Device and method for detecting resistance on line by using four-probe method

Abstract

The invention provides a device and a method for detecting a resistor on line by using a four-probe method, and belongs to the technical field of resistance testing. The device comprises a supporting column, a sliding rail and a roller group, wherein the supporting column is rotatably sleeved with the sliding rail; the roller group comprises a first roller and a second roller, and the first roller and the second roller are arranged outside the sliding rail in a sleeving manner and can move on the sliding rail; a first probe group is convexly arranged on the peripheral wall of the first roller and comprises a current probe and a voltage probe which are distributed at an interval, and a second probe group is convexly arranged on the peripheral wall of the second roller and comprises a current probe and a voltage probe which are distributed at an interval; the first probe group is used for being connected with the first conductive area, and the second probe group is used for being connected with the second conductive area; the two current probes are electrically connected with the positive electrode and the negative electrode of an external constant current source, the two voltage probes are electrically connected with the positive electrode and the negative electrode of an external voltmeter, and the device can be used for online detection of the transfer welding resistor in the continuous production process.

Description

Technical Field

[0001] The present application relates to the technical field of resistance testing, and in particular, to a device and method for online detecting resistance using the four-probe method. Background Art

[0002] Composite current collectors (usually including a polymer substrate layer and conductive layers on both sides of the polymer substrate layer) are widely used in the field of secondary battery manufacturing due to advantages such as high energy density, good safety, and low manufacturing cost. Among them, due to the polymer substrate layer in the composite current collector, it is difficult to directly weld with the tab or terminal post. Usually, it is necessary to perform a transfer weld between the composite current collector and a traditional foil, and then weld the traditional foil with the tab or terminal post. As the bridge for conductive connection, the resistance of the transfer weld area directly affects the performance of the corresponding battery cell. Therefore, it is particularly important to detect the resistance of the transfer weld area.

[0003] At present, most resistance detections are carried out using devices designed based on the two-probe resistance detection principle. For example, a micro-resistance quantization test device designed in CN218629622 U, a thin-film solar cell insulation wire resistance online test device in CN 114325099 A, and a resistivity measurement device for a pole piece in CN 221078789 U. However, due to the small resistance of the transfer weld area (only in the milliamp level), there is a problem of large resistance detection error in two-probe resistance detection, which is not suitable for detecting the resistance of the transfer weld area. The four-probe resistance detection method can make up for the defects of the two-probe resistance detection method. In addition, the current process of forming transfer welds on composite current collectors usually adopts a continuous production method, while conventional resistance detection means can only perform sampling detection (that is, it is necessary to stop the production line and then intercept a part of the sample with a transfer weld area for offline resistance detection), making it difficult to monitor the overall quality of the transfer weld, which in turn affects the consistency of the prepared battery cells. Therefore, there is an urgent need to develop a device and method based on the four-probe resistance detection method that can online detect the resistance of the transfer weld during the continuous production process to improve the consistency of the battery cells. Summary of the Invention

[0004] The purpose of the present application is to provide a device and method for online detecting resistance using the four-probe method, which can online detect the resistance of the transfer weld during the continuous production process.

[0005] The embodiments of the present application are implemented as follows: In a first aspect, an embodiment of the present application provides a device for on-line resistance detection using the four-probe method, which is used to on-line detect the resistance of the transfer welding area of a film material. The film material includes a transfer welding area and a first conductive area and a second conductive area located on both sides in the width direction thereof. The device includes a support column, a slide rail, and a roller group. The slide rail is rotatably sleeved outside the support column; the roller group includes two first rollers and second rollers spaced apart. The first rollers and the second rollers are both sleeved outside the slide rail and can move on the slide rail; a first probe group is convexly provided on the outer peripheral wall of the first roller. The first probe group includes a current probe and a voltage probe spaced apart. A second probe group is convexly provided on the outer peripheral wall of the second roller. The second probe group includes a current probe and a voltage probe spaced apart; along the axial direction of the slide rail, the two voltage probes are located between the two current probes. The first probe group located on the first roller is used to connect with the first conductive area and can make the first roller and the slide rail rotate synchronously when the first conductive area moves. The second probe group located on the second roller is used to connect with the second conductive area and can make the second roller and the slide rail rotate synchronously when the second conductive area moves; the two current probes are configured to be electrically connected to the positive and negative electrodes of an external constant current source through the axial ends of the support column, and the two voltage probes are configured to be electrically connected to the positive and negative electrodes of an external voltmeter through the axial ends of the support column.

[0006] In the above technical solution, the resistance detection device has the above structure. When the position of the first roller is fixed, by continuously changing the position of the second roller on the slide rail, a linear relationship between the total resistance of the second roller plus the second conductive area located between the two (i.e., the second roller and the transfer welding area) and the position of the second roller can be obtained; when the position of the second roller is fixed, by continuously changing the position of the first roller on the slide rail, a linear relationship between the total resistance of the first roller plus the first conductive area located between the two (i.e., the first roller and the transfer welding area) and the position of the first roller can be obtained; then, after the positions of the first roller and the second roller are fixed, by controlling the film material to move in the length direction and driving the first roller, the second roller, and the slide rail to rotate synchronously, the resistance of the transfer welding area of the film material can be calculated according to the detected internal resistance value and the above two linear relationships.

[0007] In some alternative embodiments, along the circumferential direction of the first roller, the first probe group includes multiple; along the circumferential direction of the second roller, the second probe group includes multiple, and along the axial direction of the slide rail, the first probe group and the second probe group are arranged in one-to-one correspondence.

[0008] In the above technical solution, a plurality of first probe groups and second probe groups are both arranged circumferentially along the corresponding rollers, that is, a sufficient number of resistance detection points are set, which can more accurately reflect the transfer welding resistance of different regions of the film material in the length direction; in addition, the first probe group and the second probe group are arranged in a one-to-one correspondence along the axial direction of the slide rail, which has the advantage of a relatively regular overall structure.

[0009] In some alternative embodiments, the first roller further includes a plurality of mounting components arranged in one-to-one correspondence with the first probe groups. Each mounting component includes a mounting piece, and one current probe and one voltage probe of each first probe group are mounted on the mounting piece.

[0010] In the above technical solution, a plurality of mounting components corresponding to the plurality of first probe groups are arranged in the first roller. Each mounting component includes a mounting piece, and one current probe and one voltage probe of each first probe group are mounted on the mounting piece, which has the advantages of facilitating the installation of the first probe group and a relatively reasonable layout.

[0011] In some alternative embodiments, each mounting component further includes an elastic member. Along the radial direction of the first roller, the elastic member is arranged on the side of the mounting piece facing away from the first probe group, so that the first probe group connected to the mounting piece can reciprocate in the radial direction of the first roller under the action of the elastic member.

[0012] In the above technical solution, the mounting component is provided with an elastic member, and the elastic member is arranged on the side of the mounting piece facing away from the first probe group, so that the first probe group connected to the mounting piece can reciprocate in the radial direction of the first roller, thereby improving the compatibility of the device with film materials of different thickness specifications. In particular, when the thicknesses of the first conductive region and the second conductive region are different, the device can also realize the on-line detection of the transfer welding resistance.

[0013] In some alternative embodiments, each mounting component further includes a limiting member. The limiting member is spaced from the mounting piece along the radial direction of the first roller. The limiting member is fixedly connected to the first roller, and the first probe group slides through the limiting member along the radial direction of the first roller.

[0014] In the above technical solution, the mounting component further includes a limiting member, and the first probe group slides through the limiting member along the radial direction of the first roller, which can enable the first probe group to move only along the radial direction of the first roller, thereby making the connection between the first probe group and the first conductive region more stable.

[0015] In some alternative embodiments, the interiors of the first roller and the second roller further include first current collectors extending circumferentially. The current probes of the multiple first probe groups are all connected to the first current collector within the first roller, and the current probes of the multiple second probe groups are all connected to the first current collector within the second roller. Moreover, both of the two first current collectors are configured to be connected to the positive and negative electrodes of an external constant current source via the axial two ends of the support column. The interiors of the first roller and the second roller further include second current collectors extending circumferentially. The voltage probes of the multiple first probe groups are all connected to the second current collector within the first roller, and the voltage probes of the multiple second probe groups are all connected to the second current collector within the second roller. Also, both of the two second current collectors are configured to be connected to the positive and negative electrodes of an external voltmeter via the axial two ends of the support column.

[0016] In the above technical solution, both the first roller and the second roller are provided with a first current collector and a second current collector. Among them, the multiple current probes within the first roller and the second roller are respectively connected to the corresponding first current collectors, and the multiple voltage probes within the first roller and the second roller are respectively connected to the corresponding second current collectors. By setting up the current collectors, the connection of the multiple current probes to the external constant current source and the connection of the multiple voltage probes to the external voltmeter are respectively achieved, which has the advantages of relatively simple circuit layout, convenient inspection and maintenance, etc.

[0017] In some alternative embodiments, the inner wall of the slide rail is provided with two first current guiding rings and two second current guiding rings extending circumferentially along the slide rail. The two first current guiding rings and the two second current guiding rings are spaced apart axially along the slide rail. The two first current guiding rings are respectively conductively connected to the two first current collectors, and the two second current guiding rings are respectively conductively connected to the two second current collectors. The outer wall of the support column is provided with two third current guiding rings and two fourth current guiding rings extending circumferentially along the support column. The two third current guiding rings are respectively in one-to-one correspondence with the two first current guiding rings and are connected through conductive bearings, and the two fourth current guiding rings are respectively in one-to-one correspondence with the two second current guiding rings and are connected through conductive bearings. The two third current guiding rings are respectively connected to the positive and negative electrodes of the external voltmeter via wires through the axial two ends of the support column, and the two fourth current guiding rings are respectively connected to the positive and negative electrodes of the external voltmeter via wires through the axial two ends of the support column.

[0018] In the above technical solution, the inner wall of the slide rail is respectively provided with two first current guiding rings and two second current guiding rings corresponding to the first current collector and the second current collector one by one. At the same time, the outer wall of the support column is respectively provided with two third current guiding rings and two fourth current guiding rings corresponding to the first current guiding rings and the second current guiding rings one by one. Moreover, the first current guiding rings and the third current guiding rings, and the second current guiding rings and the fourth current guiding rings are all connected through conductive bearings, so that the slide rail can be rotatably sleeved on the support column and can also achieve the transmission of internal current, which has the advantages of simple structure, easy manufacturing and relatively high structural stability.

[0019] In some alternative embodiments, along the axial direction of the slide rail, fixing blocks are provided on both sides of each roller. A plurality of fixing blocks are all connected to the outer peripheral wall of the slide rail. Each fixing block has a locked state and a disengaged state. When the fixing block is in the locked state, the fixing block is fixed to the slide rail so that the position of the roller on the slide rail is fixed; when the fixing block is in the disengaged state, the fixing block can move on the slide rail so that the roller can move on the slide rail.

[0020] In the above technical solution, fixing blocks are respectively provided on both sides of the first roller and the second roller, and the position of the roller on the slide rail can be fixed by the fixing member after the roller moves to a preset position, thereby improving the inspection accuracy of the resistance. At the same time, the stability of the roller during rotation can also be improved.

[0021] In some alternative embodiments, a limiting strip extending along the axial direction of the slide rail is convexly provided on the outer peripheral wall of the slide rail. Each fixing block is sleeved on the limiting strip and connected to the limiting strip by a bolt.

[0022] In the above technical solution, the outer peripheral wall of the slide rail is convexly provided with a limiting strip for installing the fixing block, which has the advantage of facilitating the installation of the fixing block; at the same time, the fixing block is sleeved on the limiting strip and connected to the limiting strip by a bolt, which has the advantages of simple structure and convenient operation.

[0023] In a second aspect, an embodiment of the present application provides a method for on-line detecting resistance using the four-probe method. The detection is performed using the device provided in the embodiment of the first aspect, and includes the following steps: Place the device above the film material so that the first probe group located on the first roller is connected to the first conductive region; and the second probe group located on the second roller is connected to the second conductive region; fix the position of the first roller on the slide rail, and adjust the distance D between the second roller and the transfer welding region by changing the position of the second roller on the slide rail 1 , so as to respectively test different Ds 1 corresponding DC internal resistance values R 1 , take multiple Ds 1 as the abscissa and the corresponding multiple DC internal resistance values R 1 as the ordinate for linear fitting to obtain the slope K 1 ; fix the position of the second roller on the slide rail, and adjust the distance D between the first roller and the transfer welding region by changing the position of the first roller on the slide rail 2 , so as to respectively test different Ds 2 corresponding DC internal resistance values R 2 , take multiple Ds 2 as the abscissa and the corresponding multiple DC internal resistance values R 2 as the ordinate for linear fitting to obtain the slope K 2;Meanwhile, fix the positions of the first roller and the second roller on the slide rail to obtain the distance L between the first roller and the transfer welding area 1 and the distance L between the second roller and the transfer welding area 2 , control the movement of the film material along the length direction to drive the first roller, the second roller and the slide rail to rotate synchronously to obtain the DC internal resistance value R 3 , calculate the resistance R of the transfer welding area according to the formula 转接焊 , where the calculation formula is: R 转接焊 =R 3 -L 1 ×K 2 -L 2 ×K 1 .

[0024] In the above technical solution, operate step by step according to the above method. When testing the resistance of the transfer welding area, not only the resistances of the first roller and the second roller are considered, but also the resistance of the first conductive area between the first roller and the transfer welding area and the resistance of the second conductive area between the second roller and the transfer welding area are considered. After removing them, the resistance of the transfer welding area is obtained, which can make the test result of the resistance more accurate and can reflect the transfer welding effect of the transfer welding area in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 is a combined schematic diagram of a device for online resistance detection and a film material provided by an embodiment of the present application; Figure 2 is a schematic diagram of the principle of resistance detection provided by an embodiment of the present application; Figure 3 is a schematic structural diagram of a device for online resistance detection provided by an embodiment of the present application; Figure 4 is a schematic internal structure diagram of a first roller provided by an embodiment of the present application; Figure 5 is Figure 4 an enlarged view of part A in Figure 6 is a combined schematic diagram of a slide rail and a support column provided by an embodiment of the present application; Figure 7 is Figure 6 an enlarged view of part B in Figure 8 A combined schematic diagram of the fixed block and the slide rail provided by the embodiment of the present application; Figure 9 A relative position relationship diagram of the first roller and the second roller provided by the present application with respect to the film material.

[0027] Icons: 10 - device for on-line detecting resistance; 100 - support column; 110a - third current-conducting ring; 110b - fourth current-conducting ring; 200 - slide rail; 210 - limiting strip; 300 - roller set; 310 - first roller; 320 - second roller; 330a - first probe set; 330b - second probe set; 331 - current probe; 332 - voltage probe; 340 - mounting assembly; 341 - mounting part; 342 - elastic part; 343 - limiting part; 350a - first current-collecting ring; 350b - second current-collecting ring; 360a - first current-conducting ring; 360b - second current-conducting ring; 370 - conductive bearing; 400 - fixed block; 410 - bolt; 20 - film material; 21 - transition welding area; 22 - first conductive area; 23 - second conductive area; 30 - constant current source; 40 - voltmeter. Detailed implementation manners

[0028] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. The components of the embodiments of the present application usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0029] Therefore, the detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but merely represents the selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0030] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0031] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of this application is usually placed during use. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0032] In the description of the present application, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0033] The following specifically describes a device and a method for on-line resistance detection using the four-probe method provided by the present application.

[0034] Refer to Figure 1 and Figure 2, in a first aspect, an apparatus 10 for on-line resistance detection using the four-probe method according to an embodiment of the present application is used for on-line detecting the resistance of the transfer welding area 21 of a film material 20. The film material 20 includes a transfer welding area 21 and a first conductive area 22 and a second conductive area 23 located on both sides in the width direction thereof. The apparatus includes a support column 100, a slide rail 200, and a roller set 300. The slide rail 200 is rotatably sleeved outside the support column 100; the roller set 300 includes two first rollers 310 and second rollers 320 spaced apart. Both the first rollers 310 and the second rollers 320 are sleeved outside the slide rail 200 and can move on the slide rail 200; a first probe set 330a protrudes from the outer peripheral wall of the first roller 310. The first probe set 330a includes a current probe 331 and a voltage probe 332 spaced apart. A second probe set 330b protrudes from the outer peripheral wall of the second roller 320. The second probe set 330b includes a current probe 331 and a voltage probe 332 spaced apart; along the axial direction of the slide rail 200, the two voltage probes 332 are located between the two current probes 331. The first probe set 330a located on the first roller 310 is used to connect to the first conductive area 22 and can make the first roller 310 and the slide rail 200 rotate synchronously when the first conductive area 22 moves. The second probe set 330b located on the second roller 320 is used to connect to the second conductive area 23 and can make the second roller 320 and the slide rail 200 rotate synchronously when the second conductive area 23 moves; the two current probes 331 are configured to be electrically connected to the positive and negative electrodes of an external constant current source 30 through the axial ends of the support column 100, and the two voltage probes 332 are configured to be electrically connected to the positive and negative electrodes of an external voltmeter 40 through the axial ends of the support column 100.

[0035] In this application, the resistance detection device has the above structure. When the position of the first roller 310 is fixed, by continuously changing the position of the second roller 320 on the slide rail 200 and the corresponding internal resistance value (the internal resistance value can be obtained by R = U / I, where U can be obtained by reading the voltage of the voltmeter 40, and I is determined by the constant current source 30 and remains unchanged), the linear relationship between the total resistance of the second roller 320 plus the second conductive region 23 between the two (i.e., the second roller 320 and the transfer welding region 21) and the position of the second roller 320 can be obtained; when the position of the second roller 320 is fixed, by continuously changing the position of the first roller 310 on the slide rail 200, the linear relationship between the total resistance of the first roller 310 plus the first conductive region 22 between the two (i.e., the first roller 310 and the transfer welding region 21) and the position of the first roller 310 can be obtained; then, after the positions of the first roller 310 and the second roller 320 are fixed, the calibrated resistance of the transfer welding region 21 can be calculated by combining the actual measured resistance value with the above two linear relationships; then, while keeping the positions of the first roller 310 and the second roller 320 unchanged, by controlling the movement of the film material 20 in the length direction and driving the first roller 310, the second roller 320, and the slide rail 200 to rotate synchronously, the resistance of the transfer welding region 21 of the film material 20 can be calculated according to the detected internal resistance value and the above two linear relationships.

[0036] Referring to Figure 3 , as an example, along the circumferential direction of the first roller 310, the first probe group 330a includes a plurality of; along the circumferential direction of the second roller 320, the second probe group 330b includes a plurality of, and along the axial direction of the slide rail 200, the first probe group 330a and the second probe group 330b are arranged in one-to-one correspondence.

[0037] In this embodiment, both the first probe group 330a and the second probe group 330b are provided with a plurality of along the circumferential direction of the corresponding roller, that is, a sufficient number of resistance detection points are set, which can more accurately reflect the transfer welding resistance of different regions of the film material 20 in the length direction; in addition, the first probe group 330a and the second probe group 330b are arranged in a one-to-one correspondence along the axial direction of the slide rail 200, which has the advantage of a more regular overall structure.

[0038] It should be noted that the specific number of the first probe group 330a and the second probe group 330b is not limited and can be adjusted adaptively according to actual needs.

[0039] Referring to Figure 4 and Figure 5, as an example, the first roller 310 further includes a plurality of mounting components 340 arranged in one-to-one correspondence with the first probe group 330a. Each mounting component 340 includes a mounting member 341. One current probe 331 and one voltage probe 332 of each first probe group 330a are mounted on the mounting member 341.

[0040] In this embodiment, a plurality of mounting components 340 corresponding to the plurality of first probe groups 330a are provided in the first roller 310. Each mounting component 340 includes a mounting member 341, and one current probe 331 and one voltage probe 332 of each first probe group 330a are mounted on the mounting member 341, which has the advantages of facilitating the installation of the first probe group 330a and having a more reasonable layout.

[0041] Refer to Figure 5 , as an example, each mounting component 340 further includes an elastic member 342. Along the radial direction of the first roller 310, the elastic member 342 is arranged on the side of the mounting member 341 facing away from the first probe group 330a, so that the first probe group 330a connected to the mounting member 341 can reciprocate along the radial direction of the first roller 310 under the action of the elastic member 342.

[0042] In this embodiment, the mounting component 340 is provided with an elastic member 342, and the elastic member 342 is arranged on the side of the mounting member 341 facing away from the first probe group 330a, so that the first probe group 330a connected to the mounting member 341 can reciprocate along the radial direction of the first roller 310, thereby improving the compatibility of the device with membrane materials 20 of different thickness specifications. In particular, when the thicknesses of the first conductive region 22 and the second conductive region 23 are different, the on-line detection of the transfer welding resistance can also be realized through this device.

[0043] Refer to Figure 5 , as an example, each mounting component 340 further includes a limiting member 343. The limiting member 343 is spaced from the mounting member 341 along the radial direction of the first roller 310. The limiting member 343 is fixedly connected to the first roller 310, and the first probe group 330a slidably penetrates through the limiting member 343 along the radial direction of the first roller 310.

[0044] In this embodiment, the mounting component 340 further includes a limiting member 343, and the first probe group 330a slidably penetrates through the limiting member 343 along the radial direction of the first roller 310, which can enable the first probe group 330a to move only along the radial direction of the first roller 310, thereby making the connection between the first probe group 330a and the first conductive region 22 more stable.

[0045] It should be noted that since the overall structures and basic functions of the first roller 310 and the second roller 320 are the same, the internal structure of the second roller 320 can be set with reference to the first roller 310.

[0046] As an example, the second roller 320 further includes a plurality of mounting components 340 respectively arranged in one-to-one correspondence with the second probe group 330b. Each mounting component 340 includes a mounting member 341, and one current probe 331 and one voltage probe 332 of each second probe group 330b are mounted on the mounting member 341.

[0047] As an example, each mounting component 340 further includes an elastic member 342. Along the radial direction of the second roller 320, the elastic member 342 is arranged on the side of the mounting member 341 facing away from the second probe group 330b, so that the second probe group 330b connected to the mounting member 341 can reciprocate along the radial direction of the second roller 320 under the action of the elastic member 342.

[0048] As an example, each mounting component 340 further includes a limiting member 343. The limiting member 343 is spaced from the mounting member 341 along the radial direction of the second roller 320. The limiting member 343 is fixedly connected to the second roller 320, and the second probe group 330b slides through the limiting member 343 along the radial direction of the second roller 320.

[0049] Refer to Figure 5 , as an example, the interiors of the first roller 310 and the second roller 320 further include first current collectors 350a respectively extending circumferentially. The current probes 331 of the plurality of first probe groups 330a are all connected to the first current collector 350a in the first roller 310. The current probes 331 of the plurality of second probe groups 330b are all connected to the first current collector 350a in the second roller 320, and the two first current collectors 350a are both configured to be connected to the positive and negative electrodes of the external constant current source 30 through the axial ends of the support column 100; the interiors of the first roller 310 and the second roller 320 further include second current collectors 350b respectively extending circumferentially. The voltage probes 332 of the plurality of first probe groups 330a are all connected to the second current collector 350b in the first roller 310. The voltage probes 332 of the plurality of second probe groups 330b are all connected to the second current collector 350b in the second roller 320, and the two second current collectors 350b are both configured to be connected to the positive and negative electrodes of the external voltmeter 40 through the axial ends of the support column 100.

[0050] In this embodiment, a first current collector ring 350a and a second current collector ring 350b are provided inside both the first roller 310 and the second roller 320. Among them, a plurality of current probes 331 inside the first roller 310 and the second roller 320 are respectively connected to the corresponding first current collector ring 350a, and a plurality of voltage probes 332 inside the first roller 310 and the second roller 320 are respectively connected to the corresponding second current collector ring 350b. By setting the current collector rings, the connection between the plurality of current probes 331 and the external constant current source 30 and the connection between the plurality of voltage probes 332 and the external voltmeter 40 are respectively realized, which has the advantages of relatively simple circuit layout and convenient inspection and maintenance.

[0051] Refer to Figure 6 and Figure 7 , as an example, two first current guiding rings 360a and two second current guiding rings 360b extending along the circumferential direction of the slide rail 200 are provided on the inner wall of the slide rail 200. The two first current guiding rings 360a and the two second current guiding rings 360b are spaced apart along the axial direction of the slide rail 200. The two first current guiding rings 360a are respectively conductively connected to the two first current collector rings 350a (optionally, they can be connected by wires or metal strips, etc.), and the two second current guiding rings 360b are respectively conductively connected to the two second current collector rings 350b (optionally, they can be connected by wires or metal strips, etc.); two third current guiding rings 110a and two fourth current guiding rings 110b extending along the circumferential direction of the support column 100 are provided on the outer wall of the support column 100. The two third current guiding rings 110a are respectively in one-to-one correspondence with the two first current guiding rings 360a and are connected through conductive bearings 370, and the two fourth current guiding rings 110b are respectively in one-to-one correspondence with the two second current guiding rings 360b and are connected through conductive bearings 370; the two third current guiding rings 110a are respectively connected to the positive and negative poles of the external voltmeter 40 through wires at the two axial ends of the support column 100, and the two fourth current guiding rings 110b are respectively connected to the positive and negative poles of the external voltmeter 40 through wires at the two axial ends of the support column 100.

[0052] In this embodiment, two first current guiding rings 360a and two second current guiding rings 360b corresponding to the first current collector ring 350a and the second current collector ring 350b respectively are provided on the inner wall of the slide rail 200. At the same time, two third current guiding rings 110a and two fourth current guiding rings 110b corresponding to the first current guiding ring 360a and the second current guiding ring 360b respectively are provided on the outer wall of the support column 100. And connections between the first current guiding ring 360a and the third current guiding ring 110a, and between the second current guiding ring 360b and the fourth current guiding ring 110b are all realized through conductive bearings 370, so that the slide rail 200 is rotatably sleeved on the support column 100 and can also realize the transmission of internal current, which has the advantages of simple structure, easy manufacturing and high structural stability.

[0053] It should be noted that the relative positional relationship between the two first flow guiding rings 360a and the two second flow guiding rings 360b is not limited and can be adaptively adjusted according to actual needs.

[0054] Refer to Figure 6 and Figure 7 , as an example, along the axial direction of the slide rail 200, the two second flow guiding rings 360b are located between the two first flow guiding rings 360a. Correspondingly, along the axial direction of the support column 100, the two fourth flow guiding rings 110b are located between the two third flow guiding rings 110a.

[0055] Refer to Figure 8 , as an example, along the axial direction of the slide rail 200, fixing blocks 400 are arranged on both sides of each roller. The plurality of fixing blocks 400 are all connected to the outer peripheral wall of the slide rail 200. Each fixing block 400 has a locked state and a disengaged state. When the fixing block 400 is in the locked state, the fixing block 400 is fixed on the slide rail 200 so that the position of the roller on the slide rail 200 is fixed; when the fixing block 400 is in the disengaged state, the fixing block 400 can move on the slide rail 200 so that the roller can move on the slide rail 200.

[0056] In this embodiment, fixing blocks 400 are respectively arranged on both sides of the first roller 310 and the second roller 320, and the position of the roller on the slide rail 200 can be fixed by fixing parts after the roller moves to a preset position, thereby improving the inspection accuracy of the resistance. At the same time, the stability of the roller during rotation can also be improved.

[0057] Refer to Figure 8 , as an example, a limiting strip 210 extending along the axial direction of the slide rail 200 protrudes from the outer peripheral wall of the slide rail 200. Each fixing block 400 is sleeved on the limiting strip 210 and connected to the limiting strip 210 through a bolt 410.

[0058] It should be noted that when it is necessary to fix the fixing block 400 to the slide rail 200, only need to tighten the bolt 410 so that the bolt 410 abuts against the outer wall of the limiting strip 210; when it is necessary to loosen the fixing block 400, only need to rotate the bolt 410 in the reverse direction.

[0059] In this embodiment, the limiting strip 210 for installing the fixing block 400 protrudes from the outer peripheral wall of the slide rail 200, which has the advantage of facilitating the installation of the fixing block 400; at the same time, the fixing block 400 is sleeved on the limiting strip 210 and connected to the limiting strip 210 through the bolt 410, which has the advantages of simple structure and convenient operation.

[0060] It should be noted that for the structures or functional components not specifically described in the resistance detection device, they can be set according to the conventional selection in the art.

[0061] In a second aspect, an embodiment of the present application provides a method for on-line detecting resistance using a four-probe method, and the detection is performed using the device provided in the embodiment of the first aspect, including the following steps: Place the device above the film material 20 so that the first probe group 330a located on the first roller 310 is connected to the first conductive region 22; and the second probe group 330b located on the second roller 320 is connected to the second conductive region 23; fix the position of the first roller 310 on the slide rail 200, and adjust the distance D between the second roller 320 and the transfer welding region 21 by changing the position of the second roller 320 on the slide rail 200 1 , so as to test different Ds 1 The corresponding DC internal resistance value R 1 , take multiple Ds 1 as the abscissa and the corresponding multiple DC internal resistance values R 1 as the ordinate for linear fitting to obtain the slope K 1 ; fix the position of the second roller 320 on the slide rail 200, and adjust the distance D between the first roller 310 and the transfer welding region 21 by changing the position of the first roller 310 on the slide rail 200 2 , so as to test different Ds 2 The corresponding DC internal resistance value R 2 , take multiple Ds 2 as the abscissa and the corresponding multiple DC internal resistance values R 2 as the ordinate for linear fitting to obtain the slope K 2 ; simultaneously fix the positions of the first roller 310 and the second roller 320 on the slide rail 200 to obtain the distance L between the first roller 310 and the transfer welding region 21 1 , the distance L between the second roller 320 and the transfer welding region 21 2 , control the film material 20 to move along the length direction to drive the first roller 310, the second roller 320 and the slide rail 200 to rotate synchronously to obtain the DC internal resistance value R 3 , calculate the resistance R of the transfer welding region 21 according to the formula 转接焊 , where the calculation formula is: R 转接焊 =R 3 -L 1 ×K 2 -L 2 ×K 1 .

[0062] In this application, the operations are carried out step by step according to the above method. When measuring the resistance of the transfer welding area 21, not only the resistances of the first roller 310 and the second roller 320 are considered, but also the resistance of the first conductive area 22 between the first roller 310 and the transfer welding area 21, and the resistance of the second conductive area 23 between the second roller 320 and the transfer welding area 21 are considered. After removing them, the resistance of the transfer welding area 21 can be obtained, which can make the test result of the resistance more accurate and can reflect the transfer welding effect of the transfer welding area 21 in real time.

[0063] To better understand the technical solution of this application, the relative position relationship between the first roller 310, the second roller 320 and the film material 20 is used for auxiliary explanation here. For details, please refer to Figure 9 , where D 1 , L 1 both represent the distance from the second roller 320 to the transfer welding area 21 of the film material 20, and D 2 , L 2 both represent the distance from the first roller 310 to the transfer welding area 21 of the film material 20.

[0064] It should be noted that the internal resistance values R 1 ~R 3 are all calculated according to the formula R = U / I by using the constant current provided by the constant current source 30 and the reading of the voltmeter 40, and the internal resistance value represents the total resistance within the measurement area. Specifically: total internal resistance = (internal resistance of the first roller 310 + internal resistance of the first conductive area 22 between the first roller 310 and the transfer welding area 21) + (internal resistance of the second roller 320 + internal resistance of the second conductive area 23 between the second roller 320 and the transfer welding area 21) + internal resistance of the transfer welding area 21.

[0065] It should be noted that during the process of fixing the first roller 310 and adjusting the second roller 320, the linear relationship between the sum of the internal resistance of the second roller 320 and the internal resistance of the second conductive area 23 (the area between the second roller 320 and the transfer welding area 21) and the position of the second roller 320 can be obtained; that is, the linear relationship between the sum of the internal resistance of the second roller 320 and the D 1 part of the internal resistance of the second conductive area 23 and the specific value of D 1 is obtained, and the slope K 1 is obtained; during the process of fixing the second roller 320 and adjusting the first roller 310, the linear relationship between the sum of the internal resistance of the first roller 310 and the internal resistance of the first conductive area 22 (the area between the first roller 310 and the transfer welding area 21) and the position of the first roller 310 can be obtained; that is, the linear relationship between the sum of the internal resistance of the first roller 310 and the D 2 part of the internal resistance of the first conductive area 22 and D2 The linear relationship between the specific values to obtain the slope K 2 . At the same time, combined with the calculation formula R 转接焊 =R 3 -L 1 ×K 2 -L 2 ×K 1 , when the positions of the first roller 310 and the second roller 320 are fixed, there is only R 转接焊 one variable, and R can be calculated according to this formula 转接焊 .

[0066] It should be noted that in addition to being able to online detect the resistance of the transfer welding area on the film material, the device provided by the embodiment of the present application can also be used to online monitor whether the resistance of the transfer welding area of the film material is qualified, so as to improve the yield rate of the production line.

[0067] To better understand the technical solution of the present application, an example is combined here for auxiliary explanation. Taking the preparation of a composite current collector with a transfer welding area as an example, it includes the following steps: S1 Place the device above the film material 20 (composite current collector) with a qualified transfer welding area detected, so that the first probe group 330a on the first roller 310 is connected to the first conductive area 22; and the second probe group 330b on the second roller 320 is connected to the second conductive area 23, and there is a qualified transfer welding area 21 between the first roller 310 and the second roller 320.

[0068] S2 Fix the position of the first roller 310 on the slide rail 200 (the distance between the first roller 310 and the qualified transfer welding area 21 is 1 cm), and respectively adjust the position of the second roller 320 on the slide rail 200 so that the distance D 1 between the second roller 320 and the qualified transfer welding area 21 is 1 cm, 2 cm, and 3 cm respectively. The corresponding three internal resistance values R 1 are 25.9 mΩ, 28.2 mΩ, and 29.7 mΩ in sequence. Take multiple D 1 as the abscissa and the corresponding multiple DC internal resistance values R 1 as the ordinate for linear fitting to obtain the slope K 1 =1.9.

[0069] S3 Fix the position of the second roller 320 on the slide rail 200 (the distance between the second roller 320 and the qualified transfer welding area 21 is 1 cm), and respectively adjust the position of the first roller 310 on the slide rail 200 so that the distance D 2are 1 cm, 2 cm, and 3 cm respectively, and the corresponding three internal resistance values R 2 are 25.9 mΩ, 36.1 mΩ, and 45.7 mΩ in sequence. Taking multiple D 2 as the abscissa and the corresponding multiple DC internal resistance values R 2 as the ordinate for linear fitting, the slope K 2 = 9.9.

[0070] S4 Fix the positions of the first roller 310 and the second roller 320 on the slide rail 200 simultaneously, and obtain the distance L 1 between the first roller 310 and the qualified transfer welding area 21, which is 1.5 cm, the distance L 2 between the second roller 320 and the qualified transfer welding area 21, which is 1.5 cm, and the corresponding DC internal resistance value R 3 = 31.8 mΩ. Calculate the resistance R 合格转接焊 of the qualified transfer welding area 21 according to the formula. Among them, the calculation formula is: R 合格转接焊 = R 3 - L 1 × K 2 - L 2 × K 1 = 14.1 mΩ.

[0071] It should be noted that steps S1 to S4 can be understood as the resistance calibration of the transfer welding area, that is, the specific value of the resistance of the transfer welding area that meets the quality requirements. And according to the quality requirements of the transfer welding, it is usually required that the difference between the measured resistance value of the transfer welding and the calibrated resistance is within ±5%, that is, the measured resistance value of the transfer welding is 14.1 mΩ × (1 ± 0.05) = (13.395~14.805) mΩ is acceptable.

[0072] S5 Place the device above the target film 20 (i.e., the composite current collector with a transfer welding area to be detected prepared by the production line), so that the first probe group 330a on the first roller 310 is connected to the first conductive area 22; and the second probe group 330b on the second roller 320 is connected to the second conductive area 23. At this time, the distance between the first roller 310 and the transfer welding area 21 is L 3 = 1.5 cm, and the distance L 4 between the second roller 320 and the transfer welding area 21 is 1.5 cm; control the film 20 to move along the length direction to drive the first roller 310, the second roller 320, and the slide rail 200 to rotate synchronously to obtain the real-time on-line DC internal resistance value R 4在线 , and the resistance formula of the on-line transfer welding area 21 is obtained as: R 在线转接焊 = R 4在线 - L 3×K 2 -L 4 ×K 1 。

[0073] S6 The resistance R of the bonding pad area of the obtained product 在线转接焊 is compared with the resistance R of the bonding pad area prepared in step S4 合格转接焊 within the range. If R 在线转接焊 is within the range of (13.395~14.805) mΩ, that is, the product meets the quality requirements. If it is not within the range, the preparation process of the bonding pad needs to be adjusted.

[0074] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A device for online resistance detection using a four-probe method, characterized in that: The device is used for online detection of the resistance of the transfer welding area of ​​the film material, wherein the film material comprises the transfer welding area and the first conductive area and the second conductive area located on both sides of the film material in the width direction, and comprises: Support columns; A slide rail, the slide rail is rotatably sleeved outside the support column; A roller group, the roller group includes two first rollers and a second roller that are spaced apart, the first roller and the second roller are both sleeved outside the slide rail and can move on the slide rail; a first probe group is convexly provided on the outer peripheral wall of the first roller, the first probe group includes a current probe and a voltage probe that are spaced apart, and a second probe group is convexly provided on the outer peripheral wall of the second roller, the second probe group includes a current probe and a voltage probe that are spaced apart; along the axial direction of the slide rail, the two voltage probes are located between the two current probes, the first probe group located on the first roller is used to connect with the first conductive area, and can make the first roller and the slide rail rotate synchronously when the first conductive area moves, and the second probe group located on the second roller is used to connect with the second conductive area, and can make the second roller and the slide rail rotate synchronously when the second conductive area moves; The two current probes are configured to be electrically connected to the positive and negative poles of an external constant current source via the axial ends of the support column, and the two voltage probes are configured to be electrically connected to the positive and negative poles of an external voltmeter via the axial ends of the support column.

2. The device according to claim 1, characterized in that The first probe group includes a plurality of probes along the circumference of the first roller; the second probe group includes a plurality of probes along the circumference of the second roller, and the first probe group and the second probe group are arranged in a one-to-one correspondence along the axial direction of the slide rail.

3. The device according to claim 2, characterized in that The first roller also includes a plurality of mounting components arranged in one-to-one correspondence with the first probe groups, each of the mounting components includes a mounting piece, and one current probe and one voltage probe of each first probe group are mounted on the mounting piece.

4. The device according to claim 3, characterized in that Each of the mounting components also includes an elastic member, which is arranged on a side of the mounting member away from the first probe group along the radial direction of the first roller, so that the first probe group connected to the mounting member can reciprocate along the radial direction of the first roller under the action of the elastic member.

5. The device according to claim 4, characterized in that Each of the mounting components further includes a limiting member, which is spaced apart from the mounting member along the radial direction of the first roller, and is fixedly connected to the first roller, and the first probe group is slidably disposed in the limiting member along the radial direction of the first roller.

6. The device according to claim 5, characterized in that The first roller and the second roller further include first slip rings extending in the circumferential direction respectively, and the current probes of the first probe group are all connected to the first slip ring in the first roller, and the current probes of the second probe group are all connected to the first slip ring in the second roller, and the two first slip rings are configured to be connected to the positive and negative electrodes of the external constant current source via the axial ends of the support column; The first roller and the second roller also include second slip rings extending in the circumferential direction respectively, and multiple voltage probes of the first probe group are connected to the second slip ring in the first roller, and multiple voltage probes of the second probe group are connected to the second slip ring in the second roller, and the two second slip rings are configured to be connected to the positive and negative poles of an external voltmeter via the axial ends of the support column.

7. The device according to claim 6, characterized in that The inner wall of the slide rail is provided with two first guide rings and two second guide rings extending along the circumferential direction of the slide rail, the two first guide rings and the two second guide rings are spaced apart and distributed along the axial direction of the slide rail, the two first guide rings are respectively conductively connected to the two first slip rings, and the two second guide rings are respectively conductively connected to the two second slip rings; The outer wall of the support column is provided with two third guide rings and two fourth guide rings extending along the circumference of the support column, the two third guide rings respectively correspond to the two first guide rings one by one and are connected through conductive bearings, and the two fourth guide rings respectively correspond to the two second guide rings one by one and are connected through conductive bearings; The two third guide rings are connected to the positive and negative poles of the external voltmeter through wires via the axial ends of the support column, and the two fourth guide rings are connected to the positive and negative poles of the external voltmeter through wires via the axial ends of the support column.

8. The device according to any one of claims 1 to 7, characterized in that Along the axial direction of the slide rail, fixed blocks are arranged on both sides of each of the rollers, and the multiple fixed blocks are connected to the outer peripheral wall of the slide rail. Each of the fixed blocks has a locking state and a disengaged state. When the fixed block is in the locking state, the fixed block is fixed on the slide rail so that the position of the roller on the slide rail is fixed; when the fixed block is in the disengaged state, the fixed block can move on the slide rail so that the roller can move on the slide rail.

9. The device according to claim 8, characterized in that A limiting strip extending along the axial direction of the slide rail is convexly provided on the outer peripheral wall of the slide rail, and each of the fixing blocks is sleeved on the limiting strip and connected to the limiting strip via bolts.

10. A method for online detection of resistance using a four-probe method, characterized in that: The detection is performed using the device as described in any one of claims 1 to 9, comprising the following steps: Placing the device above the film material so that the first probe group on the first roller is connected to the first conductive area; and the second probe group on the second roller is connected to the second conductive area; The position of the first roller on the slide rail is fixed, and the distance D1 between the second roller and the transfer welding area is adjusted by changing the position of the second roller on the slide rail, so as to respectively test the DC internal resistance values ​​R1 corresponding to different D1s, and a plurality of D1s are used as abscissas and the corresponding plurality of DC internal resistance values ​​R1 are used as ordinates for linear fitting to obtain a slope K1; The position of the second roller on the slide rail is fixed, and the distance D2 between the first roller and the transfer welding area is adjusted by changing the position of the first roller on the slide rail, so as to respectively test the DC internal resistance values ​​R2 corresponding to different D2s, and a plurality of D2s are used as abscissas and the corresponding plurality of DC internal resistance values ​​R2 are used as ordinates for linear fitting to obtain a slope K2; At the same time, the positions of the first roller and the second roller on the slide rail are fixed to obtain the distance L1 between the first roller and the transfer welding area, and the distance L2 between the second roller and the transfer welding area. The film material is controlled to move along the length direction to drive the first roller, the second roller and the slide rail to rotate synchronously to obtain the DC internal resistance value R3. The resistance R of the transfer welding area is calculated according to the formula 转接焊 , where the calculation formula is: R 转接焊 =R3-L1×K2-L2×K1.

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