JP2006190834A - Semiconductor package and flexible circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of manufacturing working hours by forming a BGA easily when forming the BGA by combining an FPC with a chip part, such as a semiconductor chip and a silicon substrate. <P>SOLUTION: The FPC 25 is formed by sticking a planar reinforcing member 33 to the back of lead sections at both the sides of the FPC 25, and by sticking a center reinforcing member 35 to the back of a pad 34 for packaging a silicon substrate at the center of the FPC 25. The FPC 25 is bent individually and is machined in the shape of a rectangular parallelepiped, a chip part, such as the semiconductor chip 23 and the silicon substrate 21, is packaged on the FPC 25 to form a BGA type semiconductor package 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a BGA (Ball Grid Array) type semiconductor package formed by combining an FPC (flexible circuit board) with a semiconductor chip, for example, a semiconductor package mounted on a digital device such as a portable terminal, a personal computer, and a camera, and a flexible package. The circuit board.

  FPC is a flexible circuit board and has the characteristics of being thin, light, and freely bent. Therefore, it can cope with the diversification of design and the complexity of the shape of electronic equipment and increase the degree of freedom in designing. Widely used as a material. Japanese Patent Application Laid-Open No. H10-228707 discloses a technique for configuring a BGA semiconductor package by combining this FPC with a semiconductor chip such as a bare chip or a small package (CSP).

  As shown in FIG. 5, the semiconductor package of Patent Document 1 covers a semiconductor chip 1 having a plurality of chip pads 3 a on the upper surface, and at least the upper surface, one side surface, and a part of the lower surface of the semiconductor chip 1. A pad 3b on the upper surface, which is bonded to at least the lower surface of the semiconductor chip 1 and bent along the edge of the semiconductor chip 1 and covers the upper surface of the semiconductor chip 1, is electrically connected to the pad 3a. The FPC 2 provided with the lower surface pad 3c electrically connected to the upper surface pad 3b on the outer surface of the portion covering the lower surface of the chip 1, and the lower surface solder ball 6 provided on the lower surface pad 3c. It is prepared for. However, 7 is an adhesive sheet, 9 is a resin sealing hole, and 11 is a sealing resin.

When forming this semiconductor package, as shown in FIG. 6, bumps 4 are provided on the pads 3 a on the upper surface of the semiconductor chip 1, and the surfaces of the bumps 4 are covered with a conductive material 5. The center portion of the FPC 2 is aligned and placed on the upper surface of the semiconductor chip 1, both are pressed and heated to connect the pads 3 b of the FPC 2 to the bumps 4, and the FPC 2 is bent at the groove 10 to Is covered with an FPC 2 and bonded with an adhesive sheet 7.
Japanese Patent No. 2570628

As described above, in the semiconductor package of Patent Document 1, the FPC 2 is wrapped along the outer shape of the semiconductor chip 1 so that the portion that needs to be electrically connected is closely connected to the outer surface while being electrically connected, and is folded back. It was.
However, in this structure, as shown in FIG. 7, when the second semiconductor chip 12 smaller than this is placed on the semiconductor chip 1 and stacked in two layers (or two or more layers), the FPC 2 The distance L of the overlapping portion with the semiconductor chip 1 is reduced, and the bending process is performed after the connection, and therefore there is a problem that the operation of bending the FPC 2 is difficult.

In addition, in place of the semiconductor chip 1 serving as the base, a chip component such as a silicon substrate is used for the base, a smaller semiconductor chip is placed and stacked, and the stacked semiconductor chip is combined with the FPC in the same manner as described above. But similar problems arise.
The present invention has been made in view of such problems, and is a stacked type in which two or more semiconductor chips having different external shapes are stacked on a chip component such as a semiconductor chip or a silicon substrate and a step is formed on the outer surface. An object of the present invention is to provide a semiconductor package and a flexible circuit board that can be easily formed when a BGA is formed by combining FPC with a semiconductor component.

  In order to achieve the above object, a semiconductor package according to claim 1 of the present invention is a semiconductor package in which a first member such as a silicon substrate or a first semiconductor chip on which an electric circuit is formed is mounted on a flexible circuit substrate. In the flexible circuit board, a rod-shaped first reinforcing member arranged in a frame shape or spaced apart in parallel is bonded to the central portion, and an end portion is bent to be opposite to the bonding surface of the first reinforcing member. A rectangular parallelepiped shape is formed by adhering to the side surface, and the mounting pad provided on the top surface of the rectangular parallelepiped and the pad provided on the first member are connected to the top surface of the rectangular parallelepiped. 1 member is attached, and solder balls are provided on the lower surface of the rectangular parallelepiped.

  According to this configuration, since the first reinforcing member is bonded to the flexible circuit board, the flexible circuit board is bent so that the surface of the flexible circuit board is exposed so that the first reinforcing member is positioned inside, and a rectangular parallelepiped. It is possible to easily form a BGA type semiconductor package by processing into a shape and mounting the silicon substrate or the first semiconductor chip on the processed substrate. Further, if the silicon substrate or the first semiconductor chip or the like is fixed above the first reinforcing member, the silicon substrate or the first semiconductor chip or the like can be firmly fixed.

According to a second aspect of the present invention, there is provided a semiconductor package in which a laminated semiconductor component in which a second semiconductor chip is laminated on a first member such as a silicon substrate on which an electric circuit is formed or a first semiconductor chip is flexible. In the semiconductor package mounted on the circuit board, the flexible circuit board has an opening at the center, and a rod-shaped first reinforcing member arranged in a frame shape or spaced apart parallel to the periphery of the opening is bonded. The end portion is bent and bonded to the surface of the first reinforcing member opposite to the bonding surface to form a rectangular parallelepiped shape, and the second semiconductor chip passes through the opening to form the rectangular parallelepiped. The mounting pad provided on the top surface of the rectangular parallelepiped and the pad provided on the first member are connected to the top surface of the rectangular parallelepiped. Attached member, characterized in that solder balls are provided on the lower surface of the rectangular parallelepiped.
According to this configuration, when mounting, the second semiconductor chip of the stacked semiconductor component can be strained so as to fit within the frame of the first reinforcing member or between the vertical and horizontal heights. So it is easy to implement.

According to a third aspect of the present invention, there is provided the semiconductor package according to the first or second aspect, wherein the flexible circuit board has a plate-like second reinforcing member bonded to the inner side of the portion where the solder balls are provided. It is characterized by becoming.
According to this configuration, since the plate-like second reinforcing member is adhered to the inner side of the portion where the solder balls are provided, the mounting surface on the printed circuit board on which a large number of balls are welded can be easily and accurately flattened. It can be.

The flexible circuit board according to claim 4 of the present invention is a flexible circuit board on which a first member such as a silicon substrate on which an electric circuit is formed or a first semiconductor chip is mounted. A rod-shaped first reinforcing member arranged in a shape is bonded, and an end portion is bent and bonded to a surface opposite to the bonding surface of the first reinforcing member, thereby forming a rectangular parallelepiped shape. It is characterized by that.
According to this configuration, when forming a BGA type semiconductor package, first, the flexible circuit board is bent alone, and the surface is exposed, and then bonded to the first reinforcing member to be processed into a rectangular parallelepiped shape. deep. A BGA type semiconductor package can be formed by mounting the silicon substrate or the first semiconductor chip on the processed substrate.

A flexible circuit board according to claim 5 of the present invention is the flexible circuit board according to claim 4, wherein when the first member is mounted, the second semiconductor chip mounted on the first member is inside the rectangular parallelepiped. An opening is provided in the central portion so that the first reinforcing member is bonded to the periphery of the opening.
According to this configuration, at the time of mounting, the second semiconductor chip of the stacked semiconductor component can be accommodated in the vertical and horizontal heights within the frame of the first reinforcing member or between the parallel bar shapes. Easy to implement.

A flexible circuit board according to claim 6 of the present invention is characterized in that, in claim 4 or 5, a plate-like second reinforcing member is bonded to the inner side of the lower surface of the rectangular parallelepiped.
According to this configuration, when the flexible circuit board is used for forming a BGA type semiconductor package, the plate-like second reinforcing member is bonded to the inner side of the lower surface of the rectangular parallelepiped, so that a printed board on which a large number of balls are welded. Since the mounting surface can be easily and accurately flattened, the semiconductor package can be appropriately mounted on the printed board.

  As described above, according to the present invention, since the FPC is processed into a rectangular parallelepiped shape, it becomes easy to form a BGA by combining the FPC. Further, when a BGA is formed by combining an FPC with a laminated semiconductor component in which two or more semiconductor chips having different external shapes are laminated on a chip component such as a semiconductor chip or a silicon substrate and having a step on the outer surface, There is an effect that the number of manufacturing steps can be reduced because it can be easily formed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a configuration of a semiconductor package according to an embodiment of the present invention.
A semiconductor package 20 shown in FIG. 1 has a BGA shape, a silicon substrate 21 on which a predetermined wiring circuit is formed, and a flip-chip connection to the wiring circuit of the silicon substrate 21 via bumps 22 and pads 22a and 22b. The mounted semiconductor chip 23 is bent as described later, and connected to the wiring circuit of the silicon substrate 21 by flip chip connection via the bump 24, the silicon substrate mounting pad 34, and the semiconductor chip mounting pad 37. And an FPC 25. However, the semiconductor chip 23 is a package having a solder ball or an exposed bare chip itself without a solder ball.

  The FPC 25 is a rectangular flexible sheet provided with an opening 38 having a size through which a semiconductor chip stacked at the center can pass, as shown in the FPC front view in FIG. 2A and the back view in FIG. 2B. A plate-like reinforcing member 33 having the same rectangular shape as the lead portion 32 is attached to the back surface of the lead portion 32 in which a large number of solder ball mounting pads 31 are formed in a predetermined width region on both sides of the rectangle. A square frame-shaped central reinforcing member 35 is attached to the back surface of the silicon substrate mounting pad 34 formed around the opening 38 of the FPC 25.

However, the plate-like reinforcing member 33 and the central reinforcing member 35 are made of a strong insulating material. Further, the height of the central reinforcing member 35 is set to be higher than the height of the semiconductor chip 23 mounted on the silicon substrate 21 serving as a base.
The solder ball mounting pad 31 and the silicon substrate mounting pad 34 are connected to each other by a predetermined wiring circuit.

A process of manufacturing the BGA type semiconductor package 20 by combining the FPC 25 having such a configuration with the silicon substrate 21 and the semiconductor chip 23 that are electrically connected and stacked will be described.
First, as shown in FIG. 2A, with the surface of the FPC 25 exposed, the flexible sheet-like portion is bent at the corners of the central reinforcing member 35. Further, as shown in FIG. The center reinforcing member 35 and the plate-like reinforcing member 33 are fixed with an adhesive so that the plate-like reinforcing members 33 on both sides are arranged flat below, and the FPC is processed into a rectangular parallelepiped shape.

As a result, since the plate-like reinforcing members 33 on both sides are fixed in a flat state, when the large number of solder balls 36 are welded to the silicon substrate mounting pad 34, the large number of solder balls 36 are also flat. It will be in the state where it is arranged.
Next, the laminated semiconductor component in which the semiconductor chip 23 is mounted on the silicon substrate 21 by flip chip connection is placed on the FPC 25 so that the semiconductor chip 23 enters the inside of the rectangular parallelepiped through the opening 38, and the pad Mounting is performed by flip-chip connection between the pins 34 and 37 and the bumps 24. As a result, the BGA type semiconductor package 20 is completed.

  As described above, according to the semiconductor package 20 of the present embodiment, the FPC 25 is attached to the back surface of the side lead portions 32 of the FPC 25 with the plate-like reinforcing member 33 and provided around the opening 38 of the FPC 25. A central reinforcing member 35 is attached to the back surface of the silicon substrate mounting pad 34 thus formed. Since the plate-like reinforcing member 33 and the central reinforcing member 35 are simply attached to the sheet member with an adhesive, it can be easily performed.

The FPC 25 is separately bent and processed into a rectangular parallelepiped shape separately from the laminated semiconductor component in which the semiconductor chip 23 is mounted on the silicon substrate 21, and the FPC 25 is combined with the laminated semiconductor component and mounted by flip chip. A BGA type semiconductor package 20 was formed.
When the FPC 25 and the stacked semiconductor component are combined, the second-layer semiconductor chip 23 of the stacked semiconductor component is accommodated in the vertical and horizontal height directions within the frame of the central reinforcing member 35 of the FPC 25, so that the combination becomes easy. As a result, the FPC 25 that can be easily formed can be easily combined with the stacked semiconductor components and mounted, so that the BGA type semiconductor package 20 can be easily formed.

Accordingly, a BGA type semiconductor package in which two or more layers of semiconductor chips 23 having different external shapes are stacked on a chip component such as a silicon substrate 21 or a semiconductor chip and the FPC 25 is combined with a stacked semiconductor component having a step on the outer surface. Since 20 can be easily formed, the number of manufacturing steps can be reduced.
Moreover, since the silicon substrate 21 is fixed above the central reinforcing member 35, the stacked semiconductor component can be firmly fixed.

Further, since the plate-like reinforcing members 33 are attached to the back surfaces of the lead portions 32 on both sides, the mounting surface of the lead portion 32 on the printed circuit board (not shown) on which the numerous solder balls 36 are welded can be easily and accurately flattened. it can. Thereby, the semiconductor package 20 can be appropriately mounted on the printed circuit board.
Further, the center reinforcing member 35 has a rectangular frame shape because the silicon substrate mounting pad 34 is formed all around the opening 38 in FIG. However, as shown in FIG. 3, when the silicon substrate mounting pads 41 are provided only on two sides of the opening 38, for example, square bar-shaped central reinforcing members 42 are used on the back surfaces of the two sides. Even if the FPC 43 having this configuration is used, the same effects as those of the FPC 25 can be obtained.

In the above embodiment, the case where one semiconductor chip 23 is mounted on the silicon substrate 21 as the second layer component is taken as an example. However, a plurality of semiconductor chips are mounted on the silicon substrate 21 as the second layer component. Even in this case, if the frame of the central reinforcing member 35 has a size that can accommodate all the semiconductor chips, the same effect as described above can be obtained.
In the above embodiment, the FPC has been shown in an example in which only both ends are bent into a rectangular parallelepiped shape. However, as described in Japanese Patent No. 2570628, the rectangular parallelepiped shape is bent from four directions as shown in FIG. Of course, it may be processed into. FIG. 4A shows the configuration of the FPC, in which lead portions 32 are provided in the directions of the four sides of the opening 38 provided in the central portion. By bending these four lead portions 32, an FPC processed into a rectangular parallelepiped shape can be configured as shown in the top view after processing in FIG. 4B.

  Further, the FPC 25 or 43 may have a structure in which the plate-like reinforcing member 33 is not provided on the lead portions 32 on both sides, and only the central reinforcing member 35 or 42 is attached. In this case, when mounting the semiconductor package on the printed circuit board, it takes time to mount the lead portion 32 while holding it flat compared to the above configuration, but other effects can be similarly obtained.

It is sectional drawing which shows the structure of the semiconductor package which concerns on embodiment of this invention. The structure of FPC which concerns on the said embodiment is shown, (a) is a front view, (b) is a back view. The structure of the other FPC which concerns on the said embodiment is shown, (a) is a front view, (b) is a back view. The structure of FPC which concerns on other embodiment of this invention is shown, (a) is the surface view of FPC, (b) is the top view after a process. It is sectional drawing which shows the structure of the conventional semiconductor package. It is explanatory drawing at the time of conventional semiconductor package formation. It is a figure for demonstrating the problem of the conventional semiconductor package.

Explanation of symbols

20 Semiconductor Package 21 Silicon Substrate 22 Bump 23 Semiconductor Chip 24 Bump 25, 43 FPC
31 Solder ball mounting pad 32 Lead portion 33 Plate-like reinforcing member 34, 41 Silicon substrate mounting pad 35, 42 Center reinforcing member 38 Opening

Claims (6)

In a semiconductor package in which a first member such as a silicon substrate on which an electric circuit is formed or a first semiconductor chip is mounted on a flexible circuit board,
The flexible circuit board has a rod-shaped first reinforcing member arranged in a frame shape or spaced apart in parallel at the center portion, and an end portion thereof is bent to be opposite to the bonding surface of the first reinforcing member. It is configured in a rectangular parallelepiped shape by being bonded to the surface of
The first member is attached to the upper surface of the rectangular parallelepiped so that the mounting pad provided on the upper surface of the rectangular parallelepiped and the pad provided on the first member are connected, and solder balls are provided on the lower surface of the rectangular parallelepiped. A semiconductor package characterized by being provided. In a semiconductor package in which a laminated semiconductor component in which a second semiconductor chip is laminated on a silicon substrate on which an electric circuit is formed or a first member such as a first semiconductor chip is mounted on a flexible circuit board,
The flexible circuit board has an opening at a central portion, and a rod-shaped first reinforcing member arranged in a frame shape or spaced apart parallel to the periphery of the opening is bonded, and an end portion thereof is bent to form the first circuit. 1 is formed into a rectangular parallelepiped shape by being bonded to the surface opposite to the bonding surface of the reinforcing member,
The second semiconductor chip is located inside the rectangular parallelepiped through the opening, and the mounting pad provided on the upper surface of the rectangular parallelepiped and the pad provided on the first member are connected to each other. A semiconductor package, wherein the first member is attached to an upper surface of a rectangular parallelepiped, and solder balls are provided on a lower surface of the rectangular parallelepiped. The semiconductor package according to claim 1, wherein the flexible circuit board is formed by bonding a plate-like second reinforcing member to an inner side of a portion where the solder ball is provided. In a flexible circuit board on which a first member such as a silicon substrate on which an electric circuit is formed or a first semiconductor chip is mounted,
A rod-shaped first reinforcing member arranged in a frame shape or spaced apart in parallel is bonded to the central portion, and the end is bent and bonded to the surface of the first reinforcing member opposite to the bonding surface. A flexible circuit board characterized by having a rectangular parallelepiped shape. When the first member is mounted, an opening is provided in the central portion so that the second semiconductor chip mounted on the first member is located inside the rectangular parallelepiped, and the first member The flexible circuit board according to claim 4, wherein the reinforcing member is bonded to the periphery of the opening. The flexible circuit board according to claim 4 or 5, wherein a plate-like second reinforcing member is bonded to the inner side of the lower surface of the rectangular parallelepiped.

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