Semiconductor device, and manufacturing method of semiconductor device

1. Field of the Invention

The present invention relates to a semiconductor device including a semiconductor chip connected by the wire bonding.

2. Description of the Related Art

Japanese Patent Laid-Open No. 2000-216188 and Japanese Patent Laid-Open No. 11-67808 are cited as a conventional wire bonding technique for the semiconductor device.

For example, in a wire bonding method described in Japanese Patent Laid-Open No. 2000-216188, a bonding wire is used to connect between an electrode included in the semiconductor chip and a lead. In this method, the wires are positioned by bending the wires in their middle by means of pins to prevent contact between the wires.

In a technique described in Japanese Patent Laid-Open No. 11-67808, wires are inclined in a sealing resin flowing-direction to prevent contact between adjacent wires during mold resin sealing.

However, the recent demand for high performance and small packaged semiconductor chips has called for reduction in a pitch between pads. The wiring has become complex because of the SIP (Single In-Line Package) structure. Particularly, as the number of wirings between the semiconductor chips has increased, the distance between the adjacent wires has become narrower under the restriction on the arrangement of the semiconductor chips. Since this causes a concern for short-circuit of the wires or the like, it is necessary to extend a distance between the wires.

Since the techniques described in Japanese Patent Laid-Open No. 2000-216188 and Japanese Patent Laid-Open No. 11-67808 are a technique for connecting a bonding pad of the semiconductor chip with a lead, the arrangement on the lead side is less restricted. For example, in the technique described in Japanese Patent Laid-Open No. 2000-216188, the leads are positioned with the center-to-center distance between the leads wider than that between the bonding pads to widen the pitch between wires.

On the other hand, when the bonding pads are connected to each other, the arrangement of the bonding pads imposes a restriction. Specifically, the bonding pads are arranged in line on the semiconductor chip. Thus, when the semiconductor chips whose sizes are different from each other, or the semiconductor chips in which the distances between the bonding pads are different from each other are connected to each other, the wire connected between the bonding pads is angled, and therefore the distance between the adjacent wires becomes narrower.

The present invention has been made in consideration of the above circumstance, and the technique for connecting between the bonding pads of the semiconductor chips prevents contact between the wires.

The present invention provides a semiconductor device provided with a first semiconductor chip in which a plurality of first bonding pads are arranged in line, a second semiconductor chip in which a plurality of second bonding pads are arranged in line substantially parallel to the plurality of first bonding pads, and a plurality of wires each connecting the first bonding pad to the second bonding pad, respectively, and in the semiconductor device, at least one wire is bended with respect to a reference straight line passing through the first bonding pad and the second bonding pad which are connected by the wire, and the bended wire is extended out from the second bonding pad in a certain direction in which a distance between the bended wire and an adjacent wire which is adjacent to the bended wire is larger than a distance between the reference straight line of the bended wire and the reference straight line of the adjacent wire.

According to the present invention, the wire is bended so that the distance between the wires becomes larger than the distance between the reference straight lines, and is connected between the bonding pads arranged in a substantially parallel straight line. Thereby, it is possible to widen the space between the wires, and to prevent contact between the adjacent wires which causes shot-circuit or the like.

The present invention provides a method for manufacturing a semiconductor device provided with a first semiconductor chip in which a plurality of first bonding pads are arranged in line, a second semiconductor chip in which a plurality of second bonding pads are arranged in line substantially parallel to the plurality of first bonding pads, and a plurality of wires each connecting the first bonding pad to the second bonding pad, respectively, and in the semiconductor device, at least one wire is bended with respect to a reference straight line passing through the first bonding pad and the second bonding pad which are connected by the wire, and the bended wire is extended out from the second bonding pad in a certain direction in which a distance between the bended wire and an adjacent wire which is adjacent to the bended wire is larger than a distance between the reference straight line of the bended wire and the reference straight line of the adjacent wire.

FIG. 1 is a plain view typically illustrating a semiconductor device according to an embodiment;

FIG. 2 is a diagram describing the advantageous effect of the semiconductor device according to the embodiment;

FIG. 3A is a plain view typically illustrating the semiconductor device to be compared;

FIG. 3B is a cross-section view typically illustrating the semiconductor device to be compared;

FIG. 4 is a plain view typically illustrating the semiconductor device to be compared; and

FIGS. 5A to 5F are diagrams describing a method for manufacturing the semiconductor device according to the embodiment.

Embodiments of the present invention will be described below by using the drawings. Meanwhile, in all the drawings, the same code is attached to the same component, and the description will be arbitrarily omitted.

FIG. 1 is a plain view typically illustrating a semiconductor device of the present embodiment. The semiconductor device of the present embodiment is provided with a semiconductor chip 1 in which a plurality of bonding pads 3 are arranged in line, a semiconductor chip 2 in which a plurality of bonding pads 4 are arranged in line substantially parallel to the plurality of bonding pads 3 , and a plurality of wires 7 each connecting the bonding pad 3 to the bonding pad 4 , respectively. The bonding pads 3 and the bonding pads 4 , which are connected by the wires 7 respectively, are positioned at positions relatively displaced in aligned direction. At least one of the wires 7 is bended with respect to a reference straight line S which passes through the bonding pad 3 and the bonding pad 4 which are connected by the wire 7 . The bended wire is extended out from the bonding pad 4 in a certain direction in which a distance between the bended wire and an adjacent wire which is adjacent to the bended wire is larger than a distance between the reference straight line of the bended wire and the reference straight line of the adjacent wire.

A rising part (not-illustrated) of the wire 7 is formed in a bonding part 5 connecting the bonding pad 3 with the wire 7 , and an inclined part (not-illustrated) of the wire 7 is formed in a bonding part 6 connecting the bonding pad 4 with the wire 7 . The rising part is formed by setting up the wire 7 in a substantially perpendicular direction for a surface of the bonding pad 3 . The inclined part is formed by setting the wire 7 in a substantially parallel direction for a surface of the bonding pad 4 .

The bonding part 5 connects the bonding pad 3 with the wire 7 through a ball (not-illustrated), and the rising part is formed on an upper side of the ball.

When the formula of 0<θ 2 <θ 1 is satisfied, the distance between wires can be larger, where θ 1 is an angle formed between a line L orthogonal to the aligned direction of the bonding pads 4 and the reference straight line S of the bended wire, and θ 2 is an angle formed between an extending direction of the bended wire and the reference straight line S. The bended wire may also be extended out in a direction which is substantially orthogonal to the aligned direction of the bonding pads 4 . Thereby, it is possible to maximize the distance between the wires, and to efficiently prevent contact between the wires. In the present embodiment, it is assumed that “substantially orthogonal” includes an error area of ±5° for 90°.

A bending point may be provided by bending the wire 7 . The bending point can be provided at a position which is displaced by turns in the aligned direction of the bonding pads 4 .

The semiconductor chip 1 and the semiconductor chip 2 may be positioned in parallel, or may be stacked.

Next, a method for manufacturing the semiconductor device of the present embodiment will be described by using FIG. 5 . A ball 8 , which is formed at a tip of the wire 7 inserted into a capillary 9 , is connected to the bonding pad 4 (A), a bump 10 is formed, and the wire 7 is cut (B). Next, the ball 8 of the tip of the wire 7 inserted into the capillary 9 is connected to the bonding pad 3 (C), the rising part of the wire 7 is formed on top of the formed ball 8 , and the bonding part 5 is formed (D). Since the capillary 9 is moved, the wire 7 is bended, the bended wire is formed (E), and by connecting the wire 7 to the bonding pad 4 through the bump 10 , the bonding part 6 is formed (F). Meanwhile, FIGS. 5A to 5D and 5 F are pattern diagrams illustrating a producing process, which is viewed from a lateral side, for the semiconductor device of the present embodiment, and FIG. 5E is a pattern diagram illustrating the producing process, which is viewed from an upper side, for the semiconductor device of the present embodiment.

Next, the advantageous effect of the present embodiment will be described. According to the semiconductor device of the present embodiment as illustrated in FIG. 1 , the wire 7 is bended so that the distance between the wires 7 becomes larger than the distance between the wire 7 and the reference straight line S, and the bonding pad 3 and the bonding pad 4 , which are arranged on a straight line, are connected. Thereby, it is possible to widen the space between the wires, and to prevent contact between the adjacent wires which causes shot-circuit or the like.

FIG. 3 is a diagram illustrating the semiconductor device to be compared in which the wire is not bended. FIG. 3A is a plain view of the semiconductor device to be compared, and FIG. 3B is a cross-section view of the semiconductor device to be compared. Meanwhile, a cross-section view of the semiconductor apparatus of the present embodiment illustrated in FIG. 1 is also the same as that of FIG. 3B . In the wire bonding method, the ball 8 , which is formed at the tip of the wire 7 inserted into the capillary, is bonded on the bonding part 5 between the bonding pad 3 and the wire 7 , and the wire 7 itself is bonded on the bonding part 6 between the bonding pad 4 and the wire 7 . For a wire loop shape, the rising part is formed on top of the ball provided on the bonding part 5 , and the wire 7 near the bonding part 6 is inclined on the lower side to be formed at the lower position. Thus, the wires 7 near the bonding part 6 are likely to be highly disturbed, and therefore, there is a particular problem of contact between the adjacent wires in case of a narrowed pad.

Since the semiconductor chip 1 and the semiconductor chip 2 of FIG. 3 are laterally shifted to each other, similarly to FIG. 1 , the wire 7 for wiring the semiconductor chip 1 and the semiconductor chip 2 is angled. This reduces the space between the adjacent wires 7 , and short-circuit may be caused by the disturbed wires 7 or the like between the adjacent wires 7 .

Thus, it is necessary to enlarge the space between wires to prevent contact between the wires which causes shot-circuit. Particularly, at the bonding part 6 where the wire is inclined, the wires 7 are likely to be disturbed, and therefore, the loop stability and the extended distance between the wires are also necessary in order to achieve stable assembly.

According to the present embodiment, as illustrated in FIG. 1 , the wire 7 is bended so that the distance between the wires 7 becomes larger than the distance between the wire 7 and the reference straight line S, and the bonding pad 3 and the bonding pad 4 , which are arranged on a straight line, are connected. Thereby, it is possible to widen the space between the wire 7 and the adjacent wire 7 . In addition, bending the wire 7 on a side of the bonding part 6 can widen the space between the adjacent wires at a location where the wires 7 are likely to be disturbed.

FIG. 4 is an expanded diagram of the semiconductor chip 2 illustrated in FIG. 3 . If W is designated as a width of the wire 7 , in the semiconductor device in which the wire 7 is not bended, the distance X between the wires 7 is expressed by X=A sin θ−W. For example, If θ=30°, the distance X between the wires 7 can be expressed by X 1 =A/2−W.

On the other hand, according to the present embodiment, by bending the wire 7 , it is possible to extend the distance between the adjacent wires. FIG. 2 illustrates an expanded diagram of the semiconductor chip 2 illustrated in FIG. 1 . In FIG. 2 , the wire is bended so that an equation of θ 1 =θ 2 can be satisfied, That is, in FIG. 2 , the wire 7 is extended out from the bonding pad 4 in a direction orthogonal to the aligned direction of the bonding pads 4 . In this case, the distance between the wires X 2 is expressed by X 2 =A−W. Thus, it is possible to increase the distance between the wires as twice as X 1 which is the distance between the wires in the comparative semiconductor device.

As described above, according to the present embodiment, by bending the wire 7 in a direction substantially perpendicular to the aligned direction of the bonding pads 4 , it is possible to extend the distance between the adjacent wires, and to prevent contact between the wires even when the distance between centers of the bonding pads is small.

As described above, while the embodiments of the present invention have been described with reference to the drawings, such embodiments are exemplifications of the present invention, and a variety of configurations other than the above embodiments can be also adopted.