JP2001196416A - Semiconductor device mounting structure and method, semiconductor and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable semiconductor devices to be densely and very reliably surface-mounted on a circuit board. SOLUTION: A semiconductor device 10 is arranged on a circuit board 26 bringing protrudent electrodes 22 into direct contact with circuit electrodes 28, ultrasonic vibrations and a pressure are given to the bump electrode 22 from the semiconductor device 10 by an ultrasonic pressure-bonding tool, and heat is applied to the bump electrode 22 from the circuit board 26, by which the protrudent electrode 22 is bonded to the joint surface 25 of the circuit electrode 28 by diffusion. Sealing resin 32 is filled into a gap between the semiconductor device 10 and the circuit board 26 and cured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device mounting structure and a method for electrically and mechanically connecting a surface mount type semiconductor device having a projecting electrode to a circuit board having a circuit electrode. The present invention also relates to a semiconductor device suitable for the mounting structure and a method for manufacturing the semiconductor device.

[0002]

2. Description of the Related Art Integrated circuits (ICs) and large-scale integrated circuits (L
Surface-mount type semiconductor devices are increasingly used as semiconductor devices that constitute SI) and the like. In a surface-mount type semiconductor device, when mounted on a circuit board having circuit electrodes, a large number of bump electrodes (Bumps) are formed on the surface to electrically and mechanically connect the circuit electrodes.
Some are arranged in a row.

As one example, FIG. 35 shows a cross-sectional structure of a semiconductor device provided with a straight wall-shaped protruding electrode. In this semiconductor device 10, an electrode pad 14 for connecting the integrated circuit to an external circuit is provided on a surface (an upper surface in FIG. 35) of a semiconductor chip 11 on which an integrated circuit (not shown) is formed. Many are provided along the side edge of a perpendicular direction. In FIG. 35, the semiconductor chip 11
3 shows only one of the plurality of electrode pads 14 in each row along the left and right side edges.

The periphery of each of the electrode pads 14 is covered,
An insulating film 16 having an opening formed on the electrode pad 14 so as to expose the inside thereof is provided on the entire surface of the semiconductor chip 11. A lower electrode 19 is provided in close contact with the periphery of the opening of the insulating film 16 and the exposed portion of the electrode pad 14. Further, a projection electrode 22 formed in a straight wall shape is provided on the lower electrode 19.

Some protruding electrodes have a mushroom shape in which the upper part is larger than the base part. However, the straight wall-shaped projection electrode can reduce the spread in the lateral direction along the semiconductor chip,
By so increasing the arrangement density of the protruding electrodes, the connection pitch with the external circuit can be reduced.

Next, FIG. 36 shows a conventional mounting structure in which a semiconductor device having such protruding electrodes is mounted on a circuit board having circuit electrodes. 36, the semiconductor device 10 is placed upside down from the state shown in FIG. 35 on a circuit board 26 with the protruding electrodes 22 facing down, and the semiconductor device 10 is different from the circuit board 26. They are bonded by an isotropic conductive adhesive 44.

[0007] The anisotropic conductive adhesive 44 is obtained by dispersing a large number of conductive particles 42 in an insulating adhesive 46, and the electrical connection between each protruding electrode 22 and the circuit electrode 28 on the circuit board 26 is established. By using the conductive particles 42, the semiconductor device 10
The mechanical connection between the substrate and the circuit board 26 is made by an insulating adhesive 46.

Here, a method of manufacturing the conventional semiconductor device shown in FIG. 35 will be briefly described with reference to FIGS. 33 and 34, and a conventional mounting method of the semiconductor device will be described with reference to FIG. First, as shown in FIG. 33, an insulating film 16 is formed on the entire surface of a semiconductor substrate 12 provided with a plurality of integrated circuits for semiconductor chips (not shown) and a plurality of electrode pads for connecting them to an external circuit. Is formed, and an opening 16a is formed on each of the electrode pads 14 by a photo-etching technique, so that only the peripheral portion of each of the electrode pads 14 is covered and most of the electrode pad 14 is exposed.

FIGS. 33 and 34 show the semiconductor substrate 1
2, only a part (a region slightly larger than one semiconductor device) is shown in an enlarged manner. Then, an aluminum film, a chromium film, and a copper film are sequentially formed on the entire surface of the insulating film 16 of the semiconductor substrate 12 and the electrode pads 14 exposed in the openings 16a by sputtering, and a laminate of aluminum-chromium-copper is formed. A common electrode film 18 of a film is provided.

Thereafter, the entire surface of the common electrode film 18 is
The photosensitive resin 20 shown in FIG.
An opening 20 having a thickness substantially equal to that of each electrode pad 14 is formed on each electrode pad 14 of the photosensitive resin 20 by photolithography technology.
a is formed.

Next, the semiconductor substrate 12 is immersed in a gold plating solution composed of sodium gold sulfite to form a common electrode film 18.
Is formed on the common electrode film 18 in the opening 20a of the photosensitive resin 20 by electrolytic plating using as a plating electrode.
The protruding electrode 22 shown in FIG. 34 is formed to a thickness of 15 μm to 20 μm.

Thereafter, the photosensitive resin 20 is removed, and the common electrode film 18 is formed using the protruding electrodes 22 as an etching mask.
Is etched to remove most of the parts other than the lower part of the protruding electrodes 22 to form the lower electrodes 19 shown in FIG. 35, and the protruding electrodes 22 are individually provided on the respective electrode pads 14 via the lower electrodes 19. Obtain the structure. Next, the semiconductor substrate 12 is cut into individual semiconductor chips 11 by a dicing process to obtain the semiconductor device 10 shown in FIG.

To mount the semiconductor device 10 on a circuit board, as shown in FIG. 36, an anisotropic conductive adhesive 44 in which conductive particles 42 are mixed in an insulating adhesive 46 made of epoxy resin is used. The protruding electrode 22 and the circuit electrode 26 are interposed between the semiconductor device 10 having the plurality of protruding electrodes 22 and the circuit board 26 having the plurality of circuit electrodes 28 disposed facing each other.
Apply pressure and heat in between.

As a result, the conductive particles 42 are sandwiched between each protruding electrode 22 and the circuit electrode 28, and the protruding electrode 22 and the circuit electrode 28 are electrically connected. At the same time, the semiconductor device 10 and the circuit board 26 are
And the connection between the protruding electrode 22 and the circuit electrode 28 is sealed.

[0015]

However, in such a conventional semiconductor device mounting structure and mounting method,
In order to ensure a sufficiently small connection resistance value of, for example, 0.1 Ω or less and high reliability between each of the projecting electrodes 22 and the circuit electrode 28, the connection between the projecting electrode 22 and the circuit electrode 28 of the circuit board 26 is required. It is necessary to secure 10 or more conductive particles 42 between them.

The insulating adhesive 46 of the anisotropic conductive adhesive 44
The conductive particles 42 mixed therein have a two-layer coating of nickel and gold formed on the surface of plastic beads having a diameter of about 5 μm. The connection resistance value of each conductive particle 42 is about 1Ω. By securing 10 conductive particles 42 between the protruding electrode 22 and the circuit electrode 28, the initial connection resistance value is 0.1Ω. Can be set to about
The connection resistance value after performing the high-temperature and high-humidity reliability test in an atmosphere of a temperature of 85 ° C. and a humidity of 85% for 1000 hours can be reduced to 1Ω or less.

The reason why the connection resistance value is increased by the high-temperature and high-humidity reliability test is that the adhesive strength decreases due to the deterioration of the epoxy-based adhesive which is the insulating adhesive 46 between the protruding electrode 22 and the circuit electrode 28, This is because the connection area of the conductive particles 42 is reduced by slightly increasing the distance between the projection electrode 22 and the circuit electrode 26.

In order to secure 10 or more conductive particles 42 between the projecting electrode 22 and the circuit electrode 28,
Must have an area of 3000 μm ² or more. In addition, in order to ensure insulation between the adjacent protruding electrodes 22, an interval of three times (15 μm) or more the diameter (5 μm) of the conductive particles 42 must be provided. Therefore, in the conventional mounting structure and mounting method of a semiconductor device, the circuit electrode 28 and the protruding electrode 22 are connected with a low connection resistance value, and a reliable insulation between the adjacent protruding electrodes 22 is ensured to achieve a fine structure. It was extremely difficult to make connections at the pitch.

The present invention solves the above-mentioned problems, and in the surface mounting of a semiconductor device on a circuit board, the connection resistance between the protruding electrode and the circuit electrode is made sufficiently small, and the insulation between the adjacent electrodes is sufficiently ensured. It is another object of the present invention to enable high-density connection with a fine electrode pitch.

[0020]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides the following mounting structure and mounting method of a semiconductor device, and a semiconductor device suitable for the mounting structure and a manufacturing method thereof. Things.

First, the mounting structure of the semiconductor device according to the present invention comprises a semiconductor device having a plurality of electrode pads on one surface of a semiconductor chip and a plurality of protruding electrodes individually conducting to each of the electrode pads. 1 is a mounting structure of a semiconductor device mounted on a circuit board having a plurality of circuit electrodes individually connected to protruding electrodes. Then, the opposing surfaces of the respective projecting electrodes of the semiconductor device and the respective circuit electrodes of the circuit board are directly joined, and the joining surfaces are diffusion joined. The protruding electrode is preferably formed in a straight wall shape with gold, and a surface to be bonded to the circuit electrode is substantially planar (in a bonded state).

A method of mounting a semiconductor device according to the present invention is a method for realizing the above-described mounting structure, and has the following steps. A step of arranging the semiconductor device having the plurality of projecting electrodes described above on a circuit board having a plurality of circuit electrodes such that each projecting electrode is opposed to each circuit electrode; A step of directly contacting the electrodes and the respective opposing surfaces of the circuit electrodes of the circuit board, and a step of applying pressure while applying ultrasonic vibration or heat to the projecting electrodes and the circuit electrodes to diffusely bond the contact surfaces. ,

In this method of mounting a semiconductor device, the method may further include, before the step of arranging the semiconductor device on a circuit board, a step of performing a heat treatment on each protruding electrode of the semiconductor device to reduce its hardness. Good. In this case, using a semiconductor device in which each of the protruding electrodes is made of gold, and performing a heat treatment at a temperature of 250 to 350 ° C. in a furnace introduced with nitrogen gas in a step of reducing the hardness of each of the protruding electrodes. It is preferable that the Vickers hardness of each protruding electrode be 40 to 60.

In the step of diffusing and joining the contact surface between the projecting electrode and the circuit electrode, it is desirable to heat the projecting electrode and the circuit electrode while applying ultrasonic vibration and load. In that case, the frequency of the ultrasonic vibration is set to 20 to 30.
KHz and the output is 50 to 2 per protruding electrode.
00 mW, the load is 30 to 100 g per one projecting electrode, and the heating temperature is 150 to 200 ° C.
It is good to Further, it is preferable that ultrasonic vibration and a load are applied from the surface of the semiconductor device opposite to the surface having the protruding electrodes, and heating is performed from the surface of the circuit board opposite to the surface having the circuit electrodes.

Further, in such a semiconductor device mounting method, after the step of diffusing and joining the contact surface between the protruding electrode and the circuit electrode, the gap between the semiconductor device and the circuit board is sealed with epoxy resin. It is desirable to include a step of injecting a resin, performing a baking treatment, and curing the sealing resin.

A semiconductor device according to the present invention covers an integrated circuit, a semiconductor chip provided with a plurality of electrode pads for connecting the integrated circuit to an external circuit, and a surface of the semiconductor chip provided with a plurality of electrode pads, An insulating film having an opening on each of the electrode pads, a raising member provided on a central portion of each of the electrode pads in each of the openings of the insulating film, and individually conducting with each of the electrode pads through each of the openings of the insulating film. A plurality of lower electrodes provided on the periphery of the opening of the insulating film and over the raising member; and a plurality of lower electrodes provided on each of the lower electrodes. And a plurality of protruding electrodes formed to be higher by the thickness of.

The raising member can be made of a photosensitive resin, the same material as the insulating film, a conductive material, a metal film formed by electroless plating, or the like. In addition, this raising member,
It may be provided on each lower electrode formed on each electrode pad.

A method for manufacturing a semiconductor device according to the present invention comprises:
A method for manufacturing the above-described semiconductor device, comprising the following steps A to J. A. A. forming an insulating film having an opening on each electrode pad on a semiconductor substrate provided with a plurality of integrated circuits for semiconductor chips and a plurality of electrode pads for connecting the integrated circuit to an external circuit; B. applying a first photosensitive resin thicker than the insulating film on the entire surface of the semiconductor substrate on which the insulating film is formed; Patterning the first photosensitive resin by photolithography so as to remain as a raising member only on the central portion of each of the electrode pads;

D. B. forming a common electrode film connected to each electrode pad through the opening on the entire surface of the semiconductor substrate on which the insulating film is formed; B. applying a second photosensitive resin to the entire surface of the common electrode film; Patterning the second photosensitive resin by photolithography to form openings of substantially the same size as the electrode pads on each of the electrode pads;

G. B. forming a protruding electrode by plating on the common electrode film in each opening of the second photosensitive resin; Removing the second photosensitive resin; I. Forming a lower electrode on each electrode pad by patterning the common electrode film by performing an etching process using each protruding electrode as a mask, J. Cutting the semiconductor substrate into semiconductor chips of individual semiconductor devices,

The following steps may be performed in place of steps A to C in the method of manufacturing a semiconductor device.
Forming an insulating film on an entire surface of a semiconductor substrate provided with a plurality of integrated circuits for semiconductor chips and a plurality of electrode pads for connecting the integrated circuits to an external circuit; Applying a conductive resin, patterning the first photosensitive resin by photolithography to form a ring-shaped opening on each of the electrode pads, and applying the first photosensitive resin to the first photosensitive resin. Forming a ring-shaped opening in a portion of the insulating film on each of the electrode pads by performing an etching process using a mask to pattern the insulating film; and removing the first photosensitive resin. .

The following steps may be performed instead of the steps B and C in the above-described method for manufacturing a semiconductor device. Forming a conductive film thicker than the insulating film on the entire surface of the semiconductor substrate on which the insulating film is formed, applying a first photosensitive resin to the entire surface of the conductive film, Patterning the photosensitive resin by photolithography so as to remain only on the central portion of each electrode pad, and performing an etching process using the first photosensitive resin as a mask to form the conductive film on each electrode pad. A step of patterning so as to remain as a raising member only on the central portion of the pad; and a step of removing the first photosensitive resin.

Alternatively, the following steps may be performed instead of steps B to D in the above-described method for manufacturing a semiconductor device. A step of forming a common electrode film connected to each electrode pad through the opening on the entire surface of the semiconductor substrate on which the insulating film is formed, and a step of forming a conductive film thicker than the insulating film on the entire surface of the common electrode film Applying a first photosensitive resin to the entire surface of the conductive film;
Patterning the photosensitive resin by photolithography so as to remain only on the conductive film at the center of each electrode pad, and performing an etching process using the first photosensitive resin as a mask. Patterning so as to leave as a raising member only on the common electrode film at the center of each electrode pad, and removing the first photosensitive resin.

Further, the following steps may be performed instead of the steps B and C in the above-described method for manufacturing a semiconductor device. Applying a first photosensitive resin to the entire surface of the semiconductor substrate on which the insulating film is formed;
Patterning the photosensitive resin by photolithography so as to form an opening only on the center of each electrode pad, and plating the photosensitive resin on each electrode pad in each opening of the first photosensitive resin. A step of forming a raised member by a metal film by processing, and a step of removing the first photosensitive resin.

In the above-described method of manufacturing each semiconductor device, a step of performing a heat treatment on the protruding electrodes to reduce the hardness thereof is performed between the step of forming the lower electrode and the step of cutting the semiconductor substrate. Is desirable. In that case, in the step of forming the protruding electrodes, each protruding electrode is formed of gold, and in the step of reducing the hardness of the protruding electrodes, heat treatment is performed at a temperature of 250 to 350 ° C. in a furnace introduced with nitrogen gas. Therefore, it is preferable that the Vickers hardness of the protruding electrode be 40 to 60.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a semiconductor device mounting structure and mounting method according to the present invention, and a semiconductor device and a manufacturing method thereof will be described with reference to the drawings. In the drawings used for the description, the height of the bump electrode of the semiconductor device is shown in an enlarged manner, and the integrated circuit inside the semiconductor chip is not shown. Also,
The semiconductor substrate shows only a region that is slightly larger than a semiconductor chip for one semiconductor device as a part thereof.

[First Embodiment of Mounting Structure of Semiconductor Device: FIGS. 1 and 4] First, a first embodiment of a mounting structure of a semiconductor device according to the present invention will be described with reference to FIG. In this embodiment, the structure of the semiconductor device mounted on the circuit board is the same as the conventional semiconductor device described with reference to FIG. That is, the semiconductor device 10 shown in FIG. 1 has a semiconductor chip 11 in which an integrated circuit is formed.
On one surface, a number of electrode pads 14 for connecting the integrated circuit to an external circuit are provided along a side edge in a direction perpendicular to the paper surface.

The periphery of each electrode pad 14 is covered,
An insulating film 16 having an opening formed on the electrode pad 14 so as to expose the inside thereof is provided on the entire surface of the semiconductor chip 11. A lower electrode 19 is provided in close contact with the periphery of the opening of the insulating film 16 and the exposed portion of the electrode pad 14. Further, a projection electrode 22 formed in a straight wall shape is provided on the lower electrode 19.

The lower electrode 19 is formed by forming a titanium-tungsten alloy containing 20 wt% of titanium in a thickness of 0.04 μm in a lower layer in close contact with the electrode pad 14, and further forming copper in a thickness of 0.4 μm on the titanium-tungsten alloy. It has a two-layer structure. The titanium-tungsten alloy layer below the lower electrode 19 has a role of a connection layer with the electrode pad 14 and a barrier layer for preventing mutual diffusion. The upper copper layer is a bump electrode 22
Has a role as a plating electrode when formed by electroplating and a role as a connection layer with the protruding electrode 22.

The protruding electrode 22 is formed by electroplating.
a gold plating layer formed to a thickness of 20 μm to 20 μm,
By being formed so as not to protrude from the upper surface of the photosensitive resin serving as a mask in the plating process, the side surface shape of the projecting electrode 22 is a straight straight wall shape.

On the other hand, on one surface of the circuit board 26 shown in FIG. 1, a large number of circuit electrodes 28 which are individually connected to the respective projecting electrodes 22 of the semiconductor device 10 are formed in a pattern. The circuit electrode 28 is formed of a metal material film, and has a three-layer structure in which, for example, copper, nickel, and gold films are sequentially stacked from the lower layer.

As shown in FIG. 1, the semiconductor device 10 is directly joined on the circuit board 26 with the top surface of each protruding electrode 22 facing each circuit electrode 28 of the circuit board 26. The connection of the bonding surface 25 is performed by diffusion bonding. Further, a gap between the semiconductor substrate device 10 and the circuit board 26 is filled with an insulating sealing resin 32 and cured to prevent the deterioration of the diffusion bonding portion and the invasion of moisture.

The diffusion bonding between the protruding electrode 22 and the circuit electrode 26 will be described in detail in an embodiment of a mounting method described later, but the ultrasonic wave and the load are applied from the back side of the semiconductor device 10 where the protruding electrode 22 is not formed. In addition, the projection electrode 22 is heated from the back side of the circuit board 26 where the circuit electrodes 28 are not formed.
And the circuit electrode 28. By this diffusion bonding, metal atoms and molecules near the joint surface 25 between the protruding electrode 22 and the circuit electrode 28 diffuse to each other and are firmly connected. In particular, if both sides of the bonding surface 25 are made of gold, this diffusion bonding is easily performed.

As described above, in the mounting structure of the semiconductor device according to the present invention, since the bonding surface 25 between the projecting electrode 22 and the circuit electrode 28 is directly joined by diffusion bonding, each projecting electrode 22 and the circuit electrode 28 are connected. Connection is ensured with a low connection resistance value.

As described above, in the case of the conventional mounting structure, the conductive particles sandwiched between the top surface of the projecting electrode 22 and the circuit electrode 28 using an anisotropic conductive adhesive containing the conductive particles are used. Since the conduction between the two was performed only by the contact surface with the electrode, in order to reduce the connection resistance, about 10 conductive particles had to be secured for each projection electrode. The area of the top surface had to be large.

However, according to this embodiment, since the entire joint surface 25 between the projecting electrode 22 and the circuit electrode 28 contributes to the conduction between the two, the joint surface 25 is sufficiently small even if the area of the joint surface 25 is small. Connection can be made securely with connection resistance. Moreover, since the sealing resin 32 is an insulating resin such as an epoxy resin, there is no danger that the adjacent protruding electrodes 22 are electrically connected to each other even if the distance between the adjacent protruding electrodes 22 is small.

Therefore, as shown in FIG. 4, in this semiconductor device 10, the area occupied by one protruding electrode 22 on the semiconductor chip 11 is reduced to 1/6 of the conventional 3000 μm ^2.
0, which is about 50 μm ² , and the gap G between the adjacent protruding electrodes 22 can be reduced from about 15 μm ^{2 to} about 5 μm ² . Thereby,
The arrangement pitch P of the protruding electrodes 22 can be reduced to 1/10 or less of that of the related art, and high-density mounting by highly reliable fine pitch connection becomes possible.

As a result, in the semiconductor device mounting structure according to the present invention, the electrical and mechanical characteristics of the joint between the protruding electrode 22 and the circuit electrode 28 can be significantly improved as compared with the conventional mounting structure. Therefore, high-density mounting can be easily realized.

[First Embodiment of Semiconductor Device Mounting Method: FIGS. 1 to 3] Next, a first embodiment of a semiconductor device mounting method according to the present invention will be described with reference to FIGS. I do. This is a mounting method for obtaining the mounting structure of the semiconductor device described above with reference to FIG.

In this mounting method, as shown in FIG. 3, in the first step, the semiconductor device 10 having the plurality of projecting electrodes 22 is replaced with the circuit board 26 having the plurality of circuit electrodes 28.
The projection electrodes 22 are positioned (aligned) on the circuit electrodes 28 so as to face the circuit electrodes 28, respectively. Then, the opposing surfaces of the respective projecting electrodes 22 of the semiconductor device 10 and the respective circuit electrodes 28 of the circuit board 26 are brought into direct contact.

Thereafter, the ultrasonic pressure bonding tool 30 is brought into contact with the back side of the semiconductor device 10 on which the protruding electrodes 22 are not formed, and ultrasonic vibration having a frequency of 20 to 30 KHz is output at a power of 50 to 200 mW per protruding electrode. Simultaneously with the application, a load of 30 to 100 g is applied per one protruding electrode 22. The application time of the ultrasonic vibration at this time is 0.5 to
2 seconds.

Further, the circuit board 26 is placed on the hot plate 40 with the back surface side on which the circuit electrodes 28 are not formed being in contact with the hot plate 40, and the ultrasonic vibration and the application of a load from the semiconductor device 10 side are applied. At the same time, heating at a temperature of 150 to 200 ° C. is performed from the circuit board 26 side. As a result, the top surface of the protruding electrode 22, whose central portion is slightly depressed, is pressed while being slightly softened by heating, so that it becomes almost flat and adheres to the surface of the circuit electrode 28, and the ultrasonic vibration The metal atoms and molecules near the bonding surface 25 are mutually diffused by the wave energy due to the heat and the heat energy due to the heating, and uniform diffusion bonding is performed over the entire surface.

In this example, the projecting electrode 22 is formed of gold, and the circuit electrode 28 is formed of a gold film at least on the surface layer. Therefore, the protruding electrode 22 and the circuit electrode 28 can be connected with low resistance.

Thereafter, the semiconductor substrate device 10 and the circuit board 2
The sealing resin 32 made of the epoxy resin shown in FIG. 1 is injected into the gap between the blocks 6, and the sealing resin 32 is cured by performing a baking process. Thus, the mounting structure shown in FIG. 1 is completed. In this embodiment, ultrasonic vibration is applied to the protruding electrode 22 of the semiconductor device 10 and the circuit electrode 28 of the circuit board 26, and pressure is applied while heating, so that the bonding surface 25 is formed by diffusion bonding. In this case, the bonding surface 25 can be diffused and bonded by applying pressure while performing either ultrasonic vibration application or heating.

By the way, in this method of mounting the semiconductor device, before the step of arranging the semiconductor device 10 on the circuit board 26, each bump electrode 22 of the semiconductor device 10 is subjected to a heat treatment to reduce its hardness. A step may be performed. When using the semiconductor device 10 in which each protruding electrode 22 is formed of gold as in this embodiment, the semiconductor device 1
0 in a furnace set at a temperature of 300 ° C.
By introducing at a flow rate of 0 liter and performing heat treatment for 30 minutes, the hardness of the protruding electrode 22 is reduced so that the Vickers hardness Hv becomes 40 to 60.

The purpose of reducing the hardness of the protruding electrode 22 is to make it easy to adhere to the circuit board by applying pressure during mounting. The reason that the hardness of the protruding electrode 22 is reduced by this heat treatment is that the film that becomes the protruding electrode 22 immediately after plating contains an impurity gas such as hydrogen or carbon, and has a Vickers hardness Hv of 100 to 120. This is because the recrystallization is performed, and the impurity gas is released from the gold plating film of the protruding electrode 22, so that the Vickers hardness approaches the hardness of pure gold.

As shown in FIG. 2, it is preferable that the heat treatment for reducing the hardness of the bump electrodes 22 be performed simultaneously on all the bump electrodes 22 on the semiconductor substrate 12 in which a large number of semiconductor devices are formed. It is efficient. That is, the semiconductor substrate 12 shown in FIG. 2 is cut at a position indicated by a dashed line by a dicing process, and the above-described heating process is performed before the semiconductor substrate 12 is divided into semiconductor chips 11 for individual semiconductor devices.
The hardness of all the protruding electrodes 22 may be reduced.

[First Embodiment of Semiconductor Device: FIG. 5] Next, a first embodiment of a semiconductor device according to the present invention will be described with reference to a schematic sectional view shown in FIG. FIG.
, The same reference numerals are given to the same parts as those of the semiconductor device 10 shown in FIGS.

The semiconductor device 1 of this embodiment is, like the semiconductor device 10 shown in FIG. 1, provided on an upper surface of a semiconductor chip 11 provided with an integrated circuit and a plurality of electrode pads 14 for connecting the integrated circuit to an external circuit. An insulating film 16 having an opening is provided on each of the electrode pads 14 to cover the surface of the semiconductor chip 11 on which the electrode pads 14 are provided. However, the difference from the semiconductor device 10 shown in FIG.
6 is that a raising member 241 is provided on the center of each electrode pad 14 in each opening.

The lower electrodes 19 are individually provided to be electrically connected to the respective electrode pads 14 through the respective openings of the insulating film 16 and to extend over the peripheral portion of the opening of the insulating film 16 and the raised member 241. The lower electrode 19 is given the same reference numeral as the lower electrode of the conventional semiconductor device 10 for convenience, but has a convex shape in which a central portion formed on the raising member 241 is raised.

The protruding electrodes 23 are formed on the respective lower electrodes 19, and the top surface of each of the protruding electrodes 23 is formed such that the central portion 23a is thicker than the peripheral portion 23b of the raised member 241 as shown in the figure. It is formed in a convex shape that is higher by the same amount.

As described above, by forming the top surface of the protruding electrode 23 in a convex shape, when this semiconductor device 1 is mounted on a circuit board in the same manner as the above-described mounting method, the application of ultrasonic vibration and / or Alternatively, the pressure is applied while heating, and the protruding electrode 23 is pressed.
In the step of diffusion bonding the electrode and the circuit electrode, the diffusion bonding proceeds from the central portion 23a of the protruding electrode 23 to the peripheral edge 23b, and it is possible to perform reliable diffusion bonding over the entire top surface of the protruding electrode 23. .

[Second Embodiment of Mounting Structure of Semiconductor Device: FIG. 6] Next, a second embodiment of the mounting structure of the semiconductor device according to the present invention will be described with reference to a schematic sectional view shown in FIG. This mounting structure corresponds to the first structure described with reference to FIG.
This is almost the same as the mounting structure of the embodiment, and the same reference numerals in FIG. 6 denote the same parts as in FIG. However, in the mounting structure of this embodiment, the semiconductor device 1 shown in FIG. 5 is mounted on the circuit board 26 having the circuit electrodes 28 upside down.

The top surface of each bump electrode 23 of the semiconductor device 1
When performing diffusion bonding with the circuit electrode 28, the flattened surface 25 is slightly collapsed by heating and pressurization, and is substantially flat.
Is formed. Diffusion bonding proceeds from the central portion 23a of the protruding electrode 23 shown in FIG. 5 to the peripheral edge portion 23b, and reliable diffusion bonding with the circuit electrode 28 is made over the entire top surface of the protruding electrode 23. Further, the gap between the semiconductor device 1 and the circuit board 26 is filled with the sealing resin 32 and cured, as described in FIG.
This is the same as the embodiment.

Also with this mounting structure, the connection resistance between the protruding electrode 23 of the semiconductor device 1 and the circuit electrode 28 of the circuit board 26 can be greatly reduced. Thereby, the area occupied by the protruding electrodes 23 can be reduced, and the gap between the adjacent protruding electrodes 23 can be designed to be small by not using an anisotropic conductive adhesive. The high-density mounting structure can be realized in the same manner as described in the first embodiment.

[First Embodiment of Method of Manufacturing Semiconductor Device: FIGS. 7 to 13] Next, a method of manufacturing the semiconductor device shown in FIG. 5 will be described with reference to FIGS. . 7 to 13 are schematic sectional views sequentially showing the manufacturing steps.

First, as shown in FIG. 7, a semiconductor substrate 1 in which a plurality of integrated circuits for semiconductor chips are formed inside and a plurality of electrode pads 14 for each semiconductor chip are provided on the surface.
2, an insulating film 16 having a thickness of 0.8 to 1.0 μm
To form Then, the insulating film 16 is patterned by photo-etching technology so as to cover only the peripheral portion of each electrode pad 14 and expose most of the opening.
To form

Next, as shown in FIG.
A first photosensitive resin 24 made of a photosensitive polyimide resin is applied to the entire surface of the semiconductor substrate 12 on which 6 is formed by a spin coating method to a thickness of 2 μm to 5 μm.

Thereafter, as shown in FIG. 9, a raised member 241 is formed at a substantially central portion of each electrode pad 14 by photolithography processing including exposure processing and development processing using a predetermined photomask 35. Then, patterning of the first photosensitive resin 24 is performed. The first photosensitive resin 24 is a positive-type photosensitive resin, and the photomask 35 has a circular light transmission only in a portion corresponding to a region where the raising member 241 is formed (substantially the center of each electrode pad 14). This is a light shielding member provided with a portion 35a.

Then, the photomask 35 is disposed slightly apart from the first photosensitive resin 24, and an exposure process is performed. Then, light emitted from above the photomask 35 passes through the light transmitting portion 35a and exposes the first photosensitive resin 24, but not only the portion corresponding to the circular light transmitting portion 35a but also the light The surrounding area is also slightly exposed due to the wraparound. When the exposed first photosensitive resin 24 is developed and patterned, as shown in FIG.
The trapping member 241 remaining trapezoidal can be formed substantially at the center.

Thereafter, the oxygen concentration was maintained at 20 PPM or less, at a temperature of 150 ° C. for 30 minutes, and at a temperature of 350 ° C.
And a two-stage baking process is performed under the condition of 30 minutes. Here, in the low-temperature baking treatment, the gas contained in the polyimide resin of the raising member 241 made of the first photosensitive resin 24 is volatilized, and in the high-temperature baking treatment, the polyimide resin is polymerized.

Next, as shown in FIG.
2 on the entire surface of the common electrode film 1 by sputtering.
8 is formed. The common electrode film 18 is formed, for example, by forming a titanium-tungsten alloy film containing 20 wt% of titanium in a lower layer to a thickness of 0.04 μm, and forming a copper film in an upper layer of 0.4 μm.
It is formed to a thickness of μm to form a two-layer structure.

The common electrode film 18 has good electrical and mechanical connectivity between the electrode pad 14 and the electrode material of the projection electrode 23 to be formed later, does not diffuse between electrode materials, and is made of a stable electrode material. Select. Therefore, this common electrode film 1
8 is titanium-tungsten-copper-
Three-layer structure of gold, aluminum-chromium-copper, aluminum-titanium-copper, etc., or titanium-palladium, titanium-gold, titanium-platinum, titanium-tungsten alloy-palladium, titanium-tungsten alloy-gold, titanium-tungsten alloy -It may have a two-layer structure such as platinum.

Thereafter, as shown in FIG. 11, a second photosensitive resin 34 is applied on the entire surface of the common electrode film 18 by a spin coating method to a thickness of 20 μm to 25 μm. Then, photolithography by exposure and development is performed using a predetermined photomask, and the second photosensitive resin 34 is patterned so as to form the opening 34a. The opening 34a is formed on each of the electrode pads 14 to have substantially the same size as the electrode pads 14.
The inside of the opening 34a of the second photosensitive resin 34 is a projection electrode formation region.

Next, as shown in FIG. 12, using the patterned second photosensitive resin 34 as a plating mask,
On the common electrode film 18 in the opening 34a, the protruding electrode 23 made of a gold plating layer is formed. In this plating, a gold plating solution composed of sodium gold sulfite is maintained at a temperature of 65 ° C.
When the common electrode 18 is used as a plating electrode, the current density is set to 0.
Electroplating is performed under the conditions of 8 A / dm ² , and a gold plating layer is formed to a thickness of 15 μm to 20 μm to form the bump electrode 23.

At this time, by forming the gold plating layer so that the peripheral portion does not protrude from the upper surface of the photosensitive resin 34 which is a mask in the plating process, the side surface shape in the cross section of the bump electrode 23 is as shown in the figure. And a straight wall shape. Also, the first photosensitive resin 24
As a result, the central portion of the protruding electrode 23 can be formed higher than the peripheral portion.

By this plating process, a hydrophilic treatment may be performed before forming the protruding electrode 23 in the opening 34a of the photosensitive resin 34. Thereby, the wettability of the plating solution to the photosensitive resin 34 is improved, and the photosensitive resin 34
The plating solution is sufficiently supplied into the fine opening 34a of
The throwing power of the plating film can be improved. This hydrophilization treatment can be performed by, for example, a wet treatment with a chemical solution of a mixed solution of sulfuric acid and hydrogen peroxide, or a dry treatment using, for example, oxygen plasma.

As described above, the shape of the top of each protruding electrode 23 is as shown in FIG. 13 due to the thickness of the raising member 241 made of the first photosensitive resin 24 formed in a convex shape. The central portion 23a can have a higher convex shape than the peripheral edge portion 23b. That is, the step size, which is the difference between the height of the central portion 23a and the height of the peripheral portion 23b of the protruding electrode 23, can be controlled by the film thickness of the first photosensitive resin 24.

Thereafter, the second photosensitive resin 34 used as a plating mask is removed by using a wet stripper. Then, using the protruding electrode 23 as an etching mask, copper, which is the upper layer metal of the common electrode film 18, is etched with Enstrip C (trade name), which is a copper etching solution manufactured by Meltex, with a 30% overetching time. Do.

Subsequently, the common electrode film 1 was formed using a hydrogen peroxide solution.
8 Titanium which is a barrier layer of the lower metal and an adhesion layer
The tungsten alloy is etched with a 30% overetch time. Thereby, as shown in FIG.
By patterning the common electrode film 18, each electrode pad 14 is
The lower electrode 19 is formed by the remaining portion of the common electrode film 18 between the lower electrode 19 and the projection electrode 23. Protruding electrode 2 formed thereon
3 shows that the central portion 32a at the top is 2 μm larger than the peripheral portion 23b.
It has a convex shape with a height of m to 5 μm.

Here, an over-etching process is performed in the etching process of copper as the upper layer metal of the common electrode film 18 and the etching process of the titanium-tungsten alloy as the lower metal barrier layer and the adhesion layer of the common electrode film 18. This is because the common electrode film 18 is completely removed by etching over the entire area of the semiconductor substrate 12. Further, the common electrode film 18 below the bump electrode 23 is
Due to the above-described over-etching process, the projection electrode 23 recedes from the pattern shape. That is, the pattern shape of the lower electrode 19 is smaller than the pattern shape of the bump electrode 23.

Thereafter, the semiconductor substrate 12 is placed in a furnace in which nitrogen gas is introduced at a rate of 20 liters per minute, and the temperature in the furnace is set at 3 degrees.
A heat treatment is performed for 30 minutes while controlling the temperature to
Lower hardness. Thereby, the Vickers hardness Hv of the protruding electrode 23 is set to be 40 to 60. As described above, the purpose of reducing the hardness of the protruding electrode 23 is to make it easier to adhere to the circuit electrode on the circuit board by pressurization during mounting.

Here, the projection electrode 23 is formed by this heat treatment.
The reason why the hardness of the steel sheet decreases will be described. The protruding electrode 22 immediately after plating contains an impurity gas such as hydrogen or carbon,
Although the Vickers hardness Hv is 100 to 120, the recrystallization is progressed by performing the above-described heat treatment, impurity gas is released from the protruding electrodes 23, and the Vickers hardness approaches the hardness of pure gold.

Thereafter, in a dicing step, the semiconductor substrate 12 is cut along dicing lines indicated by alternate long and short dash lines in FIG.
The semiconductor device 1 shown in FIG. 5 is completed.

[Second Embodiment of Semiconductor Device Mounting Method: FIGS. 5, 6, 14 and 15] Next, a second embodiment of a semiconductor device mounting method according to the present invention will be described with reference to FIGS. 6, and will be described with reference to FIGS. This is a mounting method for obtaining the mounting structure of the semiconductor device 1 manufactured as described above and shown in FIG.

In this mounting method, in the first step, the semiconductor device 1 having the plurality of protruding electrodes 23 whose top surface is convex as shown in FIG. 5 is turned upside down, and as shown in FIG. Each projecting electrode 23 is placed on a circuit board 26 having an electrode 28.
Are aligned (aligned) so as to face the respective circuit electrodes 28. Then, each protruding electrode 23 of the semiconductor device 1 and each circuit electrode 28 of the circuit board 26
Are brought into direct contact with each other.

Thereafter, the ultrasonic pressure bonding tool 30 shown in FIG. 14 is brought into contact with the back surface of the semiconductor device 1 where the protruding electrodes 23 are not formed, and ultrasonic vibration of a frequency of 20 to 30 KHz is applied to each of the protruding electrodes by 50 to 30 KHz. At the same time as applying an output of 200 mW, 30 to 10 per one protruding electrode 22
Apply a load of 0 g. At this time, the application time of the ultrasonic vibration is 0.5 to 2 seconds.

Further, at this time, the circuit board 26 has a hot plate 40 on the back side where the circuit electrodes 28 are not formed.
, And is heated at a temperature of 150 to 200 ° C. from the circuit board 26 side simultaneously with the application of the ultrasonic vibration and the load from the semiconductor device 1 side.

At this time, since the central portion of the projecting electrode 23 has a convex shape, the central portion 23
a, the projection electrode 23 is made of gold, and the hardness is reduced as described above, so that the central portion 23a becomes the same height as the peripheral portion 23b, and gradually becomes larger. Peripheral portion 23b of projecting electrode 23
As a result, as shown in FIG. 15, the entire top of the protruding electrode 23 finally forms a joint surface 25 with the circuit electrode 28 uniformly.

Then, by the wave energy due to the ultrasonic vibration and the heat energy due to the heating, the metal atoms and molecules near the bonding surface 25 diffuse into each other, and a strong diffusion bonding can be performed. Therefore, the projection electrode 23
And the circuit electrode 28 are securely connected with an extremely low connection resistance over the entire area of the joint surface 25.

Thereafter, the sealing resin 32 made of the epoxy resin shown in FIG. 6 is injected into the gap between the semiconductor device 1 and the circuit board 26, and the sealing resin 32 is cured by performing a baking process. Thus, the mounting structure shown in FIG. 6 is completed.

In this embodiment, ultrasonic vibration is applied to the protruding electrode 23 of the semiconductor device 1 and the circuit electrode 28 of the circuit board 26 and pressurized while heating, so that the bonding surface 25 is formed. Was made to be diffusion bonded,
Even if pressure is applied while performing either ultrasonic vibration application or heating, the bonding surface 25 can be diffusion bonded.

The effect of this embodiment is the same as that of the first embodiment.
The effects of the embodiment are further ensured and improved. In particular, since the top of the protruding electrode 23 of the semiconductor device 1 is formed in a convex shape, diffusion bonding can be performed uniformly over the entire bonding surface 25, and electrical characteristics and mechanical strength can be dramatically improved. Was completed. Therefore, high-density bonding can be realized at low cost.

[Second Embodiment of Semiconductor Device and Its Manufacturing Method: FIGS. 16 to 21] Next, a second embodiment of the semiconductor device and its manufacturing method according to the present invention will be described with reference to FIGS. I do. FIG. 16 is a sectional view similar to FIG. 5 showing the structure of a second embodiment of the semiconductor device according to the present invention, and portions corresponding to those in FIG. 5 are denoted by the same reference numerals. Omitted.

This semiconductor device 1 is different from the first embodiment shown in FIG. 5 in that a raised member 161 provided on the center of each electrode pad 14 of the semiconductor chip 11 is the same as the insulating film 16. The height of the central portion of the lower electrode 19 provided thereon is slightly reduced, and the step between the central portion 23a of the protruding electrode 23 and the peripheral portion 23b is insulated. The only difference is that the film thickness is the same as that of the film 16.

Even if this semiconductor device 1 is used, if the method of mounting on a circuit board is carried out in the same manner as in the second embodiment of the above-described mounting method, the same mounting as in the second embodiment shown in FIG. Since a structure can be obtained and the effect thereof is the same, the description thereof is omitted.

Therefore, the method of manufacturing the semiconductor device 1 described with reference to FIG. 16 will be described with reference to FIGS. 17 to 21 only for steps different from those of the first embodiment. First, as shown in FIG. 17, an integrated circuit for a plurality of semiconductor chips is formed therein, and a plurality of electrode pads 14 for each of the semiconductor chips are provided on the surface thereof. 0.8 to 1.0 μm insulating film 1
6 is formed.

Then, the entire surface of the insulating film 16 is covered with FIG.
A first photosensitive resin 31 made of a photosensitive polyimide resin shown in FIG. 8 is applied to an arbitrary thickness by a spin coating method. Then, using a predetermined photomask, the first photosensitive resin 31 is patterned by a photolithography process including an exposure process and a development process, and a ring-shaped pattern is formed on each electrode pad 14 as shown in FIG. Opening 31a is formed. As a result, the first photosensitive resin 31b remains on the center of each electrode pad 14.

Then, the insulating film 16 is patterned by performing an etching process using the first photosensitive resin 31 as a mask. As shown in FIG. Opening 16a is formed,
A part of the insulating film 16 is left as a raised member 161 at the center.

Next, a common electrode film 18 shown in FIG. 20 is formed on the entire surface of the semiconductor substrate 12 by sputtering. The material and the laminated structure of the common electrode film 18 are the same as those of the first embodiment. Then, FIG.
As shown in FIG. 0, a second photosensitive resin 34 is coated on the entire surface of the common electrode film 18 by a spin coating method in a range of 20 μm to 25 μm.
m.

Then, photolithography by exposure and development is performed using a predetermined photomask, and patterning is performed so as to form openings 34 a in the second photosensitive resin 34. The opening 34a is formed on each of the electrode pads 14 to have substantially the same size as the electrode pads 14.

Next, as shown in FIG. 21, using the patterned second photosensitive resin 34 as a plating mask,
On the common electrode film 18 in the opening 34a, the protruding electrode 23 made of a gold plating layer is formed. The conditions of the electrolytic plating process at this time are the same as those in the first embodiment.

By forming the gold plating layer so that the peripheral portion does not project from the upper surface of the photosensitive resin 34 which is a mask in the plating process, the side surface shape in the cross section of the projecting electrode 23 becomes as shown in FIG. It has a straight wall shape. In addition, due to the convex shape of the raising member 161 due to the insulating film 16, the central portion of the bump electrode 23 can be formed higher than the peripheral edge.

By this plating, it is preferable to perform a hydrophilic treatment before forming the protruding electrodes 23 in the openings 34a of the photosensitive resin 34. The hydrophilization treatment can be performed by, for example, a wet treatment with a chemical solution of a mixed solution of sulfuric acid and hydrogen peroxide, or a dry treatment using, for example, oxygen plasma.

Thus, the protruding electrode 23 is formed,
After removing the second photosensitive resin 34, the step of forming the lower electrode 19, the step of reducing the hardness of the protruding electrode 23, and the dicing step are the same as the steps described with reference to FIG. 13 in the first embodiment. The description is omitted because it is the same.

[Third Embodiment of Semiconductor Device and Its Manufacturing Method: FIGS. 22 to 25] Next, a third embodiment of the semiconductor device and its manufacturing method according to the present invention will be described with reference to FIGS. I do. FIG. 22 is a sectional view similar to FIG. 5 showing the structure of the third embodiment of the semiconductor device according to the present invention. Parts corresponding to those in FIG. 5 are denoted by the same reference numerals, and description thereof is omitted. I do.

This semiconductor device 1 is different from the semiconductor device 1 of the first embodiment shown in FIG.
1. Raising member 2 provided on the center of each electrode pad 14
11 is only made of a conductive film instead of a photosensitive resin. The thickness of the raised member 211 made of the conductive film is larger than the thickness of the insulating film 16 and may be a stacked film of two or more metal films. The lower electrode 19 and the protruding electrode 23 are formed on each of the electrode pads 14 on which the raising member 211 is provided, and the top surface of the protruding electrode 23 has a central portion 23a that is larger than the peripheral portion 23b. The convex shape is higher by the thickness.

Even if this semiconductor device 1 is used, if the method of mounting on a circuit board is carried out in the same manner as in the above-described second embodiment of the mounting method, the same mounting as in the second embodiment shown in FIG. A structure can be obtained, and the effect by that is the same. However, since the raising member 211 is formed of a conductive film, the electrical connection between the protruding electrode 23 and the electrode pad 14 is also made via the raising member 211.
The entire area of the contact surface with the lower electrode 19 contributes to conduction, and the connection resistance can be further reduced. Accordingly, it is possible to make the size of the protruding electrode smaller.

Therefore, a method of manufacturing the semiconductor device 1 described with reference to FIG. 22 will be described with reference to FIGS. 23 to 25, only for steps different from those of the first embodiment. First, as shown in FIG. 23, each electrode pad 1 is placed on a semiconductor substrate 12 on which a plurality of electrode pads 14 are provided.
An insulating film 16 having an opening 16 a is formed on the insulating film 4.

Then, the conductive film 2 thicker than the insulating film 16 is formed on the entire surface of the semiconductor substrate 12 on which the insulating film 16 is formed.
Form one. This conductive film 21 may be formed of one or more layers of a metal material such as aluminum, nickel, copper, titanium, tantalum, tungsten, molybdenum by sputtering or the like, or a chromium layer may be formed thereunder. .

Thereafter, the entire surface of the conductive film 21 is covered with FIG.
The first photosensitive resin 31 shown in FIG. 4 is applied by a spin coating method. Next, the first photosensitive resin is patterned by photolithography so as to be left only on the central portion of each electrode pad 14 as shown in FIG.
Then, an etching process is performed using the first photosensitive resin 31 as a mask, and as shown in FIG.
Is raised only on the central portion of each electrode pad 14.
Patterning to leave as After that, the first photosensitive resin 31 is removed.

The subsequent steps are the same as those described with reference to FIGS. 10 to 13 for the first embodiment, and a description thereof will not be repeated.

[Fourth Embodiment of Semiconductor Device and Its Manufacturing Method: FIGS. 26 to 30] Next, a fourth embodiment of the semiconductor device and its manufacturing method according to the present invention will be described with reference to FIGS. 26 to 30. I do. 26 and 27 show the structure of the fourth embodiment of the semiconductor device according to the present invention.
FIG. 22 is a similar cross-sectional view, in which portions corresponding to those in FIGS. 5 and 22 are denoted by the same reference numerals, and description thereof will be omitted.

The semiconductor device of the fourth embodiment is similar to that of FIG.
2 is different from the semiconductor device of the third embodiment shown in FIG.
The only difference is that the raising member 211 made of a conductive film is provided on the lower electrode 19 corresponding to the center of each electrode pad 14 of the semiconductor chip 11.

Even if this semiconductor device 1 is used, if the method of mounting on a circuit board is carried out in the same manner as in the second embodiment of the above-described mounting method, the same mounting as in the second embodiment shown in FIG. A structure can be obtained, and the effect thereof is exactly the same as the case where the semiconductor device of the third embodiment described above with reference to FIG. 22 is used.

Therefore, the method of manufacturing the semiconductor device 1 described with reference to FIG. 26 will be described with reference to FIGS. 27 to 30 only for steps different from those in the first embodiment. First, as shown in FIG. 27, each electrode pad 1 is placed on a semiconductor substrate 12 on which a plurality of electrode pads 14 are provided.
An insulating film 16 having an opening 16 a is formed on the insulating film 4.

Then, the insulating film 16 of the semiconductor substrate 12 is formed.
A common electrode film 18 connected to each electrode pad 14 through the opening 16a is formed on the entire surface on which is formed. Next, as shown in FIG. 28, a conductive film 21 is formed on the entire surface of the common electrode film 18 so as to be thicker than the insulating film 16. This conductive film 21
Are the same as those in the third embodiment.

Next, over the entire surface of the conductive film 21, FIG.
Is applied by a spin coating method. Then, the first photosensitive resin 31 is patterned by photolithography so as to remain only on the conductive film 21 at the center of each electrode pad. afterwards,
An etching process is performed using the first photosensitive resin 31 as a mask, and the conductive film 21 is patterned as shown in FIG.
It is left as a raising member 211 only on the top. Then, the first photosensitive resin 31 is removed.

The subsequent steps are the same as those described with reference to FIGS. 11 to 13 for the first embodiment, and a description thereof will not be repeated.

[Fifth Embodiment of Semiconductor Device and Its Manufacturing Method: FIGS. 31 and 32] Next, a fifth embodiment of the semiconductor device and its manufacturing method according to the present invention will be described with reference to FIGS.
It will be explained by. FIG. 31 is a sectional view similar to FIGS. 5 and 22 showing the structure of a fifth embodiment of the semiconductor device according to the present invention, and portions corresponding to FIGS. 5 and 22 are denoted by the same reference numerals. And description thereof is omitted.

The semiconductor device according to the fourth embodiment is different from the semiconductor device shown in FIG.
2 is different from the semiconductor device of the third embodiment shown in FIG.
The raising member 37 is connected to each of the electrode pads 1 of the semiconductor chip 11.
The only difference is that a metal film formed by plating is provided on the central portion of No. 4.

Even if the semiconductor device of the fifth embodiment is used, if the method of mounting on a circuit board is carried out in the same manner as in the second embodiment of the mounting method described above, the second embodiment shown in FIG. A mounting structure similar to that of the embodiment can be obtained, and the effect thereof is exactly the same as the case of using the semiconductor device of the third embodiment described above with reference to FIG.

Therefore, the method of manufacturing the semiconductor device 1 described with reference to FIG. 31 will be described with reference to FIG. 32, only for steps different from those of the first embodiment. First, the formation of the insulating film 6 having an opening on each electrode pad 14 on the semiconductor substrate 12 provided with the plurality of electrode pads 14 shown in FIG. 32 is the same as in the first embodiment.

Next, a first photosensitive resin 38 is applied on the entire surface of the semiconductor substrate 12 on which the insulating film 16 is formed by a spin coating method. Then, the first photosensitive resin 3
8 are patterned by a photolithography process to form openings 38 a only on the central portions of the respective electrode pads 14.
To form

Thereafter, on each electrode pad 14 in each opening 38a of the first photosensitive resin 38, a raised member 37 made of a metal film is formed by plating.
This plating process is an electroless plating process in which a metal film such as nickel or copper is formed as the raising member 37. Then, the first photosensitive resin 38 is removed.

The subsequent steps are the same as those described with reference to FIG. 10 to FIG. 13 in the first embodiment, and a description thereof will not be repeated.

[0127]

As described above, according to the semiconductor device mounting structure and the mounting method of the present invention, an anisotropic conductive adhesive is used to mount a surface mount type semiconductor device on a circuit board. Instead, each protruding electrode of the semiconductor device and each circuit electrode of the circuit board can be electrically connected with an extremely low connection resistance, and can be mechanically connected firmly.
Therefore, the area occupied by one protruding electrode is reduced,
In addition, the arrangement pitch of the protruding electrodes is reduced, and high-density connection can be realized with high reliability.

Further, the semiconductor device according to the present invention provides a semiconductor device having a more reliable and effective mounting structure. According to the invention of the method of manufacturing the semiconductor device, each semiconductor device according to the present invention is provided. The device can be manufactured efficiently with high quality.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a first embodiment of a mounting structure of a semiconductor device according to the present invention.

FIG. 2 is a schematic cross-sectional view showing a part of a semiconductor substrate used for describing a first embodiment of a semiconductor device mounting method according to the present invention.

FIG. 3 is a schematic cross-sectional view showing a mounting step according to the first embodiment of the semiconductor device mounting method according to the present invention.

FIG. 4 is an explanatory diagram of a planar arrangement of protruding electrodes on a semiconductor chip in a semiconductor device according to the present invention.

FIG. 5 is a schematic cross-sectional view showing a first embodiment of the semiconductor device according to the present invention.

FIG. 6 is a schematic cross-sectional view showing a second embodiment of the semiconductor device mounting structure according to the present invention.

FIG. 7 is a schematic sectional view of a part of the semiconductor substrate showing a first step of the first embodiment of the method for manufacturing a semiconductor device according to the present invention;

FIG. 8 is a schematic cross-sectional view showing the next step.

FIG. 9 is also a schematic cross-sectional view showing the next step.

FIG. 10 is a schematic cross-sectional view showing the next step.

FIG. 11 is also a schematic cross-sectional view showing the next step.

FIG. 12 is also a schematic cross-sectional view showing the next step.

FIG. 13 is a schematic cross-sectional view showing the next step.

FIG. 14 shows a second embodiment of the semiconductor device mounting method according to the present invention.
It is a typical sectional view showing the mounting process by an embodiment.

FIG. 15 is a schematic cross-sectional view showing the next mounting step.

FIG. 16 is a schematic sectional view showing a second embodiment of the semiconductor device according to the present invention.

FIG. 17 shows a second example of the method of manufacturing a semiconductor device according to the present invention.
FIG. 13 is a schematic cross-sectional view of a part of the semiconductor substrate, showing a first step of the embodiment.

FIG. 18 is also a schematic cross-sectional view showing the next step.

FIG. 19 is also a schematic cross-sectional view showing the next step.

FIG. 20 is a schematic cross-sectional view showing the next step.

FIG. 21 is a schematic cross-sectional view showing the next step.

FIG. 22 is a schematic sectional view showing a third embodiment of the semiconductor device according to the present invention.

FIG. 23 is a third view illustrating the method of manufacturing a semiconductor device according to the present invention;
FIG. 13 is a schematic cross-sectional view of a part of the semiconductor substrate, showing a first step of the embodiment.

FIG. 24 is a schematic cross-sectional view showing the next step.

FIG. 25 is a schematic cross-sectional view showing the next step.

FIG. 26 is a schematic sectional view showing a fourth embodiment of the semiconductor device according to the present invention.

FIG. 27 is a fourth view of the method for manufacturing a semiconductor device according to the present invention;
FIG. 13 is a schematic cross-sectional view of a part of the semiconductor substrate, showing a first step of the embodiment.

FIG. 28 is a schematic cross-sectional view showing the next step.

FIG. 29 is a schematic cross-sectional view showing the next step.

FIG. 30 is also a schematic cross-sectional view showing a next step.

FIG. 31 is a schematic sectional view showing a fifth embodiment of the semiconductor device according to the present invention.

FIG. 32 is a fifth view of the method for manufacturing a semiconductor device according to the present invention;
FIG. 13 is a schematic cross-sectional view of a part of the semiconductor substrate, showing a step in the middle of the embodiment.

FIG. 33 is a schematic cross-sectional view showing an intermediate step in a conventional semiconductor device manufacturing method.

FIG. 34 is a schematic cross-sectional view showing the next step.

FIG. 35 is a schematic cross-sectional view of a conventional surface mount type semiconductor device.

FIG. 36 is a schematic cross-sectional view showing a mounting structure of a conventional semiconductor device.

[Explanation of symbols]

 1, 10: semiconductor device 11: semiconductor chip 12: semiconductor substrate 14: electrode pad 16: insulating film 18: common electrode film 19: lower electrode 20, 38: photosensitive resin 21: conductive film 22, 23: projecting electrode 24, 31: first photosensitive resin 25: bonding surface 26: circuit board 28: circuit electrode 30: ultrasonic pressure bonding tool 32: sealing resin 34: second photosensitive resin 35: mask plate 37, 161, 211, 241 : Raising member 40: Hot plate

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] February 28, 2001 (2001.2.2
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 24

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

To mount the semiconductor device 10 on a circuit board, as shown in FIG. 36, an anisotropic conductive adhesive 44 in which conductive particles 42 are mixed in an insulating adhesive 46 made of epoxy resin is used. is interposed between the circuit board 26 having a plurality of circuit electrodes 28 facing arrangement with the semiconductor device 10 having a plurality of projecting electrodes 22, protruding electrodes 22 and circuit electrodes 28
Apply pressure and heat in between.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0027

[Correction method] Change

[Correction contents]

The raising member can be made of a photosensitive resin, the same material as the insulating film, a conductive material, a metal film formed by electroless plating, or the like. In addition, this raising member,
It may be provided on each lower electrode formed on each electrode pad .

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction contents]

The diffusion bonding between the protruding electrode 22 and the circuit electrode 28 will be described in detail in an embodiment of a mounting method described later, but the ultrasonic wave and the load are applied from the back side of the semiconductor device 10 where the protruding electrode 22 is not formed. In addition, the projection electrode 22 is heated from the back side of the circuit board 26 where the circuit electrodes 28 are not formed.
And the circuit electrode 28. By this diffusion bonding, metal atoms and molecules near the joint surface 25 between the protruding electrode 22 and the circuit electrode 28 diffuse to each other and are firmly connected. In particular, if both sides of the bonding surface 25 are made of gold, this diffusion bonding is easily performed.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0045

[Correction method] Change

[Correction contents]

As described above, in the case of the conventional mounting structure, the conductive particles sandwiched between the top surface of the projecting electrode 22 and the circuit electrode 28 using an anisotropic conductive adhesive containing the conductive particles are used. because it was subjected to conduction between only Thus both the contact surface with, in order to lower the connection resistance has to ensure 10 or so of the conductive particles in each protruding electrode, the top of the bump electrode 22 The surface area had to be increased accordingly.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0058

[Correction method] Change

[Correction contents]

[0058] First implementation of the semiconductor device: 5 Next, with the first embodiment of a semiconductor device according to the invention
This will be described with reference to the schematic sectional view shown in FIG. FIG.
, The same reference numerals are given to the same parts as those of the semiconductor device 10 shown in FIGS.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0073

[Correction method] Change

[Correction contents]

The common electrode film 18 has good electrical and mechanical connectivity between the electrode pad 14 and the electrode material of the projection electrode 23 to be formed later, does not diffuse between electrode materials, and is made of a stable electrode material. Select. Therefore, this common electrode film 1
8 is a titanium-tungsten alloy other than the above-mentioned materials.
Copper-gold, aluminum-chromium-copper, aluminum-
Titanium-copper or other three-layer structure, or titanium-palladium, titanium-gold, titanium-platinum, titanium-tungsten alloy-palladium, titanium-tungsten alloy-
It may have a two-layer structure of gold, titanium / tungsten alloy-platinum, or the like.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name]

[Correction method] Change

[Correction contents]

Thereafter, the semiconductor substrate 12 is placed in a furnace in which nitrogen gas is introduced at a rate of 20 liters per minute, and the temperature in the furnace is set at 3 degrees.
A heat treatment is performed for 30 minutes while controlling the temperature to
Lower hardness. Thereby, the Vickers hardness Hv of the protruding electrode 23 is set to be 40 to 60. As described above, the purpose of reducing the hardness of the protruding electrode 23 is to make it easier to adhere to the circuit electrode on the circuit board by pressurization during mounting.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0085

[Correction method] Change

[Correction contents]

[Second Embodiment of Semiconductor Device Mounting Method: FIGS. 5, 6, 14 and 15] Next, a second embodiment of a semiconductor device mounting method according to the present invention will be described with reference to FIGS. This will be described with reference to FIGS. 6, 14 and 15. This is a mounting method for obtaining the mounting structure of the semiconductor device 1 manufactured as described above and shown in FIG.

[Procedure amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0087

[Correction method] Change

[Correction contents]

Thereafter, the ultrasonic pressure bonding tool 30 shown in FIG. 14 is brought into contact with the back surface of the semiconductor device 1 where the protruding electrodes 23 are not formed, and ultrasonic vibration having a frequency of 20 to 30 KHz is applied to each protruding electrode 23 by 50. at the same time it is applied at the output of ~200mW, 30~ per one projection electrode 23
Apply a load of 100 g. At this time, the application time of the ultrasonic vibration is 0.5 to 2 seconds.

[Procedure amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0089

[Correction method] Change

[Correction contents]

At this time, since the central portion of the projecting electrode 23 has a convex shape, the central portion 23
with bonding starts with the circuit electrode 28 from a, the projection electrodes 23 is made of gold, and because it is a process of reducing the hardness as described above, the central portion 23a peripheral portion 23b
And the peripheral portion 23 of the protruding electrode 23 gradually becomes
As shown in FIG. 15, the bonding spreads to b, and finally, the entire top of the protruding electrode 23 uniformly forms the bonding surface 25 with the circuit electrode 28 as shown in FIG.

[Procedure amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0123

[Correction method] Change

[Correction contents]

Therefore, the method of manufacturing the semiconductor device 1 described with reference to FIG. 31 will be described with reference to FIG. 32, only for steps different from those of the first embodiment. First, the formation of the insulating film 16 having openings on the respective electrode pads 14 on the semiconductor substrate 12 provided with the plurality of electrode pads 14 shown in FIG. 32 is the same as in the first embodiment.

Claims (24)

[Claims] 1. A semiconductor device having a plurality of electrode pads on one surface of a semiconductor chip and a plurality of projecting electrodes individually conducting to each of the electrode pads, and a plurality of semiconductor devices individually connected to the plurality of projecting electrodes on one surface. A mounting structure of a semiconductor device mounted on a circuit board having a circuit electrode, wherein each protruding electrode of the semiconductor device and a surface of each circuit electrode of the circuit board facing each other are directly bonded, and the bonding surface is diffusion bonded. A semiconductor device mounting structure. 2. The mounting structure of a semiconductor device according to claim 1, wherein said projecting electrode has a straight wall shape, and a surface to be joined to said circuit electrode is substantially planar. 3. The mounting structure of a semiconductor device according to claim 1, wherein said protruding electrode is formed of gold. 4. A semiconductor device having a plurality of electrode pads on one surface of a semiconductor chip and a plurality of projecting electrodes individually conducting to the respective electrode pads, and a plurality of semiconductor devices individually connected to the plurality of projecting electrodes on one surface. A method for mounting a semiconductor device mounted on a circuit board having circuit electrodes, wherein the semiconductor device is positioned on the circuit board such that the plurality of projecting electrodes face the plurality of circuit electrodes, respectively. Aligning and arranging; directly contacting each of the protruding electrodes of the semiconductor device with the respective opposing surfaces of the circuit electrodes of the circuit board; and applying ultrasonic vibration or heat to the protruding electrodes and the circuit electrodes. Applying a pressure while applying pressure to diffuse and bond the contact surface. 5. The method for mounting a semiconductor device according to claim 4, wherein before the step of arranging the semiconductor device on a circuit board, each bump electrode of the semiconductor device is subjected to a heat treatment to reduce its hardness. A method for mounting a semiconductor device, comprising a step of lowering the height. 6. The method for mounting a semiconductor device according to claim 5, wherein the step of reducing the hardness of each of the protruding electrodes using a semiconductor device in which each of the protruding electrodes is formed of gold is performed. Wherein the heat treatment is performed in a furnace at a temperature of 250 to 350 ° C. so that the Vickers hardness of each of the protruding electrodes is 40 to 60. 7. The method of mounting a semiconductor device according to claim 4, wherein in the step of diffusing and joining the contact surface between the projecting electrode and the circuit electrode, ultrasonic vibration and a load are applied to the projecting electrode and the circuit electrode. A method for mounting a semiconductor device, comprising heating. 8. The method for mounting a semiconductor device according to claim 7, wherein the frequency of the ultrasonic vibration is 20 to 30 KHz, the output is 50 to 200 mW per one of the bump electrodes, and the load is the bump electrode. 30. A method for mounting a semiconductor device, wherein the weight of the semiconductor device is 30 to 100 g, and the heating temperature is 150 to 200 ° C. 9. The method for mounting a semiconductor device according to claim 7, wherein the ultrasonic vibration and the load are applied from a surface of the semiconductor device opposite to a surface having the protruding electrodes, and the semiconductor substrate is mounted on the circuit board. A method for mounting a semiconductor device, wherein the heating is performed from a surface opposite to a surface having circuit electrodes. 10. The method for mounting a semiconductor device according to claim 4, wherein after the step of diffusing a contact surface between the projecting electrode and the circuit electrode, the semiconductor device and the circuit board are connected to each other. A method for mounting a semiconductor device, comprising: a step of injecting a sealing resin made of an epoxy resin into a gap therebetween, performing a baking process, and curing the sealing resin. 11. A semiconductor chip provided with an integrated circuit and a plurality of electrode pads for connecting the integrated circuit to an external circuit, and a surface provided with the plurality of electrode pads of the semiconductor chip, wherein each of the electrode pads is covered. An insulating film having an opening thereon, a raising member provided on a central portion of each of the electrode pads in each of the openings of the insulating film, and individually conducting with each of the electrode pads through each of the openings of the insulating film; A plurality of lower electrodes provided on the periphery of the opening of the insulating film and over the raising member; and a plurality of lower electrodes provided on each of the lower electrodes. A semiconductor device comprising a plurality of protruding electrodes formed higher by a thickness. 12. The semiconductor device according to claim 11, wherein said raising member is formed of a photosensitive resin. 13. The semiconductor device according to claim 11, wherein said raising member is formed of the same material as said insulating film. 14. The semiconductor device according to claim 11, wherein said raising member is formed of a conductive material. 15. The semiconductor device according to claim 14, wherein said conductive material is a metal film formed by electroless plating. 16. A semiconductor chip provided with an integrated circuit and a plurality of electrode pads for connecting the integrated circuit to an external circuit, and a surface of the semiconductor chip provided with the plurality of electrode pads, wherein each of the electrode pads is covered. An insulating film having an opening on the top thereof; and a plurality of insulating films which are individually connected to the respective electrode pads through the respective openings of the insulating film, and are provided from above the respective electrode pads to a peripheral portion of the opening of the insulating film. A lower electrode, a raising member provided on a central portion of each lower electrode, and a raising portion provided on each of the lower electrodes, wherein a central portion of a top surface is formed higher than a peripheral portion thereof by the thickness of the raising member. And a plurality of protruding electrodes. 17. The semiconductor device according to claim 16, wherein said raising member is formed of a conductive material. 18. A step of forming an insulating film having openings on each of said electrode pads on a semiconductor substrate provided with a plurality of integrated circuits for semiconductor chips and a plurality of electrode pads for connecting the same to an external circuit. Applying a first photosensitive resin thicker than the insulating film over the entire surface of the semiconductor substrate on which the insulating film is formed; and applying the first photosensitive resin to the respective electrodes by photolithography. Patterning so as to remain as a raised member only on the central portion of the pad; and forming a common electrode film connected to each of the electrode pads through the opening over the entire surface of the semiconductor substrate on which the insulating film is formed. Applying a second photosensitive resin to the entire surface of the common electrode film, and applying the second photosensitive resin to each of the electrode pads by photolithography. Patterning so as to form an opening having substantially the same size as the pole pad; and forming a protruding electrode by plating on the common electrode film in each of the openings of the second photosensitive resin. Removing the second photosensitive resin; forming an lower electrode on each of the electrode pads by patterning the common electrode film by performing an etching process using each of the bump electrodes as a mask; And a step of cutting the semiconductor substrate into semiconductor chips of individual semiconductor devices. 19. A step of forming an insulating film on an entire surface of a semiconductor substrate provided with a plurality of integrated circuits for semiconductor chips and a plurality of electrode pads for connecting the integrated circuits to an external circuit; Applying a first photosensitive resin to the substrate; patterning the first photosensitive resin by photolithography so as to form a ring-shaped opening on each of the electrode pads; Forming a ring-shaped opening in a portion of the insulating film on each of the electrode pads by performing an etching process using the photosensitive resin as a mask, and patterning the insulating film; Removing the resin; forming a common electrode film connected to each of the electrode pads through the opening on the entire surface of the semiconductor substrate on which the insulating film is formed; A step of applying a second photosensitive resin to the entire surface of the film, and forming an opening of substantially the same size as the electrode pads on each of the electrode pads by photolithography of the second photosensitive resin. Patterning, forming a projecting electrode on the common electrode film in each of the openings of the second photosensitive resin by plating, and removing the second photosensitive resin. Forming a lower electrode on each of the electrode pads by patterning the common electrode film by performing an etching process using each of the bump electrodes as a mask; And a step of cutting into chips. 20. A step of forming an insulating film having openings on each of said electrode pads on a semiconductor substrate provided with a plurality of integrated circuits for semiconductor chips and a plurality of electrode pads for connecting the same to an external circuit. Forming a conductive film thicker than the insulating film on the entire surface of the semiconductor substrate on which the insulating film is formed; applying a first photosensitive resin to the entire surface of the conductive film; Patterning a first photosensitive resin by photolithography so as to remain only on the central portion of each of the electrode pads; and performing an etching process using the first photosensitive resin as a mask to form the conductive film. Patterning so as to leave as a raising member only on the central portion of each of the electrode pads; removing the first photosensitive resin; and forming the insulating film of the semiconductor substrate. Forming a common electrode film connected to each of the electrode pads through the opening on the entire surface of the surface; applying a second photosensitive resin on the entire surface of the common electrode film; Patterning by photolithography processing so as to form openings of substantially the same size as the electrode pads on each of the electrode pads; and the common electrode in each of the openings of the second photosensitive resin. A step of forming a projecting electrode on the film by plating, a step of removing the second photosensitive resin, and an etching process using the projecting electrodes as a mask to pattern the common electrode film. Forming a lower electrode on each of the electrode pads, and cutting the semiconductor substrate into semiconductor chips of individual semiconductor devices. The method of manufacturing a semiconductor device. 21. A step of forming an insulating film having openings on each of said electrode pads on a semiconductor substrate provided with a plurality of integrated circuits for semiconductor chips and a plurality of electrode pads for connecting the same to an external circuit. Forming a common electrode film connected to each of the electrode pads through the opening on the entire surface of the semiconductor substrate on which the insulating film is formed; and forming a conductive film on the entire surface of the common electrode film from the insulating film. Forming a first photosensitive resin on the entire surface of the conductive film; applying the first photosensitive resin to the conductive film at the center of each of the electrode pads by photolithography; Patterning such that only the first conductive resin is left, and performing an etching process using the first photosensitive resin as a mask to form the conductive film on the common electrode film at the center of each of the electrode pads. A step of patterning so as to leave as a raising member; a step of removing the first photosensitive resin; a step of applying a second photosensitive resin to the entire surface on the common electrode film; Patterning a resin by photolithography so as to form an opening of substantially the same size as the electrode pad on each of the electrode pads; and forming the common resin in each of the openings of the second photosensitive resin. Forming a protruding electrode on the electrode film by plating, removing the second photosensitive resin, performing an etching process using the protruding electrode as a mask, and patterning the common electrode film. Forming a lower electrode on each of the electrode pads, and cutting the semiconductor substrate into semiconductor chips of individual semiconductor devices. The method of manufacturing a semiconductor device according to claim. 22. A step of forming an insulating film having openings on each of said electrode pads on a semiconductor substrate provided with a plurality of integrated circuits for semiconductor chips and a plurality of electrode pads for connecting the same to an external circuit. Applying a first photosensitive resin to the entire surface of the semiconductor substrate on which the insulating film is formed; and applying the first photosensitive resin to a central portion of each of the electrode pads by photolithography. Patterning so as to form only openings, and forming a raised member made of a metal film by plating on each of the electrode pads in each of the openings of the first photosensitive resin. Removing a photosensitive resin, and forming a common electrode film connected to each of the electrode pads through the opening on the entire surface of the semiconductor substrate on which the insulating film is formed. Applying a second photosensitive resin to the entire surface of the common electrode film; and applying the second photosensitive resin to each of the electrode pads by photolithography to have the same size as the electrode pads. Patterning so as to form an opening of the second photosensitive resin; forming a projecting electrode by plating on the common electrode film in each of the openings of the second photosensitive resin; Removing the conductive resin, performing an etching process using each of the protruding electrodes as a mask, and forming a lower electrode on each of the electrode pads by patterning the common electrode film. Cutting the semiconductor device into semiconductor chips. 23. The method of manufacturing a semiconductor device according to claim 18, wherein the step of forming the lower electrode and the step of cutting the semiconductor substrate are performed with respect to the projecting electrode. A method of performing a heat treatment to reduce the hardness of the semiconductor device. 24. The method of manufacturing a semiconductor device according to claim 23, wherein each of the projecting electrodes is formed of gold in the step of forming the projecting electrodes, and nitrogen gas is introduced in the step of reducing the hardness of the projecting electrodes. The heat treatment is performed in a furnace at a temperature of 250 to 350 ° C. so that the Vickers hardness of the bump electrode is 40 to 60.
A method for manufacturing a semiconductor device.