JPS6132533A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent any defective connection due to expansion or warp from happening by a method wherein a photosetting or thermosetting resin is laid between an electrode of semiconductor element and a film lead provided with a bump on the opposing position to the electrode and formed of a hole or a recession in said bump region. CONSTITUTION:A bump 4 is formed on a position opposing to an electrode 2 of semiconductor element 1 of a film lead 3 coming into contact with said electrode 2. The plane of bump 4 coming into contact with the electrode 2 is irregularly formed while a hole is formed in an arbitrary position of the bump 4. Besides, the hole 5 and the gaps between irregular recessions are filled with photosetting or thermosetting resin 6 however, a conductive adhesive or alloy material with low melting point mixed with conductive material such as Ag, Au or C may be laid between the hole 5 only and the electrode 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for easily connecting electrode pads of a semiconductor element and an external circuit.

2. Description of the Related Art Conventional configurations and their problems In recent years, the development of devices and equipment that use a large number of semiconductor elements has been accelerated. For example, there are memory cards, liquid crystal and EL display panels, etc., which all have a large number of ICs and LSIs mounted on a substrate with a certain area.
It must be mounted in a high-density yet thin design. The film carrier method and the flip chip method are well known as mounting means for these ICs and LSIs, but they have the following problems: Both the film carrier method and the flip chip method have metal protrusions on the electrode pads of the semiconductor element. However, in the flip-chip method, the wiring pattern on the wiring board and the metal protrusion of the semiconductor element are aligned, heated, and fixed by soldering. Therefore, in the case of the flip-chip method, the electrical connection and the fixing of the semiconductor element on the wiring board are performed at the soldered and fixed position, and the wiring board is not subject to expansion due to external heat or mechanical strain. In the case of warping, since the soldering position is firmly fixed, the soldering position cannot be sufficiently accommodated to the change, leading to damage to the connecting portion or the semiconductor element itself.

In addition, in the film carrier method, metal protrusions on the semiconductor element and film leads are connected, and the film leads are connected to the wiring pattern of the wiring board. Although this can be fully coped with, metal protrusions must be formed on the electrodes of the semiconductor element.

For this reason, the yield of semiconductor devices has been reduced and manufacturing costs have been increased. Forming the metal protrusion is the same in the case of the flip chip method,
Had the same problem.

By the way, the inventor of the present invention has discovered that in connection between the electrodes of a semiconductor element and the wiring pattern of a circuit board, a film lead having a protrusion with a hole or a recess is connected to the electrode without performing any processing on the electrode of the semiconductor element. It has been found that by focusing on pressure-welding and fixing this with a resin material, expansion and distortion of the connection part can be absorbed, thereby eliminating connection failures and high costs.

OBJECTS OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to provide an inexpensive connection method that can cope with expansion and distortion of one circuit board and prevents connection failures.

Structure of the Invention The present invention provides pressure bonding between a film lead having a protrusion at a position corresponding to the electrode of a semiconductor element and a hole or a recess formed in the protrusion area, with a photocurable or thermosetting resin interposed.・It has a structure that allows multiple connections when fixed.

Description of examples A first embodiment will be explained with reference to FIG.

A protrusion 4 is formed on the film lead 3 at a position corresponding to the electrode 2 of the semiconductor element 1, and is in contact with the electrode 2 of the semiconductor element 1. The protrusion 4 of the film lead 3 has an uneven surface formed in contact with the electrode of the semiconductor element, and furthermore, a hole 6 is formed at an arbitrary position of the protrusion 4. Furthermore, although the holes 6 and the gaps between the unevenness of the protruding surface are filled with a photocuring resin or thermosetting resin 6, a conductive material such as Ag, Au, and C is mixed only in the holes 6. A conductive adhesive or a low melting point alloy material may also be used.

Such a configuration can be realized by the method shown in FIG. A photocurable resin or thermosetting resin 6 is applied on the electrode 2 of the semiconductor element 1, and a protrusion 4 is formed on the tip thereof.
Then, the holes 6 and the film lead 4 having at least an uneven surface are aligned (FIG. 2a), and pressure is applied with a tool 7, and light or heat 8 is applied. As a result, the photocurable resin or thermosetting resin 6 is cured, and the protrusion of the film lead and the electrode of the semiconductor element are fixed in pressure contact, thereby obtaining electrical continuity (FIG. 2b).

With such a configuration, the hole is filled with a thick resin, so that the protrusion and the electrode of the semiconductor element are firmly fixed, and the numerous unevenness on the surface of the protrusion makes contact with the electrode of the semiconductor element.
The contact resistance at this interface can be significantly reduced. Furthermore, the resin interposed in the numerous uneven gaps also serves to fix the film lead and the electrode.

Furthermore, since the resin covers the surface of the electrode 2, it also has the effect of preventing corrosive solution from entering from the outside.

Furthermore, if the holes 6 are filled with a conductive substance, not only can the connection resistance be significantly reduced, but also the connection can be made at the boundary between the protrusion of the film lead 3 and the electrode 2 of the semiconductor element due to thermal expansion, etc. Even if the electrodes separate, the conductive material filled in the hole 6 expands to the extent that it is bonded to the electrode surface, so the bond will not be broken.

FIG. 3 is an embodiment of FIG. 2.

A recess 6' is formed in the protrusion 4 of the film lead a,
This has a structure in which a photocurable resin, a thermosetting resin, or a conductive substance 6 is filled. The effect is the same as the first embodiment.

Further, the shape of the protrusion of the film lead is as shown in FIG.
Although only the tip of the protrusion 4 is etched and left to form the protrusion 4, the hole 6 can also be formed at the etching step. Furthermore, in the figure (b), a protrusion 4' having a recess 6' different from the material of the film lead 3 is joined to the tip of the film lead 3. With such a structure, (
-) Unlike the embodiment shown in the figure, there is no need to perform etching on the film lead 3 itself, so there is no waste of material and manufacturing costs are reduced.

Still another embodiment will be explained with reference to FIG. A flexible film 10' is placed on the opposite side of the film lead 3 on which the protrusion 4 is formed.
In this structure, a flexible film 10' is formed to cover at least the semiconductor element 1. With such a configuration, not only is it not necessary to form an opening in the flexible film 10' for protruding the film lead 3, but also the upper surface of the semiconductor element 1 is not connected to the flexible film 10'.
', therefore, by filling the space between the semiconductor element and the flexible film with the protective resin 12, it is possible to obtain a semiconductor device with significantly high reliability.

Advantageous Effects of the Invention 1 Due to the structure in which a protrusion is provided at the tip of the filler lead in contact with the electrode of the semiconductor element, and a recess or hole is provided in the protrusion,
Since the recess or hole of the protrusion can be filled with a thick resin,
The lunar strength of the filled resin can be significantly increased. For this reason, the electrode of the semiconductor element and the film lead are connected, and the film lead does not come into contact with the end of the semiconductor element, thereby preventing an electrical connection failure from occurring.

Furthermore, in the configuration of the present invention, the recess or hole formed in the protrusion of the film lead is provided in the central region of the protrusion, so that it is firmly pressed against the central region of the protrusion that contacts the electrode. Therefore, a uniform weight is obtained over almost the entire contact interface with the electrode.

Therefore, even if the circuit board warps or distorts, the mechanical expansion and contraction of the film lead is taken into consideration, and a stable and highly reliable connection can be obtained.

Furthermore, since the unevenness of the protruding surface significantly increases the number of contact points with the electrode, it has the effect of reducing contact resistance.

2 Furthermore, if the holes or recesses of the protrusions are filled with a conductive substance, the contact resistance can be significantly reduced and a highly reliable connection can be obtained. If the contact interface between the protrusion and the electrode is separated due to warping or distortion of the circuit board, the low melting point alloy material will be able to respond flexibly and constantly maintain a stable state. The connection can be continued.

[Brief explanation of drawings]

FIG. 1 shows a first embodiment of the present invention, which is a cross-sectional view of a structure in which holes are provided in the protrusions of the film lead, and FIG. 2(a). (b) is a process cross-sectional view showing the manufacturing method of the first embodiment, FIG. 3 is a cross-sectional view of a structure in which a concave portion is provided for the protrusion of the film lead in the second embodiment of the present invention, and FIG. ). -) is a cross-sectional view showing the cross-sectional shape of the film lead of the present invention, and Fig. 6 is a cross-sectional view of a third embodiment of the present invention, in which a flexible film is formed on the opposite side of the film lead. 1... Semiconductor element, 2... Electrode, 3...
...Film lead, 4...Protrusion, 6.
Old: hole or recess. Name of agent: Patent attorney Toshi Nakao (3rd person)
Figure 5

Claims (3)

[Claims] (1) Having a protrusion at a position corresponding to the electrode of the semiconductor element,
A semiconductor device, characterized in that a photocurable or thermosetting resin is interposed between the protrusion of the film lead in which a hole or a recess is formed in the protrusion region and the electrode of the semiconductor element, and the protrusion is bonded to the protrusion. (2) The semiconductor device according to claim 1, wherein the hole or recess in the protrusion region is filled with a conductive material. (3) The semiconductor device according to claim 1, wherein a flexible film is formed on the opposite side of the protrusion of the film lead having a protrusion.