Method for manufacturing a connection structure, and connection structure

Abstract

To provide a method for manufacturing a connection structure capable of obtaining excellent conductivity of a chip component by irradiation with laser light, and a connection film.SOLUTION: A method for manufacturing a connection structure includes: a landing step of causing a chip component provided on a base material having permeability to a laser beam and a wiring substrate to face each other and irradiating the chip component with the laser beam from a base material side to land the chip component on the wiring substrate side; and a connection step of connecting the chip component and the wiring substrate via a connection film. The connection film includes a rubber layer and an adhesive layer. The rubber layer is broken through in the connection step.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This technology relates to a method for manufacturing a connection structure for connecting chip components to a substrate, and to the connection structure itself. [Background technology]

[0002] In recent years, the development of micro-LEDs has been active as the next-generation display technology following LCDs (Liquid Crystal Displays) and OLEDs (Organic Light Emitting Diodes). A challenge with micro-LEDs is the need for a technology called mass transfer, which involves mounting micro-sized LEDs onto a panel substrate, and this technology is being researched in various fields.

[0003] A currently dominant method of mass transfer involves using a stamping material to transfer LEDs to the panel substrate. Figure 11 schematically shows the stamping method of mass transfer. In the stamping method, as shown in Figures 11A and 11B, the LEDs 101 are transferred from the transfer material 102 to the stamping material 103 and picked up, and then, as shown in Figures 11C and 11D, the LEDs 101 are attached to the connecting film 105 of the panel substrate 104. However, the method using stamping material has limitations: the pitch of the LEDs 101 depends on the pattern of the stamping material 103, resulting in low design flexibility, a low chip transfer rate, and a very long processing time, making it unsuitable for mass production.

[0004] Therefore, a chip placement method using lasers is currently attracting attention (see, for example, Patent Documents 1 to 4). Figure 12 is a schematic diagram showing a laser-based mass transfer. In the laser method, as shown in Figures 12A and 12B, the LED 111 is transferred from the transfer material 112 to the release material 113 and picked up, and as shown in Figure 12C, laser light is shone onto the release material 113 to cause the LED 111 to land on the connecting film 115 of the panel substrate 114. Compared to stamp materials, laser-based chip transfer offers greater design flexibility and a very fast chip transfer cycle time.

[0005] However, in the laser-based chip placement method, the LEDs are ejected and land on the panel substrate at a very high speed, which can lead to defects such as misalignment, deformation, detachment, or breakage of the LEDs, as shown in Figure 12D. Furthermore, even if the LEDs land properly, poor conductivity may occur. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-096144 [Patent Document 2] Japanese Patent Publication No. 2020-145243 [Patent Document 3] Japanese Patent Publication No. 2019-176154 [Patent Document 4] Japanese Patent Publication No. 2020-053558 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] This technology was proposed in light of the conventional situation, and provides a method for manufacturing a connection structure and a connection structure that can achieve excellent conductivity of chip components by irradiation with laser light. [Means for solving the problem]

[0008] A method for manufacturing a connection structure according to this technology includes a chip component provided on a substrate that is transparent to laser light, and a wiring board, and a projecting step in which laser light is irradiated from the substrate side to cause the chip component to project onto the wiring board side, and a connecting step in which the chip component and the wiring board are connected via a connecting film, wherein the connecting film has a rubber layer and an adhesive layer, and in the connecting step, the rubber layer is punctured.

[0009] In the manufacturing method of the connection structure, the rubber layer is pierced by the electrode of the chip component.

[0010] In the manufacturing method of the connection structure, the adhesive layer contains conductive particles, and the rubber layer is pierced by the conductive particles.

[0011] The connection structure according to the present technology includes a chip component, a wiring board, and a connection film provided between the electrode surface of the chip component and the electrode surface of the wiring board. The connection film is a cured film of a connection film having a rubber layer and an adhesive layer, and the rubber layer is pierced by the electrode of the chip component.

[0012] The connection structure according to the present technology includes a chip component, a wiring board, and a connection film provided between the electrode surface of the chip component and the electrode surface of the wiring board. The connection film is a cured film of a connection film having a rubber layer and an adhesive layer. The adhesive layer contains conductive particles, and the rubber layer is pierced by the conductive particles.

Advantages of the Invention

[0013] According to the present technology, when connecting the chip component and the wiring board, the rubber layer of the connection film is pierced, so excellent electrical conductivity of the chip component can be obtained.

Brief Description of the Drawings

[0014] [Figure 1] FIG. 1 is a cross-sectional view schematically showing a state in which a light-emitting element provided on a substrate and a connection film on a wiring board are opposed to each other. [Figure 2] FIG. 2 is an enlarged view showing the opposed light-emitting element and the connection film on the wiring board. [Figure 3] FIG. 3 is a cross-sectional view schematically showing a state in which a laser beam is irradiated from the substrate side, and the light-emitting element is transferred to a predetermined position on the wiring board and arranged. [Figure 4] FIG. 4 is a cross-sectional view schematically showing a state in which a light-emitting element is mounted on a wiring board. [Figure 5]FIG. 5 is a cross-sectional view schematically showing a state in which a light-emitting element provided on a base material and having a rubber layer on an electrode surface is opposed to an anisotropic conductive adhesive layer on a wiring substrate. [Figure 6] FIG. 6 is a cross-sectional view schematically showing a state in which a light-emitting element provided on a base material and having a connection film on an electrode surface is opposed to a wiring substrate. [Figure 7] FIG. 7 is a cross-sectional view schematically showing a state in which a light-emitting element provided on a base material and having an anisotropic conductive adhesive layer on an electrode surface is opposed to a rubber layer on a wiring substrate. [Figure 8] FIG. 8 is a cross-sectional view schematically showing a first configuration example of a connection film. [Figure 9] FIG. 9(A) is a plan view showing two rubber layers having voids inside by processing, and FIG. 9(B) is a cross-sectional view schematically showing a second configuration example of a connection film. [Figure 10] FIG. 10 is a cross-sectional view schematically showing a third configuration example of a connection film. [Figure 11] FIG. 11 is a diagram schematically showing stamp method mass transfer. [Figure 12] FIG. 12 is a diagram schematically showing laser method mass transfer.

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present technology will be described in detail in the following order with reference to the drawings. 1. Manufacturing method of connection structure 2. Connection film 3. Examples

[0016] <1. Manufacturing method of connection structure> [First Embodiment] The manufacturing method for the connection structure according to the first embodiment includes a chip component provided on a substrate that is transparent to laser light, and a wiring board, and a striking step in which laser light is irradiated from the substrate side to cause the chip component to land on the wiring board side, and a connection step in which the chip component and the wiring board are connected via a connecting film, wherein the connecting film has a rubber layer and an adhesive layer, and in the striking step the connecting film is placed on the electrode surface of the wiring board and the rubber layer and the electrode surface of the chip component collide. As a result, defects such as displacement, deformation, breakage, and detachment of the chip component are suppressed in the striking step and the chip component can be transferred and arranged with high precision and efficiency, and in the connection step the chip component penetrates the rubber layer and excellent conductivity can be obtained, thereby shortening the cycle time.

[0017] The adhesive layer in the connecting film is preferably an anisotropic conductive adhesive layer containing conductive particles. This makes it possible to connect the chip component to the wiring board even if the chip component does not have connection points such as eutectic solder bumps. Furthermore, if the electrodes of the chip component are in the form of protrusions, and an electrical connection can be made with the wiring on the wiring board, the adhesive layer does not need to contain conductive particles.

[0018] Examples of chip components include semiconductor chips and LED chips, and are not particularly limited. However, the manufacturing method of the connection structure related to this technology can be suitably used in mass transfers for mounting a large number of micro-sized LED chips onto a panel substrate, which is a wiring board.

[0019] The following describes a method for manufacturing a connected structure, specifically a method for manufacturing a display device in which multiple light-emitting elements, which are LED chips, are arranged on a wiring board, which is a panel substrate, to form a light-emitting element array.

[0020] As the light-emitting element, a so-called flip-chip type LED having a first conductivity type electrode and a second conductivity type electrode on one side can be used. The light-emitting elements are arranged on the substrate corresponding to each subpixel that makes up one pixel, forming a light-emitting element array. One pixel may be composed of, for example, three subpixels R (red), G (green), and B (blue), four subpixels RGBW (white) and RGBY (yellow), or two subpixels RG and GB.

[0021] Methods for arranging subpixels include, for example, stripe arrangement, mosaic arrangement, and delta arrangement for RGB. Stripe arrangement arranges RGB pixels in vertical stripes, enabling high-resolution images. Mosaic arrangement arranges identical RGB colors diagonally, producing a more natural image than stripe arrangement. Delta arrangement arranges RGB pixels in a triangle, with each dot shifted by half a pitch between fields, resulting in a more natural image display.

[0022] Table 1 shows the estimated lateral pitch between RGB chips, estimated chip size, and estimated electrode size relative to the PPI (Pixels Per Inch) when each RGB chip is arranged horizontally. The minimum chip distance is assumed to be 5 μm, and the estimated RGB distance is maximized when the chips are evenly spaced. These values ​​were calculated as reference values ​​to consider this technology with a clear application in mind.

[0023] [Table 1]

[0024] As shown in Table 1, a chip size of 10 × 20 μm allows for a resolution of up to 500 PPI. Furthermore, a chip size of 7 × 14 μm allows for a resolution of up to 1000 PPI, and by further reducing the chip size, resolutions exceeding 1000 PPI can be achieved. Note that the chip does not necessarily have to be rectangular; it can also be square.

[0025] The following describes the impaction process (A1), in which the light-emitting element is projected onto the wiring board by irradiating it with laser light, and the connection process (B1), in which the light-emitting element is connected to the wiring board, with reference to Figures 1 to 4.

[0026] [Impact Process (A1)] Figure 1 is a schematic cross-sectional view showing a state in which a light-emitting element provided on a substrate and a connecting film on a wiring board are facing each other, and Figure 2 is an enlarged view showing the facing light-emitting element and the connecting film on the wiring board. As shown in Figures 1 and 2, first, in the impact step (A1), the chip component substrate 10 and the wiring board 30 are facing each other.

[0027] The chip component substrate 10 comprises a base material 11, a release material 12, and a light-emitting element 20, with the light-emitting element 20 attached to the surface of the release material 12. The base material 11 can be any material that is transparent to laser light, and is preferably quartz glass having high light transmittance across all wavelengths.

[0028] The release material 12 only needs to have absorption properties with respect to the wavelength of the laser light, and generates a shock wave upon irradiation with the laser light, which propels the light-emitting element 20 toward the wiring board 30. Examples of the release material 12 include polyimide. The thickness T12 of the release material 12 is, for example, 0.5 μm or more.

[0029] The light-emitting element 20 comprises a main body 21, a first conductivity type electrode 22, and a second conductivity type electrode 23, and has a horizontal structure in which the first conductivity type electrode 22 and the second conductivity type electrode 23 are arranged on the same plane. The main body 21 comprises a first conductivity type cladding layer made of, for example, n-GaN, and, for example, In x Al y Ga 1-x-yThe device comprises an active layer made of an N layer and a second conductivity type cladding layer made of, for example, p-GaN, and has a so-called double heterostructure. The first conductivity type electrode 22 is formed in a part of the first conductivity type cladding layer by a passivation layer, and the second conductivity type electrode 23 is formed in a part of the second conductivity type cladding layer. When a voltage is applied between the first conductivity type electrode 22 and the second conductivity type electrode 23, carriers concentrate in the active layer and light emission occurs through recombination.

[0030] The width W20 of the light-emitting element 20 is, for example, 1 to 100 μm, and the thickness T20 of the light-emitting element 20 is, for example, 1 to 20 μm.

[0031] The wiring board 30 comprises a circuit pattern for a first conductivity type and a circuit pattern for a second conductivity type on a substrate 31, and has a first electrode 32 and a second electrode 33 at positions corresponding to the first conductivity type electrode on the p side and the second conductivity type electrode on the n side, respectively, so that the light-emitting elements are arranged in units of subpixels that constitute one pixel. The wiring board 30 also forms circuit patterns such as data lines and address lines for matrix wiring, and allows the light-emitting elements corresponding to each subpixel that constitutes one pixel to be turned on and off. Furthermore, the wiring board 30 is preferably a light-transmitting substrate, the substrate 31 is preferably a transparent substrate such as glass, PET (Polyethylene Terephthalate), or polyimide, and the circuit patterns, the first electrode 32, and the second electrode 33 are preferably transparent conductive films such as ITO (Indium-Tin-Oxide), IZO (Indium-Zinc-Oxide), ZnO (Zinc-Oxide), or IGZO (Indium-Gallium-Zinc-Oxide).

[0032] As described later, the connecting film 40 has a rubber layer 41 and an anisotropic conductive adhesive layer 42, and is attached to the wiring substrate 30 with the rubber layer 41 side facing the light-emitting element 20. The rubber layer 41 is preferably one or more selected from silicone rubber and acrylic rubber. The thickness of the rubber layer 41 is preferably 0.5 μm to 3.0 μm, more preferably 0.5 μm to 2.0 μm, and even more preferably 0.5 μm to 1.5 μm. Furthermore, the rubber layer 41 preferably has voids inside, and is preferably in the shape of a mesh or protrusions. This improves cushioning in the impact process and improves the ability to penetrate the light-emitting element 20 in the connection process. The anisotropic conductive adhesive layer 42 preferably contains conductive particles 43 in a thermosetting binder.

[0033] The thickness T40 of the connecting film 40 is, for example, 20 μm or less. The distance D between the light-emitting element 20 and the connecting film 40 is preferably 10 to 1000 μm, more preferably 50 to 500 μm, and even more preferably 80 to 200 μm.

[0034] Figure 3 is a schematic cross-sectional view showing the state in which laser light is irradiated from the substrate side, transferring the light-emitting elements to predetermined positions on the wiring board and arranging them. As shown in Figures 2 and 3, in the impaction process (A1), laser light 50 is irradiated from the substrate 11 side, transferring the light-emitting elements 20 to predetermined positions on the wiring board 21 and arranging them on the connecting film 40.

[0035] For example, a LIFT (Laser Induced Forward Transfer) device can be used to transfer the light-emitting element 20. The LIFT device includes, for example, a telescope that makes pulsed laser light emitted from a laser device into parallel light, a shaping optical system that uniformly shapes the spatial intensity distribution of the pulsed laser light that has passed through the telescope, a mask that allows the pulsed laser light shaped by the shaping optical system to pass through in a predetermined pattern, a field lens positioned between the shaping optical system and the mask, and a projection lens that reduces and projects the laser light that has passed through the pattern on the mask onto the donor substrate. The chip component substrate 10, which is the donor substrate, is held on the donor stage, and the wiring substrate 30, which is the receptor substrate, is held on the receptor stage.

[0036] As a laser device, for example, an excimer laser that emits laser light with a wavelength of 180 nm to 360 nm can be used. The oscillation wavelengths of the excimer laser are, for example, 193, 248, 308, and 351 nm, and can be suitably selected from these oscillation wavelengths according to the light absorption properties of the release 12 material.

[0037] The mask uses a pattern in which a predetermined number of windows of a predetermined size are formed at a predetermined pitch so that the projection at the interface between the substrate 11 and the release material 12 results in a desired laser beam arrangement. The mask is made by applying a pattern to the substrate 11, for example, by chrome plating, so that the window areas that are not chrome plated transmit the laser beam, while the chrome plated areas block the laser beam.

[0038] The light emitted from the laser device enters the telescopic optical system and propagates to the shaping optical system beyond it. The laser light is adjusted by the telescopic optical system so that it is approximately parallel at any position within the X-axis movement range of the donor stage just before it enters the shaping optical system. Therefore, it always enters the shaping optical system at approximately the same size and angle (perpendicular).

[0039] The laser light that has passed through the shaping optical system enters the mask through a field lens that constitutes an image-side telecentric reduction projection optical system in combination with a projection lens. The laser light that has passed through the mask pattern changes its propagation direction vertically downward by an epi-mirror and enters the projection lens. The laser light emitted from the projection lens enters from the side of the base material 11 and is accurately projected onto a predetermined position of the release material 12 formed on the surface (lower surface) thereof at the reduced size of the mask pattern.

[0040] The pulse energy of the laser light that is imaged and irradiated on the interface between the base material 11 and the release material 12 is preferably 0.001 to 2 J, more preferably 0.01 to 1.5 J, and still more preferably 0.1 to 1 J. The fluence is preferably 0.001 to 2 J / cm 2 and more preferably 0.01 to 1 J / cm 2 and still more preferably 0.05 to 0.5 J / cm 2 The pulse width (irradiation time) is preferably 0.01 to 1×10 9 picoseconds, more preferably 0.1 to 1×10 7 picoseconds, and still more preferably 1 to 1×10 5 picoseconds. The pulse frequency is preferably 0.1 to 10,000 Hz, more preferably 1 to 1,000 Hz, and still more preferably 1 to 100 Hz. The number of irradiation pulses is preferably 1 to 30,000,000.

[0041] By using such a lift device, a shock wave is generated in the release material 12 irradiated with the laser light at the interface between the base material 11 and the release material 12, and the plurality of light-emitting elements 20 are peeled off from the base material 11 and lifted toward the wiring board 30, and the plurality of light-emitting elements 20 can be landed on a predetermined position of the wiring board 30 via a connection film 40. <于 <于

[0042] <于 Since the connecting film 40 has a rubber layer 41 on the side of the multiple light-emitting elements 20, it mitigates the impact when the light-emitting elements 20, which are launched at ultra-high speed, hit their target, suppressing defects such as displacement, deformation, breakage, and detachment of the light-emitting elements 20, and enabling a high success rate of hits.

[0043] [Connection process (B1)] Figure 4 is a schematic cross-sectional view showing the state in which light-emitting elements are mounted on a wiring board. As shown in Figure 4, in the connection step (B1), light-emitting elements 20 arranged at predetermined positions on the wiring board 30 are mounted.

[0044] As a method for thermocompressing the light-emitting element 20 to the wiring board 30, connection methods used in known anisotropic conductive films can be appropriately selected and used. For example, the thermocompression conditions are a temperature of 150°C to 260°C, a pressure of 5 MPa to 60 MPa, and a time of 5 seconds to 300 seconds.

[0045] The rubber layer 41 of the connecting film 40 is punctured by the first conductive electrode 22 and the second conductive electrode 23 of the light-emitting element 20 during heat-press bonding. Then, the conductive particles 43 of the anisotropic conductive adhesive layer 42 are sandwiched between the first conductive electrode 22 and the second conductive electrode 23 of the light-emitting element 20 and the first electrode 32 and the second electrode 33 of the wiring board 30, and as the binder of the anisotropic conductive adhesive layer 42 hardens, an anisotropic conductive film is formed.

[0046] According to the manufacturing method of the connection structure according to the first embodiment, a connection film having a rubber layer and an adhesive layer is placed on the electrode surface of a wiring board, and the rubber layer and the electrode surface of the chip component are brought into collision. This suppresses the occurrence of defects such as displacement, deformation, breakage, and detachment of the chip component in the impact process, and enables the transfer and arrangement of the chip component with high precision and efficiency. In the connection process, the chip component penetrates the rubber layer, and excellent conductivity can be obtained.

[0047] In the first embodiment, the connecting film is applied to the entire surface of the wiring board, but individual pieces of the connecting film may be transferred to the electrode positions on the wiring board using, for example, mass transfer technology. By selectively applying the connecting film only to the positions where chip components are ejected, rather than applying it to the entire surface, the transparency of, for example, the light-emitting element array can be improved.

[0048] [Second Embodiment] In the first embodiment, a connecting film having a rubber layer and an adhesive layer was placed on the wiring board, but the rubber layer may be placed on the electrode surface of the chip component and the adhesive layer on the wiring board.

[0049] In other words, the method for manufacturing a connection structure according to the second embodiment includes a striking step in which a chip component provided on a substrate that is transparent to laser light is placed opposite a wiring board, and laser light is irradiated from the substrate side to cause the chip component to land on the wiring board side, and a connection step in which the chip component and the wiring board are connected via a connecting film, wherein the connecting film has an adhesive layer, and the chip component has a rubber layer on its electrode surface, and in the striking step, the connecting film is placed on the electrode surface of the wiring board and the adhesive layer and the rubber layer of the chip component collide.

[0050] Hereinafter, similar to the first embodiment, the impact step (A2) and connection step (B2) in the manufacturing method of a display device in which a plurality of light-emitting elements, which are LED chips, are arranged on a wiring board, which is a panel substrate, to form a light-emitting element array will be described as a method for manufacturing a connection structure. Note that the same reference numerals are used for components that are the same as in the first embodiment, and their descriptions are omitted.

[0051] [Impact process (A2)] Figure 5 is a schematic cross-sectional view showing a state in which a light-emitting element, provided on a substrate and having a rubber layer on its electrode surface, is facing an anisotropic conductive adhesive layer on a wiring board. As shown in Figure 5, first, in the impact step (A2), the chip component substrate 10 and the wiring board 30 are faced towards each other.

[0052] The chip component substrate 10 comprises a base material 11, a release material 12, and a light-emitting element 20, with the light-emitting element 20 attached to the surface of the release material 12. A rubber layer 51 is also attached to the electrode surface of the light-emitting element 20. Since the rubber layer 51 is the same as the rubber layer 41 in the first embodiment, its description is omitted.

[0053] The connecting film 50 consists of an anisotropic conductive adhesive layer 52 and is attached to the first electrode 32 and the second electrode 33 of the wiring board 30. The anisotropic conductive adhesive layer 22 is the same as the anisotropic conductive adhesive layer 42 in the first embodiment, so its description is omitted.

[0054] In the impact process (A2), the rubber layer 51 attached to the light-emitting element 20 mitigates the impact when the light-emitting element 20, launched at ultra-high speed, hits the anisotropic conductive adhesive layer 52, suppressing defects such as displacement, deformation, breakage, and detachment of the light-emitting element 20, and enabling a high success rate of impact.

[0055] [Connection process (B2)] In the connection process (B2), the light-emitting elements 20 arranged in predetermined positions on the wiring board 30 are mounted. The method for thermocompressing the light-emitting elements 20 to the wiring board 30 is the same as in the first embodiment. The rubber layer 51 attached to the light-emitting elements 20 is punctured by the first conductive electrode 22 and the second conductive electrode 23 of the light-emitting elements 20 during thermocompression. Then, the conductive particles 53 of the anisotropic conductive adhesive layer 52 are sandwiched between the first conductive electrode 22 and the second conductive electrode 23 of the light-emitting elements 20 and the first electrode 32 and the second electrode 33 of the wiring board 30, and an anisotropic conductive film is formed as the binder of the anisotropic conductive adhesive layer 52 hardens.

[0056] According to the manufacturing method of the connection structure of the second embodiment, a rubber layer is placed on the electrode surface of a chip component, a connection film consisting of an adhesive layer is placed on the electrode surface of a wiring board, and the rubber layer and the connection film are brought into collision. This suppresses the occurrence of defects such as displacement, deformation, breakage, and detachment of the chip component during the impact process, and enables the transfer and arrangement of the chip component with high precision and efficiency. In the connection process, the chip component penetrates the rubber layer, resulting in excellent conductivity.

[0057] [Third Embodiment] In the first embodiment, a connecting film having a rubber layer and an adhesive layer was placed on a wiring board, but the connecting film may also be placed on the electrode surface of a chip component.

[0058] In other words, the manufacturing method of the connection structure according to the third embodiment includes a chip component provided on a substrate that is transparent to laser light and a wiring board, and a striking step in which laser light is irradiated from the substrate side to cause the chip component to land on the wiring board side, and a connection step in which the chip component and the wiring board are connected via a connecting film, wherein the connecting film has a rubber layer and an adhesive layer, and in the striking step, the connecting film is placed on the electrode surface of the chip component and the rubber layer is brought into contact with the electrode surface of the wiring board.

[0059] Hereinafter, similar to the first embodiment, the impact step (A3) and connection step (B3) in the manufacturing method of a display device in which a plurality of light-emitting elements, which are LED chips, are arranged on a wiring board, which is a panel substrate, to form a light-emitting element array will be described as a method for manufacturing a connection structure. Note that the same reference numerals are used for components that are the same as in the first embodiment, and their descriptions are omitted.

[0060] [Impact Process (A3)] Figure 6 is a schematic cross-sectional view showing a state in which a light-emitting element, which is provided on a substrate and has a connecting film on its electrode surface, is facing a wiring board. As shown in Figure 6, first, in the impact step (A2), the chip component substrate 10 and the wiring board 30 are facing each other.

[0061] The chip component substrate 10 comprises a base material 11, a release material 12, and a light-emitting element 20, with the light-emitting element 20 attached to the surface of the release material 12. Additionally, a connecting film 60 is attached to the electrode surface of the light-emitting element 20.

[0062] The connecting film 60 has a rubber layer 61 and an anisotropic conductive adhesive layer 62, with the rubber layer 61 side facing the wiring board 30. The rubber layer 61 and the anisotropic conductive adhesive layer 62 are the same as the rubber layer 41 and the anisotropic conductive adhesive layer 42 in the first embodiment, so their description is omitted.

[0063] In the impact process (A3), the rubber layer 61 to which the light-emitting element 20 is attached mitigates the impact when the light-emitting element 20, launched at ultra-high speed, hits the electrode surface of the wiring board 30, suppressing defects such as displacement, deformation, breakage, and detachment of the light-emitting element 20, and enabling a high success rate of impact.

[0064] [Connection process (B3)] In the connection process (B3), the light-emitting elements 20 arranged in predetermined positions on the wiring board 30 are mounted. The method for thermocompressing the light-emitting elements 20 to the wiring board 30 is the same as in the first embodiment. The rubber layer 61 attached to the light-emitting elements 20 is punctured by the conductive particles 63 of the anisotropic conductive adhesive layer 62 during thermocompression. The conductive particles 63 of the anisotropic conductive adhesive layer 62 are then sandwiched between the first conductive electrode 22 and the second conductive electrode 23 of the light-emitting elements 20 and the first electrode 32 and the second electrode 33 of the wiring board 30, and an anisotropic conductive film is formed as the binder of the anisotropic conductive adhesive layer 62 hardens.

[0065] According to the manufacturing method of the connection structure of the third embodiment, a connection film having a rubber layer and an adhesive layer is placed on the electrode surface of a chip component, and the rubber layer and the electrode surface of the wiring board are brought into contact, thereby suppressing defects such as displacement, deformation, breakage, and detachment of the chip component in the impact process, enabling high-precision and high-efficiency transfer and arrangement of the chip component, and providing excellent conductivity in the connection process.

[0066] [Fourth Embodiment] In the first embodiment, a connecting film having a rubber layer and an adhesive layer was placed on the wiring board, but the adhesive layer may be placed on the electrode surface of the chip component and the rubber layer on the wiring board.

[0067] In other words, the manufacturing method of the connection structure according to the fourth embodiment includes a chip component provided on a substrate that is transparent to laser light and a wiring board, and a striking step in which laser light is irradiated from the substrate side to cause the chip component to strike the wiring board side, and a connection step in which the chip component and the wiring board are connected via a connecting film, wherein the connecting film has an adhesive layer and the wiring board has a rubber layer on its electrode surface, and in the striking step, the connecting film is placed on the electrode surface of the chip component and the adhesive layer and the rubber layer of the wiring board are brought into contact.

[0068] Hereinafter, similar to the first embodiment, the impact step (A4) and connection step (B4) in the manufacturing method of a display device in which a plurality of light-emitting elements, which are LED chips, are arranged on a wiring board, which is a panel substrate, to form a light-emitting element array will be described as a method for manufacturing a connection structure. Note that the same reference numerals are used for components that are the same as in the first embodiment, and their descriptions are omitted.

[0069] [Impact Process (A4)] Figure 7 is a schematic cross-sectional view showing a state in which a light-emitting element, provided on a substrate and having an anisotropic conductive adhesive layer on its electrode surface, is facing a rubber layer on a wiring board. As shown in Figure 7, first, in the impact step (A4), the chip component substrate 10 and the wiring board 30 are faced towards each other.

[0070] The chip component substrate 10 comprises a base material 11, a release material 12, and a light-emitting element 20, with the light-emitting element 20 attached to the surface of the release material 12. Furthermore, a connecting film 70 made of an anisotropic conductive adhesive layer 72 is attached to the electrode surface of the light-emitting element 20. The anisotropic conductive adhesive layer 72 is the same as the anisotropic conductive adhesive layer 42 in the first embodiment, so its description is omitted.

[0071] Furthermore, rubber layers 71 are attached to the first electrode 32 and the second electrode 33 of the wiring board 30. Since the rubber layer 71 is the same as the rubber layer 41 in the first embodiment, its description is omitted.

[0072] In the impact process (A4), the rubber layer 71 attached to the wiring board 30 mitigates the impact of the light-emitting element 20, which is launched at ultra-high speed, suppressing defects such as displacement, deformation, breakage, and detachment of the light-emitting element 20, thereby achieving a high success rate of impact.

[0073] [Connection process (B4)] In the connection process (B4), the light-emitting elements 20 arranged in predetermined positions on the wiring board 30 are mounted. The method for thermocompressing the light-emitting elements 20 to the wiring board 30 is the same as in the first embodiment. The rubber layer 71 attached to the wiring board 30 is punctured by the conductive particles 73 of the anisotropic conductive adhesive layer 72 during thermocompression. The conductive particles 73 of the anisotropic conductive adhesive layer 72 are then sandwiched between the first conductive electrode 22 and the second conductive electrode 23 of the light-emitting elements 20 and the first electrode 32 and the second electrode 33 of the wiring board 30, and an anisotropic conductive film is formed as the binder of the anisotropic conductive adhesive layer 72 hardens.

[0074] According to the manufacturing method of the connection structure of the fourth embodiment, a connection film consisting of an adhesive layer is placed on the electrode surface of a chip component, a rubber layer is placed on the electrode surface of a wiring board, and the adhesive layer and the rubber layer are brought into contact with each other. This suppresses the occurrence of defects such as displacement, deformation, breakage, and detachment of the chip component during the impact process, and enables the transfer and arrangement of the chip component with high precision and efficiency, and provides excellent conductivity during the connection process.

[0075] <2. Connecting film> The connecting film according to this embodiment has a rubber layer and an adhesive layer, with the thickness of the rubber layer being 0.5 μm or more and 3.0 μm or less. This improves the impact rate when chip components are impacted onto a wiring board using, for example, laser mass transfer, and provides excellent conductivity.

[0076] The adhesive layer is preferably an anisotropic conductive adhesive layer containing conductive particles. This makes it possible to connect the chip component to the wiring board even when the chip component does not have connection points such as solder bumps. Furthermore, it is preferable that the anisotropic conductive adhesive layer is constructed with the conductive particles aligned in a direction, and that the conductive particles are biased toward the wiring board side in the thickness direction. This improves the capture ability of the conductive particles between the electrodes of the chip component and the electrodes of the wiring board. However, if the electrodes of the chip component are protruding or otherwise form an electrical connection with the wiring on the wiring board, the adhesive layer does not need to contain conductive particles.

[0077] Figure 8 is a schematic cross-sectional view showing a first example of the configuration of the connecting film. As shown in Figure 8, the connecting film 40 has a rubber layer 41 and an anisotropic conductive adhesive layer 42 containing conductive particles 43.

[0078] The rubber layer 41 is not particularly limited as long as it is an elastomer with high cushioning (shock absorption) properties. Specific examples include silicone rubber, acrylic rubber, butadiene rubber, and polyurethane resin (polyurethane elastomer). Among these, it is preferable that the rubber layer 41 be one or more selected from silicone rubber and acrylic rubber.

[0079] The thickness of the rubber layer 41 is preferably 0.5 μm or more and 3.0 μm or less, more preferably 0.5 μm or more and 2.0 μm or less, and even more preferably 0.5 μm or more and 1.5 μm or less. If the thickness of the rubber layer 41 is too small, it tends to be difficult to obtain shock absorption, and if the thickness of the rubber layer 41 is too small, it tends to be difficult to obtain conductivity.

[0080] The durometer A hardness of the rubber layer 41 is preferably 20 to 40, more preferably 20 to 35, and even more preferably 20 to 30. If the durometer A hardness is too high, the rubber layer is too hard, which tends to cause defects such as deformation and breakage of the chip component. If the durometer A hardness is too low, the rubber layer 41 is too soft, which tends to cause defects such as displacement of the chip component. The durometer A hardness of the rubber layer 41 can be measured using durometer A in accordance with JIS K 6253, according to the Japanese Industrial Standard JIS-A hardness scale.

[0081] The storage modulus of the rubber layer 41 in a dynamic viscoelasticity test using an indentation test device at a temperature of 30°C and a frequency of 200Hz is preferably 60MPa or less, more preferably 40MPa or less, and even more preferably 30MPa or less. If the storage modulus of the rubber layer 41 at a temperature of 30°C and a frequency of 200Hz is too high, it is not possible to absorb the impact of the chip component ejected at high speed by laser irradiation, and the transfer rate of the chip component tends to decrease. The storage modulus of the rubber layer 41 at a temperature of 30°C and a frequency of 200Hz can be measured using an indentation test device, for example, by using a flat punch with a diameter of 100μm, setting the target indentation depth to 1μm, and sweeping in the frequency range of 1 to 200Hz.

[0082] The anisotropic conductive adhesive layer 42 may be a so-called anisotropic conductive film (ACF) containing conductive particles 43. Conductive particles can be appropriately selected from those used in known anisotropic conductive films. Examples include metal particles such as nickel, copper, silver, gold, palladium, and solder, or metal-coated resin particles in which the surface of resin particles such as polyamide and polybenzoguanamine is coated with a metal such as nickel or gold. This enables conductivity even when connection points such as solder bumps are not provided on the chip component.

[0083] Furthermore, it is preferable that the anisotropic conductive adhesive layer 42 is configured with conductive particles 43 aligned in the planar direction. By aligning the conductive particles in the planar direction, the particle surface density becomes uniform, and excellent conductivity can be obtained. It is also preferable that the conductive particles 43 of the anisotropic conductive adhesive layer 42 are biased toward the wiring substrate side in the thickness direction. For example, in the first embodiment described above, the conductive particles 43 in the anisotropic conductive adhesive layer 42 may be biased toward the opposite side of the rubber layer 41, and in the third embodiment described above, the conductive particles 43 in the anisotropic conductive adhesive layer 42 may be biased toward the side of the rubber layer 41. This makes it possible to improve the capture of conductive particles between the electrodes of the chip component and the electrodes of the wiring substrate.

[0084] The particle size of the conductive particles 43 is not particularly limited, but the lower limit of the particle size is preferably 1 μm or more, and the upper limit of the particle size is preferably 50 μm or less, and more preferably 20 μm or less, from the viewpoint of the capture efficiency of conductive particles in the connecting structure. The particle size of the conductive particles can be the value measured by an image-type particle size analyzer (for example, FPIA-3000: manufactured by Malvern). The number of particles is preferably 1000 or more, preferably 2000 or more. The particle surface density of the conductive particles can be determined according to the electrode area of ​​the chip component, for example, 500 to 140000 pcs / mm 2 It can be set to the range of

[0085] The anisotropic conductive adhesive layer 42 is preferably composed of a thermosetting binder containing a film-forming resin, a thermosetting resin, and a curing agent. The thermosetting binder is not particularly limited and includes, for example, a thermoanionic polymerization resin composition containing an epoxy compound and a thermoanionic polymerization initiator, a thermocation polymerization resin composition containing an epoxy compound and a thermocation polymerization initiator, and a thermoradical polymerization resin composition containing a (meth)acrylate compound and a thermoradical polymerization initiator. Note that (meth)acrylate compound includes both acrylic monomers (oligomers) and methacrylic monomers (oligomers).

[0086] Among these thermosetting binders, it is preferable that the thermosetting resin contains an epoxy compound and the curing agent is a thermal cationic polymerization initiator. This suppresses the curing reaction by laser light and allows for rapid curing by heat. In the following, as a specific example, a thermal cationic polymerization resin composition containing a film-forming resin, an epoxy compound, and a thermal cationic polymerization initiator will be given and explained.

[0087] The film-forming resin is, for example, a high molecular weight resin with an average molecular weight of 10,000 or more, and from the viewpoint of film formation, an average molecular weight of about 10,000 to 80,000 is preferred. Examples of film-forming resins include phenoxy resin, polyester resin, polyurethane resin, polyester urethane resin, acrylic resin, polyimide resin, and butyral resin, which may be used individually or in combination of two or more. Among these, phenoxy resin is preferred from the viewpoint of film formation state and connection reliability. The content of the film-forming resin in the anisotropic conductive adhesive layer is preferably 20 to 50 wt%, more preferably 25 to 45 wt%, and even more preferably 30 to 40 wt%.

[0088] The epoxy compound is not particularly limited as long as it is an epoxy compound having one or more epoxy groups in its molecule. For example, it may be a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, or a urethane-modified epoxy resin. Among these, a high-purity bisphenol A type epoxy resin is preferably used. A specific example of a high-purity bisphenol A type epoxy resin is the product name "YL980" manufactured by Mitsubishi Chemical Corporation. The epoxy compound content in the anisotropic conductive adhesive layer is preferably 10 to 55 wt%, more preferably 15 to 50 wt%, and even more preferably 20 to 45 wt%.

[0089] As the thermal cationic polymerization initiator, known thermal cationic polymerization initiators for epoxy compounds can be used. For example, those that generate an acid capable of cationic polymerization of cationic polymer-type compounds upon heating, such as known iodonium salts, sulfonium salts, phosphonium salts, ferrocenes, etc., can be used. Among these, aromatic sulfonium salts that exhibit good latent properties with respect to temperature are preferably used. A specific example of an aromatic sulfonium salt-based polymerization initiator is, for example, the product name "SI-60L" manufactured by Sanshin Chemical Industry Co., Ltd. The content of the thermal cationic polymerization initiator in the anisotropic conductive adhesive layer is preferably 1 to 20 wt%, more preferably 2 to 15 wt%, and even more preferably 3 to 12 wt%.

[0090] In addition, other additives that may be incorporated into the thermosetting binder, as needed, include inorganic fillers, silane coupling agents, diluent monomers, fillers, softeners, colorants, flame retardants, thixotropic agents, etc.

[0091] Examples of inorganic fillers that can be used include silica, talc, titanium dioxide, calcium carbonate, and magnesium oxide. Inorganic fillers may be used alone or in combination of two or more types. The inorganic filler content in the anisotropic conductive adhesive layer is preferably 1 to 30 wt%, more preferably 5 to 25 wt%, and even more preferably 10 to 20 wt%. When two or more inorganic fillers are used in combination, it is preferable that the total inorganic filler content in the thermosetting binder is within the above-mentioned range.

[0092] The lower limit of the thickness of the anisotropic conductive adhesive layer 42 may be the same as the particle diameter of the conductive particles, and preferably it can be 1.3 times or more the conductive particle diameter or 3 μm or more. The upper limit of the thickness of the connecting film may be 20 μm or less or 2 times or less the particle diameter of the conductive particles. The connecting film may also consist of laminated adhesive layers or tack layers that do not contain conductive particles, and the number of layers and the lamination surface can be appropriately selected according to the target and purpose. The insulating resin of the adhesive layers or tack layers can be the same as that of the connecting film. The film thickness can be measured using a known micrometer or digital thickness gauge. The film thickness can be determined by measuring at 10 or more locations and averaging the results.

[0093] [Differentiation] In the first configuration example, the rubber layer preferably has internal voids and is preferably in the shape of a mesh or protrusions. This improves shock absorption due to the air layer, and can improve the hit rate of the chip component. In addition, when connecting the chip component, the chip component is more likely to penetrate the rubber layer, so excellent conductivity resistance can be obtained.

[0094] Figure 9(A) is a plan view showing two rubber layers having internal voids due to processing, and Figure 9(B) is a schematic cross-sectional view showing a second example of the configuration of the connecting film. As shown in Figure 9, the connecting film 80 as a second example of the configuration has a rubber layer 81 and an anisotropic conductive adhesive layer 82 containing conductive particles 83. The rubber layer 81 is formed by laminating a first rubber layer 81A and a second rubber layer 81B, and is, for example, in a mesh shape. The first rubber layer 81A and the second rubber layer 81B have multiple holes formed on their surfaces by curing the rubber using, for example, multiple convex molds. The rubber layer 81 may also be a porous layer, for example, instead of a mesh shape. Note that the anisotropic conductive adhesive layer 82 is the same as the anisotropic conductive adhesive layer 42, so its explanation is omitted.

[0095] Figure 10 is a schematic cross-sectional view showing a third configuration example of the connecting film. As shown in Figure 10, the connecting film 90 in the third configuration example has a rubber layer 91 and an anisotropic conductive adhesive layer 92 containing conductive particles 93. The rubber layer 91 is, for example, protruding (protruding type), and multiple holes are formed on the surface by curing the rubber using, for example, multiple convex molds. Note that the anisotropic conductive adhesive layer 92 is the same as the anisotropic conductive adhesive layer 42, so its explanation is omitted.

[0096] As shown in the modified example, the presence of internal voids in the rubber layer improves shock absorption and increases the accuracy of chip component impacts. Furthermore, the puncture resistance of the rubber layer is improved, resulting in superior conductivity resistance. [Examples]

[0097] <3. Examples> In the examples, a chip component provided on quartz glass and a connecting film provided on a glass substrate were placed facing each other, and laser light was irradiated from the substrate side to cause the chip component to land on the connecting film, and the impact elasticity was evaluated. In addition, a connecting structure was fabricated and its conductivity was evaluated. Note that this technology is not limited to these examples.

[0098] [Fabrication of anisotropic conductive adhesive layer] The following materials were prepared. Phenoxy resin (product name: PKHH, manufactured by Tomoe Chemical Industry Co., Ltd.) High-purity bisphenol A type epoxy resin (product name: YL-980, manufactured by Mitsubishi Chemical Corporation) Hydrophobic silica (product name: RY200, manufactured by Nippon Aerosil Co., Ltd.) Cationic polymerization initiator (product name: SI-60L, manufactured by Sanshin Chemical Industry Co., Ltd.) Conductive particles (average particle size 3 μm, resin core metal coated fine particles, 0.2 μm thick Ni plating, manufactured by Sekisui Chemical Co., Ltd.)

[0099] As shown in Table 2, each material was mixed in predetermined mass parts, and an anisotropic conductive adhesive layer with a thickness of 6 μm was fabricated on a glass substrate with a thickness of 0.5 mm. The anisotropic conductive adhesive layer was prepared, for example, by the method described in Japanese Patent No. 6187665, with a particle surface density of 58,000 pcs / mm² on one side of the binder layer. 2 The conductive particles were aligned in such a way.

[0100] [Table 2]

[0101] [Evaluation of the impact elasticity of chip components] Using a listing device (MT-30C200), chip components mounted on quartz glass were projected onto a connecting film on a glass substrate. For the chip components (outer dimensions 30 × 50 μm, thickness 5 μm, electrode thickness 2 μm), a TEG (Test Element Group) was used, with a release material (polyimide) placed between the quartz glass and the chip component.

[0102] As described above, the list device comprises a telescope that converts pulsed laser light emitted from a laser device into parallel light, a shaping optical system that uniformly shapes the spatial intensity distribution of the pulsed laser light that has passed through the telescope, a mask that allows the pulsed laser light shaped by the shaping optical system to pass through in a predetermined pattern, a field lens positioned between the shaping optical system and the mask, and a projection lens that reduces and projects the laser light that has passed through the pattern on the mask onto the donor substrate. The donor substrate is a quartz substrate with chip components held in place by a release material, which is held on the donor stage, and a receptor substrate is a glass substrate with a connecting film attached, which is held on the receptor stage, with a distance of 100 μm between the chip components and the connecting film.

[0103] The laser device used was an excimer laser with an oscillation wavelength of 248 nm. The pulse energy of the laser light was 600 J, and the fluence was 150 J / cm². 2The pulse width (irradiation time) was 30,000 picoseconds, the pulse frequency was 0.01 kHz, and the number of irradiation pulses was 1 pulse per ACF1 piece. The pulse energy of the imaged laser light irradiated at the interface between the anisotropic conductive adhesive layer and the substrate was 0.001 to 2 J, and the fluence was 0.001 to 2 J / cm². 2 The pulse width (irradiation time) is 0.01 to 1 × 10⁻⁶. 9 The pulse duration was picosecond, the pulse frequency ranged from 0.1 to 10,000 Hz, and the number of pulses ranged from 1 to 30,000,000.

[0104] The mask used a pattern in which windows of a predetermined size were arranged at a predetermined pitch so that the projection at the interface between the quartz glass donor substrate and the release material would have an outer shape of 30 × 50 μm for the chip component.

[0105] A total of 100 chip components were transferred to a connecting film, and the number of chip components that landed successfully on the connecting film was counted using a microscope. A success rate of 90% or higher for the chip components is desirable.

[0106] [Creating connection structures] A chip component was deposited onto a connection film on a wiring board, and the connection structure was fabricated by thermocompression bonding under the conditions of 170°C, 10 MPa pressure, and 30 seconds. The chip component (outer dimensions 50 μm × 50 μm, thickness 150 μm) used was a TEG (Test Element Group) with a pair of electrodes (Cr / Au-plated bump 12 μm × 12 μm) attached to the chip component. The wiring board used was a glass substrate (thickness 0.5 mm, Ti / Al / Ti pattern 12 μm × 12 μm).

[0107] [Evaluation of conductivity] The conductivity resistance of the connection structure was measured using the conductive wiring on the circuit board. Continuity was evaluated using a classification from A to D based on the resistance value. A rating of C or higher is desirable. A: 50Ω or less B: More than 50Ω and less than 100Ω C: More than 100Ω and less than 200Ω D: Over 200Ω

[0108] [Example 1] A silicone (product name: STP-106T-UV, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied and then UV (ultraviolet) cured to create a 1 μm thick silicone rubber layer. Then, the 1 μm thick silicone rubber layer was bonded to the surface of a 6 μm thick anisotropic conductive adhesive layer to form a connecting film.

[0109] Furthermore, the rubber hardness (Japanese Industrial Standard JIS-A hardness) of the silicone rubber was measured using a durometer A in accordance with JIS K 6253. The result was a rubber hardness of 30. In addition, a dynamic viscoelasticity test was performed on the silicone rubber using an indentation test device (KLA iMicro type nanoindenter). A flat punch with a diameter of 100 μm was used, with a target indentation depth of 1 μm, and the frequency range of 1 to 200 Hz was swept. The storage modulus was measured at a temperature of 30°C and a frequency of 200 Hz. The Poisson's ratio of the sample was set to 0.5, and the average value of 12 measurement points for each sample was calculated. As a result, the storage modulus was 27 MPa.

[0110] As shown in Table 3, the chip impact rate when chip components were landed on the silicone rubber layer of the connecting film was 98%. Furthermore, the conductivity resistance of the connection structure in which the chip components and the wiring board were heat-pressed together via the connecting film was evaluated as "B".

[0111] [Example 2] A connecting film was prepared in the same manner as in Example 1, except that a silicone rubber layer with a thickness of 0.5 μm was created.

[0112] As shown in Table 3, the chip impact rate when chip components were landed on the silicone rubber layer of the connecting film was 90%. Furthermore, the conductivity resistance of the connection structure in which the chip components and the wiring board were thermocompressed via the connecting film was evaluated as "A".

[0113] [Example 3] A connecting film was prepared in the same manner as in Example 1, except that a silicone rubber layer with a thickness of 2.0 μm was created.

[0114] As shown in Table 3, the chip impact rate when chip components were landed on the silicone rubber layer of the connecting film was 100%. Furthermore, the conductivity resistance of the connection structure in which the chip components and the wiring board were heat-pressed together via the connecting film was evaluated as "C".

[0115] [Example 4] A 1 μm thick layer of silicone (product name: STP-106T-UV, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied, and numerous 1 μm diameter holes were processed using a convex embossing tool. The layer was then cured with UV (ultraviolet) to create a silicone rubber layer. Two silicone rubber layers were then bonded together (mesh type) to the surface of a 6 μm thick anisotropic conductive adhesive layer to create a connecting film, with a total thickness of 2 μm.

[0116] As shown in Table 3, the chip impact rate when chip components were landed on the silicone rubber layer of the connecting film was 100%. Furthermore, the conductivity resistance of the connection structure in which the chip components and the wiring board were heat-pressed together via the connecting film was evaluated as "A".

[0117] [Example 5] After applying silicone (product name: STP-106T-UV, manufactured by Shin-Etsu Chemical Co., Ltd.) to a predetermined thickness, numerous holes with a diameter of 1 μm were processed using a convex embossing tool. The silicone rubber layer was then cured with UV (ultraviolet) to create a silicone rubber layer with a protrusion height of 1 μm or more and a total thickness of 2 μm. The silicone rubber layer was then bonded (protruding type) to the surface of a 6 μm thick anisotropic conductive adhesive layer to form a connecting film.

[0118] As shown in Table 3, the chip impact rate when chip components were landed on the silicone rubber layer of the connecting film was 100%. Furthermore, the conductivity resistance of the connection structure in which the chip components and the wiring board were heat-pressed together via the connecting film was evaluated as "A".

[0119] [Comparative Example 1] Without bonding a silicone rubber layer to the surface of the anisotropic conductive adhesive layer, only the 6 μm thick anisotropic conductive adhesive layer was used as the connecting film.

[0120] As shown in Table 3, the chip landing rate when chip components were deposited onto the anisotropic conductive adhesive layer was 20%. Furthermore, the conductivity resistance of the connection structure in which the chip components and the wiring board were thermocompressed via a connecting film was evaluated as "A".

[0121] [Comparative Example 2] 80 parts by mass of silicone (product name: STP-106T-UV, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed with 20 parts by mass of conductive particles (average particle size 3 μm, resin core metal coated fine particles, Ni plating 0.2 μm thick, manufactured by Sekisui Chemical Co., Ltd.). This mixture was applied to a 0.5 mm thick glass substrate and UV cured to produce a 6 μm thick conductive particle-containing silicone rubber layer, which was used as a connecting film.

[0122] As shown in Table 3, the chip impact rate when chip components were deposited onto the conductive particle-containing silicone rubber layer was 100%. Furthermore, the conductivity resistance of the connection structure in which the chip components and the wiring board were thermocompressed via a connecting film was evaluated as "D".

[0123] [Table 3]

[0124] As shown in Table 3, in Comparative Example 1, the chip impact rate was low because no silicone rubber layer was provided on the anisotropic conductive adhesive layer. In Comparative Example 2, the conductivity resistance was poorly evaluated because the connecting film was a silicone rubber layer containing conductive particles.

[0125] On the other hand, in Examples 1 to 5, a high chip impact rate was obtained because a silicone rubber layer was provided on an anisotropic conductive adhesive layer. Furthermore, in Examples 4 and 5, because the silicone rubber layer had internal voids, such as a mesh type or a protruding type, the chip components could easily penetrate the silicone rubber layer, and a good evaluation of conductivity resistance was obtained. [Explanation of symbols]

[0126] 10 Chip component substrate, 11 Base material, 12 Release material, 20 Light-emitting element, 21 Main body, 22 First conductive electrode, 23 Second conductive electrode, 30 Wiring board, 31 Base material, 32 First electrode, 33 Second electrode, 40 Connecting film, 41 Rubber layer, 42 Anisotropic conductive adhesive layer, 50 Connecting film, 51 Rubber layer, 52 Anisotropic conductive adhesive layer, 60 Connecting film, 61 Rubber layer, 62 Anisotropic conductive adhesive layer, 70 Connecting film, 71 Rubber layer, 72 Anisotropic conductive adhesive layer, 80 Connecting film, 81 Rubber layer, 82 Anisotropic conductive adhesive layer, 83 Conductive particles, 90 Connecting film, 91 Rubber layer, 92 Anisotropic conductive adhesive layer, 93 Conductive particles, 101 LED, 102 Transfer material, 103 Stamp material, 104 Panel substrate, 105 Connecting film, 111 LED, 112 Transfer material, 113 release material, 114 panel substrate, 115 connecting film

Claims

1. A chip component provided on a substrate that is transparent to laser light is placed opposite a wiring board, and a projectile step is made by irradiating the substrate with laser light to cause the chip component to land on the wiring board side. The process includes a connection step of connecting the chip component and the wiring board via a connecting film, The connecting film has a rubber layer and an adhesive layer, A method for manufacturing a connecting structure, wherein the rubber layer is punctured in the connection step.

2. The method for manufacturing a connecting structure according to claim 1, wherein the rubber layer is one or more selected from acrylic rubber and silicone rubber.

3. A method for manufacturing a connecting structure according to any one of claims 1 to 2, wherein the thickness of the rubber layer is 0.5 μm or more and 3.0 μm or less.

4. A method for manufacturing a connecting structure according to any one of claims 1 to 3, wherein the rubber layer has voids inside.

5. A method for manufacturing a connecting structure according to any one of claims 1 to 4, wherein the durometer A hardness of the rubber layer is 20 to 40, and the storage modulus of elasticity in a dynamic viscoelasticity test using an indentation test device at a temperature of 30°C and a frequency of 200 Hz is 60 MPa or less.

6. A method for manufacturing a connecting structure according to any one of claims 1 to 5, wherein the adhesive layer contains a film-forming resin, a thermosetting resin, and a curing agent.

7. A method for manufacturing a connecting structure according to any one of claims 1 to 6, wherein the adhesive layer contains conductive particles.

8. The method for manufacturing a connecting structure according to claim 7, wherein the adhesive layer is configured by aligning the conductive particles in the planar direction.

9. A method for manufacturing a connection structure according to any one of claims 1 to 8, wherein the chip component is a light-emitting element.

10. The method for manufacturing a connection structure according to claim 1, wherein the rubber layer is punctured by the electrode of the chip component.

11. The adhesive layer contains conductive particles, A method for manufacturing a connecting structure according to claim 1, wherein the rubber layer is punctured by the conductive particles.

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