Patent Publication Number: US-2023163094-A1

Title: Apparatus for bonding chip band and method for bonding chip using the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority and benefit of Korean Patent Application No. 10-2021-0162166, filed on Nov. 23, 2021, with the Korean Intellectual Property Office, the inventive concept of which is incorporated herein by reference. 
     BACKGROUND 
     Field 
     The present inventive concept relates to a chip bonding apparatus and a method for bonding a chip. 
     Description of Related Art 
     In general, in order to bond a chip to a substrate, a process of aligning and processing the chip on the substrate is necessary. In a bonding process, not using any other medium for bonding the chip to the substrate, it may be necessary to manage parallelism within 100 nm to control parallelism between the chip and the substrate to suppress generation of air bubbles. However, it becomes difficult in practice to manage the parallelism in a die bonding device operating at a high speed and frequently applying a bonding load. 
     Accordingly, a method of bonding the chip and the substrate after deforming a shape of the chip by applying a load to a central portion of the chip is used, but in this case, the deformed shape of the chip is not constant, there is a problem in that the chip may be damaged when the substrate and the chip are in contact. Furthermore, since the chip is deformed as a load is directly applied to the chip, there is a problem in that a risk of chip breakage increases. 
     Accordingly, there is a need to develop a device capable of preventing chip breakage while preventing air bubbles from being generated between the chip and the substrate. 
     SUMMARY 
     An aspect of the present inventive concept is to provide a chip bonding apparatus and a method of manufacturing for bonding a chip that is capable of preventing chip breakage. 
     An aspect of the present inventive concept is to provide a chip bonding apparatus and a method of manufacturing for bonding a chip capable of preventing air bubbles from being generated between a chip and a substrate. 
     According to an aspect of the present inventive concept, a chip bonding apparatus includes: a body; a substrate conveyor installed on the body to transfer a substrate; a bonding head conveyor disposed on an upper surface of the body; an alignment unit installed on the body configured to adjust a position of the substrate and a position of the chip; and a bonding head installed in the bonding head conveyor and moved to attach a chip therebelow, wherein the bonding head is provided with a chip bonding unit for attaching the chip therebelow, wherein the chip bonding unit includes: a chip bonding unit body having an installation groove formed therein; a pushing module having one end portion inserted in the installation groove; and an attachment module having a deformable member deformable by the pushing module; wherein the deformable member is provided with a deformable portion which is deformed by being pressed by the pushing module, and having a bottom surface that contacts the chip to exert a force on the chip to bond the chip to the substrate. 
     According to an aspect of the present inventive concept, a method for bonding a chip includes: determining whether a deformable portion provided in a deformable member and a chip are in contact; controlling a degree of deformation of the chip while detecting the degree of deformation of the deformable portion through a displacement sensor; determining whether the chip and the substrate are in contact; and sequentially bonding portions of the chip to the substrate while controlling driving of an actuator of a push module and a Z-axis driver of a bonding head so that a load applied to the chip remains constant during the sequential bonding. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The above and other aspects, features, and advantages of the present inventive concept will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    is a block diagram illustrating a die bonding device including a chip bonding apparatus according to an example embodiment; 
         FIG.  2    is an explanatory diagram for illustrating an operation of a chip separation module provided in a die bonding device according to an exemplary embodiment; 
         FIG.  3    is a schematic side view illustrating a chip bonding apparatus according to an example embodiment; 
         FIG.  4    is a schematic configuration diagram illustrating a bonding head of a chip bonding apparatus according to an example embodiment; 
         FIG.  5    is a schematic cross-sectional view illustrating the chip bonding unit of  FIG.  4   ; and 
         FIGS.  6  to  12    are explanatory views for illustrating an operation of the bonding head. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, preferred example embodiments of the present inventive concept will be described with reference to the accompanying drawings as follows. 
       FIG.  1    is a block diagram illustrating a die bonding device  10  including a chip bonding apparatus according to an example embodiment. 
     Referring to  FIG.  1   , a die bonding device  10  may include a chip and substrate supply module  20 , a chip separation module  30 , a chip transfer module  40 , and a chip bonding apparatus  100 . 
     The chip and substrate supply module  20  may include an Equipment Front End Module (EFEM) or a Load Port Module (LPM), and serve to withdraw the substrate from the substrate storage unit  21  and supply the same to the chip bonding apparatus  100 , and supply a chip from the chip storage unit  22  to the chip separation module  30 . For example, the substrate storage unit  21  may be a 300 mm Front Opening Unified Pod (FOUP) or a Front Opening Shipping Box (FOSB). In addition, the chip storage unit  22  may be a 400 mm FOUP (Front Opening Unified Pod) or a MAC storing a chip attached to a ring frame. 
     The chip separation module  30  is a device expanding a film so that the chip can be easily detached from the film  31  (see,  FIG.  2   ) of a ring frame, and includes an ejector  33  (see  FIG.  2   ) physically pushing up the chip  102  so that it can be detached from the film. Here, referring briefly to an operation of the chip separation module  30  with reference to  FIG.  2   , first, the film  31  to which the chip  102  is attached is expanded in an expander  32 , so that the chip  102  is in a good state to be detached from the film  31 . Thereafter, after the ejector  33  is aligned and positioned under the chip  102 , the film  31  and the chip  102  are pushed upwardly. In this case, the area of attachment between the chip and the film is reduced, so that the chip  102  is easily separated from the film. Thereafter, a pickup device  42  of the chip transfer module  40  (see  FIG.  1   ) separates the chip  102  pushed up by the ejector  33  from the film  31 , and then transfers the same to the chip bonding apparatus  100  (see  FIG.  1   ). In this case, the pickup device  42  may transfer the chip  102  to the chip bonding apparatus  100  as it is in a state separated from the film  31 , or may transfer the chip  102  upside down. 
     Referring back to  FIG.  1   , the chip transfer module  40  serves to transfer the chip  102  (refer to  FIG.  2   ) separated from the film  31  in the chip separation module  30  to the chip bonding apparatus  100 . To this end, the chip transfer module  40  may include a pickup device  42  as illustrated in  FIG.  2   . The chip transfer module  40  may be disposed on one side of the chip separation module  30  and the chip bonding apparatus  100 . In addition, the chip transfer module  40  may serve to discharge the film  31  (see  FIG.  2   ) from which the chip  102  (see  FIG.  2   ) has been removed to al location external to the die bonding device  10 . 
     The chip bonding apparatus  100  is disposed adjacently to the chip transfer module  40  and bonds the chip  102  (refer to,  FIG.  2   ) to a substrate  104 . 
       FIG.  3    is a schematic side view illustrating a chip bonding apparatus  100  according to an example embodiment. 
     Referring to  FIG.  3   , a chip bonding apparatus  100  according to an example embodiment, may include, for example, a body  110 , a substrate conveyor  120 , a bonding head conveyor  130 , an alignment unit  140  , and a bonding head  150 . 
     The body  110  has, for example, a bonding head conveyor  130  disposed on an upper surface thereof. In addition, the body  110  may be a frame in which the substrate conveyor  120  is disposed in an internal space formed (or defined) by the body  110  (e.g., a space about which the frame is formed). For example, the body  110  may include an upper frame  112  in which the bonding head conveyor  130  is installed and a column frame  114  in which the substrate conveyor  120  is disposed therebetween. However, the present inventive concept is not limited thereto, and a shape of the body  110  may be variously changed. In addition, the body  110  may further include a lower frame  116  from which the pillar frame  114  extends upwardly. 
     The substrate conveyor  120  serves to transfer a substrate  104  supplied by the above-described chip and substrate supply module  20  (refer to  FIG.  1   ) to a position where it will bonded to the chip (chip not shown in  FIG.  3   ). For example, the substrate conveyor  120  may be disposed between the pillar frames  114  of the body  110 . The substrate conveyor  120  moves the substrate  104  in an X-axis direction (perpendicular to the paper of  FIG.  3   ). For example, when the bonding of the chip and the substrate  104  is completed, the substrate conveyor  120  may transfer the substrate  104  on which the chip is stacked to the chip and substrate supply module  20  (refer to  FIG.  1   ) and the chip and the substrate supply module  20  may be discharged to a location external to the die bonding device  10  using a Load Port Module (LPM). 
     The bonding head conveyor  130  is installed on an upper frame  112  of the body  110  to move the bonding head  150  along the upper frame  112  in a Y-axis direction of  FIG.  3   . For example, the bonding head conveyor  130  may include a first moving frame  132  that moves along a rail  112   a  of the upper frame  112 . In addition, the bonding head  150  may be installed on the first moving frame  132  of the bonding head conveyor  130  to move in association with the first moving frame  132 . The bonding head conveyor  130  may include a driver (not shown) for generating driving force for the movement of the first moving frame  132 . 
     The alignment unit  140  serves to confirm a position to align the chip and the substrate. For example, the alignment unit  140  may include a first alignment unit  142  for adjusting a position of the substrate, and a second alignment unit  144  for adjusting a position of the chip  102  (not shown). The first alignment unit  142  may be installed in a second moving frame  142   a  movably installed in the upper frame  112  of the body  110 . A first alignment detection member  142   b  of the first alignment unit  140  may be installed in the second moving frame  142   a  to move together with the second moving frame  142   a  to detect a position of the substrate disposed therebelow. Meanwhile, in the present example embodiment, a case in which the second moving frame  142   a  is configured separately from the first moving frame  132  is described as an example, but the present inventive concept is not limited thereto, and the second moving frame  142   a  and the first moving frame  132  may be integrally formed and can be moved in association with each other. 
     The second alignment unit  144  may be installed in a lower frame  116  disposed below the body  110  so as to be disposed on a movement path of the bonding head  150 . For example, the second alignment unit  144  may include a second alignment detection member  144   a  having a number of second alignment detection members  144   a , equal to the number of the bonding heads  150  and a fixing member  144   b  on which the second alignment detection member  144   a  is installed. For example,  FIG.  3    illustrates a case in which one bonding head  150  and the second alignment detection member  144   a  are provided as an example, but the present inventive concept is not limited thereto and the bonding head  150  and the second alignment detection member  144   a  may be provided in plural. 
     The bonding head  150  is installed on a first moving frame  132  and moves together with the first moving frame  132 . For example, a plurality of bonding heads  150  may be installed in the first moving frame  132 . Further details of the bonding head  150  will be described later. 
       FIG.  4    is a schematic configuration diagram illustrating a bonding head of the chip bonding apparatus  100  according to an example embodiment. 
     Referring to  FIG.  4   , a bonding head  150  according to the example embodiment may include, as an example, a theta-axis driver  152 , a Z-axis driver  154 , a tilt adjusting driver  156 , and a chip bonding unit  160 . 
     The bonding head  150  is positioned above the substrate by the bonding head conveyor  130  (refer to  FIG.  3   ) in a state in which a chip is held by the chip bonding unit  160 . Thereafter, the bonding head  150  transfers the chip in the Z-axis direction (refer to  FIG.  3   ) by the Z-axis driver  154  provided in the bonding head  150 . As the chip approaches a bonding position with the substrate, the bonding head  150  corrects a position error by adjusting a theta axis through a theta axis driver  152 . Theta refers to a rotation component in the X-Y plane. Thereafter, parallelism between the chip and the substrate is adjusted through the tilt adjusting driver  156 , which may comprise an a, which may be automatically adjusted by a controller (not shown) operatively connected to the tilt adjustment driver  156 , to control the same to perform this parallelism adjustment. This parallelism adjustment may act to reduce any angle between surfaces of the chip and the substrate. For example, when opposing surfaces of the chip and substrate are planar surfaces, parallelism adjustment may reduce an angle between these surfaces. 
     The chip bonding unit  160  is constitutes a lower end portion of the bonding head  150 , and a chip  120  is held on a bottom surface thereof.  FIG.  5    is a schematic cross-sectional view illustrating the chip bonding unit of  FIG.  4   .The chip bonding unit  160  according to an example embodiment may include, for example, a chip bonding unit body  162 , a pushing module  170 , and an attachment module  180 . 
     The chip bonding unit body  162  may be provided with a chip attachment passage  162   a  for supplying suction force so that the chip  102  is attached to and held by the attachment module  180 . In addition, a vacuum flow path  162   b  may be provided in the chip bonding unit body  162  to attach the attachment module  180  to the chip bonding unit body  162 . Suction grooves  162   b ′ in the lower surface of the chip bonding unit  162  may be in communication with the vacuum flow path  162   b  (not shown in the cross sectional view of  FIG.  5   ) to provide suction across the upper surface of the attachment module  180 . The attachment module  180  may be fixedly installed on the chip bonding unit body  162  by the suction force provided by the fixing vacuum flow path  162   b . The chip bonding unit body  162  may be provided with an installation groove  162   c  in which the pushing module  170  is installed, and a portion of the pushing module  170  may be inserted into the installation groove  162   c . In this present example embodiment, a case in which the attachment module  180  is fixedly installed to the chip bonding unit body  162  by a vacuum suction method has been described as an example, but an example embodiment thereof is not limited thereto, and the chip bonding unit body  162  and the attachment module  180  may be coupled to each other by magnetic force by a magnet. Furthermore, the chip bonding unit body  162  and the attachment module  180  may be fixed by screw fastening. 
     The pushing module  170 , may include, for example, an actuator  172 , a contact detection sensor  174  disposed below the actuator  172 , and a push member  176  disposed below the contact detection sensor  174 . The actuator  172  may be provided with a displacement sensor  178  for detecting displacement of the push member  176 . The actuator  172  serves to raise the push member  176  so that the push member  176  presses the deformable member  184  of an attachment module  180  to be described later. The contact detection sensor  174  may detect whether the deformable member  184  and the chip  102  are in contact by detecting a load applied to the push member  176 . In addition, the contact detection sensor  174  may detect a load applied to the push member  176  to detect whether the chip  102  and the substrate  104  are in contact. Furthermore, the contact detection sensor  174  may also detect whether the chip  102  and the substrate  104  are in contact with a constant load. 
     The displacement sensor  178  serves to detect the displacement of the push member  176  when the deformable member  184  is deformed and when the chip  102  and the substrate  104  are bonded. In other words, the controller (not shown) controls an degree of deformation of the deformable member  184  through a signal for the displacement of the push member  176  sensed by the displacement sensor  178  so that the deformable member  184  is deformed, and further, the chip  102  and the substrate  104  are bonded to each other. 
     For example, a lower end portion of the push member  176  may have a hemispherical shape. However, the present inventive concept is not limited thereto, and the lower end portion of the push member  176  may have a triangular cross-section or a ‘+’ cross-section. That is, it will be possible to change a shape of the lower end portion of the push member  176  to any shape that can be sequentially contacted at the edges after first contacting the push member  176  in the central portion of the deformable member  184  to be described later. 
     The attachment module  180  may be provided with an attachment module body  182  having an opening  182   a  into which the push member  176  is inserted and a deformable member  184  installed in the attachment module body  182  and having a deformable portion  184   a  deformed by the push member  176 . The attachment module body  182  may include an extension passage  182   b  in communication with (e.g., connected to) the chip attachment passage  162   a  of the chip bonding unit body  162 , such that the extension passage  182   b  provides a suction force to the chip  102 . Accordingly, the chip  102  may be coupled to the attachment module  180 . The deformable member  184  may have a cylindrical shape with an open upper end portion (i.e., in the shape of a cylindrical cup), and the deformable portion  184   a  of the deformable member  184  may be formed of an elastic material which may be deformed by the push member  176 . For example, the deformable member  184  may be made of aluminum or steel, such as stainless steel. The thickness of the deformable portion  184   a  may be larger than the thickness of the chip  102 . 
     Hereinafter, an operation of a bonding head will be described in more detail with reference to the drawings. 
       FIGS.  6  to  12    are explanatory views for illustrating the operation of the bonding head. 
     Thereafter, as illustrated in  FIG.  6   , a push member  176  is lowered by an actuator  172 , so that the push member  176  is in contact with a deformable portion  184   a  of a deformable member  184  provided in an attachment module  180 . In this case, a contact detection sensor  174  detects a contact between the deformable portion  184   a  of the deformable member  184  and the push member  176 . 
     Thereafter, as illustrated in  FIG.  7   , the push member  176  is continuously lowered by the actuator  172 , and accordingly, the deformable portion  184   a  of the deformable member  184  is deformed to a convex shape (protruding downwardly). Accordingly, a chip  102  attached to a bottom surface of the deformable member  184  is also deformed together with the deformable portion  184   a  and may also include a convex shape (protruding downwardly) in the central portion of the chip  102 . For example, the bottom surface at the center of the chip  102  may be the lowest portion of the chip. In this case, the deformation of the deformable portion  184   a  by the actuator  172  is performed while a degree of deformation is controlled through information about displacement of the push member  176  detected by a displacement sensor  178 . 
     Thereafter, first, a bonding head  150 , having the chip  102  attached to its chip bonding unit  160  (refer to,  FIG.  4   ) is positioned directly above an upper portion of the substrate  104  by the bonding head conveyor  130  (moving the substrate the X-axis direction) and the bonding head conveyor  130  (moving the bonding head  150  with the chip  102  attached thereto in the Y direction) (refer to,  FIG.  3   ). With the bonding head  150  and the attached chip  102  located directly over the substrate  104 , the chip bonding unit  160 , provided in the bonding head  150 , transfers the chip  102  in the Z-axis direction (refer to  FIG.  3   ) by the Z-axis driver  154  (refer to,  FIG.  4   ). As the chip  102   reaches a bonding position with the substrate, the bonding head  150  corrects for any position error by adjusting a theta axis through the theta axis driver  152  (refer to  FIG.  4   ). Thereafter (or at the same time, or just before), the controller adjusts the parallelism between the chip  102  and the substrate  104  through the tilt adjusting driver (refer to  FIG.  4   ). 
     Thereafter, as illustrated in  FIG.  8   , the chip  102  and the substrate  104  become in contact by the Z-axis driver  154  (see  FIG.  4   ) provided in the bonding head  150  (moving the bonding head  150  and the attached chip  102  downwardly (in the Z-axis direction)). In this case, the contact detection sensor  174  detects the contact between the chip  102  and the substrate  104 . 
     Thereafter, as illustrated in  FIG.  9   , the bonding head  150  continues to move downwardly in the Z-axis direction (see  FIG.  3   ) by virtue of the Z-axis driver  154  (see  FIG.  4   ) provided in the bonding head  150 . As a result, there is an increased force exerted between the substrate  104  and the bonding head  150  / chip  102 , which is applied and detected by the contact detection sensor  174 . When this load increases to a predetermined target level, the push member  176  is raised by the actuator  172  so that the same load is maintained between the chip  102  and the substrate  104 . 
       FIG.  10    illustrates raising the push member  176 . Raising the push member  176  also may be performed by information regarding displacement of the push member  176  detected by the displacement sensor  178  and information about downward displacement of the push member  176  in the Z-axis direction of the bonding head  150 . For example, after the load reaches a predetermined target level (as detected by the contact detection sensor  174 ), the push member  176  may be raised within the bonding head  150  (e.g., relative to remaining portion the bonding head  150 ) to positions (relative to remaining portions of the bonding head  150 ) that are determined by the downward displacement of the bonding head  150  (e.g., after the load reaches a predetermined target level, the increased height (relative to the remaining portions of the bonding head  150 , such as with respect to the chip bonding unit body  162  and the attachment module  180 ) of the push member  176  is a function of the decreased height of the bonding head  150 ). It will be appreciated that during this operation, the push member  176  may maintain its position with respect to the substrate  104  while the bonding head  150 , and the portions of the chip bonding unit  160  (other than the push member  176 ) continue to move downwardly, and thus the center of the chip  102  may maintain its position relative to the substrate  104 , while edges and the outer sides of the chip  102  continue to move downwardly. The raising of the push member  176  and the lowering of the bonding head  150  may be performed to increase a contact area between the chip  102  and the substrate  104 . 
     Thereafter, as illustrated in  FIG.  11   , the bonding head  150  continues to move downwardly by the Z-axis driver  154  (see  FIG.  4   ) provided in the bonding head  150 , and at the same time, the push member  176  is raised (e.g., relative to remaining portions of the bonding head  150 ) by the actuator  172  until the entire bottom surface of the chip  102 ) (e.g., between the opposing edges of the chip  102 ) is in contact with the substrate. Accordingly, the chip  102  is sequentially bonded to the substrate  104  outwardly from a central portion of the chip  102  until the edges of the chip  102  are bonded to the substrate  104 . As described above, since the chip  102  and the substrate  104  are sequentially bonded to the substrate  104  from the central portion of the chip  102  until the edges of the chip  102  are bonded to the substrate  104 , air bubbles may not be generated and captured between the chip  102  and the substrate  104 . 
     Thereafter, as illustrated in  FIG.  12   , a bonding process of the chip  102  and the substrate  104  is completed as the bonding head  150  is moved upwardly in the Z-axis direction by the Z-axis driver  154  provided in the bonding head  150  (see  FIG.  4   ). 
     As described above, by deforming the deformable portion  184   a  of the deformable member  184  to bond the chip  102  and the substrate  104 , it is possible to prevent intensively applying an excessive load to the chip  102 . Accordingly, the risk of breaking the chip  102  can be reduced. 
     Furthermore, by controlling the load applied to the deformable portion  184   a  through the information on the displacement of the push member  176  sensed by the displacement sensor  178 , the chip  102  and the substrate  104  are bonded to each other, such that the risk of breaking the chip  102  may be further reduced. 
     Furthermore, it is possible to prevent air bubbles from being generated between the chip  102  and the substrate  104  by sequentially bringing the substrate  104  and the chip  102  into contact outwardly from a central portion of the chip  102  to the edges of the chip  102 . 
     As set forth above, according to an example embodiment of the present inventive concept, a chip bonding apparatus capable of preventing or reducing the risk of chip breakage and a method for bonding a chip using the same may be provided. 
     In addition, a chip bonding apparatus capable of preventing air bubbles from being generated between a chip and a substrate, and a method for bonding a chip using the same, may be provided. 
     As used herein, directional descriptions (e.g., “upper,” “lower,” “downwardly,” etc.) are used in reference to the substrate  104  to assist in describing relative positions and movement. However, these directions are set forth for convenience of explanation, and should be understood not to require a particular orientation or movement with respect to the real world operating environment of the chip bonding apparatus. 
     The meaning of a “connection” of a component to another component in the description includes an indirect connection through an adhesive layer as well as a direct connection between two components. It should be appreciated that the chip  102  may be bonded to the substrate  104  without an adhesive layer, but that the disclosed embodiments may also be used to attach the chip  102  to the substrate  104  with the use of an adhesive layer therebetween. Unless context indicates otherwise, it should be understood that when an element is referred to with ordinal numbers such as “first” and “second”, the element is not limited thereby, and such ordinal numbers may be used only for the purpose of distinguishing one element from other similar elements. As use of ordinal numbers are typically introduced in sequence, it may be the case that the same element is referenced using different ordinal terms - e.g., a “first” element (e.g., in the specification) may be referred to elsewhere (e.g., at another portion of the specification or in the claims) as a “second” element. 
     The term “an example embodiment” used herein does not necessarily refer to the same example embodiment throughout the disclosure, and may be used to emphasize a particular feature or characteristic in one example embodiment that is different from that of another example embodiment. In addition, features and characteristics of example embodiments provided herein should be understood to be able to be implemented by being combined in whole or in part one with one another. For example, one element described in a particular example embodiment, even if it is not explicitly described in another example embodiment, may be understood as a description related to another example embodiment, unless context indicates otherwise. 
     Terms used herein are used only in order to describe an example embodiment rather than limiting the present invention. In addition, singular forms should be understood to be applicable to plural forms unless context indicates otherwise. 
     While example embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations could be made without departing from the scope of the present inventive concept as defined by the appended claims.