JP2001118955A - BGA wiring tape and BGA package - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To reliably solder an external connection solder ball connected to a chip electrode of a semiconductor chip mounted on a wiring tape to a land, thereby improving the reliability of an electric circuit. Improved BGA wiring tape and BGA package. A wiring tape (1) is formed by etching a copper foil attached to one surface of a heat-resistant and electrically insulating base film (2) having a ball opening (3) with an adhesive. It has a lead wire 5 connecting the lead 4 and the land 6 and a lead wire 5 connecting the inner lead 4 and the land 6, and has an elastomer layer 10 such as a silicone resin adhered to the lead wire 5 side of the base film 2. In the land 6 located in the portion 3, a protruding portion 7 protruding toward the ball opening 3 is formed to constitute a BGA wiring tape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring board for a semiconductor integrated circuit and a semiconductor device using the wiring board. More particularly, the present invention relates to a method for connecting an inner lead of a wiring tape to an electrode of a semiconductor chip without using bonding wires. BGA (Ball Grid Ar)
(Ray) wiring tape and a BGA package having a semiconductor chip mounted on the wiring tape.

[0002]

2. Description of the Related Art In recent years, the trend toward smaller, lighter and thinner semiconductor packages has been advancing at a rapid pace along with higher performance of electronic devices. Along with this, a BGA semiconductor package in which a semiconductor chip is mounted by providing an elastic resin layer for stress relaxation on a flexible wiring board which is easy to realize a narrow pitch, light weight and small size has been developed and put into practical use. In this format,
The semiconductor device is constructed by directly connecting the inner leads of the wiring board to the electrodes of the semiconductor chip without using bonding wires.

FIG. 4 shows a semiconductor package using a conventional wiring board. The wiring board 1 has a base film 2, a ball opening 3, an inner lead 4, routing wires 5, lands 6, and an elastomer layer 10 attached to the routing wires 5 side with an adhesive such as a silicone resin. The inner leads 4 of the wiring board 1
The routing wiring 5 and the land 6 are formed, for example, by etching a copper foil attached to the base film 2 using an adhesive. The semiconductor chip 11 is mounted on the wiring board 1 on the side of the elastomer layer 10. A solder ball 8 for connection to the land 6 is placed on the ball opening 3, and the solder ball 8 is melt-bonded to the land 6 in a solder ball reflow process performed later. The chip electrode 12 of the semiconductor chip 11 and the wiring board 1
After the inner leads 4 are electrically connected, the electrical connection portions are filled with a sealing agent 13 such as a liquid epoxy resin in contact with the base film 2, the elastomer layer 10, and the semiconductor chip 11. A sealed semiconductor package is constructed. FIG. 5 is a plan view of the semiconductor package of FIG.

FIG. 6 shows a state (an enlarged view of a partial cross section) when a solder ball is placed on a conventional wiring board. The wiring board 1 includes a base film 2, a ball opening 3, a routing wiring 5, a land 6, and a routing wiring 5.
Has an elastomer layer 10 attached with an adhesive such as a silicone resin. (Note that the wiring board in FIG. 6 does not show the inner leads connected to the chip electrodes of the semiconductor chip.) The ball opening 3 of the wiring board 1 is supplied using a solder ball mounting device or the like. Solder balls 8 to be mounted are placed and temporarily fixed to the lands 6 by flux.
The temporarily fixed solder ball 8 is then melted in a reflow process, so that the solder ball 8 is joined to the land 6.

[0005]

However, according to the structure of the conventional wiring board (FIG. 6), it has been found that the following problem exists between the ball opening, the land and the solder ball. That is, the base film 2 in which the plurality of ball openings 3 corresponding to the plurality of lands 6 are formed is designed so that the lands 6 are as small as possible for miniaturization and high density. For this reason, the diameter of the ball opening 3 also becomes small, and the dimensional tolerance of the diameter of the solder ball 8 and the diameter of the ball opening 3 is severe. As a result, when the diameter of the solder ball 8 placed on the ball opening 3 is slightly larger than the diameter of the ball opening 3, or when the diameter of the ball opening 3 is slightly smaller than the diameter of the solder ball 8, Then, the solder ball 8 to be loaded comes into contact with the entrance of the ball opening 3 and the solder ball 8 is mounted in a state of being floated from the land 6. In the reflow process of the solder ball 8, the molten solder ball 8 is removed. Solder non-contact portions 9 that do not bond well to the lands 6 occur, which causes a problem that the solder connection between the lands 6 and the solder balls 8 is not sufficient, and the reliability of the electric circuit of the semiconductor package (FIG. 4) is reduced. It was found to affect.

Therefore, an object of the present invention is to place the wiring tape on the ball opening of the wiring tape even when the land spacing of the wiring tape is designed to be narrow or the land diameter is designed to be small. BG that allows solder balls to be properly fused and connected to lands in the reflow process
A wiring tape for A and a BGA package are provided.

Another object of the present invention is to provide a semiconductor device mounted on a wiring tape, in which solder balls for external connection connected to chip electrodes of a semiconductor chip are reliably melt-connected to lands to improve the reliability of an electric circuit. An object of the present invention is to provide an improved BGA wiring tape and BGA package.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a heat-resistant and insulating base film having an opening for a ball on which a solder ball for external connection is mounted; A wiring layer having a land formed on a film and exposed to the ball opening and on which the solder ball is mounted is provided, wherein the land has a raised portion protruding toward the ball opening. BGA wiring tape is provided.

According to another aspect of the present invention, in order to achieve the above object, the raised portion formed on the land is provided with the ball opening formed at the time of pressure bonding of an elastomer layer bonded to the wiring layer side. The present invention provides a BGA wiring tape characterized by being formed by protruding deformation.

Further, in order to achieve the above object, the present invention provides a heat-resistant and insulating base film having an opening for a ball used for external connection, and a base film on a first surface of the base film. A semiconductor having a wiring layer formed and having a land exposed at the ball opening, and a chip electrode bonded to the first surface of the base film via an elastomer layer and connected to the wiring layer. A chip, a sealing portion for sealing a connection portion connecting the chip electrode and the wiring layer of the semiconductor chip, and the ball opening and the land mounted on the second surface side of the base film on the second surface side A BGA package comprising a solder ball, wherein the land has a bulge protruding toward the ball opening.

According to the present invention, in order to achieve the above object, the raised portion formed on the land is provided with the ball opening formed at the time of pressure bonding of an elastomer layer bonded to the wiring layer side. A BGA package characterized by being formed by a protruding deformation to a BGA.

[0012]

FIG. 1 shows a state (an enlarged view of a partial cross section) when a solder ball is put on a BGA wiring tape according to an embodiment of the present invention. Wiring tape 1
Is an elastomer which is attached to one surface of a heat-resistant and electrically insulating base film 2 having a ball opening 3 on one side of the lead-out wiring 5, land 6 and the lead-out wiring 5 by an adhesive such as silicone resin. It has a layer 10. (In the wiring tape of FIG. 1, the illustration of the inner leads connected to the chip electrodes of the semiconductor chip is omitted. In addition, the inner leads and lands of the wiring tape, and the leading wires connecting the inner leads and the lands are formed as follows.
For example, it is formed by etching a copper foil attached to a base film using an adhesive. On the land 6 located in the ball opening 3 formed in the base film 2 of the wiring tape 1, a raised portion 7 protruding toward the ball opening 3 is formed. A solder ball 8 supplied by using a solder ball mounting device or the like is placed in the ball opening 3 of the wiring tape 1 and temporarily fixed to the land 6 by a flux. Thereafter, the solder ball 8 is melted in a reflow process, and the solder ball 8 is joined to the land 6.

According to the wiring tape 1 of the embodiment shown in FIG. 1, a plurality of inner leads (not shown) for connecting to chip electrodes of a semiconductor chip and a plurality of solder balls for external connection are provided. The base film 2 having a wiring pattern 5 formed in a predetermined pattern connected to a plurality of lands 6 connected to the base 8 on one side has a ball opening 3 at a position where the land 6 exists. Elastomeric layer 10 adhered to the routing wiring 5 side
The land 6 located at the ball opening 3 has a raised portion 7 protruding toward the ball opening 3. Due to the presence of the raised portion 7 protruding toward the ball opening 3 formed on the land 6 located in the ball opening 3, the solder ball 8 placed on the ball opening 3 is provided.
Is melted in the subsequent reflow process, so that the solder balls 8 are properly joined to the lands 6, and the solder balls 8 placed on the ball openings 3 of the wiring tape 1.
However, proper fusion connection to the land 6 is realized in the reflow process.

FIG. 2 shows a BGA according to an embodiment of the present invention.
The method of manufacturing the wiring tape for use is shown. In this embodiment, an inner lead 4, a land 6, and a lead-out wiring 5 connecting the inner lead 4 and the land 6 are provided on one surface of a heat-resistant and electrically insulating base film 2 having a ball opening 3. Then, a wiring tape 1 having an elastomer layer 10 to be attached to the routing wiring 5 side with an adhesive such as a silicone resin or an epoxy resin-based resin is prepared. The prepared wiring tape 1 is placed on a heating stage 16 and sandwiched by a heating tool 15, and a pressing force is applied to the entire wiring tape 1 including the elastomer layer 10 by the heating tool 15 in a heated environment.

In FIG. 2, when a pressing force is applied to the elastomer layer 10, for example, in an environment heated to about 130 ° C., the elastomer layer 10 disposed on the side of the wiring 5 is wired with an adhesive. 5, the elastomer layer 10 expands under the heating environment, and the relief of the bulging due to the bulging raises the land 6 on the ball opening 3 side. Thereby, the configuration of the raised portion 7 protruding toward the ball opening 3 is realized on the land 6 located at the ball opening 3.

FIG. 3 shows a BGA according to an embodiment of the present invention.
1 shows a BGA package using a circuit wiring tape. The wiring tape 1 has an inner lead 4, a land 6, and a routing wire 5 connecting the inner lead 4 and the land 6 on one surface of a heat-resistant and electrically insulating base film 2 having a ball opening 3. And an elastomer layer 10 adhered to the wiring line 5 side with an adhesive such as a silicone resin. Wiring tape 1
Inner lead 4, routing wiring 5, and land 6
Is formed, for example, by etching a copper foil attached to the base film 2 using an adhesive. The land 6 located at the ball opening 3 has a raised portion 7 protruding toward the ball opening 3. The semiconductor chip 11 is mounted on the wiring tape 1 on the side of the elastomer layer 10. A solder ball 8 for connection to a land 6 supplied using a ball mounting device or the like is placed in the ball opening 3, and the solder ball 8 is connected to the land 6 in a solder ball reflow process performed later.
Is melt-bonded. Chip electrode 12 of semiconductor chip 11
After the inner leads 4 of the wiring tape 1 are electrically connected to each other, the electrical connection portion is formed of a sealing agent such as a liquid epoxy resin in contact with the base film 2, the elastomer layer 10, and the semiconductor chip 11. 13 to form a sealed semiconductor package.

According to the BGA package of the embodiment shown in FIG. 3, the semiconductor chip 11, the plurality of inner leads 4 connected to the plurality of chip electrodes 12 of the semiconductor chip 11, and the plurality of inner leads 4 are connected to an external circuit. A base film 2 provided on one side with a wiring pattern 5 formed in a predetermined pattern connected to a plurality of lands 6 to be connected, and a ball opening 3 provided at a position where the land 6 of the base film 2 exists. And an elastomer layer 10 for routing the semiconductor chip 11 to the wiring 5 side, a solder ball 8 for external connection electrically connected to the lands 6 of the base film 2, a plurality of inner leads 4, and a plurality of inner leads 4. Sealant 13 for sealing a connection portion with chip electrode 12
Having. Further, the land 6 located at the ball opening 3 has a raised portion 7 protruding toward the ball opening 3 and a solder ball 8 placed on the ball opening 3 is subjected to a reflow process. Is melted and joined to the land 6 to form a BGA package.

According to the BGA package of the embodiment shown in FIG. 3, the space between the lands of the wiring tape is designed to be narrow,
Even when the land is designed to have a small diameter, the land located at the ball opening has a raised portion protruding toward the ball opening, so that the ball opening of the wiring tape is formed. Thus, a BGA package is realized in which the solder balls placed on the lands can be properly melt-connected to the lands in the reflow process.

In the embodiment of the present invention, as the base film of the wiring tape, for example, an insulating plastic such as polyimide which has flexibility, heat resistance, etc., is easy to handle, and has excellent thickness uniformity. Film is suitable. A metal film such as a copper foil is used as a material for forming a wiring pattern such as a routing wiring, a land, and an inner lead of a wiring tape. Copper foil, for example, after attaching a predetermined adhesive-attached base film to the copper foil, by performing a photolithography process and etching treatment, inner leads, lands for solder ball formation, these inner leads and lands It is possible to form a wiring layer including a wiring pattern including a leading wiring to be connected.

In the embodiment of the present invention, the elastic resin elastomer layer is used for the purpose of relieving the thermal stress caused by the difference in thermal expansion between the semiconductor chip to be mounted and the wiring tape. An elastic resin material such as an elastomer or a plastomer, such as a polymer material having remarkable elasticity, for example, a synthetic resin system such as an epoxy resin or a crosslinked synthetic rubber system is suitable. In addition, a thermosetting liquid resin such as an epoxy resin can be used as a sealant for sealing a connection portion between the chip electrode and the inner lead.

[0021]

The wiring tape and BG for BGA of the present invention
According to the A package, the land located in the ball opening has a raised portion protruding toward the ball opening, so that the spacing between the lands of the wiring tape is designed to be narrow or the land diameter is reduced. In the case where the solder ball is placed in the ball opening of the wiring tape, the solder ball placed on the ball opening of the wiring tape can be properly melt-connected to the land in the reflow process.
A package can be provided.

Further, according to the BGA wiring tape and the BGA package of the present invention, the land located at the ball opening has a raised portion protruding toward the ball opening, so that the land is mounted on the wiring tape. The external connection solder balls connected to the chip electrodes of the semiconductor chip are reliably melt-connected to the lands, so that the BGA wiring tape and the BGA package with improved reliability of the electric circuit can be provided. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a BGA wiring tape according to an embodiment of the present invention.

FIG. 2 is an explanatory sectional view showing a method of manufacturing the BGA wiring tape according to the embodiment of the present invention.

FIG. 3 is an explanatory sectional view showing a BGA package using the BGA wiring tape according to the embodiment of the present invention;

FIG. 4 is an explanatory sectional view showing a semiconductor package according to a conventional technique.

FIG. 5 is a plan view of the semiconductor package of FIG. 4;

FIG. 6 is an enlarged explanatory view when a solder ball is placed on a conventional wiring board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wiring tape (wiring board) 2 Base film 3 Ball opening 4 Inner lead 5 Leading wiring 6 Land 7 Raised part 8 Solder ball 9 Solder non-contact part 10 Elastomer layer 11 Semiconductor chip 12 Chip electrode 13 Sealant 15 Heating tool (Pressure side) 16 Heating stage

Claims (4)

[Claims] A heat-resistant and insulating base film having an opening for a ball on which a solder ball for external connection is mounted; and a base film formed on the base film and exposed to the opening for the ball. A BGA wiring tape, comprising: a wiring layer having a land on which a solder ball is mounted, wherein the land has a protruding portion protruding toward the ball opening. 2. The method according to claim 1, wherein the protruding portion formed on the land is formed by a protruding deformation to the ball opening when the elastomer layer adhered to the wiring layer side is pressure-bonded. The wiring tape for BGA according to claim 1. 3. A heat-resistant and insulating base film having a ball opening used for external connection, and a land formed on a first surface of the base film and exposed to the ball opening. A semiconductor chip having a chip electrode bonded to the first surface of the base film via an elastomer layer and connected to the wiring layer; and A sealing portion for sealing a connection portion connecting the wiring layers, and a solder ball mounted on the ball opening and the land on the second surface side of the base film; A BGA package having a raised portion on the opening side. 4. The method according to claim 1, wherein the protruding portion formed on the land is formed by a protruding deformation to the ball opening when the elastomer layer adhered to the wiring layer side is pressed and adhered. The BGA package according to claim 3, wherein