JP2008218542A - Connecting structure and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connecting structure improving an adhesion between a transfer original board and a transfer-place board and being capable of reducing a connection resistance between the transfer-place board and a wiring board. <P>SOLUTION: The connecting structure (an electrooptic device) has a plurality of first terminals 19, projecting sections 17 formed among the adjacent first terminals 19, target transfer layers containing the first terminals 19 and the projecting sections 17, the transfer-place board 10 transferring the transferred layers and a plurality of second terminals 31 corresponding to a plurality of the first terminals 19 respectively. The connecting structure further has the wiring board 3 forming the second terminals 31 and an anisotropic conductive member 35 containing a plurality of conductive particles 35a electrically connecting the first terminals 19 and the second terminals 31. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a manufacturing technique of a connection structure in which a substrate on which a transfer layer is transferred and a wiring substrate are connected.

  In recent years, development of a flexible device that is thin, lightweight, and can be bent freely is underway. For example, a flexible display typified by electronic paper can be an electronic device that plays a role in the ubiquitous society in addition to lightness when carried, absorption of impact, and flexibility to adapt to the hand. As such an electronic device, a device in which a thin film element such as a low-temperature polysilicon thin film transistor is transferred onto a flexible plastic substrate using a transfer technique is known.

In a conventional transfer process, first, a release layer is formed on a glass substrate that is a transfer source substrate, and a thin film element and a wiring that is a transfer layer are formed thereon using a normal low-temperature polysilicon process. Then, the transfer source substrate and the plastic substrate that is the transfer destination substrate are bonded with an adhesive, and the adhesion between the release layer and the transfer source substrate is weakened by light, heat, or the like, and the transfer target layer is transferred to the transfer destination substrate. Transfer to the plastic substrate may be performed using two or more transfer processes. For example, in Patent Document 1, a transfer target layer is transferred from a transfer source substrate to a glass substrate that is a first transfer destination substrate, and then transferred to a plastic substrate that is a second transfer destination substrate. As a result, transfer can be performed on the transfer destination substrate in the same stacking relationship as that on the transfer source substrate.
JP 2004-327836 A

  When transferring the transfer layer from the transfer source substrate to the transfer destination substrate, it is necessary to secure a sufficient adhesive force between the transfer source substrate and the transfer destination substrate. This is because if the adhesive force is insufficient, the transferred layer is not reliably transferred, and the transferred layer may partially remain on the transfer source substrate.

  On the other hand, the performance of the electronic device is also affected by the connection resistance between the transfer destination substrate and the wiring substrate. 10A and 10B are a cross-sectional view (FIG. 10A) and a plan view (FIG. 10B) of a connection portion between a conventional transfer destination substrate and a wiring substrate. As shown in the figure, when the transfer destination substrate 10 and the wiring substrate 3 are connected, an anisotropic conductive member 35 in which conductive particles 35a are dispersed in an adhesive 35b is used. When a sufficient number of conductive particles 35a are not disposed between the one terminal 19 and the second terminal 31 of the wiring board 3, the connection resistance between the terminals 19 and 31 increases, resulting in poor connection. For example, the density of the conductive particles 35 a between the terminals 19 and 31 varies depending on the size of the gap between the first substrate 10 and the wiring substrate 3, but the portion where the terminals 19 and 31 are formed corresponds to the terminals 19 and 31. The interval is narrower than the other portions by the thickness, and therefore, the conductive particles 35a tend to gather in the region between the terminals 19, 19 having a large interval. As a result, the density of the conductive particles 35a between the terminals 19 and 31 may be reduced, and sufficient connection resistance may not be obtained.

  The present invention has been made in view of such circumstances, and can improve the adhesive force between the transfer source substrate and the transfer destination substrate, and further reduce the connection resistance between the transfer destination substrate and the wiring substrate. An object is to provide a structure and a method for manufacturing the structure. Another object of the present invention is to provide an electronic device having a high yield and excellent connection reliability by including such a connection structure.

  In order to solve the above problems, the connection structure of the present invention includes a transfer layer including a plurality of first terminals and a protrusion provided between each of the plurality of first terminals, and the transfer target. The transfer destination substrate to which the layer is transferred, the wiring substrate having a plurality of second terminals respectively corresponding to the plurality of first terminals, and the plurality of first terminals and the plurality of second terminals are electrically connected to each other. And an anisotropic conductive member connected to. According to this configuration, since the protruding portion is provided in the region between the adjacent first terminals, when the transfer source substrate is bonded to another substrate, the bonding area is increased by the surface area of the protruding portion. Can do. For this reason, sufficient adhesive force can be secured between the transfer source substrate and the other substrate, and a connection structure with a high yield can be provided. Further, since the distance between the transfer destination substrate and the wiring substrate can be reduced by the protrusion, the conductive particles in the anisotropic conductive member are connected when the transfer destination substrate and the wiring substrate are connected by the anisotropic conductive member. Is difficult to move to the region between the terminals, and many conductive particles can contribute to the electrical connection between the first terminal and the second terminal. Moreover, since it becomes difficult for a conductive particle to move to the area | region between adjacent terminals, it becomes difficult to produce a short circuit between terminals and can provide the connection structure excellent in reliability.

  In the present invention, it is desirable that the protrusion is composed of a plurality of protrusions. For example, it is desirable that the plurality of protrusions be provided along an array axis of the plurality of first terminals. Further, it is desirable that the plurality of protrusions be provided along the extending direction of the plurality of first terminals. According to this configuration, since the surface area of the protruding portion is increased, the adhesive force between the transfer source substrate and the other substrate is further improved. When a plurality of protrusions are provided between the first terminals, the plurality of protrusions need not be provided between all the first terminals, and may be provided between at least one of the first terminals.

  In the present invention, it is desirable that the protrusion has a rectangular or trapezoidal cross section cut along the arrangement axis of the plurality of first terminals. According to this configuration, the adhesive force between the transfer source substrate and the other substrate can be increased as compared with the case where the cross section of the protrusion has a curved shape. In addition, when the cross-sectional shape of the protrusions is a forward tapered trapezoidal shape in which the width of the groove between the protrusions becomes narrower as the distance from the surface of the transfer destination substrate increases, the adhesive in the anisotropic conductive member causes protrusions It becomes easy to fill the area between them, and the adhesive force is further improved.

  In the present invention, the transfer layer includes a plurality of wirings electrically connected to the plurality of first terminals, and an insulating film covering the plurality of wirings, and the protrusion includes the insulating film. It is desirable to be formed by the same member. According to this configuration, since the protrusion can be formed at the same time when the insulating film is patterned, the manufacturing process can be simplified.

  In the present invention, it is desirable that the thickness of the protrusion is not more than the sum of the thickness of the first terminal, the thickness of the conductive particles contained in the anisotropic conductive member, and the thickness of the second terminal. According to this configuration, the protrusion does not get in the way when connecting the first terminal and the second terminal. In addition, when the thickness of the protruding portion is substantially the same as the total thickness of the first terminal, the second terminal, and the conductive particles, the conductive particles are hardly disposed between the protruding portion and the wiring board. Many conductive particles can contribute to the electrical connection between the first terminal and the second terminal.

  In the present invention, the density of the conductive particles in the facing region where the plurality of first terminals and the plurality of second terminals are opposed to each other is the region between each of the plurality of first terminals and the plurality of second terminals. It is desirable that the density of the conductive particles in the region between each of the above is larger. According to this configuration, it is possible to reduce the number of wasted conductive particles that do not contribute to the electrical connection between the first terminal and the second terminal. Further, since the number of conductive particles arranged between adjacent terminals is reduced, a short circuit between the terminals can be prevented.

  The method for manufacturing a connection structure according to the present invention includes a step of forming a transfer layer including a plurality of first terminals and a protrusion disposed between each of the plurality of first terminals on a transfer source substrate; Adhering the first transfer destination substrate to the surface of the transfer source substrate on the transfer layer side, peeling the transfer layer from the transfer source substrate, and placing the transfer layer on the first transfer destination substrate A step of transferring, a step of adhering a second transfer destination substrate to a surface of the first transfer destination substrate on the side of the transfer target layer, and peeling off the transfer target layer from the first transfer destination substrate to form the second transfer A step of transferring the transferred layer onto the destination substrate; and a wiring substrate including a plurality of second terminals respectively corresponding to the plurality of first terminals on a surface of the second transfer destination substrate on the transferred layer side. And a step of connecting via the isotropic conductive member. According to this method, since the protrusion is provided in the region between the adjacent first terminals, the bonding area is increased by the surface area of the protrusion when the transfer source substrate is bonded to the first transfer destination substrate. can do. For this reason, sufficient adhesive force can be ensured between the transfer source substrate and the first transfer destination substrate, and a connection structure with a high yield can be provided. In addition, since the gap between the second transfer destination substrate and the wiring substrate can be reduced by the protrusion, the anisotropic conductive member is used when connecting the second transfer destination substrate and the wiring substrate with the anisotropic conductive member. The inside conductive particles are difficult to move to the region between the terminals, and many conductive particles can contribute to the electrical connection between the first terminal and the second terminal. Moreover, since it becomes difficult for a conductive particle to move to the area | region between adjacent terminals, it becomes difficult to produce a short circuit between terminals and can provide the connection structure excellent in reliability.

  Embodiments of the present invention will be described below with reference to the drawings. Such an embodiment shows one aspect of the present invention and does not limit the present invention. In the following embodiments, various shapes, combinations, and the like of the constituent members are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention. Moreover, in the following drawings, in order to make each structure easy to understand, an actual structure and a scale, a number, and the like in each structure are different.

  In the following description, an XYZ orthogonal coordinate system is set, and the positional relationship of each member will be described with reference to the XYZ orthogonal coordinate system. At this time, the predetermined direction in the horizontal plane is the X-axis direction, the direction orthogonal to the X-axis direction in the horizontal plane is the Y-axis direction, and the direction orthogonal to each of the X-axis direction and the Y-axis direction (that is, the vertical direction) is the Z-axis direction. And In this embodiment, the X-axis direction is the scanning line extending direction, the Y-axis direction is the data line extending direction, and the Z-axis direction is the observation direction of the electro-optic panel by the observer.

[First Embodiment]
FIG. 1 is an exploded perspective view of an electro-optical device 1 which is an embodiment of a connection structure according to the present invention. The electro-optical device 1 includes an electro-optical panel 2 and a wiring board 3. The electro-optical device 1 is provided with a frame and other auxiliary devices as needed, but these are not shown in FIG.

The electro-optical panel 2 includes a first substrate 10 and a second substrate 20 that face each other. An electrophoretic layer is sandwiched between the first substrate 10 and the second substrate 20. The electrophoretic layer is mainly composed of an electrophoretic dispersion liquid in which one or more electrophoretic particles are dispersed in a dispersion medium. Electrophoretic particles are fine particles having a diameter of about 0.01 μm to 10 μm made of inorganic oxide or inorganic hydroxide such as TiO ₂ , and the surface charge density (charge amount) is controlled by the hydrogen ion index PH of the dispersion medium. Yes. The electrophoretic particles migrate by an electric field between the first substrate 10 and the second substrate 20, and display by attaching to the surface of one substrate. The electrophoretic dispersion liquid may be enclosed in the microcapsule.

  A display area Ad is provided at the center of the facing area where the first substrate 10 and the second substrate 20 face each other. In the display area Ad, a plurality of scanning lines 12 extending in the X-axis direction and a plurality of data lines 11 extending in the Y-axis direction are provided in a lattice shape in plan view. Sub-pixels corresponding to any one of red, green, and blue are provided at the intersections between the scanning lines 12 and the data lines 11. Such sub-pixels are arranged in a matrix on the first substrate 10, and a display area Ad as a whole is formed by the plurality of sub-pixels. Each sub-pixel is provided with a pixel switching element such as a TFT (Thin Film Transistor), which is not shown in FIG.

  The first substrate 10 is provided with an overhang portion 10 c that protrudes to the outside of the second substrate 20. A plurality of first terminals 19 that are electrically connected to the scanning lines 12 and the data lines 11 are provided in the overhanging portion 10 c. The wiring board 3 is electrically connected to the projecting portion 10c via an anisotropic conductive member 35 such as an anisotropic conductive film (ACF). The wiring board 3 includes a plurality of second terminals 31 that respectively correspond to the plurality of first terminals 19 of the first substrate 10. The first terminal 19 and the second terminal 31 are electrically connected via conductive particles (not shown) in the anisotropic conductive member 35.

  FIG. 2 is an enlarged view of the overhang portion 10c. A transferred layer 15 is transferred onto the first substrate 10 via an adhesive layer 14. The transferred layer 15 includes a set of thin film elements and wiring including a pixel circuit including a plurality of pixel switching elements and peripheral driving circuits such as a data line driving circuit and a scanning line driving circuit provided around the pixel circuit. It has. In FIG. 2, the first terminal 19, the wiring 13, the interlayer insulating film 16 and the protrusion 17 are included in the transferred layer 15. In the case of this embodiment, the pixel switching element and the peripheral drive circuit include a thin film transistor including a low-temperature polysilicon semiconductor layer, and these are integrally formed on the same substrate, so that an electro-optical panel with a built-in peripheral drive circuit is provided. Is formed.

  In FIG. 2, reference numeral 13 denotes a wiring for drawing out the scanning line 12 and the data line 11 to the overhanging portion 10c. A first terminal 19 is electrically connected to the wiring 13. An interlayer insulating film 16 is provided on the first substrate 10 so as to cover the wiring 13. A plurality of pixel electrodes (not shown) are provided on the interlayer insulating film 16 corresponding to each subpixel.

  A protrusion 17 is provided between the adjacent first terminals 19. The protrusion 17 is made of the same material as the interlayer insulating film 16. A groove H for exposing the first terminal 19 is provided in a portion overlapping the first terminal 19 of the interlayer insulating film 16. The grooves H are provided in stripes in the extending direction of the first terminal 19 (Y-axis method). The groove H is provided separately for each first terminal 19, and the portion where the groove H is not formed is a protrusion 17.

  FIG. 3 is a schematic configuration diagram of a connection portion between the first terminal 19 and the second terminal 31. In the same figure, (a) is a cross-sectional view of the connecting portion cut along the arrangement axis (X axis) of the first terminals 19, and (b) is a plan view of the connecting portion viewed from the Z-axis direction. As shown in FIG. 3A, a protrusion 17 that protrudes toward the wiring board 3 is provided between adjacent first terminals 19. The protrusion 17 has a rectangular or trapezoidal cross-sectional shape. In the case of this embodiment, the cross-sectional shape of the protrusion 17 has a forward tapered trapezoidal shape such that the width of the groove H between the protrusions 17 becomes narrower as the distance from the surface of the first substrate 10 increases. The thickness of the protruding portion 17 is designed according to the thickness of the connecting portion between the first substrate 10 and the wiring substrate 3. Specifically, the thickness is designed to be smaller than the sum of the thickness of the first terminal 19, the thickness of the second terminal 31, and the particle size of the conductive particles 35 a in the anisotropic conductive member 35, and preferably the total thickness Designed to approximately the same thickness.

  The distance between the first substrate 10 and the base substrate 30 of the wiring substrate 3 is reduced by the protrusion 17. Therefore, it is difficult for the conductive particles 35a to be disposed in the portion where the protrusion 17 is provided. The number and density of the conductive particles 35 a disposed between the protrusions 17 and the base substrate 30 can be controlled by the thickness of the protrusions 17. When the thickness of the protrusion 17 is substantially the same as the sum of the thickness of the first terminal 19, the thickness of the second terminal 31, and the particle size of the conductive particles 35 a, the protrusion 17 is interposed between the protrusion 17 and the base substrate 30. The conductive particles 35a are hardly arranged. On the other hand, when the thickness of the protruding portion 17 is small, the conductive particles 35a move to the space between the protruding portion 17 and the base substrate 30 when connecting the wiring substrate 3 and the first substrate 10, and the first The conductive particles 35 a are hardly disposed between the terminal 19 and the second terminal 31.

  On the other hand, when the thickness of the protrusion 17 is substantially the same as the sum of the thickness of the first terminal 19, the thickness of the second terminal 31, and the particle diameter of the conductive particles 35a, the protrusion 17 and the base substrate 30 The adhesive 35b is hardly disposed between the two and the adhesive force is weakened. For this reason, in this embodiment, the thickness of the protrusion 17 is set to be slightly smaller than the sum of the thickness of the first terminal 19, the thickness of the second terminal 31, and the particle diameter of the conductive particles 35a. A certain amount of adhesive 35 b is arranged between the material 30. By doing so, as shown in FIG. 3B, the density of the conductive particles 35a disposed between the first terminal 19 and the second terminal 31 is set to be equal to that of the conductive particles 35a disposed in other regions. The density can be made larger than the density, and a short circuit between the terminals can be surely prevented.

  Next, a method for manufacturing the electro-optical device 1 will be described with reference to FIGS. 4 to 7, the manufacturing process of the electro-optical panel 2 will be mainly described, and description of other processes will be omitted.

  First, as shown in FIG. 4, the peeling layer 41 and the transferred layer 15 are formed on the transfer source substrate 40. As the transfer source substrate 40, a substrate having translucency such as glass, quartz, plastic or the like is used. The transfer source substrate 40 may be any substrate as long as it can maintain the transferred layer 15 before and after transfer, and may not have rigidity such as a flexible film. However, it is necessary to have heat resistance that can withstand the process temperature of the transferred layer 15. For example, it is desirable to use a material having a strain point (glass transition temperature Tg or softening point) equal to or higher than Tmax, where Tmax is the maximum temperature for forming the transferred layer 15. When forming the transferred layer 15 having a low-temperature polysilicon semiconductor layer, the strain point is preferably 350 ° C. or higher, more preferably 500 ° C. or higher.

  The peeling layer 41 has such a property that peeling occurs in the layer or at the interface (hereinafter referred to as “in-layer peeling” or “interfacial peeling”) by application of energy. Preferably, the peeling layer 41 is irradiated by light irradiation. It is preferable that the bonding force between atoms or molecules of the substance constituting the material disappears or decreases, that is, ablation occurs to cause delamination or interfacial delamination. In some cases, gas is released from the release layer 41 by light irradiation, and a separation effect is exhibited. That is, there are a case where the component contained in the release layer 41 is released as a gas, and a case where the release layer 41 absorbs light and becomes a gas for a moment, and its vapor is released, contributing to separation. As the peeling layer 41, a known material such as amorphous silicon, hydrogen-containing amorphous silicon, nitrogen-containing amorphous silicon, hydrogen-containing alloy, nitrogen-containing alloy, multilayer film, ceramics, metal, organic polymer material, or the like can be used.

  Next, as shown in FIG. 5, the first transfer destination substrate 50 is bonded onto the transfer source substrate 40 via an adhesive. The first transfer destination substrate 50 may be inferior in heat resistance and corrosion resistance as compared to the transfer source substrate 40 on which the transfer target layer 15 is formed. This is because, unlike the transfer source substrate 40, the characteristics required for the first transfer destination substrate 50, particularly heat resistance, does not depend on the temperature conditions in forming the transfer layer. Accordingly, a material having a strain point (glass transition temperature Tg or softening point) equal to or lower than Tmax when the maximum temperature when forming the transferred layer 15 is Tmax can be used.

  As the types of adhesives, reactive curable adhesives, thermosetting adhesives, photocurable adhesives (such as UV curable adhesives), anaerobic curable adhesives, and other various curable adhesives should be used. Can do. Specifically, acrylic adhesives, epoxy adhesives, silicone adhesives, natural rubber adhesives, polyurethane adhesives, phenolic adhesives, vinyl acetate adhesives, cyanoacrylate adhesives, polyvinyl alcohol A system adhesive, a polyimide system adhesive, a polyamide system adhesive, etc. can be used, and these may be modified according to the purpose.

  The adhesive is disposed so as to cover the protrusion 17. For this reason, the adhesion area between the first transfer destination substrate 50 and the transfer source substrate 40 is increased by the surface area of the projections and depressions formed by the protrusions 17, and the adhesion force is also improved. Therefore, the adhesive layer 51 (see FIG. 6) is not inadvertently peeled off in the peeling step described later, and an electro-optical device with a high yield can be provided.

  Next, as shown in FIG. 6, light L is applied to the release layer 41 (see FIG. 5) from the transfer source substrate 40 side to weaken the adhesion of the release layer 41. When the light L is irradiated with the peeling layer 41, peeling (in-layer peeling or interface peeling) occurs. The principle of delamination or interfacial delamination is due to the occurrence of ablation in the constituent material of the delamination layer 41, the release of gas contained in the delamination layer 11, and the phase change such as melting and transpiration that occurs immediately after irradiation. is there.

  Here, the ablation means that the constituent material of the release layer 41 that has absorbed the irradiation light is photochemically or thermally excited, and the surface or internal atomic or molecular bonds are cut and released. All or part of the constituent material of the release layer 41 appears as a phenomenon that causes a phase change such as melting and transpiration (vaporization). In addition, the phase change may result in a fine foamed state, resulting in a decrease in bonding strength. Whether the peeling layer 41 causes in-layer peeling, interfacial peeling, or both depends on the composition of the peeling layer 41 and various other factors, and one of the factors is the type of light to be irradiated. , Conditions such as wavelength, intensity, and reaching depth.

  The light L to be irradiated may be any as long as it causes the peeling layer 41 to undergo in-layer peeling or interfacial peeling. For example, X-rays, ultraviolet rays, visible light, infrared rays (heat rays), laser light, millimeter waves, Microwave, electron beam, radiation (α wave, β wave, γ wave) and the like can be mentioned. Among these, laser light is preferable in that peeling (ablation) of the peeling layer 41 is likely to occur and local irradiation with high accuracy is possible. The laser light is coherent light, and is suitable for irradiating the peeling layer 41 through the lower transfer substrate 40 with high output pulsed light to cause peeling at a desired portion with high accuracy. Therefore, the transferred layer 15 can be easily and reliably peeled off by using laser light.

  When the bonding force of the peeling layer 41 is weakened, a force for separating the transfer source substrate 40 and the first transfer destination substrate 50 is applied, and the transfer source substrate 40 is peeled from the first transfer destination substrate 50. After peeling, the residue of the peeling layer 41 may adhere to the bottom surface of the transferred transfer target layer 15 or the transferred first transfer destination substrate 50 surface. As a method for completely removing the residue, for example, a method such as cleaning, etching, ashing, polishing, or a combination of these methods may be selected as appropriate.

  When the transferred layer 15 is transferred to the first transfer destination substrate 50, as shown in FIG. 7, the second transfer destination substrate 10 and the first transfer destination substrate 50 are opposed to each other, and two substrates 50 are interposed via an adhesive. , 10 are pasted together. As the second transfer destination substrate 10, a substrate made of glass, quartz, plastic, stainless steel or the like is used. The second transfer destination substrate 10 may be any substrate that can maintain the form after transfer and can maintain the transferred layer 15 without change before and after transfer, and does not have rigidity like a flexible film. But it ’s okay. The second transfer destination substrate 10 is desirably subjected to a surface treatment for forming fine irregularities at the interface with the adhesive layer in order to improve the adhesive force with the adhesive layer. Examples of such surface treatment include plasma treatment and corona treatment.

  The second transfer destination substrate 30 may be inferior in heat resistance and corrosion resistance compared to the transfer source substrate 10 on which the transfer target layer 12 is formed. This is because, unlike the transfer source substrate 10, the characteristics required for the second transfer destination substrate 30, particularly heat resistance, does not depend on the temperature conditions when forming the transfer layer. Accordingly, a material having a strain point (glass transition temperature Tg or softening point) equal to or lower than Tmax when the maximum temperature when forming the transferred layer 12 is Tmax can be used.

  Examples of the adhesive layer 32 include reactive curable adhesives, thermosetting adhesives, photocurable adhesives (such as ultraviolet curable adhesives), anaerobic curable adhesives, and other various curable adhesives. Can be used. Specifically, acrylic adhesives, epoxy adhesives, silicone adhesives, natural rubber adhesives, polyurethane adhesives, phenolic adhesives, vinyl acetate adhesives, cyanoacrylate adhesives, polyvinyl alcohol A system adhesive, a polyimide system adhesive, a polyamide system adhesive, etc. can be used, and these may be modified according to the purpose.

  As described above, according to the electro-optical device 1 of the present embodiment, since the protrusions 17 are provided in the region between the adjacent first terminals 19, the transfer source substrate 40 is connected to the first transfer destination substrate 50. When bonding, the bonding area can be increased by the surface area of the protrusion 17. For this reason, sufficient adhesive force can be secured between the transfer source substrate 40 and the first transfer destination substrate 50, and an electro-optical device with a high yield can be provided. Moreover, since the space | interval of the 2nd transcription | transfer destination board | substrate 10 and the wiring board 3 (base base material 30) can be made small by the projection part 17, the 2nd transcription | transfer destination board | substrate 10 and the wiring board 3 are made into an anisotropic conductive member. When the connection is made at 35, the conductive particles 35 a in the anisotropic conductive member 35 are less likely to move to the region between the terminals 19, 19, and many of the conductive particles 35 a are electrically connected to the first terminal 19 and the second terminal 31. It is possible to contribute to the general connection. In addition, since the conductive particles 35a are less likely to move to the region between the adjacent terminals 19 and 19, a short circuit between the terminals is less likely to occur, and an electro-optical device with excellent reliability can be provided.

  In the present embodiment, one protrusion 17 is provided between adjacent first terminals 19, but the number of protrusions 17 is not limited to this. For example, FIG. 8 shows an example in which the protrusion 17 is constituted by a plurality (two in FIG. 8) of protrusions 17A provided along the arrangement axis of the first terminals 19. FIG. 9 shows an example in which the protrusion 17 is constituted by a plurality (four in FIG. 9) of protrusions 17B provided along the extending direction (Y-axis direction) of the first terminal 19. In these configurations, since the surface area of the protrusion 17 is larger than that of the above-described embodiment, the adhesive force with the first transfer destination substrate can be further improved. When a plurality of protrusions are provided between the first terminals 19, the plurality of protrusions do not need to be provided between all the first terminals, and may be provided between at least one of the first terminals.

  In this embodiment, an electro-optical device (electrophoresis device) using electrophoretic particles has been described as an embodiment of the connection structure. However, the present invention is not limited to the electrophoretic device, and any electro-optical device. Can be applied to. Here, “electro-optical device” is a generic term that includes an electro-optical effect that changes the light transmittance by changing the refractive index of a substance by an electric field, and also includes devices that convert electric energy into optical energy. It shall be. That is, the present invention is not only a non-light-emitting electro-optical device using a liquid crystal or an electrophoretic dispersion as an electro-optical material, but also an organic EL device using an organic EL (Electro-Luminescence), an inorganic EL device using an inorganic EL, and an electro-optical device. The present invention can be applied to a light-emitting electro-optical device such as a plasma display device using a plasma gas as a substance, and a field emission display device (Field Emission Display: FED).

  In the present embodiment, the display device has been described as an embodiment of the connection structure, but the present invention can also be applied to a connection structure other than the display device. As such a connection structure, any connection structure provided with a transfer destination substrate having a layer to be transferred and a wiring substrate may be used, and the present invention is generally applicable to semiconductor devices used for purposes other than display applications. it can.

It is a schematic block diagram of the electro-optical device which is one Embodiment of a connection structure. It is an enlarged view of the overhang | projection part of the same electro-optical apparatus. FIG. 3 is a schematic configuration diagram of a connection portion between a first terminal and a second terminal of the electro-optical device. FIG. 10 is an explanatory diagram of the manufacturing method of the same electro-optical device. FIG. 10 is an explanatory diagram of the manufacturing method of the same electro-optical device. FIG. 10 is an explanatory diagram of the manufacturing method of the same electro-optical device. FIG. 10 is an explanatory diagram of the manufacturing method of the same electro-optical device. It is explanatory drawing of the other structural example of the same electro-optical apparatus. It is explanatory drawing of the other structural example of the same electro-optical apparatus. It is a schematic block diagram of the connection part of the 1st terminal of a conventional connection structure, and a 2nd terminal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electro-optical apparatus (connection structure), 2 ... Electro-optical panel, 3 ... Wiring board, 10 ... 1st board | substrate (2nd transfer destination board | substrate), 15 ... Transfer target layer, 16 ... Interlayer insulation film, 17 ... Protrusion 17A, 17B ... projection, 19 ... first terminal, 31 ... second terminal, 35 ... anisotropic conductive member, 35a ... conductive particle, 40 ... transfer source substrate, 50 ... first transfer destination substrate

Claims (9)

A transfer layer comprising a plurality of first terminals and a protrusion provided between each of the plurality of first terminals;
A transfer destination substrate onto which the transfer layer is transferred;
A wiring board provided with a plurality of second terminals respectively corresponding to the plurality of first terminals;
A connection structure comprising an anisotropic conductive member that electrically connects the plurality of first terminals and the plurality of second terminals, respectively.   The connection structure according to claim 1, wherein the protrusion includes a plurality of protrusions.   The connection structure according to claim 2, wherein the plurality of protrusions are provided along an arrangement axis of the plurality of first terminals.   The connection structure according to claim 2, wherein the plurality of protrusions are provided along an extending direction of the plurality of first terminals.   5. The connection structure according to claim 1, wherein the protrusion has a rectangular or trapezoidal cross section cut along an arrangement axis of the plurality of first terminals. 6. body. The transferred layer includes a plurality of wirings electrically connected to the plurality of first terminals, and an insulating film covering the plurality of wirings,
The connection structure according to claim 1, wherein the protrusion is formed of the same member as the insulating film.   The thickness of the protruding portion is equal to or less than the sum of the thickness of the first terminal, the thickness of the conductive particles contained in the anisotropic conductive member, and the thickness of the second terminal. The connection structure according to the section.   The density of the conductive particles in the facing region where the plurality of first terminals and the plurality of second terminals face each other is between the region between each of the plurality of first terminals and each of the plurality of second terminals. The connection structure according to claim 7, wherein the connection structure has a density greater than that of the conductive particles in the region. Forming a transfer layer including a plurality of first terminals and a protrusion disposed between each of the plurality of first terminals on the transfer source substrate;
Bonding the first transfer destination substrate to the surface of the transfer source substrate on the transfer layer side;
Peeling the transferred layer from the transfer source substrate and transferring the transferred layer onto the first transfer destination substrate;
Bonding a second transfer destination substrate to the surface of the first transfer destination substrate on the transfer layer side;
Peeling the transfer layer from the first transfer destination substrate and transferring the transfer layer onto the second transfer destination substrate;
Connecting a wiring board including a plurality of second terminals respectively corresponding to the plurality of first terminals to the surface on the transfer layer side of the second transfer destination substrate via an anisotropic conductive member. A method for manufacturing a connection structure, characterized by comprising:

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