KR20220118244A - Method for detecting soldering defect of icb module and method for manufacturing battery module including the same - Google Patents

Abstract

The present invention relates to a method for detecting a soldering defect of an inter connected board (ICB) module. The method includes: a step of preparing the ICB module with a structure in which a PCB and at least one busbar are assembled on an ICB housing; a step of measuring a weight of the ICB module before soldering; a step of soldering the busbar on the PCB; a step of measuring a weight of the ICB module after soldering; and a step of detecting whether the soldering has a defect from a change in the weight of the ICB module before and after soldering.

Description

ICB module soldering defect detection method and battery module manufacturing method including the same

The present invention relates to a method for detecting a soldering defect of an ICB module and a method for manufacturing a battery module including the same.

Recently, a rechargeable battery capable of charging and discharging has been widely used as an energy source for a wireless mobile device. In addition, the secondary battery is attracting attention as an energy source for electric vehicles, hybrid electric vehicles, etc., which have been proposed as a way to solve air pollution such as conventional gasoline vehicles and diesel vehicles using fossil fuels. Therefore, the types of applications using secondary batteries are diversifying due to the advantages of secondary batteries, and it is expected that secondary batteries will be applied to more fields and products in the future than now.

In particular, as technology development and demand for mobile devices increase, the demand for batteries as an energy source is rapidly increasing. In addition, the field of use is expanding to the use of power auxiliary power through grid-ization, and accordingly, a lot of research on batteries that can meet various needs is being conducted.

On the other hand, in small mobile devices, one or two or three battery cells are used per device, whereas in mid-to-large devices such as automobiles, due to the need for high output and large capacity, a battery pack including a battery module electrically connecting a plurality of battery cells this is used

Such a battery module includes a bus bar to electrically connect a plurality of battery cells, and a printed circuit board (PCB) is used to sense voltages of the plurality of battery cells.

Here, when the PCB and the bus bar are electrically connected, the bus bar is fixed on the PCB through welding or soldering, and in this situation, the bus bar and the PCB are coupled to a case or a housing supporting the same. At this time, when the PCB and the bus bar are combined through soldering, it is necessary to check whether the soldering is defective, such as excessive soldering, insufficient soldering, or a short circuit.

Korean Patent Registration No. 10-1441326 discloses that automatic optical inspection can be used when inspecting whether soldering is defective. However, if the soldering surface of the PCB and the bus bar is covered by the case or housing, there is a problem that the soldering defect cannot be checked through automatic optical inspection.

Korean Patent Publication No. 10-1441326

The present invention has been devised to solve the above problems, and the soldering defect detection of the ICB module that can improve the defect detection power by checking the soldering state even when the soldered portion of the PCB and the bus bar is covered by the case or the housing An object of the present invention is to provide a method and a method for manufacturing a battery module including the same.

A soldering defect detection method according to the present invention comprises the steps of: preparing an ICB (Inter Connected Board) module having a structure in which a PCB and at least one bus bar are assembled on an ICB housing; weighing the ICB module before soldering; soldering the busbar on a PCB; measuring the weight of the ICB module after soldering; and detecting whether soldering is defective from the weight change of the ICB module before and after soldering. includes

In a specific example, in the step of preparing the ICB module, the bus bar and the PCB may be assembled to the ICB housing while being mounted on the front and rear surfaces of the ICB housing, respectively.

In this case, one end of the bus bar may be connected to the PCB through a through hole formed on the ICB housing and the PCB.

In this case, the soldering of the bus bar may be performed on both sides of the PCB.

In a specific example, the soldering of the bus bar may be performed so that a solder material fills a gap between the bus bar and the through hole formed in the PCB.

In one example, the weight of the ICB module after the soldering may be measured after all the busbars mounted on the ICB housing are soldered.

In another example, the measurement of the weight change amount of the ICB module before and after the soldering may be performed every time one bus bar is soldered.

In a specific example, when the measured value of the change in weight is out of a preset range, it may be determined as defective.

In another example, the method for detecting a soldering defect according to the present invention may further include performing an automatic optical inspection on a soldered portion between the bus bar and the PCB.

In this case, the automatic optical inspection may be performed on the surface of the PCB exposed to the outside from the ICB housing.

The present invention also provides a method for manufacturing a battery module.

The manufacturing method of the battery module according to the present invention includes the steps of selecting an ICB module determined to be a good product according to the soldering defect detection method as described above; and electrically connecting the electrode leads of the battery cells to the ICB module while the selected ICB module is mounted on one side of the plurality of battery cells accommodated in the module frame. may include.

According to the present invention, by measuring the weight difference of the ICB module before and after soldering, the soldering state can be checked even when the soldered portion of the PCB and the busbar is covered by the case or the housing, thereby improving the defect detection power.

1 is a flowchart showing the sequence of a soldering defect detection method according to the present invention.
2 to 4 are schematic views showing the structure of the ICB module used in the soldering defect detection method according to the present invention.
5 is a flowchart illustrating a sequence of a method for detecting a soldering defect according to an embodiment of the present invention.
6 is a flowchart illustrating a sequence of a method for detecting a soldering defect according to another embodiment of the present invention.
7 is a flowchart illustrating a sequence of a method for detecting a soldering defect according to another embodiment of the present invention.

Hereinafter, the present invention will be described in detail. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to their ordinary or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined in

In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It is to be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof. Also, when a part of a layer, film, region, plate, etc. is said to be “on” another part, this includes not only cases where it is “directly on” another part, but also cases where another part is in between. Conversely, when a part of a layer, film, region, plate, etc. is said to be “under” another part, this includes not only cases where it is “directly under” another part, but also cases where there is another part in between. In addition, in the present application, “on” may include the case of being disposed not only on the upper part but also on the lower part.

Hereinafter, the present invention will be described in detail.

1 is a flowchart showing the sequence of a soldering defect detection method according to the present invention.

Referring to Figure 1, the soldering defect detection method according to the present invention is a soldering defect detection method according to the present invention, an ICB (Inter Connected Board) module having a structure in which a PCB and at least one bus bar are assembled on an ICB housing. step (S10); Measuring the weight of the ICB module before soldering (S11); soldering the bus bar on the PCB (S12); measuring the weight of the ICB module after soldering (S13); and detecting whether or not soldering is defective from the weight change of the ICB module before and after soldering (S14); includes

As described above, if the soldering surface of the PCB and the busbar is covered by the case or housing, there is a problem that it is impossible to check whether the soldering is defective through automatic optical inspection. The soldering state can be checked even when the soldered portion of the bus bar and the bus bar is covered by the case or housing, thereby improving the defect detection ability.

Hereinafter, each step of the present invention will be described in detail.

<Preparation of ICB module>

First, prepare the ICB module to be soldered.

2 to 4 are schematic views showing the structure of the ICB module used in the soldering defect detection method according to the present invention.

The ICB module 100 is used to detect voltages of battery cells in the battery module. Specifically, referring to FIGS. 2 to 4 , in the present invention, the ICB module 100 has a structure in which a PCB 120 and at least one bus bar 110 are assembled on an ICB housing 130 . Here, the structure in which the PCB 120 and the bus bar 110 are assembled means that the PCB 120 and the bus bar 110 are mounted on the ICB housing 130 and then fixed.

Specifically, in the ICB module 100, the bus bar 110 is for making an electrical connection between battery cells, and a bar-shaped metal or metal strip, etc. may be used, and some are electrically connected to an electrode lead, Another part is a structure electrically connected to the PCB 120 for voltage detection of the battery cells. The PCB 120 may be further equipped with a connector (not shown) to which these bus bars 110 are connected, and for transmitting the detected voltage to a Battery Management System (BMS, not shown). The bus bar 110 and the PCB 120 have a structure assembled to the ICB housing 130 , and the ICB housing 130 may be made of an insulating material.

In addition, the number of the bus bars 110 may be appropriately adjusted according to the number of battery cells used in the battery module, and a plurality of bus bars 110 may be arranged in parallel in one direction. The ICB housing 130 has, for example, a mounting part having a shape corresponding to the shape of the bus bar 110 and the PCB 120 so that the bus bar 110 and the PCB 120 can be mounted, or the bus bar ( Since the fixing member having a protrusion shape is formed around the 110 ) and the PCB 120 , the bus bar 110 and the PCB 120 may be stably fixed on the ICB housing 130 . For example, referring to FIG. 2 , the mounting part 131 on which the bus bar 110 is mounted in the ICB housing 130 is formed to have a size corresponding to the size of the bus bar 110 , and between the mounting parts 131 . A hole for the electrode lead to pass therethrough is formed, so that a plurality of mounting parts 131 to which the bus bar 110 is mounted may have a rib shape. Protrusion-shaped fixing members 132 are formed on both sides of the mounting part 131 in the width direction, so that the bus bar 110 mounted on the mounting part 131 may be fixed to the ICB housing 130 .

The ICB module 100 may further include input/output terminals (not shown) for electrical connection between the battery module and an external device. For example, the external input/output terminals may be located at the upper end of the ICB module according to FIGS. 2 and 3 . One of the external input/output terminals may be a positive terminal, and the other may function as a negative terminal.

These external input/output terminals may be connected to any one of a plurality of bus bars assembled in the ICB module, for example, may be electrically connected to a bus bar at the most edge of the bus bars.

2 to 4 , in the step of preparing the ICB module 100 , the bus bar 110 and the PCB 120 are mounted on the front and rear surfaces of the ICB housing 130 , respectively, and the ICB housing It may be assembled to 130 . That is, the bus bars 110 are mounted on one surface of the ICB housing 130 , and the PCB 120 is mounted on the other surface. Accordingly, the area of the PCB 120 can be freely adjusted within the ICB housing 130 of a limited size, the number of parts can be saved, and the space utilization in the battery module can be improved by designing the ICB module 100 compactly. can do it

As described above, in the present invention, since the ICB housing 130 is positioned between the bus bar 110 and the PCB 120 , an electrical connection is performed between the bus bar 110 and the PCB 120 in the ICB housing 130 . A through hole 133 to be formed may be formed. In this case, as shown in FIG. 4 , one end at which the bus bar 110 is connected to the PCB 120 is bent, passes through the through hole 133 formed in the ICB housing 130 , and then is connected to the PCB 120 . Since one end of the bus bar 110 has a narrower width than the body of the bus bar 110 , it can be easily inserted into the through hole 133 . The through hole 133 may have a slit shape corresponding to the width of the bus bar.

Similarly, since a through hole 121 through which the bus bar 110 passes is also formed in the PCB 120 , one end of the bus bar 110 passes through each formed in the ICB housing 130 and the PCB 120 . It may be connected to the PCB 120 through the holes 121 and 133 successively. Accordingly, it is possible to exhibit a more improved bonding force than when one end of the bus bar 110 is fixed on the PCB 120 in a simple contact state.

<Detecting soldering and soldering defects>

When the ICB module 100 is prepared as above, the PCB 120 and the bus bar 110 are soldered. The soldering method is not particularly limited, and, for example, a cream soldering method may be used.

As described above, since the bus bar 110 has a structure in which one end connected to the PCB 120 passes through the through hole 121 formed in the PCB 120 and is connected to the PCB 120 , the When soldering is performed on only one surface, the bonding force between the bus bar 110 and the PCB 120 may be weak, and when a force is applied in the through direction of the bus bar 110 , the bus bar 110 is easily separated from the PCB 120 . is likely to be Accordingly, in the present invention, the soldering of the bus bar 110 may be performed on both surfaces of the PCB 120 as shown in FIG. 4 . As a method of performing soldering of the bus bar on both sides of the PCB, for example, by injecting a solder material into a through hole formed in the PCB, the solder material rides through the through hole and settles on the opposite side (the side where the PCB and the ICB housing face) method can be used.

Furthermore, in order to prevent the coupling force between the PCB 120 and the bus bar 110 from weakening due to a gap between the through hole 121 formed in the PCB 120 and the bus bar 110 , the bus bar 110 . The soldering may be performed so that the solder material 140 fills the gap between the through hole 121 and the bus bar 110 formed in the PCB 120 . As the solder material 140, a well-known thing, such as lead, can be used.

When the soldering of the bus bar 110 is completed, it is detected whether the soldering is defective. Here, the defective soldering means a case in which the solder material 140 used for soldering is insufficient (non-soldering) or excessively used (over-soldering) than normal.

On the other hand, when soldering is performed on both sides of the PCB 120 as in the present invention, all the states of soldering performed on both sides of the PCB 120 should be inspected. However, when using a method of directly checking the soldering state such as visual inspection or automatic optical inspection, the surface of the PCB 120 facing the ICB housing 130 is covered by the ICB housing 130 , so the inspection cannot be performed.

Accordingly, the present invention measures the weight of the ICB module 100 before and after the step of soldering the bus bar 110 on the PCB 120, and measures the weight change of the ICB module 100 before and after soldering, so that the bus bar ( It is possible to detect a soldering defect state without directly checking the soldering state of 110) and the PCB 120 with the naked eye.

5 is a flowchart illustrating a sequence of a method for detecting a soldering defect according to an embodiment of the present invention.

In one example, the weight of the ICB module 100 after the soldering may be measured after all the bus bars 110 mounted on the ICB housing 130 are soldered. In this case, the soldering defect detection method according to an embodiment of the present invention is an ICB module having a structure in which a PCB 120 and n bus bars 110 (n is an integer greater than or equal to 1) are assembled on an ICB housing 130 . preparing (100) (S20); Measuring the weight of the ICB module 100 before soldering (S21); Soldering each of the n bus bars 110 on the PCB 120 (S22); Measuring the weight of the ICB module 100 after soldering (S23); and detecting whether or not soldering is defective from the weight change of the ICB module 100 before and after soldering (S24); includes That is, the weight change amount of the ICB module 100 before and after soldering means the weight of the solder material used for all the bus bars 110 assembled in the ICB housing 130 .

As described above, if the weight measurement is performed after all the bus bars 110 are soldered, it is easy and has the advantage of saving time and money.

6 is a flowchart illustrating a sequence of a method for detecting a soldering defect according to another embodiment of the present invention.

In another example, the measurement of the weight change amount of the ICB module 100 before and after the soldering may be performed whenever one bus bar 110 is soldered. Specifically, referring to FIG. 6 , the soldering defect detection method is an ICB module 100 having a structure in which a PCB 120 and n bus bars 110 (n is an integer greater than or equal to 1) are assembled on an ICB housing 130 . ) preparing (S30); Measuring the weight of the ICB module 100 before soldering (S31); soldering any one of the n bus bars 110 that is not soldered on the PCB 120 (S32); Measuring the weight of the ICB module 100 after soldering (S33); and detecting whether or not soldering is defective from the weight change of the ICB module 100 before and after soldering (S34); includes In this case, when soldering of one bus bar is completed, whether or not soldering is defective is detected and if it is determined that the soldering state is good, the same steps may be repeated for the next bus bar. In this way, when each busbar is detected whether or not soldering is defective, it takes a little longer than the method described above. There is an advantage in that the defect detection power can be improved.

On the other hand, in the step of detecting whether the soldering is defective from the weight change of the ICB module 100 before and after the soldering, if the measured value of the weight change is out of a preset range, it may be determined as defective. To this end, a database regarding the reference value of the weight change measurement value may be configured in advance. Specifically, in the step of detecting the soldering defect, the measured value of the weight change is compared with the values extracted from the database, and the process of determining whether the soldering is defective such as overpayment or non-payment according to the calculation result may be performed. .

7 is a flowchart illustrating a sequence of a method for detecting a soldering defect according to another embodiment of the present invention.

In another example, the method for detecting a soldering defect according to the present invention may further include performing an automatic optical inspection on a soldered portion between the bus bar 110 and the PCB 120 ( S15 ). The method of measuring the weight difference of the ICB module 100 before and after soldering as described above has an advantage in that it can accurately measure whether excess or non-soldering is performed, but it may be difficult to determine the surface state and appearance of the soldered portion. Accordingly, the present invention can further improve the defect detection ability by additionally inspecting the appearance of the soldered portion through the automatic optical inspection.

Specifically, the automatic optical inspection can be performed through an optical inspection means, and by acquiring an external image of the soldered part through the optical inspection means, it is possible to determine whether the parts are twisted, stand up, short, overpaid/non-payment of the soldered part, etc. can The optical inspection may convert a photographed image into visual data, and for this purpose, a predetermined program storage unit for data conversion and calculation, converts an actual photographed screen into visual data based on the program, and a soldering state from the visual data It may be provided with a display unit for displaying the soldering state on the screen and a calculation unit for converting to a numerical value.

However, as described above, in the ICB module 100, the bus bar 110 and the PCB 120 are assembled to the ICB housing 130 in a state mounted on the front and rear surfaces of the ICB housing 130, respectively, the bus bar ( One end of the 110 has a structure connected to the PCB 120 through a through hole formed on the ICB housing 130 and the PCB 120 , and soldering of the bus bar 110 is performed on both sides of the PCB 120 . In this case, it is difficult to perform automatic optical inspection on the surface where the PCB 120 and the ICB housing 130 contact each other. In this case, the automatic optical inspection may be performed on the surface of the PCB 120 exposed to the outside from the ICB housing 130 .

In addition, the present invention provides a method for manufacturing a battery module.

The manufacturing method of the battery module according to the present invention includes the steps of selecting an ICB module determined to be a good product according to the soldering defect detection method as described above; and electrically connecting the electrode leads of the battery cells to the ICB module while the selected ICB module is mounted on one side of the plurality of battery cells accommodated in the module frame. includes

Specifically, the battery module according to the present invention includes a battery cell assembly having a structure in which a plurality of battery cells are stacked; module frame; and an ICB module.

In this case, the battery cell forming the battery cell assembly may be a pouch-type battery cell, and electrode leads may be formed at both ends of the pouch-type battery case. The battery cells are stacked in a vertical or horizontal direction with wide surfaces facing each other to form a battery cell assembly. Such a secondary battery may be provided with a cartridge in the form of a square ring surrounding the rim of the secondary battery to facilitate stacking, or the secondary battery may be mounted in a stacked state in the module frame.

The module frame may be formed of a metal material having high mechanical strength and excellent thermal conductivity, and there is no particular limitation on the shape of the module frame, but may be formed as a mono frame in the form of a tube of a square pillar, and a U-shaped frame is used as a secondary frame. After bonding to both sides of the battery stack, the U-shaped frame may be connected with a separate plate-shaped frame. A groove for mounting the secondary battery may be formed in the module frame. Such a module frame may prevent the flow of the secondary battery by holding it.

The electrode leads are respectively located on the open front and rear portions of the module frame, and the ICB module is mounted on these portions to electrically connect the electrode leads and the ICB module. As described above, the ICB module may be an ICB module determined as a good product according to the soldering defect detection method. In this case, the electrode lead may be electrically connected to the bus bar assembled in the ICB module through welding or the like. For example, after connecting electrode leads of adjacent battery cells by first bending them in opposite directions and stacking them, the electrode leads and bus bars are electrically connected, or each electrode lead is stacked on the bus bars. and the bus bar can be electrically connected.

When the ICB module is connected, the battery module can be completed by mounting the cover on the open front and rear parts of the module frame.

In addition, one or more electronic components are mounted on one surface of the battery module, if necessary. The electrical equipment is mounted adjacent to the battery module, the battery management system (BMS) for monitoring and controlling the operation of the battery module; a Battery Disconnect Unit (BDU) mounted adjacent to the battery module and the BMS, and controlling the electrical connection of the battery module; a fuse positioned between the battery module and the BMS and providing an overcurrent blocking function; a bus bar connected to a module terminal of the battery module to electrically connect the battery module; and an LV wire electrically connecting the electrical equipment. etc.

According to the present invention, by measuring the weight difference of the ICB module before and after soldering, the soldering state can be checked even when the soldered portion of the PCB and the busbar is covered by the case or the housing, thereby improving the defect detection power. Furthermore, through this, it is possible to improve the failure and safety problems due to the occurrence of defects in the battery module.

The above description is merely illustrative of the technical spirit of the present invention, and various modifications and variations will be possible without departing from the essential characteristics of the present invention by those skilled in the art to which the present invention pertains. Accordingly, the drawings disclosed in the present invention are for explanation rather than limiting the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these drawings. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

Meanwhile, although terms indicating directions such as up, down, left, right, front, and back are used in this specification, these terms are for convenience of explanation only, and may vary depending on the location of the object or the location of the observer. It is self-evident that it can

100: ICB module
110: bus bar
120: PCB
121, 133: through hole
130: ICB housing
131: mounting part
132: fixing member
140: solder material

Claims (11)

Preparing an ICB (Inter Connected Board) module having a structure in which a PCB and at least one bus bar are assembled on an ICB housing;
weighing the ICB module before soldering;
soldering the busbar on a PCB;
measuring the weight of the ICB module after soldering; and
detecting whether soldering is defective from the weight change of the ICB module before and after soldering; A soldering defect detection method comprising a.
According to claim 1,
In the step of preparing the ICB module,
A soldering defect detection method in which the bus bar and the PCB are assembled to the ICB housing while being mounted on the front and rear surfaces of the ICB housing, respectively.
3. The method of claim 2,
A soldering defect detection method in which one end of the bus bar is connected to the PCB through a through hole formed on the ICB housing and the PCB.
4. The method of claim 3,
Soldering of the bus bar is a soldering defect detection method performed on both sides of the PCB.
4. The method of claim 3,
The soldering of the bus bar is performed so that a solder material fills a gap between the through hole formed in the PCB and the bus bar.
4. The method of claim 3,
After the soldering, the weight of the ICB module is measured after all the bus bars mounted on the ICB housing are soldered.
4. The method of claim 3,
The measurement of the weight change of the ICB module before and after the soldering is a soldering defect detection method performed every time one bus bar is soldered.
According to claim 1,
A soldering defect detection method for determining that the weight change measurement value is out of a predetermined range as defective.
According to claim 1,
The soldering defect detection method further comprising the step of performing an automatic optical inspection on the soldered portion between the bus bar and the PCB.
10. The method of claim 9,
The automatic optical inspection is a soldering defect detection method performed on the surface of the PCB exposed to the outside from the ICB housing.
Selecting the ICB module determined to be a good product according to the soldering defect detection method according to claim 1; and
electrically connecting the electrode leads of the battery cells to the ICB module in a state in which the selected ICB module is mounted on one side of the plurality of battery cells accommodated in the module frame; A method of manufacturing a battery module comprising a.

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