requirements for the temporary storage time. Especially for the Cu CMP process, if the temporary storage time is slightly longer, it will cause irreparable damage to the chip.

[0003] In the prior art, the temporary storage structure mainly includes a temporary storage station platform, on which wafer support columns and multiple nozzles are installed. During temporary storage, the wafer is placed on the wafer support columns, and multiple nozzles are used to spray water mist on the wafer to form a moisturizing effect on the wafer.

[0004] The above temporary storage method has the following disadvantages: 1. The water spraying effect of the nozzles is affected by various conditions such as water pressure fluctuations, and the stability is poor; 2. Affected by the number and distribution positions of the nozzles, the water volume consistency in different regions is poor, and when the temporary storage time is short, there will also be a situation where some regions of the wafer are not fully covered; 3. Although the nozzles can be selected to spray in an atomized manner, after all, they are still water droplets, and the long-term impact force of the water droplets may cause damage to the wafer. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a wafer temporary storage device, which can reduce the impact on the wafer surface, improve the tolerance range of the wafer temporary storage time, meet the effective moisturizing during wafer temporary storage, and reduce the risk during wafer temporary storage.

[0006] To achieve the above purpose, the technical solution adopted by the utility model is: to provide a wafer temporary storage device, including a temporary storage box, a first lifting plate, a second lifting plate, a temporary storage rack, and a wafer adsorption arm. The first lifting plate and the second lifting plate are respectively arranged in the temporary storage box in the up and down direction, and can divide the temporary storage box into a sequentially arranged water storage area, an immersion area, and a drainage area. The temporary storage rack is arranged in the immersion area, and the wafer adsorption arm is arranged outside the temporary storage box and is used to place the wafer on the temporary storage rack or transfer the wafer on the temporary storage rack;

[0007] Among them, the water in the water storage area can flow into the immersion area to immerse the wafer when the first lifting plate moves upward, and the water in the immersion area can flow into the drainage area and be discharged from the temporary storage box when the second lifting plate moves upward.

[0008] In a possible implementation, the temporary storage rack includes a plurality of support columns connected to the inner bottom wall of the temporary storage box. The support columns extend in the vertical direction and are arranged at intervals in the circumferential direction, and are used to support under the edge of the wafer.

[0009] In some embodiments, a supporting groove is provided on the top surface of the support column. The supporting groove penetrates through the side wall of the support column. The bottom wall of the supporting groove supports under the wafer, and the side wall of the supporting groove is arc-shaped, and the side wall of the supporting groove is used to limit the peripheral wall of the wafer.

[0010] In a possible implementation, the height of the first lifting plate is greater than the height of the second lifting plate, and the height of the second lifting plate is greater than the height of the temporary storage rack.

[0011] In a possible implementation, the first lifting plate and the second lifting plate are installed above the temporary storage box through a mounting frame. The first lifting plate and the second lifting plate both include a lifting driving member, a connecting frame, and a lifting plate body. The outer extending end of the lifting driving member extends downward, and the lifting plate body is connected to the lower part of the lifting driving member through the connecting frame.

[0012] In some embodiments, first vertical guide grooves extending in the vertical direction and used to guide the up and down movement of the first lifting plate are respectively provided on the opposite side walls of the temporary storage box, and second vertical guide grooves extending in the vertical direction and used to guide the up and down movement of the second lifting plate are respectively provided on the opposite side walls of the temporary storage box. The two side edges of the first lifting plate are respectively slidably connected to the first vertical guide grooves, and the two side edges of the second lifting plate are respectively slidably connected to the second vertical guide grooves.

[0013] In some embodiments, flexible sealing strips are respectively coated on the two side edges of the lifting plate body. The flexible sealing strips are used to abut and seal against the inner wall of the first vertical guide groove or the second vertical guide groove, and a bottom sealing strip abutting against the bottom wall of the temporary storage box is provided at the lower edge of the lifting plate body.

[0014] In a possible implementation, a drain pipe is connected to the bottom of the temporary storage box. The drain pipe is communicated with the drainage area and is used to drain the water in the drainage area.

[0015] In a possible implementation, a water supply pipe is further provided above the temporary storage box. The water supply pipe is used to supply deionized water to the water storage area.

[0016] In the solution shown in the embodiments of the present application, compared with the prior art, in the solution shown in the embodiments of the present application, a temporary storage rack for placing wafers is provided in the immersion area of the temporary storage box. The lifting cooperation of the first lifting plate and the second lifting plate is used to achieve the effect of supplying water or draining water to the immersion area, so that the wafers can be fully immersed in deionized water during the temporary storage period, and the wafers are in a fully moisturized state, avoiding the problem that the spraying area formed by the traditional nozzle does not fully cover the wafers, and at the same time avoiding damage to the wafers, effectively ensuring the processing quality of the wafers. Brief Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a front view sectional structure schematic diagram of the first state of the wafer temporary storage device provided by the embodiment of the present invention;

[0019] Figure 2 For the embodiment of the present invention Figure 1 It is a sectional structure schematic diagram of A-A in the embodiment;

[0020] Figure 3 For the embodiment of the present invention Figure 1 It is a sectional structure schematic diagram of B-B in the embodiment;

[0021] Figure 4 For the embodiment of the present invention Figure 1 It is a partial top view structure schematic diagram of the temporary storage box and the temporary storage rack in the embodiment;

[0022] Figure 5 It is a front view sectional structure schematic diagram of the second state of the wafer temporary storage device provided by the embodiment of the present invention;

[0023] Figure 6 It is a front view sectional structure schematic diagram of the third state of the wafer temporary storage device provided by the embodiment of the present invention.

[0024] Among them, the reference numerals in the drawings are as follows:

[0025] 1. Temporary storage box; 11. Second vertical guide groove; 12. Drain pipe; 2. First lifting plate; 21. Lifting driving member; 22. Connecting frame; 221. Connecting cross bar; 222. Connecting vertical bar; 23. Lifting plate body; 24. Flexible sealing strip; 3. Second lifting plate; 4. Temporary storage rack; 41. Support column; 42. Support groove; 43. Mounting rack; 5. Wafer adsorption arm; 61. Water storage area; 62. Immersion area; 63. Drainage area; 7. Water supply pipe; 8. Wafer. Detailed Embodiments

[0026] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the following further details the present invention in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or indirectly on the other element. It should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, the meaning of "a plurality of" is two or more, unless otherwise specifically defined.

[0028] Please refer to Figures 1 to 6 , and now the wafer temporary storage device provided by the present invention will be described. The wafer temporary storage device includes a temporary storage box 1, a first lifting plate 2, a second lifting plate 3, a temporary storage rack 4, and a wafer suction arm 5. The first lifting plate 2 and the second lifting plate 3 are respectively arranged in the temporary storage box 1 along the up and down direction, and can divide the temporary storage box 1 into a sequentially arranged water storage area 61, an immersion area 62, and a drainage area 63. The temporary storage rack 4 is arranged in the immersion area 62, and the wafer suction arm 5 is arranged outside the temporary storage box 1 and is used to place the wafer 8 on the temporary storage rack 4 or transfer the wafer 8 on the temporary storage rack 4;

[0029] Among them, the water in the water storage area 61 can flow into the immersion area 62 to immerse the wafer 8 when the first lifting plate 2 moves upward, and the water in the immersion area 62 can flow into the drainage area 63 and be discharged from the temporary storage box 1 when the second lifting plate 3 moves upward.

[0030] Compared with the prior art, in the wafer temporary storage device provided in this embodiment, a temporary storage rack 4 for placing the wafer 8 is provided in the immersion area 62 of the temporary storage box 1. The lifting cooperation of the first lifting plate 2 and the second lifting plate 3 is used to achieve the effect of supplying water or draining water to the immersion area 62, so that the wafer 8 can be fully immersed in deionized water during the temporary storage period, and the wafer 8 is in a fully moisturized state, avoiding the problem that the spraying area formed by the traditional nozzle does not fully cover the wafer, and at the same time avoiding damage to the wafer 8, effectively ensuring the processing quality of the wafer 8.

[0031] In this embodiment, by arranging a first lifting plate 2 and a second lifting plate 3 in the temporary storage box 1, the internal space of the temporary storage box 1 can be divided into a water storage area 61, an immersion area 62, and a drainage area 63. The temporary storage rack 4 in the immersion area 62 is used to support the wafer 8 from below. According to the temporary storage requirements of the wafer 8, the water supply and drainage operations of the immersion area 62 are completed through the lifting actions of the first lifting plate 2 and the second lifting plate 3. The specific process is as follows.

[0032] First, please refer to Figure 1 . The first lifting plate 2 moves down to contact the inner bottom wall of the temporary storage box 1, separating the water storage area 61 from the immersion area 62. The water storage area 61 can be used to store deionized water. At this time, the second lifting plate 3 is in a lifted state, enabling the immersion area 62 to communicate with the drainage area 63. At this time, there is no deionized water in the immersion area 62.

[0033] Second, please refer to Figure 2 . The wafer 8 is placed on the temporary storage rack 4 for temporary storage. The second lifting plate 3 moves down, and then the first lifting plate 2 moves down, causing the water storage area 61 to communicate with the immersion area 62. The deionized water in the water storage area 61 gradually flows into the immersion area 62, fully immersing the wafer 8 with deionized water. At this time, the wafer 8 is in a fully moisturized state.

[0034] When the wafer 8 has completed temporary storage and needs to be taken out, please refer to Figure 3 . The first lifting plate 2 moves down, and then the second lifting plate 3 moves up, causing the immersion area 62 to communicate with the drainage area 63. The deionized water in the immersion area 62 can be discharged outwards through the drainage area 63 until the immersion area 62 is drained completely and the wafer 8 is exposed. At this time, the wafer 8 can be transferred out of the temporary storage box 1 by means of the wafer suction arm 5, and the temporary storage process of the wafer 8 is completed at this time.

[0035] It should be noted that after the wafer 8 is in an immersed state, the immersion area 62 can be in an overflow state by keeping the first lifting plate 2 in a lifted state to ensure fresh water quality. The above overflow can be continuous or intermittent.

[0036] In a possible implementation, please refer to Figures 1 to 6 . The temporary storage rack 4 includes a plurality of support columns 41 connected to the inner bottom wall of the temporary storage box 1. The support columns 41 extend in the vertical direction and are arranged at intervals in the circumferential direction, and are used to support under the edge of the wafer 8.

[0037] In this embodiment, the wafer 8 is effectively supported by a plurality of support columns 41 connected to the inner bottom wall of the temporary storage box 1. When the wafer 8 needs to be temporarily stored, the wafer 8 is adsorbed above the support columns 41 by means of the wafer suction arm 5, and the support columns 41 form a supporting effect on the wafer 8. A suction cup for adsorbing the wafer 8 is provided at the lower end of the wafer suction arm 5, enabling the position transfer of the wafer 8.

[0038] In some embodiments, referring to Figures 1 to 6 , a supporting groove 42 is provided on the top surface of the supporting column 41. The supporting groove 42 penetrates through the side wall of the supporting column 41. The bottom wall of the supporting groove 42 supports the lower part of the wafer 8. The side wall of the supporting groove 42 is arc-shaped, and the side wall of the supporting groove 42 is used to limit the peripheral wall of the wafer 8.

[0039] In this embodiment, the supporting groove 42 provided on the top surface of the supporting column 41 can support the outer peripheral part of the bottom surface of the wafer 8, effectively support the wafer 8, facilitate immersing the wafer 8 in deionized water, and further effectively moisturize the wafer 8.

[0040] The side wall of the supporting groove 42 is arc-shaped, which can be consistent with the radian of the peripheral wall of the wafer 8, form an effective limit on the outer peripheral wall of the wafer 8, avoid the position displacement of the wafer 8 when deionized water enters the immersion area 62 from the water storage area 61, enable the supporting groove 42 to effectively contact the outer peripheral wall of the wafer 8, make the wafer 8 stably located on the temporary storage rack 4 formed by a plurality of supporting columns 41, and utilize the supporting groove 42 to form a good limiting effect on the wafer 8 to ensure the position stability of the wafer 8.

[0041] It should be noted that the supporting column 41 should not only reliably support the wafer 8, but also avoid having too large a contact area with the wafer 8, so that the wafer 8 can be in full contact with deionized water to form a good moisturizing state.

[0042] In a possible implementation manner, referring to Figures 1 to 6 , the height of the first lifting plate 2 is greater than the height of the second lifting plate 3, and the height of the second lifting plate 3 is greater than the height of the temporary storage rack 4. The height of the first lifting plate 2 determines the height of the water storage area 61. The first lifting plate 2 is higher than the second lifting plate 3 to facilitate meeting the water supply requirements of the water storage area 61 to the immersion area 62. The height of the immersion area 62 is determined by the lower second lifting plate 3. The height of the second lifting plate 3 should be greater than the height of the temporary storage rack 4 so that the water level height in the immersion area 62 is greater than the height of the wafer 8, thereby ensuring the full immersion of the wafer 8 in the immersion area 62.

[0043] In a possible implementation manner, referring to Figures 1 to 6 , the first lifting plate 2 and the second lifting plate 3 are installed above the temporary storage box 1 through the mounting frame 43. Both the first lifting plate 2 and the second lifting plate 3 include a lifting driving member 21, a connecting frame 22, and a lifting plate body 23. The outer extending end of the lifting driving member 21 extends downward, and the lifting plate body 23 is connected to the lower part of the lifting driving member 21 through the connecting frame 22.

[0044] In this embodiment, the structures of the first lifting plate 2 and the second lifting plate 3 are the same. Taking the structure of the first lifting plate 2 as an example for illustration. The lifting driving member 21 drives the connecting frame 22 and the lifting plate body 23 to move up and down, and then controls the communication states of the water storage area 61, the immersion area 62 and the drainage area 63 through the lifting action of the lifting plate body 23.

[0045] Specifically, the connecting frame 22 includes a connecting cross bar 221 and a plurality of connecting vertical bars 222. The connecting cross bar 221 is arranged perpendicular to the main axis of the lifting driving member 21 and is parallel to the upper edge of the lifting plate body 23. The connecting vertical bars 222 are arranged perpendicular to the connecting cross bar 221, and the plurality of connecting vertical bars 222 are arranged at intervals along the direction of the connecting cross bar 221. The lifting driving member 21 drives the connecting cross bar 221 to move up and down, and then enables the plurality of connecting vertical bars 222 below to synchronously drive the lower lifting plate body 23 to perform ascending or descending actions, ensuring the effectiveness of the driving and avoiding structural damage caused by excessive force on local nodes.

[0046] In some embodiments, please refer to Figures 1 to 6 , on the opposite side walls of the temporary storage box 1, there are respectively provided first vertical guide grooves extending in the up and down direction and used for guiding the up and down movement of the first lifting plate 2, and on the opposite side walls of the temporary storage box 1, there are respectively provided second vertical guide grooves 11 extending in the up and down direction and used for guiding the up and down movement of the second lifting plate 3. The two side edges of the first lifting plate 2 are respectively slidably connected to the first vertical guide grooves, and the two side edges of the second lifting plate 3 are respectively slidably connected to the second vertical guide grooves 11.

[0047] In this embodiment, the first vertical guide grooves are slidably matched with the first lifting plate 2 to form good guidance for the lifting action of the first lifting plate 2 and avoid jamming during its lifting process. Similarly, the second vertical guide grooves 11 are also slidably matched with the second lifting plate 3 to ensure the smoothness of the lifting action of the second lifting plate 3.

[0048] In some embodiments, please refer to Figures 1 to 6 In some embodiments, please refer to Figures 1 to 6 , on the two side edges of the lifting plate body 23, there are respectively covered with flexible sealing strips 24. The flexible sealing strips 24 are used to abut and seal against the inner walls of the first vertical guide grooves or the second vertical guide grooves 11, and the lower edge of the lifting plate body 23 is provided with a bottom sealing strip abutting against the bottom wall of the temporary storage box 1. The flexible sealing strips 24 covered on the two side edges of the lifting plate body 23 can improve the sealing performance and avoid the circulation of deionized water caused by gaps.

[0049] On the basis of the above structure, a bottom sealing strip is also provided at the lower edge of the lifting plate body 23, which is convenient to form a sealing effect between the lifting plate body 23 and the inner bottom wall of the temporary storage box 1, and avoid the deionized water from flowing between the water storage area 61 and the immersion area 62 or between the immersion area 62 and the drainage area 63 when the first lifting plate 2 and the second lifting plate 3 are in the descending state.

[0050] In a possible implementation manner, please refer to Figures 1 to 6 , a drain pipe 12 is connected to the bottom of the temporary storage box 1, and the drain pipe 12 is in communication with the drainage area 63 for discharging the water in the drainage area 63. The water in the drainage area 63 can be conveniently discharged from the temporary storage box 1 through the drain pipe 12, ensuring that the subsequent wafers 8 can be immersed in deionized water with a required cleanliness.

[0051] In a possible implementation manner, please refer to Figures 1 to 6 , a water supply pipe 7 is further provided above the temporary storage box 1, and the water supply pipe 7 is used to supply deionized water to the water storage area 61. The water supply pipe 7 is used to be connected to a deionized water storage tank. By providing a water pump and a flow valve on the water supply pipe 7, the supply situation of the water supply pipe 7 is controlled to ensure the water required for immersing the wafers 8.

[0052] The above wafer temporary storage device realizes the effect of supplying water or draining water to the immersion area 62 by the lifting cooperation of the first lifting plate 2 and the second lifting plate 3, so that the wafers 8 can be fully immersed in deionized water during the temporary storage period, keeping the wafers 8 in a fully moisturized state, avoiding the problem that the spraying area formed by the traditional nozzle does not fully cover the wafers, and at the same time avoiding damage to the wafers 8, effectively ensuring the processing quality of the wafers 8.

[0053] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A wafer temporary storage device, characterized in that: The invention comprises a temporary storage box (1), a first lifting plate (2), a second lifting plate (3), a temporary storage rack (4) and a wafer adsorption arm (5); the first lifting plate (2) and the second lifting plate (3) are respectively arranged in the temporary storage box (1) along the up and down directions, and can separate the temporary storage box (1) into a water storage area (61), an immersion area (62) and a drainage area (63) arranged in sequence; the temporary storage rack (4) is arranged in the immersion area (62); the wafer adsorption arm (5) is arranged on the outside of the temporary storage box (1) and is used for placing a wafer (8) on the temporary storage rack (4) or transferring a wafer (8) on the temporary storage rack (4); The water in the water storage area (61) can flow into the immersion area (62) to immerse the wafer (8) when the first lifting plate (2) moves upward, and the water in the immersion area (62) can flow into the drainage area (63) and be discharged from the temporary storage box (1) when the second lifting plate (3) moves upward.

2. The wafer temporary storage device according to claim 1, characterized in that: The temporary storage rack (4) comprises a plurality of support columns (41) connected to the inner bottom wall of the temporary storage box (1); the support columns (41) extend in the up-down direction and are arranged at intervals in the circumferential direction; the support columns (41) are used to support wafers (8).

3. The wafer temporary storage device according to claim 2, characterized in that: A supporting groove (42) is provided on the top surface of the supporting column (41), and the supporting groove (42) is arranged through the side wall of the supporting column (41). The bottom wall of the supporting groove (42) is supported below the wafer (8), and the groove side wall of the supporting groove (42) is arc-shaped. The groove side wall of the supporting groove (42) is used to limit the peripheral wall of the wafer (8).

4. The wafer temporary storage device according to claim 1, characterized in that: The height of the first lifting plate (2) is greater than the height of the second lifting plate (3), and the height of the second lifting plate (3) is greater than the height of the temporary storage rack (4).

5. The wafer temporary storage device according to claim 4, characterized in that: The first lifting plate (2) and the second lifting plate (3) are installed above the temporary storage box (1) through a mounting frame (43); the first lifting plate (2) and the second lifting plate (3) both comprise a lifting drive member (21), a connecting frame (22) and a lifting plate body (23); the outer end of the lifting drive member (21) extends downward, and the lifting plate body (23) is connected to the bottom of the lifting drive member (21) through the connecting frame (22).

6. The wafer temporary storage device according to claim 5, characterized in that: The connecting frame (22) comprises a connecting cross bar (221) and a plurality of connecting vertical bars (222); the connecting cross bar (221) is arranged perpendicular to the main axis of the lifting drive member (21) and parallel to the upper edge of the lifting plate body (23); the connecting vertical bars (222) are arranged perpendicular to the connecting cross bar (221); and the plurality of connecting vertical bars (222) are arranged at intervals along the direction of the connecting cross bar (221).

7. The wafer temporary storage device according to claim 5, characterized in that: The temporary storage box (1) is provided with first vertical guide grooves extending in the up-down direction and used for guiding the first lifting plate (2) to move up and down, respectively, on the opposite side walls of the temporary storage box (1), and second vertical guide grooves (11) extending in the up-down direction and used for guiding the second lifting plate (3) to move up and down, respectively, on the opposite side walls of the temporary storage box (1), and the two side edges of the first lifting plate (2) are respectively slidably connected to the first vertical guide grooves, and the two side edges of the second lifting plate (3) are respectively slidably connected to the second vertical guide grooves (11).

8. The wafer temporary storage device according to claim 7, characterized in that: The two side edges of the lifting plate body (23) are respectively covered with flexible sealing strips (24), and the flexible sealing strips (24) are used to abut and seal with the inner wall of the first vertical guide groove or the second vertical guide groove (11). The lower edge of the lifting plate body (23) is provided with a bottom sealing strip abutting with the bottom wall of the temporary storage box (1).

9. The wafer temporary storage device according to any one of claims 1 to 8, characterized in that: The bottom of the temporary storage box (1) is connected to a drainage pipe (12), and the drainage pipe (12) is in communication with the drainage area (63) and is used to drain water from the drainage area (63).

10. The wafer temporary storage device according to any one of claims 1 to 8, characterized in that: A water supply pipe (7) is also provided above the temporary storage box (1), and the water supply pipe (7) is used to supply deionized water to the water storage area (61).

Images