JP2009099593A - Circuit board, manufacturing method thereof, and battery pack equipped with the circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit board where the occurrence of cracks or fractures in the board body or the resin-molding portion is suppressed when a load is applied, and to provide a method of manufacturing the circuit board, and a battery pack. <P>SOLUTION: The battery pack 1 is formed by providing a protecting circuit board 5 on the side face on the longer side of a battery case 2a for a battery 2. Connection terminals 5b, 5c are mounted on both end portions of the backside of the board body 5a of the protecting circuit board 5. The projection length of the connection terminals 5b, 5c from the board body 5a is longer than that of the other electronic component. The resin-molding portion 5g is provided on the board body 5a by covering each electronic component with a synthetic resin such as an epoxy resin etc. in a state where the surfaces of the connection terminals 5b, 5c are exposed. The protecting circuit board 5 is provided on the side face on the longer side in a state where: the surface of the resin-molding portion 5g is opposite to the side face on the longer side; and the connection terminals 5b, 5c are connected to the leads 6, 7. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a circuit board in which generation of cracks or cracks in a board body or a resin mold part when a load is applied, a method for manufacturing the circuit board, and a battery pack including the circuit board.

  In recent years, as a power source for portable electronic devices (electrical devices) such as video cameras, mobile computers, and mobile phones that are rapidly spreading, rechargeable secondary batteries such as lithium ion secondary batteries are mainly used. Yes. A lithium ion secondary battery is configured by housing an electrode group in which a positive electrode and a negative electrode are wound through a separator, and a non-aqueous electrolyte in a metal case.

In one aspect of this lithium ion secondary battery (hereinafter referred to as battery), a protection circuit for controlling the battery in order to prevent overcharge and overdischarge, and for taking out electric power from the battery or taking in electric power from the outside An internal member (hereinafter referred to as a core pack) of the battery pack is configured by arranging a protective circuit board having input / output terminals. The protective circuit board and the battery are electrically connected by metal leads.
A battery pack can be obtained by covering the side surface of the core pack with an insulating frame made of, for example, a synthetic resin, or by housing the core pack in an outer case made of, for example, a synthetic resin and further covering with a label.

  Patent Document 1 discloses an invention of a battery pack including a circuit board on which a plurality of circuit components constituting a protection circuit are mounted on one surface, and a resin that seals the entire mounting surface side of the circuit board after mounting the circuit components. Is disclosed.

  Patent Document 2 discloses a circuit board in which a step portion is formed at a corner opposite to a side facing a resin substrate for sealing circuit components, and an invention of a method for manufacturing the circuit board.

FIG. 8 is a side view showing a core pack 21 of a conventional battery pack.
The core pack 21 is configured by arranging a protective circuit board 25 on one side of the battery 22. The battery 22 is a flat wound electrode in which a negative electrode plate obtained by applying a negative electrode mixture to a copper current collector and a positive electrode plate obtained by applying a positive electrode mixture to an aluminum current collector are wound through a separator. A group (not shown) and a non-aqueous electrolyte (not shown) are accommodated in the case 22a. A negative electrode terminal 22b is provided on one side surface of the case 22a.

  One lead 23a of the protective element 23 is connected to the negative electrode terminal 22b by welding. A lead 26 is connected to the other lead 23 b of the protection element 23, and the lead 26 is connected to a terminal of the protection circuit board 25.

A protection circuit is mounted on the center of the back surface of the substrate body 25a of the protection circuit board 25, and a resin mold portion 25g is provided by covering the protection circuit with an insulating synthetic resin such as an epoxy resin.
The protective circuit board 25 is disposed such that the resin mold portion 25g faces the negative terminal 22b.

In the battery 22, the entire case 22a excluding the portion where the negative electrode terminal 22b is provided is a positive electrode (terminal).
A lead 27 is provided at the end of the case 22a opposite to the side where the protective element 23 is provided, and the lead 27 is connected to the other terminal of the protective circuit board 25.

  In the core pack 21, both ends of the board body 25a are supported by leads 26 and 27 connected to terminals. As shown in FIG. 8, the board body is assembled and assembled when the battery pack is used. When a load is applied to 25a, stress concentrates on the portion between the terminal to which the lead 27 is connected and the resin mold portion 25g, and the portion between the terminal to which the lead 26 is connected and the resin mold portion 25g, There was a problem that the resin mold portion 25g was cracked or cracked.

FIG. 9 is a side view showing a core pack 31 of another conventional battery pack.
In the core pack 31, a negative electrode terminal 32b is provided on the short side surface of the case 32a of the battery 32, and a protective circuit board 35 is disposed on the long side surface.
A protection circuit is mounted on the central portion of the substrate body 35a of the protection circuit board 35, and a resin mold portion 35g is provided by covering the protection circuit with an insulating synthetic resin such as an epoxy resin.
The protective circuit board 35 is arranged such that the resin mold portion 35g contacts the long side surface.
The lead 36 connects the terminal provided at one end of the back surface of the substrate body 35 a to the negative electrode terminal 32 b, and the lead 37 connects the other terminal provided at the other end of the back surface to the other end of the battery 32. Are connected to the short side surface (positive electrode).

  In the core pack 31, the resin mold portion 35g is supported on the long side surface of the battery 32, but the portion connected to the leads 36 and 37 of the substrate body 35a is suspended in the air and supported. Therefore, as shown in FIG. 9, when a load is applied to both ends of the substrate main body 35a when the battery pack is assembled and used, the terminal is connected between the terminal to which the lead 36 is connected and the resin mold portion 35g. There is a problem that stress concentrates on the portion and the portion between the terminal to which the lead 37 is connected and the resin mold portion 35g, and the substrate body 35a is cracked or broken.

FIG. 10 is a schematic plan view showing another conventional battery pack 41.
A negative terminal 42 b is provided on the short side surface of the case 42 a of the battery 42 of the battery pack 41, and a protection circuit board 45 is disposed on the long side surface.
A protection circuit is mounted on the back surface of the substrate body 45a of the protection circuit board 45, and a resin mold portion 45g is provided by covering the entire back surface with an insulating synthetic resin such as an epoxy resin.
The protective circuit board 45 is disposed so that the resin mold part 45g contacts the long side surface.

  In the battery pack 41, a lead 46 connects a terminal provided at one end of the surface of the substrate body 45a and the negative electrode terminal 42b, and a lead 47 connects the other terminal provided at the other end to the battery. The other short side surface (positive electrode) of 42 is connected.

The battery pack 41 is configured by housing a battery 42 in which a protective circuit board 45 is arranged on the side surface on the long side in a case 43.
Unlike the structure shown in FIGS. 8 and 9, the battery pack 41 does not concentrate stress on the protective circuit board 45 even when a load is applied from the outside of the battery pack 41, and the board body 45 a and the resin mold. The part 45g is not cracked or cracked. However, since the leads 46 and 47 are connected on the surface of the substrate body 45a, the case 43 has to be protruded to the outside by an amount corresponding to the thickness of the leads 46 and 47, and the length of the case 43 in the short direction. There was a problem that the length became long.
JP-A-11-283593 JP 2003-31526 A

As described above, the resin mold part is provided in the center part of the substrate body, each terminal is connected to each lead of the battery on the back side of the substrate body, and the substrate body is supported at both ends, or the resin mold part In the case of a battery pack including a protection circuit board configured to be supported, there is a problem that the substrate body or the resin mold part is cracked or cracked when a load is applied to the protection circuit board.
In the case of a battery pack having a protection circuit board configured such that each terminal is connected to each lead of the battery on the surface side of the board body and the entire surface of the board body is supported by the resin mold part, the battery is stored. Since the exterior frame that covers the case or the side surface on which the protection circuit board of the battery is disposed protrudes to the outside corresponding to the thickness of the lead, there is a problem that the battery pack cannot be reduced in size.

  The present invention has been made in view of such circumstances, and by forming the resin mold portion in a state where the surface of the connection terminal is exposed, the surface (exposed surface) of the resin mold portion on one surface of a device such as a battery. By arranging the connection terminals in a state of being connected to the connection parts of the device, the entire surface of the substrate body can be supported by the resin mold part, and the connection terminal and the part covering the connection terminal of the resin mold part Is supported in a state where it is in contact with the one surface via the connection component, and therefore, when a load is applied, the circuit board body or the resin mold part is prevented from being cracked or cracked, and the circuit board An object is to provide a manufacturing method.

  Moreover, this invention is comprised so that the protrusion length of the part which covers the connection terminal of a resin mold part in the board | substrate thickness direction from the board | substrate body may become shorter than the protrusion length of the part which covers the other electronic components of a resin mold part. Therefore, when the battery is disposed on one surface of the device, the connection part of the device is accommodated in the recessed portion, and the portion covering the other electronic components of the resin mold portion can be brought into contact with the one surface. An object of the present invention is to provide a circuit board in which cracks or cracks are further suppressed from occurring when a load is applied, and a method for manufacturing the circuit board.

  In the present invention, by arranging a circuit board configured to support the entire surface of the substrate body with the resin mold part on one surface of the battery, a part or all of the surface of the resin mold part contacts the one surface. When a load is applied in combination with being supported in contact with the substrate, it is possible to suppress the occurrence of cracks or cracks in the substrate body or the resin mold part, and it is also necessary to project the case or the outer frame that houses the battery to the outside. The object is to provide a battery pack that can be reduced in size.

  Further, according to the present invention, the electronic parts of the circuit board constitute a circuit for preventing overcharge and overdischarge of the battery, so that the entire surface of the board body of the circuit board on which the electric protection circuit is mounted is formed by the resin mold part. It is an object of the present invention to provide a battery pack that can be supported, can suppress the occurrence of cracks and cracks in a substrate body or a resin mold part, and can favorably protect an electric device to be mounted.

  According to a first aspect of the present invention, there is provided a circuit board comprising: a substrate body; an electronic component mounted on the substrate body; and a resin mold portion made of a synthetic resin and covering the substrate body and the electronic component. And a connection terminal having a protrusion length in the substrate thickness direction from the substrate body longer than the protrusion length of other electronic components, and the resin mold portion is provided so that the surface of the connection terminal is exposed. Features.

  In the present invention, since the resin mold portion is provided in a state where the surface of the connection terminal is exposed, the connection terminal is connected to the lead of a device such as a battery on the back side of the substrate body (the surface of the resin mold portion). It can be connected to a component, and the entire surface of the substrate body can be supported by the resin mold portion. That is, the circuit board is disposed in a state where the surface of the resin mold portion is opposed to one surface of the device and the connection terminal is connected to the connection component of the device. Accordingly, a load is applied to the substrate body in combination with the connection terminal and the portion covering the connection terminal of the resin mold part being supported by being in contact with the one surface via the connection component (and also via an insulating member if necessary). In such a case, the stress does not concentrate on a part of the circuit board and is generated substantially uniformly on the circuit board.

  A circuit board according to a second aspect of the present invention is a circuit board comprising a substrate body, an electronic component mounted on the substrate body, and a resin mold part made of a synthetic resin and covering the substrate body and the electronic component. The resin mold portion is provided so that the surface of the connection terminal is exposed, and the portion of the resin mold portion covering the connection terminal in the substrate thickness direction from the substrate body is provided. The protruding length is shorter than the protruding length of the portion covering the other electronic component of the resin mold part.

  In the present invention, the circuit board is configured to support the entire surface of the substrate body with the resin mold part, the circuit board is opposed to one surface of a device such as a battery, the surface of the resin mold part is opposed, and the connection terminal is the Distribute in a state where it is connected to connecting parts such as equipment leads. And since the part which covers the connection terminal of the resin mold part is recessed rather than the part which covers other electronic components, space can be used effectively by accommodating the said connection component in this recessed part. Furthermore, the part which covers the other electronic components of the resin mold part can also be brought into contact with the one surface. Therefore, when a load is applied to the substrate body, the stress is more evenly generated on the circuit board.

  According to a third aspect of the present invention, there is provided a circuit board manufacturing method including a step of mounting an electronic component on a substrate, wherein the step has a protrusion length in the substrate thickness direction from the substrate that is a protrusion of another electronic component. A step of mounting a connection terminal longer than the length, a step of covering the electronic component with a synthetic resin and forming a resin mold portion, and a step of polishing the surface of the resin mold portion so that the surface of the connection terminal is exposed It is characterized by having.

  In the present invention, it is possible to manufacture a circuit board in which the resin mold portion and the connection terminal have the same thickness.

  According to a fourth aspect of the present invention, there is provided a method for manufacturing a circuit board according to the third aspect, further comprising a step of cutting the surface of the connection terminal and the surface of the resin mold portion surrounding the connection terminal by substantially the same thickness. It is characterized by.

  In the present invention, it is possible to obtain a circuit board in which the portion covering the connection terminal of the resin mold portion is recessed from the portion covering the other electronic component.

  A battery pack according to a fifth aspect of the invention is characterized in that the circuit board of the first or second aspect of the invention is arranged on one surface of the battery with the surface of the connection terminal facing.

  In the present invention, the circuit board configured to support the entire surface of the substrate body with the resin mold portion is faced to one surface of the battery, the surface of the resin mold portion is opposed, and the connection terminal is connected to a connection component such as a battery lead. Distribute in the state. Therefore, when a part of or all of the surface of the resin mold portion is supported by being in contact with the one surface and a load is applied to the substrate body, the stress is generated substantially uniformly on the circuit board.

  According to a sixth aspect of the present invention, there is provided the battery pack according to the fifth aspect, wherein the electronic components on the circuit board constitute a circuit for preventing overcharge and overdischarge of the battery.

  In the present invention, the entire surface of the substrate body of the circuit board on which the electrical protection circuit is mounted can be supported by the resin mold portion.

According to the first invention, the board body of the circuit board is provided with a connection terminal having a protruding length in the board thickness direction from the board body that is longer than the protruding length of other electronic components, and the surface of the connecting terminal is provided on the surface of the connecting terminal. Since it is provided in an exposed state, the circuit board can be placed on one side of the device such as a battery, the surface of the resin mold part is opposed, and the connection terminal is connected to the connection component such as the lead of the device. The entire surface of the substrate body can be supported by the resin mold part.
Accordingly, a load is applied to the substrate body during assembly and use of the device, coupled with the connection terminal and the portion covering the connection terminal of the resin mold part being in contact with and supported by the one surface via the connection component. In some cases, the stress does not concentrate on a part of the circuit board and occurs substantially uniformly on the circuit board. Therefore, it is suppressed that a crack or a crack arises in a substrate main part or a resin mold part.
Further, since the connection component is connected to the circuit board on the surface of the resin mold portion and not connected to the surface of the substrate body, a case or an exterior frame for housing the device on which the circuit board is arranged is connected to the connection component. Since it corresponds to the thickness, it is not necessary to protrude outward, and the device can be downsized.

According to the second invention, the protruding length from the substrate body of the portion covering the connection terminal of the resin mold portion is configured to be shorter than the protruding length of the portion covering the other electronic components of the resin mold portion. When the circuit board is placed on one surface of a device such as a battery, the surface of the resin mold portion is opposed, and the connection terminal is arranged in a state of being connected to a connection component such as a lead of the device, the connection component is in a recessed portion. Can be accommodated, and the size of the device can be reduced.
Accordingly, the portion covering the connection terminal of the resin mold portion and the portion covering the other electronic component of the resin mold portion can be brought into contact with the one surface. Therefore, since the circuit board is favorably supported on the one surface, it is even better that the circuit board body or the resin mold part is cracked or cracked when a load is applied during assembly and use of the device. To be suppressed.

According to the third aspect of the invention, since the resin mold part is formed with the surface of the connection terminal exposed, a circuit board having the same thickness as the resin mold part and the connection terminal can be obtained.
Therefore, a rectangular parallelepiped circuit board can be produced without using an expensive mold such as a transfer mold.

According to the 4th invention, it has the process of further shaving the surface of a connection terminal, and the perimeter side part of the connection terminal of a resin mold part, and the part which covers the connection terminal of a resin mold part is the part which covers other electronic parts. A recessed circuit board is obtained.
Therefore, a circuit board having a desired step in the resin mold part can be produced.

According to the fifth invention, the circuit board configured to support the entire surface of the substrate body with the resin mold portion is faced to one surface of the battery, the surface of the resin mold portion is opposed, and the connection terminal is a connection component such as a battery lead. When a load is applied to the board body when assembling and using the battery pack, coupled with the fact that part or all of the surface of the resin mold part is in contact with and supported by the one surface. In addition, the stress is generated substantially uniformly on the circuit board. Therefore, the occurrence of cracks or cracks in the substrate body of the circuit board or the resin mold part is well suppressed.
The connecting component is connected to the circuit board on the surface of the resin mold portion and not connected to the surface of the substrate body. Therefore, the case or the exterior frame for storing the battery is divided into parts corresponding to the thickness of the connecting component. Therefore, it is not necessary to protrude outward, and the battery pack can be downsized.

According to the sixth invention, the electronic components on the circuit board constitute a circuit for preventing overcharge and overdischarge of the battery, so that the entire surface of the board body of the circuit board on which the electrical protection circuit is mounted is formed by the resin mold part. Can be supported.
Therefore, it is possible to satisfactorily protect the electric device to which the battery pack is mounted by suppressing the occurrence of cracks and cracks in the substrate body or the resin mold part.

Hereinafter, the present invention will be specifically described with reference to the drawings illustrating embodiments thereof.
Embodiment 1 FIG.
1 is a perspective view showing a battery pack 1 according to Embodiment 1 of the present invention, FIG. 2 is a schematic cross-sectional view showing the battery pack 1, and FIG. 3 is an enlarged cross-sectional view showing a protection circuit board 5. .
The battery pack 1 is used as a power source for portable electronic devices such as a cellular phone.
The battery pack 1 is a lithium ion secondary battery, and a battery 2 in which a protective circuit board 5 to be described later is arranged on the long side surface is replaced with a case 3 made of, for example, PC (polycarbonate) or ABS (acrylonitrile butadiene styrene). The case 3 is configured by closing the opening of the case 3 with a lid 4 made of, for example, PC or ABS.
In the side wall portion 3a of the case 3, in order to expose power to the outside of the battery 2, and conversely, positive and negative electrodes for taking in power from the outside for charging, and an output terminal (not shown) as a temperature terminal are exposed. Window portions 3b, 3b, 3b are provided.

  The battery 2 is a flat wound electrode in which a negative electrode plate obtained by applying a negative electrode mixture to a copper current collector and a positive electrode plate obtained by applying a positive electrode mixture to an aluminum current collector are wound through a separator. A group (not shown) and a non-aqueous electrolyte (not shown) are accommodated in an aluminum battery case 2a.

On the short side surface of the battery case 2a, a negative electrode terminal 2b is provided so as to penetrate in a state surrounded by an insulating member (not shown) made of a synthetic resin except for the surface of the negative electrode terminal 2b. .
In the battery 2, the entire battery case 2 a excluding a portion where the negative electrode terminal 2 b is provided is a positive electrode (terminal).

  A negative-side connection terminal 5b and a positive-side connection terminal 5c are mounted on both ends of the back surface of the substrate body 5a made of, for example, glass-epoxy material of the protective circuit board 5, and are arranged at the center of the substrate body 5a. IC 5d is mounted, and the IC 5d is connected to wiring (not shown) formed on the substrate body 5a by wire bonding. A capacitor 5e is mounted between the connection terminal 5b and the IC 5d, and a resistor 5f is mounted between the connection terminal 5c and the IC 5d. 2 and 3, other electronic components are omitted.

In the protection circuit board 5, the protruding lengths of the connection terminals 5b and 5c from the board body 5a in the board thickness direction are longer than the protruding lengths of other electronic components such as the IC 5d, the capacitor 5e, and the resistor 5f.
The substrate body 5a is provided with a resin mold portion 5g by covering each electronic component with an insulating synthetic resin such as an epoxy resin with the surfaces of the connection terminals 5b and 5c exposed.

The protective circuit board 5 is disposed on the long side surface in a state where the surface (exposed surface) of the resin mold portion 5 g faces the long side surface of the battery 2.
The connection terminal 5 b is connected to the negative electrode terminal 2 b of the battery 2 by the lead 6, and the connection terminal 5 c is connected to the other short side surface (positive electrode) of the battery 2 by the lead 7.
The lead 6 is disposed on the long side surface via the insulating tape 9, and the connection terminal 5 b is in contact with the long side surface via the lead 6 and the insulating tape 9. The connection terminal 5 c is in contact with the long side surface via the lead 7. The central side portion of the resin mold portion 5g is in contact with the long side surface via the insulating tape 9.

Below, the manufacturing method of the protection circuit board 5 is demonstrated.
FIG. 4 is a cross-sectional view showing a method for manufacturing the protection circuit board 5. The protective circuit board 5 is formed with a circuit so that a plurality of protective circuit boards 5, 5,... Are obtained on the board body 5a, and sealed with a sealing resin to form the resin mold portion 5g. These are obtained by chip-on-board (COB) technology by dividing them into protective circuit boards 5, 5,. FIG. 4 shows a case where two protection circuit boards 5 are produced.

First, the connection terminals 5b, 5c, IC 5d, capacitor 5e, resistors 5f,... Are mounted on the substrate body 5a (FIG. 4A). The heights of the connection terminals 5b and 5c are higher than those of other electronic components.
Next, a mask (not shown) having an opening corresponding to the size of a resin mold portion 5h described later is arranged on the substrate body 5a, and an epoxy resin or the like is used inside the opening using a squeegee. The sealing resin is loaded, and then the heat treatment is performed to cure the sealing resin, thereby forming the resin mold portion 5h (FIG. 4B). At this time, all the electronic components including the connection terminals 5b and 5c are covered with the resin mold portion 5h.

Then, the surface of the resin mold portion 5h is polished by using a blade or a disk-shaped polishing tool or the like until the surfaces of the connection terminals 5b and 5c are exposed to form the resin mold portion 5g (FIG. 4C). )).
Finally, it is cut using a blade or the like (FIG. 4 (d)) to obtain individual protection circuit boards 5, 5,... (FIG. 4 (e)).

The protection circuit board 5 obtained as described above is configured so that the entire surface of the board body 5a is supported by the resin mold portion 5g. And since the surface of the resin mold portion 5g is opposed to the long side surface of the battery 2 and the connection terminals 5b and 5c are connected to the leads 6 and 7, the connection terminals 5b and 5c and the resin mold portion are arranged. A portion covering the 5 g connection terminals 5 b and 5 c comes into contact with the long side surface via the leads 6 and 7, and the protection circuit board 5 is supported on the long side surface.
Therefore, when the battery pack 1 is assembled and used, when a load is applied in a direction perpendicular to the substrate body 5a, the stress is generated substantially uniformly on the protective circuit board 5, and the stress is applied to the substrate body 5a or the resin mold portion. It does not concentrate on a part of 5g, and it is suppressed that a crack or a crack arises. Therefore, the portable electronic device including the battery pack 1 is well protected.
Furthermore, since the leads 6 and 7 are connected to the connection terminals 5b and 5c on the surface of the resin mold portion 5g and are not connected to the surface of the substrate body 5a, the side wall portion 3a of the case 3 that houses the battery 2 is provided. The battery pack 1 can be reduced in size because it does not need to protrude outwardly by an amount corresponding to the thickness of the lead 6 and the insulating tape 9 and an amount corresponding to the thickness of the lead 7.

Embodiment 2. FIG.
FIG. 5 is a schematic cross-sectional view showing the battery pack 11 according to Embodiment 2 of the present invention, and FIG. 6 is an enlarged cross-sectional view showing the protection circuit board 8. In the figure, the same parts as those in FIG. 2 and FIG.

A protective circuit board 8 is disposed on the side surface of the battery pack 11 on the long side of the battery case 2a.
A negative-side connection terminal 8b and a positive-side connection terminal 8c are mounted on both ends of one surface of the substrate body 8a made of, for example, glass-epoxy material of the protective circuit board 8, and are formed at the center of the substrate body 8a. IC 8d is mounted, and IC 8d is connected to wiring (not shown) formed on the substrate body 8a by wire bonding. A capacitor 8e is mounted between the connection terminal 8b and the IC 8d, and a resistor 8f is mounted between the connection terminal 8c and the IC 8d. 5 and 6, other electronic components are omitted.

  The substrate body 8a is provided with a resin mold portion 8g by covering each electronic component with an insulating synthetic resin such as an epoxy resin with the surfaces of the connection terminals 8b and 8c exposed. The portions of the resin mold portion 8g that cover the outer peripheral side portions of the connection terminals 8b and 8c are recessed portions 8j and 8k that have a shorter protruding length than the portions that cover other electronic components.

The protective circuit board 8 is disposed in a state where the surface of the resin mold portion 8 g faces the long side surface of the battery 2.
The connection terminal 8 b is connected to the negative electrode terminal 2 b of the battery 2 by the lead 6, and the connection terminal 8 c is connected to the other short side surface (positive electrode) of the battery 2 by the lead 7.

The lead 6 is arranged on the side surface of the long side through the insulating tape 9, and the connection terminal 8b is connected to the lead 6 and the insulating tape 9 with the lead 6 and the insulating tape 9 being accommodated in the recess 8j. In contact with the long side surface.
The connection terminal 8c is in contact with the long side surface via the lead 7 in a state where the lead 7 is accommodated in the recess 8k.
Since the portions other than the recesses 8j and 8k of the resin mold portion 8g protrude from the surfaces of the connection terminals 8b and 8c by an amount corresponding to the thickness of the lead 6 and the insulating tape 9 and an amount corresponding to the thickness of the lead 7. The battery 2 is in contact with the long side surface.

Below, the manufacturing method of the protection circuit board 8 is demonstrated.
FIG. 7 is a cross-sectional view showing a method for manufacturing the protection circuit board 8.
First, the connection terminals 8b and 8c, the IC 8d, the capacitor 8e, the resistors 8f,... Are mounted on the substrate body 8a (FIG. 7A).
Next, a mask (not shown) having an opening corresponding to the size of a resin mold portion 8h described later is disposed on the substrate body 8a, and an epoxy resin or the like is used inside the opening using a squeegee. The sealing resin is loaded, and then the heat treatment is performed to cure the sealing resin, thereby forming the resin mold portion 8h (FIG. 7B). At this time, all the electronic components including the connection terminals 8b and 8c are covered with the resin mold portion 8h.

Then, the surface of the resin mold portion 8h is polished by using a blade or a disk-shaped polishing tool or the like until the surfaces of the connection terminals 8b and 8c are exposed to form the resin mold portion 8i (FIG. 7C). )).
Further, using the blades 10, 10,..., The surface of the connection terminals 8 c, 8 c... And the outer peripheral side portion of the connection terminal 8 c of the resin mold portion 8 i are shaved by the amount corresponding to the thickness of the lead 7 to form the recesses 8 k. Provide. Then, using the blades 10, 10,..., The surface of the connection terminals 8 b, 8 b, and the outer peripheral side portion of the connection terminal 8 b of the resin mold portion 8 i are shaved by the amount corresponding to the thickness of the lead 6 and the insulating tape 9. The recess 8j is provided (FIG. 7E). As described above, the resin mold portion 8g provided with the recesses 8j and 8k is obtained.

Finally, it is cut using a blade or the like (FIG. 7 (f)) to obtain individual protection circuit boards 8, 8,... (FIG. 7 (g)).
7C, the resin mold portion 8i having a surface height of about ± 0.075 mm is obtained. However, this polishing process is omitted, and the surfaces of the connection terminals 8b and 8c are exposed. Alternatively, the recesses 8j and 8k may be directly formed. However, it is preferable to perform the polishing treatment because the flatness of the surface of the resin mold portion 8g increases and the protective circuit board 8 can be brought into contact with the side surface of the long side of the battery 2 better.

The protective circuit board 8 obtained as described above has the resin mold portion 8g opposed to the long side surface of the battery 2, and the lead 6, the insulating tape 9, and the lead 7 are accommodated in the recesses 8j and 8k. Since the connection terminals 8b, 8c are brought into contact with the long side surface of the battery 2 via the lead 6, the insulating tape 9, and the lead 7, the portion covering the other electronic components of the resin mold portion 8g is also provided in the battery. 2 can be brought into contact with the side surface of the long side.
Accordingly, since the protection circuit board 8 is supported more favorably on the long side surface, the stress is protected when a load is applied in a direction perpendicular to the board body 8a when the battery pack 11 is assembled and used. The occurrence of cracks or cracks in the circuit board 8 substantially uniformly and in the substrate main body 8a of the protection circuit board 8 or the resin mold portion 8g is more effectively suppressed. Therefore, the portable electronic device in which the battery pack 11 is arranged is well protected.
Furthermore, since the leads 6 and 7 are connected to the connection terminals 8b and 8c on the surface of the resin mold portion 8g and not on the surface of the substrate body 8a, the case for housing the battery 2 is connected to the lead 6 and the insulation. The battery pack 11 can be reduced in size because there is no need to protrude outwardly by an amount corresponding to the thickness of the tape 9 and an amount corresponding to the thickness of the lead 7.

In the first and second embodiments, the case where the resin mold parts 5g and 8g are formed of an epoxy resin has been described. However, the present invention is not limited to this, and the resin mold part has an impact resistance. You may decide to form with the polyamide resin, acrylic resin, etc. which are favorable.
Moreover, although the case where the battery 2 is a lithium ion secondary battery has been described, the present invention is not limited thereto, and may be another secondary battery such as a nickel / hydrogen secondary battery or a nickel / cadmium secondary battery. .
In the first and second embodiments, the case where the battery 2 provided with the protection circuit boards 5 and 8 is housed in the case 3 is described. However, the present invention is not limited to this. May be covered with, for example, a synthetic resin exterior frame.

Moreover, the electric device to which the battery packs 1 and 11 of the present invention are applied is not limited to the portable electronic device.
Further, in the first and second embodiments, the case where the protective circuit boards 5 and 8 are applied as the circuit board has been described, but the present invention is not limited to this. Also, the device on which the circuit board is arranged is not limited to a battery.

It is a perspective view which shows the battery pack which concerns on Embodiment 1 of this invention. 1 is a schematic cross-sectional view showing a battery pack according to Embodiment 1 of the present invention. It is an expanded sectional view showing the protection circuit board concerning Embodiment 1 of the present invention. It is sectional drawing which shows the manufacturing method of the protection circuit board which concerns on Embodiment 1 of this invention. It is a general | schematic cross-sectional view which shows the battery pack which concerns on Embodiment 2 of this invention. It is an expanded sectional view which shows the protection circuit board concerning Embodiment 2 of this invention. It is sectional drawing which shows the manufacturing method of the protection circuit board which concerns on Embodiment 2 of this invention. It is a side view which shows the core pack of the conventional battery pack. It is a side view which shows the core pack of the other conventional battery pack. It is a schematic plan view showing another conventional battery pack.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11 Battery pack 2 Battery 2a Battery case 2b Negative electrode terminal 3 Case 3a Side wall part 3b Window part 4 Lid part 5, 8 Protection circuit board 5a, 8a Substrate body 5b, 5c, 8b, 8c Connection terminal 5d, 8d IC
5e, 8e Capacitors 5f, 8f Resistors 5g, 5h, 8g, 8h, 8i Resin mold part 8j, 8k Recess 6, 7 Lead 9 Insulating tape 10 Blade

Claims (6)

In a circuit board comprising a substrate body, an electronic component mounted on the substrate body, and a resin mold portion made of synthetic resin and covering the substrate body and the electronic component,
The board body includes a connection terminal having a protruding length in the board thickness direction from the board body longer than the protruding length of other electronic components,
The circuit board, wherein the resin mold portion is provided so that a surface of the connection terminal is exposed. In a circuit board comprising a substrate body, an electronic component mounted on the substrate body, and a resin mold portion made of synthetic resin and covering the substrate body and the electronic component,
The board body includes a connection terminal,
The resin mold part is provided so that the surface of the connection terminal is exposed,
A circuit board characterized in that a protrusion length of the resin mold portion covering the connection terminal in the substrate thickness direction from the substrate body is shorter than a protrusion length of a portion covering the other electronic component of the resin mold portion. . In a circuit board manufacturing method including a step of mounting an electronic component on a board,
The step is a step of mounting a connection terminal in which the protruding length in the substrate thickness direction from the substrate is longer than the protruding length of other electronic components,
Covering the electronic component with synthetic resin and forming a resin mold part;
Polishing the surface of the resin mold portion so that the surface of the connection terminal is exposed.   The method for manufacturing a circuit board according to claim 3, further comprising a step of cutting the surface of the connection terminal and the surface of the portion of the resin mold portion surrounding the connection terminal by substantially the same thickness.   A battery pack comprising the circuit board according to claim 1 or 2 in a state where the surface of the connection terminal faces one surface of the battery.   The battery pack according to claim 5, wherein the electronic components on the circuit board constitute a circuit for preventing overcharge and overdischarge of the battery.

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