JP2000294043A - Anisotropic conductive connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure a connected object and simultaneously restrain large deformation at an electrode portion of a conductive element of an inspected object, by arranging a plurality of conductive passages so as to penetrate through the front and rear surfaces of a film in an mutually electrically insulating state in a insulating-resin-made film, and providing a plurality of micro projections on at least one end surface of end surfaces of the conductive passages exposing to a film surface. SOLUTION: This anisotropic conductive connector 10 has a structure where a plurality of conductive passages 2 penetrate through the front and rear surfaces of a film 1 in a state that they are mutually electrically insulated in the insulating-resin-made film 1. A plurality of micro projections 3 are provided on both end surfaces 21, 22 of the conductive passages 2 exposing to a surface of the film 1. The conductive connector 10 provides conductivity in the thickness direction with the plurality of conductive passages 2, and provides an electrically insulating characteristic in the surface direction with insulating resin. Preferably, height of the micro projections 3 is 0.5 μm-15 μm, and its density is 0.02/μm2-2/μm2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anisotropic conductive connector, and more particularly, to an anisotropic conductive connector suitably used for connecting a semiconductor element to a circuit board.

[0002]

2. Description of the Related Art The number of electrodes of a semiconductor element in a bare chip state has increased with the recent increase in the number of functions and miniaturization of electronic devices, and the wiring patterns have been further reduced in pitch. An anisotropic conductive connector is used to cope with such a semiconductor element. The anisotropically conductive connector is intended to electrically connect the circuit board and the semiconductor element only by inserting it between the circuit board and the semiconductor element and crimping it. For this reason, the anisotropic conductive connector is useful for, for example, quality inspection of semiconductor devices, and its use in this aspect is also increasing.

The present inventors have previously proposed an anisotropic conductive connector shown in FIG. 4 (WO 98/07).
216). FIG. 4 is a diagram showing this already proposed anisotropic conductive connector. FIG. 4A shows the upper surface of the anisotropic conductive connector, and only a part thereof is shown. FIG.
FIG. 4B shows a cross section of the anisotropic conductive connector along the line XX in FIG. In FIG. 4, 1
Is a film made of an insulating resin, 2 is a conduction path made of a conductive material such as a conductive metal, and both 21 and 22 are end faces of the conduction path 2. In FIG. 4B, the cut surface of the conduction path 2 is hatched.

[0004] As shown in FIG. 4, the anisotropic conductive connector is configured such that a plurality of conductive paths 2 penetrate through the film 1 while being electrically insulated from each other by an insulating resin which is a material for forming the film 1. It has a provided structure. Both end surfaces 21 and 22 of the conduction path 2 are exposed on both sides of the film 1. The anisotropic conductive connector exhibits conductivity in the thickness direction due to the plurality of conductive paths 2 and exhibits electrical insulation in the surface direction, for example, the direction along the XX line.

[0005] In recent years, semiconductor devices have become more highly value-added products with further higher integration. Therefore, continuity tests such as burn-in tests are performed before mounting on desired electronic devices. It is necessary to supply only those whose reliability in terms of electrical continuity is guaranteed to the market.

[0006]

In the continuity test, the anisotropically conductive connector is sandwiched between the semiconductor element and the circuit board and pressurized. However, when the conventional anisotropically conductive connector is used, when pressure is applied to obtain sufficient conductivity, the electrode portion of the semiconductor element is deformed as much as about 20% as shown in Comparative Example 1 described later. May cause. Several% of electrode part of semiconductor element
Although slight deformation before and after is practically acceptable, if the deformation occurs beyond that level, reflow is necessary if the electrode part of the semiconductor element is a solder ball, and if it is a gold ball, connection is required. There is a problem that the amount of solder used sometimes changes.

SUMMARY OF THE INVENTION An object of the present invention is to provide an anisotropically conductive connector capable of suppressing a large deformation of an electrode portion of a semiconductor element to be inspected while securing a preferable connection state in a continuity inspection. .

[0008]

The anisotropically conductive connector of the present invention has the following features. (1) A plurality of conductive paths are provided in the insulating resin film,
It is arranged so as to penetrate the front and back surfaces of the film in a state of being electrically insulated from each other, and has a plurality of minute projections on at least one end surface of an end surface of the conduction path exposed on the film surface. An anisotropic conductive connector.

(2) The anisotropic conductive connector according to the above (1), wherein an end face of the conduction path protrudes from a film surface.

(3) The above (1) or (2), wherein the area of the region obtained by projecting the end face of the conduction path onto the same plane as the film surface is 20% to 80% of the sectional area of the conduction path. Anisotropic conductive connector.

(4) The density of the fine projections is 0.02 /
The anisotropic conductive connector according to any one of the above (1) to (3), wherein the number of the anisotropic conductive connectors is 2 μm ^{2 to} 2 pieces / μm ² .

(5) The height of the minute projection is 0.5 μm or more.
The anisotropic conductive connector according to any one of the above (1) to (3), which is 15 μm.

[0013]

When the end face of the conductive path is flat like a conventional anisotropic conductive connector, it is necessary to apply a large contact pressure to make sure that the end face and the electrode portion of the semiconductor element are electrically contacted. There is a problem of large deformation at the electrode portion.

However, as shown in the above (1) to (8), if a plurality of minute projections are provided on the exposed end face, the conduction path and the electrode portion of the semiconductor element can be electrically connected even with a small contact pressure. Can be reliably connected. Since the pressurization at the time of the continuity test can be reduced in this way, the above-described object of the present invention can be achieved without using the anisotropic conductive connector of the present invention with large deformation of the electrode portion of the semiconductor element. it can.

Further, the surface of the electrode portion of a semiconductor element to be subjected to a continuity test may be covered with an oxide film having a large electric resistance. For example, aluminum is deposited on most of the electrode portions, and an aluminum oxide film is formed. In such a case, in the conventional anisotropic conductive connector, higher pressure is required to break the oxide film. However, if the anisotropic conductive connector of the present invention is used, the oxide film can be pierced by the minute projections, particularly, the minute projections formed with a surface layer made of a hard conductive metal at the tip. Even at low pressure,
The conductive path and the electrode portion of the semiconductor element can be electrically connected reliably.

In the above aspect (3), the total number of the minute projections is reduced by reducing the end face on which the minute projections exist. As a result, conduction can be achieved with a smaller pressing force and the number of contact points is reduced, so that the end of the conduction path does not cause large deformation of the partner electrode when it comes into contact with the electrode.

Before the additional processing, the end face of the conduction path is flat or curved depending on the method of forming the conduction path, such as cutting a metal wire or growing by plating. When performing additional processing to reduce the area of the end face, the end face is projected on the same plane as the film surface so that the degree of reduction of the area can be easily compared even if the end face is flat or curved. The comparison will be made in terms of the area of the obtained region.

The "cross-sectional area of the conductive path" is the area of the cross section when the conductive path is cut perpendicular to the direction of the passage before performing additional processing. When the conduction path is a metal wire, it may have a uniform cross-sectional area. When the inside of the through-hole is obtained by plating with a metal, the conduction path may be tapered according to the shape of the through-hole. In this case, the maximum cross-sectional area is used.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The anisotropic conductive connector of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a view showing an example of the anisotropic conductive connector of the present invention, and is shown by a cross section cut in a thickness direction thereof. As shown in the example of FIG.
The anisotropic conductive connector 10 of the present invention includes a plurality of conductive paths 2.
Has a structure arranged in the insulating resin film 1 so as to penetrate through the front and back of the film 1 while being electrically insulated from each other. A plurality of minute projections 3 are provided on at least one end face of the end face (21, 22) of the conductive path exposed on the surface of the film 1. In the example of FIG. 1, a plurality of minute projections 3 are provided on both end surfaces (21, 22). The anisotropic conductive connector 10 exhibits conductivity in the thickness direction by the plurality of conductive paths 2 and exhibits electrical insulation characteristics in the surface direction by the insulating resin.

In the present invention, the insulating resin as the material for forming the film is not particularly limited as long as it has insulating properties, and can be selected from known insulating materials.
As the insulating resin, it is preferable to use a thermosetting resin or a thermoplastic resin. Specific examples include thermoplastic polyimide resin, epoxy resin, polyetherimide resin, polyamide resin, phenoxy resin, acrylic resin, polycarbodiimide resin, fluorine resin, polyester resin, polyurethane resin, polyamideimide resin, and the like. These resins may be used alone or in combination.

A semiconductor element to be subjected to a continuity test usually has a surface which is not always flat and has some unevenness. Therefore, it is preferable that the anisotropic conductive connector of the present invention can be deformed in response to possible irregularities on the surface of the semiconductor element at the time of the continuity test and can be in close contact with the surface of the semiconductor element to be contacted. For this reason, it is preferable that the insulating resin used as the material for forming the film has an appropriate flexibility. The elastic modulus of the insulating resin is 1 MPa to 1000
It is sufficient if the pressure is MPa, and it is preferably 5 MPa to 500 MPa. The elastic modulus of the insulating resin is measured using a viscoelasticity measuring device under a constant frequency, for example, 10 Hz in a tensile mode.

The thickness of the film is not particularly limited and may be set appropriately. However, since it is necessary to reduce the unevenness of the contact surface of the semiconductor element and the distortion of the surface of the film, the thickness of the film is preferably 5 μm to 500 μm, and more preferably 10 μm to 200 μm.

As a material for forming the conductive path in the present invention, a known conductive material can be mentioned, but copper, gold, aluminum, nickel and the like are preferable from the viewpoint of electrical characteristics, and copper and gold are preferable from the viewpoint of conductivity. . The shape of the cross section of the conduction path (a cross section cut perpendicular to the passage direction) is not particularly limited, and may be a circle, an ellipse, a polygon such as a triangle or a quadrangle, or the like.

The number, cross-sectional area and spacing of the conductive paths may be appropriately set according to the number, size and spacing of the electrode portions of the semiconductor element. However, if the cross-sectional area of the conductive path is too small or the number of conductive paths is small, the pressure concentrates on the electrode portion of the semiconductor element to form a dent, and the gap between the electrode portions of the semiconductor element is small. It is necessary to take into account the point that it will not be possible to respond to When the cross-sectional shape of the conduction path is circular, the diameter is 10 μm because the diameter of the electrode portion of a known semiconductor element is about 10 μm to 300 μm.
Preferably it is あ る 100 μm. Similarly, the interval (center-to-center distance) between the conductive paths 2 is preferably 10 μm to 100 μm.

In the example shown in FIG. 1, the end faces (21, 22) of the conductive path 2 provided with the minute projections are flat to enhance connection reliability. Further, in the example of FIG. 1, the area of the end face of the conduction path provided with the minute projection is the same as the cross-sectional area of the conduction path. As described in the above description of the operation, in the present invention, it is recommended that the area of the end face be 20% to 80% of the sectional area of the conduction path. As a method of setting the area of the end face of the conduction path to the above value, for example, a predetermined mask pattern is applied to a conventional anisotropic conductive film as shown in FIG. And the like. As a result, the embodiment shown in FIG. 2 is obtained. Further, by etching the film, the embodiment shown in FIG. 3 is obtained.

In the example of FIG. 1, the end face 21 of the conductive path 2 and the film surface 11 and the end face 22 of the conductive path 2 and the film surface 1
2 are both at the same level and on one plane. In the present invention, the end face of the conduction path may project from the film surface or may be depressed from the film surface. However, it is preferable that the end face of the conductive path protrudes from the film surface in order to make the end face of the conductive path be in good electrical contact with the electrode portion of the semiconductor element and the conductor pattern of the circuit board. In this case, the height of the end face of the conduction path from the film surface is usually about 1 μm to 40 μm, particularly 5 μm to 20 μm.
It is preferably about μm.

Examples of the method for projecting the end face of the conductive path from the film surface include a method of removing the film surface by etching, and a method of further depositing a metal on the end face of the conductive path by plating or the like. In the case where the minute projection is formed by etching as described later, it is necessary to project the end face of the conduction path in consideration of the part to be the minute projection.

There is no particular limitation on the shape of the end face of the conduction path.
Any shape may be used as long as it can form minute projections on its surface. For example, a columnar shape, a prismatic shape, a hemispherical shape, a conical shape, a truncated conical shape, a partially etched shape thereof, and the like can be given.
As described above, from the viewpoint of connection reliability, a shape in which the end surface is flat, such as a columnar shape, a prismatic shape, or a truncated cone, and a shape in which the area of the end surface is reduced by partially etching them is preferable. It is listed as.

The shape of the fine projection is not particularly limited as long as the electrical connection between the conduction path and the electrode portion of the semiconductor element can be reliably achieved at a low pressure. However, an oxide film is often formed on the electrode portion of the semiconductor element, and from the viewpoint of reducing damage to the electrode portion, the shape of the minute projection is sharply projected, for example, a cone or a pyramid. And the like.

For the same reason as described above, the height of the microprojections is preferably 0.5 μm to 15 μm, and particularly preferably 1 μm
-10 μm is preferred. Note that the height of the minute protrusion is a height from the end surface of the conductive path on which the protrusion is based. In the example of FIG. 1, the distance is the distance h from the end face (21, 22) to the top of the minute projection 3.

The number of minute projections to be formed is not particularly limited as long as it can ensure electrical connection between the conduction path at a low pressure and the electrode portion of the semiconductor element. However, when the number of the fine protrusions is small, the electrical contact between the fine protrusions and the electrode portion of the semiconductor element becomes good due to the concentration of pressure on the fine protrusion, but the damage to the electrode portion of the semiconductor element tends to increase. . On the other hand, when the number of the fine projections is large, the tendency is opposite to the above. Therefore, the number of microprojections to be formed is preferably about 10 to 1000, and particularly preferably about 50 to 500 per one end surface. In terms of the density of microprojections, 0.02 / μm ² to 2 / μm
^{About 2} is preferred, and 0.02 pieces / μm ^{2 to} 0.5 pieces / μ
m ² is particularly preferable.

In the example of FIG. 1, the minute projections 3 are formed on both end surfaces (21, 22) of the conduction path 2, but in the present invention, they are not necessarily formed on both end surfaces. In the present invention, the minute projection may be formed only on one end face that is on the semiconductor element side during the continuity test, or may be formed only on one end face of the conduction path that contacts the electrode portion of the semiconductor element. Is also good. However, if minute projections are formed on both end surfaces of the conduction path, there is no need to check the side on which the minute projections are formed at the time of the conduction inspection, so that there is an advantage that the conduction inspection can be performed efficiently.

The microprojections may be formed of a single material, or may be formed by laminating two or more materials. As a material for forming the minute projection, a known conductive material can be used. The material for forming the minute projections may be the same as or different from the material of the conduction path. However, the hardness of the oxide film at the electrode portion of the semiconductor element is generally 200 Hv or less, and at least the surface of the tip of the microprojection has a hardness of 200 Hv because the oxide film is easily broken through and the durability is improved. ~ 1
It is preferably formed of a 200 Hv material, for example, nickel, copper, nickel-tin alloy, nickel-palladium alloy, rhodium, ruthenium, cobalt, chromium, tungsten, or the like. Further, among these materials, hardness is 70.
It is a particularly preferred embodiment to use rhodium, ruthenium, cobalt, chromium, and tungsten which have 0 Hv to 1200 Hv. The hardness was measured according to JIS H 861.
According to No. 6, a micro hardness tester such as a micro Vickers hardness tester may be used.

Examples of the method for forming the fine projections include plating, such as electrolytic plating and electroless plating, mechanical processing, such as cutting and pressing, and etching, but are not particularly limited. However, in the present invention, from the point that the shape of the minute projection can be easily made into a shape with a sharp tip, and the fact that the minute projection can be collectively formed on the end face of the conductive path constituting the anisotropic conductive connector of the present invention, The microprojections are preferably formed by etching or plating.

Next, a method for forming minute projections by etching will be described. In the example of FIG.
Are projected from the film surface, and then the both end surfaces of the projected conductive path 2 are etched to form minute projections. In this case, as a method of projecting the end face of the conduction path, the above-described method of removing the film surface by etching, a method of depositing a metal on the end face of the conduction path by plating or the like can be used. Further, the height h of the minute projection formed on the end face of the conductive path by etching can be arbitrarily changed by changing the etching conditions. In order to increase the hardness on the minute projections, a conductive metal material may be further coated by plating. Further plating after etching is effective when the hardness of the material forming the conductive path is low.

The etching may be isotropic etching or anisotropic etching, and is not particularly limited. Types of etching include wet etching, chemical etching such as gas etching and plasma etching, sputter etching such as physical sputter etching and reactive sputter etching, and ion etching such as physical ion beam etching and reactive ion beam etching. Beam etching and the like.

Next, the case where the fine projections are formed only by plating will be described. In the case of depositing a metal by electrolytic plating, a current density for uniformly depositing a plating thickness usually exists as a specific range for each metal and for each type of plating solution. By setting the current density higher than that range, the metal crystal grows rapidly, becomes a rough surface state, and becomes a fine projection. The set value of the current density, for example when the material to be deposited was rhodium, the range of ^{1.0A / dm 2 ~4.0A / dm 2} . Note that the value of the current density of manufacturers recommended that a uniform plating thickness is ^{0.8A / dm 2 ~2.5A / dm 2} . In the case of electrolytic plating, to smooth the metal surface,
A leveling agent called a brightening agent is mixed into the plating solution, and adjusting the amount of the leveling agent also changes the surface state of the obtained metal.

The shape of the microprojections depends on how the metal crystals of the contact material to be deposited grow. Depending on various metals, there are those in which the metal crystal easily grows in the height direction and those in which the metal crystal easily spreads in the horizontal direction with respect to the surface serving as the base of deposition (the end face of the conduction path). These can be grown in the above-mentioned conical shape or pyramid shape by changing the amount of the leveling agent and the current density, respectively, and have a shape suitable for breaking through the oxide film on the electrode portion of the semiconductor element. Can be.

Electroless plating is generally used as a base for electrolytic plating or for surface treatment, and is a technique suitable for forming a rough surface and obtaining minute projections in the present invention. Also in this case, the crystallinity of various metals, that is, the growth shape of the surface may be used. Specifically, in the electroless copper plating solution and the interplate solution, the crystals are easily roughened in the height direction, and by setting the immersion time to be long, it is possible to form projections of 2 μm or more.

Next, a method of manufacturing the anisotropic conductive connector 10 of the present invention shown in FIG. 1 will be described. Although the material of the conductive path 2 is as described above, various characteristics such as the conductivity and the elastic modulus of the anisotropic conductive film differ depending on the method of forming the conductive path even with the same metal material. The conductive path may be obtained by depositing a metal material in a through-hole formed in the film 1 by plating. However, the most preferable mode for the present invention is to guide a metal wire through the film 1. This is an embodiment in which a passage is provided. Among metal wires, for example, JI
A metal wire manufactured to conduct electricity, such as a copper wire specified in SC3103, is preferable, and it is a conductive path having the best electrical characteristics, mechanical characteristics, and cost.

In order to obtain a metal wire having the above-described state in which the metal wires penetrate the film 1, a large number of insulated wires are tightly bundled and fixed so as not to be separated from each other. Is used as a cut surface, and a method of slicing to a desired film thickness is exemplified. Among them, the most preferable method for producing the anisotropic conductive connector of the present invention includes a production method having the following steps.

A step of forming one or more coating layers made of an insulating resin on the surface of a metal wire having a diameter of 10 to 100 μm to form an insulated wire, and winding this around a core material. A step of heating and / or pressurizing the coil obtained by the winding, and fusing and / or crimping the wound coating layers of the insulated conductor to integrate them to form a coil block. A step of cutting the coil block obtained in the above step into a predetermined film thickness with a plane intersecting at an angle with the wound insulated conducting wire as a cross section. A step of forming minute projections on the end surfaces of the insulated wires in the film by plating.

The above steps (1) to (3) are methods in which the insulated wires can be bundled most efficiently and densely, and the densest aggregate pattern of the conductive paths 2 can be easily obtained. Further, if the end face of the conduction path is further projected from the film surface, the following steps and / or steps may be performed before the above steps. If the end face of the conduction path is depressed from the film, the following steps may be performed before the above steps.

A step of etching the insulating resin portion of the film-like material obtained above to project a metal conductive wire from the film surface. A step of further depositing a metal on the end face of the metal wire exposed on the film surface of the film-like product obtained above and projecting the metal wire from the film surface. A step of performing etching on the end face of the metal conductor exposed on the film surface of the film-like material obtained above to remove the metal material and depress the metal material from the film surface.

According to the above-described manufacturing method, when forming a coating layer on the surface of a metal conductive wire, it is possible to form multiple layers of materials according to various characteristics such as for insulation and adhesion. The resulting anisotropically conductive connector has various electrical and mechanical properties such as conductivity, dielectricity, insulation, adhesion, and strength that change in the plane direction of the film.

In the above-mentioned manufacturing method, the outer diameter of the metal conductor used in the step is the diameter of the above-mentioned conductive path. The material for forming the film 1 is used as the insulating resin used as the material of the coating layer formed on the surface. In addition, for each step except the step in the above manufacturing method,
The technology described in International Publication WO98 / 07216 “Anisotropic conductive film and method for producing the same” may be referred to.

[0047]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. An anisotropic conductive connector of the present invention was actually manufactured and evaluated.

Example 1 [Production of an anisotropic conductive connector of the present invention] An anisotropic conductive connector shown in FIG. 1 was produced. According to the above-mentioned steps (1) to (3), a film-like product in which a conductive path (diameter: 30 μm, material: copper) penetrates in a thickness direction in a film (thickness: 60 μm, material: polyester resin) was produced. next,
Etching was performed on both surfaces of the film using a plasma etcher such that both ends of the conduction path each protruded from the film surface by about 5 mm. Further, both ends of the conductive path protruding from the film surface are subjected to an etching process (etching solution: PB228, manufactured by Ebara Ujilight Co., Ltd.) for 1 minute, followed by electroless nickel plating (bath bath temperature 85 ° C., 15 ° C.). Min) and electroless gold plating (bath temperature 85 ° C, 10 min) in order, and a height of 1 μm to 5 μm
Are formed on one end face (density of microprojections: 0.1 / μm ² ) to obtain an anisotropic conductive connector of the present invention.

[Continuity test] The anisotropic conductive connector obtained above was inserted between the semiconductor element and the circuit board, and a continuity test was performed by applying pressure. As a semiconductor element, a stud bump (bump diameter 70 μm) formed by a wire bonding method is arranged along a periphery of a silicon chip (10 mm × 10 mm square) by aluminum vapor deposition (interval: 160 μm, 39 in a row, total of 39). 156
) Were used. As a circuit board, an FR4 board (70 mm × 70 mm) made of a known glass epoxy resin board for a circuit board of a semiconductor element is used.
A gold-plated copper wiring (width 100 μm, height 15 μm) is arranged on the surface of a square (mm square) in the same arrangement as the above-described semiconductor element (3 rows per row)
A circuit board formed of nine (a total of 156) was used.

Next, using a flip chip bonder,
The semiconductor element was sucked by a tool for applying heat and pressure of the flip chip bonder, and the circuit board was sucked by the stage of the flip chip bonder. Next, using the upper and lower observation mirrors of the flip chip bonder, the bumps of all the semiconductor elements were arranged so as to correspond to the wiring of the circuit board.

Thereafter, the anisotropic conductive connector prepared in Example 1 was interposed between the semiconductor element and the circuit board, the tool holding the semiconductor element was lowered, and pressure was applied from the semiconductor element side. Was. Next, the resistance value of the wiring portion of the circuit board was measured by a four-terminal method. As a result, resistance values are output at all resistance measurement points at a pressure of 10 g per bump,
It was confirmed that the electrical connection was made. From this, it can be said that complete electrical connection can be obtained with a pressure of 10 g per bump by using the anisotropic conductive connector manufactured in Example 1.

[Confirmation of Pump Deformation After Conduction Inspection] After the continuity inspection, a portion of the bump of the semiconductor element which was in contact with the conduction path of the anisotropic conductive connector was observed. As a result,
The deformation amount of all bumps was 5% or less. The amount of deformation of the bump of 5% or less is a number that is not considered to have a great effect on the amount of solder or conductive adhesive used for connection after the continuity test of the semiconductor element.

Example 2 After a film was produced in the same manner as in Example 1, a stripe pattern (width of a strip-shaped mask portion of 10 μm and width of a strip-shaped exposed portion of 10 μm) was alternately applied to the film-shaped material. Is provided on the film surface using the resist of
Etching was performed at a depth of 5 μm from one end face of the conduction path to obtain a film-like material shown in FIG. Thereby, the area of the end face 21 of the conduction path is 30% to 7% of the sectional area of the conduction path.
It became 0%.

Further, both surfaces of the film were etched in the same manner as in Example 1 to protrude both ends of the conduction path from the film surface, thereby obtaining a film-like material shown in FIG. Further, for this film-like material, as in Example 1,
Fine projections were formed to obtain the anisotropic conductive connector of the present invention.

Using the anisotropic conductive film obtained above, a continuity test was conducted in the same manner as in Example 1. As a result, resistance values were output at all resistance measurement points at a pressure of 7 g per bump, and electrical connection was made. Has been confirmed. Further, when the deformation amount of the bump was also confirmed, the deformation amount of all the bumps was 3% or less.

Comparative Example A film was produced in the same manner as in Example 1. Next, for both end surfaces of the conduction path exposed from the film surface,
The electroless nickel plating treatment (bath bath temperature 85 ° C., 15 minutes) and the electroless gold plating treatment (bath bath temperature 85 ° C., 10 minutes) were sequentially performed to produce an anisotropic conductive connector having no fine protrusions formed thereon.

The continuity test of the anisotropically conductive connector produced above was conducted in the same manner as in Example 1. As a result, a pressure of 20 g per bump was required to obtain complete electrical connection. The amount of deformation of the bump was 20%.

From the above Examples 1 and 2 and Comparative Example, when the anisotropic conductive connector of the present invention is used, electrical connection between the semiconductor element and the circuit board can be obtained at a low pressure, and the bump (electrode) of the semiconductor element can be obtained. It was confirmed that the amount of deformation of (portion) could be suppressed.

[0059]

As is clear from the above description, the anisotropic conductive connector of the present invention has a plurality of minute projections for electrical connection on at least one end face of both end faces of the exposed conductive path. ing. Therefore, when an oxide film is formed on the electrode portion of the semiconductor element, it can be easily broken through. Therefore, at the time of the continuity test, the electrical connection between the semiconductor element and the circuit board can be reliably performed at a lower pressure than in the related art.

Further, since the pressure at the time of the continuity test may be low, deformation at the electrode portion of the semiconductor element can be suppressed. Further, by reducing the area of the end face of the conduction path, deformation of the electrode can be more preferably suppressed.
Therefore, when the electrode portion is a solder bump,
The step of reflowing after the continuity test as in the related art can be omitted. Also, there is no substantial effect on the amount of the conductive adhesive applied.

[Brief description of the drawings]

FIG. 1 is a view showing one example of an anisotropic conductive connector of the present invention.

FIG. 2 is a view showing a film-like object subjected to pattern etching in Example 2. FIG. 2A shows the upper surface of the film-like material, and shows only a part thereof. FIG. 2B shows a cross section of the film-like object along the line AA in FIG. In FIG. 2A, only the end face of the conduction path is hatched. FIG. 2 (b)
Shows only the cut surface.

FIG. 3 is a view showing an anisotropic conductive film of the present invention produced in Example 2.

FIG. 4 shows an already proposed anisotropic conductive connector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Film 2 Conductive path 21, 22 End face of conductive path 2 3 Microprojection 10 Anisotropic conductive connector

Continued on the front page (72) Inventor Fuyuki Eriguchi 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Akiko Matsumura 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko stock F term in the company (reference) 5G307 HA02 HB03 HB06 HC01

Claims (5)

[Claims] A plurality of conductive paths are arranged in a film of an insulating resin so as to penetrate through the front and back of the film in a state of being electrically insulated from each other. An anisotropic conductive connector having a plurality of microprojections on at least one end face of an end face of a passage. 2. The anisotropically conductive connector according to claim 1, wherein an end face of the conduction path protrudes from a film surface. 3. The area of a region obtained by projecting the end face of the conduction path onto the same plane as the film surface is equal to 2% of the sectional area of the conduction path.
The anisotropic conductive connector according to claim 1, wherein the content is 0% to 80%. 4. The density of the fine projections is 0.02 / μm ^2.
The anisotropic conductive connector according to any one of claims 1 to 3, wherein the number of the anisotropic conductive connectors is ² / μm ² . 5. The height of the micro projections is 0.5 μm to 15 μm.
The anisotropic conductive connector according to claim 1, wherein m is m.