KR20230037875A - Sensing Module and Battery Module Having the same - Google Patents

Abstract

A sensing module according to one embodiment of the present invention comprises: a sensing member measuring the operating state of a battery cell; a circuit member including a circuit connected to the sensing member; and a joining member joining the sensing member to the circuit member, wherein the sensing member may have a plurality of through holes through which the joining member flows and the diameter of the through holes may range from 0.5 to 1.0 mm. In addition, the battery module according to one embodiment of the present invention comprises: a cell assembly including a plurality of battery cells; a bus bar assembly having an electrically conductive bus bar electrically connected to the battery cell; and a sensing module measuring the operating state of the battery cell. According to one embodiment of the present invention, by using surface mounting technology, it is possible to easily connect the sensing member and reduce the amount of voids in the joint member (joint layer) to facilitate the discharge of gas or air from the joint member which joins the sensing member and the circuit member.

Description

Sensing module and battery pack having the same

The present invention relates to a sensing module having a sensing member for measuring an operating state of a battery cell and a battery module having the same, and more particularly, to a sensing module capable of stably maintaining a junction state of a sensing member and a battery module having the same It is about.

Unlike primary batteries, secondary batteries can be charged and discharged, so they can be applied to various fields such as digital cameras, mobile phones, laptop computers, hybrid vehicles, and electric vehicles. Secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-hydrogen batteries, lithium secondary batteries, and the like.

Among these secondary batteries, many studies on lithium secondary batteries having high energy density and discharge voltage are in progress. Recently, a lithium secondary battery is manufactured as a pouch type battery cell having flexibility or a prismatic or cylindrical can type battery cell having rigidity, and a plurality of battery cells are electrically connected and used. At this time, a plurality of battery cells form a cell stack in a stacked form and are disposed inside the module housing to form a battery module.

The battery module includes a sensing module for measuring the voltage of the battery cell in order to manage the battery cell. Such a sensing module is used by attaching a sensing member (voltage sensing terminal, temperature sensor, etc.) to a circuit member composed of a printed circuit board (PCB). In order to attach the sensing member to the circuit member, connecting, welding, terminal compression, soldering processes, and the like are used.

In order to stably monitor the operating state of the battery cell through the sensing member, it is necessary to stably maintain a state in which the sensing member is bonded to the circuit member. To this end, it is necessary to secure strong bonding strength between the circuit member and the sensing member (voltage sensing terminal, temperature sensor, etc.).

As an example, Patent Publication No. 2018-0091325 discloses that a through hole and an insertion protrusion are formed in a printed circuit board and a sensing member, respectively, and the insertion protrusion of the sensing member penetrates the through hole of the printed circuit board and then exposed to the outside of the through hole. A method of soldering the inserted protrusion and the printed circuit board is proposed. Although this through-hole bonding method can increase bonding reliability, since bonding is performed on the opposite side of the printed circuit board, the thickness of the sensing module itself increases and the through-hole must be formed on the printed circuit board, which complicates the process.

In addition, Patent Publication No. 2014-0015838 discloses a method of additionally using a connecting member to cover a protection circuit module in order to secure bonding strength in a soldering process. However, this method also has a problem in that the thickness of the soldering joint part increases due to the installation of a separate connecting member, and additional parts are required and the process is complicated.

In particular, the above-mentioned Patent Publication No. 2018-0091325 and Patent Publication No. 2014-0015838 use a conventional soldering method in which solder melted by heating is applied to a joint and then cooled and hardened, so the soldering process is somewhat complicated. there is

On the other hand, in order to facilitate the soldering process, a method of applying solder paste to a printed circuit board, heating and melting the solder paste in a state where a sensing member is placed on the solder paste, and then hardening it (surface mounting technology; surface mounting technology) has been proposed. The process using solder paste has the advantage that the thickness of the sensing module itself does not increase and it is easy to automate the process. does not exist.

In addition, the prior art using the solder paste has a problem in that a large amount of voids due to gas or air remain in the bonding layer in which the solder paste is cured. Such voids not only cause a decrease in bonding strength, but also have a problem in that cracks or damage easily occur in the bonding layer due to heat or external shock.

Korean Patent Publication No. 2018-0091325 Korean Patent Publication No. 2014-0015838

As one aspect, an object of the present invention is to provide a sensing module capable of reducing the occurrence of voids in a bonding member for bonding a sensing member and a circuit member while facilitating bonding of a sensing member, and a battery module having the same. .

In addition, as one aspect, an object of the present invention is to provide a sensing module having excellent bonding performance and a battery module having the same by managing the amount of air gaps generated in bonding members in a stable range.

And, as one aspect, an object of the present invention is to provide a sensing module capable of minimizing an increase in the overall thickness of the sensing module when bonding the sensing member and the circuit member, and a battery module having the same.

As one aspect for achieving at least some of the above objects, the present invention, the sensing member for measuring the operating state of the battery cell; a circuit member having a circuit connected to the sensing member; and a bonding member for bonding the sensing member to the circuit member, wherein the sensing member has a plurality of through-holes through which the bonding member is introduced, and the through-holes have a diameter of 0.5 mm to 1.0 mm. module is provided.

In an embodiment of the present invention, the circuit member includes a flexible printed circuit board (FPCB), and the sensing member may be attached to a conductive region of the FPCB through the bonding member.

In addition, in an embodiment of the present invention, the bonding member forms a fillet surface between an edge surface of a portion corresponding to the circuit member of the circumference of the sensing member and the circuit member, and among the inner space formed by the through hole It can be configured to fill at least part of it.

In an embodiment of the present invention, the minimum distance between the through holes adjacent to each other among the through holes may have a value of 1 mm to 2 mm, preferably 1.3 mm to 1.7 mm. In addition, a minimum distance between an edge surface of a portion corresponding to the circuit member and the through hole of the perimeter of the sensing member may have a value of 0.75 mm to 1.25 mm.

In an embodiment of the present invention, each of the through-holes is arranged such that at least one of the distance between the nearest through-hole and the distance between the edge surface of the portion corresponding to the circuit member among the perimeters of the sensing member is 2 mm or less. can

In an embodiment of the present invention, the sensing member may have a shape in which the five through holes are disposed at the vertexes and the center of a rectangle.

The sensing member may include at least one of a voltage sensing terminal and a temperature sensor, and the bonding member may include solder paste applied to the circuit member.

As another aspect of the present invention, a cell assembly having a plurality of battery cells; a bus bar assembly having an electrically conductive bus bar electrically connected to the battery cell; and a sensing module configured to measure an operating state of the battery cell, wherein the sensing module includes a sensing member configured to measure an operating state of the battery cell, a circuit member having a circuit connected to the sensing member, and A battery module including a bonding member for bonding the sensing member to the circuit member, the sensing member having a plurality of through-holes through which the bonding member flows, and a diameter of the through-holes having a value of 0.5 mm to 1.0 mm. do.

In an embodiment of the present invention, the sensing member may include a voltage sensing terminal, and the voltage sensing terminal may have a circuit junction portion bonded to the circuit member and a bus bar junction portion bonded to the bus bar.

In an embodiment of the present invention, the bonding member forms a fillet surface between an edge surface of the circuit bonding portion and the circuit member, and is configured to fill at least a part of an internal space formed by the through hole, and the voltage sensing The dragon terminal may be joined to the bus bar through welding.

In an embodiment of the present invention, a minimum distance between adjacent through holes among the through holes has a value of 1 mm to 2 mm, and an edge surface of a portion corresponding to the circuit member among the circumference of the sensing member and the through hole The minimum distance between them may have a value of 0.75 mm to 1.25 mm.

According to one embodiment of the present invention having such a configuration, surface mounting technology is used to facilitate the bonding of the sensing member and to facilitate the discharge of gas or air from the bonding member for bonding the sensing member and the circuit member. An effect of reducing the amount of voids generated in the bonding member (bonding layer) can be obtained.

In addition, according to one embodiment of the present invention, by forming through-holes in the sensing member and adjusting the size and arrangement of the through-holes, gas or air is easily discharged in the bonding process, thereby reducing air gaps generated in the bonding member (bonding layer). The amount generated can be managed within a stable range. Accordingly, it is possible to obtain an effect that the bonding performance of the sensing member is excellent and that cracks or damage do not easily occur in the bonding layer due to heat or external shock.

And, according to one embodiment of the present invention, when bonding the sensing member and the circuit member, since a strong bonding force can be secured only through the bonding member without a separate auxiliary part, the effect that the increase in the overall thickness of the sensing module can be minimized. there will be

1 is an exploded perspective view of a battery module according to an embodiment of the present invention;
2 is an enlarged perspective view of the sensing module shown in FIG. 1;
3 is a front view showing a state in which a sensing module according to an embodiment of the present invention is coupled to a bus bar assembly;
Figure 4 (a) is an enlarged view of part "A" in Figure 3;
Figure 4 (b) is a cross-sectional view taken along line II' of Figure 4 (a).
5 is a schematic view showing a junction between a sensing member and a circuit member;
6 is a schematic view showing a portion of a circuit member to which a sensing member is bonded;
7(a) to 7(g) are schematic views showing various modifications of the sensing member according to an embodiment of the present invention.
Figure 8 (a) is an X-ray photograph of the state of the bonding member with respect to the sensing member according to the embodiment of the present invention.
Figure 8 (b) is an X-ray photograph of the state of the bonding member with respect to the sensing member according to the comparative example.

Prior to the detailed description of the present invention, the terms or words used in this specification and claims described below should not be construed as being limited to a common or dictionary meaning, and the inventors should use their own invention in the best way. It should be interpreted as a meaning and concept corresponding to the technical idea of the present invention based on the principle that it can be properly defined as a concept of a term for explanation. Therefore, the embodiments described in this specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all of the technical ideas of the present invention, so various equivalents that can replace them at the time of the present application. It should be understood that there may be water and variations.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. At this time, it should be noted that the same components in the accompanying drawings are indicated by the same reference numerals as much as possible. In addition, detailed descriptions of well-known functions and configurations that may obscure the gist of the present invention will be omitted. For the same reason, some components in the accompanying drawings are exaggerated, omitted, or schematically illustrated, and the size of each component does not entirely reflect the actual size.

First, referring to FIGS. 1 and 2 , the battery module 100 according to an embodiment of the present invention will be described. 1 is an exploded perspective view of a battery module 100 according to an embodiment of the present invention, and FIG. 2 is an enlarged perspective view of the sensing module 130 shown in FIG. 1 .

The battery module 100 according to an embodiment of the present invention includes a cell assembly 110 including a plurality of battery cells 120 and a bus bar assembly 140 having electrically conductive bus bars 141 ), and a sensing module 130 configured to sense at least one of temperature and voltage of the battery cell. In addition, the battery module 100 according to an embodiment of the present invention may further include a module housing 150 accommodating the cell stack therein.

First, the cell assembly 110 is composed of a plurality of battery cells 120 . For example, a plurality of battery cells 120 may be stacked in a specific direction to form the cell assembly 110 . In this embodiment, the battery cells 120 are stacked in a left-right direction (or horizontal direction). However, it is also possible to stack the battery cells 120 in the vertical direction as needed.

Each battery cell 120 may be composed of a pouch type secondary battery, that is, a pouch type battery cell in which an electrode assembly (not shown) and an electrolyte are accommodated in a pouch (casing) 121 .

The electrode assembly (not shown) includes a plurality of electrode plates composed of a positive electrode plate and a negative electrode plate and is accommodated in the pouch 121 . The electrode assembly may be configured in a form in which a positive electrode plate and a negative electrode plate are stacked with a separator interposed therebetween in a state in which wide surfaces of the positive electrode plate and the negative electrode plate face each other. Electrode tabs are provided on each of the plurality of positive electrode plates and the plurality of negative electrode plates, and each electrode tab is connected to the electrode lead 126 so that the same polarities come into contact with each other. The electrode lead 126 may be exposed to the outside of the pouch 121 .

In order to maintain the shape of the cell assembly 110, neighboring battery cells 120 may be attached to each other by double-sided tape (not shown). The double-sided tape is attached to the side (wide side) of the battery cell 120 to fix the plurality of battery cells 120 to each other.

Meanwhile, in the embodiment of the present invention, the battery cell 120 is not limited to a pouch type battery cell, and may be configured as a prismatic or cylindrical battery cell.

The bus bar assembly 140 may include an electrically conductive bus bar 141 electrically connected to the electrode lead 126 of the battery cell 120 and an electrical insulating support plate 145 .

The bus bar assembly 140 is coupled to one side or both sides where the electrode leads 126 of the battery cell 120 are disposed. The electrode lead 126 passes through the body of the bus bar assembly 140 and is electrically connected in series and/or parallel form by the bus bar 141 outside the bus bar assembly 140 . To this end, a coupling hole 143 through which the electrode lead 126 is coupled may be formed in the bus bar 141 . The coupling between the electrode lead 126 and the bus bar 141 may be performed by welding in a state in which the electrode lead 126 protrudes outward from the bus bar 141 through the coupling hole 143 .

In addition, the bus bar assembly 140 may be provided with a connection terminal 146 for electrical connection with the outside. Thus, the battery cell 120 may be electrically connected to the outside through the connection terminal 146 . The connection terminal 146 may be exposed to the outside of the module housing 150 through a through hole formed in the housing cover 155 to be described later.

The support plate 145 is disposed between the body portion of the battery cell 120 (a portion where the electrode assembly is accommodated) and the electrically conductive bus bar 141 to support the bus bar 141 and through which the electrode lead 126 passes. is formed to That is, the electrode lead 126 may pass through the support plate 145 and then be connected to the coupling hole 143 formed in the bus bar 141 .

The sensing module 130 is provided to measure the operating state of the battery cell 120 . The sensing module 130 may be connected to a battery management system (BMS) or the like to prevent overcharging of the battery cells 120 or perform voltage balancing.

The sensing module 130 may include a sensing member 135 for measuring an operating state of the battery cell 120 and a circuit member 131 having a circuit 134 connected to the sensing member 135 .

The sensing member 135 may include a voltage sensing terminal 136 for receiving a voltage signal of the battery cell 120 and a temperature sensor 137 for measuring the temperature of the battery cell 120 .

The circuit member 131 may include a first circuit unit 133 in which a voltage sensing terminal 136 is installed and a second circuit unit 132 connected to the first circuit unit 133 . The voltage sensing terminal 136 may be connected to the bus bar 141 . When the bus bar 141 is provided on both sides of the cell assembly 110 in the longitudinal direction, the voltage sensing terminal 136 and the first circuit unit 133 may be provided on both sides of the cell assembly 110 in the longitudinal direction, respectively. . In order to detect voltages of the plurality of battery cells 120 , a plurality of voltage sensing terminals 136 may be installed in the first circuit unit 133 . The second circuit unit 132 may have a structure connecting the first circuit unit 133 provided on both sides of the cell assembly 110 in the longitudinal direction. A plurality of temperature sensors 137 may be installed on top of the battery cell 120 to measure the temperature of the battery cell 120 . However, the installation position and number of temperature sensors 137 can be changed in various ways.

The circuit member 131 may include a flexible printed circuit board (FPCB) to reduce the volume (thickness) of the sensing module 130 and apply surface mounting technology. However, the circuit member 131 may also include a printed circuit board (PCB).

On the other hand, in order to support the circuit member 131, in particular, the second circuit unit 132 and at the same time insulate between the second circuit unit 132 and the battery cell 12, between the second circuit unit 132 and the battery cell 12 A circuit support member 138 made of an insulating material may be provided.

The module housing 150 forms the exterior of the battery module 100 and accommodates at least a portion of the cell assembly 110 therein. That is, the module housing 150 may be disposed outside the cell assembly 110 to structurally support the cell assembly 110, and may incidentally protect the battery cell 120 from the external environment. can be done

As an example, the module housing 150 may include a housing body 151 having a cross-sectional shape with one side open, and a housing cover 155 combined with the housing body 151 to form an inner space. . In addition, the module housing 150 has a structure in which end plates 156 are coupled to the longitudinal front and rear surfaces of the module housing 150 so as to cover the inner space formed by the housing body 151 and the housing cover 155. can

The cell assembly 110 may be disposed in the inner space of the module housing 150 . At least one surface constituting the module housing 150 may function as a heat dissipation plate that dissipates heat generated in the battery cell 120 to the outside.

In order to form a U-shaped cross section with one side open, the housing body 151 includes a lower plate 152 supporting the lower portion of the cell assembly 110 and a vertical direction at both ends of the lower plate 152 (upper side in FIG. 1). ) and may include a side plate 153 supporting the side of the cell assembly 110. The side plate 153 supports the side surface of the cell assembly 110 in correspondence with the side surface (wide surface) of the cell assembly 110 stacked in the left and right directions.

At this time, the housing body 151 may have a structure in which the lower plate 152 and the side plate 153 are integrally formed. In addition, the housing body 151 may have a constant cross-sectional shape along the longitudinal direction, and in this case, the housing body 151 may be manufactured by an extrusion process. However, if necessary, it is also possible to configure the housing body 151 by combining/joining the side plate 153 and the lower plate 152 as independent components.

The housing cover 155 is disposed to face the lower plate 152 and may be connected to an upper end of the side plate 153 . Therefore, when the housing cover 155 is coupled to the housing body 151 in the form of covering the side plate 153, the housing cover 155 and the housing body 151 have the shape of a hollow tubular member.

The housing body 151 and/or the housing cover 155 may be made of a material having high thermal conductivity such as metal. For example, the housing body 151 may be made of aluminum. However, the materials of the housing body 151 and the housing cover 155 are not limited thereto, and even if they are not metal, various materials may be used as long as they have strength and thermal conductivity similar to those of metal.

The end plate 156 is coupled to a portion corresponding to the wide surface of the battery cell 120, that is, to the front and rear surfaces of the module housing 150 in the longitudinal direction, respectively, so as to cover the open front and rear surfaces of the module housing 150. It can be. The end plate 156 is coupled to the housing body 151 and the housing cover 155 to form the exterior of the battery module 100 together with the housing body 151 and the housing cover 155 . The end plate 156 may be formed of a metal such as aluminum.

However, the shape and division structure of the module housing 150 is not limited to the above-described form, and various changes are possible. In addition, the module housing 150 may have a shape in which a partial surface of the cell stack 120 is open to the outside. For example, the module housing 150 may also have a structure that surrounds only the side surface of the cell stack 120 .

Meanwhile, an insulating plate 161 may be disposed between the housing body 151 and the bus bar 141 to insulate between the bus bar assembly 140 and the housing body 151 .

Next, the sensing module 130 will be described in more detail with reference to FIGS. 3 to 7 .

3 is a front view showing a state in which the sensing module 130 is coupled to the bus bar assembly 140 according to an embodiment of the present invention, and FIG. 4 (a) is an enlarged view of part “A” in FIG. 3 , FIG. 4(b) is a cross-sectional view taken along line II′ of FIG. 4(a). In addition, FIG. 5 is a schematic diagram showing a junction between the sensing member 135 and the circuit member 131, FIG. 6 is a schematic diagram showing a portion of the circuit member 131 to which the sensing member 135 is joined, and FIG. 7 (a) to 7 (g) are schematic diagrams showing various modified examples of the sensing member 135 according to an embodiment of the present invention.

As described with reference to FIGS. 1 and 2 , the sensing module 130 according to an embodiment of the present invention may include a sensing member 135 and a circuit member 131 . In addition, the sensing member 135 may include a voltage sensing terminal 136 and a temperature sensor 137, and the circuit member 131 includes a first circuit unit 133 in which the voltage sensing terminal 136 is installed. , may include a second circuit unit 132 in which the temperature sensor 137 is installed.

Hereinafter, for convenience of description, the circuit member 131 and the sensing member 135 are respectively described as the first circuit unit 133 and the voltage sensing terminal 136 as an example, but the description will be given below for the second circuit unit 132 ) and the junction structure between the temperature sensor 137.

Referring to FIG. 3 , the sensing module 130 according to an embodiment of the present invention may include a sensing member 135 and a circuit member 131 . The sensing member 135 may include a voltage sensing terminal 136 for receiving and measuring a voltage signal of the battery cell 120 . The circuit member 131 may include a first circuit unit 133 to which the voltage sensing terminal 136 is bonded. One side (upper part in FIG. 3) of the voltage sensing terminal 136 is bonded to the first circuit part 133, and the other side (lower part in FIG. 3) of the voltage sensing terminal 136 is connected to the bus bar 141. can be joined. Therefore, the voltage sensing terminal 136 receives the voltage signal of the battery cell 120 transmitted from the battery cell 120 to the bus bar 141 and receives the battery management system (BMS) outside the battery module 110 (Battery Management System). System) (not shown). The battery management system measures the voltage of the battery cell 120 based on the voltage signal received from the voltage sensing terminal 136 . However, in the embodiment of the present invention, direct bonding of the voltage sensor to the first circuit unit 133 instead of the voltage sensing terminal 136 is not excluded.

The first circuit unit 133 may include a circuit 134 for input/output of a signal sensed by the voltage sensing terminal 136 . Since the plurality of voltage sensing terminals 136 are mounted on the first circuit unit 133 , the plurality of circuits 134 may be provided on the first circuit unit 133 . Although not shown, the second circuit unit 132 may also include a circuit 134 for input/output of a signal detected by the temperature sensor 137 .

Referring to FIG. 4 (a), the voltage sensing terminal 136, which is an example of the sensing member 135, has a circuit junction 135a coupled to the circuit member 131 and a bus bar coupled to the bus bar 141. It can be divided into junction (135b). That is, one side of the voltage sensing terminal 136 may be bonded to the circuit member 131 and the other side may be bonded to the bus bar 141 . Since the voltage sensing terminal 136 and the bus bar 141 are made of a metal material, the voltage sensing terminal 136 may be bonded to the bus bar 141 through welding. A welding line WL may be formed between the rim of the bus bar junction 135b and the bus bar 141 . Unlike this, welding may be performed on the contact surface between the bus bar junction 135b and the bus bar 141. The voltage sensing terminal 136 may have a through hole H for discharging gas or air remaining in the bonding member SP, which will be described later, to the outside.

Referring to FIG. 4( b ) , the sensing module 130 may include a bonding member SP for bonding the sensing member 135 to the circuit member 131 . The bonding member SP is positioned between the circuit member 131 and the sensing member 135 . Since the circuit member 131 is formed of a material having a low melting temperature, such as resin, the voltage sensing terminal 136 and the circuit member 131 cannot be joined by welding. Therefore, in the embodiment of the present invention, the circuit member 131 and the sensing member 135 may be soldered through the joint member SP. In particular, in an embodiment of the present invention, a surface mounting technology using solder paste (solder cream) may be applied to the soldering joint.

The bonding member SP is made of a low melting point material, and may include, for example, solder paste (solder cream). The bonding member SP is applied to the circuit member 131 in a predetermined amount, and the sensing member 135 is placed on the bonding member SP applied to the circuit member 131 . In this state, when heated to a preset temperature and then cooled, the bonding member SP is melted and hardened. Accordingly, the cured bonding member SP forms a bonding layer between the sensing member 135 and the circuit member 131 . Specifically, the bonding member SP forms a fillet surface F between the edge surface (LE in FIG. 5) of the portion corresponding to the circuit member 131 of the circumference of the sensing member 135 and the circuit member 131 will do In addition, the bonding member SP fills at least a part of the inner space formed by the through hole H.

In this way, according to the embodiment of the present invention, not only is the fillet surface (F) formed by the bonding member (SP) on the edge surface of the sensing member 135, but also the bonding member (SP) is introduced into the through hole (H). Therefore, the contact area between the bonding member SP and the sensing member 135 increases, so that the bonding strength of the sensing member 135 can be improved.

Meanwhile, gas and air may remain inside the bonding member SP during the curing process, so that gaps may be formed in the cured bonding member (bonding layer) SP. Such voids not only cause a decrease in bonding strength, but also have a problem in that cracks or damage easily occur in the bonding layer due to heat or external shock.

However, according to an embodiment of the present invention, gas or air generated from the molten bonding member SP or contained in the bonding member SP is discharged to the outside of the bonding member SP through the through hole H. can Therefore, according to the embodiment of the present invention, it is possible to minimize the formation of voids in the cured bonding member SP.

Meanwhile, a method of forming a large gas discharge hole in the sensing member 135 to discharge gas or air may be considered (see FIG. 8(b)). However, when the gas discharge hole is formed to be large, there is a problem in that the bonding force is reduced because the bonding area between the sensing member 135 and the bonding member SP is reduced. Furthermore, even when the gas discharge hole is formed to be large, a plurality of air gaps may occur in a region of the sensing member 135 that is far from the gas discharge hole. In particular, there is a limit to managing the generation amount of voids in a stable range because there is a variation in the application amount of the bonding member SP.

In order to solve this problem, the embodiment of the present invention has a configuration in which a plurality of small-sized through-holes (H) are formed in the sensing member (135).

Referring to FIG. 5 , in an embodiment of the present invention, the diameter D of the through hole H has a value of 0.5 mm to 1.0 mm, and the plurality of through holes H may be spaced apart from each other.

If the diameter (D) of the through hole (H) is smaller than 0.5 mm, it is difficult to form the through hole (H) in the sensing member 135, and the diameter (D) of the through hole (H) is too small to allow gas However, it is difficult for air to be discharged through the through hole (H). In addition, when the diameter D of the through hole H is larger than 1 mm, there is a problem in that the bonding force is lowered because the bonding member SP is not sufficiently filled in the through hole H. That is, when the diameter D of the through hole H is greater than 1 mm, the joint member SP cannot completely fill the inner space of the through hole H, and the joint member SP cannot fill a portion of the inner circumference of the through hole H. SP) may not be placed. In addition, considering that the entire area of the sensing member 135 is small, when the diameter D of the through hole H is greater than 1 mm, the distance L2 between the through holes H and the through hole H There is a problem in that it is difficult to sufficiently secure the distance L1 between the circumference and the sensing member 135 . In addition, when the diameter (D) of the through hole (H) is greater than 1 mm, there is a limit to managing the generation amount of voids within a stable range due to the variation in the application amount of the bonding member (SP).

In addition, among the through holes H, the minimum distance among the distances L2 between adjacent through holes H may have a value of 1 mm to 2 mm. When the minimum distance between the through holes (H) is 1 mm or less, the distance (L2) between the through holes (H) is too close, making punching difficult. Moreover, when the minimum distance between the through holes (H) is 1 mm or less, stress is applied to adjacent through holes in the through hole processing (for example, punching processing) process, resulting in uneven surfaces such as wrinkles around the through holes (H). can be formed In this way, when the bonding surface is not flat, the bonding is not smoothly performed in the soldering process. Conversely, when the minimum distance between the through holes (H) is 2 mm or more, there is a problem in that a plurality of air gaps are generated in a part far from the through holes (H).

Considering the above problems, more preferably, the minimum distance among the distances L2 between the through holes H adjacent to each other among the through holes H may have a value of 1.3 mm to 1.7 mm.

In addition, the minimum distance among the distances L1 between the edge surface LE of the portion corresponding to the circuit member 131 and the through hole H of the perimeter of the sensing member 135 has a value of 0.75 mm to 1.25 mm. can When the minimum distance between the rim surface LE and the through hole H is smaller than 0.75 mm, the punching process may not be smooth because the distance L1 between the through hole H and the rim surface LE is too close. . In addition, irregular surfaces such as wrinkles are formed around the through hole H and the edge surface LE during the punching process, so that the bonding is not smoothly performed in the soldering process. Conversely, when the minimum distance between the edge surface and the through hole H is greater than 1.25 mm, since the entire area of the sensing member 135 is small, it is necessary to sufficiently secure the distance L2 between the plurality of through holes H. There is a difficult problem.

On the other hand, in order to smoothly discharge gas and air from the bonding member SP, each through hole H is at least one of a distance from the nearest through hole H and a distance from the edge surface LE. may be arranged to be 2 mm or less. In this case, considering that the area of the sensing member 135 bonded to the circuit member 131 has a substantially rectangular shape, the sensing member 135 has five through holes H at the vertexes and the center of the rectangle. It can be arranged to have a shape disposed on.

Referring to FIGS. 5 and 6 , the circuit member 131 has a bonding area where the sensing member 135 is bonded. The circuit member 131 may include an FPCB. The junction area consists of a conductive area (A2) where electrically conductive material such as copper is exposed to the outside, and an edge area (A1) covered by an insulating film (for example, polyimide (PI) film) although the electrically conductive material is applied. ). In addition, a bonding member application area A3 may be formed in a central area of the conductive area A2 where a bonding member SP such as solder paste is applied.

A preset amount of bonding material SP is applied to the bonding material application area A3, and the applied bonding material SP spreads widely over the entire area of the sensing member 135 when melted. A separation distance LS1 is formed by a preset value (for example, 0.5 mm) between the outer circumferential surface of the application area A3 and the outer circumferential surface of the conductive area A2 in consideration of the amount of spreading of the bonding member SP to the periphery. can be..

The sensing member 135 is disposed inside the edge area A1 and may be seated on the conductive area A2. The width WS and height HS of the sensing member 135 bonded to the circuit member 131 are smaller than the width WC and height HC of the electrically conductive material. The edge surface LE of the sensing member 135 substantially corresponds to the outer circumferential surface of the conductive region A2.

A separation distance LS2 may be formed between the outer circumferential surface of the edge region A1 and the outer circumferential surface of the conductive region A2 by a preset value. In the portion corresponding to the separation distance LS2, the bonding member SP applied to the application area A3 moves to the outside of the sensing member 135 and forms a fillet surface on the edge surface LE of the sensing member 135 (Fig. F) of 4(b) can be formed.

In the above, surface mounting technology in which solder paste (solder cream) is used as an example of a joint member (SP) has been described, but the specific material or shape of the joint member (SP) is not limited as long as it is a low melting point material. Solder wire, solder bar, etc. are not excluded.

7 (a) to 7 (g), the number and arrangement of through holes H formed in the sensing member 135 are the width of the sensing member 135 bonded to the circuit member 131 ( Various changes are possible according to WS) and height (HS). At this time, the diameter D of the through hole H may have a value of 0.5 mm to 1.0 mm. In addition, the minimum distance between adjacent through holes H among the through holes H has a value of 1 mm to 2 mm, and the minimum distance between the edge surface LE and the through hole H has a value of 0.75 mm to 1.25 mm. can have a value of

Next, with reference to FIG. 8 (a) and FIG. 8 (b), operation effects according to an embodiment of the present invention will be described.

Figure 8 (a) is an X-ray photograph of the state of the bonding member (SP) with respect to the sensing member 135 according to an embodiment of the present invention, Figure 8 (b) is a sensing member 135 according to a comparative example It is an X-ray photograph of the state of the bonding member SP.

The sensing member 135 according to the embodiment of the present invention shown in FIG. 8 (a) has a shape in which five through holes H are disposed at the vertexes and the center of a rectangle, and the five through holes A case in which five through holes H occupy 3.5% of the total bonding area of the sensing member 135 including the hole H (corresponding to the area by HS and WS in FIG. 6 ) is shown. In addition, the sensing member 135 according to the comparative example shown in FIG. 8 (b) has a shape in which one slot-shaped gas discharge hole (S) is disposed, and the sensing member 135 including the gas discharge hole (S) '), the case where the area occupied by the gas discharge hole (S) is 13.5% of the total bonding area is shown.

Comparing Figure 8 (a) with Figure 8 (b), it can be seen that the amount of voids (V) in Figure 8 (a) according to the embodiment of the present invention is significantly reduced compared to Figure 8 (b) according to the comparative example. can

That is, when the gas discharge hole S is formed to be large as shown in FIG. can In particular, there is a limit to managing the generation amount of the voids V in a stable range because there is a variation in the application amount of the bonding member SP.

Table 1 below shows experimental results comparing the ratio of the voids V in the embodiment of the present invention according to FIG. 8 (a) and the comparative example according to FIG. 8 (b).

The embodiment according to FIG. 8 (a) is a sensing member having five through holes H having a diameter of 0.5 mm and occupying 3.5% of the area occupied by the five through holes H based on the outer area (green area). The ratio of the air gap (V) was measured for (135), and in the comparative example according to FIG. 8 (b), the area occupied by one gas discharge hole (S) is 13.5% based on the outer area (green area) The ratio of voids V to member 135' was measured.

Solder paste is used as a joint member (SP), the squeeze pressure is 10 kgf/cm ² , the squeeze speed is 40 mm/sec, and the metal-mask opening size is 70%. The experiment was performed with The application of the solder paste was divided into mesh type application and whole type application, and the experiment was performed 5 times.

The ratio (%) of voids was expressed as "(area of voids) / (total area - hole area)" as a percentage.

As shown in Table 1, it can be seen that the ratio of voids according to the embodiment of the present invention is generally lower than that of the comparative example, and the average value of the void ratio is also low. In particular, in the case of the comparative example, the ratio of voids is more than 20% due to the variation in the coating amount of the solder paste. Accordingly, it is difficult to stably manage the ratio of voids. However, in the case of the embodiment of the present invention, the ratio of voids It can be seen that the values are generally stable.

As described above, since the occurrence of voids in the bonding member is reduced in the case of the embodiment of the present invention, the bonding performance of the sensing member is excellent and cracks or damage to the bonding layer are not easily caused by heat or external impact.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and variations are possible without departing from the technical spirit of the present invention described in the claims. It will be obvious to those skilled in the art.

For example, it may be implemented by deleting some components from the above-described embodiments, and each embodiment may be implemented in combination with each other.

100... battery module 110 ... cell stack
120 ... battery cell 121... Pouch
126... electrode lead 130 ... sensing module
131... circuit member 135... sensing member
135a ... circuit junction 135b ... busbar junction
136... terminal for voltage sensing 137... Temperature sensor
140... busbar assembly 141... bus bar
145... support plate 150... module housing
A1... edge area A2... conductive area
A3... application area of joint member D... Diameter of through hole
F... fillet faces H... through hole
L1... Gap between the through hole and the rim face
L2... Spacing between through-holes LE... border plane
SP... connection member

Claims (14)

a sensing member for measuring an operating state of a battery cell;
a circuit member having a circuit connected to the sensing member; and
a bonding member for bonding the sensing member to the circuit member;
Including,
The sensing member has a plurality of through holes through which the bonding member flows,
A sensing module having a diameter of the through hole having a value of 0.5 mm to 1.0 mm. According to claim 1,
The circuit member includes a flexible printed circuit board (FPCB),
The sensing module is attached to the conductive area of the FPCB through the bonding member. The method of claim 1, wherein the bonding member forms a fillet surface between an edge surface of a portion corresponding to the circuit member and the circuit member of the perimeter of the sensing member, and at least a portion of an internal space formed by the through hole. A sensing module that fills the According to claim 1,
A sensing module having a minimum distance between adjacent through holes among the through holes having a value of 1 mm to 2 mm. According to claim 1,
A sensing module having a minimum distance between adjacent through holes among the through holes having a value of 1.3 mm to 1.7 mm. According to claim 1,
The sensing module having a value of 0.75 mm to 1.25 mm in a minimum distance between an edge surface of a portion corresponding to the circuit member of the perimeter of the sensing member and the through hole. According to claim 1,
Each of the through-holes is disposed so that at least one of a distance between a nearest through-hole and a distance between an edge surface of a portion corresponding to the circuit member among the perimeters of the sensing member is 2 mm or less. According to claim 1,
The sensing module has a shape in which the five through-holes are disposed at the vertexes and the center of a rectangle. According to claim 1,
The sensing module includes at least one of a voltage sensing terminal and a temperature sensor. According to claim 1,
The bonding member includes a solder paste applied to the circuit member Sensing module.
A cell assembly having a plurality of battery cells;
a bus bar assembly having an electrically conductive bus bar electrically connected to the battery cell; and
a sensing module for measuring an operating state of the battery cell;
Including,
The sensing module includes a sensing member for measuring an operating state of the battery cell, a circuit member having a circuit connected to the sensing member, and a bonding member for bonding the sensing member to the circuit member,
The sensing member has a plurality of through holes through which the bonding member flows,
A battery module having a diameter of the through hole is 0.5 mm to 1.0 mm. According to claim 11,
The sensing member includes a voltage sensing terminal,
The battery module according to claim 1 , wherein the voltage sensing terminal includes a circuit junction portion bonded to the circuit member and a bus bar junction portion bonded to the bus bar. According to claim 12,
The bonding member forms a fillet surface between an edge surface of the circuit bonding portion and the circuit member, and is configured to fill at least a part of an internal space formed by the through hole,
The battery module wherein the voltage sensing terminal is bonded to the bus bar through welding. According to claim 12,
Among the through-holes, the minimum distance between adjacent through-holes has a value of 1 mm to 2 mm,
A minimum distance between an edge surface of a portion corresponding to the circuit member and the through hole of the perimeter of the sensing member has a value of 0.75 mm to 1.25 mm.

Images