TWI759711B - Needle thread forming method and wire bonding device - Google Patents

Abstract

The present invention provides a method for forming a needle-shaped wire capable of suppressing damage to a semiconductor element. The forming method of the needle-shaped wire of the present invention includes: a bending line forming step S101, the porcelain nozzle extending from the front end of the tail wire is lowered obliquely toward the reference plane, and the tail wire is bent in the direction along the reference plane to form the bending line; The erection line forming step S102 is to move the porcelain nozzle laterally in the state where the bending line is sandwiched between the front end of the porcelain nozzle and the reference surface, so that the bending line is erected upward to form the erection line; in the joining step S103, the erection line is formed. Joining at the joining position; and thread cutting step S104, cutting the thread inserted into the porcelain nozzle to make the erect thread into a needle-shaped thread.

Description

Needle wire forming method and wire bonding device

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

In recent years, a semiconductor device in which a semiconductor package is laminated, or a semiconductor device in which a semiconductor element is laminated are used. In such a three-dimensional packaged semiconductor device, it is necessary to form a needle-shaped line having a predetermined height on the substrate or the electrode of the semiconductor element.

As a method of forming such a needle-like wire, there has been proposed a method in which, after ball bonding is performed 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. A notch is formed in the side surface of the wire, the wire is then erected at the joining position, and the wire is cut at the notch position (for example, refer to Patent Document 1).

In addition, there has also been proposed a method in which a thin portion is similarly formed on the side surface of the wire, the wire is then erected at the joining position, and the joining tool is moved laterally to cut the wire (for example, refer to Patent Document 2).

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent No. 6297553

[Patent Document 2] Japanese Patent No. 5686912

The prior art methods described in Patent Document 1 and Patent Document 2 are as follows. After ball bonding is performed at the bonding position, the wire is bent at a position different from the bonding position and the side surface of the wire is pressed to form a notch or a thin wall on the side surface of the wire. After making the thread stand upright, the thread is cut at the notch or the thin-walled portion to form a needle-like thread. 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 degree of force. Therefore, when the needle-shaped wire is formed on the electrode of the semiconductor element using the conventional techniques described in Patent Document 1 and Patent Document 2, the semiconductor element may be damaged. In addition, there is a problem in that it is difficult to apply to a small-sized semiconductor element with a narrow electrode pitch because a space for forming a notch portion or a thin-walled portion is required in the vicinity of the bonding position.

Therefore, an object of the present invention is to provide a method for forming a needle-shaped wire that can save space and suppress damage to a semiconductor element.

The needle-shaped wire forming method of the present invention is a needle-shaped wire forming method for forming a needle-shaped wire at a bonding position of a substrate or a semiconductor element using a bonding tool inserted with a wire, which includes: a bending wire forming step to extend a predetermined wire from the front end. The bonding tool of the length of wire is lowered obliquely toward the reference plane, the lower end of the wire is brought into contact with the reference plane, and the wire is bent in the direction along the reference plane to form the bending line; With the bending line held between the faces, orient the joining tool toward the The bending line is moved laterally in the opposite direction to the extension direction of the bending line, so that the bending line rises up along the bonding tool to form the rising line; in the bonding step, the bonding tool is moved to the bonding position of the substrate or the semiconductor element, and the rising wire is bonded in the joining position; and the wire cutting step, the joining tool is raised and the wire inserted through the joining tool is cut, thereby making the erected thread into a needle-like thread erected from the engagement position. Here, the reference plane 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 plane, the wire is bent in the direction along the reference plane to form a bending line, the bent wire is clamped between the front end of the bonding tool and the reference plane, and the bonding tool is moved laterally Since the bending line is raised upward to form a raised wire, and the formed raised wire is bonded to the bonding position, it is not necessary to press the wire to a position other than the electrode of the semiconductor element, and the formation of needle-shaped wires can be suppressed. damage. In addition, since the wire can be bent and raised at a position away from the joining position, the needle-shaped wire can be formed in a small space.

In the needle-shaped wire forming method of the present invention, the bending line forming step can also lower the joining tool obliquely toward the reference plane so that the angle formed between the moving direction of the joining tool and the reference plane becomes smaller as the joining tool is lowered. .

Thereby, the wire can be bent smoothly.

In the needle thread forming method of the present invention, the bonding step may be performed by deviating the center position of the bonding tool from the center position of the bonding position.

Thereby, the needle-like thread can be formed in the center of the joining position.

In the needle-shaped wire forming method of the present invention, before the bending wire forming step, the method includes: a crimping ball forming step, the joining tool is lowered toward the joining position, and the A crimp ball is formed by bonding the wire whose front end is formed into an airless ball at the bonding position; and a bump forming step of raising the bonding tool while pulling out the wire from the front end of the bonding tool, and placing the drawn wire on the crimp ball. Fold back, press to form bumps, and the bonding step can also bond the erected lines on the bumps.

Since the riser wire is bonded to the crimp ball and the bump, damage to the semiconductor element can be more appropriately suppressed.

In the needle thread forming method of the present invention, in the step of forming the bump, the drawn thread can also be folded back on the crimping ball, so that the center position of the joining tool is deviated from the joining position and the thread is pressed, and the thread is formed on the thread having a concave portion on the upper surface. In the bonding step, the center position of the bonding tool is deviated from the bonding position so that the root of the erection line is aligned with the recessed portion of the protrusion, and bonding is performed.

In this way, the needle-shaped thread can be formed more vertically by aligning the root of the erected thread with the concave portion of the bump and engaging it.

In the needle-shaped wire forming method of the present invention, in the bending wire forming step, the bonding tool of the wire extending a predetermined length from the front end may be lowered obliquely toward the surface of the substrate or the surface of the semiconductor element, so that the lower end of the wire contacts the bump and The bending line is formed by bending the wire in a direction along the surface of the substrate or the surface of the semiconductor element.

Thereby, the needle-shaped thread can be formed with less space.

The wire bonding apparatus of the present invention uses a bonding tool inserted with wires to form a needle-shaped wire at the bonding position of a substrate or a semiconductor element, and includes: a control part for adjusting the position of the bonding tool; The tool for engaging a wire of a predetermined length is lowered obliquely toward the reference plane, so that the lower part of the wire is lowered. The end contacts the datum plane and bends the line in the direction along the datum plane to form a bending line; in the step of erecting line forming, in the state where the bending line is sandwiched between the front end of the bonding tool and the reference plane, the bonding tool is made to face Move laterally in the direction opposite to the extension direction of the bending line, so that the bending line rises upwards to form the rising wire; in the bonding step, the bonding tool is moved to the bonding position of the substrate or the semiconductor element, and the rising wire is bonded to the bonding position; And the thread cutting step is to raise the joining tool and cut the thread inserted through the joining tool, whereby the standing thread is formed into a needle-like thread standing up from the joining position.

The present invention provides a method for forming a needle-shaped wire that saves space and can suppress damage to a semiconductor element.

1: wire bonding device

2: Abutment

3: XY stage

4: Splice head

5: Torch Electrode

6: Ultrasonic speaker

7: Ultrasonic oscillator

8: Thread tensioner

9: Rotary valve core

10: Porcelain mouth

12: Front end

13: Chamfered part

15: Chuck

19, 52: Centerline

20: Line

21: tail line

22: Bottom

23: Bend Line

24: Stand Up Line

24a: roots

25: Needle thread

30: Airless Balloon

31: Crimp Ball

35: bump

36: Recess

40: Datum plane

50: Semiconductor components

51: Electrodes

60: Engagement platform

61: Heater

62: Workpiece

70: Control Department

91~93: A little chain line

94~109: Arrow

d, e, f, g: distance

S101~S105, S201, S202: Steps

θ1~θ3: Angle

FIG. 1 is a system diagram showing the configuration of a wire bonding apparatus according to an embodiment.

FIG. 2 is a flowchart showing a needle thread forming method performed by the wire bonding apparatus according to the embodiment.

FIGS. 3( a ) to 3 ( h ) are explanatory diagrams showing the operation of the bending line forming step of the wire bonding apparatus according to the embodiment.

FIGS. 4( a ) and 4 ( b ) are explanatory diagrams showing the operation of the erect wire forming step of the wire bonding apparatus according to the embodiment.

FIGS. 5( a ) and 5 ( b ) are explanatory diagrams showing the operation of the bonding step of the wire bonding apparatus according to the embodiment.

FIG. 6 is a diagram showing the operation of the wire cutting step of the wire bonding apparatus according to the embodiment. Illustrating.

FIG. 7 is a flowchart showing another needle thread forming method performed by the wire bonding apparatus according to the embodiment.

FIGS. 8( a ) to 8 ( e ) are explanatory diagrams showing the operation of the crimp ball forming step and the operation of the bump forming step of the wire bonding apparatus according to the embodiment.

FIGS. 9( a ) and 9 ( b ) are explanatory diagrams showing other operations of the bonding step of the wire bonding apparatus according to the embodiment.

10 is an explanatory diagram showing another operation of the wire cutting step of the wire bonding apparatus according to the embodiment.

11 is an explanatory diagram showing another operation of the bending line forming step of the wire bonding apparatus of the 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 of the present embodiment includes a base 2, an XY stage 3, a bonding head 4, a torch electrode 5, a ceramic nozzle 10, an ultrasonic horn 6, a chuck 15, a wire The tensioner 8 , the rotary valve core 9 , the bonding platform 60 , the heater 61 , and the control unit 70 .

In the following embodiments, the plane parallel to the semiconductor element 50 (eg, semiconductor wafer), the lead frame, or the substrate to be bonded is referred to as the XY plane, and the direction perpendicular to the XY plane is referred to as the Z direction. The position of the front end of the mouthpiece 10 is determined by the spatial coordinates (X, Y, Z) represented by the X coordinate, the Y coordinate and the Z coordinate.

The base 2 is configured to slidably mount the XY stage 3 . The XY stage 3 is a moving device that can move the nozzle 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 front end 12 of the ceramic nozzle 10 mounted on the front end of the ultrasonic horn 6 is connected to the surface of a workpiece 62 such as a substrate based on a driving signal from the control unit 70 . A mobile device that is movably held in the Z direction by way of separation.

The ultrasonic horn 6 is a rod-shaped member including each of the distal end portion, the flange portion, the horn portion, and the distal end portion from the distal end to the distal end. The distal end portion is provided with an ultrasonic oscillator 7 that vibrates in accordance with a drive signal from the control unit 70 . The flange portion is resonably attached to the bonding head 4 via the bonding arm at a position that becomes a node of ultrasonic vibration. The horn portion is an arm extending longer than the diameter of the distal end portion, and includes a structure for amplifying the amplitude of the vibration obtained by the ultrasonic oscillator 7 and transmitting it to the distal end portion. The front end portion serves as a mounting portion for holding the mouthpiece 10 replaceably. The ultrasonic horn 6 includes a resonant structure that resonates with the vibration of the ultrasonic oscillator 7 as a whole, and is configured such that the ultrasonic oscillator 7 and the flange are located at the nodes of the vibration during resonance, and the nipple 10 is located at the antinode of the vibration. With these configurations, the ultrasonic horn 6 functions as a transducer that converts an electrical drive signal into mechanical vibration.

The porcelain mouth 10 is one of the bonding tools used for bonding. A penetration hole is provided in the porcelain mouth 10, and a wire 20 for joining is inserted therethrough. The nozzle 10 is replaceably attached to the front end of the ultrasonic horn 6 .

The chuck 15 includes an opening and closing operation based on a control signal from the control unit 70 . The piezoelectric element is configured to hold or release the wire 20 at a predetermined timing.

The thread tensioner 8 can be configured to give an appropriate tension to the thread 20 being joined by inserting the thread 20 to freely change the tension on the thread 20 based on a control signal from the control unit 70 .

The rotary valve body 9 is configured to replaceably hold a reel on which the wire 20 is wound, and to draw out the wire 20 in accordance with the tension applied by the wire tensioner 8 . Furthermore, the material of the wire 20 is selected for ease of processing and low resistance. Generally, gold (Au), silver (Ag), aluminum (Al), copper (Cu), or the like can be used.

The torch electrode 5 is connected to a high-voltage power supply (not shown) through a discharge stabilization resistor (not shown) to generate a spark (discharge) based on a control signal from the control unit 70, and the heat of the spark can be used in the self-ceramic nozzle. The lower end 22 of the wire 20 drawn from the front end 12 of the 10 is formed so that the airless ball 30 is formed.

The bonding stage 60 is a stage on which a workpiece 62 (for example, a substrate, a semiconductor element 50 , etc.) for forming the needle wire 25 (see FIGS. 6 and 10 ) is placed on a processing surface. The heater 61 is provided in the lower part of the processing surface of the bonding stage 60, and is comprised so that the workpiece 62 may be heated to the temperature suitable for bonding. Moreover, the reference surface 40 is arrange|positioned on the upper surface of the bonding stage 60. As shown in FIG.

The control unit 70 is configured to output various control signals for controlling the wire bonding apparatus 1 based on a predetermined software program. Specifically, as a non-limiting example, the control unit 70 performs the following control.

(1) Determine the spatial position (X, Y, Z) of the front end 12 of the nozzle 10 based on the detection signal from the position detection sensor (not shown), so that the front end 12 of the nozzle 10 is determined. A drive signal for moving the end 12 to the spatial position specified by the program is output to the XY stage 3 and the bonding head 4 . Thereby, the control part 70 adjusts the position of the front-end|tip 12 of the mouthpiece 10.

(2) The ultrasonic oscillator 7 of the ultrasonic horn 6 outputs a control signal that generates ultrasonic vibration when the joint is joined.

(3) Outputting a control signal for controlling the opening and closing operation of the chuck 15 so that the wire 20 is drawn out by the program. Specifically, when the wire 20 is drawn out, the collet 15 is set to a released state, and when the wire 20 is formed with a bending point or cut, the collet 15 is set to a closed state.

(4) When the airless ball 30 is formed at the lower end 22 of the tail wire 21 , a control signal for discharging the torch electrode 5 is output.

In addition, the structure of the said wire bonding apparatus 1 is an illustration, and it is not limited to the said structure. For example, the moving device that moves in the X direction, the Y direction, or the Z direction may be provided on the bonding platform 60 side, or may be provided on both the wire bonding device 1 side and the bonding platform 60 side.

Next, referring to FIGS. 2 to 6 , a description will be given of a method of forming the needle thread 25 (see FIGS. 6 and 10 ) performed by the wire bonding apparatus 1 of the embodiment. As shown in step S101 to step S104 of FIG. 2 , the needle-shaped thread forming method of the embodiment includes four steps of a bending thread forming step, an erect thread forming step, a joining step, and a thread cutting step.

The control unit 70 initially executes the bending line forming step shown in step S101 of FIG. 2 . As shown in FIG. 3( a ), the control unit 70 extends the tail wire 21 of a predetermined length from the front end 12 of the nozzle 10 . Regarding the extension of the tail line 21, for example, it can also be controlled by The control part 70 joins the wire 20 at an arbitrary position, opens the collet 15 and pulls out the wire 20 from the front end 12 of the mouthpiece 10 by a predetermined length, then closes the collet 15 and closes the mouthpiece 10 and the clip The head 15 is raised, and the wire 20 is cut and formed at the junction point. In addition, a plurality of chucks 15 may be included, and the opening and closing of the plurality of chucks 15 and the vertical movement of the nozzle 10 may be combined, and the wire 20 may be drawn out from the front end 12 of the nozzle 10 by a predetermined length.

Next, as shown in FIGS. 3( a ) to 3 ( h ), the control unit 70 lowers the tip 12 of the mouthpiece 10 inclined gradually toward the reference plane 40 with the chuck 15 closed. Here, the reference plane 40 may be a plane disposed on the upper surface of the bonding stage 60 as shown in FIG. 1 , or may be a surface of a substrate or semiconductor element 50 placed on the bonding stage 60 . In the following example, the reference plane 40 is assumed to be a plane disposed on the upper surface of the bonding stage 60 and described.

As shown in FIGS. 3( a ) to 3 ( h ), the control unit 70 executes the bending line forming step, that is, the nozzle is made to contact the reference surface 40 while the lower end 22 of the tail wire 21 extending from the front end 12 is brought into contact with the reference surface 40 . The front end 12 of the 10 moves obliquely downward, and bends the tail wire 21 to form a bending line 23 .

First, as shown in FIGS. 3( a ) to 3 ( c ), in the state where the chuck 15 is closed, the control unit 70 makes the angle with the reference plane 40 the angle θ1 along the Following a chain line 91, the front end 12 of the mouthpiece 10 is gradually moved downwardly obliquely. At this time, the control unit 70 makes the lower end 22 of the tail wire 21 contact the reference surface 40 , and moves the front end 12 of the nozzle 10 downward gradually while bending the tail wire 21 in the direction along the reference surface 40 .

Next, as shown in FIG. 3(c) to FIG. 3(e), the control unit 70, In the state where the chuck 15 is closed, the front end 12 of the mouthpiece 10 is moved obliquely downward along the one-point chain line 92 so that the angle formed with the reference plane 40 becomes the angle θ2 smaller than the angle θ1, so that the The tail wire 21 is further gradually bent in the direction along the reference plane 40 .

Furthermore, as shown in FIGS. 3(e) to 3(h) , the control unit 70 makes the angle θ3 smaller than the angle θ2 in the state where the chuck 15 is closed so that the angle with the reference plane 40 is smaller than the angle θ2 In the way, the front end 12 of the porcelain mouth 10 is moved downwards obliquely along the one-point chain line 93 , so that the tail line 21 is further gradually bent in the direction along the reference plane 40 . Next, as shown in FIG. 3( h ), the tail wire 21 is bent at a substantially right angle until the lower end 22 of the tail wire 21 becomes the direction along the reference plane 40 , and the bending line 23 is formed.

In this way, the control unit 70 makes the front end 12 of the nozzle 10 face the reference plane so that the angle θ1 to the angle θ3 formed by the moving direction of the front end 12 of the nozzle 10 and the reference plane 40 decreases as the nozzle 10 is lowered. 40 is lowered obliquely to form the bending line 23 . After the control unit 70 forms the bending line 23 as shown in FIG. 3( h ), the bending line forming step ends.

Next, as shown in step S102 of FIG. 2 , the control unit 70 executes the step of forming a rising line. As shown in FIG. 4( a ) and FIG. 4( b ), the control unit 70 makes the front end of the porcelain mouth 10 in a state where the bending line 23 is sandwiched between the front end 12 of the porcelain mouth 10 and the reference surface 40 . 12 is moved laterally, and the bending line 23 is raised upward to form the erection line 24 .

After the control unit 70 completes the bending line forming step, as shown in FIG. 4( a ) As shown, in the state where the chuck 15 is closed, the front end 12 of the porcelain mouth 10 is slightly lowered as shown by the arrow 94 in FIG. The root portion of the bending line 23 is clamped. Then, in the state where the chuck 15 is closed, the control unit 70 laterally moves the front end 12 of the mouthpiece 10 in the direction opposite to the extending direction of the bending line 23 as indicated by the arrow 95 in FIG. 4( b ). . Then, as shown by the arrow 96 of FIG. 4(b), the bending line 23 rises upward along with the lateral movement of the mouthpiece 10, and the rising line 24 is formed.

As shown in FIG. 4( b ), the control unit 70 completes the raising wire forming step after forming the raising wire 24 .

Next, the control unit 70 executes the joining step as shown in step S103 of FIG. 2 . As shown by arrows 97 in FIGS. 5( a ) and 5 ( b ), the control unit 70 moves the ceramic nozzle 10 from the reference plane 40 to the electrode 51 which is the bonding position of the semiconductor element 50 , and sets the rising line. 24 is bonded to the electrode 51 .

As shown in FIG. 5( a ), the control unit 70 moves the nozzle 10 from the reference plane 40 to above the electrode 51 of the semiconductor element 50 which is the bonding position. Next, the control unit 70 sets the position of the center line 19 in the Z direction of the mouthpiece 10 to a position laterally offset by a distance d from the position of the center line 52 in the Z direction of the electrode 51 . Next, in the state where the chuck 15 is closed, the controller 70 lowers the mouthpiece 10 as indicated by the arrow 99 in FIG. .

When the rising wire 24 is joined to the electrode 51, the rising wire 24 rises in a substantially vertical direction as shown by the arrow 98 in FIG. The needle thread 25 extends in the direction of the center line 52 .

After the control unit 70 joins the erected thread 24 to form the needle-like thread 25, the joining step is ended, and the thread cutting step is executed as shown in step S104 in FIG. 2 .

The control unit 70 raises the nozzle 10 in a state where the chuck 15 is opened as shown by the dotted line in FIG. Next, as shown by the solid line in FIG. 6 , the control unit 70 closes the chuck 15 to raise the chuck 15 and the nozzle 10 as shown by arrows 100 , and cuts the lower end 22 of the tail wire 21 inserted through the nozzle 10 . break. Thereby, the control part 70 forms the independent needle-shaped wire 25 on the center line 52 of the electrode 51 .

After finishing the wire cutting step, the control unit 70 moves the mouthpiece 10 above the reference surface 40 . Next, the control unit 70 determines in step S105 of FIG. 2 whether all the needle-shaped threads 25 have been formed, and if it is determined to be NO in step S105 of FIG. 2 , it returns to step S101 of FIG. 2 and repeatedly executes FIG. 2 . Step S101 and the bending line forming step shown in FIG. 3(a) to FIG. 3(h), step S102 in FIG. 2 and the erection line shown in FIG. 4(a) and FIG. 4(b) The forming step, the step S103 in FIG. 2 , the joining step shown in FIGS. 5( a ) and 5( b ), and the step S104 in FIG. 2 and the wire cutting step shown in FIG. 6 . In addition, if it is judged as YES in step S105 of FIG. 2, the shaping|molding of the needle-shaped thread 25 is complete|finished.

The needle-shaped wire forming method of the above-described embodiment is as follows. The lower end 22 of the tail wire 21 is brought into contact with the reference plane 40 , and the tail wire 21 is bent in the direction along the reference plane 40 to form the bending line 23 . The bending line 23 is sandwiched between the front end 12 and the reference surface 40, and the nozzle 10 is moved laterally, the bending line 23 is raised upward to form the rising wire 24, and the formed rising wire 24 is bonded to the semiconductor element as the bonding position Since the electrode 51 of the semiconductor element 50 does not need to be pressed at a position other than the electrode 51 of the semiconductor element 50 as in the prior art, damage to the semiconductor element 50 when the needle-shaped wire 25 is formed can be suppressed. In addition, since the tail wire 21 can be bent and raised at a position away from the electrode 51 of the semiconductor element 50, even when the surface area of the semiconductor element 50 is small, the needle wire 25 can be formed.

In the needle-shaped wire forming method of the embodiment described above, in the bending line forming step, the description has been made on the assumption that the moving direction of the tip 12 of the mouthpiece 10 as the mouthpiece 10 is lowered is the same as the direction of movement of the tip 12 of the mouthpiece 10. The angle θ1 to the angle θ3 formed by the reference plane 40 is reduced, so that the front end 12 of the ceramic nozzle 10 is inclined downward toward the reference plane 40 to form the bending line 23 , but not limited to this, the front end 12 of the ceramic nozzle 10 can also be The bending line 23 is formed by descending obliquely toward the reference plane 40 at a certain angle.

In addition, in the joining step, the description has been given as follows: the control unit 70 shifts the position of the center line 19 of the mouthpiece 10 from the position of the center line 52 of the electrode 51 to perform the joining, but the present invention is not limited to this. The control part 70 may align the position of the center line 19 of the porcelain mouth 10 with the position of the center line 52 of the electrode 51 and join them.

Next, while referring to FIGS. 7 to 10 , and FIGS. 3( a ) to 3 ( h ), 4 ( a ) and 4 ( b ), the needle thread forming methods of other embodiments will be described. Be explained. The description of the same parts as those of the embodiment described above with reference to FIGS. 2 to 6 is omitted.

In the needle-shaped thread forming method according to the other embodiment, the control unit 70 executes step S201 in FIG. 7 and steps S201 in FIG. 8 and (a) to (b) in FIG. The crimp ball forming steps shown in Figure 7 Step S202 and the bump forming steps shown in FIGS. 8( c ) to 8 ( e ) are performed.

In the crimping ball forming step shown in step S201 of FIG. 2 , the control unit 70 moves the nozzle 10 to the vicinity of the torch electrode 5 as shown in (a) of FIG. A discharge is generated between the tail wires 21 extending from the front end 12 of the tail wires 21 to form the tail wires 21 into airless balls 30 . The airless ball 30 is held by the chamfered portion 13 provided at the front end of the hole in the center of the mouthpiece 10 . Next, as shown in FIG. 8( b ), the control unit 70 aligns the position of the center line 19 in the Z direction of the nozzle 10 with the center line 52 in the Z direction of the electrode 51 of the semiconductor element 50 , and sets the chuck 15 . In the open state, the mouthpiece 10 is lowered as indicated by the arrow 101 . Next, the control unit 70 uses the ceramic tip 10 to bond the airless ball 30 to the electrode 51 of the semiconductor element 50 . The peripheral portion of the airless ball 30 is pressed by the front end 12 to form a disc shape, and the central portion is pressed by the chamfered portion 13 to form a pedestal-shaped crimping ball 31 protruding slightly upward from the peripheral portion of the disc shape.

As shown in FIG. 8( b ), the control unit 70 executes step S202 in FIG. 7 and bump forming steps shown in FIG. 8( c ) to FIG. .

In the bump forming step shown in step S202 of FIG. 2 , the control unit 70 raises the mouthpiece 10 in a state where the chuck 15 is opened, as indicated by the arrow 102 in FIG. 8( c ). After the wire 20 is extended from the front end 12, it is moved laterally by a distance e, and then the porcelain mouth 10 is slightly lowered. Next, as shown by the arrow 103 of FIG.8(d), after the control part 70 raises the mouthpiece 10 to the original height, the mouthpiece 10 is laterally moved in the opposite direction to that shown in FIG.8(c). Distance (e+f), so that the porcelain nozzle 10 is lowered. By the above operation, the control unit 70 makes the extended wire 20 connect to the electric power of the semiconductor element 50 . The top of the pole 51 is folded left and right, and the folded wire 20 is pressed against the lower wire 20 by the front end 12. As shown in FIG. The bumps 35 of the concave portion 36 .

After the control unit 70 forms the bumps 35, in a state where the chuck 15 is opened as indicated by the broken line in FIG. The front end 12 of 10 extends out. Next, the control unit 70 closes the chuck 15 as shown by the solid line in FIG. 8( e ), so that the mouthpiece 10 and the chuck 15 are closed as shown in FIGS. 8( a ) to 8 ( The arrow 104 shown in e) rises up and cuts the lower end 22 of the tail wire 21 .

Then, the control unit 70 executes the bending line forming step as shown in step S101 of FIG. 7 and FIG. 3( a ) to FIG. The tip 12 of the nozzle 10 is moved obliquely downward while being in contact with the surface of the semiconductor element 50 , and the tail wire 21 is bent in a direction along the surface of the semiconductor element 50 to form a bending line 23 . The bending line forming step is the same as 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 , FIG. 4( a ), and FIG. 4( b ), the control unit 70 executes the step of forming the rising line, that is, the front end 12 of the ceramic nozzle 10 and the surface of the semiconductor element 50 . The root portion of the bending line 23 is sandwiched therebetween, and the front end 12 of the porcelain mouth 10 is moved laterally to form the erect line 24 . The rising line forming step is the same as the above-described embodiment except that the bending line 23 is sandwiched between the tip 12 of the nozzle 10 and the surface of the semiconductor element 50 .

Next, as shown in step S103 of FIG. 7 , (a) of FIG. 9 , and (b) of FIG. 9 , the control unit 70 executes the bonding step. As shown by arrow 105 in FIG. 9( a ), the control unit 70 moves the nozzle 10 over the electrode 51 of the semiconductor element 50 , and sets the position of the center line 19 of the nozzle 10 in the Z direction from the electrode 51 . The position of the center line 52 in the Z direction is laterally offset by a distance g. Here, the distance g is such a distance that the root portion 24a of the erected line 24 is aligned with the recessed portion 36 of the bump 35 .

As shown by the arrow 106 in FIG. 9( b ), the control unit 70 lowers the mouthpiece 10 with the chuck 15 closed, and joins the root 24 a of the erect line 24 to the molded projection 35 . on the upper surface of the recessed portion 36 . As shown in FIG.9(b), the base part 24a of the rising wire 24 is formed in the shape along the shape of the upper surface of the bump 35, and is joined to the bump 35. As shown in FIG.

When the rising wire 24 is bonded to the bump 35 of the electrode 51 , the rising wire 24 rises in a substantially vertical direction as indicated by the arrow 107 in FIG. 9( b ), and is formed at the center of the electrode 51 For the needle thread 25 extending substantially in the direction of the centerline 52 .

After the control unit 70 joins the erected thread 24 to form the needle-shaped thread 25, the joining step is ended, and the thread cutting step shown in step S104 of FIG. 7 is executed.

The control unit 70 raises the nozzle 10 to extend the tail wire 21 from the front end 12 by a predetermined length in a state in which the chuck 15 is opened as indicated by the dotted line in FIG. 10 . Next, as shown by the solid line in FIG. 10 , the control unit 70 closes the chuck 15 , moves the chuck 15 and the nozzle 10 upward as indicated by the arrow 108 , and cuts the lower end 22 of the tail wire 21 inserted through the nozzle 10 . break. Thereby, the control part 70 is formed independently on the bump 35 of the electrode 51 The needle thread 25.

After finishing the wire cutting step, the control unit 70 moves the nozzle 10 over the semiconductor element 50 . Next, the control unit 70 determines in step S105 of FIG. 7 whether or not all the needle-like threads 25 have been formed, and if it is determined to be NO in step S105 of FIG. 7 , it returns to step S201 of FIG. 7 and repeatedly executes FIG. 7 Step S201 and the crimp ball forming step shown in FIG. 8(a) and FIG. 8(b), step S202 in FIG. 7 and bumps shown in FIG. 8(c) to FIG. 8(e) The forming step, step S101 in FIG. 7 , the bending line forming step shown in FIGS. 3( a ) to 3 ( h ), step S102 in FIG. The erected wire forming step shown in FIG. 7 , the joining step shown in FIG. 9( a ) and FIG. 9( b ), and the wire cutting step shown in step S104 in FIG. 7 and FIG. In addition, if it is judged as YES in step S105 of FIG. 2, the shaping|molding of the needle-shaped thread 25 is complete|finished.

The needle-shaped wire forming method according to the above-described embodiment is as follows. The crimping ball 31 and the bump 35 are formed on the electrode 51 of the semiconductor element 50 , the rising wire 24 is bonded to the bump 35 , and the needle-shaped wire 25 is formed. Therefore, the force applied to the semiconductor element 50 in the step of forming the needle-shaped wire 25 is small, the damage of the semiconductor element 50 can be suppressed and the needle-shaped wire 25 can be formed more appropriately. In addition, since the lower end 22 of the tail wire 21 is brought into contact with the surface of the semiconductor element 50 to form the bending line 23, the needle-shaped wire 25 can be formed with a small space.

In the needle-shaped wire forming method of the above-described embodiment, the description has been made on the assumption that the control unit 70 brings the lower end 22 of the tail wire 21 into contact with the surface of the semiconductor element 50 in the wire forming step, and makes the tail wire 21 bending, but not limited to, For example, as shown by the arrow 109 in FIG. 11 , the lower end 22 may contact the bump 35 and be bent. In this case, the needle-like thread 25 can be formed with less space.

Furthermore, in the present embodiment, the control unit 70 can also make the lower end 22 contact the surface of the substrate or the reference plane 40 and bend the tail wire 21 in the bending line forming step. In addition, not only on the electrode 51 of the semiconductor element 50, but also the needle-shaped wire 25 may be formed on the electrode of the substrate.

S101~S105: Steps

Claims (8)

A needle-shaped wire forming method, using a bonding tool inserted with wires to form a needle-shaped wire at a bonding position of a substrate or a semiconductor element, comprising: a bending wire forming step, so that the bonding tool extending from the front end of the wire of a predetermined length faces The reference plane is lowered obliquely, 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 to form a bending line; In the state where the bending line is sandwiched between the reference planes, the joining tool is moved laterally in a direction opposite to the extending direction of the bending line, so that the bending line is erected upward to form an erecting line; the joining step, moving the bonding tool above the bonding position of the substrate or the semiconductor element, and bonding the erected wire at the bonding position; and a wire cutting step of raising the bonding tool and inserting the wire into the bonding position The thread of the joining tool is cut, whereby the standing thread is made into a needle thread standing up from the joining location. The needle thread forming method according to claim 1, wherein the bending line forming step is such that an angle formed by the moving direction of the joining tool and the reference plane becomes smaller as the joining tool is lowered , and the bonding tool is lowered obliquely toward the reference plane. The needle thread forming method according to claim 1 or claim 2, wherein the joining step performs joining by deviating the center position of the joining tool from the central position of the joining position. The needle thread forming method according to claim 1 or claim 2, wherein Before the bending line forming step, the method includes: a crimping ball forming step, wherein the joining tool is lowered toward the joining position, and the wire whose front end is formed into an airless ball is joined at the joining position to form crimping ball; and a bump forming step, after raising the bonding tool while extending the wire from the front end of the bonding tool, folding the extended wire back on the crimping ball, and pressing to form a bump, The bonding step bonds the riser lines on the bumps. The needle wire forming method of claim 4, wherein the bump forming step folds the protruding wire back over the crimp ball, so that the center position of the bonding tool is deviated from the bonding position and A pressing line is formed on the protrusion having a concave portion on the upper surface, and the bonding step causes the center of the bonding tool to move from the The engagement position is offset and engaged. The needle-shaped wire forming method according to claim 1 or claim 2, wherein the reference plane is the surface of the substrate or the surface of the semiconductor element. The needle-shaped wire forming method according to claim 4, wherein the bending wire forming step causes the bonding tool extending the wire of a predetermined length from the front end to descend obliquely toward the surface of the substrate or the surface of the semiconductor element The bending line is formed by contacting the lower end of the wire with the bump and bending the wire in a direction along the surface of the substrate or the surface of the semiconductor element. A wire bonding device for forming a needle-shaped wire at a bonding position of a substrate or a semiconductor element using a bonding tool inserted with wires, characterized by comprising: a control unit for adjusting the position of the bonding tool, and the control unit performs: bending line forming The step is to make the joining tool extending from the front end of the wire with a predetermined length to descend obliquely toward the reference plane, make the lower end of the wire contact the reference plane, and bend the wire in the direction along the reference plane to form a bending line a step of erecting line forming, in the state where the bending line is sandwiched between the front end of the bonding tool and the reference plane, the bonding tool is made transversely in a direction opposite to the extending direction of the bending line In the step of moving, the bending line is raised upward to form a rising wire; in the bonding step, the bonding tool is moved to the bonding position of the substrate or the semiconductor element, and the rising wire is bonded to the bonding position; and a wire cutting step of raising the joining tool to cut the wire inserted through the joining tool, thereby making the rising thread a needle-like thread rising from the joining position.

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