JP2000243147A - Anisotropic conductive film, semiconductor device using it, and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To connect together a semiconductor element and a wiring board in a short time by the conductive filament bodies to improve connecting reliability by providing adhesive layers fusing by heat on both faces of an insulating core layer filled with the conductive filament bodies, and revealing electric conductivity by thermocompression bonding only in the thickness direction. SOLUTION: On both faces of a core material 12 having an insulation property and filled with conductive filament bodies 11 having smooth surfaces in the thickness direction of an insulating film 12a, adhesive layers 13 which fuses by heat are provided. The adhesive layer 13 consists of deformable electrical conductive particles uniformly dispersed therein, the conductive filament bodies 11 penetrate the core material 12 in the thickness direction, and project from the surface of the core material 12. The conductive filament body 11 is buried in the adhesive layers 13 provided on both sides of the core material 12, and reveals conductivity only in the thickness direction by thermocompression bonding. Hereby, the metallic projections 18 of the semiconductor connecting terminals 17 of a semiconductor element 15 can be surely and quickly connected to the wiring board connecting terminals 19 of a wiring board 16 through the conductive filament bodies 11 to improve reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an anisotropic conductive film, a semiconductor device using the same, and a method for manufacturing the same.
In particular, the present invention relates to an anisotropic conductive film having improved reliability by ensuring electrical connection and mechanical bonding between a semiconductor element or a package and a substrate, a semiconductor device using the same, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become smaller and thinner,
The necessity of connecting a micro component such as a semiconductor chip to a micro circuit such as a substrate is increasing, and the wiring pitch is becoming smaller. Conventionally, for these connections, the method of wire-bonding the component connection terminals to each other has been the mainstream. However, it is advantageous to directly connect the connection terminals to each other so as to be faster, lighter and shorter, and so on. Chip connections are being made actively. The connection between these terminals is mainly sealed with an inexpensive resin for the purpose of protection from the external environment and improvement of the connection reliability. A method of flowing resin has been adopted. The connection between the connection terminals is performed by, for example, solder connection, gold-gold compression bonding, conductive paste connection, or the like.

However, as miniaturization and thinning progress, the gap between the opposing component and the circuit and the gap between adjacent terminals become smaller, and the inflow of liquid resin (so-called underfill) occurs.
Is getting harder. Generally, a thermosetting resin such as a low-viscosity epoxy resin is used. On the other hand, when connecting the semiconductor chip and the substrate, a liquid resin or a film-like resin was previously applied to the substrate region on which the chip was mounted, and the mutual connection terminals were aligned. Thereafter, a method has been proposed in which electrical connection is performed by thermocompression bonding and mechanical connection is performed (underfill is not required). One of the methods is connection using an anisotropic conductive resin.

[0004] There are roughly two types of anisotropic conductive resins. One is a type in which conductive particles 81 as shown in FIG. 8 are dispersed in a binder resin 82. The anisotropic conductive resin has insulating properties as it is because the number of conductive particles dispersed in the resin is smaller than that of the conductive paste or the like. An anisotropic conductive resin 80 is interposed between two electronic components 85 and 86 each having a metal protrusion (bump) formed on at least one of the electrodes, and is thermally pressed to form conductive particles 81 between the two electrodes 88 and 89. Are sandwiched, and an electrical connection is obtained via the conductive particles 81. At the same time, the electronic components are mechanically joined to each other by the binder resin 82. At this time, no pressure is applied between the adjacent electrodes and the number of conductive particles is small, so that the insulation between the adjacent electrodes is maintained. As the resin form, there are a liquid (paste) form and a film form. For example, JP-A-5-32799, JP-A-5-32799
223633, JP-A-7-197001, and the like.

Another method uses a type in which a conductive linear body 91 is oriented in one direction in a binder resin 92 as shown in FIG. Anisotropic conductive resin is interposed between the two electronic components and pressed, whereby the conductive filaments 91 are sandwiched between the two electrodes, so that the electrodes of the electronic components directly contact the conductive filaments, Connection is obtained. In order not to disturb the orientation of the conductive filament,
This type of anisotropic conductive resin is a solid such as a film or a block.
No. 25669, JP-A-8-124435, and the like.

[0006] As described above, when conductive particles are uniformly dispersed in a binder resin as a flip-chip connecting resin, it is necessary to increase the density of the conductive particles in order to accurately perform fine connection. In this case, there is a disadvantage that the conductive particles that are not sandwiched between the opposing electrodes flow between the adjacent terminals, making it difficult to ensure insulation. Further, since only the conductive particles are usually blended in the binder resin, the coefficient of thermal expansion is large, and the connection reliability is low. To improve this, it is conceivable to lower the coefficient of thermal expansion by blending silica particles etc. like the underfill material,
In this case, since the resin becomes hard and the adhesion at the interface with the electronic component is reduced, the connection reliability also tends to be reduced.

[0007] On the other hand, when a conductive filament is oriented in one direction of the binder resin, it is necessary to increase the melt viscosity of the binder resin so that the orientation of the filament is not disturbed during thermocompression bonding. In general, thermoplastic resins have high melt viscosity, and in order to obtain high connection reliability using thermoplastic resins, it is necessary to use a resin with a high melting temperature, so it is naturally difficult to connect at low temperatures It is. In addition, electrical connection can be obtained by contact between the electrode surface of the electronic component and the conductive wire, but in the case of a thermoplastic resin, the curing shrinkage force unlike a thermosetting resin does not act, and the connection reliability is generally low. Low.
As this type of anisotropic conductive resin material, a material using thermoplastic polyimide or polyamide imide having good heat resistance has been developed. However, the operating temperature is as high as about 300 ° C., and the pressing time is also 30 seconds. Level and somewhat longer. Further, when the electrode height is relatively high as shown in FIG. 9, the anisotropic conductive film does not follow the surface of the electronic component, and a gap is easily generated between the two. Many of the practical applications use a rubber material such as silicone rubber, and there is a gap between the electronic component and the anisotropic conductive film except for the electrical connection part. It has no adhesiveness and requires constant external pressure to obtain electrical connection.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned disadvantages of the prior art, and in particular, to achieve a short connection time suitable for flip-chip connection and to improve the connection reliability. And a novel anisotropic conductive film, a semiconductor device using the same, and a method for manufacturing the same.

[0009]

SUMMARY OF THE INVENTION The present invention basically employs the following technical configuration to achieve the above object. That is, the first embodiment of the anisotropic conductive film according to the present invention is a method in which a core layer filled with conductive filaments in the thickness direction of an insulating film is provided on both surfaces of the core layer and bonded by heat. And a conductive layer formed in the thickness direction of the insulating film. And wherein the surface thereof protrudes from the surface of the insulating film, and the conductive filaments are embedded in adhesive layers provided on both surfaces of the core layer. The conductive particles are uniformly dispersed in the adhesive layer that is melted by the heat, and the fourth embodiment is characterized in that the conductive filaments penetrate in the thickness direction of the insulating film. And the surface of the insulating film is smooth. In a fifth aspect, the diameter of the conductive filament is at least three times the diameter of the conductive particles uniformly dispersed in the adhesive layer. The sixth aspect is characterized in that the conductive filaments are arranged at a pitch smaller than 1/3 of the diameter of the conductive particles uniformly dispersed in the adhesive layer. The seventh aspect is characterized in that the core layer does not melt at a thermocompression bonding temperature.
The adhesive layer is characterized by being a thermosetting resin, and a ninth aspect is characterized in that the adhesive layer is a thermoplastic resin, Tenth
An aspect is characterized in that the thickness of the core layer is larger than the thickness of the adhesive layer provided on both surfaces thereof, and the eleventh aspect is that the thickness of the adhesive layer is In the twelfth aspect, the tensile elastic modulus of the core layer is preferably smaller than the diameter of the conductive particles uniformly dispersed in the layer. It is characterized by being smaller than the tensile modulus.

A first aspect of the semiconductor device according to the present invention is a semiconductor device in which two electronic components are electrically connected to each other via an anisotropic conductive film. An anisotropic conductive film consisting of a core layer filled with conductive filaments in the thickness direction of the insulating film and adhesive layers provided on both sides of the core layer and melted by heat is interposed, and the core layer Both ends of the conductive filaments filled in the thickness direction of the insulating film are in contact with the respective electrodes of the two electronic components, and the surface of the electronic component and the anisotropic conductive film are on both sides of the core layer. Characterized in that they are each fixedly integrated with an adhesive layer provided in,
The second aspect is characterized in that conductive particles are uniformly dispersed in the adhesive layer that is melted by the heat, and the third aspect is that one of the two electronic components is A semiconductor element or a semiconductor package, wherein the other electronic component is a wiring board, and a fourth mode is one in which one of the two electronic components is a semiconductor package,
The other electronic component is a wiring substrate, and has a gap other than an electrical connection between the semiconductor package and the anisotropic conductive film.

A first aspect of the method of manufacturing a semiconductor device according to the present invention is a method of manufacturing a semiconductor device in which two electronic components are electrically connected via an anisotropic conductive film. An anisotropic conductive film consisting of a core layer filled with conductive filaments in the thickness direction of the insulating film between two electronic components, and an adhesive layer provided on both sides of the core layer and melted by heat. By interposing and heating the anisotropic conductive film, both ends of the conductive strip filled in the thickness direction of the insulating film as the core layer are brought into contact with the respective electrodes of the two electronic components. And the step of melting the adhesive layer, and the step of solidifying the adhesive layer to fix and integrate the two electronic components respectively.
In a second aspect, the conductive filaments uniformly filled in the adhesive layer that is melted by the heat are interposed, and the both ends of the conductive filament that is filled in the thickness direction of the insulating film as the core layer. And contacting each electrode of the two electronic components.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The anisotropic conductive film according to the present invention is provided on both sides of a core layer filled with conductive filaments in the thickness direction of the insulating film, and is melted by heat. It consists of an adhesive layer and is characterized by expressing conductivity only in the thickness direction by thermocompression bonding,
Further, the conductive particles are uniformly dispersed in the adhesive layer that is melted by the heat.

Further, a semiconductor device according to the present invention is a semiconductor device in which two electronic components are electrically connected via an anisotropic conductive film, and a thickness of an insulating film is provided between the two electronic components. Anisotropic conductive film consisting of a core layer filled with conductive filaments in the direction and adhesive layers provided on both sides of the core layer and melted by heat is interposed, and the insulating film as the core layer Both ends of the conductive filament filled in the thickness direction contact the respective electrodes of the two electronic components, and the surface of the electronic component and the anisotropic conductive film are provided on both surfaces of the core layer. It is characterized by being integrally fixed by an adhesive layer.

According to the present invention, by using a resin which does not melt at the thermocompression bonding temperature for the core layer, it is possible to perform thermocompression bonding without disturbing the orientation of the conductive filaments filled in the thickness direction. Therefore, the electronic component and the core layer adhere well, and at the same time, the contact state between the electrode surface of the electronic component and the conductive filament filled in the thickness direction of the core layer is firmly and reliably maintained, and is stable. Connection reliability is obtained.

By disposing conductive particles deformable by pressure in the adhesive layer, the conductive particles deformed between the electrode surface of the electronic component and the conductive filament filled in the thickness direction of the core layer. The particles are interposed, and the temperature cycle characteristics in the thickness direction are further improved. Furthermore, by using a resin whose core layer is thicker than the adhesive layer and has low elasticity, the internal stress generated in the vicinity of the connection portion can be reduced, and better connection reliability can be obtained.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific examples of an anisotropic conductive film according to the present invention, a semiconductor device using the same, and a method of manufacturing the same will be described in detail with reference to the drawings. 1 to 7
FIGS. 3A and 3B are diagrams showing the structure of a specific example of an anisotropic conductive film according to the present invention, a semiconductor device using the same, and a method of manufacturing the same. FIGS. It comprises a core layer 12 filled with the body 11 and an adhesive layer 13 provided on both sides of the core layer 12 and melted by heat, and exhibits conductivity only in the thickness direction by thermocompression bonding. An anisotropic conductive film 10 is shown, and the conductive filament 11 penetrates in the thickness direction of the insulating film 12a, and the surface thereof is
a anisotropic conductive film, which protrudes from the surface and is embedded in the adhesive layer 13 provided on both surfaces of the core layer 12, and
An anisotropic conductive film 40 is shown in which conductive particles 44 are uniformly dispersed in the adhesive layer 13 which is melted by the heat.

Furthermore, a semiconductor device in which two electronic components 15 and 16 are electrically connected via an anisotropic conductive film 10, wherein a thickness of an insulating film 12 a is provided between the two electronic components 15 and 16. The anisotropic conductive film 10 consisting of a core layer 12 filled with conductive strips 11 in the direction and adhesive layers 13 provided on both sides of the core layer 12 and melted by heat is interposed, and Both ends of the conductive linear body 11 filled in the thickness direction of the insulating film 12a as the layer 12 are in contact with the respective electrodes 18 and 19 of the two electronic components 15 and 16, and the surfaces of the electronic components 15 and 16 are formed. The semiconductor device is characterized in that the anisotropic conductive film 10 and the anisotropic conductive film 10 are respectively fixed and integrated by adhesive layers 13 provided on both surfaces of the core layer 12.

Hereinafter, the present invention will be described in more detail. First, the anisotropic conductive film of the present invention will be described.
FIG. 1 shows an example of a cross-sectional view of an anisotropic conductive film 10 of the present invention and a cross-sectional view of a connection between a semiconductor chip 15 and a wiring board 16 using the same. Anisotropic conductive film 10 of the present invention
Has a three-layer structure in which an adhesive layer 13 is provided on both surfaces of a core layer 12 in which a conductive linear body 11 is filled in an insulating film 12a in a thickness direction.

The resin that can be used as the insulating film 12a of the core layer 12 may be any resin that can maintain the orientation of the conductive strip 11 filled in the thickness direction during thermocompression bonding. For that purpose, it is preferable that the melt viscosity at the thermocompression bonding temperature is high, and it is most preferable not to melt. That is, a resin that hardly flows at all at the thermocompression bonding temperature, or a resin that does not flow at all is preferable. Specifically, a cured epoxy resin, a phenol resin, a heat or light curable resin such as a silicone resin, a polyimide,
Polyamide imide, aramid resin and the like, or amorphous thermoplastic resin having a high melting point crystalline or high glass transition point such as polysulfone, polyether imide, aromatic polyester, fluorine resin and the like can be mentioned. In particular, use of a silicone resin, a silicone-modified epoxy resin, a fluororesin, or the like having a low elastic modulus is advantageous in terms of stress relaxation, and is preferably equal to or less than the elastic modulus of an adhesive layer described later.

The insulating film 1 for forming the core layer 12
The conductive filament 11 filled in the thickness direction of 2a is not particularly limited. For example, a conductive paste in which a metal powder such as copper, nickel, gold, and solder, a metal powder such as silver, copper, and palladium is mixed with a binder resin such as an epoxy resin, or a conductive resin such as polythiophene, polypyrrole, and polyaniline can be used. However, a metal having a small resistance value is most preferable. The method for producing a material in which these conductive materials are filled in the thickness direction of the insulating film is not particularly limited. A conductive material can be filled in the holes opened in advance by plating, printing, or the like, or a resin is poured in a state where metal wires are arranged in parallel at predetermined intervals in advance, and then formed in a plane perpendicular to the orientation direction of the wires. It can also be manufactured by cutting.

An adhesive layer 13 is provided on both sides of the core layer 12 in which the conductive wire 11 is filled in the thickness direction.
This adhesive layer 13 is melted at the time of thermocompression bonding, and the electronic components 15,
16 and integrated. As the adhesive 13, it is preferable to use a thermosetting resin having good connection reliability. Specifically, epoxy resin, silicone-modified epoxy resin,
Silicone resin and the like are preferred. Fillers such as silica particles can be added to these adhesive layers as needed. In this case, the elastic modulus of the resin increases, which is disadvantageous in terms of stress relaxation. However, by making the core layer 12 smaller and thicker than the elastic modulus of the adhesive layer 13, the connection reliability is reduced. Can be suppressed. Here, the adhesive layer 1
3 is preferably as thin as possible within a range that covers the electronic component surface. That is, by setting the electrode height of the electronic component to be as low as possible in consideration of the warpage of the substrate and the variation in the height of the bump, it is possible to reduce the displacement caused by the temperature cycling process in the thickness direction of the adhesive layer 13. it can. The minimum height varies depending on the material of the substrate and the size of the semiconductor element.
In addition, when mounting the semiconductor package on the wiring board, there is no need for sealing, so it is only necessary to have a reinforcing function of the connection portion,
It can be used even if there is a gap between the semiconductor package and the wiring board.

The conductive filaments 11 are filled in the thickness direction of the core layer 12, but need to protrude from the surface of the core layer 12. At the time of thermocompression bonding, the adhesive layers 13 formed on both surfaces of the core layer 12 are melted, and the surface of the conductive filament 11 comes into contact with the bumps 18 of the electronic component. If it is concave, sufficient contact cannot be obtained and stable connection cannot be obtained. Here, the protruding height of the conductive wire 11 from the surface of the core layer 12 is determined by the adhesive layer 1 formed on both surfaces.
It is preferable that the thickness of the conductive wire 11 is equal to or less than the thickness of the adhesive layer 3, that is, the tip of the conductive wire 11 is embedded in the adhesive layer 13. If the thickness of the adhesive layer 13 is smaller than the protruding height of the tip of the conductive strip 11, a gap is formed between the adhesive and the electronic component, resulting in insufficient bonding.

The diameter of the conductive wire can be set arbitrarily according to the shape of the electrode of the electronic component to be connected. As shown in FIG. 2, conductive filaments 22 having a fine diameter may be arranged at a fine pitch so that a large number of conductive filaments come into contact with the electrode, or as shown in FIG. 3. The bump 38 of the semiconductor element 35
, Conductive wire 31 and wiring board connection terminal 3 of wiring board 36
9 may be arranged at an equal pitch with the electrodes so as to correspond one-to-one. In the latter case, in order to increase the contact area as much as possible, it is preferable to increase the diameter of the conductive filament 22 and smoothen the surface. In addition, the cross section of the conductive wire does not necessarily have to be circular, but may be elliptical or polygonal.

As shown in FIG. 1, the conductive wire 11 and the bumps 18 provided on the aluminum pads 17 of the semiconductor chip 15 are formed by thermocompression bonding using the anisotropic conductive film 10.
And the pad 19 of the wiring board 16 are in direct contact with each other, and the contact is maintained by the surrounding adhesive 13 being cured and contracted. In this case, as the adhesive 13 deteriorates due to the temperature cycling process, the holding force tends to decrease, and the connection reliability is not always sufficient.

By incorporating conductive particles in the adhesive layer, connection reliability can be further improved. FIG. 4 shows an example of a cross-sectional view of the anisotropic conductive film 40 in this case and a connection cross-sectional view of a semiconductor chip 45 and a wiring board 46 using the same. Deformable conductive particles 4 on adhesive layer 43
4, the conductive wire 41 and the semiconductor chip 45
The conductive particles 44 are interposed between the bumps 48 provided on the aluminum pads 47 and the pads 49 of the wiring board 46 in a state where the conductive particles 44 are deformed, and the deformation of the conductive particles 44 is suppressed even if the holding force of the adhesive layer 43 is reduced. By restoring, the electrical connection between the conductive filament 41 and the electronic components 45 and 46 is maintained.
The conductive particles 44 are not particularly limited as long as they are deformable and can be restored after thermocompression bonding. Specifically, there may be mentioned, for example, particles of gold plated around polystyrene or acrylic resin, or soft metal particles such as silver-copper alloy. The diameter of the conductive particles can be arbitrarily set according to the pad shape of the electronic component, but is usually preferably about 3 to 20 μm, more preferably 5 to 10 μm.

The diameter of the conductive wire 41 can be arbitrarily set according to the shape of the electrode of the electronic component to be connected. As shown in FIG. 5, conductive filaments 51 having a fine diameter may be arranged at a fine pitch so as to correspond to a large number of conductive filaments per electrode area, or as shown in FIG. , Electrodes and conductive filaments 6
The electrodes may be arranged at equal pitches with the electrodes so that the electrodes 1 and 1 correspond to each other. In the former case, it is preferable that the diameter of the conductive filaments 51 be 1/3 or less of the diameter of the conductive particles 54.
If it is more than this, even if the conductive particles 54 are flattened by thermocompression bonding, it is difficult to make the number of conductive wire tips in contact with the conductive particles 5 or more, which is considered to provide a stable connection. In the latter case, in order to increase the contact area as much as possible, it is preferable to increase the diameter of the conductive wire 61 and to smooth its surface. Here, it is preferable that the diameter of the conductive wire 61 be three times or more the diameter of the conductive particles 64. If the diameter of the conductive filaments 61 is less than three times the diameter of the conductive particles 64, it is extremely difficult to mount five or more. Note that the conductive wire surfaces 51 and 61 do not need to protrude from the core layers 52 and 62. It may be recessed from the surface of the core layer in a range flush with the core layer or in a range smaller than the diameter of the conductive particles. In addition, the cross section of the conductive wire does not necessarily have to be circular, but may be elliptical or polygonal.

Next, an embodiment of the present invention will be described with reference to the drawings. The present invention is not limited to the contents shown in the following embodiments. (Example 1) The core layer of the anisotropic conductive film was a silicone-modified epoxy resin-cured sheet 150 μm thick, and gold wires having a diameter of 8 μm projecting 4 μm from the front and back of the core layer at a pitch of approximately 15 μm. Is filled. The anisotropic conductive film has a thickness of 15 on both sides of the core layer.
It has a three-layer structure in which a B-stage epoxy resin adhesive layer having a naphthalene skeleton of μm is arranged, and the core layer has a lower elastic modulus than the adhesive. The semiconductor element is 1
It is a 120 μm pitch peripheral specification in which gold-plated bumps are formed on a 75 mm square aluminum pad of 0 mm square. Here, the shape of the gold plated bump has a surface area of 70 μm square and a plating thickness of 10 μm. On the other hand, the wiring substrate is a build-up substrate using FR4 formed by a semi-additive method as a core material, and the connection terminals on the surface layer are formed on a photosensitive plating resist layer having a thickness of 18 μm by electrolysis at openings formed by exposure. By subjecting the copper plating to 10 μm, and then to the surface of the copper plating with electrolytic nickel and gold plating, a projection having a thickness of 15 μm and a square of 75 μm is finally obtained. The above-mentioned anisotropic conductive film is temporarily pressure-bonded on a wiring board, and after aligning the semiconductor element and the wiring board, 20
The semiconductor element and the wiring board were integrated without gaps by thermocompression bonding at 0 ° C. for 10 seconds.

The obtained 20 semiconductor devices were subjected to a temperature cycle treatment (−40 ° C./125° C., 30 minutes each) for 600 cycles, but no failure occurred. (Embodiment 2) The semiconductor element and the wiring board are the same as in Embodiment 1. The core layer of the anisotropic conductive film is a polyimide film having a thickness of 100 μm, and a hole having a diameter of 40 μm provided therein is filled with copper by electrolytic plating, and both ends thereof are treated with nickel / gold. This conductive filament is 120μ
They are arranged at m pitches. The anisotropic conductive film of this example has a thickness of 1 in which silica particles having an average particle size of 0.2 μm on both surfaces of the core layer and plastic particles having an average particle size of 5 μm plated with nickel / gold on the surface are uniformly dispersed.
It has a three-layer structure in which a B-stage epoxy resin adhesive layer having a 5 μm dicyclopentadiene-modified phenol novolak skeleton is arranged, and the core layer has a lower elastic modulus than the adhesive. The conductor surface is substantially flush with the surface of the core layer and is smooth. Semiconductor device and wiring board are Example 1
The same as above was used. The anisotropic conductive film was preliminarily pressure-bonded on a wiring board, and the semiconductor element and the wiring board were aligned and then thermocompression-bonded at 210 ° C. for 10 seconds to integrate the semiconductor element and the wiring board without gaps.

The 20 semiconductor devices obtained were subjected to a temperature cycle treatment (−40 ° C./125° C., 30 minutes each) for 600 cycles, but no failure occurred. (Example 3) As in Example 1, the core layer of the anisotropic conductive film was a sheet 1 cured with silicone-modified epoxy resin.
A gold wire having a thickness of 50 μm and a diameter of 1 μm projecting from the front and back of the core layer by 1 μm each is filled at a pitch of approximately 3 μm. Then, silica particles having an average particle size of 0.2 μm and nickel /
It has a three-layer structure in which a B-staged epoxy resin adhesive layer having a 15-μm-thick naphthalene skeleton in which gold-plated plastic particles having an average particle diameter of 10 μm are uniformly dispersed is provided, and the core layer has an adhesive. It has a lower elastic modulus. The semiconductor element is 120 μm in which a gold-plated bump is formed on a 90 mm square aluminum pad of 10 mm square.
It is pitch peripheral specification. Here, the shape of the gold plated bump has a surface area of 80 μm square and a plating thickness of 10 μm. On the other hand, the wiring substrate is a build-up substrate using FR4 formed by a semi-additive method as a core material, and the connection terminals on the surface layer are formed in a 20 μm-thick photosensitive plating resist layer through an opening formed by exposure to light. Copper plating is 10 μm, followed by electrolytic nickel and gold plating on the surface of the copper plating, so that the final plating is 15 μm.
It has a thick, 75 μm square convex part. The anisotropic conductive film was preliminarily pressure-bonded on a wiring board, and the semiconductor element and the wiring board were aligned and thermocompression-bonded at 200 ° C. for 10 seconds to integrate the semiconductor element and the wiring board without gaps.

The 20 semiconductor devices obtained were subjected to a temperature cycle treatment (−40 ° C./125° C., 30 minutes each) for 600 cycles, but no failure occurred. (Comparative Example 1) A semiconductor element and a wiring board were integrated without any gap except that the thickness of the core layer of the anisotropic conductive film used in Example 1 was changed to 50 µm.

When the obtained 20 semiconductor devices were subjected to a temperature cycle treatment (-40 ° C./125° C., 30 minutes each),
The failure occurred from 200 cycles, and all failures occurred in 600 cycles. (Comparative Example 2) The semiconductor element and the wiring board were completely identical except that the gold filaments filled in the core layer of the anisotropic conductive film used in Example 1 were almost flush with the core layer. Integrated.

In the obtained semiconductor device, a defect occurred in the initial connection. (Comparative Example 3) The core layer of the anisotropic conductive film used in Example 1 was replaced with a cured adhesive layer (C having a naphthalene skeleton).
The semiconductor device and the wiring board were integrated without any gap except for changing to a stage-shaped epoxy resin).

When the obtained 20 semiconductor devices were subjected to a temperature cycle treatment (-40 ° C./125° C., 30 minutes each),
Failure occurred in 300 cycles and 15 in 600 cycles
Individual defective. (Comparative Example 4) A semiconductor element and a wiring substrate were integrated without any gap except that the diameter of the conductive filament filled in the core layer of the anisotropic conductive film used in Example 2 was changed to 12 µm. Was.

When the obtained 20 semiconductor devices were subjected to a temperature cycle treatment (-40 ° C./125° C., 30 minutes each),
Failure occurred in 200 cycles and 18 in 600 cycles
Individual defective. (Comparative Example 5) Except that the diameter of the conductive filament filled in the core layer of the anisotropic conductive film used in Example 3 was changed to 3 μm and 5 μm pitch, the semiconductor element and the wiring substrate were completely closed. Integrated.

When the obtained 20 semiconductor devices were subjected to a temperature cycle treatment (−40 ° C./125° C., 30 minutes each),
The failure occurred from 200 cycles, and all failures occurred in 600 cycles. (Other Embodiments of the Invention) When a semiconductor element is connected to a wiring board as described above, it is preferable that the resin is filled without a gap between the semiconductor element and the wiring board from the viewpoint of protection from a use environment. However, when a package, such as a chip size package, in which a semiconductor element surface is already sealed is mounted on a wiring board, there may be a gap between the semiconductor package and the wiring board. As shown in FIG. 7, the solder bumps 78 of the chip size package 74 come into contact with the conductive strips 71 of the anisotropic conductive film 70, and the adhesive 73 is applied only to the periphery of the tip of the solder bumps 78 and reinforced. It may be. When a thermoplastic resin is used as the adhesive layer on the semiconductor package 74 side of the anisotropic conductive film 70, the solder bump 78 and the adhesive layer 43 are both melted, so that repair is possible. In this case, the melting temperature of the thermoplastic resin is preferably higher than the melting point of the solder. By reflowing at a temperature equal to or higher than the melting point of the solder bump 78 and equal to or lower than the melting temperature of the thermoplastic resin, the solder bump and the conductive wire are metal-bonded, and higher connection reliability can be obtained. In addition,
It goes without saying that conductive particles can be blended in the adhesive layer.

As described above, the anisotropic conductive film according to the present invention is provided on both sides of the core layer in which the conductive filaments are filled in the thickness direction of the insulating film, and is melted by heat. It consists of an adhesive layer and is characterized by exhibiting conductivity only in the thickness direction by thermocompression bonding, and the conductive filaments penetrate in the thickness direction of the insulating film, and the surface thereof Protrudes from the insulating film surface,
And the conductive wire is embedded in an adhesive layer provided on both surfaces of the core layer,
Further, the conductive particles are characterized by being uniformly dispersed in the adhesive layer that is melted by the heat, and the conductive filaments penetrate in the thickness direction of the insulating film, The surface of the insulating film is smooth, and the diameter of the conductive filament is at least three times the diameter of the conductive particles uniformly dispersed in the adhesive layer. Wherein the conductive filaments are arranged at a pitch smaller than 1/3 of the diameter of the conductive particles uniformly dispersed in the adhesive layer. And the core layer is characterized in that it does not melt at the thermocompression bonding temperature, and the adhesive layer is characterized by being a thermosetting resin, Further, the adhesive layer is made of a thermoplastic resin. The thickness of the core layer is larger than the thickness of the adhesive layer provided on both sides thereof, and the thickness of the adhesive layer is evenly distributed in the adhesive layer. It is characterized by being larger than the dispersed conductive particle diameter, and the tensile elastic modulus of the core layer is smaller than the tensile elastic modulus of the adhesive layer provided on both sides thereof. Things.

A semiconductor device according to the present invention is a semiconductor device in which two electronic components are electrically connected via an anisotropic conductive film, and a thickness of an insulating film is provided between the two electronic components. Anisotropic conductive film consisting of a core layer filled with conductive filaments in the direction and adhesive layers provided on both sides of the core layer and melted by heat is interposed, and the insulating film as the core layer Both ends of the conductive filament filled in the thickness direction contact the respective electrodes of the two electronic components, and the surface of the electronic component and the anisotropic conductive film are provided on both surfaces of the core layer. The adhesive layer is fixed and integrated with each other, and the conductive particles are uniformly dispersed in the adhesive layer that is melted by the heat. , One of the two electronic components is half A body element or a semiconductor package, wherein the other electronic component is a wiring board, and one of the two electronic components is a semiconductor package and the other electronic component is a wiring board; There is a gap other than the electrical connection between the package and the anisotropic conductive film. Also, a method of manufacturing a semiconductor device according to the present invention is a method of manufacturing a semiconductor device in which two electronic components are electrically connected via an anisotropic conductive film, wherein an insulating material is provided between the two electronic components. A step of interposing an anisotropic conductive film comprising a core layer filled with conductive filaments in the thickness direction of the film and an adhesive layer provided on both surfaces of the core layer and melted by heat,
By heating the anisotropic conductive film, both ends of the conductive filament filled in the thickness direction of the insulating film as the core layer are brought into contact with respective electrodes of the two electronic components, and the bonding is performed. A step of melting the agent layer; and a step of fixing and integrating the two electronic components by solidifying the adhesive layer. Contacting both ends of a conductive filament filled in a thickness direction of the insulating film as the core layer with conductive particles uniformly dispersed in the layer, to contact respective electrodes of the two electronic components. It is characterized by the following.

[0038]

By using the anisotropic conductive film of the present invention, a semiconductor device having good connection reliability can be provided. The reason is that the anisotropic conductive film has a three-layer structure. That is, by using a resin that does not melt at the thermocompression bonding temperature as the insulating film core layer, the orientation of the conductive strip filled in the thickness direction is not disturbed,
In addition, by disposing an adhesive that melts at the thermocompression bonding temperature on both sides of the insulating film core layer, the electronic component and the core layer are well bonded by thermocompression bonding. The contact state of the conductive strip filled in the direction is maintained.

Further, by disposing conductive particles that can be deformed by pressure in the adhesive layer, the conductive particles deformed between the electrode surface of the electronic component and the conductive filaments filled in the thickness direction of the core layer. Particles are interposed, and the conductive particles deform and follow the temperature cycle processing. Here, by using a resin that is thicker and lower in elasticity than the adhesive layer as the core layer, internal stress generated near the connection portion can be reduced.

When a thermoplastic resin is used as the adhesive, the reliability of connection of the semiconductor package to the wiring board is improved, and the semiconductor package can be repaired.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an anisotropic conductive film showing a specific example of the present invention and a semiconductor device using the same.

FIG. 2 is a diagram illustrating a corresponding state of an electrode of a semiconductor device and a conductive filament filled in a core layer of an anisotropic conductive film.

FIG. 3 is a diagram illustrating another correspondence state between the electrodes of the semiconductor device and the conductive filaments filled in the core layer of the anisotropic conductive film.

FIG. 4 is a cross-sectional view of an anisotropic conductive film showing another specific example of the present invention and a semiconductor device using the same.

FIG. 5 is a diagram illustrating a corresponding state of an electrode of a semiconductor device and a conductive filament filled in a core layer of an anisotropic conductive film.

FIG. 6 is a diagram illustrating another corresponding state of the electrodes of the semiconductor device and the conductive filaments filled in the core layer of the anisotropic conductive film.

FIG. 7 is a diagram showing another specific example of the present invention.

FIG. 8 is a diagram illustrating a conventional example.

FIG. 9 is a diagram illustrating a conventional example.

[Explanation of symbols]

Anisotropic conductive film: 10, 20, 30, 40, 50,
60, 70, 80, 90 conductive filaments: 11, 21, 31, 41, 51, 61, 7
1, 91 Core material: 12, 22, 32, 42, 52, 62, 72 Adhesive layer: 13, 23, 33, 43, 53, 63, 73 Conductive particles: 44, 54, 64, 81 Semiconductor element: 15 , 25, 35, 45, 55, 65, 7
5, 85, 95 Wiring board: 16, 26, 36, 46, 56, 66, 7
6, 86, 96 Semiconductor element connection terminals (aluminum pads): 17, 2
7, 37, 47, 57, 67, 87, 97 Metal projections (bumps): 18, 28, 38, 48, 58,
68, 88, 98 Wiring board connection terminals: 19, 29, 39, 49, 59, 6
9, 79, 89, 99 Semiconductor package: 74 Solder bump: 78 Binder resin: 82, 92 Insulating film: 12a

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[Procedure amendment]

[Submission date] June 12, 2000 (2006.1.
2)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

[0009]

SUMMARY OF THE INVENTION The present invention basically employs the following technical configuration to achieve the above object. That is, in the first embodiment of the anisotropic conductive film according to the present invention, in the thickness direction of the insulating film, a conductive filament having a smooth surface is filled.
An insulating core layer, and a core layer provided on both sides of the core layer.
And an adhesive layer that is melted by heat and is uniformly distributed in the adhesive layer.
Consisting of deformable conductive particles dispersed in one,
A conductive filament penetrates in the thickness direction of the core layer, and
Has a surface protruding from the surface of the core layer, and the conductive wire
Strips are embedded in the adhesive layers provided on both sides of the core layer.
It is state, and are not characterized by expression conductivity only in its thickness direction by thermocompression bonding, or the second aspect, the diameter of the conductive striatum, 3 times or more before Kishirube electrostatic particle size and characterized in that it is, or, third aspects, in which the conductive striatum, characterized in that it is arranged in one-third less than the pitch of the front Kishirube electrostatic particle size The fourth mode is characterized in that the core layer does not melt at the temperature at the time of thermocompression bonding, and the fifth mode is that the adhesive layer is formed of a thermosetting resin. The sixth aspect is characterized in that the adhesive layer is a thermoplastic resin, and the seventh aspect is that the thickness of the core layer is Wherein the thickness is larger than the thickness of the adhesive layer provided on both surfaces thereof.
8 embodiment, the thickness of the adhesive layer, which being greater than the conductive particle size, or, ninth aspect,
It is characterized in that the tensile elastic modulus of the core layer is smaller than the tensile elastic moduli of the adhesive layers provided on both sides thereof.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

A first aspect of the semiconductor device according to the present invention is a semiconductor device in which two electronic components are electrically connected to each other via an anisotropic conductive film. Smooth the surface in the thickness direction of the insulation film
Core layer filled with conductive strips
Are provided on both sides of the core layer and are melted by heat.
Adhesive layer, deformable evenly dispersed in the adhesive layer
Conductive filaments, wherein the conductive filaments are
Through the core layer surface
Projecting, and the conductive filaments are on both sides of the core layer.
Allowed interposed anisotropic conductive film is embedded in the adhesive layer provided on both ends of the conductive striatum, which is filled in the thickness direction of the insulating film which is the core layer, the conductive
The particles are in contact with the respective electrodes of the two electronic components via the particles, and the surface of the electronic component and the anisotropic conductive film are respectively fixed and integrated by the adhesive layers provided on both surfaces of the core layer. it all SANYO characterized by, or second aspect the 2
One of the two electronic components is a semiconductor element or a semiconductor package, and the other electronic component is a wiring board. In a third mode, one of the two electronic components is a semiconductor package, The other electronic component is a wiring substrate, and has a gap other than an electrical connection between the semiconductor package and the anisotropic conductive film.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

Further, a method of manufacturing a semiconductor device according to the present invention.
State like is an electrically connected manufacturing method of the semiconductor device via the two electronic components is an anisotropic conductive film,
Between the two electronic components, in the thickness direction of the insulating film ,
Insulating properties filled with conductive filaments with smooth surfaces
And a core layer provided on both sides of the core layer,
An adhesive layer that melts more and is uniformly dispersed in the adhesive layer.
Said conductive filaments made of deformable conductive particles.
The body penetrates in the thickness direction of the core layer, and the surface thereof
Projecting from the surface of the core layer, and the conductive filaments
Melting the adhesive layer by interposing an anisotropic conductive film embedded in an adhesive layer provided on both sides of the core layer and heating the anisotropic conductive film; Let
Together with both ends of the conductive filament filled in the thickness direction of the insulating film as the core layer with the conductive particles.
Through, said the higher two husband Ru <br/> Me Shi not contact the people electrode Engineering of the electronic component, wherein by allowed to solidify said adhesive layer 2
Ru der which is characterized in that it comprises the steps of: allowed to each fixed integrally One of the electronic components.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Correction contents]

When the obtained 20 semiconductor devices were subjected to a temperature cycle treatment (−40 ° C./125° C., 30 minutes each),
The failure occurred from 200 cycles, and all failures occurred in 600 cycles. (Other Embodiments of the Invention) When a semiconductor element is connected to a wiring board as described above, it is preferable that the resin is filled without a gap between the semiconductor element and the wiring board from the viewpoint of protection from a use environment. However, when a package, such as a chip size package, in which a semiconductor element surface is already sealed is mounted on a wiring board, there may be a gap between the semiconductor package and the wiring board. As shown in FIG. 7, the solder bumps 78 of the chip size package 74 come into contact with the conductive strips 71 of the anisotropic conductive film 70, and the adhesive 73 is applied only to the periphery of the tip of the solder bumps 78 and reinforced. It may be. When a thermoplastic resin is used as the adhesive layer on the semiconductor package 74 side of the anisotropic conductive film 70, the solder bumps 78 and the adhesive layer 73 are both melted, so that repair is possible. In this case, the melting temperature of the thermoplastic resin is preferably higher than the melting point of the solder. By reflowing at a temperature equal to or higher than the melting point of the solder bump 78 and equal to or lower than the melting temperature of the thermoplastic resin, the solder bump and the conductive wire are metal-bonded, and higher connection reliability can be obtained. In addition,
It goes without saying that conductive particles can be blended in the adhesive layer.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H01B 1/20 H01B 1/20 D H01L 21/60 311 H01L 21/60 311S 23/32 23/32 D H01R 11/01 H01R 11/01 A H05K 3/32 H05K 3/32 B F term (reference) 4F100 AB01A AB25 AB25H AK01A AK53 AK53G AR00A AR00B AR00C AT00D AT00E BA03 BA05 BA06 BA07 BA10B BA10C BA10D BA10E CA21A CA21B DE01C JB13B JB13C JB16B JB16C JG01B JG01C JG04A JK07A JL12B JL12C 5E319 AA03 AB05 BB16 CC61 CD31 5F044 KK01 LL09 QQ01 5G301 DA05 DA10 DA29 DA51 DA57 DD03 5G307 HA02 HB03 HC01

Claims (18)

[Claims] 1. An insulating film comprising: a core layer filled with conductive filaments in a thickness direction of an insulating film; and adhesive layers provided on both sides of the core layer and melted by heat. An anisotropic conductive film characterized by exhibiting conductivity only. 2. An adhesive in which the conductive wire penetrates in the thickness direction of the insulating film, a surface of which protrudes from the surface of the insulating film, and wherein the conductive wire is provided on both surfaces of the core layer. 2. The anisotropic conductive film according to claim 1, wherein the anisotropic conductive film is embedded in the layer. 3. The conductive particles are uniformly dispersed in the adhesive layer which is melted by the heat.
Or the anisotropic conductive film according to 2. 4. The anisotropic conductive film according to claim 3, wherein said conductive strip penetrates in a thickness direction of the insulating film, and a surface of said insulating film is smooth. 5. The anisotropic conductive film according to claim 3, wherein the diameter of the conductive filament is at least three times the diameter of the conductive particles uniformly dispersed in the adhesive layer. . 6. The method according to claim 1, wherein the conductive filaments are arranged at a pitch smaller than one third of a diameter of the conductive particles uniformly dispersed in the adhesive layer. The anisotropic conductive film according to any one of the above. 7. The anisotropic conductive film according to claim 1, wherein the core layer does not melt at a thermocompression bonding temperature. 8. The anisotropic conductive film according to claim 1, wherein the adhesive layer is a thermosetting resin. 9. The anisotropic conductive film according to claim 1, wherein the adhesive layer is a thermoplastic resin. 10. The anisotropic conductive film according to claim 1, wherein the thickness of the core layer is larger than the thickness of the adhesive layers provided on both surfaces thereof. 11. The anisotropic conductive film according to claim 3, wherein the thickness of the adhesive layer is larger than the diameter of the conductive particles uniformly dispersed in the adhesive layer. . 12. The anisotropic conductive material according to claim 1, wherein a tensile modulus of the core layer is smaller than a tensile modulus of the adhesive layer provided on both sides of the core layer. the film. 13. A semiconductor device in which two electronic components are electrically connected via an anisotropic conductive film, wherein a conductive linear body is filled between the two electronic components in a thickness direction of the insulating film. Anisotropic conductive film composed of a core layer and an adhesive layer provided on both sides of the core layer and melted by heat is interposed therebetween, and is filled in a thickness direction of the insulating film as the core layer. Both ends of the conductive filament come into contact with the respective electrodes of the two electronic components, and the surface of the electronic component and the anisotropic conductive film are respectively fixed and integrated by adhesive layers provided on both surfaces of the core layer. A semiconductor device characterized by being performed. 14. The semiconductor device according to claim 13, wherein conductive particles are uniformly dispersed in the adhesive layer melted by the heat. 15. The semiconductor device according to claim 13, wherein one of the two electronic components is a semiconductor element or a semiconductor package, and the other electronic component is a wiring board. 16. The semiconductor device according to claim 16, wherein one of the two electronic components is a semiconductor package and the other electronic component is a wiring board, and there is a gap other than an electrical connection between the semiconductor package and the anisotropic conductive film. 15. The semiconductor device according to 13 or 14. 17. A method for manufacturing a semiconductor device in which two electronic components are electrically connected via an anisotropic conductive film, wherein a conductive wire is provided between the two electronic components in a thickness direction of an insulating film. Interposing an anisotropic conductive film composed of a core layer filled with a body and an adhesive layer provided on both sides of the core layer and melted by heat; and heating the anisotropic conductive film. Contacting both ends of the conductive filaments, which are filled in the thickness direction of the insulating film as the core layer, with the respective electrodes of the two electronic components, and melting the adhesive layer; A step of solidifying the agent layer to fix and integrate the two electronic components, respectively. 18. Both ends of a conductive filament filled in the thickness direction of the insulating film as the core layer, with conductive particles uniformly dispersed in the adhesive layer melted by the heat, 18. The method for manufacturing a semiconductor device according to claim 17, wherein the respective electrodes of the two electronic components are brought into contact with each other.