JPH05102385A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a semiconductor device which is not increased in size even if multiple pins are employed. CONSTITUTION:Lead patterns 3 are alternately formed on both side surfaces of a base film 2. Fingers 5 of a film carrier tape 1 in which the fingers 5 protrude from device holes 4 formed on one side surface of the film 2 are electrically connected to pad electrodes of a semiconductor chip 14 mounted on a die pad 12, and resin-sealed to obtain a semiconductor device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device which can be electrically connected by a bonding wire, and more particularly to a technique which is effective when applied to a multi-pin semiconductor device in which a gap between electrodes of a semiconductor chip is narrow. is there.

[0002]

2. Description of the Related Art In semiconductor devices used for electronic equipment such as computers and personal computers, the outer leads have a gull-wing shape for the purpose of downsizing the electronic equipment and improving the production efficiency during its manufacture. A resin-encapsulated semiconductor device compatible with surface mounting, such as a known QFP-type resin-encapsulated semiconductor device, is used. Here, FIG. 9 shows a sectional view of a conventional QFP type resin-sealed semiconductor device. In the figure, a is a semiconductor chip, b is a die pad forming a part of a lead frame, c is an outer lead forming a part of a lead frame, d is a resin sealing portion made of epoxy resin, and e is a lead and a semiconductor. Bonding wires for electrically connecting the chips, and f are epoxy resin adhesive layers for bonding the semiconductor chip onto the die pad.

[0003]

In recent years, as electronic devices have become more multifunctional and have higher performance, semiconductor devices have become larger, more highly integrated, and have more pins. As a result, electrodes of semiconductor chips have been developed. The number is increasing, and the electrode pitch is becoming narrower in order to suppress the size of the semiconductor chip. In a conventional semiconductor device package, when electrically connecting such a semiconductor chip and a lead frame with a bonding wire,
Since the tip pitch of the inner leads forming a part of the lead frame, that is, the pitch of the bonding wires is limited, there is a limit to disposing many inner leads in the vicinity of the semiconductor chip. The pitch of the tips of the inner leads is generally determined by the etching rate of the lead frame and its thickness, and is, for example, 0.15 mm.
In the case of a thick lead frame, the tip pitch of the inner leads has a limit of 0.22 mm. As the number of inner leads forming one side of the package increases, the tips of the inner leads move away from the center of the semiconductor chip, resulting in a longer bonding wire.
There is a possibility that the bonding wire may be deformed or broken due to the resin injection pressure at the time of resin encapsulation, or the impedance mainly of the electric resistance component of the bonding wire portion may increase and the signal transmission speed of the semiconductor chip may decrease. .. Further, the length of the bonding wire may increase the outer shape of the semiconductor device in a semiconductor device having a large number of pins, which may reduce the packaging density of electronic equipment.

It is an object of the present invention to provide a multi-pin semiconductor device having a short bonding wire and a narrow bonding wire pitch, and further providing a semiconductor device which does not become large even if the number of pins is increased.

[0005]

The present invention has solved the above-mentioned problems, and the outline thereof is as follows. That is, (1) a semiconductor chip, a film carrier tape having leads formed on both sides of an insulating base material, a first lead formed on one surface of the insulating base material, and another surface formed on the other side of the insulating base material. And the semiconductor chip is electrically connected to the first lead and the second lead by a bonding wire, the second lead being integrally formed with fingers protruding from the end of the insulating base material. It is a thing. (2) The film carrier tape has a first lead and a second lead.
The second leads are arranged at positions where they do not overlap with each other, and the second leads have electrodes arranged on the surface where the first leads are arranged through the electrical conduction holes. (3) The film carrier tape is provided with a rod-shaped insulator at the tips of the fingers integrally formed with the second leads. (4) The second lead formed on the film carrier tape is joined to the insulating thin plate on which the metal film wiring is formed, and the semiconductor chip is placed on the insulating thin plate.

[0006]

According to the means of the first aspect of the present invention, since the leads are formed on both sides of the film carrier tape, the wiring density of the leads is improved, and the tip pitch of the first lead and the tip of the second lead are improved. Since the pitch between the first lead and the second lead, which is the bonding point, can be made narrower than the pitch, the tips of the first lead and the second lead can be brought closer to the semiconductor chip. Therefore, the signal transmission speed can be improved and the deformation of the bonding wire at the time of resin injection can be reduced. According to the means of the second term, the tip position of the first lead and the tip position of the second lead, which are the bonding points, that is, the tip positions of the fingers are alternately arranged in a zigzag pattern, A short circuit between the bonding wires can be avoided, and further, the first lead and the second lead are alternately arranged, and a constant distance can be maintained. Therefore, the crossing of the first lead and the second lead adjacent to each other can be achieved. Electrical noise such as talk noise can be reduced. According to the means of the third aspect, since the fingers protruding from the insulating substrate of the film carrier tape are fixed by the rod-shaped insulator forming a part of the insulating substrate, the positional accuracy of the fingers and the mechanical strength against external force are improved. However, the productivity of wire bonding and the processing yield thereof can be improved. According to the measure of the fourth item, the position fixing of the fingers is strengthened in order to alloy-bond the part of the second lead including the fingers to the insulating thin plate,
The productivity of wire bonding and the processing yield thereof can be improved. Further, by using the metal film wiring formed on the insulating thin plate as the ground wiring and connecting the ground wiring to the second lead of the ground, the ground electrode and the ground wiring provided at any position of the semiconductor chip are electrically connected. Since the connection can be made, electrical noise can be reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. 1, 2 and 3. FIG. 1 is a partially cutaway perspective view of a first embodiment of a semiconductor device of the present invention, and FIG. 2 is an AA line of FIG.
3 is a sectional view taken along the line, FIG. 3 shows the first semiconductor device of the present invention.
FIG. 3 is an enlarged perspective view showing a main part of the embodiment of FIG. In the figure,
Reference numeral 1 is a film carrier tape, 2 is a base film of the film carrier tape 1, and is, for example, a polyimide resin film. 3 and 3 are leads made of copper formed on the front surface and the back surface of the base film 2, and 4 is a device hole formed with a window in the base film. The leads 3, 3− are formed so as to extend substantially radially from the vicinity of the device hole 4, and 3a, 3a− are the first leads 3b, 3 formed on the surface of the base film 2.
b- is a second lead formed on the back surface of the base film 2.

The second leads 3b, 3b-project from the end face of the device hole 4 to the inside as they are to form fingers 5, 5 '. Also, this second lead 3b
The base film 2 through the through hole 6 described below.
It extends so that it can be connected to the connection lead 3c formed on the surface of the. In this way, the outer ends of the first leads 3a, 3a--and the connecting leads 3c, 3c--formed on the outer peripheral edge of the upper surface of the base film 2 and the inner leads 8,8-- of the lead frame 7 are Connection is made via gold-tin eutectic bonding or gold-gold bonding. Reference numeral 9 denotes a sealing resin, and the portions of the inner leads 8 and 8 − disposed from the sealing resin 9 and 9 − form the outer leads 10 and 10 −. Reference numeral 11 is a solder resist that protects the leads 3 on the film carrier tape 1.

The film carrier tape 1 is different from a normal film carrier tape in that it has a multilayer wiring structure. That is, while a normal film carrier tape has a single-sided single-layer wiring structure, this film carrier tape 1 has leads 3 on both front and back surfaces,
It has the fingers 5 integrally formed with the second lead 3b formed on the back surface, and further, the first lead 3a formed on the front surface and the second lead 3b formed on the back surface do not overlap each other. They are arranged alternately.

Further, the film carrier tape 1 is formed so as to cover the device hole 4 of the film carrier tape 1.
An insulative die pad 12 made of, for example, an alumina thin plate is provided on the back surface of the, and the metal film 13 made of, for example, gold and the finger 5 formed on the upper surface of the die pad 12 are joined by gold-gold joining. It is also possible to bond the film carrier tape 1 and the die pad 12 with an epoxy adhesive to increase the adhesive strength.

On the other hand, the die pad 1 thus formed
2, the semiconductor chip 14 is adhered onto the semiconductor chip 14 with an epoxy adhesive, and the pad electrodes 15, 15-
And the first leads 3a, 3a- and the second leads 3b,
The tip end of 3b-is electrically connected by the bonding wires 16 and 16-. At this time, the first lead 3a,
The position of the tip of 3a and the position of the tip of the second leads 3b, 3b, that is, the positions of the tips of the fingers 5 and 5 are alternately seen from a plane or a vertical plane.
Moreover, because of the zigzag shape, the first lead 3a,
The bonding wires 16 and 1 which are adjacent to each other even if the pitch formed by the third leads 3a and the second leads 3b and 3b is narrow.
It is unlikely that the 6-contact each other, and the pitch formed by the adjacent leads can be narrowed. As a result, the first leads 3a, 3a- and the second leads 3b, 3b are
It is possible to bring the tip of-to the semiconductor chip 14 and to shorten the length of the bonding wires 16 and 16-. After forming the leads 3 of the copper thin film, the solder resist 11 is selectively coated on the front surface and the back surface of the film carrier tape 1.
Using the mask 1 as a mask, the exposed leads 3 are plated with gold.
By this gold plating, wire bonding and connection between the lead 3 and the lead frame 7 can be favorably performed.

The signal transmission path according to the first embodiment of the present invention is divided into two types from the outer lead 10 of the lead frame 7 through the inner lead 8 and the first branch 3a to the bonding wire. And the second lead 3b, the finger 5, the bonding wire 16 from the connection lead 3c through the through hole 6 formed in the film carrier tape 1. And the semiconductor chip 14
However, it has two signal transmission paths.

In the semiconductor device of the present invention, since the leads 3 are formed on both sides of the film carrier tape 1, the lead wiring density is high, and the pitch between the first leads 3a and the second leads 3b can be narrowed. The length of the bonding wire 16 connecting the tip of the first lead 3a and the second lead 3b to the semiconductor chip 14 can be shortened. Therefore, the impedance of the bonding wire portion in the signal path can be lowered, the signal transmission speed can be improved, and at the same time, the deformation of the bonding wire due to the injection pressure at the time of resin injection can be prevented.
Further, the first lead 3a and the second lead 3b are
Since they are arranged alternately and in a zigzag shape both when viewed from the plane and when viewed from the vertical surface, there is little possibility of a short circuit due to contact between the bonding wires 16 adjacent to each other. Since the first leads 3a and the second leads 3b have a stereoscopically constant distance even if the pitch thereof is narrowed, electrical noise such as crosstalk noise can be reduced.

First Embodiment of First Embodiment of Semiconductor Device of the Present Invention
A modified example will be described with reference to FIG. 4A. FIG. 4A is a partially cutaway perspective view showing a first modified example of the first embodiment, in which the upper surface of the film carrier tape 1 is not bonded to the lead frames forming the outer lead and the inner lead. The formed first leads 3a, 3a and the connecting leads 3c, 3c are extended from the base film 2 to the outside to form the outer leads 10, and the sealing resin 9 is formed slightly inside the base film 2. Here is an example. The rest of the configuration is the same as that described in the first embodiment, and it is clear that its function does not change at all.

Second Embodiment of First Embodiment of Semiconductor Device of the Present Invention
A modified example will be described with reference to FIG. 4B. FIG. 4B is a cross-sectional view showing a second modified example of the first embodiment, in which two normal film carrier tapes 1 each having a single-sided single-layer wiring structure are attached to each other.
The first lead 3a is formed on the second film carrier tape 1b, and the second lead 3b is formed on the second film carrier tape 1b. In addition, the first lead 3a and the second lead 3b
Are projectingly provided from the outer peripheral ends of the first base film 2a and the second base film 2b, respectively. The projecting portions of the first lead 3a and the second lead 3b are provided on the inner lead 8, for example, It is joined by gold-tin joining. The rest of the configuration is the same as that described in the first embodiment, and it is clear that its function does not change at all.

A second embodiment of the semiconductor device of the present invention is shown in FIG.
I will explain based on. FIG. 5 is an enlarged perspective view showing a main part of a second embodiment of the semiconductor device of the present invention. As shown in FIG. 5, on the upper surface of the die pad 12 provided on the back surface of the film carrier tape 1, in addition to the metal film 13, the metal film 13
A metal film wiring 17 for connecting the two is formed between the semiconductor chip 14 and the fingers 5 protruding from the end surface of the base film 2. Of the second leads 3b, 3b formed on the back surface of the film carrier tape 1, the second lead 3b engaged with a grounded outer lead (not shown).
s, 3bs (not shown), ie fingers 5s, 5
The metal film wiring 17 functioning as a ground plane is pulled out to the vicinity of the semiconductor chip 14 from the metal films 13s and 13s joined to s. Therefore, the ground pad electrode 15s provided at an arbitrary position provided on the semiconductor chip 14 and the metal film wiring 17 forming the ground potential are connected to each other, and the fluctuation of the ground potential due to the ON / OFF of the signal at the same time is reduced, It is possible to reduce noise due to the fluctuation and prevent malfunction.

A third embodiment of the semiconductor device of the present invention is shown in FIG.
Also, description will be made based on FIG. 7. FIG. 6 is a partially cutaway perspective view of a third embodiment of the semiconductor device of the present invention.
FIG. 3 is an enlarged perspective view showing the main part thereof. 6 and 7, 18 is a support film 1 for the base film 2.
The tip end of the finger 5 formed on the back surface of the film carrier tape 1 is fixed by a rod-shaped insulator supported by 9. As a result, the positional accuracy of the fingers 5, 5-is kept very high because it is supported by the base film 2 and the rod-shaped insulator 18, and the strength of the fingers 5, 5-is also improved. The stability of the wire bonding is increased, and the productivity of wire bonding and the processing yield thereof can be improved.

A fourth embodiment of the semiconductor device of the present invention is shown in FIG.
I will explain based on. FIG. 8 is a partially cutaway perspective view of the fourth embodiment of the semiconductor device of the present invention. In FIG.
The semiconductor chip 14 is supported by a lead frame die pad 21 adhered to the upper surface of the semiconductor chip 14 via an insulating film 20 and a support bar 22 engaged with the lead frame die pad 21.
Is done by. The fourth embodiment is different in that the die pad as described in the first, second and third embodiments does not exist and the lead frame die pad 21 supports the semiconductor chip 14. .. Shinagawa,
In the fourth embodiment, the semiconductor chip 14 is bonded to the lead frame die pad 21 of the lead frame 7, and the film carrier tape 1 is bonded to the inner lead 8. The lead frame die pad 21 is disposed so as to avoid the pad electrode 15 of the semiconductor chip 14, and the support bar 22 has a part of the bar widened to improve heat dissipation. As a result, the thermal emissivity of the semiconductor device can be improved.

[0019]

The effects obtained by the present invention will be briefly described. It is possible to improve the signal transmission speed and reduce the crosstalk noise between adjacent leads, and the bonding wires are short and the pitch of the bonding wires is narrow. It is possible to provide a multi-pin semiconductor device, particularly a semiconductor device that does not increase in size even if the number of pins is increased.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a first embodiment of a semiconductor device of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is an enlarged perspective view showing a main part of the first embodiment of the semiconductor device of the present invention.

FIG. 4 is a view showing a modified example of the first embodiment of the semiconductor device of the present invention, FIG. 4A is a partially cutaway perspective view showing the first modified example, and FIG. It is sectional drawing which shows the modification.

FIG. 5 is an enlarged perspective view showing a main part of a second embodiment of the semiconductor device of the present invention.

FIG. 6 is a partially cutaway perspective view of a third embodiment of the semiconductor device of the present invention.

FIG. 7 is an enlarged perspective view showing a main part of a third embodiment of the semiconductor device of the present invention.

FIG. 8 is a partially cutaway perspective view of a fourth embodiment of the semiconductor device of the present invention.

FIG. 9 is a cross-sectional view of a conventional QFP type resin-sealed semiconductor device.

[Explanation of symbols]

 1 film carrier tape 1a 1st film carrier tape 1b 2nd film carrier tape 2 base film 2a 1st base film 2b 2nd base film 3 lead 3a 1st lead 3b 2nd lead 3c connection lead 4 Device hole 5 Finger 6 Through hole 7 Lead frame 8 Inner lead 9 Sealing resin 10 Outer lead 11 Solder resist 12 Die pad 13 Metal film 14 Semiconductor chip 15 Pad electrode 16 Bonding wire 17 Metal film wiring 18 Rod insulator 19 Support film 20 Insulation Film 21 Lead frame die pad 22 Support bar

Claims (4)

[Claims] 1. A semiconductor element chip, a film carrier tape having leads formed on both sides of an insulating base material, a first lead formed on one surface of the insulating base material, and another surface of the insulating base material. The semiconductor chip is formed of a second lead integrally formed with a finger projecting from an end of the insulating base, and the semiconductor chip is bonded to the first lead and the second lead by a bonding wire. A semiconductor device characterized by being electrically connected to. 2. The film carrier tape is arranged at a position where the first lead and the second lead do not overlap with each other, and the second lead has an electrically conducting hole, and a surface on which the first lead is arranged. The semiconductor device according to claim 1, wherein an electrode is provided in the semiconductor device. 3. The film carrier tape comprises a rod-shaped insulator at a tip portion of the finger formed integrally with the second lead.
The semiconductor device described. 4. The second lead formed on the film carrier tape and an insulating thin plate on which a metal film wiring is formed are joined together, and a semiconductor chip is mounted on the insulating thin plate. The semiconductor device described.