JP7331420B2 - Composite substrate and manufacturing method thereof - Google Patents

Description

An embodiment of the present disclosure relates to a composite substrate in which a plurality of wiring substrates are tiled and a manufacturing method thereof.

An example of the wiring substrate is a TFT (Thin Film Transistor) substrate. The TFT substrate is incorporated into, for example, a display device or a pressure sensor device.

A plurality of thin film transistors arranged in a matrix are formed on the TFT substrate, and the thin film transistors can be formed by laminating a gate electrode, a source electrode, a drain electrode, a semiconductor layer, and the like by printing or the like. Therefore, it can be said that the TFT substrate has a structure that facilitates a large area. However, in order to manufacture a large-sized TFT substrate, a dedicated manufacturing apparatus also becomes large-sized, resulting in an increase in equipment cost. In consideration of such points, a technique called tiling may be used (for example, Patent Documents 1 and 2).

Tiling is a method of forming a large TFT substrate unit (composite substrate) by, for example, arranging a plurality of TFT substrates in a sheet and electrically connecting adjacent TFT substrates.

In recent years, TFT substrates are sometimes required to be large and flexible. In this case, both the TFT substrates and the connecting portions that connect the TFT substrates are required to be flexible. In addition, flexibility means flexibility and/or stretchability. Techniques for imparting flexibility to the TFT substrate include using a flexible plastic substrate as the substrate of the TFT substrate, and using an organic semiconductor material as the semiconductor layer. As a technique for imparting flexibility to the connection portion, there is a method of configuring the connection portion with a flexible printed circuit board (FPC).

JP 2006-108525 A JP 2006-253564 A

As described above, when adjacent wiring boards are connected by FPC, the flexibility of the boundary portion can be improved, but it is difficult to say that stretchability is sufficiently ensured.

If good stretchability can be ensured for the joints used in the tiling, the durability will be further improved and the fields of application can be expanded. For example, when a tiled TFT substrate is used in a sensor device that precisely detects the movement of the human body, both good flexibility and good stretchability are required to detect complex movements of the human body over a long period of time. It is required to ensure Such a demand cannot be fully met when connecting adjacent wiring boards with an FPC.

An object of the embodiments of the present disclosure is to provide a composite substrate capable of ensuring good stretchability between adjacent wiring substrates that are tiled, and a method of manufacturing the same.

In one embodiment of the present disclosure, a plurality of wiring boards arranged in a sheet form, and a wiring board straddling between the adjacent wiring boards in order to electrically connect the adjacent wiring boards among the plurality of wiring boards. and a plurality of connecting portions provided so as to form a ridge, wherein the wiring substrate has a plurality of connection electrodes arranged on a surface along at least a portion of an outer edge thereof, and one of the adjacent wiring substrates has a plurality of connection electrodes. The connection electrodes of the wiring substrate are close to the corresponding connection electrodes of the other wiring substrate in the direction in which the wiring substrates adjacent to each other are aligned, and the connection portions each have elasticity, and the wiring substrates adjacent to each other are aligned. In the composite substrate, the connection electrodes of one of the wiring substrates adjacent in direction and the connection electrodes of the other wiring substrate are connected in series.

In the composite substrate according to an embodiment of the present disclosure, the connection portion has a linear shape when viewed in a direction orthogonal to both the direction in which the plurality of connection electrodes are arranged and the direction in which the adjacent wiring substrates are arranged. may be

In the composite substrate according to one embodiment of the present disclosure, the connection portion may include a stretchable binder and a plurality of conductive particles contained in the binder.

In the composite substrate according to an embodiment of the present disclosure, a part of the connection portion is a connection electrode of one of the wiring substrates and a connection electrode of the other wiring substrate that are adjacent in a direction in which the adjacent wiring substrates are arranged. may enter between

In the composite substrate according to one embodiment of the present disclosure, the portion of the connecting portion may further enter the space between the adjacent wiring substrates.

In the composite substrate according to an embodiment of the present disclosure, the surface of the connection portion has a recessed portion, and the recessed portion is adjacent to the adjacent wiring substrates in the direction in which the wiring substrates are arranged. It may be recessed toward between the connection electrodes of the other wiring board.

In the composite substrate according to an embodiment of the present disclosure, the wiring substrates adjacent to each other may be in contact with each other, and the surfaces of the connection portions may be flat.

In the composite substrate according to one embodiment of the present disclosure, a spacer insulating portion is provided between the adjacent connection portions, and the spacer insulating portion is located at least in the space between the adjacent wiring substrates. good.

In the composite substrate according to one embodiment of the present disclosure, a space between the adjacent wiring substrates may be filled with a filling insulating portion extending in a direction in which the connection portions are arranged.

A composite substrate according to an embodiment of the present disclosure may be provided with a covering insulating portion that extends along the direction in which the plurality of connection portions are arranged and that covers the plurality of connection portions.

A composite substrate according to an embodiment of the present disclosure may further include a support substrate that supports the plurality of wiring substrates arranged in a sheet.

Further, one embodiment of the present disclosure includes a step of preparing a plurality of wiring substrates having a plurality of connection electrodes arranged on a surface along at least a part of an outer edge; bringing the connection electrodes of one of the adjacent wiring boards closer to the corresponding connection electrodes of the other of the adjacent wiring boards in the direction in which the adjacent wiring boards are aligned; and aligning the adjacent wiring boards. a step of applying a conductive paste material so as to straddle a connection electrode of one of the wiring boards and a connection electrode of the other wiring board that are adjacent in direction; and curing the conductive paste material. and forming a connection portion by using a material that exhibits elasticity at least after curing as the conductive paste material, and the connection portion is one of the adjacent wiring substrates in the direction in which they are arranged. In the method of manufacturing a composite substrate, the connection electrodes of the wiring substrate and the connection electrodes of the other wiring substrate are connected in series.

In the method of manufacturing a composite substrate according to an embodiment of the present disclosure, the conductive paste material may be applied using a dispenser.

In the method for manufacturing a composite substrate according to an embodiment of the present disclosure, the conductive paste material may be linearly applied.

In the method of manufacturing a composite substrate according to an embodiment of the present disclosure, the connection portion may include a stretchable binder and a plurality of conductive particles contained in the binder.

In the method for manufacturing a composite substrate according to an embodiment of the present disclosure, a part of the connection part is a connection electrode of one of the wiring substrates and a connection electrode of the other wiring substrate that are adjacent in a direction in which the adjacent wiring substrates are arranged. The conductive paste material may be applied so as to enter between the connection electrodes.

In the method for manufacturing a composite substrate according to an embodiment of the present disclosure, the conductive paste material is applied such that the part of the connection part further enters the space between the adjacent wiring boards. good too.

In the method for manufacturing a composite substrate according to an embodiment of the present disclosure, the wiring board is directed between the connection electrode of one of the wiring boards and the connection electrode of the other wiring board that are adjacent in the direction in which the adjacent wiring boards are arranged. The conductive paste material may be applied and cured such that a concave portion is formed on the surface of the connection portion.

In the method for manufacturing a composite substrate according to an embodiment of the present disclosure, the adjacent wiring substrates are arranged so as to be in contact with each other, and the conductive paste material is applied so that the surfaces of the connection portions are flat. and may be cured.

In a method for manufacturing a composite substrate according to an embodiment of the present disclosure, spacer insulation is provided at least in a space between the adjacent wiring substrates where the connection electrodes are not located on both sides in the direction in which the adjacent wiring substrates are arranged. The step of providing a portion may be further provided, and the conductive paste material may be intermittently applied to a position not overlapping the spacer insulating portion.

A method for manufacturing a composite substrate according to an embodiment of the present disclosure further includes a step of filling a space between the adjacent wiring substrates with a filling insulating portion, wherein the conductive paste material contains the filling insulating portion may be applied on top.

The method for manufacturing a composite substrate according to an embodiment of the present disclosure may further include the step of providing a covering insulating portion that extends along the direction in which the plurality of connection portions are arranged and covers the plurality of connection portions.

In the method for manufacturing a composite substrate according to an embodiment of the present disclosure, the plurality of wiring substrates may be arranged in a sheet on a support substrate.

According to the embodiments of the present disclosure, good stretchability can be ensured between adjacent wiring boards that are tiled.

It is a figure which shows the composite substrate which concerns on one Embodiment. 2 is an enlarged view of a main part of a wiring board that constitutes the composite board shown in FIG. 1; FIG. FIG. 2 is a cross-sectional view of the composite substrate shown in FIG. 1; 2 is an enlarged view of area IV shown in FIG. 1; FIG. FIG. 5 is a cross-sectional view taken along line VV of FIG. 4; It is a figure explaining the manufacturing method of the composite substrate shown in FIG. It is a figure explaining the manufacturing method of the composite substrate shown in FIG. It is a figure explaining the manufacturing method of the composite substrate shown in FIG. It is a figure explaining the manufacturing method of the composite substrate shown in FIG. It is a figure explaining the manufacturing method of the composite substrate shown in FIG. FIG. 4 is a cross-sectional view of a composite substrate according to another embodiment; FIG. 4 is a cross-sectional view of a composite substrate according to another embodiment; FIG. 9 is a view of the composite substrate shown in FIG. 8 as viewed in the direction of arrow IX in FIG. 8; FIG. 4 is a cross-sectional view of a composite substrate according to another embodiment;

Hereinafter, a configuration of a composite substrate and a manufacturing method thereof according to embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments shown below are examples of the embodiments of the present disclosure, and the present disclosure should not be construed as being limited to these embodiments. Also, in this specification, terms such as "substrate", "base material", "sheet" and "film" are not to be distinguished from each other based only on the difference in designation. For example, "base material" is a concept that includes members that can be called substrates, sheets, and films. Furthermore, terms used herein to specify shapes and geometrical conditions as well as degrees thereof, such as terms such as "parallel" and "perpendicular," length and angle values, etc., are bound by strict meanings. However, it is interpreted to include the extent to which similar functions can be expected. In addition, in the drawings referred to in this embodiment, the same reference numerals or similar reference numerals may be assigned to the same portions or portions having similar functions, and repeated description thereof may be omitted. Also, the dimensional ratios in the drawings may differ from the actual ratios for convenience of explanation, and some of the configurations may be omitted from the drawings.

An embodiment of the present disclosure will be described below.

(Composite substrate)
First, the composite substrate 1 according to this embodiment will be described. A composite substrate 1 shown in FIG. 1 includes a support substrate 2 , a plurality of wiring substrates 10 arranged in a sheet on the support substrate 2 , and a plurality of connection portions 20 . The composite substrate 1 is obtained by tiling a plurality of wiring substrates 10, and the plurality of connecting portions 20 are arranged between the adjacent wiring substrates 10 in order to electrically connect the adjacent wiring substrates 10 among the plurality of wiring substrates 10. It is provided so as to straddle between 10.

Spacer insulating portions 30 are provided between adjacent connection portions 20 among the plurality of connection portions 20 . Further, on the plurality of connection portions 20 and the plurality of spacer insulation portions 30, a covering insulation portion 40 extending in the direction in which the plurality of connection portions 20 are linearly arranged is provided. In FIG. 1, the covering insulating portion 40 is indicated by a chain double-dashed line for convenience of explanation.

As an example, the composite substrate 1 is configured as a pressure sensor device having flexibility, and is used by being incorporated in a device such as a bed or a vehicle seat that receives the load of the human body. However, the present disclosure is not limited to the composite substrate 1 configured as a pressure sensor device, and may be configured to be incorporated in a large display device. Each component of the composite substrate 1 will be described below.

[Supporting substrate]
The support substrate 2 is a sheet-like member, and in this example, its main surface is formed in a rectangular shape, but the shape is not particularly limited. It is preferable that the support substrate 2 is a member having flexibility, particularly flexibility, and as the material constituting the support substrate 2, for example, polyethylene naphthalate, polyimide, polyethylene terephthalate, polycarbonate, acrylic resin, etc. can be used. can. Among them, polyethylene naphthalate or polyimide having good durability and heat resistance can be preferably used.

The thickness of the support substrate 2 may be, for example, 10 μm or more and 100 μm or less, but the dimensions are not particularly limited.

[Wiring board]
The wiring substrate 10 is a sensor substrate having a plurality of TFTs (Thin Film Transistors) arranged in a matrix in this embodiment. FIG. 2 is a diagram schematically showing the transistor 12T formed on the wiring board 10, and FIG. 3 is a cross-sectional view of the wiring board 10. As shown in FIG.

The wiring board 10 includes a sheet-like base material 11 and a transistor layer 12 having a plurality of transistors 12T arranged in a matrix on the base material 11 along a first direction D1 and a second direction D2 intersecting the first direction. a plurality of first electrodes 13 provided on the transistor layer 12 in a matrix corresponding to the arrangement of the transistors 12T and electrically connected to each of the transistors 12T; a pressure sensitive element 14, a sheet-like second electrode 15 provided so as to cover the plurality of pressure sensitive elements 14, a counter substrate 16 supporting the second electrode 15 on the side opposite to the pressure sensitive element 14 side, have. In this example, the first direction D1 and the second direction D2 indicate the directions in which the transistors are arranged, and the first direction D1 and the second direction D2 are orthogonal to each other.

The total thickness of the base material 11 and the transistor layer 12 may be, for example, 0.1 μm or more and 100 μm or less. The thickness of the pressure sensitive body 14 may be, for example, 10 μm or more and 100 μm or less. The total thickness of the second electrode 15 and the counter substrate 16 may be, for example, 10 μm or more and 100 μm or less. However, these dimensions are not particularly limited and can be changed as appropriate depending on the application.

The base material 11 is a sheet-like member and has a rectangular main surface in this example, but the shape is not particularly limited. The base material 11 is preferably a member having flexibility, particularly flexibility, and examples of the material forming the base material 11 include plastic films having flexibility and thermosetting properties.

Here, the adhesive layer 50 is positioned between the base material 11 and the support substrate 2 , and the wiring board 10 is attached to the support substrate 2 by fixing the base material 11 to the support substrate 2 with the adhesive layer 50 . Fixed. The adhesive layer 50 is made of, for example, a thermosetting adhesive, but the constituent material of the adhesive layer 50 may be any material as long as it does not significantly deform when heated during formation of the composite substrate 1 . Also, the thickness of the adhesive layer 50 may be, for example, 1 μm or more and 50 μm or less, but is not particularly limited. However, the thickness of the adhesive layer 50 is desirably as thin as possible so as not to impair the flexibility of the wiring board 10 .

As shown in FIGS. 2 and 3, the transistor layer 12 includes a gate terminal 100 and a first wiring line 111 provided on the substrate 11, and a gate insulating layer 112 provided on the gate terminal 100 and the first wiring line 111. and a first terminal 101 and a second terminal 102 provided adjacent to each other on the gate insulating layer 112 and facing the gate terminal 100 with the gate insulating layer 112 interposed therebetween; a second wiring line 121 provided on the gate insulating layer 112, a semiconductor layer 103 provided between the first terminal 101 and the second terminal 102 and in contact with the first terminal 101 and the second terminal 102, respectively; An upper insulating layer 122 provided on the first terminal 101, the second terminal 102, the semiconductor layer 103, and the second wiring line 121; and a plurality of connection electrodes 130 arranged along the rectangular outer edge of the wiring board 10 formed by the base material 11 . The transistor 12T is composed of a gate terminal 100, a first terminal 101, a second terminal 102 and a semiconductor layer 103. FIG.

As materials for forming the gate terminal 100, the first terminal 101, the second terminal 102, the gate insulating layer 112, and the upper insulating layer 122, known materials used in transistors are used. For example, materials disclosed in JP-A-2010-79196 can be used.

As a material constituting the semiconductor layer 103, either an inorganic semiconductor material or an organic semiconductor material may be used, but an organic semiconductor material is preferably used. Organic semiconductor materials can generally be formed at lower temperatures than inorganic semiconductor materials. Therefore, a flexible material such as plastic can be used as a material for forming the base material 11 that supports the transistor 12T. This makes it possible to provide a lightweight transistor sheet that has stability against mechanical impact. In addition, since the organic semiconductor material can be formed on the base material 11 using a coating process such as a printing method, a large number of organic transistors can be efficiently formed on the base material 11 as compared with the case where an inorganic semiconductor material is used. It becomes possible to form Therefore, there is a possibility that the manufacturing cost of the transistor sheet can be reduced.

As the organic semiconductor material, a low-molecular-weight organic semiconductor material such as pentacene or a high-molecular-weight organic semiconductor material such as polypyrroles can be used. More specifically, low-molecular-weight organic semiconductor materials and high-molecular-weight organic semiconductor materials disclosed in JP-A-2013-21190 can be used. Here, "low-molecular-weight organic semiconductor material" means, for example, an organic semiconductor material having a molecular weight of less than 10,000. The term "polymeric organic semiconductor material" means, for example, an organic semiconductor material having a molecular weight of 10,000 or more.

The first wiring line 111 extends parallel to the first direction D1 as shown in FIG. It is connected to the. Also, the first wiring line 111 is connected at both ends thereof to one of the plurality of connection electrodes 130 arranged in the second direction D2.

Further, in this embodiment, the first terminal 101 functions as a drain terminal and is electrically connected to the first electrode 13 . On the other hand, the second terminal 102 functions as a source terminal. Here, as shown in FIG. 2, the second wiring line 121 extends parallel to the second direction D2, and the plurality of second terminals 102 arranged in the second direction D2 are adjacent to each other in the first direction D1. 2 is connected to the wiring line 121 . Both ends of the second wiring line 121 are connected to one of the plurality of connection electrodes 130 arranged in the first direction D1.

The pressure-sensitive bodies 14 are arranged in a matrix corresponding to the first electrodes 13. In this embodiment, the pressure-sensitive bodies 14 are formed in a dome shape. , forming a circle. The pressure sensing element 14 is electrically connected to the first electrode 13 and electrically connected to the second electrode 15 .

The pressure sensitive body 14 is a member whose electrical resistance or capacitance changes according to the pressure applied to the pressure sensitive body 14 . The pressure-sensitive body 14 is, for example, a so-called pressure-sensitive conductor configured to change electrical resistance in accordance with pressure applied to the pressure-sensitive body. The pressure-sensitive conductor includes, for example, rubber such as silicone rubber, and a plurality of conductive particles such as carbon added to the rubber. When pressure is applied to the pressure sensing element 14, the electrical resistance of the pressure sensing element 14 decreases. As a result, the value of the current that flows between the first electrode 13 and the second electrode 15 via the pressure sensing element 14 changes, making it possible to measure the value of the pressure applied to the pressure sensing element 14. becomes.

The second electrode 15 has a rectangular sheet shape and is configured as a common electrode for the first electrode 13 . The second electrode 15 preferably has flexibility, and may be formed by vacuum deposition of copper, aluminum, titanium, silver, or the like, or may be formed from a conductive paste material, for example.
The conductive particles contained in the conductive paste material may contain at least one of metal and carbon. The metal contained in the conductive particles may include at least one of nickel, gold, silver, copper or aluminum. As the carbon contained in the conductive particles, for example, graphite, carbon black, or other substances composed of carbon and having conductivity can be used. Also, the conductive particles may contain plating powder. The plated powder is a particle obtained by forming a metal layer on the surface of the base powder by electroless plating or the like. Nickel, gold, silver, copper, aluminum, or the like can be used as the metal contained in the metal layer of the plating powder. On the other hand, the binder contained in the conductive paste material may contain thermoplastic resin and thermosetting resin.

The opposing substrate 16 has a rectangular sheet shape and supports the second electrode 15 . The counter substrate 16 also preferably has flexibility, and for example, polyethylene naphthalate, polyimide, polyethylene terephthalate, polycarbonate, acrylic resin, or the like can be used. Among them, polyethylene naphthalate or polyimide having good durability and heat resistance can be preferably used.

Moreover, in this embodiment, a spacer 60 is provided between the upper insulating layer 122 and the second electrode 15 . The spacer 60 has a thickness equivalent to that of the pressure sensitive body 14, and is interposed between the upper insulating layer 122 and the second electrode 15, thereby suppressing contact between the upper insulating layer 122 and the second electrode 15. .

A plurality of wiring boards 10 configured as described above, four in this example, are provided on the support board 2 and arranged in a sheet form so as to be adjacent to each other. Here, as shown in FIGS. 1 and 3, the connection electrodes 130 of one wiring board 10 of the adjacent wiring boards 10 are aligned in the direction in which the adjacent wiring boards 10 are arranged (first direction D1 or second direction D2). ) to approach the corresponding connection electrode 130 of the other wiring substrate 10 . In the present embodiment, “corresponding connection electrode” means another connection electrode 130 that is scheduled to be electrically connected to a certain connection electrode 130 . Also, in the present embodiment, the adjacent wiring boards 10 are adjacent to each other with a space therebetween, but such a space may not be present. When such a space is formed, the dimension of the space is preferably equal to or greater than the width of the pressure sensitive body 14, preferably 10 μm or more and 100 μm or less.

[Connection part]
The connection part 20 is provided so as to straddle the two adjacent connection electrodes 130 of the wiring substrates 10 different from each other as described above, thereby electrically connecting these connection electrodes 130 .

The connecting portion 20 has stretchability and conductivity. As shown in FIGS. 1 and 3, the connection portion 20 connects the connection electrode 130 of one wiring substrate 10 and the connection electrode 130 of the other wiring substrate 10 that are adjacent in the direction in which the adjacent wiring substrates 10 are arranged. connected to. Here, "connected in series" means that the connection portion 20 is not composed of a plurality of members, but that the connection electrodes 130 are connected in the form of an integral body. An integrated body means that it does not include a plurality of conductive parts such as an adhesive conductive part and a film-like conductive part connected thereto. In the present embodiment, as an example, the connecting portion 20 is formed by applying a conductive paste material with a dispenser and curing it, thereby forming an integral form.

When viewed in the direction normal to the main surface of the wiring board 10 as shown in FIG. is linear when viewed in a direction orthogonal to both The linear connecting portion 20 preferably has a line width of 10 μm or more and 1000 μm or less, and a length of 20 μm or more and 2000 μm or less.

The connection part 20 is not particularly limited as long as it has stretchability and conductivity, but in this embodiment, it contains a stretchable binder and a plurality of conductive particles contained in this binder. is used. More specifically, the connecting portion 20 includes a stretchable binder and a plurality of conductive particles contained in the binder, and is formed of a conductive paste material that develops stretchability at least after curing. .

The conductive particles contained in the conductive paste material may contain at least one of metal and carbon. The metal contained in the conductive particles may include at least one of nickel, gold, silver, copper or aluminum. As the carbon contained in the conductive particles, for example, graphite, carbon black, or other substances composed of carbon and having conductivity can be used. Also, the conductive particles may contain plating powder. The plated powder is a particle obtained by forming a metal layer on the surface of the base powder by electroless plating or the like. Nickel, gold, silver, copper, aluminum, or the like can be used as the metal contained in the metal layer of the plating powder. On the other hand, the binder contained in the conductive paste material may contain thermoplastic resin and thermosetting resin.

In this embodiment, stretchable silver paste is used as the conductive paste material, but the conductive paste material can be of various compositions as described above.

Since the connection part 20 has elasticity, it imparts elasticity and flexibility to the portion between the interconnected wiring boards 10 . Here, as shown in FIG. 3, in the connection portion 20 in the present embodiment, a portion 20A thereof includes the connection electrode 130 of one wiring substrate 10 and the wiring of the other wiring substrate 10 adjacent in the direction in which the adjacent wiring substrates 10 are arranged. It enters the space between the connection electrodes 130 of the substrate 10 and further between the wiring substrates 10 . Further, the surface of the connection portion 20 has a recessed portion 20B, and the recessed portion 20B is recessed between the connection electrode 130 of one wiring substrate 10 and the connection electrode 130 of the other wiring substrate 10. .

In this embodiment, the connection portion 20 is formed of a conductive paste material applied by a dispenser, and the connection electrode 130 of one wiring substrate 10 and the connection electrode 130 of the other wiring substrate 10 to which the connection portion 20 is connected are connected. The portion between the connection electrodes 130 is in a recessed state, and as a result of this, the conductive paste material is applied so as to be partially recessed, so that the portion 20A of the connection portion 20 becomes the connection electrode. Enter between 130. Further, a space is formed between the adjacent wiring boards 10, and as a result of applying the conductive paste material so as to enter the space, the part 20A of the connection portion 20 enters the space. In addition, as a result of applying the conductive paste material so as to be partially recessed, a recessed portion 20B is formed on the surface of the connection portion 20 .

The portion 20A of the connection portion 20 formed as described above couples the wiring substrates 10 so as to fill the gap between the adjacent wiring substrates 10, so that the bonding strength between the wiring substrates 10 can be improved. In addition, the above-described recessed portion 20B provides good flexibility between adjacent wiring boards 10 by notching a portion of the connection portion 20 .

The stretchability of the connection part 20 means the property that the connection part 20 can expand and contract, that is, it can be stretched from a normal non-stretched state, and can be restored when released from this stretched state. It refers to the nature of being able to The non-stretched state is the state of the joint 20 when no tensile stress is applied. In this embodiment, the stretchable connection 20 is preferably capable of stretching 1% or more, more preferably 20% or more, and even more preferably 75% from its unstretched state without breaking. % or more.

Moreover, it is preferable that the difference between the shape of the connecting portion 20 in the non-stretched state and the shape of the connecting portion 20 when it returns to the non-stretched state after being stretched from the non-stretched state is small. This difference is also referred to as shape change in the following description. The shape change of the connecting portion 20 is, for example, 20% or less, more preferably 10% or less, and still more preferably 5% or less in terms of area ratio.

An elastic modulus of the connection portion 20 can be given as an example of a parameter representing the stretchability of the connection portion 20 . The elastic modulus of the connecting portion 20 is, for example, 10 MPa or less, more preferably 1 MPa or less. Also, the elastic modulus of the connecting portion 20 may be 1 kPa or more.

As a method for calculating the elastic modulus of the connecting portion 20, a method of performing a tensile test in accordance with JIS K6251 using a sample of the connecting portion 20 can be adopted. A method of measuring the elastic modulus of a sample of the connecting portion 20 by a nanoindentation method in compliance with ISO14577 can also be adopted. A nanoindenter can be used as a measuring instrument used in the nanoindentation method. As a method of preparing a sample of the connection portion 20, a method of taking out a part of the connection portion 20 as a sample is conceivable. In addition, as a method of calculating the elastic modulus of the connecting portion 20, adopting a method of analyzing the material forming the connecting portion 20 and calculating the elastic modulus of the connecting portion 20 based on an existing material database. can also In addition, the elastic modulus in this application is an elastic modulus in a 25 degreeC environment.

[Spacer insulating part]
Next, the spacer insulating portion 30 will be explained. FIG. 4 is an enlarged view of area IV shown in FIG. FIG. 5 is a cross-sectional view along line VV of FIG.

As shown in FIG. 4 , spacer insulating portions 30 are provided between adjacent connecting portions 20 . In this example, the spacer insulating part 30 is positioned at least in the space between the adjacent wiring boards 10 and has a function of suppressing a short circuit between the connection parts 20 positioned on both sides thereof. When the connecting portion 20 is formed of a conductive paste material as in the present embodiment, there is a risk that when the conductive paste material is applied, it may enter between the adjacent wiring boards 10 and expand in the longitudinal direction of the space. There is At this time, in the present embodiment, the spacer insulating portion 30 suppresses the flow of the conductive paste material, thereby suppressing the mixing of the adjacent conductive paste materials, and as a result, suppressing the short circuit of the connection portion 20. will be

In this embodiment, the spacer insulating part 30 is located in the space between the adjacent wiring substrates 10 and also located on the surface of the upper insulating layer 122 of the adjacent wiring substrate 10 . In this case, short-circuiting between the connecting portions 20 can be suppressed even on the upper insulating layer 122, which is useful. However, even if the spacer insulating portion 30 is positioned in the space between the adjacent wiring substrates 10, the short circuit of the connection portion 20 can be effectively suppressed.

The spacer insulating portion 30 can be formed by using a dispenser like the connecting portion 20, but the forming method is not particularly limited. When using a dispenser, a paste material having insulating properties is applied from a dispenser to a portion of the space between the adjacent wiring substrates 10 where the connection electrodes 130 are not located on both sides in the direction in which the adjacent wiring substrates 10 are arranged. , the spacer insulation 30 can be formed by curing. Although the material forming the spacer insulating portion 30 is not particularly limited, it is desirable that the material has flexibility and stretchability. As a material for forming the spacer insulating portion 30, for example, general thermoplastic elastomers and thermosetting elastomers can be used. , urethane rubber, fluororubber, nitrile rubber, polybutadiene, and polychloroprene. In addition, acrylic-, urethane-, epoxy-, polyester-, epoxy-, vinyl-ether-, polyene-thiol-, and silicone-based fluorine-based oligomers and polymers can also be used.

[Coating insulation part]
Next, the covering insulating portion 40 will be described. As described above, the covering insulating portion 40 extends in the direction (the first direction D1 and the second direction D2) in which the plurality of connecting portions 20 provided between the adjacent wiring boards 10 are arranged. The covering insulating portion 40 protects the connection portions 20 by covering the plurality of connection portions 20 . As shown in FIG. 3, the covering insulating portion 40 is formed so as not to protrude from the opposing substrate 16 in the out-of-plane direction. is suppressed, and a decrease in accuracy of pressure detection is suppressed.

The insulating covering portion 40 can be formed by using a dispenser in the same manner as the connecting portion 20, but the forming method is not particularly limited. When using a dispenser, the covering insulating portion 40 can be formed by applying an insulating paste material from the dispenser and then curing the paste material. Although the material forming the covering insulating portion 40 is not particularly limited, it is desirable that the material has flexibility and stretchability. As a material forming the material forming the covering insulating portion 40, for example, general thermoplastic elastomers and thermosetting elastomers can be used. Elastomers, silicone rubbers, urethane rubbers, fluororubbers, nitrile rubbers, polybutadiene, and polychloroprene. In addition, acrylic-, urethane-, epoxy-, polyester-, epoxy-, vinyl-ether-, polyene-thiol-, and silicone-based fluorine-based oligomers and polymers can also be used.

(Manufacturing method of composite substrate)
Next, an example of a method for manufacturing the composite substrate 1 will be described with reference to FIGS. 6A to 6E.

First, a plurality of wiring substrates 10 and a support substrate 2 are prepared. After that, an adhesive layer 50 is formed on the support substrate 2 by applying, for example, an adhesive agent, and then, as indicated by the arrow α in FIG. They are arranged in a sheet on the support substrate 2 . Thereby, the plurality of wiring boards 10 are fixed to the support substrate 2 via the adhesive layer 50 . At this time, the adjacent wiring boards 10 are arranged so that the connection electrodes 130 of one wiring board 10 are close to the corresponding connection electrodes of the other wiring board 10 in the direction in which they are arranged (FIG. 6B).

Next, as shown in FIG. 6C, spacer insulating portions 30 are provided in the spaces between the adjacent wiring substrates 10 at portions where the connection electrodes 130 are not located on both sides in the direction in which the adjacent wiring substrates 10 are arranged. That is, the spacer insulating portions 30 are intermittently provided along the outer edges of the wiring substrates 10 that define the spaces between the adjacent wiring substrates 10 .

In this example, the spacer insulating portion 30 is formed by applying an insulating paste material with a dispenser 201 and then curing it. At this time, the dispenser 201 applies the paste material as it moves straight in the direction in which the adjacent wiring substrates 10 are aligned, and intermittently repeats this operation along the outer edge of the wiring substrate 10, thereby insulating the plurality of spacers. It is adapted to form a section 30 .

Next, as shown in FIG. 6D, the conductive paste is applied so as to straddle the connection electrodes 130 of one wiring substrate 10 and the connection electrodes 130 of the other wiring substrate 10 that are adjacent in the direction in which the adjacent wiring substrates 10 are arranged. A material 20P is applied. Then, the connecting portion 20 is formed by curing the conductive paste material 20P.

In this example, a conductive paste material 20P is applied by a dispenser 202, as shown in FIG. 6D. The conductive paste material 20P is intermittently applied to a position that does not overlap with the insulating spacer portion 30, and is sequentially provided between the set of the connection electrode 130 of one wiring board 10 and the connection electrode 130 of the other wiring board 10. . At this time, the dispenser 202 also applies the conductive paste material 20P along with the linear movement in the direction in which the adjacent wiring boards 10 are arranged, and intermittently repeats this movement along the outer edge of the wiring board 10, so that a plurality of A conductive paste material 20P, that is, a connecting portion 20 is formed. Further, as a result, the conductive paste material 20P is applied in a linear shape when viewed in a direction orthogonal to both the direction in which the plurality of connection electrodes 130 are arranged and the direction in which the adjacent wiring substrates 10 are arranged. is also formed linearly.

In this example, the part 20A of the connection part 20 is located between the connection electrode 130 of one wiring board 10 and the connection electrode 130 of the other wiring board 10, which are adjacent in the direction in which the adjacent wiring boards 10 are arranged. A conductive paste material 20P is applied so as to enter the space between adjacent wiring boards 10 . In addition, a recessed portion 20B directed between the connection electrode 130 of one wiring substrate 10 and the connection electrode 130 of the other wiring substrate 10, which are adjacent in the direction in which the adjacent wiring substrates 10 are arranged, is formed on the surface of the connection portion 20. The conductive paste material 20P is applied and cured as shown in FIG.

Next, as shown in FIG. 6E , a covering insulating portion 40 that extends along the direction in which the plurality of connecting portions 20 are arranged linearly and covers the plurality of connecting portions 20 is provided. In this example, the covering insulating portion 40 is formed by applying an insulating paste material with a dispenser 203 and then curing the paste material.

In the composite substrate 1 according to the present embodiment described above, the connection electrodes 130 of one wiring substrate 10 and the connection electrodes 130 of the other wiring substrate 10 are adjacent to each other in the direction in which the adjacent wiring substrates 10 are arranged. 10 corresponding connection electrodes 130 are connected in series. Thereby, good stretchability can be ensured between adjacent wiring boards 10 that are tiled. In this case, when the composite substrate 1 is bent from between the adjacent wiring substrates 10, the connection portions 20 can be stretched. Therefore, the durability of the composite substrate 1 can be improved.

Moreover, the connecting portion 20 has a linear shape when viewed in a direction orthogonal to both the direction in which the plurality of connection electrodes 130 are arranged and the direction in which the adjacent wiring substrates 10 are arranged. Thereby, even when the density of a pair of adjacent connection electrodes 130 is high, the connection electrodes 130 can be electrically connected easily.

In addition, the part 20A of the connection part 20 enters between the connection electrode 130 of one wiring board 10 and the connection electrode 130 of the other wiring board 10 that are adjacent in the direction in which the adjacent wiring boards 10 are arranged. there is Accordingly, since the connecting portion 20 connects the wiring substrates 10 so as to fill the gap between the adjacent wiring substrates 10, the bonding strength between the wiring substrates 10 can be improved. In addition, in the above-described embodiment, the portion 20A of the connection portion 20 further enters the space between the adjacent wiring boards 10, so that the bonding strength between the wiring boards 10 can be effectively improved.

In addition, the surface of the connection portion 20 has a recessed portion 20B, and the recessed portion 20B is formed by connecting the connection electrodes 130 of one wiring substrate 10 and the connection electrodes 130 of the other wiring substrate 10 adjacent to each other in the direction in which the adjacent wiring substrates are arranged. And it's concave towards the middle. In this case, by notching a part of the connecting portion 20 with the recessed portion 20B, good flexibility can be imparted between the adjacent wiring substrates 10 .

A spacer insulating portion 30 is provided between the adjacent connecting portions 20 , and the spacer insulating portion 30 is positioned at least in the space between the adjacent wiring boards 10 . In this case, it is possible to suppress short-circuiting of adjacent connection portions 20 and improve reliability.

(Other embodiments)
Other embodiments will be described below.

In the composite substrate according to another embodiment shown in FIG. 7, a sheet-like pressure-sensitive body covering the plurality of first electrodes 13 is provided between the first electrodes 13 on the transistor layer 12 of the wiring substrate 10 and the opposing substrate 16. 14S is provided. The connecting portion 20 can also be applied to such a wiring board 10 .

8 is a cross-sectional view of a composite substrate according to still another embodiment, and FIG. 9 is a view of the composite substrate shown in FIG. 8 as viewed in the direction of arrow IX in FIG. In the embodiment shown in FIGS. 8 and 9, the space between the adjacent wiring boards 10 is filled with a filling insulating portion 70 extending in the direction in which the connecting portions 130 are arranged. In this case, the connecting portion 20 is formed by curing the conductive paste applied on the filling insulating portion 70 . With such a configuration, it is possible to effectively suppress the short circuit of the connection portion 20 in the space between the adjacent wiring boards 10 . Note that the filling insulating portion 70 may be formed by applying an insulating paste material to the space between the adjacent wiring boards 10 using a dispenser and then curing the paste material.

Also, FIG. 10 is a cross-sectional view of a composite substrate according to still another embodiment. In the embodiment shown in FIG. 10, adjacent wiring boards 10 are in contact with each other. In this case, the connection part 20 formed by applying the conductive paste material and then curing it does not enter between the adjacent wiring boards 10, or even if it does enter, the board thickness of the entering part The dimensions are less than 50 μm. Moreover, the surface of the connecting portion 20 is flat, and the concave portion 20B as shown in FIG. 3 is not formed.

Although a plurality of embodiments of the present disclosure have been described above, various modifications may be made to each embodiment.

Reference Signs List 1 Composite substrate 2 Supporting substrate 10 Wiring substrate 11 Base material 12 Transistor layer 12T Transistor 13 First electrodes 14, 14S Pressure-sensitive element 15 Second electrode 16 Counter substrate 20 Connecting portion 20A Part 20B... Recessed part 20P... Conductive paste material 30... Spacer insulating part 40... Coating insulating part 50... Adhesive layer 60... Spacer 70... Filling insulating part 100... Gate terminal 101... First terminal 102... Second terminal 103 Semiconductor layer 111 First wiring line 112 Gate insulating layer 121 Second wiring line 122 Upper insulating layer 130 Connection electrodes 201, 202, 203 Dispenser D1 First direction D2 Second direction

Claims (23)

a plurality of wiring boards arranged in a sheet;
a plurality of connecting portions provided to straddle between the adjacent wiring substrates in order to electrically connect the adjacent wiring substrates among the plurality of wiring substrates;
The wiring board has a plurality of connection electrodes arranged on the inner surface of the outer edge along at least a part of the outer edge of the wiring board when viewed in the direction normal to the main surface of the wiring board ,
a connection electrode of one of the adjacent wiring boards is close to a corresponding connection electrode of the other wiring board in a direction in which the adjacent wiring boards are arranged;
Each of the connection portions has elasticity, and connects the connection electrode of one of the wiring substrates and the connection electrode of the other wiring substrate, which are adjacent in the direction in which the adjacent wiring substrates are arranged, in series ,
A part of the connection portion extends from the surface in the normal direction of each of the connection electrode of one of the wiring substrates and the connection electrode of the other wiring substrate that are adjacent in the direction in which the adjacent wiring substrates are arranged. A composite substrate that is inserted between a connection electrode of one of the wiring substrates and a connection electrode of the other wiring substrate in a direction perpendicular to the direction. 2. The composite substrate according to claim 1, wherein said connection portion has a linear shape when viewed in a direction orthogonal to both the direction in which said plurality of connection electrodes are arranged and the direction in which said adjacent wiring substrates are arranged. 3. The composite substrate according to claim 1, wherein said connecting portion includes a stretchable binder and a plurality of conductive particles contained in said binder. 2. The composite substrate according to claim 1 , wherein said part of said connecting portion further enters a space between said adjacent wiring substrates. 5. The composite substrate according to claim 1, wherein said part of said connecting portion joins said adjacent wiring substrates so as to fill a space between said adjacent wiring substrates. a plurality of wiring boards arranged in a sheet;
a plurality of connecting portions provided to straddle between the adjacent wiring substrates in order to electrically connect the adjacent wiring substrates among the plurality of wiring substrates;
The wiring board has a plurality of connection electrodes arranged on the surface along at least part of the outer edge,
a connection electrode of one of the adjacent wiring boards is close to a corresponding connection electrode of the other wiring board in a direction in which the adjacent wiring boards are arranged;
Each of the connection portions has elasticity, and connects the connection electrode of one of the wiring substrates and the connection electrode of the other wiring substrate, which are adjacent in the direction in which the adjacent wiring substrates are arranged, in series,
The surface of the connecting portion has a recessed portion,
The composite substrate, wherein the recessed portion is recessed between the connection electrode of one of the wiring substrates and the connection electrode of the other wiring substrate that are adjacent in the direction in which the adjacent wiring substrates are arranged. a plurality of wiring boards arranged in a sheet;
a plurality of connecting portions provided to straddle between the adjacent wiring substrates in order to electrically connect the adjacent wiring substrates among the plurality of wiring substrates;
The wiring board has a plurality of connection electrodes arranged on the surface along at least part of the outer edge,
a connection electrode of one of the adjacent wiring boards is close to a corresponding connection electrode of the other wiring board in a direction in which the adjacent wiring boards are arranged;
Each of the connection portions has elasticity, and connects the connection electrode of one of the wiring substrates and the connection electrode of the other wiring substrate, which are adjacent in the direction in which the adjacent wiring substrates are arranged, in series,
The adjacent wiring boards are in contact with each other,
The composite substrate, wherein the surface of the connecting portion is flat. a plurality of wiring boards arranged in a sheet;
a plurality of connecting portions provided to straddle between the adjacent wiring substrates in order to electrically connect the adjacent wiring substrates among the plurality of wiring substrates;
The wiring board has a plurality of connection electrodes arranged on the surface along at least part of the outer edge,
a connection electrode of one of the adjacent wiring boards is close to a corresponding connection electrode of the other wiring board in a direction in which the adjacent wiring boards are arranged;
Each of the connection portions has elasticity, and connects the connection electrode of one of the wiring substrates and the connection electrode of the other wiring substrate, which are adjacent in the direction in which the adjacent wiring substrates are arranged, in series,
A spacer insulating portion is provided between the adjacent connection portions,
the spacer insulating portion is positioned at least in a space between the adjacent wiring substrates,
A composite substrate, wherein a plurality of said spacer insulating parts are provided intermittently along a space between said adjacent wiring substrates . 4. The composite substrate according to claim 1, wherein a space between said adjacent wiring substrates is filled with a filling insulating portion extending in a direction in which said connection portions are arranged. 10. The composite substrate according to any one of claims 1 to 9, further comprising a covering insulating portion extending along the direction in which the plurality of connection portions are arranged and covering the plurality of connection portions. 11. The composite substrate according to any one of claims 1 to 10, further comprising a support substrate that supports said plurality of wiring substrates arranged in a sheet. A wiring board having a plurality of connection electrodes arranged on an inner surface of the outer edge along at least a part of the outer edge of the wiring board when viewed in a direction normal to the main surface of the wiring board. a step of preparing a plurality of substrates;
The plurality of wiring boards are arranged in a sheet form, and in the direction in which the adjacent wiring boards are arranged, the connection electrodes of one of the adjacent wiring boards are connected to the corresponding connection electrodes of the other wiring board. and
a step of applying a conductive paste material so as to straddle a connection electrode of one of the wiring substrates and a connection electrode of the other wiring substrate that are adjacent in the direction in which the adjacent wiring substrates are arranged;
forming a connecting portion by curing the conductive paste material;
As the conductive paste material, using a material that exhibits stretchability at least after curing,
The connection portion connects in series the connection electrode of one of the wiring substrates adjacent in the direction in which the adjacent wiring substrates are arranged, and the connection electrode of the other wiring substrate. from the surfaces of the connection electrodes of one of the wiring boards and the connection electrodes of the other wiring board in the normal direction, the connection electrodes of the one wiring board and the connection electrodes of the other wiring board in the direction orthogonal to the normal direction. and the connection electrodes of the wiring substrate of the above . 13. The method of manufacturing a composite substrate according to claim 12, wherein said conductive paste material is applied by a dispenser. 14. The method of manufacturing a composite substrate according to claim 12, wherein said conductive paste material is applied linearly. 15. The method of manufacturing a composite substrate according to claim 12, wherein said connecting portion includes a stretchable binder and a plurality of conductive particles contained in said binder. The conductive paste is arranged such that a part of the connection portion enters between the connection electrode of one of the wiring substrates and the connection electrode of the other wiring substrate that are adjacent in the direction in which the adjacent wiring substrates are arranged. 16. The method for manufacturing a composite substrate according to any one of claims 12 to 15, wherein the material is applied. 17. The method of manufacturing a composite substrate according to claim 16, wherein said conductive paste material is applied such that said part of said connecting portion further enters a space between said adjacent wiring substrates. preparing a plurality of wiring substrates having a plurality of connection electrodes arranged on the surface along at least a portion of the outer edge;
The plurality of wiring boards are arranged in a sheet form, and in the direction in which the adjacent wiring boards are arranged, the connection electrodes of one of the adjacent wiring boards are connected to the corresponding connection electrodes of the other wiring board. and
a step of applying a conductive paste material so as to straddle a connection electrode of one of the wiring substrates and a connection electrode of the other wiring substrate that are adjacent in the direction in which the adjacent wiring substrates are arranged;
forming a connecting portion by curing the conductive paste material;
As the conductive paste material, using a material that exhibits stretchability at least after curing,
so that a concave portion directed between the connection electrode of one of the wiring substrates and the connection electrode of the other wiring substrate, which are adjacent in the direction in which the adjacent wiring substrates are arranged, is formed on the surface of the connection portion; applying and curing the conductive paste material ;
The connection portion is formed so as to connect the connection electrode of one of the wiring substrates and the connection electrode of the other wiring substrate, which are adjacent in the direction in which the adjacent wiring substrates are arranged, in series.
A method for manufacturing a composite substrate. preparing a plurality of wiring substrates having a plurality of connection electrodes arranged on the surface along at least a portion of the outer edge;
The plurality of wiring boards are arranged in a sheet form, and in the direction in which the adjacent wiring boards are arranged, the connection electrodes of one of the adjacent wiring boards are connected to the corresponding connection electrodes of the other wiring board. and
a step of applying a conductive paste material so as to straddle a connection electrode of one of the wiring substrates and a connection electrode of the other wiring substrate that are adjacent in the direction in which the adjacent wiring substrates are arranged;
forming a connecting portion by curing the conductive paste material;
As the conductive paste material, using a material that exhibits stretchability at least after curing,
the adjacent wiring substrates are arranged so as to be in contact with each other;
applying and curing the conductive paste material so that the surface of the connecting portion is flat ;
Manufacture of a composite substrate, wherein the connection part is formed so as to connect the connection electrode of one of the wiring substrates and the connection electrode of the other wiring substrate, which are adjacent in the direction in which the adjacent wiring substrates are arranged, in series. Method. preparing a plurality of wiring substrates having a plurality of connection electrodes arranged on the surface along at least a portion of the outer edge;
The plurality of wiring boards are arranged in a sheet form, and in the direction in which the adjacent wiring boards are arranged, the connection electrodes of one of the adjacent wiring boards are connected to the corresponding connection electrodes of the other wiring board. and
a step of applying a conductive paste material so as to straddle a connection electrode of one of the wiring substrates and a connection electrode of the other wiring substrate that are adjacent in the direction in which the adjacent wiring substrates are arranged;
A method for manufacturing a composite substrate, comprising a step of forming a connection portion by curing the conductive paste material,
As the conductive paste material, using a material that exhibits stretchability at least after curing,
the connection portion is formed so as to connect in series a connection electrode of one of the wiring substrates adjacent in a direction in which the adjacent wiring substrates are arranged and a connection electrode of the other wiring substrate;
The method for manufacturing the composite substrate further comprises the step of providing spacer insulating portions in at least portions of the space between the adjacent wiring substrates where the connection electrodes are not positioned on both sides in the direction in which the adjacent wiring substrates are arranged. ,
The method of manufacturing a composite substrate, wherein the conductive paste material is intermittently applied to a position that does not overlap the insulating spacer portion. further comprising filling a space between the adjacent wiring substrates with a filling insulating portion;
16. The method of manufacturing a composite substrate according to any one of claims 12 to 15, wherein said conductive paste material is applied onto said filling insulating portion. 22. The method of manufacturing a composite substrate according to claim 12, further comprising the step of providing a covering insulating portion that extends along the direction in which the plurality of connection portions are arranged and covers the plurality of connection portions. 23. The method of manufacturing a composite substrate according to claim 12, wherein said plurality of wiring substrates are arranged in a sheet on a support substrate.

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