JPH02229442A - Mounting structure of semiconductor device - Google Patents

Abstract

PURPOSE:To easily bond a connection lead to an outer substrate without executing a high-accuracy positioning operation by a method wherein through holes are formed in an insulating film inside a bonding region or inside said region and its neighboring region, their inside is filled with a metal substance and a bump-shaped protrusion is formed. CONSTITUTION:A semiconductor element 1 is mounted on a film carrier 3, composed of an insulating film, on which a connection lead 4 has been formed on one side; a metal substance 2' is filled into through holes; the insulating film 3 on which a bump-shaped protrusion has been formed (this bump-shaped protrusion is situated on the rear surface of the insulating film 3) is connected via a metal wiring part (a land part) 6 on an outer electrode 5 and the bump- shaped protrusion. The insulating film 3 may be a film provided with an electrically insulating property; a polyimide-based resin is preferable from a viewpoint of a heat-resisting property and a mechanical strength. The connection lead 4 formed on one side of the film 3 is formed of various metals such as gold, silver, copper, nickel, cobalt and the like or of conductive materials such as various alloys composed mainly of these metals; it is connected electrically to a metal wiring part on the outer substrate.

Description

[Detailed description of the invention] Industrial application field> The present invention relates to a mounting structure for a semiconductor device, and more particularly to a structure for mounting a film carrier and an external board easily and reliably in a minimum area. It is something. Conventional technology> Conventionally, in order to connect a semiconductor device using a film carrier to an external substrate such as a package board or case (outer lead bonding), a conductive metal such as copper is wired onto the film carrier of the semiconductor device. A connection lead formed into a shape is used. For example, as shown in Figure 5,
The semiconductor device, in which the connection leads 4 formed on the film carrier 3 and the semiconductor element 1 are connected via the bumps 2, is mounted on the external substrate 5 by connecting the metal wiring (land portion) 6 formed on the surface of the external substrate 5. The connection lead 4 on the film carrier 3 is used. However, such a mounting method requires cutting and bending the connection leads 4, resulting in poor workability and difficulty in connection. Furthermore, connection lead 4
Since it has a structure that protrudes from the film carrier, it has poor mechanical strength and is difficult to work with. Further, a thermal bonding method such as a solder reflow method is usually used to connect the connection lead 4 and the land portion 6. For example, when mounting on a metal oxide transparent electrode such as a liquid crystal panel, It is necessary to metalize the transparent electrode in advance so that it can be soldered.

In recent years, methods have been proposed for bonding the film carrier and external substrate using anisotropically conductive films or paints, but both methods require highly accurate positioning of the connection parts and are not economical. This also results in high costs. Problems to be Solved by the Invention The present invention has been made in order to solve the drawbacks of the above-mentioned conventional techniques.
The purpose of this invention is to provide a mounting structure in which the connection lead and the external board can be easily bonded with high precision positioning when performing outer lead bonding (outer lead bonding), and which improves electrical connection reliability. ．． Means for Solving the Problem> As a result of extensive studies, the present inventors used an insulating film with conductive through holes on the front and back sides as a film carrier, and filled the through holes with a metal substance. Furthermore, they discovered that by forming a bump-like protrusion, the connection lead in contact with the through-hole and the land portion on the external board could be easily connected with good reliability just by rough positioning, and the present invention was completed. I ended up doing it. That is, in the mounting structure of a semiconductor device of the present invention, in a mounting structure of an external substrate and a semiconductor device in which a semiconductor element is bonded to a film carrier made of an insulating film with connection leads formed on one side, the land portion on the external substrate and At least one fine through hole is provided in the thickness direction in the bonding region of the contacting insulating film or in the region and its vicinity, and the through hole provided in the bonding region is filled with a metal substance. In addition, a bump-like protrusion is formed, and the connection lead is connected to a land portion on the external substrate via the bump-like protrusion. <Examples> Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the mounting structure of a semiconductor device according to the present invention. A semiconductor element l is mounted on a film carrier 3 made of an insulating film with connection leads 4 formed on one side, and a metal A material is filled into the through hole to form a bump-like protrusion (not shown; the bump-like protrusion is formed by filling the insulating film 3
An insulating film 3 provided with a metal wiring (located on the lower surface of the substrate) is connected to a metal wiring (land portion) 6 on an external substrate 5 via a bump-shaped protrusion.

FIGS. 2(a) and 2(b) show an insulating film 3 in which the through hole 7 is filled with a metal substance 2° to form a bump-like protrusion.
FIG. 2(a) shows a state in which a bump-like protrusion is provided in each through-hole 7 filled with a metal substance 2, and FIG. This shows the state in which a common bump-like protrusion is provided. FIG. 3 is a cross-sectional view showing a structure in which a semiconductor device is mounted on the metal wiring (land portion) 6 on the external substrate 5 via a bump-like protrusion in the state shown in FIG. 2(a).

Figure 4 shows the insulating film 3 constituting the film carrier.
FIG. 3 is a cross-sectional view showing a state in which a heat-adhesive resin layer 8 is provided on the surface on which bump-like protrusions are formed.

Starting from zero. In this specification, the material of the insulating film 3 is not limited as long as it has electrical insulation properties, and examples include polyester resin, epoxy resin, urethane resin, polystyrene resin, polyethylene resin, polyamide resin, and polyimide. Any thermosetting resin or thermoplastic resin can be used, such as ABS resin, polycarbonate resin, or silicone resin. Among these, polyimide resins are preferably used in terms of heat resistance and mechanical strength. Connection lead 4 formed on one side of the insulating film 3
is formed of conductive materials such as various metals such as gold, silver, copper, nickel, and cobalt, or various alloys containing these as main components, and is electrically connected to metal wiring on an external substrate, and is used to connect semiconductor devices. The wires are wired in a desired linear pattern so that the semiconductor elements mounted on the board can perform their predetermined functions.

The through hole 7 provided in the insulating film 3 of the film carrier is important for connecting the connection lead 4 with the metal wiring (land part) 6 on the external board 5, and is important for achieving the connection between the connection lead 4 and the metal wiring (land part) 6 on the external board 5. At least one fine through-hole 7 is provided in the thickness direction in the bonding region of the flexible film 3 or in the bonding region and in the vicinity thereof, with a pitch between the holes smaller than the width of the connection lead. The through holes 7 can be formed with any hole diameter and hole pitch using methods such as machining, laser processing, optical processing, and chemical etching. For example, it is preferable to perform the drilling process by irradiating an excimer laser. . In addition, it is recommended that the diameter of the through-holes 7 be made large enough that adjacent through-holes do not connect with each other, and the pitch between the holes be made as small as possible to increase the number of through-holes in contact with the leads in the subsequent filling process. This is preferable in order to reduce the electrical resistance of the metallic substance.

Among the through-holes 7 provided as described above, the through-holes provided in the bonding area are filled with a metal substance 2'' such as solder, making the front and back surfaces of the insulating film 3 electrically conductive. .Furthermore, on the surface of the through hole opposite to the contact surface of the connection lead 4 filled with the metal substance 2°, a bump-like protrusion shown in FIGS. 2 to 4 is formed at a height of several μm to more than ten μm. Filling the through hole 7 with the metal substance 2° and forming the bump-like metal protrusion can be selectively performed only in the through hole in the bonding region, for example, by electroplating using the connection lead 4 as an electrode. In the present invention, the connection leads 4 on the film carrier are connected to the land portions 6 on the external substrate 5 through the bump-like protrusions by ordinary electrical connection means such as thermal bonding, thereby forming a semiconductor. A device can be mounted and electrical continuity can be obtained.

In addition, as shown in FIG. 4, when the heat-adhesive resin layer 8 is provided on the bump-like protrusion formation surface, it is usually provided with a thickness of 5 to 50 μm, preferably 10 to 30 μm, and the resin is made of epoxy resin or the like. Any thermoplastic resin such as a thermosetting resin or a fluororesin can be used. Further, the resin layer may be provided by coating on the surface on which the bump-like protrusions are formed, or a film or ribbon may be sandwiched and thermocompressed during bonding.

When a semiconductor device is mounted on the external substrate 5 with the thermal adhesive resin layer 8 interposed in this way, the resin flows into the through-holes that are not filled with metal material, which improves the adhesion between the semiconductor device and the external substrate. This improves the electrical connection and makes the electrical connection stronger. Furthermore, since the resin layer can also protect the surface, the manufacturing process can also be simplified. Furthermore, after connection, excess resin flows into the through-hole that is not filled with metal material and pushes out the air inside, which may cause voids or cracks when sealing with resin in the later process. This makes it highly reliable.

In addition, in the mounting structure of the present invention, an insulating film with specific through holes is used in the outer lead bonding part between the external board and the semiconductor, but the above-mentioned connection is also used in the inner lead bonding part between the semiconductor element and the film carrier part. It goes without saying that the methods may be used in combination (see Figure 1).

Effects of the Invention> As described above, in the semiconductor device mounting structure of the present invention, a through hole is provided in the insulating film in the bonding region or in the bonding region and in the vicinity thereof for connection between the film carrier and the external substrate. , since the inside is filled with a metal substance and a bump-like protrusion is formed, when forming the through-hole, it is only necessary to roughly align it with the connection lead forming part, and it is also possible to connect it to an external board. The bump-shaped protrusion allows highly accurate positioning and provides highly reliable electrical connection.

Additionally, there is no need to cut or bend the connection leads as in the past, making connection and mounting easier. Furthermore, since relatively expensive anisotropically conductive films and paints are not used, costs can be reduced, and the connection area can be freely designed by selecting the through-hole size and hole pitch, reducing the connection area. It is also possible to

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the mounting structure of the semiconductor device of the present invention;
FIGS. 2(a) and 2(b) are partial cross-sectional views of an insulating film in which through-holes are filled with a metal substance to form bump-like protrusions, and FIG. 3 is a partial cross-sectional view of an insulating film in which through-holes are filled with a metal substance to form bump-like protrusions. A cross-sectional view showing a structure in which a semiconductor device is mounted on a land portion through a bump-shaped protrusion shown in FIG. 2(a), and FIG. FIG. 3 is a cross-sectional view showing a state in which a thermally adhesive resin layer is provided on a forming surface. DESCRIPTION OF SYMBOLS 1...Semiconductor element, 2''...Metallic substance, 3...Insulating film, 4...Connection lead, 5...External board, 6...Land part, 7...Minute penetration Hole, 8...Thermoadhesive resin layer Fig.

Claims (2)

[Claims] (1) In a mounting structure of an external board and a semiconductor device in which a semiconductor element is bonded to a film carrier made of an insulating film with connection leads formed on one side, the bonding area of the insulating film that contacts the land portion on the external board Or, at least one fine through hole is provided in the thickness direction in the region and in the vicinity thereof, and the through hole provided in the bonding region is filled with a metal substance and a bump-like protrusion is provided. A mounting structure for a semiconductor device, in which the connection lead is connected to a land portion on an external substrate via the bump-like protrusion. (2) The mounting structure for a semiconductor device according to claim (1), wherein the metal substance is solder.