JP2000216182A - Semiconductor device, its manufacture, and its mounting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contrive the downsizing of a module by lessening the connection area between a semiconductor device and a circuit board, thereby enabling high-density mounting. SOLUTION: An electrode pad 14 is made on the surface 12a of a semiconductor chip 12, and a first bump electrode 22 is provided on the lower electrode 19 provided thereon, and a second bump electrode 24 is provided outside the first bump electrode 2. For the semiconductor chip 12, the sidewall on the side of the right end in the figure is formed stepwise, and the first bump electrode 22 and the second bump electrode 24 are provided to straddle from the surface 12a of the semiconductor chip 12 to the flank 12b of the step. Then, the outside of the second bump electrode 24 jut out rightward in figure more than the flank 12c of the semiconductor chip 12. Accordingly, it can be mounted, with the outside of the projecting second bump electrode 24 in contact with a circuit board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device provided with a protruding electrode (bump) that can be electrically and mechanically connected to a circuit board, a method of manufacturing the semiconductor device, and a method of manufacturing the semiconductor device. The present invention relates to a mounting structure of a semiconductor device in which a semiconductor device is mounted so as to be electrically and mechanically connected to a circuit board. The circuit board is a resin board made of glass fiber reinforced epoxy or the like, a ceramics board, a glass board forming a liquid crystal display panel, or the like.

[0002]

2. Description of the Related Art Conventionally, as a semiconductor device having a projecting electrode which can be electrically and mechanically connected to a circuit board, there is a semiconductor device 71 as shown in FIG. 15, for example. In the semiconductor device 71, a plurality of electrode pads 74 are arranged in a row on an upper surface 72a of a semiconductor chip 72, and the upper surface 72a is covered with an insulating film 76 that opens only the upper surface of the electrode pad 74. In addition, a lower electrode 79 is formed on each electrode pad 74, and a side surface of each lower electrode 79 is formed on the semiconductor chip 7.
A projection electrode 82 in the form of a straight wall substantially perpendicular to the upper surface 72a of the second electrode 72 is provided.

Next, a method of manufacturing the semiconductor device 71 shown in FIG. 15 will be described with reference to FIGS. In order to manufacture the semiconductor device 71, first, as shown in FIG. 16, a plurality of electrode pads 74 are formed on a semiconductor substrate 70 for forming a plurality of semiconductor chips arranged in a direction perpendicular to the plane of the drawing. An insulating film 76 is formed on the entire surface. After that, the insulating film 76 is patterned by photolithography and etching so that the upper surface of each electrode pad 74 is exposed.

Next, the insulating film 76 and the electrode pad 74
A common electrode film 78 is formed on the entire surface 70a of the semiconductor substrate 70 including the upper surface by a sputtering method. The common electrode film 78 is formed of 0.8 μm of aluminum, 0.01 μm of chromium, and 0.8 μm of copper from the semiconductor substrate 70 side.
It is formed sequentially with a thickness of μm. The common electrode film 78 having the multilayer structure plays a role of a connection layer with the electrode pad 74 and a barrier layer for preventing mutual diffusion, and also plays a role of an electrode when the protruding electrode is formed by plating.

Thereafter, as shown in FIG. 17, a photosensitive resin (photoresist) 80 is formed to a thickness of 17 μm on the entire surface of the common electrode film 78 by a spin coating method. Further, the photosensitive resin 8 is exposed using a predetermined photomask by an exposure device.
The photosensitive resin 80 is patterned by a photolithography process that exposes 0 and then performs a development process. By this patterning, the photosensitive resin 80 becomes
An opening is formed in a region where the bump electrode 82 is to be formed later to expose the common electrode film 78.

Next, a protruding electrode 82 having a thickness of 10 μm to 15 μm in a straight wall shape is formed on the common electrode film 78 in the opening of the photosensitive resin 80 by gold plating using the common electrode film 78 as a plating electrode. I do. Thereafter, the photosensitive resin 80 is removed, and the common electrode film 78 is etched by a wet etching method using the protruding electrodes 82 as a mask, thereby forming a lower electrode 79 in a region aligned with the protruding electrodes 82 as shown in FIG. .

[0007] Finally, by cutting (dicing) the boundary portion between the semiconductor chips adjacent to the semiconductor substrate 70,
As shown in FIG. 15, the semiconductor substrate 70 is divided into single semiconductor chips 72, and each semiconductor device 71 is completed. The reason why the wet etching is performed when forming the lower electrode 79 by etching the common electrode film 78 described with reference to FIGS. 18 and 19 is as follows.

That is, the common electrode film 78 is formed of 0.8 μm of aluminum and 0.1 μm of chromium from the semiconductor substrate 72 side.
In order to form a three-layer structure with a thickness of 0.1 μm and copper with a thickness of 0.8 μm, in a dry etching method, a composite etching gas must be used as an etching gas used to obtain an etching selectivity between a layer to be etched and another layer. Must be
This is because the selection of the composite etching gas becomes complicated.

In addition, the dry etching method is disadvantageous in industrial production because the time required for the etching process is very long, and the equipment used for the etching process is also expensive. This is because there is a problem. However, according to the wet etching method, by selecting an etching solution having an etching selectivity, an etching process can be easily performed without requiring a large-scale facility.

Next, an example of a conventional mounting structure for connecting a semiconductor device 71 formed by the above-described manufacturing method to a circuit board will be described with reference to FIG. 19 using a liquid crystal display panel as an example. Note that FIG. 19 shows a cross section of a portion other than the semiconductor device 71 and the glass substrates 86a and 86b of the liquid crystal display panel 86 and the flexible printed circuit board 68.
A liquid crystal display panel 86 shown in FIG.
A liquid crystal 96 is sealed between the glass substrates 86a and 86b, and a plurality of transparent electrodes 88a and 88b are provided on the opposing surfaces of the glass substrates 86a and 86b in directions orthogonal to each other.

To mount the semiconductor device 71 on a glass substrate 86a which is a circuit substrate of the liquid crystal display panel 86,
The semiconductor device 71 is turned upside down with respect to the position shown in FIG. Then, the semiconductor device 71
Is arranged such that the lower protruding electrode 82 is aligned with the transparent electrode 88a on the glass substrate 86a. At this time, the anisotropic conductive adhesive 54 is interposed between the protruding electrode 82 and the glass substrate 86a. This anisotropic conductive adhesive 54 is obtained by mixing conductive particles 52 in an insulating adhesive.

As described above, in a state where the semiconductor device 71 is set on the glass substrate 86a of the liquid crystal display panel 86, the semiconductor device 71 is subjected to a heat treatment while being pressed against the glass substrate 86a. 86a
It is electrically connected to each of the upper transparent electrodes 88a. Further, the flexible printed circuit board is also provided on the terminal electrode 88c formed on the right side of FIG. 19 on the glass substrate 86a with the anisotropic conductive adhesive 54 mixed with the conductive particles 52 interposed therebetween. (FPC) 68 is arranged, and the FPC 68 is heated while being pressed against the glass substrate 86a.

The FPC 68 is a film on which copper wiring electrodes for supplying power to the semiconductor device 71 and providing input signals are patterned. By doing so, the distance between the projecting electrode 82 and the transparent electrode 88a and the FP
The conductive particles 52 of the anisotropic conductive adhesive 54 are secured between the C68 and the terminal electrode 88c, thereby forming the protruding electrode 82 and the transparent electrode 88a, and the copper wiring electrode and the terminal electrode 88c of the FPC 68. Are electrically connected to each other, and are mechanically connected by an insulating adhesive.

Thereafter, as shown in FIG. 19, a protective material 62 is provided on the upper surfaces of the semiconductor device 71 and the FPC 68 and on the periphery thereof.
Is applied. As a result, the projection electrode 82 and the transparent electrode 88
In addition, it is possible to prevent moisture from entering the connection portion between the terminal a and the connection portion between the copper wiring electrode of the FPC 68 and the terminal electrode 88, and to enhance the reliability by performing mechanical protection.

[0015]

However, such a conventional semiconductor device and its mounting structure on a circuit board have a problem that the occupied area for mounting the semiconductor device on the circuit board becomes large. Therefore, it has been difficult to reduce the size of the circuit board for connecting the semiconductor device.

For example, the liquid crystal display panel 8 shown in FIG.
6 and the FPC 6 on the glass substrate 86a.
8 has a width of 2 mm of the semiconductor device 71,
The connection margin of the semiconductor device 71 is 1 mm, and the connection margin of the flexible film 68 is 2 mm, so that about 5 mm is required.

The portion of the glass substrate 86a where the semiconductor device 71 and the FPC 68 are connected is a portion serving as a non-display portion of the liquid crystal panel 86. Therefore, there is a problem that the area of the non-display portion becomes very large with respect to the area of the display portion. That is, the area occupied by mounting the semiconductor device and the FPC on the liquid crystal display panel increases.

The present invention solves the problems of the above-described conventional semiconductor device and its mounting structure on a circuit board, and reduces the area of a connection portion required for connecting the semiconductor device or the FPC to the circuit board to reduce the circuit area. It is an object of the present invention to provide a semiconductor device capable of reducing the size of a substrate or a module of a liquid crystal display panel, a manufacturing method thereof, and a mounting structure thereof.

[0019]

In order to achieve the above object, the present invention provides a semiconductor chip, an electrode pad formed on an upper surface of the semiconductor chip, and an opening on the electrode pad to form an upper surface of the semiconductor chip. A semiconductor device comprising: an insulating film covering the electrode pad; a lower electrode provided over the electrode pad and a side surface of the semiconductor substrate; and a protruding electrode provided on the lower electrode.

According to this semiconductor device, the lower electrode is provided so as to extend over the electrode pad and the side surface of the semiconductor chip.
Since the protruding electrode is provided on the lower electrode, it can be connected to the electrode of the circuit board by using the protruding electrode in a portion straddling the side surface. Therefore, the surface for connecting to the circuit board of the semiconductor device can be a side surface, and the area for the connection can be significantly reduced.

Further, it is preferable that the side wall of the semiconductor chip has a stepped shape. Then, when electrically connecting the projecting electrodes of the semiconductor device to the electrodes on the circuit board, the side faces of the semiconductor chip having the projecting electrodes can be simply and simply connected to the planar circuit board directly. Connection can be made securely. Further, it is preferable that the protruding electrode is constituted by a plurality of metal layers.

Further, it is preferable that the protruding electrode is formed so as to protrude outside the side surface of the semiconductor chip. By doing so, the connection of the bump electrode of the semiconductor device to the circuit board is simple and reliable. Furthermore, it is preferable that the protruding electrodes are formed of solder. that way,
When connecting a semiconductor device to an electrode of a circuit board, the semiconductor device is securely connected and fixed to the circuit board by the solder only by heating the solder to a temperature at which the solder melts while the protruding electrode is in contact with the electrode of the circuit board. be able to.

Further, in the method of manufacturing a semiconductor device according to the present invention for obtaining such a semiconductor device, there is provided a method of manufacturing a semiconductor chip having a plurality of electrode pads arranged in a row. A first dicing step of forming a street line by forming a groove at the boundary so that the semiconductor substrate remains at a predetermined thickness; and a step of forming a common electrode film over the entire surface of the semiconductor chip. Forming a photosensitive resin on an electrode film, and patterning the photosensitive resin so as to form an opening for forming a protruding electrode in a predetermined region extending from the electrode pad to the street line of the photosensitive resin. Forming a projecting electrode in the opening of the photosensitive resin on the common electrode film, removing the photosensitive resin, and using the projecting electrode as a mask. And a step of etching the electrode film, the street line portion of the semiconductor substrate, and a second dicing step of cutting a narrow working width than the processing width of the first dicing step. According to this method, the semiconductor device can be manufactured relatively easily.

In the method of manufacturing a semiconductor device, a step of plating the surface of the bump electrode may be performed after the second dicing step.
Further, after the second dicing step, a step of reflowing the protruding electrode into a spherical shape may be performed.

Further, in the semiconductor device mounting structure for connecting the semiconductor device to a circuit board according to the present invention, the side of the semiconductor chip constituting the semiconductor device on which the protruding electrode is provided is connected to the circuit board and connected to the circuit board. The electrodes and the electrodes on the circuit board are electrically connected.

In the mounting structure of the semiconductor device, a side surface of the semiconductor chip opposite to a side surface connected to the circuit board or a side surface orthogonal to the side surface is connected to a flexible printed circuit board and connected to the side surface. The provided protruding electrode and the electrode on the flexible printed circuit board may be electrically connected.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a semiconductor device according to the present invention, and embodiments of a method of manufacturing the semiconductor device and a mounting structure will be described below with reference to the drawings. [Description of the structure of the semiconductor device according to the present invention: FIG. 1] First, the structure of the semiconductor device according to the present invention will be described with reference to FIGS. FIG. 1 shows only a main part of a semiconductor device according to the present invention, and FIG. 2 is a schematic sectional view showing the whole.

The semiconductor device 1 includes a semiconductor chip 12
An electrode pad 14 formed on the surface 12 a of the semiconductor chip 12, an insulating film 16 covering the periphery of the electrode pad 14, and a lower electrode 19 formed on the electrode pad 14 and on the side wall of the semiconductor substrate 12. have.

Then, a first projecting electrode 22 is provided on the lower electrode 19, and a second projecting electrode 22 is formed on the surface of the first projecting electrode 22.
By providing the projecting electrodes 24, the projecting electrodes 23 are formed in a plurality of layers. The semiconductor chip 12 has a stepped shape of a sidewall serving as a right end face in FIG. The first protruding electrode 22 and the second protruding electrode 24 are provided so as to extend over the surface 12a of the semiconductor substrate 12 and the side surface 12b of the step.

The right end of the second protruding electrode 24 is one to one from the side surface 12 c of the semiconductor chip 12 where the step portion protrudes.
It protrudes by 10 μm. The lower electrode 19
Has a role as a wiring for electrically guiding the electrode pad 14 to the side surface of the semiconductor chip 12, and a projection electrode 23 composed of a first projection electrode 22 and a second projection electrode 24 connects the semiconductor device 1 to a circuit board. Function as a connection electrode for connection. The protruding electrode 23 is made of gold (Au).
It may be composed of a single metal that is difficult to oxidize.

[Description of Manufacturing Method of Semiconductor Device According to the Present Invention: FIGS. 2 to 10] Next, a method of manufacturing the semiconductor device 1 having the shape shown in FIG. 2 will be described. First, as shown in FIG. 3, an integrated circuit including a large number of active elements and passive elements for a semiconductor chip (not shown).
And a number of electrode pads 1 for connecting it to an external circuit
The semiconductor substrate (wafer) 10 provided with the semiconductor wafer 4 is subjected to a first groove forming step (dicing step) at the boundary between the adjacent semiconductor chips 12 and 12 to form a street line 10b.
To form The thickness t of the portion of the semiconductor substrate 10 left after the groove processing is 200 μm to 300 μm.
So that

Next, as shown in FIG.
An insulating film 16 made of photosensitive polyimide is formed on the entire surface by a spin coating method to a thickness of 2 μm to 3 μm. As the insulating film 16, a silicon oxide film containing boron, phosphorus, or boron and phosphorus other than photosensitive polyimide may be formed by a chemical vapor deposition method, or a silicon nitride film may be formed by a plasma chemical vapor deposition method. It may be formed by a growth method.

Thereafter, the photosensitive polyimide film is subjected to an exposure process using a predetermined photomask, and then a development process is performed to form an opening 1 on the electrode pad 14 as shown in FIG.
6a is formed, and patterning is performed so that the periphery of the electrode pad 14 is covered with the insulating film 16. Next, as shown in FIG. 6, over the entire surface of the semiconductor substrate 10 including the insulating film 16 and the electrode pads 14, aluminum is formed to a thickness of 0.8 μm and chromium to a thickness of 0.0
A film of 1 μm and a film of 0.8 μm of copper are sequentially formed, thereby forming a common electrode film 18 in a three-layer structure. The common electrode film 18 shown in FIG. 6 has good electrical connectivity and mechanical adhesion with the electrode material forming the electrode pad 14 and the first bump electrode 22 (see FIG. 2). Further, it is necessary to use a stable electrode material without diffusion between the electrode materials.

For this reason, the common electrode 18 has a three-layer structure of aluminum, chromium, and copper, as well as titanium-palladium, titanium-gold, titanium-platinum, titanium-tungsten alloy-palladium. Or a two-layer film structure of titanium-tungsten alloy-gold, titanium-tungsten alloy-platinum, chromium-copper,
An aluminum-titanium-copper three-layer structure is effective.

Thereafter, as shown in FIG.
0 is applied on the entire surface of the common electrode film 18 by a spin coating method to a thickness
Formed at 7 μm. Further, the photosensitive resin 20 is exposed to light using a predetermined photomask, and then subjected to development processing, thereby forming an opening for forming a protruding electrode in a region extending from above the electrode pad 14 to above the street line 10b. The photosensitive resin 20 is patterned as described above.

Next, using the photosensitive resin 20 as a plating mask, copper plating is performed to a thickness of 10 μm to 15 μm to thereby form the first protruding electrode 22 to the photosensitive resin 2.
0 is formed on the common electrode film 18 in the opening. The first protruding electrode 22 formed here may have a material of gold or nickel structure.

Thereafter, as shown in FIG. 9, the photosensitive resin 20 used as a plating mask is removed using a wet stripper. Further, etching is performed with a copper etching solution Enstrip C (trade name) manufactured by Meltex using the first protruding electrode 22 as an etching mask, and the first electrode of copper, which is the uppermost film of the common electrode film 18, is formed. The region exposed from the protruding electrode 22 is removed. In this etching process, etching is performed in just over etching time of 30%.

Next, chromium (middle layer), which is a barrier layer and an adhesion layer, and aluminum (lowest layer) of the common electrode film 18 are etched with a mixed solution of cerium ammonium nitrate, potassium ferricyanide, and sodium hydroxide. In this etching process, etching is performed for 30% of the overetching time from the just etching, and unnecessary portions of the common electrode film 18 are removed. To form

Next, the street line 1 in which the thickness of the semiconductor substrate 10 is reduced in the first groove processing step described with reference to FIG.
0b is cut by a second groove processing step (dicing step) as shown in FIG.
0 is cut into a single semiconductor chip 12. At this time,
The cutting width W in the second groove processing step is set to be narrower by about 30 μm to 50 μm than the cutting width in the first groove processing step.

Thereafter, as shown in FIG. 2, gold is plated on the entire exposed surface of the first protruding electrode 22 to a thickness of 2 μm to 3 μm by an electroless plating method. 24 are formed. Note that the second protruding electrode 24
May have a nickel-gold two-layer structure. Through these steps sequentially, the protruding electrode 23 is connected to the surface 1 of the semiconductor chip 12.
The semiconductor device 1 formed so as to straddle the 2a and the side surface 12c is obtained.

[Description of Mounting Structure of Semiconductor Device on Circuit Board: FIG. 11] Next, an example of a mounting structure for mounting the semiconductor device 1 of FIG. 2 on a circuit board will be described. As shown in FIG. 11, transparent electrodes 28 and 29 were formed on opposing surfaces, respectively.
When the semiconductor device 1 of the present invention is mounted on the liquid crystal panel 2 in which the liquid crystal 56 is sealed between the glass substrates 26a and 26b with the sealing material 27, the semiconductor device 1 is placed such that the side surface 12c is oriented vertically. To place.

The semiconductor device 1 is provided on the lower surface of the lower second protruding electrode 23 (shown in a simplified form) in FIG. 11 and on the upper surface of the glass substrate 26a as the lower circuit substrate. Anisotropic conductive adhesive 3 between transparent electrode 28
6, the side surface 12b of the semiconductor device 1 and the circuit board 2
And are arranged so as to face each other.

Further, the upper second protruding electrode 23 in FIG.
(Shown in a simplified manner) and a flexible printed circuit board (F
Anisotropic conductive adhesive 36 is also interposed between PC and 58. The anisotropic conductive adhesive 36 is a film on which copper wiring electrodes for supplying power and input signals for driving the semiconductor device 1 are patterned. The anisotropic conductive adhesive 36 is an adhesive obtained by dispersing conductive particles in an insulating adhesive. The anisotropic conductive adhesive 36 conducts in the opposite thickness direction and insulates in the lateral direction.

Then, the FPC 58 is pressed against the glass substrate 26a, and the space between the protruding electrode 23 and the transparent electrode 28 and the FP
400 kg / c between C58 and the protruding electrode 23
Apply a pressure of m ² and simultaneously heat at a temperature of 180 ° C to 220 ° C.

Thus, between the lower protruding electrode 23 and the transparent electrode 28, and between the upper protruding electrode 23 and the FPC 58.
Can be electrically connected to the copper wiring electrode by conductive particles in the anisotropic conductive adhesive 36, and the semiconductor device 1 and the glass substrate 26a and the FPC 58 are mechanically connected by the insulating adhesive. Can be connected.

Further, a protective member 62 is formed around the semiconductor device 1 to prevent moisture from entering each of the above-mentioned connecting portions and to provide mechanical protection to enhance reliability. In addition, as the anisotropic conductive adhesive 36, a thermosetting epoxy adhesive which is an insulating adhesive, nickel-gold plated two layers on the surface of a spherical plastic, and a bead shape having an outer diameter of 4 μm to 6 μm. A material in which conductive materials are mixed at about 40% by volume is used.

In the example shown in FIG. 11, the FPC 58 is bonded to the side of the semiconductor chip 12 on which the protruding electrodes 23 are provided.
11, that is, the protruding electrode 23 is provided on the side surface on the near side of the paper surface in FIG.
May be connected. As described above, the semiconductor device 1 has the side surface 12 c mounted in the up-down direction, thereby forming the side surface 12 b of the bump electrode 23 in the thickness direction of the semiconductor device 1.
Can be mounted on the glass substrate 26a at a portion parallel to the substrate. Therefore, the area occupied by the mounting can be significantly reduced as compared with the related art, the size of the liquid crystal panel 2 can be reduced, and the semiconductor device can be mounted on the liquid crystal panel 2 with high density.

Next, another embodiment of the semiconductor device according to the present invention, its manufacturing method and the mounting structure of the semiconductor device will be described with reference to FIGS. FIG.
In FIGS. 2 to 14, parts corresponding to those in FIGS. 1 to 11 are denoted by the same reference numerals, and description thereof is omitted.

[Another Embodiment of Semiconductor Device According to the Present Invention and Its Manufacturing Method: FIGS. 12 and 13] As shown in FIG. 12, the semiconductor device described in the above embodiment has been described with reference to FIGS. As in the case, the semiconductor substrate 10 is subjected to the first groove processing step (dicing step) so that the thickness t of the portion left after the groove processing becomes 200 μm to 300 μm.

Next, an insulating film 16 made of photosensitive polyimide is formed on the entire surface of the semiconductor substrate 10 to a thickness of 2 μm to 3 μm. After that, an exposure process and a development process are performed using a predetermined photomask, and the insulating film 16 is patterned so as to open the electrode pad 14. The insulating film 1
6 may be formed by forming a silicon nitride film having a thickness of 2 μm to 3 μm by plasma-enhanced chemical vapor deposition instead of photosensitive polyimide, or forming a silicon dioxide film containing boron or phosphorus or boron and phosphorus. It may be formed by a chemical vapor deposition method.

As the insulating film 16, an inorganic film such as tantalum oxide or aluminum oxide may be used in addition to silicon nitride or silicon dioxide. Further, the insulating film 16 has a multilayer structure of the above-described inorganic film and organic film.
May be formed. Further, as a method of forming the insulating film 16, a sputtering method may be used in addition to the above-described plasma chemical vapor deposition method or chemical vapor deposition method.

A film of aluminum having a thickness of 0.8 μm, chromium of 0.01 μm, and copper of 0.8 μm is sequentially formed on the entire surface of the insulating film 16 thus formed by sputtering. An electrode film 18 (which will be a lower electrode 19 later) is formed in a three-layer structure. The common electrode 18
Examples include a two-layer film structure of titanium-palladium, titanium-gold, titanium-platinum, titanium-tungsten alloy-palladium, titanium-tungsten alloy-gold, titanium-tungsten alloy-platinum, aluminum-
A titanium-copper three-layer structure or the like can be used.

Then, as in the case described with reference to FIG.
It is formed with a thickness of 30 μm. After that, the photosensitive resin 20 is patterned so as to form an opening in a region where a protruding electrode is to be formed by performing an exposure process using a predetermined photomask and a development process thereafter.

Next, as in the case described with reference to FIG. 8, using the photosensitive resin 20 as a plating mask, solder plating is performed to a thickness of 15 μm to 20 μm so that the projecting electrode 32 is The photosensitive resin 20 is formed on the common electrode film 18 in the opening (in FIG. 12, only one side of the photosensitive resin 20 is shown by a virtual line for simplification).

By doing so, the projection electrode 32
Are formed on the common electrode film 18 so as to extend over the surface 12a and the side surface 12b of the semiconductor substrate 12. The composition of the solder plating solution used here is selected so that the composition after plating is 60% tin and 40% lead.

Next, after forming the protruding electrodes 32, the photosensitive resin 20 used as a plating mask is removed using a wet stripping solution. Further, the same etching as in the embodiment described above with reference to FIG. 9 is performed by using the protruding electrode 32 as an etching mask, and the copper which is the uppermost film of the common electrode film 18 is exposed from the protruding electrode 32. Remove the area. The etching process at this time is the same as the case described with reference to FIG. 9 in that the etching is performed with just over etching time of 30% from the just etching.

Next, chromium (middle layer) and aluminum (lowest layer) which are a barrier layer and an adhesion layer of the common electrode film 18 are etched with a mixed solution of cerium ammonium nitrate, potassium ferricyanide, and sodium hydroxide. Also in this etching process, the etching is performed for 30% of the overetching time from the just etching, and unnecessary portions of the common electrode film 18 are removed, and the lower electrode 19 is formed in a region matching the protruding electrode 32.

Next, as in the case described with reference to FIG. 10, a second groove processing step (dicing step) is performed with a cutting width W, and the thickness of the semiconductor substrate 10 is first reduced in the first groove processing step. Cut the thinned part. Thereby, the semiconductor substrate 12 is cut into a single semiconductor chip 12. In addition,
The point that the cutting width W in the second groove processing step is made smaller by about 30 μm to 50 μm than the cutting width in the first groove processing step is the same as in the embodiment described with reference to FIGS. 1 to 11. .

Next, as shown in FIG. 13, the single semiconductor chip 12 is heated at a temperature of 230.degree. C. to 250.degree. C. to melt the solder, and the protruding electrodes 32 are formed using surface tension. Round. At this time, the rightmost portion of the rounded protruding electrode 32 in FIG.
1 μm to the right in FIG.
It protrudes by 10 μm. Thus, the semiconductor device 31 using the solder for the protruding electrodes 32 can be formed.

[Mounting Structure of Semiconductor Device According to Another Embodiment: FIG. 14] Next, a mounting structure of the semiconductor device 31 of FIG. 13 on a circuit board will be described. When the semiconductor device 31 shown in FIG. 13 is mounted on a circuit board 46, FIG.
As shown in FIG. 4, the semiconductor device 31 is arranged so that the side surface of the semiconductor device 31 (shown in a simplified manner) is on the lower side, and the protruding electrode 32 is located on the electrode 28 of the circuit board 46. .

In this state, when heating is performed at a temperature of 230 ° C. to 250 ° C., the solder of the protruding electrodes 32 is melted. Therefore, the semiconductor device 31 is fixed to the electrode 28 by cooling after the solder is welded to the electrode 28.
Then, the vicinity of the connection between the protruding electrode 32 and the electrode 28 is covered with a protective material 62 including the portion of the semiconductor device 31 so as to reinforce the connection portion. The reliability in dynamic connectivity.

As described above, in this embodiment,
Since the protruding electrodes 32 are formed by solder plating,
The protruding electrode 32 protruding from the side surface 12c of the semiconductor chip 12 can be easily formed. Further, since the protruding electrodes 32 can be melted by a heating reflow process at 230 ° C. to 250 ° C., the semiconductor device 31 can be easily fixed on the circuit board 46.

Further, by performing the reflow process at 230 ° C. to 250 ° C., the reliability of the electrical connection and the mechanical connection of the connecting portion to the circuit board 46 of the semiconductor device 31 can be further improved. Can be. Although the semiconductor device according to the above embodiments has been described as being mounted on a liquid crystal display panel, the mounting structure of the semiconductor device can be applied to mounting of the semiconductor device on a resin substrate or a ceramic substrate.

[0064]

As described above, according to the semiconductor device and the mounting structure of the present invention, the lower electrode is provided so as to extend over the electrode pad and the side surface of the semiconductor chip, and the protruding electrode is provided on the lower electrode. Therefore, the connection of the semiconductor device to the circuit board can be performed on the surface having the protruding electrodes serving as the side surfaces of the semiconductor device, so that the connection area for the connection can be reduced.

Accordingly, high-density mounting of the semiconductor device on a liquid crystal display device, a circuit board, or the like is possible, and high reliability is obtained with respect to the electrical connection and the mechanical connection of the connection portion. Further, when this semiconductor device is applied to a liquid crystal display device, the frame can be narrowed, and the size of the glass substrate can be reduced.

Further, when the method of manufacturing a semiconductor device according to the present invention is implemented, a semiconductor device can be manufactured relatively easily without greatly changing the steps as compared with the conventional method of manufacturing a semiconductor device.

[Brief description of the drawings]

FIG. 1 is a sectional view showing only a main part of an embodiment of a semiconductor device according to the present invention.

FIG. 2 is a sectional view showing the overall shape of the semiconductor device.

FIG. 3 is a cross-sectional view showing a semiconductor substrate for describing a first groove processing step similarly performed for manufacturing the semiconductor device.

FIG. 4 is a cross-sectional view for explaining a step of forming an insulating film which is also performed for manufacturing the semiconductor device.

FIG. 5 is a cross-sectional view for explaining a step of patterning the insulating film.

6 is a cross-sectional view for describing a step of forming a common electrode film performed after the step of FIG.

FIG. 7 is a cross-sectional view for explaining a step of forming a photosensitive resin on the common electrode film after the step of FIG. 6;

FIG. 8 is a cross-sectional view for explaining a process of leaving only a predetermined portion of the photosensitive resin.

FIG. 9 is a cross-sectional view for explaining a step of forming a lower electrode after the step of FIG. 8;

FIG. 10 is a cross-sectional view showing a state where the semiconductor substrate is cut into semiconductor chips after the step of FIG. 9;

11 is a cross-sectional view illustrating an example of a mounting structure in which the semiconductor device of FIG. 2 is mounted on a circuit board.

FIG. 12 is a sectional view showing another embodiment of the semiconductor device according to the present invention;

13 is a cross-sectional view for explaining a step of reflowing a protruding electrode formed of solder in the semiconductor device of FIG. 12 into a spherical shape.

14 is a cross-sectional view showing an example of a mounting structure of the semiconductor device of FIG. 12 on a circuit board.

FIG. 15 is a cross-sectional view illustrating an example of a conventional semiconductor device.

16 is a cross-sectional view for describing a step of forming a common electrode film performed when manufacturing the semiconductor device of FIG.

FIG. 17 is a cross-sectional view for explaining a step performed after FIG. 16;

FIG. 18 is a cross-sectional view for explaining a step performed after FIG. 17;

19 is a cross-sectional view illustrating an example of a mounting structure in which the conventional semiconductor device of FIG. 15 is mounted on a circuit board.

[Explanation of symbols]

 1, 31: semiconductor device 2, 86: circuit board 12: semiconductor substrate 12b, 12c: side surface 14: electrode pad 16: insulating film 18: common electrode film 19: lower electrode 20: photosensitive resin 22: first projection electrode 23, 32: protruding electrode 24: second protruding electrode 58, 68: flexible printed circuit board (FPC)

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[Procedure amendment]

[Submission date] January 25, 1999 (1999.1.2
5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0027

[Correction method] Change

[Correction contents]

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a semiconductor device according to the present invention, and embodiments of a method of manufacturing the semiconductor device and a mounting structure will be described below with reference to the drawings. [Description of the structure of the semiconductor device according to the present invention: FIG. 1 and FIG.
2 ] First, the structure of the semiconductor device according to the present invention will be described with reference to FIGS. FIG. 1 shows only a main part of a semiconductor device according to the present invention, and FIG. 2 is a schematic sectional view showing the whole.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0040

[Correction method] Change

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Thereafter, as shown in FIG. 2, gold is plated on the entire exposed surface of the first protruding electrode 22 to a thickness of 2 μm to 3 μm by an electroless plating method. 24 are formed. Note that the second protruding electrode 24
May have a nickel-gold two-layer structure. Through these steps sequentially, the protruding electrode 23 is formed on the surface 1 of the semiconductor chip 12.
The semiconductor device 1 formed so as to straddle the 2a and the side surface 12c is obtained.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0042

[Correction method] Change

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The lower side of the semiconductor device 1 in FIG.
An anisotropic conductive adhesive 36 is interposed between the lower surface of the protruding electrode 23 (shown in a simplified form) and the transparent electrode 28 provided on the upper surface of the glass substrate 26a as the lower circuit substrate. The circuit board 2 and the side surface 12b of the semiconductor device 1 are arranged so as to face each other.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

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Further, the upper second protruding electrode 23 in FIG.
(Shown in a simplified manner) and a flexible printed circuit board (F
Anisotropic conductive adhesive 36 is also interposed between PC and 58. The FPC 58 is a film on which copper wiring electrodes for supplying power and input signals for driving the semiconductor device 1 are patterned. Anisotropic conductive adhesive 3
Numeral 6 is an adhesive in which conductive particles are dispersed in an insulating adhesive, which conducts in the opposite thickness direction and insulates in the lateral direction.

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[Document name to be amended] Statement

[Correction target item name] Explanation of sign

[Correction method] Change

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[Description of Signs] 1, 31: Semiconductor device 2, 86: Liquid crystal panel 10: Semiconductor substrate 12: Semiconductor chips 12b, 12c: Side surface 14: Electrode pad 16: Insulating film 18: Common electrode film 19: Lower electrode 20: Photosensitive Resin 22: first protruding electrode 23, 32: protruding electrode 24: second protruding electrode 58, 68: flexible printed circuit board (FPC)

[Procedure amendment 6]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

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FIG.

Claims (11)

[Claims] A semiconductor chip, an electrode pad formed on a surface of the semiconductor chip, an insulating film opened on the electrode pad to cover an upper surface of the semiconductor chip, and the electrode pad formed on the insulating film. A semiconductor device comprising: a lower electrode provided so as to extend over an upper portion and a side surface of the semiconductor chip; and a protruding electrode provided on the lower electrode. 2. The semiconductor device according to claim 1, wherein said semiconductor chip has a stepped side wall. 3. The semiconductor device according to claim 1, wherein said protruding electrode comprises a plurality of metal layers. 4. The semiconductor device according to claim 2, wherein said protruding electrode has a shape protruding outside a side surface of said semiconductor chip. 5. The semiconductor device according to claim 1, wherein said protruding electrode is formed of solder. 6. A groove is formed at a boundary between adjacent semiconductor chips of a semiconductor substrate for forming a plurality of semiconductor chips on which a plurality of electrode pads are arranged so that the semiconductor substrate remains at a predetermined thickness. A first dicing step of forming a street line by performing a step of forming an insulating film having an opening on an electrode pad on the entire surface of the semiconductor substrate; and a step of forming a common electrode film on the entire surface of the semiconductor chip. Forming a photosensitive resin on the common electrode film and patterning the photosensitive resin so as to form an opening for forming a protruding electrode in a predetermined region extending from the electrode pad of the photosensitive resin to the street line; Forming a projecting electrode in an opening of the photosensitive resin on the common electrode film; removing the photosensitive resin; and using the projecting electrode as a mask to form the common electrode. Etching the electrode film; and forming the street line portion of the semiconductor substrate in the first
A second dicing step of cutting at a processing width narrower than the processing width of the dicing step. 7. The method for manufacturing a semiconductor device according to claim 6, further comprising a step of plating the surface of the bump electrode after the second dicing step. 8. The method of manufacturing a semiconductor device according to claim 6, further comprising, after the second dicing step, a step of reflowing the projecting electrode into a spherical shape. 9. A semiconductor device mounting structure for connecting the semiconductor device according to claim 1 to a circuit board, wherein a side surface of the semiconductor chip constituting the semiconductor device on which the protruding electrodes are provided faces the circuit board. Wherein the protruding electrodes and the electrodes on the circuit board are electrically connected to each other. 10. The mounting structure of a semiconductor device according to claim 9, wherein a side surface of said semiconductor chip opposite to a side surface connected to said circuit board is connected to a flexible printed circuit board and provided on said side surface. A mounting structure for a semiconductor device, wherein the protruding electrode provided is electrically connected to an electrode on the flexible printed circuit board. 11. The mounting structure of a semiconductor device according to claim 9, wherein a side surface of the semiconductor chip orthogonal to a side surface connected to the circuit board is connected to a flexible printed circuit board and provided on the side surface. A mounting structure of the semiconductor device, wherein the protruding electrode and the electrode on the flexible printed circuit board are electrically connected.