Board assembly, board, and electronic device

Abstract

Provided are a substrate assembly, a substrate, and an electronic device having a simpler wiring structure and in which the connection state between substrates can be inspected. A first substrate (30) and a second substrate (50) that constitute the substrate assembly (18) are fixed so that signal wiring (42, 60) constituting a first signal line group (44) and a second signal line group (62) is connected, respectively, in straight lines. On the second substrate (50), additional signal lines (64, 66) are provided extending so as to traverse a second connection terminal group comprising a plurality of connection terminals connected to the second signal line group (62) or the first signal line group (44), while being separated from the second signal line group (62) in the thickness direction of the second substrate (50).

Description

[Technical field]

[0001] The present invention relates to a board assembly, a board, and an electronic device. [Background technology]

[0002] Conventionally, there are known techniques for inspecting whether or not a signal line mounted on an electronic circuit board is disconnected. For example, Patent Document 1 discloses an inspection method for a capacitive touch sensor in which multiple line electrodes are arranged in a two-dimensional lattice pattern. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-145066 A Summary of the Invention [Problem to be solved by the invention]

[0004] For example, when connecting boards together, pressure bonding using anisotropic conductive film (ACF) may be used. This type of pressure bonding has the advantage of making it easier to achieve low profile and narrow pitch compared to connections using soldering or connectors. However, pressure bonding increases the possibility of connection failures and disconnections.

[0005] The present invention has been made in consideration of such problems, and its purpose is to provide a board assembly, a board, and an electronic device that are capable of inspecting the connection state between boards despite having a simpler wiring structure. [Means for solving the problem]

[0006] A substrate assembly in a first aspect of the present invention comprises a first substrate including a first signal line group consisting of a plurality of signal lines extending in a first direction and arranged side by side in a direction perpendicular to the first direction, and a second substrate including a second signal line group consisting of a plurality of signal lines extending in a second direction and arranged side by side in a direction perpendicular to the second direction, wherein the first substrate and the second substrate are fixed to each other such that the signal lines constituting the first signal line group and the second signal line group are respectively connected in a line, and an additional signal line is provided on the second substrate, the additional signal line being spaced apart from the second signal line group in the thickness direction of the second substrate and extending so as to cross the second signal line group or a second connection terminal group which is a plurality of connection terminals connected to the first signal line group.

[0007] The substrate in the second aspect of the present invention comprises a base material, a signal line group consisting of a plurality of signal lines arranged in a row on one main surface of the base material, or a connection terminal group consisting of a plurality of connection terminals arranged in a row, and one or more additional signal lines arranged on the other main surface of the base material and extending across the signal line group or the connection terminal group.

[0008] An electronic device according to a third aspect of the present invention comprises the substrate assembly according to the first aspect of the present invention or the substrate according to the second aspect of the present invention. Effect of the Invention

[0009] According to the present invention, it is possible to inspect the connection state between substrates even with a simpler wiring structure. [Brief description of the drawings]

[0010] [Figure 1] 1 is an exploded perspective view of an electronic device incorporating a sensor board group as a board assembly according to a first embodiment of the present invention. [Diagram 2] 2 is a partial plan view of the sensor substrate group shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along the line AA shown in FIG. [Figure 4] 4 is a diagram showing an example of a method for determining a connection state in the sensor board group of FIG. 2 and FIG. 3. [Diagram 5] 6 is a cross-sectional view of a sensor substrate group in a first modified example of the first embodiment. FIG. [Figure 6] 13 is a partial plan view of a sensor substrate group in a second modified example of the first embodiment. FIG. [Figure 7] FIG. 11 is a plan view of a display substrate according to a second embodiment of the present invention. [Figure 8] FIG. 11 is a partial plan view of a sensor substrate group serving as a substrate assembly in a third embodiment of the present invention. [Figure 9] 9 is a diagram showing an example of a method for determining the connection state in the sensor board group of FIG. 8. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components in each drawing are denoted with the same reference numerals as much as possible, and duplicated description will be omitted. Note that the present invention is not limited to the following first to third embodiments and modified examples, and can be freely modified without departing from the spirit of the present invention. Alternatively, each configuration may be arbitrarily combined within the scope of no technical contradiction.

[0012] [First embodiment] A board assembly and an electronic device in a first embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG.

[0013] <Overall composition> 1 is an exploded perspective view of an electronic device 10 incorporating a sensor board group 18 as a board assembly in a first embodiment of the present invention. The electronic device 10 may be any type of device equipped with an electronic circuit board, for example, a tablet-type computer used with an electronic pen. The electronic device 10 is configured by stacking, in order from the rear side, a rear cover 12, a main board 14, a display panel 16, a sensor board group 18, and a front cover 20.

[0014] The rear cover 12 and the front cover 20 are members that form a housing that houses electronic components in the electronic device 10. The front cover 20 is provided with a highly light-transmitting protective panel 22 so as to cover the entire opening formed in the main surface thereof.

[0015] The main board 14 is a board that configures an electric circuit for operating the electronic device 10. On the main board 14, various electronic components are arranged, such as a host processor, a memory, a driving IC (Integrated Circuit) for the display panel 16, a connector for connecting to the sensor board group 18, a wireless communication module, a power circuit, and the like.

[0016] The display panel 16 is configured, for example, by a liquid crystal panel, an organic EL (Electro Luminescence) panel, electronic paper, etc. The display panel 16 displays an image or video within a display area by applying a driving voltage to a matrix of signal lines arranged in row and column directions to drive a plurality of pixels.

[0017] The sensor board group 18 functions as an "external type" touch panel that is attached from the outside of the display panel 16. The sensor board group 18 includes a detection board 30 (first board) having a function of detecting an indicated position, and a flexible board 50 (second board) having flexibility. Here, the detection board 30 and the flexible board 50 are electrically connected without a connector.

[0018] The detection substrate 30 has a touch sensor 32 capable of detecting a position pointed to by a user's finger or electronic pen. The touch sensor 32 is formed by arranging linear or block-shaped sensor electrodes (not shown) in a planar shape.

[0019] An integrated circuit (hereinafter, referred to as a "touch control IC 52") that controls the driving of the touch sensor 32 is mounted on the flexible substrate 50. This mounting method may be FOC (Chip on Film) or TAB (Tape Automated Bonding).

[0020] 1, the positional relationship between the display panel 16 and the sensor substrate group 18 may be changed according to the detection method of the touch sensor 32. For example, for a touch sensor 32 that employs an active electrostatic coupling method (AES), it is more preferable that the sensor substrate group 18 be provided above the display panel 16. On the other hand, for a touch sensor 32 that employs an electromagnetic induction method (EMR), it is more preferable that the sensor substrate group 18 be provided below the display panel 16.

[0021] <Configuration of sensor substrate group 18> Fig. 2 is a partial plan view of the sensor substrate group 18 shown in Fig. 1. Fig. 3 is a cross-sectional view taken along line AA shown in Fig. 2. Hereinafter, directions are defined based on the position and posture of flexible substrate 50. More specifically, the long side direction, short side direction, and height direction of flexible substrate 50 are referred to as the "length direction," the "width direction," and the "thickness direction," respectively.

[0022] As shown in Fig. 3, the detection substrate 30 and the flexible substrate 50 are arranged so that their ends overlap each other. The detection substrate 30 is formed by sequentially laminating a base material 34 on which a touch sensor 32 (Fig. 1) is mounted, a conductive layer 36, and an insulating layer 38. The base material 34 is made of a material having insulating and heat resistance (e.g., a resin such as polyethylene terephthalate). The conductive layer 36 is made of a material having high conductivity (e.g., a metal such as copper, silver, or gold). The insulating layer 38 is provided so as to cover the entire surface of the conductive layer 36 except for the end in the length direction (hereinafter, the tip exposed portion 40).

[0023] On the other hand, the flexible substrate 50 includes a base material 54 on which a touch control IC 52 (FIGS. 1 and 2) is mounted, a conductive layer 56 provided on the lower surface of the base material 54, and a conductive layer 58 provided on the upper surface of the base material. The base material 54 is made of a material having insulating properties, heat resistance, and flexibility (e.g., a resin such as polyimide). The conductive layers 56 and 58 are made of a material having high conductivity (e.g., a metal such as copper, silver, or gold). The protective film 68 is provided to protect the conductive layer 58 (more specifically, additional signal lines 64 and 66 described later).

[0024] An anisotropic conductive film (hereinafter referred to as "ACF 70") is interposed between the detection substrate 30 and the flexible substrate 50. The ACF 70 is formed by molding a mixed material, which is a mixture of fine metal particles and a thermosetting resin, into a film. The detection substrate 30 and the flexible substrate 50 are bonded together at a bonding portion 72 including the tip exposed portion 40. In other words, by applying heat and pressure to the bonding portion 72, a conductive region 74 that electrically connects the conductive layers 36, 56 to each other is formed in a part of the ACF 70.

[0025] As shown in FIG. 2, a signal line group 44 (first signal line group) consisting of a plurality of signal lines 42 is formed on the detection substrate 30 by a conductive layer 36 (FIG. 3). A signal line group 62 (second signal line group) consisting of a plurality of signal lines 60 is formed on the flexible substrate 50 by a conductive layer 56 (FIG. 3). The plurality of signal lines 60 extend in the length direction and are arranged side by side in the width direction. The plurality of signal lines 42 extend in the length direction and are arranged side by side in the width direction. The signal lines 42, 60 constituting the two signal line groups 44, 62 are aligned so as to be connected in a line.

[0026] Furthermore, two additional signal lines 64, 66 are formed on the flexible substrate 50 by the conductive layer 58 (FIG. 3). A portion of the additional signal line 64 is provided at a position on the tip side of the crimped portion 72 in the length direction, extending in the width direction so as to cross the signal line group 44. A portion of the additional signal line 66 is provided at a position on the rear end side of the crimped portion 72 in the length direction, extending in the width direction so as to cross the signal line group 62.

[0027] Each of the signal lines 42 is connected to a sensor electrode that constitutes a part of the touch sensor 32 (FIG. 1). Each of the signal lines 60 is connected to a detection pin of the touch control IC 52. Each of the additional signal lines 64, 66 is connected to a test pin of the touch control IC 52.

[0028] <Description of judgment operation> The electronic device 10 and the sensor board group 18 in the first embodiment are configured as described above. Next, the operation of determining the connection state of the sensor board group 18 will be described with reference to Figures 2 to 4. First, the touch control IC 52 starts a control mode (i.e., a test mode) for inspecting the connection state of the sensor board group 18 periodically or irregularly.

[0029] In the first operation of the test mode, the touch control IC 52 transmits a test signal via the first test pin. Then, a capacitive coupling CC (FIG. 3) is formed between the additional signal line 64 and the signal line 60, generating a response signal to the test signal. The touch control IC 52 sequentially receives the response signals via the signal line 60. If the strength of the response signal exceeds a threshold, it is determined that the "first reception result is OK," whereas if the strength of the response signal is equal to or less than the threshold, it is determined that the "first reception result is N / A."

[0030] In the second operation of the test mode, the touch control IC 52 transmits a test signal via the second test pin. Then, a capacitive coupling CC (FIG. 3) is formed between the additional signal line 66 and the signal line 42, generating a response signal to the test signal. The touch control IC 52 sequentially receives the response signal via the signal line 42, the conductive area 74, and the signal line 60. If the strength of the response signal exceeds a threshold, it is determined that the second reception result is OK, whereas if the strength of the response signal is equal to or less than the threshold, it is determined that the second reception result is N / A.

[0031] Fig. 4 is a diagram showing an example of a method for determining the connection state in the sensor board group 18 of Fig. 2 and Fig. 3. If the first reception result and the second reception result are both "OK", it is determined that there are no breaks in both the signal line 42 of the detection board 30 and the signal line 60 of the flexible board 50 and that they are "normal" (Result 1). On the other hand, if there is any other combination of results (Results 2 to 4), it is determined that there is an "abnormality" and the following causes are identified.

[0032] If only the first reception result is "OK", it is determined that there is no break in the signal lines 42, 60, but there is a malfunction of the touch control IC 52 (Result 2). If only the second reception result is "OK", it is determined that there is either [1] a break in the signal line 42, [2] a crimping defect in the board, or [3] a malfunction of the touch control IC 52 (Result 3). If both the first reception result and the second reception result are "N / A", it is determined that there is either [1] a break in the signal line 60, or [2] a malfunction of the touch control IC 52 (Result 4).

[0033] <Action and effect> As described above, the sensor board group 18 (board assembly) in the first embodiment includes a detection board 30 (first board) including a signal line group 44 (first signal line group) consisting of a plurality of signal lines 42 extending in a first direction and arranged side by side in a direction perpendicular to the first direction, and a flexible board 50 (second board) including a signal line group 62 (second signal line group) consisting of a plurality of signal lines 60 extending in a second direction and arranged side by side in a direction perpendicular to the second direction. The detection board 30 and the flexible board 50 are fixed so that the signal lines 42, 60 constituting the signal line groups 44, 62 are connected to each other in a line. Additional signal lines 64, 66 are provided on the flexible board 50, extending across the signal line group 62 while being spaced apart from the signal line group 62 in the thickness direction of the flexible board 50.

[0034] By providing the additional signal lines 64, 66 that extend across the signal line group 62, capacitive coupling CC is formed between each of the signal lines 60 constituting the signal line group 62 and the additional signal lines 64, 66. For example, by transmitting a test signal from the additional signal lines 64, 66 and receiving a response signal to the test signal from each of the signal lines 60, it becomes possible to identify the connection state of the signal lines 60. This makes it possible to inspect the connection state between boards even with a simpler wiring structure.

[0035] In addition, an ACF70 (anisotropic conductive film) containing a thermosetting resin is interposed between the detection substrate 30 and the flexible substrate 50, and the detection substrate 30 and the flexible substrate 50 may be fixed in a heat-pressurized state at the bonding portion 72 where the ACF70 is interposed.

[0036] Furthermore, at least one additional signal line 64 may be provided on the flexible substrate 50 at a position on the tip side of the crimped portion 72 in the length direction (second direction). Furthermore, at least one additional signal line 66 may be provided on the flexible substrate 50 at a position on the rear side of the crimped portion 72 in the length direction. Furthermore, at least two additional signal lines 66 may be provided on the flexible substrate 50 so as to sandwich the crimped portion 72 along the length direction.

[0037] Moreover, the signal line group 62 may be provided on one main surface of the flexible substrate 50, and the additional signal lines 64, 66 may be provided on the other main surface of the flexible substrate 50. This makes it possible to arrange the additional signal lines 64, 66 in positions that overlap with the signal line group 62 in a plan view, thereby increasing the degree of freedom in design.

[0038] Moreover, the first substrate is a detection substrate 30 having a touch sensor 32, and the second substrate is a flexible substrate 50 having flexibility, and the touch sensor 32 may be connected to a touch control IC 52 (integrated circuit) for controlling the touch sensor 32 via signal line groups 44, 62. In particular, by providing the touch control IC 52 on the flexible substrate 50, the degree of freedom in the layout design of the substrate is further increased.

[0039] <First Modification> 5 is a cross-sectional view of a sensor substrate group 80 in a first modified example of the first embodiment. The sensor substrate group 80 includes a detection substrate 30 (first substrate) having a configuration similar to that of the first embodiment, and a flexible substrate 82 (second substrate) having a configuration different from that of the first embodiment.

[0040] The flexible substrate 82 includes a base material 84 on which the touch control IC 52 (FIGS. 1 and 2) is mounted, and a conductive layer 86 provided on the lower surface of the base material 84. The base material 84 is made of a material having insulating properties, heat resistance, and flexibility (e.g., a resin such as polyimide). The conductive layer 86 is made of a material having high conductivity (e.g., a metal such as copper, silver, or gold).

[0041] As in the first embodiment (FIG. 2), a plurality of signal lines 42 (i.e., signal line group 44) are formed on the detection substrate 30 by the conductive layer 36. A plurality of signal lines 60 (i.e., signal line group 62) are formed on the flexible substrate 82 by the conductive layer 86. The signal lines 42, 60 constituting the signal line groups 44, 62 are aligned so as to be connected in a line. Furthermore, one additional signal line 64 is formed on the flexible substrate 82 by the conductive layer 86. A portion of the additional signal line 64 is provided extending in the width direction across the signal line group 44 at a position on the tip side of the crimped portion 72 in the length direction.

[0042] In this manner, the signal line group 62 and the additional signal line 64 may be provided on one main surface of the flexible substrate 50. With this configuration, as in the first embodiment, the connection state between the substrates can be inspected with a simpler wiring structure.

[0043] <Second Modification> 6 is a cross-sectional view of a sensor board group 100 in a second modified example of the first embodiment. The sensor board group 100 includes a detection board 30 having a similar configuration to that of the first embodiment, a flexible board 102 (first board), and a main board 14 (second board).

[0044] A signal line group 62 (first signal line group) consisting of a plurality of signal lines 60, and two additional signal lines 104, 106 are formed on the flexible substrate 102. In addition, the flexible substrate 102 and the main substrate 14 are crimped at a crimping portion 108 on the opposite side to the crimping portion 72.

[0045] The signal lines 60 extend in the length direction and are arranged side by side in the width direction. A portion of the additional signal line 104 is provided to extend in the width direction so as to cross the signal line group 62 at a position on the rear end side of the crimped portion 108 in the length direction. A portion of the additional signal line 106 is provided to extend in the width direction so as to cross the signal line group 62 at a position on the tip end side of the crimped portion 108 in the length direction.

[0046] On the other hand, on the main substrate 14, there are provided a touch control IC 52, a signal line group 112 (second signal line group) consisting of a plurality of signal lines 110, and two signal lines 114 and 116. The plurality of signal lines 110 extend in the length direction and are arranged side by side in the width direction. The signal lines 42, 60, and 110 constituting the three signal line groups 44, 62, and 112 are aligned so as to be connected in a line. The two additional signal lines 104 and 106 are aligned so as to be connected in a line with the signal lines 114 and 116, respectively.

[0047] Each signal line 42 is connected to a sensor electrode that constitutes a part of the touch sensor 32 (FIG. 1). Each signal line 110 is connected to a detection pin of the touch control IC 52. The two signal lines 114 and 116 are connected to test pins of the touch control IC 52.

[0048] In this manner, the touch control IC 52 may be provided on a substrate (for example, the main substrate 14) separate from the flexible substrate 102. With this configuration, as in the first embodiment, the connection state between the substrates can be inspected with a simpler wiring structure.

[0049] <Other Modifications> In the first embodiment (FIGS. 2 and 3), a case has been described in which the additional signal lines 64, 66 extend so as to cross the signal line group 62 at right angles, but the arrangement of the additional signal lines is not limited to this. For example, an additional signal line may be provided on the flexible substrate 50 so as to extend so as to cross a plurality of connection terminals (i.e., a connection terminal group) connected to the signal line group 44 of the detection substrate 30 while being spaced apart from the signal line group 62 in the thickness direction. The additional signal lines 64, 66 may also extend so as to cross at an angle smaller than 90 degrees.

[0050] In the first embodiment (FIGS. 2 and 3), a case has been described in which the additional signal lines 64, 66 are provided only on the flexible substrate 50, but the arrangement of the additional signal lines is not limited to this. For example, an additional signal line may be provided on the detection substrate 30, extending so as to cross the signal line group 44 (or the connection terminal group connected to the signal line group 62 of the flexible substrate 50) while being spaced apart from the signal line group 44 in the thickness direction of the detection substrate 30. This makes it possible to inspect the connection state of the signal line 42 as well, making it easier to isolate the cause.

[0051] In the first embodiment (FIGS. 2 and 3), a case has been described in which the additional signal lines 64, 66 are provided at positions sandwiching the crimped portion 72, but the arrangement of the additional signal lines is not limited to this. For example, at least one additional signal line may be provided at a position including the crimped portion 73 on the flexible substrate 50. This makes it possible to directly inspect the connection state at the connecting portion of the signal lines 42, 60.

[0052] In the first embodiment (FIG. 2), the additional signal lines 64, 66 are connected to the touch control IC 52, but the connection form of the additional signal lines is not limited to this. For example, an input terminal may be provided on one end of the additional signal line. For example, connecting an external inspection device to the input terminal makes it easier to inspect the connection state.

[0053] In the first embodiment (FIG. 4), the touch control IC 52 transmits the test signals from the additional signal lines 64 and 66. However, the operation of the touch control IC 52 may be reversed. Specifically, the touch control IC 52 may sequentially transmit the test signals via the signal line 60 and receive the response signals via the additional signal lines 64 and 66.

[0054] [Second embodiment] <Configuration of Display Board 130> 7 is a plan view of a display substrate 130 in a second embodiment of the present invention. This display substrate 130 functions as a "built-in type" (further classified as an on-cell type or an in-cell type) touch panel display in which a display panel and a touch sensor are integrally configured. This display substrate 130 includes a base material 132, an integrated panel 136 consisting of a plurality of divided panels 134, a control integrated circuit (hereinafter, a control IC 138), and a plurality of signal line groups 140.

[0055] The base material 132 is made of an insulating and heat-resistant material (e.g., glass). The integrated panels 136, the control ICs 138, and the signal line group 140 are all disposed on one main surface (i.e., the front surface) of the base material 132. The number of control ICs 138 is equal to the number of divisions of the integrated panel 136. That is, each divided panel 134 is connected to a corresponding control IC 138 via the signal line group 140.

[0056] As shown in the enlarged view of part B, the signal line group 140 is configured with signal lines 142 connected to the display panel side and signal lines 144 connected to the touch sensor side arranged at approximately equal intervals and at regular intervals. Also, one additional signal line 146 is arranged for each control IC 138 on the base material 132. The additional signal line 146 starts from a test pin of the control IC 138, extends laterally on the front surface of the base material 132, and extends across the signal line group 140 on the back surface of the base material 132 via a through hole (not shown).

[0057] <Description of judgment operation> The display board 130 in the second embodiment is configured as described above. Next, a description will be given of the operation of determining the connection state of the display board 130. First, the control IC 138 starts a control mode (i.e., a test mode) for inspecting the connection state of the display board 130 periodically or irregularly.

[0058] When the test mode is executed, the control IC 138 transmits a test signal via the test pin. Then, a capacitive coupling CC is formed between the additional signal line 146 and the signal line 144, generating a response signal to the test signal. The control IC 138 sequentially receives the response signals via the signal line 144. If the strength of the response signal exceeds a threshold, it is determined that the "reception result is OK" and that there is no break in the signal line 144. On the other hand, if the strength of the response signal is equal to or less than the threshold, it is determined that the "reception result is N / A" and that there is a break in the signal line 144.

[0059] <Action and effect> Thus, the display substrate 130 comprises a base material 132, a signal line group 140 consisting of a plurality of signal lines 142, 144 arranged side by side on one main surface of the base material 132, and one or more additional signal lines 146, at least a portion of which is arranged on the other main surface of the base material 132 and extends across the signal line group 140.

[0060] With this configuration, as in the first embodiment, it is possible to inspect the connection state of the display board 130 while using a simpler wiring structure.

[0061] [Third embodiment] Next, a method for inspecting the board assembly and its connection state according to the third embodiment will be described with reference to FIGS.

[0062] <Configuration of the sensor substrate group 200> 8 is a partial plan view of a sensor substrate group 200 in the third embodiment. The sensor substrate group 200 includes a detection substrate 30 having a configuration similar to that of the first embodiment, and a flexible substrate 202. The flexible substrate 202 differs in configuration from that of the first embodiment (FIG. 2) in that the additional signal lines 64, 66 are not provided. In addition, the flexible substrate 202 is provided with a touch control IC 204 having a function different from that of the first embodiment.

[0063] <Description of judgment operation> The sensor substrate group 200 in the third embodiment is configured as described above. Next, a description will be given of an operation for determining the connection state of the sensor substrate group 200. First, the touch control IC 204 starts a control mode (i.e., a test mode) for inspecting the connection state of the sensor substrate group 200 periodically or irregularly.

[0064] When the touch control IC 204 is in the test mode, it transmits a test signal via the first detection pin. Then, a capacitive coupling CC is formed between the first signal line 60 and a signal line 60 nearby, generating a response signal to the test signal. The touch control IC 204 sequentially receives the response signals via the signal lines 60. As a result, the closer to the first signal line 60, the higher the signal level of the response signal received.

[0065] Next, the touch control IC 204 transmits a test signal through the second detection pin and sequentially receives response signals through adjacent signal lines 60. Thereafter, the signal line 60 for transmitting the test signal is sequentially changed and the response signals are sequentially received.

[0066] 9 is a diagram showing an example of a method for determining the connection state in the sensor substrate group 200 of FIG. 8. Here, a connection state is assumed in which only the n-th signal line 60 out of the N signal lines 60 is disconnected. When a test signal is transmitted from the (n-2)th signal line 60, response signals whose signal levels exceed a threshold are received from the adjacent (n-3)th and (n-1)th signal lines 60. When a test signal is transmitted from the (n-1)th signal line 60, a response signal whose signal level exceeds a threshold is received from the adjacent (n-2)th signal line 60, but a response signal whose signal level is equal to or lower than the threshold is received from the adjacent n-th signal line 60. When a test signal is transmitted from the nth signal line, response signals whose signal levels are equal to or lower than the threshold are received from the adjacent (n-1)th and (n+1)th signal lines 60.

[0067] In this manner, the touch control IC 204 can determine the connection state of the signal lines 60 by utilizing the capacitive coupling CC formed between adjacent signal lines 60.

[0068] <Action and effect> As described above, the touch control IC 204 as a touch controller is connected to a signal line group 62 consisting of a plurality of signal lines 60 arranged side by side. The touch control IC 204 may transmit a test signal from one signal line 60, receive a response signal associated with capacitive coupling CC formed between the signal lines 60 from another signal line 60 adjacent to the one signal line 60, and determine the connection state of the signal lines 60 based on the strength of the response signal.

[0069] With this configuration, the connection state of the sensor substrate group 200 can be inspected without providing additional signal lines 64, 66 (FIGS. 2 and 3).

[0070] [Explanation of symbols] 10...electronic device, 18, 80, 100, 200...sensor board group (board assembly), 30...detection board, 50, 82, 202...flexible board, 44, 62, 112, 140...signal line group, 64, 66, 104, 106, 146...additional signal line, 130...display board (board)

Claims

1. a first substrate including a first signal line group including a plurality of signal lines extending in a first direction and arranged side by side in a direction perpendicular to the first direction; a second substrate including a second signal line group including a plurality of signal lines extending in a second direction and arranged side by side in a direction perpendicular to the second direction; Equipped with the first substrate and the second substrate are fixed to each other such that the signal lines constituting the first signal line group and the signal lines constituting the second signal line group are connected in a line, an additional signal line is provided on the second substrate, the additional signal line extending across the second signal line group or a second connection terminal group including a plurality of connection terminals connected to the second signal line group or the first signal line group while being spaced apart from the second signal line group in a thickness direction of the second substrate; A substrate assembly, wherein the additional signal line is configured to form capacitive coupling with a signal line constituting the first signal line group or the second signal line group through transmission of a signal.

2. another additional signal line is provided on the first substrate, the additional signal line extending across a first connection terminal group including a plurality of connection terminals connected to the first signal line group or the second signal line group while being spaced apart from the first signal line group in a thickness direction of the first substrate; The other additional signal line is configured to form capacitive coupling with a signal line constituting the first signal line group or the second signal line group through transmission of a signal. The substrate assembly of claim 1 .

3. an anisotropic conductive film containing a thermosetting resin is interposed between the first substrate and the second substrate; The first substrate and the second substrate are fixed in a state where they are heated and pressed at a pressure-bonding portion where the anisotropic conductive film is interposed. The substrate assembly of claim 1 .

4. At least one of the additional signal lines is provided at a position further distal than the crimping portion in the second direction. The substrate assembly of claim 3 .

5. At least one of the additional signal lines is provided at a position rearward of the crimped portion in the second direction. The substrate assembly of claim 3 .

6. At least one of the additional signal lines is provided at a position including the crimped portion. The substrate assembly of claim 3 .

7. At least two of the additional signal lines are arranged to sandwich the crimped portion along the second direction. The substrate assembly of claim 3 .

8. the second signal line group is provided on one main surface of the second substrate, the additional signal line is provided on the other main surface of the second substrate; The substrate assembly of claim 1 .

9. the second signal line group and the additional signal line are provided on one main surface of the second substrate; The substrate assembly of claim 1 .

10. the first substrate is a detection substrate having a touch sensor, the second substrate is a flexible substrate having flexibility, the touch sensor is connected to an integrated circuit for controlling the touch sensor via the first signal line group and the second signal line group; The substrate assembly of claim 1 .

11. The integrated circuit is provided on the flexible substrate. The substrate assembly of claim 10.

12. A substrate; A signal line group including a plurality of signal lines arranged side by side on one main surface of the base material, or a connection terminal group including a plurality of connection terminals arranged side by side; one or more additional signal lines provided on the other main surface of the base material and extending across the signal lines or the connection terminals; Equipped with A substrate, wherein the additional signal line is configured to form capacitive coupling with the signal lines that make up the group of signal lines through the transmission of a signal.

13. An electronic device comprising the substrate assembly according to any one of claims 1 to 11.

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