Bonding condition inspection device and bonding condition inspection method using the same

Abstract

The present invention relates to a bonding status inspection device and a bonding status inspection method using the same, and more particularly, to a bonding status inspection device including a transfer unit that transfers a battery module containing a plurality of battery cells, a thermal image inspection unit that scans an upper surface of the battery module, and a shear inspection unit that applies a shear force to bonding balls formed on the battery module, and a bonding status inspection method using the same.

Description

[Technical field]

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2021-0169950 dated December 1, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a bonding status inspection apparatus and a bonding status inspection method using the same, and more particularly to a bonding status inspection apparatus and a bonding status inspection method using the same that can improve work efficiency by automating and continuously performing bonding status inspection. [Background technology]

[0003] Recently, the demand for secondary batteries that can store electrical energy produced by the development of alternative energy sources due to air pollution caused by the use of fossil fuels and energy depletion is increasing. Rechargeable secondary batteries are used in mobile devices, electric vehicles, hybrid electric vehicles, etc., and are closely related to daily life.

[0004] Secondary batteries are used as energy sources for various electronic devices that are essential in modern society, and the required capacity is increasing due to the increased use and complication of mobile devices and the development of electric vehicles, etc. To meet user demand, many battery cells are arranged in small devices, and automobiles use battery modules that electrically connect many battery cells, and battery packs equipped with many such battery modules.

[0005] Meanwhile, secondary batteries have excellent electrical properties, but when they are abnormally operated, such as overcharged, overdischarged, exposed to high temperatures, or have an electrical short circuit, decomposition reactions occur in the active materials and electrolytes that are components of the battery, generating heat and gas. These generated heat and gas can affect adjacent battery cells, causing additional secondary damage.

[0006] For this reason, in order to improve the safety of secondary batteries during the manufacturing process and reduce the occurrence of defects, there is a need for an inspection method that can inspect the bonding state of secondary batteries accurately and improve process efficiency.

[0007] In the conventional bonding condition inspection, battery cells in a battery module or battery pack are electrically connected by wire bonding, and the quality of the bonding condition is judged by a thermal image inspection.

[0008] In addition, if the bonding is determined to be defective as a result of the thermal image inspection, the worker must directly check the bonding position in the next process. In this case, the more battery cells are housed in the battery module or battery pack, the more difficult it becomes for the worker to directly check, which causes problems such as worker fatigue and reduced reliability and accuracy. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Korean Patent Publication No. 10-2021-0065297 Summary of the Invention [Problem to be solved by the invention]

[0010] In order to solve the above problems, an object of the present invention is to provide a bonding status inspection apparatus and a bonding status inspection method using the same, which can automate the bonding status inspection process to improve accuracy and reliability.

[0011] Another object of the present invention is to provide a bonding status inspection device and a bonding status inspection method using the same, which can improve process efficiency by continuously performing an inspection to check for defects by applying a shear force to the bonding balls after a thermal image inspection. [Means for solving the problem]

[0012] In order to achieve the above-mentioned object, the bonding status inspection device according to the present invention is characterized by including a transfer unit (100) for transferring a battery module (M) containing a plurality of battery cells, a thermal image inspection unit (200) for scanning the upper surface of the battery module (M), and a shear inspection unit (300) for applying a shear force to bonding balls (B) formed on the battery module (M).

[0013] In addition, in the bonding state inspection apparatus according to the present invention, the transfer unit (100) includes a first transfer roller (110) for transferring the battery module (M), a second transfer roller (120) for changing the moving direction of the battery module (M) transferred on the first transfer roller (110), and a transfer carriage (130) on which the battery module (M) transferred by the second transfer roller (120) is seated.

[0014] In addition, in the bonding state inspection apparatus according to the present invention, the moving direction of the first transfer roller (110) and the moving direction of the second transfer roller (120) are perpendicular to each other.

[0015] In addition, in the bonding status inspection device according to the present invention, the thermal image inspection unit (200) is characterized by including an imaging unit (210) including a thermal image camera, and an illumination unit (220) located a predetermined distance away from the imaging unit (210).

[0016] In addition, in the bonding state inspection device according to the present invention, the shear inspection unit (300) includes a moving shaft (310) having a predetermined length, a body part (320) located at the lower part of the moving shaft (310), an inspection chip (330) provided on the lower surface of the body part (320), and a displacement sensor (340) provided on the side of the body part (320).

[0017] In the bonding state inspection apparatus according to the present invention, the moving shaft (310) is positioned to have a predetermined length in a direction perpendicular to a transport direction of the battery module (M).

[0018] In addition, in the bonding state inspection device according to the present invention, the moving shaft (310) can move in a direction parallel to and perpendicular to a transport direction of the battery module (M), and the body part (320) can move in a longitudinal direction of the moving shaft (310).

[0019] In the bonding condition inspection device according to the present invention, the inspection tip (330) is made of an insulating metal material.

[0020] In the bonding condition inspection device according to the present invention, the inspection chip (330) is characterized in that a slope (331) inclined at a predetermined angle is formed on the lower part.

[0021] In addition, the bonding state inspection method according to the present invention is characterized by including a first step of transporting a battery module (M); a second step of inspecting an upper surface of the battery module (M) with a thermal image inspection unit (200); a third step of positioning an inspection tip 330 of a shear inspection unit (300) at a position determined to be defective after inspection by the thermal image inspection unit (200); a fourth step of applying a shear force to a bonding ball (B) with the inspection tip (330); and a fifth step of transporting the battery module (M) along a first transport roller (110) if the bonding ball (B) is normal, and removing the bonding ball (B) by a second transport roller (120) if the bonding ball (B) is defective.

[0022] The bonding state inspection method according to the present invention is characterized in that it further comprises, prior to the second step, a step of charging and discharging the battery module (M).

[0023] In the bonding state inspection method according to the present invention, in the third step, the inspection chip (330) is positioned at a side of the bonding ball (B) at a predetermined distance.

[0024] In addition, the bonding state inspection method according to the present invention is characterized in that in the fourth step, a shear force is applied to a side surface of the bonding ball (B). Effect of the Invention

[0025] As described above, the bonding status inspection device and bonding status inspection method using the same according to the present invention have the advantage of improving process efficiency by continuously performing a primary inspection by a thermal image inspection unit and a secondary inspection by a shear inspection unit.

[0026] In addition, the bonding status inspection apparatus and bonding status inspection method using the same according to the present invention have the advantage of improving accuracy and reducing process time by automating the process of performing a bonding status inspection using the apparatus. [Brief description of the drawings]

[0027] [Figure 1] 1 is a perspective view showing a bonding state inspection device according to a first preferred embodiment of the present invention; [Diagram 2] 1 is a plan view showing a shear testing unit according to a first preferred embodiment of the present invention, as viewed from the front. [Diagram 3] 1 is a perspective view showing a state in which a test chip according to a first preferred embodiment of the present invention is positioned to the side of a bonding ball; [Figure 4] 1 is a plan view showing a state in which a test chip according to a first preferred embodiment of the present invention is positioned to the side of a bonding ball; [Diagram 5] 11 is a plan view showing a state in which a test chip according to a second preferred embodiment of the present invention is positioned at the side of a bonding ball. FIG. [Figure 6] 2 is a flowchart showing a bonding condition inspection method according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, in which a person having ordinary skill in the art to which the present invention pertains can easily carry out the present invention. However, when describing the operation principle of the preferred embodiment of the present invention in detail, detailed description of related well-known functions or configurations will be omitted if it is determined that such detailed description may unnecessarily obscure the gist of the present invention.

[0029] In addition, the same reference numerals are used throughout the drawings for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only the case where the part is directly connected to another part, but also the case where the part is indirectly connected via another element between the two parts. In addition, when a part includes a certain component, it does not mean that the other component is excluded, but that the part may further include the other component, unless otherwise specified.

[0030] Hereinafter, a bonding state inspection apparatus and a bonding state inspection method using the same according to the present invention will be described with reference to the accompanying drawings.

[0031] FIG. 1 is an oblique view showing a bonding status inspection device according to a first preferred embodiment of the present invention, FIG. 2 is a plan view showing the shear inspection section according to the first preferred embodiment of the present invention from the front, FIG. 3 is an oblique view showing a state in which an inspection chip according to the first preferred embodiment of the present invention is positioned on the side of a bonding ball, and FIG. 4 is a plan view showing a state in which an inspection chip according to the first preferred embodiment of the present invention is positioned on the side of a bonding ball.

[0032] 1 to 4, the bonding condition inspection device according to the present invention includes a transport unit 100, a thermal image inspection unit 200, and a shear inspection unit 300. The bonding condition inspection device 100 includes a transport unit 100, a thermal image inspection unit 200, and a shear inspection unit 300.

[0033] First, the transport unit 100 includes a first transport roller 110, a second transport roller 120, and a transport carriage .

[0034] The first transfer roller 110 includes a plurality of rollers, and transfers the battery module M seated on the first transfer roller 110 to a position for processing and inspection.

[0035] Here, the battery module M may include a plurality of cylindrical battery cells C and a module case that houses the plurality of cylindrical battery cells C.

[0036] The cylindrical battery cell C described above includes a cell case that houses an electrode assembly and is electrically connected to the negative electrode lead of the electrode assembly, and a top cap that is located on the top of the cell case.

[0037] The top cap is not electrically connected to the cell case by an insulating member (not shown) and serves as a positive terminal by being electrically connected to a positive electrode lead of the electrode assembly.

[0038] The top surface of the cell case is positioned along the outer periphery of the top cap with an insulating member interposed therebetween so that the cell case and the top cap are fixed to each other. It is preferable that the top cap protrudes from the top surface of the cell case, and more preferably, a positive electrode terminal protruding upward is further provided at the center of the top cap.

[0039] Meanwhile, the electrode assembly includes a cell assembly and a lead. The cell assembly may be, but is not limited to, a jelly-roll type cell assembly having a structure in which a separator is interposed between long sheet-like positive and negative electrodes and then wound up, a stack type cell assembly having unit cells in which rectangular positive and negative electrodes are stacked with a separator interposed therebetween, a stack folding type cell assembly in which unit cells are wound up with a long separator film, or a lamination stack type cell assembly in which unit cells are stacked with a separator interposed therebetween and attached to each other.

[0040] Of the pair of leads consisting of a positive electrode lead and a negative electrode lead, the positive electrode lead is directly or indirectly connected to the positive electrode and the top cap of the cell assembly, and the negative electrode lead is electrically connected to the cell case. The electrode assembly constituting the cylindrical battery cell as described above corresponds to a commonly known structure, and therefore a detailed description thereof will be omitted.

[0041] Next, the second transfer roller 120 is positioned vertically to the first transfer roller 110 and is located behind the position on the vertical line of the shear testing unit 300, so that it can divert the movement path of the battery module M that is determined to be defective as a result of inspection by the shear testing unit 300.

[0042] Here, the second transfer roller 120 may be formed between the multiple rollers of the first transfer roller 110, and may rise and fall a predetermined distance in the vertical direction. It is usually in a lowered state, but when it is necessary to change the moving path of the battery module M determined to be defective, it may rise and move, and then be positioned in a lowered state again.

[0043] The transfer trolley 130 ejects the battery module M, which has been diverted from the movement path of the first transfer roller 110 by the second transfer roller 120, from the manufacturing process when it is seated thereon. The transfer trolley 130 may have the shape of a shelf or a support with castors, and is not limited thereto as long as it is capable of ejecting the battery module M, which has been transferred by the second transfer roller 120, from the manufacturing process.

[0044] Next, the thermal image inspection section 200 includes an imaging section 210 and an illumination section 220 .

[0045] The photographing unit 210 may be a thermal imaging camera that scans the upper surface of the battery module M transported on the upper surface of the first transport roller 110 to measure the temperature of the bonding balls B, and transmits the position of any bonding balls B outside the normal range to the control device.

[0046] The lighting unit 220 is arranged horizontally at a predetermined distance from the photographing unit 210 and illuminates the upper surface of the battery module M, thereby enabling the photographing unit 210 to more accurately check the temperature state of the bonding balls B.

[0047] The shear test unit 300 includes a moving shaft 310 , a body unit 320 , a test tip 330 , and a displacement sensor 340 .

[0048] The moving shaft 310 has a shape having a predetermined length in a vertical direction of the battery module M, and is positioned on the first transfer roller 110. The moving shaft 310 can move in a direction parallel to and perpendicular to the transfer direction of the battery module M.

[0049] The body part 320 is attached to the lower surface of the moving shaft 310 and can move in the longitudinal direction of the moving shaft 310. The body part 320 can move in the forward / backward, left / right, up / down directions by the moving shaft 310.

[0050] The test tip 330 may have a columnar shape protruding from the lower surface of the body 320 by a predetermined length, and preferably has an inclined portion 331 inclined at a predetermined angle formed at the lower portion of the test tip 330. This is because it is possible to prevent the test tip 330 from coming into contact with other components such as a bus bar when the test tip 330 is lowered to apply a shear force to the bonding ball B.

[0051] Moreover, the test tip 330 is preferably made of an insulating metal material in order to prevent a short circuit caused by electrical conduction due to contact when a shear force is applied to the bonding ball B.

[0052] The displacement sensor 340 may be located on a side of the body 320, and by measuring the distance of the battery module M, it is possible to prevent the inspection chip 330 from lowering more than necessary and applying pressure to the battery cell C. This may be a laser displacement sensor, but is not limited to this, as long as it is a displacement sensor that can recognize the distance between the inspection chip 330 and the battery cell C.

[0053] FIG. 5 is a plan view showing a state in which a test chip according to a second preferred embodiment of the present invention is positioned at the side of a bonding ball.

[0054] Referring to Figure 5, a bonding status inspection device according to a preferred second embodiment of the present invention is similar to the first embodiment described in Figures 1 to 4, except for the lower shape of the inspection chip, so a description of the same configuration will be omitted.

[0055] In the test chip 330 according to the second preferred embodiment of the present invention, inclined portions 331 inclined at a predetermined angle are formed on both sides of the lower portion of the test chip 330, so that when the test chip 330 is lowered and positioned at a predetermined coordinate, it can be prevented from coming into contact with components such as the bus bar and the module case from both sides.

[0056] FIG. 6 is a flow chart showing a bonding condition inspection method according to a preferred embodiment of the present invention.

[0057] Explaining with reference to FIG. 6, the bonding status inspection method according to a preferred embodiment of the present invention includes a first step of transporting a battery module M, a second step of inspecting the top surface of the battery module M using a thermal image inspection unit 200, a third step of positioning the inspection tip 330 of the shear inspection unit 300 at a position determined to be defective after inspection using the thermal image inspection unit 200, a fourth step of applying a shear force to the bonding ball B using the inspection tip 330, and a fifth step of transporting the battery module M along a first transport roller 110 if the bonding ball B is normal, and removing the bonding ball B by a second transport roller 120 if the bonding ball B is defective.

[0058] The first step of transporting the battery module M is to transport the battery module M to an inspection position by a first transport roller 110 for inspection.

[0059] The second step of inspecting the top surface of the battery module M using the thermal imaging inspection unit 200 is a step in which the top surface of the battery module M is scanned as the transported battery module M passes under the photographing unit 210 to measure the temperature of the bonding balls B and determine whether the battery module is good or bad.

[0060] Here, prior to the second stage, charging and discharging of the battery module M is performed, which causes an increase in the temperature of the bonding balls B. The photographing unit 210 measures the temperature of the bonding balls B after the increase in temperature, and compares it with the temperature of the bonding balls B before charging and discharging to calculate the temperature difference before and after charging and discharging.

[0061] The quality is judged by checking whether the temperature difference of the bonding ball B is within the normal range. Here, the temperature difference of the bonding ball B in the normal state can be judged as being in the normal state when the positive electrode is 0.66°C or more and 1.38°C or less, the negative electrode is 1.59°C or more and 3.19°C or less during charging, and the positive electrode is 1.12°C or more and 2.27°C or less during discharging.

[0062] During discharge, the normal state can be determined as follows: the positive electrode is at least 1.12°C and at most 2.27°C, and the negative electrode is at least 0.88°C and at most 2.20°C.

[0063] In the case of a defective state, for example, if there is no bonding, the temperature difference can be measured to be below the lower limit, and if there is weak bonding, the temperature can be measured to be above the upper limit.

[0064] Here, the normal range of temperature difference is a value that can vary depending on the type of battery module and the power during charging and discharging.

[0065] The third step, in which the inspection chip 330 of the shear inspection unit 300 is positioned at the position determined to be defective after inspection by the thermal image inspection unit 200, is a step in which the inspection chip 330 is positioned a predetermined distance away from the side of the bonding ball B determined to be defective in the second step.

[0066] The fourth step of applying a shear force to the bonding ball B using the inspection chip 330 is a step in which the inspection chip 330 positioned on the side of the bonding ball B in the third step is moved toward the bonding ball B to apply a shear force to the side of the bonding ball B to determine whether the bonding ball is good or bad.

[0067] If the bonding balls B are normal, the battery module M is transported along the first transport rollers 110, and if the bonding balls B are defective, the battery module M is removed by the second transport rollers 120. This is a step in which, after the shear test in the fourth step, if the bonding balls B are normal, the battery module M is transported in the transport direction of the first transport rollers 110, and if the battery module M is determined to be defective, the battery module M is removed from the transport direction of the first transport rollers 110 by the second transport rollers 120 and seated on the transport cart 130, thereby removing it from the manufacturing process.

[0068] Although certain parts of the contents of the present invention have been described in detail above, it will be apparent to those skilled in the art that such specific techniques are merely preferred embodiments and do not limit the scope of the present invention. It is possible to make various changes and modifications within the scope of the present invention and the technical ideas thereof, and it goes without saying that such changes and modifications are also within the scope of the appended claims. [Explanation of symbols]

[0069] 100 Transfer section 110 First transfer roller 120 Second transfer roller 130 Transport trolley 200 Thermal imaging inspection section 210 Photography Department 220 Lighting Department 300 Shear Test Section 310 Moving axis 320 Body 330 Inspection Chip 331 Slope 340 Displacement Sensor M Battery Module C Battery cell B Bonding ball

Claims

1. a transfer unit that transfers a battery module containing a plurality of battery cells; a thermal image inspection unit that scans a top surface of the battery module; a shear test unit that applies a shear force to the bonding balls formed on the battery module; A bonding condition inspection device comprising:

2. The transport unit includes: a first transport roller for transporting the battery module; a second transfer roller for changing a moving direction of the battery module transferred on the first transfer roller; The bonding condition inspection apparatus according to claim 1 , further comprising: a transfer carriage on which the battery module transferred by the second transfer roller is seated.

3. 3. The bonding condition inspection apparatus of claim 2, wherein a moving direction of the first transfer roller and a moving direction of the second transfer roller are perpendicular to each other.

4. The thermal image inspection unit includes: An imaging unit including a thermal imaging camera; an illumination unit located a predetermined distance away from the imaging unit; The bonding condition inspection device according to claim 1 , comprising:

5. The shear test unit includes a moving shaft having a predetermined length, a body portion located below the moving shaft; A test chip provided on the underside of the body portion; A displacement sensor provided on a side of the body portion; The bonding condition inspection device according to claim 1 , comprising:

6. 6. The bonding condition inspection device according to claim 5, wherein the movement axis is positioned to have a predetermined length in a direction perpendicular to a transfer direction of the battery module.

7. The moving shaft may move in a direction parallel to and perpendicular to a transport direction of the battery module, 7. The bonding condition inspection device according to claim 6, wherein the body portion is movable in a longitudinal direction of the movement axis.

8. 6. The bonding condition inspection device according to claim 5, wherein said inspection tip is made of an insulated metallic material.

9. 6. The bonding condition inspection device according to claim 5, wherein the inspection chip has a sloped portion formed at a lower portion thereof, the sloped portion being inclined at a predetermined angle.

10. A bonding state inspection method using the bonding state inspection device according to any one of claims 1 to 9, comprising: A first step of transferring a battery module; a second step of inspecting a top surface of the battery module with the thermal image inspection unit; a third step of positioning the inspection tip of the shear inspection unit at a position determined to be defective after the inspection by the thermal image inspection unit; a fourth step of applying a shear force to the bonding ball with the test tip; a fifth step of transferring the battery module along a first transfer roller if the bonding balls are normal, and removing the battery module by a second transfer roller if the bonding balls are defective; A bonding condition inspection method comprising:

11. The method of claim 10 , further comprising the step of charging and discharging the battery module prior to the second step.

12. 11. The method of claim 10, wherein in the third step, the test tip is positioned at a side of the bonding ball at a predetermined distance.

13. 13. The method of inspecting a bonding condition according to claim 12, wherein in the fourth step, a shear force is applied to a side surface of the bonding ball.

Images