CN1886226A

CN1886226A - Low loop height ball bonding method and apparatus

Info

Publication number: CN1886226A
Application number: CNA2004800350372A
Authority: CN
Inventors: 秦巍; 罗伯特·怀斯
Original assignee: Kulicke and Soffa Investments Inc
Current assignee: Kulicke and Soffa Investments Inc
Priority date: 2003-11-26
Filing date: 2004-11-24
Publication date: 2006-12-27

Abstract

In accordance with the invention, a bump is formed on top of a die bond pad by forming a ball bond there. Then, without severing the wire, the capillary undergoes a set of coordinated motions to fold the wire on top of the ball bond. The wire is then stich bonded on top of the ball bond bump without severing the wire. This is then followed by a further set of coordinated xy motions to form the loop and bring the capillary over the second bond site (e.g., on the lead frame). The wire is then stitch bonded to the second bond site and the tail severed to complete the wire loop interconnect.

Description

Low loop height ball bonding method and equipment

Technical field

The present invention relates to the wire bond method on the semiconductor devices.

Background technology

Ball bonding is to be used for the pad on the semiconductor element (die) (bond pad) and lead frame or described tube core are mounted the interconnective current techique of contact point on thereon other substrate.The electric connection line pad on the die top usually extends to lead-in wire fingers on the lead frame, so that the circuit on the tube core is electrically connected with the pin of lead frame, after described tube core is sealed, described pin will stretch out from described encapsulation.Usually use the ball bonding machine to form the pad of tube core and the wire bond between the lead-in wire fingers.Figure 1A-1I shows the step in the conventional art of ball bonding.Conventional circuit form (looping) technology (being known as forward loop in the text forms) comprise an end ball bonding with gold thread on tube core pad and with the other end automatic spot of described gold thread in lead frame.More particularly, use the ball bonding machine, make lead 17 pass one group of anchor clamps 18 and pass the centre bore of capillary 11.When technology began, lead " afterbody " 23 was outstanding from the end of capillary 11, as shown in Figure 1A.Make the afterbody 23 at place, lead 17 ends be heated by the electric spark 16 that comes from the electric flame of being known as of EFO rod 24 (EFO).Spark makes the end of lead melt, and the end of lead forms ball 19 when fusing, as shown in Figure 1B.Anchor clamps 18 are closed so that provide the electric current return path by described anchor clamps during EFO, and are opened afterwards so that described ball is positioned at capillary end with himself again.Capillary 11 is moved to the position of pad 13 tops of tube core 15 afterwards, shown in Fig. 1 C.

Afterwards during the initial acceleration capillaceous under the situation that anchor clamps 18 are still opened capillary 11 move down, between deceleration period capillaceous, be closed then, so that described ball is held in place during capillaceous moving down.Described anchor clamps are opened before described ball is about to Contact welding contact 13 then.Contact with pad 13 on the tube core 15 in ball under the situation that anchor clamps 18 are still opened 19 beginning, as shown in Fig. 1 D.Heat energy and/or ultrasonic energy are applied in described tube core so that described ball is welded in pad 13.This welding is commonly referred to as ball bonding or weldering (first bond) just.Under the situation that anchor clamps 18 are opened, make capillary 11 raise afterwards so that ease out the lead of a bit of length that still invests the ball bonding top, as shown in Fig. 1 E.Then, under the situation that anchor clamps 18 are opened, capillary 11 moves to by the towing along with the predetermined loop motion of lead (described lead still is connected in ball bonding) and capillary 11 and is close to lead-in wire fingers 21 usually and is positioned at position above it.Under the situation above capillary 11 is positioned at lead-in wire fingers 21, anchor clamps 18 are closed, as shown in Fig. 1 F.Afterwards capillary 11 reduce so that with wire clamp between the surface of capillary and the fingers 21 that goes between, as shown in Fig. 1 G.Heat energy and/or ultrasonic energy can be applied in once more so that the quilt of described lead is clamped part and be welded in lead-in wire fingers 21.This welding is commonly referred to as automatic spot or secondary welding (first bond).Now, anchor clamps 18 are opened once more and are made capillary 11 raise along with the lead that still invests automatic spot so that other lead " afterbody " 23 eases out from capillary, as shown in Fig. 1 H.Anchor clamps 18 are closed and capillary 11 is further raise so that at the weakest point place afterwards, that is, wire tail 23 fractures in the automatic spot position.The connection of being finished 22 is known as wire loop and is illustrated in Fig. 1 I.

Here, capillary is moved to such an extent that be close to the next pad on the tube core 15 so that begin the wire loop forming process of the next pad on the tube core 15.After finishing, the formation of wire loop formerly still will be melted by EFO as mentioned above, so that be formed for beginning the next ball of next ball bonding operation from the outstanding wire tail 23 of the end of capillary 11.Above-mentioned conventional forward ball bonding technology is quick, reliable and inexpensive.Yet it has limitation.It should be noted that most that minimum loop height is usually also more than 150 microns.Loop height is defined as for example maximum height of the lead of the top surface top of pad of face of weld.The loop height of attempting to reach lower can cause the neck shape portion of wire loop is damaged.Neck shape portion is the wire loop part of direct and ball bonding adjacency.Loop height is reduced to is easy to reduction below 150 microns or damages described neck shape portion.

Has the demand of growth for more and more littler integrated circuit encapsulation.A remarkable aspect that reduces the size of integrated chip encapsulation is to reduce its thickness or height.Encapsulation thin in commerce is commonly referred to as low profile package.What be equal to the requirement that reduces described packaging height is the height that requirement reduces the peak of wire loop, and the height of peak is the limiting factor about the height of integrated circuit encapsulation in many cases.

In order to reduce to be used for the loop height of integrated circuit encapsulation and other purpose, researched and developed a kind of wire loop formation technology that is called the return circuit.Prerequisite under the return circuit is, because the peak of wire loop is connected with ball bonding, thereby preferably make the loop forming process put upside down because the surface of lead frame is lower than the surface of tube core, form second automatic spot on the pad at tube core in lead frame (or other substrate) last formation first ball bonding.Therefore, the peak of wire loop is close to lower face of weld, thereby reduces overall height.

Yet the direction of putting upside down the loop forming process simply is impossible, and this is because automatic spot requires capillary to contact with face of weld.Pad on the tube core is very little usually, therefore, is difficult to form automatic spot not having capillary contact and therefore damage under the situation of the peripheral circuits on the tube core on the pad on the tube core.And wire loop is easy to hang down into their minimum point that is close to automatic spot.Therefore, if the automatic spot position is higher than the ball bonding position, lead may contact the edge or the top surface of tube core.This can cause the damage of electrical short fault or lead.

Therefore, researched and developed return circuit formation technology, to shown in the 2C, wherein first step is to form ball bonding 25 according to the standard technique that is used to form ball bonding on the top of the pad on the tube core 29 27 basically such as Fig. 2 A.Yet, replace as the situation after forming ball bonding, easing out lead 17 in the conventional forward loop formation technology, with capillary 11 raise, closed anchor clamps 18 and capillary further raise so that break lead from ball bonding, only ball bonding (or protuberance) 25 is stayed on the pad 27, as shown in Fig. 2 A.Wire loop along reverse (that is, from the substrate to the pad) complete forms program afterwards.That is to say that form second ball bonding 37 subsequently on lead frame 39, capillary 11 moves to the position of first ball bonding, 25 tops to form the wire loop shape of expectation, as shown in Fig. 2 B by a series of motions afterwards.Afterwards, automatic spot 43 is formed on the top of first ball bonding (or protuberance) 25.The wire loop of finishing has been shown in Fig. 2 C.

This return circuit formation program can be low profile package provides low loop height.Yet it is to form the slower technology in loop than forward, and this is to need to form two ball bondings because the return circuit forms technology in each loop.And tube core must stand bigger impact, and this is because capillary must twice formation welding on tube core (once be used to form first ball bonding, be used for forming automatic spot on the ball bonding top for the second time) in each wire loop.Another limitation that the return circuit forms is how it normally makes the meticulous limiting factor of pitch of the pad on the tube core.Especially, the protuberance on the die bond pad top 25 is must be enough big so that provide support for automatic spot.In addition, the diameter of protuberance will increase along horizontal direction when forming automatic spot on its top.

Summary of the invention

Therefore, an object of the present invention is to provide a kind of improved wire loop and form method and apparatus.

Another object of the present invention provides a kind of wire loop with very low loop height and interconnects.

According to the present invention, form protuberance thereon by on die bond pad, forming ball bonding.Afterwards, do not cutting off lead and under the situation that anchor clamps are opened, the motion that it is xyz that capillary experiences one group of coordinate so that with wire fold on the ball bonding top.Afterwards under the situation of the afterbody that do not fracture with the lead automatic spot on the protuberance top.Follow another to organize the motion that coordinate is xyz afterwards, thereby the afterbody that fractures is afterwards finished this process so that take capillary to second welding position (for example, lead frame or other substrate) and on described substrate, carry out second automatic spot.

According to the one particular embodiment of the present invention that are used to form aforementioned wire fold, form ball bonding, afterwards along the z direction with the capillary specified altitude assignment (hereinafter, being referred to as transport disengaging height) that raises.Make it afterwards along usually away from the direction of second welding position (in the xy plane) mobile distance to a declared goal (being referred to as the fold offset distance hereinafter) flatly.Capillary can or not raise another apart from (being referred to as folding factor hereinafter) along the z direction once more.Follow afterwards and move along another of xy plane so that substantially capillary is brought back to the protuberance top, be used on described protuberance top, forming aforementioned automatic spot.Following another coordinate afterwards is the motion of xyz so that take capillary the position (for example, on the lead frame) of second welding position to, will form second automatic spot in described position.

Description of drawings

Figure 1A shows the front view that the conventional forward loop forms the step of operation to 1I.

Fig. 2 A shows the front view that the return circuit forms the step of operation to 2C.

Fig. 3 is according to the interconnective front view of folding wire loop of the present invention.

Fig. 4 shows the front view of each component of xyz exercise group related in folding protuberance formed according to the present invention.

Fig. 5 A shows the front view that forms the step of operation according to folded forward of the present invention loop to 5O.

Fig. 6 shows in that certain preferred one exemplary embodiment forms the front view of each component of xyz exercise group related in the folding protuberance according to the present invention.

Protuberance that the exemplary of parameters that Fig. 7 is to use among Fig. 6 to be proposed forms and folding side view.

Fig. 8 A and 8B are the scanning electron micrographs in the completed loop of generation after having formed the protuberance shown in Fig. 7 A.

The specific embodiment

Fig. 3 is the side view of folded forward wire loop 45 formed according to the present invention.Fig. 3 shows integrated circuit lead 51 and the leadframe substrate 55 that comprises pad 53 on its top surface, wherein has wire loop between pad 53 and leadframe substrate 55 and interconnects.Can think that the wire loop 45 that forms according to technology of the present invention comprises five common parts.With reference to Fig. 3, they are that wire fold 57, the automatic spot 58 on (3) protuberance top, (4) on (1) protuberance, (2) protuberance top is with interconnective wire loop 59 in first and second welding positions and (5) second automatic spot 60.

Can use the ball bonding machine to form above-described these five common parts.

Fig. 5 A show to 5O the specific embodiment according to the present invention the ball bonding machine position capillaceous and be used to form the state of each stage lower wire of the exemplary processes of folded forward wire loop.In the employed term, vertical direction is meant the z direction in this specification, and horizontal direction is meant the xy direction.Certainly, the figure in this application is an X-Y scheme, so all xy motion all is illustrated in paper plane, therefore can be seen as one dimension simply and move, that is, and along x or y, rather than along xy.Yet in reality, because the wire loop on the given tube core not all is parallel to each other, therefore all transverse movements must be defined as the xy motion in machine code, the motion capillaceous of described machine code control ball bonding machine.Therefore, we use identical term in this manual.In addition, term vertically and the level top surface that only is based on tube core be such supposition illustrative of horizontal orientation, described supposition is a typicalness, but needn't be always accurate supposition.

As shown in Fig. 5 A, when previous loop forming process finished, the folded forward wire loop forming process started from capillary 11, wire tail 23 was stretched out and anchor clamps 18 are closed from capillary.Near the pad 61 that described capillary is disposed in tube core 63 and the relevant lead-in wire fingers 65, between pad 61 and lead-in wire fingers 65, will form next wire loop and be connected.

Electricity consumption flame 67 makes the lead fusing so that the fusing of its end.When fusing, it is naturally formed as ball 72, as shown in Fig. 5 B.Capillary is lowered and moves towards pad 61, as shown in Fig. 5 C.Capillary is lowered so that ball 72 contacts on pad 61 afterwards.Apply heat energy and/or ultrasonic energy so that described ball bonding is connected to described pad.Fig. 5 D shows the technology of this moment, and it is the terminal point of protuberance 56 forming processes substantially for folded forward wire loop first.

Then, capillary 11 raises so that will ease out certain-length from the lead that stretch out at the top of protuberance 56 under the situation that anchor clamps 18 are opened.The distance of this rising here is known as transport disengaging height, shown among Fig. 4 75.Fig. 5 E shows the capillary position after this step.Move usually and towards the opposite first direction of the direction of second welding position 65 (left side in towards Fig. 5 A to 5O) on capillary 11 edge in the xy plane afterwards.Best, the direction of fold offset is just in time with opposite towards the xy direction of second welding position 65.Here the distance of this xy motion is known as fold offset and illustrates by 76 in Fig. 4.Fold offset motion capillary position afterwards has been shown among Fig. 5 F.

In some embodiments of the invention, when fold offset motion finished, capillary 11 quilts raise (along the z direction of forward) a bit of distance (being referred to as folding factor here) once more so that ease out other lead.Show folding factor by 77 among Fig. 4.Yet, in application more of the present invention, be that zero folding factor is suitable.Fig. 5 G shows in this technology position capillaceous and lead this moment.The amount of lead during fold offset and folding factor pilot are folding.

Capillary 11 is moving so that lead is gone back on the top of himself to travelling backwards towards protuberance 56 afterwards, thereby beginning forms wire fold on the protuberance top.Fig. 5 H shows when capillary and moves with the position that forms capillary 11 when folding and the state of lead.Here the motion of mentioning at last is known as fold return motion, shown among Fig. 4 78.Described fold return motion is preferably along just in time opposite with the xy direction of fold offset motion xy direction.Folding factor 77 is that described fold return motion is preferably pure level (being xy) motion among those embodiment of zero therein.If folding factor 77 is non-vanishing, fold return motion 78 can comprise negative z component so that capillary turn back to ball bonding during the residing equal height of capillary.Another kind of situation makes capillary turn back to transport disengaging height when described fold return motion finishes.Yet this is not a necessary condition.In fact, at least some preferred embodiments of the present invention, as described further below, capillary turns back to the height that is lower than transport disengaging height.In fact, fold return motion 78 can comprise forward (making progress) or negative (downwards) z component, even folding factor 77 is zero.Important aspect is that wire fold is formed on the top of protuberance 56, preferably extends along complete direction away from second pad 65.Difference when transport disengaging height and fold return motion 78 finish here between the position capillaceous is known as the protuberance height.It can be positive number or negative.Yet, as already noted, in implementations more of the present invention, will not exist z motion capillaceous and/or folding factor will just in time equate between the finishing of transport disengaging height and wire fold and opposite reaching, so that the protuberance height will be zero with the z component of fold return motion.

And the horizontal component of fold return motion 78 needn't be a same distance with fold offset motion.According to concrete application, it preferably turn back to the position that is used at original xy coordinate capillaceous before not reaching fold offset motion (as Fig. 4 by shown in the 78a of path), just the position identical with original xy coordinate capillaceous before the fold offset motion (as among Fig. 4 by shown in the 78b of path), than the long position of original xy coordinate capillaceous before the fold offset motion (as among Fig. 4 by shown in the 78c of path) position of carrying out automatic spot.

Level error when this moment, xy coordinate capillaceous was with respect to the formation protuberance between the xy capillaceous position is known as fold return offset.In other words, fold return offset is poor in the xy dimension between the horizontal component of fold offset motion and fold return motion.If the xy component of fold return motion 78 is less than fold offset motion 76, fold return offset is represented as positive number.If the horizontal component of fold return motion 78 is longer than fold offset motion 76, fold return offset is represented as negative.If fold offset motion 76 has identical xy (that is, level) value with fold return motion 78, fold return offset is zero so.

When fold return motion finishes, the top of capillary contact protuberance 56 and with wire clamp between end capillaceous and protuberance, shown in 5I.At this moment, lead is clamped, but also is not cut off.And, at this moment, finished the second portion (that is, folding 57) of five aforementioned parts of overall folded forward wire loop., technology also is not cut off folding 57 thereby link to each other since beginning lead with protuberance 56.

Lead is by the top of automatic spot in protuberance 56 afterwards.Heat energy and/or ultrasonic energy can be applied in the top that is welded in protuberance 56 with the compression section that helps lead.At this moment, finished the third part (that is first automatic spot 58) of five aforementioned parts of overall loop.Fig. 5 J shows the technology of this moment, because capillary does not move usually during automatic spot, so it is in and the same position shown in Fig. 5 I substantially.

The motion that is xyz by one group of coordinate now makes capillary move towards second welding position, thereby forms required wire loop shape (the 4th part of overall loop) and capillary is positioned at the top of second welding position 65.Fig. 5 K and 5L show along to the illustrative trace of second welding position 65 position at 2 capillaries of locating 11.

Coordinate is that the motion of xyz can be simple relatively, comprises the motion towards the straight line xy of second welding position.Yet, help wire loop is formed most preferred shape thereby also exist along moving of z direction usually.Owing to be not cut off yet since technology begins lead, so wire loop 59 links to each other with the automatic spot of locating in first welding position 58 with protuberance 56, folding 57.

Then, make capillary reduce so that with wire clamp between the end of second face of weld 65 and capillary 11, and lead by automatic spot in second welding position.Heat energy and/or ultrasonic energy can be applied in to help welding.At this moment, lead is clamped, but also is not completely severed, as shown in Fig. 5 M.Still open and lead still invests and makes capillary 11 raise under the situation of second automatic spot 60 at anchor clamps 18 afterwards, so that wire tail 69 eases out from capillary 11.Fig. 5 N shows in this technology position capillaceous this moment.Anchor clamps 18 are closed and make capillary 11 further raise so that fracture lead at second automatic spot, 60 places afterwards, as shown in Fig. 5 O.Finished the 5th part of overall folded forward wire loop now, that is, second automatic spot 60, and whole folded forward wire loop forms the technology end.

The main purpose of protuberance 56 is to prevent capillary and the height (z direction) that pad directly contacts and the rising lead withdraws from from first welding position.Particularly, lead lowland like this is withdrawed from from first welding position, that is, as not being by forming the extra height that is positioned at above the die surfaces at beginning wire loop on the protuberance top, wire loop 59 may contact the die surfaces in the middle of first and second welding positions.

On the protuberance top, form folding 57 main purpose and be and make lead withdraw from from first welding position with level and the mode of pointing to second welding position usually, thereby form low loop height.Described folding shape is normally oval-shaped, and its major axis is positioned at the xy plane, and lead withdraws from from folding end with level and the direct usually mode of pointing to second welding position usually.The orientation that the common straight line of lead makes progress when lead withdraws from from first welding position in this orientation and the conventional forward wire loop is different fully.Therefore, because lead points to rather than withdraws from from the ball bonding position straight up along level, therefore formation technology in loop of the present invention provides ultralow loop height.

In addition, reduced impact for tube core with respect to the conventional counter ball bonding, this is owing to form the situation the conventional secondary welding of execution on the protuberance top not as in the return circuit.Lead only by compress slightly so that form the loop, and compare with conventional automatic spot, the automatic spot among Fig. 7 A on the ball top with oppositely weld in Fig. 7 B similar.

In addition, can realize the pitch that the ratio inverse ball bonding is meticulousr by the present invention, this be since protuberance unlike being compressed in the reverse wire loop formation technology and laterally extruding so much.

Wirebond machine is by the kinetic control system control that comprises control circuit, and described kinetic control system can make described machine carry out the technology described in the literary composition.Usually, described circuit comprises the digital processing unit such as programmed general purpose computer, digital signal processor, state machine, combinational logic circuit, microprocessor, special IC or any other known digital treating apparatus etc.If described circuit comprises computer, the present invention can be present in (if not exclusively) largely and be used in the software of described computer programming, carries out the technology described in the literary composition so that control described wirebond machine.

By making with reference to described each component motion optimization of Fig. 4 the required form that we can obtain to have low loop height and not have neck shape portion to damage.As example, Fig. 6 shows the exemplary parameter that is used to form the loop shape shown in folding and Fig. 8 A and the 8B shown in Fig. 7.The amount of folding middle lead and folding shape are jointly determined in three motions (transport disengaging height 75, fold offset 76 and folding factor 77) at first.If these motions are too big, may form than folding big the folding of expection.If these motions are too little, the neck shape portion zone that may at all can not form folding and lead may be damaged.

We have found that by test the transport disengaging height and the fold offset that are slightly larger than diameter of wire (for example, be approximately diameter of wire 1.01 to 1.55 times) have obtained superior results.In addition, folding factor should be on the occasion of.In the example of Fig. 7, be the lead of 1 mil for diameter, transport disengaging height 75 is that 1.5 mils, fold offset 76 are 1.3 mils and folding factor 77 is 1 mil.These setting values have eased out the lead of appropriate amount, and before fold return motion 78 beginning, the angle of lead is decided to be with vertical direction be about 30 degree.

Fold return motion 78 is determined the net shape of protuberance.In the concrete machine that we use, fold return motion 78 is specified by two parameters.Be specially (1) aforementioned fold return offset parameter (described parameter is specified the horizontal component of fold return motion with fold offset) and (2) protuberance height (described protuberance height is specified the vertical component of fold return motion with folding factor).

Have the good folding of enough distortion so that keep described folding under the situation that can excessively not make protuberance flatten in order to form, the protuberance height normally should be negative value (the protuberance height is the vertical distance apart from transport disengaging height).In this example, the protuberance height is-1.25 mils, and transport disengaging height is 1.5 mils.Therefore, about 0.25 mil place above protuberance 56, final position capillaceous.This provides enough flat ratios for lead so that form folding under the situation that protuberance is obviously flattened.Fold return offset in this example is 0.5 mil, and this is meant in central horizontal ground skew 0.5 mil (away from second welding 60) the afterwards capillaceous final position of fold return motion 78 from protuberance.These setting values have guaranteed that the position of automatic spot 58 is positioned at the center on protuberance 56 tops.

Figure 8 illustrates the wire loop that from the welding of using these parameters, obtains.In a plurality of test examples, the average loop height of using these parameters is 2.3 mils.The most loop height is 2.5 mils.

Though described specific embodiments more of the present invention, those skilled in the art can easily make various changes, correction and improvement.Although Wen Zhongwei clearly describes, described change, correction and the improvement made by the disclosure obviously should be the part of this disclosure, and should be in spirit of the present invention and protection domain.Therefore, aforementioned description only is as example, and nonrestrictive.The present invention is only limited by following claim and equivalent thereof.

Claims

1. one kind forms the interconnective method of wire loop between first welding position and second welding position, said method comprising the steps of:

(1) with the lead ball bonding to described first welding position so that on described first welding position, form protuberance;

(2) form wire fold on described ball bonding top, described wire fold links to each other with described ball bonding;

(3) with described wire fold automatic spot on described ball bonding top;

(4) between described wire fold and described second welding position, form wire loop continuously; And

(5) at the described lead of the described second welding position automatic spot to stop described wire loop.

2. the method for claim 1 is characterized in that, described wire fold is the ellipse with horizontally extending major axis substantially.

3. method as claimed in claim 2 is characterized in that, described wire fold along basic with extend in the opposite direction to the side of second welding position from first welding position.

4. method as claimed in claim 3 is characterized in that described wire loop essentially horizontally withdraws from from the ball bonding top.

5. the method for claim 1 is characterized in that, described wire loop is by comprising that at least ball bonding machine capillaceous forms, and wherein step (2) may further comprise the steps:

(2.1) capillary that above ball bonding, raises vertically;

(2.2) the capillary water level land is moved apart described second welding position; And

(2.3) along the flatly mobile capillary of direction that returns towards described first welding position.

6. method as claimed in claim 5 is characterized in that, step (2) is further comprising the steps of:

(2.4) capillary that between step (2.2) and (2.3), raises.

7. method as claimed in claim 6 is characterized in that, step (2.3) comprises and moves down described capillary.

8. method as claimed in claim 5 is characterized in that, step (2.3) comprises flatly mobile capillary one segment distance, and described distance is less than the horizontal range of crossing in the step (2.2).

9. the method for claim 1 is characterized in that, described first welding position is higher than described second welding position.

10. method as claimed in claim 9 is characterized in that, described first welding position is positioned on the semiconductor element, and described second welding position is positioned on the substrate of the described semiconductor element of carrying.

11. method as claimed in claim 6 is characterized in that, step (2.1) comprises rising capillary one segment distance, and described distance is slightly larger than the diameter of described lead.

12. method as claimed in claim 11 is characterized in that, the described distance in the step (2.1) is approximately 1.5 times of described diameter of described lead.

13. method as claimed in claim 6 is characterized in that, step (2.2) comprises mobile capillary one segment distance, and described distance is slightly larger than the diameter of described lead.

14. method as claimed in claim 13 is characterized in that, the described distance in the step (2.2) is approximately 1.3 times of described diameter of described lead.

15. method as claimed in claim 14 is characterized in that, step (2.4) comprises one section vertical distance of rising capillary, and described distance approximates the diameter of described lead greatly.

16. method as claimed in claim 6, it is characterized in that, distance in step (2.1), (2.4) and (2.2) is relative to each other selected with the diameter of described lead, makes in step (2.2) when finishing, and described lead is to stretch out from described protuberance in vertical direction with about 30 degree angles.

17. method as claimed in claim 7 is characterized in that, step (2.3) comprises one section vertical distance of the described capillary of reduction, and described distance is greater than the distance that moves described in the step (2.4).

18. an interconnective wire loop between first welding position and second welding position, described wire loop comprises:

(1) in the ball bonding of described first welding position;

(2) in the wire fold that comprises on the described ball bonding top of the lead that links to each other with described ball bonding, described wire fold by automatic spot on described ball bonding top;

(3) wire loop between described wire fold and described second welding position, described wire loop comprises the lead that links to each other with described wire fold; And

(4) stop the automatic spot of described wire loop at place, described second welding position.

19. wire loop as claimed in claim 18 is characterized in that, described wire fold is the ellipse with horizontally extending major axis substantially.

20. wire loop as claimed in claim 19 is characterized in that, described wire fold along basic with extend in the opposite direction to the side of second welding position from first welding position.

21. wire loop as claimed in claim 20 is characterized in that, described wire loop essentially horizontally withdraws from from the ball bonding top.

22. wire loop as claimed in claim 18 is characterized in that, described first welding position is higher than described second welding position.

23. method as claimed in claim 22 is characterized in that, described first welding position is positioned on the semiconductor element, and described second welding position is positioned on the substrate of the described semiconductor element of carrying.

24. a method that is formed for the interconnective wire loop of semi-conductor electricity said method comprising the steps of:

(1) use the wirebond machine with lead to form ball bonding in first welding position, described wirebond machine has capillary;

(2) make described capillary raise first highly, ease out from described capillary so that invest the lead of described ball bonding;

(3) make described capillary flatly move first distance along first direction;

(4) described capillary is moved along basic second horizontal direction opposite with described first horizontal direction;

(5) on described ball bonding top, form first automatic spot;

(6) make described capillary move to second welding position that separates with described first welding position;

(7) form second automatic spot in described second welding position; And

(8) cut off the described lead adjacent with described second welding position.

25. method as claimed in claim 26 is characterized in that, described wire loop is by comprising that at least ball bonding machine capillaceous forms, described first direction substantially away from described second welding position and described second direction substantially towards described second welding position.

26. a wirebond machine comprises:

Capillary;

Be used for lead induction system by the hole suppling wire of described capillary;

Be used to control the kinetic control system of described motion capillaceous, described kinetic control system comprises circuit, and described circuit is used for:

(1) forms ball bonding in first welding position;

(3) with described wire fold automatic spot on described ball bonding top;

(5) form automatic spot to stop described wire loop in described second welding position.

27. wirebond machine as claimed in claim 26, it is characterized in that the described circuit of be used to execute the task (2) comprises and is used to form described wire fold so that its circuit along the opposite horizontal direction extension of direction basic and from first welding position to second welding position.

28. wirebond machine as claimed in claim 27 is characterized in that, the described circuit of be used to execute the task (3) makes wire loop essentially horizontally withdraw from from the ball bonding top.

29. wirebond machine as claimed in claim 27 is characterized in that, the described circuit of be used to execute the task (2) comprises and is used for following circuit:

(2.1) capillary that above ball bonding, raises vertically;

30. wirebond machine as claimed in claim 29 is characterized in that, the described circuit of be used to execute the task (2.3) comprises the circuit of flatly mobile capillary one segment distance, and described distance is less than the horizontal range of crossing in the step (2.2).

31. wirebond machine as claimed in claim 30 is characterized in that, described circuit comprises digital processing unit.

32. wirebond machine as claimed in claim 30 is characterized in that, described digital processing unit comprises the computer that moves computer software.

33. a computer-readable product is used for control and comprises wirebond machine capillaceous, described computer-readable product comprises computer executable instructions, and described computer executable instructions is used for:

(1) forms ball bonding in described first welding position;

(3) with described wire fold automatic spot on described ball bonding top;

34. computer-readable product as claimed in claim 33 is characterized in that, the described computer executable instructions that is used to form described wire fold makes that described wire fold is the ellipse with horizontally extending major axis substantially.

35. computer-readable product as claimed in claim 34, it is characterized in that, the described computer executable instructions that is used to form described wire fold make described wire fold along basic side with from first welding position to second welding position horizontal-extending in the opposite direction.

36. computer-readable product as claimed in claim 35 is characterized in that, the described computer executable instructions that is used to form described automatic spot forms described automatic spot, makes described wire loop essentially horizontally withdraw from from the ball bonding top.

37. computer-readable product as claimed in claim 36 is characterized in that, the described computer executable instructions that is used to form described wire fold comprises and is used to carry out following computer executable instructions:

(2.1) capillary that above ball bonding, raises vertically;