JP5018612B2 - Anisotropic conductive sheet and method for producing anisotropic conductive sheet - Google Patents

Description

  The present invention relates to an anisotropic conductive sheet that is electrically connected to a test electrode of a circuit device, for example, and used for conducting a continuity test of the test electrode, and a method for manufacturing the anisotropic conductive sheet.

  The anisotropic conductive sheet has conductivity only in the thickness direction, or has a pressure conductive path forming portion that shows conductivity only in the thickness direction when pressed in the thickness direction, Features such as being able to achieve a compact electrical connection without using means such as soldering or mechanical fitting, and being able to make a soft connection by absorbing mechanical shock and strain It is what has.

  An anisotropic conductive sheet having such features is used in the fields of electronic computers, electronic digital watches, electronic cameras, computer keyboards, etc., for example, with circuit devices such as printed circuit boards and leadless chip carriers, liquid crystal panels, etc. It is widely used because it is suitable as a connector for achieving electrical connection between them.

  In the electrical inspection of circuit devices such as printed circuit boards and semiconductor integrated circuits, for example, electrodes to be inspected formed on one surface of the circuit device to be inspected and for inspection formed on the surface of the circuit substrate for inspection In order to achieve electrical connection with the electrodes, an anisotropic conductive sheet is interposed as a connector between the electrode region of the circuit device and the inspection electrode region of the circuit board for inspection.

  Conventionally, the anisotropic conductive sheet having various structures is known. For example, Patent Document 1 discloses an anisotropic conductive sheet (hereinafter, referred to as an anisotropic conductive sheet) obtained by uniformly dispersing metal particles in a sheet. This is referred to as a “dispersed anisotropic conductive sheet”).

  Further, Patent Document 2 discloses an anisotropic structure in which a plurality of conductive path forming portions extending in the thickness direction and insulating portions that insulate them from each other are formed by unevenly distributing conductive particles in a sheet. A conductive sheet (hereinafter, referred to as an “unevenly anisotropic conductive sheet”) is disclosed.

  Further, in the unevenly distributed anisotropic conductive sheet 100 shown in FIG. 7, the surface of the conductive path forming portion 102 is disclosed having protruding portions 106 and 106 protruding in the vertical direction from the insulating portion 104 ( For example, see Patent Document 3).

Among the anisotropic conductive sheets as described above, in particular, the unevenly distributed anisotropic conductive sheet has the conductive path forming portion formed according to the pattern corresponding to the electrode pattern of the circuit device to be connected. The electrical connection between the electrodes can be achieved with high reliability even for a circuit device or the like in which the arrangement pitch of the electrodes to be connected as compared with the conductive sheet, that is, the distance between the centers of adjacent electrodes is small.
JP 51-93393 A Japanese Patent Laid-Open No. 53-147772 JP-A-61-250906

  However, such an unevenly-distributed anisotropic conductive sheet 100 is connected from the thickness direction (vertical direction indicated by arrows in FIG. 8) when connecting to the inspected electrode of the circuit device as shown in FIG. When a repeated force is applied, the protruding portions 106 and 106 protruding in the vertical direction from the insulating portion 104 of the conductive path forming portion 102 are crushed, and as the circuit board is repeatedly tested for continuity, the crushed protruding portion 106 is cracked. In some cases, such as a problem occurs, or the conductive particles 108 jump out of the cracked part.

  In the present invention, in view of such a current situation, even if the continuity inspection of the inspected electrode of the circuit board is repeatedly performed, the protruding portion of the conductive path forming portion connected to the inspected electrode is locally crushed to cause a crack. An object is to provide an anisotropic conductive sheet excellent in durability and a method for producing the anisotropic conductive sheet.

The present invention was invented in order to achieve the problems and objects in the prior art as described above, the anisotropic conductive sheet of the present invention,
An insulating sheet body made of an elastic polymer material in which a plurality of through-holes each extending in the thickness direction are formed;
A conductive path forming part formed in the plurality of through-holes and containing a conductive material in an elastic polymer substance;
An anisotropic conductive sheet having
The elastic polymer material forming the conductive path forming portion is made of an elastic polymer material that is less susceptible to load deformation than the elastic polymer material forming the insulating sheet body.

Moreover, the manufacturing method of the anisotropic conductive sheet of the present invention is
Preparing a laminate in which thin film layers are formed on both sides of an insulating sheet made of an elastic polymer material,
Forming a plurality of through-holes extending in the thickness direction in the laminate,
A plurality of through-holes in the laminate are filled with a conductive path forming material in which a conductive material is contained in an elastic polymer material that is less susceptible to load deformation than the elastic polymer material forming the insulating sheet body. And a process of
Forming a conductive path forming portion in which a conductive material is magnetically oriented in the thickness direction of the laminate;
Removing each thin film layer formed on both surfaces of the insulating sheet of the laminate;
It is characterized by having.

  In this way, if the elastic polymer material forming the conductive path forming portion is an anisotropic conductive sheet made of an elastic polymer material that is less susceptible to load deformation than the elastic polymer material forming the insulating sheet body, When a force is applied in the thickness direction of the conductive path forming part during the inspection of the substrate, the conductive path forming part is deformed as a whole. It is possible to obtain durability that can be repeatedly used for inspection without causing any problems.

In addition, since the durability of the anisotropic conductive sheet is improved, the cost for inspecting the electrode to be inspected can be suppressed as compared with the conventional case.
As an index for judging the difficulty of deformation of the elastic polymer substance under load, the durometer hardness, international rubber hardness (IRHD) or elastic modulus as defined in JIS K 6253 (ISO 7619) is increased. Any of these may be used, but the durometer hardness generally used in the present invention is adopted as an index.

  By using such an index to obtain the difficulty of load deformation of the conductive path forming portion and the insulating sheet body, the optimum condition of the elastic polymer material forming the conductive path forming portion and the insulating sheet body is determined. You can definitely get it.

The anisotropic conductive sheet of the present invention is
When the durometer hardness after curing of the elastic polymer material forming the conductive path forming portion is 1, the durometer hardness after curing of the elastic polymer material forming the insulating sheet is 0.99 or less, Preferably it is 0.95 or less, More preferably, it is 0.90 or less.

Moreover, the manufacturing method of the anisotropic conductive sheet of the present invention is
When the durometer hardness after curing of the elastic polymer material forming the conductive path forming portion is 1, the durometer hardness after curing of the elastic polymer material forming the insulating sheet is 0.99 or less, Preferably it is 0.95 or less, More preferably, it is 0.90 or less.

  Thus, when the durometer hardness after curing of the elastic polymer material forming the conductive path forming portion is 1, the durometer hardness after curing of the elastic polymer material forming the insulating sheet is 0.99. Below, preferably 0.95 or less, more preferably 0.90 or less, when a force is applied in the thickness direction of the conductive path forming part during the continuity test of the electrode to be inspected on the circuit board, the entire conductive path forming part Therefore, the number of times that can be used for the continuity test can be greatly improved as compared with the conventional case.

The anisotropic conductive sheet of the present invention is
The elastic polymer substance is silicone rubber.
Moreover, the manufacturing method of the anisotropic conductive sheet of the present invention is
The elastic polymer substance is silicone rubber.

  In this way, if the elastic polymer substance is silicone rubber, it can be used in a very wide temperature range of about -40 ° C to about 150 ° C, and durability, molding processability, electrical characteristics, etc. by repeated use are possible. Therefore, it can be suitably used for continuity inspection of the electrode to be inspected on the circuit board.

The anisotropic conductive sheet of the present invention is
The anisotropic conductive sheet is characterized in that a support is disposed on the peripheral edge.
Moreover, the manufacturing method of the anisotropic conductive sheet of the present invention is
In the step of preparing a laminate in which thin film layers are formed on both sides of an insulating sheet made of an elastic polymer material,
The method includes a step of disposing a support body on a peripheral edge portion of the insulating sheet body.

  Thus, if a support body is arrange | positioned in the peripheral part of an anisotropic conductive sheet, positioning with a circuit board and an anisotropic conductive sheet can be favorably performed by a support body.

  According to the present invention, since the conductive path forming portion is formed of an elastic polymer material that is less susceptible to load deformation than the insulating portion, the conductive path formation that is connected to the electrode to be inspected even when the circuit board is repeatedly inspected. The protrusion part of a part does not collapse locally and produces a crack, The anisotropic conductive sheet excellent in durability, and the manufacturing method of an anisotropic conductive sheet can be provided.

Hereinafter, embodiments (examples) of the present invention will be described in more detail with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing a configuration in an example of an anisotropic conductive sheet of the present invention, and FIG. 2 is a schematic diagram showing a configuration in which a support is provided at the peripheral edge in the anisotropic conductive sheet of the present invention. Cross-sectional views, FIGS. 3 and 4 are process diagrams in the method for producing an anisotropic conductive sheet of the present invention, FIG. 5 is a schematic cross-sectional view of a laminate having a support, and FIG. 6 is an anisotropic conductive sheet of the present invention. It is a schematic sectional drawing which shows the state after using a property sheet | seat repeatedly.

  The anisotropic conductive sheet and the method for manufacturing the anisotropic conductive sheet according to the present invention are used for, for example, electrically connecting to an inspected electrode of a circuit device, thereby conducting a continuity test of the inspected electrode. .

<Anisotropic conductive sheet 10>
As shown in FIG. 1, the anisotropic conductive sheet 10 of the present invention includes an insulating sheet body 20 made of an elastic polymer material 18 in which a plurality of through holes 22 extending in the respective thickness directions are formed, and a plurality of sheets. The elastic polymer material 12 is formed in the through hole 22 and is different from the elastic polymer material 18 forming the insulating sheet body 20 described above, and conductive particles as a conductive material in the elastic polymer material 12 14 and the conductive path forming portion 16 including the conductive path forming portion 16, and the conductive path forming portion 16 has protrusions 23 and 23 that protrude in the vertical direction from the surface of the insulating sheet body 20. ing.

  In particular, the elastic polymer material 12 forming the conductive path forming portion 16 is made of a material that is less susceptible to load deformation than the elastic polymer material 18 forming the insulating sheet 20, and the degree of deformation differs between the two. It is configured.

  As such elastic polymer substances 12 and 18, a heat-resistant polymer substance having a crosslinked structure is preferable. Various materials can be used as the curable polymer substance-forming material that can be used to obtain such a crosslinked polymer substance. Specific examples thereof include silicone rubber, polybutadiene rubber, natural rubber, and polyisoprene. Conjugated diene rubbers such as rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber and their hydrogenated products, styrene-butadiene-diene block copolymer rubber, styrene-isoprene block copolymer, etc. Block copolymer rubber and hydrogenated products thereof, chloroprene, urethane rubber, polyester rubber, epichlorohydrin rubber, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, soft liquid epoxy rubber, etc. . Among these, silicone rubber is preferable from the viewpoint of the usable temperature range, molding processability, and electrical characteristics.

  As the silicone rubber, those obtained by crosslinking or condensing liquid silicone rubber are preferable. The liquid silicone rubber may be any of a condensation type, an addition type, a vinyl group or a hydroxyl group-containing one. Specific examples include dimethyl silicone raw rubber, methyl vinyl silicone raw rubber, methyl phenyl vinyl silicone raw rubber, and the like.

  As an index for judging the degree of load deformation of such elastic polymer substances 12 and 18, for example, durometer hardness after the elastic polymer substances 12 and 18 are cured (measured by a method according to JISK6253), elastic modulus , Thickness width and the like.

  Here, when the durometer hardness is used as an index, when the durometer hardness after curing of the elastic polymer material forming the conductive path forming portion 16 is 1, the elastic polymer material forming the insulating sheet body 20 The durometer hardness after curing is usually 0.99 or less, preferably 0.95 or less, more preferably 0.90 or less.

  Furthermore, it is preferable to control the thickness of the insulating sheet body 20 in order to suppress local deformation of the protrusions 23 and 23 of the conductive path forming portion 16. Specifically, when the thickness width T1 of the conductive path forming portion 16 is 100, the thickness width T2 of the insulating sheet body 20 is preferably 95 to 5, more preferably 85 to 15, and further preferably 75 to 25. It is desirable to be. Even if the insulating sheet member 20 is too thin, problems such as difficulty in securing the positional accuracy of the conductive path forming portion 16 may occur.

  In the present specification, durometer hardness is given as an example as an index for determining the degree of deformation of the elastic polymer substances 12 and 18, but is not particularly limited. Any index may be used as long as the elastic polymer material 18 to be formed and the elastic polymer material 12 to form the conductive path forming portion 16 can be reliably identified.

  In the elastic polymer material 12 forming the conductive path forming portion 16, the conductive particles 14 are contained so as to be aligned in the thickness direction of the conductive path forming portion 16. A conductive path is formed in the thickness direction of the conductive path forming portion 16 by the chain of particles 14.

  As such electroconductive particle 14, it is preferable to use what shows magnetism from a viewpoint that the electroconductive particle 14 can be easily moved in the electroconductive path formation material 30 with the manufacturing method mentioned later.

  Specific examples of the conductive particles 14 exhibiting magnetism include particles of metal such as iron, nickel and cobalt, particles of these alloys, particles containing these metals, or these particles as core particles, The surface of the core particle is plated with a metal having good conductivity such as gold, silver, palladium, rhodium, or non-magnetic metal particles or inorganic particles such as glass beads or polymer particles. Examples include those in which the surface of the core particles is plated with a conductive magnetic material such as nickel or cobalt, or the core particles are coated with both a conductive magnetic material and a metal having good conductivity.

  In addition, after forming a base plating layer by performing base plating on the surface of the core particles, the surface of the base plating layer may be plated with a metal having good conductivity to form a coating layer. You may form by the metal layer of.

Among these, it is preferable to use nickel particles as core particles and the surfaces thereof plated with a metal having good conductivity such as gold or silver.
The means for coating the surface of the core particles with the conductive metal is not particularly limited, but can be performed, for example, by electroless plating.

  In the case of using the conductive particles 14 whose core particles are coated with a conductive metal, from the viewpoint of obtaining good conductivity, the coverage of the conductive metal on the particle surface (surface area of the core particles). The ratio of the covering area of the conductive metal with respect to is preferably 40% or more, more preferably 45% or more, and particularly preferably 47 to 95%.

  The coating amount of the conductive metal is preferably 2.5 to 50% by weight of the core particles, more preferably 3 to 45% by weight, still more preferably 3.5 to 40% by weight, and particularly preferably 5%. ~ 30% by weight.

  Moreover, it is preferable that the particle diameter of the electroconductive particle 14 is 1-500 micrometers, More preferably, it is 2-400 micrometers, More preferably, it is 5-300 micrometers, Most preferably, it is 10-150 micrometers.

Moreover, it is preferable that the particle diameter distribution (Dw / Dn) of the electroconductive particle 14 is 1-10, More preferably, it is 1-7, More preferably, it is 1-5, Most preferably, it is 1-4.
By using the conductive particles 14 satisfying such conditions, the anisotropic conductive sheet 10 obtained is easily deformed under pressure, and the conductive path forming portion 16 in the anisotropic conductive sheet 10 is conductive. Sufficient electrical contact between the particles 14 is obtained.

  The shape of the conductive particles 14 is not particularly limited, but is spherical, star-shaped, or aggregated because they can be easily dispersed in the conductive path forming material 30. It is preferable that it is a lump with secondary particles.

Furthermore, the moisture content of the conductive particles 14 is preferably 5% or less, more preferably 3% or less, still more preferably 2% or less, and particularly preferably 1% or less.
Moreover, what processed the surface of the electroconductive particle 14 with coupling agents, such as a silane coupling agent, can be used suitably. By treating the surface of the conductive particles 14 with a coupling agent, the adhesion between the conductive particles 14 and the elastic polymer material 12 is increased, and as a result, the anisotropic conductive sheet 10 obtained can be repeatedly formed. Durability in use is high.

  The amount of the coupling agent to be used is appropriately selected within a range that does not affect the conductivity of the conductive particles 14, but the coverage of the coupling agent on the surface of the conductive particles 14 (the cup relative to the surface area of the conductive core particles). The ratio of the ring agent covering area) is preferably 5% or more, more preferably 7 to 100%, further preferably 10 to 100%, and particularly preferably 20 to 100%. Amount.

  The content ratio of the conductive particles 14 to the conductive path forming material 30 is preferably 10 to 60%, preferably 15 to 50% in terms of volume fraction. When this ratio is less than 10%, the conductive path forming portion 16 having a sufficiently small electric resistance value may not be obtained.

On the other hand, when this ratio exceeds 60%, the obtained conductive path forming portion 16 tends to be fragile, and the elasticity required for the conductive path forming portion 16 may not be obtained.
In the conductive path forming material 30 to be described later, an inorganic filler such as normal silica powder, colloidal silica, airgel silica, or alumina can be contained as necessary. By including such an inorganic filler, the thixotropy of the obtained conductive path forming material 30 is ensured, the viscosity thereof is increased, the dispersion stability of the conductive particles 14 is improved, and the curing treatment is performed. The strength of the conductive path forming part 16 obtained in this way is increased.

  The amount of the inorganic filler used is not particularly limited, but if it is used too much, the movement of the conductive particles 14 due to the magnetic field is greatly hindered in the production method described later.

  In addition, it is preferable that the thickness width T1 of the conductive path formation part 16 is 5 micrometers-10000 micrometers, More preferably, they are 10 micrometers-5000 micrometers, More preferably, they are 30 micrometers-2000 micrometers.

  On the other hand, the thickness width T2 of the insulating sheet body 20 is preferably 1 μm to 9500 μm, more preferably 2 μm to 4750 μm, and further preferably 5 μm to 1900 μm.

  The insulating sheet body 20 forming the anisotropic conductive sheet 10 uses an exposure mask formed according to a pattern corresponding to the pattern of the conductive path forming portion 16 in which each through hole 22 is to be formed. It is formed by irradiating laser light through a mask for use.

  Each through-hole 22 in the insulating sheet body 20 has a shape that forms a columnar internal space extending perpendicularly to one surface and the other surface of the insulating sheet body 20, and is in an independent state, that is, the through-hole 22. The conductive path forming portions 16 formed inside are separated from each other so as to ensure sufficient insulation.

  In addition, as shown in FIG. 2, the support 24 may be arrange | positioned in the peripheral part of the anisotropic conductive sheet 10 mentioned above. The material constituting the support 24 is not particularly limited, but it is preferable to use a material having a certain degree of shape retention so that the insulating sheet 20 made of the elastic polymer substance 18 can be reliably held. For example, it is preferable to use metal or plastic.

As the metal, for example, iron, copper, nickel, titanium, or an alloy or alloy steel thereof can be used.
In addition, as the plastic, for example, a polyimide resin, an epoxy resin, a polycarbonate resin, a polyester resin, or a composition in which glass fibers or fillers are blended with these resins can be used.

As described above, the anisotropic conductive sheet 10 of the present invention is made of the material as described above, and in particular, the elastic polymer material 12 forming the conductive path forming portion 16 forms the insulating sheet body 20. Therefore, even if the continuity inspection of the circuit board is repeatedly performed, the protruding portion 23 of the conductive path forming portion 16 connected to the electrode to be inspected is formed. , 23 are not locally crushed and cracked, and the durability is excellent.
For this reason, since the anisotropic conductive sheet 10 can be used longer than before, the cost required for the continuity inspection of the electrode to be inspected can be suppressed.

<Method for manufacturing anisotropic conductive sheet 10>
Next, a method for manufacturing the anisotropic conductive sheet 10 will be described.

  First, as shown in FIG. 3A, an insulating sheet body 20 made of an elastic polymer material 18 and thin film layers 26 and 26 are formed on one side surface and the other side surface of the insulating sheet body 20, respectively. A laminated body 28 is prepared. For example, an insulating film can be used as the thin film layer 26.

  Next, an exposure mask (not shown) is disposed so as to be in contact with one surface of the laminate 28. In this exposure mask, a light transmitting hole (not shown) is formed in advance at a position corresponding to a plurality of through holes 22 to be described later, and laser light is irradiated through the light transmitting hole. As shown in FIG. 3B, a plurality of through-holes 22 extending in the thickness direction of each laminate 28 are formed.

  In addition, as a laser beam, a carbon dioxide pulse laser etc. can be utilized, for example. Further, specific laser light irradiation conditions can be appropriately selected in consideration of the type of elastic polymer substance 18 constituting the insulating sheet body 20, the thickness width T2, and other structural conditions.

  Next, as shown in FIG. 3C, the conductive path forming material 30 is applied to one surface of the stacked body 28, so that the conductive path forming material 30 is placed inside each of the through holes 22 in the stacked body 28. Fill.

  In addition, the conductive path forming material 30 filled at this time includes the conductive particles 14 in the elastic polymer material 12 that is less susceptible to load deformation than the elastic polymer material 18 forming the insulating sheet body 20. Is. As means for applying the conductive path forming material 30, for example, means by a printing method such as screen printing can be used.

The conductive path forming material 30 is applied to a chamber (not shown) whose internal space is adjusted to a reduced pressure atmosphere of 1 × 10 ⁻³ atm or less, preferably 1 × 10 ⁻⁴ to 1 × 10 ⁻⁵ atm. ), The conductive path forming material 30 is applied using a printing mask, and then the atmospheric pressure in the chamber is increased to, for example, normal pressure, thereby forming a conductive path in the plurality of through holes 22. Filling with material 30 is preferred.

  With such a method, by increasing the atmospheric pressure in the chamber, the conductive path forming material 30 is brought into the through hole 22 due to the pressure difference between the atmospheric pressure and the pressure in the through hole 22 in the laminate 28. It can be filled with high density. For this reason, it can prevent effectively that a bubble arises in the conductive path formation part 16 obtained at the subsequent process.

Next, as shown in FIG. 4A, the laminate 28 in which the through hole 22 is filled with the conductive path forming material 30 is disposed between the upper die 32 and the lower die 34. .
4B, a pair of electromagnets 36 and 38 provided on the upper mold 32 and the lower mold 34 are operated, so that a magnetic field parallel to the thickness direction of the conductive path forming material 30 is obtained. Thus, the conductive particles 14 dispersed in the conductive path forming material 30 are oriented in the thickness direction of the conductive path forming material 30.

In this state, the conductive path forming material 30 is integrally formed in each through-hole 22 of the laminated body 28 by curing the conductive path forming material 30.
The curing process of the conductive path forming material 30 can be performed while the parallel magnetic field is applied, but can also be performed after the parallel magnetic field is stopped.

The intensity of the parallel magnetic field applied to the conductive path forming material 30 is preferably, for example, an average of 0.1 to 3 T (Tesla).
The curing treatment of the conductive path forming material 30 is appropriately selected depending on the material to be used. For example, the laminated body 28 in which the through hole 22 is filled with the conductive path forming material 30 is applied with a predetermined pressing force. It can carry out by heating in the pressed state.

When the conductive path forming material 30 is cured by such a method, the electromagnets 36 and 38 may be provided with heaters (not shown).
Specific pressurizing conditions, heating temperature, and heating time are appropriately selected in consideration of the type of the elastic polymer substance 12 constituting the conductive path forming material 30, the time required to move the conductive particles 14, and the like.

Next, as shown in FIG. 4C, the laminate 28 is taken out from the mold, and the thin film layers 26 and 26 of the laminate 28 are peeled and removed.
Thereby, as shown in FIG. 1, the anisotropic conductive sheet 10 of the present invention having the projecting portions 23, 23 in which the conductive path forming portion 16 projects vertically from the insulating sheet body 20 can be obtained.

  In addition, when manufacturing the anisotropic conductive sheet 10 which has the support body 24 in a peripheral part like the anisotropic conductive sheet 10 shown in FIG. 2, the lamination prepared by the process of FIG. Instead of the body 28, a laminated body 28 in which the support 24 is disposed in advance on the peripheral edge of the insulating sheet body 20, such as the laminated body 28 shown in FIG. 5, may be used.

  In this case, for example, the support 24 is disposed at a predetermined position in the mold for producing the insulating sheet body, and in this state, the paste made of the elastic polymer substance 18 is applied and cured. Thus, it is only necessary to obtain the insulating sheet 20 in which the support 24 is disposed at the peripheral edge.

And the anisotropic conductive sheet 10 which arrange | positions the support body 24 as shown in FIG. 2 in the peripheral part is obtained by passing through the manufacturing process similar to FIG.3 (b)-FIG.4 (c). be able to.
The anisotropic conductive sheet 10 of the present invention is not limited to the manufacturing method described above. For example, in this manufacturing method, an insulating film is provided on the thin film layers 26 and 26 as shown in FIG. Although the case where it was used has been described as an example, various changes can be made, such as making the thin-film layers 26 and 26 easy-to-etch metal plating (for example, copper plating).

  In the case where the thin film layers 26 and 26 are formed by metal plating, the thin film layers 26 and 26 may be removed by immersing the laminated body 28 in an etching solution instead of the step of FIG. good.

  Thus, the anisotropic conductive sheet 10 of the present invention can be variously modified without departing from the object of the present invention.

  Hereinafter, specific examples of the present invention will be described, but the present invention is not limited to the following examples.

[Example 1]
Production of insulating sheet body 20:
As a liquid silicone rubber, Shin-Etsu Chemical Co., Ltd. product: KE-1950-10 (A / B) (with a durometer A hardness of 13 after curing) is prepared and cured to have a thickness width T2 of 100 μm and dimensions. An insulating sheet 20 having a size of 12 mm × 10 mm was obtained.

Preparation of conductive path forming material 30:
As a liquid silicone rubber, Shin-Etsu Chemical Co., Ltd. product: KE-1950-70 (A / B) (with durometer A hardness of 70 after curing) is prepared, and nickel is plated on the surface with an average particle diameter of 20 μm. A conductive path forming material 30 containing the particles 14 was obtained.

  Through the manufacturing process shown in FIGS. 3 to 4 using the insulating sheet 20 and the conductive path forming material 30 described above, the conductive path forming portions 16 are arranged in a row at intervals of 0.5 mm on the center line of the short side. An anisotropic conductive sheet 10 arranged in a row was obtained.

In addition, the conductive path formation part 16 in the anisotropically conductive sheet 10 obtained was a cylindrical shape having a diameter of 300 μm and a thickness width T1 of 170 μm.
The anisotropic conductive sheet 10 is positioned so that each conductive path forming portion 16 of the anisotropic conductive sheet 10 is connected to the inspected electrode of the circuit device, and a load of 30 g is applied to each conductive path forming portion 16. The load is repeatedly applied by adjusting as described above, and after applying a predetermined number of loads, the anisotropic conductive sheet 10 is taken out and the resistance value of the conductive path forming portion 16 is measured, and the protrusion 23 of the conductive path forming portion 16 is measured. The height was measured. The measurement was carried out for all 10 conductive path forming portions 16, and the average was taken as the measurement result.

  The resistance value was measured in a state where a load of 30 g was applied. Moreover, the height of the protrusion part 23 was measured using COMMS Co., Ltd. three-dimensional shape measurement system: MAP-3D in the state which does not apply a load.

  The measurement results are as shown in Table 1.

実施例１の測定結果からすれば、異方導電性シート１０の抵抗値は、初期値から５００００回経過後に至るまで殆ど変化がなかった。

From the measurement result of Example 1, the resistance value of the anisotropic conductive sheet 10 hardly changed until 50000 times from the initial value.

  Also, the height of the protrusion 23 hardly changed from the initial value to 50,000 times, and it was confirmed that the anisotropic conductive sheet 10 of Example 1 can be used for the repeated load inspection of 50,000 times. .

  The state of the longitudinal cross section of the anisotropic conductive sheet 10 after 50,000 repetitions of the load is shown in FIG. 6, and the entire conductive path forming portion 16 bulges slightly toward the insulating sheet body 20 and deforms into a drum shape. However, it was confirmed that the projecting portions 23 and 23 were hardly deformed, and the pressure received from the thickness direction by the repeated load was received by the entire conductive path forming portion 16.

[Comparative Example 1]
The liquid silicone rubber used for the insulating sheet body 20 and the conductive path forming material 30 is also manufactured by Shin-Etsu Chemical Co., Ltd .: KE-1950-70 (A / B) (with a durometer A hardness of 70 after curing) The continuity test was conducted in the same manner as in Example 1 except that the anisotropic conductive sheet 10 was obtained.

The measurement results are as shown in Table 1.
According to the measurement result of Comparative Example 1, the resistance value of the anisotropic conductive sheet 10 increased rapidly after 100 times, and the resistance could not be measured after 50000 times.

  Moreover, about the height of the protrusion part 23, it decreased rapidly after 100 times, and when it was 50000 times, it was confirmed that the protrusion part 23 has almost no height and the crack and crushing have arisen. Further, when the longitudinal section of the conductive path forming portion 16 was observed, it was confirmed that the conductive path forming portion 16 in contact with the insulating sheet body 20 was hardly deformed and only the protruding portions 23 and 23 were crushed. It was done.

  That is, the state of the anisotropic conductive sheet 10 after 50,000 repetitions of the load is similar to the view shown in FIG. 8 in that only the protrusions 23 and 23 of the conductive path forming part 16 are partially distorted. Thus, it was confirmed that the pressure received from the thickness direction was concentrated on the protrusions 23 and 23.

  As described above, the insulating sheet body 20 is formed from the elastic polymer material 12 forming the conductive path forming portion 16 like the anisotropic conductive sheet 10 of the present invention by comparing Example 1 and Comparative Example 1. If formed from an elastic polymer material that is less susceptible to load deformation than the elastic polymer material 18, the protruding portion of the conductive path forming portion 16 connected to the electrode to be inspected even if the continuity inspection of the electrode to be inspected is repeated. 23 and 23 were not locally crushed and cracked, and it was proved to be excellent in durability.

FIG. 1 is a schematic cross-sectional view showing a configuration in an example of an anisotropic conductive sheet of the present invention. FIG. 2 is a schematic cross-sectional view showing a configuration in which a support is provided at the peripheral edge in the anisotropic conductive sheet of the present invention. 3A and 3B are process diagrams in the method for manufacturing an anisotropic conductive sheet of the present invention, in which FIG. 3A is a process diagram for preparing a laminate, and FIG. 3B is a process for forming a through hole in the laminate. FIG. 3C is a process diagram in which a through hole is filled with a conductive path forming material in which a conductive material is contained in an elastic polymer substance. FIG. 4 is a process diagram in the method for producing an anisotropic conductive sheet of the present invention, in which FIG. 4 (a) is a process diagram in which a laminate is disposed in a mold, and FIG. 4 (b) is a diagram of the laminate. FIG. 4C is a process diagram for obtaining an anisotropic conductive sheet by removing a thin film layer from a magnetically oriented laminate. FIG. 5 is a schematic cross-sectional view of a laminate having a support. FIG. 6 is a schematic cross-sectional view showing a state after repeatedly using the anisotropic conductive sheet of the present invention. FIG. 7 is a schematic cross-sectional view showing a configuration of a conventional unevenly distributed anisotropic conductive sheet. FIG. 8 is a schematic cross-sectional view showing a state after repeatedly using a conventional unevenly distributed anisotropic conductive sheet.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Anisotropic conductive sheet 12 ... Elastic polymer substance 14 ... Conductive particle 16 ... Conduction path formation part 18 ... Elastic polymer substance 20 ... Insulating sheet body 22. ..Through hole 23 ... projection 24 ... support 26 ... thin film layer 28 ... laminated body 30 ... conductive path forming material 32 ... upper die 34 ... lower die 36 ... Electromagnet 38 ... Electromagnet T1 ··· Thickness width of the conductive path forming portion T2 ··· Thickness width of the insulating sheet body 100 · · · An unevenly distributed anisotropic conductive sheet 102 · · · Conductive path forming portion 104 · · ..Insulating portion 106 ... protruding portion 108 ... conductive particles

Claims (10)

An insulating sheet body made of an elastic polymer material in which a plurality of through-holes each extending in the thickness direction are formed;
A conductive path forming part formed in the plurality of through-holes and containing a conductive material in an elastic polymer substance;
An anisotropic conductive sheet having
An anisotropic conductive sheet, wherein the elastic polymer material forming the conductive path forming portion is made of an elastic polymer material that is less susceptible to load deformation than the elastic polymer material forming the insulating sheet body.   The anisotropic conductive sheet according to claim 1, wherein an index for determining the difficulty of load deformation of the elastic polymer substance is durometer hardness.   When the durometer hardness after curing of the elastic polymer material forming the conductive path forming portion is 1, the durometer hardness after curing of the elastic polymer material forming the insulating sheet body is 0.99 or less. The anisotropic conductive sheet according to claim 2, wherein the anisotropic conductive sheet is provided.   The anisotropic conductive sheet according to claim 1, wherein the elastic polymer substance is silicone rubber.   The anisotropic conductive sheet according to any one of claims 1 to 4, wherein the anisotropic conductive sheet is provided with a support at a peripheral portion thereof. Preparing a laminate in which thin film layers are formed on both sides of an insulating sheet made of an elastic polymer material,
Forming a plurality of through-holes extending in the thickness direction in the laminate,
A plurality of through-holes in the laminate are filled with a conductive path forming material in which a conductive material is contained in an elastic polymer material that is less susceptible to load deformation than the elastic polymer material forming the insulating sheet body. And a process of
Forming a conductive path forming portion in which a conductive material is magnetically oriented in the thickness direction of the laminate;
Removing each thin film layer formed on both surfaces of the insulating sheet of the laminate;
A method for producing an anisotropic conductive sheet, comprising:   The method for producing an anisotropic conductive sheet according to claim 6, wherein the index for determining the difficulty of load deformation of the elastic polymer substance is durometer hardness.   When the durometer hardness after curing of the elastic polymer material forming the conductive path forming portion is 1, the durometer hardness after curing of the elastic polymer material forming the insulating sheet body is 0.99 or less. The method for producing an anisotropic conductive sheet according to claim 7, wherein the anisotropic conductive sheet is provided.   The method for producing an anisotropic conductive sheet according to claim 6, wherein the elastic polymer substance is silicone rubber. In the step of preparing a laminate in which thin film layers are formed on both sides of an insulating sheet made of an elastic polymer material,
The method for producing an anisotropic conductive sheet according to any one of claims 6 to 9, further comprising a step of disposing a support body at a peripheral edge portion of the insulating sheet body.

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