JP2976060B2 - Film carrier for mounting electronic components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film carrier for mounting an electronic component, and more particularly to a film carrier for mounting an electronic component having inner leads protruding from a device hole formed in an insulating base material.

[0002]

2. Description of the Related Art A film carrier for mounting electronic components (hereinafter sometimes simply referred to as a film carrier) is formed mainly of a flexible and long film-like material as an insulating base material. In recent years, since plating and other processing can be performed continuously, many of them have been adopted and the amount of production has been increasing. Then, the film-shaped insulating base material is finally cut into individual film carriers on which one or more electronic components are mounted. Various types of film carriers are available. There are things.

[0003] Among them, a film carrier having a device hole for an electronic component can accommodate an electronic component in the device hole, so that a so-called semiconductor device can be formed in a book form when the whole is sealed with resin. And are very often adopted.

In this type of film carrier, one end of each lead is connected to the device hole in order to electrically connect each lead formed on the insulating base material to an electronic component in the device hole. Must be protruding. The portion protruding toward the device hole is generally called an inner lead, but since this inner lead has no other support, it is in a very unstable state, and is easily bent at all times.

A lead including the inner lead is generally formed by etching a metal foil provided on a film-like insulating base material, and the etching is performed from one side of the metal foil. Often. For this reason, when observing the cross section of each lead, as shown in FIG. 7, as shown in FIG. 7, the etching resist side (hereinafter referred to as the front side according to the illustrated state) is narrow and the insulating base side (hereinafter referred to as the rear side according to the illustrated state) is wide. The shape must be trapezoidal. Therefore, in order to increase the density of each lead in order to cope with the increase in the density of electronic components, it is natural that the interval of each pitch must be reduced, and it is anticipated that the cross section of each lead will be as shown in FIG. In other words, since the bottom part of each lead is in a spread state, it is anticipated that it can be etched so as not to short-circuit
The width of the etching resist must be reduced.

From the above situation, the higher the density of the leads on this type of film carrier, the more the surface side of the inner leads connected to each lead becomes narrower. It is becoming more difficult to mount electronic components on a computer. In particular, if there is a bend in each of the inner leads that is easily bendable, it is almost impossible to mount electronic components on the inner leads.

Therefore, the present inventors have found that even if the leads have been densified, the inner leads integral with the leads are surely protected against bending or the like, and the mounting of electronic components on them is always sufficient. The present invention was completed as a result of various studies on how to make it possible.

[0008]

SUMMARY OF THE INVENTION The present invention has been made on the basis of the above circumstances, and the problem to be solved is to reliably protect the inner leads in the film carrier and to prevent the electronic components from being protected. This is to improve the reliability of the mounting.

An object of the present invention is to provide an electronic device which can sufficiently protect leads including inner leads, and can always surely make an electrical connection of electronic components to the inner leads. An object of the present invention is to provide a component mounting film carrier with a simple configuration.

[0010]

In order to solve the above problems, the means adopted by the present invention will be described with reference to the reference numerals used in the embodiments.
A device hole 12 for an electronic component 20 is formed on the insulating substrate 11, a number of leads 13 having one end protruding toward the device hole 12 are formed, and one end of each of the leads 13 is connected to the electronic component 20. In the electronic component mounting film carrier 10 serving as the inner leads 14 for making electrical connection, the insulating coating 15 is formed mainly between the inner leads 14 of the respective leads 13 and on the surface thereof.
Plating layer 16 on the back surface of the inner lead 14
And a film carrier 10 for mounting an electronic component.

[0011]

The operation of the electronic component mounting film carrier 10 (hereinafter simply referred to as the film carrier 10) constructed as described above will be described as follows.

First, each lead 1 formed on a film-shaped insulating base material 11 constituting the film carrier 10 is formed.
As shown in FIG. 1 and FIG. 2, reference numeral 3 denotes an inner lead 14 having one end protruding toward a device hole 12 of an insulating base material 11 and serving as an inner lead 14. Part of the lead 13 is protected by an insulating film 15 formed on the surface side. That is, even if the insulating film 15 is continuous at the portion where the inner leads 14 face each other as shown in FIG. 1 and FIG. 6 (g), it is also divided as shown in FIG. 5 (h). In any case, the insulating coating 15
In FIG. 3, the inner leads 14 and the leads 13 connected to the inner leads 14 are wrapped as shown in FIGS.

Therefore, in particular, as shown in FIG. 4, each inner lead 14 is prevented from being bent by the presence of the insulating coating 15 between and on the surface side, so that the outer air and the inner air can be prevented from being bent. It is isolated from the moisture and the like contained in. Further, as shown in FIG. 3, the entire surface of each lead 13 is surrounded by the insulating coating 15 and the insulating base material 11, so that not only is it sufficiently isolated from the outside air and the like, Even if solder for electrical connection adheres to the coating 15, each lead 13 does not short-circuit.

In each inner lead 14,
As shown in FIG. 4, the plating layer 16 for connecting the electronic component 20 to the connection terminal 21 is formed on the back surface side. Therefore, even if the interval between the inner leads 14 becomes small, Even if the density of the leads 13 is increased, the mounting of the electronic component 20 on each of the inner leads 14 can be surely performed. In other words, in the film carrier 10 according to the present invention,
Since the back surface wider than the front surface of each inner lead 14 is used as the connection surface for the electronic component 20, the electrical connection of each inner lead 14 to the electronic component 20 can be performed more reliably.

[0015]

Next, a film carrier 10 according to the present invention will be described.
Will be described in accordance with each embodiment shown in the drawings while also taking into account its manufacturing method.

First, the film carrier 10 shown in FIG.
As shown in FIG. 4 to FIG. 4, based on the film-shaped insulating base material 11, the insulating base material 11 is cut along a cutting line 19 in FIG. A device hole 12 which becomes a substantially central portion when cut is formed in the insulating base material 11. A large number of leads 13 having inner leads 14 projecting toward the device hole 12 at one end are formed on the surface side of the insulating base material 11, and at least the space between the inner leads 14 and the surface side are formed. The insulating film 15 to be coated is formed. Incidentally, the outer end side of each lead 13 is in the case of the embodiment shown in FIG.
The electronic component 20 is bridged on an opening 18 formed in an outer peripheral portion surrounding the device hole 12 of the insulating base material 11 and cut along a cutting line 19 in FIG. After mounting and resin sealing, the outer leads 17 project outward from the sealing resin.

The cutting line 19 may be located near the outside of the opening 18, that is, the individualized film carrier 10
The insulating base material 11 may be left on the outer periphery of.

(Embodiment 1) FIGS. 5A and 5B sequentially show a manufacturing process of a film carrier 10 in which opposing portions of each inner lead 14 are not connected by an insulating base material 11 as shown in FIG. Yes, a method for manufacturing such a film carrier 10 will be described in order.

First, as shown in FIG. 5A, a device hole large enough to accommodate the electronic component 20 at a predetermined position of the film-like insulating base material 11 coated with an adhesive on the surface side. The metal foil 13a to be the lead 13 is integrated by forming the openings 12, the openings 18 and the like by means such as punching. Note that this step and the following steps are performed continuously while winding or unwinding the film-shaped insulating base material 11 on a reel.

Next, as shown in FIG. 5B, a solder resist 31 is formed only on the surface of the metal foil 13a, and then exposed in the device hole 12 as shown in FIG. A solder plating 30 is formed on the back surface of the metal foil 13a. Thereafter, the solder resist 31 is removed, and an etching resist 13b having a predetermined pattern is formed on the surface of the metal foil 13a as shown in FIG. By etching the metal foil 13a using the etching resist 13b, the leads 13 are formed with the inner leads 14 protruding toward the device holes 12, as shown in FIG. . In this case, the metal foil 1
3a is solder plated 3
0 is covered with the metal foil 13
The etching is not performed by the etching solution a, and the solder plating 30 is provided for this purpose.

Then, as shown in FIG. 5F, the insulating film 15 is formed so as to cover at least the space between the inner leads 14 and the upper surface thereof. At this time,
The formation of the insulating film 15 is performed by (i) or (i) in FIG.
Although any of the methods i) may be adopted, in the present embodiment, the method shown in the method (i), that is, the insulating coating 15 is formed on the end faces of the inner leads 14 facing each other. In the case of (ii), the end faces of the inner leads 14 facing each other are made continuous with the insulating coating 15. For example, as shown in FIG. 1, when it is desired to completely cover the device hole 12 with the insulating coating 15. This is the method that is adopted. The specific material of the insulating coating 15 in this embodiment is a polyimide resin.

Thereafter, as shown in FIG. 5G, the solder plating 30 is peeled off, and as shown in FIG. 5H, each of the insulating coating 15 and the insulating base material 11 is formed as a plating resist. The plating layer 16 made of tin or the like is formed on the back surface of the inner lead 14.

After the formation of the plating layer 16 as described above, the individual film carrier 10 is taken out by cutting along the cutting line 19 in FIG. 1 as described above.

(Embodiment 2) FIG. 6 shows a second embodiment of the method of manufacturing the film carrier 10 according to the present invention. In this method, the device hole 12 for the electronic component 20 is finally formed. It is formed in stages.

That is, in this manufacturing method, the film is formed on the surface of the insulating substrate 11 in the form of a film (FIG. 6A).
The metal lead 13a is etched by an ordinary method using an etching resist to obtain desired leads 13a.
Is formed ((b) in FIG. 6). Thereafter, as shown in FIG. 4C, an insulating film 15 made of polyimide is formed, and as shown in FIG. 4D, a resist 13b for protecting the insulating film 15 and the insulating base material 11 is coated on both sides. Formed all over. Then, the resist 13b located on the lower side in the figure
An opening is formed in a portion where the device hole 12 is to be formed (FIG. 5E), and the insulating substrate 11 is etched through the opening, so that the device hole 1 is
2 is formed (FIG. 6F).

Finally, a plating layer 16 made of tin or the like is formed on the back surface of each inner lead 14 exposed from the device hole 12, as shown in FIG.

[0027]

As described in detail above, in the present invention,
As exemplified in each of the above-described embodiments, “a large number of leads each having a device hole 12 for an electronic component 20 formed in a film-shaped insulating base 11 and one end protruding toward the device hole 12 on the insulating base 11. In the electronic component mounting film carrier 10 in which one end of each of the leads 13 is formed as an inner lead 14 for making an electrical connection with the electronic component 20, the lead 13 is mainly provided between the inner leads 14 and on the surface thereof. In addition to the formation of the insulating film 15, the plating layer 16 is formed on the back surface of the inner lead 14 protruding toward the device hole 12 ", whereby the lead including the inner lead is protected from bending. That can sufficiently achieve the electrical connection of the electronic component to the inner lead at all times. It is possible to provide a goods mounting the film carrier with a simple configuration.

That is, according to the film carrier 10 of the present invention, since the wide surface of each inner lead 14 is effectively used, the connection terminals 21 of the electronic component 20 are particularly effective.
Electrical connection to the device can be reliably performed, and positioning for the connection can be easily performed. Of course, the respective inner leads 14 are held so as not to be displaced from each other by the insulating coating 15 formed therebetween and on the surface side, and are sufficiently protected from the outside air or the like. Thus, the inner leads 14 and the leads 13 can be sufficiently protected from external stress and the like until the entire structure is sealed with resin.

[Brief description of the drawings]

FIG. 1 is an enlarged plan view of a film-shaped insulating substrate according to the present invention.

FIG. 2 is a partially enlarged cross-sectional view taken along line 1 of FIG.

FIG. 3 is a partially enlarged cross-sectional view of the film carrier, taken along line 2-2 of FIG. 2;

FIG. 4 is a partially enlarged cross-sectional view of the film carrier taken along line 3-3 in FIG.

FIG. 5 is a partially enlarged cross-sectional view showing a first method of manufacturing a film carrier according to the present invention.

FIG. 6 is a partially enlarged cross-sectional view showing a second method of manufacturing a film carrier according to the present invention.

FIG. 7 is a partially enlarged sectional view showing a state in which leads are formed by etching a metal foil.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Film carrier for electronic component mounting 11 Film-shaped insulating base material 12 Device hole 13 Lead 14 Inner lead 15 Insulating coating 16 Plating layer 20 Electronic component

Claims (1)

(57) [Claims] 1. A device hole for an electronic component is formed in a film-like insulating base material, and a large number of leads having one end protruding toward the device hole side are formed on the insulating base material. In the electronic component mounting film carrier, one end of which is an inner lead for making an electrical connection with the electronic component, an insulating film is formed mainly between the inner leads and on the surface of each of the leads, and the lead protrudes toward the device hole. A film carrier for mounting electronic components, wherein a plating layer is formed on the back surface of the inner lead.