Abstract:
A battery pack providing power to a portable electronic device is disclosed which inhibits electromagnetic waves generated by the battery pack from interfering with the portable electronic device. The portable electronic device may include a radiofrequency (RF) circuit including a transceiver. The battery pack may include a battery cell and a protection circuit module (PCM) which operates to prevent the battery cell from overcharge/overdischarge and overheating. The PCM may include a substrate and a protection device mounted to the substrate. Electromagnetic waves generated when the protection device operates are shielded from the portable electronic device by a shielding layer formed on the substrate of the PCM. The substrate may include a plurality of circuit layers, each including a circuit layer, with the circuit layers in electrical communication with one another. A shielding pattern is formed on at least one of the circuit layers.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority of U.S. Provisional Application No. 61/593,163, filed on Jan. 31, 2012, entitled “BATTERY PACK”, the entire contents of which are incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    b  1 . Field 
         [0003]    One or more embodiments of the present disclosure relate to a battery pack. 
         [0004]    2. Description of the Related Art 
         [0005]    Unlike primary batteries that cannot be charged, secondary batteries can be charged and discharged and are widely used not only in small high-tech electronic devices including mobile phones, personal digital assistants (PDAs), notebook computers, or the like, but also in energy storage systems. 
         [0006]    As described above, in a case where a secondary battery is used as a power source of an electronic device, it is required to design the electronic device and the secondary battery so as to allow them to stably exhibit functions of their configuring elements without physical and electrical interferences between the configuring elements forming the electronic device and the configuring elements forming the secondary battery. 
       SUMMARY 
       [0007]    In an embodiment, a battery pack is provided. The battery pack comprises a battery cell and a protection circuit module (PCM) in electrical communication with the battery cell. 
         [0008]    The PCM may comprise a plurality of circuit layers that each include respective circuit patterns. At least one of the circuit patterns is a shielding pattern that shields at least a portion of electromagnetic waves generated by the protection circuit module. 
         [0009]    The PCM further comprises a substrate including the plurality of circuit layers and a protection device mounted to the substrate that outputs a control signal to monitor charging of the battery cell and controls charging and discharging of the battery cell. The shielding pattern shields at least a portion of electromagnetic waves generated by operation of the protection device from being emitted outside of the battery pack. 
         [0010]    The shielding pattern may be positioned between the protection device and an outer surface of the battery pack. 
         [0011]    The battery pack may further comprise a first circuit layer including a first shielding pattern. At least a portion of the first shielding pattern may overlap the protection device in a direction out of the plane of the first circuit layers. 
         [0012]    The first shielding pattern may extend over an area greater than a lateral dimension of a portion of the protection device that generates the electromagnetic waves. 
         [0013]    The battery pack may also comprise a second circuit layer including a plurality of second shielding patterns. At least one of the first and second shielding patterns may overlap in a direction out of the planes of the first and second circuit layers. 
         [0014]    The plurality of second shielding patterns may comprises two second shielding patterns, with each second shielding pattern positioned at a respective end of the second circuit layer. 
         [0015]    The first and second shielding patterns may be positioned adjacent to the protection device. 
         [0016]    The first and second circuit layers are may be electrically connected. 
         [0017]    The battery pack may additionally comprise third and fourth circuit layers interposed between the first and second circuit layers. A hole may be formed in each of the third and fourth circuit layers and the first and second circuit layers may be electrically connected by a current path formed by the first shielding pattern, the holes in the third and fourth circuit layers, and the plurality of second shielding patterns. 
         [0018]    The first shielding pattern may extends over at least an area corresponding to position of the protection device, the plurality of second shielding patterns, and the holes in the third and fourth layers. 
         [0019]    The plurality of second shielding patterns may be exposed outside of the substrate. 
         [0020]    The battery pack may further comprise a plurality of connection members that separate the protection circuit module and the battery cell. 
         [0021]    The battery pack may also comprise a safety device mounted to the substrate. At least one of the protection circuit module and the safety device may be positioned between the protection circuit module and the battery cell. 
         [0022]    The protection circuit module may be positioned adjacent to a cap plate sealing the battery cell. 
         [0023]    The battery pack may additionally comprise a plurality of connection members interposed between the protection circuit module and the battery cell. The second shielding patterns may be electrically connected to the cap plate by the connection members. 
         [0024]    In another embodiment, an electronic device is provided. The electronic device comprises a battery pack that supplies electrical power to the electronic device and a transceiver. The battery pack includes a plurality of circuit layers that each include respective circuit patterns, wherein at least one of the circuit patterns is a shielding pattern that shields at least a portion of electromagnetic waves generated by the battery cell from the transceiver. 
         [0025]    The electronic device may further comprise a protection circuit module (PCM) that generates electromagnetic waves in operation. 
         [0026]    The PCM may include the plurality of circuit layers. 
         [0027]    The electronic device may also comprise a first circuit layer and a plurality of second circuit layers. The first and second circuit layers may overlap in a direction out of the plane of the first and second circuit layers. 
         [0028]    The electronic device may additionally comprise a first circuit layer and a second circuit layer. The plurality of second shielding patterns may comprise at least two shielding patterns positioned at respective ends of the second circuit layer. 
         [0029]    The first and second circuit layers may be electrically connected. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]      FIG. 1  is a diagram schematically illustrating a relation between configuring elements forming a battery pack and configuring elements forming a mobile device, when the battery pack is used as a power source of the mobile device including a mobile phone or the like, according to an embodiment of the present disclosure. 
           [0031]      FIG. 2  is an exploded perspective view of the battery pack according to an embodiment of the present disclosure. 
           [0032]      FIG. 3  is a cross-sectional side view of a battery cell and a protection circuit module (PCM) that is extracted from the battery pack. 
           [0033]      FIG. 4  is a perspective view of the PCM that is extracted from the battery pack, according to an embodiment of the present disclosure. 
           [0034]      FIG. 5  illustrates bottom views of a plurality of circuit layers forming a substrate of the PCM of  FIG. 4 . 
           [0035]      FIG. 6  is a cross-sectional side view schematically illustrating a disposition state between the battery pack and an antenna transceiving unit, when the battery pack supplies power to a mobile device. 
       
    
    
     DETAILED DESCRIPTION 
       [0036]    Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the disclosed concepts to those skilled in the art, and the present disclosure will only be defined by the appended claims. Throughout the specification, a singular form may include plural forms, unless there is a particular description contrary thereto. Also, terms such as “comprise” or “comprising” are used to specify existence of a recited form, a number, a process, operations, a component, and/or groups thereof, not excluding the existence of one or more other recited forms, one or more other numbers, one or more other processes, one or more other operations, one or more other components and/or groups thereof. While terms “first” and “second” are used to describe various components, it is obvious that the components are not limited to the terms “first” and “second”. The terms “first” and “second” are used only to distinguish between each component. 
         [0037]      FIG. 1  is a diagram schematically illustrating a relation between configuring elements forming a battery pack  10  and configuring elements forming an electronic device (e.g., a mobile device  1 ), when the battery pack  10  is used as a power source of the mobile device  1  including a mobile phone or the like, according to an embodiment of the present disclosure. 
         [0038]    Referring to  FIG. 1 , the battery pack  10  according to the present embodiment may be embedded in the mobile device  1  or may be detachable from the mobile device  1 . The battery pack  10  may include a battery cell  110  and a protection circuit module (hereinafter, referred to as ‘PCM’)  120 . The mobile device  1  may include a radio frequency (RF) circuit unit  20  including an antenna transceiving unit  21 , and a signal processing unit  30 . 
         [0039]    The RF circuit unit  20  includes the antenna transceiving unit  21  that receives a wireless signal from a base station or transmits a signal, which is generated by the mobile device  1 , to the base station. The signal processing unit  30  may process and control operations of the mobile device  1 , thereby informing a user of contents related to the wireless signal based on the wireless signal received via the antenna transceiving unit  21 , or processing an input from the user and then transmitting the input to the RF circuit unit  20 . 
         [0040]    The antenna transceiving unit  21  included in the RF circuit unit  20  may be affected by a protection device mounted in the PCM  120  included in the battery pack  10 . For example, a transceiving function of the antenna transceiving unit  21  may deteriorate due to electromagnetic waves generated by the protection device mounted in the PCM  120 . 
         [0041]    Also, in a case where an operation of the battery pack  10  is not smooth, e.g., when a flow of current flowing in the PCM  120  is impeded due to a large resistance in the PCM  120 , the transceiving function of the antenna transceiving unit  21  that is adjacent to the battery pack  10  may also deteriorate. 
         [0042]    In order to solve the aforementioned problems, a pattern to shield electromagnetic waves is formed in the PCM  120  of the battery pack  10 , and by decreasing a resistance of a path wherein current flows, an effect that affects the antenna transceiving unit  21  due to the battery pack  10  is minimized. Hereinafter, structures of the PCM  120  and the battery pack  10  having the aforementioned functions will now be described with reference to  FIGS. 2 through 6 . 
         [0043]      FIG. 2  is an exploded perspective view of the battery pack  10  according to an embodiment of the present disclosure, and  FIG. 3  is a cross-sectional side view of the battery cell  110  and the PCM  120  that are extracted from the battery pack  10 . 
         [0044]    Referring to  FIG. 2 , the battery pack  10  may include the battery cell  110 , the PCM  120 , connection members  130 , an upper cover  140 , a lower cover  150 , and a label  160 . 
         [0045]    The battery cell  110  supplies electric energy. The battery cell  110  may include an electrode assembly (not shown), a can  111  internally accepting the electrode assembly and an electrolyte, and a cap plate  112  sealing an open end of the can  111 . The electrode assembly includes a negative electrode plate (not shown) coated with a negative active material, a positive electrode plate (not shown) coated with a positive active material, and a separator (not shown) interposed between the negative electrode plate and the positive electrode plate. The electrode assembly in the shape of a jelly roll may be formed by rolling the negative electrode plate, the positive electrode plate, and the separator. 
         [0046]    The electrode assembly may be accepted in the can  111  while the electrolyte is absorbed into the electrode assembly. The open end of the can  111  may be sealed by the cap plate  112  and thus may prevent a leakage of the electrolyte. The cap plate  112  and the can  111  may be coupled by laser welding. 
         [0047]    The can  111  and the cap plate  112  are formed of a metal material, and an electrode terminal  113  having a projected shape with respect to the cap plate  112  is formed above the cap plate  112 . For example, the electrode terminal  113  may be disposed in a central region of the cap plate  112 , and a gasket  114  that is an insulating material may be disposed between the electrode terminal  113  and the cap plate  112 . 
         [0048]    The can  111  and the cap plate  112  may function as a terminal, e.g., a positive terminal of the battery cell  110 . In this case, the electrode terminal  113  having the projected shape with respect to the cap plate  112  may function as a negative terminal. In the present embodiment, the electrode terminal  113  functions as a negative electrode, and the can  111  and the cap plate  112  each function as a positive electrode. However, it is obvious that the electrode terminal  113  may function as a positive electrode, and the can  111  and the cap plate  112  may function as a negative electrode. 
         [0049]    The PCM  120  may measure a voltage of the battery cell  110 , may prevent the battery cell  110  from being over-charged and over-discharged, based on a measured voltage value, and may protect the battery cell  110  against high temperatures. To do so, the PCM  120  may include a substrate  121 , and a protection device  122  and a safety device  123  that are mounted on the substrate  121 . 
         [0050]    The PCM  120  may be disposed above the battery cell  110  and thus may be electrically connected to the battery cell  110 . For example, the PCM  120  may be electrically connected to the electrode terminal  113 , (e.g., a negative electrode of the battery cell  110 ), via the safety device  123  to be described below, and may be electrically connected to the cap plate  112 , (e.g., a positive electrode of the battery cell  110 ), by the connection members  130 . The connection members  130  may separate the PCM  120  from the cap plate  112  by a predetermined gap and thus there may be a space between a first surface of the PCM  120  and a top surface of the battery cell  110  in which the protection device  122  and the safety device  123  are disposed. 
         [0051]    The substrate  121  may have a wiring pattern for delivering an electrical signal, the protection device  122  and the safety device  123  may be mounted on a first surface of the substrate  121 , and exterior terminals  124  for supplying electric energy to an external electronic device, e.g., the mobile device  1  of  FIG. 1 , may be formed on a second surface of the substrate  121 . 
         [0052]    The protection device  122  is a primary device that may output a control signal to monitor over-charge and over-discharge in the battery cell  110  and to control a charging operation and a discharging operation in a case of over-charge and over-discharge. The protection device  122  may be electrically connected to the wiring pattern formed on the substrate  121 , thereby controlling over-charge and over-discharge in the battery cell  110 . The protection device  122  may be formed as an integration circuit (IC) and may be mounted on the first surface of the substrate  121 . 
         [0053]    Electromagnetic waves that are generated when the protection device  122  operates are shielded by a shielding layer or shielding patterns formed on the substrate  121  of the PCM  120 . The shielding layer may shield the electromagnetic waves that are generated from the operation of the protection device  122 , and thus, may prevent the electromagnetic waves from interfering with an operation of the antenna transceiving unit  21 . A shielding function of the PCM  120  and a detailed structure therefor are described below with reference to  FIGS. 4 and 5 . 
         [0054]    The safety device  123  is a secondary device that may prevent a flow of current when a secondary battery is overheated by a predetermined temperature. For example, with a high temperature, over-charge or over-discharge in the battery cell  110  occurs and the flow of current may be broken by the safety device  123 . The safety device  123  may be disposed on the first surface of the substrate  121  and may be electrically connected to the electrode terminal  113  and the substrate  121 . The safety device  123  may include one or more of a positive temperature coefficient (PTC), a fuse, a current breaking device, bi-metal, and the like. 
         [0055]    The upper cover  140  may be combined with an upper portion of the battery cell  110  and may include the PCM  120 . The upper cover  140  may be formed of a cover plate  141  and a sidewall  142  that downwardly extends from the cover plate  141 . The lower cover  150  may be combined with a lower portion of the battery cell  110  and may include a bottom plate  151  and a sidewall  152  that upwardly extends from the bottom plate  151 . 
         [0056]    The label  160  may be attached around side surfaces of the battery cell  110 . Here, the label  160  surrounds the side surfaces of the battery cell  110  while covering the sidewall  142  of the upper cover  140  and the sidewall  152  of the lower cover  150 . 
         [0057]      FIG. 4  is a perspective view of the PCM  120  extracted from the battery pack  10 , according to an embodiment of the present disclosure, and  FIG. 5  illustrates bottom views of a plurality of circuit layers  510 ,  520 ,  530 , and  540  included in the substrate  121  of the PCM  120  of  FIG. 4 . 
         [0058]    Referring to  FIG. 4 , the protection device  122  and the safety device  123  are mounted on the first surface of the substrate  121 , which faces the top surface of the battery cell  110 , and the exterior terminals  124  are formed on the second surface of the substrate  121 . Here, the protection device  122  may be formed on one side of the first surface, and the safety device  123  may be formed on one the other side of the first surface. 
         [0059]    Referring to a magnified portion of  FIG. 4 , the substrate  121  may include the circuit layers  510 ,  520 ,  530 , and  540 , and insulating layers (I) interposed therebetween. The circuit layers  510 ,  520 ,  530 , and  540  formed in the substrate  121  may each include a circuit pattern (not shown), and the circuit layers  510 ,  520 ,  530 , and  540  may be electrically connected to each other via an inner-via hole formed in each of the circuit layers  510 ,  520 ,  530 , and  540 . A shielding pattern  512  to shield electromagnetic waves generated in the protection device  122  is formed on at least one of the circuit layers  510 ,  520 ,  530 , and  540 . 
         [0060]    Referring to  FIG. 5 , the circuit patterns are formed on the circuit layers  510 ,  520 ,  530 , and  540 , respectively. From among the circuit layers  510 ,  520 ,  530 , and  540 , the first circuit layer  510  is disposed in an upper portion of the substrate  121 , the fourth circuit layer  540  is disposed in a lower portion of the substrate  121 , and the second and third circuit layers  520  and  530  are between the first circuit layer  510  and the fourth circuit layer  540 . 
         [0061]    Referring to a rear surface of the first circuit layer  510  illustrated in  FIG. 5 , the shielding pattern  512  is formed in a region of the rear surface of the first circuit layer  510 , which corresponds to a location where the protection device  122  is mounted. The shielding pattern  512  may include nickel. Alternatively, the shielding pattern  512  may include other metal materials such as copper. The shielding pattern  512  may be formed together with the circuit pattern by a process in which the circuit pattern is formed on the first circuit layer  510 . For example, the shielding pattern  512  may be formed by a printing method. 
         [0062]    An area of the shielding pattern  512  may be greater than an area of the protection device  122 . For example, the shielding pattern  512  may be formed to cover a region of the rear surface corresponding to a region in which the protection device  122  is mounted, a connection pattern  542  to be described below, and via holes  521  and  531  formed in the second and third circuit layers  520  and  530 , respectively. 
         [0063]    A circuit pattern  513  that is electrically connected to the safety device  123  may be formed next to the shielding pattern  512 , and terminal patterns  514  that are electrically connected to the exterior terminals  124 , respectively, may be formed on an opposite side to the shielding pattern  512 . 
         [0064]    Although not illustrated, the exterior terminals  124  (refer to  FIG. 4 ) may be disposed on a side of a front surface of the first circuit layer  510 , and the front surface of the first circuit layer  510  may be coated with an insulating film (not shown), except for the exterior terminals  124 . 
         [0065]    Referring to a rear surface of the fourth circuit layer  540  illustrated in  FIG. 5 , a plurality of connection patterns (e.g.,  542  and  542 ′) that are connected to the connection members  130 , respectively, are formed on the rear surface of the fourth circuit layer  540 . The plurality of connection patterns may be formed on one or both side ends of the fourth circuit layer  540 . For example, the connection patterns  542  and  542 ′ may be formed on both side ends of the fourth circuit layer  540 , respectively. The connection patterns  542  and  542 ′ may be exposed to the outside of the substrate  121 , and may be electrically connected to the cap plate  112  of the battery cell  110  via the connection members  130  described above with reference to  FIG. 2 . The connection pattern  542  that is from among the connection patterns  542  and  542 ′ formed on both side ends of the fourth circuit layer  540  and that is adjacent to the shielding pattern  512  may function as a second shielding pattern. For example, the connection pattern  542  together with the shielding pattern  512  formed in the first circuit layer  510  may shield electromagnetic waves generated by the protection device  122 . 
         [0066]    Because the shielding pattern  512  and/or the connection pattern  542  are arranged on the circuit layers  510 ,  520 ,  530 , and  540  of the substrate  121  to shield the electromagnetic waves generated by the protection device  122 , a separate process for shielding is not necessary and space utilization is improved. 
         [0067]    The shielding pattern  512  formed on the first circuit layer  510 , and the connection pattern  542  formed on the fourth circuit layer  540  may be electrically connected through the via holes  521  and  531  formed in the second and third circuit layers  520  and  530 , respectively, that are interposed between the first circuit layer  510  and the fourth circuit layer  540 . The shielding pattern  512 , the connection pattern  542 , and the via holes  521  and  531  therebetween form a current path. 
         [0068]    Since the shielding pattern  512  is formed with a large area, a resistance of the current path is decreased, so that a flow of current moving in the current path becomes smooth. That is, the flow of current moving in the substrate  121 , i.e., in the PCM  120 , is smooth, so that an operation efficiency of the PCM  120  is improved. Also, an effect by the battery pack  10  that affects the antenna transceiving unit  21  is minimized. 
         [0069]    As described above, the number of circuit layers included in the substrate  121  is four. However, in alternative embodiments, the number of circuit layers included in the substrate  121  may different. The substrate  121  may include at least one circuit layer. 
         [0070]      FIG. 6  is a cross-sectional side view schematically illustrating a disposition state between the battery pack  10  and the antenna transceiving unit  21 , when the battery pack  10  supplies power to a mobile device. For convenience of description, the substrate  121  includes only the shielding pattern  512  and the connection pattern  542  formed on the first circuit layer  510  and the fourth circuit layer  540 , respectively, of the circuit layers  510 ,  520 ,  530 , and  540  of the substrate  121 , which are described above with reference to  FIGS. 4 and 5 . 
         [0071]    Referring to  FIG. 6 , the protection device  122  is mounted on the first surface of the PCM  120  disposed above the battery cell  110 , and the shielding pattern  512  and the connection pattern  542  are formed around the protection device  122 . However, in alternative embodiments, the placement of the protection device  122  may be varied, with the placement of the shielding pattern  512  and the connection pattern correspondingly varied so as to remain formed around the protection device  122 . 
         [0072]    As described above with reference to  FIGS. 4 and 5 , the shielding pattern  512  has a sufficient area sufficient that covers the protection device  122 , and the connection pattern  542  functions as a secondary shielding pattern that prevents electromagnetic waves generated by the protection device  122  from being emitted to the antenna transceiving unit  21 . 
         [0073]    Also, a current path is formed where the connection pattern  542  that is electrically connected to the battery cell  110  via the connection members  130  is electrically connected to the shielding pattern  512  via the via holes  521  and  531 , and by forming the current path having a large area, a resistance is decreased so that an effect by the battery pack  10  that affects the antenna transceiving unit  21  may be minimized. 
         [0074]    According to the aforementioned structure, performance deterioration of the antenna transceiving unit  21  may be prevented, so that the battery pack  10  may be included in the mobile device  1  without limitations to a location of the protection device  122 . 
         [0075]    It should be understood that the exemplary embodiments described therein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments.