JP2001110831A - External connecting protrusion and its forming method, semiconductor chip, circuit board and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outside connecting protrusion whose aspect ratio is high capable of reducing the usage of metal being materials and a method for forming the outside connecting protrusion, and for the provide a semiconductor chip using the protrusion, and a circuit board and electronic equipment. SOLUTION: In an outside connecting protrusion 10, a projecting body 22 made of resin is formed adjacently to an electrode pad 20, and a conductor 24 made of metal is formed across an electrode pad 14 and the projecting body 22. Thus, the outside connecting protrusion having a high aspect ratio can be easily formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external connection projection and a method for forming the same, a semiconductor chip, a circuit board, and an electronic device, and more particularly to an external connection projection having a high aspect ratio, a semiconductor chip having the same, a circuit board, and an electronic device. About.

[0002]

2. Description of the Related Art In recent years, in mounting semiconductor chips,
A flip-chip mounting method in which connection is performed using solder bumps is often used. That is, bumps are formed on the active element forming surface (hereinafter referred to as the active surface) of a semiconductor chip by a plating method, a vapor deposition method, or a method in which a substantially spherical solder ball is previously arranged on an electrode pad, and these are used. To connect a semiconductor chip to a substrate or the like.

[0003]

However, in recent years, as semiconductor chips have become smaller, it has been required to further reduce the distance between bumps formed on an LSI chip, that is, to reduce the pitch. Therefore, bumps are required to have a high aspect ratio, that is, a bump having a height higher than its width. Therefore, for example, a method of forming a bump as disclosed in Japanese Patent Application Laid-Open No. 10-107038 has been considered. That is, a solder containing zinc (Zn) and antimony (Sb) is bonded on the electrode pad on the active surface, and conductive particles are bonded on the solder.

However, when the above-described forming method is used, as the height of the bump is increased, the amount of metal used for forming the bump increases. Therefore, when expensive gold is used, it causes a cost increase.
Further, in order to increase the height of the bump, a more complicated manufacturing process is required as compared with the conventional one, and this also causes an increase in cost.

The present invention has been made to solve the above-mentioned drawbacks of the prior art, and has an external connection projection having a high aspect ratio and capable of reducing the amount of metal used as a material. It is an object of the present invention to provide a semiconductor device, a method of forming the same, and a semiconductor chip, a circuit board, and an electronic device using the same.

[0006]

According to the present invention, in order to achieve the above object, an external connection projection formed on an active element forming surface of a semiconductor chip is formed near an electrode of the semiconductor chip. It is characterized by having at least a protruding body, and a conductor formed continuously on the electrode and the protruding body.

In the present invention having the above-described structure, the external connection projection is formed of a projection and a conductor, and the projection is formed at a predetermined height, and the conductor is formed thereon. An external connection projection having a high ratio can be easily formed.

The conductors are gold (Au), copper (Cu)
Alternatively, it is preferable to use nickel (Ni).

In the above-mentioned external connection projection, the conductor is formed so as to cover the top of the projection.

[0010] In the present invention configured as described above, the top of the protrusion can be used for electrical connection.
External connection protrusions having a high aspect ratio can be obtained.

Further, in the above-mentioned external connection projection, a top of the projection is formed to be flat.

According to the present invention, the contact area between the protruding body and the wiring pattern of the substrate can be increased, and the electrical conduction between them can be more reliably ensured.

In the external connection projection, the protrusion is formed in parallel with the arrangement of the electrodes and in the vicinity of the electrode, and the conductor is formed one by one for each of the electrodes. To do.

In the present invention thus configured, 1
One external connection projection can be used for electrical connection of a plurality of electrodes.

In the external connection projection, the projection is formed in a frame shape in a region surrounded by the electrode on the active element forming surface.

In the present invention thus configured, the external connection projection can be used for electrical connection of all electrodes formed on the semiconductor chip.

In the external connection projection, the projection is made of resin.

In the present invention configured as described above, the protrusion can be easily formed in a predetermined shape and height. In addition, since the protrusion has flexibility, external stress can be absorbed by the external connection protrusion.

Further, the external connection projection formed on the active element forming surface of the semiconductor chip is formed as a bottomed cylindrical shape on the electrode of the semiconductor chip. .

In the present invention thus configured, since the external connection projection is hollow, the amount of material used for forming the external connection projection can be reduced.

According to another aspect of the present invention, there is provided a semiconductor chip having any of the above-described external connection projections formed thereon.

According to the present invention configured as described above, it is possible to provide a semiconductor chip in which the external connection protrusions are arranged at a smaller pitch than the conventional one. As a result, the size of the semiconductor chip itself can be reduced.

In addition, the present invention is characterized in that any one of the above semiconductor chips is mounted on a circuit board.

According to the present invention configured as described above, it is possible to provide a circuit board smaller in size than the conventional one.

Further, an electronic device is provided with the above-mentioned circuit board.

In the present invention configured as described above, a circuit board smaller than a conventional circuit board is used.
It is easy to reduce the size of the electronic device itself.

In the method of forming external connection projections on a semiconductor wafer, a step of bonding a projection to the vicinity of an electrode formed on the semiconductor wafer, and a step of plating on the electrode and the projection by plating. And a step of forming a conductor.

In the present invention configured as described above, it is possible to easily form the external connection projection having a predetermined size and height near the electrode of the semiconductor chip.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an external connection projection and a method for forming the same according to the present invention, a semiconductor chip, a circuit board, and electronic equipment will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a sectional view of an external connection projection according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view showing a modification of the external connection projection according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view showing a modification of the external connection projection according to the first embodiment of the present invention. FIG. 4 is a cross-sectional view of the external connection projection according to the second embodiment of the present invention. FIG. 5 is a perspective view of an external connection projection according to the third embodiment of the present invention. FIG. 6 is a plan view of the external connection projection according to the fourth embodiment of the present invention. FIG. 7 is an explanatory diagram of a manufacturing process of the external connection projection according to the first embodiment of the present invention. FIG. 8 is an explanatory diagram of a semiconductor chip manufacturing process according to the second embodiment of the present invention. FIG. 9 is an explanatory diagram of a circuit board on which a semiconductor chip having external connection protrusions according to the first embodiment of the present invention is mounted. further,
FIG. 10 is an explanatory diagram of an electronic device including the circuit board shown in FIG.

First, a first embodiment of the present invention will be described. As shown in FIG. 1, the external connection projection 20 according to this embodiment is
Is provided on the active surface on which is formed. Further, the external connection protrusion 20 includes a protrusion 22 formed to protrude on the active surface,
A conductor 24 is formed over the electrode pad 14 and the protrusion 22. Note that a protective film 12 is formed on the surface of the active surface of the semiconductor chip 10. The protective film 12 also has a function of protecting an active element and a metal wiring layer (not shown) formed inside the semiconductor chip 10, and is formed of a silicon oxide film (SiO ₂ ) or a silicon nitride film (SiN). I have.

The protruding body 22 is formed of a thermosetting epoxy resin, and has a predetermined height, for example, 30 to 100 μm, in a region adjacent to the electrode pad 20. In addition, the top of the protruding body 22 is formed flat so as to more reliably establish electrical connection with a substrate or the like (not shown). The material of the protruding body 22 may be any resin other than the thermosetting epoxy resin as long as the protruding body 22 can be easily formed on the active surface by a method described later. Further, an inorganic material such as glass may be used.

The conductor 24 is made of gold (Au), is formed so as to cover the electrode pad 14 and the top of the protrusion 22, and is continuous from the electrode pad 14 to the top of the protrusion 22. Is formed. The thickness is 3 to 10 μm. In addition, as a material of the conductor 24, in addition to gold, the electrode pad 1 may be formed by a method described later.
Other metals such as copper (Cu) and nickel (Ni) can be preferably used as long as the conductor 24 can be easily formed on the protrusions 4 and the protruding body 22.

Therefore, in the external connection projection 20, a conductor 24 is formed on the top of the protrusion 22 formed at a predetermined height, and the conductor 24 is electrically connected to the electrode pad 14. Therefore, the semiconductor chip 10 can be electrically connected to the substrate or the like by connecting the wiring pattern of the substrate (not shown) to the top of the protruding body 22. In addition, since the protruding body 22 can be easily formed at an arbitrary height, an external connection protrusion having a higher aspect ratio than the bump according to the related art, that is, having a height 52 larger than the width 50 can be easily obtained. .

Further, since the projecting body 22 is formed of a resin, external stress applied to the semiconductor chip 10 and the like can be absorbed by the projecting body 22. In addition, the conductor 24
Is formed to a thickness of 3 to 10 μm, so that even when the external connection projection 20 has a considerable height, the amount of the conductive material 24 used can be reduced. Also,
Since the protruding body 22 is formed on the insulating protective film 12, no leak current flows from the protruding body 22 directly to the semiconductor chip 10.

The portion where the protruding body 22 is formed is not limited to a region adjacent to the electrode pad 14, but may be formed separately from the electrode pad 14 if necessary. In this case, the conductor 24 may be formed continuously from the electrode pad 14 to the top of the protrusion 22. Further, a part of the protruding body 22 may be formed on the electrode pad 14.
In this case, it is preferable to form the conductive layer 24 leaving a space for ensuring electrical conduction between the conductor 24 and the electrode pad 14. The top of the protruding body 22 may be formed in another shape such as a gentle convex surface as long as electrical connection with the substrate or the like can be reliably ensured.

The conductor 24 is formed only in the range from the electrode pad 14 to the top of the protrusion 22 in FIG. 1, but as shown in FIG. It may be formed on the entire surface. Also, the protrusion 2
2, the side surface is inclined in FIG. 1, but may be vertical as shown in FIG.

Here, a method of forming the external connection projection according to the first embodiment will be described with reference to FIG.

As shown in FIG. 7A, in the semiconductor wafer 16 on which the protective film 12 and the electrode pads 14 have been formed, first, as shown in FIG. Place on adjacent site and continue heating.
By heating, the resin forming the protruding body 22 is hardened and adheres to the site. When the protruding body 22 is formed of a photocurable resin, the protruding body 22 is cured by irradiating ultraviolet rays or the like. When the protrusion 22 is made of an inorganic material, the protrusion 22 is attached with an adhesive. next,
A barrier film and a plating base film are formed on the entire surface of the semiconductor wafer 16.

Next, as shown in FIG. 7C, a photoresist is applied to the entire active surface of the semiconductor wafer 16 to form a photoresist film 40, and then the photoresist film 4 is formed.
Exposure and development of 0 are performed, and the film at the portion where the conductor is to be formed is removed to form the opening 42. Note that the thickness of the photoresist film 40 is desirably equal to or greater than the height of the external connection protrusion to be formed.

Next, as shown in FIG.
The conductor 24 is formed on the substrate 2 by plating. The thickness of the conductor 24 is preferably 3 to 10 μm as described above.

Next, as shown in FIG. 7E, the photoresist film 40 is peeled off. The peeling method may be either a dry method or a wet method. Next, using the conductor 24 as a mask, unnecessary portions of the barrier film and the plating base film are etched.

The external connection projections 20 are formed by the steps described above. The above steps are all wafer processes, and processing for each semiconductor chip can be performed collectively. The dicing of the semiconductor wafer 16 is performed after the above steps are completed.

Next, a second embodiment of the present invention will be described. As shown in FIG. 4, the external connection projection 20 according to this embodiment has a shape in which a bottomed cylindrical portion stands upright on the electrode pad 14. Further, the hollow portion 28 is formed in a state of being opened at the tip end side of the bottomed cylindrical portion, and a flange portion 26 projecting in the horizontal direction is formed at the opening portion at the tip side of the bottomed cylindrical portion. Have been. In addition, the height of the external connection protrusion 20 is formed in the range of 30 to 150 μm, and the thickness of the bottomed cylindrical portion and the flange portion 26 is 3 to 10 μm.
m. The external connection projection 20 is entirely formed of gold.

Therefore, in the external connection projection 20, the semiconductor chip 1 is connected by connecting a wiring pattern or the like of a substrate (not shown) to the tip portion including the flange portion 26.
0 can be electrically connected to a substrate or the like. Also,
Since the hollow portion 28 is formed, the external connection projection having a high aspect ratio can be easily obtained as compared with the amount of gold used for forming the external connection projection 20. Further, the provision of the flange portion 26 increases the planar area near the tip of the external connection projection 20, so that the area contributing to the connection with the substrate or the like increases, and the connection with the substrate or the like increases. Improve reliability.

The material of the external connection protrusion 20 is as follows.
In addition to gold, other metals such as copper, nickel, and aluminum (Al) can be preferably used as long as they can be easily formed on the electrode pads 14 by a method described later. In addition, the height of the external connection projection 20 and the thickness of the bottomed cylindrical portion and the flange portion 26 are not limited to those described above, and may be appropriately changed as needed.

Here, a method of forming the external connection projection according to the second embodiment will be described with reference to FIG.

As shown in FIG. 8A, in the semiconductor wafer 16 on which the protective film 12 and the electrode pads 14 have been formed, first, as shown in FIG.
6, a photoresist film is formed by coating a photoresist on the entire active surface. Subsequently, the photoresist film 40 is exposed and developed to remove the film where the external connection projections are to be formed. Form. Next, a metal film serving as a plating base is formed on the inner surface of the opening by sputtering.
Next, the surface other than the inner surface of the opening, that is, the metal film on the upper surface of the resist is removed by a reverse sputtering process or a polishing process to leave only the metal film on the inner surface of the opening. The photoresist film 40
It is desirable to match the thickness of the cylinder with the height of the bottomed cylindrical portion to be formed.

Next, as shown in FIG.
The external connection projections 20 are formed on the substrate 2 by plating. At this time, gold is deposited on the photoresist film 40 around the opening 42 so that the flange 26 is formed. The thickness of the external connection projection 20 is 3 to 1 as described above.
Preferably, it is 0 μm.

Next, as shown in FIG. 8D, the photoresist film 40 is peeled off. The peeling method may be either a dry method or a wet method.

The external connection projections 20 are formed by the steps described above. The above steps are all wafer processes, and processing for each semiconductor chip can be performed collectively. The dicing of the semiconductor wafer 16 is performed after the above steps are completed.

Next, a third embodiment of the present invention will be described. In this embodiment, a plurality of external connection projections according to the first embodiment are integrally provided. That is, as shown in FIG.
No. 0 forms a protruding body 22 adjacent to and parallel to the four electrode pads 14, and forms a conductor 24 so as to straddle over the electrode pad 12 and the protruding body 22 for every four electrode pads. are doing. Other configurations are the same as those described in the first embodiment.

Therefore, in this embodiment,
The same operation and effects as those of the first embodiment can be obtained,
By providing one projection for a plurality of electrode pads, the process of forming the external connection projection can be simplified.

In FIG. 5, one protruding body 22 is provided for four electrode pads 14. However, the number of electrode pads 14 is not limited to this, and any number of electrode pads 14 may be used as long as it is two or more. May be used. The shape of the protruding body 22 and the formation range of the conductor 24 may be the same as those shown in FIG. 2 or FIG. 3 as in the first embodiment. The external connection projections 20 are formed in the same manner as in the first embodiment, except that the plurality of protrusions 22 are integrally formed.

Further, a fourth embodiment of the present invention will be described. In this embodiment, all the external connection projections formed on one semiconductor chip are integrated. That is, as shown in FIG. 6, the external connection projections 20 are arranged such that the frame-shaped projections 30 are arranged adjacent to the insides of the respective electrode pads 14 of the semiconductor chip 10, and the conductor 24 is further provided for each of the electrode pads. It is formed so as to extend over the electrode pad 12 and the frame-shaped protrusion 30. Other configurations are the same as those described in the first embodiment.

Therefore, in this embodiment,
The same operation and effects as those of the first embodiment can be obtained,
By providing one projection for all the electrode pads formed on one semiconductor chip, the process of forming the external connection projection can be simplified.

The frame-shaped protrusion 30 may be formed in a shape without an opening at the center, that is, the whole may be formed as a single plate. Further, the shape of the protruding body 22 and the conductor 2
The formation range of 4 may be the same as that shown in FIG. 2 or 3 as in the first embodiment. The external connection projections 20 are formed in the same manner as in the first embodiment, except that all the protrusions 22 are formed integrally.

FIG. 9 shows an example in which a semiconductor chip having the external connection projections described above is used. That is, FIG. 9 shows a circuit board 10 on which a semiconductor chip 110 having external connection protrusions according to the embodiment of the present invention is mounted.
0 is shown. As the circuit board 100, an organic substrate such as a glass epoxy substrate is generally used. On the circuit board 100, a bonding portion made of, for example, copper is formed so as to form a desired circuit. Then, by electrically connecting the bonding portion and the external electrode of the semiconductor chip 110, their electrical continuity is achieved.

The semiconductor chip 110 can reduce the mounting area to the area for mounting with bare chips, and if the circuit board 100 is used for an electronic device, the size of the electric device itself can be reduced. Also, in the same area, more mounting space can be secured,
It is also possible to increase the functionality.

FIG. 10 shows a notebook personal computer 120 as an electronic apparatus having the circuit board 100.

As described above, in the embodiment of the present invention, since the external connection projections having a small aspect ratio and a high aspect ratio can be formed, the external connection projections particularly suitable for a small semiconductor chip can be provided. Further, since one external connection projection is formed for a plurality of electrode pads, the process of forming the external connection projection can be simplified.

[0062]

As described above, according to the present invention, in a semiconductor chip having electrodes formed thereon, the protrusions connected to the electrodes and projecting in parallel with the active element forming surface of the semiconductor chip. Since the configuration has the external connection projections formed with the portions, the external connection projections having a high aspect ratio and a small amount of metal used as the material can be easily formed. Further, the present invention contributes to miniaturization of the semiconductor chip having the external connection projections formed thereon, furthermore, a circuit board on which the semiconductor chip is mounted, and an electronic device including the circuit board. In addition, it significantly contributes to cost reduction.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an external connection projection according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a modification of the external connection projection according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing a modification of the external connection projection according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view of an external connection projection according to a second embodiment of the present invention.

FIG. 5 is a perspective view of an external connection projection according to a third embodiment of the present invention.

FIG. 6 is a plan view of an external connection projection according to a fourth embodiment of the present invention.

FIG. 7 is an explanatory diagram of a manufacturing process of the external connection projection according to the first embodiment of the present invention.

FIG. 8 is an explanatory diagram of a manufacturing process of a semiconductor chip according to a second embodiment of the present invention.

FIG. 9 is an explanatory diagram of a circuit board on which a semiconductor chip having external connection protrusions according to the first embodiment of the present invention is mounted.

FIG. 10 is an explanatory diagram of an electronic apparatus including the circuit board shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Semiconductor chip 12 Protective film 14 Electrode pad 16 Semiconductor wafer 20 External connection projection 22 Projection body 24 Conductor 26 Flange part 28 Hollow part 30 Frame-like projection body 40 Photoresist film 42 Opening part 50 Width 52 Height 100 Circuit board 110 Semiconductor device 120 Notebook type personal computer

Claims (11)

[Claims] An external connection projection formed on an active element forming surface of a semiconductor chip, wherein a projection formed near an electrode of the semiconductor chip is continuously formed on the electrode and the projection. And a conductor formed. 2. The external connection projection according to claim 1, wherein the conductor is formed so as to cover a top of the projection. 3. The external connection projection according to claim 1, wherein a top of the projection is formed flat. 4. The device according to claim 1, wherein said projecting body is formed in parallel with the arrangement of said electrodes and in the vicinity of said electrodes, and said conductor is formed one for each said electrode. The external connection projection according to claim 3. 5. The external connection projection according to claim 4, wherein the projection is formed in a frame shape in a region surrounded by the electrodes on the active element formation surface. 6. The external connection projection according to claim 1, wherein the projection is made of a resin. 7. An external connection projection formed on an active element forming surface of a semiconductor chip, wherein the external connection projection is formed in a bottomed cylindrical shape on an electrode of the semiconductor chip. 8. A semiconductor chip comprising the external connection projection according to claim 1. 9. A circuit board on which the semiconductor chip according to claim 8 is mounted. 10. An electronic apparatus comprising the circuit board according to claim 9. 11. A method of forming an external connection projection on a semiconductor wafer, comprising: bonding a protruding body near an electrode formed on the semiconductor wafer; and plating the protruding body on the electrode and the protruding body by a plating method. And a step of forming a conductor.