JP3349465B2 - Semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor device in which a plurality of semiconductor chips are arranged in a plane on an island.

[0002]

2. Description of the Related Art In recent years, a mold type semiconductor chip has become highly functional, and a type in which a plurality of semiconductor chips are integrated into one package has been developed.

As this technique, for example, Japanese Patent Laid-Open No. 5-121 is disclosed.
There is a conventional example of JP-A-645-645. This is, as shown in FIG. 7, the first semiconductor chip 1 and the second semiconductor chip 2
Are fixed to one island 3. The bonding pads 4 and 5 of the first and second semiconductor chips 1 and 2 and the tips of the leads 6 are connected by thin metal wires 7, and the whole is sealed with resin. The connection between the first semiconductor chip 1 and the second semiconductor chip is realized by a thin metal wire 9 between the bonding pads 7 and 8.

In general, electrical connection using thin metal wires is realized by wire bonding, one end is realized by ball bonding, and the other end is realized by stitch bonding. Further, in the stitch bonding, since a thin metal wire is torn off by force while strongly pressing it with a capillary head (bonding tool), stress from the capillary head is directly applied to a portion under the stitch bonding.
If stitch bonding is performed on the lead side and ball bonding is performed on the bonding pad side of the semiconductor chip between the lead 6 and the bonding pad 5, stress is less likely to be applied to the semiconductor chip. However, between the first semiconductor chip 1 and the second semiconductor chip 2, between the bonding pad 7 and the bonding pad 8, one of them is always stitch-bonded, and the bonding of one of the semiconductor chips is performed. The pad is stressed by the stitch bond. Recently, since a semiconductor element such as a protection diode is incorporated under the bonding pad, there has been a problem that the semiconductor device itself becomes defective or the semiconductor element under the bonding pad is destroyed by the stress. In addition, it caused deterioration of the semiconductor substrate.

[0005] For this reason, the present applicant has filed Japanese Patent Application No. 10-16 / 1998.
No. 3994 filed an application as shown in FIG.

That is, the first and second semiconductor chips 50, 5
On one silicon surface, bonding pads 52 and 53 for external connection are formed in a peripheral portion of the chip.

Then, the first semiconductor chips 50 and 51 are attached on the island 54 of the lead frame by a bonding material (here,
One end of a bonding wire 55 such as a gold wire is wire-bonded to the bonding pads 52 and 53 on the surfaces of the semiconductor chips 50 and 51 by ball bonding. The other end of the bonding wire 55 is wire-bonded by stitch bonding to the tip of an external lead.

In addition, an opening 56 is provided in the island 54 corresponding to between the two semiconductor chips 50 and 51.
Among them, the required number of island-shaped bridges 5
7 are provided.

In the above description, the opening 54 is provided in the island 54. However, the first island 80 and the second island 81 are bridged by two bridging leads 82, 83, and the islands 80, 81, It can be said that a region surrounded by the bridging leads 82 and 83 constitutes the opening 56. Further, a separation portion 84 is provided at each bridge portion.

At the time of forming the lead frame (press cut or etching), the bridge 57 integrated with the island 54 and the bridging leads 82 and 83 integrated with the island (provided that the separation portion 84 is formed at the bridging portion at the same time). The bridge 57 may be cut off from the island 54 after the adhesive tape 58 is applied as shown in FIG. The adhesive tape 58 attaches a bridging lead that forms a separated portion from the bridge.

That is, in connecting the bridge 57 to the bonding pads 53 of the semiconductor chip, the bonding pads 53 on the semiconductor chips 50 and 51 are realized by ball bonding, and the bridge 57 is realized by stitch bonding. The above-mentioned problem is solved.

[0012]

However, when the number of bonding pads arranged on the side of the semiconductor chip located on the opening 56 side increases,
There is a problem that the arranged bridges 57 are insufficient.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and firstly, at least two bridges are provided, and the bridge train provided after the first bridge train is provided. Can be solved by displacing the semiconductor chips along the extending direction of the side of the semiconductor chip.

By preparing a plurality of bridge rows as shown in FIG. 1, even if the number of connection points between the first semiconductor chip and the second semiconductor chip increases, the connection can be realized, and by shifting the bridge row, It is possible to prevent contact between adjacent first and second thin metal wires.

Second, by providing an isolation region on the bridging lead for electrically isolating the first island and the second island, the first semiconductor chip (or the first island) and the second island are separated. Semiconductor chip (or second island)
Can be electrically separated from each other.

Third, the problem is solved by providing the separation region by cutting, and fixing the bridging leads arranged on both sides of the separation region with a first adhesive tape.

When the separation region is cut by, for example, press cutting, the first island and the second island are misaligned afterwards, but the misalignment can be prevented by being fixed with the first adhesive tape.

Fourthly, by fixing the bridge rows together with the bridging leads provided at both ends with a second adhesive tape, each bridge can be fixed.

Fifth, the problem is solved by setting one region and the other region to one end and the other end of the bridge.

Further, another object of the present invention is to solve the above problem by setting one area and the other area to be one and the other areas where the end of the bridge is divided into two. As will be described later, by forming two stitch bonds at one bridge end, the bond area can be gathered in one place, and the adhesive area of the adhesive tape can be secured accordingly.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below in detail with reference to FIG.

In the figure, reference numerals 50 and 51 denote first and second semiconductor chips. First and second semiconductor chips 50, 5
Various active elements and passive circuit elements are formed on the silicon surface in the previous process, and bonding pads 52 and 53 for external connection are formed on the periphery of the chip. A passivation film such as a silicon nitride film, a silicon oxide film, or a polyimide-based insulating film is formed so as to cover the bonding pads 52 and 53, and these films are opened above the bonding pads 52 and 53 for bonding connection. The opening is formed. Here, the circles filled in black indicate the bonding pads and the ball bonding portions of the fine metal wires for the sake of illustration.

The first semiconductor chips 50 and 51 are die-bonded onto the islands 54 of the lead frame with an adhesive (here, solder, silver paste, or the like).
The bonding pads 52, 53 on the surfaces 0, 51 are formed by bonding one end of a bonding wire 55 such as a gold wire, an Al wire, or a Cu wire by ball bonding, and the other end of the bonding wire 55 is a tip of an external lead. The part is wire-bonded by stitch bonding.

On the other hand, the connection between the first semiconductor chip 50 and the second semiconductor chip 51 has the following configuration.
First, an opening portion 56 is provided in an island 54 corresponding to between the two semiconductor chips 50 and 51, and a required number of island-like bridges 57 are provided therein. The bridge 57 may be any conductive means capable of realizing wire bonding, such as a metal plate of copper, Al, or the like.
An insulating substrate or the like having a surface coated with a conductive material is conceivable.
Here, since it is formed integrally with the Cu lead frame, it is made of the same material as the island, and is made of a metal mainly composed of Cu. The first semiconductor chip 5 close to the opening
A plurality of bridge rows are prepared on the side L1 of 0 and the side L2 of the second semiconductor chip 51 because there are many bonding pads for connecting each other. Here, for the sake of illustration, a configuration is shown in which first and second bridge rows 57a... And 7b are arranged in parallel with the side L1 or L2.

In the preceding sentence, the opening 54 is provided in the island 54. However, the first island 80 and the second island 81 are bridged by two bridging leads 82, 83, and the islands 80, 81, It can be said that a region surrounded by the bridging leads 82 and 83 constitutes the opening 56. Further, as will be described later, in order to prevent mutual interference of the semiconductor chips via the frame, a separation portion 84 is provided at each bridging portion.

In this embodiment, when forming the lead frame (press cut or etching), the bridge 57 integrated with the island 54, and the bridging leads 82, 83 integrated with the island.
(However, the separation portion 84 is formed at the bridge portion at the same time) is prepared in advance, and after the adhesive tape 58 is attached as shown in FIG.
The bridge 57 is formed separately from the island 54. The adhesive tape 58 attaches a bridging lead that forms a separated portion from the bridge. The symbol T is a ridge-side residue generated when the island and the bridge are cut.

The adhesive tape 58 may be used to connect the separated bridging leads and fix the island-like bridge rows to the bridging leads. That is, as shown by the dotted line in FIG.
Are separated by four sides, two longitudinal sides are used as a first adhesive tape for fixing the bridging lead, and two lateral sides are used as a second adhesive tape for fixing the bridge and the bridging lead. Is also good.

According to the present invention, in connecting the bridge 57 and the bonding pad 53, the semiconductor chips 50, 5
The bonding pad 53 on one side is formed by ball bonding, and the bridge 57 is formed by stitch bonding.

Since the semiconductor chip side can be realized by ball bonding instead of stitch bonding, distortion applied to the semiconductor chip can be suppressed.

If necessary, mutual interference may occur due to circuits incorporated in the first semiconductor chip and the second semiconductor chip. For example, the first semiconductor chip 50
When noise generated from the semiconductor chip enters the second semiconductor chip via the first island 80, the bridging leads 82, 83, and the second island 81, a separation portion 84 is provided here by press cutting or the like. This noise can be prevented from entering.

The wire bonding by the thin metal wire is realized by ball bonding at one end and stitch bonding at the other end. In particular, stitch bonding
Since the thin metal wire is strongly pressed by the capillary head and torn off by force, stress is applied to the part under the stitch bonding.However, the bridge 57 side is stitch bonded and the semiconductor chip side is ball bonded. The applied stress can be suppressed. Therefore, deterioration of the semiconductor element under the bonding pad can be suppressed.

Semiconductor chips 50, 51, island 54
The leading ends of the plurality of leads 59 extending to the vicinity and the main part including the fine metal wires are molded with an epoxy-based thermosetting resin 58 as shown by a dashed line, thereby forming a product.

Here, the island 54 on which the semiconductor chips 50 and 51 are mounted is stepped so that the bonding pad surfaces of the chip and the leads 59 are substantially the same. Further, a portion where the support lead 61 is exposed from the sealing resin 60 is cut.

Next, a second embodiment will be described with reference to FIG. In this embodiment, the arrangement of the bridge rows and the positions of the thin metal wires, the bonding positions, and the bonding positions of the adhesive tape are different, and the other structures are substantially the same. Therefore, only different points will be described here.

That is, the side L1 of the first semiconductor chip 50
A first bridge row 57a is provided on the side, and a second bridge row 57b is provided on the lower row, and each bridge row is shifted at a predetermined pitch. In the present embodiment, since there are two bridge rows, bridges 57b of the second bridge row are arranged between bridges 57a arranged in the first bridge row. The position where the first bridge 57a and the second bridge row 57b are bonded to the bridge 57 is formed at the end on the side adjacent to the first bridge 57a and the second bridge row 57b.

More specifically, a thin metal wire 62 extending from the first semiconductor chip 50 is connected to the right side at the lower end of the first bridge 57a with respect to the paper surface, and the second semiconductor A thin metal wire 63 extending from the chip 51 side is connected to the left side. At the upper end of the second bridge 57b, a thin metal wire 64 extending from the first semiconductor chip 50 side is connected to the right side, and a thin metal wire 65 extending from the second semiconductor chip 51 side is connected to the left side. It is connected to the.
Here, the thin metal wire 62 is connected to the right side of the bridge 57a, but may be on the left side. In this case, the thin metal wire 63 is on the right side. FIG. 3 shows a perspective view of the connection relationship here.
It is.

The point of the present invention is that, unlike the first embodiment, the two stitch bond positions can be concentrated at one end (the lower end in the first bridge 57a). Thus, the adhesive area of the adhesive tape 58 can be increased, and the fixing strength of the bridge can be enhanced. In other words, a bonding tool can be abutted, and in order to secure the bonding strength, it cannot be disposed extremely at the edge of the bridge, and a certain margin is required. However, by concentrating at one end, this margin can be reduced. The adhesive area of the adhesive tape can be increased, and conversely, the size of the bridge can be reduced by the excess.

Conversely, in the first embodiment, since the bonding is performed at both ends of the bridge, the region excluding this region is narrower than that in FIG. 2 and there is a problem that the bonding area is reduced. Further, if the adhesive area of the adhesive tape is to be made equal to that of FIG. 2, it is necessary to increase the area of the upper surface of the bridge, which increases the size of the entire semiconductor device.

Here, the adhesive tape may be bonded to the island in consideration of the fixing strength. However, in FIGS. 1 and 2, since the bridge is cut after the adhesive tape is applied, it cannot be bonded to the island. That is, it is for cutting between the island and the bridge to be formed. The result remains as a residue T as described above.

Referring again to FIG. 3, there is a possibility that a thin metal wire extending from the stitch bond position may contact a bridge hanging downward as shown in the drawing at a portion extending to the semiconductor chip. However, since the adhesive tape 58 is provided below the extending direction, the contact can be prevented.

In the present invention, three or more bridge rows may be provided. FIG. 4 shows a bonding example in the case of three rows. In this case as well, the connection structure shown in the bridge of FIG. 1 and FIG.
The connection structure shown in FIG. 2 is shown here. The connection structure shown in FIG. 2 is shown here.

Further, since the six thin metal wires 90 to 95 (in the case of n rows, 2n wires) are repeated as a unit in the horizontal direction with respect to the paper surface, the first bridge 57a
Of the third bridge 57c are arranged substantially uniformly at a distance from the left end of the third bridge 57c to the right end of the third bridge 57c.

FIG. 5 is a diagram for explaining a specific diagram of the second embodiment. Here, the support leads are 100, the upper island is from the corner, and the lower island is
It is pulled out from the center of the left and right sides of the land. This may also extend from the corner. Also, since the number of pads drawn out differs depending on the chip size, the number of leads differs. Therefore, the pitch between the lead group connected to the upper chip and the lead group connected to the lower chip naturally differs.

[0044]

As described above, according to the present invention,
First, a bridge is provided between two semiconductor chips, the connection on the semiconductor chip side is performed by ball bonding, and the connection on the bridge side is performed by wire bonding of a thin metal wire by stitch bonding, thereby forming a semiconductor element under the bonding pad. Deterioration can be prevented.

In addition, since the connection between the chips is changed from one thin metal wire to two thin metal wires via a bridge, the height of the thin metal wires can be reduced during bonding. Therefore, the thickness of the sealing resin can be reduced.

The installation of the bridging leads or the use of the insulating adhesive can suppress the penetration of noise from one chip to the other chip.

Further, since the bridge is formed simultaneously with the formation of the lead frame, the bridge can be easily separated by pressing, and the bridge can be fixed with an adhesive tape, so that good wire bonding can be performed.

By preparing a plurality of bridge rows as shown in FIG. 1, even if the number of connection points between the first semiconductor chip and the second semiconductor chip increases, the connection can be realized and the bridge row is shifted. Thus, it is possible to prevent contact between the adjacent first and second thin metal wires.

Further, the stitch bond positions are combined at one bridge end, so that the adhesive tape adhesive area can be secured accordingly.

[0050]

[Brief description of the drawings]

FIG. 1 is a plan view of a semiconductor device for describing a first embodiment of the present invention.

FIG. 2 is a plan view of a semiconductor device for describing a second embodiment of the present invention.

FIG. 3 is a diagram illustrating connection of the thin metal wires in FIG. 2;

FIG. 4 is a diagram illustrating a structure in which three bridge rows are provided.

FIG. 5 is a diagram illustrating a specific structure of FIG. 2;

FIG. 6 is a diagram illustrating a conventional semiconductor device.

FIG. 7 is a diagram illustrating a conventional semiconductor device.

──────────────────────────────────────────────────の Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 23/50

Claims (3)

(57) [Claims] 1. A fixing region of the first island and the second semiconductor chip serving as the fixing region of the first semiconductor chip and
Comprising a second island, the first island, the plurality of leads extending on the periphery of the second island, the first semiconductor chip and the second island which is fixed to the first island A second semiconductor chip fixed to the first semiconductor chip, a first thin metal wire for electrically connecting the first semiconductor chip and the second semiconductor chip to the lead, and a second semiconductor chip fixed to the first semiconductor chip and the second semiconductor chip. Between semiconductor chips
Plurality in there, arranged said are electrically separated along the extending direction of the side of the semiconductor chip which faces a plurality of rows
A bridge row composed of the following bridges; and the first semiconductor chip and the first semiconductor chip adjacent to each other.
A second thin metal wire provided between the adjacent bridge rows, and a second thin metal wire adjacent to the second semiconductor chip and the second semiconductor chip;
In a semiconductor device having a third thin metal wire provided between the bridge row and the bridge row adjacent thereto, the bridge row adjacent to the first semiconductor chip and
Affixed on a bridge row adjacent to the second semiconductor chip
And the second thin metal wire and the third thin metal wire
And an adhesive tape provided below the extension region of the semiconductor device. 2. At least two bridge rows are provided.
Are provided for the first bridge row thereafter.
Bridge rows are shifted along the direction in which the side edges extend.
The semiconductor device according to claim 1, wherein the semiconductor device is arranged in a line . 3. The first island and the second eye.
The bridge island located between the lands has the first island
An isolation region is provided to electrically separate the island from the second island.
And the bridging leads arranged on both sides of the separation region
Is fixed by the adhesive tape.
The semiconductor device of claim 1, wherein that.