JPH0831857A - Method and structure for controlling vacuum tensioner in wire bonder - Google Patents

Abstract

PURPOSE:To enhance a reliability while facilitating maintenance by providing a method and structure for controlling a vacuum tensioner in a clog-free wire bonder. CONSTITUTION:In a method for controlling a vacuum tensioner in a wire bonder where vacuum is fed to the vacuum tensioner 1 and a wire 9 is held in nozzles 3, 5 by vacuum, an air blow is fed at an arbitrary timing to the nozzles 3, 5 in the direction reverse to the air flow under vacuum. In the control structure, one of more than one switching valves is coupled with a control port 7 and a vacuum pipe 17 and an air pipe 15 are coupled with the other switching valve such that the pipes 17, 15 can be coupled with the control port 7 while being switched selectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire tension control method for a wire of a wire bonder using a mechanism for applying a proper tension to the wire by using a vacuum (hereinafter referred to as "vacuum tensioner") and its structure. is there.

[0002]

2. Description of the Related Art Conventionally, in a vacuum tensioner in a wire bonder, a vacuum for holding a wire is continuously supplied. That is, in order to obtain an appropriate loop shape from the bonding of the first point to the bonding of the second point, the wire must be held at a constant position relative to the capillaries and wire clampers described later. I have to. Therefore, the vacuum was always supplied so that a sufficient wire holding force could be maintained in the vacuum tensioner. Therefore, the vacuum supplied to the vacuum tensioner is generally cut (cut) only when the wire is passed through the vacuum tensioner. This is because when the vacuum tensioner acts on the vacuum tensioner, the wire is held in the vacuum tensioner, which makes it difficult to insert the wire.

[0003]

However, in the conventional vacuum tensioner control method, since the vacuum is continuously supplied, the minute dust around the vacuum tensioner is sucked in, and the vacuum tensioner nozzle is sucked. Occasionally clogging occurred. And
When dust is temporarily sucked into the nozzle, the wire tension varies, resulting in a decrease in reliability. In other words, with complete clogging, continuous defective products will be generated, so detection will be easier and appropriate measures can be taken, but with temporary clogging, dust will be removed from the nozzle by vacuum after clogging. Then, the function of the vacuum tensioner returns to normal, and it becomes difficult to detect defective products. Needless to say, the vacuum tensioner / nozzle requires regular disassembly and
It needs cleaning and maintenance is complicated. The present invention has been made in view of the above situation,
(EN) A method and a structure for controlling a vacuum tensioner in a wire bonder that does not cause clogging, and an object thereof is to improve reliability and save maintenance.

[0004]

In order to achieve the above object, a method of controlling a vacuum tensioner in a wire bonder according to the present invention is to supply a vacuum to a vacuum tensioner having a nozzle through which a wire is inserted, and use this vacuum to feed the wire. In the method of controlling the vacuum tensioner in the wire bonder, which holds the
It is characterized in that an air blow in the opposite direction to the air flow during vacuum is supplied to the nozzle at an arbitrary timing. The structure of the vacuum tensioner is such that the control port for supplying vacuum to the nozzle is provided, and one of the switching valves of two or more systems is connected to the control port, and the vacuum pipe and the air pipe are connected to the control port. It is characterized in that it is selectively switchably connected to the other of the switching valves. Further, the structure of the vacuum tensioner may be characterized in that an intake port dedicated to air intake is provided in communication with the nozzle.

[0005]

In the method of controlling the vacuum tensioner in the wire bonder, when the vacuum is supplied to hold the wire, the air around the nozzle opening is sucked in, and the dust mixed in the air tends to be clogged in the nozzle. Is supplied, the air in the direction opposite to the air flow at the time of vacuum is discharged, and the state is the same as when cleaning blow is performed. In the structure of the vacuum tensioner, the vacuum pipe or the air pipe is connected to the control port via the switching valve, vacuum and air blow can be alternately supplied to the control port, and intake and exhaust to the nozzle can be easily performed. Moreover, in the structure of the vacuum tensioner in which the suction port is connected to the nozzle, most of the air is sucked from the suction port, the suction of air from the nozzle is relatively reduced, and the probability that dust is sucked from the nozzle Will be lower.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a vacuum tensioner control method and its structure in a wire bonder according to the present invention will now be described in detail with reference to the drawings. FIG. 1 is a piping circuit diagram showing a first embodiment of the structure of the vacuum tensioner of the present invention. The vacuum tensioner 1 is provided with a thick nozzle 3 and a thin nozzle 5 which are nozzles connected to each other at the same center, and the thick nozzle 3 and the thin nozzle 5 communicate with a control port 7. A wire 9 is inserted through the thick nozzle 3 and the thin nozzle 5, and the tip end side of the wire 9 is led out from the capillary 13 via a wire clamper 11. An air system pipe 15 and a vacuum system pipe 17 are connected to the control port 7 via a branch pipe, and the air system pipe 15 and the vacuum system pipe 17 are connected to the control switching valve 1
It has 9 and 21. Control valve changeover switches 23, 25 are connected to the control changeover valves 19, 21. The control valve changeover switches 23, 25 alternately open and close the control changeover valves 19, 21 to perform switching. Vacuum tensioner 1, control port 7, wire 9, capillary 13, control changeover valves 19, 21, control valve changeover switches 23, 25
The structure 27 of the vacuum tensioner is constituted by using as a main member.

The function of the vacuum tensioner structure 27 thus constructed will be described. When the vacuum is supplied to the control port 7 of the vacuum tensioner 1, the wire 9 is held in the vacuum tensioner 1 and a high tension is generated when the wire 9 is paid out. At this time, air around the openings of the thick nozzles 3 and the thin nozzles 5 is sucked in, so that there is a possibility that dust mixed in the air may cause clogging in the nozzles. Under such a circumstance, when air is supplied to the control port 7 which has been supplied with vacuum until now, the air is discharged in the opposite direction from the thick nozzle 3 and the thin nozzle 5, so that the cleaning blow is performed. The effect of is obtained.

The control method for supplying air is performed by a combination of the following three forms of switching. That is, the wire 9
When it is desired to apply tension to the control valve (first mode), the control valve changeover switch 23 is turned off and the switch 25 is turned on to supply vacuum to the control port 7. When the wire 9 is passed through (second mode), it is better to have neither air nor vacuum in the vacuum tensioner 1, so that the control valve changeover switches 23 and 25 are both turned off. When cleaning the inside of the vacuum tensioner 1 (third embodiment), the control valve changeover switch 23 is turned on, the switch 25 is turned off, and air is supplied to the control port 7 to clean the inside of the nozzle.

According to the structure 27 and the control method of the vacuum tensioner described above, since the control changeover valve 19 and the control valve changeover switch 23 are provided in the vacuum tensioner 1, clogging is eliminated by discharging air in the opposite direction. The vacuum tensioner 1 can be cleaned without disassembling. Further, in the wire bonder, the wires 9 and the capillaries 13 are inevitably replaced.
It is an extremely easy and rational means that the inside of the vacuum tensioner can be cleaned and blown at any time by operating 5. Further, performing the cleaning blow when the apparatus is stopped without adjusting to the above-described replacement of the wire 9 and the capillary 13 is technically no problem and is effective as a regular cleaning blow.

FIG. 2 is a piping circuit diagram showing a second embodiment of the structure of the vacuum tensioner of the present invention. In this embodiment, the vacuum tensioner 1, the thick nozzle 3, the thin nozzle 5, the control port 7, the wire 9, the wire clamper 11, and the capillary 13 are the vacuum tensioner structure 27 described above.
Is configured similarly to. On the other hand, a switching valve 31 is connected to the control port 7, and the switching valve 31 is connected to the air system pipe 15 and the vacuum system pipe 17. That is, CPU3
The signal output from 3 is transmitted to the switching valve 31 via the driver 35, so that air or vacuum is supplied to the control port 7. A vacuum tensioner structure 37 is configured with the vacuum tensioner 1, the switching valve 31, the CPU 33, and the driver 35 as main members.

The one-cycle operation of the wire bonder will be described with reference to FIG. Figure 3 shows 1 for wire bonding
It is an explanatory view showing the outline of cycle operation. (A) in the figure
In, the wire 9 is inserted into the wire clamper 11 and the capillary 13, and a ball-shaped gold ball 39 is arranged at the tip of the capillary 13. Capillary 1
Since No. 3 bonds to the first bonding point 41, it descends and tries to press the gold ball 39 to the point 41 on the chip 43. Capillary 13 descended to point 41
Moves again in the horizontal direction after rising again, starts descending toward the point 47 on the post 45 which is the second bonding point, and performs the second bonding at the point 45. This is the state of (B) in the figure. Finally, as shown in (C) in the figure, the wire 9 extended to the tip of the capillary 13
A high voltage is discharged between the electric torch 49 and the wire 9 at the lower part of the, and the heat energy causes the gold ball 39 to be formed. As described above, the operation of (A) to (B) is one cycle, but normally, these operations are repeated continuously by the required number.

FIG. 4 is an explanatory view showing the trajectory of the tip of the capillary in a time-division manner in one cycle operation. In the figure, t
₀ is the start point, t ₁ is the first bonding point, t ₃ is the second bonding point, t ₄ is the electric torch discharge, and t ₅ is the time when one cycle ends. Although a typical trajectory is used in this drawing, it is actually represented by various complicated shapes. FIG. 5 is a timing chart when the vacuum and air are supplied to the control port corresponding to the time axes t _{0 to} t ₅ shown in FIG. In this embodiment, by supplying the vacuum at between t ₀ ~t _4, it is supplied with air in between t ₄ ~t _5. That is, in the present embodiment, the point is that the vacuum and the air are alternately supplied in a fixed time period of one cycle, and the vacuum and the air may be switched at an arbitrary time t _n in FIG.

According to the vacuum tensioner structure 37 and the control method described above, it is possible to alternately supply the vacuum and the air blow to the control port 7 in one cycle of operation, so that at the nozzle opening of the vacuum tensioner 1. , Intake and exhaust will be performed alternately. As a result, nozzle clogging due to dust suction, which is a problem of the conventional method, can be solved, and at the same time, operational reliability and maintainability can be improved (maintenance free). Note that the timing of the air blowing is not particularly limited as described above, as in the time zone t ₄ ~t ₅ shown in FIG. 3 (A) (C), a state where clamper 11 is closed (i.e. Since the wire 9 is mechanically clamped), even if air blow is performed,
Since the wire 9 itself is in the same state as when it is fixed in the vacuum tensioner 1, it is expected that the most stable air blow can be obtained in this time zone.

Next, a modification of the vacuum tensioner structure 37 and control method described above will be described. In the control method by the structure 37 of the vacuum tensioner described above, the method of removing foreign matters such as dust by performing air blow in an arbitrary time zone of one cycle bonding has been described. By the way, there is a remarkable improvement in the operating speed of the wire bonder these days,
High-speed ones of 0.1 sec per cycle have also appeared. As a result, the responsiveness of the switching valve 31, the responsiveness of the fluid, or the durability of the switching valve 31 may be impaired, and the switching valve 31 may not operate as designed. Therefore,
This function can also be realized by performing air blowing once every n cycles instead of within one cycle. this is,
This is because the dust suction time from the nozzle is reduced due to the improvement of the operation speed, and therefore it can be considered equivalent even if it is performed every n cycles. Further, when the air blow time is separately inserted in this way, loss time is periodically generated. Therefore, the air blow should be performed during the work transfer time, that is, the time when the wire bond completion IC is replaced with the next IC. Is effective.

FIG. 6 is a sectional view showing a third embodiment of the structure of the vacuum tensioner of the present invention. In the example above,
The vacuum tensioner 1 has a thick nozzle 3, a thin nozzle 5,
Although the control port 7 is used, in the present embodiment, an intake port 51 is newly provided in communication with the thick nozzle 3 and the thin nozzle 5. An air filter 53 is attached to the tip of the intake port 51. The intake port 51 is sufficiently thicker than the thick nozzle 3 and the thin nozzle 5, and when vacuum is supplied to the control port 7, most of the air is sucked from the intake port 51. A vacuum tensioner structure 53 is configured with the vacuum tensioner 1, the thick nozzle 3, the thin nozzle 5, the control port 7, and the intake port 51 as main members or portions.

In the vacuum tensioner structure 53 having such a structure, since the intake port 51 is provided, the intake of air from the thick nozzle 3 and the thin nozzle 5 is reduced to a relatively negligible amount. Further, since the air filter 53 is attached to the tip of the intake port 51, the suction of dust into the vacuum tensioner 1 becomes extremely small. Structure of this vacuum tensioner 53
According to this, since the conventional vacuum tensioner 1 is provided with the intake port 51, the intake of air from the thick nozzle 3 and the thin nozzle 5, which are easily clogged, is minimized, and
Since the air filter 53 is attached to the intake port 51,
Intake of dust into the vacuum tensioner 1 is minimized. As a result, it is possible to prevent deterioration of reliability due to inhalation of dust and to realize maintenance-free at the same time. The structure 53 of the vacuum tensioner is sufficiently effective when used alone, but if the means of Examples 1 and 2 are used together, the self-cleaning effect of the air filter 53 is expected, and the most effective effect is obtained. Operation can be realized.

Next, a modification of the above vacuum tensioner structure 53 will be described with reference to FIG. FIG. 7 is a sectional view of a vacuum tensioner to which an air filter is connected via an extension tube. In this modification, the intake port 5
1 and the air filter 53 are connected by an extension tube 55 to form a vacuum tensioner structure 57.
In the vacuum tensioner structure 53 shown in FIG. 6, the air filter 53 is directly attached to the main body of the vacuum tensioner 1, which may cause an increase in weight and hinder high-speed operation. Further, even if the small air filter 53 is attached, not only a sufficient function cannot be obtained, but also in a space where dust (contamination) should not be present originally, sucked dust is discharged again by a cleaning blow. May occur. According to the structure 57 of the vacuum tensioner, the extension tube 55 is formed of a flexible material such as a silicon tube, and the dust is discharged from the air filter 53 in a sufficiently distant space, whereby the above-mentioned problems can be solved. it can.

[0018]

As described above in detail, according to the method of controlling the vacuum tensioner in the wire bonder of the present invention, when the air blow is supplied, the air in the direction opposite to the air flow at the time of vacuum is discharged, and the cleaning blow blows. Since the state is the same as when performing, the nozzle can be prevented from clogging, reliability can be improved, and cleaning blow can be performed without disassembling the vacuum tensioner, which saves maintenance labor. be able to. According to the structure of the vacuum tensioner, since the vacuum piping and the air piping are connected to the control port via the switching valve, vacuum and air blow can be alternately supplied to the control port, and intake and exhaust to the nozzle can be easily performed. it can. Further, in the structure of the vacuum tensioner in which the suction port is connected to the nozzle, most of the air is sucked from the suction port, so the suction of air from the nozzle is relatively reduced and dust is sucked from the nozzle. The probability of the occurrence of clogging is reduced, and clogging of the nozzle portion is less likely to occur.

[Brief description of drawings]

FIG. 1 is a piping circuit diagram showing a first embodiment of the structure of a vacuum tensioner of the present invention.

FIG. 2 is a piping circuit diagram showing a second embodiment of the structure of the vacuum tensioner of the present invention.

FIG. 3 is an explanatory diagram showing an outline of one cycle operation of wire bonding.

FIG. 4 is an explanatory view showing a trajectory of a capillary tip point in one cycle operation in a time division manner.

5 is a timing chart when vacuum and air are supplied to the control port corresponding to the time axes t _{0 to} t ₅ shown in FIG. 4.

FIG. 6 is a sectional view showing a third embodiment of the structure of the vacuum tensioner of the present invention.

FIG. 7 is a sectional view of a vacuum tensioner to which an air filter is connected via an extension tube.

[Explanation of symbols]

 1 Vacuum Tensioner 3 Thick Nozzle (Nozzle) 5 Fine Nozzle (Nozzle) 7 Control Port 9 Wire 15 Air Piping 17 Vacuum Piping 27, 37, 53, 57 Vacuum Tensioner Structure 31 Switching Valve 33 Wire Bonder CPU 51 Suction Port

Claims (5)

[Claims] 1. A method of controlling a vacuum tensioner in a wire bonder, comprising: supplying a vacuum to a vacuum tensioner having a nozzle through which a wire is inserted, and holding the wire in the nozzle by the vacuum. A method of controlling a vacuum tensioner in a wire bonder, characterized in that air blow in the opposite direction is supplied to the nozzle at an arbitrary timing. 2. The method for controlling a vacuum tensioner in a wire bonder according to claim 1, wherein the air blow is supplied to the vacuum tensioner at a preprogrammed timing. 3. A vacuum tensioner structure having a control port for supplying vacuum to a nozzle, wherein one of two or more switching valves is connected to the control port, and a vacuum pipe and an air pipe are connected to the control port. A vacuum tensioner structure characterized in that the vacuum tensioner is connected to the other of the switching valves so as to be selectively switchable. 4. A wire bonder CPU for controlling the switching valve is connected to the switching valve so that vacuum and air blow are alternately supplied to the vacuum tensioner based on programmed timing. The structure of the vacuum tensioner described. 5. A structure of a vacuum tensioner, wherein an intake port dedicated to air intake is provided in communication with the nozzle.