JP3086124B2 - Method and apparatus for forming bonding bump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for forming a bump on an electrode of a semiconductor chip or a lead portion bonded to the electrode when manufacturing a semiconductor device.

[0002]

2. Description of the Related Art In manufacturing a semiconductor device, bonding of an electrode of a semiconductor chip to an external lead portion via a bump is performed. For example, TAB (Tape Automate
In the d bonding method, as shown in FIG. 6, an inner lead 23 aligned with the position of the electrode 22 on the semiconductor chip 21 is formed on a tape-shaped insulating film 24, and a bump 25 made of Au or the like is formed thereon. They are interposed and joined together by thermocompression bonding.

Such bumps are formed in advance on a lead portion such as an electrode of a semiconductor chip or an inner lead of a TAB, and the semiconductor chip having the bump and the TAB are formed in advance.
B tape or the like or a semiconductor chip and a TAB tape having bumps or the like are overlapped and bonded by collective joining. At the time of bonding, in the case of the Au bump, the Au bump itself is compressed by thermocompression bonding to join them. There is also a method in which a bump having a low melting point metal such as solder is formed and joined by reflow (remelting). As means for forming the bumps, there are a vapor deposition method, a plating method, a metal ball method, and the like, and a metal ball method capable of forming a bump having a required thickness by a relatively simple means has attracted attention.

As a method of forming a bump by the metal ball method, Japanese Patent Application Laid-Open No. 62-25435 discloses a method in which a metal ball is set in a hemispherical concave portion formed at a predetermined position on a transparent plate, and a chip is mounted thereon. It is disclosed that a metal ball is fused to a predetermined portion of a chip by reflow.

[0005]

As the scale and density of integrated circuits such as LSIs and VLSIs increase, the number of electrodes on a semiconductor chip has increased dramatically, and the pitch between the electrodes has become narrower. Therefore, there are the following problems when bumps are formed on all the electrodes of such a semiconductor chip, or on all the lead portions of a TAB, a lead frame or a printed circuit board to be connected to the electrodes.

First, for a large number of electrodes of a semiconductor chip to be joined together as described above, the bumps must have a predetermined height and the height must be uniform. If the bump height is insufficient, the required bonding strength cannot be obtained, and if the height is not uniform, there is a risk of poor bonding at low bump locations and chip damage at high bump locations. is there. In this regard, the metal ball method is superior to the vapor deposition method and the plating method since a bump having a uniform predetermined height can be formed by selecting and using metal balls having a required diameter and a uniform size.

Next, the metal balls must be precisely arranged and joined to a large number of narrow-pitch electrodes and leads as described above. More specifically, alignment displacement accuracy of 5 μm or less is often required.
Japanese Patent Application Laid-Open No. Sho 62-25435 discloses a method in which metal balls are arranged on a transparent plate, a semiconductor chip is stacked thereon, and bumps are formed on the chip. It does not describe the alignment between the joint and the metal ball.

According to the present invention, a metal ball is arranged with high precision on a large number of electrodes having a narrowed pitch even if the integrated circuit such as an LSI or an VLSI is a large-scale and high-density semiconductor chip. Then, bumps having a uniform predetermined height are formed, and the same bumps are formed by arranging them in the same way on the TAB to be connected to the electrodes of such a semiconductor chip, the lead frame or the lead portion of a printed circuit board or the like. To provide a method and apparatus for the same.

[0009]

According to the present invention, there is provided a method of forming a bump on a predetermined portion of a bump forming member comprising an electrode of a semiconductor chip or a lead portion bonded to the electrode. When arranging metal balls on an array substrate and overlapping the substrate and the bump forming member and pressing the metal balls on the substrate at predetermined positions of the bump forming member to form bumps, After arranging the arrangement substrate and the bump forming member in a positional relationship facing each other with a transparent reference plate having a marker therebetween, and adjusting the position by separately observing the arrangement substrate and the bump forming member through the reference plate, Retracting the transparent reference plate, and overlapping and pressing the bump forming member and the arrayed substrate, thereby forming a bonding bump. That.

The device of the present invention for achieving the above object comprises three inventions. The first invention is to form a bump on a predetermined portion of a bump forming member comprising a semiconductor chip electrode or a lead portion bonded to the electrode. An apparatus for forming, comprising: an array substrate on which metal balls are arrayed; a first goniometer for holding and adjusting the position of the substrate; a first guide rail for moving the goniometer; A second goniometer for holding and adjusting the position of the member, a second guide rail for moving the goniometer, a transparent reference plate having a marker disposed between the array substrate and the bump forming member, and a mechanism for moving the reference plate A first microscope disposed above the reference plate and observing the array substrate through the reference plate; a first microscope disposed below the reference plate and passing through the reference plate; Second observing the bump forming member
An apparatus for forming a bonding bump, comprising: a microscope; and a pressing mechanism for pressing the bump forming member and the array substrate.

According to a second aspect of the present invention, there is provided an apparatus for forming a bump on a predetermined portion of a bump forming member comprising an electrode of a semiconductor chip or a lead portion bonded to the electrode, wherein an array substrate for arranging metal balls is provided. A first goniometer for holding and adjusting the position of the substrate, a first guide rail for moving the goniometer, a second guide rail disposed above the array substrate and for moving the bump forming member, the array substrate and the array A transparent reference plate having a marker disposed between the bump forming members, a third goniometer for holding and adjusting the position of the reference plate, a moving mechanism for the goniometer, and disposed above the reference plate and passing through the reference plate; A first microscope that observes the array substrate, a second microscope that is provided below the reference plate and observes the bump forming member through the reference plate, A forming apparatus of the bonding bumps, characterized by comprising the sequence substrate and pump forming member from pressurizing the pressurizing mechanism.

According to a third aspect of the present invention, there is provided an apparatus for forming a bump on a predetermined portion of a bump forming member comprising an electrode of a semiconductor chip or a lead portion bonded to the electrode, wherein an array substrate for arranging metal balls is provided. A first guide rail for moving the substrate, a second goniometer disposed above the substrate for holding and adjusting the position of the bump forming member, a second guide rail for moving the goniometer,
A transparent reference plate having a marker disposed between the array substrate and the bump forming member, a third goniometer for holding and adjusting the position of the reference plate, a moving mechanism for the goniometer, and disposed above the reference plate A first microscope for observing the array substrate through the reference plate, and a second microscope disposed below the reference plate and observing the bump forming member through the reference plate
An apparatus for forming a bonding bump, comprising: a microscope; and a pressing mechanism for pressing the bump forming member and the array substrate.

[0013]

First, the method of the present invention will be described with reference to the first example of the invention shown in FIGS. FIG. 1 is a side view, and FIG. 2 is a plan view corresponding to an arrow AA in FIG. According to the method of the present invention, as shown in FIG. 1, metal balls 1 are arranged on an arrangement substrate 2, and a transparent reference plate 4 having a marker 5 is sandwiched above the metal balls 1.
The bump forming member 3 is arranged so as to have a positional relationship facing the arrangement substrate 2, and the position adjustment is performed by separately observing the arrangement substrate 2 and the bump forming member 3 through the transparent reference plate 4 to adjust the position. The metal ball 1 is made to overlap a predetermined portion of the bump forming member 3 where a bump is to be formed. Then, the transparent reference plate 4 is retracted, and the array substrate 2 and the bump forming member 3 are overlaid and pressed to form a bump at a predetermined position of the bump forming member 3. In the present invention, the bump forming member 3 is a semiconductor chip or a TAB tape, a lead frame, a printed circuit board or the like bonded to the chip, and a predetermined portion of the bump forming member 3 is provided with a semiconductor chip electrode or a TAB overlapping the electrode. It is a place of a lead portion of a tape, a lead frame, a printed circuit board or the like.

As shown in FIG. 1, a first example of an apparatus according to the present invention comprises an arrangement substrate 2 on which metal balls 1 are arranged, an arrangement substrate 2
A first goniometer 6 for holding and adjusting the position, a first guide rail 7 for moving the first goniometer 6, a second goniometer 8 disposed above the array substrate 2 and holding and adjusting the position of the bump forming member 3, A second guide rail 9 for moving the second goniometer 8, a transparent reference plate 4 having a marker 5 disposed between the array substrate 2 and the bump forming member 3, an arm 16 as a moving mechanism of the transparent reference plate 4, and The first microscope 12 is disposed above the transparent reference plate 4 and is configured to observe the array substrate 2 through the transparent reference plate 4. The first microscope 12 is disposed below the transparent reference plate 4 and is configured to observe the bump forming member 3 through the transparent reference plate 4. The microscope comprises a microscope 13, a bump forming member 3, a pressing jig 19 as a pressing mechanism for pressing the array substrate 2, and a control device 20 therefor.

The position adjustment of the array substrate 2 and the bump forming member 3 in the method of the present invention will be described with reference to a first invention apparatus example in FIG. The arrangement substrate 2 is provided with a suction port 14-1 which is opened at a position corresponding to the predetermined position of the bump forming member 3, and the metal ball 1 is sucked to the suction port 14-1. This array substrate 2 is held by a first goniometer 6. The bump forming member 3 is held by the fixing head 15 fixed to the second goniometer 8 at the suction port 14-2. Then, as shown in FIG. 1, the first goniometer 6 is brought into contact with the stopper 18-1 of the first guide rail, and the transparent reference plate 4 is located directly above the array substrate 2. The second goniometer 8 is retracted to the position shown in the figure along the second guide rail 9, observes the array substrate 2 with the first microscope 12 through the transparent reference plate 4 from above, Axis adjustment (x direction, y direction, z direction, θ rotation in xy plane, α inclination in xy plane) is performed, and the position of metal ball 1 is aligned with marker 5 of reference plate 4. At this time, the movement in the z direction is for focusing of the first microscope 12.

Next, the first goniometer 6 is retracted along the first guide rail 7, the first microscope 12 is retracted along the second guide rail, and the second goniometer 8 is placed directly above the transparent reference plate 4. Position. Then, the bump forming member 3 is observed from below through the reference plate 4 with the second microscope 13, and the five axes are adjusted by the second goniometer 8, for example, as described above. Match with marker 5. After that, the arm 16 supporting the transparent reference plate 4 is turned around the axis 17 to retract the transparent reference plate 4, the first goniometer 6 is moved along the first guide rail 7, and the stopper 18 -1. Thus, the metal ball 1 on the array substrate 2 and the predetermined position of the bump forming member 3 where the bump is to be formed coincide with the z direction. Then, the pressing jig 19 is lowered, the bump forming member 3 is pressed against the array substrate 2, and the metal balls 1 are collectively bonded to a predetermined portion of the bump forming member 3 by thermocompression. The fixing head 15 has a built-in heater, and the controller 20 controls the heater temperature and pressure. After the bonding, the suction of the suction port 14-1 of the array substrate 2 is released, and the process proceeds to the next bump formation.

In the first invention, the first guide rail 7 has two guide rails as shown in FIG. 2, for example, and when the first goniometer 6 is retracted, the second microscope 13 is positioned between the rails. The second microscope 1
At 3, the bump forming member 3 can be observed through the transparent reference plate 4. As a moving mechanism of the transparent reference plate 4, in addition to the above-described turning method, a third guide as shown in FIGS. 3, 4, and 5 showing examples of the second invention device and the third invention device described below. A parallel movement method using the rail 11 may be used. However, the third goniometer 10 is unnecessary in the first invention device.

In the method of the present invention, the position adjustment of the arrangement substrate 2 and the bump forming member 3 can be performed by the following method in addition to the above method. In FIG. 1, first, the second goniometer 8 holding the bump forming member 3 is positioned directly above the transparent reference plate 4, and observed from below using a second microscope, and the bump forming member 3 is aligned with the transparent reference plate 4. Next, the first goniometer 6 is positioned immediately below the transparent reference plate 4, the second goniometer 8 is retracted, and the first microscope 12 is moved.
Is positioned directly above the transparent reference plate 4 and the array substrate 2 is positioned from above.
And adjust the position of the metal ball 1 to the reference plate 4.
Then, the first microscope 12 is retracted, the second goniometer 8 is positioned immediately above the reference plate 4, the reference plate 4 is retracted, and the pressing jig 19 is lowered to move the bump forming member 3 to the array substrate 2. Apply pressure. When the second goniometer 8 is positioned directly above the transparent reference plate 4, for example, as shown in FIG. 3, the stopper 18-2 is positioned near the second guide rail 9 so as not to hinder the movement of the first microscope 12. To ensure that the bump forming member 3 is returned to the adjusted position and can be pressed.

Further, the method of the present invention can be carried out by a second apparatus as illustrated in FIG. The second invention device is:
As in the example of FIG. 3, the transparent reference plate 4 is held by the third goniometer 10, and the third goniometer 10 can move along the third guide rail. The transparent reference plate 4 is, for example, as shown in FIG.
A hollow portion is provided in the device, and it is held there, so that it can be observed from above and below by the microscopes 12 and 13. The bump forming member 3 is held by the fixing head 15 at the suction port 14-2 as shown in FIG. 3 and can be moved along the second guide rail 9 as shown in FIG. The goniometer 8 is not provided. Other configurations are the same as those in FIG.

When the method of the present invention is carried out by the second apparatus of the present invention shown in FIG. 3, the position adjustment between the array substrate 2 and the bump forming member 3 can be performed as follows. First, the third goniometer 10 holding the transparent reference plate 4 is brought into contact with the stopper 18-3 of the third guide rail 11 and is located immediately above the second microscope 13. And the bump forming member 3
Is moved along the second guide rail 9, and the stopper 18
-2, and placed just above the transparent reference plate 4, the second microscope 13 observes the bump forming member 3 through the transparent reference plate 4, and moves the third goniometer 10 to, for example, a 5-axis Adjustment, adjust the position of the transparent reference plate 4,
The marker 5 is set at a predetermined position on the bump forming member 3.
Next, the bump forming member 3 is retracted to the right in FIG.
The microscope 12 is moved and positioned just above the transparent reference plate 4,
With the first goniometer 6 positioned directly below the reference plate 4,
The arrangement substrate 2 is observed through the reference plate 4 by the first microscope 12, and the first goniometer 6 is adjusted to
Is aligned with the marker 5 of the reference plate 4. Thereafter, the third goniometer 10 is retracted to the left along the third guide rail, and the bump forming member 3 is moved to stop the stopper 1.
8-2. Thus, the predetermined positions on the array substrate 2 where the metal balls 1 and the bump forming members 3 are to be bumped are
coincides with the z direction. Others are described in the first part of FIG.
This is as described for the inventive device.

Further, the method of the present invention can be carried out by a third apparatus as illustrated in FIG. In the third invention device, as in the example of FIG. 4, the transparent reference plate 4 is similar to that of FIG.
The third goniometer 10 is held by the third goniometer 10 so that the third goniometer 10 can move along the third guide rail. The transparent reference plate 4 is, for example, as shown in FIG.
The goniometer 10 is provided with a hollow portion and held therein, so that the goniometer 10 can be observed by the microscopes 12 and 13 from above and below. And array board 2
Can be moved along the first guide rail 7 as shown in FIG. 4, but the first goniometer 6 as shown in FIG. 1 is not provided. Other configurations are the same as those in FIG.

When the method of the present invention is carried out by the third invention apparatus shown in FIG. 4, the position adjustment between the array substrate 2 and the bump forming member 3 can be performed as follows. First, the third goniometer 10 holding the transparent reference plate 4 is brought into contact with the stopper 18-3 of the third guide rail 11, and is located immediately below the first microscope 12. Then, the array substrate 2 is moved to the first
It moves along the guide rail 7, contacts the stopper 18-1, is positioned immediately below the transparent reference plate 4, and observes the array substrate 2 through the transparent reference plate 4 by the first microscope 12, and the third gonio The position of the transparent reference plate 4 is adjusted by adjusting, for example, the five axes of the meter 10 as described above, and the marker 5 is aligned with the metal ball 1 on the array substrate 2. Next, the array substrate 2 is retracted to the right in the drawing, the first microscope 12 is moved to the left, the second goniometer 8 is positioned directly above the reference plate 4, and the reference plate 4 is moved by the second microscope 13. The second goniometer 8 is adjusted by adjusting the second goniometer 8 so that a predetermined portion of the bump forming member 3 is aligned with the marker 5 of the reference plate 4. Then, the third goniometer 10 is moved to the third
The array substrate 2 is retreated to the left along the guide rail, and is moved to contact the stopper 18-1. As a result, the predetermined positions on the array substrate 2 where the metal balls 1 and the bump forming members 3 are to be bumped coincide with each other in the z direction. Others are as described for the first invention device of FIG.

In the method of the present invention and the apparatus of the present invention, Au can be used as the metal ball, and a low melting point metal such as solder can also be used. The shape of the metal ball is selected according to the situation of the target semiconductor chip, such as an ellipse or a square, in addition to a sphere. The materials, shapes and dimensions of the metal balls are the same in the bump forming members to be joined together. When Au is used, bumps are formed by thermocompression bonding, and when low melting point metal such as solder is used, bonding can be performed by thermocompression bonding or melting.

According to the method of the present invention and the apparatus of the present invention, a large number of bumps are narrowed on the electrodes of various semiconductor chips, or on the bump forming members formed of lead portions such as TABs, lead frames, and printed circuit boards bonded to the electrodes. It is formed at a reduced pitch, and is excellent in positional deviation accuracy, uniformity of bump height, and bonding property. Further, according to the present invention, since the position can be adjusted by observing the entire surface of the bump forming member or an arbitrary required portion, it can be used for a LOC (Lead On Chip) structure in which electrodes are also arranged at the center of the semiconductor chip. Is also applicable.

[0025]

EXAMPLE A bump was formed on a semiconductor chip by an apparatus as shown in FIG. As the metal ball 1, an Au fine wire (purity of 99.9% by weight or more) for wire bonding is cut to a fixed size, melted into a spherical shape having a diameter of 70 μm, and arranged at a pitch of 150 μm. Total 20
It bonded to zero electrodes by thermocompression bonding. As the transparent reference plate 4, a glass plate in which the positions of metal balls were marked by a photoresist process was used. All of the formed bumps were free from bonding failure, were arranged with a high positional accuracy of 5 μm or less, and had a uniform bump height.

[0026]

According to the method and the apparatus of the present invention, metal balls are arranged with a positional deviation accuracy of 5 μm or less on a large number of electrodes provided on a semiconductor chip with a narrow pitch and high density. Bumps with a uniform height can be formed without bonding failure by bonding. Also, bumps can be formed in the same manner on lead portions of a TAB, a lead frame or a printed circuit board connected to the semiconductor chip. Therefore, by employing a semiconductor chip, a TAB, a lead frame, a printed board, or the like on which bumps are formed according to the present invention, a highly reliable semiconductor device can be manufactured with high yield.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of a first invention device of the present invention.

FIG. 2 shows an example of the first invention apparatus of the present invention, and FIG.
It is a top view equivalent to the arrow A view.

FIG. 3 is a side view showing an example of the second invention apparatus of the present invention.

FIG. 4 is a side view showing an example of the third invention apparatus of the present invention.

5 is a plan view showing an example of the second invention device and the third invention device according to the present invention, and is a plan view taken along the line BB of FIGS. 3 and 4. FIG.

FIG. 6 is a sectional view showing an example of a conventional resin-sealed semiconductor device using a TAB method.

[Explanation of symbols]

 1: Metal ball 2: Array substrate 3: Bump forming member 4: Transparent reference plate 5: Marker 6: First goniometer 7: First guide rail 8: Second goniometer 9: Second guide rail 10: Third goniometer Meter 11: Third guide rail 12: First microscope 13: Second microscope 14-1, 14-2: Suction port 15: Fixing head 16: Arm 17: Shaft 18-1, 18-2, 18-3: Stopper 19: Pressing jig 20: Control device 21: Semiconductor chip 22: Electrode 23: Inner lead 24: Insulating film 25: Bump

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/60

Claims (4)

(57) [Claims] 1. A method for forming a bump on a predetermined portion of a bump forming member comprising an electrode of a semiconductor chip or a lead portion bonded to the electrode, comprising: arranging metal balls on an array substrate; When the metal balls on the substrate are bonded to predetermined positions of the bump forming member to form bumps by overlapping and pressing the bump forming members, the arrangement is performed in a positional relationship facing the transparent reference plate having a marker. After arranging the substrate and the bump forming member, separately observing the arrangement substrate and the bump forming member through the reference plate and adjusting the position, retracting the transparent reference plate, the bump forming member and the arrangement A method for forming a bonding bump, wherein a substrate is overlaid and pressed. 2. An apparatus for forming a bump on a predetermined portion of a bump forming member comprising an electrode of a semiconductor chip or a lead portion bonded to the electrode, comprising: an array substrate on which metal balls are arrayed; A first goniometer to be adjusted, a first guide rail for moving the goniometer, a second goniometer arranged above the array substrate for holding and adjusting the position of the bump forming member, and a second guide for moving the goniometer A rail, a transparent reference plate having a marker disposed between the arrangement substrate and the bump forming member, a mechanism for moving the reference plate, and a first mechanism disposed above the reference plate for observing the arrangement substrate through the reference plate. A microscope, a second microscope disposed below the reference plate and observing the bump forming member through the reference plate, the bump forming member and the array An apparatus for forming a bonding bump, comprising a pressing mechanism for pressing a substrate. 3. An apparatus for forming a bump on a predetermined portion of a bump forming member comprising an electrode of a semiconductor chip or a lead portion bonded to the electrode, comprising: an array substrate on which metal balls are arrayed; A first goniometer to be adjusted, a first guide rail for moving the goniometer, a second guide rail disposed above the array substrate to move the bump forming member, and disposed between the array substrate and the bump forming member Reference plate having a marker, a third goniometer for holding and adjusting the position of the reference plate, a moving mechanism for the goniometer, a first goniometer disposed above the reference plate and observing the array substrate through the reference plate A microscope, a second microscope disposed below the reference plate and observing the bump forming member through the reference plate, the bump forming member and the array An apparatus for forming a bonding bump, comprising a pressing mechanism for pressing a substrate. 4. An apparatus for forming a bump on a predetermined portion of a bump forming member comprising an electrode of a semiconductor chip or a lead portion bonded to the electrode, comprising: an array substrate on which metal balls are arrayed; 1 guide rail, a second goniometer disposed above the substrate and holding and adjusting the position of the bump forming member, a second guide rail for moving the goniometer, and disposed between the array substrate and the bump forming member Transparent reference plate having a marker, a third goniometer for holding and adjusting the position of the reference plate, a moving mechanism for the goniometer, and a first microscope disposed above the reference plate and observing the array substrate through the reference plate A second microscope disposed below the reference plate and observing the bump forming member through the reference plate; An apparatus for forming a bonding bump, comprising a pressing mechanism for pressing.