JP2003218173A - Tape bonder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that bonding can not be carried out when a conductive tape is brought into contact with an undesired part where ultrasonic vibration is imparted at the time of pressurizing and connecting the conductive tape of a large cross sectional area with inferior flexibility by a bonding tool to which an ultrasonic connection is imparted. <P>SOLUTION: A tape bonder is provided with a rod 14 to which the ultrasonic vibration is imparted to be vertically moved and horizontally moved, a tape guide 15 for guiding the conductive tape 8 so as not to be in contact with a part excluding the lower end of the rod 14 and supplying it to the lower part of the rod 14, and a cutter 10 for cutting the conductive tape 8 connecting first and second conductive parts. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape bonder for electrically connecting first and second conductive parts with a wide conductive tape.

[0002]

2. Description of the Related Art In an electronic component (semiconductor device) in which an electronic component body such as a semiconductor pellet and a lead externally connected are internally connected by a wire, the thickness of the wire is appropriately set according to the operating current. Capillaries and wedges are generally used as a bonding tool for connecting the wires, and the bonding is performed by a thermocompression bonding method, an ultrasonic bonding method, or a combination thereof. To be done.

On the other hand, the conduction resistance of the semiconductor device is determined by the series resistance of each element including the lead, wire, and semiconductor pellet, and the maximum allowable current is determined by this, so if the resistance locally increases, heat is generated at that portion. However, this heat generation not only increases the resistance and limits the operating current value, but also causes the wire to melt due to heat generation. It is also important. Further, when the electrode on the semiconductor pellet spreads in a plane and a wire is connected to one point on the electrode, a current passing through the semiconductor pellet moves in the surface direction of the electrode thin film and flows into the wire.

Therefore, there is a problem that the reduction of the on-resistance of the semiconductor device is limited even if the on-resistance of the semiconductor pellet itself is reduced.

In order to solve such a problem, a plurality of thick wires are connected in parallel, or instead of the wires, a wide conductive tape or a conductive member obtained by processing a thin metal flat plate by etching or punching is used to form a semiconductor pellet. It is known to electrically connect with leads. (See, for example, JP-A-64-35922, JP-A-11-354702, and JP-A-2000-114445.) In the method of connecting a plurality of wires in parallel, it is difficult to handle a thick wire and it takes time for bonding. There is a problem that when the wire and the bonding tool rub against each other, the wire is scraped and a conductive foreign substance is generated, and the semiconductor pellet and the lead are connected by using a conductive member formed by cutting the conductive tape or punching a metal flat plate. However, it is necessary to electrically connect each connection part by using viscous conductive adhesive or spot welding, which makes it difficult to control the supply amount and viscosity of the adhesive, When this occurs, a short circuit or withstand voltage decrease may occur. Further, in the case where one end of the lead is extended to above the semiconductor pellet and directly connected by using a conductive adhesive, there is a problem that positioning of the semiconductor pellet and the lead is complicated.

On the other hand, there is known a tape bonder in which a conductive tape made of aluminum or its alloy is directly connected to a semiconductor pellet by using a bonding tool. Figure 4
Shows an example. In the figure, reference numeral 1 is a horn that fixes an ultrasonic transducer 2 at one end and transmits the ultrasonic vibration generated by the ultrasonic transducer 2 in the axial direction, and has both ends around an axis 3 fixed at an intermediate position in the axial direction. Rotates. The shaft 3 is pivotally supported by a box-shaped support 4 mounted on a moving mechanism 5 that horizontally moves in at least one direction. 6 is a bonding tool (rod) fixed to the other end of the horn 1, 7 is a conductive tape 8
It is mounted on a rotary shaft 9 which is supported by a support body 4 and is arranged above the horn 1 by a reel wound around the. The conductive tape 8 fed from the reel 7 passes through a through hole 1a obliquely penetrating the middle portion of the horn 1, and a tip is bonded through a guide hole 6a formed from the side wall of the bonding tool 6 toward the lower end. It extends below the tool 6. A mechanism for guiding the conductive tape 8 and a mechanism for clamping the conductive tape 8 are attached to the moving path of the conductive tape 8, but they are not shown. Reference numeral 10 denotes a cutter that is supported by an arm 11 extending from the support body 4 and moves up and down in the vicinity of the bonding tool 6 by an elevating mechanism (not shown).

In this apparatus, as shown in FIG. 5, the bonding tool 6 is arranged on the electrode 12a on the upper surface of the semiconductor pellet 12, and the conductive tape 8 is pressed against the electrode 12a while applying ultrasonic vibration to the conductive tape 8. Electrically connect one end. Then, as shown in FIG. 6, the bonding tool 6 is raised and horizontally moved to be positioned on the lead 13. Since one end of the conductive tape 8 is fixed to the semiconductor pellet 12, when the bonding tool 6 moves, the intermediate portion of the conductive tape 8 fed from the reel 7 is positioned on the lead 13. Next, the bonding tool 6 is lowered, and the conductive tape 8 is pressed onto the leads 13 while applying ultrasonic vibration, whereby the conductive tape 8 and the leads 13 are electrically connected. After connecting the semiconductor pellet 12 and the lead 13 in this way, the bonding tool 6 is slightly moved to position the cutter 10 on the non-connecting portion 8a of the conductive tape 8 as shown in FIG. 7, and the cutter 10 is lowered. Then, the notch 8b is formed in the conductive tape 8. Next, the conductive tape 8 is clamped, the bonding tool 6 is moved horizontally, the conductive tape 8 is cut off from the notch portion 8b, the bonding tool 6 is raised, and the bonding tool 6 is moved above the next semiconductor pellet. . Since the tip portion of the conductive tape 8 is located at the lower end of the bonding tool 6, the next bonding work can be immediately started.

[0008]

By the way, when a plurality of wires are connected in parallel, the wire load on the bonding tool 6 is not a problem because the diameter of each wire is small, but it causes heat generation. Since the conductive tape 8 having a cross-sectional area, that is, a width and a thickness so that the electronic component can operate at the maximum current even in a high temperature state loses flexibility like a thin wire, it contacts the side wall of the bonding tool 6 or the like. Then, there is a problem that it becomes an obstacle to ultrasonic vibration and affects the bondability.

Therefore, the conductive tape 8 may be guided so as not to come into contact with an undesired portion of the bonding tool 6, but the conductive tape 8 wound on the reel 7 is curled and the unwound conductive tape 8 is moved. Even if it was molded on the way, the curled state could not be completely corrected, and it was difficult to draw the conductive tape 8 around the bonding tool 6 without contacting it.

[0010]

Means for Solving the Problems The present invention has been proposed for the purpose of solving the above-mentioned problems, and includes a rod which is vertically moved and horizontally moved above the first and second conductive portions to which ultrasonic vibration is applied. , A tape guide that guides the conductive tape so that it does not come into contact with the portion other than the lower end of the rod and supplies the tip of the conductive tape to the lower part of the rod, and a conductive tape that electrically connects the first and second conductive portions. A cutter for cutting is provided to connect the first conductive portion to the second conductive portion while applying ultrasonic vibration while pressing the tip of the conductive tape at the lower end of the rod to the first conductive portion. After connecting by applying ultrasonic vibration while pressurizing the intermediate part with the rod, the rod is moved to the outside of the second conductive part, and at the intermediate position between the lower end position of the rod and the connecting part position of the second conductive part. Cut the conductive tape first,
Provided is a tape bonder characterized by electrically connecting a second conductive portion.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The tape bonder according to the present invention is
Ultrasonic vibration is applied so that the conductive tape can be bonded even with a large cross-sectional area by guiding the conductive tape so that it does not come into contact with the parts other than the lower end of the rod that moves vertically and horizontally above the first and second conductive parts. Specifically, the conductive tape is attached to the rod from a direction intersecting the vibration direction of the ultrasonic vibration applied to the rod or an extension direction connecting the rod and the ultrasonic vibration source that applies the ultrasonic vibration to the rod. It is designed to be supplied below. The conductive tape is fed along a line connecting the first and second conductive portions, and the rod moves on the conductive tape. When forming a step at the lower end of the rod to form an inclined tape guide between the side wall of the rod and the lower surface of the step, an inclined guide groove is formed from the side wall of the rod to the lower surface of the step. By arranging the guide members facing each other and fixing the guide members to a supporting member to which ultrasonic vibration is not applied, even if the conductive tape comes into contact with the guide member during bonding, the bonding property of the bonding tool is not affected. it can. This tape bonder can be applied to the manufacture of electronic components in general, but when applied to a semiconductor device, it can be applied to a semiconductor device for high power generation accompanied by heat generation because the ON resistance of the semiconductor device including the resistance of the conductive tape can be reduced. be able to.

[0012]

Embodiments Embodiments of the present invention will be described below with reference to FIGS. In the figure, the same parts as those in FIG. 4 are designated by the same reference numerals, and duplicated description will be omitted. Similar to the tape bonder shown in FIG. 4, the tape bonder according to the present invention has an ultrasonic transducer 2 fixed to one end of a horn 1 and a bonding tool (rod) 14 fixed to the other end thereof, and the horn 1 is rotated at an intermediate position in the axial direction. It is axially supported by the support body 4 via the shaft 3. The support 4 is horizontally moved in at least one direction by the moving mechanism 5.
Therefore, the bonding tool 14 can be moved vertically and horizontally in at least one direction. The horn 1 of this device does not have a through hole for inserting the conductive tape 8, and the bonding tool 14 has no hole for inserting and guiding the conductive tape.

The reel 7 around which the conductive tape 8 is wound is mounted on the rotating shaft 9 supported by the support body 4. The conductive tape 8 unwound from the reel 7 extends non-parallel to the horn 1 and is It is guided below the bonding tool 14 from the side. A guide mechanism 15 is arranged near the bonding tool 14 and guides the tip of the conductive tape 8 below the bonding tool 14, and is connected to the arm 11 extending from the support 4. Therefore, except that the conductive tape 8 contacts the lower end of the bonding tool 14,
It does not come into contact with an undesired portion of the horn 1 or the bonding tool 14 to which ultrasonic vibration is applied.

As described above, in the tape bonder according to the present invention, the conductive tape 8 is not connected to the horn 1 so that the conductive tape having a larger cross-sectional area than the bonding wire and less flexibility does not hinder the ultrasonic vibration applied to the horn 1. The point that they are extended in parallel is significantly different from the device in FIG. This device has a cutter 10 as in the device shown in FIG. 4, and is further provided with a clamp mechanism for the conductive tape 8 although not shown.

The operation of this device will be described below. First,
The bonding tool 14 is arranged on the first conductive portion, for example, the electrode 12 a of the semiconductor pellet 12. At this time, the direction of the horn 1 is the feeding direction of the conductive tape 8, that is, the line connecting the bonding tool 14 and the reel 7 is the first and the second.
It is set so as to pass through the conductive parts 12 and 13. In this state, the horn 1 is swung and the tip of the conductive tape 8 is pressed and connected to the first conductive portion 12a at the lower end of the bonding tool 14 to which ultrasonic vibration is applied. Next, when the bonding tool 14 is raised and the horn 1 is moved in one direction, the conductive tape 8 whose tip is fixed to the first conductive portion is fed out from the reel 7, and the bonding tool 14 is passed through the conductive tape 8. The lower end of 14 is located on the second conductive portion 13. Following this, the bonding tool 14 to which ultrasonic vibration is applied is lowered to connect the intermediate portion of the conductive tape 8 to the second conductive portion 13. After electrically connecting the first and second conductive parts 12a and 13 with the conductive tape 8 in this way, the bonding tool 14 is slightly raised to be separated from the conductive tape 8 and moved outward to move the cutter 10 Is stopped on the unconnected portion of the conductive tape 8, the movement is stopped and the cutter 10 is moved up and down to form a notch in the conductive tape 8. After that, when the bonding tool 14 is further moved outward, the conductive tape 8 is pulled off from the notch portion, and the new tip portion of the conductive tape 8 is positioned below the bonding tool 14. Furthermore, when the bonding tool 14 is moved onto the new first conductive portion 12a, the initial state is restored,
By repeating the above operation, the bonding work can be continued.

As described above, the tape bonder according to the present invention has the conductive tape 8 which is inferior in flexibility during the bonding work.
Since it does not come into contact with an undesired portion such as the horn 1 or the bonding tool 14 to which ultrasonic vibration is applied, stable bonding is possible even with the conductive tape 8 having a large cross-sectional area. Further, the guide mechanism 15 for guiding the tip of the conductive tape 8 to the lower side of the bonding tool 14 is not only fixedly arranged near the bonding tool 14, but also movably arranged so as to be close to and separated from the bonding tool 14. While the tip of the conductive tape 8 is being pressed by the bonding tool 14, the guide mechanism 1
5 is moved horizontally to the side of the second conductive portion 13 and the middle portion of the conductive tape 8 is molded substantially horizontally, and then the bonding tool 1
It is also possible to raise 4 and move it to the position of the second conductive portion 13. By making the guide mechanism 15 movable in this manner, good bonding can be achieved even with the inflexible conductive tape 8 having a larger cross-sectional area, which is suitable as a tape bonder for a high-power semiconductor device.

Similar to the conventional apparatus shown in FIG. 4, in the above embodiment, the feeding direction of the conductive tape 8 is limited to one direction. Therefore, a diode or the like in which the arrangement direction of the first and second conductive portions is limited to one direction can be used without any trouble.
On the other hand, when the conductive tapes such as transistors are not parallel to each other, the problem can be solved by arranging a plurality of tape bonders by making the conductive tapes 8 different from each other.

When the number of the first and second conductive portions is large and the conductive tape is fed in various directions as in the semiconductor integrated circuit device, the moving mechanism 5 for horizontally moving the horn 1 is placed in the horizontal plane. It suffices to additionally provide a rotation mechanism for rotating with.

In the above embodiment, the conductive tape 8 is guided to the lower side of the bonding tool 14 through the side of the horn 1, but the conductive tape 8 is guided to the lower side of the bonding tool 14 from the extension direction of the horn 1. Good. In this case, the cutter 10 may be arranged below the horn 1 inside the bonding tool 14.

Further, the diameter of the bonding tool 14 needs to be increased according to the cross-sectional area of the conductive tape 8. In this case, a step is formed at the lower end of the bonding tool 14 so as to make contact with the conductive tape 8. The area of the lower end of the tool 14 can be reduced, and ultrasonic vibration can be concentrated on the bonding portion to increase the pressure.

When the bonding tool 14 is moved after being connected to the first conductive portion, the step can prevent the intermediate portion of the conductive tape 8 from coming into contact with the bonding tool 14 and move the bonding tool 14 horizontally. At this time, it is not necessary to raise it high, and it is possible to prevent the bonding tool 14 from coming into contact with the conductive tape 8 and scraping it to generate a conductive foreign substance.

The present invention is not limited to the above embodiments, but can be applied not only to semiconductor devices, but also to general electronic components whose inside is connected by a conductive tape.

[0023]

As described above, according to the present invention, since a conductive tape having a large cross-sectional area and poor flexibility can be stably bonded, continuous bonding work can be performed using a continuous conductive tape, and etching or etching can be performed. The present invention can also be applied to electrical connection of high current operation electronic components that must be connected by using a conductive member processed by pressing, and the number of work steps can be significantly reduced and stable bonding can be performed.

[Brief description of drawings]

FIG. 1 is a side sectional view of a tape bonder according to the present invention.

FIG. 2 is a plan view of FIG. 1 tape bonder.

FIG. 3 is a front view of FIG. 1 tape bonder.

FIG. 4 is a side sectional view of a conventional tape bonder.

FIG. 5 is an enlarged side sectional view of an essential part showing the operation of the tape bonder in FIG.

FIG. 6 is an enlarged side sectional view of an essential part showing the operation of the tape bonder following the state of FIG. 5;

FIG. 7 is an enlarged side sectional view of an essential part showing the operation of the tape bonder following the state of FIG. 6;

[Explanation of symbols]

1 horn 4 support 7 reel 8 Conductive tape 10 cutters 12a First conductive portion 13 Second conductive part 14 Bonding tool (rod) 15 Guide mechanism

Claims (6)

[Claims] 1. A rod which is vertically moved and horizontally moved above the first and second conductive portions to which ultrasonic vibration is applied, and the conductive tape is guided so as not to come into contact with a portion other than the lower end of the rod. The rod guide is provided with a tape guide for supplying the tip portion below the rod and a cutter for cutting the conductive tape electrically connecting the first and second conductive portions. After applying ultrasonic vibration while pressing at the lower end and connecting, moving the rod onto the second conductive part and applying ultrasonic vibration while connecting the middle part of the conductive tape with the rod and connecting, To the outside of the second conductive portion and cut the conductive tape at an intermediate position between the lower end position of the rod and the connecting portion position of the second conductive portion to electrically connect the first and second conductive portions. Tape bonder characterized by. 2. The tape bonder according to claim 1, wherein the conductive tape is supplied below the rod from a direction intersecting a vibration direction of ultrasonic vibration applied to the rod. 3. The tape bonder according to claim 2, wherein the conductive tape is fed along a line connecting the first conductive portion and the second conductive portion. 4. The tape bonder according to claim 1, wherein the conductive tape is supplied below the rod in an extension direction connecting the rod and an ultrasonic vibration source that applies ultrasonic vibration to the rod. 5. The tape bonder according to claim 1, wherein a step portion is formed at the lower end of the rod. 6. The tape bonder according to claim 1, wherein the electrodes on the semiconductor pellet and the leads are connected by a conductive tape.