KR20170082244A - Battery protection circuit module and battery pack including the same - Google Patents

Abstract

In order to effectively prevent overcurrent and overheating, and to achieve a compact and low cost, the present invention provides a battery charger comprising a first terminal and a second terminal electrically connected to an electrode terminal of a battery bare cell, A third terminal and a fourth terminal, at least one transistor connected between the first terminal and the third terminal or between the second terminal and the fourth terminal, and at least one transistor for controlling the at least one transistor And a second protection integrated circuit element for controlling the at least one transistor, wherein the first protection integrated circuit element and the second protection integrated circuit element output a signal synchronized with each other to the at least one To a gate terminal of the transistor.

Description

A battery protection circuit module, and a battery pack including the battery protection circuit module.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery for an electronic device, and more particularly, to a battery protection circuit module for protecting a battery cell and a battery pack including the battery protection circuit module.

Generally, batteries are used in electronic devices such as mobile phones and PDAs. Lithium-ion batteries are the most widely used batteries in portable handsets, and they have overcharging and over-currents, and when the temperature rises due to the heat generation, the performance deteriorates as well as the risk of explosion. Therefore, in order to prevent such performance deterioration, there is an increasing need to provide a battery protection circuit device that cuts off the operation of the battery.

Typically, a thermistor element, such as a PTC (Positive Temperature Coefficient) element, is additionally used in the battery protection circuit device to prevent overcurrent and overheating. Such a PTC device can be formed, for example, by dispersing conductive particles in a crystalline polymer. Below the set temperature, the PTC element becomes a passage through which the current flows between the conductive connecting members. However, when the temperature exceeds the set temperature due to the occurrence of the overcurrent, the crystalline polymer swells and the resistance between the conductive particles dispersed in the crystalline polymer is separated and the resistance is rapidly increased. Accordingly, the flow of the current between the conductive connecting members is blocked or the flow of the current is reduced. Since the flow of current can be cut off by the PTC element, the PTC element serves as a safety device for preventing the battery from being ruptured. When the temperature is lower than the set temperature again, the crystalline polymer is shrunk in the PTC device and the connection between the conductive particles is restored, so that the current can flow smoothly. However, such a PTC device has a problem that the manufacturing cost is increased and the size of the battery is increased because the unit price of the PTC device is high.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a battery protection circuit module and a battery pack which are advantageous in terms of integration and miniaturization while effectively preventing overcurrent and / or overheating. However, these problems are exemplary and do not limit the scope of the present invention.

According to an aspect of the present invention, there is provided a battery bare cell including a first terminal and a second terminal electrically connected to an electrode terminal of a battery bare cell, a third terminal and a fourth terminal electrically connected to the charger or the electronic device, At least one transistor connected between the first terminal and the third terminal or between the second terminal and the fourth terminal, a first protection integrated circuit element for controlling the at least one transistor, Wherein the first protection integrated circuit element and the second protection integrated circuit element transmit a synchronized signal to a gate terminal of the at least one transistor, do.

In the battery protection circuit module, the first protection integrated circuit element and the second protection integrated circuit element may be connected to each other through respective synchronization terminals to send synchronized signals to the gate terminals of the at least one transistor .

In the battery protection circuit module, the at least one first transistor may include a first field effect transistor and a second field effect transistor connected in series with each other.

Wherein the first protection integrated circuit element and the second protection integrated circuit element each include a discharge control terminal and a charge control terminal, and the discharge control terminal of the first protection integrated circuit element and the discharge control terminal of the first protection integrated circuit element, The discharge control terminals of the two protection integrated circuit elements are connected to each other to be connected to the gates of the first field effect transistor and the charge control terminals of the first protection integrated circuit elements and the charge control terminals of the second protection integrated circuit elements are connected to each other And may be connected to the gate of the second field effect transistor.

In the battery protection circuit module, the first protection integrated circuit element and the second protection integrated circuit element may have the same structure.

A battery pack according to another aspect of the present invention includes a battery bare cell and a battery protection circuit module connected to the battery bare cell. The battery protection circuit module includes a first terminal and a second terminal electrically connected to an electrode terminal of a battery bare cell, a third terminal and a fourth terminal electrically connected to the charger or the electronic device, At least one transistor connected between the first terminal and the third terminal or between the second terminal and the fourth terminal, a first protection integrated circuit element for controlling the at least one transistor, And a second protection integrated circuit device. The first protection integrated circuit element and the second protection integrated circuit element send a synchronized signal to a gate terminal of the at least one transistor.

According to the embodiments of the present invention described above, it is possible to provide a battery protection circuit that can effectively prevent overcurrent and overheating, and a battery protection circuit package that can be compactly implemented at a low cost. Of course, the scope of the present invention is not limited by these effects.

1 is a schematic circuit diagram showing a battery protection circuit module according to an embodiment of the present invention.
2 is a schematic perspective view illustrating a battery protection circuit module according to an embodiment of the present invention.
3 is a perspective view illustrating a battery pack according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention are described in order to more fully explain the present invention to those skilled in the art, and the following embodiments may be modified into various other forms, It is not limited to the embodiment. Rather, these embodiments are provided so that this disclosure will be more thorough and complete, and will fully convey the concept of the invention to those skilled in the art. In the drawings, the thickness and size of each layer are exaggerated for convenience and clarity of explanation.

In describing embodiments of the present invention, the same reference numerals can be used to describe the concept of a circuit from the viewpoint of a battery protection circuit, but the concept of a device or a circuit part can be described from the viewpoint of a battery protection circuit package.

In describing embodiments of the present invention, an integrated circuit (IC) may mean an electronic component in which many devices are integrated into one chip to process a specific complicated function.

1 is a schematic circuit diagram showing a battery protection circuit module according to an embodiment of the present invention.

Referring to FIG. 1, a battery protection circuit module according to this embodiment of the present invention includes a first terminal 102 and a second terminal 104 electrically connected to an electrode terminal of a battery bare cell, And may include a third terminal 106 and a fourth terminal 108 electrically connected to each other. For example, the first terminal 102 is an internal positive terminal B + connected to the positive terminal of the battery bare cell in the battery pack, and the second terminal 104 is connected to the negative terminal of the battery bare cell B-), the third terminal 106 is an external positive terminal (P +) connected to the charger of the battery pack or the positive electrode of the electronic device and the fourth terminal 108 is connected to the charger or the external May be a negative terminal (P-).

Further, although not shown in the drawings, the battery protection circuit module according to some embodiments of the present invention may further include a separate additional external connection terminal.

At least one transistor 112 may be connected between the first terminal 102 and the third terminal 106 or between the second terminal 104 and the fourth terminal 108. The first protection integrated circuit device 118 and the second protection integrated circuit device 128 may be coupled to the at least one transistor 112 to control the at least one transistor 112. For example, the first protection integrated circuit device 118 and the second protection integrated circuit device 128 can output signals synchronized with each other to the gate terminals of at least one transistor 112.

For example, the transistor 112 is connected between the second terminal 104 and the fourth terminal 108 and the first protection integrated circuit device 118 and the second protection integrated circuit device 128 are connected between these transistors 112 at least to the gate terminal of the transistor 112. [

The first protection integrated circuit device 118 and the second protection integrated circuit device 128 may detect overdischarge, overcharge, and / or overcurrent of the battery, thereby preventing charging / discharging or operation of the battery bare cell. The first protection integrated circuit device 118 and the second protection integrated circuit device 128 may be used complementarily.

For example, the first protection integrated circuit device 118 and the second protection integrated circuit device 128 are configured in parallel to sense overdischarge, overcharge, and / or overcurrent of the battery, Or < / RTI > Accordingly, even if one of the first and second protection integrated circuit devices 118 and 128 fails, it is possible to protect the battery using the other one. However, even if one of the devices detects overdischarge, overcharge or overcurrent, and the other device can not detect it, the two devices synchronize the sensed signal so that the two devices block the charge / discharge or operation of the battery bare cell Can operate.

As another example, the first protection integrated circuit device 118 and the second protection integrated circuit device 128 may be functionally separated from each other. In this case, at least one of the first protection integrated circuit device 118 and the second protection integrated circuit device 128 may operate to replace a conventional overcurrent protection device, such as a PTC thermistor. For example, one of the first protection integrated circuit device 118 and the second protection integrated circuit device 128 may control overdischarge and overcharge of the battery and the other to sense overcurrent. In this case, however, if a control signal is output from any one of the two devices, the two devices can be synchronized with each other and output to the transistor 112 in the same manner.

More specifically, the transistor 112 may include a first field effect transistor 114 and a second field effect transistor 116 connected in series with each other. For example, the first field effect transistor 114 and the second field effect transistor 116 may be the same type, for example, an N-type MOSFET (NMOSFET), and the second terminal 104 and the fourth terminal 108, To share a drain with respect to each other. Thereby, at least one reverse diode is formed between the drain and the source of the first field effect transistor 114 and the second field effect transistor 116 so that a current flows between the second terminal 104 and the fourth terminal 108 Thereby controlling the current flow of the transistor.

The first protection integrated circuit device 118 and the second protection integrated circuit device 128 may each contain therein control logic for controlling the first field effect transistor 114 and the second field effect transistor 116 . For example, the control logic may include a reference voltage setting unit, a comparison unit for comparing the reference voltage with the charge / discharge voltage, an overcurrent detection unit, and a charge / discharge detection unit.

The charging and discharging state determination criteria can be changed to the SPEC required by the user and the voltage of each terminal of the first protection integrated circuit element 118 and the second protection integrated circuit element 128 And the charge / discharge state is determined. For example, the first protection integrated circuit device 118 and the second protection integrated circuit device 128 are connected to the reference terminal Vss, the power supply terminal Vdd, the sensing terminal V-, A discharge control terminal Dout and a charge control terminal Cout.

Furthermore, the first protection integrated circuit device 118 and the second protection integrated circuit device 128 may each include a synchronization terminal Sout for synchronizing output signals. To this end, the first protection integrated circuit device 118 and the second protection integrated circuit device 128 may further include a synchronization control unit in the control logic or separately from the control logic. The first protection integrated circuit device 118 and the second protection integrated circuit device 128 send signals synchronized with each other to the gate terminals of the first field effect transistor 114 and the second field effect transistor 116 The synchronization terminals Sout may be connected to each other. The signals of the synchronization control section of one of the first and second protection integrated circuit elements 118 and 128 are transmitted to the other elements through the synchronization terminals Sout so that the two signals are output .

According to this configuration, the first protection integrated circuit element 118 and the second protection integrated circuit element 128 can have the same structure. However, in a modified example of this embodiment, the first protection integrated circuit device 118 and the second protection integrated circuit device 128 have substantially the same structure but have different structures to additionally perform different functions It is possible.

The first protection integrated circuit device 118 may be connected to the nodes n2, n4 and n6 via at least one passive element. For example, the power supply terminal Vdd is connected to the node n2 between the first terminal 102 and the third terminal 106 via the resistor R11, the reference terminal Vss is connected to the second terminal 104, And the node n4 between the fourth terminal 108 and the fourth terminal 108. [ A capacitor C11 may be interposed between the reference terminal Vss and the power supply terminal Vdd between the nodes n2 and n4 to prevent a short circuit between the two nodes n2 and n4. The sensing terminal V- may be connected to the node n6 via the resistor R12.

The second protection integrated circuit device 128 may be connected to the nodes n1, n3, n5 via at least one passive element. For example, the power supply terminal vdd is connected to the node n1 between the first terminal 102 and the third terminal 106 via the resistor R21, the reference terminal Vss is connected to the second terminal 104, And the node n3 between the fourth terminal 108 and the fourth terminal 108. [ A capacitor C21 may be interposed between the reference terminal Vss and the power supply terminal Vdd between the node n1 and the node n3 to prevent a short circuit between the two nodes n1 and n3. The sensing terminal V- can be connected to the node n5 through the resistor R22.

The resistors R11 and R21 and the capacitors C11 and C21 serve to stabilize fluctuations in the power supply of the first and second protection integrated circuit devices 118 and 128. When the resistance values of the resistors R11 and R21 are increased, the detection voltage increases due to the current penetrated into the first and second protection integrated circuit elements 118 and 128 at the time of voltage detection, R21) may be set to a predetermined value, for example, a value of 1 K or less. Also, for stable operation, the capacitance value of the capacitors C11 and C21 can be appropriately adjusted, and can have an appropriate value of, for example, 0.01 占 F or more.

The capacitors C11 and C21 do not significantly affect the characteristics of the battery protection circuit product, but are added for user's request or stability. The capacitors C11 and C21 are for stabilizing the system by improving resistance to voltage fluctuation and external noise.

Alternatively, although not shown in the drawing, a structure in which a resistor and a varistor are connected in parallel may be added for ESD (Electrostatic Discharge) and surge protection. The varistor device has a low resistance when overvoltage is generated. When the overvoltage is generated, the resistance is lowered to minimize circuit damage due to overvoltage. The number or arrangement of the above-described passive elements can be appropriately modified in accordance with the additional function.

The first protection integrated circuit device 118 and the second protection integrated circuit device 128 can be configured to apply the charging voltage or the discharging voltage through the power supply terminal Vdd based on the voltage of the reference terminal Vss And it is possible to detect the charging / discharging and the overcurrent state through the sensing terminal (V-).

The discharge control terminals Dout of the first protection integrated circuit elements 118 and the second protection integrated circuit elements 128 are connected in parallel to each other in order to control the on- Lt; RTI ID = 0.0 > 1 < / RTI > The charge control terminals Cout of the first protection integrated circuit device 118 and the second protection integrated circuit devices 128 are connected to the charge control terminal Cout Lt; / RTI > field effect transistor 116, as shown in FIG.

The charging current flows from the third terminal 106 to the first terminal 102 and from the second terminal 104 to the fourth terminal 108 when the battery is charged. The discharging current flows from the first terminal 102 to the third terminal 106 and from the fourth terminal 108 to the second terminal 104 when the battery is discharged.

When the first protection integrated circuit device 118 and / or the second protection integrated circuit device 128 detects an overcurrent state or an overdischarge state at the time of battery discharge, a synchronized low signal The first field effect transistor 114 is turned off to sense the overcurrent or the overcharged state at the time of charging the battery and output a synchronized low signal through the charge control terminal Cout to output a second field effect And to turn transistor 116 off. Accordingly, as at least one of the first field effect transistor 114 and the second field effect transistor 116 connected in series is turned off, the circuit between the second terminal 104 and the fourth terminal 108 is cut off Overcharging, overdischarging and / or overcurrent of the battery may be interrupted.

This behavior can be shown in Table 1 below. In the following, "H" may be a logic high signal, for example a power supply voltage (Vdd), and "L" may be a logic low signal, for example a reference voltage (Vss).

Referring to Table 1, the output signals of the first and second protection integrated circuit devices 118 and 128 when the overcharge, over-discharge, over-current, or short state is detected through the synchronization terminal S out It can be seen that they are synchronously output in the same manner.

According to the above-described protection circuit configuration of the present invention, since the battery bare cell can be synchronized while being doubly protected by using the first and second protection integrated circuit elements 118 and 128, Or an overheating protection device such as a PTC thermistor or a bimetallic junction structure can be omitted, thereby reducing the total volume. The first protection integrated circuit device 118 and the second protection integrated circuit devices 128 can be implemented as a semiconductor chip, so that they can be manufactured in a micro or nanometer scale by using a silicon process technology.

For example, both the first protection integrated circuit device 118 and the second protection integrated circuit devices 128, the first and second field effect transistors 114 and 116 can be manufactured as semiconductor chips, Devices, such as resistors R11, R12, R21, R22, and capacitors C11, C21, may also be fabricated in chip form. Such a chip structure can be easily mounted on a substrate using surface mounting technology (SMT).

Although the field effect transistor 112 has been described as having a dual field effect transistor structure in the above described embodiment, in other embodiments the field effect transistor 112 may have a single field effect transistor structure, The structure of the first protection integrated circuit device 118 and the second protection integrated circuit device 128 may be modified to perform with one terminal.

2 is a perspective view schematically showing a battery protection circuit module according to an embodiment of the present invention.

Referring to FIG. 2, the above-described protection circuit structure may be mounted on the substrate 50. For example, the substrate 50 may comprise a printed circuit board or a leadframe. The first protection integrated circuit device 118 and the second protection integrated circuit devices 128, the first and second field effect transistors 114 and 116, the resistors R11, R12, R21 and R22, (C11, C21) may be sealed in a single package by using the molding material 55.

The first protection integrated circuit device 118 and the second protection integrated circuit devices 128 are each provided with a substrate 50 in the form of a chip scale package (CSP) As shown in FIG. In this case, the first protection integrated circuit device 118 and the second protection integrated circuit device 128 may be packaged and mounted on the substrate 50, respectively.

In another variation of this embodiment, the first field effect transistor 114, the second field effect transistor 116 and the first protection integrated circuit element 118 are connected to the first field effect transistor 114 and the second field effect transistor 114. [ Or a package on package (POP) structure in which the first protection integrated circuit device 118 is stacked on the transistor 116. [

The second field effect transistor 116 and the second protection integrated circuit element 128 are disposed between the first field effect transistor 114 and the second field effect transistor 114. In another variation of this embodiment, the first field effect transistor 114, the second field effect transistor 116, A stacked package structure in which the second protection integrated circuit elements 128 are stacked on the effect transistor 116 or a package on package (POP) structure.

In another variation of this embodiment, the dual MOSFET structure of the first field effect transistor 114 and the second field effect transistor 116 may be replaced by a single field effect transistor, The structure of the protection integrated circuit elements 118 and the second protection integrated circuit elements 128 may be partially changed.

3 is a schematic exploded perspective view showing a battery pack according to an embodiment of the present invention.

Referring to FIG. 3, the battery protection circuit module 300 is inserted between the upper surface of the battery bare cell and the upper case 500, and the battery pack 600 is formed. The upper case 500 is formed with a through hole 550 in a portion corresponding to the external connection terminals P + and P- so that the external connection terminals P + and P- can be exposed by plastic and / or metal.

The battery bare cell includes an electrode assembly and a cap assembly. The electrode assembly includes a positive electrode plate formed by applying a positive electrode active material to a positive electrode collector, a negative electrode plate formed by applying a negative electrode active material to a negative electrode collector, and a negative electrode plate interposed between the positive electrode plate and the negative electrode plate, As shown in Fig. A positive electrode tab attached to the positive electrode plate and a negative electrode tab attached to the negative electrode plate are drawn out from the electrode assembly.

The cap assembly includes an anode terminal 410, a gasket 420, a cap plate 430, and the like. The cap plate 430 may serve as a positive electrode terminal. The cathode terminal 410 may be referred to as a cathode cell or an electrode cell. The gasket 420 may be formed of an insulating material to insulate the cathode terminal 410 from the cap plate 430. Therefore, the electrode terminal of the battery bare cell may include the negative terminal 410 and the cap plate 430.

The electrode terminal of the battery bare cell includes a plate 430 of a first polarity (e.g., an anode) and an electrode cell 410 of a second polarity (e.g., cathode) disposed centrally within the plate 430 The first internal connection terminal lead B + is connected to the plate 430 of the first polarity (for example, an anode) to be electrically connected, and the second internal connection terminal lead B- is electrically connected to the second And can be electrically connected to the electrode cell 410 of the polarity (for example, the cathode). In this case, the length of the lead frame 50 corresponds to the length from one end of the plate 430 of the first polarity (for example, an anode) to the electrode cell 410 of the second polarity (for example, can do.

According to this embodiment, since the battery protection circuit package module 300 is mounted using only one side region of the upper portion with respect to the electrode cell 410 of the second polarity (for example, the cathode), the battery can be miniaturized or increased in capacity Can be implemented. For example, it is possible to contribute to miniaturization of an application product having such a battery by further forming a cell on the other side of the electrode cell 410 to increase the capacity of the battery or disposing a chip or the like having another additional function.

The battery protection circuit module and the battery pack having the battery protection circuit module according to the embodiments of the present invention have the following advantages as compared with the conventional overcurrent or overheat protection device, for example, a product using the PTC thermistor.

First, in the embodiments of the present invention, it is possible to effectively prevent the overcurrent while using an electronic component having a relatively lower component price than the PTC thermistor. In general, the unit price of PTC thermistor is high, which is a major cause of increasing the production cost of the battery protection circuit device. According to the present invention, it is expected that this problem can be effectively overcome.

Second, since the PTC thermistor is disposed outside the battery protection circuit package, a process of bonding the PTC thermistor and the battery protection circuit package is additionally required, and the strength of the structure may be reduced due to the failure in the bonding process. That is, a process of joining the metal layer of the PTC thermistor and the lead of the battery protection circuit module by laser welding or resistance welding is additionally required, and the structural strength of the bonded assembly may be relatively weak.

While the present invention has been described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

118, 128: Protection integrated circuit device
114, 116: field effect transistor

Claims (9)

A first terminal and a second terminal electrically connected to an electrode terminal of the battery bare cell;
A third terminal and a fourth terminal electrically connected to the charger or the electronic device;
At least one transistor connected between the first terminal and the third terminal or between the second terminal and the fourth terminal;
A first protection integrated circuit device for controlling said at least one transistor; And
And a second protection integrated circuit device for controlling the at least one transistor,
Wherein the first protection integrated circuit element and the second protection integrated circuit element transmit a synchronized signal to a gate terminal of the at least one transistor,
Battery protection circuit module. 2. The battery protection circuit of claim 1, wherein the first and second protection integrated circuit elements are coupled to each other through respective synchronization terminals to send synchronized signals to gate terminals of the at least one transistor, module. 3. The battery protection circuit module of claim 2, wherein the at least one transistor comprises a first field effect transistor and a second field effect transistor connected in series with each other. 4. The apparatus of claim 3, wherein the first protection integrated circuit element and the second protection integrated circuit element each include a discharge control terminal and a charge control terminal,
A discharge control terminal of the first protection integrated circuit element and a discharge control terminal of the second protection integrated circuit element are connected to each other and connected to a gate of the first field effect transistor,
Wherein the charge control terminal of the first protection integrated circuit element and the charge control terminal of the second protection integrated circuit element are connected to the gate of the second field effect transistor. The method according to claim 1,
Wherein the first protection integrated circuit element and the second protection integrated circuit element have the same structure. Battery bare cell; And
And a battery protection circuit module connected to the battery bare cell,
The battery protection circuit module includes:
A first terminal and a second terminal electrically connected to the electrode terminal of the battery bare cell;
A third terminal and a fourth terminal electrically connected to the charger or the electronic device;
At least one transistor connected between the first terminal and the third terminal or between the second terminal and the fourth terminal;
A first protection integrated circuit device for controlling said at least one transistor; And
And a second protection integrated circuit device for controlling the at least one transistor,
Wherein the first protection integrated circuit element and the second protection integrated circuit element transmit a synchronized signal to a gate terminal of the at least one transistor,
Battery pack. 7. The battery pack of claim 6, wherein the first protection integrated circuit element and the second protection integrated circuit element are connected to each other through respective synchronization terminals to send signals synchronized with each other to a gate terminal of the at least one transistor. 8. The battery pack of claim 7, wherein the at least one first transistor comprises a first field effect transistor and a second field effect transistor connected in series with each other. 9. The apparatus of claim 8, wherein the first protection integrated circuit element and the second protection integrated circuit element each include a discharge control terminal and a charge control terminal,
A discharge control terminal of the first protection integrated circuit element and a discharge control terminal of the second protection integrated circuit element are connected to each other and connected to a gate of the first field effect transistor,
Wherein the charge control terminal of the first protection integrated circuit element and the charge control terminal of the second protection integrated circuit element are connected to the gate of the second field effect transistor.

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