KR100728812B1 - Chip for protecting battery and method of manufacturing the same and battery pack having the chip - Google Patents

Abstract

The present invention relates to a battery protection chip, a method for manufacturing the same, and a battery pack including the same, wherein the first and second external electrode terminals are operated according to a control voltage, and the first external electrode terminal and the second external electrode terminal are operated. A switch unit for conducting the control unit, a control voltage generation unit for generating the control voltage by distributing a voltage between the first and second external electrode terminals according to a temperature, and a body unit for packaging the switch unit and the control voltage generation unit. It provides a battery protection chip and a manufacturing method thereof, and provides a battery pack comprising a battery protection chip. In this way, a simple control module including a temperature sensor capable of sensing temperature and a switching element driven according to a predetermined voltage can not only drastically reduce production costs, but also prevent overcharge and control overcurrent. In addition, the thermal stability can be ensured, and the characteristic variation between the plurality of battery protection circuit chips can be adjusted within a predetermined range, thereby enabling mass production, and the malfunction and failure of the battery protection circuit chip can be prevented.

Cell, Battery, Switching Element, Voltage Distribution, Transistor, NTC, PTC, Chip

Description

Battery protection chip, a method of manufacturing the same and a battery pack comprising the same {Chip for protecting battery and method of manufacturing the same and battery pack having the chip}

1 is a conceptual diagram of a battery pack according to a first embodiment of the present invention.

2 is a conceptual diagram of a battery protection chip according to a first embodiment.

3 to 5 are manufacturing process diagrams of the battery protection chip according to the present embodiment.

6 is a conceptual diagram of a battery pack according to a second embodiment of the present invention.

7 is a conceptual diagram of a battery pack according to a third embodiment of the present invention.

8A and 8B are conceptual views illustrating a fourth embodiment of the battery pack of the present invention.

9A and 9B are conceptual views illustrating a fifth embodiment of the battery pack of the present invention.

10 is a conceptual view illustrating a sixth embodiment of the battery pack of the present invention.

<Explanation of symbols for the main parts of the drawings>

10: battery body 100: battery pack

200: battery protection chip 210, 220: external electrode terminal

230: switch unit 240: control voltage generation unit

250: body part

The present invention relates to a battery protection chip, a method of manufacturing the same, and a battery pack including the same. One-chip circuit elements for battery protection can be prevented from malfunctioning or failure of circuit elements by using one chip. The present invention relates to a battery protection chip having a stabilizer capable of protecting overcharge and overcurrent under conditions, and ensuring thermal stability.

Generally, a battery is composed of a positive and negative electrode plate and an electrolyte, and refers to a device that generates a direct current electromotive force by a chemical reaction and can be used as a power source. It is a device that converts into electrical energy by reduction reaction.

These batteries are divided into primary batteries that cannot be recharged after use and secondary batteries that can be recharged and reused when the voltage drops below the service interval.

Looking at the operation of the battery described above, the negative electrode of the battery is usually used to give electrons and the material is oxidized itself, the positive electrode receives the electrons are used to reduce the material itself. When the battery is operated in connection with an external device such as a light or an electronic device, that is, when the discharge reaction of the battery proceeds, the two electrodes each change to an electrochemically different state. At this time, the electrical circuit is completed in the electrolyte by the mass transfer of negative ions and positive ions toward the cathode and the anode.

The primary battery is a battery that cannot be charged because the opposite reaction cannot occur. The secondary battery is a battery that can be charged to return to its original chemical state.

Therefore, the secondary battery is reusable, easy to manufacture in a small size, and has a lot of advantages in weight and light weight, while when overcharged, oxygen gas is generated at the positive electrode, lithium metal is precipitated at the negative electrode, and the electrolyte is a gas. It may decompose, and if this reaction continues, there is a high risk of explosion or fire. In particular, due to the unstable materials forming the lithium battery (lithium ion battery and lithium polymer battery) used as the secondary battery, the internal temperature of the battery rapidly rises due to external mechanical shock, thermal environment change, electrical connection, and the like, thereby expanding the battery. And explosions and the like.

In order to prevent such a risk, a protection circuit such as a protection circuit module (PCM) is used in most secondary batteries.

The PCM performs overcurrent protection, overcharge protection, overdischarge protection, and short-circuit protection when charging from a battery. For this purpose, PCM consists of active devices such as ICs or packaged FETs and passive devices such as resistors and capacitors.

Such PCM is disclosed in Korean Patent Publication No. 10-301346, Korean Patent Publication No. 10-2004-13354, and Patent Publication No. 10-422758. In Patent Publication No. 10-301346, a secondary battery is protected through a PCM using an IC circuit. However, there is a problem that an IC circuit is expensive and a circuit is complicated. In addition, Korean Patent Laid-Open Publication No. 10-2004-13354 protects a secondary battery through a PCM using a plurality of sensing sensors and discharge units. That is, the control unit determines the value input from the voltage sensor or the temperature sensor in the control unit and controls the protection circuit unit and the charge / discharge unit. However, the circuit becomes very complicated because the cost is high by the voltage sensor and the temperature sensor, and the transient current must be discharged through the discharge unit by determining the value of the sensor. In addition, the actual implementation of this is a factor that increases the unit cost of the entire battery.

In addition, Patent Publication No. 10-422758 prevents the loss of the NTC element by blocking an overcurrent flowing into the NTC element through a temperature sensing device in which an overcurrent blocking element or a PTC element is connected in series to the NTC element. This is only for the purpose of protecting the NTC element when the temperature sensing terminal and the hot side terminal to which the NTC element is connected are not able to control the secondary battery directly using the temperature sensing device. Therefore, separate FETs and regulator ICs are essential to detect changes in NTC and thus protect secondary batteries. However, as mentioned above, in order to control the temperature sensed through the external NTC by using a regulator IC and a FET, the circuit configuration becomes complicated and the cost of the secondary battery increases.

In addition, the devices constituting the conventional PCM have a large self-consumption current and are summed with the leakage current of the battery, causing a decrease in the open circuit voltage (OCV). In addition, a problem of shortening the battery usage time occurs due to power consumption of the PCM itself. In addition, PCM secures the stability of the battery by the role of overcharge control, overcurrent introduction control, etc. during the charging of the battery, but there is a problem that it is difficult to ensure the stability of the battery under normal use conditions except the charging conditions.

In addition, since the PCM is a circuit manufactured by using an active element and a passive element, as described above, a problem arises in that the characteristic of the entire circuit changes due to the characteristic variation of individual elements. That is, for example, in the case of a packaged transistor, its operating voltage is different for each transistor. Even after fabricating on the same wafer, there is a slight difference in the operating voltage of the packaged transistors, and in the case of NTC, the change in resistance value with temperature is different for each device. Therefore, when a plurality of PCM circuits are manufactured using such circuit elements and mounted for battery protection, characteristic variations between PCM circuits occur due to individual variations of circuit elements. As a result, some PCM circuits do not operate under the desired conditions, resulting in a problem of not only deteriorating battery usage time and battery performance but also preventing expansion or explosion of the battery.

Therefore, in order to solve the above problems, the production cost can be drastically reduced by one-chip simple control module including a temperature sensor capable of sensing temperature and a switching element driven according to a predetermined voltage change. In addition, it is possible to prevent overcharge, to control overcurrent, to ensure thermal stability, and to control the variation of characteristics among a plurality of control modules within a certain range, thereby enabling mass production, and to prevent malfunction and failure of the control module. It is an object of the present invention to provide a battery protection chip, a method of manufacturing the same, and a battery pack including the same.

A first and a second external electrode terminal according to the present invention, a switch unit operating according to a control voltage to conduct between the first external electrode terminal and the second external electrode terminal, and the first and second according to temperature It provides a battery protection chip comprising a control voltage generation unit for generating the control voltage by distributing the voltage between the external electrode terminal and a body portion for packaging the switch unit and the control voltage generation unit.

Here, the switch unit preferably includes a transistor connected to the first and second external electrode terminals, respectively, and having a collector terminal and an emitter terminal, the transistor being operated according to the control voltage. The resistor further includes a resistor connected between the first external electrode terminal and the collector terminal or between the second external electrode terminal and the emitter terminal, and the resistor is connected to the first external electrode terminal or the second external electrode terminal. It is preferable that it is done.

On the other hand, the control voltage generation unit includes a first voltage distribution means connected between the first external electrode terminal and the control voltage node and a second voltage distribution means connected between the second external electrode terminal and the control voltage node. It is effective. Here, the first and second voltage distribution means use at least one of an NTC element, a PTC element, and a distribution resistor element whose resistance value changes with temperature, and they may be connected in series or in parallel.

In addition, the battery pack according to the present invention provides a battery pack including a battery main body having a positive electrode and a negative electrode and a battery protection chip to operate between the positive electrode and the negative electrode to operate in accordance with temperature.

In addition, providing a switching device, a voltage distribution device, and the first and second external electrode terminals according to the present invention, by varying the voltage between the first and second external electrode terminals according to the temperature to vary the voltage, Electrically connecting and packaging the switching element, the voltage distribution element and the first and second external electrodes so as to conduct between the first and second external electrode terminals in accordance with a variable voltage and being packaged and electrically connected A method of manufacturing a battery protection chip comprising testing a circuit to detect a failure is provided.

Here, a transistor is used as the switching element, and at least any one of an NTC element, a PTC element, and a distribution resistor element whose resistance value changes with temperature is used as the voltage distribution element, and they use an element connected in series or in parallel. It is preferable.

In this case, electrically connecting and packaging the switching device, the voltage distribution device, and the first and second external electrodes may include connecting the voltage distribution device and the switching device to each other between the first and second external electrode terminals. And connecting one end of the voltage distribution element and the switching element with a wire, and packaging the voltage distribution element and the switching element.

And electrically connecting and packaging the switching element, the voltage distribution element, and the first and second external electrodes may include providing an upper body and a lower body, and the switching element and the voltage distribution in the lower body. Disposing an element and disposing first and second external electrodes at both ends of the lower body; connecting the switching element, the voltage distribution element, and the first and second external electrodes with wires; And preferably sealingly sealing the upper body on the lower body on which the connected switching element and the voltage distribution element are disposed.

Of course, the step of electrically connecting and packaging the switching element, the voltage distribution element and the first and second external electrodes may include providing an upper body and a lower body, and the switching element and the voltage on the lower body. Forming a pad to be connected with the distribution element, electrically connecting the pad, coupling the pad, the switching element and the voltage distribution element, and allowing them to be electrically connected to the first and second external electrode terminals; And combining the upper body with the lower body to package the switching element and the voltage distribution element.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention in more detail. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention, and the scope of the invention to those skilled in the art. It is provided for complete information. Like numbers refer to like elements in the figures.

1 is a conceptual diagram of a battery pack according to a first embodiment of the present invention, Figure 2 is a conceptual diagram of a battery protection chip according to the first embodiment.

1 and 2, the battery pack 100 according to the present embodiment includes a battery main body 10 having a positive electrode 11 and a negative electrode 12, and a positive electrode 11 and a negative electrode 12 according to temperature. And a battery protection chip 200 for conducting the liver. At this time, it may further include a PTC device (not shown) connected to the negative electrode 12 to block the external current according to the temperature.

As the battery, various batteries including a secondary battery or a fuel cell may be used. As the secondary battery, a lead acid battery, an alkaline storage battery, a gas battery, a lithium ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a polymer battery, and the like can be used. As small secondary batteries, nickel-cadmium batteries have been replaced by nickel-hydrogen batteries and lithium ion batteries. Lithium polymer batteries, in which only electrolytes are converted to polymers, are used in lithium ion batteries. The fuel cell may be a molten carbonate fuel cell, a solid electrolyte fuel cell, a phosphate electrolyte fuel cell, or the like using an alkaline aqueous solution as an electrolyte. In this case, as the electrolyte, pure hydrogen and oxygen may be used, and gaseous fuel using fossil fuels such as methane and natural gas in addition to hydrogen, and liquid fuels such as methanol and hydrazine may be used.

The battery protection chip 200 operates between the first and second external electrode terminals 210 and 220 and the first external electrode terminal 210 and the second external electrode terminal 220 of the chip by operating according to a control voltage. A control voltage generation unit 240 and the switch unit for generating a control voltage by dividing a voltage between the switch unit 230 which conducts the first and second external electrode terminals 210 and 220 according to temperature. A body 250 for packaging the 230 and the control voltage generator 240 is included. It is preferable to use the transistor 230 as the switch unit 230.

The control voltage generator 240 is connected between the first external electrode terminal 210 and the control voltage node Q1 and the NTC 242 and the second external electrode terminal 220 whose resistance values change according to temperature. And a resistor 244 connected between the control voltage node Q1 and the control voltage node Q1. The collector terminal of the transistor 230 used as the switch unit is connected to the first external electrode terminal 210, and the base is connected to the control voltage node Q1 between the NTC 242 and the resistor 244 and emitter The terminal is connected to the second external electrode terminal 220.

In this case, it is effective that the transistor 230 uses an NPN type transistor. It is preferable that turn-on voltage is 0.3-0.7V. Of course, a PNP type transistor can also be used. It is preferable to use a resistance of 10?

The NTC device 242 is a device in which the resistance value decreases nonlinearly with increasing temperature. For example, the NTC element 242 has a resistance value of about 100 kΩ at room temperature, but at a temperature of 100 degrees, the resistance value rapidly decreases to have a resistance value of about 7.4 kΩ. In this embodiment, it is preferable to use the NTC element 242 having a resistance value of 90 to 1000 kΩ at a temperature of 18 to 30 degrees and a resistance value of 1 to 100 kΩ at a temperature of 70 to 120 degrees. Of course, the characteristics of the NTC device 242 of the present invention is not limited thereto, and the value may vary depending on the characteristics of the resistor 244 and the transistor 230.

The operating range of the battery protection chip 200 described above is preferably operated at a temperature of 70 to 100 degrees to have a current amount of about 1mA to 20A. When the internal temperature of the battery pack 100 is lower than the temperature of the above operating range, the internal temperature of the battery pack 100 rapidly increases due to overcharge, external mechanical shock, thermal environment change, and electrical connection. When the temperature rises to the operating range, a current path may be formed from the first external electrode terminal 210 to the second external electrode terminal 220 to prevent overcharge, to control overcurrent, and to ensure thermal stability. That is, the present invention uses the voltage decomposition between the fixed resistance and the variable resistance of the battery pack to change the operation time of the switching element that forms a current path between both terminals and the negative terminal of the battery. The battery pack can be protected by controlling.

In this embodiment, a part of the body portion of the battery protection chip may be connected to the battery protection chip to immediately detect a change in temperature of the battery main body 110.

The characteristics of the individual elements constituting the battery protection chip 200 of the present invention are not limited to the above-described values, and may be variously changed according to voltages and currents generated by the battery main body 110.

The battery protection chip described above can be manufactured by various methods.

3 to 5 are manufacturing process diagrams of the battery protection chip according to the present embodiment.

As shown in the figure, various modifications for manufacturing the battery protection chip are possible.

Referring to FIG. 3, a transistor 230, an NTC 242, and a resistor 244 are provided. In the transistor 230, it is preferable to use a bare chip device that is not wire bonded. That is, a separate electrode terminal for connecting the base terminal, the emitter terminal and the collector terminal to the outside is not formed, and the transistor 230 in which they are directly exposed is used. The NTC 242 and the resistor 244 preferably use a device made in a chip shape.

Thereafter, as shown in FIG. 3A, the first external electrode terminal 210 is connected to one end of the NTC 242, and the second external electrode terminal 220 is connected to one end of the resistor 230. Connect The transistor 230, the NTC 242, and the resistor 244 are connected using the wires 231 to 234. That is, one terminal of the NTC 242, to which the collector terminal of the transistor 230 and the first external electrode terminal 210 are connected, is connected using the first wire 231, and the base terminal and NTC of the transistor 230 are connected. The other terminal of 242 and the other terminal of the resistor 244 are connected using the second and third wires 232 and 233, and the emitter terminal of the transistor 230 and the second external electrode terminal 220 are connected to each other. One terminal of the connected resistor 244 is connected using a fourth wire 234.

Next, as shown in FIG. 3B, a predetermined packaging process is performed to form a body part 250 that protects the transistor 230, the NTC 242, and the resistor 244 to form a battery protection chip ( 200) is prepared. In the above packaging process, the transistors 230, NTC 242, and resistors 244 connected by wires are disposed in the center of a predetermined frame, and a part of the first and second external electrode terminals 210 and 220 are placed outside the frame. After exposing the material, a material such as a liquid epoxy or plastic is poured into the mold and cured to manufacture the body part 250. That is, it can also manufacture using the metal mold | die of any one of an inlet type | mold, an outflow type, an injection mold, and a semi-indentation type | mold.

In addition to this, the body portion may also be made of an upper body and a lower body. Such a modification will be described below with reference to the drawings. In the following description, a description overlapping with the above-described embodiment will be omitted.

Referring to FIG. 4, a transistor 230, an NTC 242, and a resistor 244 are provided. As shown in FIG. 4A, the transistor 230, the NTC 242, and the resistor 244 are connected to each other using wires 231, 232, 233, and 244 to fabricate a predetermined protection circuit. . That is, the collector terminal of the transistor 230 and one end of the NTC 242 are connected using the first wire 231, and the emitter terminal of the transistor 230 and one end of the resistor 244 are connected to the fourth wire 234. ), The other terminal of the NTC 242 and the other terminal of the resistor 244 using the second wire 232, and the second wire 232 and the base terminal of the transistor 230 The third wire 233 is used for connection.

 Thereafter, as shown in FIGS. 4B and 4C, the transistors 230, NTCs 242, and resistors 244 connected to the lower body 251 by wires 231, 232, 233, and 234. , And connect them to the first and second external electrode terminals 210 and 220. That is, the first wire 231 and the first external electrode terminal 210 are connected by the fifth wire 235, and the fourth wire 234 and the second external electrode terminal 220 are the sixth wire 236. Use to connect. In this case, the first and second external electrode terminals 210 and 220 extend from the upper surface of the lower body to be refracted.

Next, the upper body 252 is coupled to the upper portion of the lower body 251 in which the transistor 230, the NTC 242, and the resistor 244 are disposed to form the battery protection chip 200.

The battery protection chip of this invention is not limited to this, Various methods are possible. That is, the transistor 230, the NTC 242, and the resistor 244 are disposed on the lower body 251, and then connected to each other using a wire or metal wire, and connected to the first and second external electrode terminals. The junction box may then be covered and packaged with an upper body.

In addition, transistors, NTCs, and resistors may be connected using separate pads and metal wires. Bumps can also be used as the pad. Such a modification will be described below with reference to the drawings. In the following description, descriptions that overlap with the above description will be omitted.

Referring to FIG. 5, a transistor 230, an NTC 242, a resistor 244, a lower body 251, and an upper body 252 are provided. As shown in FIG. 5A, a plurality of bumps 261 to 267 to be connected to the transistor 230, the NTC 242, and the resistor 244 are formed on the lower body 251, and the bumps are formed. Metal wirings 271 to 276 connecting the 261 to 267 are formed.

That is, the first and third bumps 261, 262 and 263 to be connected to the collector terminal, the base terminal and the emitter terminal of the transistor 230 are formed on the lower body 251, respectively. Fourth and fifth bumps 264 and 265 to be connected to one terminal and the other terminal, respectively, and sixth and seventh bumps 266 and 267 to be connected to one terminal and the other terminal of the resistor 244, respectively. Form. In addition, the first metal wire 271 connecting the first bump 261 and the fourth bump 264 and the second metal wire 272 connecting the second bump 262 and the fifth bump 265. ), A third metal wire 273 connecting the second bump 262 and the seventh bump 267, and a fourth metal wire 274 connecting the third bump 263 and the sixth bump 266. ), A fifth metal wire 275 extending from the fourth bump 264 to one end of the lower body 251 to be connected to the first external electrode terminal 210, and the lower body (in the sixth bump 266). Extending to the other end of 251 to form a sixth metal wire 276 to be connected to the second external electrode terminal 220.

Thereafter, as illustrated in FIG. 5B, the collector, base, and emitter terminals of the transistor 230 are coupled to the first to third bumps 261, 262, and 263, respectively, and the NTC 242 is removed. Couples to fourth and fifth bumps 264 and 265, and resistors 244 couple to sixth and seventh bumps 266 and 267. The first and second external electrode terminals 210 and 220 are coupled to the fifth and sixth metal wires 275 and 276, respectively. Through this, the protection circuit described in FIG. 2 may be manufactured. Next, the lower body 251 is packaged into the upper body 252 to fabricate the battery protection chip 200 as shown in FIG. In this case, some of the first and second external electrode terminals 210 and 220 may protrude to the outside of the body part 250 and protrude in a straight line without being refracted.

The method for manufacturing the battery protection chip is not limited to the above description and can be variously modified. It is also possible to fabricate the lower body in the form of metal pads instead of bumps, and then connect the transistors, NTC, and resistors to the metal pads by soldering. In addition, a protective circuit including a transistor, an NTC, and a resistor may be manufactured on a separate PCB, then packaged, and the battery protection chip may be manufactured by connecting the protective circuit to an external electrode terminal.

In addition, a semiconductor manufacturing process is used to form circuit elements including transistors, NTCs, and resistive elements on a wafer, to fabricate a number of dies electrically connected between them, to package individual dies, and to external electrodes. A battery protection chip can be manufactured by connecting with a terminal. In the above-described embodiment, the battery protection chip forms individual elements, and these are connected through wires or metal wires, respectively, and then packaged. However, the present invention is not limited thereto, and the elements constituting the battery protection chip may be formed on a single wafer, and then electrically connected to each other at a wafer level, and manufactured to be connected to the outside through a bonding pad. That is, a transistor is fabricated on the wafer, and then a resistor and NTC, which are connected to the base electrode, the emitter electrode, and the collector electrode of the transistor, respectively, are formed to be stacked thereon. Thereafter, they are passivated to form bonding pads, which are external electrode terminals connected to the outside. Next, the wafer is cut to form a die chip, and then the die chip is packaged to fabricate a battery protection chip.

In addition, the method of manufacturing the battery protection chip according to the above-described modifications is not limited to one modification, but the technology of the modifications may be used in a redundant or interchangeable manner.

The manufacturing method of the battery protection chip according to the present embodiment tests the operation of the circuit at a predetermined temperature after packaging as described above.

The test measures the amount of current by applying predetermined heat and current to the package, and determines that the measured value is a pass when the measured value is within a predetermined range. That is, the package is mounted in a device capable of controlling a predetermined temperature, and the test is performed by applying current to both terminals of the package. In this case, when the amount of current flowing in the package is about 5 mA or less and about 100 or more hundreds of mA at 80 degrees, it is determined as pass. That is, if it is 100mA or more at 80 degrees, it is determined as pass. This is because the battery protection chip of the present invention should not normally generate a leakage current because a current of 5 mA or less flows, and should be conducted at a temperature of 80 degrees or higher to allow current to flow well.

The battery pack of the present invention is not limited to the above description and is possible in various embodiments. Hereinafter, a battery pack according to a second embodiment of the present invention will be described. In the following embodiment, description overlapping with the first embodiment is omitted.

6 is a conceptual diagram of a battery pack according to a second embodiment of the present invention.

Referring to FIG. 6, the battery pack 100 according to the present embodiment is electrically connected between the battery body 10 having the positive electrode 11 and the negative electrode 12, and the positive electrode 11 and the negative electrode 12 according to temperature. And a battery protection chip 200. And a PTC element 20 connected to the negative electrode 12 to block external current according to the temperature.

The battery protection chip 200 operates between the first and second external electrode terminals 210 and 220 and the first external electrode terminal 210 and the second external electrode terminal 220 of the chip by operating according to a control voltage. A control voltage generation unit 240 and the switch unit for generating a control voltage by dividing a voltage between the switch unit 230 which conducts the first and second external electrode terminals 210 and 220 according to temperature. A body 250 for packaging the 230 and the control voltage generator 240 is included. The control voltage generator 240 includes an NTC 242 and a first resistor 244 connected between the first and second external electrode terminals 210 and 220. The switch 230 includes a transistor 231 and a second resistor 232 connected between the first and second external electrode terminals 210 and 220.

The control voltage generator 240 and the switches constituting the switch 230 will be described based on the overall connection relationship.

The internal circuit of the battery protection chip 200 is connected between a transistor 231 having a collector terminal connected to a first external electrode terminal 210, and a base terminal of the transistor 231 and a first external electrode terminal 210. The first NTC element 242, the first resistor 244 connected between the base terminal of the transistor 231 and the second external electrode terminal 220, the emitter terminal of the transistor 231, and the second external device. And a second resistor 232 connected between the electrode terminals 220. In this case, although the first resistor 244 is illustrated as a circuit connected between the base terminal and the second external electrode terminal 220 in FIG. 6, the present invention is not limited thereto, and the first resistor 244 is the base terminal and the emitter terminal. It may be connected between. In addition, a separate capacitor may be further included between the first external electrode terminal 210 and the second external electrode terminal 220. In addition, the capacitor may further include a capacitor connected in parallel with the NTC 242, or may further include a capacitor connected in parallel with the first resistor 244.

Here, it is effective that the resistance value of the first resistor 244 is 0.5Ω to 2Ω, and the resistance value of the second resistor 232 is effectively 10 to 50Ω. In this case, a digital transistor in which the transistor 231 and the second resistor 232 are embedded in one chip may be used.

In the above, the second resistor 232 is physically connected to the second external electrode terminal 220, and the second external electrode terminal 220 is physically connected to the PTC 30 through the switch unit 230. When the current flows, that is, when the current flows due to overcharge, external mechanical shock, thermal environment change, electrical connection, or the like, the temperature of the second resistor 232 physically connected to the PTC 30 is increased. Accordingly, the heat applied to the PTC 30 may rise to block the electrical connection between the outside and the battery body.

Looking at the operation of the battery pack of the present embodiment having the above-described structure and characteristics are as follows.

Referring to the case in which the battery performs normal operation, when a constant DC power is applied from the battery to the outside, or when the positive electrode 11 and the negative electrode 12 are floated, the temperature inside the battery does not rise so that the battery protection chip 200 The resistance value of the NTC 242 in the R1 is very large compared to the first resistor 244 and the second resistor 232. As a result, voltage distribution by the NTC 242, the first resistor 244, and the second resistor 232 occurs, but most of the voltage of the battery main body is caught by the NTC 242. As a result, the magnitude of the control voltage across the first resistor 244 does not become a voltage enough to turn on the transistor 231, so that the transistor 231 is turned off. As a result, no current path is formed between the positive electrode 11 and the negative electrode 12. For example, the voltage of the battery body is 4.2V, the temperature inside the battery is 25 degrees, the resistance value of the NTC 242 at this time is 100 kΩ, the resistance value of the first resistor 244 is 1 kΩ, and the second If the resistance value of the resistor 232 is 30Ω, the voltage of about 4.16V is applied to the NTC 242, and a voltage of 0.04V is applied between the base of the transistor 231 and the emitter terminal, that is, between the first resistor 244. I get caught. Thus, the transistor 231 is turned off because not enough voltage is applied between the base of the transistor 231 and the emitter terminal to drive it.

On the other hand, when the temperature inside the battery suddenly increases due to overcharge, external mechanical shock, thermal environment change, electrical connection, etc., the resistance value of the NTC 242 decreases due to the increase in temperature. As a result, the voltage across the NTC 242 falls, and the voltage across the first resistor 244 rises.

When the temperature inside the battery rises to a predetermined temperature and the control voltage across the first resistor 244 rises to the driving voltage of the transistor 231, the transistor 231 is turned on so that the current flows from the collector terminal to the emitter terminal. The path is created. As a result, a current path is formed between the positive electrode 11 and the negative electrode 12 of the battery to automatically discharge the battery, thereby preventing the battery from being overheated and detonated due to overheating. The predetermined temperature may be a temperature immediately before the battery pack 100 is blasted, or may be a temperature separately set. This may be set by adjusting the characteristics of the NTC 242, adjusting the driving voltage of the transistor 231, or adjusting the resistance of the first resistor 244.

For example, assuming that the predetermined temperature is set to 100 degrees and the battery protection chip 200 is set to operate when the temperature reaches this temperature, it is as follows. When the temperature inside the battery gradually rises from 25 degrees to a temperature of 100 degrees, the resistance value of the NTC 242 drops to about 7.4 kΩ, and the NTC 242 is subjected to a voltage of 3.7 V. On the other hand, the first resistor 244 is subjected to a voltage of 0.5V (operating voltage), the transistor 231 is turned on. That is, a path in which the transistor 231 and the second resistor 232 are connected in series is formed between the positive electrode 11 and the negative electrode 12. As a result, the battery is electrically shorted to make the battery low in the high electrical energy state, thereby preventing the battery from expanding and exploding. At this time, when the transistor 231 is turned on, a rapid current flows from the battery, but the rapid flow of current is limited by the second resistor 232.

In addition, if the battery pack 100 rises due to overcharging while charging from the external charger, the temperature of the second resistor 232 is increased by the current flowing through the second resistor 232. As a result, the resistance of the PTC 30 physically connected through the second resistor 232 and the second external electrode terminal 220 is rapidly increased, thereby shorting the charger 40 between the terminal and the battery pack 100 ( Negative electrode), blocking external current to prevent overcharge.

Subsequently, when the battery is unstable by the discharge and the temperature of the battery is lowered, the resistance value of the NTC 242 is increased. Accordingly, the voltage value across the first resistor 244 is lowered to form a transistor ( Turn off 231). Thereafter, the battery pack 100 may be used again by performing a predetermined charging.

As such, when the electrical energy of the battery becomes high due to an external factor, the battery protection chip 200 operates to forcibly discharge the battery, thereby lowering the energy state of the battery, thereby expanding and exploding the battery. Will be prevented.

In the first and second embodiments described above, NTC is used to generate a control voltage (operation voltage) by operating in accordance with temperature, but the present invention is not limited thereto. Various elements whose resistance values change depending on temperature may be used. Can be. PTC, CTR, etc. can be used as an element whose resistance value changes with temperature. In addition, not only transistors, but also various devices that perform switching operations according to changes in voltage values may be used. That is, in this embodiment, the turn-on and turn-off of the transistor, which is a switching element, are controlled according to the voltage distribution by the difference in resistance between the NTC and the first resistor. Therefore, it is preferable to place the element whose resistance value decreases as the temperature rises at the above-described NTC element position, and preferably place the element whose resistance value decreases as the temperature rises at the position of the first resistor.

In addition, the battery pack of the present invention may include a chip capable of protecting overcharge and overcurrent as well as securing thermal safety. Such a third embodiment of the present invention will be described with reference to the drawings. In the following embodiment, a description overlapping with the above-described first and second embodiments will be omitted.

7 is a conceptual diagram of a battery pack according to a third embodiment of the present invention.

Referring to FIG. 7, the battery main body 10 having the positive electrode 11 and the negative electrode 12 and capable of charging and discharging, and the positive electrode 11 and the negative electrode 12 in accordance with the current / voltage change of the battery main body 10. And a battery protection chip 200 for conducting the liver, and a PTC element 30 that is physically connected to a part of the battery protection chip 200 and cuts off an external current according to temperature.

The battery protection chip 200 includes a switch unit 230 and a control voltage generator 240, and the first and second external terminal electrodes 210 are connected to the positive electrode 11 and the negative electrode 12, respectively. 220).

The circuit diagram of the battery protection chip 200 is described as follows.

The battery protection chip 200 may include a transistor 231 having a collector terminal connected to a first external terminal electrode 210, and a base terminal of the transistor 231 connected to a first external terminal electrode 210. A third resistor 246, a fourth resistor 248 connected between the base terminal and the emitter terminal of the transistor 231, an emitter terminal and a second external terminal electrode 220 of the transistor 231. And a second resistor 232 connected therebetween.

The operation of the above-described battery pack is as follows.

When the voltage of the battery pack 100 is normal by normal charging, the voltage is divided by the third and fourth resistors 246 and 248 of the battery protection chip 200 connected to the battery pack 100 to form a transistor ( A voltage applied to the base and the heater terminals of 231 is not sufficient to drive transistor 231 to turn off transistor 231. Therefore, no current path is formed between the positive terminal 11 and the negative terminal 12 of the battery pack 100. However, when the voltage of the battery pack 100 deviates from the normal state due to overcharging, voltage is divided by the third and fourth resistors 246 and 248 to apply the voltage applied to the base and emitter terminals of the transistor 231. A voltage sufficient to drive transistor 231 is turned on to turn on transistor 231. As the transistor 231 is turned on, a current path is formed between both terminals 11 and the negative terminal 12 of the battery pack 100 to forcibly discharge the battery body 10. In this manner, the battery current is discharged to lower the battery voltage. At this time, when the transistor 231 of the battery protection chip 200 is turned on, the rapid current flow is controlled by the second resistor 232. In addition, the temperature of the second resistor 232 rises rapidly, and the resistance of the PTC 30 physically connected thereto increases rapidly, blocking the current path to the external charger 40 terminal, thereby further charging. It can also be prevented.

For example, when the maximum voltage of the target battery pack 100 is 4.3 V and the operating voltage of the transistor 231 is 0.5 V, the resistance value of the third resistor 246 is 304 kΩ, and the fourth resistor ( The resistance value of 248 is 40 kΩ and the resistance value of the second resistor 232 is 30 Ω.

When the voltage of the battery pack 100 is less than or equal to 4.3 V due to normal charging, voltages less than or equal to 4.3 V are divided by the second, third, and fourth resistors 232, 246, and 248. A voltage of 3.799 V or less is applied, a voltage of 0.499 V or less is applied to the fourth resistor 248, and a voltage of 0.0003 V or less is applied to the second resistor 232. That is, since the voltage across the fourth resistor 248 connected between the emitter and the base terminal of the transistor 231 is 0.5 V or less, the transistor 231 is turned off. On the other hand, when the voltage of the battery pack 100 is 4.3V or more due to overcharging, a voltage of 3.799V or more is applied to the third resistor 246 and 0.499V or more is applied to the fourth resistor 248. That is, since the voltage across the fourth resistor 248 connected between the emitter and the base terminal of the transistor 231 is 0.5V or more, the transistor 231 is turned on. As a result, a current path is formed between the positive electrode 11 and the negative electrode 12 of the battery pack 100 to discharge the current of the battery, thereby lowering the voltage of the battery.

As described above, the battery protection chip of the present embodiment can provide overcharge protection and overcurrent protection of the battery, thereby replacing the existing battery protection system, and providing a low-cost battery protection system due to the simple circuit configuration. In addition, it is possible to improve the uniformity of the circuit in mass production by manufacturing it in a chip shape.

In addition, the battery protection chip of the present invention may be composed of one chip including the chip according to the second and third embodiments described above. This fourth embodiment of the present invention will be described with reference to the drawings. In the following embodiments, descriptions overlapping with those of the first to third embodiments described above will be omitted.

8A and 8B are conceptual views illustrating a fourth embodiment of the battery pack of the present invention.

8A and 8B, the battery pack 100 of this embodiment includes a battery protection chip 200 connected between both terminals 11 and the negative terminal 12 of the battery main body.

The battery protection chip 200 may include first and second external electrode terminals 210 and 220 respectively connected to both terminals and the negative terminal of the battery body 10. Then, the voltage is changed between the first and second external electrode terminals 210 and 220 by the NTC 242 and the first resistor 244 whose values change according to the temperature, and the first according to the divided voltage. And a third resistor 246 for distributing a voltage between the first transistor 231a forming a current path between the second external electrode terminals 210 and 220 and the first and second external electrode terminals 210 and 220. And a second transistor 231b which divides the voltage by the fourth resistor 248 and forms a current path between the first and second external electrode terminals 210 and 220 according to the result of the voltage division. And second resistors 232a and 232b connected between the second transistors 231a and 231b and the second external electrode terminal 220. In this case, the second resistors 232a and 232b may be replaced with one resistor. That is, as shown in FIG. 8B, a second resistor 231 connected between the base terminals of the first and second transistors 231a and 231b and the second external electrode terminal 220 may be included.

In addition, the present invention may utilize a single switching element by integrating a circuit for protecting thermal stability, overcharge and overcurrent, respectively. This fifth embodiment of the present invention will be described with reference to the drawings. In the following embodiments, descriptions overlapping with those of the first to fourth embodiments described above will be omitted.

9A and 9B are conceptual views illustrating a fifth embodiment of the battery pack of the present invention.

9A and 9B, the battery pack 100 of the present embodiment includes a battery protection chip 200 connected between both terminals 11 and the negative terminal 12 of the battery main body. ).

The battery protection chip 200 may include first and second external electrode terminals 210 and 220 respectively connected to both terminals and the negative terminal of the battery body 10. And, the first and second in accordance with the parallel resistance value of the NTC 242 and the third resistor 246, the value of which varies with temperature, and the parallel resistance values of the first and fourth resistors 244 and 248. And a transistor 231 forming a current path between the external electrode terminals 210 and 200.

As shown in FIG. 9B, the first resistor 244 and the fourth resistor 248 may be replaced with one resistor. That is, one fifth resistor 249 having a parallel resistance value between the first resistor 244 and the fourth resistor 248 may be used.

In the present invention, the PTC may be connected between both terminals. This sixth embodiment of the present invention will be described with reference to the drawings. In the following embodiments, descriptions overlapping with the first to fifth embodiments described above will be omitted.

10 is a conceptual view illustrating a sixth embodiment of the battery pack of the present invention.

Referring to FIG. 10, the battery pack 100 of the present embodiment includes a battery protection chip 200 connected between both terminals 11 and the negative terminal 12 of the battery main body. do.

The battery protection chip 200 may include first and second external electrode terminals 210 and 220 respectively connected to both terminals and the negative terminal of the battery body 10. Then, the voltage is changed between the first and second external electrode terminals 210 and 220 by the NTC 242 and the first resistor 244 whose values change according to the temperature, and the first according to the divided voltage. And a transistor 231 forming a current path between the second external electrode terminals 210 and 220, and a second resistor 232 connected between the collector terminal of the transistor 231 and the first external electrode terminal 210. Include.

It includes a PTC (30) which is physically connected to the first external electrode terminal 210, and controls the current of both terminals (11). Thus, by placing the PTC element at both terminals, it is possible to electrically separate the battery and the external circuit connected thereto when the battery is overheated, overcharged, or overcurrent.

In the following, a swelling test and a hot box test were performed using a battery pack including a battery protection chip according to a second embodiment of the present invention. Here, a lithium ion battery having a voltage of 4.2 V was used as the battery main body, and a capacity thereof was 1000 mAh. As a transistor, a 1.24 watt 2.5V MOFET of a P channel was used, and a transistor having a threshold voltage of 0.45V was used. Then, an element having a resistance of 20 Ω for the first resistor, 10 Ω for the second resistor, and a resistance value of 875 ㏀ at 25 degrees with NTC and a 76.2 Ω resistance at 85 degrees was used.

Table 1 shows a result of performing a swelling test and a hot box test using a battery pack including a battery protection chip.

Battery pack number 25 ℃ current 85 ℃ current Swell test (% change in battery thickness) Hot Box Test (Fire) One 5.0 11.5 3% or less No fire 2 4.5 12.0 3% or less No fire 3 4.8 11.3 3% or less No fire 4 4.6 13.5 3% or less No fire 5 4.4 15.0 3% or less No fire 6 4.6 14.0 3% or less No fire 7 4.7 12.0 3% or less No fire

In the swelling test, the temperature of the battery pack is increased from room temperature to 85 ° C. at a temperature increase rate of about 5 ° C./min, and then maintained for about 4 hours, and then reduced to room temperature at a temperature reduction rate of about 5 ° C./min. The change rate before and after the test was measured. As a result of the seven experiments, the rate of change was less than 3%.

In the above hot box test, the temperature is raised to 150 ° C from room temperature at a temperature increase rate of about 5 ° C./min, and then maintained for about 10 minutes. Determine whether or not. However, it can be seen that the battery packs according to the present invention are not all ignited.

In addition, it can be seen that the current flows at 4.5 to 5 mA at room temperature, that is, at about 25 ° C., almost no current flows, and at about 85 ° C., the amount of current increases to 11.3 to 15 mA.

As described above, the present invention can not only drastically reduce the production cost by one-chip simple control module including a temperature sensor capable of sensing temperature and a switching element driven according to a predetermined voltage change, but also prevent overcharge. To control overcurrent, and to ensure thermal stability.

In addition, the characteristic variation between the plurality of battery protection circuit chips can be adjusted within a certain range, so that mass production is possible, and malfunctions and defects of the battery protection circuit chips can be prevented.

Claims (11)

First and second external electrode terminals; A control voltage generator for distributing a voltage between the first and second external electrode terminals to generate a control voltage that varies with temperature; A switch unit operating according to the control voltage and conducting between the first external electrode terminal and the second external electrode terminal; And And a body part for packaging the switch part and the control voltage generation part. The method according to claim 1, The switch unit, And a transistor connected to the first and second external electrode terminals, respectively, the collector terminal and the emitter terminal being operated according to the control voltage. The method according to claim 2, And a resistor connected between the first external electrode terminal and the collect terminal or the second external electrode terminal and the emitter terminal, wherein the resistor is connected to the first external electrode terminal or the second external electrode terminal. Protection chip. The method of claim 1, wherein the control voltage generator, First voltage distribution means connected between the first external electrode terminal and a control voltage node; And And a second voltage distribution means connected between said second external electrode terminal and said control voltage node. The method according to claim 4, And the first and second voltage distribution means use at least one of an NTC element, a PTC element, and a distribution resistance element whose resistance value changes with temperature, and these are connected in series or in parallel. In the battery pack, A battery body having a positive electrode and a negative electrode; And Generating a control voltage for generating a control voltage that varies with temperature by distributing a voltage between a first electrode terminal connected to the positive electrode, a second electrode terminal connected to the negative electrode, and the first and second external electrode terminals. And a battery protection chip including a switch unit configured to operate between the first and second external electrode terminals to operate according to the control voltage, and a body unit to package the switch unit and the control voltage generator. . Providing a switching element, a voltage distribution element, and first and second external electrode terminals; The switching element and the voltage distribution element so as to divide a voltage between the first and second external electrode terminals in accordance with a temperature to vary the voltage, and to conduct between the first and second external electrode terminals according to the variable voltage. Electrically connecting the first and second external electrodes to form a circuit; Forming a body portion for protecting the switching element, the voltage distribution element, and at least a portion of the first and second external electrode terminals, and exposing a portion of the first and second external electrode terminals to the outside of the body portion; Method of manufacturing a battery protection chip comprising a. Providing a switching element, a voltage distribution element, first and second external electrode terminals, and an upper body and a lower body; Disposing the switch element and the voltage distribution element in an inner region of the lower body, and disposing first and second external electrode terminals in the lower body end region, respectively; Electrically connecting the switch element, the voltage distribution element, and the first and second external electrode terminals to distribute a voltage between the first and second external electrode terminals according to a temperature to vary the voltage, and according to the changed voltage. Forming a circuit for conducting between the first and second external electrode terminals; Coupling the lower body and the upper body on which the circuit is formed to form a body portion for protecting the circuit. The method according to claim 7 or 8, Battery protection using a transistor as the switching element and at least one of a NTC element, a PTC element and a distribution resistor element whose resistance value changes with temperature as the voltage distribution element, and a device in which they are connected in series or in parallel Method of manufacturing the chip. The method of claim 7, wherein the forming of the body portion and exposing a portion of the first and second external electrode terminals to the outside of the body portion include: Positioning the circuit within a predetermined mold and exposing a portion of the first and second external electrode terminals out of the mold; And A method of manufacturing a battery protection chip comprising the step of curing the liquid epoxy or plastic inside the mold and then curing. The method according to claim 7 or 8, After forming the body portion, And applying heat and current to the circuit to test a current amount of the circuit to detect a failure.

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