JPH10256299A - Wire-bonding method and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent overlap of minute faces to be connected by positioning a bonding wire in a prescribed direction by a suction or spray operation by a hole communicated with the almost central part of a capillary press-fitting face and press-fitting and connecting the wire to the connected part. SOLUTION: The tip part of a bonding wire 3 which is inserted and supplied through a wire passing hole 2 is sucked and acquired by a press-fitting face 4 of a main body 1 by the suction operation of a suction hole 8 in the capillary main body 1. Since the suction hole 8 opens to the almost central part of the press-fitting face 4, it is sucked and acquired along the supply extension line of the wire 3 by the suction operation of the suction hole 8. Even if the direction of the wire 3 which is inserted and supplied through the passing hole 2 is shifted slightly, it is forcibly sucked and acquired along the almost central line of the press-fitting face 4, and it is press-fitted and connected on the connected part face. Thus, shorting by a wire bonding between the adjacent connected parts can be avoided completely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wire bonding method and a wire bonding apparatus.

[0002]

2. Description of the Related Art On a lead frame or wiring board surface,
2. Description of the Related Art A semiconductor device configured by mounting and mounting a semiconductor chip such as an IC element is widely and practically used as an electronic component or a circuit element. In the structure of this type of semiconductor device, a semiconductor chip is mounted at a predetermined position on a lead frame or a wiring board, and, on the other hand, bonding pads previously arranged and formed around a region where the semiconductor chip is mounted. The surface and the electrode terminals on the semiconductor chip surface are bonded (connected) with an Al wire or an Au wire.

That is, a semiconductor chip such as an IC element is mounted on a lead frame or a wiring board in which a mounting agent or the like is previously applied to and adhered to a predetermined area surface.
Place and fix on the bonding stage surface. Then, by the operation of the bonding tool (capillary) of the so-called bonding apparatus, the supply of the bonding wire
Positioning is performed, and the bonding wire is pressed (pressed) and cut on the surface to be connected on the crimping surface of the capillary.
By the repetitive operation of the pressure bonding / cutting, wire bonding is performed between the bonding pads of the lead frame or the wiring board and the corresponding electrode terminals of the semiconductor chip to perform electrical connection.

FIG. 5A is a perspective view showing the configuration of the capillary used for the wire bonding on the crimping surface side, and FIG. 5B is a perspective view schematically showing the mode of wire bonding. It is. In FIGS. 5 (a) and 5 (b), 1
Is a capillary main body, 2 is provided in the capillary main body 1, and a wire passage hole for guiding the bonding wire 3, and 4 is a bonding surface of the capillary body 1 to which the bonding wire 3 supplied through the wire passage hole 2 is connected. This is a crimping surface to be crimped by a load and ultrasonic waves (or heating). Here, the crimping surface 4 of the capillary body 1 bends and bonds the bonding wire 3 to the surface to be connected, clamps the bonding wire 3 and cuts it at the supply side 4a.

[0005]

However, the above-mentioned wire bonding means has the following practical problems. That is, the wire bonding is performed in accordance with FIG.
In (a) to (f), the embodiment is performed as schematically shown. First, as shown in a side view in FIG. 6A, after mounting a semiconductor chip 6 on, for example, a wiring board 5, a wire bonding apparatus is applied to an electrode pad 6a (a surface to be connected) of the semiconductor chip 6. It drives and positions the crimping surface 4 of the capillary main body 1. On the other hand, in a state where the bonding wire 3 is clamped by the clamp 7, the tip of the bonding wire 3 guided / supplied through the through-hole 2 is applied to the electrode pad 6 a by the load of the capillary body 1 and ultrasonic waves (or heating). Crimp on the surface.

Next, the capillary body 1 is connected to the wiring board 5.
Is moved to the connection pad 5a (the surface to be connected), and the crimping surface 4 of the capillary body 1 is positioned on the connection pad 5a. On the other hand, while the bonding wire 3 is clamped by the clamp 7, the wire passing hole 2 is guided and guided. The supplied bonding wire 3 is pressed against the surface of the connection pad 5a by the load of the capillary body 1 and ultrasonic waves (or heating).

After that, as shown in FIG.
Bonding wire 3 crimped and connected to connection pad 5a surface
6C, the cut end of the bonding wire 3 is fed out to the crimping surface 4 side of the capillary body 1, and the crimping surface 4 of the capillary body 1 is connected to the semiconductor as shown in FIG. The step of aligning the chip 6 with another electrode pad 6a and crimping the chip is repeated.

When the cut end of the bonding wire 3 is fed out to the crimping surface 4 side of the capillary body 1 after crimping, connecting and disconnecting the connection pad 5a,
The cut end (tip) of the bonding wire 3 is shown in FIG.
As shown in the plan view of FIG. 6D, it is sufficient that the capillary body 1 is located at the center of the crimping surface 4 of the capillary body 1. However, as shown in plan views of FIGS. Cases often happen. If the crimping is performed on the connected surfaces 5a and 6a while the positions are misaligned, abnormal deformation of the crimped portion and protrusion or connection from the connected surfaces 5a and 6a may occur. It becomes a problem in miniaturization or miniaturization. In other words, when the connected surfaces 5a and 6a are miniaturized and the pitch is reduced due to the miniaturization and high capacity of the semiconductor chip or the like, the reliability of the connection may be impaired. Absent.

The present invention has been made in view of such circumstances, and has as its object to provide a wire bonding method and a wire bonding apparatus capable of mass-producing a highly reliable semiconductor device.

[0010]

According to a first aspect of the present invention, there is provided a method for supplying a bonding wire to a surface to be connected through a wire-passing hole, and bonding the bonding wire supplied to the surface to be connected to substantially the center of the crimping surface. A wire bonding method comprising the steps of: positioning by suction / suction or gas blowing of a hole communicating with a hole; and crimping the positioned bonding wire to a surface to be connected.

According to a second aspect of the present invention, in the wire bonding method of the first aspect, the step of positioning the bonding wire is performed by optimizing the strength of suction / suction or gas blowing depending on the strength of the bonding wire. I do.

According to a third aspect of the present invention, there is provided a wire through hole for guiding a bonding wire, a crimping surface for crimping a bonding wire supplied through the wire through hole to a surface to be connected, and a substantially central portion of the crimping surface. And a hole provided with a hole for adsorbing or blowing a bonding wire.

According to a fourth aspect of the present invention, in the wire bonding apparatus according to the third aspect, the hole for sucking or blowing the bonding wire of the capillary is provided in a predetermined direction with respect to the extending direction of the bonding wire supplied through the wire passage hole. Having a length of

In the above invention, the opening of the hole for sucking / sucking the bonding wire may have a size enough to sufficiently suck the bonding wire, and the opening shape thereof is circular, elliptical, square, or rhombic. Any of these may be used, but an elliptical shape, a rectangular shape, or the like along a line through which the bonding wire is extended and supplied is preferable. Further, a suction hole or a gas blowing hole connected to the opening surface,
It may be extended along the axial direction of the capillary main body, or may be configured to be led out to the side of the capillary main body.

According to the first and second aspects of the present invention, since the bonding wire is sucked or blown and positioned in a certain direction by the hole communicating with the substantially central portion of the capillary crimping surface, and is crimped and connected to the portion to be connected. Necessary wire bonding can be easily performed without causing protrusion or the like to a minute connected surface. That is, highly reliable electrical connection can be performed constantly and mass-produced with a fine pitch and for a fine electrode pad or connection pad.

According to the third and fourth aspects of the present invention, a highly reliable electrical connection can be made to a fine pitch and a fine electrode pad or connection pad, and the semiconductor device can be manufactured with high yield. Equipment can be mass-produced.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, FIGS. 1A to 1C and FIG.
The present invention will be described with reference to (a) and (b) and FIGS.

FIGS. 1 (a) to 1 (c) show a main part of a capillary provided in a wire bonding apparatus according to one embodiment. FIG. 1 (a) is a front view, and FIG. FIG. 1 (c) is a perspective view schematically showing a configuration of the crimping surface side, and FIG. 1 (c) is a perspective view schematically showing a bonding wire supply mode. Fig. 1 (a)-(c)
In the figure, reference numeral 1 denotes a capillary main body, 2 denotes a diameter provided on the capillary main body 1 and guides a bonding wire 3 (for example, an Au wire or an Al wire) having a diameter of about 20 to 100 μm.
It is a through-hole of about 50 to 150 μm. Reference numeral 4 denotes a crimping surface for press-bonding the bonding wire 3 supplied through the wire-through hole 2 to the surface to be connected by the load of the capillary body 1 and ultrasonic (or heating), and 8 denotes one end of the crimping of the capillary body. At the approximate center of the surface 4, the other end communicates with a vacuum system (or a reduced pressure system) with a diameter of 20 to 150μ
The suction hole is about m.

Here, the crimping surface 4 of the capillary body 1
Is to suck and position the supplied bonding wire 3 in a certain direction by the vacuum suction action of the suction hole 8 and, after clamping the bonding wire 3, bend and press-bond it to the surface to be connected. Has the function of cutting the bonding wire 3 on the supply side 4a.

Next, an example of wire bonding by a wire bonding apparatus having the above-mentioned capillary (bonding head) will be described.

FIGS. 2A and 2B schematically show an embodiment in which an Au wire is wire-bonded to an electrode pad surface of a semiconductor chip, for example. Au inserted and supplied through wire hole 2
The distal end of the wire 3 is attracted to the crimping surface 4 of the capillary body 1 by the suction action of the suction hole 8 of the capillary body 1.
Supplemented. At this time, since the suction hole 8 is opened substantially at the center of the crimping surface 4 of the capillary body 1, the suction operation of the suction hole 8 causes the suction and supplement along the supply extension line of the Au wire 3.

That is, even if the direction of the Au wire 3 inserted / supplied through the hole 2 through the wire is slightly shifted, as shown in a plan view in FIG. It is forcibly sucked / supplemented and crimped / connected to the surfaces to be connected 5a and 6a. As described above, the Au wire 3 can be crimped and connected to the surfaces of the connected portions 5a and 6a without causing a displacement or the like, so that a short circuit due to wire bonding between the adjacent connected portions 5a or 6a can be completely avoided or eliminated. You.

The connected part 5a by this wire bonding
Or that the short circuit between 6a is completely avoided or eliminated, providing a highly reliable semiconductor device, improving the yield and productivity of the highly reliable semiconductor device, and in particular,
A great advantage is brought about in the miniaturization of the surfaces of the connected parts 5a and 6a and the fine pitch of the connected parts 5a and 6a. For example, a conventional wire bonding method (or a wire bonding apparatus) is used for the generation of a defective rate such as a short circuit due to a positional shift (tail swing) and for a large number of connected parts due to miniaturization.
Table 1 and Table 2 show the comparison between the wire bonding according to the present invention and the wire bonding according to the wire bonding method (or the wire bonding apparatus) according to the present invention.

[0024] FIG. 4 shows the above results in a curve, and shows the occurrence of a defective rate such as a short circuit due to a displacement (tail swing) by a curve A (Example).
And a curve a (conventional example), and a curve B (example) and a curve b (conventional example) respectively show the formation of multiple connected parts by miniaturization.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention. For example, the surface size of the connected part, the pitch of the connected part, or the material of the bonding wire is Au.
Similar functions and effects can be obtained by changing from Al to Al.

In the configuration of the wire bonding apparatus, one end has a circular opening substantially at the center of the crimping surface 4 of the capillary body, and the other end has a diameter of 20 mm communicating with the air compression system.
Except for using an air blowout hole of about 100 μm, even when the same configuration was adopted, highly accurate and highly reliable wire bonding was possible. That is, in this embodiment, the bonding wire supplied and led out to the capillary main body crimping surface 4 is attracted to the center of the air blowing opening by the Bernoulli action of the blown air, and can be easily bonded to a predetermined position. .

[0027]

According to the first aspect of the present invention, required wire bonding can be easily performed without incurring protrusion or the like to a minute connected surface. In other words, a highly reliable electrical connection can be easily performed with a fine pitch, fine electrode pads and connection pads, etc.
And it can be performed in mass production.

According to the second aspect of the present invention, fine pitch,
Since highly reliable electrical connection or the like is easily performed for minute electrode pads or connection pads, high-performance semiconductor devices with high yield can be mass-produced.

[Brief description of the drawings]

FIG. 1 shows an example of a configuration of a main part of a capillary provided in a wire bonding apparatus according to the present invention, wherein (a) is a front view, (b) is a perspective view, and (c) is a mode in which a bonding wire is supplied. FIG.

FIG. 2 schematically shows an embodiment of the wire bonding method using the capillary shown in FIG. 1;
FIG. 4B is a side view showing a state at the time of starting the supply of the bonding wire, and FIG. 4B is a side view showing a state in which the tip end of the bonding wire is suction-supplied to the crimping surface.

FIG. 3 is a plan view showing a state in which a tip end of a bonding wire is suction-supplied to a crimping surface of the capillary shown in FIG. 1;

FIG. 4 is a characteristic diagram showing a relationship between a connection portion size and a connection failure occurrence rate and a relationship between a connection portion size and a pitch by the wire bonding method according to the present invention and the conventional wire bonding method, respectively.

FIGS. 5A and 5B show a main configuration of a capillary provided in a conventional wire bonding apparatus, wherein FIG. 5A is a perspective view, and FIG.
FIG. 3 is a perspective view showing a mode of supplying a bonding wire.

FIG. 6 schematically shows an embodiment using a conventional wire bonding apparatus, in which (a) a side view showing a state in which wire bonding is performed on an electrode pad surface and a connection pad surface, and (b) cutting after bonding a bonding wire; Side view of the state,
(c) is a side view of the state in which the bonding wire is extended,
(d) is a side view of the state where the tip of the bonding wire is aligned with the connected part surface in a fixed position, and (e) and (f) are the positions where the tip of the bonding wire is aligned with a fixed position on the connected part surface. The side view of the state which did not exist.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Capillary main body 2 ... Wire through hole (guide hole) 3 ... Bonding wire 4 ... Crimp surface 4a ... Bonding wire supply side 5 ... Wiring board 5a ... Connection pad 6 ... Semiconductor chip 6a ... Electrode pad 7 ... Clamp 8 ... Suction hole

Claims (4)

[Claims] 1. A step of supplying a bonding wire to a surface to be connected through a wire passing hole, and suctioning / adsorbing or blowing a gas through a hole communicating the bonding wire supplied to the surface to be connected to substantially the center of the crimping surface. A wire bonding method, comprising: positioning by an action; and crimping the positioned bonding wire to a surface to be connected. 2. The wire bonding method according to claim 1, wherein the step of positioning the bonding wire is performed by optimizing the strength of suction / suction or gas blowing depending on the strength of the bonding wire. 3. A wire passing hole for guiding a bonding wire, a crimping surface for crimping a bonding wire supplied through the wire passing hole to a surface to be connected, and a substantially central portion of the crimping surface, and A wire bonding apparatus comprising: a capillary having a hole for sucking or blowing a bonding wire. 4. The capillary according to claim 3, wherein the hole for sucking or blowing the bonding wire of the capillary has a predetermined length in the extending direction of the bonding wire supplied through the wire passage hole. Wire bonding equipment.