JP2003007899A - Semiconductor device and manufacturing method thereof - Google Patents

Abstract

An object of the present invention is to provide a semiconductor device having an external connection electrode on the back surface which is slightly larger than a planar dimension of an integrated circuit chip and has a wide pitch, and a method of manufacturing the same. SOLUTION: A semiconductor device 50 of the present invention has a plurality of internal electrodes 3 corresponding to bumps (electrodes) 1 of an integrated circuit chip S.
A plurality of wirings 32 are formed on the inner side and external electrodes 322 connected to the internal electrodes 321 are formed on the outer side, and a portion excluding the internal electrodes 321 and the external electrodes 322 is an insulating protective film. 34, the bumps 1 of the integrated circuit chip S are directly connected to the internal electrodes 321, respectively.
Are covered with a flexible wiring board 30, and external electrodes 322 are formed as external connection electrodes at a relatively wide pitch on the back side of the integrated circuit chip.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring which can be connected on the back surface of an integrated circuit chip, and which is particularly suitable for obtaining a laminated semiconductor device in which a plurality of integrated circuit chips are stacked one above the other and having an external connection electrode on the back surface. The present invention relates to a semiconductor device having a connection structure and a manufacturing method thereof.

[0002]

2. Description of the Related Art First, a conventional semiconductor device will be described with reference to FIGS.

FIG. 7 is a half sectional view showing a semiconductor device having an external connection electrode formed on the back surface of the prior art, and FIG. Y is a half sectional view showing another semiconductor device having an external connection electrode formed on the back surface. 9 is a sectional view of a stacked semiconductor device in which a plurality of semiconductor devices shown in FIG. Y are stacked.

Conventionally, as a structure of a semiconductor device for electrically connecting an integrated circuit chip and a wiring substrate on the back side of the integrated circuit chip, US Pat. No. 5,216,278 and AS
IC & EDAP pages 9-15, March, 19
93 disclosed by Motorola "OMPA"
A semiconductor device 6 such as C ″ shown in a half cross section in FIG.
There is 00. In this semiconductor device 600, an integrated circuit chip S is mounted on the surface of a printed wiring board 610 using an adhesive or the like. A plurality of upper lands 611 are provided on the front surface of the printed wiring board 610, and external connection electrodes 61 are provided on the back surface.
2 and then via hole 613 is formed,
In the integrated circuit chip S, the bumps 1 such as solder and gold formed on the plurality of electrodes are electrically connected to the corresponding upper lands 611 using metal wires 614 such as gold. Then, in order to protect the integrated circuit chip S and the metal wire 114, the upper surface is sealed with a sealing material 615 such as epoxy resin. In addition,
The external electrodes 612 on the back surface of the printed wiring board 610 are provided in a peripheral arrangement or a lattice arrangement.

However, in the structure of the semiconductor device 600, the distance between the integrated circuit chip S required for connection with the metal wire 614 and the end face of the semiconductor device 600 is required to be at least about 0.5 mm. . Therefore, there is a problem that the planar size of the semiconductor device 600 becomes larger than the planar size of the integrated circuit chip S by 1 mm or more.

In order to solve this problem, the No. No. filed by the present inventor and filed by the present applicant was applied. 01002717 &
No. There is a semiconductor device 700 disclosed in 01002718 (look up and fill in application number). In the semiconductor device 700 of this prior application, as shown in FIG. Y, an electrical insulating layer 2 is formed in advance on the back surface of the integrated circuit chip S, and a plurality of thin conductive wires are formed on the side surface of the integrated circuit chip S. 731
Thin conductive U-shaped conductive component 7 made by hardening resin with resin 732.
30 is fitted, and the upper ends 233 of the conductive wires 731 respectively corresponding to the plurality of bumps 1 of the integrated circuit chip S are connected to the side surfaces of the integrated circuit chips S, and from the upper part thereof, a thin rod called a capillary (not shown) The lower end 734 of the conductive wire 731 is connected by crimping and connecting by applying sonic vibration and heat.
Is disposed on the back surface of the integrated circuit chip S.

As described above, in the semiconductor device 700, since the U-shaped conductive component 730 can be mounted along the outer peripheral surface of the integrated circuit chip S, the semiconductor device 700 itself can be made compact.

The semiconductor device 700 can also be used alone by mounting it on a printed wiring board incorporated in an electronic device. Further, as shown in FIG. 9, the conductive wire 231 of the lowermost semiconductor device 700A can be used. At the top tip 733,
A semiconductor device 7 stacked above the semiconductor device 700A
Directly connect the lower tip 734 of the conductive wire 731 of 00B,
Hereinafter, the semiconductor devices 700 stacked in the same manner are electrically connected in this manner to form a plurality of semiconductor devices 700.
Can be laminated in multiple stages and can be used as a laminated component.

[0009]

However, in the semiconductor device 700 having the above-described structure, the integrated circuit chip S and the semiconductor device 600 which are the structural problems of the semiconductor device 600 shown in FIG. The distance from the end face is 0.05 mm
Although it can be shortened to some extent, the lower tip 734 of the conductive wire 731, which becomes the external connection electrode of the semiconductor device 700, is only the peripheral arrangement of the integrated circuit chip S due to the manufacturing method of the conductive component 730, and the external connection electrode The problem remains that a semiconductor device having a grid array of external connection electrodes that can be designed with a wider pitch cannot be realized.

Therefore, the present invention is intended to solve the above-mentioned problems, and does not require the side and back surfaces of the integrated circuit chip to be sealed with an insulating sealing material, and moreover, the flat surface of the integrated circuit chip. Slightly larger than the target size,
It is another object of the present invention to obtain a semiconductor device having external connection electrodes with a wide pitch on its back surface and a method for manufacturing the same.

[0011]

Therefore, a semiconductor device according to the present invention comprises an integrated circuit chip having a plurality of electrodes formed thereon and a flexible wiring board on which the integrated circuit chip is mounted. The side surface and the back surface are covered with the flexible wiring board, and external connection electrodes are provided on the back surface side.

Further, as a specific structure, the semiconductor device of the present invention has an integrated circuit chip on which a plurality of electrodes are formed, and the flexible insulating plate protruding from an opening formed in a central portion of the flexible insulating plate. A plurality of electrically conducting portions are formed, the protruding portions of the electrically conducting portions are internal electrodes, the electrically conducting portions on the opposite side of the plurality of internal electrodes are external electrodes, and A flexible wiring board formed by covering an electrically conductive portion in an intermediate portion between the internal electrode and the plurality of external electrodes with an insulating protective film, and the flexible wiring board and the plurality of electrodes of the integrated circuit chip. Of the plurality of inner electrodes are electrically connected to each other, the electrically conductive portion covered with the insulating protective film covers the side surface of the integrated circuit chip, and The external electrodes are formed as external connection electrodes on the back surface of the integrated circuit chip.

A method of manufacturing a semiconductor device according to the present invention is
The plurality of electrically conducting portions formed in the insulating plate and protruding from the opening formed in the central portion of the flexible insulating plate are used as internal electrodes, and the electrically conducting portions outside the plurality of internal electrodes are external electrodes. An integrated circuit chip in which a plurality of electrodes are formed on the surface of a flexible wiring substrate formed by covering an electrically conductive portion connecting the plurality of internal electrodes and the plurality of external electrodes with an insulating film. In the method of manufacturing a semiconductor device, in which an external connection electrode is formed on the back surface of the integrated circuit chip by mounting the integrated circuit chip, the surface of the integrated circuit chip is faced to the internal electrode side of the flexible wiring board and is exposed to the opening. A positioning step for positioning,
An electrode connecting step of directly connecting the positioned plurality of electrodes of the integrated circuit chip to the inner electrodes of the flexible wiring board, and an outer portion of the flexible wiring board on which the plurality of outer electrodes are formed. And a folding-back step of folding and fixing the same on the back surface side of the integrated circuit chip. In the flexible wiring board, it is desirable that an adhesive layer is formed on the surface opposite to the surface on which the internal electrodes and the external electrodes are formed.

Therefore, in the semiconductor device of the present invention, it can be formed in an area slightly larger than the planar size of the integrated circuit chip, and the side surface and the back surface of the integrated circuit chip are covered with the insulating protective film and the flexible insulating plate to protect them. Therefore, only the surface of the integrated circuit chip needs to be sealed with the sealing material. Moreover, a plurality of external connection electrodes can be formed at a wide pitch.

In the method of manufacturing a semiconductor device according to the present invention, the integrated circuit chip is easily positioned on the flexible wiring board, and the electrodes of the integrated circuit chip are directly connected to the internal electrodes of the flexible wiring board. The overall thickness can be reduced, and the planar dimensions of the semiconductor device can be formed in a structure that is not so large as the planar dimensions of the integrated circuit chip. Furthermore, the external electrodes can be arranged in a grid outside the flexible wiring board. The external electrodes can be formed as an external connection electrode simply by folding them back on the back surface of the integrated circuit chip by forming them in an arbitrary array such as, and can be formed in an arbitrary array in which the pitch of the external connection electrodes can be widely designed. In addition, by folding the outer part of the flexible wiring board to the back surface of the integrated circuit chip, It is possible to form a semiconductor device having a structure covered with the insulating material of the flexible wiring board. Further, the presence of the adhesive layer provided on the back surface of the flexible wiring board enables the outer portion of the flexible wiring board bent to the back surface of the integrated circuit chip to be bonded and fixed to the side surface and the back surface thereof.

[0016]

DETAILED DESCRIPTION OF THE INVENTION A semiconductor device and a method of manufacturing the same according to an embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a semiconductor device according to an embodiment of the present invention. FIG. 1A is a sectional view thereof, FIG. 1B is a rear view of the semiconductor device of FIG. 1A, and FIG. 2 shows a semiconductor device of the present invention. 1 shows a flexible wiring board of one unit suitable for use in the present invention, FIG. A is a plan view seen from the front side, FIG. B is a sectional view taken along line BB in FIG. FIG. 4 is a process chart showing a first manufacturing method for manufacturing the semiconductor device of the present invention shown in FIG. 1, and FIG. 4 shows a second manufacturing method for manufacturing the semiconductor device of the present invention shown in FIG. 5 is a sectional view of a sealing device used to seal the surface of the integrated circuit chip with an insulating sealing material, and FIG. 6 shows the flexible wiring board according to the other two embodiments. FIG. 6 is a back view of two types of semiconductor devices when an integrated circuit chip is sealed by the sealing method of the present invention. .

In FIG. 1, reference numeral 50A indicates a semiconductor device according to an embodiment of the present invention. The semiconductor device 50 includes an integrated circuit chip S and a flexible wiring board 30A.

On the surface of the integrated circuit chip S, bumps 1 such as gold and solder are formed on a plurality of electrodes, and the bumps (electrodes) 1 are arranged in a quadrilateral shape along the four sides of the surface. Structure (quad in-line arrangement), which is arranged in a straight line at a predetermined interval along two opposite sides (dual in-line arrangement), along the four sides of the surface Even if it has a quadrangular structure (quadrangular arrangement),
The integrated circuit chip S may have a so-called area array arrangement structure, which is arranged in a grid pattern on the entire surface. The illustrated integrated circuit chip S has a plurality of electrodes (bumps) 1
Are formed in a quad in-line arrangement.

As shown in FIG. 2, the flexible wiring board 30A connects an internal electrode 321 and an external electrode 322 to the surface of a flexible insulating plate 31 (FIG. 2B) formed of an insulating material such as polyimide. A plurality of wirings 32 are formed, and an opening 33 is formed at the center. The inner electrodes 321 of the plurality of wirings 32 are formed so as to project toward the center of the opening 33, and the outer electrodes 322 are formed on the outer portions 311, 312, 31 of the flexible insulating plate 31.
The external electrodes 322 adjacent to the electrodes 3 and 314 are arranged with a wider pitch. The dimensions of these pitches are the outer portion 311,
It can be expanded according to the area and shape of 312, 313, and 314. The wiring 32 and the like except the internal electrode 321 and the external electrode 322 are covered with an insulating protective film 34 (FIG. 2B). The length of one side is L at each corner of the opening 33.
A square small hole 35 of c is formed. This small hole 35
Alternatively, a cut line may be formed along the side of the opening 33. The length Lc of one side has a dimension corresponding to the thickness of the integrated circuit chip S.

The flexible wiring board 30A is drawn by simplifying the drawing. Therefore, the plurality of internal electrodes 321 and the external electrodes 322 are also representative ones, and the other ones are omitted.

The semiconductor device 50 is constructed by mounting the integrated circuit chip S on the flexible wiring substrate 30A having such a structure, and each electrode (bump) 1 of the integrated circuit chip S has each internal electrode 321. 1C, the side surface and the back surface of the integrated circuit chip S are covered with the flexible wiring board 30A, that is, the flexible insulating plate 31 and the insulating protective film 34, and as shown in FIG. A plurality of external electrodes 322 are formed as external connection electrodes on the back surface of, and only the front surface is sealed with the sealing resin In.

By adopting such a structure, the wiring 32, which is an electric conductor, is not exposed on the side surface of the semiconductor device 50, and it becomes unnecessary to protect those side surfaces with a special insulating protective material. Therefore, only the surface of the integrated circuit chip S need be protected by the insulating sealing material.

Next, a first method of manufacturing the semiconductor device 50 will be described with reference to FIG.

First, the flexible wiring board 30A shown in FIG. 2 is horizontally mounted on a mounting table (not shown), and the integrated circuit chip S is inserted into the opening 33 of the flexible wiring board 30A from the lower side thereof. As shown in FIG. B, the electrodes (bumps) 1 of the integrated circuit chip S and the internal electrodes 321 are brought into contact with each other. And a thin rod called a tool (not shown)
The electrode 1 of the integrated circuit chip S and the internal electrode 321 are directly connected to each other by ultrasonic waves while heating. In this case, if at least the internal electrode 321 is plated with Au, Ni or the like in advance, the electrode 1 of the integrated circuit chip S
A metal alloy is formed between them and they can be easily connected. Then, as illustrated, the outer peripheral portion of the flexible wiring board 30A is cut into a predetermined size and shape along the alternate long and short dash line La shown in FIG. 2A.

Next, as shown in FIG. 3C, the outer portions 311, 312, 313, 3 of the flexible wiring board 30A.
14 is bent downward along the side surface of the integrated circuit chip S, then also bent to the back surface of the integrated circuit chip S along the dotted line Lb, and fixed to the back surface portion with an adhesive or the like. In this way, the semi-finished semiconductor device 50 is obtained. As shown in FIG. 5, the surface of the semiconductor device 50 of this semi-finished product is put into another encapsulation step, covered with an encapsulant In of an insulating resin such as an epoxy resin, and heat-cured for encapsulation. The semiconductor device 50 of the present invention shown in FIG. 1 is obtained.

Next, a second manufacturing method for manufacturing the semiconductor device 50 of the present invention will be described with reference to FIG.

Flexible wiring board 3 used in this manufacturing
The structure of 0B is substantially the same as the structure of the flexible wiring board 30A as shown in FIG. 4A, and the wiring 32 is formed on the surface thereof as described above, and therefore the description thereof is omitted. However, the different point is the back surface portion of the flexible insulating plate 31, which is a substrate having a structure in which an adhesive layer 36 is laminated on the back surface and a release film 37 is laminated on the surface thereof. The adhesive layer La has a central opening 33.
The peeling film 37 is laminated on the entire back surface of the flexible insulating plate 31 except for the area other than the opening larger than the size of the integrated circuit chip S. The flexible insulating plate 31 can also be formed by using an insulating material such as a polyimide resin.

In the second manufacturing method of the present invention, the flexible wiring board 30B having such a structure is used. First, as shown in FIG. 4A, when the flexible wiring board 30B is horizontally mounted on a mounting table (not shown) and the integrated circuit chip S is inserted into the opening 33 of the flexible wiring board 30 from below, The state shown in FIG. Then, as in the case of the first manufacturing method, a thin rod (not shown) called a tool is used, and ultrasonic waves are applied while heating.
The electrodes (bumps) 1 and the wiring 32 of the integrated circuit chip S are directly connected.
To the internal electrode 321 of.

Next, as in the case of cutting the flexible wiring board 30A in the step of FIG. 3B, the outer peripheral portion of the flexible wiring board 30B is cut along the alternate long and short dash line La shown in FIG. 2A. Then, the flexible wiring board on which the integrated circuit chip S having the shape shown in FIG. 4B is mounted is obtained.

Then, the release film 37 on the back surface of the flexible wiring board 30B is peeled off, and the outer portion 31 of the flexible wiring board 30 existing outside the integrated circuit chip S is removed.
1 and 312 are folded back from each side surface of the integrated circuit chip S to the back surface side. Then, the flexible insulating plate 31 is automatically adhered to the side surface and the back surface of the integrated circuit chip S by the adhesive layer 36, and the outer portions 311 and 312 can be easily fixed to the back surface of the integrated circuit chip S, As shown in FIG. 6C, a semi-finished semiconductor device having a structure in which the external electrode 322 is formed as an external connection electrode is obtained. The outer shape of this semi-finished semiconductor device is the same as that shown in FIG. 3C.

Next, the semiconductor device thus obtained is transferred to a sealing step equipped with the sealing device shown in FIG. 5, and only the surface of the integrated circuit chip S is epoxy-treated by using this sealing device. The semiconductor device 50 as shown in FIG. 1 is obtained by covering with a sealing material In such as resin and heating and curing.

By adopting the second manufacturing method as described above, the side surface and the back surface of the integrated circuit chip S can be covered with the flexible wiring board 30B as described above. The flexible insulating plate 31 can be automatically adhered and fixed to the side surface and the back surface of the integrated circuit chip S. The wiring 32, which is an electric conductor, is not exposed on the side surface of the semiconductor device 50, and there is no need to protect those side surfaces with an insulating protective material in a separate process.
Only the surface of the integrated circuit chip S needs to be sealed with the sealing material.

In the above-described embodiment, the case where the plurality of electrodes of the integrated circuit chip S are formed in the quadrangular arrangement will be described, and the flexible wiring boards 30A and 30B that are folded back to the back surface of the integrated circuit chip S will be described. Although the outer portions 311, 312, 313, 314 have the same triangular shape, the present invention is not limited to these structures and shapes, and the outer portions 311 and 312 bent to the back surface of the integrated circuit chip S are not limited thereto. As for the shape of the external connection electrode portions of 313, 314, as shown in FIG. 6A, a flexible wiring board may be used in which two opposing sides are respectively trapezoidal and flat triangular sections. When the plurality of electrodes of the integrated circuit chip S are in a dual in-line arrangement, an outer view of bending the back surface of the integrated circuit chip S to
Note that a flexible wiring board having a shape that can be configured by two rectangular pieces as shown in FIG. 6B may be used.

[0035]

As described above, according to the semiconductor device of the present invention, there is provided a semiconductor device having external connection electrodes on the back surface which are slightly larger than the planar size of the integrated circuit chip and have a wide pitch. Further, since the side surface and the back surface of the integrated circuit chip are covered and protected by the insulating protective film and the flexible insulating plate, it is not necessary to insulate and protect the side surface and the back surface of the integrated circuit chip again.

Further, by using the flexible wiring board having the adhesive layer formed on the back surface in advance, the flexible insulating plate can be automatically fixed to the side surface and the back surface of the integrated circuit chip, and the working efficiency is improved.

[Brief description of drawings]

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

FIG. 2 is a flexible wiring board according to an embodiment suitable for use in the semiconductor device of the present invention, in which FIG. 2A is a plan view of one unit thereof, and FIG. 2B is a cross section taken along line BB of FIG. FIGS. 11C and 11C are plan views of the back surface of the flexible insulating plate when it is bent on the back surface of the integrated circuit chip.

FIG. 3 is a process drawing showing a first manufacturing method for manufacturing the semiconductor device of the present invention shown in FIG.

FIG. 4 is a process drawing showing a second manufacturing method for manufacturing the semiconductor device of the present invention shown in FIG.

FIG. 5 is a back view of two types of semiconductor devices when an integrated circuit chip is sealed by the sealing method of the present invention using the flexible wiring boards of the other two types of embodiments.

FIG. 6 is a back view of two types of semiconductor devices when an integrated circuit chip is sealed by the sealing method of the present invention using the flexible wiring boards of the other two types of embodiments.

FIG. 7 is a half sectional view showing a semiconductor device in which an external connection electrode is formed on the back surface of a conventional technique.

FIG. 8 is a half cross-sectional view showing another semiconductor device having an external connection electrode formed on the back surface.

9 is a cross-sectional view of a stacked semiconductor device in which a plurality of semiconductor devices shown in FIG. 8 are stacked.

[Explanation of symbols]

1 ... Bump (electrode) of integrated circuit chip S, 30C, 30
D ... Flexible wiring board, 31 ... Flexible insulating plate, 311, 312 ... Outer portion of flexible insulating plate 31, 32 ... Wiring, 321 ... Internal electrode, 322 ... External electrode (external connection electrode), 33 ... Opening portion, 34 … Insulating film,
35 ... Notch, 36 ... Adhesive layer, 37 ... Release film, 50A ... Semiconductor device of one embodiment of the present invention, S ... Integrated circuit chip, In ... Insulating material, W ... Metal wire, Lb ...
Broken line

Claims (4)

[Claims] 1. An integrated circuit chip having a plurality of electrodes formed thereon, and a flexible wiring board on which the integrated circuit chip is mounted, wherein a side surface and a back surface of the integrated circuit chip are covered with the flexible wiring board, and the back surface is formed. A semiconductor device having an external connection electrode on its side. 2. An integrated circuit chip having a plurality of electrodes formed therein, and a plurality of electrically conducting portions formed in the flexible insulating plate protruding into an opening formed in a central portion of the flexible insulating plate. The protruding portion of the electrically conducting portion is an internal electrode, the electrically conducting portion on the opposite side of the plurality of inner electrodes is an outer electrode, and the intermediate portion between the plurality of inner electrodes and the plurality of outer electrodes is A flexible wiring board in which an electrically conductive portion is covered with an insulating protective film, and the plurality of electrodes of the integrated circuit chip and the plurality of inner electrodes of the flexible wiring board are electrically connected to each other. An electrically conductive portion that is connected and is covered with the insulating protective film covers a side surface of the integrated circuit chip,
The semiconductor device is characterized in that the plurality of external electrodes are formed as external connection electrodes on the back surface of the integrated circuit chip. 3. A plurality of electrically conductive portions formed in the insulating plate and projecting into an opening formed in a central portion of the flexible insulating plate are used as internal electrodes, and electrical parts outside the plurality of internal electrodes are electrically connected. A plurality of electrodes are formed on the surface of a flexible wiring board which is formed by covering the electrically conductive portion connecting the plurality of internal electrodes and the plurality of external electrodes with an insulating film, and the conductive portion as an external electrode. A method of manufacturing a semiconductor device, comprising: mounting an integrated circuit chip, wherein an external connection electrode is formed on a back surface of the integrated circuit chip, wherein the front surface of the integrated circuit chip faces the internal electrode side of the flexible wiring board and the opening is formed. A positioning step of positioning the integrated circuit chip so as to face it, and the plurality of electrodes of the positioned integrated circuit chip are directly contacted with the internal electrodes of the flexible wiring board, respectively. And a folding step of folding and fixing the outer portion of the flexible wiring board on which the plurality of external electrodes are formed to the back surface side of the integrated circuit chip. Device manufacturing method. 4. The semiconductor device according to claim 2, wherein an adhesive layer is formed on a surface of the flexible wiring board opposite to a surface on which the internal electrodes and the external electrodes are formed. Production method.