JP5165543B2 - Battery monitoring device and battery monitoring semiconductor device - Google Patents

Description

  The present invention relates to a battery monitoring device, for example, a technique effective for use in a lithium ion secondary battery.

  The lithium ion secondary battery is provided with a battery monitoring device that monitors overcharge and overdischarge of the battery. With regard to such a battery monitoring device, the inventors of the present application have proposed an invention for improving reliability in Japanese Patent Application Laid-Open No. 2006-208152. In this publication, in order to improve the peelability of the semiconductor device due to the bending of the elongated mounting substrate constituting the monitoring device, it is provided on the elongated tab in the longitudinal direction of the mounting substrate, and externally on both sides in the longitudinal direction across the pin. Place the electrode.

JP 2006-208152 A

In Patent Document 1, wirings are formed in a desired pattern on an elongated mounting substrate, and wirings to which electrodes of a lithium ion secondary battery are connected are arranged at both ends in the longitudinal direction. In the battery monitoring device, two semiconductor devices constituting a MOS switch for charge / discharge control and its control circuit are mounted side by side in a longitudinal direction on an elongated mounting substrate. Between the MOS switch (charge / discharge control chip) and the control circuit (monitoring chip) and between the two semiconductor devices (charge / discharge control chip and monitoring chip) and the wiring arranged at both ends. It is connected by the desired pattern which is formed on the wiring and the bonding wires provided in the mounting substrate. The inventor of the present application has studied a monitoring semiconductor device as shown in FIG. 14A in order to reduce the size and thickness of a lithium ion secondary battery. FIG. 14A shows a top view of the semiconductor chip. In this monitoring semiconductor device, a charge / discharge control chip 2 having a MOS switch and a monitoring chip 3 are integrally housed in a package. In this configuration, since the monitoring chip and the charge / discharge control chip can be connected by the bonding wire 11, the mounting area on the mounting substrate can be reduced.

  In the case where the monitoring semiconductor device 1 composed of the charge / discharge control chip 2 and the monitoring chip 3 as described above is mounted on the mounting board having an elongated shape so that it can be mounted on the side surface of the battery pack, the above-mentioned patent document As shown in FIG. 14, in order to improve the peelability of the semiconductor device due to the curvature of the mounting substrate, the charge / discharge control chip 2 is monitored in the longitudinal direction of the mounting substrate as shown in the rear view of FIG. Elongated tabs 4 and 5 corresponding to the respective chips 3 are provided, and external electrodes 6 and 7 are arranged on both sides in the longitudinal direction with the tabs interposed therebetween.

  As shown in the side views of FIGS. 15 (A) and 15 (B), in the battery monitoring device having an elongated mounting substrate, the substrate bending stress due to the external stress generated during the handling or the like from the shape of the mounting substrate is as described above. The electrode of the monitoring semiconductor device IC is peeled off when the bending of the mounting substrate increases as shown in FIG. In order to improve the peel strength of the monitoring semiconductor device IC due to the bending of the mounting substrate corresponding to the substrate bending stress, external electrodes are arranged on both sides in the longitudinal direction as in Patent Document 1. In the battery monitoring device shown in FIG. 14, the bonding electrode 6 is formed elongated in the short direction in order to reduce the parasitic resistance in the current path of the charge / discharge control chip 2, and a plurality of bonding wires 8 are arranged in parallel therewith. To form a low-resistance current path. On the other hand, the monitoring chip 3 does not need to have a low resistance as described above, and it is sufficient that one bonding wire 9 can be connected. Therefore, the monitoring chip 3 is smaller than the bonding electrode 6 connected to the MOS switch. The bonding electrode 7 is used.

  In the inventor of the present application, in the battery monitoring apparatus configured as shown in FIG. 14, the peel strength differs between individual external electrodes of the semiconductor device due to the bending of the mounting board as shown in FIG. I found a new problem. That is, as a result of forming the bonding electrode 6 elongated in the short direction in order to reduce the parasitic resistance in the current path of the charge / discharge control chip 2, the bonding area with the mounting substrate is increased. As a result of the area of the bonding electrode 7 corresponding to the monitoring chip 3 being significantly reduced, the peeling strength of the connection electrode 7 of the monitoring chip 3 corresponds to the connection of the charge / discharge control chip 2 corresponding to the difference in bonding area. It becomes relatively weak with respect to the peel strength of the electrode 6. Therefore, even when the connection electrode of the monitoring chip 3 is peeled off as shown in FIG. 15B and the monitoring function is disabled, the current path by the charge / discharge control chip 2 still exists. The possibility of becoming is greatly increased. For this reason, the fact that the current path by the charge / discharge control chip 2 still exists in the state where the monitoring function is disabled causes a serious accident such as ignition due to overcurrent when an overcharge or load short circuit occurs. It means having potential.

  An object of the present invention is to provide a battery monitoring device that achieves miniaturization and high reliability. The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  One embodiment disclosed in the present application is as follows. The battery monitoring device includes an elongated mounting substrate and a battery monitoring semiconductor device that is affixed to the mounting substrate. The battery monitoring semiconductor device is mounted on a tab, a first electrode disposed on each side of the tab, a second electrode disposed on both sides of the tab, and the tab. A plurality of first bonding wires provided between a semiconductor chip, the first electrode, and a plurality of first bonding pads of the semiconductor chip corresponding to the first chip, the second electrode, and the semiconductor corresponding thereto One second bonding wire provided between the second bonding pads of the chip and the semiconductor chip, the first and the second electrodes, with the tab, the first electrode, and the back surface of the second electrode exposed. And a resin package for sealing including the second bonding wire. The back surfaces of the tab, the first electrode, and the second electrode of the battery monitoring semiconductor device are connected to the corresponding electrodes of the mounting substrate by a conductive bonding material, and are imbedded. The first electrode has an elongated shape in a short direction perpendicular to the longitudinal direction of the mounting substrate, and one ends of the plurality of bonding wires are connected side by side in the short direction, and the second electrode has a short direction. The length of the first electrode is shorter than the length of the first electrode in the short direction, and the outermost side in the longitudinal direction is a rectangle inside the outermost side of the first electrode and along the longitudinal direction. One end of the wire is connected.

  Since the battery monitoring device can be constituted by a single semiconductor device, it is possible to reduce the size, and high reliability can be realized by enhancing the peeling strength of the connection electrode of the monitoring chip.

  FIG. 1A is a top transparent view of one embodiment of a monitoring semiconductor device used in the battery monitoring device according to the present invention. FIG. 1B shows a back view of the monitoring semiconductor device. In this embodiment, as described above, a so-called multi-chip structure is adopted in which two semiconductor chips are built in one package in order to reduce the size of the battery monitoring device. One of them is a charge / discharge control chip 2 having a MOS switch, and the other is a monitoring chip 3 constituting the control circuit for the MOS switch.

  In FIG. 1A, the charge / discharge control chip 2 is mounted on a tab 4 which is horizontally long in the figure. The monitoring chip 3 is mounted on a tab 5 that is horizontally long in the figure. The tab 4 and the tab 5 are arranged in parallel so that the centers in the horizontal direction in FIG.

  A pair of bonding electrodes 6 are arranged on the left and right of the figure with respect to the charge / discharge control chip 2. The pair of bonding electrodes 6 are formed vertically long in the vertical direction of the figure so that a plurality of bonding wires 8 can be arranged in parallel with the charge / discharge control chip 2. Providing the plurality of bonding wires 8 can reduce the parasitic resistance in the charge / discharge path of the lithium ion secondary battery.

  A pair of bonding electrodes 6 are arranged on the left and right of the figure with respect to the charge / discharge control chip 2. The pair of bonding electrodes 6 are formed vertically long in the vertical direction of the figure so that a plurality of bonding wires 8 can be arranged in parallel with the charge / discharge control chip 2. By providing the plurality of bonding wires 8 as described above, the parasitic resistance in the charge / discharge path of the lithium ion secondary battery can be reduced.

  A pair of bonding electrodes 7 are arranged on the left and right of the figure with respect to the monitoring chip 3. The pair of bonding electrodes 7 provide an operating voltage to the monitoring chip, and the operating voltage is applied by a single bonding wire 9. Therefore, basically, the size may be smaller than that of the bonding electrode 6 as described above. However, in order to reinforce the peel strength due to the curvature of the mounting board as described above, it is formed long in the horizontal direction in the figure, and its central end is extended toward the center of the monitoring semiconductor device.

  In other words, when the outermost ends of the bonding electrode 66 and the bonding electrode 7 are aligned as shown in the figure, the innermost end of the bonding electrode 7 is closer to the innermost end of the bonding electrode 6 than the innermost end of the monitoring semiconductor device. The structure extends toward the center. Specifically, when the lateral width of the bonding electrode 6 is a, the lateral length of the bonding electrode 7 is increased as a + d. In other words, the length from the center line of the monitoring semiconductor device to the innermost end of the bonding electrode 7 is c, and the length from the center line of the monitoring semiconductor device to the innermost end of the bonding electrode 6 is It is lengthened as c + d.

  In FIG. 1A, the charge / discharge control chip 2, the monitoring chip 3, the bonding wires 8 to 11, the tabs 4 and 5, and the upper surfaces of the bonding electrodes 6 and 7 are sealed bodies made of an insulating resin ( Package) 1 is sealed. As shown in FIG. 1B, on the back surface side, the back surfaces of the tabs 4 and 5 and the bonding electrodes 6 and 7 are exposed from the sealing body (package) 1 made of the insulating resin (land). Is done. In addition, although 1 is shown as a sealing body like the figure, in FIG. 10 mentioned later, the monitoring semiconductor device itself is represented.

  As shown in FIG. 15, the peeling force due to the substrate bending due to the external stress of the battery monitoring device is smaller as the bonding area is larger, and if the area is the same, the center of the battery monitoring device is smaller and the resistance to the peeling force is stronger. . Therefore, in the embodiment of FIGS. 1A and 1B, the bonding electrode 7 is elongated in the lateral direction to increase the area, and the area increase is allocated closer to the center of the battery monitoring device. The resistance can be enhanced, and the difference in the peeling force between the bonding electrodes 6 and 7 can be reduced while reducing the size of the monitoring semiconductor device, thereby reducing the possibility of occurrence of the problem.

  In this embodiment, a signal path for transmitting a control signal for controlling on / off of the MOS switch of the charge / discharge control chip 2 from the monitoring chip 3 can be constituted by the bonding wire 11. As a result, as shown in Patent Document 1, the battery monitoring device can be downsized as compared with the case where two semiconductor devices are mounted on one mounting substrate and connected using a wiring pattern provided on the mounting substrate. Can be achieved.

  In this embodiment, two semiconductor chips are provided in one package, the positional relationship between the bonding electrodes 6 and 7 as external terminals is uniquely specified, and connected to the mounting substrate by solder or the like. Accordingly, the peeling force due to various curvatures of the substrate is generated with a certain relationship with respect to the two electrodes 6 and 7. Therefore, in this invention, the peeling force calculated | required from the above joining areas and its positional relationship can be estimated, and the peeling tolerance of the monitoring chip | tip can be improved reliably. That is, in the configuration in which two semiconductor devices are mounted at different positions in the longitudinal direction of the mounting substrate as in Patent Document 1, even if the electrode arrangement direction is the same as the longitudinal direction of the mounting substrate, Corresponding to various curved forms, it is predicted that the peeling force received by the two semiconductor devices each time changes variously. In this invention, generation | occurrence | production of the worst state that the current path of a lithium ion secondary battery remains formed in the state which the monitoring function became impossible as mentioned above can be avoided more reliably.

  In FIGS. 1A and 1B, although not particularly limited, a tab 4 on which the charge / discharge control chip 2 is mounted is provided with a rectangular notch 4 ′, and similarly, a tab 5 on which the control chip 3 is mounted. Is also provided with a rectangular notch 5 '. These notches 4 ′ and 5 ′ are used as gas vents when the monitoring semiconductor device is joined to the mounting substrate with solder or the like.

  FIG. 2A is a top transparent view of another embodiment of the monitoring semiconductor device used in the battery monitoring device according to the present invention. FIG. 2B shows a back view of the monitoring semiconductor device. In this embodiment, in order to increase the peeling resistance of the bonding electrode 7 for connection with the monitoring chip 3, instead of increasing the area as in the embodiment of FIG. Focusing on the fact that the peeling force acts at the center portion smaller than both ends of the semiconductor device, the bonding electrode 7 is moved closer to the center portion of the monitoring semiconductor device than the bonding electrode 6.

  That is, the bonding electrodes 6 and 7 are made the same as the horizontal length a in the figure. And while the length from the center line of the monitoring semiconductor device to the innermost end of the bonding electrode 6 is b, the length to the innermost end of the bonding electrode 7 is shortened as c. Then, the bonding electrode 7 is moved toward the center of the monitoring semiconductor device with respect to the bonding electrode 6. The movement of the bonding electrode 7 closer to the center portion reduces the peeling force itself when the substrate is bent as described above, so that the peeling of the bonding electrode 7 without increasing the area of the bonding electrode 7 as shown in FIG. Resistance to force can be increased. Other configurations are the same as those in FIGS. 1A and 1B.

  FIG. 3A is a top transparent view of another embodiment of the monitoring semiconductor device used in the battery monitoring device according to the present invention. FIG. 3B shows a back view of the monitoring semiconductor device. In this embodiment, the improvement of FIG. 2 is intended. As shown in FIG. 2, the bonding electrode 7 that connects to the monitoring chip 3 is moved closer to the center of the monitoring semiconductor device in order to increase the peeling resistance. Then, a dummy electrode 12 is provided on the outside of the semiconductor device on the lateral extension line of the bonding electrode 7 for resistance reinforcement. The dummy electrode 12 is not for connecting the bonding wires 8 and 9 like the bonding electrodes 6 and 7, but the monitoring semiconductor device is mounted on the mounting substrate by solder or the like in the same manner as the other electrodes 6 and 7. It is only for connection. In view of the arrangement of the dummy electrode 12 on the lateral extension of the bonding electrode 7, the tab 5 on which the monitoring chip 3 is mounted in order to secure the space has the shape of the embodiment shown in FIGS. Has been changed for things.

  In this embodiment, the bonding electrode 7 is mounted on the dummy electrode 12 in addition to reducing the peeling force caused by being moved closer to the center of the monitoring semiconductor device as in the embodiment of FIG. Since it acts to weaken the peeling force directed to the bonding electrode 7 due to the curvature of the substrate, the peeling resistance of the bonding electrode 7 can be made much higher than that of the embodiment of FIG.

  FIG. 4A shows a top transparent view of another embodiment of the monitoring semiconductor device used in the battery monitoring device according to the present invention. FIG. 4B shows a back view of the monitoring semiconductor device. This embodiment is a modification of FIG. That is, in this embodiment, the shape of the dummy electrode 12 is L-shaped in the horizontal direction of the figure. That is, the dummy electrode is formed by combining a portion elongated in the horizontal direction in the drawing and a portion elongated in the vertical direction inside the semiconductor device. The vertically long portion extends to the lateral extension line of the bonding electrode 7 to relieve the peeling force due to the bending of the mounting substrate with respect to the bonding electrode 7.

  FIG. 5A shows a top transparent view of another embodiment of the monitoring semiconductor device used in the battery monitoring device according to the present invention. FIG. 5B shows a back view of the monitoring semiconductor device. This embodiment is a modification of FIG. That is, in this embodiment, the dummy electrode 12 and the bonding electrode 7 shown in FIGS. 4A and 4B are integrally formed. In other words, the shape of the bonding electrode 7 is devised so as to enhance the peeling resistance, and the shape of the integrated dummy electrode 7 is an elongated L-shape in the horizontal direction of FIG.

  That is, the bonding electrode 7 has its outermost end aligned with the outermost end of the bonding electrode 6, and is extended laterally inward in the horizontal direction of FIG. 4A and 4B, the bonding electrode 7 is bent in the vertical direction and formed into a vertically long shape. One end of the bonding wire 9 is connected to the vertically long portion. In this configuration, since the dummy electrode 12 and the bonding electrode 7 are integrally formed as described above, the peeling force closer to the center of the semiconductor device while having the same action as the dummy electrode 12 in the horizontally long portion. A vertically long portion that provides the bonding electrode 7 in a small portion is formed to increase the connection area and increase the peeling resistance. In this embodiment, it is devised to improve the peeling resistance by acting synergistically.

  FIG. 6A is a top transparent view of another embodiment of the monitoring semiconductor device used in the battery monitoring device according to the present invention. FIG. 6B shows a back view of the monitoring semiconductor device. This embodiment is a modification of FIG. That is, in this embodiment, the bonding electrode 7 in FIGS. 5A and 5B is provided with a vertically long portion extending in the vertical direction at the outermost end. As a result, the shape of the integrated dummy electrode 7 is a horizontally long concave shape in the horizontal direction of FIG. In this configuration, the longitudinally extending portion extending in the vertical direction at the outermost end increases the connection area at the end portion where the peeling force is large, thereby improving the peeling resistance.

  FIG. 7A is a top transparent view of another embodiment of the monitoring semiconductor device used in the battery monitoring device according to the present invention. FIG. 7B shows a back view of the monitoring semiconductor device. This embodiment is a modification of FIG. That is, in this embodiment, another shape is devised so as to increase the peeling resistance in the bonding electrode 7, and the shape of the integrated dummy electrode 7 is an elongated convex shape in the horizontal direction of FIG.

  That is, the bonding electrode 7 has its outermost end aligned with the outermost end of the bonding electrode 6, and is extended laterally inward in the horizontal direction of FIG. 4A and 4B, the bonding electrode 7 is formed in a vertically long shape so as to extend in the vertical direction. One end of the bonding wire 9 is connected to the vertically long portion. In this configuration, since the dummy electrode 12 and the bonding electrode 7 are integrally formed in the same manner as described above, the peeling force closer to the center of the semiconductor device can be obtained while the horizontal portion has the same action as the dummy electrode 12. A vertically long portion is provided in the small portion to serve as the bonding electrode 7 to increase the connection area and increase the peeling resistance.

  FIG. 8A shows a top transparent view of another embodiment of the monitoring semiconductor device used in the battery monitoring device according to the present invention. FIG. 8B shows a back view of the monitoring semiconductor device. In this embodiment, as shown in FIG. 3, the bonding electrode 7 for connection to the monitoring chip 3 is moved closer to the center of the monitoring semiconductor device. Then, the bonding electrode 6 is extended in the vertical direction of the drawing to the extension line in the horizontal direction of the bonding electrode 7, and this extended portion has the role of the dummy electrode 12 of FIG. In accordance with the increase in the area of the bonding electrode 6, this configuration improves the peeling resistance to the bonding electrode 6 and the bonding electrode 7, increases the connection area, and increases the number of bonding wires 8. The effect that the parasitic resistance on the discharge control chip 2 side can be reduced can also be obtained.

  FIG. 9A shows a top transparent view of still another embodiment of the monitoring semiconductor device used in the battery monitoring device according to the present invention. FIG. 9B shows a back view of the monitoring semiconductor device. In this embodiment, a single semiconductor chip 2 is formed with a charge / discharge control unit corresponding to the charge / discharge control chip 2 and a monitoring unit corresponding to the monitoring chip 3. The bonding electrode 7 for connection with the monitoring unit is moved closer to the center of the monitoring semiconductor device as described above. Then, the dummy electrode 12 as shown in FIG. 3 is provided on the lateral extension of the bonding electrode 7. In this configuration, the bonding wire 11 connecting the charge / discharge control chip 2 and the monitoring chip 3 is omitted, and is replaced by a wiring means formed on the semiconductor chip 2. In addition, an electrode 5 corresponding to the tab 5 is formed, and a predetermined terminal of the monitoring unit is connected.

FIGS. 10A, 10B, and 10C show an overall configuration diagram of the battery monitoring device according to the present invention. FIG. 10A shows a top view thereof. In FIG. 10A, although not particularly limited, the electrodes 6 and 7 provided on both sides in the longitudinal direction of the monitoring semiconductor device 1 at the central portion of the elongated mounting substrate 20 are arranged in the longitudinal direction (X direction) of the mounting substrate. ) To be lined up. The mounting substrate 20 is a wiring substrate made of, for example, a glass / epoxy resin substrate or the like, and is elongated so that it can be mounted on the side surface of the battery pack. For example, the length (horizontal) in the X direction, which is the longitudinal direction, of the mounting substrate 20 is 30 mm, the length (vertical) in the Y direction orthogonal to the X direction is 4 mm, and the thickness is about 0.8 mm. It has become. Although not shown in the figure, the mounting substrate 20 is provided with wirings 23, 24, and 25 shown in FIG. 11 arranged in a desired pattern, and resistors and capacitors are provided in predetermined wiring portions as will be described later. The constituent chip parts are also connected.

  The position where the monitoring semiconductor device 1 is mounted on the elongated mounting board 20 does not need to be in the center as shown in FIG. Considering the curvature of the mounting substrate 20 due to the external stress as shown in FIG. 15, it is predicted that the peeling force is smaller on the end side of the mounting substrate 20 than on the center portion. If possible, it is recommended that the mounting position of the monitoring semiconductor device 1 be on the end side of the mounting substrate 20. As described above, the monitoring semiconductor device 1 may be mounted at any position in the longitudinal direction of the elongated mounting substrate 20.

  FIG. 10B is a cross-sectional view taken along line X-X ′ in FIG. On the back side of the monitoring semiconductor device 1, the back side of the bonding electrode 6 and the tab 4 is connected to the mounting substrate 20 by solder 13 or the like. The bonding electrode 6 and the charge / discharge control chip 2 are connected by a bonding wire 8. The monitoring chip 3, the corresponding tab 5, the bonding electrode 7, and the bonding wires 9, 10 are the same as described above.

  FIG. 10C is a cross-sectional view taken along the line Y-Y ′ of FIG. On the back side of the monitoring semiconductor device 1, the back sides of the tab 4 and the tab 5 are connected to the mounting substrate 20 by solder 13 or the like. The charge / discharge control chip 2 and the monitoring chip 3 are connected by a bonding wire 11.

FIG. 11 is a block diagram showing an embodiment of a battery pack equipped with a battery monitoring device to which the present invention is applied. This embodiment is applied to a battery pack such as a lithium ion secondary battery. The battery pack according to this embodiment includes a battery cell CELL, a fuse FS, the monitoring chip 3, a charge / discharge control chip 2, and resistors Rvcc and Ridt, capacitors C1 and C2 as additional circuits. The charge / discharge control chip 2 has two power MOSFETs M1 and M2 connected in series. The positive electrode + of the battery cell CELL is connected to the first power supply terminal 26 of the mounting substrate via the fuse FS and the wiring 45, and the first power supply terminal 26 is connected to the positive electrode terminal (+) 21 of the battery pack via the wiring 23. Is done. The negative electrode of the battery cell CELL is connected to the second power supply terminal 27 of the mounting substrate, and is connected to the source of the power MOSFET M1 and the ground terminal GND of the monitoring chip 3 via the wiring 24 . The drain of the power MOSFET M1 is connected to the drain of the power MOSFET M2. The source of the power MOSFET M2 is connected to the negative terminal (−) 22 of the battery pack via the wiring 25 .

  The MOSFET M1 is used to cut off a discharge current, and has a gate connected to a discharge control terminal DCH of the monitoring chip 3. The MOSFET M2 is used to cut off a charge (charge) current, and has a gate connected to the charge control terminal CHG of the monitoring chip 3. The source of the MOSFET M2 is connected to the second ground terminal IDT of the monitoring chip 3 through a resistor Ridt. The positive terminal (+) of the battery pack is connected to the power supply terminal VCC of the monitoring chip 3 via a resistor Rvcc. A capacitor C1 for stabilizing the power supply is connected between the power supply terminal VCC and the ground terminal GND of the monitoring chip 3. In addition, a capacitor C2 is connected between the ground terminal GND of the monitoring chip 3 and the negative terminal (−) of the battery pack.

  A charger or a load circuit is connected to the positive terminal (+) and the negative terminal (−) of the battery pack. For example, the load circuit is an electronic device such as a laptop microcomputer or a mobile phone device. In the charging operation, a charger is connected, current flows from the positive electrode terminal (+) of the battery pack toward the positive electrode (+) of the battery cell CELL, and the negative electrode (−) of the battery cell CELL is negative electrode terminal (−). Current flows toward In this case, since a current always flows through the body diode in the MOSFET M1, the charging operation is stopped by turning off the MOSFET M2. In the discharging operation, a load circuit is connected, a current flows from the positive electrode (+) of the battery cell CELL to the positive electrode terminal (+) of the battery pack, and the negative electrode of the battery cell CELL from the negative electrode terminal (−) of the battery pack. Current flows toward (-). In this case, since a current always flows through the body diode in the MOSFET M2, the discharge operation is stopped by turning off the MOSFET M1. A protective diode is provided between the gates and sources of the MOSFETs M1 and M2.

  The IDT terminal (detection terminal) is a negative (ground potential) side power supply terminal for the overcurrent voltage detection input, the charge overcurrent detection input, and the CHG output. The discharge current increases and the input voltage at the IDT terminal becomes the overcurrent detection voltage. When the short circuit current detection voltage is exceeded, the DCH output becomes low level (ground side voltage), and the MOSFET M1 is turned off. Thereafter, when the input voltage becomes equal to or lower than the overcurrent detection voltage, the DCH output becomes a high level (power supply voltage), and the MOSFET M1 is turned on to recover from the overcurrent state.

  The DCH terminal outputs the control signal of the MOSFET M1 supplied to the gate for cutting off the discharge path as described above. When the voltage of the battery cell CELL is normal, the DCH terminal becomes high level (VCC), and the MOSFET M1 is turned on. When a discharge state or an overcurrent state is detected, the level becomes low level (ground potential), and the MOSFET M1 is turned off.

  The CHG terminal outputs the control signal of the MOSFET M2 supplied to the gate for cutting off the charging path as described above. When the voltage of the battery cell CELL is normal, the CHG terminal becomes high level (VCC), and the MOSFET M2 is turned on. When a charged state or an excessive charging voltage is detected, the low level (IDT) is set, and the MOSFET M2 is turned off.

  FIG. 12 is a block diagram showing an embodiment of the monitoring chip. The monitoring chip of this embodiment is not particularly limited, but a reference voltage generation circuit, a control circuit, a drive circuit corresponding to the DCH terminal and the CHG terminal, an upper limit voltage detection circuit, a lower limit voltage detection circuit, an oscillator, and an oscillation of the oscillator It is composed of an overcharge timer, an overdischarge timer, an overcurrent timer, a charger voltage detection circuit, a discharge current, a charge current detection circuit, etc. that operate by pulses. The reference voltage formed by the reference voltage generation circuit is used as a reference for detection operations of the upper limit voltage detection circuit, the lower limit voltage detection circuit, the charger voltage, the discharge current, and the charge current voltage detection circuit.

FIG. 13 is a schematic diagram of a lithium ion secondary battery pack in which the battery monitoring device according to the present invention is mounted. The battery monitoring device 30 includes the monitoring semiconductor device 1 and the mounting substrate 20. Although not particularly limited, the battery monitoring device 30 is mounted on the upper side surface of the flat lithium ion secondary battery pack 41 where the (−) electrode 42 is provided. On the first surface (upper surface in FIG. 13) of the mounting substrate 20 of the battery monitoring device 30, the monitoring semiconductor device 1 and the additional circuit element (not shown in the figure) are mounted. One end of the mounting substrate 20 is connected to the (+) electrode 43 of the lithium ion secondary battery pack 41 by wiring means 44-45 made of thin and long aluminum having a crease. The other end of the mounting substrate 20 is connected to the (−) electrode 42 of the lithium ion secondary battery pack 41 by the wiring means 46 made of thin and thin aluminum as described above. Although not shown, a first power supply terminal 26 to which the wiring means 44 is connected is provided at one end of the mounting substrate 20, and a second power supply terminal 27 to which the wiring means 46 is connected is provided at the other end. Although not shown, the mounting board 20 is provided with external connection terminals 21 (positive terminal (+)) and 22 (negative terminal (−)) to which a charger or a load circuit is connected.

  The wiring means 44 has a length equal to the length of the side surface in the vertical direction of the lithium ion secondary battery pack 41 in the figure, and the wiring means 45 and 46 have the same length. So that the battery terminal device and its wiring means 44-45 and 46 are adhered to the left side surface and the top surface of the lithium ion secondary battery pack 41 as a whole. Installed.

  As described above, the mounting substrate 20 is formed thin as described above, and its length in the longitudinal direction is increased, and the mounting method of the battery pack 41 is a thin plate as shown in FIG. Therefore, undesired external stress is generated in the assembly or the like, and there is a high risk of electrode peeling of the monitoring semiconductor device. The risk of ignition or the like due to electrode peeling can be greatly reduced by devising the electrode position and shape for connection with the monitoring chip or monitoring unit as in the present application.

  Although the invention made by the inventor has been specifically described based on the above embodiment, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. For example, the monitoring chip 3 may be anything as long as it performs charge / discharge control as described above. The charge / discharge control chip 2 may be composed of two MOSFET chips. That is, three chips such as a monitoring chip and two MOSFET chips may be mounted in one package, or a resistance element, a capacitor, and the like may be mounted in one package.

  It can be widely used as a battery monitoring device provided in various secondary batteries such as lithium ion secondary batteries.

It is the upper surface transparent view and back surface figure of one Example of the monitoring semiconductor device used for the battery monitoring apparatus which concerns on this invention. It is the upper surface transparent view and back surface figure of other one Example of the semiconductor device for monitoring used for the battery monitoring apparatus which concerns on this invention. It is the upper surface transparent view and back surface figure of other one Example of the semiconductor device for monitoring used for the battery monitoring apparatus which concerns on this invention. It is the upper surface transparent view and back surface figure of other one Example of the semiconductor device for monitoring used for the battery monitoring apparatus which concerns on this invention. It is the upper surface transparent view and back surface figure of other one Example of the semiconductor device for monitoring used for the battery monitoring apparatus which concerns on this invention. It is the upper surface transparent view and back surface figure of other one Example of the semiconductor device for monitoring used for the battery monitoring apparatus which concerns on this invention. It is the upper surface transparent view and back surface figure of other one Example of the semiconductor device for monitoring used for the battery monitoring apparatus which concerns on this invention. It is the upper surface transparent view and back surface figure of other one Example of the semiconductor device for monitoring used for the battery monitoring apparatus which concerns on this invention. It is the upper surface transparent view and back surface figure of other one Example of the semiconductor device for monitoring used for the battery monitoring apparatus which concerns on this invention. It is a whole block diagram of one Example of the battery monitoring apparatus which concerns on this invention. It is a block diagram of one Example of the battery pack by which the battery monitoring apparatus to which this invention was applied was mounted. 1 is a block diagram of an embodiment of a monitoring chip according to the present invention. FIG. It is a schematic diagram of the lithium ion secondary battery pack equipped with the battery monitoring device according to the present invention. It is the upper surface transparent view and back surface view of the monitoring semiconductor device examined previously by this inventor. It is explanatory drawing of the electrode peeling by the external stress of the battery monitoring apparatus which has the elongate mounting board | substrate examined previously by this inventor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sealing body (Semiconductor device for monitoring), 2 ... Chip for charge / discharge control, 3 ... Chip for monitoring, 4 ..., 5 ... Tab, 6, 7 ... Bonding electrode, 8-11 ... Bonding wire, 12 ... Dummy Electrode, 13 ... solder,
DESCRIPTION OF SYMBOLS 20 ... Mounting substrate, 30 ... Battery monitoring apparatus, 41 ... Lithium ion secondary battery pack, 42 ... (-) electrode, 43 ... (+) electrode, 44-46 ... Wiring means ,
21 ... Positive electrode terminal (+), 22 ... Negative electrode terminal (-), 23-25 ... Wiring, 26 ... First power supply terminal, 27 ... Second power supply terminal.

Claims (18)

A mounting substrate in the longitudinal direction of the bending stress has an elongated shape is handled in such an environment, a battery monitoring device you have a a semi conductor device attached surface to the mounting substrate,
The semiconductor device includes a charge / discharge control unit and a monitoring unit, and constitutes a battery pack together with a battery to be monitored. The battery pack includes first and second external connection terminals to which a charger or a load circuit is connected. And one electrode of the battery is connected to the first external connection terminal, and the other electrode of the battery is connected to the second external connection terminal via the charge / discharge control unit. Become
Upper Symbol semi conductor arrangement,
Tabs,
A first electrode that is disposed on both sides of the tab in the longitudinal direction and is elongated in a direction orthogonal to the longitudinal direction when the mounting substrate is impregnated;
A second electrode provided corresponding to both sides of the tab and provided with a portion positioned at least on the inner side of the position of the elongated first electrode at a position from a side edge of the semiconductor device;
A semiconductor chip including the charging and discharging control unit and the monitoring unit mounted on the tab,
Said elongated a first electrode and a plurality of first bonding wires respectively connecting between the plurality of first bonding pads of the charge and discharge control unit corresponding to that of said first electrode of the bonding wire of the plurality of A plurality of first bonding wires respectively connected so that connecting portions thereof are aligned in the elongated direction of the elongated first electrode;
And one of the second bonding wires respectively connecting between the second bonding pad of the monitoring unit corresponding thereto and the second electrode,
A resin package for sealing including the semiconductor chip and the first and second bonding wires in a state where the back surfaces of the tab, the first electrode, and the second electrode are exposed;
The mounting board is
A third electrode provided corresponding to the tab;
A fourth electrode provided corresponding to the first electrode ;
A fifth electrode provided corresponding to the second electrode ;
Provided at one end portion in the longitudinal direction of the mounting substrate, a first power supply terminal connected to the one electrode of the battery,
A second power supply terminal provided at the other end in the longitudinal direction of the mounting substrate and connected to the other electrode of the battery ;
Wiring means for connecting the fifth electrode to the first power supply terminal and the first external connection terminal, wiring means for connecting one of the fourth electrodes to the second power supply terminal , and the other of the fourth electrode Wiring including wiring means connected to the second external connection terminal ,
The upper Symbol rear surface side and the mounting substrate of the surface of the third electrode tabs are connected by a conductive bonding material, and the fourth electrode and fifth electrode of the upper Symbol first electrode and the second electrode and the mount board Are each connected by a conductive bonding material, and are impositioned above,
Battery monitoring device. In claim 1,
The second electrode is formed in an elongated shape that is shorter than the length of the first electrode in the elongated direction in the orthogonal direction and extends inwardly of the first electrode in the longitudinal direction.
Battery monitoring device. In claim 1,
The semiconductor chip includes a first semiconductor chip that constitutes the charge / discharge control unit that performs charge / discharge control of the battery to be monitored, and a second semiconductor that constitutes the monitor unit that forms the control signal for charge / discharge control. Consisting of chips,
The tab includes a first tab corresponding to the first semiconductor chip and a second tab corresponding to the second semiconductor chip.
The first electrode is connected to the first semiconductor chip;
The second electrode is connected to the second semiconductor chip;
A bonding wire for transmitting the control signal formed by the second semiconductor chip to the first semiconductor chip;
The third electrode of the mounting board is composed of two electrodes respectively corresponding to the first tab and the second tab.
Battery monitoring device. In claim 3,
Each of the second electrodes is provided on the inner side closer to the center than the innermost side of the first electrode in the longitudinal direction, and further includes a first dummy electrode on the outer side of the longitudinal extension line of the second electrode. And
The mounting board further includes a second dummy electrode corresponding to the first dummy electrode,
It said the first dummy electrode and said second dummy electrode are connected by the bonding material,
Battery monitoring device. In claim 4,
The first and second dummy electrodes have a larger area than the corresponding second and fifth electrodes.
Battery monitoring device. In claim 4,
The second electrode and the first dummy electrode are integrally formed,
The fifth electrode and the second dummy electrode are integrally formed,
The integrally formed second electrode, first dummy electrode, fifth electrode, and second dummy electrode are connected by the bonding material.
Battery monitoring device. In claim 6,
The integrally formed second electrode, the first dummy electrode, the fifth electrode, and the second dummy electrode are concave with respect to the short direction of the mounting substrate.
Battery monitoring device. In claim 6,
The integrally formed second electrode and first dummy electrode, and the fifth electrode and second dummy electrode are convex with respect to the longitudinal direction of the mounting substrate.
Battery monitoring device. In claim 6,
The integrally formed second electrode, first dummy electrode, and fifth electrode and second dummy electrode are L-shaped with respect to the longitudinal direction of the mounting substrate.
Battery monitoring device. In claim 3,
The second electrode is provided such that the outermost side in the longitudinal direction is closer to the center than the innermost side of the first electrode,
The first electrode is extended in the short direction so as to extend to an extension line in the longitudinal direction of the second electrode.
Battery monitoring device. A battery monitoring semiconductor device used by being incorporated in a battery monitoring device mounted on a secondary battery,
The semiconductor device constitutes a battery pack together with a battery to be monitored,
The battery pack includes first and second external connection terminals to which a charger or a load circuit is connected, one electrode of the battery is connected to the first external connection terminal, and the other electrode of the battery is the above It is configured to be connected to the second external connection terminal via a charge / discharge control unit included in the semiconductor device,
The battery monitoring device includes a mounting substrate and a battery monitoring semiconductor device attached to the mounting substrate, the semiconductor device includes a charge / discharge control unit and a monitoring unit, and the mounting substrate is elongated. are those longitudinally bending stresses have the shape is handled in such an environment, it provided the electrode portion electrode of the semiconductor device are connected by a conductive bonding material, on one end in the longitudinal direction of the mount board et Re a first power supply terminal connected to one electrode of the upper Symbol rechargeable battery, a second power supply terminal connected to the other electrode of the secondary battery is provided at the other end portion in the longitudinal direction of the mounting board First wiring means for connecting the monitoring unit to the first power supply terminal and the first external connection terminal; and a second wiring unit for connecting the charge / discharge control unit between the second power supply terminal and the second external connection terminal. 2 and a wiring including a third wiring means ,
The semiconductor device for battery monitoring is
Tabs,
A first electrode that is disposed on both sides of the tab in the longitudinal direction and is elongated in a direction orthogonal to the longitudinal direction when the mounting substrate is impregnated;
A second electrode provided corresponding to both sides of the tab and provided with a portion positioned at least on the inner side of the position of the elongated first electrode at a position from a side edge of the semiconductor device;
A semiconductor chip including a charge / discharge control unit and a monitoring unit mounted on the tab;
A plurality of first bonding wires respectively provided between the elongated first electrodes and a plurality of first bonding pads corresponding to the elongated first electrodes, the first of the plurality of bonding wires; A plurality of first bonding wires connected so that connection portions to the electrodes are aligned in the elongated direction of the elongated first electrode;
A second bonding wire provided between the second electrode and the corresponding second bonding pad of the monitoring unit;
A resin package for sealing including the semiconductor chip and the first and second bonding wires in a state where the back surfaces of the tab, the first electrode, and the second electrode are exposed;
The tab is exposed on the back surface of the semiconductor device, Ri name the first electrode and the second electrode are configured to be respectively imposition through the conductive bonding material on the electrode unit corresponding formed on the mount board ,
When the semiconductor device is mounted on the mounting substrate and connected to the battery, one of the first electrodes is connected to the second power supply terminal via the second wiring means, and the other of the first electrodes is the above The second electrode is connected to the second external connection terminal via a third wiring means, the second electrode is connected to the first power supply terminal and the first external connection terminal via the first wiring means, and the monitoring unit A battery monitoring semiconductor device comprising a battery pack that monitors overcharging and overdischarging of a battery and controls charging / discharging of the battery by the charge / discharge control unit. In claim 11,
The semiconductor chip includes a first semiconductor chip that constitutes the charge / discharge control unit that performs charge / discharge control of the battery to be monitored, and a second semiconductor that constitutes the monitor unit that forms the control signal for charge / discharge control. Consisting of chips,
The tab includes a first tab corresponding to the first semiconductor chip and a second tab corresponding to the second semiconductor chip.
The first electrode is connected to the first semiconductor chip;
The second electrode is connected to the second semiconductor chip;
A bonding wire for transmitting the control signal formed by the second semiconductor chip to the first semiconductor chip;
The electrode portion of the mounting substrate is composed of two electrode portions corresponding to the first tab and the second tab, respectively.
Battery monitoring semiconductor device. In claim 11 or 12,
The second electrode is formed in an elongated shape that is shorter than the length of the first electrode in the elongated direction in the orthogonal direction and extends inwardly of the first electrode in the longitudinal direction.
Battery monitoring semiconductor device. In any of claims 11 to 13,
Each of the second electrodes is provided on the inner side closer to the center than the innermost side of the first electrode in the longitudinal direction, and further includes a dummy electrode on the outer side of the extension line in the longitudinal direction of the second electrode, The second electrode and the dummy electrode are respectively connected to the corresponding electrode portions of the mounting board by the conductive bonding material,
Battery monitoring semiconductor device. In claim 14,
The dummy electrode corresponding to the second electrode is integrally formed so as to form a concave shape in the orthogonal direction, and the corresponding electrode portion of the mounting substrate is formed in a concave shape corresponding to the concave electrode configuration. Become,
Battery monitoring semiconductor device. In claim 14,
The dummy electrode corresponding to the second electrode is integrally formed so as to form a convex shape in the longitudinal direction, and the corresponding electrode portion of the mounting substrate is convex corresponding to the convex electrode configuration. Formed into,
Battery monitoring semiconductor device. In claim 14,
The dummy electrode corresponding to the second electrode is integrally formed in an L shape in the longitudinal direction, and the corresponding electrode portion of the mounting substrate is formed in an L shape corresponding to the L shape.
Battery monitoring semiconductor device. In claim 14,
The second electrode is disposed between the elongated end portion of the first electrode and the tab in the longitudinal direction, and the elongated end portion of the first electrode constitutes the dummy electrode.
Battery monitoring semiconductor device.