JP2002289769A - Stacked semiconductor device and method of manufacturing the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In a stacked semiconductor device, a plurality of semiconductor elements are integrated into one.
The structure is to be mounted on a single wiring board, and it has been desired to reduce the weight as a whole. SOLUTION: At least two or more semiconductor elements are mounted on a wiring board 10 to constitute a one-package CSP, and a peripheral portion of an upper surface of a sealing resin 15 has a cut portion 17 by grinding to have a volume. The structure has been reduced. Therefore, it is possible to reduce the weight of the stacked semiconductor device in which the plurality of semiconductor elements 12 and 14 are configured in one package. Further, the first semiconductor element 12 and the second semiconductor element 1
Since the film wiring conductor 13 is interposed between the semiconductor device and the semiconductor device 4, the laminated semiconductor device as a whole has flexibility and can cope with stress due to thermal expansion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stacked semiconductor device in which semiconductor elements having a plurality of functions are stacked in a three-dimensional direction and a method of manufacturing the same. The present invention relates to a stacked semiconductor device with high connection reliability and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, a stacked semiconductor device has been developed in which semiconductor elements having a plurality of functions are stacked and mounted on one circuit board (carrier board) having a circuit structure to constitute one package.

Hereinafter, a conventional stacked semiconductor device which has been developed will be described as a typical structure of a stacked semiconductor device in which two semiconductor elements are stacked and mounted on a substrate.

FIG. 9 is a sectional view showing the structure of a conventional stacked semiconductor device.

As shown in FIG. 9, in a conventional stacked semiconductor device, a wiring board 3 having wiring electrodes 1a and 1b and a terminal electrode 2 on the bottom surface, and a surface side of the wiring board 3 with a resin 4 interposed therebetween. A first semiconductor element 5 flip-chip connected to the wiring substrate 3 and a second semiconductor mounted on the back surface of the first semiconductor element 5 via an adhesive 6 with its front side up; The first semiconductor element 5 has a protruding electrode 5b provided on an electrode pad 5a on the surface thereof.
Of the second semiconductor element 7, the electrode pad 7a on the surface thereof is connected to the wiring electrode 1b of the wiring board 3 by a thin metal wire 8, and the upper surface area of the wiring board 3 is an insulating sealing resin. 9 is a structure sealed.

The semiconductor elements mounted on the wiring board 3 are a plurality of types of semiconductor elements such as a memory element and a logic element, and are high-function type semiconductor devices formed of multifunctional elements in one package.

Next, a conventional method for manufacturing a stacked semiconductor device will be described with reference to the drawings. 10 and 11 are main cross-sectional views for each process showing a conventional method for manufacturing a stacked semiconductor device.

First, as shown in FIG. 10A, projecting electrodes (bumps) 5b are respectively formed on a plurality of electrode pads 5a on the surface of the first semiconductor element 5. The bump electrodes are formed by a plating bump, a stud bump by a wire bonding method, or the like.

Next, as shown in FIG. 10B, a sheet-like anisotropic conductive (ACF) resin 4 is supplied to the upper surface of the wiring board 3 and the first semiconductor element 5 is The surface of the protruding electrode 5 b faces the upper surface of the wiring board 3. Here, the resin 4 is supplied to the wiring board so as to cover the wiring electrodes 1a of the wiring board 3, and a liquid resin other than the sheet shape may be supplied by potting.

Next, as shown in FIG. 10C, the first semiconductor element 5 is pressed against the upper surface of the wiring substrate 3 to project the protruding electrode 5b of the first semiconductor element 5 and the wiring electrode 1a of the wiring substrate 3. And connect.

Next, as shown in FIG. 10D, the first semiconductor element 5 having the second semiconductor element 7 mounted on the wiring board 3 is formed.
Is bonded and fixed to the back surface (back surface side) of the device with the adhesive 6.

Next, as shown in FIG. 11A, the electrode pads 7a of the mounted second semiconductor element 7 and the wiring electrodes 1b on the upper surface of the wiring board 3 are electrically connected by thin metal wires 8.

Then, as shown in FIG. 11B, a stacked semiconductor device is formed by sealing the upper surface area of the wiring board 3 with an insulating sealing resin 9.

Through the above steps, a one-package type stacked semiconductor device in which two semiconductor elements are mounted on a wiring board has been conventionally realized.

[0015]

However, the conventional stacked semiconductor device has a structure in which two semiconductor elements are mounted on a single wiring board, so that the components added to the upper surface area of the wiring board are not provided. In many cases, warpage of the wiring board due to thermal expansion or damage to a connection portion between the semiconductor element and the wiring electrode of the wiring board due to thermal expansion or warpage has been concerned.

That is, when the semiconductor element expands due to the difference in thermal expansion coefficient between the constituent members such as the wiring board, the semiconductor element, and the protruding electrode constituting the stacked semiconductor device due to the thermal expansion, the semiconductor element moves slightly inside the package. In addition, there is a possibility that the connection portion between the semiconductor element and the wiring electrode of the wiring board is broken. Conventionally, wiring boards that constitute a stacked semiconductor device,
Semiconductor elements, such as by approximating the thermal expansion coefficient of each component such as bump electrodes, or by making the structure capable of resisting the thermal expansion and the resulting warpage of the stacked semiconductor device itself, In the future, there will be more than three semiconductor elements mounted on a single wiring board to form one package, instead of mounting two semiconductor elements. Was needed.

Further, since a plurality of semiconductor elements are mounted in one package, the volume increases as a whole, and the weight also increases. Therefore, there has been a demand for a stacked semiconductor device which is lighter in weight.

The present invention solves the above-mentioned conventional problems. In a stacked semiconductor device in which two or more semiconductor elements are three-dimensionally mounted on a wiring board to constitute one package, each semiconductor element has It is an object of the present invention to provide a stacked semiconductor device capable of improving the reliability of connection of a connection portion with a wiring electrode of a wiring board and achieving weight reduction, and a method of manufacturing the same.

[0019]

In order to solve the above-mentioned conventional problems, a stacked semiconductor device according to the present invention comprises a wiring board having wiring electrodes, and a wiring board on a surface of the wiring board via a resin. A first semiconductor element which is flip-chip connected to a substrate, and a flip chip having a front side opposed to the back side of the first semiconductor element via a film wiring conductor on a back side of the first semiconductor element; Connected second
Having at least two semiconductor elements with a semiconductor element of
In the first semiconductor element, the protruding electrode provided on the surface thereof is connected to the wiring electrode of the wiring board, and in the second semiconductor element, the protruding electrode provided on the surface thereof is connected to the wiring conductor of the film wiring conductor. The wiring conductor is connected to a wiring electrode of the wiring board, and the upper surface area of the wiring board is a stacked semiconductor device sealed with a sealing resin; The stacked semiconductor device has a reduced volume.

More specifically, the film wiring conductor is a laminated semiconductor device having a structure in which the wiring conductor is sandwiched between soft resins.

The wiring substrate is a stacked semiconductor device which is a wiring substrate having a wiring electrode on an upper surface and a terminal electrode connected to the wiring electrode on the upper surface on a lower surface.

Further, the area of the first semiconductor element or the second semiconductor element and the area of the wiring board are substantially the same under the condition that the area of the wiring board is large, so that a chip size package is formed. Is a stacked semiconductor device.

As described above, since the second or more stacked semiconductor elements are stacked and mounted via a film wiring conductor made of a soft resin, the semiconductor element is thermally expanded by the stacked semiconductor device. When the semiconductor device expands, even if it moves slightly inside the package, the connection portion also moves in conjunction with the expansion movement, so that the connection portion between the semiconductor element and the wiring electrode of the wiring board is prevented from breaking, and the connection is prevented. Reliability can be improved. Further, since the film wiring conductor has a three-layer structure in which the wiring conductor is sandwiched between the front and back surfaces by the soft resin, the wiring conductor itself in the inner layer can be prevented from being fixed and can cope with slight movement due to thermal expansion. Further, since a film wiring conductor made of a soft resin is interposed between the semiconductor elements, the laminated semiconductor device has flexibility as a whole, and has a structure capable of coping with stress due to thermal expansion.

Further, the peripheral portion of the upper surface of the sealing resin is removed by grinding and the volume of the entire sealing resin is reduced. Therefore, a stacked semiconductor device in which a plurality of semiconductor elements are formed in one package. Can be realized.

Further, according to the method of manufacturing a stacked semiconductor device of the present invention, there is provided a method for manufacturing a stacked semiconductor device, comprising the steps of: providing a wiring substrate having a wiring electrode on an upper surface and a terminal electrode connected to the wiring electrode on the upper surface on a lower surface; The first in which the protruding electrode is formed on the electrode pad of
A first step of flip-chip connecting the semiconductor elements to connect the protruding electrodes to the wiring electrodes of the wiring board; and bonding a film wiring conductor integrally to the back surface of the first semiconductor element and the top face of the wiring board. A second step of connecting an outer end of the wiring conductor of the film wiring conductor to a wiring electrode of the wiring board; and a step of connecting the film wiring conductor to the back surface of the first semiconductor element via the film wiring conductor. A third step of flip-chip connecting a second semiconductor element having a protruding electrode to an electrode pad on the surface thereof and connecting the protruding electrode to an inner end of a wiring conductor of the film wiring conductor; The fourth step of sealing the upper surface area of the wiring board with the sealing resin
And a fifth step of performing a grinding process on the peripheral portion of the upper surface of the sealing resin formed on the upper surface of the wiring substrate to reduce the volume of the peripheral portion of the upper surface of the sealing resin. It is a manufacturing method of.

According to the method of manufacturing a stacked semiconductor device of the present invention, a plurality of semiconductor elements are individually mounted on the upper surface, wiring electrodes corresponding to the individual semiconductor elements are provided on the upper surface, and the lower surface is provided on the lower surface. Is provided with terminal electrodes connected to the wiring electrodes on the upper surface inside the substrate. One large wiring substrate with a structure that can be divided into individual semiconductor element units is applied to the electrode pads on the surface via resin. A first step of flip-chip connecting the first semiconductor element on which the protruding electrode is formed, and connecting the protruding electrode to a wiring electrode of the wiring board; a back surface of the first semiconductor element and an upper face of the wiring board A second step of bonding a film wiring conductor integrally with the wiring conductor and connecting an outer end of the wiring conductor of the film wiring conductor to a wiring electrode of the wiring board; Flip-chip connecting a second semiconductor element having a protruding electrode to an electrode pad on the surface thereof via the film wiring conductor, and connecting the protruding electrode to an inner end of the wiring conductor of the film wiring conductor; Third
And a fourth step of sealing the upper surface area of the wiring substrate with a sealing resin. The wiring substrate is cut and separated into individual stacked semiconductor devices and formed on the upper surface of the wiring substrate. A fifth step of performing a grinding process on the peripheral portion of the upper surface of the sealing resin to reduce the volume of the peripheral portion of the upper surface of the sealing resin.

More specifically, the second semiconductor element having a protruding electrode formed on an electrode pad on the surface of the first semiconductor element is flip-chip connected to the back surface of the first semiconductor element via a film wiring conductor. In the third step of connecting the protruding electrode and the inner end of the wiring conductor of the film wiring conductor,
A method of manufacturing a stacked semiconductor device, in which a second semiconductor element is pressed against the film wiring conductor, the projecting electrode breaks through the film material of the film wiring conductor, and connects the inner end of the wiring conductor. is there.

In addition, a film wiring conductor is integrally bonded to the back surface of the first semiconductor element and the upper surface of the wiring board, and an outer end of the wiring conductor of the film wiring conductor is connected to a wiring electrode of the wiring board. The second step is a method of manufacturing a stacked semiconductor device using a film wiring conductor having a structure in which a wiring conductor is sandwiched between soft resins.

As described above, since the second or more stacked semiconductor elements are stacked and mounted via a film wiring conductor made of a soft resin, the semiconductor elements are thermally expanded by the stacked semiconductor device. When the semiconductor device expands, even if it moves slightly inside the package, the connection portion also moves in conjunction with the expansion movement, so that the connection portion between the semiconductor element and the wiring electrode of the wiring board is prevented from being broken, and the connection is prevented. A structure that can increase the reliability of the device can be realized. Also, when connecting the semiconductor element to the film wiring conductor by pressing the protruding electrode, the film material of the film wiring conductor absorbs the external pressure, thereby eliminating the influence on the lower semiconductor element and stably. It can be flip-chip connected with high reliability.

Further, in the step of cutting and separating into individual stacked semiconductor devices after the collective molding, the peripheral portion of the sealing resin is ground along with the cutting, so that the peripheral portion of the upper surface of the sealing resin is removed. The volume of the entire sealing resin can be reduced, and the weight can be reduced.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a stacked semiconductor device and a method of manufacturing the same according to the present invention will be described below.

First, the stacked semiconductor device of the present embodiment will be described with reference to the drawings. FIG. 1 is a main cross-sectional view showing the stacked semiconductor device of the present embodiment.

The stacked semiconductor device according to the present embodiment includes a wiring board having wiring electrodes, a first semiconductor element having a front surface facing the wiring board and flip-chip connected to the wiring board, and A stacked type having at least two semiconductor elements on a back surface of the first semiconductor element and a second semiconductor element flip-chip-connected to the back side of the first semiconductor element with the front side facing the back surface of the first semiconductor element via a film wiring conductor; In the semiconductor device, the first semiconductor element has a protruding electrode provided on a surface thereof connected to a wiring electrode of a wiring board, and a semiconductor element other than the first semiconductor element flip-chip connected to the wiring board is provided. The projecting electrodes provided on the surface are flip-chip connected via the film wiring conductor, and the wiring conductor of the film wiring conductor is connected to the wiring electrode of the wiring board to form a chip in one package. And it has a layer structure.

Specifically, as shown in FIG. 1, the stacked semiconductor device of this embodiment has a wiring electrode 10
a, 10b, and each wiring electrode 10a,
10b having a terminal electrode electrically connected to the inside of the substrate, and anisotropic conductive (AC)
F) A first semiconductor element 12 such as a microcomputer element flip-chip connected with its front side facing the wiring board 10 via the resin 11 and a film wiring conductor 13 on the back surface of the first semiconductor element 12. A stacked semiconductor device having at least two semiconductor elements with a second semiconductor element such as a memory element flip-chip-connected with the front side facing the back side of the first semiconductor element via a second semiconductor element; The first semiconductor element 12 has an electrode pad 12 on its surface.
The protruding electrode 12b provided on the wiring substrate 10 is connected to the wiring electrode 10a of the wiring board 10, and the protruding electrode 14b provided on the electrode pad 14a on the surface of the second semiconductor element 14 is connected to the wiring conductor 13a of the film wiring conductor 13. It is connected to the inner end, and the outer end of the wiring conductor 13a is connected to the wiring electrode 1 of the wiring board 10.
0b. And the second semiconductor element 1
4 is exposed and the upper surface area of the wiring board 10 is sealed with a sealing resin 15.

The film wiring conductor 13 has a structure in which a wiring conductor 13a is sandwiched between film materials 13b made of a soft resin such as an epoxy resin, an elastomer, or a silicone resin, and has a structure that absorbs shocks between respective elements. is there.

The stacked semiconductor device of this embodiment is
The area of the first semiconductor element 12 or the second semiconductor element 14 and the area of the wiring board 10 are substantially equal to each other under the condition that the area of the wiring board 10 is large, and constitute a CSP (chip size package). Is what you are doing.

As described above, the stacked semiconductor device of this embodiment is
At least two or more semiconductor elements are mounted on a wiring board to form a one-package CSP. In particular, the second or more stacked semiconductor elements are connected via a film wiring conductor 13 made of a soft resin. When the semiconductor element expands due to the thermal expansion of the stacked semiconductor device, even if it moves slightly inside the package, the connection part also moves in conjunction with the expansion movement. The connection between the wiring electrodes 10a and 10b of the wiring substrate 10 can be prevented from being broken, and the connection reliability can be improved. The film conductor 13a is made of a film material 13 made of a soft resin on the front and back sides of the wiring conductor 13a.
b, so that the wiring conductors 13 in the inner layer
The fixing of a itself can be avoided, and it can cope with the slight movement of thermal expansion. Further, since the film wiring conductor 13 made of a soft resin is interposed between the semiconductor elements, the laminated semiconductor device has flexibility as a whole and can cope with stress due to thermal expansion. .

Since the back surface of the second semiconductor element 14 is exposed and the upper surface area of the wiring board 10 is sealed with the sealing resin 15, a heat-generating semiconductor element is used as the second semiconductor element 14. Also, the heat radiation effect can be enhanced.
This is because a flip-chip structure is suitable for exposing the back surface of the semiconductor element outside the sealing resin, and all the semiconductor elements mounted on the substrate have a flip-chip connection structure as in this embodiment. Therefore, the package structure is suitable for enhancing the heat radiation effect.

Next, a method for manufacturing the stacked semiconductor device of the present embodiment will be described with reference to the drawings. Figures 2 and 3
FIG. 4 is a main cross-sectional view for each step showing the method for manufacturing the stacked semiconductor device of the embodiment.

First, as shown in FIG. 2A, projecting electrodes (bumps) 12b are formed on a plurality of electrode pads 12a on the surface of the first semiconductor element 12, respectively. The bump electrodes are formed by a plating bump, a stud bump by a wire bonding method, or the like.

Next, as shown in FIG.
In addition to supplying a sheet-like anisotropic conductive (ACF) resin 11 to the upper surface of the wiring board 10, the first semiconductor element 12 such as a microcomputer (logic) element is connected to the surface of the projecting electrode 12 b of the wiring board 10. Face the upper surface. Here, the supply of the resin 11 to the wiring board 10 is performed by using the wiring electrodes 10 of the wiring board 10.
The liquid resin is supplied so as to cover the sheet a, and a liquid resin other than the sheet shape may be supplied by potting. The filling of the resin 11 into the gap between the wiring board 10 and the first semiconductor element 12 is performed by first supplying the sheet-shaped resin 11 onto the wiring board 10 as described above.
After connecting the wiring electrode 2 and the wiring electrode 10a of the wiring board 10, the filling may be performed by injection. In the subsequent filling by injection, an insulating resin may be used.

Next, as shown in FIG. 2C, the first semiconductor element 12 is pressed against the upper surface of the wiring board 10 to project the protruding electrode 12b of the first semiconductor element 12 and the wiring electrode 10a of the wiring board 10. And connect. After connecting and fixing the elements, a step of reducing the element thickness by performing grinding with a grinder and further polishing to reduce the thickness of the first semiconductor element 12 may be added.

Next, as shown in FIG. 2D, a film wiring conductor 13 is integrally bonded to the back surface of the first semiconductor element 12 and the upper surface of the wiring board 10. In this case, the wiring conductor 13
In this example, a film wiring conductor having a three-layer structure in which the front and back surfaces of a are sandwiched between film materials 13b made of a soft resin is used. Further, the film wiring conductor 13 is provided with adhesiveness, or is heated to soften and adhere the film wiring conductor 13.

Further, as shown in FIG. 3A, the outer ends of the wiring conductors 13a of the film wiring conductors 13 are connected to the wiring electrodes 10b of the wiring board 10 together with the adhesion of the film wiring conductors.
Connect with

Next, as shown in FIG. 3B, a memory element in which a projecting electrode 14b is formed on an electrode pad 14a on the front surface of the first semiconductor element 12 via a film wiring conductor 13 on the back surface of the first semiconductor element 12 The second semiconductor element 14 is flip-chip connected, and the protruding electrode 14b is connected to the inner end of the wiring conductor 13a of the film wiring conductor 13. In this case, the second semiconductor element 14 is pressed against the film wiring conductor 13 in a heated state, and the projecting electrode 14b breaks through the film material 13b of the film wiring conductor 13 and pressurizes the wiring conductor 1.
3a is connected to the inner end. Here, the second semiconductor element 14 is connected to the film wiring conductor 13.
When the protruding electrodes 14b are connected by pressurizing, the film material 13b of the film wiring conductor 13 absorbs the external pressure, so that the influence on the lower first semiconductor element 12 is eliminated,
Flip-chip connection can be performed stably and reliably. After the connection and fixing of the elements, a step of reducing the element thickness by grinding with a grinder and further polishing to reduce the thickness of the second semiconductor element 14 may be added.

Then, as shown in FIG. 3C, the upper surface area of the wiring board 10 is sealed with a sealing resin 15 such as an insulating epoxy resin. In this resin sealing, sealing can be performed by a transfer molding method using a mold or a potting method. In the resin sealing, the back surface of the second semiconductor element 14 is exposed, and the upper surface area of the wiring substrate 10 is sealed with the sealing resin 15. With this sealing structure, the second
Even if a heat-generating semiconductor element is used as the semiconductor element 14, the heat radiation effect can be enhanced.

As described above, in the manufacturing method of the stacked semiconductor device of the present embodiment, since the second or more stacked semiconductor elements are stacked and mounted via the film wiring conductor 13 made of a soft resin, When the semiconductor element expands due to the thermal expansion of the stacked semiconductor device, even if the semiconductor element slightly moves inside the package, the connection portion also moves in conjunction with the expansion movement.
It is possible to realize a structure that can prevent the connection portion with 0a and 10b from breaking, and can improve the reliability of the connection. In connecting the semiconductor element to the film wiring conductor 13 by pressing the protruding electrode, the film wiring conductor
Since the third film material 13b absorbs external pressure, the influence on the lower semiconductor element is eliminated, and the flip-chip connection can be stably and reliably performed.

In the method of manufacturing a stacked semiconductor device according to the present embodiment, each of the steps of mounting each semiconductor element on the substrate, forming the film wiring conductor, and encapsulating is performed by individually mounting a plurality of semiconductor elements on the upper surface. On the upper surface, wiring electrodes corresponding to individual semiconductor elements are provided on the upper surface, and terminal electrodes connected to the wiring electrodes on the upper surface inside the substrate are provided on the lower surface,
This method is performed on one large wiring board having a structure that can be divided for each semiconductor element unit, and is a manufacturing method suitable for mass production called a collective molding method. Then, after sealing the upper surface of the wiring substrate with the sealing resin, a final step is a step of cutting and separating into individual stacked semiconductor devices using a dicing blade. Therefore, as the outer shape of the stacked semiconductor device of the embodiment as shown in FIG.
Is located on the same plane as the side surface of the, and has a shape divided by batch cutting.

As shown in the plan view of FIG. 4, the film wiring conductors used in the method of manufacturing the stacked semiconductor device according to the present embodiment are arranged as shown in the plan view of FIG. Wiring conductors 13a whose size, pitch, etc. are adjusted for the arrangement of the electrodes.
Is sandwiched between film materials 13b of a soft resin, and the structure shown in the figure shows a structure in which electrode pads of a semiconductor element correspond to peripheral pad arrangements arranged around the element. Of course, the length of the wiring conductor 13a and the area of the film material 13b itself are also set according to the area of the wiring substrate and the lower semiconductor element and the step.

Next, in the cross-sectional view of FIG. 5, three semiconductor elements are represented by one in the stacked semiconductor device described in this embodiment.
This shows a form of a package CSP.

As shown in FIG. 5, the second semiconductor element 14 other than the first semiconductor element 12 and the third semiconductor element 16 which are flip-chip connected to the wiring board 10 include a bump electrode 14b and a bump electrode. 16b each film wiring conductor 1
3, and the wiring conductor 13a of the film wiring conductor 13 is connected to the wiring electrode 1 of the wiring board 10.
0b and has a chip laminated structure in one package. Even when three semiconductor elements are stacked and mounted as described above, the second and more stacked semiconductor elements are stacked and mounted via the film wiring conductor 13 made of a soft resin. When the semiconductor element expands due to the thermal expansion of the semiconductor device, even if the semiconductor element slightly moves inside the package, the connection portion also moves in conjunction with the expansion movement. A structure that can prevent the connection portion from breaking and improve the reliability of the connection can be realized. Further, even when the semiconductor element is connected to the film wiring conductor 13 by pressing the protruding electrode, the film material of the film wiring conductor 13 absorbs the external pressure. Flip-chip connection can be performed with high reliability.

Next, a stacked semiconductor device of another embodiment and a method of manufacturing the same will be described.

FIG. 6 is a main sectional view showing a stacked semiconductor device of another embodiment.

As shown in FIG. 6, in the stacked semiconductor device of this embodiment, the structure inside the sealing resin 15 on the upper surface of the wiring board 10 is the same as the structure shown in FIG.
The periphery of the upper surface has a cut portion 17 by grinding to reduce the volume. In this embodiment, the volume of the sealing resin of the stacked semiconductor device shown in FIG.
Is reduced by grinding.

With this structure, it is possible to reduce the weight of a stacked semiconductor device in which a plurality of semiconductor elements are formed in one package.

Next, a method for manufacturing the stacked semiconductor device of the present embodiment will be described with reference to the drawings.

FIGS. 7 and 8 are cross-sectional views showing the main steps of a method for manufacturing a stacked semiconductor device according to this embodiment.

First, as shown in FIG. 7A, as described in the above-described method for manufacturing a stacked semiconductor device,
A plurality of semiconductor elements are mounted on and electrically connected to each other, and the upper surface of the wiring board 10 is sealed with a sealing resin 15. Here, one large wiring board 10 having a structure that can be divided for each semiconductor element unit is used.

Next, as shown in FIG.
A rotating blade 20 having a grinding function section 18 and a cutting function section 19 is arranged in each of the divided areas above the wiring board 10 on which the wiring board 5 is formed.

Next, as shown in FIG. 8A, the rotating blade 20 is brought into contact with the sealing resin 15, and the sealing resin 15 is ground and removed by the grinding function section 18 of the rotating blade 20. 15. By cutting the divided region of the wiring board 10 by the cutting function unit 19, individual stacked semiconductor devices 21 are obtained.

As a result, as shown in FIG. 8B, a stacked semiconductor device 21 having a structure in which the peripheral portion of the upper surface of the sealing resin 15 has a cut portion 17 by grinding to reduce the volume can be realized. Things.

The width of the grinding function portion 18 of the rotating blade 20 to be used, the width and length of the cutting function portion 19, and the length of the grinding function portion 18 and the cutting function portion 19 are determined by the sealing to be cut and separated. The thickness is appropriately set depending on the thickness of the resin and the thickness of the wiring board. The same applies to the roughness of the grinding function unit 18.

As described above, in the present embodiment, the wiring substrate having the wiring electrodes, the first semiconductor element on the wiring substrate whose front side is flip-chip connected to the wiring substrate, and the first semiconductor element A stacked semiconductor device having at least two semiconductor elements on a back surface of the element and a second semiconductor element flip-chip-connected to the back surface of the first semiconductor element with the front side facing the back surface of the first semiconductor element via a film wiring conductor. In the first semiconductor element, the protruding electrodes provided on the surface thereof are connected to the wiring electrodes of the wiring board, and the semiconductor elements other than the first semiconductor element flip-chip connected to the wiring board are provided on the surface thereof. Flip-chip connection is made with the provided protruding electrode via the film wiring conductor, and the wiring conductor of the film wiring conductor is connected to the wiring electrode of the wiring board to form a chip laminated structure in one package. Since the second or more stacked semiconductor elements are stacked and mounted via a film wiring conductor made of a soft resin, and when the semiconductor element expands due to thermal expansion of the stacked semiconductor device, Even if it moves slightly inside the package, the connection part moves in conjunction with the expansion movement, so that the connection part between the semiconductor element and the wiring electrode of the wiring board is prevented from breaking, and the connection reliability is improved. be able to. Further, since the film wiring conductor has a three-layer structure in which the wiring conductor is sandwiched between the front and back surfaces by the soft resin, the wiring conductor itself in the inner layer can be prevented from being fixed and can cope with slight movement due to thermal expansion. Further, since a film wiring conductor made of a soft resin is interposed between the semiconductor elements, the laminated semiconductor device has flexibility as a whole, and has a structure capable of coping with stress due to thermal expansion.

[0064]

According to the stacked semiconductor device of the present invention, the second or more stacked semiconductor elements are stacked and mounted via a film wiring conductor made of a soft resin. When the semiconductor element expands due to thermal expansion, even if it moves slightly inside the package, the connection part also moves in conjunction with the expansion movement, and the connection part between the semiconductor element and the wiring electrode of the wiring board is broken. To prevent
This is a stacked semiconductor device capable of improving connection reliability. Further, since a film wiring conductor made of a soft resin is interposed between the semiconductor elements, the laminated semiconductor device has flexibility as a whole and has a structure capable of coping with stress due to thermal expansion. A highly reliable stacked semiconductor device can be realized.

In the method of manufacturing a stacked semiconductor device according to the present invention, the stacked semiconductor elements are stacked and mounted via a film wiring conductor made of a soft resin. When the semiconductor element expands due to the thermal expansion of the device, even if the semiconductor element slightly moves inside the package, the connection part also moves in conjunction with the expansion movement. A structure that can prevent breakage and enhance the reliability of connection can be realized. Also, for film wiring conductors,
Even when connecting semiconductor elements by pressing the protruding electrodes,
Because the film material of the film wiring conductor absorbs external pressure,
This eliminates the influence on the lower semiconductor element and enables stable and reliable flip-chip connection.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a stacked semiconductor device according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view illustrating a method of manufacturing a stacked semiconductor device according to one embodiment of the present invention.

FIG. 3 is a sectional view showing the method of manufacturing the stacked semiconductor device according to one embodiment of the present invention;

FIG. 4 is a plan view showing a film wiring conductor used in the method for manufacturing a stacked semiconductor device according to one embodiment of the present invention;

FIG. 5 is a sectional view showing a stacked semiconductor device according to one embodiment of the present invention;

FIG. 6 is a sectional view showing a stacked semiconductor device according to one embodiment of the present invention;

FIG. 7 is a sectional view showing the method of manufacturing the stacked semiconductor device according to one embodiment of the present invention;

FIG. 8 is a sectional view showing the method of manufacturing the stacked semiconductor device according to one embodiment of the present invention;

FIG. 9 is a cross-sectional view showing a conventional stacked semiconductor device.

FIG. 10 is a cross-sectional view illustrating a method for manufacturing a conventional stacked semiconductor device.

FIG. 11 is a sectional view showing a conventional method of manufacturing a stacked semiconductor device.

[Explanation of symbols]

 1a, 1b Wiring electrode 2 Terminal electrode 3 Wiring board 4 Resin 5 First semiconductor element 5a Electrode pad 5b Protruding electrode 6 Adhesive 7 Second semiconductor element 7a Electrode pad 8 Fine metal wire 9 Sealing resin 10 Wiring board 10a, 10b Wiring electrode 11 Resin 12 First semiconductor element 12a Electrode pad 12b Protruding electrode 13 Film wiring conductor 13a Wiring conductor 13b Film material 14 Second semiconductor element 14a Electrode pad 14b Protruding electrode 15 Sealing resin 16 Third semiconductor element 16b Projection Electrode 17 Cutting part 18 Grinding function part 19 Cutting function part 20 Rotating blade 21 Stacked semiconductor device

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Claims (8)

[Claims] A wiring board having wiring electrodes; a first semiconductor element flip-chip-connected to the wiring board with a front surface facing the wiring board via a resin on the wiring board; and the first semiconductor. The semiconductor device further includes at least two semiconductor elements on a back surface of the element and a second semiconductor element flip-chip-connected to the back side of the first semiconductor element with the front side facing the back surface of the first semiconductor element via a film wiring conductor; In the semiconductor element, the protruding electrode provided on the surface thereof is connected to the wiring electrode of the wiring board, and in the second semiconductor element, the protruding electrode provided on the surface thereof is connected to the wiring conductor of the film wiring conductor, The conductor is connected to a wiring electrode of the wiring board, and the upper surface area of the wiring board is a stacked semiconductor device sealed with a sealing resin, and the volume of the peripheral portion of the upper surface of the sealing resin is reduced by grinding. A stacked semiconductor device, comprising: 2. The stacked semiconductor device according to claim 1, wherein the film wiring conductor has a structure in which the wiring conductor is sandwiched between soft resins. 3. The stacked semiconductor device according to claim 1, wherein the wiring board is a wiring board having a wiring electrode on an upper surface and a terminal electrode connected to the wiring electrode on the upper surface on a lower surface. . 4. The area of the first semiconductor element or the second semiconductor element and the area of the wiring board are substantially equal to each other under the condition that the area of the wiring board is large. The stacked semiconductor device according to claim 1, wherein: 5. A wiring board having a wiring electrode on an upper surface and a terminal electrode connected to the wiring electrode on the upper surface on a lower surface, wherein a protruding electrode is formed on an electrode pad on the surface via a resin. A first semiconductor element that is flip-chip connected to connect the protruding electrode to a wiring electrode of the wiring board;
And bonding a film wiring conductor integrally to the back surface of the first semiconductor element and the upper surface of the wiring board, and connecting an outer end of the wiring conductor of the film wiring conductor to a wiring electrode of the wiring board. A second step of: flip-chip-connecting a second semiconductor element having a projecting electrode to an electrode pad on the front surface of the first semiconductor element via the film wiring conductor to a back surface of the first semiconductor element; A third step of connecting an electrode and an inner end of the wiring conductor of the film wiring conductor, a fourth step of sealing an upper surface area of the wiring board with a sealing resin, A fifth step of performing a grinding process on a peripheral portion of the upper surface of the formed sealing resin to reduce a volume of the peripheral portion of the upper surface of the sealing resin. 6. A plurality of semiconductor elements are individually mounted on the upper surface, and wiring electrodes corresponding to the individual semiconductor elements are provided on the upper surface, and the lower surface is connected to the wiring electrodes on the upper surface inside the substrate. A first semiconductor element in which a protruding electrode is formed on an electrode pad on the surface of a large wiring board having a structure in which terminal electrodes are provided and which can be divided into individual semiconductor element units via resin. A first step of connecting the protruding electrodes and the wiring electrodes of the wiring board by flip-chip bonding, and bonding a film wiring conductor integrally to the back surface of the first semiconductor element and the top surface of the wiring board; A second step of connecting an outer end of the wiring conductor of the film wiring conductor to a wiring electrode of the wiring board; and a front surface of the first semiconductor element via the film wiring conductor with respect to a back surface of the first semiconductor element. A third step of flip-chip connecting a second semiconductor element having a protruding electrode formed on an electrode pad, and connecting the protruding electrode to an inner end of a wiring conductor of the film wiring conductor; A fourth step of sealing the upper surface region with a sealing resin, and cutting and separating the wiring substrate into individual stacked semiconductor devices, and a peripheral portion of an upper surface of the sealing resin formed on the upper surface of the wiring substrate And a grinding process for reducing the volume of the peripheral portion of the upper surface of the sealing resin. 7. A second semiconductor element having a protruding electrode formed on an electrode pad on the surface of the first semiconductor element via a film wiring conductor is flip-chip connected to the back surface of the first semiconductor element, and the protruding electrode is connected to the second electrode. In the third step of connecting the film wiring conductor to the inner end of the wiring conductor, the second semiconductor element is pressed against the film wiring conductor, and the projecting electrode breaks through the film material of the film wiring conductor. 7. The method for manufacturing a stacked semiconductor device according to claim 5, wherein the wiring conductor is connected to an inner end of the wiring conductor. 8. A method of bonding a film wiring conductor integrally to a back surface of the first semiconductor element and an upper surface of the wiring board, and connecting an outer end of the wiring conductor of the film wiring conductor to a wiring electrode of the wiring board. 7. The method according to claim 5, wherein in the step (2), a film wiring conductor having a structure in which the wiring conductor is sandwiched between soft resins is used.