Patent Publication Number: US-7591714-B2

Title: Wafer grinding and tape attaching apparatus and method

Description:
PRIORITY STATEMENT 
     This U.S. non-provisional application claims benefit of priority under 35 U.S.C. §119 of Korean Patent Application No. 2005-101729, filed on Oct. 27, 2005, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an apparatus and method for fabricating a semiconductor package, and more particularly, to an apparatus and method for grinding a back side of a wafer and attaching dicing tape to the back side of a wafer. 
     2. Description of the Related Art 
     Conventionally, a wafer fabrication process may use a relatively thick wafer because a wafer may be damaged during handling. The back side of the wafer may be ground to reduce the thickness of the wafer. 
     For example, an 8-inch diameter wafer may have an initial thickness between 730 μm and 750 μm, and a 12-inch diameter wafer may have an initial thickness between 790 μm and 800 μm. After a grinding process, the wafers may have a final thickness within the range of 50 μm to 450 μm. The final thickness may vary depending on the semiconductor product, demand of users, product characteristics, etc. 
     For a wafer sawing process, a dicing tape may be attached to the back side of the thinned and/or ground wafer. Conventionally, a robot arm may transfer a wafer to a dicing tape attaching apparatus, and the dicing tape attaching apparatus may attach the dicing tape to the wafer. A wafer may be provided to the dicing tape attaching apparatus while the wafer is loaded in a wafer cassette. If a wafer grinding apparatus is installed in-line with a dicing tape attaching apparatus, the wafer may be directly provided to the dicing tape attaching apparatus. The attachment of the dicing tape to the wafer may reduce a chip separation fault which may occur to the package during a wafer sawing process. 
     Conventionally, an in-line wafer grinding and tape attaching apparatus may include a wafer grinding apparatus and a tape attaching apparatus. The wafer grinding apparatus may include a turntable having a plurality of chuck tables installed thereon. The tape attaching apparatus may be installed near the wafer grinding apparatus and may be configured to attach a dicing tape to a back side of a wafer and/or remove a protection tape from a front side of a wafer. 
     Referring to  FIGS. 1A and 1B , a robot arm  3  may transfer a wafer  60  between a wafer grinding apparatus and a tape attaching apparatus. For example, the robot arm  3  may adsorb the wafer  60  using a vacuum and may transfer the wafer  60  to the tape attaching apparatus. 
     The thinner the wafer  60  is, the more the wafer may be subject to warpage. The wafer  60  may have a front side  61  with an integrated circuit layer and a silicon layer. The thickness of the silicon layer may be reduced by a grinding process. Further, the coefficient of thermal expansion of the silicon layer may be different from that of the integrated circuit layer, and the wafer  60  may be bent toward the front side  61  of the wafer as shown in  FIG. 1B . 
     As a result, if a robot arm  3  transfers the wafer  60  using a vacuum, the vacuum may leak through the bent portion of the wafer  60 , and the connection between the robot arm  3  and the wafer my be lost. Accordingly, the wafer  60  may be dropped by the robot arm  3 . 
     A wafer  60  may be inadvertently dropped from the robot arm  3  as described above during processes resulting in lost time and resources. For example, a wafer  60  may be inadvertently dropped during a process for loading a wafer to a wafer cassette, a process for removing a protection tape from a wafer and/or a process for attaching dicing tape to a wafer. 
     SUMMARY OF THE INVENTION 
     An example embodiment of the present invention is directed to stably handling a thinned wafer without damaging the wafer. 
     An example embodiment of the present invention is directed to providing a wafer grinding and tape attaching apparatus and method. 
     According to an example embodiment of the present invention, an apparatus may include a wafer providing unit, a grinding unit, a tape attaching unit and a wafer ring receiving unit. The wafer providing unit may be configured to provide a wafer having a front side and a back side. The grinding unit may be configured to grind the back side of the wafer. The grinding unit may include chuck tables configured to support the wafer and grinding wheels located on the chuck tables. The tape attaching unit may be configured to provide a wafer ring having a dicing tape to the chuck table having the wafer so the dicing tape may be attached to the back side of the ground wafer. The wafer ring receiving unit may be configured to receive the wafer ring having the ground wafer. 
     According to an example embodiment of the present invention, a wafer providing unit may include a wafer cassette configured to contain a wafer before a grinding process, an alignment table configured to align the wafer, and a loader configured to transfer the wafer from the wafer cassette to the alignment table and from the alignment table to a grinding unit. 
     According to an example embodiment of the present invention, a chuck table may include a buffer table configured to provide a wafer and/or a wafer ring having the wafer, and at least one grinding table located near the buffer table and configured to grind the back side of the wafer. 
     According to an example embodiment of the present invention, a grinding unit may further include a turntable having chuck tables radially arranged thereon. The turntable may be rotated to change the positions of the chuck tables. 
     According to an example embodiment of the present invention, a tape attaching unit may include a wafer ring cassette located near a buffer table and configured to contain a wafer ring, a first transfer configured to transfer a wafer ring from the wafer ring cassette to the buffer table and unload the wafer ring having the wafer from the grinding unit, and a roller configured to attach the dicing tape to the back side of the ground wafer. 
     According to an example embodiment of the present invention, a tape attaching unit may include a wafer ring container configured to contain a wafer ring, a tape attaching device configured to attach dicing tape to the wafer ring, a first transfer configured to load the wafer ring to the buffer table having the wafer and unload the wafer ring having the ground wafer from the grinding unit, and a roller configured to attach dicing tape to the back side of the ground wafer. 
     According to an example embodiment of the present invention, a tape attaching unit may also include a second transfer configured to flip a ground wafer so the front side of the ground wafer faces upward. 
     According to an example embodiment of the present invention, a wafer may have a protection adhesive, and an apparatus according to an example embodiment of the present invention may include a tape remover configured to remove the protection adhesive from a ground wafer. 
     According to an example embodiment of the present invention, a wafer ring receiving unit may include an unloader configured to unload a wafer ring from a tape remover, and a wafer ring cabinet configured to receive the wafer ring. 
     According to an example embodiment of the present invention, a method for wafer grinding and tape attaching may include providing a wafer to a chuck table, the wafer having a back side facing upward. The back side of the wafer may be supported on the chuck table and may be ground by a grinding wheel. A wafer ring having dicing tape may be provided to the chuck table having the ground wafer. The dicing tape may be attached to the back side of the ground wafer. The wafer ring having the ground wafer may be unloaded from the chuck table. 
     According to an example embodiment of the present invention, providing a wafer ring may include preparing a wafer ring cassette having the wafer ring and transferring the wafer ring to the chuck table having the ground wafer to mount the dicing tape to the back side of the ground wafer. 
     According to an example embodiment of the present invention, providing a wafer ring may include preparing a wafer ring container having the wafer ring, attaching the dicing tape to the wafer ring, and transferring the wafer ring having the dicing tape to the chuck table having the wafer to mount the dicing tape to the back side of the ground wafer. 
     According to an example embodiment of the present invention, attaching dicing tape to the back side of a ground wafer may include pressing a roller onto the back side of the ground wafer using heat to adhere dicing tape to the back side of the ground wafer. 
     According to an example embodiment of the present invention, a method for wafer grinding and tape attaching may also include removing protection tape from a ground wafer and receiving a wafer ring having the wafer in a wafer ring cabinet. 
     According to an example embodiment of the present invention, a method for wafer grinding and tape attaching may also include flipping a wafer ring before removing protection tape so the front side of a ground wafer faces upward. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Example embodiments of the present invention will be readily understood with reference to the following detailed description thereof provided in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements. 
         FIG. 1A  is a cross-sectional view of a conventional process for transferring a thinned wafer. 
         FIG. 1B  is a cross-sectional view illustrating warpage of a wafer of  FIG. 1A . 
         FIG. 2  is a schematic view of a wafer grinding and tape attaching apparatus in accordance with an example embodiment of the present invention. 
         FIG. 3  is a flow chart of method for wafer grinding and tape attaching according to an example embodiment of the present invention shown. 
         FIGS. 4A through 11  are views illustrating a method for wafer grinding and tape attaching in accordance with an example embodiment of the present invention. 
         FIG. 12  is a block diagram of a wafer grinding and tape attaching apparatus and method according to an example embodiment of the present invention. 
     
    
    
     These drawings are provided for illustrative purposes only and are not drawn to scale. The spatial relationships and/or relative sizing of the elements illustrated in the various embodiments may have been reduced, expanded and/or rearranged to improve the clarity of the figure with respect to the corresponding description. The figures, therefore, should not be interpreted as accurately reflecting the relative sizing and/or positioning of the corresponding structural elements that could be encompassed by an actual device manufactured according to example embodiments of the present invention. 
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Various example embodiments of the present invention will now be described more fully with reference to the accompanying drawings in which some example embodiments of the invention are shown. In the drawings, the thicknesses of layers and regions may be exaggerated for clarity. 
     Detailed illustrative embodiments of the present invention are disclosed herein. However, specific structural and functional details disclosed herein are merely representative for purposes of describing example embodiments of the present invention. Accordingly, while example embodiments of the invention are capable of various modifications and alternative forms, embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit example embodiments of the invention to the particular forms disclosed, but on the contrary, example embodiments of the invention are to cover all modifications, equivalents, and alternatives falling within the scope of the invention. 
     It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments of the present invention. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between”, “adjacent” versus “directly adjacent”, etc.). 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising,”, “includes” and/or “including”, when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the FIGs. For example, two FIGs. shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved. 
     Further, well-known structures and processes are not described or illustrated in detail to avoid obscuring example embodiments of the present invention. Like reference numerals are used for like and corresponding parts of the various drawings. 
       FIG. 2  is a schematic view of a wafer grinding and tape attaching apparatus  100  according to an example embodiment of the present invention.  FIG. 4B  is a cross-sectional view of a wafer supported on a chuck table according to an example embodiment of the present invention. 
     Referring to  FIGS. 2 and 4B , a wafer grinding and tape attaching apparatus  100  may include a wafer providing unit  10 , a grinding unit  20 , a tape attaching unit  30 , a protection tape removing unit  40 , and a wafer ring receiving unit  50 . 
     The wafer providing unit  10  may be configured to provide a wafer  60   a  to the grinding unit  20  for a grinding process. The wafer providing unit  10  may include a wafer cassette  12 , an alignment table  14  and a loader  13 . The wafer cassette  12  may contain a wafer  60   a . The wafer  60   a  may face downward in the wafer cassette  12 . The alignment table  14  may align the wafer  60   a  on the alignment table  14  and/or grinding unit  20 . The loader  13  may transfer the wafer  60   a  from the wafer cassette  12  to the alignment table  14  and from the alignment table  14  to the grinding unit  20 . The loader  13  may use a transfer arm for transferring the wafer  60   a  using mechanical contact. The wafer  60   a  may have a front side  61  with a protection tape  63  and a back side  62  opposite to the front side  61 . The protection tape  63  may protect integrated circuits on the front side  61  of the wafer  60   a  during a grinding process and may be removed from the front side  61  of the wafer  60   a  after the grinding process. The protection tape  63  may include, use and/or be an ultraviolet tape. 
     The grinding unit  20  may include a turntable  21 , a plurality of chuck tables  22   a ,  22   b ,  22   c  and  22   d  arranged on the turntable  21 , and grinding wheels  23   a ,  23   b  and  23   c . The turntable  21  may be configured to support the wafers  60   a ,  60   b ,  60   c ,  60   d  and  60   e  using a vacuum connection, for example. The chuck tables  22   a ,  22   b ,  22   c  and  22   d  may include a first chuck table  22   a , second chuck table  22   b , third chuck table  22   c  and fourth chuck table  22   d . The grinding wheels  23   a ,  23   b  and  23   c  may be installed on the chuck tables  22   b ,  22   c  and  22   d.    
     According to an example embodiment of the present invention, chuck tables  22   a ,  22   b ,  22   c  and  22   d  may be radially arranged on a turntable  21 , and a turntable  21  may rotate in a clockwise direction to change the positions of the chuck tables  22   a ,  22   b ,  22   c  and  22   d.    
     According to an example embodiment of the present invention, a first chuck table  22   a  may serve as a buffer table for temporarily holding a wafer  60   a . A second chuck table  22   b , third chuck table  22   c  and fourth chuck table  22   d  may serve as grinding tables for grinding the wafers  60   b ,  60   c  and  60   d . The second chuck table  22   b  may grind the back side of a wafer  60   b  using the grinding wheel  23   a , which may have a rough surface. The third chuck table  22   c  may grind the back side of a wafer  60   c  using the grinding wheel  23   b , which may have a fine surface. The fourth chuck table  22   d  may polish the back side of a wafer  60   d  using a slurry and the grinding wheel  23   c , which may have a polishing pad. The fourth chuck table  22   d  may further clean the back side of a wafer  60   d . After a grinding process, a wafer  60   e  may be returned to the first chuck table  22   a.    
     Referring to an example embodiment of the present invention shown in  FIG. 4B , a first chuck table  22   a  may have a table body  24  and an adsorption plate  25 . The adsorption plate  25  may be provided on the table body  24  and may be formed from a porous material. The first chuck table  22   a  may be configured to support a front side  61  of a wafer  60   a  and/or  60   e . The first chuck table  22   a  may uniformly support the front side  61  of the wafer  60   a  and/or  60   e . The size of the first chuck table  22   a  may be such that a wafer ring may be placed on the table body  24  extending the adsorption plate  25 . 
     According to an example embodiment of the present invention, a tape attaching unit  30  may be configured to attach dicing tape  73  to the back side  62  of a thinned wafer  60   e  (e.g., a wafer that has undergone a grinding process). The tape attaching unit  30  may provide a wafer ring  70  having the dicing tape  73  attached thereto and/or supported thereon to the first chuck table  22   a  supporting the wafer  60   e  to adhere the dicing tape  73  to the back side  62  of the wafer  60   e . The tape attaching unit  30  may include a wafer ring cassette  31 , a first transfer  34  and a roller  36 . The wafer ring cassette  31  may be installed near the first chuck table  22   a  and may be configured to contain the wafer ring  70  having dicing tape  73 . The first transfer  34  may transfer the wafer ring  70  from the first wafer ring cassette  31  to first chuck table  22   a . The roller  36  may be configured to adhere the dicing tape  73  to the back side  62  of the wafer  60   e . The first transfer  34  may further be configured to unload the wafer  60   e  having the dicing tape  73  adhered thereto from the grinding unit  20 . 
     A transfer arm  32  may transfer the wafer ring  70  from the wafer ring cassette  31  to a buffer stage  33 . According to an example embodiment of the present invention, a buffer stage  33  may temporarily hold the wafer ring  70  for a tape attaching process. At this time, the wafer ring  70  may have a dicing tape attaching surface facing upward. 
     A first transfer  34  may have an adsorption unit  34   a  for picking up the wafer ring  70  using vacuum, for example. The first transfer  34  may transfer the wafer ring  70  from the buffer stage  33  to the first chuck table  22   a  and from the first chuck table  22   a  to a protection tape removing unit  40 . 
     A roller  36  may be placed outside the turntable  21  adjacent to the first chuck table  22   a  when a wafer ring  70  is provided to the first chuck table  22   a . The roller  36  may attach the dicing tape  73  of the wafer ring  70  to the back side  62  of the wafer  60  using pressure and heat, for example. 
     According to an example embodiment of the present invention, a tape attaching unit  30  may also include a second transfer  35 . The second transfer  35  may be configured to flip the wafer ring  70  so the front side  61  of the wafer  60  faces upward, for example. The second transfer  35  may have the same structure as the first transfer  34 . However, the second transfer may be positioned lower than the first transfer  34 . The second transfer  35  may receive the wafer ring  70  from the first transfer  34  and may transfer the wafer ring  70  to a protection tape removing unit  40 . 
     A protection tape removing unit  40  may remove the protection tape  63  from the front side  61  of the wafer  60 . The protection tape removing unit  40  may include an ultraviolet (UV) irradiator  41  and/or a tape remover  42 . The UV irradiator  41  may irradiate the protection tape  63  with UV rays, which may reduce the adhesive strength of the protection tape  63 . The tape remover  42  may peel off the protection tape  63  from the front side  61  of the wafer  60 . For example, an adhesive tape for removal may be attached to the protection tape  63 , after the protection tape  63  has been irradiated with UV rays. The tape remover  62  may remove the adhesive tape for removal to peel off the protection tape  63  from the front side  61  of the wafer  60 . 
     The wafer ring receiving unit  50  may include an unloader  51  and a wafer ring cabinet  52 . The unloader  51  may transfer the wafer ring  70  having the wafer  60   e  to the wafer ring cabinet  52 . 
       FIG. 3  is a flow chart  90  of a method for wafer grinding and tape attaching, which may be implemented by an apparatus  100  of an example embodiment of the present invention as shown in  FIG. 2 .  FIGS. 4A through 11  are views illustrating a method for wafer grinding and tape attaching according to an example embodiment of the present invention. 
     Referring to an example embodiment of the present invention shown in  FIGS. 4A and 4B , a method for wafer grinding and tape attaching may begin with loading a wafer  60   a  to a grinding unit  20  ( 91  of  FIG. 3 ). For example, the wafer  60   a  in a wafer cassette  12  may be transferred to an alignment table  14  by a loader  13 . The wafer  60   a  may be aligned in and/or on an alignment table  14  and may be transferred to a first chuck table  22   a  of the grinding unit  20  by the loader  13 . The wafer  60   a  may have a front side  61  with a protection tape  63  attached thereto and a back side  62 . The wafer  60   a  may be transferred to the first chuck table  22   a . The back side  62  of the wafer  60   a  may face upward as shown in  FIGS. 4A and 4B . 
     Referring to an example embodiment of the present invention shown in  FIGS. 5A and 5B , the back side  62  of the wafer may be ground ( 92  of  FIG. 3 ). While the grinding unit  20  may be rotated to change the positions of a second chuck table  22   b , a third chuck table  22   c  and a fourth chuck table  22   d , wafers  60   b ,  60   c  and  60   d  may be ground via a rough grinding process, a fine grinding process and a polishing and cleaning process, respectively. A thinned wafer  60   e  (e.g., a wafer that experienced the rough grinding process, a fine grinding process and/or a polishing and cleaning process) may be returned to the position of the first chuck table  22   a .  FIG. 5B  shows the rough grinding process for grinding the back side  62  of the wafer  60   b . According to an example embodiment of the present invention, the wafer  60   d  may be thicker than a target thickness by about 20 μm to about 30 μm after the rough grinding process using a rough grinding wheel  23   a  is completed. 
     Next, a tape attaching process may be performed. Referring to an example embodiment of the present invention shown in  FIGS. 6A and 6B , a wafer ring  70  having dicing tape  73  may be provided to the grinding unit  20  ( 93  of  FIG. 3 ). For example, the wafer ring  70  may be transferred from a wafer ring cassette  31  to a buffer stage  33  by a transfer arm  32  and then to the first chuck table  22   a  by a first transfer  34 . According to an example embodiment of the present invention, the wafer ring  70  may be transferred so an adhesive surface of the dicing tape  73  may face the back side  62  of the wafer  60   e.    
     Referring to an example embodiment of the present invention as shown in  FIGS. 7A and 7B , the dicing tape  73  may be attached to the back side  62  of the wafer  60   e  ( 94  of  FIG. 3 ). A roller  36  may be located outside turntable  21  and may be moved above the first chuck table  22   a . The roller  36  may roll on the dicing tape  73  using pressure and heat to adhere the dicing tape  73  to the back side  62  of the wafer  60   e.    
     Referring to an example embodiment of the present invention as shown in  FIGS. 8A and 8B , the wafer ring  70  may be unloaded from the grinding unit  20  ( 95  of  FIG. 3 ). For example, a roller  36  may be restored to the original position of the roller  36 . A first transfer  34  may be moved above the first chuck table  22   a . The first transfer  34  may adsorb the wafer ring  70  having the wafer  60   e  using a vacuum, while the adsorption of the first chuck table  22   a  may be intercepted, removed and/or overcome. The first transfer  34  may be moved upward to transfer the wafer ring  70  from the grinding unit  20  to the tape removing unit ( 40  of  FIG. 2 ). 
     In accordance with an example embodiment of the present invention, after a grinding process, the thinned wafer  60   e  may be unloaded from the grinding unit  20  with a wafer  60   e  being attached to a wafer ring  70 . 
     Referring to an example embodiment of the present invention as shown in  FIGS. 9A and 9B , a wafer ring  70  may be flipped ( 96  of  FIG. 3 ). As shown in  FIG. 9A , the first transfer  34  may be moved above the second transfer  35 , and a first adsorption unit  34   a  of the first transfer  34  may be moved downward to place the wafer ring  70  on a second adsorption unit  35   a  of the second transfer  35 . 
     As shown in an example embodiment of the present invention in  FIG. 9B , the second adsorption unit  35   a  may adsorb the wafer ring  70 , while the first adsorption unit  34   a  may reduce and/or stop the vacuum applied to the wafer ring  70 . The first transfer  34  may be slipped above the second transfer  35 , and the adsorption unit  35   a  of the second transfer  35  may be turned over to flip the wafer ring  70 . Accordingly, the front side  61  of the wafer  60   e  of the wafer ring  70  may face upward. The second transfer  35  may transfer the wafer ring  70  to the protection tape removing unit ( 40  of  FIG. 2 ). 
     Referring to an example embodiment of the present invention shown in  FIG. 10 , protection tape  63  may be removed from the front side  61  of the wafer  60   e  ( 37  of  FIG. 3 ). For example, an UV irradiator  41  may irradiate the protection tape  63  with UV rays to reduce the adhesive strength of the protection tape  63 . A tape remover  42  may remove the protection tape  63  from the front side  61  of the wafer  60   e.    
     Referring to an example embodiment of the present invention shown in  FIG. 11 , the wafer ring  70  may be transferred to and/or received in a wafer ring receiving unit  50  ( 98  of  FIG. 3 ). The wafer ring  70  may be transferred to the wafer ring cabinet  52  by an unloader  51 . 
     In accordance with an example embodiment of the present invention, a tape attaching process may be performed on a first chuck table  22   a . This may lead to stable adhesion between a wafer and dicing tape. For example, the thinned wafer created by a conventional device and or a conventional method may be subject to warpage, whereas a thinned wafer produced according to example embodiments of the present invention may be supported on a chuck table, whereby the likelihood of warpage of the thinned wafer may be reduced. 
     Further, according to example embodiments of the present invention, a thinned wafer is handled while the wafer is attached to a wafer ring. Accordingly, the thinned wafer may be stably handled during subsequent processes and damage which may occur to a wafer during handling may be reduced. 
       FIG. 12  is a block diagram of a wafer grinding and tape attaching apparatus  200  in accordance with an example embodiment of the present invention. 
     Referring to  FIG. 12 , a wafer grinding and tape attaching apparatus  200  may have the same structure as a previous example embodiment of the present invention described with respect to  FIG. 2 , except for a tape attaching unit  130  may have a tape attaching device  132 . The wafer grinding and tape attaching apparatus  200  may include a wafer providing unit  110 , a grinding unit  120 , a tape attaching unit  130 , a protection tape removing unit  140  and a wafer ring receiving unit  150 . 
     The tape attaching unit  130  may include a wafer ring container  131 , a mount table  133  and a tape attaching device  132 . The ring container  131  may contain a wafer ring  170 . The mount table  133  may support the wafer ring  170 . The tape attaching device  132  may attach dicing tape  173  to the wafer ring  170 . A first transfer  134  may provide the wafer ring  170  from the mount table  133  to a first chuck table  122   a . A roller  136  may adhere a wafer  60   a  to the dicing tape  173 . The first transfer  134  may unload the wafer ring  170  having a wafer  60   e  from the grinding unit  120 . 
     A method for wafer grinding and tape attaching according to this example embodiment may include providing the wafer ring  170  having the dicing tape  173  to the first chuck table  122   a  after the dicing tape  173  is attached to the wafer ring  170 . 
     Although example, non-limiting embodiments of the present invention have been described in detail hereinabove, it should be understood that variations and/or modifications of the basic inventive concepts herein taught, which may appear to those skilled in the art, still fall within the spirit and scope of example embodiments of the present invention.