JP6966815B2 - Pin-shaped wire forming method and wire bonding equipment - Google Patents

Description

The present invention relates to a method of forming a pin-shaped wire on a substrate or a semiconductor element and a wire bonding apparatus for forming a pin-shaped wire.

In recent years, semiconductor devices in which semiconductor packages are laminated and semiconductor devices in which semiconductor elements are laminated have been used. In such a three-dimensionally mounted semiconductor device, it is necessary to form a pin-shaped wire having a predetermined height on a substrate or an electrode of a semiconductor element.

As a method of forming such a pin-shaped wire, after ball bonding at the bonding position, the wire is looped at a position different from the bonding position and the side surface of the wire is pressed to form a notch on the side surface of the wire. After that, a method of erecting the wire at the bonding position and cutting the wire at the notch position has been proposed (see, for example, Patent Document 1).

Similarly, a method has been proposed in which a thin portion is formed on the side surface of the wire, then the wire is erected upright at the bonding position, and then the bonding tool is moved laterally to cut the wire (for example, a patent). See Document 2).

Japanese Patent No. 6297553 Japanese Patent No. 5686912

In the method of the prior art described in Patent Documents 1 and 2, after ball bonding to a bonding position, the wire is looped at a position different from the bonding position to press the side surface of the wire, and a notch or a thin portion is formed on the side surface of the wire. Is formed, and after the wire is made upright, the wire is cut at the notch or the thin wall portion to form a pin-shaped wire. In order to form a notch or a thin portion on the side surface of the wire, it is necessary to press the wire to a position other than the electrode of the semiconductor element with a certain force. Therefore, when the pin-shaped wire is formed on the electrode of the semiconductor element by the conventional technique described in Patent Documents 1 and 2, there is a possibility that the semiconductor element may be damaged. Further, since a space for forming a notch portion or a thin-walled portion is required in the vicinity of the bonding position, there is a problem that it is difficult to apply to a small semiconductor element having a narrow electrode pitch.

Therefore, an object of the present invention is to provide a method for forming a pin-shaped wire that can suppress damage to a semiconductor element in a space-saving manner.

The pin-shaped wire forming method of the present invention is a pin-shaped wire forming method for forming a pin-shaped wire at a bonding position of a substrate or a semiconductor element by using a bonding tool through which the wire is inserted, and is a pin-shaped wire forming method having a predetermined length from the tip. Bending wire forming to form a bent wire by lowering the bonding tool with the extended wire diagonally toward the reference plane and bringing the lower end of the wire into contact with the reference plane to bend the wire in the direction along the reference plane. With the bending wire sandwiched between the process and the tip of the bonding tool and the reference plane, the bonding tool is moved laterally in the direction opposite to the extending direction of the bending wire, and the bending wire is moved up along the bonding tool. The erecting wire forming step of erecting in the direction to form the erecting wire, the bonding step of moving the bonding tool over the bonding position of the substrate or the semiconductor element to bond the erecting wire to the bonding position, and raising the bonding tool. It is characterized by having a wire cutting step of cutting a wire inserted through a bonding tool to make an upright wire a pin-shaped wire rising from a bonding position. Here, the reference surface may be the surface of the substrate or the surface of the semiconductor element.

In this way, the lower end of the wire is brought into contact with the reference surface, the wire is bent in the direction along the reference surface to form a bent wire, and the bent wire is sandwiched between the tip of the bonding tool and the reference surface for bonding. The tool is moved laterally to erect the bent wire upward to form the erect wire, and the formed erect wire is bonded to the bonding position, so there is no need to press the wire to a position other than the electrode of the semiconductor element, and the pin Damage to the semiconductor element when forming the shaped wire can be suppressed. Further, since the wire can be bent and erected at a position distant from the bonding position, the pin-shaped wire can be formed in a small space.

In the pin-shaped wire forming method of the present invention, in the bending wire forming step, the bonding tool is slanted toward the reference surface so that the angle between the moving direction of the bonding tool and the reference surface becomes smaller as the bonding tool is lowered. It may be lowered.

As a result, the wire can be bent smoothly.

In the pin-shaped wire forming method of the present invention, in the bonding step, the center position of the bonding tool may be shifted from the center position of the bonding position for bonding.

This makes it possible to form a pin-shaped wire at the center of the bonding position.

In the pin-shaped wire forming method of the present invention, before the bending wire forming step, the bonding tool is lowered toward the bonding position and the wire whose tip is formed into a free air ball is bonded to the bonding position to form a crimping ball. Bonding includes a crimping ball forming step and a bump forming step of raising the bonding tool while feeding out a wire from the tip of the bonding tool, then folding the drawn wire onto the crimping ball and pressing it to form a bump. The process may bond the upright wire onto the bump.

Since the upright wire is bonded on the crimping ball and the bump, damage to the semiconductor element can be suppressed more preferably.

In the pin-shaped wire forming method of the present invention, in the bump forming step, the unwound wire is folded back on the crimping ball, the center position of the bonding tool is shifted from the bonding position, and the wire is pressed to form a bump having a recessed portion on the upper surface. In the molding and bonding step, the center position of the bonding tool may be shifted from the bonding position so that the root of the upright wire fits into the recessed portion of the bump.

In this way, by bonding the root of the upright wire to the recessed portion of the bump, the pin-shaped wire can be formed more vertically.

In the pin-shaped wire forming method of the present invention, in the bending wire forming step, a bonding tool in which a wire having a predetermined length is extended from the tip thereof is slanted down toward the surface of a substrate or the surface of a semiconductor element, and the wire is formed. The bent wire may be formed by bringing the lower end of the wire into contact with the bump and bending the wire in a direction along the surface of the substrate or the surface of the semiconductor element.

As a result, the pin-shaped wire can be formed in a smaller space.

The wire bonding apparatus of the present invention is a wire bonding apparatus that forms a pin-shaped wire at a bonding position of a substrate or a semiconductor element by using a bonding tool through which a wire is inserted, and includes a control unit for adjusting the bonding tool position. , The control unit lowers the bonding tool, which extends a wire of a predetermined length from the tip, diagonally toward the reference plane, brings the lower end of the wire into contact with the reference plane, and directs the wire along the reference plane. The bonding tool is moved laterally in the direction opposite to the extending direction of the bending wire while the bending wire is sandwiched between the tip of the bonding tool and the reference surface in the bending wire forming process in which the bending wire is formed. An upright wire forming step of forming an upright wire by erecting the bent wire upward, and a bonding step of moving a bonding tool over the bonding position of a substrate or a semiconductor element to bond the erecting wire to the bonding position. It is characterized by performing a wire cutting step of raising a bonding tool to cut a wire inserted through the bonding tool to make an upright wire a pin-shaped wire rising from a bonding position.

The present invention can provide a method for forming a pin-shaped wire that can suppress damage to a semiconductor element in a small space.

It is a system diagram which shows the structure of the wire bonding apparatus of embodiment. It is a flowchart which shows the pin-shaped wire forming method performed by the wire bonding apparatus of embodiment. It is explanatory drawing which shows the operation of the bending wire forming process of the wire bonding apparatus of embodiment. It is explanatory drawing which shows the operation of the upright wire forming process of the wire bonding apparatus of embodiment. It is explanatory drawing which shows the operation of the bonding process of the wire bonding apparatus of embodiment. It is explanatory drawing which shows the operation of the wire cutting process of the wire bonding apparatus of embodiment. It is a flowchart which shows the other pin-shaped wire forming method performed by the wire bonding apparatus of embodiment. It is explanatory drawing which shows the operation of the crimp ball forming process and the operation of a bump forming process of the wire bonding apparatus of embodiment. It is explanatory drawing which shows the other operation of the bonding process of the wire bonding apparatus of embodiment. It is explanatory drawing which shows the other operation of the wire cutting process of the wire bonding apparatus of embodiment. It is explanatory drawing which shows the other operation of the bending wire forming process of the wire bonding apparatus of embodiment.

Hereinafter, the wire bonding apparatus 1 of the embodiment will be described with reference to the drawings. As shown in FIG. 1, the wire bonding apparatus 1 according to the present embodiment includes a base 2, an XY table 3, a bonding head 4, a torch electrode 5, a capillary 10, an ultrasonic horn 6, a clamper 15, a wire tensioner 8, and a rotation. It includes a spool 9, a bonding stage 60, a heater 61, and a control unit 70.

In the following embodiments, the plane parallel to the semiconductor element 50 (for example, the semiconductor die) to be bonded, the lead frame, or the substrate is the XY plane, and the direction perpendicular to the XY plane is the Z direction. The tip position of the capillary 10 is specified by the X coordinate, the Y coordinate, and the spatial coordinates (X, Y, Z) represented by the Z coordinate.

The base 2 is configured by slidably mounting the XY table 3. The XY table 3 is a moving device capable of moving the capillary 10 to a predetermined position on the XY plane based on a drive signal from the control unit 70.

The bonding head 4 is integrally formed with a bonding arm (not shown), and the tip 12 of the capillary 10 attached to the tip of the ultrasonic horn 6 based on a drive signal from the control unit 70 is a work such as a substrate. It is a moving device that is movable and held in the Z direction so as to be in contact with and separated from the surface of 62.

The ultrasonic horn 6 is a rod-shaped member composed of a terminal portion, a flange portion, a horn portion, and a tip portion from the end to the tip. An ultrasonic oscillator 7 that vibrates in response to a drive signal from the control unit 70 is arranged at the terminal portion. The flange portion is resonably attached to the bonding head 4 via the bonding arm at a position where it becomes a node of ultrasonic vibration. The horn portion is an arm that extends longer than the diameter of the end portion, and has a structure that expands the amplitude of vibration by the ultrasonic oscillator 7 and transmits it to the tip portion. The tip portion is a mounting portion that holds the capillary 10 interchangeably. The ultrasonic horn 6 has a resonance structure that resonates with the vibration of the ultrasonic oscillator 7 as a whole, so that the ultrasonic oscillator 7 and the flange are located at the vibration node at the time of resonance, and the capillary 10 is located at the antinode of the vibration. Structure. With these configurations, the ultrasonic horn 6 functions as a transducer that converts an electrical drive signal into mechanical vibration.

The capillary 10 is one of the bonding tools used for bonding. The capillary 10 is provided with an insertion hole, and the wire 20 used for bonding is inserted through the capillary 10. The capillary 10 is replaceably attached to the tip of the ultrasonic horn 6.

The clamper 15 includes a piezoelectric element that opens and closes based on a control signal of the control unit 70, and is configured to be able to grip and release the wire 20 at a predetermined timing.

The wire tensioner 8 is configured to be able to give an appropriate tension to the wire 20 during bonding by inserting the wire 20 and freely changing the tension with respect to the wire 20 based on the control signal of the control unit 70. There is.

The rotary spool 9 holds the reel around which the wire 20 is wound interchangeably, and is configured to feed the wire 20 according to the tension applied through the wire tensioner 8. The material of the wire 20 is selected from the ease of processing and the low electrical resistance. Usually, gold (Au), silver (Ag), aluminum (Al), copper (Cu) and the like are used.

The torch electrode 5 is connected to a high voltage power supply (not shown) via a discharge stabilizing resistor (not shown), generates a spark (discharge) based on a control signal from the control unit 70, and the heat of the spark causes the capillary 10 to generate a spark (discharge). A free air ball 30 can be formed on the lower end 22 of the wire 20 that is unwound from the tip 12.

The bonding stage 60 is a stage on which a work 62 (for example, a substrate or a semiconductor element 50) for forming a pin-shaped wire 25 (see FIGS. 6 and 10) is placed on a machined surface. A heater 61 is provided below the machined surface of the bonding stage 60 so that the work 62 can be heated to a temperature suitable for bonding. Further, a reference surface 40 is arranged on the upper surface of the bonding stage 60.

The control unit 70 is configured to be able to output various control signals for controlling the wire bonding device 1 based on a predetermined software program. Specifically, the control unit 70 performs the following control as an example without limitation.

(1) The spatial position (X, Y, Z) of the tip 12 of the capillary 10 is specified based on the detection signal from the position detection sensor (not shown), and the tip 12 of the capillary 10 is moved to the spatial position specified by the above program. The drive signal to be driven is output to the XY table 3 and the bonding head 4. As a result, the control unit 70 adjusts the position of the tip 12 of the capillary 10.

(2) Output a control signal that generates ultrasonic vibration at the time of bonding to the bonding point to the ultrasonic oscillator 7 of the ultrasonic horn 6.

(3) Output a control signal for controlling the opening / closing operation of the clamper 15 so that the wire 20 is unwound as defined by the above program. Specifically, the clamper 15 is released when the wire 20 is unwound, and the clamper 15 is closed when the bending point is formed or cut on the wire 20.

(4) Output a control signal for discharging to the torch electrode 5 when the free air ball 30 is formed on the lower end 22 of the tail wire 21.

The configuration of the wire bonding apparatus 1 is an example, and is not limited to the above. For example, the moving device for moving in the X direction, the Y direction, or the Z direction may be provided on the bonding stage 60 side, or may be provided on both the wire bonding device 1 side and the bonding stage 60 side.

Next, a method of forming the pin-shaped wire 25 (see FIGS. 6 and 10) executed by the wire bonding apparatus 1 of the embodiment will be described with reference to FIGS. 2 to 6. As shown in steps S101 to S104 of FIG. 2, the pin-shaped wire forming method of the embodiment includes four steps of a bent wire forming step, an upright wire forming step, a bonding step, and a wire cutting step.

The control unit 70 first executes the bending wire forming step shown in step S101 of FIG. As shown in FIG. 3A, the control unit 70 extends a tail wire 21 having a predetermined length from the tip 12 of the capillary 10. For the extension of the tail wire 21, for example, the control unit 70 bonds the wire 20 to an arbitrary position, opens the clamper 15 and extends the wire 20 from the tip 12 of the capillary 10 by a predetermined length, and then causes the clamper 15 to extend. The wire 20 may be cut and molded at the bonding point by raising the capillary 10 and the clamper 15 as closing. Further, a plurality of clampers 15 may be provided, and the wire 20 may be extended by a predetermined length from the tip 12 of the capillary 10 by combining the opening and closing of the plurality of clampers 15 and the vertical movement of the capillary 10.

Next, as shown in FIGS. 3A to 3H, the control unit 70 obliquely lowers the tip 12 of the capillary 10 toward the reference surface 40 with the clamper 15 closed. Here, the reference surface 40 may be a flat surface arranged on the upper surface of the bonding stage 60 as shown in FIG. 1, or may be a surface of a substrate or a semiconductor element 50 mounted on the bonding stage 60. You may. In the following example, the reference surface 40 will be described as a plane arranged on the upper surface of the bonding stage 60.

As shown in FIGS. 3A to 3H, the control unit 70 moves the tip 12 of the capillary 10 diagonally downward while bringing the lower end 22 of the tail wire 21 extending from the tip 12 into contact with the reference surface 40. The folding wire forming step of bending the tail wire 21 to form the bending wire 23 is executed.

First, as shown in FIGS. 3A to 3C, the control unit 70 is connected to the alternate long and short dash line 91 so that the angle formed with the reference surface 40 is the angle θ1 with the clamper 15 closed. The tip 12 of the capillary 10 is moved diagonally downward along the line. At this time, the control unit 70 brings the lower end 22 of the tail wire 21 into contact with the reference surface 40, and moves the tip 12 of the capillary 10 diagonally downward while bending the tail wire 21 in the direction along the reference surface 40. ..

Next, as shown in FIGS. 3 (c) to 3 (e), the control unit 70 makes an angle θ2 with the reference surface 40 smaller than the angle θ1 with the clamper 15 closed. The tip 12 of the capillary 10 is moved diagonally downward along the alternate long and short dash line 92, and the tail wire 21 is further bent in the direction along the reference plane 40.

Further, as shown in FIGS. 3 (e) to 3 (h), the control unit 70 makes an angle θ3 with the reference surface 40 smaller than the angle θ2 with the clamper 15 closed. The tip 12 of the capillary 10 is moved diagonally downward along the alternate long and short dash line 93, and the tail wire 21 is further bent in the direction along the reference plane 40. Then, as shown in FIG. 3H, the tail wire 21 is bent at a substantially right angle until the lower end 22 of the tail wire 21 is in the direction along the reference surface 40 to form the bent wire 23.

In this way, the control unit 70 sets the tip 12 of the capillary 10 to the reference surface 40 so that the angles θ1 to θ3 between the moving direction of the tip 12 of the capillary 10 and the reference surface 40 become smaller as the capillary 10 is lowered. The bending wire 23 is formed by lowering it diagonally toward it. The control unit 70 ends the bending wire forming step after forming the bending wire 23 as shown in FIG. 3 (h).

Next, the control unit 70 executes an upright wire forming step as shown in step S102 of FIG. As shown in FIGS. 4A and 4B, the control unit 70 laterally moves the tip 12 of the capillary 10 in a state where the bending wire 23 is sandwiched between the tip 12 of the capillary 10 and the reference surface 40. The bending wire 23 is erected upward to form the erection wire 24.

After the bending wire forming step is completed, the control unit 70 shows the tip 12 of the capillary 10 as shown by the arrow 94 in FIG. 4 (a) with the clamper 15 closed, as shown in FIG. 4 (a). The root portion of the bent wire 23 is sandwiched between the tip 12 of the capillary 10 and the reference surface 40. Then, with the clamper 15 closed, the control unit 70 laterally moves the tip 12 of the capillary 10 in the direction opposite to the extending direction of the bending wire 23 as shown by an arrow 95 in (b) of FIG. .. Then, as shown by the arrow 96 in FIG. 4B, the bending wire 23 stands up as the capillary 10 moves laterally, and the standing wire 24 is formed.

As shown in FIG. 4B, the control unit 70 ends the upright wire forming step after forming the upright wire 24.

Next, the control unit 70 executes the bonding step as shown in step S103 of FIG. As shown in FIGS. 5A and 5B, the control unit 70 moves the capillary 10 from the reference surface 40 onto the electrode 51 which is the bonding position of the semiconductor element 50, and moves the upright wire 24 of the electrode 51 to the electrode 51. Bond on top.

As shown in FIG. 5A, the control unit 70 moves the capillary 10 from the reference surface 40 onto the electrode 51 of the semiconductor element 50 which is the bonding position. Then, the control unit 70 sets the position of the center line 19 in the Z direction of the capillary 10 to a position shifted laterally by a distance d from the position of the center line 52 in the Z direction of the electrode 51. Then, with the clamper 15 closed, the control unit 70 lowers the capillary 10 as shown by an arrow 99 in FIG. 5B to bond the root of the standing wire 24 onto the electrode 51.

When the upright wire 24 is bonded onto the electrode 51, the upright wire 24 stands up substantially in the vertical direction as shown by the arrow 98 in FIG. 5 (b), and substantially along the center line 52 at the center position of the electrode 51. A pin-shaped wire 25 extending in a vertical direction is formed.

The control unit 70 ends the bonding step after bonding the upright wire 24 to form the pin-shaped wire 25, and executes the wire cutting step as shown in step S104 of FIG.

As shown by the broken line in FIG. 6, the control unit 70 raises the capillary 10 with the clamper 15 open, and extends the tail wire 21 from the tip 12 by a predetermined length. Then, as shown by the solid line in FIG. 6, the control unit 70 closes the clamper 15 and raises the clamper 15 and the capillary 10 as shown by an arrow 100, and the lower end 22 of the tail wire 21 inserted into the capillary 10 is inserted. To disconnect. As a result, the control unit 70 forms an independent pin-shaped wire 25 on the center line 52 of the electrode 51.

After completing the wire cutting process, the control unit 70 moves the capillary 10 onto the reference surface 40. Then, the control unit 70 determines whether or not all the pin-shaped wires 25 have been formed in step S105 of FIG. 2, and if it is determined to be NO in step S105 of FIG. 2, returns to step S101 of FIG. Step S101 of FIG. 2, the bending wire forming step shown in FIGS. 3 (a) to 3 (h), step S102 of FIG. 2, the standing wire forming step shown in FIGS. 4 (a) and 4 (b), FIG. Step S103, the bonding process shown in FIGS. 5A and 5B, and the wire cutting process shown in Step S104 and FIG. 6 of FIG. 2 are repeatedly executed. Then, if YES is determined in step S105 of FIG. 2, the molding of the pin-shaped wire 25 is completed.

In the pin-shaped wire forming method of the embodiment described above, the lower end 22 of the tail wire 21 is brought into contact with the reference surface 40, the tail wire 21 is bent in the direction along the reference surface 40 to form the bent wire 23, and the capillary 10 is formed. The bending wire 23 is sandwiched between the tip 12 and the reference surface 40, the capillary 10 is moved laterally, the bending wire 23 is raised upward to form the standing wire 24, and the molded standing wire 24 is placed at the bonding position. Since the wire 20 is bonded to the electrode 51 of the semiconductor element 50, it is not necessary to press the wire 20 to a position other than the electrode 51 of the semiconductor element 50 as in the prior art, and the semiconductor element 50 when forming the pin-shaped wire 25 is formed. Damage can be suppressed. Further, since the tail wire 21 can be bent and erected at a position away from the electrode 51 of the semiconductor element 50, the pin-shaped wire 25 can be formed even when the surface area of the semiconductor element 50 is small.

In the pin-shaped wire forming method of the embodiment described above, in the bending wire forming step, the angles θ1 to θ3 formed by the moving direction of the tip 12 of the capillary 10 and the reference surface 40 become smaller as the capillary 10 is lowered. , The explanation has been made as forming the bent wire 23 by lowering the tip 12 of the capillary 10 diagonally toward the reference surface 40, but the present invention is not limited to this, and the tip 12 of the capillary 10 is directed toward the reference surface 40 at a constant angle. The bent wire 23 may be formed by lowering it diagonally.

Further, in the bonding step, the control unit 70 has described that the position of the center line 19 of the capillary 10 is shifted from the position of the center line 52 of the electrode 51 to perform bonding, but the control unit 70 is not limited to this. Bonding may be performed by aligning the position of the center line 19 of the capillary 10 with the position of the center line 52 of the electrode 51.

Next, the pin-shaped wire forming method of another embodiment will be described with reference to FIGS. 7 to 10 and FIGS. 3 and 4. The description of the same parts as those of the embodiment described above with reference to FIGS. 2 to 6 will be omitted.

In the pin-shaped wire forming method of another embodiment, the control unit 70 is shown in steps S201 of FIG. 7 and (a) to (b) of FIG. 8 before the bending wire forming step shown in step S101 of FIG. The crimp ball forming step and the bump forming step shown in step S202 of FIG. 7 and (c) to (e) of FIG. 8 are executed.

In the crimping ball forming step shown in step S201 of FIG. 2, the control unit 70 moves the capillary 10 in the vicinity of the torch electrode 5 as shown in FIG. 8A, and the tip of the torch electrode 5 and the capillary 10 is moved. A discharge is generated between the tail wire 21 extending from the 12 and the tail wire 21 is formed into a free air ball 30. The free air ball 30 is held by a chamfer portion 13 at the tip of a hole provided in the center of the capillary 10. Then, as shown in FIG. 8B, the control unit 70 aligns the position of the center line 19 in the Z direction of the capillary 10 with the center line 52 in the Z direction of the electrode 51 of the semiconductor element 50, and opens the clamper 15. In this state, the capillary 10 is lowered as shown by the arrow 101. Then, the control unit 70 bonds the free air ball 30 onto the electrode 51 of the semiconductor element 50 by the capillary 10. The free air ball 30 is formed into a pedestal-shaped crimping ball 31 whose peripheral portion is pressed by the tip 12 to form a disk shape and whose central portion is pressed by the chamfer portion 13 and protrudes slightly upward from the disk-shaped peripheral portion. ..

As shown in FIG. 8B, when the forming of the crimping ball 31 is completed, the control unit 70 executes the bump forming step shown in step S202 of FIG. 7 and (c) to (e) of FIG.

In the bump forming step shown in step S202 of FIG. 2, as shown by the arrow 102 of FIG. 8C, the control unit 70 raises the capillary 10 with the clamper 15 open and wires from the tip 12. After extending 20, the capillary 10 is moved laterally by a distance e, and then the capillary 10 is slightly lowered. Next, as shown by the arrow 103 in FIG. 8D, the control unit 70 raises the capillary 10 to its original height, and then raises the capillary 10 in the direction opposite to the case shown in FIG. 8C. The capillary 10 is lowered by moving it laterally by a distance (e + f). By this operation, the control unit 70 folds the extended wire 20 left and right on the electrode 51 of the semiconductor element 50, presses the folded wire 20 on the lower wire 20 with the tip 12, and presses the folded wire 20 with the tip 12 in FIG. As shown in (d), a bump 35 is formed in which one is raised and the other pressed by the tip 12 is a recessed portion 36.

After forming the bump 35, the control unit 70 raises the capillary 10 with the clamper 15 open as shown by the broken line in FIG. 8 (e), and has a predetermined length from the tip 12 of the capillary 10. The tail wire 21 is extended. Then, as shown by the solid line in FIG. 8 (e), the control unit 70 raises the capillary 10 and the clamper 15 with the clamper 15 closed as shown by the arrow 104 in FIG. 8, and the tail wire 21. Cut off the lower end 22 of the.

Next, as shown in steps S101 of FIG. 7 and (a) to (h) of FIG. 3, the control unit 70 brings the lower end 22 of the tail wire 21 extending from the tip 12 into contact with the surface of the semiconductor element 50. While moving the tip 12 of the capillary 10 diagonally downward, the tail wire 21 is bent in the direction along the surface of the semiconductor element 50 to execute the bent wire forming step of forming the bent wire 23. The bending wire forming step is the same as that of the above-described embodiment except that the lower end 22 is brought into contact with the surface of the semiconductor element 50.

Next, as shown in step S102 of FIG. 7 and (a) and (b) of FIG. 4, the control unit 70 is the root portion of the bent wire 23 between the tip 12 of the capillary 10 and the surface of the semiconductor element 50. The tip 12 of the capillary 10 is laterally moved by sandwiching the above, and the upright wire forming step of forming the upright wire 24 is executed. The standing wire forming step is the same as that of the above-described embodiment except that the bent wire 23 is sandwiched between the tip 12 of the capillary 10 and the surface of the semiconductor element 50.

Next, the control unit 70 executes the bonding step as shown in step S103 of FIG. 7 and (a) and (b) of FIG. As shown by the arrow 105 in FIG. 9A, the control unit 70 moves the capillary 10 onto the electrode 51 of the semiconductor element 50, and positions the center line 19 of the capillary 10 in the Z direction in the Z of the electrode 51. The position is shifted laterally by the distance g from the position of the center line 52 in the direction. Here, the distance g is such that the root 24a of the upright wire 24 fits into the recessed portion 36 of the bump 35.

As shown by the arrow 106 in FIG. 9B, the control unit 70 lowered the capillary 10 with the clamper 15 closed, and formed the root 24a of the standing wire 24 on the upper surface of the bump 35. Bonding onto the recess 36. As shown in FIG. 9B, the root 24a of the upright wire 24 is formed into a shape that follows the shape of the upper surface of the bump 35 and is bonded onto the bump 35.

When the upright wire 24 is bonded onto the bump 35 of the electrode 51, the upright wire 24 stands up substantially in the vertical direction as shown by the arrow 107 in FIG. 9B, and the center line 52 is located at the center position of the electrode 51. A pin-shaped wire 25 extending in a direction substantially along the line is formed.

The control unit 70 ends the bonding step after bonding the upright wire 24 to form the pin-shaped wire 25, and executes the wire cutting step shown in step S104 of FIG. 7.

As shown by the broken line in FIG. 10, the control unit 70 raises the capillary 10 with the clamper 15 open, and extends the tail wire 21 from the tip 12 by a predetermined length. Then, as shown by a solid line in FIG. 10, the control unit 70 closes the clamper 15 and raises the clamper 15 and the capillary 10 as shown by an arrow 108, and the lower end 22 of the tail wire 21 inserted into the capillary 10 is inserted. To disconnect. As a result, the control unit 70 forms an independent pin-shaped wire 25 on the bump 35 of the electrode 51.

After completing the wire cutting process, the control unit 70 moves the capillary 10 onto the semiconductor element 50. Then, the control unit 70 determines whether or not all the pin-shaped wires 25 have been formed in step S105 of FIG. 7, and if it is determined to be NO in step S105 of FIG. 7, returns to step S201 of FIG. Step S201 of FIG. 7, crimp ball forming process shown in FIGS. 8A and 8B, step S202 of FIG. 7, bump forming process shown in FIGS. 8C to 8E, and FIG. Step S101, the bending wire forming step shown in FIGS. 3A to 3H, step S102 of FIG. 7, the standing wire forming step shown in FIGS. 4A and 4B, step S103 of FIG. 7, FIG. The bonding step shown in (a) and (b) of 9 and the wire cutting step shown in step S104 and FIG. 10 of FIG. 7 are repeatedly executed. Then, if YES is determined in step S105 of FIG. 2, the molding of the pin-shaped wire 25 is completed.

In the pin-shaped wire forming method of the embodiment described above, the crimp ball 31 and the bump 35 are formed on the electrode 51 of the semiconductor element 50, and the upright wire 24 is bonded onto the bump 35 to form the pin-shaped wire 25. Therefore, the force applied to the semiconductor element 50 in the process of forming the pin-shaped wire 25 is small, and the pin-shaped wire 25 can be formed while more preferably suppressing damage to the semiconductor element 50. Further, since the bent wire 23 is formed by bringing the lower end 22 of the tail wire 21 into contact with the surface of the semiconductor element 50, the pin-shaped wire 25 can be formed in a small space.

In the pin-shaped wire forming method of the above-described embodiment, the control unit 70 has described as bending the tail wire 21 by bringing the lower end 22 of the tail wire 21 into contact with the surface of the semiconductor element 50 in the wire forming step. However, for example, as shown in FIG. 11, the lower end 22 may be brought into contact with the bump 35 and bent. In this case, the pin-shaped wire 25 can be formed in less space.

In this embodiment as well, the control unit 70 may bend the tail wire 21 by bringing the lower end 22 into contact with the surface of the substrate or the reference surface 40 in the bending wire forming step. Further, the pin-shaped wire 25 may be formed not only on the electrode 51 of the semiconductor element 50 but also on the electrode of the substrate.

1 Wire bonding device, 2 bases, 3 XY tables, 4 bonding heads, 5 torch electrodes, 6 ultrasonic horns, 7 ultrasonic oscillators, 8 wire tensioners, 9 rotary spools, 10 capillaries, 12 tips, 13 chamfers, 15 Clamper, 19, 52 center line, 20 wire, 21 tail wire, 22 lower end, 23 bent wire, 24 standing wire, 25 pin-shaped wire, 30 free air ball, 31 crimping ball, 35 bump, 36 recess, 40 reference plane , 50 semiconductor element, 51 electrode, 60 bonding stage, 61 heater, 62 work, 70 control unit.

Claims (8)

A pin-shaped wire forming method for forming a pin-shaped wire at a bonding position of a substrate or a semiconductor element using a bonding tool through which a wire is inserted.
The bonding tool, in which a wire of a predetermined length is extended from the tip, is lowered diagonally toward a reference plane, the lower end of the wire is brought into contact with the reference plane, and the wire is bent in a direction along the reference plane. Bending wire forming process to form the folding wire
With the bending wire sandwiched between the tip of the bonding tool and the reference surface, the bonding tool is laterally moved in a direction opposite to the extending direction of the bending wire to move the bending wire upward. An upright wire forming process that erects and forms an upright wire,
A bonding step of moving the bonding tool onto the bonding position of the substrate or semiconductor element to bond the upright wire to the bonding position.
A wire cutting step of raising the bonding tool to cut the wire inserted through the bonding tool to make the standing wire a pin-shaped wire rising from the bonding position.
Pin-shaped wire forming method having. The pin-shaped wire forming method according to claim 1.
The bending wire forming step is to lower the bonding tool diagonally toward the reference surface so that the angle between the moving direction of the bonding tool and the reference surface becomes smaller as the bonding tool is lowered.
A pin-shaped wire forming method characterized by. The pin-shaped wire forming method according to claim 1 or 2.
In the bonding step, bonding is performed by shifting the center position of the bonding tool from the center position of the bonding position.
A pin-shaped wire forming method characterized by. The pin-shaped wire forming method according to claim 1 or 2.
Before the bending wire forming step,
A crimping ball forming step of lowering the bonding tool toward the bonding position and bonding a wire having a tip formed into a free air ball to the bonding position to form a crimping ball.
A bump forming step of raising the bonding tool while feeding out a wire from the tip of the bonding tool, folding the drawn wire onto the crimping ball, and pressing the wire to form a bump is included.
The bonding step is to bond the upright wire onto the bump.
A pin-shaped wire forming method characterized by. The pin-shaped wire forming method according to claim 4.
In the bump forming step, the unwound wire is folded back on the crimping ball, the center position of the bonding tool is displaced from the bonding position, the wire is pressed, and the bump having a recessed portion on the upper surface is formed.
In the bonding step, bonding is performed by shifting the center position of the bonding tool from the bonding position so that the root of the upright wire matches the recessed portion of the bump.
A pin-shaped wire forming method characterized by. The pin-shaped wire forming method according to claim 1 or 2.
The reference surface is the surface of the substrate or the surface of the semiconductor element.
A pin-shaped wire forming method characterized by. The pin-shaped wire forming method according to claim 5.
In the bending wire forming step, the bonding tool in which a wire having a predetermined length is extended from the tip thereof is obliquely lowered toward the surface of the substrate or the surface of the semiconductor element, and the lower end of the wire is made into the bump. Forming the bent wire by contacting and bending the wire in a direction along the surface of the substrate or the surface of the semiconductor element.
A pin-shaped wire forming method characterized by. A wire bonding device that forms a pin-shaped wire at the bonding position of a substrate or semiconductor element using a bonding tool through which a wire is inserted.
A control unit for adjusting the position of the bonding tool is provided.
The control unit
The bonding tool, in which a wire of a predetermined length is extended from the tip, is lowered diagonally toward a reference plane, the lower end of the wire is brought into contact with the reference plane, and the wire is bent in a direction along the reference plane. Bending wire forming process to form the folding wire
With the bending wire sandwiched between the tip of the bonding tool and the reference surface, the bonding tool is laterally moved in a direction opposite to the extending direction of the bending wire to move the bending wire upward. An upright wire forming process that erects and forms an upright wire,
A bonding step of moving the bonding tool onto the bonding position of the substrate or semiconductor element to bond the upright wire to the bonding position.
A wire cutting step of raising the bonding tool to cut the wire inserted through the bonding tool to make the standing wire a pin-shaped wire rising from the bonding position.
A wire bonding device characterized by performing.

Images