Method for manufacturing a semiconductor device and manufacturing apparatus

Abstract

Provided is a method for manufacturing a semiconductor device and a manufacturing apparatus, which can improve the degree of freedom of wire shape. The method for manufacturing a semiconductor device includes: a bonding step of bonding a wire to an electrode (35a); a loop wire forming step of forming a loop wire (50a) by looping the wire from the electrode (35a) to a dummy electrode (34); a pressing step of pressing a portion of the wire; a moving step of moving the pressed portion of the wire to directly above the electrode; and a wire separating step of separating the wire from a wire supply source at the portion, as a leg wire (55a) extending vertically upward from the electrode (35a). The loop wire forming step adjusts the loop height of the wire to adjust the length of the loop wire to a prescribed length.

Description

Technical Field

[0001] The present invention relates to a method for forming wire bonding on electrodes of a semiconductor chip or substrate, and a method and manufacturing apparatus for manufacturing a semiconductor device including the formed wire bonding. Background Technology

[0002] It is required to form pinwires extending vertically upward from the electrodes on the electrodes of a semiconductor chip or substrate. Therefore, a method has been proposed: after bonding the wire to the bonding position on the substrate using a bonding tool, the wire is extended to other positions on the substrate, a portion of the wire is pressed at the other positions, and then the bonding tool is moved so that the wire becomes vertically upward from the electrode, and the wire is cut to form the pinwire (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 6297553 Specification Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] Furthermore, when forming lead wires on the electrodes of a semiconductor chip using the conventional technique described in Patent Document 1, a portion of the wire is pressed onto other locations, such as on the substrate outside the semiconductor chip. In this case, these other locations can be freely selected, and therefore the height of the lead wires can be freely adjusted by adjusting the positions of these other locations.

[0008] On the other hand, in recent years, semiconductor devices with densely packed electrodes, such as semiconductor devices that stack semiconductor chips in multiple layers, have been used. If the conventional technology described in Patent Document 1 is used to form lead wires for the electrodes of such semiconductor devices, due to space constraints, it is necessary to press a portion of the wire bonding onto a semiconductor chip with low durability and load capacity, which can sometimes lead to damage to the semiconductor chip.

[0009] At this point, it is considered to press a portion of the wire at a specific location with high durability and load, such as a dummy electrode on the semiconductor chip. However, since the distance between each electrode and the pressing position cannot be freely selected, it is sometimes difficult to adjust the height of the lead wire, and thus sometimes it is not possible to freely form the wire.

[0010] Therefore, the purpose of this invention is to increase the degree of freedom in wire bonding shape.

[0011] Technical means to solve the problem

[0012] The wire forming method of the present invention forms lead wires using a joining tool. The wire forming method includes: a joining step, in which the wire is joined to a first joining point using the joining tool; a loop forming step, in which the loop height of the wire is adjusted to form a loop between the first joining point and a second joining point, and the length of the loop is adjusted to a predetermined length; a pressing step, in which a portion of the wire is pressed to the second joining point to form a thin-walled portion; and a wire separating step, in which the joining tool is raised to cut the wire at the thin-walled portion.

[0013] Therefore, the length of the loop can be adjusted to a specified length, increasing the freedom of the lead wire shape.

[0014] In the wire forming method of the present invention, the loop forming step may also include: a first step, in which the tip of the bonding tool is raised from the first bonding point; a second step, after the first step, in which the tip of the bonding tool is moved in the opposite direction to the second bonding point; a third step, after the second step, in which the tip of the bonding tool is raised again; and a fourth step, after the third step, in which the tip of the bonding tool is moved in an arc shape toward the second bonding point. By adjusting the amount of movement of the tip of the bonding tool in at least one step from the first step to the third step, the length of the loop is adjusted to a predetermined length.

[0015] In this way, a simple method can be used to adjust the length of the loop to the specified length, increasing the freedom of the lead wire shape.

[0016] The wire forming method of the present invention may also include: a moving step, in which the thin-walled portion is moved to directly above the first joint point by a joining tool; the wire separating step is performed after the thin-walled portion of the wire is cut from the wire supply source and serves as a lead wire extending vertically upward from the first joint point.

[0017] Therefore, a simple method can be used to form the lead wire.

[0018] In the wire bonding method of the present invention, the second bonding point may be a dummy electrode, and a bump forming step may be included before the bonding step to form a bump on the dummy electrode. The bonding step is to ball bond the first bonding point, and the pressing step is to press a portion of the wire bonding onto the bump formed on the dummy electrode to form a thin-walled portion.

[0019] Thus, by forming bumps on dummy electrodes with high durability and load capacity, and pressing a portion of the wire bonding onto these bumps, damage to the semiconductor chip can be effectively suppressed. Furthermore, by using ball bonding for the first junction point, damage near the first junction point of the semiconductor chip can be effectively suppressed.

[0020] The semiconductor device manufacturing method of the present invention manufactures a semiconductor device comprising a plurality of leads extending vertically upward from the electrodes on a plurality of electrodes of a semiconductor chip or substrate. The semiconductor device manufacturing method includes: (a) a bonding step, wherein wire bonding is performed to the electrodes using a wire bonding tool; (b) a loop forming step, wherein the wire is looped from the electrodes to a common pressing position disposed on the surface of the semiconductor chip or substrate using a wire bonding tool to form a loop; (c) a pressing step, wherein a portion of the wire is pressed to the pressing position using a wire bonding tool; (d) a moving step, wherein the pressed portion of the wire is moved to directly above the electrodes using a wire bonding tool; and (e) a wire separation step, wherein a portion of the wire is separated from the wire supply source. Each lead is formed on each electrode by repeatedly performing (a) to (e), wherein the loop forming step involves adjusting the loop height of the wire to adjust the length of the loop to a predetermined length.

[0021] Thus, even when a portion of the bonding wire is pressed onto multiple electrodes at a common pressing position, the winding height of the bonding wire can be adjusted to change the length of the winding wire to the specified length, thereby allowing for free adjustment of the lead wire height.

[0022] In the semiconductor device manufacturing method of the present invention, the winding wire forming step may also include: a first step, raising the tip of the bonding tool from the electrode; a second step, after the first step, moving the tip of the wire bonding tool in the opposite direction to the pressing position; a third step, after the second step, raising the tip of the wire bonding tool again; and a fourth step, after the third step, moving the tip of the wire bonding tool toward the pressing position in an arc shape, thereby adjusting the length of each winding wire to a predetermined length by adjusting the amount of movement of the tip of the wire bonding tool in at least one step from the first to the third step.

[0023] Therefore, a simple method can be used to adjust the length of the loop to the specified length, thereby easily adjusting the height of the lead wire.

[0024] In the semiconductor device manufacturing method of the present invention, a dummy electrode may be disposed at a pressing position, and a bump forming process may be included before the bonding process to form bumps on the dummy electrode. The bonding process is to ball bond the electrode, and the pressing process is to press a portion of the wire bonding onto the bumps formed on the dummy electrode.

[0025] Thus, by forming bumps on common dummy electrodes with high durability and load capacity, and pressing a portion of the wire bonding onto these bumps, damage to the semiconductor chip can be effectively suppressed. Furthermore, by using ball bonding for the semiconductor chip to the electrodes, damage near the electrodes can be effectively suppressed.

[0026] In the semiconductor device manufacturing method of the present invention, each electrode may be recessed from the surface of a semiconductor chip or substrate, and the bump forming process may be performed by forming bumps on the electrodes in such a way that the upper end of the bump is higher than the surface of the semiconductor chip or substrate.

[0027] In this way, the bump is formed with its upper end higher than the surface of the semiconductor chip or substrate, and a portion of the wire bonding is pressed onto the bump. This can prevent the wire bonding from touching the surface of the semiconductor chip or substrate during the pressing of the wire bonding, thus preventing damage to the semiconductor chip or substrate.

[0028] The semiconductor device manufacturing apparatus of the present invention manufactures a plurality of leads extending vertically upward from the electrodes on a plurality of electrodes of a semiconductor chip or substrate. The semiconductor device manufacturing apparatus includes: a wire bonding tool for inserting wires; a wire clamper for holding the wires above the wire bonding tool; a moving mechanism for moving the wire bonding tool and the wire clamper along the XYZ directions; and a control unit for controlling the drive of the moving mechanism. The control unit (A) presses the tip of the wire bonding tool with the inserted wires to the electrodes of the semiconductor chip or substrate via the moving mechanism to bond the wires to the electrodes; (B) moves the tip of the wire bonding tool around the electrodes to a common pressing position disposed on the surface of the semiconductor chip or substrate via the moving mechanism, forming a loop extending from the electrodes to the pressing position; and (C) lowers the tip of the wire bonding tool to a common pressing position via the moving mechanism. (A) Pressing position to press a portion of the wire to the pressing position; (D) Moving the front end of the wire bonding tool to directly above the electrode via the moving mechanism, so that the pressed portion of the wire moves directly above the electrode; (E) Raising the wire gripper with the wire gripper in the closed state via the moving mechanism, so that the wire is separated from the wire supply source on a portion of the wire, forming a lead wire extending vertically upward from the electrode. Repeating (A) to (E) to form each lead wire on each electrode. When forming the loop wire, adjusting the trajectory of the front end of the wire bonding tool so that the length of each loop wire is the specified length.

[0029] In the semiconductor device manufacturing apparatus of the present invention, the control unit may, when forming a loop wire, raise the tip of the wire bonding tool from the electrode using a moving mechanism, move the tip of the wire bonding tool in the opposite direction to the pressing position, raise the tip of the wire bonding tool again using the moving mechanism, and then move the tip of the wire bonding tool toward the pressing position in an arc shape using the moving mechanism. At least one of the following can be adjusted: the rising height of the tip of the wire bonding tool, the amount of movement of the tip of the wire bonding tool in the opposite direction to the pressing position, and the rising height when the tip of the wire bonding tool rises again, so as to adjust the length of the loop wire to a predetermined length.

[0030] The semiconductor device manufacturing apparatus of the present invention may also include: a discharge electrode for shaping a wire tail end extending from the front end of a wire bonding tool into a free air ball; a control unit for controlling the operation of the discharge electrode; a dummy electrode disposed at a pressing position; the control unit, before bonding the wire to the electrode, shapes a first wire tail end extending from the front end of the wire bonding tool into a first free air ball by means of the discharge electrode; a moving mechanism presses the front end of the wire bonding tool against the dummy electrode to form a bump; and a second wire tail end extends from the front end of the wire bonding tool, and the discharge electrode shapes the extended second wire tail end into a second free air ball; the second free air ball is bonded to the electrode, thereby bonding the wire to the electrode; and a portion of the wire is pressed onto the bump formed on the dummy electrode.

[0031] The effects of the invention

[0032] This invention can increase the degree of freedom in wire shaping. Attached Figure Description

[0033] Figure 1 This is an elevation view showing the structure of the wire bonding device according to the embodiment.

[0034] Figure 2 It is installed in Figure 1 The diagram shows a cross-sectional view of the capillary of the wire bonding device.

[0035] Figure 3 It is a plan view showing the electrode configuration of a semiconductor chip.

[0036] Figure 4 This is an explanatory diagram showing the movement of the tip of the welding pin when forming a bump on a dummy electrode.

[0037] Figure 5A It means to use Figure 1 The diagram shows the forming process of airless solder balls when forming bumps using a wire bonding device.

[0038] Figure 5B It means to use Figure 1 The diagram shows the state of forming a crimped ball by ball bonding when the wire bonding device is used to form a bump.

[0039] Figure 5C It means from Figure 5B The diagram shows the state in which the welding needle rises.

[0040] Figure 5D It means from Figure 5C The diagram shows the state in which the welding needle moves laterally towards the reverse side.

[0041] Figure 5E It means from Figure 5D The diagram shows the state in which the welding needle rises.

[0042] Figure 5F It means from Figure 5E The diagram shows a state in which the welding needle moves laterally forward, so that the face on the opposite side is directly above the ball neck.

[0043] Figure 5G This diagram illustrates the state in which the side of the wire is pressed against the ball neck using the back side of the soldering pin, creating a crushed area.

[0044] Figure 5H It means from Figure 5G The diagram shows the state in which the welding needle rises.

[0045] Figure 5I It means from Figure 5H The diagram shows a state in which the welding needle is moved laterally to the back side, so that the front side face is directly above the crushed part.

[0046] Figure 5J This diagram illustrates the state in which the side of the wire is pressed against the crushing part using the forward-facing face of the welding pin to form a protrusion.

[0047] Figure 5K It means from Figure 5J The diagram shows a state where the wire bonding gripper and the soldering needle rise, and the wire end extends from the front end of the soldering needle. Then, with the wire bonding gripper in the off state, the gripper and the soldering needle rise further, causing the wire end to separate from the bump.

[0048] Figure 6 [This represents a planar view of the electrodes of a semiconductor chip after bumps have been formed.]

[0049] Figure 7 It is a planar diagram showing the loop formed between electrode A and the dummy electrode.

[0050] Figure 8 This is an explanatory diagram showing the movement of the tip of the soldering pin when forming a lead wire on electrode A.

[0051] Figure 9A This diagram shows the state of forming a press-fit ball by ball welding on electrode A.

[0052] Figure 9B It means from Figure 9A The diagram shows the state in which the welding needle rises.

[0053] Figure 9C It means from Figure 9B The diagram shows the state in which the welding needle moves laterally in the opposite direction.

[0054] Figure 9D It means from Figure 9C The diagram shows the state in which the welding needle rises again.

[0055] Figure 9E This diagram shows the state in which a portion of the wire is pressed onto the dummy electrode.

[0056] Figure 9F It means from Figure 9E The diagram shows the state in which the tip of the welding needle is moved directly above electrode A.

[0057] Figure 9G This diagram shows the state in which the end of the wire extends from the front end of the soldering pin and separates from the wire supply source to form a lead wire.

[0058] Figure 10 It is a planar diagram showing the state of the lead wires formed on electrode A.

[0059] Figure 11 It is a planar diagram that displays the overlapping loops formed between electrodes A to E and the dummy electrode.

[0060] Figure 12 It is a planar diagram showing the pins formed on electrodes A through E.

[0061] Figure 13 It is a diagram that overlays the side views of the loops formed between electrodes A, B, C and the dummy electrode.

[0062] Figure 14 It is a graph showing the relationship between the distance between the joints and the height of the loop when the length of the loop is fixed.

[0063] Figure 15 It is a diagram showing the shape of electrodes, dummy electrodes, and loops when the electrodes of each layer of a semiconductor device with multiple semiconductor chips stacked are formed with lead wires.

[0064] Figure 16 It is a diagram showing the shape of electrodes, dummy electrodes, and loops when the electrodes of each layer of a semiconductor device with multiple semiconductor chips stacked are formed with lead wires.

[0065] [Explanation of Symbols]

[0066] 10: Base

[0067] 11: XY Platform

[0068] 11a: Moving mechanism

[0069] 12: Connector

[0070] 13: Z-axis motor

[0071] 13a: Axis

[0072] 13b: Stator

[0073] 14: Connecting Arm

[0074] 14a: Root

[0075] 15: Ultrasonic speaker

[0076] 16: Stringing

[0077] 17: Wire clamp

[0078] 18: Discharge electrode

[0079] 19: Joining platform

[0080] 20: Welding needle

[0081] 21: Through hole

[0082] 22: Chamfered section

[0083] 23: Face

[0084] 24, 36a, 38: Centerline

[0085] 25: Frontend

[0086] 30: Substrate

[0087] 34, 341-344: Semiconductor chips

[0088] 35, 35a~35e, 351~354: Electrodes

[0089] 37, 371-374: Dummy Electrodes

[0090] 40: Airless solder balls

[0091] 41, 51, 51a: Press-fit welded balls

[0092] 42: Ball neck

[0093] 43, 44: Crushing Zone

[0094] 45, 451-454: Bumps

[0095] 46: Connecting part

[0096] 47, 57: Kneading the end of the wire

[0097] 50a~50e, 501~505, 501a~502a: Loop lines

[0098] 52, 52a~52e: Ring section

[0099] 53, 53a~53e: Part

[0100] 55, 55a~55e, 551~552, 551a, 552a: Lead wires

[0101] 60: Control Department

[0102] 61: CPU

[0103] 62: Memory

[0104] 100: Wire bonding device Detailed Implementation

[0105] The following is a reference to the appendix. Figure 1 The wire bonding apparatus 100 of the embodiment will be described below. The wire bonding apparatus 100 is a semiconductor device manufacturing apparatus that forms lead wires 55 on the electrodes 35 of the semiconductor chip 34 to manufacture the semiconductor device.

[0106] like Figure 1 As shown, the wire bonding device 100 includes a base 10, an XY platform 11, a bonding head 12, a Z-direction motor 13, a bonding arm 14, an ultrasonic horn 15, a bonding pin 20 (as a wire bonding tool), a wire bonding gripper 17, a discharge electrode 18, a bonding stage 19, and a control unit 60. In the following description, the extension direction of the bonding arm 14 or the ultrasonic horn 15 will be defined as the X-direction, the direction perpendicular to the X-direction in the horizontal plane will be defined as the Y-direction, and the vertical direction will be defined as the Z-direction.

[0107] The XY platform 11 is mounted on the base 10, allowing the object mounted on it to move along the XY direction.

[0108] The coupling head 12 is mounted on the XY platform 11 and moves along the XY direction via the XY platform 11. The coupling head 12 houses a Z-direction motor 13 and a coupling arm 14 driven by the Z-direction motor 13. The Z-direction motor 13 includes a stator 13b. The root 14a of the coupling arm 14 faces the stator 13b of the Z-direction motor 13, forming a rotor rotatably mounted about the axis 13a of the Z-direction motor 13.

[0109] An ultrasonic horn 15 is mounted at the front end of the joint arm 14 in the X direction, and a welding pin 20 is mounted at the front end of the ultrasonic horn 15. The ultrasonic horn 15 uses the vibration of an ultrasonic transducer (not shown) to ultrasonically excite the welding pin 20 mounted at the front end. The welding pin 20 is described in detail below. Figure 2 As described, a through hole 21 extending vertically is provided inside, and a wire 16 is inserted into the through hole 21. The wire 16 is supplied by a wire supply source such as a wire spool (not shown).

[0110] Furthermore, a wire-punch gripper 17 is provided on the upper side of the front end of the ultrasonic speaker 15. The wire-punch gripper 17 is opened and closed to grip and release the wire 16.

[0111] A discharge electrode 18 is provided on the upper side of the bonding stage 19. The discharge electrode 18 may also be mounted on a frame (not shown) provided on the base 10. The discharge electrode 18 discharges between itself and the wire 16 extending from the front end 25 of the welding pin 20, causing the wire 16 to melt and form an airless solder ball 40.

[0112] The bonding stage 19 adsorbs and fixes the substrate 30 on which the semiconductor chip 34 is mounted on its upper surface, and heats the substrate 30 and the semiconductor chip 34 by a heater (not shown).

[0113] When the root 14a of the engaging arm 14 constituting the rotor is subjected to the electromagnetic force of the stator 13b of the motor 13 in the Z direction of the engaging head 12, as... Figure 1 When rotated as indicated by arrow 71, the welding needle 20 mounted at the front end of the ultrasonic horn 15 moves in the Z direction as indicated by arrow 72. Furthermore, the bonding platform 19 moves in the XY direction via the XY platform 11. Therefore, the welding needle 20 moves in the XYZ direction via the XY platform 11 and the Z-direction motor 13. Moreover, the wire bonding gripper 17 moves together with the welding needle 20 in the XYZ direction. Therefore, the XY platform 11 and the Z-direction motor 13 constitute a moving mechanism 11a that moves the welding needle 20 and the wire bonding gripper 17 in the XYZ direction.

[0114] The XY platform 11, Z-direction motor 13, wire bonding gripper 17, discharge electrode 18, and bonding stage 19 are connected to the control unit 60 and operate based on the commands of the control unit 60. The control unit 60 adjusts the position of the welding pin 20 in the XYZ directions through the moving mechanism 11a, which includes the XY platform 11 and the Z-direction motor 13, and performs the opening and closing of the wire bonding gripper 17, the driving of the discharge electrode 18, and the heating control of the bonding stage 19.

[0115] The control unit 60 is a computer that includes a central processing unit (CPU) 61 and a memory 62. The CPU 61 is a processor that performs information processing internally, and the memory 62 stores operation programs or operation data, etc.

[0116] Next, while referring to Figure 2 The structure of the welding pin 20 is explained. Figure 2 This diagram shows an example of the front end of the welding needle 20. A through hole 21 is formed in the welding needle 20, extending along the center line 24. A wire 16 is inserted into the through hole 21. Therefore, the inner diameter d1 of the through hole 21 is larger than the outer diameter d2 of the wire 16 (d1 > d2). The lower end of the through hole 21 extends in a conical shape. This conical extension is called a chamfer 22. Furthermore, the maximum diameter in the conical space (i.e., the diameter at the lowermost end) is called the chamfer diameter d3.

[0117] The lower end face of the welding pin 20 becomes a pressing surface. Figure 1 The airless solder ball 40 shown has a face 23. The face 23 can be a flat horizontal surface or an inclined surface that slopes upwards towards the outer edge. The width of the face 23, i.e., the distance between the chamfered portion 22 and the outer periphery of the lower end of the solder needle 20, is called the "face width W". The face width W is calculated based on the chamfer diameter d3 and the outer periphery diameter d4 of the solder needle 20, using the formula W = (d4 - d3) / 2. Furthermore, in the following description, the point on the center line 24 of the lower end of the solder needle 20 is referred to as the tip 25 of the solder needle 20.

[0118] like Figure 2 As shown by the dashed line, when the tip 25 of the welding pin 20 is lowered to point a at height h1, Figure 1 When the airless solder ball 40 is pressed onto the electrode 35, it is flattened by the face 23, forming a flat cylindrical crimp solder ball 41 with a diameter d5 and a thickness hb. Furthermore, a portion of the metal forming the airless solder ball 40 enters the through hole 21 from the chamfered portion 22, forming a ball neck 42 connected to the upper side of the crimp solder ball 41.

[0119] like Figure 3 As shown, multiple electrodes 35 and a dummy electrode 37 shared by multiple electrodes are disposed on the surface of the semiconductor chip 34. Figure 3In the text, "35" refers to the five electrodes 35a through 35e (A electrodes 35a to E electrodes 35e) and a dummy electrode 37 shared with respect to A electrodes 35a through 35e. Furthermore, the number of electrodes 35 may be five or more, and the number of dummy electrodes 37 may also be multiple. Moreover, in the following description, when distinguishing the five electrodes of the semiconductor chip 34, they are referred to as A electrodes 35a through 35e; when not distinguishing, they are referred to as electrode 35.

[0120] Multiple electrodes 35 are connected to circuitry formed within the semiconductor chip 34 and have a mechanical structure capable of withstanding the pressing load during wire bonding 16. A dummy electrode 37 has the same mechanical structure as each electrode 35 and can withstand the pressing load during bonding, but is not connected to the circuitry within the semiconductor chip 34. Furthermore, the surfaces of both electrodes 35 and dummy electrodes 37 are recessed from the surface of the semiconductor chip 34 (see reference). Figures 5A to 5K , Figures 9A to 9G ).

[0121] As described below, the wire bonding device 100 forms loop wires 50a to 50e between electrodes A 35a to E 35e and the dummy electrode 37, respectively, and then erects the loop wires 50a to 50e in a manner perpendicular to electrodes A 35a to E 35e, so that lead wires 55a to 55e are formed on electrodes A 35a to E 35e, respectively.

[0122] When forming lead wires 55a to 55e, the first bonding points P1a to P1e are located on the surfaces of electrodes A 35a to E 35e, and the second bonding point P2 is located on the surface of the dummy electrode 37. The following describes a wire bonding method for forming lead wires 55a to 55e using the wire bonding apparatus 100.

[0123] First, refer to Figures 4-6 The process of forming bumps 45 on the dummy electrode 37 is described.

[0124] In the following description, the direction from electrode A 35a (located at the first junction P1a) toward the dummy electrode 37 (located at the second junction P2) is called the "forward direction," and the direction away from the dummy electrode 37, or the direction opposite to the dummy electrode 37 (viewed from electrode A 35a), is called the "backward direction." The symbol "F" in each figure represents the forward direction, and the symbol "R" represents the backward direction. Furthermore, Figure 4 Arrows 81 to 90 shown correspond to Figures 5A to 5K Arrows 81 to 90 are shown in the diagram.

[0125] The processor (CPU) 61 of the control unit 60 first activates the wire bonding gripper 17 to drive and control the XY platform 11 and the Z-axis motor 13, so that the tip 25 of the welding pin 20 moves to the vicinity of the discharge electrode 18. Then, the CPU 61 causes a discharge between the discharge electrode 18 and the wire bonding tail extending from the tip 25 of the welding pin 20, thereby achieving... Figure 5A As shown, the bonding wire 16 extending from the front end 25 of the welding pin 20 is shaped into an airless welding ball 40.

[0126] Then, as Figure 4 , Figure 5A As shown, CPU 61 drives and controls the XY platform 11 and the Z-axis motor 13 to align the XY coordinates of the centerline 24 of the welding pin 20 with the XY coordinates of the centerline 38 of the second junction point P2 on the dummy electrode 37. Then, CPU 61... Figure 4 , Figure 5B As shown by arrow 81, the tip 25 of the welding pin 20 is lowered towards the second joint point P2 until it reaches point a, and as shown... Figure 5B As shown, ball welding is performed by pressing the airless solder ball 40 onto the dummy electrode 37 using the face 23 of the soldering needle 20.

[0127] When the welding pin 20 presses the airless welding ball 40 onto the dummy electrode 37, as previously referred to Figure 2 As explained, the face 23 and the chamfered portion 22 shape the airless solder ball 40 into a press-fit solder ball 41 and a ball neck 42.

[0128] Next, CPU61 as Figure 4 , Figure 5C As shown, the XY platform 11 and the Z-direction motor 13 are driven and controlled, thereby achieving the desired effect. Figure 4 , Figure 5C As shown by arrow 82, raise the tip 25 of the solder pin 20 to point b. Next, CPU 61... Figure 4 , Figure 5D As shown by arrow 83, move the tip 25 of the solder pin 20 laterally in the opposite direction to point c. Then, CPU 61... Figure 4 , Figure 5E As shown by arrow 84, raise the tip 25 of the solder pin 20 to point d. Then, CPU 61... Figure 4 , Figure 5F As shown by arrow 85, the welding pin 20 is moved laterally towards the forward side until the center of the face 23 on the back side of the welding pin 20 in the width direction becomes the position of the center line 38 of the second joint point P2 in the XY coordinate.

[0129] As shown by arrows 82 to 85, the tip 25 of the welding pin 20 is raised and then moved laterally in the opposite direction. Then, the welding pin 20 is raised again and moved in the forward direction. Thus, as... Figure 5F As shown, the string 16 on the upper side of the neck 42 is folded back and forth on the neck 42.

[0130] Then, CPU 61 performs drive control on the XY platform 11 and the Z-direction motor 13, thereby achieving... Figure 4 , Figure 5G As shown by arrow 86, the tip 25 of the welding needle 20 is lowered to point f, pressing the side of the bonding wire 16, which is folded back in the opposite and forward directions, onto the ball neck 42 and crushing it to form a crushed part 43.

[0131] Subsequently, CPU61 as Figure 4 , Figure 5H As shown by arrow 87, after raising the tip 25 of the welding pin 20 to point g, as... Figure 4 , Figure 5I As shown by arrow 88, move the welding pin 20 laterally toward the back side until the center of the front side face 23 of the welding pin 20 in the width direction becomes the position of the center line 38 of the second joint point P2 in the XY coordinate.

[0132] Through the rising of this welding pin 20 and its lateral movement towards the opposite direction, from Figure 5H The stitching 16, which is vertically raised on the front side of the crushing part 43, is folded on the upper side of the crushing part 43.

[0133] Then, CPU 61 performs drive control on the XY platform 11 and the Z-direction motor 13, thereby achieving... Figure 4 , Figure 5J As shown by arrow 89, the tip 25 of the welding needle 20 is lowered to point i, and the side of the bonding wire 16 is pressed onto the crushing part 43 to form a second crushing part 44. At this time, the crushing part 44 is connected to the bonding wire 16 entering the through hole 21 of the welding needle 20 by a thin connecting part 46.

[0134] Next, CPU 61 performs drive control on the XY platform 11 and the Z-direction motor 13, thereby achieving... Figure 5K As shown by arrow 90, the solder pin 20 is raised, causing the wire bonding tail 47 to extend from the front end 25 of the solder pin 20. Subsequently, the CPU 61 closes the wire bonding gripper 17 and raises the wire bonding gripper 17 and solder pin 20 further, thereby cutting off the lower end of the wire bonding tail 47 connected to the wire bonding supply source from the connecting portion 46. Thus, as... Figure 5K , Figure 6 As shown, a bump 45 is formed on the dummy electrode 37. (As indicated...) Figure 5KAs shown, the upper end of the bump 45 is higher than the surface of the semiconductor chip 34.

[0135] Next, refer to Figures 7-12 This section explains the method for forming the lead wire 55a on electrode A 35a. When forming the lead wire 55a, as follows... Figure 7 As shown, after forming a loop 50a between electrode A 35a and dummy electrode 37, the loop 50a is made to stand vertically relative to electrode A 35a, thereby forming a lead wire 55a on electrode A 35a. Figure 7 As shown, the distance between the first junction point P1a on electrode A 35a and the second junction point P2 on dummy electrode 37 is La. First, let me explain... Figure 7 The formation of the loop 50a shown. Furthermore, Figure 8 Arrows 91 to 96 shown correspond to Figures 9A to 9G Arrows 91 to 96 are shown in the diagram.

[0136] The CPU 61 of the control unit 60 drives and controls the XY platform 11 and the Z-direction motor 13 to move the tip 25 of the welding pin 20 to the vicinity of the discharge electrode 18. Then, during the formation of... Figure 5K When the protrusion 45 is shown, a discharge is generated between the wire bonding tail 47 extending from the front end 25 of the welding pin 20 and the discharge electrode 18, shaping the wire bonding tail 47 into... Figure 5A The airless solder ball 40 shown.

[0137] Next, CPU 61 drives and controls the XY platform 11 and the Z-axis motor 13 to align the XY coordinates of the centerline 24 of the welding pin 20 with the XY coordinates of the centerline 36a of the first bonding point P1a on electrode A 35a. Then, CPU 61... Figure 8 , Figure 9A As shown by arrow 91, the tip 25 of the welding needle 20 is lowered to point p, and the airless welding ball 40 is pressed onto electrode A 35a to perform ball welding, thereby forming a press-fit welding ball 51 (joining process).

[0138] Next, CPU 61 drives and controls the XY platform 11 and the Z-axis motor 13 to execute the loop forming process. First, CPU 61 moves the tip 25 of the welding pin 20 as... Figure 8 , Figure 9B As shown by arrow 92, it rises △h1 to point q (first step). Then, CPU61... Figure 8 , Figure 9C As shown by arrow 93, the tip 25 of the solder pin 20 is moved laterally △x1 in the opposite direction to point r (second step). Then, the CPU 61 moves the tip 25 of the solder pin 20 as shown... Figure 8 , Figure 9DAs shown by arrow 94, rise again △h2 to point s (third process).

[0139] Subsequently, CPU 61 drives and controls the XY platform 11 and the Z-axis motor 13, causing the tip 25 of the welding pin 20 to face the bump 45 formed on the dummy electrode 37. Figure 8 , Figure 9E As shown by arrow 95, it moves forward and to the side in an arc shape. At this time, CPU 61 moves the front end 25 of the welding pin 20 in an arc shape so that the center of the face width direction of the face 23 on the back side of the welding pin 20 becomes the XY coordinate position of the center line 38 of the second joint point P2 (fourth process).

[0140] Subsequently, CPU61 drives and controls the XY platform 11 and the Z-axis motor 13, causing the tip 25 of the welding pin 20 to descend to... Figure 8 , Figure 9E Up to point t, the side portion 53a of the wire bonding 16 is pressed onto the protrusion 45 by the back face portion 23 of the solder pin 20 to form a thin-walled portion (pressing process). Therefore, the protrusion 45 or point t1 located at the XY coordinate position of the second joint point P2 becomes the pressing position. At this time, the CPU 61 adjusts the pressing load so that the side portion of the wire bonding 16 is not connected to the upper surface of the protrusion 45.

[0141] Furthermore, although the upper end of the bump 45 is higher than the surface of the semiconductor chip 34, the lower surface of the wire bond 16 will not contact the surface of the semiconductor chip 34 when the wire bond 16 is looped around by the solder pin 20 or when the side of the wire bond 16 is pressed onto the bump 45. Therefore, damage to the semiconductor chip 34 caused by the wire bond 16 can be suppressed during the looping and pressing processes.

[0142] like Figure 9E As shown, when the pressing process is completed, a loop 50a is formed. The loop 50a extends in a loop from the first bonding point P1a on electrode A 35a to point t1 on the upper surface of the protrusion 45, where the linear XY coordinate position of the center line 38 of the second bonding point P2 on the dummy electrode 37 is located. The loop 50a includes: a press-fit solder ball 51a bonded to electrode A 35a, a loop portion 52a, and a portion 53a that becomes a thin-walled portion after pressing. The height of the loop portion 52a of the loop 50a measured from the surface of electrode A 35a is Ha, and the length along the loop portion 52a from the first bonding point P1a to point t1 is M0. Furthermore, as... Figure 9E As shown, the wire 16 extends from a portion 53a into the through hole 21 of the welding needle 20.

[0143] Next, CPU61 as Figure 8 , Figure 9FAs shown by arrow 96, the tip 25 of the solder pin 20 is moved in an arc shape toward the opposite side until point u (moving step). This causes the loop wire 50a to stand upright, so that a portion 53 of the bonding wire 16 pressed by the pressing step comes directly above the first bonding point P1a. Then, the CPU 61... Figure 8 , Figure 9G As shown by arrow 97, the solder pin 20 is raised, causing the wire bonding end 57 to extend beyond the lower end of the solder pin 20. Subsequently, the CPU 61 sets the wire bonding gripper 17 to close, causing the solder pin 20 to rise from the wire bonding gripper 17, and at part 53, the wire bonding end 57 connected to the wire bonding supply source is separated, thereby forming a lead wire 55a of length Y extending vertically upward on electrode A 35a (wire bonding separation process).

[0144] Using the methods described above, such as Figure 10 After the lead wire 55a is formed on electrode A 35a as shown, the dummy electrode 37 will have a residual bump 45.

[0145] Next, the CPU 61 of the control unit 60 undergoes the same process, such as... Figure 11 , Figure 12 As shown, after forming loop lines 50b to 50e between the B electrode 35b to E electrode 35e and the protrusion 45 of the dummy electrode 37, the loop lines 50b to 50e are made to stand upright to form lead lines 55b to 55e.

[0146] At this time, the distance between the first junction point P1b on electrode B 35b and the second junction point P2 on dummy electrode 37 is Lb, which is shorter than the distance La between the first junction point P1a on electrode A 35a and the second junction point P2 on dummy electrode 37. Similarly, the distance Lc between the first junction point P1c on electrode C 35c and the second junction point P2 on dummy electrode 37 is shorter than the distance Lb.

[0147] Here, when the lead wires 55b and 55c formed on electrode B 35b and electrode C 35c have the same height as the lead wires 55a formed on electrode A 35a, the shape of the loop wires 50b and 50c must be adjusted so that the length of the loop portion 52b and loop portion 52c along the height of the lead wires 55b and 55c is the same as the length M0 of the loop portion 52a of the loop wire 50a.

[0148] Therefore, CPU61, as Figure 13 , Figure 14As shown, the loop heights Hb and Hc of loop lines 50b and 50c are higher than the loop height Ha of loop line 50a. As a result, the lengths of the loop portions 52b and 52c along loop lines 50b and 50c are the same as the length M0 of the loop portion 52a of loop line 50a.

[0149] Specifically, CPU61... Figure 8 The following adjustments are made to one or more of the following movements: the height movement Δh1 of the welding needle 20 in the first process, the movement Δx1 of the welding needle 20 in the opposite direction in the second process, and the movement Δh2 of the welding needle 20 during its re-ascent in the third process. This adjusts the length of the loop portion 52b and loop portion 52c along the loop line 50b and loop line 50c to be the same as the length M0 of the loop portion 52a along the loop line 50a. That is, as shown... Figure 14 As shown, adjust the heights Ha, Hb, and Hc of the loop wire so that they intersect with the distances La, Lb, and Lc between the joint points at an angle V. Furthermore, the lengths of the loop wires 50a to 50c can be adjusted not only by adjusting the amount of movement but also by adjusting the movement trajectory of the tip 25 of the welding pin 20.

[0150] The above explains the cases where lead lines 55b and 55c, formed on electrodes B and C respectively, have the same height as lead lines 55a formed on electrode A. Similarly, the case where lead lines 55d, formed on electrode D respectively, have the same height as lead lines 55a formed on electrode A is the same as the case where lead lines 55b are formed on electrode B. Likewise, the case where lead lines 55e, formed on electrode E respectively, have the same height as lead lines 55a formed on electrode A is the same as the case where lead lines 55a are formed on electrode A.

[0151] As explained above, the wire bonding apparatus 100 of the embodiment adjusts the length M of the loop portion 52a to 52e along the loop line 50a to loop line 55e to a predetermined length by adjusting the loop height H of the wire bonding 16. Therefore, even when the pressing position for pressing the wire bonding 16 is set to a specific position with high durability load, such as the dummy electrode 37 on the semiconductor chip 34, the height of the lead wire 55a to lead wire 55e can be easily adjusted. As a result, damage to the semiconductor chip 34 can be suppressed, and the degree of freedom in the shape of the lead wire 55a to lead wire 55e can be increased.

[0152] Furthermore, the wire bonding apparatus 100 of the embodiment forms bumps 45 on the dummy electrode 37 with high durability and load capacity, and presses a portion 53a to a portion 53e of the wire bonding 16 onto the bumps 45, thereby effectively suppressing damage to the semiconductor chip 34. Moreover, by setting the bonding of the A electrode 35a to the E electrode 35e as ball bonding, damage near the A electrode 35a to the E electrode 35e of the semiconductor chip 34 can be effectively suppressed.

[0153] Furthermore, the above description assumes that a bump 45 is formed on the dummy electrode 37 and a portion 53a to a portion 53e of the wire bonding 16 is pressed on the bump 45. However, it is not limited to this. If the portion 53a to a portion 53e of the wire bonding 16 is pressed on a location with a large durable load on the surface of the semiconductor chip 34, the bump 45 may not be formed and the wire bonding 16 may be pressed on the surface of the semiconductor chip 34.

[0154] Furthermore, if the durability and strength of electrodes A 35a to E 35e are high, the connection between electrodes A 35a to E 35e may not be ball-welded, but may be performed, for example, by stitch bonding.

[0155] Next, refer to Figure 15 To illustrate the following situation, by means of the wire bonding apparatus 100 of the embodiment, lead wires 551 to lead wires 554 with the same upper end height Z1 are formed on the electrodes 351 to electrodes 354 of each layer of the semiconductor device 340 in which multiple semiconductor chips 341 to 344 are stacked.

[0156] Dummy electrodes 371 to 374 are respectively configured on semiconductor chips 341 to 344 in each layer. First, as... Figure 15 As shown by arrows 981 to 984, loop lines 501 to loop lines 504 are formed between each electrode 351 to electrode 354 and each bump 451 to bump 454 formed on each dummy electrode 371 to dummy electrode 374. Then, as... Figure 15 As shown by arrows 991 to 994, each of the formed loops 501 to 504 is erected to form each of the lead wires 551 to 554. Furthermore, the detailed operations of forming the bumps 451 to 454, forming the loops 501 to 504, erecting the loops 501 to 504, and separating them from the wire feeding source are the same as those described previously, therefore detailed explanations are omitted.

[0157] like Figure 15As shown, the semiconductor device 340 is a device in which four layers of semiconductor chips 341 to 344 are stacked on a substrate 30. Therefore, the heights of the electrodes 351 to 354 of each layer of semiconductor chips 341 to 344 are all different. Figure 15 As shown, the electrode 351 of the first-layer semiconductor chip 341 has the lowest height, and the heights of the electrodes of the second to fourth layers of semiconductor chips 342 to 344 increase sequentially in a stepped manner. Figure 15 As shown, in order to make the upper height Z1 of each pin line 551 to pin line 554 formed on each electrode 351 to electrode 354 consistent, the height of the pin line 551 on the electrode 351 of the semiconductor chip 341 in the first layer must be increased, and the height of each pin line 552 to pin line 554 on each electrode 352 to electrode 354 of each semiconductor chip 342 to semiconductor chip 344 in the second to fourth layers must be decreased sequentially.

[0158] Therefore, as Figure 15 As shown by arrow 981, when forming the first layer of lead wire 551, the loop height H1 of the loop wire 501 formed between the electrode 351 and the bump 471 is increased, the length of the loop wire 501 is extended, and the loop wire 501 is made to stand upright as shown by arrow 991 to form a tall lead wire 551.

[0159] Furthermore, when forming each of the second to fourth layers of the lead wires 552 to 554, the loop heights H2 to H4 of the loop wires 502 to 504 are sequentially reduced according to the height of the lead wires 552 to 554, so that each loop wire 502 to 504 is upright and the height of each lead wire 552 to 554 is sequentially lowered.

[0160] By adjusting the winding heights H1 to H4 of the winding lines 501 to 504 in this way, lead lines 551 to 554 of various heights can be freely formed.

[0161] As explained above, the wire bonding device 100 of the embodiment can freely form lead wires 551 to 554 of various heights.

[0162] Furthermore, Figure 15 In this paper, the case in which the electrodes 351 to 354 of each layer of the semiconductor device 340, which has multiple semiconductor chips 341 to 344 stacked, form pin lines 551 to pin lines 554 with the same upper end height Z1 is described, but it is not limited to this. For example, it can also be configured such that the height of the pin lines 551 to pin lines 554 is different for each layer.

[0163] Next, refer to Figure 16To illustrate another method for forming lead wires 551a to 552a with the same upper end height Z1 on the electrodes 351 to 352 of each layer of a semiconductor device 340a having multiple semiconductor chips 341 to 342 stacked together. Furthermore, the detailed operations of forming the bump 452, forming the loop wires 501a to 502a, erecting the loop wires 501a to 502a, and separating them from the wire bonding supply source are the same as those described previously, therefore detailed descriptions are omitted.

[0164] In this example, as Figure 16 As shown, a dummy electrode 372 is configured only on the semiconductor chip 342 of the second layer. When forming each pin line 551a to pin line 552a of each layer of the first layer and the second layer, loop lines 501a to loop lines 502a are formed between the electrode 351 to electrode 352 of each layer and the bump 452 formed on the dummy electrode 372 of the second layer, so that they are erected to form each pin line 551a to pin line 552a.

[0165] Between the electrode 351 and the bump 452 of the first-layer semiconductor chip 341, such as Figure 16 The loop line 501a is formed as shown by arrow 981a. The loop height of the loop line 501a is H1a. Furthermore, the loop line 501a is formed as shown... Figure 16 As shown in the figure, the arrow 991a stands upright to form the foot line 551a.

[0166] Furthermore, between the electrodes 352 and the bumps 452 of the second-layer semiconductor chip 342, such as Figure 16 As shown by arrow 982a, form a loop 502a. Then, as... Figure 16 As indicated by arrow 992a, the loop line 502a is made upright to form the foot line 552a.

[0167] The distance L1 between the electrode 351 and the bump 452 in the first layer is longer than the distance L2 between the electrode 352 and the bump 452 in the second layer. Therefore, the winding height H1a of the loop 501a is lower than the winding height H2a of the loop 502a.

[0168] By adjusting the winding height H according to the distances L1 and L2 between each electrode 351-352 and the protrusion 452, the upper height Z1 of the lead wires 551-552 can be made consistent. Furthermore, by adjusting the winding heights H1 and H2 of each winding wire 501-502, the height of each lead wire 551-552 can be freely adjusted.

[0169] Furthermore, in the case of the method described above, the number of dummy electrodes 372 can be reduced, thereby allowing for the formation of each pin 551 to pin 552 using a simple method.

[0170] The above describes the method of forming lead wires 55, 55a, 55e, 551, 552, 551a, and 552a on the electrodes 35, 35a, 35e, 351, and 354 of the semiconductor chip 34, semiconductor chip 341 to semiconductor chip 344 by means of wire bonding apparatus 100. However, wire bonding apparatus 100 can also form lead wires 55 on electrodes disposed on substrate 30.

Claims

1. A method for manufacturing a semiconductor device, comprising manufacturing a semiconductor device including a plurality of leads extending vertically upward from said electrodes on a plurality of electrodes stacked on a semiconductor chip or substrate, the method for manufacturing the semiconductor device being characterized by comprising: (a) A bonding process in which wire bonding is performed on the electrode using a wire bonding tool; (b) A loop wire forming process, wherein the wire bonding tool is used to loop the wire from the electrode to a common pressing position disposed on the surface of the semiconductor chip or the substrate to form a loop wire; (c) Pressing process: using the wire bonding tool to press a portion of the wire to the pressing position; (d) Moving process, wherein the pressed portion of the wire bonding tool is used to move the wire bonding process to directly above the electrode; as well as (e) Wire bonding separation process, wherein the portion of the wire bonding is separated from the wire bonding supply source, as the lead wire extending vertically upward from the electrode. Repeat steps (a) through (e) to form the respective lead wires on each of the respective electrodes. There are various distances between the pressing position and each of the electrodes. The winding wire forming process adjusts the winding height of the wire bonding according to the type of distance and the height of the stacked semiconductor chip from the substrate, thereby adjusting the length of the winding wire to a specified length and aligning it with the height of the lead wire formed at each step. A dummy electrode is provided at the pressing position, and the dummy electrode is used to form the loop wires of different lengths. The loop forming process includes: a first step, raising the tip of the wire bonding tool from the electrode; a second step, after the first step, moving the tip of the wire bonding tool in the opposite direction to the pressing position; a third step, after the second step, raising the tip of the wire bonding tool again; and a fourth step, after the third step, moving the tip of the wire bonding tool in an arc shape toward the pressing position. By adjusting the amount of movement of the tip of the wire bonding tool in at least one of the first to the third steps, the length of each loop wire is adjusted to a predetermined length.

2. The method for manufacturing a semiconductor device according to claim 1, characterized in that... Prior to the bonding process, a bump forming process is included in the process of forming bumps on the dummy electrodes. The joining process involves ball welding the electrodes. The pressing process involves pressing a portion of the wire bonding onto the bump formed on the dummy electrode.

3. The method for manufacturing a semiconductor device according to claim 2, characterized in that... Each of the electrodes is recessed from the surface of the semiconductor chip or the substrate. The bump forming process involves forming the bump on the electrode such that the upper end of the bump is higher than the surface of the semiconductor chip or the substrate.

4. A semiconductor device manufacturing apparatus for manufacturing a semiconductor device comprising a plurality of leads extending vertically upward from each of the electrodes on a plurality of electrodes stacked on a semiconductor chip or substrate, the semiconductor device manufacturing apparatus characterized in that it comprises: A punch-in tool to ensure proper punch-in connection; A wire-attaching gripper holds the wire above the wire-attaching tool; The moving mechanism causes the wire bonding tool and the wire bonding gripper to move along the XYZ directions; and The control unit controls the drive of the moving mechanism. The control unit (A) The moving mechanism presses the tip of the wire bonding tool, through which the wire is inserted, against the electrode of the semiconductor chip or the substrate to bond the wire to the electrode. (B) By means of the moving mechanism, the tip of the wire bonding tool is wound around the electrode to a common pressing position disposed on the surface of the semiconductor chip or the substrate, forming a loop extending from the electrode to the pressing position. (C) Using the moving mechanism, the tip of the wire bonding tool is lowered to the pressing position to press a portion of the wire to the pressing position. (D) The moving mechanism moves the tip of the wire bonding tool directly above the electrode, so that the pressed portion of the wire bonding is moved directly above the electrode. (E) By means of the moving mechanism, the wire bonding gripper is raised in the closed state to separate the wire from the wire supply source at the portion of the wire being bonded, forming a lead wire extending vertically upward from the electrode. Repeat steps (A) through (E) to form the respective pins on each of the electrodes. There are various distances between the pressing position and each of the electrodes. When forming the loop wire, the trajectory of the tip of the wire bonding tool is adjusted according to the type of distance and the height of the stacked semiconductor chip from the substrate, so that the length of each loop wire is a predetermined length and aligned with the height of the lead wire formed at each step. A dummy electrode is provided at the pressing position, and the dummy electrode is used to form the loop wires of different lengths. When forming the loop wire, the control unit uses the moving mechanism to raise the tip of the wire bonding tool from the electrode, then moves the tip of the wire bonding tool in the opposite direction to the pressing position. Subsequently, the moving mechanism raises the tip of the wire bonding tool again, and then moves the tip of the wire bonding tool in an arc shape toward the pressing position. Adjust at least one of the following: the rising height of the tip of the wire bonding tool, the amount of movement of the tip of the wire bonding tool in the direction opposite to the pressing position, and the rising height when the tip of the wire bonding tool rises again, so as to adjust the length of the loop wire to a predetermined length.

5. The semiconductor device manufacturing apparatus according to claim 4, characterized in that, Include: The discharge electrode shapes the wire bonding tail end extending from the front end of the wire bonding tool into an airless solder ball. The control unit controls the operation of the discharge electrode. Before bonding the wire to the electrode, the control unit uses the discharge electrode to shape the first wire tail end extending from the front end of the wire bonding tool into a first airless solder ball, and uses the moving mechanism to press the front end of the wire bonding tool against the dummy electrode to form a bump, and causes the second wire tail end to extend from the front end of the wire bonding tool. The extended end of the second bonding wire is shaped into a second air-free solder ball using the discharge electrode, and the second air-free solder ball is bonded to the electrode, thereby bonding the bonding wire to the electrode. The portion of the wire is pressed onto the bump formed on the dummy electrode.

Images