Patent Publication Number: US-2022231319-A1

Title: Flexible printed circuit board bending apparatus for battery cells and bending method using the same

Description:
TECHNICAL FIELD 
     This application claims the benefit of priority to Korean Patent Application No. 2019-0144758 filed on Nov. 13, 2019, the disclosure of which is hereby incorporated by reference herein its entirety. 
     The present invention relates to a flexible printed circuit board bending apparatus for battery cells and a bending method using the same, and more particularly to a bending apparatus capable of accurately and rapidly bending a flexible printed circuit board of a battery cell and a bending method using the same. 
     BACKGROUND ART 
     With technological development of mobile devices, such as mobile phones, laptop computers, camcorders, and digital cameras, and an increase in the demand therefor, research on secondary batteries, which are capable of being charged and discharged, has been actively conducted. In addition, secondary batteries, which are energy sources substituting for fossil fuels causing air pollution, have been applied to an electric vehicle (EV), a hybrid electric vehicle (HEV), and a plug-in hybrid electric vehicle (P-HEV), and therefore there is an increasing necessity for development of secondary batteries. 
     There are a nickel-cadmium battery, a nickel-hydride battery, a nickel-zinc battery, and a lithium secondary battery as currently commercialized secondary batteries. Thereamong, the lithium secondary battery is in the spotlight, since the lithium secondary battery has little memory effect, whereby the lithium secondary battery is capable of being freely charged and discharged, has a very low self-discharge rate, and has high energy density, compared to the nickel-based secondary batteries. 
     Such a lithium secondary battery mainly uses a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively. The lithium secondary battery includes an electrode assembly, in which a positive electrode sheet having a positive electrode active material applied thereto and a negative electrode sheet having a negative electrode active material applied thereto is disposed in the state in which a separator is interposed therebetween, and a sheathing member configured to receive the electrode assembly together with an electrolytic solution in a hermetically sealed state, i.e. a battery case. 
     Based on the shape of a battery case, a secondary battery may be classified as a cylindrical battery having an electrode assembly mounted in a cylindrical metal can, a prismatic battery having an electrode assembly mounted in a prismatic metal can, or a pouch-shaped battery having an electrode assembly mounted in a pouch-shaped case made of an aluminum laminate sheet. 
     Meanwhile,  FIG. 1  is a schematic view of a battery cell before a flexible printed circuit board is bent. The flexible printed circuit board (FPCB) is a circuit board including flexibly bendable metal foil (particularly, copper foil) and a flexible film formed as an outer layer. In general, the flexible printed circuit board is mounted to a battery cell so as to transmit and receive electric power and signals. 
     In the case in which the flexible printed circuit board (FPCB) is mounted to the battery cell, as described above, it is possible to more freely change the shape of a connection terminal, whereby it is possible to improve use and space utilization thereof. However, it is necessary to bend the flexible printed circuit board (FPCB) at various angles depending on the kind of a device and installation environments. 
     In connection therewith, Patent Document 1 discloses a jig apparatus for battery cells including a jig body having a seating portion in which a battery cell is seated in the state in which a printed circuit board (PCB) is exposed to the other side thereof, a fixing member provided at one side of the jig body, the fixing member being configured to fix the battery cell seated in the seating portion, and a folding member rotatably provided at the other side of the jig body, the folding member being configured to press the PCB exposed from the seating portion such that the PCB is folded so as to be located at the battery cell when being rotated. 
     Patent Document 1 has an advantage in that the printed circuit board (PCB) is folded, whereby it is possible to secure force of fastening between a system and a battery but has problems in that folding is limited since flexibility of the printed circuit board (PCB) is lower than that of a flexible printed circuit board (FPCB), in that space utilization is low, which is inefficient, and in that cost related to energy necessary for folding is additionally incurred. 
     PRIOR ART DOCUMENT 
     (Patent Document 1) Korean Patent Application Publication No. 2015-0141810 
     Technical Problem 
     The present invention has been made in view of the above problems, and it is an object of the present invention to provide a bending apparatus capable of accurately bending a flexible printed circuit board of a battery cell and a bending method using the same. 
     It is another object of the present invention to provide a bending apparatus capable of bending a flexible printed circuit board of a battery cell at low cost and a bending method using the same. 
     It is a further object of the present invention to provide a bending apparatus capable of securing force of fastening between a system and a battery and a bending method using the same. 
     Technical Solution 
     In order to accomplish the above object, the present invention provides a flexible printed circuit board bending apparatus for battery cells, the flexible printed circuit board bending apparatus including a die ( 300 ) including a horizontal body ( 310 ) and a support wall ( 320 ) configured to receive a battery cell ( 100 ) having a flexible printed circuit board ( 110 ) exposed outwards from one side thereof, a bending guide unit ( 400 ) located at one side of the die ( 300 ), and a bending unit ( 500 ) located at the one side of the die ( 300 ), wherein the bending unit ( 500 ) includes a stationary body ( 510 ), a turning body ( 530 ) connected to the stationary body ( 510 ), the turning body being configured to be turnable by a predetermined angle, and a board seating portion ( 520 ) connected to the turning body ( 530 ), the board seating portion having a board seating groove ( 521 ), configured to receive the flexible printed circuit board ( 110 ), formed therein. 
     Also, in the bending apparatus according to the present invention, the bending guide unit ( 400 ) may include a first support member ( 410 ) having one side surface inclined at a predetermined angle, a first auxiliary support member ( 420 ) fixed to one surface of the first support member ( 410 ), and a first moving portion ( 430 ) configured to be movable along the inclined surface of the first support member ( 410 ), wherein the first moving portion ( 430 ) may be provided at one side surface thereof with a first pushing portion ( 431 ) configured to support a predetermined region of the flexible printed circuit board ( 110 ). 
     Also, in the bending apparatus according to the present invention, the bending guide unit ( 400 ) may further include a first elastic member ( 440 ) configured to connect the first auxiliary support member ( 420 ) and the first moving portion ( 430 ) to each other. 
     Also, the bending apparatus according to the present invention may further include a press unit ( 600 ) located at one side of the die ( 300 ), wherein the press unit ( 600 ) may include a second support member ( 610 ), a second auxiliary support member ( 620 ) fixed to one side of the second support member ( 610 ), and a second moving portion ( 630 ) configured to be movable in a vertical direction, and the second moving portion ( 630 ) may be provided with a second pushing portion ( 631 ) configured to press a bent portion of the flexible printed circuit board ( 110 ). 
     Also, in the bending apparatus according to the present invention, the second pushing portion ( 631 ) is provided at one end thereof with a projecting portion ( 631 ′). 
     Also, in the bending apparatus according to the present invention, the die ( 300 ) may be provided with a third space portion (S 3 ) formed in a predetermined shape by incision, the third space portion being configured to allow the battery cell ( 100 ) to be easily seated and detached. 
     Also, in the bending apparatus according to the present invention, the die ( 300 ) may be provided at one side thereof with a second space portion (S 2 ) formed in a predetermined shape by incision. 
     Also, in the bending apparatus according to the present invention, the board seating portion ( 520 ) may be located in the second space portion (S 2 ). 
     Also, the bending apparatus according to the present invention may further include a support base ( 200 ) configured to space the die ( 300 ) from a floor by a predetermined height and to fix the bending guide unit ( 400 ) and the bending unit ( 500 ), wherein the support base may be located under the die ( 300 ). 
     Also, in the bending apparatus according to the present invention, the support base ( 200 ) may be provided with a first space portion (S 1 ) formed in a predetermined shape by incision, the first space portion being configured to allow the battery cell ( 100 ) to be easily seated and detached. 
     Also, in the bending apparatus according to the present invention, the first pushing portion ( 431 ) may have a quadrangular horizontal sectional surface, the sectional surface being parallel to the flexible printed circuit board ( 110 ). 
     In addition, the present invention provides a bending method using the flexible printed circuit board bending apparatus for battery cells described above, the bending method including a first step of seating a battery cell ( 100 ) on the die ( 300 ), a second step of bringing one end of the first pushing portion ( 431 ) of the bending guide unit ( 400 ) into tight contact with a flexible printed circuit board ( 110 ), and a third step of turning the board seating portion ( 520 ) of the bending unit ( 500 ) by a predetermined angle so as to come into tight contact with one side surface of the first pushing portion ( 431 ). 
     Also, the bending method according to the present invention may further include a fourth step of moving the first pushing portion ( 431 ) of the bending guide unit ( 400 ) in tight contact with the flexible printed circuit board ( 110 ) to the original position thereof and a fifth step of turning the board seating portion ( 520 ) of the bending unit ( 500 ) by a predetermined angle so as to come into tight contact with an upper surface of the die ( 300 ). 
     Also, the bending method according to the present invention may further include a sixth step of moving the second pushing portion ( 631 ) of the second moving portion ( 630 ) to press a bent portion of the flexible printed circuit board ( 110 ). 
     Advantageous Effects 
     A flexible printed circuit board bending apparatus for battery cells according to the present invention includes a bending guide unit and a bending unit, whereby it is possible to perform bending at an accurate position. 
     In addition, the flexible printed circuit board bending apparatus for battery cells according to the present invention further includes a press unit, whereby it is possible to prevent a spring back phenomenon. 
     Furthermore, in the flexible printed circuit board bending apparatus for battery cells according to the present invention, bending is performed at a die configured to fix a battery cell, whereby it is possible to remarkably reduce a defect rate. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic view of a battery cell before a flexible printed circuit board is bent. 
         FIG. 2  is a perspective view of a flexible printed circuit board bending apparatus for battery cells according to the present invention. 
         FIG. 3  is an enlarged perspective view of a bending guide unit of the bending apparatus shown in  FIG. 2 . 
         FIG. 4  is an enlarged perspective view of a bending unit of the bending apparatus shown in  FIG. 2 . 
         FIG. 5  is an enlarged perspective view of a press unit of the bending apparatus shown in  FIG. 2 . 
         FIGS. 6 to 11  are flowcharts illustrating a method of bending a flexible printed circuit board using the bending apparatus according to the present invention. 
         FIG. 12  is a schematic view of an inspection jig configured to check a bent battery cell. 
     
    
    
     BEST MODE 
     In the present application, it should be understood that the terms “comprises,” “has,” “includes,” etc. specify the presence of stated features, numbers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof. 
     In addition, the same reference numbers will be used throughout the drawings to refer to parts that perform similar functions or operations. In the case in which one part is said to be connected to another part in the specification, not only may the one part be directly connected to the other part, but also, the one part may be indirectly connected to the other part via a further part. In addition, that a certain element is included does not mean that other elements are excluded, but means that such elements may be further included unless mentioned otherwise. 
     Hereinafter, a flexible printed circuit board bending apparatus for battery cells according to the present invention will be described. 
       FIG. 2  is a perspective view of a flexible printed circuit board bending apparatus for battery cells according to the present invention. Referring to  FIG. 2 , the flexible printed circuit board bending apparatus for battery cells according to the present invention may include a support base  200 , a die  300 , on which a battery cell  100  is seated, a bending guide unit  400  configured to hold a bending position of a flexible printed circuit board  110 , a bending unit  500  configured to rotate the flexible printed circuit board  110  to the bending position, and a press unit  600  configured to press a bent portion of the flexible printed circuit board  110 . 
     First, the support base  200  will be described. The support base is configured to space the die  300  from a floor by a predetermined height and to fix the bending guide unit  400 , the bending unit  500 , and the press unit  600 . The support base is located under the die  300 . 
     When viewed from above (in a Z-axis direction), the support base is approximately quadrangular. A first space portion S 1  is formed in one side of the support base by a first incision portion  220 , and a protruding portion  210  is located toward a stationary body  510 , a description of which will follow. A second space portion S 2  is formed in the vicinity of the protruding portion  210  by a second incision portion  230 . 
     Here, the first space portion S 1  is configured to allow the hand of a worker to easily hold a battery cell  100  when the battery cell  100  is seated on the die  300  or is detached therefrom, and the second space portion S 2  is configured to secure a rotation space for a board seating portion  520 , a description of which will follow. 
     The die  300 , which provides a seating space for the battery cell  100 , is located along the upper part of the support base  200 , more specifically the second space portion S 2  of the support base  200 . The die includes a flat horizontal body  310  and a support wall  320  extending upwards along the edge of the horizontal body  310  by a predetermined height, the support wall being configured to limit leftward-rightward movement of the battery cell  100  after being seated. 
     Meanwhile, at one side of the horizontal body  310 , specifically above the first space portion S 1  of the support base  200 , a third space portion S 3  is formed by a third incision portion  311  and a pair of fourth incision portions  312  disposed so as to face each other. The third space portion S 3  is configured to easily attach and detach the battery cell  100 , in the same manner as the first space portion S 1  described above. 
     The support wall  320  may be constituted by a first support wall  321 , a second support wall  322 , a third support wall  323 , and a fourth support wall  324  configured to support four sides of the battery cell  100 . 
     Next, the bending guide unit will be described.  FIG. 3  is an enlarged perspective view of the bending guide unit of the bending apparatus shown in  FIG. 2 . 
     The bending guide unit  400  will be described with reference to  FIGS. 2 and 3 . The bending guide unit  400  may include a first support member  410 , a first auxiliary support member  420 , a first moving portion  430 , a first elastic member  440 , and a first moving means  450 . 
     The first support member  410  is formed so as to have an approximately triangular shape, one side surface of which is inclined such that the first moving portion  430  is movable in a state of being inclined at a predetermined angle. The first auxiliary support member  420  extends long in the state of being fixed to one surface of the first support member  410  by a fastening means (not shown). 
     The first moving portion  430  is moved along the inclined surface of the first support member  410 . At this time, the first moving portion  430  may be smoothly moved by the first moving means  450  without deviating from a predetermined path. 
     A M “ ”-shaped first pushing portion  431  is connected to one side surface of the first moving portion  430  in an inclined state. The lower end of the first pushing portion  431  has a sharp knife edge shape having an acute angle so as to be parallel to the ground in order to support a predetermined region of the flexible printed circuit board  110 , a description of which will follow. 
     Here, the reason that the first support member  410  is inclined at the predetermined angle is that it is advantageous to work for the first moving portion  430 , which is configured to push the predetermined region of the flexible printed circuit board  110 , to move in the inclined state. 
     The first elastic member  440 , which connects the first moving portion  430  and the first auxiliary support member  420  to each other, is configured to assist movement of the first moving portion  430 . When force applied to the first pushing portion  431  is released, the first moving portion  430  is returned to the original position thereof by elastic force of the first elastic member  440 . 
     Here, it is preferable that the first elastic member  440  be a spring. However, the present invention is not limited thereto as long as the first elastic member has sufficient force to return the first moving portion  430  to the original position thereof. 
       FIG. 4  is an enlarged perspective view of the bending unit of the bending apparatus shown in  FIG. 2 . The bending unit will be described with reference to  FIGS. 2 and 4 . 
     The bending unit  500 , which is configured to bend the flexible printed circuit board  110  exposed from the battery cell  100 , includes a stationary body  510 , a board seating portion  520 , a turning body  530 , a handle  540 , and a turning shaft  550 . 
     The stationary body  510  serves to support the board seating portion  520 , the turning body  530 , the handle  540 , and the turning shaft  550  such that the above components can be operated in the state of being organically connected to each other. A passage, along which the turning shaft  550  extends, is provided at a predetermined position of the stationary body. 
     The board seating portion  520 , which is turnably coupled to the stationary body  510  in the state in which the turning shaft  550  is connected to one side thereof, is located in the second space portion S 2  between the protruding portion  210  of the support base  200  and the die  300 . The board seating portion  520  is provided with a board seating groove  521 , which is hollowed by a predetermined depth so as to allow the flexible printed circuit board  110  connected to the battery cell  100  to be seated therein. 
     The turning body  530  is configured to rotate the board seating portion  520  by a predetermined angle. The other side of the turning shaft  550  is connected to one side of the turning body. In addition, the handle  540 , which is configured to be held by hand, is attached to the turning body such that the turning body can be easily rotated. Of course, as previously described, the turning shaft  550  extends through the stationary body  510 . 
       FIG. 5  is an enlarged perspective view of the press unit of the bending apparatus shown in  FIG. 2 . Referring to  FIGS. 2 and 5  together, the press unit  600  may include a second support member  610 , a second auxiliary support member  620 , a second moving portion  630 , a second elastic member  640 , and a second moving means  650 . 
     The second support member  610  is fixed to one side of the support base  200 , and may be a vertical bar or an L-shaped bar. 
     The second auxiliary support member  620  extends long in the state of being fixed to one side surface of the second support member  610  by a fastening means (not shown). The second auxiliary support member  620  is located perpendicular to the ground such that the second moving portion  630  is movable in a vertical direction. 
     Meanwhile, the second moving means  650 , which is configured to have a structure, such as a sliding structure, is located between the second support member  610  and the second moving portion  630 . As a result, the second moving portion  630  is smoothly movable upwards and downwards without deviating from a predetermined path. 
     A “ ”-shaped second pushing portion  631  is connected to one side surface of the second moving portion  630 . A “ ”-shaped projecting portion  631 ′ is formed at the end of the second pushing portion that faces in a downward direction (the Z-axis direction). The projecting portion  631 ′ is configured to more securely bend a bent portion of the flexible printed circuit board  110 , and a more detailed description thereof will be given below. 
     The second elastic member  640 , which connects the second moving portion  630  and the second auxiliary support member  620  to each other, is configured to assist movement of the second moving portion  630 . When force applied to the second pushing portion  631  is released, the second moving portion is returned to the original position thereof by elastic force of the second elastic member  640 . 
     Here, it is preferable that the first elastic member  440  be a spring. However, the present invention is not limited thereto as long as the second elastic member has sufficient force to return the first moving portion  430  to the original position thereof. 
       FIGS. 6 to 11  are flowcharts illustrating a method of bending a flexible printed circuit board using the bending apparatus according to the present invention. 
     A method of bending a flexible printed circuit board of a battery cell will be described with reference to  FIGS. 6 to 11 . 
     The bending method according to the present invention includes a first step of seating a battery cell  100  on the die  300 , a second step of bringing one end of the first pushing portion  431  of the bending guide unit  400  into tight contact with a flexible printed circuit board  110 , a third step of turning the board seating portion  520  of the bending unit  500  by a predetermined angle so as to come into tight contact with one side surface of the first pushing portion  431 , a fourth step of moving the first pushing portion  431  of the bending guide unit  400 , which is in tight contact with the flexible printed circuit board  110 , to the original position thereof, a fifth step of turning the board seating portion  520  of the bending unit  500  by a predetermined angle so as to come into tight contact with the upper surface of the die  300 , and a sixth step of moving the second pushing portion  631  of the second moving portion  630  to press a bent portion of the flexible printed circuit board  110 . 
     First, the first step will be described in more detail with reference to  FIG. 6 . The first step is a step of seating the battery cell  100  on the horizontal body  310  of the die  300  and seating the flexible printed circuit board  110  in the board seating groove  521 . The battery cell  100  may be easily seated due to the first space portion S 1  of the support base  200  and the third space portion S 3  of the die  300 . 
     The second step will be described with reference to  FIG. 7 . The first moving portion  430  of the bending guide unit  400  is moved downwards in an inclined state such that the knife-edge-shaped end of the first pushing portion  431  is brought into tight contact with the flexible printed circuit board  110 . This step is performed such that the flexible printed circuit board  110  is folded at a correct position thereof. 
     Next,  FIG. 8  is a view illustrating the third step. In the third step, the handle  540  of the bending unit  500  is turned until the board seating portion  520  comes into contact with the first pushing portion  431  in the state in which the flexible printed circuit board  110  is pushed by the end of the first pushing portion  431 . As a result, the flexible printed circuit board  110  is primarily folded by a predetermined angle. 
       FIG. 9  is a view illustrating the fourth step. The fourth step is a step of moving the first moving portion  430  of the bending guide unit  400  to the original position thereof. When force applied to the first moving portion  430  or the first pushing portion  431  is released, the first moving portion  430  is returned to the original position thereof by the first elastic member  440 . 
     The fifth step will be described with reference to  FIG. 10 . The handle  540  of the bending unit  500  is further rotated until the board seating portion  520  is no longer rotated, i.e. until the flexible printed circuit board  110  is completely folded such that opposite portions thereof come into contact with each other. 
       FIG. 11  is a view illustrating the sixth step, which is a step of pressing a bent portion of the flexible printed circuit board  110  formed as the result of folding again to minimize a spring back phenomenon, i.e. a phenomenon in which the flexible printed circuit board returns to the original state thereof. The second pushing portion  631  of the press unit  600  is moved downwards to press the bent portion of the flexible printed circuit board  110  formed as the result of folding. At this time, the bent portion may be accurately pressed by the “ ”-shaped projecting portion  631 ′. 
     After the above step, the battery cell  100  mounted in the die  300  is withdrawn. 
       FIG. 12  is a schematic view of an inspection jig configured to check a bent battery cell. A battery cell  100  having a bent flexible printed circuit board  110  may be mounted in an inspection jig  700  having a flexible printed circuit board receiving groove  710  in order to check for bending defects, as shown in  FIG. 9 . 
     Although the specific details of the present invention have been described in detail, those skilled in the art will appreciate that the detailed description thereof discloses only preferred embodiments of the present invention and thus does not limit the scope of the present invention. Accordingly, those skilled in the art will appreciate that various changes and modifications are possible, without departing from the category and the technical idea of the present invention, and it will be obvious that such changes and modifications fall within the scope of the appended claims. 
     DESCRIPTION OF REFERENCE SYMBOLS 
     
         
         
           
               100 : Battery cell 
               110 : Flexible printed circuit board 
               200 : Support base 
               210 : Protruding portion  220 : First incision portion 
               230 : Second incision portion 
               300 : Die 
               310 : Horizontal body 
               311 : Third incision portion  312 : Fourth incision portion 
               320 : Support wall 
               321 : First support wall  322 : Second support wall 
               323 : Third support wall  324 : Fourth support wall 
               400 : Bending guide unit 
               410 : First support member  411 : First guide rail 
               420 : First auxiliary support member 
               430 : First moving portion  431 : First pushing portion 
               440 : First elastic member  450 : First moving means 
               500 : Bending unit 
               510 : Stationary body 
               520 : Board seating portion  521 : Board seating groove 
               530 : Turning body  540 : Handle 
               550 : Turning shaft 
               600 : Press unit 
               610 : Second support member  611 : Second guide rail 
               620 : Second auxiliary support member 
               630 : Second moving portion 
               631 : Second pushing portion  631 ′: Projecting portion 
               632 : Second fixing frame 
               640 : Second elastic member  650 : Second moving means 
               700 : Inspection jig 
               710 : Flexible printed circuit board receiving groove 
             S 1 : First space portion S 2 : Second space portion 
             S 3 : Third space portion