Non-contact short circuit detection method

Abstract

The application discloses a non-contact short circuit detection method for determining whether a short circuit exists in a circuit with two or more non-hanging electrodes, which comprises the following steps: obtaining a first magnetic field intensity of a magnetic field generated by a coil supplied with an alternating current when the coil is away from the circuit; applying a strip-shaped conductive structure to electrically connect the two or more electrodes; obtaining a second magnetic field intensity of a magnetic field generated by the coil supplied with the alternating current when the coil is adjacent to the circuit after the two or more electrodes are electrically connected, wherein the direction of the magnetic field generated by the coil is transverse to the plane where the circuit is located; and comparing the first magnetic field intensity with the second magnetic field intensity, so as to determine that a short circuit exists in the circuit when the second magnetic field intensity is 5% to 50% less than the first magnetic field intensity, and otherwise, it is determined that no short circuit exists in the circuit. The application is simple to implement, fast and convenient to detect, and does not need to contact the circuit structure of a product, so as to not affect the yield and cost of the product, and not hinder the electrical function of the product.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit detection, and particularly relates to a non-contact short circuit detection method. BACKGROUND

[0002] Touch screen is the most simple, convenient and natural human-computer interaction mode at present, and is widely applied to information inquiry, industrial control, self-service, multimedia teaching, electronic game and many other fields. The touch screen usually comprises a touch panel and a display screen fixedly connected with each other, wherein the touch panel is a screen part providing touch function, and the display screen is a screen part providing display function.

[0003] Taking the touch panel of a capacitive touch screen as an example, as shown in Figures 1-3 , the touch panel can be single-sided structure (for example Figure 1 , 3 ) or double-sided structure (for example Figure 2 ). The sensing and driving units on the touch panel are usually arranged in rows and columns perpendicular to each other on one surface (single-sided structure) or two surfaces (double-sided structure) of the touch panel, and the rows and columns of the sensing and driving units are respectively electrically connected to the electrodes via a plurality of electrode wires arranged in the non-operable area at the edges of the touch panel (i.e. the non-operable area of the touch panel), so as to be electrically connected to the control board through the FPC (flexible printed circuit board) arranged at the edge of the touch panel.

[0004] As shown in Figure 1 , the touch panel 1 of single-sided structure (for example, formed by bridging) comprises an array of sensing and driving units 13 formed on one surface of the touch panel 1, wherein the array of sensing and driving units 13 comprises rows of sensing units and columns of driving units. In the non-operable area 11 of the touch panel 1, two end portions of each row of sensing units are respectively connected to the sensing electrodes 13a and 13b formed in the lower portion of the non-operable area 11 through corresponding electrode wires; one end portion of each column of driving units is suspended, and the other end portion is respectively connected to the driving electrodes 13c formed in the lower portion of the non-operable area 11 through corresponding electrode wires.

[0005] Figure 2A touch panel 1 with a double-sided structure is shown, in which the rows of sensing units in the sensing and driving unit array 13 are formed on one surface (the front surface in the drawing), and the columns of driving units are formed on the other surface (the back surface in the drawing, i.e. the surface facing away from the paper, the structures on which are depicted in dotted lines). On the front surface, in the non-operable area 11, the two ends of each row of sensing units are connected to the sensing electrodes 13a, 13b formed in the lower part of the non-operable area 11 through corresponding electrode traces, respectively; on the back surface, one end of each column of driving units is left hanging, and the other end is connected to the driving electrodes 13c formed in the lower part of the non-operable area 11 through corresponding electrode traces, respectively.

[0006] Figure 3 A touch panel 1 with a single-sided structure is shown, in which the rows of sensing units in the sensing and driving unit array 13 are formed as sensing lines, i.e. horizontally extending strip structures of conductive material such as ITO, and the columns of driving units are formed as driving lines, i.e. vertically extending strip structures of conductive material such as ITO. In the non-operable area 11 of the touch panel 1, one end of each row of sensing units is left hanging, and the other end is connected to the sensing electrodes 13a formed in the lower part of the non-operable area 11 through corresponding electrode traces; one end of each column of driving units is left hanging, and the other end is connected to the driving electrodes 13c formed in the lower part of the non-operable area 11 through corresponding electrode traces, respectively.

[0007] The sensing and driving units of a touch panel can also take other graphic shapes. Also, the two ends of each row of sensing units can be left hanging, one connected to a corresponding sensing electrode through a trace to output a sensing signal, or connected to two sensing electrodes through two traces to output a sensing signal through one or both of the sensing electrodes. The two ends of each column of driving units can be left hanging, one connected to a corresponding driving electrode through a trace to input a driving signal, or connected to two driving electrodes through two traces, one of which is used to input a driving signal in use, while the other is left hanging.

[0008] In the detection of a touch panel, short circuit detection is an important content. It can be imagined that if conductive debris (e.g. debris of conductive material such as silver paste particles peeled off by a laser etching process) falls on two or more adjacent rows of sensing units, or on two or more adjacent columns of driving units, or on two or more adjacent traces, or on two or more adjacent sensing and driving electrodes, it will all cause the output / input of sensing / driving signals to be incorrect, thereby affecting the normal operation of the touch panel. Figure 4 Two places where conductive debris falls between two adjacent traces, causing a short circuit between the traces, are shown in the middle.

[0009] However, the above-mentioned circuit structure of the touch panel, especially the structure of the sensing and driving units and the wirings connected thereto, is very small and dense. Therefore, the conventional method of detecting the electrical characteristics of the circuit by physically connecting the probes of a detection instrument to the circuit structure is not suitable, because the probes of the conventional detection instrument are usually large, which restricts the convenience and efficiency of using the instrument. Moreover, the detection by physically contacting the circuit structure with the probes can damage the circuit structure, such as causing scratches and point damages on the surface of the circuit structure, thereby affecting the yield and cost of the product, and even affecting the electrical function thereof. In addition, the low efficiency of the physical contact type circuit detection affects the delivery efficiency of precision devices such as the touch panel. Therefore, it is particularly urgent to develop a non-contact short circuit detection technology for the circuit of a precision device such as the touch panel.

[0010] The skilled in the art is committed to developing a non-contact short circuit detection method to solve the above technical problems. SUMMARY

[0011] To achieve the above-mentioned purpose, the present application provides a non-contact short circuit detection method for determining whether there is a short circuit in a circuit having two or more non-hanging electrodes, wherein the first aspect comprises:

[0012] applying a strip-shaped conductive structure to electrically connect the two or more electrodes, so that in the circuit with a short circuit, at least one closed circuit structure will be formed by the two or more electrodes electrically connected;

[0013] obtaining a first magnetic field strength of the magnetic field generated when a coil with an alternating current passes far away from the circuit; the obtaining of the first magnetic field strength can be performed before, after or simultaneously with the application of the strip-shaped conductive structure;

[0014] arranging the coil with the alternating current to be adjacent (not in contact) to the circuit after the two or more electrodes are electrically connected, and the direction of the magnetic field generated by the coil is transverse to the plane where the circuit is located;

[0015] obtaining a second magnetic field strength of the magnetic field generated when the coil is adjacent to the circuit, and comparing the first magnetic field strength and the second magnetic field strength, so that when the second magnetic field strength is less than 5%-50% of the first magnetic field strength, it is determined that there is a short circuit in the circuit; otherwise, it is determined that there is no short circuit in the circuit.

[0016] Preferably, the coil is moved from one side of the circuit to the opposite side substantially along the direction in which the two or more electrodes are arranged, and the second magnetic field strength is obtained during the movement of the coil.

[0017] The present application comprises in a second aspect:

[0018] applying a strip-shaped conductive structure to electrically connect the two or more electrodes, so that at least one closed circuit structure is formed by the two or more electrodes electrically connected in the circuit in which short circuit exists;

[0019] obtaining a first current amplitude of the alternating current when the coil supplied with the alternating current is away from the circuit; the obtaining of the first current amplitude can be performed before, after or simultaneously with the applying of the strip-shaped conductive structure;

[0020] arranging the coil supplied with the alternating current adjacent to (not in contact with) the circuit in which the two or more electrodes are electrically connected, and the direction of the magnetic field generated by the coil is transverse to the plane in which the circuit is located;

[0021] obtaining a second current amplitude of the alternating current outputted when the coil is adjacent to the circuit, and comparing the first current amplitude and the second current amplitude, so that when the second current amplitude is less than the first current amplitude by 5%-50%, it is determined that there is a short circuit in the circuit; otherwise, it is determined that there is no short circuit in the circuit.

[0022] Preferably, the coil is moved from one side of the circuit to the opposite side substantially along the direction in which the two or more electrodes are arranged, and the second current amplitude is obtained during the movement of the coil.

[0023] In the above two aspects, further preferably, the coil is adjacent to and along the strip-shaped conductive structure during the movement of the coil.

[0024] In the present disclosure, the electrode that is not suspended refers to the electrode that is electrically connected rather than suspended during the operation of the circuit; the direction of the magnetic field generated by the coil is transverse to the plane in which the circuit is located refers to the direction of the magnetic field is inclined to the plane in which the circuit is located; the coil is moved substantially along the direction in which the electrodes are arranged refers to the included angle between the direction of the movement of the coil and the direction in which the electrodes are arranged is not greater than 15°; the coil is adjacent to and along the strip-shaped conductive structure during the movement of the coil refers to the distance between the coil and the strip-shaped conductive structure during the movement of the coil is not greater than 1-30 mm.

[0025] Preferably in the present disclosure, the strip-shaped conductive structure is applied at the end of the two or more electrodes away from the circuit in which the electrodes are located; further preferably, the strip-shaped conductive structure is releasably applied.

[0026] The present application provides a non-contact short circuit detection method in the third and fourth aspects for determining whether there is a short circuit in the circuit of a circuit product to be tested with two or more non-hanging electrodes, wherein the third aspect comprises:

[0027] using a circuit product with the same circuit as the circuit product to be tested and without a short circuit in its circuit as a standard circuit product;

[0028] applying the same strip-shaped conductive structure to electrically connect the two or more electrodes of the circuit of the standard circuit product and the circuit product to be tested respectively, so that the circuit with a short circuit in the circuit product to be tested will form at least one closed circuit structure through the two or more electrodes electrically connected;

[0029] using the same coil supplied with alternating current to be electrically connected to the two or more electrodes of the circuit of the standard circuit product and the circuit product to be tested respectively adjacent (not in contact) to the two or more electrodes; and when the coil is at the same position corresponding to the circuit of the standard circuit product and the circuit product to be tested, respectively acquiring the first magnetic field strength of the first magnetic field generated when the coil is adjacent to the circuit of the standard circuit product and the second magnetic field strength of the second magnetic field generated when the coil is adjacent to the circuit of the circuit product to be tested, wherein the directions of the first magnetic field and the second magnetic field are substantially the same and are transverse to the plane in which the adjacent circuit is located; comparing the first magnetic field strength and the second magnetic field strength, so that when the second magnetic field strength is less than the first magnetic field strength by 5%-50%, it is determined that there is a short circuit in the circuit of the circuit product to be tested; otherwise, it is determined that there is no short circuit in the circuit of the circuit product to be tested.

[0030] Further preferably, for the standard circuit product and the circuit product to be tested, respectively, the coil is moved from one side of the circuit to the opposite side substantially along the direction in which the two or more electrodes are arranged, and the first magnetic field strength and the second magnetic field strength are respectively acquired during the movement of the coil.

[0031] The fourth aspect of the present application comprises:

[0032] using a circuit product with the same circuit as the circuit product to be tested and without a short circuit in its circuit as a standard circuit product;

[0033] applying the same strip-shaped conductive structure to electrically connect the two or more electrodes of the circuit of the standard circuit product and the circuit product to be tested respectively, so that the circuit with a short circuit in the circuit product to be tested will form at least one closed circuit structure through the two or more electrodes electrically connected;

[0034] The two or more electrodes of the standard circuit product and the circuit under test are electrically connected respectively using the same coil supplied with an alternating current; and when the coil is at the same position corresponding to the circuit of the standard circuit product and the circuit of the circuit under test, the first current amplitude of the first alternating current output by the coil adjacent to the circuit of the standard circuit product and the second current amplitude of the second alternating current output by the coil adjacent to the circuit of the circuit under test are obtained respectively, wherein the directions of the magnetic field generated by the coil adjacent to the circuit of the standard circuit product and the circuit of the standard circuit product are substantially the same and are transverse to the plane where the adjacent circuit is located; the first current amplitude and the second current amplitude are compared, so that when the second current amplitude is less than the first current amplitude by 5%-50%, it is determined that there is a short circuit in the circuit of the circuit under test; otherwise, it is determined that there is no short circuit in the circuit of the circuit under test.

[0035] Further preferably, for the standard circuit product and the circuit under test, the coil is moved from one side of the circuit to the opposite side substantially along the direction in which the two or more electrodes are arranged, and the first current amplitude and the second current amplitude are obtained respectively during the movement of the coil.

[0036] In the above two aspects, further preferably, the coil is adjacent to and along the strip-shaped conductive structure during the movement of the coil.

[0037] Further preferably, for the standard circuit product and the circuit under test, the circuit is divided into two or more transverse regions in a direction perpendicular to the arrangement of the electrodes, and the coil is moved from one side of the circuit to the opposite side in each of the two or more transverse regions respectively.

[0038] Alternatively, preferably, for the standard circuit product and the circuit under test, the circuit is divided into two or more transverse regions in a direction perpendicular to the arrangement of the electrodes, and each of the two or more coils is moved from one side of the circuit to the opposite side in a corresponding one of the two or more transverse regions respectively.

[0039] Further preferably, for the standard circuit product and the circuit under test, the circuit is further divided into two or more longitudinal regions in a direction parallel to the arrangement of the electrodes, and the coil is moved from one side of the circuit to the opposite side substantially perpendicular to the direction of the arrangement of the two or more electrodes in each of the two or more longitudinal regions respectively.

[0040] Preferably, the standard circuit product and the circuit of the circuit product to be tested are further divided into two or more longitudinal regions in a direction parallel to the electrode arrangement, and each of the two or more coils is caused to move from one side of the circuit to the opposite side substantially perpendicular to the direction of the two or more electrode arrangements in a corresponding one of the two or more longitudinal regions.

[0041] In the present disclosure, the movement of the coil substantially along the direction of the electrode arrangement means that the angle between the direction of the movement of the coil and the direction of the electrode arrangement is not greater than 15°; the movement of the coil adjacent to and along the strip-shaped conductive structure means that the distance between the coil and the strip-shaped conductive structure is not greater than 1-30 mm; the directions of the first magnetic field and the second magnetic field (or the magnetic field generated when the coil is adjacent to the circuit of the standard circuit product and the standard circuit product) are substantially the same and are transverse to the plane in which the circuit is located, which means that the directions of the two magnetic fields are inclined to the plane in which the circuit is located and the degree of inclination is substantially the same, for example, the difference between the angles of the directions of the two magnetic fields and the plane is not greater than 5°.

[0042] Preferably in the present disclosure, the coil is a planar coil; further, the coil is a spiral coil, the coil is a single-layer or multi-layer coil, and / or the coil is a hollow or iron core coil; the magnetic fields generated when the coil is adjacent to the standard circuit product and the circuit of the standard circuit product are both the central magnetic fields of the respective coils; further preferably, the directions of the two magnetic fields are both perpendicular to the plane. Preferably, when the coil is adjacent to the circuit, the coil plane of the coil is substantially parallel to the plane in which the circuit is located, i.e., the angle between the two is not greater than 15°.

[0043] In the present disclosure, when the coil is adjacent to the circuit, the minimum distance between the coil and the circuit is not greater than 1-30 mm, i.e., the minimum value of the distance between any part of the coil and any part of the circuit is not greater than 1-30 mm; when the coil is away from the circuit, the minimum distance between the coil and the circuit is not less than 50 mm, i.e., the minimum value of the distance between any part of the coil and any part of the circuit is not less than 50 mm.

[0044] Further preferably, when the second magnetic field strength is 5%-20% less than the first magnetic field strength, it is determined that there is a short circuit in the circuit of the circuit product to be tested.

[0045] Further preferably, when the second magnetic field strength is 10% less than the first magnetic field strength, it is determined that there is a short circuit in the circuit of the circuit product to be tested.

[0046] Preferably, the circuit product is any one of a touch panel, a display screen, a PCB board, or an FPC.

[0047] Preferably, the circuit product includes any one of a touch panel, a display screen, a PCB board, and an FPC.

[0048] Furthermore, when the strip-shaped conductive structure is not applied, there is no closed circuit structure in the circuit of the circuit product.

[0049] As can be seen, the non-contact short-circuit detection method provided by this invention can detect the presence of short circuits in a circuit without physical contact. This is particularly suitable for detecting circuit products with very small and dense circuit structures, such as touch panels, displays, PCBs, FPCs, or precision devices that include touch panels, displays, PCBs, and FPCs. This invention is simple to implement, fast and convenient to detect, and does not require contact with the product's circuit structure, thus not affecting the product's yield rate or cost, nor impairing the product's electrical function.

[0050] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0051] Figure 1 The illustration schematically shows a single-sided touch panel.

[0052] Figure 2 The illustration schematically shows a touch panel with a dual-sided structure.

[0053] Figure 3 This schematically illustrates another single-sided touch panel structure.

[0054] Figure 4 The illustration shows two short circuits occurring in the circuit.

[0055] Figure 5 This illustrates, in a preferred embodiment of the invention, the method for... Figure 1 The touch panel shown uses a strip-shaped conductive structure to electrically connect the electrodes on the touch panel.

[0056] Figure 6 It shows the completion Figure 5 After the electrical connection is established, a circuit is formed when there is a short circuit between two adjacent drive unit columns on the touch panel.

[0057] Figures 7-10 The schematic diagram illustrates the principle of the non-contact short-circuit detection method of the present invention, wherein... Figure 7 , Figure 9showing the circuit situation when there is no short circuit between adjacent electrodes after the electrical connection of the circuit parts such as electrodes by the strip-shaped conductive structure, Figure 8 、 Figure 10 showing the output current of the coil through which an alternating current is passed, arranged above the circuit of Figure 7 、 Figure 9 .

[0058] Figure 11 showing the touch panel and the strip-shaped conductive structure thereon, sectioned along the A-A line in Figure 5 .

[0059] Figure 12 showing the touch panel and the strip-shaped conductive structure thereon, sectioned along the B-B line in Figure 5 .

[0060] Figure 13 schematically showing the fixation of the strip-shaped conductive structure on the touch panel by applying a pressure F.

[0061] Figure 14 showing the touch panel shown in Figure 2 , to which electrodes on the touch panel are electrically connected by the strip-shaped conductive structure.

[0062] Figure 15 schematically showing the short circuit detection of the touch panel in a scanning manner by the coil through which an alternating current is passed after the electrical connection shown in Figure 5 .

[0063] Figure 16 schematically showing the detection of a short circuit in the touch panel in the detection shown in Figure 15 .

[0064] Figure 17 schematically showing the detection of a short circuit in the touch panel in another manner in the detection shown in Figure 15 .

[0065] Figure 18 schematically showing the detection of a short circuit in the touch panel in a partitioned multiple scanning manner by the coil through which an alternating current is passed in another preferred embodiment of the present application.

[0066] Figure 19 schematically showing the non-contact detection of a short circuit in the touch panel in a scanning manner by a plurality of coils through which an alternating current is passed in another preferred embodiment of the present application.

[0067] Figure 20 schematically showing the touch panel shown in Figure 19The illustrated touch panel, in another direction, uses an array of coils through which an alternating current is passed in a scanning manner to non-contactingly detect a short circuit in the touch panel. DETAILED DESCRIPTION

[0068] As Figures 5-19 illustrated, in the preferred embodiment of the present application, the non-contact short circuit detection method of the present application is performed on the illustrated touch panel 1 to determine whether a short circuit exists in the touch panel 1. Figure 1

[0069] First, as Figure 5 illustrated, the electrodes on the touch panel 1 are electrically connected using the strip-like conductive structure 20, specifically, the sensing electrodes 13a and the driving electrodes 13c of the touch panel 1 are electrically connected using the strip-like conductive structure 20, but the sensing electrodes 13b are not electrically connected at the same time. That is, only the sensing electrodes corresponding to one end of each sensing unit row and the driving electrodes corresponding to one end of each driving unit column are electrically connected by the strip-like conductive structure 20.

[0070] Thus, after the above electrical connection, for a touch panel in which no short circuit exists, the conductive parts (including the sensing and driving units, the sensing and driving electrodes, and the wirings therebetween) on the touch panel will not form a closed circuit structure through the strip-like conductive structure 20. For a touch panel in which a short circuit exists, after the above electrical connection, at least one closed circuit structure will be formed in the touch panel, as Figure 6 illustrated.

[0071] In Figure 6 the illustrated embodiment, there is a conductive debris 40 on the two adjacent driving unit columns 1311, 1312 of the touch panel 1, which causes a short circuit between the two driving unit columns 1311, 1312. After the sensing electrodes 13a and the driving electrodes 13c are electrically connected by the strip-like conductive structure 20 as described above, a closed circuit structure 60 will be formed in the touch panel 1 by the part of the strip-like conductive structure 20, the part of the driving unit columns 1311, 1312, and the conductive debris 40. Thus, by detecting whether the closed circuit structure 60 exists, it can be determined whether the short circuit exists in the touch panel 1.

[0072] Referring to Figures 7-10 , which schematically illustrates the principle of the non-contact short circuit detection method of the present application, i.e., how to detect whether a short circuit exists between two conductive bodies, such as the electrodes 31, 32.

[0073] As Figure 7 , Figure 9 ​As shown, in the non-contact short-circuit detection method of the present application, the electrodes 31, 32 are first electrically connected by the conductive body 21. When there originally exists no short-circuit between the electrodes 31, 32 (i.e., the electrodes 31, 32 are electrically isolated from each other), as shown in Figure 7 , the electrodes 31, 32 and the conductive body 21 do not form a closed circuit structure. When there originally exists a short-circuit between the electrodes 31, 32 by the conductive body (i.e., the conductive debris) 40, as shown in Figure 9 , the electrodes 31, 32 and the conductive bodies 21, 40 will form a closed circuit structure (herein the description of the closed circuit structure is only for the purpose of describing the principle of the detection method of the present application, thus the special case where the conductive body 21 coincides with the conductive body 40 is not considered). Figures 7-10

[0074] Next, referring again to Figure 7 , Figure 9 , in the non-contact short-circuit detection method of the present application, the coil 50, through which an alternating current (i.e., supplied with an alternating current, for example, by connecting an external power source) is passed, is placed on the area surrounded (or partially surrounded, i.e., the case shown in Figure 7 ) by the electrodes 31, 32 and the conductive body 21, i.e., the coil plane of the coil 50 is generally parallel to the plane where the area is located, and the distance between the two planes is such that the magnetic field generated by the coil 50 can pass through at least a part of the area. Alternatively, the coil 50 can be placed under the area; or the coil 50 can be placed in or outside the area, in which case the coil plane of the coil 50 is generally coincident with the plane where the area is located, and the coil 50 cannot contact the electrodes 31, 32 and the conductive body 21 (and the conductive body 40, if it exists).

[0075] Since in the case shown in Figure 7 , no closed circuit structure is formed, although the coil 50 through which an alternating current is passed generates a varying magnetic field, the electrodes 31, 32 and the conductive body 21 do not have a closed circuit structure that can generate an induced current in response to the varying magnetic field. At this time, although the external magnetic field variation can also induce an induced eddy current and an induced magnetic field inside the conductor circuit, when the circuit structure is small (for example, the circuit structure on a touch panel or a display screen), such signals are small and will be considered as interference signals or background noise. Therefore, the output current I out of the coil 50 is generally equal to the input current I in , as shown in Figure 8 . In this example, a rectified alternating current signal is used as the input signal of the coil 50, i.e., the input current I in , the amplitude of the input current I in is, for example, 200 mA, and the frequency is, for example, 450 KHz, then the amplitude and frequency of the output current I out are the same as those of the input current I​in Generally the same, i.e. I out = I in .

[0076] It should be noted that other forms of alternating electric signals can also be used as the input signal, such as unrectified alternating current signals, alternating voltage signals, pulsed voltage signals, pulsed current signals, etc. Different signal amplitudes and frequencies can also be used, as long as the input signal can cause the coil to generate a varying magnetic field. In addition, although a planar coil is shown, any type of coil can be used in practice, such as a spiral coil, a single-layer or multi-layer coil, a coreless or cored coil, etc.

[0077] In Figure 9 the case shown, the electrodes 31, 32 and the conductive body 21, 40 form a closed circuit structure, and the varying magnetic field generated by the coil 50 will induce an induced current I i in the closed circuit structure, as shown in Figure 9 . i The induced current I out flows in the closed circuit structure, thereby generating an induced magnetic field, which affects the original magnetic field of the coil 50, and in turn affects the output signal of the coil 50, in this example, the output current I out of the coil 50, as shown in Figure 10 . out I in .

[0078] Therefore, by detecting the change in the magnetic field or the output signal of the coil 50, it can be determined whether there is a closed circuit structure in its vicinity. Specifically, if the coil 50 is placed above (or below, or in, or outside) the area surrounded (or partially surrounded) by the electrodes 31, 32 and the conductive body 21 as described above, and it is found that the magnetic field or the output signal (e.g. the output current I out in this example) of the coil 50 suddenly decreases, for example, by 20%, it can be determined that the electrodes 31, 32 and the conductive body 21 have a conductive body 40 that forms a closed circuit structure with them, i.e. there is a conductive body 40 that short-circuits the electrodes 31, 32 at the electrodes 31, 32.

[0079] It can be seen that the method described above for determining whether there is a short circuit between two conductive bodies, such as the electrodes 31, 32, is fast, simple and easy to operate, and is non-contact, without damaging the electrodes 31, 32.

[0080] Preferably, the conductive body 21 previously applied to the electrodes 31, 32 should be easily removable. The following Figure 5 , 6The first preferred embodiment of the present application is shown to describe the additional application of the conductive body, i.e. the strip conductive structure 20.

[0081] Figure 11 and Figure 12 The cross-sectional views of the touch panel 1 and the strip conductive structure 20 thereon along the A-A line and the B-B line in Figure 5 are shown respectively. As shown in Figure 5 , 6 , 11 and 12, the sensing electrodes 13a and the driving electrodes 13c are formed on one surface of the substrate of the touch panel 1, the strip conductive structure 20 is applied on the sensing electrodes 13a, the driving electrodes 13c and the surface of the substrate, and covers the ends of the sensing electrodes 13a and the driving electrodes 13c close to the outer edge of the substrate 14. It should be noted that, for the sake of clear illustration, Figures 11-13 a gap is shown between the strip conductive structure 20 and the substrate of the touch panel 1 in , but in fact, due to the small thickness of the sensing electrodes 13a and the driving electrodes 13c, the strip conductive structure 20 is actually also attached to the surface of the substrate of the touch panel 1.

[0082] The strip conductive structure 20 is, for example, a conductive wire such as a metal wire, or a conductive adhesive strip, etc. It can be fixed in place by means of attachment, pressing, releasable adhesion, etc., so as to be fixed on the touch panel 1 during the detection process and easily removed from the touch panel 1 after the detection is completed. For example Figure 13 it is shown that, during the detection process, the strip conductive structure 20 is pressed on the touch panel 1 by applying a pressing force F thereon; and after the detection is completed, the strip conductive structure 20 can be easily separated from the touch panel 1 by releasing the pressing force F.

[0083] For the double-sided structure touch panel shown in Figure 2 , the electrodes thereon are electrically connected by the strip conductive structure 20, as shown in Figure 14 . However, because the touch panel of this structure has circuit structures on both surfaces of the substrate, the above-mentioned application of the strip conductive structure needs to be performed on both surfaces respectively.

[0084] The following describes the detection steps after the application of the strip conductive structure 20 is completed.

[0085] As shown in Figure 15 , the coil 50 through which the alternating input current I in flows is placed flat on one side of the touch panel 1, above one surface of the touch panel 1, moved to the other side of the touch panel 1, and the output current I outThe change in the coil 50 can be used to determine whether there is a short circuit in the circuit structure on that surface of the touch panel 1. In this article, this method of detecting while the coil 50 is moving is called the scanning method.

[0086] Specifically, in this example, the touch panel 1 is a large-size touch panel, with each of its sensing electrodes 13a and driving electrodes 13c measuring 17.8 cm and having a gap of 0.7 cm. The corresponding coil 50 is preferably 10 cm in size. The coil plane of the coil 50 is generally parallel to the plane of the touch panel 1 and is located on the side of the surface of the circuit structure to be detected on the touch panel 1. The distance between the coil plane and this surface is preferably 1 cm, and this distance is preferably maintained during the movement of the coil 50. The coil 50 moves from left to right of the touch panel 1 at a speed v (preferably 0.5 m / s), parallel to the strip-shaped conductive structure 20. Preferably, the moving path of the coil 50 (i.e., the path traversed by the center of the coil 50) is on the side of the strip conductive structure 20 away from the edge of the touch panel 1, and preferably at a distance of no more than 3 mm from the outer edge of the strip conductive structure 20, so that the central region of the coil 50 with a large magnetic field density can scan the sensing electrode 13a and the driving electrode 13c, so as to avoid missing the detection of short circuits caused by conductive debris falling on the sensing electrode 13a and the driving electrode 13c.

[0087] Considering that conductive debris may also fall on the areas of the sensing electrode 13a and the driving electrode 13c covered by the strip conductive structure 20, the conductive debris, electrodes, and strip conductive structure 20 will not be able to form a closed circuit structure. Therefore, the short circuit caused by the conductive debris in this case cannot be blocked by the aforementioned... Figures 7-10 The method described above detects that, preferably, before applying the strip-shaped conductive structure 20 to the touch panel 1, the electrode area of ​​the touch panel 1 is visually inspected (e.g., by a microscope) to see if there are any conductive debris that could cause a short circuit at the electrode. After confirming that there is no short circuit at the electrode, the above method is then used to detect whether there is a short circuit in the remaining circuit parts of the touch panel.

[0088] like Figure 15 and Figure 16 As shown, only one conductive debris 40 exists on the touch panel 1, located between drive unit columns 1311 and 1312, causing a short circuit between them. Therefore, as the coil 50 moves from the left side to the right side of the touch panel 1, initially, the output current I of the coil 50... out The amplitude, frequency and input current I in The two are largely the same, with an amplitude of I0; as coil 50 moves closer to the closed circuit structure formed by conductive debris 40, partial drive unit columns 1311 and 1312, and partial strip conductive structure 20, the output current I of coil 50 increases.out The amplitude begins to decrease, and as coil 50 moves away from the closed circuit structure, its output current I... out The amplitude gradually increased back to I0.

[0089] Therefore, the input current I of coil 50 can be appropriately set. in The parameters, geometric parameters, material structure, and / or the distance between the coil plane of coil 50 and the upper surface of touch panel 1, etc., enable the output current I of coil 50 when scanning through the aforementioned closed circuit structure. out The amplitude can decrease significantly, for example, by no less than 20% of I0. In this example, the output current I is set... out Threshold amplitude I tr =80%I0, and correspondingly set the output current I of coil 50. out The amplitude is less than the threshold amplitude I tr At that time, coil 50 is located at or near the aforementioned closed circuit structure. For example... Figure 16 As shown, as the coil 50 moves from the left side to the right side of the touch panel 1, at time t1, the coil 50 approaches the closed circuit structure and then passes through it. At time t2, the coil 50 moves away from the closed circuit structure. Therefore, by combining the moving speed v of the coil 50, it is possible to roughly calculate which area of ​​the touch panel 1 the detected short circuit occurred in, facilitating subsequent operations, such as locating and removing conductive debris 40 from the touch panel 1.

[0090] The above-mentioned output current I of coil 50 out The change in amplitude can be observed manually, for example by comparing the output current I displayed on an oscilloscope with the human eye. out Signal changes can also be performed automatically by a machine, for example, by changing the output current I of coil 50. out The processor connects it to the input current I. in A comparison can be made. Furthermore, to improve the accuracy of the comparison, the signals can be preprocessed, such as by using a lock-in amplifier to amplify the signals, or by filtering and denoising the signals.

[0091] As mentioned earlier, the circuitry on the touch panel 1 that does not form a closed circuit structure can also generate interference signals or background noise. Eliminating this type of signal noise requires additional electronic components and circuits, as well as extensive debugging work. Therefore, when testing large batches of products of the same specifications, such as touch panels, displays, PCBs, and FPCs, a preferred approach is to reduce the output current I of coil 50. out The signal is compared to a reference signal, rather than to the input current I mentioned above. in The signals are compared.

[0092] Specifically, in this scheme, the non-contact short-circuit detection method of the present invention is first applied to a qualified product. In this example, the qualified product is a touch panel 1 whose circuitry has been found to have no short circuits by testing (here, conventional testing methods can be used, such as probe testing described in the background section). As described above, a strip-shaped conductive structure 50 is applied to a defined location on the qualified touch panel 1 (hereinafter referred to as the reference touch panel 1), and an alternating input current I is passed through it. in The coil 50 is placed horizontally at a predetermined position on the left side of the reference touch panel 1 and moves to the right parallel to the strip conductive structure 50 at a predetermined speed v, thereby increasing the output current I of the coil 50. out The current is input to the processor and stored as a reference current; then, for other touch panels 1 with the same specifications (hereinafter referred to as the touch panel under test 1), the strip conductive structure 50 is applied to a defined position on the touch panel under test 1, and an alternating input current I is passed through it. in The coil 50 is placed horizontally at a predetermined position on the left side of the touch panel 1 under test and moves to the right parallel to the strip conductive structure 50 at a predetermined speed v, thereby increasing the output current I of the coil 50. out The current is connected to the processor and compared in real time with the previously saved reference current, such as... Figure 17 As shown, the reference current is represented by a dashed line, and the output current I is the output current output by coil 50 when scanning the touch panel 1 under test. out Represented by solid lines.

[0093] Similarly, when the coil 50 scans the touch panel 1 under test, the output current I at time t is set. out Threshold amplitude I tr =80%I0, where I0 is the output current I at time t when coil 50 scans the reference touch panel 1. out The threshold amplitude is set accordingly, and the output current I when coil 50 scans the touch panel 1 under test is set accordingly. out The amplitude is less than the threshold amplitude I tr At that time, the processor determines that coil 50 is at or near the aforementioned closed circuit structure. For example, see... Figure 15 and Figure 17 As coil 50 moves from the left side to the right side of the touch panel 1 under test, at time t1, coil 50 approaches the closed circuit structure and then passes through it. At time t2, coil 50 moves away from the closed circuit structure. Therefore, by combining the moving speed v of coil 50, it is possible to roughly calculate which area of ​​the touch panel 1 under test the detected short circuit occurs in, facilitating subsequent operations, such as locating and removing conductive debris 40 from the touch panel 1 under test.

[0094] To further improve detection accuracy and more precisely indicate which area of ​​the touch panel 1 under test the short circuit occurs in, the touch panel 1 can be divided into sections, such as... Figure 18 As shown, the touch panel 1 is divided into three regions, I, II, and III, in the longitudinal direction (along the direction of the drive unit column), transverse to the direction of the drive unit column. The coil 50 can then scan through these regions sequentially. For example, the coil 50 moves laterally from the left side of the touch panel 1 to the right side of the touch panel 1 in region I, then laterally to the left side of the touch panel 1 in region II, and then laterally to the right side of the touch panel 1 in region III. If the aforementioned conductive debris 40 is present in region I, the output current I output when the coil 50 scans through region II... out The decrease in amplitude will be smaller, and the output current I output when scanning through region III will be smaller. out The magnitude of the decrease will be smaller, based on which it can be determined that the short circuit occurred in region I.

[0095] In practical use, the touch panel 1 can be divided into sections as needed, such as equal or unequal divisions, into two, three, four or more areas.

[0096] The above description describes a short circuit occurring between adjacent rows of driving units. However, it could also occur between rows of sensing units, such as sensing unit rows 1321 and 1322. Therefore, similarly, to further improve detection accuracy and more precisely indicate which area of ​​the touch panel under test the short circuit occurs in, the touch panel 1 can be divided into three regions IV, V, and VI laterally (along the direction of the driving unit rows), as shown below. Figure 18 As shown. Similarly, the coil 50 can scan through these areas sequentially. For example, the coil 50 moves vertically downward from the upper side of the touch panel 1 to the lower side of the touch panel 1 in area IV, then moves vertically upward to the upper side of the touch panel 1 in area V, and then moves vertically downward to the lower side of the touch panel 1 in area VI.

[0097] Of course, to improve detection efficiency, multiple coils can be used to scan these areas simultaneously. For example... Figure 19 As shown, three coils 51, 52, and 53 are used and placed at defined positions in regions I, II, and III on the left side of the touch panel 1, respectively. They are then moved laterally to the right side of the touch panel 1 from the left side in regions I, II, and III at a speed v, respectively. Further, as... Figure 20As shown, the sea can use three coils 51, 52 and 53, place them at determined positions in regions IV, V and VI on the upper side of the touch panel 1 respectively, and then make them move longitudinally downwards from the upper side of the touch panel 1 in regions IV, V and VI respectively to the lower side of the touch panel 1 at a speed v.

[0098] Finally, those skilled in the art can understand that although the present application is mainly directed to Figure 1 The non-contact short-circuit detection method of the present application is described above for the single-sided structure touch panel 1 as shown, but can also be used to identify short-circuit defects in the circuit of other forms of touch panels, such as the double-sided structure touch panel as shown in Figure 2 The non-contact short-circuit detection method of the present application can also be used to identify short-circuit defects in the circuit of other forms of touch panels, such as the double-sided structure touch panel as shown in Figure 3 The non-contact short-circuit detection method of the present application can also be used to identify short-circuit defects in the circuit of other forms of touch panels, such as the double-sided structure touch panel as shown in

[0099] In particular, for a touch panel such as the one shown in Figure 3 The non-contact short-circuit detection method of the present application can also be used to identify short-circuit defects in the circuit of other forms of touch panels, such as the double-sided structure touch panel as shown in Figure 1 The non-contact short-circuit detection method of the present application can also be used to identify short-circuit defects in the circuit of other forms of touch panels, such as the double-sided structure touch panel as shown in Figure 2 The non-contact short-circuit detection method of the present application can also be used to identify short-circuit defects in the circuit of other forms of touch panels, such as the double-sided structure touch panel as shown in

[0100] In addition, those skilled in the art can understand that the non-contact short-circuit detection method of the present application can also be used to identify short-circuit defects in the circuit of other devices with fine circuit structures, such as display screens, PCB boards, FPCs, etc., or circuit products including display screens, PCB boards, FPCs, as long as these circuit products have two or more non-hanging electrodes to be electrically connected by the strip-shaped conductive structure to form a closed circuit structure, and preferably the circuit of these circuit products does not have a closed circuit structure when no strip-shaped conductive structure is applied.

[0101] The preferred embodiments of the present application are described in detail above. It should be understood that those skilled in the art can make many modifications and changes without creative labor based on the concept of the present application. Therefore, any technical solutions that can be obtained by logical analysis, reasoning or limited experiments by those skilled in the art based on the concept of the present application on the basis of the prior art shall be within the protection scope defined by the claims.

Claims

1. A non-contact short-circuit detection method for determining whether a short circuit exists in a circuit of a test circuit product having two or more non-floating electrodes, characterized in that, include: A circuit product with the same circuit as the circuit product under test, and which has no short circuits, is used as the standard circuit product. Apply the same strip-shaped conductive structure to electrically connect the two or more electrodes of the circuits of the standard circuit product and the circuit product under test, respectively; The circuit is formed by electrically connecting two or more electrodes of the standard circuit product and the circuit product under test, respectively, using the same coil supplied with alternating current. When the coil is at the same position as the circuits of the standard circuit product and the circuit product under test, the first magnetic field strength of the first magnetic field generated when the coil is adjacent to the circuit of the standard circuit product and the second magnetic field strength of the second magnetic field generated when the coil is adjacent to the circuit of the circuit product under test are respectively obtained, wherein the first magnetic field and the second magnetic field have the same direction and are both inclined to the plane where the adjacent circuit is located. The first magnetic field strength and the second magnetic field strength are compared. If the second magnetic field strength is less than 5%-50% of the first magnetic field strength, it is determined that there is a short circuit in the circuit of the circuit product under test; otherwise, it is determined that there is no short circuit in the circuit of the circuit product under test.

2. The short-circuit detection method as claimed in claim 1, wherein for the standard circuit product and the circuit product under test, the coils are respectively moved from one side of their circuit to the opposite side along the direction of their two or more electrode arrangements, and the first magnetic field strength and the second magnetic field strength are respectively acquired during the movement of the coils.

3. The short-circuit detection method as described in claim 1, wherein, When the strength of the second magnetic field is less than 5%-20% of the strength of the first magnetic field, it is determined that there is a short circuit in the circuit of the circuit product under test.

4. The short-circuit detection method as described in claim 1, wherein, The circuit products include any one of touch panels, displays, PCBs, and FPCs.

5. The short-circuit detection method as described in claim 1, wherein, When the strip-shaped conductive structure is not applied, there is no closed circuit structure in the circuit of the circuit product.

6. A non-contact short-circuit detection method for determining whether a short circuit exists in a circuit of a test circuit product having two or more non-floating electrodes, characterized in that, include: A circuit product with the same circuit as the circuit product under test, and which has no short circuits, is used as the standard circuit product. Apply the same strip-shaped conductive structure to electrically connect the two or more electrodes of the circuits of the standard circuit product and the circuit product under test, respectively; The circuit is formed by electrically connecting two or more electrodes of the standard circuit product and the circuit product under test, respectively, using the same coil supplied with alternating current. When the coil is at the same position as the circuits of the standard circuit product and the circuit product under test, the first current amplitude of the first alternating current output by the coil when it is near the circuit of the standard circuit product, and the second current amplitude of the second alternating current output when it is near the circuit of the circuit product under test are respectively obtained, wherein the magnetic field generated by the coil when it is near the standard circuit product and the circuit of the standard circuit product has the same direction and is inclined to the plane of the adjacent circuit. The first current amplitude and the second current amplitude are compared. If the second current amplitude is less than 5%-50% of the first current amplitude, it is determined that there is a short circuit in the circuit of the circuit product under test; otherwise, it is determined that there is no short circuit in the circuit of the circuit product under test.

7. The short-circuit detection method as described in claim 6, comprising: For the standard circuit product and the circuit under test product, the coils are moved from one side of their circuit to the opposite side along the direction of their two or more electrode arrangements, and the first current amplitude and the second current amplitude are acquired respectively during the movement of the coils.

8. The short-circuit detection method as described in claim 7, wherein, For the standard circuit product and the circuit under test, their circuits are divided into two or more transverse regions in a direction perpendicular to the electrode arrangement, and the coil is moved from one side of the circuit to the opposite side in each of the two or more transverse regions.

9. The short-circuit detection method as described in claim 7, wherein, For the standard circuit product and the circuit under test, their circuits are divided into two or more transverse regions in a direction perpendicular to the electrode arrangement, and each of the two or more coils is moved from one side of the circuit to the opposite side in a corresponding region of the two or more transverse regions.

10. The short-circuit detection method as described in claim 7 or 8, further comprising: For the standard circuit product and the circuit under test, their circuits are further divided into two or more longitudinal regions in a direction parallel to the electrode arrangement, and the coil is moved from one side of the circuit to the opposite side in each of the two or more longitudinal regions, perpendicular to the direction of the two or more electrode arrangements.

11. The short-circuit detection method as described in claim 7 or 8, further comprising: For the standard circuit product and the circuit under test, their circuits are further divided into two or more longitudinal regions in a direction parallel to the electrode arrangement, and each of the two or more coils is moved from one side of the circuit to the opposite side in a corresponding region of the two or more longitudinal regions, perpendicular to the direction of the two or more electrode arrangements.

12. The short-circuit detection method as described in claim 6, wherein, When the amplitude of the second current is less than 5%-20% of the amplitude of the first current, it is determined that there is a short circuit in the circuit of the circuit product under test.

13. The short-circuit detection method as described in claim 6, wherein, The circuit products include any one of touch panels, displays, PCBs, and FPCs.

14. The short-circuit detection method as described in claim 6, wherein, When the strip-shaped conductive structure is not applied, there is no closed circuit structure in the circuit of the circuit product.

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