Patent Publication Number: US-2022216078-A1

Title: Mounting device

Description:
TECHNICAL FIELD 
     The disclosure relates to a mounting device. 
     BACKGROUND ART 
     A semiconductor chip which is a fragment of a semiconductor wafer is a component of an electronic device. A manufacturing process of the electronic device involves the work of picking up semiconductor chips and the work of arranging the semiconductor chips on circuit boards. Patent Literature 1 discloses a handling unit for electronic components. This handling unit reverses the directions of two held semiconductor chips. Further, this handling unit also changes the arrangement directions of two semiconductor chips. 
     CITATION LIST 
     Patent Literature 
     [Patent Literature 1] 
     
         
         International Publication No. WO 2017/119216 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     With the diversification of the electronic device, the shape of the semiconductor chip is also diversifying. For example, the shape of the semiconductor chip includes a rectangular parallelepiped shape and a thin plate shape. When the chip thickness is sufficient for the area of a chip main surface like the rectangular parallelepiped shape, the semiconductor chip has a relatively high mechanical strength. In this case, the semiconductor chip is easily handled. On the other hand, when the chip thickness for the area of the chip main surface is small like the thin plate shape, the mechanical strength of the semiconductor chip tends to be low. In this case, it is necessary to carefully handle the semiconductor chip. 
     Further, in recent years, the need for high-mix production has increased. Thus, it is desired that a manufacturing apparatus is not specialized in handling a specific component but can handle a variety of components. For example, a mounting device is required to handle not only a semiconductor chip having sufficient strength but also a semiconductor chip having low strength. 
     Furthermore, there is a demand for larger semiconductor chips. At the time of picking up the large semiconductor chips, it is necessary to suck the entire surface of the semiconductor chip with a collet in order to suppress the damage of the semiconductor chip. A large collet is required when sucking the entire surface of the semiconductor chip. Since the weight of the large collet increases, there is a problem that the thrust of a motor that moves the collet is insufficient. 
     The disclosure provides a mounting device capable of handling semiconductor chips of various shapes. 
     Solution to Problem 
     A mounting device of an aspect of the disclosure includes: a plurality of direct-acting motors in which a movable element reciprocatingly moves along an axis relative to a fixed element; and a chip holder which is attached to an end portion side of the movable element and sucks and holds a semiconductor chip, wherein the plurality of motors are arranged so that the axes are parallel to each other, and wherein the chip holder is attached to straddle end portion sides of at least two movable elements in the plurality of movable elements. 
     This device includes two motors capable of attaching and detaching the chip holder. According to this configuration, two different modes can be selected. As a first mode, a mode in which one chip holder is attached to straddle at least two motors can be selected. The chip holder which is disposed to straddle between the motors is driven by at least two motors. Thus, the chip holder can be made larger than the chip holder driven by one motor. That is, the area of the holding surface of the chip holder can be increased. As a result, the larger semiconductor chip can be held. That is, the thin semiconductor chip can be carried. Further, as a second mode, a mode in which a chip holder is attached to each of the motors can be selected. According to this mode, the small semiconductor chip can be carried. As a result, the mounting device capable of selecting the first mode and the second mode can handle the semiconductor chips of various shapes. 
     In an aspect, the mounting device may further include a control unit which provides a control signal to the motor to control the position of the fixed element. The motor may include a position information acquiring unit which obtains a position along the axis of the movable element relative to the fixed element. The control unit may acquire representative position information from the position information acquiring unit of a representative motor selected from the plurality of motors and control the positions of the movable elements of the plurality of motors using the representative position information. According to such a configuration, the position of the movable element of the representative motor can be simply controlled with high accuracy. Thus, the position of the chip holder can be simply controlled with high accuracy. 
     In an aspect, the motor may be a voice coil motor. According to this configuration, a driving force for driving the chip holder can be preferably obtained. 
     In an aspect, the motor may include a chuck which is provided at an end portion of the movable element and to which the chip holder is connected in an attachable and detachable manner. The chuck may include a chuck mechanism which connects the chip holder to the chuck and a chuck detector which detects whether or not the chip holder exists in the chuck. According to this chuck, the chip holder can be easily attached to and detached from the movable element. Further, it is possible to obtain information indicating that the chip holder is attached to the movable element and information indicating that the chip holder is not attached to the movable element. 
     In an aspect, the semiconductor chip may include a chip held surface which is held by the chip holder. The chip holder may include a chip holding surface which holds the semiconductor chip in an attachable and detachable manner. An area of the chip holder may be larger than an area of the chip held surface. According to such a configuration, the thin semiconductor chip can be reliably held. 
     In an aspect, the semiconductor chip may include a chip held surface which is held by the chip holder. The mounting device may further include a push-up mechanism which pushes a surface on the side opposite to the chip held surface and pushes up the semiconductor chip toward the chip holder. According to such a configuration, the chip holder can reliably pick up the semiconductor chip. 
     Advantageous Effects of Invention 
     According to the mounting device of an aspect of the disclosure, the semiconductor chips of various shapes can be handled. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram showing a mounting device of an embodiment. 
         FIG. 2  is a diagram illustrating a first mode of a pickup head. 
         FIG. 3  is a diagram illustrating a second mode of the pickup head. 
       Part (a) and part (b) of  FIG. 4  are diagrams illustrating an operation of the mounting device. 
       Part (a) and part (b) of  FIG. 5  are diagrams further illustrating the operation of the mounting device. 
         FIG. 6  is a diagram illustrating an effect of the mounting device. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, a mode for carrying out the disclosure will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate description will be omitted. 
     As shown in  FIG. 1 , a mounting device  1  mounts a semiconductor chip  101  on a substrate  110 . The mounting device  1  includes a bonding unit  10 , a control unit  20  (control unit), and a pickup unit  30 . The pickup unit  30  picks up the semiconductor chip  101 . The pickup unit  30  sucks a chip main surface  101   a  (chip held surface) of the semiconductor chip  101 . Next, the pickup unit  30  passes the semiconductor chip  101  to the bonding unit  10 . The bonding unit  10  bonds the received semiconductor chip  101  to the substrate  110 . The control unit  20  controls the operation of the pickup unit  30  and the operation of the bonding unit  10 . 
     &lt;Bonding Unit&gt; 
     The bonding unit  10  includes a guide rail  11 , a bonding stage  12 , and a bonding head  13 . 
     The guide rail  11  is a base body for reciprocating the bonding head  13  in a predetermined direction. The guide rail  11  extends from, for example, the pickup unit  30  over an area in which a bonding operation is performed. 
     The supplied substrate  110  is placed on the bonding stage  12 . The semiconductor chip  101  is mounted on the substrate  110  placed on the bonding stage  12 . The bonding stage  12  has, for example, a suction hole. The bonding stage  12  sucks the substrate  110  and holds the substrate from below. 
     The bonding head  13  includes a bonding body  14  and a bonding nozzle  15 . The bonding body  14  is connected to the guide rail  11 . The bonding body  14  reciprocatingly moves along the guide rail  11 . The bonding body  14  includes a motor for driving the bonding nozzle  15 . 
     The bonding nozzle  15  holds the semiconductor chip  101  in an attachable and detachable manner. For example, the bonding nozzle  15  includes a vacuum suction mechanism as an attachment and detachment mechanism. Further, the bonding nozzle  15  bonds the semiconductor chip  101  to the substrate  110 . For example, the bonding nozzle  15  may include a heater or the like and supply heat to the semiconductor chip  101 . 
     &lt;Pickup Unit&gt; 
     The pickup unit  30  includes a guide rail  31 , a wafer operation mechanism  32 , and a pickup head  33 . 
     The guide rail  31  is a base body for reciprocating the pickup head  33  in a predetermined direction. The guide rail  31  extends from, for example, an area in which a picking operation is performed to the bonding unit  10 . 
     The wafer operation mechanism  32  assists a pickup operation. The wafer operation mechanism  32  includes a wafer holder  32   a  and a push-up pin  32   b . The wafer holder  32   a  and the push-up pin  32   b  move relatively to each other. As a result, the wafer operation mechanism  32  can dispose the push-up pin  32   b  on the back surface side of the semiconductor chip  101  to be picked up. For example, the wafer holder  32   a  is movable in the Y direction. The push-up pin  32   b  is movable in the X direction. Further, the wafer holder  32   a  may be movable in the X direction and the Y direction. According to this configuration, the push-up pin  32   b  can be disposed on a back surface side of an arbitrary semiconductor chip  101  in the plurality of semiconductor chips  101  arranged in two dimensions. Then, the push-up pin  32   b  pushes up the semiconductor chip  101  toward the pickup head  33 . That is, the push-up pin  32   b  is reciprocatingly movable in the Z direction. 
     As shown in  FIG. 2 , the pickup head  33  includes two pickup motors  36 A and  36 B (motors), a motor base  37 , and a collet  34 A (chip holder). Each of the pickup motors  36 A and  36 B is fixed to the motor base  37 . The pickup motors  36 A and  36 B are arranged to be separated from each other in the direction (X direction) orthogonal to the axis A. According to such an arrangement, the axis A of the pickup motor  36 A is parallel to the axis A of the pickup motor  36 B. The gap from the pickup motor  36 A to the pickup motor  36 B may be based on, for example, the dimension B 1  of the semiconductor chip  101  and/or the arrangement interval B 2  of the semiconductor chip  101 . 
     The pickup motor  36 B is only different in arrangement from the pickup motor  36 A. The configuration of the pickup motor  36 B is common to the configuration of the pickup motor  36 A. Hereinafter, the pickup motor  36 A will be described in detail and the description of the pickup motor  36 B will be omitted. 
     The pickup motor  36 A includes a voice coil motor  38  and a chuck  39 . The voice coil motor  38  is a so-called direct-acting linear motor. The voice coil motor  38  reciprocatingly moves the chuck  39  in the Z direction. The voice coil motor  38  includes a motor casing  38   a , a fixed element  38   b , and a movable element  38   c . The motor casing  38   a  accommodates the fixed element  38   b . Further, the motor casing  38   a  accommodates the base end side of the movable element  38   c . The fixed element  38   b  includes a coil L. The movable element  38   c  includes a magnet M. The magnet M is provided in a portion facing the coil L in the movable element  38   c . A power supply  41  is connected to the coil L. The coil L generates a force for driving the movable element  38   c  in response to a current supplied from the power supply  41 . 
     Here, the connection configuration of the coil L will be described. The coil L of the pickup motor  36 A and the coil L of the pickup motor  36 B receive a current supplied from the common power supply  41 . That is, the coil L of the pickup motor  36 A is electrically connected to the coil L of the pickup motor  36 B. For example, two coils L may be connected in series to each other. Further, two coils L may be connected in parallel to each other. 
     The front end of the movable element  38   c  protrudes from the motor casing  38   a . The front end of the movable element  38   c  is provided with the chuck  39 . The chuck  39  holds the collet  34 A in an attachable and detachable manner. The chuck  39  includes a chuck holding surface  39   a , a chuck magnet  39   b  (chuck mechanism), and a chuck sensor  39   c  (chuck detector). The shape of the chuck holding surface  39   a  is, for example, a rectangular plane in the plan view. The chuck magnet  39   b  is embedded in the chuck  39 . The chuck magnet  39   b  provides a magnetic force for holding the collet  34 A. The chuck sensor  39   c  provides information indicating that the collet  34 A is mounted on the chuck holding surface  39   a . Further, the chuck sensor  39   c  provides information indicating that the collet  34 A is not mounted on the chuck holding surface  39   a . The chuck sensor  39   c  may provide information indicating that the collet  34 A is mounted on the chuck holding surface  39   a . Further, the chuck sensor  39   c  may provide information indicating that the collet  34 A is not mounted on the chuck holding surface  39   a . This information is provided to the control unit  20 . Additionally, the chuck mechanism is not limited to one that holds the collet  34 A by the chuck magnet  39   b . The chuck mechanism may be a mechanism for holding the collet  34 A by a vacuum or a mechanism for grasping and holding the collet  34 A by a member such as a claw as long as the mechanism can hold the collet  34 A. 
     The voice coil motor  38  further includes an encoder  38   d  (position information acquiring unit). The encoder  38   d  obtains, for example, information on the relative position of the movable element  38   c  relative to the fixed element  38   b . This information also corresponds to the protrusion length of the movable element  38   c . The information of the encoder  38   d  is provided to the control unit  20 . 
     That is, the output of the encoder  38   d  indicates the position along the axis of the movable element  38   c  relative to the fixed element  38   b . Thus, the “position information” mentioned in this embodiment indicates the position along the axis of the movable element  38   c  relative to the fixed element  38   b . Here, the mounting device  1  includes two pickup motors  36 A and  36 B. Each of the pickup motors  36 A and  36 B includes the voice coil motor  38 . Further, each voice coil motor  38  further includes the encoder  38   d . Thus, the mounting device  1  can use the position information obtained from the pickup motor  36 A and the position information obtained from the pickup motor  36 B. 
     The collet  34 A is provided to straddle the pickup motors  36 A and  36 B. Thus, it can be regarded that the protrusion length of the movable element  38   c  of the pickup motor  36 A is the same as the protrusion length of the movable element  38   c  of the pickup motor  36 B. Thus, for example, the mounting device  1  may select any one of the position information obtained from the pickup motor  36 A and the position information obtained from the pickup motor  36 B as representative position information. The representative position information may be calculated by using both the position information obtained from each of the pickup motors  36 A and  36 B. 
     The collet  34 A holds the semiconductor chip  101  in an attachable and detachable manner. For example, the collet  34 A includes a vacuum suction mechanism as an attaching and detaching mechanism. Thus, the collet  34 A includes a collet suction hole  34   a  as a vacuum suction mechanism. One end of the collet suction hole  34   a  is connected to a pressure source  42 . The other end of the collet suction hole  34   a  is an opening provided in a collet suction surface  34 S (chip holding surface). The collet suction surface  34 S holds the semiconductor chip  101  in an attachable and detachable manner. For example, when the shape of the chuck holding surface  39   a  is square, the shape of the collet suction surface  34 S is rectangular in the plan view. The area of the collet suction surface  34 S is larger than the area of the chuck holding surface  39   a . On the other hand, the weight of the collet  34 A is smaller than the total weight of the individual collets  34 B and  34 C (see  FIG. 3 ) respectively provided on the chuck holding surface  39   a.    
     The control unit  20  controls the operation of the pickup unit  30 . The operation of the pickup unit  30  described herein includes a suction operation of sucking the semiconductor chip  101  on the collet  34 A and a peeling operation of peeling off the semiconductor chip  101  sucked on the collet  34 A from a dicing tape  120 . The suction operation moves the movable element  38   c  of the voice coil motor  38  in the −Z direction. The peeling operation moves the movable element  38   c  of the voice coil motor  38  in the +Z direction. The operation of the movable element  38   c  is based on the information provided from the encoder  38   d . Here, the pickup unit  30  includes two pickup motors  36 A and  36 B. Thus, the pickup unit  30  includes two encoders  38   d . The control unit  20  selects, for example, the pickup motor  36 A as a representative motor. That is, the encoder  38   d  of the pickup motor  36 A is selected as a representative encoder. Then, the control unit  20  controls the operation of the pickup unit  30  based on the information provided from the representative encoder  38   d.    
     The criteria selected as a representative may satisfy desired conditions. Further, the control unit  20  may control the operation of the pickup unit  30  using the information provided from the plurality of encoders  38   d . For example, the control unit  20  averages the information provided from each encoder  38   d . Then, the control unit  20  may control the operation of the pickup unit  30  using the information obtained by averaging. 
     The pickup head  33  can select a first mode and a second mode in response to the shape of the semiconductor chip  101  to be picked up. The selection of these modes is made by replacing the collets  34 A and  34 B attached to the chuck  39 . 
     The pickup head  33  can select a mode shown in  FIG. 2  as the first mode. The first mode is selected when the surface area of the semiconductor chip  101  is relatively large. Further, the first mode is selected when the thickness of the semiconductor chip  101  is small (thin). In the first mode, the collet  34 A straddling two pickup motors  36 A and  36 B is used. 
     Further, the pickup head  33  can select a mode shown in  FIG. 3  as the second mode. The second mode is selected when the surface area of the semiconductor chip  101  is relatively small. Further, the second mode may be selected when it is necessary to carry many semiconductor chips  101  per unit hour. In the second mode, the collet  34 B is attached to the pickup motor  36 A and the collet  34 C is attached to the pickup motor  36 B. 
     Hereinafter, the operation of the mounting device  1  will be described. 
     &lt;Pickup Operation&gt; 
     As shown in (a) of  FIG. 4 , the control unit  20  moves the pickup unit  30  directly above the semiconductor chip  101  to be picked up. Further, the control unit  20  disposes the push-up pin  32   b  directly below the semiconductor chip  101 . 
     Next, as shown in (b) of  FIG. 4 , the control unit  20  moves the push-up pin  32   b  in the +Z direction. By this operation, the push-up pin  32   b  pushes up the chip back surface  101   b  of the semiconductor chip  101 . As a result, the semiconductor chip  101  approaches the pickup head  33 . Next, the control unit  20  moves the collet  34 A in the −Z direction. Then, the control unit  20  activates the suction mechanism. As a result, the pickup head  33  sucks the semiconductor chip  101 . 
     Next, as shown in (a) of  FIG. 5 , the control unit  20  moves the collet  34 A in the +Z direction. By this operation, the semiconductor chip  101  is peeled off from the dicing tape  120 . Then, the control unit  20  moves the pickup head  33  toward the bonding unit  10 . By this movement, the control unit  20  rotates the direction of the pickup head  33 . The rotation angle is 180°. By this operation, the direction of the semiconductor chip  101  changes from the downward direction to the upward direction. This operation is a so-called flip chip operation. Additionally, the control unit  20  moves the bonding head  13  toward the pickup unit  30  together with these operations. 
     Next, as shown in (b) of  FIG. 5 , the control unit  20  passes the semiconductor chip  101  from the pickup head  33  to the bonding head  13 . Then, the bonding head  13  bonds the semiconductor chip  101  to the substrate  110 . 
     Hereinafter, the operation and effect of the mounting device  1  will be described. 
     The mounting device  1  includes two voice coil motors  38  and the collet  34 A. The voice coil motor  38  is a direct-acting linear motor in which the movable element  38   c  reciprocatingly moves along the axis A relative to the fixed element  38   b . The collet  34 A holds the semiconductor chip  101  in an attachable and detachable manner. The voice coil motors  38  are separated from each other in a direction intersecting the axis A. Further, the axes A of the voice coil motors  38  are parallel to each other. The collet  34 A is attached to straddle the chucks  39  provided at the end portions of the plurality of movable elements  38   c.    
     The mounting device  1  includes two voice coil motors  38  capable of attaching and detaching the collet  34 A. According to this configuration, two different modes can be selected. As the first mode, a mode in which one collet  34 A is attached to straddle two voice coil motors  38  can be selected. The collet  34 A disposed to straddle between the voice coil motors  38  is driven by two voice coil motors  38 . Then, the collet  34 A can be made larger than, for example, the collets  34 B and  34 C which can be driven by one voice coil motor  38 . That is, the area of the collet suction surface  34 S of the collet  34 A can be increased. As a result, the area of the chip main surface  101   a  of the semiconductor chip  101  that can be held is increased. Thus, the thin semiconductor chip  101  can be carried. As the second mode, a mode in which the collets  34 B and  34 C are attached to each of the voice coil motors  38  can be selected. According to the second mode, the small semiconductor chip  101  can be carried. As a result, the mounting device  1  capable of selecting the first mode and the second mode can carry the semiconductor chips  101  of various shapes. 
     In other words, the mounting device  1  has a configuration in which the collet  34 A and the collets  34 B and  34 C can be exchanged with each other. Thus, the mounting device  1  can handle the semiconductor chips  101  of various shapes. The exchange work of the collets  34 A,  34 B, and  34 C is relatively easier than the exchange work of the voice coil motor  38 . That is, when the semiconductor chip  101  to be picked up is changed, large-scale work such as exchange work of the voice coil motor  38  does not occur. 
     The mounting device  1  can use all pickup motors  36 A and  36 B of the pickup unit  30  even when the shape of the semiconductor chip  101  to be picked up is changed. For example, as shown in  FIG. 6 , there is a case in which the semiconductor chip  101  is larger than the gap of the pickup heads  33 . In this case, if the semiconductor chip  101  is picked up only using the pickup motor  36 A, another pickup motor  36 B adjacent to the pickup motor  36 A cannot pick up the semiconductor chip  101 . This is because the semiconductor chip  101  sucked to the collet  34 B interferes with the semiconductor chip  101  sucked to the collet  34 C. Thus, even when the pickup unit  30  includes the plurality of pickup motors  36 A and  36 B, the pickup motor  36 B cannot be operated. However, in the mounting device  1  of the embodiment, both the pickup motor  36 A and the pickup motor  36 B of the pickup unit  30  can be used by selecting the first mode. 
     The mounting device  1  includes the control unit  20 . The control unit  20  controls the position of the fixed element  38   b  by providing a control signal to the voice coil motor  38 . The voice coil motor  38  includes the encoder  38   d . The encoder  38   d  obtains a position along the axis of the movable element  38   c  relative to the fixed element  38   b . The control unit  20  acquires the representative position information from the encoder  38   d  of the voice coil motor  38  as a representative selected from the plurality of voice coil motors  38 . Then, the control unit  20  controls the position of the movable element  38   c  of the voice coil motor  38  using the representative position information. According to this configuration, the position of the movable element  38   c  of the voice coil motor  38  can be simply controlled with high accuracy. Thus, the position of the collet  34 A provided in the pickup motors  36 A and  36 B can be simply controlled with high accuracy. 
     The movable element  38   c  is provided with the chuck  39 . The chuck  39  includes the chuck magnet  39   b  and the chuck sensor  39   c . The collet  34 A is connected to the chuck  39  in an attachable and detachable manner. The chuck magnet  39   b  connects the collet  34 A to the chuck  39 . The chuck sensor  39   c  detects whether or not the collet  34 A exists in the chuck  39 . According to this configuration, the collet  34 A can be easily attached to and detached from the movable element  38   c . Further, it is possible to obtain information indicating that the collet  34 A is attached to the movable element  38   c  and information indicating that the collet  34 A is not attached to the movable element  38   c.    
     The collet  34 A includes the collet suction surface  34 S that holds the semiconductor chip  101  in an attachable and detachable manner. The semiconductor chip  101  includes the chip main surface  101   a  held by the collet suction surface  34 S. The area of the collet suction surface  34 S is larger than the area of the chip main surface  101   a . According to this configuration, the thin semiconductor chip  101  can be reliably held. 
     The mounting device  1  further includes the push-up pin  32   b . The push-up pin  32   b  pushes up the semiconductor chip  101  toward the collet  34 A by pushing the chip back surface  101   b  on the side opposite to the chip main surface  101   a . According to this configuration, the collet  34 A can reliably pick up the semiconductor chip  101 . 
     As described above, the mounting device of the disclosure has been described. However, the mounting device of the disclosure may be implemented in various forms without being limited to the above-described embodiment. 
     In the above-described embodiment, the pickup unit  30  includes two pickup heads  33 . The number of the pickup heads  33  of the pickup unit  30  is not limited to two. For example, the pickup unit  30  may include four pickup heads  33 . In this case, the pickup heads  33  may be arranged in a linear shape or may be arranged in a two-dimensional shape. Then, the collet  34 A may be disposed to straddle two pickup heads  33  or four pickup heads  33  in four pickup heads  33 . 
     REFERENCE SIGNS LIST 
     
         
         
           
               1  Mounting device 
               10  Bonding unit 
               11  Guide rail 
               12  Bonding stage 
               13  Bonding head 
               14  Bonding body 
               15  Bonding nozzle 
               20  Control unit 
               30  Pickup unit 
               31  Guide rail 
               32  Wafer operation mechanism 
               32   a  Wafer holder 
               32   b  Push-up pin 
               33  Pickup head 
               34 A,  34 B,  34 C Collet 
               34 S Collet suction surface 
               36 A,  36 B Pickup motor 
               37  Motor base 
               38  Voice coil motor 
               38   b  Fixed element 
               38   c  Movable element 
               38   d  Encoder 
               39  Chuck 
               39   a  Chuck holding surface 
               39   b  Chuck magnet 
               39   c  Chuck sensor 
               101  Semiconductor chip 
               101   a  Chip main surface 
               101   b  Chip back surface 
               110  Substrate 
               120  Dicing tape 
             L Coil 
             M Magnet