Patent Publication Number: US-2023138307-A1

Title: Alignment mechanism and alignment method of bonding machine

Description:
TECHNICAL FIELD 
     The present disclosure relates to an alignment mechanism of a bonding machine, which allows rapid alignment of a wafer and a substrate and facilitates the subsequent bonding of the wafer and the substrate. 
     BACKGROUND 
     With the advancement of semiconductor technology, the thickness of wafers is continuously reduced to facilitate subsequent wafer dicing and packaging processes. In addition, the thinning of the wafer is also conducive to reducing the size of the chip, lowering the resistance, improving the calculation speed and extending the service life. However, the structure of the thinned wafer is very fragile, and the wafer is prone to warp or break in the subsequent manufacturing process, thereby decreasing the yield of the product. 
     In order to avoid the above problems, it is generally chosen to temporarily bond the wafer to a carrier substrate and support the thinned wafer by the carrier substrate to avoid warping or breaking of the thinned wafer during the manufacturing process. 
     Specifically, an adhesive may be applied to the surface of the carrier substrate and the wafer, and then the carrier substrate and the wafer are moved to a bonding machine and aligned. Subsequently, the carrier substrate and the wafer are bonded by increasing the temperature. After the bonding is completed, the wafer may be subjected to thinning, etching and metallization processes, etc., and lastly the wafer and the carrier substrate are separated. 
     Although bonding of the wafer and the carrier substrate can be done through the above steps, the alignment mechanism of a common bonding machine still has the problems of poor accuracy and low alignment efficiency, which affects the efficiency and yield of the process to a certain extent. 
     SUMMARY 
     In order to address the above-mentioned problems, the present invention proposes an alignment mechanism of a bonding machine, which effectively improves the accuracy and efficiency of the alignment between a wafer and a carrier substrate, and is beneficial to improve the efficiency and yield of the manufacturing process. In addition, by using an alignment mechanism of the present invention, the cost of installing multiple detectors on the machine can be saved. 
     An object of the present disclosure is to provide an alignment mechanism of a bonding machine, which mainly comprises a support pedestal configured with three first alignment members and three second alignment members, wherein the first and second alignment members are configured to move along a direction parallel to a supporting surface of the support pedestal and position a substrate through moving close to or away from the substrate. 
     In positioning a substrate, the first and second alignment members only need to move along a direction parallel to the supporting surface and do not need to raise or lower relative to the supporting surface. This is beneficial in simplifying the steps of aligning the substrate and the mechanisms of the machine. 
     An object of the present disclosure is to provide an alignment mechanism of a bonding machine, which mainly comprises a support pedestal configured with three alignment members and three support members, wherein the alignment members and the support members are configured to move along a direction parallel to a supporting surface of the support pedestal. 
     When the alignment members move toward a substrate, they contact and push the substrate to position the substrate. The support members are used in supporting a substrate, and the alignment members may align the substrate supported by the support members. 
     To achieve the abovementioned objects, the present disclosure provides an alignment mechanism of a bonding machine, comprising: a support pedestal including a supporting surface for supporting a first substrate, wherein the supporting surface has a placement area; three first alignment members arranged around the placement area of the supporting surface for positioning the first substrate through moving close to or away from the placement area and for supporting a second substrate, wherein the first alignment members each include a protruding part and a base, the protruding part being protruding from the base and directed to the placement area, the base being closer to the supporting surface than the protruding part, and the base being used to position the first substrate; and three second alignment members arranged around the placement area of the supporting surface for positioning the second substrate supported by the first alignment members through moving close to or away from the placement area, wherein the first alignment members move away from the placement area to place the second substrate thereon onto the first substrate. 
     The present disclosure provides another alignment mechanism of a bonding machine, comprising: a support pedestal including a supporting surface for supporting a first substrate, wherein the supporting surface has a placement area; three alignment members arranged around the placement area of the supporting surface for positioning the first substrate and a second substrate through moving close to or away from the placement area; and three support members arranged around the placement area of the supporting surface, the support members being configured to move close to or away from the placement area and being used to support the second substrate, wherein the alignment members move toward the placement area to position the second substrate supported by the support members, and the support members subsequently move away from the placement area to place the second substrate thereon onto the first substrate, wherein the support members each include a protruding part and a base, the protruding part being protruding from the base and directed to the placement area, the base being closer to the supporting surface than the protruding part. 
     The present disclosure also provides an alignment method for a bonding machine, comprising: placing a first substrate on a supporting surface of a support pedestal, wherein the supporting surface has a placement area; three alignment members moving toward the placement area to position the first substrate placed on the supporting surface to align the first substrate with the placement area; three support members moving toward the placement area and being used in supporting a second substrate; the alignment members moving toward the placement area to position the second substrate supported by the support members to align the second substrate with the first substrate; and the support members moving away from the placement area to place the second substrate thereon onto the first substrate. 
     The alignment mechanism of a bonding machine, wherein the protruding part of the first alignment members and the support members protrudes along a radial direction of the support pedestal and is used in supporting a second substrate. The first and second alignment members, the alignment members and the support members move along said radial direction close to or away from the placement area. 
     The alignment mechanism of a bonding machine, wherein the protruding part of the first alignment members and the support members includes an inclined face inclined in a direction toward the supporting surface of the support pedestal or the placement area. 
     The alignment mechanism of a bonding machine, comprising at least six connecting rods located on the supporting surface of the support pedestal and arranged around the placement area of the supporting surface, wherein each of the first and second alignment members and the alignment members and support members includes a fixing hole so as to be sleeved on one of the connecting rods. 
     The alignment method for a bonding machine, wherein one of the support members moves away from the placement area to obliquely place the second substrate thereon on the first substrate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The structure as well as preferred modes of use, further objects, and advantages of this present disclosure will be best understood by referring to the following detailed description of some illustrative embodiments in conjunction with the accompanying drawings, in which: 
         FIG.  1    is a perspective view illustrating an alignment mechanism of a bonding machine according to one embodiment of the present invention. 
         FIG.  2    is a top view illustrating an alignment mechanism of a bonding machine positioning a first substrate according to one embodiment of the present invention. 
         FIG.  3    is a top view illustrating an alignment mechanism of a bonding machine supporting a second substrate according to one embodiment of the present invention. 
         FIG.  4    is a top view illustrating an alignment mechanism of a bonding machine positioning a second substrate according to one embodiment of the present invention. 
         FIG.  5    is a side view illustrating first alignment members of an alignment mechanism of a bonding machine aligning a first substrate according to one embodiment of the present invention. 
         FIG.  6    is a side view illustrating first alignment members of an alignment mechanism of a bonding machine supporting a second substrate according to one embodiment of the present invention. 
         FIG.  7    is a side view illustrating first alignment members of an alignment mechanism of a bonding machine placing a second substrate according to one embodiment of the present invention. 
         FIG.  8    is a side view illustrating first alignment members of an alignment mechanism of a bonding machine supporting a second substrate according to another embodiment of the present invention. 
         FIG.  9    is a side view illustrating first alignment members of an alignment mechanism of a bonding machine placing a second substrate according to another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to  FIG.  1   , which is a perspective view illustrating an alignment mechanism of a bonding machine according to one embodiment of the present invention. As shown in the figure, an alignment mechanism  10  of a bonding machine mainly comprises a support pedestal  11 , at least three first alignment members  131  and at least three second alignment members  133 , wherein the first alignment members  131  and the second alignment members  133  are arranged at an area near an edge or a periphery of the support pedestal  11 . For example, a placement area  113  may be defined on a supporting surface  111  of the support pedestal  11 , wherein the supporting surface  111  and the placement area  113  are used for the placement of a substrate. The first alignment members  131  and the second alignment members  133  may be disposed in a spaced manner. As shown in  FIG.  1   , the elements with section line are the first alignment members  131 . The first alignment members  131  and the second alignment members  133  are arranged around the placement area  113 , and they may move close to or away from the placement area  113 . 
     The alignment mechanism  10  positions a first substrate  121  and a second substrate  123  located above the support pedestal  11  through the first alignment members  131  and the second alignment members  133 , respectively, such that the first substrate  121  overlaps with the second substrate  123 , wherein the second substrate  123  aligns with the first substrate  121 . 
     A minimum spacing between the first alignment members  131  and a minimum spacing between the second alignment members  133  may be adjusted according to the sizes of the first substrate  121  and the second substrate  123 , respectively. Specifically, the first substrate  121  and the second substrate  123  are in the shape of a round disc, wherein a circle formed by the first alignment members  131  in an alignment state has a similar size to the first substrate  121 , and a circle formed by the second alignment members  133  in an alignment state has a similar size to the second substrate  123 . 
     The supporting surface  111  of the support pedestal  11  may be used for supporting the first substrate  121 , wherein the first substrate  121  may be placed within or near to the placement area  113  of the supporting surface  111 , as shown in  FIG.  2   . The first alignment members  131  are located on the supporting surface  111  of the support pedestal  11  and move close to or away from the placement area  113  along a direction parallel to the supporting surface  111  to position the first substrate  121  placed on the supporting surface  111  or placement area  113  of the support pedestal  11 . For example, the supporting surface  111  and/or the placement areal  113  of the support pedestal  11  may take the shape of a circle, and the first alignment members  131  may move along a radial direction of the supporting surface  111  close to or away from the placement area  113  to position the first substrate  121 . 
     Specifically, the first substrate  121  is generally not precisely located within the placement area  113  when it is placed onto the placement area  113  of the support pedestal  11 . The first alignment members  131  may simultaneously or non-simultaneously move toward the placement area  113 , and contact with and position the first substrate  121 , such that the first substrate  121  is precisely placed within the placement area  113 . 
     As shown in  FIG.  5    to  FIG.  7   , in one embodiment of the present invention, the first alignment members  131  each include a base  1311  and a protruding part  1313 , wherein the base  1311  is closer to the supporting surface  111  of the support pedestal  11  than the protruding part  1313  is, and the protruding part  1313  protrudes from the base  1311  and is directed toward the placement area  113  of the support pedestal  11 . For example, the protruding part  1313  may protrude along a radial direction of the supporting surface  111  and/or the placement area  113  of the support pedestal  11 . When the first alignment members  131  move toward and close to the placement area  113  and the first substrate  121 , the bases  1311  of the first alignment members  131  push and position the first substrate  121 . 
     After positioning the first substrate  121 , the second substrate  123  may be placed above the placement area  113 . Now the first alignment members  131  maintain in a position where the first substrate  121  is positioned, and are used for supporting the second substrate  123 , for example, using the protruding parts  1313  of the first alignment members  131  to support the second substrate  123 , as shown is  FIG.  3   ,  FIG.  5    and  FIG.  6   . 
     Subsequently, the second alignment members  133  move toward and close to the placement area  113  and the second substrate  123 , and push and position the second substrate  123  supported by the first alignment members  131 . For example, the second alignment members  133  may move along a radial direction of the supporting surface  111 , as shown in  FIG.  4    and  FIG.  6   . In practical applications, the second alignment members  133  are not used for supporting a substrate, and thus the second alignment members  133  each may be a columnar body having a cross section of any shape, wherein the second alignment members  133  do not need to be configured with a protruding part as described above. 
     Through the above alignment process, the second substrate  123  is aligned with the first substrate  121 , wherein the second substrate  123  is still placed on the first alignment members  131 . Then the first alignment members  131  move away from the first substrate  121 , the second substrate  123  and/or the placement area  113 , for example, move away along a radial direction of the supporting surface  111 , such that the second substrate  123  falls from the first alignment members  131  and is placed onto the first substrate  121 , as shown in  FIG.  7   . 
     In practical applications, three first alignment members  131  may move away from the second substrate  123  in a non-simultaneous manner. For example, one of the first alignment members  131  first moves away from the second substrate  123  while the other two first alignment members  131  remain still, such that the second substrate  123  is obliquely placed on the first substrate  121 . Then the other two first alignment members  131  move away from the second substrate  123  to lay the second substrate  123  flat on the first substrate  121 . 
     In one embodiment of the present invention, when the first alignment members  131  move away from the second substrate  123 , the second alignment members  133  may stay still to avoid a displacement of the second substrate  123  relative to the first substrate  121  caused by a displacement of the first alignment members  131  relative to the second substrate  123 . 
     As shown in  FIG.  8    and  FIG.  9   , the protruding part  1313  of the first alignment members  131  may include a inclined face  1315 , wherein the inclined face  1315  is inclined in a direction toward the supporting surface  111  of the support pedestal  11  or the placement area  113 , and the second substrate  123  is placed on the inclined faces  1315  of the protruding parts  1313  of the first alignment members  131 . By configuring the protruding part  1313  with the inclined face  1315 , the second substrate  123  supported by the protruding part  1313  may be guided to slide along the inclined face  1315  and fall onto the first substrate  121 , and a displacement of the second substrate  123  relative to the first substrate  121  caused by a displacement of the first alignment members  131  relative to the second substrate  123  may be avoided. 
     In one embodiment of the present invention, the alignment mechanism  10  may include at least three lift pins  135  configured on the supporting surface  111  of the support pedestal  11 , wherein the first alignment members  131  and the second alignment members  133  are arranged around the lift pins  135 . For example, the lift pins  135  may be configured within the placement area  113  of the support pedestal  11 . The lift pins  135  may raise or lower relative to the supporting surface  111 , wherein lift pins  135  raise to receive and support the first substrate  121 , and the lift pins  135  lower to place the first substrate  121  thereon onto the supporting surface  111  of the support pedestal  11 . In addition, the lift pins  135  may lower simultaneously or non-simultaneously to lay the first substrate  121  flat or obliquely place the first substrate  121  on the supporting surface  111  of the support pedestal  11 . The lift pins  135  are not essential elements of the present invention. In other embodiments, the first substrate  121  may also be directly placed onto the placement area  113  of the support pedestal  11 . 
     In another embodiment of the present invention, in  FIG.  1    to  FIG.  9   , the first alignment members  131  each may be a support member  231 , and the second alignment members  133  each may be an alignment member  233 , wherein the quantity, position of arrangement and structure of the support members  231  and the alignment members  233  may be the same as those of the first and second alignment members  131 / 133 . 
     Three support members  231  and three alignment members  233  are arranged around the placement area  113  of the supporting surface  111 , and configured to move close to or away from the placement area  113 . In certain embodiments of the present invention, both the first substrate  121  and the second substrate  123  are aligned by the alignment members  233 , and the second substrate  123  is supported by the support members  231 . 
     In practical applications, the first substrate  121  may be placed to the placement area  113  of the supporting surface  111  of the support pedestal  11 , and subsequently the alignment members  233  move toward and close to the first substrate  121  and the placement area  113 , for example, move along a radial direction of the support pedestal  11 . The alignment members  233  contact and position the first substrate  121 , such that the first substrate  121  is aligned with the placement area  113  of the support pedestal  11 . 
     After positioning the first substrate  121 , the support members  231  move toward and close to the first substrate  121  and the placement area  113 , while the alignment members  233  move away from the first substrate  121 . The alignment members  233  may move away from the first substrate  121  after the support members  231  come to a stop, or the alignment members  233  may also be driven away from the first substrate  121  before the support members  231  come to a stop. In theory, the alignment members  233  moving away from the first substrate  121  after the support members  231  come to a stop may better avoid a displacement of the first substrate  121  during the process of displacement of the alignment members  233  relative to the first substrate  121 . 
     After the alignment members  233  leave the first substrate  121 , the second substrate  123  may be placed on the support members  231 , wherein the second substrate  123  is supported by the support members  231  and is not in contact with the first substrate  121 . Specifically, the structure of the support members  231  is similar to that of the first alignment members  131 , and each include a base  2311  and a protruding part  2313 , wherein the protruding part  2313  is used for supporting the second substrate  123 . 
     Subsequently, the alignment members  233  move toward and close to the second substrate  123 . For example, the alignment members  233  may move along a radial direction of the supporting surface  111  of the support pedestal  11 . The alignment members  233  contact and position the second substrate  123  supported by the support member  231 , such that the second substrate  123  is aligned with the first substrate  121  and/or the placement area  113  of the support pedestal  11 . 
     After aligning the first substrate  121  and the second substrate  123 , the support members  231  leave the placement area  113 , the first substrate  121  and/or the second substrate  123 , wherein the second substrate  123  falls from the protruding parts  2313  of the support members  231  and is placed onto the first substrate  121 . When the support members  231  move away from the second substrate  123 , the alignment members  233  may stay still and remain in contact with the second substrate  123  to avoid a displacement of the second substrate  123  during the process of displacement of the support members  231  relative to the second substrate  123 . 
     Further, three support members  231  may move away from the second substrate  123  in a non-simultaneous manner. For example, one of the support members  231  first moves away from the second substrate  123 , while the other two support members  231  remain still, such that the second substrate  123  is obliquely placed on the first substrate  121 . Then the other two support members  231  move away from the second substrate  123 , and lay the second substrate  123  flat on the first substrate  121 , such that the second substrate  123  overlaps and aligns with the first substrate  121 . 
     In the process of aligning or positioning the first substrate  121  and the second substrate  123  by the alignment mechanism  10  of the present invention, the first alignment members  131 , the second alignment members  133 , the support members  231  and/or the alignment members  233  only need to move along a direction parallel to the supporting surface  111  of the support pedestal  11 , and do not need to raise or lower relative to the supporting surface  111  of the support pedestal  11 . This is beneficial in simplifying the steps and mechanisms for aligning the first substrate  121  and the second substrate  123 . In one embodiment of the present invention, the first alignment members  131 , the second alignment members  133 , the support members  231  and/or the alignment members  233  may not only move along a direction parallel to the supporting surface  111  of the support pedestal  11 , but also raise or lower along a direction perpendicular to the supporting surface  111 . 
     In one embodiment of the present invention, as shown in  FIG.  1   , the supporting surface  111  of the support pedestal  11  may be configured with six or more connecting rods  151 , arranged around the placement area  113  of the supporting surface  111 . The first and second alignment members  131 / 133 , the support members  231  and the alignment members  233  on the other hand each include a fixing hole  153 , and each is sleeved on one of the connecting rods  153  through the fixing hole  153 . In practical applications, based on the sizes of the first substrate  121  and the second substrate  123 , first and second alignment members  131 / 133 , support members  231  and alignment members  233  having different forms or sizes may be chosen and fixed to the connecting rods  151 , such that the alignment mechanism  10  of the present invention may be used in aligning substrates of two different kinds or more. 
     In one embodiment of the present invention, the first substrate  121  includes but is not limited to a wafer or a chip, and the second substrate  123  includes but is not limited to a sapphire carrier substrate. 
     It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.