JP2808703B2 - Film carrier and semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a film carrier and a semiconductor device.

<Prior Art> Conventionally, a film carrier method has been adopted as one of the mounting methods of a semiconductor element.

Various methods have been proposed as a bonding method (inner lead bonding) between a finger-shaped lead and a semiconductor element in a film carrier method. A bump (protruding electrode) is formed on an electrode surface of the semiconductor element, and the bump is used. Then, a method of bonding to a lead on a film carrier has been proposed.

However, in the step of forming a bump on the electrode surface, an adhesion layer made of a metal such as titanium / chromium and a barrier layer made of a metal such as copper, platinum, and palladium for preventing diffusion of the bump-forming metal are formed on the electrode surface by sputter etching or vapor deposition. Not only is a complicated process of forming bumps such as gold by a plating method necessary, but also it is difficult to avoid contamination and damage of the semiconductor element, and it cannot be said that this is an excellent method. Things.

Contrary to the above-mentioned method, a method of forming a bump on a lead on the film carrier side and bonding the same has also been proposed. However, this method also requires a complicated bump forming step as in the above method. .

Further, a bumpless film carrier using an anisotropic conductive film has been proposed (JP-A-63-4633). The anisotropic conductive film used is a material in which conductive particles such as carbon black, graphite, nickel, copper, and silver are dispersed in an electrically insulating resin film and the particles are oriented in the thickness direction of the film. In order to obtain a film exhibiting electroconductivity, it becomes complicated on the manufacturing method, and when the orientation of the conductive particles is insufficient, the inner lead bonding between the electrode of the semiconductor element and the lead becomes uncertain, Connection reliability may be reduced.

On the other hand, as electronic devices have become thinner and smaller and lighter in recent years, such demands have also been made for the package form of semiconductor devices.In particular, IC cards and the like have been reduced in thickness to 0.8 mm or less. As a result, thin semiconductor devices such as TAB and COB tend to increase. Generally, such a semiconductor device is provided with a protective resin such as a polyimide-based resin or a silicone-based resin on the semiconductor device as a separate step for protecting the semiconductor device electrically and mechanically or chemically from the outside. Potting coating and heat drying are performed in the vicinity thereof to form a protective film.

However, in the resin coating by such a method, the connection portion (electrode portion) of the semiconductor element may not be sufficiently coated or a void may be present, so that the reliability is not necessarily sufficient. Things.

<Problems to be Solved by the Invention> The present invention is a film carrier that solves the drawbacks of the above-described conventional technology, and in particular, is very easy to position when bonding a semiconductor element and a lead, and it becomes extremely easy to manufacture a semiconductor device, and It is an object of the present invention to provide a film carrier that can be easily coated with a resin and a semiconductor device using the film carrier.

<Means for Solving the Problems> As a result of intensive studies, the present inventors have used an insulating film provided with a through hole conducting on the front and back surfaces, and provided a bump-shaped metal protrusion at the opening of the through hole. It has been found that the provision of a thermoadhesive resin layer on the surface of the connecting film on which the bump-shaped metal protrusions are formed further provides a film carrier that can achieve the above object, and the present invention has been completed.

That is, the present invention has a lead in an opening on one side of an insulating film having a plurality of fine through holes in the thickness direction, and a conductive path formed of a metal substance is formed only in the lead forming through hole,
A bump-shaped metal protrusion is formed in the opening on the other surface of the through hole, and a thermo-adhesive resin layer made of a thermoplastic resin is formed on the bump-shaped metal protrusion formed surface of the insulating film. An object of the present invention is to provide a film carrier, and a semiconductor device formed by connecting a semiconductor element having an external connection electrode to the film carrier.

<Example> Hereinafter, the present invention will be described based on an example shown in the drawings.

FIG. 1 is a cross-sectional view showing an example of a semiconductor device using the film carrier of the present invention. The film carrier has a plurality of fine through holes 4 in the thickness direction. In addition, only the lead forming through hole 4 is filled with the metal material 5 and the bump-shaped metal protrusion 6 is formed in the opening on the other surface. Further, a heat-adhesive resin layer 8 is provided on the surface on which the bump-shaped metal protrusion is formed, and covers and protects the bump-shaped metal protrusion 6. At this time, the resin layer 8
Is preferably 0.05 μm or more from the viewpoint of coating protection and improvement of reliability.

The semiconductor element 1 has an external connection electrode 7 such as an aluminum electrode on one side surface, and is electrically sealed by ordinary bonding between the electrode 7 and the bump-shaped metal protrusion 6 of the film carrier, thereby being sealed with a resin. Thus, the semiconductor device of the present invention is obtained.

In FIG. 1, there is no limitation on the material of the insulating film 2 as long as it is a film having an electric insulating property, and polyester resin, epoxy resin, urethane resin, polystyrene resin, polyethylene resin, polyamide resin, polyimide It can be used regardless of thermosetting resin such as base resin, ABS resin, polycarbonate resin and silicone resin or thermoplastic resin. Among these, it is preferable to use a polyimide resin from the viewpoint of heat resistance and mechanical strength.

The leads 3 on one side of the insulating film 2 are formed of a conductive material such as various metals such as gold, silver, copper, nickel, and cobalt, or various alloys containing these as a main component. It is electrically connected via the connection electrode 7, the bump-shaped metal protrusion 6, and the metal substance 5 so that the semiconductor element 1 can perform a predetermined function.
It is wired in a desired linear pattern.

In the present invention, the through-holes 4 provided in the insulating film 2 are important for achieving the connection between the leads 3 and the external connection electrodes 7 on the semiconductor element 1, and are formed in the lead contact area or in the area. At least one fine through-hole is provided in the thickness direction of the film 2 at a pitch between the holes smaller than the width of the lead 3 in a region adjacent to the lead 3. The through-holes 4 can be provided at an arbitrary hole diameter or a pitch between holes by using a method such as mechanical processing, laser processing, optical processing, or chemical etching. For example, it is preferable to perform perforation processing by excimer laser irradiation. Also, the diameter of the through hole 4 is increased to such an extent that adjacent through holes 4 are not connected to each other,
Further, it is preferable to increase the number of the through holes 4 in contact with the leads by reducing the pitch between the holes as much as possible in order to reduce the electric resistance of the metal material to be filled in a later step.

Of the through holes 4 provided as described above, the through holes in the contact areas of the leads 4 are filled with the metal substance 5 to form conductive paths. Further, a protrusion 6 is formed in a bump shape at a height of several μm to several tens μm in an opening of the through hole 4 on the surface opposite to the lead contact surface where the conduction path is formed.

The formation of the conductive path and the bump-shaped metal protrusion by the metal material can be selectively performed only in the through hole in the lead 3 contact area by, for example, electroplating using the lead 3 as an electrode.

Also, a metal substance 5 to be filled and projected into the through hole 4
Is not limited to a single metal substance, but may be a multilayer structure using a plurality of types of metals. For example, as shown in FIG. 2, an inexpensive metal material 5a such as copper is used for the first layer on the lead contact side of the through hole, and a metal such as gold having high connection reliability is used for the third layer in contact with the semiconductor element. The material 5c is used as a second layer located between the first layer and the third layer, as a barrier metal material 5b for preventing a mutual reaction between the metal materials forming the first layer and the third layer. Nickel or the like can also be used.

The heat-adhesive resin layer 8 used in the present invention is extremely important for improving the electrical, mechanical and chemical reliability of the semiconductor device. Specifically, a polyimide resin,
Silicone resin, fluorine resin and the like can be mentioned. The resin layer 8 may be formed on the entire surface of the insulating film on which bump-shaped metal protrusions are formed, or may be formed in a layered pattern.
It is formed by placing a film or ribbon on a film.

3 (a) to 3 (e) are manufacturing process diagrams for connecting a film carrier and a semiconductor element to obtain a semiconductor device.

FIG. 3 (a) is a cross-sectional view of the insulating film 2 provided with the through holes 4 as described above, and FIG. 3 (b) is filled with a metal material 5 to make the through holes conductive paths. FIG. 3 (c) is a perspective view of FIG. 3 (b), and FIG. 3 (d) is a bump-like metal protrusion 6;
FIG. 3 (e) is a cross-sectional view of the semiconductor device after the semiconductor element 1 is connected, when a thermo-adhesive resin layer 8 is provided on the surface so as to cover. In FIG. 3D, the heat-adhesive resin layer 8 covering the upper part of the bump-shaped metal protrusion 6 is
At the time of thermocompression connection in FIG. 5E, the connection is spread and removed, and the external connection electrode 7 on the semiconductor element 1 and the bump-shaped metal protrusion 6 are electrically connected. Note that the heat-adhesive resin layer 8 is
It is not always necessary to provide the bump-shaped metal protrusions 6 so as to cover the bump-shaped metal protrusions 6 as shown in FIG.

When the semiconductor element 1 is connected to the film carrier with the heat-adhesive resin layer 8 interposed therebetween, a layer of the heat-adhesive resin is formed between the carrier and the element, and the resin is filled into the through holes. Therefore, the adhesion is improved, and the electrical connection is strengthened. Furthermore, since the surface protection of the semiconductor device can be performed by the resin layer, the resin sealing can be performed simultaneously with the connection,
The manufacturing process can also be simplified. In addition, as shown in FIG. 3 (d), the excess resin flows into the through holes not filled with the metal substance and pushes out the internal air.
Even when heated at the time of connection, cracks do not occur and the reliability is high.

<Effects of the Invention> As described above, the film carrier of the present invention is provided with through holes in the insulating film in the lead contact area or in the area and in the vicinity of the area, and fills the inside with a metal substance, and further includes a bump. Since a metal-shaped metal protrusion is formed, it is only necessary to roughly align the lead formation part when forming a through hole, and the connection with the semiconductor element is positioned with high accuracy by a bump-shaped metal protrusion. And the reliability of the obtained semiconductor device is improved.

In addition, high-precision bumps can be formed at low cost, and fine wirings and through holes can be used to cope with fine pitches of semiconductor element wirings. Further, the external connection electrodes on the semiconductor element surface can be freely laid out in the element surface, and the degree of freedom in wiring design is increased.

In addition, since the film carrier of the present invention is provided with the heat-adhesive resin layer on the connection surface, resin sealing can be performed at the same time as connection with the semiconductor element, so that the manufacturing process can be simplified and strong connection can be achieved. And reliability is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a semiconductor device using the film carrier of the present invention, FIG. 2 is an enlarged cross-sectional view when a through-hole is filled with a multi-layered metal material, and FIG. ~
(E) is a manufacturing process diagram for obtaining the semiconductor device by connecting the semiconductor element 1 to a film carrier. DESCRIPTION OF SYMBOLS 1 ... Semiconductor element, 2 ... Insulating film, 3 ... Lead, 4 ... Through hole, 5 ... Metal substance, 6 ... Bump-shaped metal protrusion, 7 ... External connection electrode, 8 ... Thermal adhesive resin layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-48954 (JP, A) JP-A-63-92036 (JP, A) JP-A-56-167340 (JP, A) 110506 (JP, A) Jiko 57-27141 (JP, Y2) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 21/60 H01L 23/50

Claims (4)

(57) [Claims] An insulating film having a plurality of fine through holes in a thickness direction has a lead in an opening on one side, and a conductive path made of a metal material is formed only in the lead forming through hole, and the other surface of the through hole is provided. A film carrier in which a bump-shaped metal protrusion is formed in an opening, and a thermo-adhesive resin layer made of a thermoplastic resin is formed on a surface of the insulating film on which the bump-shaped metal protrusion is formed. 2. The film carrier according to claim 1, wherein the conductive path is formed by filling a metal substance. 3. The film carrier according to claim 1, wherein the conductive path is formed in a multilayer structure by a plurality of types of metal substances. 4. A semiconductor device comprising a semiconductor element having an external connection electrode connected to a bump-shaped metal protrusion on the film carrier according to claim 1.