JP2009117084A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack excellent in reliability capable of preventing adjacent outer connection terminals of a circuit board from short circuiting by a connecting terminal of an outside equipment, or preventing protrusions for short-circuiting prevention from being peeled off from a circuit board to have outer connection terminals short-circuited due to droplets. <P>SOLUTION: The battery pack includes a flat rectangular unit battery 2, a circuit board 5 arranged on a top face of the unit battery 2, and a resin mold 7 integrating the circuit board 5 with the unit battery 2. A plurality of outer connection terminals 9 are provided on a top face of the circuit board 5. These terminals 9 are exposed to an outside face through an opening 33 of the resin mold 7. Each protrusion 34 inhibiting short circuiting of the adjacent outer connection terminals 9 is integrally formed with the resin mold 7. A face of the circuit board 5 opposed to the protrusion 34 is given a surface roughening treatment, and the protrusion 34 and the circuit board 5 are firmly integrated through a joint part 36 entering into the surface roughened part 35. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a flat rectangular unit cell and a battery pack in which a circuit board disposed on the upper surface of the unit cell is integrated via a resin mold.

  Patent Documents 1 and 2 are known as this type of battery pack. In each of the battery packs of Patent Documents 1 and 2, the entire circuit board excluding the external connection terminals is covered with a resin mold and integrated with the unit cell. In these battery packs, adjacent external connection terminals are only separated by a thin mold layer. Therefore, under a situation where the connection terminal of the external device is deformed, the connection terminal of the external device may get over the previous mold layer and short-circuit the adjacent external connection terminals.

  In order to prevent such a short circuit between adjacent external connection terminals, a battery pack is proposed in which the outer surface of the circuit board is covered with a cover, and the unit cell, the circuit board, and the cover are integrated with a resin mold ( (See Patent Document 3). A window for exposing the external connection terminal to the outer surface of the cover is opened in the cover, and a projection for preventing a short circuit is formed between adjacent windows.

JP 2003-242947 A (paragraph number 0047, FIG. 10) Japanese Patent Laying-Open No. 2003-288871 (paragraph number 0012, FIG. 6) JP 2006-147329 A (paragraph number 0027, FIG. 2)

  If the protrusion for preventing a short circuit is provided on the outer surface of the cover as in the battery pack of Patent Document 3, it is possible to prevent the adjacent external connection terminals from being short-circuited by the connection terminal of the external device. There is also an advantage that the cover can be formed of a resin having a strength higher than that of the resin mold. However, since the resin mold is formed in a state where the cover is bonded to the circuit board, the molten resin may not be sufficiently distributed between the cover and the circuit board. In a situation where such a molding defect (short shot) occurs, water drops may permeate between the cover and the circuit board, and adjacent external connection terminals may be short-circuited.

  If the projections for short circuit prevention are integrally formed in the process of molding the resin mold, it is possible to prevent adjacent external connection terminals from being short-circuited by the connection terminals of the external device, as in the case of adding a cover. However, the protrusions protruding from the outer surface of the battery pack are likely to come into contact with other objects when the battery pack is handled, and it is inevitable that the protrusions receive a large tilting moment when contacting the other objects. For this reason, if the battery pack is handled roughly, the protrusions may be lifted away from the circuit board between adjacent external connection terminals, and soaks between the protrusions and the circuit board in the same manner as when a cover is added. The water droplets may cause a short circuit between adjacent external connection terminals.

  The object of the present invention is to prevent adjacent external connection terminals of a circuit board from being short-circuited by a connection terminal of an external device, and at the same time, reliably short-circuiting by water droplets adhering to the external connection terminal. An object of the present invention is to provide a highly reliable battery pack that can be prevented. An object of the present invention is to provide a battery pack in which a projection for preventing a short circuit is integrally formed in the process of molding a resin mold, whereby the projection and the circuit board can be firmly integrated to improve the structural strength of the projection, and the projection and the circuit. An object of the present invention is to provide a battery pack that reliably maintains a close contact with a substrate and has no room for a short circuit due to water droplets adhering to an external connection terminal, and thus has excellent reliability and durability. An object of the present invention is to provide a battery pack in which the outer surface of a circuit board is covered with a cover, the cover and the circuit board can be firmly integrated, and the close contact state between the cover and the circuit board is reliably maintained, and the external connection terminal An object of the present invention is to provide a battery pack having excellent reliability and durability without causing a short circuit due to water droplets attached to the surface.

  The battery pack 1 of the present invention includes a flat rectangular unit cell 2, a circuit board 5 disposed on the upper surface of the unit cell 2, and a resin mold 7 for integrating the unit cell 2 and the circuit board 5. On the upper surface of the circuit board 5, a plurality of external connection terminals 9 are juxtaposed in a state of being exposed to the outer surface through the openings 33 of the resin mold 7. A rough surface processed portion 35 is formed on the substrate surface between the two. A protrusion 34 that prevents a short circuit between adjacent external connection terminals 9 is formed integrally with the resin mold 7 so as to protrude from the upper surface of the circuit board 9. Thus, the projection 34 and the circuit board 9 are integrated through the joint portion 36 that enters the rough surface processed portion 35 in the process of molding the resin mold 7.

  Specifically, the upper surface of the circuit board 5 excluding the external connection terminals 9 is covered with the coating layer 10, and the coating layer 10 between the adjacent external connection terminals 9 is irradiated with laser light, so that the roughened surface processing portion 35. Are formed in an uneven shape.

  Another battery pack 1 of the present invention includes a flat rectangular unit cell 2, a circuit board 5 disposed on the upper surface of the unit cell 2, and a resin mold 7 for integrating the unit cell 2 and the circuit board 5. . On the upper surface of the circuit board 5, a plurality of external connection terminals 9 are arranged side by side so as to be exposed to the outer surface through the openings 33 of the resin mold 7. A protrusion 34 that prevents a short circuit between adjacent external connection terminals 9 is formed integrally with the resin mold 7 so as to protrude from the upper surface of the circuit board 5. Thus, a resin passage 41 that allows the molten resin to enter in the process of molding the resin mold 7 is formed on the surface of the circuit board 5 facing the protrusion 34.

  The resin passage 41 can be formed by at least one of a through hole provided in the circuit board 5 facing the protrusion 34 and a notch provided in the front and rear peripheral edges of the circuit board 5 facing the protrusion 34. . Of course, the resin passage 41 may be configured by using both the through hole and the notch.

  Another battery pack according to the present invention includes a flat rectangular unit cell 2, a circuit board 5 disposed on the upper surface of the unit cell 2, a cover 45 covering the upper surface of the circuit board 5, the unit cell 2, and the circuit board 5. And the resin mold 7 for integrating the cover 45. A plurality of external connection terminals 9 are juxtaposed on the upper surface of the circuit board 5 so as to be exposed to the outer surface of the cover 45 through the opening 48 of the cover 45. A protrusion 49 that prevents a short circuit between adjacent external connection terminals 9 is formed integrally with the cover 45 so as to protrude from the upper surface of the cover 45. A recess 50 that opens downward is formed in the inner surface of the protrusion 49. A resin passage 41 that allows the molten resin to enter in the process of forming the resin mold 7 is formed on the substrate surface of the circuit board 5 facing the recess 50. Thus, an inner protrusion 51 integrated with the resin mold 7 is formed in the recess 50, and the protrusion 49 and the circuit board 5 are integrally bonded via the inner protrusion 51.

  The resin passage 41 is formed by at least one of a through hole provided in the substrate surface of the circuit board 5 facing the recess 50 and a notch provided in the front and rear peripheral edges of the circuit board 5 facing the recess 50. be able to. The resin passage 41 may be configured by using both the through hole and the notch.

  In the present invention, since the projection 34 for preventing short circuit is formed integrally with the resin mold 7 between the adjacent external connection terminals 9 and 9 of the circuit board 5, for example, by the connection terminal of the bent external device It is possible to reliably prevent the adjacent external connection terminals 9 and 9 of the circuit board 5 from being short-circuited by receiving the projection 34. Further, the roughened portion 35 is formed on the substrate surface between the adjacent external connection terminals 9, and the projection 34 is formed by the joint portion 36 that enters the roughened portion 35 in the process of forming the resin mold 7. Since it is firmly bonded to the substrate 5, it is possible to reliably prevent the protrusion 34 that has received an external force from floating away from the circuit substrate 5 or peeling off from the circuit substrate 5.

  Therefore, according to the battery pack 1 of the present invention, the connection terminal of the external device can be received by the protrusion 34 and the adjacent connection terminals 9 and 9 can be reliably prevented from being short-circuited by the previous connection terminal. Furthermore, it is possible to prevent the protrusions 34 from floating away from the circuit board 5 and reliably prevent the adjacent external connection terminals 9 and 9 from being short-circuited by water droplets adhering to the external connection terminals 9. As a whole, a battery pack with excellent reliability can be obtained. Further, since the protrusion 34 is formed integrally with the resin mold 7 in the process of forming the resin mold 7, the overall cost of the battery pack 1 is reduced as compared with the case where the protrusion 34 is formed of a member different from the resin mold 7. can do.

  When the coating layer 10 covering the upper surface of the circuit board 5 is irradiated with laser light to form the roughened surface portion 35 in an uneven shape, the roughened surface processed portion 35 is precisely and uniformly applied to all the circuit boards 5. Since it can be formed, the projection 34 and the circuit board 5 can be reliably and firmly integrated via the joint portion 36 that binds the rough surface processed portion 35. In addition, even when the interval between the adjacent terminals for external connection 9 is small, the rough surface processed portion 35 can be formed by reliably performing the rough surface processing with a laser beam capable of fine processing.

  In another battery pack 1 of the present invention, a short-circuit preventing projection 34 is integrated with the resin mold 7 between the adjacent external connection terminals 9 and 9 of the circuit board 5 in the same manner as the battery pack 1 described above. Therefore, it is possible to reliably prevent the adjacent external connection terminals 9 and 9 on the circuit board 5 from being short-circuited by the connection terminals of the external device that has been bent, for example, by the protrusion 34. Further, since the protrusion 34 and the resin mold portion on the lower surface side of the circuit board 5 are made continuous through the resin passage 41 formed on the substrate surface of the circuit board 5 facing the protrusion 34, the protrusion 34 is connected to the circuit board 5. It can be firmly integrated, and the protrusions 34 can be well prevented from floating away from the circuit board 5 or peeling off. Further, since the protrusions 34 are prevented from floating away from the circuit board 5 and the adjacent external connection terminals 9 can be surely separated and separated by the protrusions 34, they are adjacent to each other by water droplets attached to the external connection terminals 9. It is possible to reliably prevent the external connection terminals 9 and 9 from being short-circuited, and a battery pack having excellent reliability as a whole can be obtained.

  When the resin passage 41 is formed as a through hole in the substrate surface of the circuit board 5 facing the protrusion 34, the resin passage 41 is formed at the closest position directly below the protrusion 34, so that the protrusion 34 is formed. The molten resin can smoothly flow into the space through the through-hole, and the molten resin can flow into the narrow molding space sandwiched between the upper surface of the circuit board 5 and the molding die facing the upper surface of the substrate. Thus, the resin mold 7 including the protrusions 34 can be reliably formed without accompanying a short shot. In the case where the resin passage 41 is formed as a notch provided in the peripheral portion of the circuit board 5 facing the protrusion 34, the resin passage 41 is formed at a position facing the front and rear portions of the lower surface of the protrusion 34. As in the case of the resin passage 41, the molten resin can smoothly flow into the molding space for forming the protrusion 34 through the notch. In addition, by forming resin passages 41 made of notches in the front and rear peripheral edges of the circuit board 5, the resin flows into a narrow molding space sandwiched between the upper surface of the circuit board 5 and a molding die facing the upper surface of the circuit board. Can be reliably performed through the notch. Even if the narrow molding space is divided up and down by the circuit board 5, the molten resin is allowed to flow in through the notches provided in the front and rear peripheral edge portions, without causing a short shot, and the protrusion. The resin mold 7 including 34 can be reliably formed.

  In another battery pack 1 of the present invention, a projection 45 for preventing a short circuit is provided on a cover 45 that covers the upper surface of the circuit board 5, and the cover 45, the circuit board 5, and the unit cell 2 are integrated by a resin mold 7. Therefore, for example, it is possible to reliably prevent the adjacent external connection terminals 9 and 9 of the circuit board 5 from being short-circuited by the bent connection terminals of the external device by receiving the protrusion 49. Further, since the material for forming the cover 45 can be freely selected, for example, by forming the cover 45 with a hard and tough resin material, the mechanical strength of the protrusions 49 can be remarkably improved and the durability of the battery pack 1 is remarkably improved. The reliability of the battery pack 1 can be improved accordingly.

  In addition, a recess 50 is provided on the inner surface of the protrusion 49, and a resin passage 41 is formed on the substrate surface of the circuit board 5 facing the recess 50, thereby forming an inner protrusion 51 integral with the resin mold 7 in the recess 50. Thus, since the protrusion 49 and the circuit board 5 are integrally joined via the inner protrusion 51, the cover 45 including the protrusion 49 can be firmly integrated with the resin mold 7 together with the circuit board 5. It can be well prevented from floating or peeling off. Further, since the adjacent external connection terminals 9 on the circuit board 5 can be reliably separated and separated by the inner protrusions 51, the adjacent external connection terminals 9, 9 are separated by water droplets adhering to the external connection terminals 9. It is possible to surely prevent short-circuiting, thereby further improving the reliability and durability of the battery pack.

  In the battery pack 1 provided with the cover 45 described above, when the resin passage 41 is formed as a through hole in the substrate surface of the circuit board 5 facing the recess 50, the recess 50 has the same structure as the battery pack described above. Since the resin passage 41 is formed at the closest position directly below, the molten resin can smoothly flow into the recess 50 through the through-hole, and the resin mold 7 including the inner protrusion 51 can be securely attached without a short shot. Can be formed. Further, when the resin passage 41 is formed as a notch provided in the front and rear peripheral edge portions of the circuit board 5 facing the recess 50, the resin passage 41 is formed at a position facing the front and rear portions of the lower surface of the recess 50. As in the case of the resin passage 41 through the through hole, the molten resin can smoothly flow into the recess 50 through the notch. In addition, by forming resin passages 41 made of notches in the front and rear peripheral edges of the circuit board 5, the resin can surely flow into the narrow molding space sandwiched between the upper surface of the circuit board 5 and the cover 45 through the notches. The cover 45 can be firmly integrated with the resin substrate 7 together with the circuit board 5.

First Embodiment FIGS. 1 to 4 show a first embodiment of a battery pack according to the present invention. 2 and 3, the battery pack 1 includes a unit cell 2, a protection element 3 including a temperature fuse (PTC), a circuit board 5 disposed on the top surface of the unit cell 2 and mounted with a protection circuit, The battery 2, the protection element 3, and the circuit board 5 are configured by a resin mold 7 that integrates the three components.

  The unit cell 2 is configured as a secondary battery such as a lithium ion battery that can be charged and discharged, and as shown in FIGS. 2 and 3, the front-rear thickness dimension is smaller than the vertical height dimension and the horizontal width dimension. It is formed in a flat rectangular shape. The circuit board 5 is composed of a multilayer board made of glass epoxy resin, and three rectangular external connection terminals 9 are arranged in parallel on the upper surface of the circuit board 5 at predetermined intervals in the left-right direction. As shown in FIG. 3, the upper surface of the circuit board 5 is covered with an insulating coating layer 10 except for the three external connection terminals 9. The coating layer 10 is formed of an epoxy resin layer having a thickness dimension of several μm. Electronic parts constituting a protection circuit are mounted on the lower surface of the circuit board 5, and the outer surface thereof is protected by the resin mold 6.

The unit cell 2 is configured such that an electrode body and an electrolytic solution are accommodated in an outer can 12 having an upper surface opened, and the upper surface opening is closed with a sealing plate 13. The outer can 12 is formed by deep drawing a plate material made of aluminum or an alloy thereof, and the sealing plate 13 is formed by punching a plate material such as an aluminum alloy. The electrode body is formed by spirally winding a positive electrode sheet using LiCoO ₂ as a positive electrode active material and a negative electrode sheet using graphite as a negative electrode active material with a synthetic resin separator interposed therebetween, and the whole is flat. It is crushed into a shape. The sealing plate 13 is seam welded to the periphery of the opening of the outer can 12 by laser welding.

  As shown in FIG. 3, a negative electrode terminal 17 is fixed to the center of the sealing plate 13 in the left-right direction via an insulating packing 16. The negative electrode terminal 17 is electrically connected to the negative electrode of the electrode body in the outer can 12, and the outer can 12 and the sealing plate 13 are electrically connected to the positive electrode of the electrode body in the outer can 12. A cleavage vent 19 is formed on one end side (left side in FIG. 2) of the right and left sides of the sealing plate 13, and a liquid injection hole 20 for injecting a nonaqueous electrolyte into the unit cell 2 is formed on the other end side. It is. The cleavage vent 19 is cleaved to release the battery internal pressure when the battery internal pressure rises abnormally. The liquid injection hole 20 is filled with a sealing plug 21 after injecting an electrolytic solution, and sealed by a laser welding method.

  The above-described components are connected as follows and then fixed integrally by the resin mold 7. First, in a state where the insulating plate 24 is disposed on the upper surface of the sealing plate 13, the lead plate 25 is fixed to the upper surface of the negative electrode terminal 17 by spot welding, and similarly, the clad plate 26 is fixed to the sealing plate 13 by spot welding. In parallel, the plate-like positive electrode lead 27 and the negative electrode lead 28 are respectively fixed by soldering to the positive electrode end 5a and the negative electrode end 5b of the circuit board 5 whose upper and lower surfaces are inverted. Next, one connection terminal of the protection element 3 is connected and fixed to the lead plate 25 by spot welding, and the other connection terminal is connected and fixed to the negative electrode lead 28 by spot welding. Similarly, the positive electrode lead 27 is connected to the clad plate 26 by spot welding. Thereby, the negative electrode terminal 17 and the negative electrode end 5b of the circuit board 5 are connected to each other through the lead plate 25 and the protective element 3 via the negative electrode lead 28, and the sealing plate 13 and the positive electrode end 5a of the circuit board 5 are clad. The plate 26 and the positive electrode lead 27 are connected.

  In the above state, after the spacer 31 made of an insulating plastic material is disposed on the upper side of the lead plate 25, the circuit board 5 is reversed and the positive electrode lead 27 and the negative electrode lead 28 are bent into a U-shape. As shown, the resin mold 6 on the lower surface of the circuit board 5 is tightly bonded to the spacer 31. As a result, an intermediate assembly in which the three elements of the unit cell 2, the protection element 3, and the circuit board 5 are integrally connected is formed.

  The resin mold 7 is formed by performing injection molding using, for example, a polyamide-based synthetic resin as a raw material in a state where the intermediate assembly is loaded in a molding die, and the unit cell 2, the protection element 3, and the circuit board are formed. 5 is integrated by the resin mold 7. The resin mold 7 is formed so as to simultaneously cover the upper surface of the circuit board 5 from the upper peripheral surface of the unit cell 2 and fill the entire space between the circuit board 5 and the unit cell 2. As shown in FIG. 1, three openings 33 corresponding to the respective external connection terminals 9 of the circuit board 5 are formed in a portion of the resin mold 7 that covers the upper surface side of the circuit board 5. Two trapezoidal protrusions 34 are formed on the frame portion that divides the adjacent openings 33 so as to protrude upward.

  As described above, the protrusion 34 formed integrally with the resin mold 7 is firmly bonded to the circuit board 5 to reliably prevent the protrusion 34 receiving the external force from floating away from the circuit board 5. Then, the roughened portion 35 is formed in an uneven shape by irradiating the coating layer 10 on the substrate surface between the adjacent external connection terminals 9, that is, the substrate surface of the circuit substrate 5 facing the protrusion 34. ing. As shown in FIGS. 3 and 4, the rough surface processed portion 35 is formed in, for example, a lattice pattern, and the depth thereof is necessary to prevent the printed wiring pattern of the circuit board 5 from being destroyed. It is carefully formed so as not to exceed the thickness. When the projections 34 are formed, a part of the molten resin bites into the rough surface processed portion 35 as shown in FIG. 4 to form a joint portion 36, and the projection 34 is securely fixed to the circuit board 5. In FIG. 2, reference numeral 38 denotes a bottom cover that is attached and fixed to the lower surface of the unit cell 2 with a double-sided tape, and reference numeral 39 denotes a label that is attached to the outer peripheral surface of the unit cell 2.

  According to the battery pack configured as described above, since each external connection terminal 9 is exposed to the outer surface of the battery pack 1 through the opening 33, each external connection terminal 9 is provided with a connection terminal of an external device. By making it contact, input / output of the charging / discharging current to the unit cell 2 can be performed. Further, since the adjacent external connection terminals 9 and 9 are separated by the projection 34, even if the connection terminal of the external device is bent in the left-right direction, for example, the connection terminal of the external device is received by the projection 34 and bent. Therefore, it is possible to reliably prevent the adjacent external connection terminals 9 and 9 from being short-circuited by the connection terminals. Further, since the projection 34 and the circuit board 5 are integrated at the joint portion 36 and the adjacent external connection terminals 9 and 9 are separated by the joint portion 36, the projection 34 that has received an external force can be lifted away from the circuit board 5. Further, it is possible to reliably prevent water droplets adhering to the external connection terminal 9 from permeating into the adjacent external connection terminal 9 side and short-circuiting the terminals 9 and 9.

  The rough surface processed portion 35 does not need to be formed as a lattice pattern, and can be formed in an arbitrary pattern. Further, the rough surface processing portion 35 can be formed by shot blasting in addition to being formed by laser light, or can be formed by scratching the coating layer 10 with a file or the like. Further, the rough surface processed portion 35 can be formed by bonding and fixing a particulate plastic piece or glass piece. The cross-sectional shape of the protrusion 34 does not need to be trapezoidal, and can be formed in a square or semicircular shape.

Second Embodiment FIGS. 5 to 7 show a second embodiment of the battery pack according to the present invention. There, as in the first embodiment, the short-circuit preventing protrusion 34 is integrally formed in the process of forming the resin mold 7, but the protrusion 34 and the circuit board 5 are more firmly integrated to form the structure of the protrusion 34. The difference from the first embodiment is that the strength is improved and the contact state between the protrusion 34 and the circuit board 5 is reliably maintained.

  Specifically, as shown in FIG. 6, the resin passage 41 is formed on the substrate surface of the circuit board 5 facing the projection 34, and the resin mass filling the resin passage 41 in the process of molding the resin mold 7, the projection 34 and the circuit board 5 are integrated. The resin passage 41 includes a pair of front and rear through holes formed on the circuit board surface of the circuit board 5 corresponding to the protrusions 34. In this embodiment, the resin mold 6 of the circuit board 5 is formed for each electronic component constituting the protection circuit. Therefore, the molten resin used to form the resin mold 7 is the same as that of the electronic component constituting the protection circuit. It is possible to flow into the molding space for the protrusion 34 through the resin passage 41 from the gap therebetween. Of course, the previous molten resin can also flow into the molding space for the protrusions 34 from the side of the mold layer covering the upper surface of the circuit board 5.

  As described above, when the resin mold portion located on the lower side of the circuit board 5 and the resin portion forming the protrusions 34 are continued by the resin passage 41 formed of the through holes, the molded circuit board 5 is Since the protrusion 34 and the resin mold part on the lower side of the circuit board 5 are sandwiched, the protrusion 34 and the circuit board 5 can be more firmly integrated. Further, since the diameter dimension of each through-hole constituting the resin passage 41 is set smaller than the left and right widths of the bottom surface of the projection 34, the projection 34 is formed on the circuit board as long as the resin block filling the resin passage 41 is not damaged. Thus, the structural strength of the protrusion 34 can be improved by reliably preventing it from being lifted off or peeled off. Further, by providing the resin passage 41, the flow of the molten resin toward the molding space where the protrusions 34 are formed can be smoothed, and the protrusions 34 can be reliably and rapidly formed. Since the other points are the same as those of the first embodiment, description thereof is omitted.

(Modification of Second Embodiment) FIGS. 8 and 9 show a modification of the resin passage 41. Here, instead of the through hole of the second embodiment, the resin passage 41 is formed by notches provided in the front and rear peripheral edges of the circuit board 5 facing the protrusion 34. As shown in FIG. 8, the notch is formed in a U-shaped notch so as to face the substrate surface between the adjacent external connection terminals 9, 9, and the interval between the notches is the front and back of the front and rear end faces of the protrusion 34. It is set shorter than the interval. Therefore, in the process of molding the resin mold 7, the molten resin smoothly flows through the resin passage (notch) 41 to the molding space where the protrusion 34 is formed. Also in this modified example, the protrusion 34 and the circuit board 5 are more firmly integrated to improve the structural strength of the protrusion 34, and the contact state between the protrusion 34 and the circuit board 5 can be reliably maintained. Since the other points are the same as those of the first embodiment, description thereof is omitted.

  In the second embodiment and the modification thereof, the resin passage 41 is configured by a through hole or a notch, but the resin passage 41 may be configured by using both the through hole and the notch. The shape of the notch constituting the resin passage 41 can be formed as one notch having a trapezoidal shape that is long to the left and right, as indicated by an imaginary line in FIG. Of course, three or more notches can be formed in the front and rear edges of the circuit board 5 to form the resin passage 41.

(Third Embodiment) FIGS. 10 to 14 show a third embodiment of the battery pack according to the present invention. 11 and 12, the unit cell 2, the protective element 3, the circuit board 5 disposed on the upper surface of the unit cell 2, the cover 45 covering the upper surface of the circuit board 5, and these members 2 -The battery pack 1 is comprised with the resin mold 7 which unifies 3, 5, 45.

  As shown in FIGS. 12 and 13, the cover 45 is made of an injection-molded product made of polycarbonate integrally including an upper wall 46 and a peripheral side wall 47 extending downward from the periphery of the upper wall 46. Three openings 48 corresponding to the respective external connection terminals 9 of the circuit board 5 are formed on the upper wall 46, and two protrusions having a trapezoidal cross section are formed on a frame portion that divides the adjacent openings 48. 49 is formed so as to protrude upward. On the inner surface of each projection 49 of the cover 45, as shown in FIG. 13 and FIG.

  In this embodiment, as in the second embodiment, a resin passage 41 made of a through hole is formed on the substrate surface of the circuit board 5 facing the recess 50, and in the process of molding the resin mold 7, the molten resin passes through the resin passage 41. It was made to be able to flow into the recess 50. When the resin that has flowed into the recess 50 is solidified, an inner protrusion 51 integral with the resin mold 7 is formed, and the protrusion 49 and the circuit board 5 are integrally bonded by the inner protrusion 51, and at the same time, the cover 45 and the resin mold are joined together. 7 is integrated through the inner protrusion 51. Each through hole is formed in the front and back pair on the substrate surface of the circuit board 5. As shown in FIG. 10, in this embodiment, a part of the molten resin flows into the gap between the circuit board 5 and the cover 45 on both sides of the previous three openings 48, and both 5 · 45. Are integrated. This inflow resin portion is indicated by reference numeral 52.

  As described above, in the battery pack 1 to which the cover 45 is added, each external connection terminal 9 is exposed to the outer surface through the opening 33 of the resin mold 7 and the opening 48 of the cover 45. The projection 49 provided between the adjacent openings 48 and 48 exhibits the same function as the projection 34 for preventing a short circuit in the first and second embodiments. In this embodiment, after assembling the intermediate assembly described in the first embodiment, a cover 45 is mounted on the upper surface of the circuit board 5 to obtain an intermediate assembly. Thereafter, as in the first embodiment, the intermediate assembly is loaded into a molding die, and the resin mold 7 is injection-molded, whereby the unit cell 2, the protection element 3, the circuit board 5, and the cover 45 are replaced with the resin mold 7. The battery pack 1 integrated with can be obtained.

  According to the battery pack 1 described above, in the process of forming the resin mold 7, the molten resin fills the gap between the adjacent external connection terminals 9 and 9 and the protrusion 49 of the cover 45 to form the inner protrusion 51. To do. Therefore, it is possible to reliably prevent the cover 45 from being lifted off from the circuit board 5, and water droplets adhering to one of the external connection terminals 9 are blocked by the inner protrusions 51 so that the adjacent external connection terminals 9, 9 It is possible to reliably prevent a short circuit through the. Further, the cover 45 having a high strength of the material itself can surely prevent the protrusions 49 from being partially damaged. Since the other points are the same as those of the first and second embodiments, the description thereof is omitted.

(Modification of 3rd Example) FIG.15 and FIG.16 shows the modification of the resin channel | path 41 in 3rd Example. In this case, as in the modification of the second embodiment, the resin passage 41 is formed by notches provided in the front and rear peripheral edges of the circuit board 5 facing the protrusion 49 instead of the through hole of the third embodiment. As shown in FIG. 15, the notch is formed in a U-shape so as to face the substrate surface between the adjacent external connection terminals 9. In the process of molding the resin mold 7, the molten resin smoothly flows through the resin passage (notch) 41 to the molding space where the protrusion 34 is formed. Also in this modified example, the protrusion 34 and the circuit board 5 are more firmly integrated to improve the structural strength of the protrusion 34, and the contact state between the protrusion 34 and the circuit board 5 can be reliably maintained. Since the other points are the same as those of the previous embodiments, the description thereof is omitted.

  In the third embodiment and the modification thereof, the resin passage 41 is configured by a through hole or a notch, but the resin passage 41 may be configured by using both the through hole and the notch. The shape of the notch constituting the resin passage 41 can be formed as one notch having a trapezoidal shape that is long on the left and right, as described in FIG. 8 of the second embodiment. Further, the resin passage 41 can be formed by forming three or more notches on the front and rear edges of the circuit board 5.

It is a longitudinal cross-sectional view of the battery pack which concerns on 1st Example. It is a front view of a battery pack. It is a disassembled perspective view of a battery pack. It is sectional drawing which shows the binding structure of a circuit board and protrusion. It is a longitudinal cross-sectional view of the battery pack which concerns on 2nd Example. It is a perspective view of a circuit board. It is the sectional view on the AA line in FIG. It is a perspective view which shows the modification of the circuit board which concerns on 2nd Example. It is sectional drawing of the part corresponded in FIG. It is a longitudinal cross-sectional view of the battery pack which concerns on 3rd Example. It is a front view of a battery pack. It is a disassembled perspective view of a battery pack. It is a perspective view which shows the relationship between a cover and a circuit board. It is the BB sectional drawing in FIG. It is a perspective view which shows the modification of the circuit board which concerns on 3rd Example. It is sectional drawing of the part corresponded in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery pack 2 Unit cell 5 Circuit board 7 Resin mold 9 External connection terminal 10 Coating layer 34 Protrusion 41 Resin passage 45 Cover 49 Protrusion 50 Recess 51 Inward protrusion

Claims (6)

A battery pack including a flat rectangular unit cell, a circuit board disposed on an upper surface of the unit cell, and a resin mold that integrates the unit cell and the circuit board,
On the upper surface of the circuit board, a plurality of external connection terminals are juxtaposed in a state of being exposed to the outer surface through the openings of the resin mold, and on the substrate surface between the adjacent external connection terminals. A rough surface processed part is formed,
A protrusion that prevents a short circuit between adjacent external connection terminals is formed integrally with the resin mold in a state of protruding on the upper surface of the circuit board,
The battery pack, wherein the protrusion and the circuit board are integrated through a joint portion that enters the rough surface processed portion in the process of forming the resin mold. The upper surface of the circuit board excluding the external connection terminals is covered with a coating layer,
The battery pack according to claim 1, wherein the roughened portion is formed in an uneven shape by irradiating a coating layer between adjacent external connection terminals with a laser beam. A battery pack including a flat rectangular unit cell, a circuit board disposed on an upper surface of the unit cell, and a resin mold that integrates the unit cell and the circuit board,
On the upper surface of the circuit board, a plurality of external connection terminals are juxtaposed in a state exposed to the outer surface through the opening of the resin mold,
A protrusion that prevents a short circuit between adjacent external connection terminals is formed integrally with the resin mold in a state of protruding on the upper surface of the circuit board,
A battery pack, wherein a resin passage that allows a molten resin to enter in a process of forming the resin mold is formed on a surface of the circuit board facing the protrusion.   The resin passage is formed by at least one of a through hole provided in the circuit board surface of the circuit board facing the protrusion and a notch provided in a front and rear peripheral edge of the circuit board facing the protrusion. The battery pack according to claim 3. A flat rectangular unit cell; a circuit board disposed on an upper surface of the unit cell; a cover covering the upper surface of the circuit board; and a resin mold that integrates the unit cell, the circuit board, and the cover. A battery pack,
On the upper surface of the circuit board, a plurality of external connection terminals are juxtaposed in a state of being exposed to the outer surface of the cover through the opening of the cover,
A protrusion that prevents a short circuit between adjacent external connection terminals is formed integrally with the cover in a state of protruding from the upper surface of the cover, and a recess opening downward is formed on the inner surface of the protrusion,
A resin passage that allows the molten resin to enter in the process of forming the resin mold is formed on the substrate surface of the circuit board facing the recess,
A battery pack in which an inner protrusion integral with the resin mold is formed in the recess, and the protrusion and the circuit board are integrally joined via the inner protrusion.   The resin passage is formed by at least one of a through hole provided in a circuit board surface of the circuit board facing the concave part and a notch provided in a front and rear peripheral edge part of the circuit board facing the concave part. The battery pack according to claim 5.

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