Connection Structure

Abstract

To solve the problem that short-circuiting occurs by stagnating conductive particles in an inter-terminal space in a connection structure in which a first electronic component and a second electronic component are connected in an anisotropic conductive manner.SOLUTION: The present invention relates to a connection structure 30A in which a first electronic component 10 including a terminal row 12a configured by arraying terminals 11a is adhered with a second electronic component 20 including a terminal row 22a corresponding to the terminal row 12a via an insulating resin 1, and the terminal 11a of the first electronic component 10 and the terminal 21a of the second electronic component 20 are electrically connected by a conductive particle 2 in the insulating resin 1 held therebetween. A density α of the number of terminal vicinity parts 15 adjacent to the terminal in an inter-terminal space 13a of the terminal row and a density β of the number of conductive particles in an inter-terminal intermediate part 14 excluding the terminal vicinity part 15 from the inter-terminal space 13a satisfy α<β.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a connection structure between a first electronic component and a second electronic component that can be manufactured using an anisotropic conductive film. [Background technology]

[0002] Anisotropic conductive films, which have conductive particles held in an insulating resin layer, are widely used when mounting electronic components such as IC chips on wiring boards. Here, anisotropic conductive films refer to films that are interposed between terminal rows of electronic components and terminal rows of substrates to obtain connection structures, and which exhibit conductivity only in the film thickness direction and no conductivity in the film plane direction. Furthermore, anisotropic conductive connection refers to a connection between a terminal row of an electronic component and a terminal row of a substrate, in which there is conductivity in the stacking direction of the electronic component and the substrate, but no conductivity in the terminal row direction.

[0003] There is a strong demand for anisotropic conductive adhesives that can accommodate the narrower pitch of terminals such as bumps that accompany the high-density mounting of electronic components. Simply increasing the number density of conductive particles in an anisotropic conductive film to meet this demand can result in, for example, as shown in Figure 10, insulating resin 1 extruded from between terminals 11a and 21a of opposing electronic components 10 and 20 or from between the bonding surfaces of the opposing electronic components 10 and 20 during thermocompression bonding during anisotropic conductive connection flows into inter-terminal spaces 13a and 13b and flows in the longitudinal direction of the terminals. As the resin flows, conductive particles 2 move through inter-terminal spaces 13a and 13b and accumulate near the end 13x of the inter-terminal space downstream of the resin flow, bridging adjacent terminals and potentially causing a short circuit.

[0004] To address this issue, it has been proposed to erect walls on the electrode pads or substrate to block the flow of resin, thereby preventing conductive particles from flowing into the space between terminals and thereby preventing short circuits (Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-27847 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-191015 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the techniques described in Patent Documents 1 and 2 require the creation of walls on the electrode pads or substrates to block the resin flow, which poses the problem that short circuits cannot be prevented when anisotropically connecting commonly used electronic components that do not have walls to block the resin flow.

[0007] Therefore, an object of the present invention is to provide a connection structure in which the terminal row of an arbitrary first electronic component and the terminal row of a second electronic component are anisotropically conductively connected, and in which short circuits caused by conductive particles accumulating in the space between the terminals are suppressed. [Means for solving the problem]

[0008] The present inventors have discovered that, when using an anisotropic conductive film to obtain a connection structure between a terminal row of a first electronic component and a terminal row of a second electronic component, the anisotropic conductive film is one in which an insulating high-viscosity resin layer holding conductive particles and a low-viscosity resin layer having a lower minimum melt viscosity than the high-viscosity resin layer are laminated, and in this case, (i) the ratio of the minimum melt viscosities of the high-viscosity resin layer and the low-viscosity resin layer is set to a specific range, and (ii) the ratio of the total thickness Ts of the resin layers constituting the anisotropic conductive film to the sum Tt of the terminal height of the first electronic component and the terminal height of the second electronic component is set to a specific range. It was discovered that when Ts / Tt is set within a specific range, pressing a first electronic component and a second electronic component stacked with an anisotropic conductive film interposed therebetween at a pressure below a specific pressure causes a low-viscosity resin layer to be extruded from between the opposing terminals of the first electronic component and the second electronic component, and this extrusion of the low-viscosity resin layer results in no conductive particles being present in the inter-terminal space in the terminal row direction near the terminals, or the number density of conductive particles in the inter-terminal space is significantly reduced, resulting in a connection structure in which short circuits due to conductive particles in the inter-terminal space are prevented. This is presumably because, with such pressing, the resin flow through the inter-terminal space during an anisotropic conductive connection is caused almost entirely by the low-viscosity resin layer, while the high-viscosity resin layer holding the conductive particles in the inter-terminal space is held in the inter-terminal space without contributing to the resin flow through the inter-terminal space.

[0009] On the other hand, when an anisotropic conductive film in which strong resin flow is likely to occur due to a large Ts / Tt ratio or the like is used to anisotropically conductively connect a first electronic component and a second electronic component, it has been found that even when pressing with a pressure greater than the pressure described above, the number density of conductive particles in the inter-terminal space is significantly reduced, resulting in a connection structure in which short circuits due to conductive particles in the inter-terminal space are prevented. This is presumably because, with the pressing in this case, the particle flow in the inter-terminal space is constituted not only by the low-viscosity resin layer but also by the high-viscosity resin layer, and this strong resin flow pushes the conductive particles held in the inter-terminal space out of the inter-terminal space. The present invention is based on this finding.

[0010] That is, the present invention provides a connection structure in which a first electronic component having a terminal row in which terminals are arranged is bonded to a second electronic component having a terminal row corresponding to the terminal row via an insulating resin, and the terminals of the first electronic component and the terminals of the second electronic component are electrically connected by conductive particles in the insulating resin sandwiched between them, A connection structure is provided in which the area occupancy rate of conductive particles in the vicinity of the terminals adjacent to the terminals in the space between the terminals in a terminal row is less than 1%. [Effects of the Invention]

[0011] According to the connection structure of the present invention, in the inter-terminal space, the number density α of conductive particles in the vicinity of the terminals adjacent to the terminals and the number density β of conductive particles in the intermediate portion between the terminals excluding the vicinity of the terminals from the inter-terminal space are such that α<β, and since the number density of conductive particles in the vicinity of the terminals is sparse or the number density of conductive particles in the inter-terminal space is significantly reduced, it is possible to prevent short circuits from being caused by conductive particles present in the inter-terminal space. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a top perspective view of a connection structure 30A according to an embodiment. [Figure 2] FIG. 2 is an enlarged view of a region A of the connection structure 30A of the embodiment. [Figure 3] FIG. 3 is a cross-sectional view of region A of a connection structure 30A of the embodiment. [Figure 4] FIG. 4 is a top perspective view of a connection structure 30A of the embodiment in a state before thermocompression bonding in the manufacturing process. [Figure 5] FIG. 5 is a partial cross-sectional view of a connection structure 30A of the embodiment in a state before thermocompression bonding in the manufacturing process. [Figure 6] FIG. 6 is a partial cross-sectional view of the connection structure 30A of the embodiment during thermocompression bonding in the manufacturing process. [Figure 7] FIG. 7 is a partial cross-sectional view of the connection structure 30A of the embodiment during thermocompression bonding in the manufacturing process. [Figure 8]FIG. 8 is a top perspective view of the connection structure 30A of the embodiment during thermocompression bonding in the manufacturing process. [Figure 9] FIG. 9 is a partially enlarged perspective top view of a connection structure 30B according to the embodiment. [Figure 10] FIG. 10 is a top perspective view of the connection structure of the comparative example during thermocompression bonding in the manufacturing process. [Figure 11A] FIG. 11A is a cross-sectional view of an anisotropic conductive film 5A suitable for manufacturing a connection structure. [Figure 11B] FIG. 11B is a cross-sectional view of an anisotropic conductive film 5B suitable for manufacturing a connection structure. DETAILED DESCRIPTION OF THE INVENTION

[0013] The connection structure of the present invention will be described in detail below with reference to the drawings, in which the same reference numerals denote the same or equivalent components.

[0014] <Connection structure> FIG. 1 is a top perspective view of a connection structure 30A according to an embodiment of the present invention, FIG. 2 is an enlarged view of region A thereof, and FIG. 3 is a cross-sectional view of region A thereof.

[0015] This connection structure 30A is an anisotropically conductive connection between an IC chip (first electronic component) 10 such as a driver IC having a terminal row 12a in which input side terminals (bumps) 11a are arranged in a straight line in the short side direction and a terminal row 12b in which output side terminals (bumps) 11b are arranged in a straight line in the short side direction, and a glass substrate 20 (second electronic component) having terminal rows 22a, 22b corresponding to the terminal rows 12a, 12b of the IC chip 10, via conductive particles 2 that constitute the anisotropic conductive film and insulating resin (high viscosity resin and low viscosity resin) 1. That is, the opposing surfaces of the IC chip 10 and the glass substrate 20 are bonded together by insulating resin 1, and the input side terminal 11a of the IC chip 10 and the terminal 21a of the glass substrate 20 are electrically connected by conductive particles 2 sandwiched between them, and the output side terminal 11b of the IC chip 10 and the terminal 21b of the glass substrate 20 are also electrically connected by conductive particles 2 sandwiched between them.

[0016] Thus, the connection structure of the present invention is an anisotropic conductive connection between a first electronic component such as an IC chip, IC module, other semiconductor element (e.g., semiconductor element such as an LED or Peltier element), or FPC, and a second electronic component such as a glass substrate, FPC, rigid substrate, ceramic substrate, or plastic substrate, which has a terminal row corresponding to the terminal row of the first electronic component. The connection structure of the present invention can be used for a variety of purposes, including personal digital assistants (such as mobile phones), large televisions, public displays (digital signage), wearable displays (smart watches), and in-vehicle displays.

[0017] In the present invention, the area of ​​each electrode (hereinafter also referred to as terminal area) of the electronic component is 1000 μm 2 This also includes minute electronic components whose longest side is 600 μm or less, and particularly 300 μm or less.

[0018] Furthermore, for example, in a connection structure in which an assembly of micro LEDs is connected to a substrate using an anisotropic conductive film, each micro LED does not have a terminal row, and the connection between the terminal of each micro LED and the substrate cannot be considered "anisotropic," but the assembly of micro LEDs can also be the first electronic component in the present invention. Therefore, the present invention encompasses a connection structure in which an assembly of micro LEDs is connected to a substrate using an anisotropic conductive film.

[0019] The arrangement of terminals in a terminal row of an electronic component is not limited to a linear arrangement, but may be radial, as described in, for example, JP 2007-19550 A. Furthermore, there is no limit to the number of terminal rows in each electronic component. To make the following description of the connection structure of the present invention easier to understand, the following description will be made of the input-side terminal row, but the same description also applies to the output-side terminal row.

[0020] In the connection structure 30A of this embodiment, the distribution of the conductive particles 2 in the inter-terminal space 13a of the anisotropically conductively connected terminal rows 12a, 22a in the arrangement direction X of the terminals 11a, 21a is sparser in the terminal vicinity 15 than in the inter-terminal intermediate portion 14, as shown in the top perspective view of Figure 2. In other words, the number density α of the conductive particles 2 in the terminal vicinity 15 adjacent to the terminal in the inter-terminal space 13a is α<β, and the number density β of the conductive particles 2 in the inter-terminal intermediate portion 14, which is the inter-terminal space 13a excluding the terminal vicinity 15. This arrangement direction X is generally perpendicular to the longitudinal direction of the terminals.

[0021] In a conventional connection structure in which electronic components that do not have a wall (Patent Documents 1 and 2) that blocks the resin that flows into the inter-terminal space during anisotropic conductive connection are anisotropically conductively connected, the conductive particles 2 are concentrated near the open end 13X on the outer edge side of the IC chip 10 in the inter-terminal space 13a, as shown in Figure 10, and the conductive particles may connect with each other there, causing a short circuit between adjacent terminals in the terminal arrangement direction X. In contrast, in the connection structure 30A of this embodiment, the distribution of the conductive particles 2 in the inter-terminal space 13a is sparser in the terminal vicinity 15 than in the inter-terminal intermediate portion 14, as described above, and the conductive particles 2 present in the inter-terminal space 13a are not concentrated toward the outer edge of the IC chip 10, so that short circuits are less likely to occur in the inter-terminal space 13a.

[0022] As shown in FIG. 2, the terminal vicinity 15 can be an area where the distance Lv from the terminals 11a, 21a in the arrangement direction of the terminals 11a, 21a is preferably less than 1 time, and more preferably within 0.5 times, the conductive particle diameter D. The inter-terminal intermediate area 14 is the area of ​​the inter-terminal space 13a excluding the terminal vicinity 15. A more preferred embodiment of the connection structure 30A of this embodiment is an embodiment in which, for both of the anisotropically conductively connected terminals 11a, 21a, no conductive particles 2 are present in the terminal vicinity 15, which is an area where the distance Lv from the terminal is within 0.5 times the conductive particle diameter D. This embodiment reliably eliminates short circuits between the terminals.

[0023] In the present invention, the conductive particle diameter D refers to the average particle diameter of the conductive particles 2 present in the inter-terminal space 13a. When the region in the arrangement direction of the terminals 11a, 21a where the distance Lv from the terminal is less than 1 time the conductive particle diameter D is defined as the terminal vicinity 15, whether the conductive particles 2 present at the boundary between the terminal vicinity 15 and the inter-terminal intermediate portion 14 are attributed to the terminal vicinity 15 or the inter-terminal intermediate portion 14 in measuring the number density of the conductive particles is determined based on whether the area of ​​the conductive particles is greater in the terminal vicinity 15 or the inter-terminal intermediate portion 14 in a planar view. The same applies when the terminal vicinity 15 is defined as the region in the arrangement direction of the terminals 11a, 21a where the distance Lv from the terminal is within 0.5 times the conductive particle diameter D.

[0024] The number density of the conductive particles 2 in the vicinity of the terminals 15 and the middle part between the terminals 14, and the area of one conductive particle in plan view can be measured from an observation image taken using, for example, a metal microscope. In the measurement, image analysis software (for example, WinROOF (Miyaya Trading Engineering Co., Ltd.), A-Image-kun (Asahi Kasei Engineering Co., Ltd.)) may be used. Therefore, as a method for inspecting whether the connection structure of the first electronic component and the second electronic component is the connection structure of the present invention, a microscopic image between the terminals of the connection structure to be inspected is taken, and the number density α of the conductive particles in the vicinity of the terminals (for example, Lv < D) and the number density β of the conductive particles in the middle part between the terminals are measured, and a method of confirming that α < β can be cited. This inspection method has a small number of steps required for inspection and can be easily performed. In addition, connection inspection and the like of the conventional connection structure 30A can be performed. The connection structure of the present invention has high connection accuracy and stability. Therefore, it is also suitable for applications such as in-vehicle and medical applications where high operating accuracy and safety are strongly required.

[0025] Further, in the connection structure 30A of the present embodiment, as shown in FIG. 1, it is preferable that there is a region 7 in which at least a part of the conductive particles 2 sandwiched between the terminal 11a of the first electronic component 10 and the terminal 21a of the second electronic component 20 is regularly arranged. Also, it is preferable that there is a region 8 in which the conductive particles are regularly arranged around the terminal rows 12a and 22a, and it is preferable that the arrangement states of the conductive particles in these regions 7 and 8 are equal. More specifically, in this connection structure 30A, the conductive particles 2 are arranged in a hexagonal lattice in both the regions 7 and 8. As will be described later, in the thermocompression bonding process of anisotropic conductive connection when manufacturing the connection structure 30A of the present embodiment, the flow rate of the high-viscosity resin constituting the anisotropic conductive film is reduced compared to the conventional case, so the arrangement state of the conductive particles of the anisotropic conductive film remains in the above-mentioned regions 7 and 8. Specific examples of this regular arrangement include lattice arrangements such as a square lattice, a rectangular lattice, an oblique lattice, and a triangular lattice. Further, as an aspect of this regular arrangement, a combination of a plurality of lattices of different shapes may be used, or a particle row in which conductive particles are arranged linearly at a predetermined interval may be arranged in parallel at a predetermined interval.

[0026] On the other hand, the connection structure of the present invention may have an embodiment such as a connection structure 30B shown in FIG. 9, in which the number density of conductive particles in inter-terminal spaces 13a of the terminal row is significantly reduced. In this connection structure 30B, the number density of the conductive particles 2 in the inter-terminal space 13a is significantly reduced compared to the connection structure 30A shown in Figure 2, so the number density α in the terminal vicinity 15 and the number density β of the conductive particles 2 in the inter-terminal intermediate portion 14, which is the inter-terminal space 13a excluding the terminal vicinity 15, do not necessarily satisfy α < β. However, even in this connection structure 30B, it is possible to prevent short circuits from occurring due to the conductive particles 2 in the inter-terminal space 13a.

[0027] <Method of manufacturing the connection structure> Among the connection structures of the present invention, a method for manufacturing connection structure 30A shown in FIG. 1 includes, for example, first, according to a conventional method, placing a connecting material containing conductive particles on terminal rows 22a, 22b of second electronic component 20 or terminal rows 12a, 12b of first electronic component 10. This connecting material is preferably in the form of a film, such as an anisotropic conductive film 5. Next, terminal rows 12a, 12b of first electronic component 10 or terminal rows 22a, 22b of second electronic component 20 are aligned and temporarily pressure-bonded onto the anisotropic conductive film 5 (FIGS. 4 and 5), and then performing a step of thermocompression-bonding the second electronic component and the first electronic component using a heating and pressure tool 41 (FIGS. 6 to 8). Connection structure 30B shown in FIG. 9 can also be manufactured using a similar process. That is, by appropriately changing the minimum melt viscosity and layer thickness of the high-viscosity resin layer and low-viscosity resin layer that make up the anisotropic conductive film, the heating and pressurizing conditions in the thermocompression bonding process, etc., the strength of the resin flow in the space between the terminals is adjusted to manufacture the connection structure 30A shown in Figure 1 or the connection structure 30B shown in Figure 9.

[0028] (anisotropic conductive film) In the present invention, it is preferable to use, as the anisotropic conductive film, an anisotropic conductive film 5 which is formed by laminating an insulating high-viscosity resin layer 3 holding conductive particles 2 and a low-viscosity resin layer 4 having a lower minimum melt viscosity than the high-viscosity resin layer 3 in the range of 30 to 200°C.

[0029] In this case, under heating and pressing conditions in the thermocompression bonding step where the pressure is less than 70 MPa, particularly 60 MPa or less, it is preferable that the ratio of the minimum melt viscosity of the high-viscosity resin layer to the minimum melt viscosity of the low-viscosity resin layer be at least 2. In contrast, even if the insulating resin layer of the anisotropic conductive film is composed of a single resin layer or two resin layers with different minimum melt viscosities, if the ratio of the minimum melt viscosities between the resin layers is less than 2, meaning that the difference in the minimum melt viscosities is insufficient, when the pressure is less than 70 MPa, particularly 60 MPa or less, under the thermocompression bonding step, dense areas of conductive particles 2 are likely to form in the inter-terminal spaces 13a due to resin flow during thermocompression bonding, as shown in Fig. 10 .

[0030] (Conductive particle retention in anisotropic conductive film) A preferred embodiment of the high-viscosity resin layer 3 holding the conductive particles 2 is one in which the conductive particles 2 are embedded in the high-viscosity resin 3 so that the surface of the high-viscosity resin layer 3 and the conductive particles 2 are substantially flush with each other, as shown in Figure 11A or 11B. An example of an embodiment in which the surface of the high-viscosity resin layer 3 and the conductive particles 2 are substantially flush with each other is one in which the embedding amount Lb is the distance from the tangent plane 3s of the high-viscosity resin layer 3 between adjacent conductive particles 2 to the deepest part of the conductive particles 2, and the embedding ratio Lb / D, which is the ratio of the embedding amount Lb to the average particle diameter D of the conductive particles, is 80 to 105%, particularly 90 to 100%. By making the surface of the high-viscosity resin layer and the conductive particles substantially flush with each other, unnecessary movement of the conductive particles can be suppressed during thermocompression bonding for anisotropic conductive connection.

[0031] (Viscosity of high viscosity resin and low viscosity resin) 11A and 11B, when conductive particles 2 are pressed into the high-viscosity resin layer 3, the viscosity of the high-viscosity resin layer 3 is preferably high enough that, when the conductive particles 2 are pressed into the high-viscosity resin layer 3, depressions 3a are formed on the surface of the high-viscosity resin layer 3 around the pressed conductive particles 2, or unevenness is formed on the surface of the high-viscosity resin layer directly above the pressed conductive particles, so that traces of the conductive particles 2 being embedded remain in the high-viscosity resin layer 3. Such a high-viscosity resin layer 3 preferably has a minimum melt viscosity of 1100 Pa·s or higher, more preferably 1500 Pa·s or higher, even more preferably 2000 Pa·s or higher, particularly 3000 to 15000 Pa·s, and even more preferably 3000 to 10000 Pa·s. As an example, the minimum melt viscosity can be determined using a rotational rheometer (manufactured by TA Instruments) with a measurement pressure of 5 g maintained constant and a measurement plate with a diameter of 8 mm. More specifically, the minimum melt viscosity can be determined in the temperature range of 30 to 200°C, at a temperature rise rate of 10°C / min, a measurement frequency of 10 Hz, and a load fluctuation of 5 g on the measurement plate.

[0032] It should be noted that the anisotropic conductive film used in the present invention is not limited to one having depressions 3 a or irregularities on the surface of the high-viscosity resin layer 3 .

[0033] The low-viscosity resin layer 4 is an insulating resin layer with a lower minimum melt viscosity than the high-viscosity resin layer 3 in the range of 30 to 200°C. The greater the difference between the minimum melt viscosities of the low-viscosity resin layer 4 and the high-viscosity resin layer 3, the easier it is for the low-viscosity resin layer 4 to fill the spaces formed by the electrodes and bumps of electronic components, thereby improving the adhesion between electronic components. Furthermore, the greater this difference, the smaller the amount of movement of the high-viscosity resin layer 3 holding the conductive particles 2 relative to the low-viscosity resin layer 4 during thermocompression bonding for anisotropic conductive connection, making it less likely for the conductive particles 2 to flow in the inter-terminal spaces 13a. Therefore, in the present invention, the minimum melt viscosity ratio between the low-viscosity resin layer 4 and the high-viscosity resin layer 3 is set to 2 or more, preferably 5 or more, and more preferably 8 or more. On the other hand, if this ratio is too large, resin extrusion or blocking may occur when a long anisotropic conductive film is wound; therefore, for practical purposes, a ratio of 15 or less is preferred.

[0034] The minimum melt viscosity of the low-viscosity resin layer 4 at 30 to 200° C. is preferably 3000 Pa·s or less, more preferably 2000 Pa·s or less, and particularly preferably 100 to 2000 Pa·s.

[0035] The minimum melt viscosity of the entire resin layer, which is the combination of the high-viscosity resin layer 3 and the low-viscosity resin layer 4, depends on the ratio of the thicknesses of the high-viscosity resin layer 3 and the low-viscosity resin layer 4, but in practice it may be 8000 Pa·s or less, or in order to make it easier to fill between the bumps it may be 200 to 7000 Pa·s, and preferably 200 to 4000 Pa·s.

[0036] (insulating resin) As the insulating resin used to form the high-viscosity resin layer 3 or the low-viscosity resin layer 4, a curable resin that hardens by heat or light, a thermoplastic resin, a highly adhesive resin, etc. can be used, similar to the insulating resin layer of the anisotropic conductive film described in Japanese Patent No. 6187665.

[0037] The insulating resin may contain an insulating filler to adjust the melt viscosity. Examples of such an insulating filler include silica powder and alumina powder. The insulating filler preferably has a particle diameter of 20 to 1000 nm, and the amount of the insulating filler is preferably 5 to 50 parts by mass per 100 parts by mass of the thermopolymerizable compound (photopolymerizable compound) such as an epoxy compound.

[0038] Furthermore, the insulating material may contain a filler different from the insulating filler, a softener, an accelerator, an antioxidant, a colorant (pigment, dye), an organic solvent, an ion catcher agent, and the like.

[0039] If necessary, stress relaxation agents, silane coupling agents, inorganic fillers, etc. may be blended. Examples of stress relaxation agents include hydrogenated styrene-butadiene block copolymers and hydrogenated styrene-isoprene block copolymers. Examples of silane coupling agents include epoxy-based, methacryloxy-based, amino-based, vinyl-based, mercapto sulfide-based, and ureido-based agents. Examples of inorganic fillers include silica, talc, titanium oxide, calcium carbonate, and magnesium oxide.

[0040] The resin compositions of the high-viscosity resin layer 3 and the low-viscosity resin layer 4 may be the same or different, but when they are the same, the minimum melt viscosity can be adjusted by adjusting the amount of insulating filler added. Furthermore, when the insulating resin is a curable resin, the minimum melt viscosity can be adjusted by changing the curing temperature, curing time, etc.

[0041] (conductive particles) The conductive particles 2 used in the anisotropic conductive film can be appropriately selected from those used in known anisotropic conductive films. Examples include metal particles such as nickel, copper, silver, gold, and palladium, and metal-coated resin particles in which the surface of resin particles such as polyamide and polybenzoguanamine is coated with a metal such as nickel. The size of the conductive particles is preferably 1 μm to 30 μm, more preferably 1 μm to 10 μm, and even more preferably 2 μm to 6 μm.

[0042] The average particle diameter of the conductive particles 2 before being held in the high-viscosity resin layer 3 can be determined using a particle size distribution analyzer. An example of a particle size distribution analyzer is the FPIA-3000 (Malvern Instruments). The average particle diameter of the conductive particles 2 after being held in the high-viscosity resin layer 3 (i.e., the average particle diameter of the conductive particles after being formed into an anisotropic conductive film) can be determined by observation with an electron microscope such as an SEM. In this case, it is desirable to measure the particle diameter D for 200 or more samples. Furthermore, if the shape of the conductive particles is not spherical, the particle diameter D of the conductive particles can be the maximum length or the diameter of a shape that resembles a sphere.

[0043] The surfaces of the conductive particles 2 may be insulated. For example, they may be coated with an insulating coat or insulating particle treatment. Such coatings are easily peeled off from the surfaces of the conductive particles 2 and do not interfere with anisotropic conductive connection. The particle diameter of the present invention does not include the thickness of the coating layer formed by such insulating treatment. Furthermore, protrusions may be provided on the entire or part of the surface of the conductive particles 2. The height of the protrusions is preferably within 20% of the conductive particle diameter, and more preferably within 10%.

[0044] In an anisotropic conductive film, the conductive particles are preferably regularly arranged. When the conductive particles are regularly arranged, in the connection structure obtained by anisotropically conductively connecting the first electronic component and the second electronic component, it is possible to observe a region 7 where the conductive particles 2 are regularly arranged in the region where the terminal 11 a of the first electronic component 10 faces the terminal 21 a of the second electronic component 20, and a region 8 where the conductive particles are regularly arranged around the terminal rows 12 a and 22 a. This confirms that the resin flow during anisotropic conductive connection is well controlled so as not to cause short circuits between the terminals. In contrast, if the conductive particles are randomly arranged in an anisotropic conductive film, it is impossible to determine the quality of the resin flow during anisotropic conductive connection based on the conductive particle arrangement.

[0045] The number density of the conductive particles 2 in the anisotropic conductive film is not particularly limited because the preferred conditions vary depending on the combination of electronic components to be connected and the application. However, the lower limit of the number density is 30 particles / mm 2 or more than 12,000 pieces / mm 2 or more than 150,000 pieces / mm 2 The upper limit of the number density can be, for example, 350,000 pieces / mm 2 or less than 240,000 pieces / mm 2 or less than 100,000 pieces / mm 2In the case of COG or COP connections, which connect an IC chip to a glass or plastic substrate, the density can be 12,000 to 30,000 pieces / mm 2 is particularly preferred.

[0046] (Thickness of high viscosity resin layer Ta) When the sum of the terminal height Tt1 of the first electronic component 10 and the terminal height Tt2 of the second electronic component 20 is Tt (= Tt1 + Tt2), the preferable ratio between the layer thickness Ta of the high-viscosity resin layer 3 and the sum Tt of the terminal heights of the first electronic component 10 and the second electronic component 20 varies depending on the magnitude of the pressing force in the thermocompression bonding process.

[0047] For example, when manufacturing the connection structure 30A shown in Fig. 1 with a pressing force of less than 70 MPa, particularly 60 MPa or less, if the ratio Ta / Tt is too large, the amount of pressing of the high-viscosity resin layer increases, and there is a concern that the amount of movement of the conductive particles due to resin flow will be excessively large. Therefore, the ratio Ta / Tt is preferably 0.5 or less, more preferably 0.45 or less. On the other hand, if the ratio Ta / Tt is too small, the amount of resin extruded from between the opposing terminals 11a of the first electronic component 10 and the terminals 21a of the second electronic component 20 into the inter-terminal space will decrease, and the number of conductive particles 2 moving from the terminal vicinity 15 to the inter-terminal intermediate portion 14 in the inter-terminal space will decrease. As a result, the number density α of the conductive particles 2 in the terminal vicinity 15 will not be sufficiently reduced, and there is a concern that α < β will not be achieved. Therefore, the ratio Ta / Tt is preferably 0.20 or more (Fig. 5).

[0048] On the other hand, when the pressing force in the thermocompression bonding process is set to 70 MPa or more, particularly 80 MPa or more, the ratio Ts / Tt of the film thickness Ts (the sum of the layer thickness Ta of the high-viscosity resin layer 3 and the layer thickness Tn of the low-viscosity resin layer 4) to the terminal height Tt is set to 1.6 or more, and the minimum melt viscosity of the entire resin layer consisting of the high-viscosity resin layer 3 and the low-viscosity resin layer 4 is lowered, thereby making it easier to generate strong resin flow in the thermocompression bonding process and making it easier to obtain the connection structure 30B shown in Figure 9.

[0049] In addition, the ratio (Ta / D) of the thickness Ta of the high-viscosity resin layer 3 to the average particle diameter D of the conductive particles 2 is preferably 0.6 to 10. If this ratio is too large, the conductive particles 2 are more likely to become misaligned during anisotropic conductive connection, reducing the ability of the terminal to capture the conductive particles 2. This tendency becomes more pronounced when Ta / D exceeds 10. Therefore, Ta / D is preferably 8 or less, and more preferably 6 or less. Conversely, if the thickness Ta of the high-viscosity resin layer 3 is too small, resulting in Ta / D being less than 0.6, it becomes difficult for the high-viscosity resin layer 3 to maintain the conductive particles 2 in a predetermined particle dispersion state or predetermined arrangement. In particular, when the terminal to be connected is a high-density COG, the ratio (Ta / D) of the thickness Ta of the high-viscosity resin layer 3 to the particle diameter D of the conductive particles 2 is preferably 0.8 to 2.

[0050] (Anisotropic conductive film thickness Ts) The preferred ratio Ts / Tt of the film thickness Ts of the anisotropic conductive film 5 (the sum of the thickness Ta of the high-viscosity resin layer 3 and the thickness Tn of the low-viscosity resin layer 4) to the sum Tt of the terminal heights of the first electronic component 10 and the second electronic component 20 also varies depending on the magnitude of the pressing force in the thermocompression bonding process. For example, when the pressing force is less than 70 MPa, particularly 60 MPa or less, the upper limit of the ratio Ts / Tt is preferably less than 1.6, more preferably 1.55 or less, and even more preferably 1.4 or less. Meanwhile, the lower limit of the ratio Ts / Tt is preferably 1.1 or more, more preferably 1.3 or more (FIG. 5). By setting the ratio Ts / Tt in this range and setting the minimum melt viscosity ratio between the low-viscosity resin layer 4 and the high-viscosity resin layer 3 to be 2 or more, as described above, the connection structure 30A shown in FIG. 1 can be easily obtained.

[0051] (Terminal width Lt / Terminal space width Ls) Regarding the conditions for the electronic components to be connected, when manufacturing the connection structure 30A shown in FIG. 1, it is preferable to set the ratio Lt / Ls of the terminal width Lt to the inter-terminal space width Ls (i.e., the distance between the terminals in the terminal width direction) in the input-side terminal row 12a of the first electronic component 10 and the terminal row 22a of the second electronic component 20 to be less than 1.5 (FIG. 4). If this ratio Lt / Ls exceeds 1.5, the high-viscosity resin layer 3 extruded from between the terminals of the first electronic component and the terminals of the second electronic component not only moves the conductive particles 2 in the inter-terminal space 13a toward the inter-terminal intermediate portion 14 (FIG. 2), but also significantly disrupts the arrangement of the conductive particles 2 in the inter-terminal space 13a, potentially forming a densely packed area of ​​the conductive particles 2. The ratio Lt / Ls is preferably 1.2 or less, and more preferably 1 or less.

[0052] (Thermocompression bonding process) In the thermocompression bonding process, as shown in FIG. 6 , an anisotropic conductive film 5 is interposed between a first electronic component 10 and a second electronic component 20, and the first electronic component 10 and the second electronic component 20 are heated and pressurized between a stage 40 and a heating and pressurizing tool 41. This first extrudes a high-viscosity resin layer 3 and a low-viscosity resin layer 4 from the opposing area between the terminals 11a of the first electronic component 10 and the terminals 21a of the second electronic component 20 into the inter-terminal space 13a. The flow direction and flow speed of the extruded resin vary depending on the shape and terminal layout of the electronic components. Furthermore, the magnitude of the pressure applied during the thermocompression bonding process affects the flow rate and flow speed of the extruded resin, which affects the effect of the resin flow on the arrangement of conductive particles in the anisotropic conductive film and the distribution of conductive particles in the connection structure obtained after the thermocompression bonding process.

[0053] For example, when manufacturing the connection structure 30A shown in FIG. 1, heating and pressurization are performed at a temperature of 140 to 170°C and a pressure of 40 to 60 MPa. As a result, conductive particles 2 that are not sufficiently captured by the opposing terminals 11a, 21a and conductive particles 2 in the inter-terminal space 13a that are near the terminals 11a, 21a move away from the terminals 11a, 21a due to the flow of resin extruded from the opposing region of the terminals 11a, 21a. Therefore, the distribution of conductive particles 2 in the inter-terminal space 13a in the terminal arrangement direction X is sparser in the terminal vicinity 15 than in the inter-terminal intermediate portion 14. In other words, the number density α of conductive particles 2 in the terminal vicinity 15 is lower than the number density β of conductive particles 2 in the inter-terminal intermediate portion 14. Even in this state, the conductive particles 2 are held in the high-viscosity resin layer 3 .

[0054] When heating and pressurization are continued further, the space between the first electronic component 10 and the second electronic component 20 is filled with the high-viscosity resin layer 3 and the low-viscosity resin layer 4, as shown in Fig. 7. At this time, the low-viscosity resin 4 extruded from between the first electronic component 10 and the second electronic component 20 in the terminal row non-forming region 16 flows into the inter-terminal space 13a, as shown in Fig. 8. In the conventional case, the insulating resin flowing into the inter-terminal space causes a resin flow from the center to the periphery of the crimped portion of the electronic component, causing the conductive particles to flow (see the arrows in Fig. 10).

[0055] In contrast, in the manufacturing process of the connection structure 30A shown in FIG. 1 , it is preferable to set the ratio of the minimum melt viscosities of the high-viscosity resin layer 3 holding the conductive particles 2 to the low-viscosity resin layer 4 laminated thereon to 2 or more, so that the low-viscosity resin layer 4 flows more easily during thermocompression bonding than the high-viscosity resin layer 3. Furthermore, when the sum of the height Tt1 of the terminal 11a of the first electronic component 10 and the height Tt2 of the terminal 21a of the second electronic component 20 is Tt, it is preferable to set the ratio Ta / Tt of the layer thickness Ta of the high-viscosity resin layer 3 to the sum Tt of the terminal heights. This makes it difficult for the high-viscosity resin layer 3 in the non-terminal area to be pushed out of the pressed area even when pressed during thermocompression bonding. Meanwhile, the low-viscosity resin layer 4 easily flows during thermocompression bonding. Furthermore, in the inter-terminal space 13a, the conductive particles 2 are held by the high-viscosity resin layer 3 as described above. Therefore, in the inter-terminal space 13a, the resin flow of the low-viscosity resin layer 4 passes over the high-viscosity resin layer 3 that holds the conductive particles 2. At this time, although it depends on the embedding rate of the conductive particles 2 in the high-viscosity resin layer 3 (embedded amount of conductive particles Lb / average particle diameter of conductive particles D), as will be described later, if the embedding rate is 80% or more, the conductive particles 2 held in the high-viscosity resin layer 3 will not be swept away by the flow of the low-viscosity resin layer 4 and will maintain their positions in the high-viscosity resin layer 3. Therefore, as shown in FIG. 8 , the conductive particles 2 that are pushed out by the high-viscosity resin layer 3 and move from the terminal vicinity 15 to the inter-terminal intermediate portion 14 remain at or near their new position, and the relationship α<β described above is maintained between the number density α of the terminal vicinity 15 and the number density β of the conductive particles in the inter-terminal intermediate portion 14.

[0056] In this way, as shown in Figures 1 to 3, the conductive particles 2 in the inter-terminal space 13a do not accumulate on the peripheral side of the electronic component, and the number density α of the conductive particles 2 in the terminal vicinity portion 15 is smaller than the number density β in the inter-terminal intermediate portion 14, thereby obtaining a connection structure 30A in which short circuits between terminals are prevented.

[0057] On the other hand, when manufacturing the connection structure 30B shown in FIG. 9, the thermocompression bonding process is preferably performed at a temperature of 140 to 170°C and a pressure of 80 to 120 MPa. This causes the insulating resin flowing into the inter-terminal spaces 13a to strongly flow from the center to the periphery of the crimped portion of the electronic component, sweeping away both the conductive particles 2 in the terminal vicinity 15 of the inter-terminal spaces 13a and the conductive particles 2 in the inter-terminal intermediate portions 14. In this case, the ratio Ts / Tt of the film thickness Ts of the anisotropic conductive film 5 (the sum of the thickness Ta of the high-viscosity resin layer 3 and the thickness Tn of the low-viscosity resin layer 4) to the sum Tt of the terminal heights of the first electronic component 10 and the second electronic component 20 is preferably 1.6 or greater. If this ratio Ts / Tt is less than 1.6, the conductive particles 2 that flow from the inter-terminal spaces toward the periphery of the crimped portion of the electronic component may accumulate near the periphery of the terminal, potentially causing a short circuit. In addition, in order to cause a strong resin flow in the space between the terminals, it is preferable to lower the minimum melt viscosity of the total of the high-viscosity resin layer 3 and the low-viscosity resin layer 4. [Example]

[0058] The present invention will be specifically described below with reference to examples.

[0059] Experimental Examples 1-1 to 1-6 (Fabrication of anisotropic conductive film) Resin compositions for forming the high-viscosity resin layer and the low-viscosity resin layer were prepared according to the formulations shown in Table 1.

[0060] The resin composition for forming the high-viscosity resin layer was applied to a PET film with a film thickness of 50 μm using a bar coater and dried in an oven at 80° C. for 5 minutes to form a high-viscosity resin layer on the PET film with the thickness shown in Table 2A. Similarly, a low-viscosity resin layer was formed on the PET film with the thickness shown in Table 2A.

[0061] The minimum melt viscosities of the high-viscosity resin layer and the low-viscosity resin layer were determined using a rotational rheometer (manufactured by TA Instruments) with a measurement plate of 8 mm diameter, maintained at a constant measurement pressure of 5 g, in a temperature range of 30 to 200°C, a heating rate of 10°C / min, a measurement frequency of 10 Hz, and a load fluctuation of 5 g on the measurement plate.

[0062] On the other hand, the conductive particles 2 are arranged in a hexagonal lattice in plan view, and the number density is 20,000 particles / mm 2 A resin mold was prepared having recesses to be filled with conductive particles so that the recesses were arranged in a hexagonal lattice pattern. In this case, a convex mold was first prepared using a metal mold, and then pellets of a known transparent resin were poured into the mold in a molten state and cooled to solidify, thereby forming a resin mold with recesses arranged in a hexagonal lattice pattern.

[0063] Metal-coated resin particles (Sekisui Chemical Co., Ltd., AUL703, average particle diameter 3 μm) were prepared as conductive particles. These conductive particles were filled into the recesses of a resin mold. The high-viscosity resin layer described above was then placed on top of the particles and pressed at 60°C and 0.5 MPa to adhere them. The high-viscosity resin layer was then peeled off from the mold, and the conductive particles on the high-viscosity resin layer were pressed into the high-viscosity resin layer by applying pressure (pressing conditions: 60-70°C, 0.5 MPa) to produce an anisotropic conductive film consisting of a single resin layer. The embedding state of the conductive particles was controlled by the pressing conditions. The CV value of the metal-coated resin particles used was measured using an FPIA-3000 (Malvern Instruments) with a particle count of 1,000 or more, and was found to be less than 20%.

[0064] In addition, a two-layer type anisotropic conductive film was fabricated by laminating a low-viscosity resin layer on an insulating resin layer fabricated in the same manner.

[0065] (Fabrication of connection structure) The bump formation region of the evaluation IC (outer shape: 1.7×30 mm, thickness: 0.15 mm) with the bump specifications shown in Table 2A and the electrode terminal (outer shape: 26×80 mm, thickness: 0.3 mm, ITO wiring) corresponding to the bump of the evaluation IC on a glass substrate (Corning 1737F) were opposed to each other, and the anisotropic conductive film of each experimental example was sandwiched therebetween, and heated and pressurized (180 °C, 60 MPa, 5 seconds) to obtain each evaluation connection object. The number density α of conductive particles in the vicinity of the terminal (Lv < D) and the number density β of conductive particles in the middle part between terminals of the obtained evaluation connection object were measured by visual observation using a metal microscope. These results are shown in Table 2B.

[0066] (Evaluation of the connection structure) The (a) conduction resistance, (b) reliability, (c) short-circuit occurrence rate, and (d) capture property of conductive particles of the connection structures obtained in Experimental Examples 1-1 to 1-6 were evaluated as follows. The results are shown in Table 2B.

[0067] (a) Conduction resistance The initial conduction resistance of the connection structure was measured by the four-terminal method and evaluated according to the following criteria. For the evaluation of conduction resistance, it is preferably less than 1 ohm in practical use, and more preferably less than 0.3 ohm. Even if it is NG, there is no practical problem as long as it is 2 ohms or less.

[0068] Conduction resistance evaluation criteria OK: Less than 1 Ω NG: 1 Ω or more

[0069] (b) Reliability (a) The connection structure produced was placed in a constant temperature bath at 85 °C and 85% RH for 500 hours, and then the conduction resistance was measured in the same manner as the initial conduction resistance and evaluated according to the following criteria. For conduction reliability, it is preferably less than 5 ohms in practical use, and more preferably less than 2.5 ohms. Even if it is NG, there is no practical problem as long as it is 6 ohms or less.

[0070] Reliability evaluation criteria OK: Less than 5 Ω NG: 5 Ω or more

[0071] (c) Short circuit occurrence rate The number of short-circuited channels between the bumps of the connection structure was counted, and the number of short-circuited channels per 100 bumps was taken as the short-circuit occurrence rate, which was evaluated according to the following criteria.

[0072] Evaluation criteria for short circuit occurrence rate OK: Less than 200 ppm NG:200ppm or more

[0073] (d) Capability of capturing conductive particles In the connection structure, the number of conductive particles captured by the bumps of the evaluation IC and the electrode terminals of the glass substrate was counted for 100 areas where the bumps of the evaluation IC overlapped with the electrode terminals of the glass substrate, the minimum number of captured particles was determined, and the results were evaluated according to the following criteria.

[0074] Conductive particle capture evaluation criteria OK: At least 3 captures NG: The minimum number of captures is less than 3

[0075] [Table 1]

[0076] [Table 2A]

[0077] [Table 2B]

[0078] From Table 2B, it can be seen that the connection structures of Experimental Examples 1-1, 1-2, and 1-3, in which the number density α of conductive particles near the terminals in the space between the terminals and the number density β of conductive particles in the intermediate portion between the terminals were α<β, obtained good results in all evaluation items: (a) conduction resistance, (b) conduction reliability, (c) rate of short circuit occurrence, and (d) capture ability of conductive particles, but the connection structures of Experimental Examples 1-4, 1-5, and 1-6, in which α>β, had a high rate of short circuit occurrence. The reason for this is thought to be that in Experimental Examples 1-4 and 1-5, the ratio Ts / Tt of the total film thickness Ts to the sum of the terminal heights Tt exceeded 1.6, causing the resin flow during thermocompression bonding to be greater than in Experimental Examples 1-1, 1-2, and 1-3. This caused resin to be pushed out from the opposing area between the bumps of the evaluation IC and the electrode terminals of the glass substrate in the early stages of the thermocompression bonding process, causing the conductive particles that were near the terminals to move away from the terminals, making it impossible to maintain the arrangement of the conductive particles (Figure 6) when the distribution of conductive particles in the space between the terminals became α<β.

[0079] On the other hand, in Experimental Example 1-6, even when the ratio Ts / Tt was less than 1.6, α>β, making short circuits more likely to occur. This is thought to be because the composition of the high-viscosity resin layer in Experimental Example 1-6 was different from that in the other Experimental Examples, the minimum melt viscosity ratio between the low-viscosity resin layer and the high-viscosity resin layer was less than 2, and the high-viscosity resin layer was more likely to flow during thermocompression bonding than in the other Experimental Examples.

[0080] Experimental Examples 2-1 to 2-6 Connection structures were manufactured and evaluated in the same manner as in Experimental Examples 1-1 to 1-6, except that in the manufacturing process of the connection structures of Experimental Examples 1-1 to 1-6, the pressing pressure in the thermocompression bonding step was set to 80 MPa.

[0081] As a result, in Experimental Examples 1-4 to 1-6, where the pressure in the thermocompression bonding process was 60 MPa, α > β, and short circuits were likely to occur. However, in Experimental Examples 2-4 to 2-6, where the pressure in the thermocompression bonding process was 80 MPa, short circuits were unlikely to occur. This is thought to be because increasing the pressure in the thermocompression bonding process to 80 MPa significantly strengthens the fluidity of the resin, pushing many of the conductive particles in the spaces between the terminals out of the spaces. On the other hand, in Experimental Examples 1-1 to 1-3, where the pressure in the thermocompression bonding process was 60 MPa, α < β, and short circuits were unlikely to occur. However, in Experimental Examples 2-1 to 2-3, where the pressure in the thermocompression bonding process was 80 MPa, short circuits were likely to occur. This is thought to be because even at a pressure of 80 MPa, the ratio Ts / Tt was less than 1.6, making it difficult for sufficiently strong resin flow to occur. In addition, in Experimental Example 2-6, short circuits were less likely to occur even when the ratio Ts / Tt was less than 1.6. This is thought to be because the minimum melt viscosity of the high-viscosity resin layer was lower than in the other experimental examples, which reduced the minimum melt viscosity of the entire resin layer and caused strong resin flow during the thermocompression bonding process. [Explanation of symbols]

[0082] 1. Insulating resin 2. Conductive particles 3 High viscosity resin, high viscosity resin layer 3a dent 3s unevenness 4 Low viscosity resin, low viscosity resin layer 5, 5A, 5B Anisotropic Conductive Film 7. Regions where conductive particles are regularly arranged 8 Region where conductive particles are regularly arranged 10 IC chips, first electronic components 11a Input side bump, terminal 11b Output side bump, terminal 12a, 12b terminal row 13a, 13b Space between terminals 13x Near the open edge of the IC chip outer edge of the space between terminals 14 Intermediate part between terminals 15 Terminal area 16 Area where terminal rows are not formed 20 Glass substrate, second electronic component 21a, 21b terminal 22a, 22b terminal row 26 Area where terminal rows are not formed 30A, 30B Connection structure 40 stages 41 Heat and pressure tool Lb embedment amount Ls: Width of the space between terminals Lt terminal width Distance from Lv terminal Ta: Thickness of high-viscosity resin layer Tt1 Terminal height of first electronic component Tt2 Terminal height of the second electronic component Tt Sum of the terminal height of the first electronic component and the terminal height of the second electronic component Tn: Thickness of the low viscosity resin layer Ts film thickness of anisotropic conductive film Sp thermocompression bonding area St Terminal row connection area X terminal arrangement direction

Claims

1. A method for manufacturing a connection structure, comprising: bonding a first electronic component having a terminal row in which terminals are arranged, and a second electronic component having a terminal row corresponding to the terminal row, by thermocompression bonding via an insulating resin in which a high-viscosity resin layer and a low-viscosity resin layer are laminated, the high-viscosity resin layer and the low-viscosity resin layer containing a curable resin that is cured by heat or light and a curing agent for curing the resin, respectively; and electrically connecting the terminals of the first electronic component and the terminals of the second electronic component by conductive particles in the insulating resin sandwiched between them, When the number density of the conductive particles in the vicinity of the terminals adjacent to the terminals in the space between the terminals of the terminal row is defined as α and the number density of the conductive particles in the intermediate portion between the terminals excluding the vicinity of the terminals from the space between the terminals is defined as β, α<β is satisfied, The minimum melt viscosity ratio of the low-viscosity resin layer to the high-viscosity resin layer is 2 or more, A manufacturing method in which, when the pressing force during thermocompression bonding is less than 70 MPa, the ratio of the total layer thickness of the high-viscosity resin layer and the low-viscosity resin layer to the total terminal height of the first electronic component and the second electronic component is 1.1 or more and less than 1.

6.

2. 2. The method according to claim 1, wherein the vicinity of the terminal is a region in the space between the terminals in the terminal row, the region being at a distance from the terminal that is less than one time the diameter of the conductive particles.

3. 3. The method of claim 1, wherein no conductive particles are present in the space between the terminals within a distance from the terminal that is within 0.5 times the diameter of the conductive particles.

4. The manufacturing method according to any one of claims 1 to 3, wherein the terminals of the first electronic component and the terminals of the second electronic component are anisotropically conductively connected.

5. The area of ​​each terminal of the electronic component is 1000 μm 2 The manufacturing method according to any one of claims 1 to 4, wherein the length of the longest side of the electronic component is 600 µm or less, or the length of the longest side of the electronic component is 600 µm or less.

6. The manufacturing method according to any one of claims 1 to 5, wherein the conductive particles sandwiched between the terminals of the first electronic component and the terminals of the second electronic component have a region in which they are regularly arranged.

7. The method according to any one of claims 1 to 6, wherein the conductive particles are regularly arranged in a region around the terminal row.

8. A connection structure in which a first electronic component having a terminal row in which terminals are arranged, and a second electronic component having a terminal row corresponding to the terminal row are bonded by thermocompression bonding via an insulating resin, the insulating resin containing a curable resin that is cured by heat or light and a curing agent for curing the resin, and in which a high-viscosity resin layer and a low-viscosity resin layer having a minimum melt viscosity ratio of 2 or more are laminated such that the ratio of the total layer thickness of the high-viscosity resin layer and the low-viscosity resin layer to the total terminal height of the first electronic component and the second electronic component is 1.1 or more and less than 1.6 when the pressing force during thermocompression bonding is less than 70 MPa, and the terminals of the first electronic component and the second electronic component are electrically connected by conductive particles in the insulating resin sandwiched between them, A connection structure in which the number density α of conductive particles in the vicinity of the terminals adjacent to the terminals in the space between the terminals of a terminal row and the number density β of conductive particles in the intermediate portion between the terminals excluding the vicinity of the terminals from the space between the terminals satisfy α<β.

Images