JP2003021648A - Manufacturing method of anisotropic conductive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of manufacturing, easily and highly accurately, an anisotropic conductive sheet having high connection reliability, capable of performing sufficiently electric inspection while securing the required position accuracy, even when an electrode to be inspected of an inspection object circuit board has a minute electrode pitch and a fine, high-density and complex pattern. SOLUTION: In this manufacturing method of the anisotropic conductive sheet, a molding material layer comprising polymer material containing conductive particles having magnetism is arranged between a pair of insulating sheet bodies having an opening part corresponding to the electrode to be inspected of the inspection object circuit board, and a parallel magnetic field is applied thereto in the thickness direction to move and simultaneously pressurize the conductive particles, and the polymer material in the molding material layer is fluidized, to thereby change the external shape thereof, and the polymer material is hardened to acquire a polymer substance. Hereby, the anisotropic conductive sheet body is formed, and the state where either of the pair of insulating sheet bodies is bonded to the anisotropic conductive sheet body is acquired.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to achieve electrical connection between a circuit board to be inspected and an electrical inspection device in order to inspect the electrical performance of the printed circuit board or the like as an inspection object. The present invention relates to a method for manufacturing an anisotropic conductive sheet used in.

[0002]

2. Description of the Related Art Generally, a circuit board such as a printed circuit board tends to have an increased number of electrodes and a higher density, and the wiring tends to be complicated accordingly. For this reason, a multilayer substrate including an inner layer circuit board and an outer layer circuit board has been widely used. In addition, in order to improve productivity, in manufacturing, a plurality of identical circuit boards are formed on one base material to proceed with the manufacturing, which is a multifaceted process. In order to achieve electrical connection between the lead electrode of the inner layer circuit board and other circuit terminals to be connected to the lead electrode, conventionally,
An anisotropic conductive sheet is interposed on each lead electrode region. This anisotropically conductive sheet is one that exhibits conductivity only in the thickness direction, or one that has a large number of pressed conductive parts that exhibit conductivity only in the thickness direction when pressed, and various For example, Japanese Patent Publication Sho 5
6-48951, JP-A-51-93393, JP-A-53-147772, JP-A-54-1.
It is known from Japanese Patent No. 46873. Each of the above anisotropic conductive sheets had a pressure conductive portion at any point on the sheet.

[0003]

However, an anisotropic conductive sheet having a pressure conductive conductive portion at an arbitrary point on a conventional sheet is used for a circuit board such as an inner layer circuit board where a wiring portion is exposed. It did not always exhibit sufficient performance for inspection. Furthermore, with respect to the tendency of increasing the wiring density of the inner layer circuit board in recent years and increasing the size accompanying the multifaceting during manufacturing, it becomes more and more difficult to inspect using a conventional anisotropic conductive sheet. Is coming. The present invention solves the above problems, and its purpose is to:
The electrodes to be inspected such as the lead electrodes on the circuit board to be inspected have a fine electrode pitch and have a fine and high-density complex pattern, and the fine wiring connected to these lead electrodes is exposed. In this case, the required electrical connection can be reliably achieved for the circuit board, and therefore the connection reliability is high, and the circuit board can be sufficiently inspected while ensuring the required positional accuracy. An object of the present invention is to provide a method capable of easily producing an anisotropic conductive sheet that can be produced with high accuracy.

[0004]

A method of manufacturing an anisotropic conductive sheet according to the present invention uses a pair of insulating sheet bodies having openings corresponding to electrodes to be inspected of a circuit board to be inspected, and the pair of insulating sheets. A molding material layer made of a polymer material containing conductive particles having magnetism is arranged between the bodies, and a parallel magnetic field is applied to the molding material layer in the thickness direction to move the conductive particles by the magnetic force. While applying pressure, the polymeric material of the molding material layer is caused to flow to change its outer shape, and the polymeric material is cured to form a polymeric substance, thereby forming an anisotropic conductive sheet body, and At least one of the pair of insulating sheet members is joined to the anisotropic conductive sheet member.

Further, in the method for manufacturing an anisotropic conductive sheet of the present invention, the opening covering sheet is covered by a pair of insulating sheet bodies having openings corresponding to the electrodes to be inspected of the circuit board to be inspected. And a pair of insulating sheet bodies provided with the opening covering sheet are aligned so that the corresponding openings face each other, and in this state, a molding made of a polymer material containing conductive particles having magnetism is formed. A material layer is arranged, and a mixture sheet composed of a pair of insulating sheet bodies provided with an opening covering sheet and a molding material layer is pressed to flow the polymer material of the molding material layer and change its outer shape, By applying a parallel magnetic field to the molding material layer in the thickness direction and moving the conductive particles by the magnetic force, the polymer material is cured into a polymer substance, whereby an anisotropic conductive sheet body is formed. , An anisotropic conductive sheet material layer integrated product in which an insulating sheet body provided with an opening covering sheet is integrally joined, and both opening covering sheets are obtained from the anisotropic conductive sheet material layer integrated product And removing one insulating sheet body.

According to the method of the present invention, the anisotropic conductive sheet produced has a plurality of conductive portions extending in the thickness direction while being insulated from each other by the insulating portions, and the conductive portions are on one surface side. And an anisotropic conductive sheet body in which conductive particles are densely filled in a polymeric substance which is insulative and elastic and which forms a protrusion corresponding to the electrode to be inspected of the circuit board to be inspected. A conductive sheet integrally bonded to the one surface side of the anisotropic conductive sheet body, the insulating sheet body having an opening corresponding to the electrode to be inspected of the circuit board to be inspected. It is possible to manufacture a structure in which such a protruding portion protrudes into the opening of the insulating sheet body and the surface of the end portion of the protruding portion is at substantially the same level as the surface of the insulating sheet body. Therefore, the electrodes to be inspected such as the lead electrodes on the circuit board to be inspected have a fine electrode pitch, and have a fine and high-density complex pattern,
Even if the fine wiring connected to these lead electrodes is exposed, it is possible to reliably achieve the required electrical connection of the circuit board, and therefore the connection reliability is high and the required position accuracy is high. It is possible to easily and highly accurately manufacture the anisotropic conductive sheet capable of sufficiently inspecting the circuit board while ensuring the above.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the drawings. First, the structure of the anisotropic conductive sheet manufactured by the method of the present invention will be described. 9 and 10 show a specific example of the configuration of the anisotropic conductive sheet 11 manufactured by the method of the present invention, in which the insulating sheet body 1 is arranged on one surface of the anisotropic conductive sheet body 8. Are joined together. In this anisotropic conductive sheet body 8, a plurality of conductive portions 10 extending in the thickness direction are
The conductive portions 10 are arranged corresponding to the electrodes to be inspected on the circuit board to be inspected while being insulated from each other by the insulating portion 12.
Is projected into the opening 2 of the insulating sheet body 1, and the surface of the protruding end portion of the conductive portion 10 is formed in a shape having substantially the same level as the surface of the insulating sheet body 1.

Each of the conductive parts 10 is formed by densely filling conductive particles 5 in a polymeric substance 4 which is insulative and has elasticity, and usually has a pressure conductivity in which a resistance value is reduced by pressurization. . The filling rate of the conductive particles 5 in the conductive portion 10 is 3 vol% or more and 30 vol% or less, preferably 5 vol% or more 20
Volume% or less. When the filling rate of the conductive particles 5 is low, the resistance value does not decrease even if the applied pressure is increased, and thus reliable electrical connection becomes difficult. The thickness D of the conductive portion 10 is preferably 0.1 to 5 mm, particularly 0.3 to 3 mm. If the thickness D of the conductive portion 10 is within this range, effective conductivity can be reliably obtained even with a small pressure.

The thickness d of the insulating sheet 1 is practically 0.01 to 0.8 mm, particularly preferably 0.02.
It is 0.2 mm. When the thickness d of the insulating sheet body 1 is within this range, the displacement of the conductive portion due to the molding strain generated during the molding in the production of the anisotropic conductive sheet body 8 is suppressed within the range that can sufficiently withstand the circuit board inspection. In addition, effective conductivity can be reliably obtained even with a small pressure. The height h of the conductive portion 10 protruding into the opening 2 of the insulating sheet body 1 is preferably the same as the thickness d of the insulating sheet body 1.

The conductive particles 5 constituting the conductive portion 10 are, for example, particles of a metal exhibiting magnetism such as nickel, iron and cobalt, particles of an alloy thereof, or gold, silver, palladium, rhodium and the like. And non-magnetic metal particles or glass beads or other inorganic particles or polymer particles plated with a conductive magnetic material such as nickel or cobalt. From the viewpoint of reducing the manufacturing cost, particles of nickel, iron or alloys thereof are particularly preferable,
In addition, gold-plated particles can be preferably used in terms of electrical characteristics such as low contact resistance.

The particle size of the conductive particles 5 is 10 to 4 from the viewpoint of ensuring sufficient electrical contact between the conductive particles in the conductive portion 10 and maintaining sufficient contact stability of the conductive portion 10.
00 μm is preferable, and 20 to 100 μm is particularly preferable.

As the insulating and elastic polymer substance forming the conductive portion 10, a polymer substance having a crosslinked structure is preferable, and an uncrosslinked polymer that can be used to obtain the polymer substance having such a crosslinked structure. Materials include silicone rubber, polybutadiene, natural rubber, polyisoprene, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, ethylene-propylene copolymer rubber, urethane rubber, polyester rubber, chloroprene rubber, epichlorohydrin. Examples thereof include rubber.

Further, as the insulating sheet body 1, the above-mentioned insulating and elastic polymer substance, which is mentioned as a constituent of the conductive portion 10 of the anisotropic conductive sheet body 8, or a thermoplastic resin such as polyethylene. Terephthalate resin, vinyl chloride resin, polystyrene resin, polyacrylonitrile resin, polyethylene resin, acrylic resin, polybutadiene resin, etc., thermosetting resin such as polyimide resin,
Epoxy resin or the like is used.

Next, a method for manufacturing the anisotropic conductive sheet of the present invention will be described. 1 is an explanatory perspective view showing two insulating sheet bodies in which openings corresponding to electrodes to be inspected of a circuit board to be inspected are formed, FIG. 2 is a sectional view for the same explanation, and FIG. 4 is an explanatory cross-sectional view showing a state in which the adhesive sheet is attached to the two insulating sheet bodies in which the parts are formed.
Is an explanatory cross-sectional view showing a state in which a layer of a molding material made of a mixture of conductive particles having magnetic properties and a polymer material is arranged between two insulating sheet bodies to which an adhesive sheet is attached,
FIG. 5 is an explanatory sectional view showing a state in which a pressing force and a parallel magnetic field are applied to the layer of the molding material of FIG.

As shown in FIGS. 1 and 2, in the insulating sheet body 1, a circular opening having a diameter substantially the same as the width of the electrode to be inspected is formed in a portion of the circuit board to be inspected corresponding to the electrode to be inspected. 2 is formed by using an NC controlled drilling device, a laser processing device using an excimer laser beam as a light source, or the like. Two such insulating sheet bodies 1 are prepared. 6 is a guide hole.

Next, as shown in FIG. 3, an adhesive sheet 3 having a smooth surface and a uniform thickness covers the opening 2 of the insulating sheet body 1 and its periphery, and two sheets are formed by a guide pin or the like. In a state in which the corresponding openings 2 of the insulating sheet body 1 are aligned so as to face each other, as shown in FIG.
An anisotropic conductive sheet material layer 20 is formed by forming a layer of a molding material (also referred to as a “mixture sheet”) made of a mixture of magnetically conductive particles 5 and a polymer material 4A serving as a polymer substance 4. To get

Next, as shown in FIG. 5, the anisotropic conductive sheet material layer 20 composed of the two insulating sheet bodies 1 and the layer of the molding material is pressed to flow the molding material and the outer shape of the mixture sheet. And a parallel magnetic field is applied in the thickness direction of the mixture sheet while changing the
The anisotropically conductive sheet material layer integrated as shown in FIG. 8 in which two insulating sheet bodies 1 and the cured molding material layer are integrated by curing the molding material while orienting the mixture sheet in the thickness direction of the mixture sheet. Compound 20A is manufactured. Cross-linking is generally used as a means for curing the molding material after changing the outer shape of the mixture sheet. Next, FIG.
As shown in FIG. 3, both the adhesive sheet 3 and one of the insulating sheet bodies 1 are removed to manufacture the anisotropic conductive sheet 11.

The mold shown in FIG. 5 is composed of an upper mold 21 and a lower mold 22, each of which constitutes an electromagnet. The upper mold 21 and the lower mold 22 have a ferromagnetic pattern of a pattern corresponding to the electrodes to be inspected of the circuit board to be inspected. The body portion M and the other non-magnetic body portion N,
A magnetic pole plate 23 and a magnetic pole plate 24 having flat surfaces are provided.

Instead of the pole plate 23 and the pole plate 24,
As shown in FIG. 6, a ferromagnetic material portion M having a pattern corresponding to the electrodes to be inspected of the circuit board to be inspected and a non-magnetic material portion N other than the pattern are formed.
It is also possible to use the magnetic plates 25 and 26 in which the ferromagnetic material portion M projects from the non-magnetic material portion N on the upper surface of 2. In this case, a stronger parallel magnetic field is applied to the anisotropic conductive sheet material layer 20 in the conductive portion arranged corresponding to the electrode to be inspected of the circuit board to be inspected.

Instead of the magnetic pole plate 23 and the magnetic pole plate 24, ferromagnetic plates 27 and 28 having a smooth surface and a uniform thickness can be used as shown in FIG. In this case, a uniform parallel magnetic field is applied at any point on the anisotropic conductive sheet material layer 20. In this case, the electric resistance value in the conductive portion of the formed anisotropically conductive sheet, which is arranged corresponding to the electrode to be inspected of the circuit board to be inspected, is the magnetic pole plate 23 and the magnetic pole plate 24 or the magnetic pole plate 25 and the magnetic pole plate 26. It shows a slightly higher value than the case of molding using.

Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0022]

[Example] Thickness 0.05 mm, length 300 mm, width 400
2 sheets of polyethylene terephthalate sheet are piled up, and an NC controlled drilling device is used to form an opening 2 with a hole having a diameter of 0.2 mm at the position corresponding to the electrode to be inspected on the circuit board to be inspected and four corners of the sheet. Four guide holes 6 having a diameter of 3.0 mm were punched (see FIGS. 1 and 2) to form two insulating sheet bodies 1. Next, the opening 2 excluding the guide hole 6 of the two insulating sheet bodies 1 and the periphery thereof were covered with a polyimide adhesive sheet 3 having a thickness of 0.05 mm (see FIG. 3). Next, the surface of one of the two insulating sheet bodies 1 was roughened with # 600 sandpaper, and a thermosetting silicone rubber was thinly applied to the surface.

Next, a molding material is prepared by mixing room temperature curable silicone rubber with magnetic conductive particles 5 made of gold-plated nickel having an average particle diameter of 40 μm at a ratio of 12% by volume, and this is prepared as described above. The anisotropic conductive sheet material layer 20 was formed by arranging it between a pair of insulating sheet bodies, and this was arranged in the cavity of the mold. This mold is composed of an upper mold 21 and a lower mold 22 which respectively form an electromagnet, and the upper mold 21 and the lower mold 22 each have a ferromagnetic portion M having a pattern corresponding to an electrode to be inspected of a circuit board to be inspected. The magnetic pole plate 23 and the magnetic pole plate 24, which are made of the other non-magnetic material portion N and have a flat surface, are provided. The ferromagnetic pin portions M of the magnetic pole plate 23 and the magnetic pole plate 24 and the openings 2 of the insulating sheet body 1 of the anisotropic conductive sheet material layer 20 were aligned by the guide pin so as to overlap with each other (FIG. 5). reference). In this state, the electromagnets of the upper die 21 and the lower die 22 are operated, thereby applying a pressing force and a parallel magnetic field in the thickness direction of the anisotropic conductive sheet material layer 20, and in this state, 60 ° C.
After being left for 8 hours to cure, the polyimide adhesive tape 3 and one of the pair of insulating sheet bodies 1 are removed, and one insulating sheet body 1 and an anisotropic conductive sheet body 8 made of the cured molding material are removed. An anisotropic conductive sheet 11 was manufactured.

Using the anisotropic conductive sheet obtained in the above example, an electrical inspection was conducted with the constitution shown in FIG. In FIG. 11, 61 is an inspection head, 62 is an anisotropic conductive sheet, 63 is an off-grid adapter, 64 is a printed circuit board to be inspected, 64A is an electrode to be inspected, 65
Is an inspection electrode. The anisotropic conductive sheet 62 of this example is
It has a plurality of conductive parts in the thickness direction and has a flat surface. All the wiring parts of the printed circuit board 64 to be inspected are exposed, and the minimum pitch of the wiring and the electrodes to be inspected was as small as 0.5 mm, but the electrical continuity and short circuit of the circuit board to be inspected with sufficient performance. Could be inspected.

[0025]

According to the method of the present invention, the anisotropic conductive sheet produced has a plurality of conductive portions extending in the thickness direction while being insulated from each other by the insulating portions, and the conductive portions are An anisotropic conductive sheet body, in which conductive particles are densely filled in a polymeric substance having insulation and elasticity, forming a protrusion corresponding to the electrode to be inspected of the circuit board to be inspected on one surface side, The anisotropic conductive sheet body is integrally joined to the one surface side, and the insulating sheet body has an opening corresponding to the electrode to be inspected of the circuit board to be inspected. It is possible to manufacture a structure in which the projecting part of the projecting part projects into the opening of the insulating sheet body and the surface of the end of the projecting part is at substantially the same level as the surface of the insulating sheet body. Therefore, the electrodes to be inspected such as the lead electrodes on the circuit board to be inspected have a fine electrode pitch, and have a fine and high-density complex pattern,
Even if the fine wiring connected to these lead electrodes is exposed, it is possible to reliably achieve the required electrical connection of the circuit board, and therefore the connection reliability is high and the required position accuracy is high. It is possible to easily and highly accurately manufacture the anisotropic conductive sheet capable of sufficiently inspecting the circuit board while ensuring the above.

[Brief description of drawings]

FIG. 1 is an explanatory perspective view showing two insulating sheet bodies used in a method of the present invention in a state where openings corresponding to electrodes to be inspected of an inspection target circuit board are formed.

FIG. 2 is an explanatory cross-sectional view showing two insulating sheet bodies used in the method of the present invention in a state where openings corresponding to electrodes to be inspected of an inspection target circuit board are formed.

FIG. 3 is an explanatory cross-sectional view showing a state in which an adhesive sheet is attached to two insulating sheet bodies.

FIG. 4 is a view showing a case where a pressure-sensitive adhesive sheet is attached to a layer of a molding material made of a mixture of magnetic conductive particles and a polymer material.
It is an explanatory sectional view showing a state of being arranged between a plurality of insulating sheet bodies.

5 is an explanatory cross-sectional view showing a state in which a pressing force and a parallel magnetic field are applied to the layer of the molding material of FIG.

FIG. 6 is an explanatory sectional view showing a state similar to that of FIG. 5 when a mold having another magnetic pole plate is used.

FIG. 7 is an explanatory cross-sectional view showing a state similar to that of FIG. 5 when a die having a ferromagnetic plate is used instead of the magnetic pole plate.

FIG. 8 is an explanatory cross-sectional view showing an integrated material layer for anisotropically conductive sheet in which an insulating sheet body and an anisotropically conductive sheet body are integrally molded.

9 is an explanatory cross-sectional view showing a completed anisotropically conductive sheet obtained by removing both the pressure-sensitive adhesive sheet and one of the insulating sheet members from the material layer integrated product for anisotropically conductive sheet of FIG.

FIG. 10 is an explanatory perspective view showing a completed anisotropic conductive sheet obtained by removing both the pressure sensitive adhesive sheet and one of the insulating sheet bodies from the material layer integrated product for anisotropic conductive sheet of FIG.

FIG. 11 is an explanatory cross-sectional view showing the configuration of an apparatus that performs an electrical inspection using the anisotropic conductive sheet manufactured in the example.

[Explanation of symbols]

1 Insulation sheet body 2 openings 3 Adhesive sheet 4 Insulating and elastic polymer substances 4A polymer material 5 Conductive particles 6 guide holes 7 Spacer 8 Anisotropically conductive sheet body 10 Conductive part 11 Anisotropically conductive sheet 12 Insulation part 20 Material layer for anisotropic conductive sheet 20A Anisotropically conductive sheet material layer integrated product 21 Upper mold 22 Lower mold 23 Magnetic pole plate 24 pole plate 25 pole plate 26 pole plate 27 Magnetic pole plate 28 Magnetic pole plate M Ferromagnetic part N Non-magnetic material part 61 Inspection head 62 Anisotropically conductive sheet 63 Off-grid adapter 64 printed circuit board 64A Inspected electrode 65 inspection electrodes

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // B29K 105: 16 B29K 105: 16 B29L 31:00 B29L 31:00 F term (reference) 2G011 AA16 AB06 AB08 AC14 AE01 AE03 2G014 AA02 AA03 AB59 AC06 4F204 AA33 AA45 AB13 AB16 AD05 AD08 AD24 AE03 AE04 AG05 AH36 AM29 FA01 FB01 FB11 FF01 FN11 FN17 FN30

Claims (6)

[Claims] 1. A polymer material comprising a pair of insulating sheet bodies having openings corresponding to electrodes to be inspected of a circuit board to be inspected, and containing conductive particles having magnetism between the pair of insulating sheet bodies. A molding material layer made of, and applying a parallel magnetic field in the thickness direction to the molding material layer to move the conductive particles by the magnetic force and pressurize to flow the polymer material of the molding material layer While changing the outer shape, the polymer material is cured into a polymer substance, thereby forming an anisotropic conductive sheet body, and at least one of the pair of insulating sheet bodies is the anisotropic conductive sheet body. A method for producing an anisotropically conductive sheet, characterized in that the sheet is joined to a body. 2. An opening covering sheet is provided on a pair of insulating sheet bodies having openings corresponding to electrodes to be inspected of a circuit board to be inspected, the pair of insulating sheet bodies being provided with the opening covering sheet. The insulating sheet body is aligned such that the corresponding openings face each other, and in this state, a molding material layer made of a polymer material containing conductive particles having magnetism is arranged, and an opening covering sheet is provided. A mixture sheet composed of a pair of insulating sheet bodies and a molding material layer is pressed to flow the polymer material of the molding material layer to change its outer shape and to be parallel to the molding material layer in its thickness direction. An insulating sheet body in which an opening covering sheet is provided on an anisotropic conductive sheet body by curing a polymer material while moving conductive particles by applying a magnetic field to move the conductive particles. Is obtained by integrally joining the anisotropic conductive sheet material layer integrated product, and removing both opening covering sheets and one insulating sheet body from the anisotropic conductive sheet material layer integrated product. And a method for producing an anisotropically conductive sheet. 3. An anisotropic conductive sheet to be produced has a plurality of conductive parts extending in the thickness direction while being insulated from each other by an insulating part, and the conductive parts are on one surface side of a circuit board to be inspected. An anisotropic conductive sheet body, in which conductive particles are densely filled in a polymeric substance having insulating properties and elasticity, which forms a protrusion corresponding to an electrode to be inspected, and the anisotropic conductive sheet body. An insulating sheet body integrally bonded to the one surface side and having an opening corresponding to the electrode to be inspected of the circuit board to be inspected, wherein the protrusion of the conductive portion of the anisotropically conductive sheet body is the insulating layer. 2. The sheet body protruding into the opening of the sheet body, and the surface of the end portion of the projecting portion is at substantially the same level as the surface of the insulating sheet body.
Alternatively, the method for manufacturing the anisotropic conductive sheet according to claim 2. 4. A parallel magnetic field is applied by using a magnetic pole plate in which a ferromagnetic material portion is arranged corresponding to an opening portion corresponding to an inspection electrode of a circuit board to be inspected in a pair of insulating sheets. A method for manufacturing the anisotropically conductive sheet according to claim 1. 5. The method for producing an anisotropically conductive sheet according to claim 4, wherein a magnetic pole plate having a flat surface is used. 6. The method for producing an anisotropic conductive sheet according to claim 4, wherein a magnetic plate having a ferromagnetic portion projected is used.