JP2016062962A - Wire bonding device and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform bonding without interferences of a bonding tool, a wire, a semiconductor chip and the like.SOLUTION: A wire bonding device comprises a stage, an arm to which a tool for performing bonding by a wedge bonding method can be attached and a control part for controlling the arm. The tool has a first foot and a second foot on a bottom face, which lie in a first direction. When assuming that a direction opposite to the first direction is a second direction, the tool has an insertion port toward the first direction and a first pad on the wiring board and a second pad on the semiconductor chip. The control part forms first bonding by a wire on the first pad, and moves the tool obliquely upward on the second direction and a wire is extended, and moves the tool in the first direction and operates the arm to form a loop in the wire, forms second bonding having a pressure-welding part on the second pad, and breaks the wire by extending the wire to form a breaking part on an end in the first direction.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a wire bonding apparatus and a semiconductor device.

  In bonding semiconductor chips, there is a wedge bonding method in which wires are connected using ultrasonic waves. For example, when bonding a laminated chip in which semiconductor chips are three-dimensionally stacked and bonding is performed close to the semiconductor chip, bonding tools, wires, semiconductor chips, etc. interfere with each other due to the three-dimensional positional relationship. This may interfere with bonding.

Japanese Patent Laid-Open No. 11-102925

  Provided are a wire bonding apparatus and a semiconductor device that enable bonding without bonding between a bonding tool, a wire, a semiconductor chip, and the like.

  A wire bonding apparatus according to an embodiment includes a stage on which a wiring board on which a semiconductor chip is mounted can be placed, an arm to which a tool for performing bonding by a wedge bonding method can be attached, and a control unit that controls the operation of the arm And having. The tool has a first foot and a second foot on a bottom surface, the first foot and the second foot are arranged in order in a first direction, and a direction opposite to the first direction is a second direction. In this case, the tool has an insertion port that opens from the side surface in the second direction toward the lower side in the first direction and opens between the first foot and the second foot on the bottom surface of the tool. The wiring board has a first pad and the semiconductor chip has a second pad, and the second pad is arranged so as to be positioned in the first direction when viewed from the first pad. A wire is inserted through the insertion port in the first direction so as to pass through the insertion port from the side surface in the second direction of the tool and have a protrusion on the first foot side from the opening on the bottom surface. . The control unit forms the first bonding using the wire on the first pad by operating the arm through which the wire is inserted, and the tool moves in the second direction. The arm is operated so that the wire is drawn out by moving in two directions and obliquely upward. In addition, the tool operates the arm so that a loop is formed in the wire by moving in the first direction, the tool operates the arm so that the tool moves on the second pad, and the second A second bonding having a pressure contact portion is formed on the pad. Subsequently, control is performed such that the wire is broken by pulling the wire to form a broken portion at the first direction end portion of the pressure contact portion.

An example of a diagram schematically showing a configuration of a wire bonding apparatus according to an embodiment An example of a diagram illustrating the bonding method according to the embodiment in order according to the procedure An example of a diagram illustrating the bonding method according to the embodiment in order according to the procedure An example of a diagram illustrating the bonding method according to the embodiment in order according to the procedure An example of a diagram illustrating the bonding method according to the embodiment in order according to the procedure An example of a diagram illustrating the bonding method according to the embodiment in order according to the procedure An example of a diagram illustrating the bonding method according to the embodiment in order according to the procedure An example of a diagram illustrating the bonding method according to the embodiment in order according to the procedure An example of a diagram illustrating the bonding method according to the embodiment in order according to the procedure An example of a diagram illustrating the bonding method according to the embodiment in order according to the procedure Example of enlarged view of the tip of the wedge bonding tool An example of a diagram illustrating an application example of a semiconductor device according to an embodiment An example of a diagram schematically showing the shape of a wire according to an embodiment (A) is an example of a plan view schematically showing a wiring board, a first semiconductor chip, and a second semiconductor chip. (B) is an example of a cross-sectional view taken along line 14-14 in FIG.

  Hereinafter, embodiments will be described with reference to the drawings. The drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like do not necessarily match those of the actual one. Even when the same part is represented, the dimensions and ratios may be represented differently depending on the drawing. In the present specification and drawings, the same elements as those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate. In the following description, for convenience of explanation, a coordinate system that defines front and rear and top and bottom is used. In this coordinate system, the front foot 301 direction is the front (first direction) when viewed from the rear foot 302 of the wedge bonding tool 30, and the rear foot 302 direction is the rear (second direction) when viewed from the front foot 301. Further, when viewed from the first bonding pad 66a, the direction of the second bonding pad 66b is the same as the front (first direction) and the opposite is the rear (second direction). Further, when viewed from the first bonding 90, the second bonding 92 direction coincides with the front direction (first direction) and the opposite direction as the rear direction (second direction).

(Embodiment)
Embodiments will be described below with reference to the drawings.
FIG. 1 is an example of a diagram schematically showing a configuration of a wire bonding apparatus (semiconductor manufacturing apparatus) 100 according to the present embodiment. FIG. 11 is an example of an enlarged view of the distal end portion of the wedge bonding tool 30. The wire bonding apparatus 100 includes a bonding stage 12 and an XY table 14. The bonding stage 12 mounts the semiconductor device 10 as an object to be bonded. The XY table 14 has a support 16 erected on the XY table 14 provided with a bonding drive unit on the top thereof. The arm 18 is supported by the support 16 at an intermediate portion of the support 16 so as to be movable in the vertical direction. The arm 18 can be moved up and down by a Z motor 20 installed on the XY table 14. The Z motor 20 is constituted by, for example, a linear motor.

  An ultrasonic transducer 22 is provided at the end of the arm 18 on the bonding stage 12 side. As the ultrasonic transducer 22, for example, a piezoelectric element can be used. A horn 26 is supported and connected to the arm 18 substantially horizontally. The horn 26 is connected so that the ultrasonic energy from the ultrasonic transducer 22 can be transmitted. The horn 26 functions as an ultrasonic energy transmission member. A wedge bonding tool 30 having a rod shape, for example, is attached to the tip of the horn 26 substantially vertically. An insertion hole 30 a is provided at the lower end of the wedge bonding tool 30. The distal end portion of the wire 34 wound around the reel 32 is inserted into the insertion hole 30a.

  A clamper support 36 is fixed to the tip of the arm 18. The clamper support 36 is supported by a clamper holder 38 at an intermediate portion and is suspended substantially vertically. The clamper holder 38 is provided so as to rotate in parallel with the extending direction of the horn 26. The clamper holder 38 can be reciprocated by a clamper moving mechanism 40 installed on the clamper support 36. A clamper 42 is suspended from the lower end of the clamper holder 38. The clamper 42 has a pair of sandwiching plates (not shown) arranged on both sides of the wire 34 and can be opened and closed by a clamper opening / closing device 44 made of, for example, a solenoid. The clamper 42 functions as a holding tool for the wire 34. The clamper 42 is in a state in which the wire 34 can be freely extended by opening the gap between the facing clip plates, and the extension of the wire 34 can be stopped by closing the gap between the facing clip plates.

  The wire bonding apparatus 100 has a computer 50. The XY table 14, the Z motor 20, the ultrasonic transducer 22, and the clamper opening / closing device 44 are connected to a computer 50. The wire bonding apparatus 100 is controlled by a sequence programmed in advance in the computer 50.

  The computer 50 controls the operation of each element of the wire bonding apparatus 100 as a whole. The computer 50 includes a control unit 501 that is, for example, a CPU, various interface circuits, and a memory 502. These are connected to each other via an internal bus 510.

  The various interface circuits are drive circuits or buffer circuits provided between the control unit 501 that is a CPU and each element of the wire bonding apparatus 100. In FIG. 1, the interface circuit is expressed as I / F. The computer 50 includes, as various interface circuits, a stage drive interface circuit 509 connected to the bonding stage 12, a Z motor drive interface circuit 508 connected to the Z motor 20, and an ultrasonic transducer interface connected to the ultrasonic transducer 22. A circuit 507 and a clamper opening / closing interface circuit 506 connected to the clamper opening / closing device 44 are provided.

  The memory 502 is a storage device that stores programs and data. The memory unit 502 includes a bonding program 504 related to wire bonding processing. Further, the memory 502 includes control data 505 used by the bonding program 504.

  FIG. 11 shows an enlarged view of the front end portion of the wedge bonding tool 30. The wedge bonding tool 30 is made of metal such as cemented carbide. A front foot 301 and a rear foot 302 are provided at the tip (bottom) of the wedge bonding tool 30. The front foot 301 is disposed on the front side of the bottom of the wedge bonding tool 30, and the rear foot 302 is disposed on the rear side. An insertion hole 30 a is opened between the front foot 301 and the rear foot 302. The insertion hole 30a penetrates obliquely upward from the bottom of the wedge bonding tool 30 and opens behind the wedge bonding tool 30. The wire 34 is inserted from the rear opening toward the bottom opening toward the front obliquely downward direction.

  The front foot 301 and the rear foot 302 are substantially flat. The front foot 301 and the rear foot 302 function as a processing portion that forms a bond by pressing a wire against the pad during bonding and bonding the wire with applied ultrasonic energy. A groove for guiding the wire 34 may be provided in the front foot 301 and the rear foot 302.

  Next, the bonding procedure according to the embodiment will be described in detail with reference to the drawings. 2 to 10 are examples of diagrams illustrating the bonding method according to the present embodiment and the states of the wire bonding apparatus 100 and the semiconductor device 10 in order of the procedure.

  2 to 10, the semiconductor device 10 according to the embodiment includes a first semiconductor chip 62 a and a second semiconductor chip 62 b on a wiring board 60. The first semiconductor chip 62a and the second semiconductor chip 62b are stacked while being displaced in the front-rear direction. The second semiconductor chip 62 b has a chip end 80. A die attach material 82 is provided between the wiring substrate 60, the first semiconductor chip 62a, and the second semiconductor chip 62b. A first bonding pad 66 a is provided on the wiring substrate 60. A second bonding pad 66b is provided on the second semiconductor chip 62b. The chip end 80 is located between the first bonding pad 66a and the second bonding pad 66b. The first bonding pad 66a and the second semiconductor chip 62b (chip end 80) are arranged close to each other.

  Each procedure of the wire bonding method corresponds to the processing procedure of the bonding program 504 stored in the memory 502 of the computer 50 and is controlled by the control unit 501. Coordinates and the like necessary for processing are stored in the control data 505 and called as necessary.

  First, as shown in FIG. 2, the wiring substrate 60 on which the semiconductor device 10 as a bonding target is mounted is positioned and fixed on the bonding stage 12. The wire 34 is obliquely supplied from behind the wedge bonding tool 30 to the insertion hole 30a of the wedge bonding tool 30. The tip of the wire 34 protrudes a predetermined length from the tip of the wedge bonding tool 30. This protruding portion later becomes a tail 76.

  Here, behind the wedge bonding tool 30, a space is required for the wire 34 to be supplied from the reel 32 and to be inserted into the insertion hole 30a. Therefore, when the arm 18 is operated so that a three-dimensional object such as the first semiconductor chip 62a is located close to the rear of the wedge bonding tool 30, the wire 34 and the three-dimensional object come into contact with each other. Therefore, when the first bonding 90 is formed on the bonding pad located close to the three-dimensional object, if the arm 18 is operated so that the front side of the wedge bonding tool 30 faces the direction of the three-dimensional object, the wire 34 and Contact with a three-dimensional object can be avoided. Here, the bonding pad located close to the three-dimensional object corresponds to the first bonding pad 66a in the present embodiment, and the first bonding corresponds to the first bonding 90 in the present embodiment.

  Next, the bonding program 504 is executed by the control unit 501. The wedge bonding tool 30 is moved by moving the arm 18. By the bonding program 504, the control unit 501 outputs a command (signal) for forming the first bonding 90 on the first bonding pad 66a. By this command, signals from the stage drive interface circuit 509 and the Z motor drive interface circuit 508 are output to the bonding stage 12 and the Z motor 20, and the wedge bonding tool 30 is moved above the first bonding pad 66a. A wire 34 is inserted into the insertion hole 30 a of the wedge bonding tool 30.

  The formation position of the first bonding 90 is on the first bonding pad 66a of the wiring substrate 60, and the coordinate data thereof is stored in the control data 505 in advance. Precise position control of the wedge bonding tool 30 is performed using a positioning camera or the like (not shown).

  Next, according to the bonding program 504, the control unit 501 outputs a command (signal) for causing the ultrasonic transducer 22 to emit ultrasonic waves. In response to this command, a signal from the ultrasonic transducer interface circuit 507 is input to the ultrasonic transducer 22, and the ultrasonic transducer 22 emits ultrasonic waves. The emitted ultrasonic wave is transmitted to the wedge bonding tool 30 through the horn 26.

  Next, commands (signals) from the stage drive interface circuit 509 and the Z motor drive interface circuit 508 are output to the bonding stage 12 and the Z motor 20, and the wedge bonding tool 30 is lowered to the surface of the first bonding pad 66a. The wire 34 abuts under the front foot 301 of the wedge bonding tool 30. In front of the front foot 301, the wire 34 is drawn out so that the tip portion protrudes. This part becomes the tail 76 after bonding. The front foot 301 is pressed (pressed) against the first bonding pad 66a. At this time, the wire 34 is sandwiched between the front foot 301 and the first bonding pad 66a. Since ultrasonic energy is applied to the wedge bonding tool 30, the pressed wire 34 is crimped so as to be crushed by the first bonding pad 66 a. In the press contact portion 72, the wire 34 is bonded to the first bonding pad 66a. As a result, the first bonding 90 is formed on the first bonding pad 66a, and the pressure contact portion 72 is formed at the portion of the wire 34 that is crimped by the front foot 301. A tail 76 is formed in the front direction of the press contact portion 72. The tip of the tail 76 faces forward (first semiconductor chip 62a direction, first direction when viewed from the first bonding pad 66a).

  Next, as shown in FIG. 3, the control unit 501 causes the wedge bonding tool 30 to keep the wire 34 inserted in the insertion hole 30 a as shown in the locus 68 a, in the diagonally upward direction. A command (signal) for performing an operation of moving toward is output. By this command, commands (signals) from the Z motor drive interface circuit 508 and the stage drive interface circuit 509 are output to the bonding stage 12 and the Z motor 20, and the wedge bonding tool 30 is moved rearward and obliquely upward. Here, the backward direction is also a direction away from the chip end 80 and the second bonding pad 66b when viewed from the first bonding pad 66a.

  At this time, the control unit 501 outputs a command for preventing the clamper 42 from clamping the wire 34. As a result, a command from the clamper opening / closing interface circuit 506 is output to the clamper 42, and the clamper 42 does not clamp the wire 34. As a result, the wire 34 is fed as much as necessary in accordance with the above-described movement of the wedge bonding tool 30. In addition, the locus | trajectory 68 (af) shows the locus | trajectory which the wedge bonding tool 30 moved.

  Next, as shown in FIG. 4, the control unit 501 outputs a command for performing the backward movement operation to the wedge bonding tool 30 as indicated by the locus 68 b by the bonding program 504. With this command, commands (signals) from the Z motor drive interface circuit 508 and the stage drive interface circuit 509 are output to the bonding stage 12 and the Z motor 20, and the wedge bonding tool 30 moves backward.

  At this time, the control unit 501 outputs a command for clamping the wire 34 to the clamper 42. As a result, a command from the clamper opening / closing interface circuit 506 is output to the clamper 42, and the clamper 42 clamps the wire 34. Since the clamper 42 clamps the wire 34, stress corresponding to the movement of the wedge bonding tool 30 is applied to the wire 34, and a kink 70 (bent portion) is formed on the wire 34.

  Note that the kink 70 can arbitrarily adjust the curvature and the degree of bending by controlling the movement of the wedge bonding tool 30. The kink 70 is formed as necessary, and looping may be performed so that the kink 70 is not provided.

  Furthermore, as shown in a locus 68c in FIG. 5, the wedge bonding tool 30 may be moved downward. In this case, the control unit 501 outputs a command for performing an operation of moving the wedge bonding tool 30 downward as indicated by a locus 68c by the bonding program 504. By this command, commands (signals) from the Z motor drive interface circuit 508 and the stage drive interface circuit 509 are output to the bonding stage 12 and the Z motor 20, and the wedge bonding tool 30 moves downward.

  At this time, the control unit 501 outputs a command for clamping the wire 34 to the clamper 42. As a result, a command from the clamper opening / closing interface circuit 506 is output to the clamper 42, and the clamper 42 clamps the wire 34. Thereby, the stress by the wedge bonding tool 30 is further applied to the wire 34, and the bending of the kink 70 is added.

  Next, as indicated by a locus 68d in FIG. 6, the control unit 501 outputs a command to execute an operation of moving the wedge bonding tool 30 backward and obliquely upward by the bonding program 504. By this command, commands (signals) from the Z motor drive interface circuit 508 and the stage drive interface circuit 509 are output to the bonding stage 12 and the Z motor 20, and the wedge bonding tool 30 moves rearward and obliquely upward.

  At this time, the control unit 501 outputs a command not to clamp the wire 34 to the clamper 42. As a result, a command from the clamper opening / closing interface circuit 506 is output to the clamper 42, and the clamper 42 does not clamp the wire 34. Thereby, the wire 34 is paid out according to the movement of the wedge bonding tool 30. The feeding amount of the wire 34 at this time is set according to the loop shape to be added to the wire 34 and the position of the second bonding pad 66b.

  Next, as shown in FIG. 7, by the bonding program 504, the control unit 501 moves the wedge bonding tool 30 forward as indicated by the locus 68e and moves upward on the second bonding pad 66b. Command to output. With this command, commands (signals) from the Z motor drive interface circuit 508 and the stage drive interface circuit 509 are output to the bonding stage 12 and the Z motor 20. The wedge bonding tool 30 moves in the forward direction and moves to a position above the second bonding pad 66b.

  At this time, the control unit 501 outputs a command for clamping the wire 34 to the clamper 42. As a result, a command from the clamper opening / closing interface circuit 506 is output to the clamper 42, and the clamper 42 clamps the wire 34. As a result, the wire 34 is pulled in accordance with the movement of the wedge bonding tool 30, and stress is applied, whereby the wire 34 is bent and a loop is formed.

  Subsequently, as shown in FIG. 8, by the bonding program 504, the control unit 501 moves the wedge bonding tool 30 downward as indicated by the locus 68f, and positions the wire 34 on the upper surface of the second bonding pad 66b. Outputs a command to execute the operation. By this command, commands (signals) from the Z motor drive interface circuit 508 and the stage drive interface circuit 509 are output to the bonding stage 12 and the Z motor 20, and the wedge bonding tool 30 moves downward, and the tip of the wire 34 Is moved to a position on the upper surface of the second bonding pad 66b.

  At this time, the control unit 501 outputs a command for clamping the wire 34 to the clamper 42. A command from the clamper opening / closing interface circuit 506 is output to the clamper 42, and the clamper 42 clamps the wire 34.

  Next, according to the bonding program 504, the control unit 501 outputs a command (signal) for causing the ultrasonic transducer 22 to emit ultrasonic waves. In response to this command, a signal from the ultrasonic transducer interface circuit 507 is input to the ultrasonic transducer 22, and the ultrasonic transducer 22 emits ultrasonic waves. The emitted ultrasonic wave is transmitted to the wedge bonding tool 30 through the horn 26. Thereby, an ultrasonic wave is applied to the rear foot 302 of the wedge bonding tool 30.

  Subsequently, the control unit 501 outputs a command (signal) for performing the second bonding step by the bonding program 504. In response to this command, signals from the stage drive interface circuit 509 and the Z motor drive interface circuit 508 are output to the bonding stage 12 and the Z motor 20. Accordingly, the wedge bonding tool 30 is moved onto the second bonding pad 66b, and the wire 34 is brought into contact with the upper surface (bonding surface) of the second bonding pad 66b of the second bonding pad. At this time, the wire 34 is held so as to be pressed between the rear foot 302 and the upper surface of the second bonding pad 66b. The formation position of the second bonding 92 is on the second bonding pad 66 b of the wiring substrate 60. The coordinate data is stored in the control data 505 in advance.

  The ultrasonic wave is applied by the rear foot 302 and the wire 34 is pressed, so that the wire 34 is bonded to the upper surface of the second bonding pad 66b so that the tip of the wire 34 is crushed. As a result, the press contact portion 72 is formed on the wire 34 at a portion located below the rear foot 302.

  Next, as shown in FIG. 9, the control unit 501 outputs a command (signal) for cutting the wire 34 by the bonding program 504. The control unit 501 outputs a command for clamping the wire 34 to the clamper 42. As a result, a command from the clamper opening / closing interface circuit 506 is output to the clamper 42, and the clamper 42 clamps the wire 34. With the wire 34 clamped by the clamper 42, the clamper 42 is pulled rearward and obliquely upward. As a result, the wire 34 is torn off and a fracture portion 74 is formed at a position in front of the pressure contact portion 72 pressed by the rear foot 302.

Next, as shown in FIG. 10, the wedge bonding tool 30 is moved rearward and obliquely upward, and the wedge bonding tool 30 is released from above the semiconductor device 10.
Thus, the first bonding 90 and the second bonding 92 are formed. The fracture portion 74 is formed facing the front direction of the press contact portion 72 (the second bonding pad 66b direction and the first direction as viewed from the first bonding pad 66a).

Thus, the bonding process according to this embodiment is completed.
According to this embodiment, the wedge bonding tool 30 has a front foot 301 and a rear foot 302. Accordingly, it is possible to press the bonding pad 66 against the wedge bonding tool 30 regardless of whether the wire 34 is sandwiched so as to be positioned in the front direction or the rear direction. Accordingly, in the bonding forming step, after forming the first bonding 90, the wedge bonding tool 30 is moved backward to perform looping, and then the wedge bonding tool 30 is moved forward to form the second bonding 92. It becomes possible. At this time, the wire 34 is pressed by the front foot 301 in the first bonding 90, and the wire 34 is pressed by the rear foot 302 in the second bonding 92.

  According to the present embodiment, bonding can be performed without the wires 34, the wedge bonding tool 30, the second semiconductor chip 62b, and the like interfering with each other. Therefore, the manufacturing yield of the semiconductor device 10 can be improved. Further, the reliability of the semiconductor device 10 can be improved.

  In the present embodiment, the first bonding 90 is formed such that the front side of the wedge bonding tool 30 is directed in the direction (first direction) of the semiconductor chip 62 (second semiconductor chip 62b) which is a three-dimensional object. Therefore, the first bonding pad 66a (and the first bonding 90 formed thereon) and the second semiconductor chip 62b can be formed close to each other, and the semiconductor device 10 can be reduced in size. it can.

  In the bonding procedure according to the present embodiment described above, the first bonding pad 66a located below is bonded first, and then the second bonding pad 66b located above is bonded. If this procedure is reversed, the following problems occur. That is, if the procedure is to first bond the second bonding pad 66b positioned on the upper side and then bond the first bonding pad 66a positioned on the lower side, the following trouble occurs.

  When the second bonding pad 66b positioned on the upper side is bonded first, the wire 34 extends to the upper side of the first bonding pad 66a positioned below while being fed out to the front side of the wedge bonding tool 30. At this time, the wire 34 is looped at a position sandwiched between the front side (first direction side) of the wedge bonding tool 30 and the second semiconductor chip 62b. When the wedge bonding tool 30 and the second semiconductor chip 62b (chip end 80) are located close to each other, the possibility that the wire 34 contacts the second semiconductor chip 62b and the wedge bonding tool 30 is increased.

  On the other hand, in this embodiment, the wedge bonding tool 30 first forms the first bonding 90 on the first bonding pad 66a positioned on the lower side, and then is positioned on the upper side in the forward direction. The locus that reaches the second bonding pad 66b is moved. As a result, the wire 34 is drawn out behind the wedge bonding tool 30 and looped, so that the wire 34 does not contact the wedge bonding tool 30 or the second semiconductor chip 62b.

  The above-described semiconductor device 10 shown in FIGS. 2 to 10 is shown in a simplified manner for easy understanding of the description. Actually, for example, a plurality of semiconductor chips 62 as shown in FIG. The present invention can be applied to the stacked semiconductor device 10 that is stacked. FIG. 12 shows an example of the semiconductor device 10 in which a plurality of semiconductor chips 62 are stacked on the wiring board 60 in a stepped shape that is folded back halfway. Here, an example in which eight semiconductor chips 62 are stacked is shown, but the number of stacked layers can be arbitrarily set. A die attach material 82 is provided between the semiconductor chips 62. A plurality of semiconductor chips 62 are bonded and fixed by a die attach material 82. Each semiconductor chip 62 is electrically connected to the wiring board 60 by wires 34.

  FIG. 13 is an example of a diagram schematically showing the shape of the wire according to the present embodiment. As shown in FIG. 13, the first bonding 90 has a pressure contact portion 72 and a tail 76. The second bonding 92 has a pressure contact portion 72 and a fracture portion 78. Assuming that the direction toward the second bonding 92 as viewed from the first bonding 90 is the forward direction (first direction), the tail 76 is directed forward in the first bonding 90. The wire 34 is connected in the rear direction (second direction) of the press-contact portion 72 of the first bonding 90, and once stretched in the rear direction, the wire 34 is bent while drawing a loop in the front direction. Connecting. The wire 34 is formed so as to have a convex loop shape as a whole. In the second bonding 92, the fracture portion 78 is provided at the front end of the press contact portion 72. The wire 34 is connected to an end portion in the rear direction of the pressure contact portion 72 of the second bonding 92. The direction in FIG. 13 coincides with the direction in which the direction corresponding to the front foot 301 side is the front and the direction corresponding to the rear foot 302 side is the rear when bonding is performed by the wedge bonding tool 30.

  FIG. 14A is an example of a plan view schematically showing the wiring substrate 60, the first semiconductor chip 62a, and the second semiconductor chip 62b. In FIG. 14A, the wire 34, the first bonding 90, and the second bonding 92 are omitted. FIG. 14B is an example of a cross-sectional view taken along line 14-14 in FIG. In FIG. 14A, the horizontal direction is the X direction, and the vertical direction is the Y direction. 14A and 14B, the direction of the second bonding pad 66b when viewed from the first bonding pad 66a is the front direction, and the opposite is the rear direction.

  A first bonding pad 66 a is provided on the wiring substrate 60. A second bonding pad 66b is provided on the second semiconductor chip 62b. Each of the plurality of first bonding pads 66a and the second bonding pads 66b has a rectangular shape, for example, and a plurality thereof are arranged side by side in the Y direction in the figure. The first bonding pad 66a and the second bonding pad 66b are disposed substantially parallel to the X direction (front-rear direction) in the drawing. In the X direction, the second semiconductor chip 62 b has a chip end 80. A chip end 80 is located between the first bonding pad 66a and the second bonding pad 66b.

  The first bonding pad 66a has a side 67a close to the chip end 80, and the side 67a has a width W1. The second bonding pad 66b has a side 67b in the direction away from the chip end 80 (first direction), and the side 67b has a width W2. The tail 76 of the first bonding 90 formed on the first bonding pad 66a faces the chip end 80 and the second bonding pad 66b direction (forward direction, first direction) when viewed from the first bonding pad 66a. The direction is within the range of the width W1. Thereby, a short circuit between adjacent first bonding pads 66a is suppressed, which contributes to an improvement in yield.

  Further, the fracture portion 74 of the second bonding 92 on the second bonding pad 66b is directed in the direction away from the chip end 80 and the second bonding pad 66b (forward direction, first direction) as viewed from the second bonding pad 66b. It faces the direction within the range of the width W2. Thereby, the loop of the wire 34 is also present in the region within the width W2, and short-circuiting between the adjacent second bonding pads 66b is suppressed, which contributes to an improvement in yield.

(Other embodiments)
The embodiment described above can be applied to various semiconductor devices. For example, the present invention may be applied to NAND-type or NOR-type flash memory, EPROM, DRAM, SRAM, other semiconductor memory devices, various logic devices, and other semiconductor devices.

  Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  In the drawings, 100 is a wire bonding apparatus, 10 is a semiconductor device, 12 is a bonding stage, 14 is an XY table, 20 is a Z motor, 22 is an ultrasonic transducer, 26 is a horn, 30 is a wedge bonding tool, and 30a is an insertion hole. , 34 is a wire, 42 is a clamper, 50 is a computer, 501 is a control unit (CPU), 60 is a wiring board, 62, 62a and 62b are semiconductor chips, 66a and 66b are bonding pads, 70a is a kink, and 72 is a pressure contact part. 74 is a fracture portion, 76 is a tail, 90 is a first bonding, and 92 is a second bonding.

Claims (6)

A stage on which a wiring board on which a semiconductor chip is mounted can be placed;
An arm to which a tool for bonding by the wedge bonding method can be attached;
A wire bonding apparatus having a control unit for controlling the operation of the arm,
The tool has a first foot and a second foot on the bottom surface,
The first foot and the second foot are sequentially arranged in the first direction,
When the direction opposite to the first direction is the second direction,
From the side in the second direction of the tool toward the lower side in the first direction, and having an insertion opening that opens between the first foot and the second foot on the bottom surface of the tool,
A first pad on the wiring substrate and a second pad on the semiconductor chip;
The second pad is arranged to be positioned in the first direction when viewed from the first pad,
A wire is inserted through the insertion port in the first direction so as to pass through the insertion port from the side surface in the second direction of the tool and have a protruding portion on the first foot side from the opening on the bottom surface. ,
The controller is
By operating the arm through which the wire is inserted, the first bonding is formed on the first pad using the wire,
The tool moves in the second direction, and further operates the arm so that the wire is drawn out by moving in the second direction and obliquely upward,
Operating the arm so that the tool moves in the first direction to form a loop in the wire;
Manipulating the arm so that the tool moves onto the second pad;
Forming a second bonding having a pressure contact portion on the second pad;
A wire bonding apparatus that performs control such that the wire is broken by pulling the wire to form a broken portion at an end portion in the first direction of the press contact portion. The controller is
After the tool moves in the second direction,
Furthermore, before the wire is drawn out by moving in the second direction and obliquely upward,
The wire bonding apparatus according to claim 1, wherein a control is performed such that a kink is formed on the wire by operating an arm so that the tool moves downward. The controller is
When forming the first bonding, the wire is pressed against the first pad by the first foot,
3. The wire bonding apparatus according to claim 1, wherein when forming the second bonding, control is performed such that the wire is pressed against the second pad by the second foot. 4. A wiring board;
A semiconductor chip disposed on the wiring board;
A first pad provided on the wiring board;
A first bonding provided on the first pad;
A second pad provided on the semiconductor chip;
A second bonding provided on the semiconductor chip;
A wire connecting the first bonding and the second bonding;
An end of the semiconductor chip is located between the first pad and the second pad,
When the direction from the first pad toward the end and the first pad is the first direction, and the direction opposite to the first direction is the second direction,
The first bonding includes a first pressure contact portion, a tail provided so as to extend from the first pressure contact portion in the first direction, and a wire connected to face the second direction of the first pressure contact portion. Have
In the second bonding, a second press-contact portion, a fracture portion provided to face the first direction of the second press-contact portion, and a wire connected to face the second direction of the second press-contact portion A semiconductor device having the same.   The semiconductor device according to claim 4, wherein the wire is provided with a kink. The first pad and the second pad are rectangular,
The tail of the first bonding faces a direction within a width of a side located in the first direction of the first pad;
6. The semiconductor device according to claim 4, wherein the fracture portion of the second bonding faces a direction within a range of a width of a side located in the first direction of the second pad.

Images