WO2023153313A1 - Designing method for conductive film - Google Patents

Designing method for conductive film Download PDF

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Publication number
WO2023153313A1
WO2023153313A1 PCT/JP2023/003440 JP2023003440W WO2023153313A1 WO 2023153313 A1 WO2023153313 A1 WO 2023153313A1 JP 2023003440 W JP2023003440 W JP 2023003440W WO 2023153313 A1 WO2023153313 A1 WO 2023153313A1
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lattice
conductive particles
film
conductive film
conductive
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PCT/JP2023/003440
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French (fr)
Japanese (ja)
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怜司 塚尾
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デクセリアルズ株式会社
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Publication of WO2023153313A1 publication Critical patent/WO2023153313A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R11/00—Individual connecting elements providing two or more spaced connecting locations for conductive members which are, or may be, thereby interconnected, e.g. end pieces for wires or cables supported by the wire or cable and having means for facilitating electrical connection to some other wire, terminal, or conductive member, blocks of binding posts
    • H01R11/01—Individual connecting elements providing two or more spaced connecting locations for conductive members which are, or may be, thereby interconnected, e.g. end pieces for wires or cables supported by the wire or cable and having means for facilitating electrical connection to some other wire, terminal, or conductive member, blocks of binding posts characterised by the form or arrangement of the conductive interconnection between the connecting locations
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R43/00—Apparatus or processes specially adapted for manufacturing, assembling, maintaining, or repairing of line connectors or current collectors or for joining electric conductors

Definitions

  • the present invention relates to a method for designing a conductive film.
  • a conductive film in which conductive particles are held in an insulating resin layer is widely used when mounting electronic components such as IC chips, including optical semiconductor elements such as mini LEDs and micro LEDs, on wiring boards.
  • anisotropic conductive film is a film that is interposed between a terminal row of an electronic component and a terminal row of a substrate when a connection structure is obtained, and exhibits conductivity only in the film thickness direction. , refers to a film that loses conductivity in the direction of the film surface.
  • anisotropic conductive connection relates to the connection between the terminal row of the electronic component and the terminal row of the board, and there is conductivity in the stacking direction of the electronic component and the board, but there is no conductivity in the arrangement direction of the terminals. means connection.
  • the arrangement of the conductive particles in the anisotropic conductive film is arranged in a grid pattern, and the arrangement direction of the conductive particles is inclined with respect to both the longitudinal direction and the lateral direction of the anisotropic conductive film. It has been proposed to let it be (Patent Document 1).
  • the width is just a margin (for example, 1 ⁇ m for a particle diameter of about 3 ⁇ m), but the anisotropic conductive film is required to prevent short circuits even in such cases.
  • the fan-out terminal row may Since the angle formed by the arrangement direction of the terminals and the longitudinal direction of the terminals varies sequentially, if the lattice axis is inclined with respect to the longitudinal direction of the film, the difference in the number of trapped conductive particles between the terminals increases. The arrangement state of the conductive particles trapped in the terminals is different between the terminals. As a result, problems such as difficulty in judging the quality of connection arise.
  • the space between the terminals should be less than 5 ⁇ m or a very small margin for the diameter of the conductive particles contained in the anisotropic conductive film (for example, with respect to the particle diameter of about 3 ⁇ m).
  • a new particle arrangement has been proposed to achieve a good anisotropic conductive connection even when the width is only 1 ⁇ m added.
  • a first arranging axis A1 extending in the longitudinal direction of the terminal and a first arranging axis A1 extending in the longitudinal direction of the conductive particles are arranged in the range of one terminal pitch.
  • Patent No. 6119718 Japanese Patent Application Laid-Open No. 2015-232660 JP 2020-095922 A
  • the present inventor As a method for designing the arrangement of conductive particles in a conductive film in which conductive particles are arranged in a grid pattern in an insulating resin layer, the present inventor first determined the number density of conductive particles according to the terminal pitch to be connected by the conductive film, Next, the pitch of the lattice axis is determined according to the number density, and then the inclination of the lattice axis is determined according to the length of the terminal to be connected with this conductive film, thereby making it possible to connect with a fine pitch.
  • the present invention has been completed based on the idea that the arrangement of the conductive particles for use can be easily designed.
  • the grid point B is selected, in which the straight line connecting the grid point and the grid point A makes the smallest angle with the lateral direction of the film.
  • the present invention it is possible to easily confirm the scavenging properties of conductive particles in terminals to be connected and the difficulty of short-circuiting by simulation.
  • the lattice axis is angled according to the size of the terminal to be connected, it is possible to prevent short circuits as much as possible at the set number density of the conductive particles, and to improve the ability to capture the conductive particles at each terminal. .
  • the arrangement of the conductive particles does not become complicated. Therefore, when producing a conductive film designed by the method of the present invention, it becomes easy to produce a master that determines the arrangement of the conductive particles, and the master can be produced by cutting as well as laser processing.
  • FIG. 4B is an explanatory diagram of the design method of the embodiment.
  • FIG. 5 is a cross-sectional view of the conductive film 10A cut in the film thickness direction.
  • FIG. 6 is a cross-sectional view of the conductive film 10B cut in the film thickness direction.
  • 7A is a diagram showing the particle arrangement in the connection state (i) of the conductive film of Experimental Example 1.
  • FIG. 7B is a diagram showing the particle arrangement in the connection state (ii) of the conductive film of Experimental Example 1.
  • FIG. 8A is a diagram showing the particle arrangement in the connection state (i) of the conductive film of Experimental Example 2.
  • FIG. 8B is a diagram showing the particle arrangement in the connection state (ii) of the conductive film of Experimental Example 2.
  • FIG. 9A is a diagram showing the particle arrangement in the connection state (i) of the conductive film of Experimental Example 3.
  • FIG. 9B is a diagram showing the particle arrangement in the connection state (ii) of the conductive film of Experimental Example 3.
  • FIG. 10A is a diagram showing the particle arrangement in the connection state (i) of the conductive film of Experimental Example 4.
  • FIG. 10B is a diagram showing the particle arrangement in the connection state (ii) of the conductive film of Experimental Example 4.
  • FIG. 11A is a diagram showing the particle arrangement in the connection state (i) of the conductive film of Experimental Example 5.
  • FIG. 11B is a diagram showing the particle arrangement in the connection state (ii) of the conductive film of Experimental Example 5.
  • FIG. 12A is a diagram showing the particle arrangement in the connection state (i) of the conductive film of Experimental Example 6.
  • FIG. 12B is a diagram showing the particle arrangement in the connection state (ii) of the conductive film of Experimental Example 6.
  • FIG. 13 is a diagram showing the particle arrangement in the connected state of the conductive film of Experimental Example 7.
  • FIG. 14 is a diagram showing the particle arrangement in the connected state of the conductive film of Experimental Example 8.
  • conductive particles having a predetermined particle size are held in the insulating resin layer at lattice points of a rectangular lattice or an orthorhombic lattice, and the lattice axis of the lattice is in the longitudinal direction of the conductive film.
  • This is a method of designing the arrangement of conductive particles in a conductive film when connecting terminals having a terminal length of L1 and a terminal width of L2 (L1 ⁇ L2) using a conductive film which is inclined to .
  • the gist of the design concept of the present invention will be described by taking as an example a case where conductive particles are held at lattice points of a square lattice.
  • the case where the conductive particles are held at lattice points of a rectangular lattice or an orthorhombic lattice can be similarly considered.
  • the optimum inclination angle ⁇ can be determined according to the terminal length and terminal width of the terminal to be connected with the conductive film.
  • the COG (Chip On Glass) terminal 1x indicated by the dashed line in FIG. is preferably increased.
  • the FOG (Film On Glass) terminal 1y indicated by the chain double-dashed line in FIG. 2 normally has a long terminal length L1 and a narrow terminal width L2, so it is preferable to reduce the inclination angle ⁇ .
  • FIG. 3A a particle arrangement is assumed in which the conductive particles P are located at lattice points of a square lattice whose lattice axes are orthogonal to the film longitudinal direction or the film lateral direction of the conductive film.
  • L1, the terminal width L2 (L1 ⁇ L2), and the arrangement pitch of the terminals are appropriately determined.
  • the arrangement pitch of the terminals is twice the terminal width
  • the number density of the conductive particles P in the conductive film is determined as follows according to the terminal length L1 and the terminal width L2.
  • the number density of the conductive particles can be determined according to the intended use of the conductive film based on the terminal length L1 and the terminal width L2.
  • the lower limit of the number density can be 500/mm 2 or more for applications where a sparse state is preferred, and 20,000/mm 2 or more, 40,000/mm 2 or more, or even 50,000 for applications where a dense state is preferred.
  • pcs/mm 2 or more can also be 1,500,000/mm 2 or less, 1,000,000/mm 2 or less, and further 100,000/mm 2 or less.
  • the number density of the conductive particles is set in the range of 12,000/mm 2 to 32,000/mm 2
  • the number density of the conductive particles is set in the range of 4000 pieces/mm 2 to 20000 pieces/mm 2
  • the terminal length L1 is 7 to 30 ⁇ m and the terminal width L2 is 7 to 20 ⁇ m
  • the number density of the conductive particles is preferably set in the range of 20,000/mm 2 to 100,000/mm 2 .
  • one grid is formed so that one or more conductive particles exist within the range of the terminal length L1.
  • the rectangular grid is rotated by an angle ⁇ (
  • the rotation angle ⁇ at this time is defined as the tilt angle of the lattice axis of the conductive film. That is, the final particle arrangement is the arrangement of the conductive particles P obtained by rotating the initial rectangular lattice at the rotation angle ⁇ so that the straight line connecting the lattice points A and B is in the lateral direction of the film.
  • the conductive film is made to correspond to the terminal of the fan-out type terminal row, as shown in FIG. , among the grid points at a distance of L1 or less from one grid point A, select the grid point B where the angle ⁇ ′ formed by the straight line connecting the grid point and the grid point A with the short direction of the film is the smallest.
  • the rectangular grid is rotated by an angle ⁇ around the grid point A so that the grid points A and B are overlapped in the lateral direction of the film.
  • the arrangement of the conductive particles at this time is the particle arrangement of the conductive film.
  • the particle size of the conductive particles can be appropriately determined according to the application of the conductive film of the present invention. .
  • ⁇ Position of conductive particles in film thickness direction When manufacturing a conductive film in which the arrangement of the conductive particles is determined according to the design method of the present invention, it is preferable that the positions of the conductive particles P in the film thickness direction are aligned. For example, as in the conductive film 10A shown in FIG. 5, when the conductive particles P are embedded in the laminate of the high viscosity insulating resin layer 2 and the low viscosity insulating resin layer 3, The embedding amount Lb of the conductive particles P in the film thickness direction can be made uniform so that the flexible resin layer 2 is flush. This makes it easier to stabilize the catching property of the conductive particles P on the terminal.
  • the conductive particles P may be exposed from the high-viscosity insulating resin layer 2, like the conductive film 10B shown in FIG. . Also, the conductive particles P may be completely embedded in the high-viscosity insulating resin layer 2 .
  • the embedding amount Lb is the surface of the high-viscosity insulating resin layer 2 in which the conductive particles P are embedded (the side on which the conductive particles P are exposed among the front and back surfaces of the high-viscosity insulating resin layer 2). surface, or when the conductive particles P are completely embedded in the high-viscosity insulating resin layer 2, the surface close to the conductive particles P), the contact at the center between adjacent conductive particles It means the distance between the plane 2p and the deepest part of the conductive particles P.
  • the high-viscosity insulating resin layer 2 is formed using a curable resin composition formed from a polymerizable compound and a polymerization initiator, similarly to the insulating resin layer of the anisotropic conductive film described in Japanese Patent No. 6187665. can do.
  • a polymerization initiator a thermal polymerization initiator may be used, a photopolymerization initiator may be used, or they may be used in combination.
  • a cationic polymerization initiator is used as the thermal polymerization initiator
  • an epoxy resin is used as the thermally polymerizable compound
  • a photoradical polymerization initiator is used as the photopolymerization initiator
  • an acrylate compound is used as the photopolymerizable compound.
  • a thermal anionic polymerization initiator may be used as the thermal polymerization initiator.
  • the thermal anionic polymerization initiator it is preferable to use a microcapsule-type latent curing agent comprising an imidazole modified product as a nucleus and the surface of the nucleus coated with polyurethane.
  • the low-viscosity insulating resin layer 3 is a resin layer whose minimum melt viscosity in the range of 30 to 200° C. is lower than that of the high-viscosity insulating resin layer 2 .
  • the low-viscosity insulating resin layer 3 is provided as necessary. To improve adhesion between electronic components by filling spaces formed by electrodes and bumps of the electronic components with a low-viscosity insulating resin layer 3 when the electronic components facing each other through the conductive film 10A are thermocompressed. can be done.
  • the layer thickness of the high-viscosity insulating resin layer 2 is set to the average particle diameter D of the conductive particles P in order to stably push the conductive particles P into the high-viscosity insulating resin layer 2 in the manufacturing process of the conductive film. , preferably 0.3 times or more, more preferably 0.6 times or more, still more preferably 0.8 times or more, and particularly preferably 1 time or more.
  • the upper limit of the layer thickness of the high-viscosity insulating resin layer 2 can be determined according to the terminal shape, terminal thickness, arrangement pitch, etc. of the electronic component to be connected.
  • the average particle size D of the conductive particles P is preferably 20 times or less, more preferably 15 times or less, because P becomes unnecessarily susceptible to the influence of resin flow.
  • the low-viscosity insulating resin layer 3 is provided on the conductive film as necessary.
  • the lower limit of the layer thickness of the low-viscosity insulating resin layer 3 is preferably 0.2 times or more the average particle diameter D of the conductive particles P, more preferably 1 times or more.
  • the upper limit of the layer thickness of the low-viscosity insulating resin layer 3 if it is too thick, the difficulty of lamination with the high-viscosity insulating resin layer 2 increases, so the average particle diameter D of the conductive particles P is preferably It is less than 50 times, more preferably 15 times or less, still more preferably 8 times or less.
  • the upper limit of the total thickness of the resin layer is the average particle diameter D of the conductive particles P. It is preferably 50 times or less, more preferably 15 times or less, and still more preferably 8 times or less. In order to prevent the thrust required for the pressing tool from becoming too high during thermocompression bonding, the total thickness of the resin layer is preferably 4 times or less, more preferably 3 times or less, the average particle diameter D of the conductive particles P.
  • the conductive film in which the arrangement of the conductive particles is determined according to the present invention can be a wound body in its product form.
  • the length of the wound body is not particularly limited, it is preferably 5000 m or less, more preferably 1000 m or less, and still more preferably 500 m or less from the viewpoint of handling of the shipment. On the other hand, from the point of mass production of the wound body, it is preferably 5 m or longer.
  • the film width in the wound body is not particularly limited, but the film width is preferably 0.3 mm or more from the viewpoint of the lower limit of the slit width when manufacturing a wound body by slitting a wide conductive film. From the viewpoint of stabilizing the width, it is more preferable to set the width to 0.5 mm or more.
  • the upper limit of the film width is not particularly limited, it is preferably 700 mm or less, more preferably 600 mm or less, from the viewpoint of portability and handling. From the viewpoint of practical handling of the conductive film, it is preferable to select the film width between 0.3 and 400 mm.
  • the film width is often less than several millimeters, and a relatively large electronic component (electrode wiring and mounting portion are provided on one side).
  • a film width of about 400 mm may be required.
  • the conductive film is often used with a film width of 0.5 to 5 mm.
  • the method itself for producing a conductive film in which the arrangement of conductive particles is designed according to the present invention is not particularly limited.
  • a transfer mold is first manufactured. A method of manufacturing the transfer mold will be described later.
  • the recesses of the transfer mold are filled with conductive particles, and a high-viscosity insulating resin layer formed on a release film is placed thereon and pressure is applied to press the conductive particles into the high-viscosity insulating resin layer.
  • a conductive film is produced by transferring conductive particles to a high-viscosity insulating resin layer, or further laminating a low-viscosity insulating resin layer on the conductive particles.
  • a conductive film may be produced by pressing into a flexible resin layer.
  • the transfer mold in addition to the one in which the concave portions are filled with conductive particles, the one in which a slightly adhesive agent is applied to the top surface of the convex portions so that the conductive particles adhere to the top surface may be used.
  • a method of arranging the conductive particles in a predetermined arrangement instead of using a transfer mold, a method of passing the conductive particles through through-holes provided in a predetermined arrangement, or the like may be used.
  • a transfer mold can be produced by applying a curable resin composition to the transfer mold master, curing it, and separating it from the master.
  • the conductive film in which the arrangement of conductive particles is designed according to the present invention effectively prevents shorts between terminals when the terminal row to be connected has a fine pitch, including (i) when connecting a micro LED to a display substrate. It is significant because it can be suppressed, and (ii) it is significant when at least one of the first electronic component and the second electronic component is made of a material that easily expands thermally, such as an FPC or a plastic substrate. Specifically, when connecting FOP (Film On Plastic), FOG (Film On Glass), COG (Chip On Glass), COP (Chip On Plastic), one of the above (i) and (ii) Or it is preferable because it satisfies both.
  • the significance of the present invention is further enhanced.
  • the fan-out arrangement is not limited to a mode in which the terminal row exists only on one of the components.
  • the conductive film in which the arrangement of the conductive particles is designed according to the present invention can also be applied to known arrangements such as peripheral arrangement.
  • Experimental examples 1-6 A conductive film having specifications shown in Table 1 was produced.
  • the particle size of the conductive particles was set to 3 ⁇ m.
  • the conductive particles are arranged at lattice points of a square lattice, and the angle (tilt angle) ⁇ between the lattice axis and the lateral direction of the conductive film is set to the value shown in Table 1. These particle arrangements are shown in FIGS. 7A, 7B-12A, 12B.
  • connection state when a first electronic component having a terminal row with a terminal length of 100 ⁇ m, a terminal width of 10 ⁇ m, and a terminal distance of 10 ⁇ m and a second electronic component having a similar terminal row are connected using the conductive film of each experimental example.
  • (i) the conductive particles in each terminal The minimum number of trapped particles, (b) the maximum number of particles between terminals, and (c) the maximum particle occupied area ratio between terminals were examined by simulation.
  • connection states (i) and (ii) the conductive connectivity is predicted from the minimum number of trapped conductive particles at each terminal obtained by the simulation, and evaluated as follows. A grade of C or higher was regarded as a pass, and an evaluation of D was regarded as a disqualification.
  • terminal length L1 was 30 ⁇ m
  • distance between conductors in the direction between terminals was simulated.
  • Particle diameter of conductive particles 2 ⁇ m
  • Particle density of conductive particles 12000/mm 2

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Abstract

The present invention enables easy designing for arranging conductive particles for a conductive film that is easily adaptable to connection to a mini LED or to a micro LED. This designing method is for arranging conductive particles P in a conductive film having the conductive particles P held in an insulating resin layer when the conductive film is used to connect terminals having a terminal length L1 and a terminal width L2, the method involving: setting arrangement such that the conductive particles P are at lattice points of a rectangular lattice or a rhombic lattice and have a lattice axis orthogonal to the long direction or short direction of the conductive film; then setting the number density or the like of the conductive particles P in the conductive film; then selecting, from among lattice points which are distanced by a terminal length L1 or less from a lattice point A, a lattice point B which has the smallest angle formed between a straight line connecting said lattice point to the lattice point A and the film short direction; rotating the lattice about the lattice point A to obtain a rotation angle α of the lattice where the lattice point A and the lattice point B overlap in the film short direction; and determining the inclination angle of the lattice axis of the conductive film on the basis of the angle α.

Description

導電フィルムの設計方法Conductive film design method
　本発明は、導電フィルムの設計方法に関する。 The present invention relates to a method for designing a conductive film.
　絶縁性樹脂層に導電粒子を保持させた導電フィルムが、ミニＬＥＤやマイクロＬＥＤといった光学半導体素子を含むＩＣチップ等の電子部品を配線基板等に実装する際に広く使用されている。 A conductive film in which conductive particles are held in an insulating resin layer is widely used when mounting electronic components such as IC chips, including optical semiconductor elements such as mini LEDs and micro LEDs, on wiring boards.
　ＩＣチップの実装に使用される導電フィルムは異方性導電フィルムとも称されている。本発明における導電フィルムは、この異方性導電フィルムも包含する。 The conductive film used for mounting IC chips is also called an anisotropic conductive film. The conductive film in the present invention also includes this anisotropic conductive film.
　異方性導電フィルムとは、電子部品の端子列と基板の端子列とを接続した接続構造体を得る場合にそれらの間に介在させるフィルムであって、フィルム厚方向のみに導通性が発揮され、フィルム面方向には導通性が無くなるフィルムをいう。また、異方性導電接続とは、電子部品の端子列と基板の端子列との接続に関し、電子部品と基板の積層方向には導通性があるが、端子の配列方向には導通性が無い接続をいう。 An anisotropic conductive film is a film that is interposed between a terminal row of an electronic component and a terminal row of a substrate when a connection structure is obtained, and exhibits conductivity only in the film thickness direction. , refers to a film that loses conductivity in the direction of the film surface. In addition, anisotropic conductive connection relates to the connection between the terminal row of the electronic component and the terminal row of the board, and there is conductivity in the stacking direction of the electronic component and the board, but there is no conductivity in the arrangement direction of the terminals. means connection.
　異方性導電フィルムにおいては、電子部品の高密度実装に伴う端子のファインピッチ化により、端子における導電粒子の捕捉性を高め、かつ隣り合う端子間のショートを回避することが強く求められている。 In the anisotropic conductive film, due to the finer pitch of terminals accompanying high-density mounting of electronic components, there is a strong demand to improve the ability to capture conductive particles in terminals and to avoid short circuits between adjacent terminals. .
　このような要請に対し、異方性導電フィルムにおける導電粒子の配置を格子状の配列とし、かつその導電粒子の配列方向を異方性導電フィルムの長手方向及び短手方向の双方に対して傾斜させることが提案されている（特許文献１）。 In response to such a request, the arrangement of the conductive particles in the anisotropic conductive film is arranged in a grid pattern, and the arrangement direction of the conductive particles is inclined with respect to both the longitudinal direction and the lateral direction of the anisotropic conductive film. It has been proposed to let it be (Patent Document 1).
　また、電子部品の実装時の圧着温度が変動し、その温度変動により端子の位置がずれても電子部品の接続を確実に行えるようにするため、電子部品の端子を放射状に並列させること（所謂、ファンアウト配線）が知られている（特許文献２）。 In addition, the terminals of electronic components are arranged radially in parallel (so-called , fan-out wiring) are known (Patent Document 2).
　近年、さらなるファインピッチ化の要請により、接続する端子同士のアラインメントずれがあると正味の端子間スペースが５μｍ未満となる場合や、異方性導電フィルムに含まれる導電粒子の粒子径に極わずかなマージン（例えば、３μｍ程度の粒子径に対して１μｍ）を加えただけの幅になる場合があるが、そのような場合でもショートを引き起こさないようにすることが異方性導電フィルムに求められている。 In recent years, due to the demand for finer pitches, there are cases where the net space between terminals becomes less than 5 μm due to misalignment between terminals to be connected, and there are cases where the particle size of the conductive particles contained in the anisotropic conductive film is extremely small. In some cases, the width is just a margin (for example, 1 μm for a particle diameter of about 3 μm), but the anisotropic conductive film is required to prevent short circuits even in such cases. there is
　また、異方性導電フィルムを用いてファンアウト型の端子列を接続する場合に、異方性導電フィルムの導電粒子が単に格子状に配置されているときには、ファンアウト型の端子列では、端子の配列方向と端子の長手方向とのなす角度が順次異なるので、その格子軸がフィルム長手方向に対して傾斜していると、端子同士における導電粒子の捕捉数の差が大きくなり、また、端子に捕捉された導電粒子の配置状態が端子同士で異なることになる。そのため、接続の良否判定が困難になる等の問題が生じる。 Further, when an anisotropic conductive film is used to connect a fan-out terminal row, if the conductive particles of the anisotropic conductive film are simply arranged in a grid pattern, the fan-out terminal row may Since the angle formed by the arrangement direction of the terminals and the longitudinal direction of the terminals varies sequentially, if the lattice axis is inclined with respect to the longitudinal direction of the film, the difference in the number of trapped conductive particles between the terminals increases. The arrangement state of the conductive particles trapped in the terminals is different between the terminals. As a result, problems such as difficulty in judging the quality of connection arise.
　そこで、端子の配列パターンが放射状になっていても、また、端子間スペースが、５μｍ未満又は異方性導電フィルムに含まれる導電粒子径に極わずかなマージン（例えば、３μｍ程度の粒子径に対して１μｍ）を加えただけの幅になる場合も、異方性導電接続を良好に行うために新たな粒子配置が提案されている。この粒子配置では、異方性導電フィルムの長手方向を端子ピッチで区切った場合に、一つの端子ピッチの範囲に、導電粒子の配列軸として、端子の長手方向に伸びた第１配列軸Ａ１と第２配列軸Ａ２が繰り返し配置されるとし、この第１配列軸Ａ１上の導電粒子と第２配列軸Ａ２上の導電粒子の位置関係を導電粒子の平均粒子径との関係で規定する（特許文献３）。 Therefore, even if the arrangement pattern of the terminals is radial, the space between the terminals should be less than 5 μm or a very small margin for the diameter of the conductive particles contained in the anisotropic conductive film (for example, with respect to the particle diameter of about 3 μm). A new particle arrangement has been proposed to achieve a good anisotropic conductive connection even when the width is only 1 μm added. In this particle arrangement, when the longitudinal direction of the anisotropic conductive film is divided by the terminal pitch, a first arranging axis A1 extending in the longitudinal direction of the terminal and a first arranging axis A1 extending in the longitudinal direction of the conductive particles are arranged in the range of one terminal pitch. It is assumed that the second array axis A2 is repeatedly arranged, and the positional relationship between the conductive particles on the first array axis A1 and the conductive particles on the second array axis A2 is defined by the relationship with the average particle size of the conductive particles (Patent Reference 3).
特許6119718号公報Patent No. 6119718 特開2015-232660号公報Japanese Patent Application Laid-Open No. 2015-232660 特開2020-095922号公報JP 2020-095922 A
　しかしながら、特許文献３に記載の異方性導電フィルムは、該異方性導電フィルムにおける導電粒子の配置を定めるためのパラメータが多く、実際上導電粒子の配置パターンを定める手法が煩雑になっていた。 However, the anisotropic conductive film described in Patent Document 3 has many parameters for determining the arrangement of the conductive particles in the anisotropic conductive film, and the method of actually determining the arrangement pattern of the conductive particles has become complicated. .
　これに対し、本発明は、微細なピッチに対応することができ、ミニＬＥＤやマイクロＬＥＤの基板への接続にも適応しやすい導電フィルム用の導電粒子の配置を手軽に設計できるようにすることを課題とする。 On the other hand, the present invention enables easy design of the arrangement of conductive particles for a conductive film that can correspond to a fine pitch and is easily adapted to connection to a substrate of a mini-LED or a micro-LED. is the subject.
　本発明者は、絶縁性樹脂層に導電粒子を格子状に配置した導電フィルムの導電粒子の配置の設計方法として、まず、導電フィルムで接続する端子ピッチに応じて導電粒子の個数密度を定め、次にその個数密度に応じた格子軸のピッチを定め、次にこの導電フィルムで接続する端子長に応じて格子軸の傾きを定めることにより、微細なピッチの接続に対応することのできる導電フィルム用の導電粒子の配置を簡便に設計できることを想到し、本発明を完成させた。 As a method for designing the arrangement of conductive particles in a conductive film in which conductive particles are arranged in a grid pattern in an insulating resin layer, the present inventor first determined the number density of conductive particles according to the terminal pitch to be connected by the conductive film, Next, the pitch of the lattice axis is determined according to the number density, and then the inclination of the lattice axis is determined according to the length of the terminal to be connected with this conductive film, thereby making it possible to connect with a fine pitch. The present invention has been completed based on the idea that the arrangement of the conductive particles for use can be easily designed.
　即ち、本発明は、平面視にて、所定の粒子径の導電粒子が絶縁性樹脂層に保持されている導電フィルムを用いて、端子長Ｌ1、端子幅Ｌ2の端子（但し、Ｌ1≧Ｌ2）を接続する場合の該導電フィルムにおける導電粒子の配置の設計方法であって、
まず、導電粒子の配置が矩形格子又は斜方格子の格子点にあり、導電フィルムの長手方向又は短手方向（以下、フィルム長手方向又はフィルム短手方向ともいう）に直交する格子軸を有するとし、導電フィルムにおける導電粒子の個数密度、該個数密度に応じたフィルム長手方向の格子軸における導電粒子のピッチｄ1、及びフィルム短手方向の格子軸における導電粒子のピッチｄ2（ｄ2＝ａ・ｄ1、ａは係数）を設定し、
次に、一つの格子点Ａから端子長Ｌ１以下の距離にある格子点のうち、その格子点と格子点Ａとを結ぶ直線がフィルム短手方向となす角度が最も小さい格子点Ｂを選択し、格子点Ａを中心に格子を回転させて格子点Ａと格子点Ｂがフィルム短手方向で重なる格子の回転角αを求め、その角度αにより導電フィルムの格子軸の傾斜角を決定する設計方法を提供する。 That is, in the present invention, a terminal having a terminal length L1 and a terminal width L2 (where L1≧L2) is formed by using a conductive film in which conductive particles having a predetermined particle diameter are held in an insulating resin layer in plan view. A method for designing the arrangement of conductive particles in the conductive film when connecting
First, when the conductive particles are arranged at lattice points of a rectangular lattice or an orthorhombic lattice and have a lattice axis orthogonal to the longitudinal direction or the transverse direction of the conductive film (hereinafter also referred to as the longitudinal direction of the film or the transverse direction of the film). Then, the number density of the conductive particles in the conductive film, the pitch d1 of the conductive particles on the lattice axis in the longitudinal direction of the film according to the number density, and the pitch d2 of the conductive particles on the lattice axis in the lateral direction of the film (d2 = a d1 , a is the coefficient),
Next, among the grid points located at a distance equal to or less than the terminal length L1 from one grid point A, the grid point B is selected, in which the straight line connecting the grid point and the grid point A makes the smallest angle with the lateral direction of the film. , Rotate the lattice around the lattice point A to obtain the rotation angle α of the lattice at which the lattice point A and the lattice point B overlap in the film short direction, and determine the inclination angle of the lattice axis of the conductive film from the angle α provide a way.
　本発明によれば、接続すべき端子における導電粒子の捕捉性やショートの起こりにくさをシミュレーションにより容易に確認することができる。また、接続すべき端子の大きさに応じて格子軸に角度をつけるので、設定した導電粒子の個数密度においてショートをできる限り防止し、かつ各端子における導電粒子の捕捉性を向上させることができる。 　According to the present invention, it is possible to easily confirm the scavenging properties of conductive particles in terminals to be connected and the difficulty of short-circuiting by simulation. In addition, since the lattice axis is angled according to the size of the terminal to be connected, it is possible to prevent short circuits as much as possible at the set number density of the conductive particles, and to improve the ability to capture the conductive particles at each terminal. .
　また、本発明によれば導電粒子の配列が複雑にならない。したがって、本発明の方法により設計された導電フィルムを作製する場合に、導電粒子の配置を定める原盤の作製が容易となり、原盤をレーザ加工の他に切削加工によっても作製することが可能となる。 Also, according to the present invention, the arrangement of the conductive particles does not become complicated. Therefore, when producing a conductive film designed by the method of the present invention, it becomes easy to produce a master that determines the arrangement of the conductive particles, and the master can be produced by cutting as well as laser processing.
図１は、ある導電粒子が正方格子の格子点Ａにある場合に、格子点Ａと該格子点Ａの対角にある格子点Ｂとを結ぶ直線が格子軸となす傾斜角αの説明図である。FIG. 1 is an explanatory diagram of an inclination angle α formed by a straight line connecting a grid point A and a grid point B on the diagonal of the grid point A when a certain conductive particle is located at the grid point A of a square grid and the grid axis. is. 図２は、所定の端子長及び端子幅を有する端子と、該端子の接続に好適な導電粒子の粒子配置の傾斜角αとの対応関係の説明図である。FIG. 2 is an explanatory diagram of a correspondence relationship between a terminal having a predetermined terminal length and terminal width and the inclination angle α of the particle arrangement of conductive particles suitable for connection of the terminal. 図３Ａは、実施例の設計方法の説明図である。FIG. 3A is an explanatory diagram of the design method of the embodiment. 図３Ｂは、実施例の設計方法の説明図である。FIG. 3B is an explanatory diagram of the design method of the embodiment. 図４Ａは、実施例の設計方法の説明図である。FIG. 4A is an explanatory diagram of the design method of the embodiment. 図４Ｂは、実施例の設計方法の説明図である。FIG. 4B is an explanatory diagram of the design method of the embodiment. 図５は、導電フィルム１０Ａをフィルム厚方向に切った断面図である。FIG. 5 is a cross-sectional view of the conductive film 10A cut in the film thickness direction. 図６は、導電フィルム１０Ｂをフィルム厚方向に切った断面図である。FIG. 6 is a cross-sectional view of the conductive film 10B cut in the film thickness direction. 図７Ａは、実験例１の導電フィルムの接続状態(i)の粒子配置を示した図である。7A is a diagram showing the particle arrangement in the connection state (i) of the conductive film of Experimental Example 1. FIG. 図７Ｂは、実験例１の導電フィルムの接続状態(ii)の粒子配置を示した図である。7B is a diagram showing the particle arrangement in the connection state (ii) of the conductive film of Experimental Example 1. FIG. 図８Ａは、実験例２の導電フィルムの接続状態(i)の粒子配置を示した図である。8A is a diagram showing the particle arrangement in the connection state (i) of the conductive film of Experimental Example 2. FIG. 図８Ｂは、実験例２の導電フィルムの接続状態(ii)の粒子配置を示した図である。8B is a diagram showing the particle arrangement in the connection state (ii) of the conductive film of Experimental Example 2. FIG. 図９Ａは、実験例３の導電フィルムの接続状態(i)の粒子配置を示した図である。9A is a diagram showing the particle arrangement in the connection state (i) of the conductive film of Experimental Example 3. FIG. 図９Ｂは、実験例３の導電フィルムの接続状態(ii)の粒子配置を示した図である。9B is a diagram showing the particle arrangement in the connection state (ii) of the conductive film of Experimental Example 3. FIG. 図１０Ａは、実験例４の導電フィルムの接続状態(i)の粒子配置を示した図である。10A is a diagram showing the particle arrangement in the connection state (i) of the conductive film of Experimental Example 4. FIG. 図１０Ｂは、実験例４の導電フィルムの接続状態(ii)の粒子配置を示した図である。10B is a diagram showing the particle arrangement in the connection state (ii) of the conductive film of Experimental Example 4. FIG. 図１１Ａは、実験例５の導電フィルムの接続状態(i)の粒子配置を示した図である。11A is a diagram showing the particle arrangement in the connection state (i) of the conductive film of Experimental Example 5. FIG. 図１１Ｂは、実験例５の導電フィルムの接続状態(ii)の粒子配置を示した図である。11B is a diagram showing the particle arrangement in the connection state (ii) of the conductive film of Experimental Example 5. FIG. 図１２Ａは、実験例６の導電フィルムの接続状態(i)の粒子配置を示した図である。12A is a diagram showing the particle arrangement in the connection state (i) of the conductive film of Experimental Example 6. FIG. 図１２Ｂは、実験例６の導電フィルムの接続状態(ii)の粒子配置を示した図である。12B is a diagram showing the particle arrangement in the connection state (ii) of the conductive film of Experimental Example 6. FIG. 図１３は、実験例７の導電フィルムの接続状態の粒子配置を示した図である。FIG. 13 is a diagram showing the particle arrangement in the connected state of the conductive film of Experimental Example 7. FIG. 図１４は、実験例８の導電フィルムの接続状態の粒子配置を示した図である。FIG. 14 is a diagram showing the particle arrangement in the connected state of the conductive film of Experimental Example 8. FIG.
　以下、本発明を、図面を参照しつつ詳細に説明する。なお、各図中、同一符号は、同一又は同等の構成要素を表している。 The present invention will be described in detail below with reference to the drawings. In addition, in each figure, the same code|symbol represents the same or equivalent component.
＜導電粒子の平面配置＞
　本発明の設計方法は、平面視にて、所定の粒子径の導電粒子が絶縁性樹脂層に矩形格子又は斜方格子の格子点に保持され、その格子の格子軸が導電フィルムのフィルム長手方向に傾斜している導電フィルムを用いて、端子長Ｌ1、端子幅Ｌ2（Ｌ1≧Ｌ2）の端子を接続する場合の該導電フィルムにおける導電粒子の配置を設計する方法である。 <Planar Arrangement of Conductive Particles>
In the design method of the present invention, in a plan view, conductive particles having a predetermined particle size are held in the insulating resin layer at lattice points of a rectangular lattice or an orthorhombic lattice, and the lattice axis of the lattice is in the longitudinal direction of the conductive film. This is a method of designing the arrangement of conductive particles in a conductive film when connecting terminals having a terminal length of L1 and a terminal width of L2 (L1≧L2) using a conductive film which is inclined to .
　まず、本発明の設計思想の要点を、導電粒子が正方格子の格子点に保持されている場合を例として説明する。なお、導電粒子が長方格子や斜方格子の格子点に保持されている場合も同様に考えることができる。 First, the gist of the design concept of the present invention will be described by taking as an example a case where conductive particles are held at lattice points of a square lattice. Incidentally, the case where the conductive particles are held at lattice points of a rectangular lattice or an orthorhombic lattice can be similarly considered.
　まず、図１に示すように、導電粒子が正方格子の格子点Ａにある場合に、格子点Ａと、該格子点Ａの対角にある格子点Ｂとを結ぶ直線を考える。この直線が格子点Ａを通る格子軸（フィルム短手方向）となす角度（以下、傾斜角ともいう）αは、格子点Ｂの位置が正方格子のピッチで規制されるため飛び飛びの値となる。したがって、図２に示すように、傾斜角αの方向を端子長の方向に合わせることにより、当該導電フィルムで接続する端子の端子長と端子幅に応じて最適な傾斜角αを定めることができる。例えば、図２に破線で示すＣＯＧ(Chip On Glass)の端子１ｘは、通常端子長Ｌ1と端子幅Ｌ2とに大きな差が無いので、ＣＯＧ用の導電フィルムの導電粒子の粒子配置では傾斜角αを大きくすることが好ましい。一方、図２に二点鎖線で示すＦＯＧ(Film On Glass)の端子１ｙは、通常、端子長Ｌ1が長く、端子幅Ｌ2が狭いため、傾斜角αを小さくすることが好ましい。 First, as shown in FIG. 1, when the conductive particles are at lattice point A of a square lattice, consider a straight line connecting lattice point A and lattice point B on the diagonal of lattice point A. The angle (hereinafter also referred to as the tilt angle) α formed by this straight line with the lattice axis (film lateral direction) passing through the lattice point A has a discrete value because the position of the lattice point B is regulated by the pitch of the square lattice. . Therefore, as shown in FIG. 2, by aligning the direction of the inclination angle α with the direction of the terminal length, the optimum inclination angle α can be determined according to the terminal length and terminal width of the terminal to be connected with the conductive film. . For example, the COG (Chip On Glass) terminal 1x indicated by the dashed line in FIG. is preferably increased. On the other hand, the FOG (Film On Glass) terminal 1y indicated by the chain double-dashed line in FIG. 2 normally has a long terminal length L1 and a narrow terminal width L2, so it is preferable to reduce the inclination angle α.
　以上の設計思想を踏まえた上で、次に本実施例の設計方法を詳細に説明する。まず図３Ａに示したように、格子軸が導電フィルムのフィルム長手方向又はフィルム短手方向に直交する正方格子の格子点に導電粒子Ｐがある粒子配置を想定する。 Based on the above design concept, the design method of this embodiment will be described in detail next. First, as shown in FIG. 3A, a particle arrangement is assumed in which the conductive particles P are located at lattice points of a square lattice whose lattice axes are orthogonal to the film longitudinal direction or the film lateral direction of the conductive film.
　この粒子配置において、フィルム長手方向の格子軸における導電粒子のピッチｄ1、及びフィルム短手方向の格子軸における導電粒子のピッチｄ2（ｄ2＝ａ・ｄ1、ａは係数）は、接続すべき端子長Ｌ１、端子幅Ｌ2（Ｌ1≧Ｌ2）及び端子の配列ピッチに応じて適宜定める。例えば、端子の配列ピッチが端子幅の２倍の場合、端子長Ｌ1、端子幅Ｌ2に応じて導電フィルムにおける導電粒子Ｐの個数密度を次のように定め、その個数密度から導電粒子Ｐのピッチｄ1及びピッチｄ2＝ａ・ｄ1（ａは係数）を算出する。
　この場合、設計を容易にする点からは、ｄ1＝ｄ2として矩形格子を想定することが好ましい。 In this particle arrangement, the pitch d1 of the conductive particles on the lattice axis in the longitudinal direction of the film and the pitch d2 of the conductive particles on the lattice axis in the transverse direction of the film (d2=a·d1, a is a coefficient) are the lengths of the terminals to be connected. L1, the terminal width L2 (L1≧L2), and the arrangement pitch of the terminals are appropriately determined. For example, when the arrangement pitch of the terminals is twice the terminal width, the number density of the conductive particles P in the conductive film is determined as follows according to the terminal length L1 and the terminal width L2. Calculate d1 and pitch d2=a·d1 (a is a coefficient).
In this case, from the viewpoint of facilitating the design, it is preferable to assume a rectangular lattice with d1=d2.
　導電粒子の個数密度は、端子長Ｌ1及び端子幅Ｌ2から想定される導電フィルムの用途に応じて定めることができる。大凡、個数密度の下限は、疎な状態が好ましい用途では５００個／ｍｍ2以上とすることができ、密な状態が好ましい用途では２００００個／ｍｍ2以上、４００００個／ｍｍ2以上、さらに５００００個／ｍｍ2以上とすることができる。また個数密度の上限についても同様の理由から１５０００００個／ｍｍ2以下、１００００００個／ｍｍ2以下、さらには１０００００個／ｍｍ2以下とすることができる。 The number density of the conductive particles can be determined according to the intended use of the conductive film based on the terminal length L1 and the terminal width L2. Generally, the lower limit of the number density can be 500/mm 2 or more for applications where a sparse state is preferred, and 20,000/mm 2 or more, 40,000/mm 2 or more, or even 50,000 for applications where a dense state is preferred. pcs/mm 2 or more. For the same reason, the upper limit of the number density can also be 1,500,000/mm 2 or less, 1,000,000/mm 2 or less, and further 100,000/mm 2 or less.
　より具体的には、例えば端子長Ｌ1が５０～１００μｍ、及び端子幅Ｌ2が１０～３０μｍの場合に、導電粒子の個数密度を１２０００個／ｍｍ2～３２０００個／ｍｍ2の範囲で設定し、また、端子長Ｌ1が１００～１０００μｍ、及び端子幅Ｌ2が８～３０μｍの場合に、導電粒子の個数密度を４０００個／ｍｍ2～２００００個／ｍｍ2の範囲で設定し、更には端子長Ｌ1が７～３０μｍ、及び端子幅Ｌ2が７～２０μｍの場合に、導電粒子の個数密度を２００００個／ｍｍ2～１０００００個／ｍｍ2の範囲で設定することが好ましい。 More specifically, for example, when the terminal length L1 is 50 to 100 μm and the terminal width L2 is 10 to 30 μm, the number density of the conductive particles is set in the range of 12,000/mm 2 to 32,000/mm 2 , Further, when the terminal length L1 is 100 to 1000 μm and the terminal width L2 is 8 to 30 μm, the number density of the conductive particles is set in the range of 4000 pieces/mm 2 to 20000 pieces/mm 2 , and the terminal length L1 is 7 to 30 μm and the terminal width L2 is 7 to 20 μm, the number density of the conductive particles is preferably set in the range of 20,000/mm 2 to 100,000/mm 2 .
　一方、接続すべき端子長Ｌ1及び端子幅Ｌ2が具体的に定まっている場合には、以下に説明する角度αとピッチｄ1、ｄ2とが次の関係を満たすようにｄ1、ｄ2を定めることが好ましい。これにより、各端子における導電粒子の捕捉性が向上する。
　ｄ1・cosα≦Ｌ2　又は
　ｄ2・sinα≦Ｌ1 On the other hand, when the terminal length L1 and the terminal width L2 to be connected are specifically determined, d1 and d2 can be determined so that the angle α described below and the pitches d1 and d2 satisfy the following relationship. preferable. Thereby, the catching property of the conductive particles at each terminal is improved.
d1・cosα≦L2 or d2・sinα≦L1
　本発明において導電粒子のピッチｄ1、ｄ2を設定した後は、導電フィルムの最終的な粒子配置において、端子長Ｌ1の範囲内に１個以上の導電粒子が存在するようにするため、一つの格子点Ａから端子長Ｌ1の円を考える（図３Ａ）。 After setting the pitches d1 and d2 of the conductive particles in the present invention, in the final particle arrangement of the conductive film, one grid is formed so that one or more conductive particles exist within the range of the terminal length L1. Consider a circle of terminal length L1 from point A (Fig. 3A).
　次に、格子点Ａから端子長Ｌ１以下の距離にある格子点のうち、その格子点と格子点Ａを結ぶ直線がフィルム短手方向となす角度α’（α’≠０）が最も小さい格子点Ｂを選択する。 Next, among the lattice points at a distance of L1 or less from the lattice point A, the straight line connecting the lattice point and the lattice point A forms the smallest angle α' (α'≠0) with the film lateral direction. Select point B.
　そして、図３Ｂに示すように格子点Ａを中心に矩形格子を角度α（│α│＝│α’│）だけ回転させて格子点Ａと格子点Ｂとをフィルム短手方向で重ねる。このときの回転角αを導電フィルムの格子軸の傾斜角とする。即ち、格子点Ａと格子点Ｂとを結ぶ直線がフィルム短手方向となるように、当初の矩形格子を回転角αで回転させた導電粒子Ｐの配置を最終的な粒子配置とする。 Then, as shown in FIG. 3B, the rectangular grid is rotated by an angle α (|α|=|α'|) around the grid point A to overlap the grid points A and B in the film lateral direction. The rotation angle α at this time is defined as the tilt angle of the lattice axis of the conductive film. That is, the final particle arrangement is the arrangement of the conductive particles P obtained by rotating the initial rectangular lattice at the rotation angle α so that the straight line connecting the lattice points A and B is in the lateral direction of the film.
　このように導電粒子の配置を決定すると、端子１が微細で端子幅Ｌ2がピッチｄ2より小さい場合でも、端子長Ｌ1の円内にある格子点Ｂの導電粒子が端子で捕捉されることになる。したがって、端子長Ｌ1、端子幅Ｌ2の端子が該端子の端子幅方向に所定間隔で配列している一般的な通常の電子部品の端子列では、各端子は最低でも１個の導電粒子を捕捉することが可能となる。よって、本発明の設計方法によれば、微細な端子において、各端子に１個以上の導電粒子が捕捉される導電粒子の配置を得ることができる。言い換えると、当該端子長で各端子に１個の導電粒子が捕捉されるための最長の格子ピッチを得ることができる。 If the arrangement of the conductive particles is determined in this way, even if the terminal 1 is fine and the terminal width L2 is smaller than the pitch d2, the conductive particles at the lattice point B within the circle of the terminal length L1 will be captured by the terminal. . Therefore, in a terminal array of a general electronic component in which terminals having a terminal length L1 and a terminal width L2 are arranged at predetermined intervals in the terminal width direction of the terminals, each terminal captures at least one conductive particle. It becomes possible to Therefore, according to the design method of the present invention, it is possible to obtain an arrangement of conductive particles in which one or more conductive particles are trapped in each fine terminal. In other words, the longest lattice pitch for trapping one conductive particle at each terminal can be obtained with the terminal length.
　本発明の設計方法において、図３Ｂに示したように角度αで傾斜している格子軸であって、互いに隣接するものを第１配列軸、第２配列軸とした場合に、第１配列軸における導電粒子Ｐ1と、第２配列軸における導電粒子Ｐ2とが、フィルム長手方向に重畳しないように角度αを定めることが好ましい。これにより、端子間で導電粒子同士が連なりショートが引き起こされることを防止することができる。 In the design method of the present invention, as shown in FIG. It is preferable to determine the angle α so that the conductive particles P1 at the second alignment axis and the conductive particles P2 at the second alignment axis do not overlap with each other in the longitudinal direction of the film. As a result, it is possible to prevent the conductive particles from connecting to each other between the terminals and causing a short circuit.
　本発明の設計方法において、導電フィルムをファンアウト型の端子列の端子に対応させる場合にも図４Ａに示すように、まず格子ピッチｄ1、ｄ2の導電粒子Ｐの矩形格子を設定し、次に、一つの格子点Ａから端子長Ｌ１以下の距離にある格子点のうち、その格子点と格子点Ａとを結ぶ直線がフィルム短手方向となす角度α’が最も小さい格子点Ｂを選択し、図４Ｂに示すように格子点Ａを中心に矩形格子を角度αだけ回転させて格子点Ａと格子点Ｂとをフィルム短手方向で重ねる。このときの導電粒子の配置を導電フィルムの粒子配置とする。 In the design method of the present invention, even when the conductive film is made to correspond to the terminal of the fan-out type terminal row, as shown in FIG. , among the grid points at a distance of L1 or less from one grid point A, select the grid point B where the angle α′ formed by the straight line connecting the grid point and the grid point A with the short direction of the film is the smallest. As shown in FIG. 4B, the rectangular grid is rotated by an angle α around the grid point A so that the grid points A and B are overlapped in the lateral direction of the film. The arrangement of the conductive particles at this time is the particle arrangement of the conductive film.
　この場合、こうしてできる粒子配置の配列軸がフィルム長手方向となす角度β（β＝９０－α）がファンアウト角θよりも小さくなるように格子ピッチｄ1、ｄ2を設定することが望ましい。これにより、ファンアウト型の端子列内のいずれの端子も導電粒子の配列軸と交叉するので各端子に導電粒子を捕捉させることが可能となる。 In this case, it is desirable to set the grating pitches d1 and d2 so that the angle β (β=90−α) formed between the array axis of the thus-obtained particle arrangement and the longitudinal direction of the film is smaller than the fan-out angle θ. As a result, since any terminal in the fan-out terminal row intersects the arrangement axis of the conductive particles, each terminal can capture the conductive particles.
　一方、本発明の設計方法において導電粒子の粒子径は、本発明の導電フィルムの用途に応じて適宜定めることができ、例えば、１μｍ以上３０μｍ以下、または１．５μｍ以上１０μｍ未満とすることができる。 On the other hand, in the design method of the present invention, the particle size of the conductive particles can be appropriately determined according to the application of the conductive film of the present invention. .
＜導電粒子のフィルム厚方向の位置＞
　本発明の設計方法にしたがって導電粒子の配置を決定した導電フィルムを製造する場合に、導電粒子Ｐのフィルム厚方向の位置は揃っていることが好ましい。例えば、図５に示す導電フィルム１０Ａのように、導電粒子Ｐが高粘度絶縁性樹脂層２と低粘度絶縁性樹脂層３の積層体に埋め込まれている場合に、導電粒子Ｐと高粘度絶縁性樹脂層２が面一となるように導電粒子Ｐのフィルム厚方向の埋込量Ｌｂを揃えることができる。これにより、端子における導電粒子Ｐの捕捉性が安定し易い。 <Position of conductive particles in film thickness direction>
When manufacturing a conductive film in which the arrangement of the conductive particles is determined according to the design method of the present invention, it is preferable that the positions of the conductive particles P in the film thickness direction are aligned. For example, as in the conductive film 10A shown in FIG. 5, when the conductive particles P are embedded in the laminate of the high viscosity insulating resin layer 2 and the low viscosity insulating resin layer 3, The embedding amount Lb of the conductive particles P in the film thickness direction can be made uniform so that the flexible resin layer 2 is flush. This makes it easier to stabilize the catching property of the conductive particles P on the terminal.
　一方、本発明の設計方法にしたがって導電粒子の配置を決定した導電フィルムとしては、図６に示す導電フィルム１０Ｂのように、導電粒子Ｐが高粘度絶縁性樹脂層２から露出していてもよい。また、導電粒子Ｐは高粘度絶縁性樹脂層２に完全に埋め込まれていてもよい。 On the other hand, as the conductive film in which the arrangement of the conductive particles is determined according to the design method of the present invention, the conductive particles P may be exposed from the high-viscosity insulating resin layer 2, like the conductive film 10B shown in FIG. . Also, the conductive particles P may be completely embedded in the high-viscosity insulating resin layer 2 .
　ここで、埋込量Ｌｂは、導電粒子Ｐが埋め込まれている高粘度絶縁性樹脂層２の表面（高粘度絶縁性樹脂層２の表裏の面のうち、導電粒子Ｐが露出している側の表面、又は導電粒子Ｐが高粘度絶縁性樹脂層２に完全に埋め込まれている場合には、導電粒子Ｐとの距離が近い表面）であって、隣接する導電粒子間の中央部における接平面２ｐと、導電粒子Ｐの最深部との距離をいう。 Here, the embedding amount Lb is the surface of the high-viscosity insulating resin layer 2 in which the conductive particles P are embedded (the side on which the conductive particles P are exposed among the front and back surfaces of the high-viscosity insulating resin layer 2). surface, or when the conductive particles P are completely embedded in the high-viscosity insulating resin layer 2, the surface close to the conductive particles P), the contact at the center between adjacent conductive particles It means the distance between the plane 2p and the deepest part of the conductive particles P.
＜高粘度絶縁性樹脂層＞
　高粘度絶縁性樹脂層２は、特許６１８７６６５号公報に記載の異方性導電フィルムの絶縁性樹脂層と同様に、重合性化合物と重合開始剤から形成される硬化性樹脂組成物を用いて形成することができる。この場合、重合開始剤としては熱重合開始剤を使用してもよく、光重合開始剤を使用してもよく、それらを併用してもよい。例えば、熱重合開始剤としてカチオン系重合開始剤、熱重合性化合物としてエポキシ樹脂を使用し、光重合開始剤として光ラジカル重合開始剤、光重合性化合物としてアクリレート化合物を使用する。熱重合開始剤として、熱アニオン重合開始剤を使用してもよい。熱アニオン重合開始剤としては、イミダゾール変性体を核としその表面をポリウレタンで被覆してなるマイクロカプセル型潜在性硬化剤を用いることが好ましい。 <High viscosity insulating resin layer>
The high-viscosity insulating resin layer 2 is formed using a curable resin composition formed from a polymerizable compound and a polymerization initiator, similarly to the insulating resin layer of the anisotropic conductive film described in Japanese Patent No. 6187665. can do. In this case, as the polymerization initiator, a thermal polymerization initiator may be used, a photopolymerization initiator may be used, or they may be used in combination. For example, a cationic polymerization initiator is used as the thermal polymerization initiator, an epoxy resin is used as the thermally polymerizable compound, a photoradical polymerization initiator is used as the photopolymerization initiator, and an acrylate compound is used as the photopolymerizable compound. A thermal anionic polymerization initiator may be used as the thermal polymerization initiator. As the thermal anionic polymerization initiator, it is preferable to use a microcapsule-type latent curing agent comprising an imidazole modified product as a nucleus and the surface of the nucleus coated with polyurethane.
＜高粘度絶縁性樹脂層の最低溶融粘度＞
　高粘度絶縁性樹脂層２の最低溶融粘度は、特に制限はないが、導電フィルムを用いた電子部品の接続における熱圧着において、導電粒子Ｐの不用な流動を抑制するため、好ましくは１５００Ｐａ・ｓ以上、より好ましくは２０００Ｐａ・ｓ以上、さらに好ましくは３０００～１５０００Ｐａ・ｓ、特に好ましくは３０００～１００００Ｐａ・ｓである。この最低溶融粘度は、一例として回転式レオメータ（ＴＡ ｉｎｓｔｒｕｍｅｎｔｓ社製）を用い、測定圧力５ｇで一定に保持し、直径８ｍｍの測定プレートを使用して求めることができ、より具体的には、温度範囲３０～２００℃において、昇温速度１０℃／分、測定周波数１０Ｈｚ、前記測定プレートに対する荷重変動５ｇとすることにより求めることができる。なお、最低溶融粘度の調整は、溶融粘度調整剤として含有させる微小固形物の種類や配合量、樹脂組成物の調整条件の変更などにより行うことができる。 <Minimum Melt Viscosity of High Viscosity Insulating Resin Layer>
The minimum melt viscosity of the high-viscosity insulating resin layer 2 is not particularly limited. Above, more preferably 2,000 Pa·s or more, still more preferably 3,000 to 15,000 Pa·s, and particularly preferably 3,000 to 10,000 Pa·s. This minimum melt viscosity can be obtained by using a rotary rheometer (manufactured by TA Instruments) as an example, maintaining a constant measurement pressure of 5 g, and using a measurement plate with a diameter of 8 mm. In the range of 30 to 200° C., it can be obtained by setting the temperature increase rate to 10° C./min, the measurement frequency to 10 Hz, and the load variation to the measurement plate to 5 g. The minimum melt viscosity can be adjusted by changing the type and blending amount of fine solids contained as a melt viscosity modifier, adjusting conditions for the resin composition, and the like.
＜低粘度絶縁性樹脂層＞
　低粘度絶縁性樹脂層３は、３０～２００℃の範囲の最低溶融粘度が高粘度絶縁性樹脂層２よりも低い樹脂層である。本発明により粒子配置が設計される導電フィルムにおいて、低粘度絶縁性樹脂層３は必要に応じて設けられるが、低粘度絶縁性樹脂層３を高粘度絶縁性樹脂層２に積層することにより、導電フィルム１０Ａを介して対峙する電子部品を熱圧着する場合に、電子部品の電極やバンプによって形成される空間を低粘度絶縁性樹脂層３で充填し、電子部品同士の接着性を向上させることができる。 <Low viscosity insulating resin layer>
The low-viscosity insulating resin layer 3 is a resin layer whose minimum melt viscosity in the range of 30 to 200° C. is lower than that of the high-viscosity insulating resin layer 2 . In the conductive film in which the particle arrangement is designed according to the present invention, the low-viscosity insulating resin layer 3 is provided as necessary. To improve adhesion between electronic components by filling spaces formed by electrodes and bumps of the electronic components with a low-viscosity insulating resin layer 3 when the electronic components facing each other through the conductive film 10A are thermocompressed. can be done.
　また、高粘度絶縁性樹脂層２の最低溶融粘度と低粘度絶縁性樹脂層３の最低溶融粘度との差があるほど導電フィルム１０Ａを介して接続する電子部品間の空間が低粘度絶縁性樹脂層３で充填され、電子部品同士の接着性が向上しやすくなる。また、この差があるほど導電粒子Ｐを保持している高粘度絶縁性樹脂層２の熱圧着時の移動量が低粘度絶縁性樹脂層３に対して相対的に小さくなるため、端子における導電粒子Ｐの捕捉性が向上しやすくなる。 In addition, the space between the electronic components connected via the conductive film 10A is more likely to be made of the low-viscosity insulating resin as the difference between the minimum melt viscosity of the high-viscosity insulating resin layer 2 and the minimum melt viscosity of the low-viscosity insulating resin layer 3 increases. It is filled with the layer 3, and the adhesiveness between the electronic components is easily improved. In addition, the greater the difference, the smaller the amount of movement of the high-viscosity insulating resin layer 2 holding the conductive particles P during thermocompression bonding relative to the low-viscosity insulating resin layer 3. It becomes easy to improve the catching property of the particles P.
＜高粘度絶縁性樹脂層と低粘度絶縁性樹脂層の層厚＞
　高粘度絶縁性樹脂層２の層厚は、導電フィルムの製造工程において、高粘度絶縁性樹脂層２へ導電粒子Ｐを安定して押し込めるようにするため、導電粒子Ｐの平均粒子径Ｄに対して、好ましくは０．３倍以上、より好ましくは０．６倍以上、さらに好ましくは０．８倍以上、特に好ましくは１倍以上である。また、高粘度絶縁性樹脂層２の層厚の上限については接続する電子部品の端子形状、端子厚、配列ピッチ等に応じて定めることができるが、層厚が厚くなりすぎると接続時に導電粒子Ｐが樹脂流動の影響を不用に受け易くなるため、導電粒子Ｐの平均粒子径Ｄの好ましくは２０倍以下、より好ましくは１５倍以下である。 <Layer thickness of high-viscosity insulating resin layer and low-viscosity insulating resin layer>
The layer thickness of the high-viscosity insulating resin layer 2 is set to the average particle diameter D of the conductive particles P in order to stably push the conductive particles P into the high-viscosity insulating resin layer 2 in the manufacturing process of the conductive film. , preferably 0.3 times or more, more preferably 0.6 times or more, still more preferably 0.8 times or more, and particularly preferably 1 time or more. The upper limit of the layer thickness of the high-viscosity insulating resin layer 2 can be determined according to the terminal shape, terminal thickness, arrangement pitch, etc. of the electronic component to be connected. The average particle size D of the conductive particles P is preferably 20 times or less, more preferably 15 times or less, because P becomes unnecessarily susceptible to the influence of resin flow.
　低粘度絶縁性樹脂層３は、導電フィルムにおいて必要に応じて設けられる。低粘度絶縁性樹脂層３を導電フィルムに設ける場合に、低粘度絶縁性樹脂層３の層厚の下限としては、導電粒子Ｐの平均粒子径Ｄの好ましくは０．２倍以上、より好ましくは１倍以上である。また、低粘度絶縁性樹脂層３の層厚の上限については、厚くなりすぎると高粘度絶縁性樹脂層２との積層の困難性が増すことから、導電粒子Ｐの平均粒子径Ｄの好ましくは５０倍未満、より好ましくは１５倍以下、さらに好ましくは８倍以下である。 The low-viscosity insulating resin layer 3 is provided on the conductive film as necessary. When the low-viscosity insulating resin layer 3 is provided on the conductive film, the lower limit of the layer thickness of the low-viscosity insulating resin layer 3 is preferably 0.2 times or more the average particle diameter D of the conductive particles P, more preferably 1 times or more. In addition, regarding the upper limit of the layer thickness of the low-viscosity insulating resin layer 3, if it is too thick, the difficulty of lamination with the high-viscosity insulating resin layer 2 increases, so the average particle diameter D of the conductive particles P is preferably It is less than 50 times, more preferably 15 times or less, still more preferably 8 times or less.
　また、高粘度絶縁性樹脂層２と低粘度絶縁性樹脂層３との総厚は、電子部品の接続時に導電粒子Ｐの不用な流動を抑制する点、接続する電子部品におけるバンプの低背化に対応させる点、導電フィルムを巻装体とする場合の樹脂のはみ出しやブロッキングを抑制する点、導電フィルムの単位重量あたりのフィルム長を長くする点等からは、薄い方が好ましい。しかし、薄くなりすぎると導電フィルムの取り扱い性が劣る。また、導電フィルムを電子部品に貼着し難くなり、電子部品を接続する際の仮圧着において必要な粘着力を得られない虞があり、本圧着においても樹脂量の不足により必要な接着力を得られない虞がある。そのため、総厚の下限は、導電粒子Ｐの平均粒子径Ｄに対して好ましくは０．６倍以上、より好ましくは０．８倍以上、さらに好ましくは１倍以上、特に好ましくは１．２倍以上である。 In addition, the total thickness of the high-viscosity insulating resin layer 2 and the low-viscosity insulating resin layer 3 suppresses unnecessary flow of the conductive particles P when connecting the electronic parts, and reduces the height of the bumps in the electronic parts to be connected. , suppression of resin extrusion and blocking when the conductive film is wound, and lengthening of the film length per unit weight of the conductive film, the thinner one is preferable. However, if the thickness is too thin, the handleability of the conductive film is poor. In addition, it becomes difficult to attach the conductive film to the electronic parts, and there is a risk that the necessary adhesive strength cannot be obtained in the temporary pressure bonding when connecting the electronic parts. You may not get it. Therefore, the lower limit of the total thickness is preferably 0.6 times or more, more preferably 0.8 times or more, still more preferably 1 time or more, and particularly preferably 1.2 times the average particle diameter D of the conductive particles P. That's it.
　一方、総厚が厚くなりすぎると導電フィルムを電子部品に熱圧着するときに導電粒子Ｐが樹脂流動の影響を不用に受け易くなり、また、これらの樹脂層に粘度調整等の点からフィラーが含まれている場合には、フィラーの絶対量が多くなることにより電子部品の熱圧着が阻害される虞があることから、樹脂層の総厚の上限としては導電粒子Ｐの平均粒子径Ｄの好ましくは５０倍以下、より好ましくは１５倍以下、さらに好ましくは８倍以下である。また、熱圧着時に押し込みツールに必要な推力が高くなり過ぎないようにする点からは、樹脂層の総厚は導電粒子Ｐの平均粒子径Ｄの好ましくは４倍以下、より好ましくは３倍以下、さらに好ましくは２倍以下、さらにより好ましくは１．８倍以下、特に好ましくは１．５倍以下である。高粘度絶縁性樹脂層２と低粘度絶縁性樹脂層３の厚みの比率については、導電粒子Ｐの平均粒子径Ｄとバンプ高さや求められる接着力などの関係から適宜調整することができる。 On the other hand, if the total thickness is too large, the conductive particles P are likely to be unnecessarily affected by resin flow when the conductive film is thermocompression bonded to the electronic component. If it is contained, the absolute amount of the filler increases, which may hinder the thermocompression bonding of the electronic component. Therefore, the upper limit of the total thickness of the resin layer is the average particle diameter D of the conductive particles P. It is preferably 50 times or less, more preferably 15 times or less, and still more preferably 8 times or less. In order to prevent the thrust required for the pressing tool from becoming too high during thermocompression bonding, the total thickness of the resin layer is preferably 4 times or less, more preferably 3 times or less, the average particle diameter D of the conductive particles P. , more preferably 2 times or less, still more preferably 1.8 times or less, and particularly preferably 1.5 times or less. The ratio of the thicknesses of the high-viscosity insulating resin layer 2 and the low-viscosity insulating resin layer 3 can be appropriately adjusted depending on the relationship between the average particle diameter D of the conductive particles P, the bump height, and the desired adhesive strength.
＜導電フィルムの巻装体＞
　本発明により導電粒子の配置が定められた導電フィルムは、その製品形態において巻装体とすることができる。巻装体の長さについて特に制限はないが、出荷物の取り扱い性の点から好ましくは５０００ｍ以下、より好ましくは１０００ｍ以下、さらに好ましくは５００ｍ以下である。一方、巻装体の量産性の点からは５ｍ以上が好ましい。 <Wound Body of Conductive Film>
The conductive film in which the arrangement of the conductive particles is determined according to the present invention can be a wound body in its product form. Although the length of the wound body is not particularly limited, it is preferably 5000 m or less, more preferably 1000 m or less, and still more preferably 500 m or less from the viewpoint of handling of the shipment. On the other hand, from the point of mass production of the wound body, it is preferably 5 m or longer.
　巻装体におけるフィルム幅について特に制限はないが、幅広の導電フィルムをスリットして巻装体を製造する場合のスリット幅の下限の点からフィルム幅を０．３ｍｍ以上とすることが好ましく、スリット幅を安定させる点から０．５ｍｍ以上とすることがより好ましい。フィルム幅の上限には特に制限はないが、持ち運びや取り扱いの観点から、７００ｍｍ以下が好ましく、６００ｍｍ以下がより好ましい。導電フィルムの実用的な取り扱い性の点からは、フィルム幅を０．３～４００ｍｍの間で選択することが好ましい。即ち、導電フィルムが、接続する電子部品の端に用いられる場合には、フィルム幅は数ｍｍ程度以下とされることが多く、比較的大きな電子部品（電極配線と実装部が一面に設けられた基板や切削前のウェーハーなど）にそのまま貼り付けて使用される場合には、４００ｍｍ程度のフィルム幅が必要とされることがある。一般には、導電フィルムのフィルム幅は０．５～５ｍｍで使用されることが多い。 The film width in the wound body is not particularly limited, but the film width is preferably 0.3 mm or more from the viewpoint of the lower limit of the slit width when manufacturing a wound body by slitting a wide conductive film. From the viewpoint of stabilizing the width, it is more preferable to set the width to 0.5 mm or more. Although the upper limit of the film width is not particularly limited, it is preferably 700 mm or less, more preferably 600 mm or less, from the viewpoint of portability and handling. From the viewpoint of practical handling of the conductive film, it is preferable to select the film width between 0.3 and 400 mm. That is, when a conductive film is used at the edge of an electronic component to be connected, the film width is often less than several millimeters, and a relatively large electronic component (electrode wiring and mounting portion are provided on one side). When the film is used by being directly attached to a substrate, a wafer before cutting, etc., a film width of about 400 mm may be required. In general, the conductive film is often used with a film width of 0.5 to 5 mm.
＜導電フィルムの製造方法＞
　本発明により導電粒子の配置が設計された導電フィルムの製造方法自体には特に限定はない。例えば、導電粒子を所定の配列に配置するため、まず転写型を製造する。転写型の製造方法については後述する。 <Method for producing conductive film>
The method itself for producing a conductive film in which the arrangement of conductive particles is designed according to the present invention is not particularly limited. For example, to place the conductive particles in a predetermined array, a transfer mold is first manufactured. A method of manufacturing the transfer mold will be described later.
　次に、転写型の凹部に導電粒子を充填し、その上に、剥離フィルム上に形成した高粘度絶縁性樹脂層を被せて圧力をかけ、高粘度絶縁性樹脂層に導電粒子を押し込むことにより、高粘度絶縁性樹脂層に導電粒子を転着させ、あるいはさらにその導電粒子上に低粘度絶縁性樹脂層を積層することで導電フィルムを製造する。 Next, the recesses of the transfer mold are filled with conductive particles, and a high-viscosity insulating resin layer formed on a release film is placed thereon and pressure is applied to press the conductive particles into the high-viscosity insulating resin layer. A conductive film is produced by transferring conductive particles to a high-viscosity insulating resin layer, or further laminating a low-viscosity insulating resin layer on the conductive particles.
　また、転写型の凹部に導電粒子を充填した後、その上に高粘度絶縁性樹脂層を被せ、転写型から高粘度絶縁性樹脂層の表面に導電粒子を転写させ、導電粒子を高粘度絶縁性樹脂層内に押し込むことにより導電フィルムを製造してもよい。 In addition, after filling the recesses of the transfer mold with conductive particles, a high-viscosity insulating resin layer is covered thereon, the conductive particles are transferred from the transfer mold to the surface of the high-viscosity insulating resin layer, and the conductive particles are highly viscous insulating. A conductive film may be produced by pressing into a flexible resin layer.
　なお、転写型としては、凹部に導電粒子を充填するものの他、凸部の天面に微粘着剤を付与してその天面に導電粒子が付着するようにしたものを用いても良い。 As the transfer mold, in addition to the one in which the concave portions are filled with conductive particles, the one in which a slightly adhesive agent is applied to the top surface of the convex portions so that the conductive particles adhere to the top surface may be used.
　また、導電粒子を所定の配列に配置する方法としては、転写型を用いる方法に代えて、所定の配置で設けられた貫通孔に導電粒子を通過させる方法等を使用してもよい。 Also, as a method of arranging the conductive particles in a predetermined arrangement, instead of using a transfer mold, a method of passing the conductive particles through through-holes provided in a predetermined arrangement, or the like may be used.
＜転写型の製造方法＞
　転写型は公知の方法で製造することができる。例えば、まず、ニッケルプレート等の金属プレートに公知の切削加工またはレーザ加工を行うことにより、金属プレートに導電粒子の配置パターンを凹部又は凸部として形成し、転写型原盤とする。金属原盤はフォトリソグラフィ、印刷法等の技術を用いたパターニングによって製造してもよい。 <Manufacturing method of transfer mold>
A transfer mold can be produced by a known method. For example, first, a metal plate such as a nickel plate is subjected to known cutting or laser processing to form an arrangement pattern of conductive particles as recesses or protrusions on the metal plate, thereby forming a transfer mold master. The metal master may be manufactured by patterning using techniques such as photolithography and printing.
　次に、転写型原盤に硬化性樹脂組成物を塗布し、硬化させ、原盤から引き離すことにより転写型を作製することができる。 Next, a transfer mold can be produced by applying a curable resin composition to the transfer mold master, curing it, and separating it from the master.
＜導電フィルムを用いた電子部品の接続方法＞
　本発明により導電粒子の配置が設計された導電フィルムを用いて電子部品を接続する方法としては、例えば、ステージに一方の電子部品を載置し、その上に導電フィルムを介してもう一方の電子部品を載置し、圧着ツールで加熱押圧することにより接続構造体を製造する。この場合、ステージに載置する電子部品をミニＬＥＤやマイクロＬＥＤといった発光素子、ＩＣチップ、ＩＣモジュール、ＦＰＣ、ガラス基板、プラスチック基板、リジッド基板、セラミック基板などの第２電子部品とし、圧着ツールで加熱加圧する電子部品をＦＰＣ、ＩＣチップ、ＩＣモジュール、発光素子などの第１電子部品とする。より詳細な方法としては、各種基板等の第２電子部品に導電フィルムを仮貼りして仮圧着し、仮圧着した導電フィルムにＩＣチップ等の第１電子部品を合わせ、熱圧着することにより接続構造体を製造する。なお、第２電子部品ではなく、第１電子部品に導電フィルムを仮貼りして接続構造体を製造することもできる。また、接続方法における圧着は熱圧着に限定されるものではなく、光硬化を利用した圧着や、熱と光を併用した圧着などを行っても良い。 <Method for Connecting Electronic Components Using Conductive Film>
As a method of connecting electronic components using a conductive film in which the arrangement of conductive particles is designed according to the present invention, for example, one electronic component is placed on a stage, and the other electronic component is placed on it via the conductive film. A connection structure is manufactured by placing the parts and heat-pressing them with a crimping tool. In this case, the electronic parts to be placed on the stage are light emitting elements such as mini LEDs and micro LEDs, second electronic parts such as IC chips, IC modules, FPCs, glass substrates, plastic substrates, rigid substrates, ceramic substrates, etc., and are pressed with a crimping tool. The electronic component to be heated and pressurized is a first electronic component such as an FPC, an IC chip, an IC module, or a light emitting element. As a more detailed method, a conductive film is temporarily attached to a second electronic component such as various substrates and is temporarily pressure-bonded, and the first electronic component such as an IC chip is combined with the temporarily pressure-bonded conductive film and connected by thermocompression bonding. Manufacture the structure. Note that the connection structure can be manufactured by temporarily attaching the conductive film to the first electronic component instead of the second electronic component. Moreover, the crimping in the connection method is not limited to thermocompression bonding, and crimping using photocuring or crimping using both heat and light may be performed.
　本発明により導電粒子の配置が設計された導電フィルムは、(i)マイクロＬＥＤをディスプレイ用基板に接続する場合をはじめとして、接続する端子列がファインピッチの場合に端子間のショートを効果的に抑制できるので意義が高く、また、(ii)第１電子部品および第２電子部品の少なくとも一方を、ＦＰＣやプラスチック基板などの熱膨張しやすい材質のものとする場合に意義が高い。具体的には、ＦＯＰ（Film On Plastic）、ＦＯＧ（Film On Glass）、ＣＯＧ（Chip On Glass）、ＣＯＰ（Chip On Plastic）接続する場合に上述の(i)、(ii)の何れか一つもしくは両方を満足するので好ましい。さらに接続する端子列がファンアウト型の場合にはより一層本発明の意義が高くなる。なお、ファンアウト配列は端子列が部品の何れか一方にのみ存在する態様に限定されるものではない。本発明により導電粒子の配置が設計された導電フィルムはペリフェラル配列などの公知の配列にも適用することができる。 The conductive film in which the arrangement of conductive particles is designed according to the present invention effectively prevents shorts between terminals when the terminal row to be connected has a fine pitch, including (i) when connecting a micro LED to a display substrate. It is significant because it can be suppressed, and (ii) it is significant when at least one of the first electronic component and the second electronic component is made of a material that easily expands thermally, such as an FPC or a plastic substrate. Specifically, when connecting FOP (Film On Plastic), FOG (Film On Glass), COG (Chip On Glass), COP (Chip On Plastic), one of the above (i) and (ii) Or it is preferable because it satisfies both. Further, when the terminal row to be connected is of the fan-out type, the significance of the present invention is further enhanced. Note that the fan-out arrangement is not limited to a mode in which the terminal row exists only on one of the components. The conductive film in which the arrangement of the conductive particles is designed according to the present invention can also be applied to known arrangements such as peripheral arrangement.
　以下、本発明を実験例により具体的に説明する。
実験例１～６
　表１に示す仕様の導電フィルムを製造した。この導電フィルムでは、導電粒子の粒子径を３μｍとした。また、導電粒子が正方格子の格子点に配置されており、その格子軸と導電フィルムの短手方向とのなす角度（傾斜角）αを表１に示す値とした。
　これらの粒子配置を図７Ａ、図７Ｂ～図１２Ａ、図１２Ｂに示す。 Hereinafter, the present invention will be specifically described with reference to experimental examples.
Experimental examples 1-6
A conductive film having specifications shown in Table 1 was produced. In this conductive film, the particle size of the conductive particles was set to 3 μm. In addition, the conductive particles are arranged at lattice points of a square lattice, and the angle (tilt angle) α between the lattice axis and the lateral direction of the conductive film is set to the value shown in Table 1.
These particle arrangements are shown in FIGS. 7A, 7B-12A, 12B.
　各実験例の導電フィルムを用いて、端子長１００μｍ、端子幅１０μｍ、端子間距離１０μｍの端子列を有する第１電子部品と同様の端子列を有する第２電子部品とを接続した場合の接続状態(i)として、第１電子部品と第２電子部品の対向する端子同士が端子幅方向に位置ズレしなかった場合を考え、そのときの性能評価として、(ａ)個々の端子における導電粒子の最少捕捉数、(ｂ)端子間あたりの最大粒子数、(ｃ)端子間あたりの最大粒子占有面積率、をシミュレーションにより調べた。 Connection state when a first electronic component having a terminal row with a terminal length of 100 μm, a terminal width of 10 μm, and a terminal distance of 10 μm and a second electronic component having a similar terminal row are connected using the conductive film of each experimental example. As (i), considering the case where the opposing terminals of the first electronic component and the second electronic component are not displaced in the terminal width direction, as a performance evaluation at that time, (a) the conductive particles in each terminal The minimum number of trapped particles, (b) the maximum number of particles between terminals, and (c) the maximum particle occupied area ratio between terminals were examined by simulation.
　また、接続状態(ii)として、第１電子部品と第２電子部品の対向する端子同士が端子幅方向に４μｍずれた場合を考え、そのときの性能評価を同様に調べた。 In addition, as the connection state (ii), the case where the facing terminals of the first electronic component and the second electronic component are displaced by 4 μm in the terminal width direction was considered, and the performance evaluation at that time was similarly investigated.
　さらに、接続状態(i)及び(ii)の性能判定として、(ｄ)シミュレーションで得られた個々の端子における導電粒子の最少捕捉数から導通接続性を予測して次のように評価し、評価Ｃ以上で合格、評価Ｄで不合格とした。 Furthermore, as a performance judgment of the connection states (i) and (ii), (d) the conductive connectivity is predicted from the minimum number of trapped conductive particles at each terminal obtained by the simulation, and evaluated as follows. A grade of C or higher was regarded as a pass, and an evaluation of D was regarded as a disqualification.
(ｄ)導通接続性
　評価Ａ：５個以上
　評価Ｂ：３～４個
　評価Ｃ：１～２個
　評価Ｄ：０個 (d) Continuity connectivity Evaluation A: 5 or more Evaluation B: 3 to 4 Evaluation C: 1 to 2 Evaluation D: 0
　また、接続状態(i)及び(ii)の性能判定として、（ｅ）シミュレーションで得られた導電粒子の端子間最大粒子数からショートのしにくさを予測して次のように評価し、評価Ｃ以上で合格、評価Ｄで不合格とした。
　具体的には導電粒子の端子間最大粒子数と端子間面積から下記の式に当てはめ端子間粒子占有面積率を算出する。
　端子間粒子占有面積率（％）＝（端子間最大粒子数×粒子面積）/端子間面積 ×１００ In addition, as a performance judgment of the connection states (i) and (ii), (e) the difficulty of short-circuiting is predicted from the maximum number of particles between the terminals of the conductive particles obtained in the simulation, and evaluated as follows. A grade of C or higher was regarded as a pass, and an evaluation of D was regarded as a disqualification.
Specifically, the inter-terminal particle occupied area ratio is calculated by applying the following formula from the maximum number of inter-terminal particles of the conductive particles and the inter-terminal area.
Particle occupation area ratio between terminals (%) = (maximum number of particles between terminals x particle area) / area between terminals x 100
(ｅ)ショートのしにくさ
　評価Ａ：１０％未満
　評価Ｂ：１０以上～１８％未満
　評価Ｃ：１８以上～２６％未満
　評価Ｄ：２６％以上 (e) Difficulty of shorting Evaluation A: less than 10% Evaluation B: 10 to less than 18% Evaluation C: 18 to less than 26% Evaluation D: 26% or more
　結果を表１に示す。 The results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１から、粒子配置を正方格子とし、傾斜角αを図２に示した飛び飛びの大きさで傾けることにより、導電フィルムの性能評価や性能判定をシミュレーションで容易に確認できることがわかる。 From Table 1, it can be seen that the performance evaluation and performance judgment of the conductive film can be easily confirmed by simulation by setting the particle arrangement to a square lattice and tilting the tilt angle α by the discrete size shown in FIG.
　実験例７、実験例８
　傾斜角αの変更により、個々の端子における導電粒子の最少捕捉数が変わることを確認するため、端子長Ｌ1が３０μｍ、端子幅Ｌ2＝有効接続端子幅Ｌ3＝５μｍ、端子間方向の導体間距離Ｌ５＝５μｍの端子を、次の導電粒子の粒子配置で接続する場合をシミュレーションした。
導電粒子の粒子径：２μｍ
導電粒子の粒子密度：１２０００個／ｍｍ2
粒子配置格子間距離（ピッチｄ1，ｄ2）：９．１μｍ Experimental example 7, experimental example 8
In order to confirm that the minimum number of trapped conductive particles in each terminal is changed by changing the inclination angle α, terminal length L1 was 30 μm, terminal width L2 = effective connection terminal width L3 = 5 μm, distance between conductors in the direction between terminals. A case of connecting terminals with L5=5 μm with the following particle arrangement of conductive particles was simulated.
Particle diameter of conductive particles: 2 μm
Particle density of conductive particles: 12000/mm 2
Particle arrangement lattice distance (pitch d1, d2): 9.1 μm
　この場合、実験例７では傾斜角αを１４°とし、実験例８では傾斜角αを９．５°とした。結果を図１３、図１４及び表１に示す。 In this case, the inclination angle α was set to 14° in Experimental Example 7, and the inclination angle α was set to 9.5° in Experimental Example 8. The results are shown in FIGS. 13, 14 and Table 1.
　本実験例の端子に対し、格子間距離９．１μｍの正方格子に粒子径２μｍの導電粒子を配置した場合に傾斜角αを１４°（図１３）とすると各端子に１個以上の導電粒子が捕捉されていることがわかり、傾斜角αを９．５°（図１４）とすると、導電粒子を捕捉しない端子が出現することがわかる。 For the terminal of this experimental example, when conductive particles with a particle diameter of 2 μm are arranged in a square lattice with an interstitial distance of 9.1 μm, and the inclination angle α is 14° (FIG. 13), one or more conductive particles are attached to each terminal. is captured, and when the inclination angle α is set to 9.5° (FIG. 14), it can be seen that terminals that do not capture the conductive particles appear.
１、１ｘ、１ｙ　端子
２　高粘度絶縁性樹脂層
３　低粘度絶縁性樹脂層
１０Ａ、１０Ｂ　導電フィルム
Ｐ　導電粒子 1, 1x, 1y Terminal 2 High-viscosity insulating resin layer 3 Low-viscosity insulating resin layers 10A, 10B Conductive film P Conductive particles

Claims (8)

  1. 　平面視にて、所定の粒子径の導電粒子が絶縁性樹脂層に保持されている導電フィルムを用いて、端子長Ｌ1、端子幅Ｌ2の端子（但し、Ｌ1≧Ｌ2）を接続する場合の該導電フィルムにおける導電粒子の配置の設計方法であって、
    まず、導電粒子の配置が矩形格子又は斜方格子の格子点にあり、導電フィルムの長手方向又は短手方向（以下、フィルム長手方向又はフィルム短手方向ともいう）に直交する格子軸を有するとし、導電フィルムにおける導電粒子の個数密度、該個数密度に応じたフィルム長手方向の格子軸における導電粒子のピッチｄ1、及びフィルム短手方向の格子軸における導電粒子のピッチｄ2（ｄ2＝ａ・ｄ1、ａは係数）を設定し、
    次に、一つの格子点Ａから端子長Ｌ１以下の距離にある格子点のうち、その格子点と格子点Ａとを結ぶ直線がフィルム短手方向となす角度が最も小さい格子点Ｂを選択し、格子点Ａを中心に格子を回転させて格子点Ａと格子点Ｂがフィルム短手方向で重なる格子の回転角αを求め、その角度αにより導電フィルムの格子軸の傾斜角を決定する設計方法。     When connecting terminals having a terminal length of L1 and a terminal width of L2 (where L1≧L2) using a conductive film in which conductive particles having a predetermined particle diameter are held in an insulating resin layer in plan view. A method for designing the arrangement of conductive particles in a conductive film,
    First, when the conductive particles are arranged at lattice points of a rectangular lattice or an orthorhombic lattice and have a lattice axis orthogonal to the longitudinal direction or the transverse direction of the conductive film (hereinafter also referred to as the longitudinal direction of the film or the transverse direction of the film). Then, the number density of the conductive particles in the conductive film, the pitch d1 of the conductive particles on the lattice axis in the longitudinal direction of the film according to the number density, and the pitch d2 of the conductive particles on the lattice axis in the lateral direction of the film (d2 = a d1 , a is the coefficient),
    Next, among the grid points located at a distance equal to or less than the terminal length L1 from one grid point A, the grid point B is selected, in which the straight line connecting the grid point and the grid point A makes the smallest angle with the lateral direction of the film. , Rotate the lattice around the lattice point A to obtain the rotation angle α of the lattice at which the lattice point A and the lattice point B overlap in the film short direction, and determine the inclination angle of the lattice axis of the conductive film from the angle α Method.
  2. 　格子が正方格子である請求項１記載の設計方法。 The design method according to claim 1, wherein the lattice is a square lattice.
  3. 　端子長Ｌ1及び端子幅Ｌ2が７μｍ以上１０００μｍ以下の場合に、導電粒子の個数密度を５００個／ｍｍ2以上１５０００００個／ｍｍ2以下の範囲で設定する請求項１又は２記載の設計方法。 3. The designing method according to claim 1, wherein when the terminal length L1 and the terminal width L2 are 7 μm or more and 1000 μm or less, the number density of the conductive particles is set in the range of 500 pieces/mm 2 or more and 1500000 pieces/mm 2 or less.
  4. 　導電粒子の粒子径を１．０μｍ以上３０μｍ以下とする請求項１～３のいずれかに記載の設計方法。 The design method according to any one of claims 1 to 3, wherein the particle diameter of the conductive particles is 1.0 μm or more and 30 μm or less.
  5. 　フィルム短手方向に対して角度αで傾斜している格子軸であって、互いに隣接するものを第１配列軸、第２配列軸とした場合に、第１配列軸における導電粒子と、第２配列軸における導電粒子とがフィルム長手方向に重畳しないように角度αを定める請求項１～４のいずれかに記載の設計方法。 When lattice axes inclined at an angle α with respect to the transverse direction of the film and adjacent to each other are defined as a first arrangement axis and a second arrangement axis, the conductive particles on the first arrangement axis and the second The design method according to any one of claims 1 to 4, wherein the angle α is determined so that the conductive particles on the alignment axis do not overlap with each other in the longitudinal direction of the film.
  6. 　ｄ1・cosα≦Ｌ2　又は
    　ｄ2・sinα≦Ｌ1
    が満たされるように導電粒子のピッチｄ1、ｄ2を定める請求項１～５のいずれかに記載の設計方法。     d1・cosα≦L2 or d2・sinα≦L1
    6. The design method according to any one of claims 1 to 5, wherein the pitches d1 and d2 of the conductive particles are determined so as to satisfy
  7. 　絶縁性樹脂層に導電粒子を所定の配置パターンで転写するために使用する転写型の製造方法であって、請求項１～６のいずれかに記載の方法で設計した所定の配置パターンを凹部又は凸部として金属プレートに加工する工程を有する方法。 A method for manufacturing a transfer mold used for transferring conductive particles to an insulating resin layer in a predetermined arrangement pattern, wherein the predetermined arrangement pattern designed by the method according to any one of claims 1 to 6 is formed in recesses or A method comprising machining a metal plate as a protrusion.
  8. 　金属プレートの加工を切削加工により行う請求項７記載の方法。 The method according to claim 7, wherein the metal plate is processed by cutting.
PCT/JP2023/003440 2022-02-10 2023-02-02 Designing method for conductive film WO2023153313A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0582199A (en) * 1991-05-28 1993-04-02 Minato Electron Kk Structure for arranging connector having anisotropic conducting connector and anisotropic conducting connector
JP2016015205A (en) * 2014-06-30 2016-01-28 デクセリアルズ株式会社 Anisotropic conductive film and connection structure
WO2016068127A1 (en) * 2014-10-28 2016-05-06 デクセリアルズ株式会社 Anisotropic conductive film and connecting structure
WO2016190424A1 (en) * 2015-05-27 2016-12-01 デクセリアルズ株式会社 Anisotropic conductive film and connection structure
JP2020027798A (en) * 2018-08-08 2020-02-20 デクセリアルズ株式会社 Anisotropic conductive film

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0582199A (en) * 1991-05-28 1993-04-02 Minato Electron Kk Structure for arranging connector having anisotropic conducting connector and anisotropic conducting connector
JP2016015205A (en) * 2014-06-30 2016-01-28 デクセリアルズ株式会社 Anisotropic conductive film and connection structure
WO2016068127A1 (en) * 2014-10-28 2016-05-06 デクセリアルズ株式会社 Anisotropic conductive film and connecting structure
WO2016190424A1 (en) * 2015-05-27 2016-12-01 デクセリアルズ株式会社 Anisotropic conductive film and connection structure
JP2020027798A (en) * 2018-08-08 2020-02-20 デクセリアルズ株式会社 Anisotropic conductive film

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