JP2004363125A - Ultrasonic bonding method, ultrasonic bonding device - Google Patents

Abstract

In an ultrasonic bonding method, all bonding pads of a semiconductor chip are satisfactorily connected to electrodes on a substrate side.
A rectangular semiconductor chip (1) is divided into four regions (110 to 140) including bumps (21) to (24) on each side (11 to 14), and each region (110 to 140) is parallel to a bonding pad forming surface of the semiconductor chip (1). Then, ultrasonic vibration in a direction perpendicular to each side 11 to 14 is applied.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ultrasonic bonding method for connecting a semiconductor chip and a substrate.
[0002]
[Prior art]
2. Description of the Related Art As a method of mounting a semiconductor chip on a substrate and electrically connecting the semiconductor chip, a method using a projecting electrode called a “bump” has conventionally been used. In this method, a plurality of electrodes (bonding pads) are formed on a semiconductor chip, and a plurality of corresponding electrodes are formed on a substrate side. Then, after the bump is formed on one of the electrodes, the bump is thermocompression-bonded by adjusting the position between the two electrodes. As a result, the two electrodes are bonded and fixed by the bumps and are electrically connected.
[0003]
Conventionally, instead of such a thermocompression bonding method, a connection method using the energy of ultrasonic vibration has been proposed (for example, see Patent Document 1).
Patent Document 2 below discloses a stage on which a substrate is mounted, a bonding tool that supports a semiconductor chip and applies a load to the semiconductor chip disposed on the substrate via a protruding electrode, An ultrasonic bonding apparatus including a vibration imparting device is described. In the technique described in Patent Document 2, an ultrasonic vibration device and a heating / cooling temperature profile control device are provided in both a stage and a bonding tool.
[0004]
On the other hand, with recent miniaturization and high integration of semiconductor elements, it is required to form a large number of bonding pads on a semiconductor chip at high density. In order to meet this demand, for example, a strip-shaped (elongated rectangle, for example, a rectangle whose long side is twice or more longer than the short side) bonding pads are formed on a semiconductor chip, and bumps having substantially the same shape are formed directly above the bonding pads. That is being done.
[0005]
In this case, a plurality of strip-shaped (narrowly-defined rectangular) bumps are arranged along the sides of the rectangular semiconductor chip along the sides of the rectangular semiconductor chip. Aligned to the direction perpendicular to the side. That is, between the bumps arranged on the mutually perpendicular sides of the rectangular semiconductor chip, both long-side directions are arranged perpendicular to each other.
[0006]
[Patent Document 1]
JP-A-59-208844 [Patent Document 2]
JP-A-7-115109
[Problems to be solved by the invention]
When the semiconductor chip having the above configuration and the substrate are connected via bumps (protruding electrodes) by an ultrasonic bonding method, there are the following problems.
In a normal ultrasonic vibration applying apparatus, the direction of the ultrasonic vibration is one direction, so that when the direction of the ultrasonic vibration is adjusted to the long side direction of one bump, the other (the long side direction is the long side of one bump) With respect to the bump (perpendicular to the direction), the direction of the ultrasonic vibration is in the short side direction (perpendicular to the long side direction). If the direction of the ultrasonic vibration is in the short side direction of the strip-shaped bump, the bump is likely to be inclined in the short side direction (the ultrasonic vibration direction).
[0008]
Even when the bump is square, if the electrode on the substrate side is a lead (strip-shaped electrode), the ultrasonic vibration applied in a direction perpendicular to the longitudinal direction of the lead is Of the lead, and the bump is likely to be displaced from the position of the lead.
The present invention has been made in order to solve the problems of the related art, and a plurality of bonding pads are arranged along each side of the rectangular semiconductor chip at a peripheral portion of the rectangular semiconductor chip. In the ultrasonic bonding method of connecting the electrodes formed on the substrate side with the protruding electrodes using the energy of ultrasonic vibration, all the bonding pads and the electrodes on the substrate side are connected well. The purpose is to be.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a semiconductor device having a plurality of bonding pads arranged along each side of a rectangle (a rectangle in a broad sense, including a square) along each side of the rectangle. In an ultrasonic bonding method in which a pad and each electrode formed on the substrate side are connected by a protruding electrode using the energy of ultrasonic vibration, the protruding electrodes arranged on the respective sides of the semiconductor chip are provided. And an ultrasonic bonding method in which ultrasonic vibrations in a direction parallel to a bonding pad forming surface of the semiconductor chip and perpendicular to the respective sides are applied to the respective regions. I do.
[0010]
According to the method of the present invention, for example, when a lead extending perpendicular to each side of the rectangle forming the semiconductor chip is formed as an electrode on the substrate side, an ultra-long line is formed on all sides of the rectangle forming the semiconductor chip. Since the direction of the sound wave vibration is the same as the longitudinal direction of the lead, all the bonding pads and the electrodes on the substrate side are connected well.
[0011]
In the method of the present invention, the shape of the protruding electrode is a rectangle having a long side and a short side (a rectangle in a narrow sense, not including a square). This is particularly preferable when the direction is a direction perpendicular to the side where it is arranged. In this case, the direction of the ultrasonic vibration is the long side direction of all the protruding electrodes.
According to the present invention, a plurality of bonding pads are arranged in a peripheral portion of the semiconductor chip, and each of the bonding pads is connected to each of the electrodes formed on the substrate side by a protruding electrode by utilizing the energy of ultrasonic vibration. In the ultrasonic bonding method, the electrode on the substrate side is a rectangular lead having a long side and a short side, and the semiconductor chip is divided into a plurality of regions having different long side directions of the lead. An ultrasonic bonding method is provided, wherein ultrasonic vibration is applied in a direction parallel to a bonding pad forming surface of the semiconductor chip and parallel to a long side direction of the lead. According to this method, the direction of the ultrasonic vibration is in the long side direction of all the leads, so that all the bonding pads and the leads (the electrodes on the substrate side) are connected well.
[0012]
According to the present invention, a plurality of bonding pads are arranged in a peripheral portion of the semiconductor chip, and each of the bonding pads is connected to each of the electrodes formed on the substrate side by a protruding electrode by utilizing the energy of ultrasonic vibration. In the ultrasonic bonding method described above, the shape of the protruding electrode is a rectangle having a long side and a short side, and the semiconductor chip is divided into a plurality of regions having different long side directions of the protruding electrode. In addition, the present invention provides an ultrasonic bonding method, wherein ultrasonic vibration is applied in a direction parallel to a bonding pad forming surface of the semiconductor chip and parallel to a long side direction of the protruding electrode. According to this method, since the direction of the ultrasonic vibration is in the long side direction of all the protruding electrodes, all the bonding pads and the electrodes on the substrate side are connected well.
[0013]
The present invention also provides a stage for mounting a substrate, a bonding tool that supports a rectangular semiconductor chip, and applies a load to the semiconductor chip disposed on the substrate via a protruding electrode, and an ultrasonic vibration applying apparatus. In the ultrasonic bonding apparatus comprising: a region dividing the semiconductor chip into a plurality of regions including projecting electrodes arranged on each side of the rectangle at a position below the semiconductor chip on the stage. A member is disposed so as to be in contact with the substrate, and the ultrasonic vibration applying device is configured such that each side corresponding to a member for each region constituting the region dividing member in parallel with a bonding pad forming surface of the semiconductor chip. The present invention provides an ultrasonic bonding apparatus for applying ultrasonic vibration in a direction perpendicular to the ultrasonic bonding apparatus.
[0014]
According to the ultrasonic bonding apparatus of the present invention, the method of the present invention can be easily performed.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a plan view for explaining one example (one embodiment) of the ultrasonic bonding method of the present invention. FIG. 2 is a partial sectional side view showing the ultrasonic bonding apparatus.
[0016]
As shown in FIG. 1, in the method of this embodiment, a plurality of bonding pads are arranged along the four sides 11 to 14 of the rectangular semiconductor chip 1 at the periphery of the rectangular semiconductor chip 1. Bumps (protruding electrodes) 21 to 24 are formed. Each of the bumps 21 to 24 is a rectangle of the same size including a long side and a short side.
[0017]
The long side direction of the rectangle forming the bump 21 is a direction perpendicular to the side 11 on which the bump 21 is arranged. The long side direction of the rectangle forming the bump 22 is a direction perpendicular to the side 12 on which the bump 22 is arranged. The long side direction of the rectangle forming the bump 23 is a direction perpendicular to the side 13 on which the bump 21 is arranged. The long side direction of the rectangle forming the bump 24 is a direction perpendicular to the side 14 on which the bump 24 is arranged.
[0018]
The semiconductor chip 1 is divided into four regions 110 to 140 by a region dividing member 3 including plate members (members for respective regions) 31 to 34. The first region 110 is a region including the bump 21 arranged along the rectangular side 11 forming the semiconductor chip 1.
The second region 120 is a region including the bumps 22 arranged along the rectangular side 12 forming the semiconductor chip 1. The third region 130 is a region including the bumps 23 arranged along the rectangular side 13 forming the semiconductor chip 1. The fourth region 140 is a region including the bumps 24 arranged along the rectangular sides 14 forming the semiconductor chip 1.
[0019]
Then, the plate-like bodies 31 to 34 in each of the regions 110 to 140 and the ultrasonic vibration applying devices 41 to 44 independently attached to the plate-like bodies 31 to 34 are used to separate the semiconductor in each of the regions 110 to 140. Ultrasonic vibration is applied in a direction (Y direction or X direction) that is parallel to the bonding pad formation surface of the chip 1 (a surface parallel to the paper surface of FIG. 1) and perpendicular to each of the sides 11 to 14. Each of the ultrasonic vibration applying devices 41 to 44 includes an ultrasonic vibrator and an ultrasonic horn, and each ultrasonic horn is attached to each of the plate members 31 to 34.
[0020]
The ultrasonic vibration applying device 41 applies ultrasonic vibration to the region 110 in a direction (Y direction) parallel to the bonding pad formation surface of the semiconductor chip 1 and perpendicular to the side 11. The ultrasonic vibration applying device 42 applies ultrasonic vibration to the region 120 in a direction (X direction) parallel to the bonding pad formation surface of the semiconductor chip 1 and perpendicular to the side 12.
[0021]
The ultrasonic vibration applying device 43 applies ultrasonic vibration to the region 130 in a direction parallel to the bonding pad formation surface of the semiconductor chip 1 and perpendicular to the side 13 (Y direction). The ultrasonic vibration applying device 44 applies ultrasonic vibration to the region 140 in a direction (X direction) parallel to the bonding pad formation surface of the semiconductor chip 1 and perpendicular to the side 14.
[0022]
As shown in FIG. 2, the ultrasonic bonding apparatus includes a stage 6 on which a substrate 5 is placed, a bonding tool 7 for supporting the semiconductor chip 1 and applying a load, and ultrasonic vibration applying apparatuses 41 to 44. ing. In FIG. 2, the ultrasonic vibration applying devices 41 to 44 are not displayed.
In the upper part of the stage 6, a concave portion 61 is formed at a position directly below the semiconductor chip 1, and each plate-like body (member for each region) 31 to 34 is arranged so as to be in contact with the substrate 5. ing. The bonding tool 7 is formed by integrating a fixing part 71 made of artificial diamond for fixing the semiconductor chip 1 and a metal body 72 containing a heater. The ultrasonic bonding apparatus further includes an air piston that applies a load P to the metal body 72 of the bonding tool 7.
[0023]
This ultrasonic bonding apparatus is used as follows.
First, the substrate 5 is placed on the stage 6, and a region of the substrate 5 for connecting the semiconductor chip 1 is arranged on the concave portion 61. At that time, the semiconductor chip 1 and the plate-like bodies 31 to 34 in the recess 61 are arranged as shown in FIG. Bumps 21 to 24 are formed on each bonding pad of the semiconductor chip 1 (only 82 and 84 are shown in FIG. 2).
[0024]
Note that leads 50 are formed on the substrate 5 (only 52 and 54 are shown in FIG. 2). The longitudinal direction of each lead 50 is aligned with the long side direction of each bump 21 to 24 to be connected.
Next, the semiconductor chip 1 is fixed to the fixing portion 71 of the bonding tool 7, and the bonding tool 7 is arranged on the substrate 5 with the semiconductor chip 1 side facing the substrate 5 side. At this time, the tips of the leads 50 on the substrate 5 side and the corresponding bumps 21 to 24 of the semiconductor chip 1 are matched.
[0025]
In this state, the metal body 72 is heated to about 150 ° C. by the built-in heater, a load P is applied to the metal body 72 of the bonding tool 7 by the air piston, and the ultrasonic vibration applying devices 41 to 44 are operated. Thereby, the bumps 21 to 24 and the lead 50 are welded mainly by the energy of the ultrasonic vibration. That is, ultrasonic bonding is performed. As a result, the lead 50 and the bonding pad are bonded and fixed by the bumps 21 to 24 and are electrically connected.
[0026]
And since the direction of the ultrasonic vibration applied by this ultrasonic bonding is the long side direction of all the bumps 21 to 24 and the longitudinal direction of all the leads 50, all the bumps 21 to 24 and the leads 50 are inclined. Therefore, all the bonding pads of the semiconductor chip 1 and the leads 50 of the substrate 5 can be connected well. This will be described below using the bump 24 as an example.
[0027]
In this embodiment, as shown in FIG. 3, since the ultrasonic vibration in the direction (X direction) along the long side direction of the bump 24 (and the longitudinal direction of the lead 54) is applied, the bump 24 tilts. Is prevented, as shown in FIG. FIG. 4A corresponds to a view taken in the direction of the arrow A in FIG.
On the other hand, if the semiconductor chip 1 is not divided into the four regions 110 to 140 and ultrasonic vibrations in the Y direction are applied to the whole, for example, the bumps 24 will have short sides (and width directions of the leads 54) Is applied, the bumps 24 and the leads 54 are likely to be inclined, and connection failures are likely to occur. For example, the bump 24 may be inclined as shown in FIG. 4B, or the bump 24 may slide down from the lead 54 as shown in FIG. 4C.
[0028]
In the above embodiment, the semiconductor chip 1 is divided into four regions 110 to 140 including the bumps 21 to 24 arranged on the respective sides 11 to 14, but the present invention is not limited to this. For example, FIG. The first area 110 and the third area 130 may be integrated without being divided. However, in this case, it is necessary to prevent the integrated region from interfering with the other second region 120 and fourth region during ultrasonic vibration. Further, the first to fourth regions 110 to 140 may be further divided.
[Brief description of the drawings]
FIG. 1 is a plan view illustrating an ultrasonic bonding method according to an embodiment.
FIG. 2 is a partial cross-sectional side view showing the ultrasonic bonding apparatus of the embodiment.
FIG. 3 is a diagram showing a connection portion between a bonding pad and a lead by a bump.
4 is a view taken in the direction of arrow A in FIG. 3 and shows the case (a) of the present invention and the cases (b) and (c) of a comparative example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Semiconductor chip, 11-14 ... Four sides of the rectangle which comprises a semiconductor chip, 21-24 ... Bump (protruding electrode), 110-140 ... Region, 3 ... Region dividing member, 31-34 ... Plate ( 41 to 44: ultrasonic vibration applying device, 5: substrate, 6: stage, 61: concave portion, 7: bonding tool, 71: fixing portion, 72: metal body.

Claims (5)

A plurality of bonding pads are arranged along each side of the rectangle on the periphery of the rectangular semiconductor chip, and the bonding pads and the electrodes formed on the substrate side are formed by utilizing the energy of ultrasonic vibration, In the ultrasonic bonding method of connecting by the protruding electrodes,
The semiconductor chip is divided into a plurality of regions including the protruding electrodes arranged on each side, and each region has an ultrasonic wave in a direction parallel to a bonding pad formation surface of the semiconductor chip and perpendicular to each side. An ultrasonic bonding method characterized by applying vibration. The ultrasonic wave according to claim 1, wherein the shape of the protruding electrode is a rectangle having a long side and a short side, and a long side direction of the rectangle is a direction perpendicular to a side on which each protruding electrode is arranged. Bonding method. An ultrasonic bonding method in which a plurality of bonding pads are arranged in a peripheral portion of a semiconductor chip, and each of the bonding pads is connected to each electrode formed on the substrate side by a protruding electrode by using the energy of ultrasonic vibration. At
The substrate-side electrode is a rectangular lead having a long side and a short side, and the semiconductor chip is divided into a plurality of regions having different long side directions of the lead, and each region has a bonding pad of the semiconductor chip. An ultrasonic bonding method characterized by applying ultrasonic vibration in a direction parallel to a forming surface and parallel to a long side direction of the lead. An ultrasonic bonding method in which a plurality of bonding pads are arranged in a peripheral portion of a semiconductor chip, and each of the bonding pads is connected to each electrode formed on the substrate side by a protruding electrode by using the energy of ultrasonic vibration. At
The shape of the protruding electrode is a rectangle having a long side and a short side, and the semiconductor chip is divided into a plurality of regions having different long side directions of the protruding electrode. An ultrasonic bonding method characterized by applying ultrasonic vibration in a direction parallel to a pad formation surface and parallel to a long side direction of the protruding electrode. A stage for mounting a substrate, a bonding tool that supports a rectangular semiconductor chip, and applies a load to the semiconductor chip disposed on the substrate via a protruding electrode; and an ultrasonic vibration applying device. In ultrasonic bonding equipment,
An area dividing member that divides the semiconductor chip into a plurality of areas including protruding electrodes arranged on each side of the rectangle is arranged at a position below the semiconductor chip on the stage so as to be in contact with the substrate. And
The ultrasonic vibration applying device applies ultrasonic vibration to a member for each region constituting the region dividing member in a direction parallel to a bonding pad formation surface of the semiconductor chip and perpendicular to each corresponding side. An ultrasonic bonding apparatus, comprising:

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