JPH0969588A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device which can be effectively made thin and miniaturized, has improved heat dissipation property, and at the same time is suited for achieving multiple pins. SOLUTION: A semiconductor element 20 is electrically connected to a wiring pattern 12 of a flexible wiring substrate 10 where a wiring pattern 12 is provided, at the same time the element mounting region of the flexible wiring substrate 10 where the semiconductor element 20 is mounted is sealed by resin to form a resin sealing part 22, the flexible wiring substrate 10 at an area other than the element mounting region is folded back and is joined to the upper surface of the resin sealing part 22, and an external connection terminal 8 which continues to the wiring pattern 12 is connected the flexible wiring substrate 10 which is folded back and is joined to the upper surface of the resin sealing part 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device constructed by using a flexible wiring board.

[0002]

2. Description of the Related Art In a semiconductor device having a semiconductor element mounted therein, a semiconductor device having a high integration and a small size and a large number of pins has been required. FIG. 17 shows a conventional example of a cavity-down type semiconductor device. In the case of such a cavity-down type semiconductor device, the heat radiation fins 3 are easily attached to the upper surface of the package body 2, so that the heat dissipation property is suitably improved. However, the area where the external connection terminals 4 such as solder balls and lead pins are joined is limited to the lower surface (mounting surface side) of the package body 2 excluding the cavities 5, which limits the increase in the number of pins. There is.

The applicant of the present invention has previously proposed a semiconductor device using a flexible wiring board as a product in which such a cavity-down type semiconductor device can be made compact and have a large number of pins (Japanese Patent Application Laid-Open No. 6-58242). -334098). In this semiconductor device, as shown in FIG. 18, a heat radiating plate 7 is joined to one surface of a flexible wiring board 6, and a package main body 2 made of a multilayer printed circuit board is provided on the other surface corresponding to the joined portion of the heat radiating board 7. The flexible wiring board 6 that is joined and extends to the outside of the package body 2 is folded back and joined to the surface side of the package body 2 where the cavity 5 is opened. FIG. 19 shows the structure of the semiconductor device thus formed. A heat dissipation fin 7a is further attached to the heat dissipation plate 7, and a circuit board 6a such as a printed circuit board is provided on the outer surface of the flexible wiring board 6 joined to the package body 2.
The lead pin as the external connection terminal 8 is joined via the.

It is of course possible to use a ball-shaped terminal such as a solder ball instead of the lead pin as the external connection terminal 8. In FIG. 20, the heat dissipation plate 7 and the package body 2 are attached to the flexible wiring board 6, the semiconductor element is mounted in the cavity 5 of the package body, and the semiconductor element mounting portion (in the cavity) is sealed by resin 9 by potting. A method for manufacturing a semiconductor device by folding back the flexible wiring board 6 and joining it to the surface side of the package body 2 where the cavity 5 is opened, and then joining solder balls as external connection terminals 8 to the outer surface of the folded flexible wiring board 6. Indicates.

A wiring pattern for connecting the semiconductor element and the external connection terminal 8 is previously formed on the front surface of the flexible wiring board 6, and the back surface of the flexible wiring board 6 for joining the wiring pattern and the external connection terminal 8 (folded back). The land portion formed on the surface (which will be the outer surface later) is electrically connected to the inner surface of the through hole by a through hole in which plating or a conductive material is applied.

[0006]

In the semiconductor device described above, the entire lower surface of the semiconductor device can be set as the bonding range of the external connection terminals, whereby the number of pins can be efficiently increased. However, the above semiconductor device is manufactured by laminating the printed wiring boards on which predetermined wiring patterns are formed in multiple layers on one surface of the flexible wiring board 6 and joining the package main body 2 having the cavities 5 to each other. However, there is a problem in that the size cannot be effectively reduced.

The present invention has been made to solve these problems, and an object thereof is to manufacture a semiconductor device using a flexible wiring board, which is easier to manufacture.
It is an object of the present invention to provide a semiconductor device which can be suitably made smaller and thinner.

[0008]

The present invention has the following constitution in order to achieve the above object. That is, the semiconductor element is electrically connected to the wiring pattern of the flexible wiring board provided with the wiring pattern, and the element mounting area of the flexible wiring board on which the semiconductor element is mounted is resin-sealed to be resin-sealed. A portion is formed, the flexible wiring board other than the element mounting region is folded back and joined to the upper surface of the resin sealing portion, and the flexible wiring board folded back and joined to the upper surface of the resin sealing portion, An external connection terminal that is electrically connected to the wiring pattern is connected.

A support is provided on the surface of the flexible wiring board opposite to the surface on which the semiconductor element is mounted, corresponding to the sealing region of the resin sealing portion.
In addition, a semiconductor device in which the semiconductor element is connected to the wiring pattern by a flip chip bonding method can be suitably miniaturized. Further, it is characterized in that an opening for accommodating a semiconductor element is formed in the flexible wiring board and a wiring pattern is formed in the vicinity of the peripheral edge of the opening. Further, the semiconductor element housed in the opening is joined to the support and connected to the wiring pattern by a wire bonding method. Further, the support is characterized by being made of a metal having good thermal conductivity. Further, the flexible wiring board is folded back from a plurality of directions.

Further, it is characterized in that a solder ball is used as the external connection terminal. Further, a through hole is formed in the flexible wiring board at a portion folded back on the resin sealing portion to expose a wiring pattern, and the solder ball is joined to the exposed wiring pattern. . Further, it is characterized in that the folded-back portion is double-folded so that the wiring pattern is positioned on the front surface side of the folded-back portion, and the external connection terminal is formed on the wiring pattern positioned on the front surface side. Furthermore, the resin sealing portion is made of a mold resin. Alternatively,
Instead of the resin sealing portion, a cap may be used for sealing. Also, an elastic sheet is interposed between the folded-back portion and the resin sealing portion. further,
A plurality of the semiconductor elements are mounted.

[0011]

The semiconductor device according to the present invention utilizes a flexible wiring board provided with a predetermined wiring pattern. The semiconductor element is electrically connected to one end side of the wiring pattern of the flexible wiring board and mounted, and after sealing the element mounting area with resin, the flexible wiring board provided with the other end of the wiring pattern is mounted on the resin sealing part. It is configured to be folded back along the side surface and integrally joined to the upper surface of the resin sealing portion. By bonding the flexible wiring board to the upper surface of the resin sealing portion of the semiconductor element, the size of the semiconductor device can be formed to be substantially the same as the resin sealing portion. Therefore, it is preferable to reduce the thickness and size of the semiconductor device. Can be planned. Further, since the flexible wiring board can be folded back and the external connection terminals can be joined to the entire outer surface of the portion joined to the upper surface of the resin sealing portion, the number of pins can be easily increased. Further, by attaching a support having excellent thermal conductivity as a part of the semiconductor device, it is possible to provide a semiconductor device having good heat dissipation.

[0012]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 3 show a first embodiment of a semiconductor device. The semiconductor device of the present embodiment is configured by mounting the semiconductor element 20 on the flexible wiring board 10 by a flip chip bonding method and sealing the element mounting region with resin. FIG. 1A shows a flexible wiring board 10 on which a semiconductor element 20 is mounted. The flexible wiring board 10 is formed by patterning a predetermined wiring pattern 12 on a flexible film made of an electrically insulating resin such as polyimide.

The wiring pattern 12 electrically connects the semiconductor element 20 and the external connection terminal. Therefore, the connection portion 13 for electrically connecting to the semiconductor element 20 is provided on one end side of the wiring pattern 12, and the land 14 for joining the external connection terminal 8 is provided on the other end side of the wiring pattern 12. In the embodiment, since the semiconductor element 20 is mounted on the flexible wiring board 10 by the flip chip bonding method, the connection portion 13 of the wiring pattern 12 is formed according to the arrangement of the electrode terminals provided on the semiconductor element 20.

The land 14 for electrically connecting the external connection terminal 8 is formed on the back surface of the flexible wiring board 10 at the end of the wiring pattern 12 drawn from the connection portion 13 in FIG. 1 (a). In the semiconductor device of this embodiment, after mounting the semiconductor element 20 on the flexible wiring board 10 and resin-sealing the flexible wiring board 10, the flexible wiring board 10 is folded back along the side surface of the resin sealing portion to the upper surface of the resin sealing portion. Therefore, the land 14 is located on the outer surface of the package when the flexible wiring board 10 is folded back.

In FIG. 1A, reference numeral 16 is a through hole which electrically connects the wiring pattern 12 and the land 14. FIG.
The enlarged view of the vicinity of the through hole 16 and the land 14 is shown. The through hole 16 can be formed by a method of plating the through hole on the inner surface of the through hole provided in the flexible film which is the base material of the flexible wiring substrate 10, a method of filling the through hole with a conductive substance, or the like.

The wiring pattern 12 and the land 14
A conventional method of forming a wiring pattern on a flexible film can be applied to the method of manufacturing the flexible wiring board 10 having the above. For example, a copper foil may be adhered and formed on a flexible film made of polyimide or the like, and the copper foil may be etched to form predetermined wiring patterns 12, lands 14, and the like. In addition, a conductor film may be formed on the surface of the flexible film by vapor deposition or sputtering, and the conductor film may be etched to form the wiring pattern 12 or the like. In addition,
In order to protect the wiring pattern 12 formed on the surface of the flexible film, a protective resin such as polyimide may be applied to form a protective film except for the connection portion with the semiconductor element 20. Further, a protective film may be formed on the front and back surfaces of the film except the land 14 formed on the back surface of the flexible film.

FIG. 1B shows a state in which the semiconductor element 20 is mounted on the flexible wiring board 10 formed as described above by the flip chip bonding method. The electrode terminal of the semiconductor element 20 is connected to the connecting portion 13 of the wiring pattern 12.
After the connection, the protective resin 18 is applied to the connecting portion of the semiconductor element 20 to the flexible wiring board 10 in order to protect the connecting portion between the semiconductor element 20 and the wiring pattern 12 (FIG. 3). In the flip chip bonding method, the electrode terminals of the semiconductor element 20 are directly connected to the connecting portions 13 of the wiring pattern 12 within the element mounting area of the flexible wiring board 10, so that the loop height and the loop length of the wire are longer than in the wire bonding method. It is possible to minimize the height and sealing area of the resin-sealed portion that seals the semiconductor element 20 without consideration of the size, and thus it is possible to suitably reduce the size and thickness of the semiconductor device. be able to.

The semiconductor element 20 is connected to the flexible wiring board 1
After being mounted on the flexible wiring board 10, the element mounting area on the flexible wiring board 10 is resin-sealed as shown in FIG. 1 (c). For the resin sealing, a transfer molding method using a molding die or a potting method using a potting resin can be used. At the time of resin sealing, the flexible wiring board 10 is folded back and bonded to the upper surface of the resin sealing portion 22 in a later step, so that the resin sealing portion 22 needs to be resin-molded into a predetermined shape. Therefore, when the resin is sealed by the potting method, a sealing frame made of resin or the like is fixed to the periphery of the resin sealing range for potting.

After the semiconductor element 20 is sealed with resin, the flexible wiring board 10 extends from the lower surface of the resin sealing portion 22.
Is folded back along the side surface of the resin encapsulation portion 22 and adhered to the upper surface of the resin encapsulation portion 22 as shown in FIG. When the flexible wiring board 10 is adhered, an adhesive is applied to the upper surface of the resin sealing portion 22, or a resin agent is applied and adhered to the surface of the flexible wiring board 10 that contacts the upper surface of the resin sealing portion 22. In the embodiment, since the flexible wiring board 10 is folded back so as to coincide with the upper surface of the resin sealing portion 22, the shape and dimensions of the flexible wiring board 10 are set in advance in consideration of the outer shape and thickness of the resin sealing portion 22. ing.

The flexible wiring board 10 extending from the lower surface of the resin encapsulation portion 22 is folded back along the side surface of the resin encapsulation portion 22 and joined to the upper surface of the resin encapsulation portion 22, as shown in FIG. 1 (d). The land 14 provided on the back surface of the flexible wiring board 10 is exposed on the outer surface of the package. In this state, the external connection terminal 8 such as a solder ball is joined to each land 14 to obtain a semiconductor device. FIG. 1E is an external view of a semiconductor device to which the external connection terminals 8 are joined. Thus, a surface-mounted semiconductor device in which the external connection terminals 8 are arranged in an array is obtained. The spherical external connection terminal 8
For this, a copper ball plated with solder may be used. Also, a lead pin that stands on the surface of the mounting board or a lead pin that is inserted into the mounting board may be used as the external connection terminal, but a solder ball is optimal in view of mounting efficiency.

FIG. 3 is a sectional view of the semiconductor device of the embodiment. The semiconductor device of this embodiment is a flexible wiring board 10.
The semiconductor element 20 is mounted on the connection portion of the wiring pattern 12 provided on the substrate by the flip chip bonding method and is sealed by the resin sealing portion 22. The flexible wiring board 10 is folded back along one side surface of the resin encapsulation portion 22 to obtain a semiconductor device having substantially the same size as the outer dimensions of the resin encapsulation portion 22. In addition, the flexible wiring board bonded to the entire upper surface of the resin sealing portion 22 of the semiconductor device serves as a bonding area of the external connection terminal 8 and can effectively increase the number of pins.

The above embodiment is an example in which the semiconductor element 20 is mounted on the flexible wiring board 10 by the flip chip bonding method, but it goes without saying that a method of connecting the semiconductor element 20 to the wiring pattern by the wire bonding method can also be used. 4 and 5 show a second semiconductor device.
The following shows an example. FIG. 4 shows a state in which the semiconductor element 20 is connected to the wiring pattern 12 by the wire bonding method on the flexible wiring board 10 formed in the same manner as in the above embodiment. Also in this embodiment, after mounting the semiconductor element 20 on the flexible wiring board 10 and performing wire bonding, the element mounting area including the wire bonding area of the wiring pattern 12 is resin-sealed, and the flexible wiring board 1
0 is folded back along one side surface of the resin sealing portion, and the external connection terminal 8 is joined to the land 14 to manufacture.

FIG. 5 is a sectional view of a semiconductor device manufactured by the above manufacturing method. The semiconductor element 20 is bonded to the flexible wiring board 10 with an adhesive such as an epoxy-based silver paste, and the wiring pattern 12 is formed by wire bonding.
Is connected to the external connection terminal 8 through the through hole 16.
To be electrically connected to. In the case of the semiconductor device of this embodiment, since the semiconductor element 20 is connected to the wiring pattern 12 by the wire bonding method, it is necessary to avoid the element mounting portion to form the wiring pattern 12, whereas the flip chip shown in FIG. When the bonding method is used, the wiring pattern 12 can be formed on the element mounting portion.
There is an advantage that the degree of freedom of wiring can be increased and the high-density wiring pattern 12 can be wired.

In the semiconductor device of each of the above embodiments, the flexible wiring substrate 10 also serves as a support for the semiconductor element 20, but a heat radiator for improving the heat dissipation of the semiconductor device may be attached. For example, in the semiconductor device shown in FIGS. 3 and 5, the heat dissipation of the semiconductor device can be improved by attaching the heat dissipation plate 24 to the outer surface (back surface) of the flexible wiring board 10 corresponding to the mounting portion of the semiconductor element 20. As the heat dissipation plate 24, a metal material having good thermal conductivity such as copper or aluminum can be preferably used.

As a method for improving the heat dissipation of the semiconductor device, the heat dissipation plate 24 is provided separately from the flexible wiring board 10 and the semiconductor element 20 is used when the wiring pattern is formed on the flexible film. It is possible to improve heat dissipation by forming a metal layer such as a copper foil in advance on the back surface of the mounting surface.

When the semiconductor device is formed by using the heat dissipation plate 24 separate from the flexible wiring board 10 as described above, the heat dissipation plate 24 may be joined to the heat dissipation plate 24 after the semiconductor device is assembled. After the heat dissipation plate 24 is bonded to the flexible wiring board 10 in advance, the semiconductor element 2
Assembly such as zero loading may be performed.

6 and 7 show the structure of a third embodiment of the semiconductor device formed by using the heat dissipation plate 24 and its manufacturing method. This embodiment is characterized in that the heat dissipation plate 24 is used as a support for supporting the semiconductor element 20. In FIG. 6A, the semiconductor element 2 of the flexible wiring board 10 is attached to the heat sink 24.
It is a state where the back surface on the side storing 0 is adhered. The structure of the flexible wiring board 10 is the same as that used in the above-described embodiment, and has the required wiring pattern 12, lands 14, etc., but since the semiconductor element 20 is directly joined to the heat sink 24, an opening for accommodating the semiconductor element 20 is possible. The hole 10a is connected to the heat sink 2
4 is provided on the flexible wiring substrate 10 and the semiconductor element 2
One end of the wiring pattern 12 connected to 0 is provided with an opening 10a.
The flexible wiring board 10 provided near the periphery of is used.

In FIG. 6 (b), the semiconductor element 20 is joined to the heat dissipation plate 24 with Au-Si eutectic alloy, solder, thermosetting resin, etc., and the semiconductor element 20 and the wiring pattern 12 are electrically connected by wire bonding. It is in the connected state. Then, the element mounting region is resin-sealed in the same manner as in the above embodiment, and the flexible wiring board 10 is provided along the side surface of the resin sealing portion 22.
Is folded back and joined to the upper surface of the resin sealing portion 22 (see FIG. 6).
(d)). Next, the external connection terminals 8 are joined to the lands 14 of the flexible wiring board 10 on the outer surface of the resin sealing portion 22 to obtain a semiconductor device (FIG. 6 (e)). It should be noted that the heat dissipation plate 24 corresponds to the resin sealing region so that the flexible wiring board 10 is
Is provided on the back side of.

FIG. 7 is a sectional view of the semiconductor device of this embodiment. The semiconductor device of this embodiment is a flexible wiring board 10.
The semiconductor element 20 is housed in the opening 10a provided in
The semiconductor element 20 is directly joined to the heat sink 24.
As a result, the heat generated from the semiconductor element 20 can be effectively dissipated to the outside. The structure in which the semiconductor element 20 is resin-sealed and the external connection terminal 8 is joined to the outer surface of the folded flexible wiring board 10 is the same as that of the above-described embodiment.

Although the semiconductor element 20 and the wiring pattern 12 are connected by wire bonding in this embodiment, the semiconductor element 20 and the wiring pattern 12 are connected to the TAB (Ta
It is also possible to connect by the pe Automated Bonding) method.

FIG. 8 shows a fourth embodiment of a semiconductor device provided with a heat dissipation plate 24. Also in the semiconductor device of this embodiment, the flexible wiring board 10 provided with the predetermined wiring pattern 12 and the opening 10a on the surface is used, and the semiconductor element 20 is used.
After mounting, the element mounting region is resin-sealed, and the flexible wiring board 10 is folded back along the side surface of the resin sealing portion 22 to the upper surface side to be manufactured, which is similar to the above-described embodiment.
However, in this embodiment, in order to extend the flexible wiring board 10 from the four sides of the resin sealing portion 22, the opening portion 10a is provided in the substantially central portion of the flexible wiring board 10.
The resin sealing portion 22 is formed in the central portion of the flexible wiring board 10 and is folded back at each of the four sides of the resin sealing portion 22.

In FIG. 8A, the back surface of the flexible wiring board 10 is adhered to the heat dissipation plate 24 so that the semiconductor element 20 is attached to the heat dissipation plate 24.
It shows a state in which the semiconductor element 20 and the wiring pattern 12 are directly joined and connected to each other by wire bonding. In order that the flexible wiring board 10 is folded back on four sides, the end portions of the flexible wiring board 10 are extended from each side of the lower surface of the resin sealing portion 22.

FIG. 8B shows a state in which the element mounting region of the semiconductor element 20 is resin-sealed. FIG. 8C shows the resin sealing portion 22.
After the flexible wiring board 10 is folded back along each side surface and adhered to the upper surface of the resin sealing portion 22, the external connection terminal 8 is joined to the land to obtain a semiconductor device. In this embodiment, when the flexible wiring board 10 is folded back on each side, the folded portions of the flexible wiring board 10 do not overlap each other, and the four folding pieces of the flexible wiring board 10 make the upper surface of the resin sealing portion 22. It is good to cover the whole.

In the semiconductor device of this embodiment, as compared with the method of folding back the flexible wiring board 10 on one side of the resin sealing portion 22 as in the above-described embodiment, the wiring patterns 12 are provided on the four sides of the flexible wiring board 10 respectively. Since the wiring patterns 12 can be routed, the wiring patterns 12 can be routed in consideration of the shortest length, and the length of the wiring patterns 12 can be shortened, whereby the electrical characteristics of the semiconductor device can be improved. There are advantages.

When the flexible wiring board 10 is folded back along the side surface of the resin encapsulation portion 22 to form a semiconductor device as in this embodiment, it is not limited to one side of the resin encapsulation portion 22, and, for example, two. Alternatively, it can be manufactured by folding back at a plurality of side positions such as three. This may be appropriately selected depending on the outer shape of the semiconductor device and the manufacturing process.

The flexible wiring board 10 used in each of the above-mentioned embodiments has a form in which the wiring pattern 12 is provided on one surface of the film. Since the wiring pattern 12 provided on the flexible wiring board 10 is for electrically connecting the semiconductor element 20 and the external connection terminal 8, it is not necessarily limited to one provided on one surface of the film. Due to the arrangement of the wiring pattern 12, it is also possible to provide it on both sides of the film. When the wiring patterns 12 are provided on both sides of the film, a protective film such as polyimide is provided on both sides of the film so as to cover the wiring patterns 12, and the heat dissipation plate 2
When the 4 etc. are joined, the heat dissipation plate 24 is formed at the wiring pattern 12 part.
It is better to prevent an electrical short circuit from occurring.

FIG. 9 shows a fifth embodiment of the semiconductor device 110. Reference numeral 112 is a flexible film made of an electrically insulating resin such as polyimide. A wiring pattern 114 is formed on the flexible film by etching a metal film such as a copper foil, and the wiring pattern 114 is formed on the flexible wiring board. 11
Reference numerals 6 and 116 denote semiconductor elements, which are mounted on the flexible film 112 on the side where the wiring pattern 114 is formed, and are electrically connected to the wiring pattern 114 by wires 118. Reference numeral 120 denotes a resin sealing portion, which is the semiconductor element 11
6 and 116 are molded on the flexible film 112 so as to cover them. An elastic sheet 122 made of silicone rubber or the like is fixed to the front surface side of the resin sealing portion 120.

Reference numeral 124 denotes a heat dissipation plate made of a material having excellent thermal conductivity such as metal, and an adhesive is appropriately used on the surface side of the flexible film 112 opposite to the surface on which the semiconductor elements 116, 116 are mounted. It is fixed. The peripheral portion of the flexible film 112 protruding outward from the resin sealing portion 120 is folded back so as to overlap the front surface side of the resin sealing portion 120, and is formed into a folded portion 112a. This folding part 11
2a may be folded back on the resin sealing portion 120 from two directions, or may be folded back from four directions as shown in FIG. External connection terminals 126, such as ball bumps, that are electrically connected to the wiring pattern 114 are formed on the front surface side of the folded portion 112a. The external connection terminal 126 may be a pin.

The external connection terminal 126 is the flexible film 11.
2 may be electrically connected to the wiring pattern 114 through a via filled with a conductive material in a through hole (not shown) provided in the wiring 2. Alternatively, as shown in FIG.
It is also possible to fill the through holes provided in the above with solder and further attach solder balls to form ball bumps. Alternatively, the bumps may be formed by stacking nickel or gold plating. Since the folded-back portion 112a having the external connection terminal 126 formed thereon is arranged so as to be folded-back on the front surface side of the resin sealing portion 120, the size of the semiconductor device 110 is substantially the same as that of the semiconductor elements 116 and 116. Since the size can be formed to be almost the same as the occupied area, the mounting density is improved. Since the semiconductor elements 116, 116 are mounted on the flexible film 112, an MCM (multi-chip module) structure can be easily obtained. Of course, three or more semiconductor elements can be mounted.

Further, since the folded-back portion 112a formed with the external connection terminal 126 is fixed to the resin sealing portion 120 via the elastic sheet 122, the coefficient of thermal expansion is provided between the mother board, which is a mounting substrate, and the semiconductor device 110. Even if a mismatch occurs, the stress is relieved, the external connection terminal 126 is not cracked, and the reliability can be improved.
In some cases, the elastic sheet 122 may not necessarily be provided, and even in this case, the flexible film 1
12 functions as a buffer layer, and stress concentration on the external connection terminals can be relaxed. Further, the elastic sheet may be omitted by using a silicone resin as the sealing resin and giving elasticity. This point is the same as in the first to fourth embodiments, and the flexible film functions as a buffer layer, so that stress concentration on the external connection terminals can be relaxed. Also, this first to fourth
Similarly, in the embodiment described above, an elastic sheet may be interposed between the folded-back portion and the resin sealing portion (not shown) to further alleviate stress concentration on the external connection terminals.

FIG. 12 shows a sixth embodiment of the semiconductor device 110. The same members as those shown in FIG. 9 are designated by the same reference numerals and the description thereof will be omitted. In the present embodiment, the semiconductor element 116 is sealed by the resin sealing portion 120a made of potting resin instead of the resin sealing portion made by molding. In this case, the frame 128 is arranged so as to surround the semiconductor element 116,
The flatness of the surface may be ensured by filling the frame 128 with potting resin. Also in the present embodiment, the same operational effects as the above can be obtained. The elastic sheet 12
2 does not necessarily have to be provided.

FIG. 13 shows a seventh embodiment of the semiconductor device 110. The same members as those shown in FIG. 9 are designated by the same reference numerals and the description thereof will be omitted. In this embodiment, the cap 130 is fixed to the flexible film 112, and the semiconductor elements 116 and 116 are hermetically sealed by the cap 130. Also in the present embodiment, the same operational effects as the above can be obtained. Similarly, the elastic sheet 122 may not be provided.

FIG. 14 shows an eighth embodiment of the semiconductor device 110. The same members as those shown in FIG. 9 are designated by the same reference numerals and the description thereof will be omitted. In the present embodiment, the folded portion 112a
After being folded back on the elastic body sheet 122, it is further folded outward to form a double folded portion 112a. As a result, the wiring pattern 114 appears on the front surface side of the folded portion 112a, and therefore external connection terminals 126 such as ball bumps are provided on the wiring pattern 114.
The wiring pattern 114 other than the external connection terminals 126 may be covered with a solder resist film (not shown). In this embodiment, since the wiring pattern 114 of the folded portion 112a appears on the front surface side, the external connection terminal 126 can be easily formed. In addition, the same operational effects as those of the above-mentioned respective embodiments are exhibited. The elastic sheet 122 does not necessarily have to be provided.

FIG. 15 shows a ninth embodiment of the semiconductor device 110. The same members as those shown in FIG. 9 are designated by the same reference numerals and the description thereof will be omitted. In this embodiment, the flexible film 11
2 is provided with through holes 112b and 112b that are slightly larger than the semiconductor elements 116 and 116, and
6 is positioned in the through holes 112b, 112b to dissipate the heat radiation plate 1
It is mounted directly on the 24. In this embodiment, the same operational effects as those of the above-mentioned respective embodiments are exhibited, and further excellent heat dissipation is provided. The elastic sheet 122 is not always necessary.

FIG. 16 shows a tenth embodiment of the semiconductor device 110. The same members as those shown in FIG. 9 are designated by the same reference numerals and the description thereof will be omitted. This embodiment is the same as the embodiment of FIG. 9 except that one semiconductor element 116 is mounted. The semiconductor device can have a size substantially equal to the chip size. In addition, the same effect as that of the above-described embodiment is obtained.

Although the present invention has been variously described with reference to the preferred embodiments, the present invention is not limited to these embodiments, and many modifications can be made without departing from the spirit of the invention. Of course.

[0047]

As described above, according to the semiconductor device of the present invention, a semiconductor element is mounted on a flexible wiring board, resin-sealed, and the flexible wiring board is folded and joined to the upper surface of the resin-sealed portion. By doing so, it is possible to favorably reduce the thickness and size of the semiconductor device, and favorably increase the number of pins. Further, by attaching a support, it is possible to prevent the semiconductor device from being deformed, and by using a metal having good thermal conductivity for the support, a semiconductor device having excellent heat dissipation can be obtained. Furthermore, by fixing the folded-back portion formed with the external connection terminal to the resin-sealed portion via the elastic sheet,
Even if there is a mismatch in the coefficient of thermal expansion between the mother board, which is the mounting board, and the semiconductor device, the stress is relieved and problems such as cracks in the external connection terminals are resolved.
Reliability can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a semiconductor device on which a semiconductor element is mounted by a flip chip method and a manufacturing method thereof (first embodiment).

FIG. 2 is a cross-sectional view showing a configuration near a through hole and a land of a flexible wiring board.

FIG. 3 is a cross-sectional view of a semiconductor device on which a semiconductor element is mounted by a flip chip method.

FIG. 4 is an explanatory view showing a state in which a semiconductor element is mounted on a flexible wiring board by wire bonding (second embodiment).

FIG. 5 is a cross-sectional view of a semiconductor device on which a semiconductor element is mounted by a wire bonding method.

6A and 6B are explanatory views showing a structure and a manufacturing method of a semiconductor device provided with a heat dissipation plate (third embodiment).

FIG. 7 is a cross-sectional view of a semiconductor device provided with a heat sink.

FIG. 8 is an explanatory diagram showing another configuration example of a semiconductor device provided with a heat dissipation plate (fourth embodiment).

FIG. 9 is a sectional view showing a fifth embodiment.

FIG. 10 is a bottom view of the semiconductor device shown in FIG.

FIG. 11 is a partial cross-sectional view showing the structure of a ball bump.

FIG. 12 is a sectional view showing a sixth embodiment.

FIG. 13 is a sectional view showing a seventh embodiment.

FIG. 14 is a sectional view showing an eighth embodiment.

FIG. 15 is a cross-sectional view showing a ninth embodiment.

FIG. 16 is a sectional view showing a tenth embodiment.

FIG. 17 is a sectional view of a conventional example of a cavity-down type semiconductor device.

FIG. 18 is an explanatory diagram showing a conventional method for manufacturing a semiconductor device using a flexible wiring board.

FIG. 19 is a cross-sectional view showing a conventional configuration of a semiconductor device using a flexible wiring board.

FIG. 20 is an explanatory diagram showing a manufacturing example of a semiconductor device using a multilayer printed board for a package body.

[Explanation of symbols]

 2 Package Body 6 Flexible Wiring Board 7 Heat Sink 8 External Connection Terminal 10 Flexible Wiring Board 10a Opening 12 Wiring Pattern 13 Connection 14 Land 16 Through Hole 18 Protective Resin 20 Semiconductor Element 22 Resin Sealing 24 Heat Sink 110 Semiconductor device 112 Flexible insulator sheet 112a Folded part 112b Through hole 114 Wiring pattern 116 Semiconductor element 120 Resin encapsulation part 122 Elastic body sheet 124 Heat dissipation plate 126 External connection terminal 128 Frame body 130 Cap

Claims (14)

[Claims] 1. A semiconductor element is electrically connected to the wiring pattern of a flexible wiring board provided with a wiring pattern, and an element mounting region of the flexible wiring board on which the semiconductor element is mounted is resin-sealed. A flexible wiring board in which a resin sealing portion is formed, the flexible wiring board other than the element mounting area is folded back and bonded to the upper surface of the resin sealing portion, and the flexible wiring board is folded back and bonded to the upper surface of the resin sealing portion. An external connection terminal electrically connected to the wiring pattern is connected to the semiconductor device. 2. A support is provided on the surface of the flexible wiring board opposite to the surface on which the semiconductor element is mounted, in correspondence with the sealing region of the resin sealing portion. 1. The semiconductor device according to 1. 3. The semiconductor device according to claim 1, wherein a semiconductor element is connected to the wiring pattern by a flip chip bonding method. 4. The semiconductor device according to claim 2, wherein the flexible wiring board is formed with an opening for accommodating a semiconductor element, and a wiring pattern is formed in the vicinity of the periphery of the opening. 5. The semiconductor device according to claim 4, wherein the semiconductor element housed in the opening is bonded to the support and connected to the wiring pattern by a wire bonding method. 6. The semiconductor device according to claim 2, wherein the support is made of a metal having good thermal conductivity. 7. The flexible wiring board is folded back from a plurality of directions.
The semiconductor device according to 4, 5, or 6. 8. The semiconductor device according to claim 1, wherein a solder ball is used as the external connection terminal. 9. A flexible wiring board at a portion folded back on the resin encapsulation portion is formed with a through hole to expose a wiring pattern, and the solder ball is bonded to the exposed wiring pattern. 9. The semiconductor device according to claim 8, wherein the semiconductor device is a semiconductor device. 10. The folded portion is double folded back so that the wiring pattern is positioned on the front surface side of the folded portion, and the external connection terminal is formed on the wiring pattern positioned on the front surface side. Claims 1, 2, 3, 4,
The semiconductor device according to 5, 6, 7 or 8. 11. The resin sealing portion is a mold resin, and the resin sealing portion is formed of a mold resin.
The semiconductor device according to 8, 9, or 10. 12. A semiconductor element is sealed with a cap instead of the resin sealing portion,
The semiconductor device according to 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11. 13. An elastic sheet is interposed between the folded portion and the resin sealing portion, and the elastic sheet is interposed between the folded portion and the resin sealing portion. 13. The semiconductor device according to 10, 11, or 12. 14. The semiconductor device according to claim 1, wherein a plurality of the semiconductor devices are mounted.
The semiconductor device according to 7, 8, 9, 10, 11, 12 or 13.