Circuit board, battery pack, and method for manufacturing circuit board

Abstract

A circuit board (100) according to an embodiment of the present invention comprises: a wiring board (10) having a main surface (11); a plurality of electronic components (20) mounted on the main surface (11); and a continuous resin portion (30) provided in contact with only a portion of the main surface (11) and covering the plurality of electronic components (20). The main surface (11) of the wiring board (10) includes a continuous covered region (S1) which is covered by the resin portion (30), and an uncovered region (S2) which is not covered by the resin portion (30). The resin portion (30) has an end portion (33) in contact with a region of the main surface (11) on which the plurality of electronic components (20) are not mounted.

Description

Circuit board, battery pack, and method for manufacturing circuit board

[0001] The present technology relates to a circuit board, a battery pack, and a method for manufacturing a circuit board.

[0002] The battery pack is provided with a circuit board that controls the charging and discharging of the multiple batteries built into the battery pack (see, for example, Patent Document 1).

[0003] International Publication No. WO2023 / 176124

[0004] Electronic components such as ICs mounted on circuit boards are sometimes coated with waterproof resin to prevent deterioration due to moisture in the ambient air or water. Such waterproof resins are formed, for example, during the manufacturing process by sandwiching the circuit board between molds, plasticizing solid resin pellets in a melting furnace to form a liquid, injecting the liquid resin into the mold through a gate, and cooling and hardening the resin in the mold. When waterproof resins are formed by such mold molding, burrs and voids may occur in the waterproof resin. If burrs or voids occur in the waterproof resin, and electronic components are placed in the locations where the burrs or voids occur, the burrs or voids may reduce the waterproofing properties. Provided are a circuit board, a battery pack, and a method for manufacturing a circuit board that can suppress the reduction in waterproofing properties due to burrs and voids.

[0005] A circuit board according to a first aspect of the present technology includes a wiring board having a first main surface, a plurality of electronic components mounted on the first main surface, and a continuous resin portion provided in contact with only a portion of the first main surface and covering the plurality of electronic components. The first main surface includes a continuous covered region covered by the resin portion and an uncovered region not covered by the resin portion. The resin portion has an end portion that contacts the unmounted region of the plurality of electronic components on the first main surface.

[0006] A battery pack according to a second aspect of the present technology includes a circuit board that controls charging and discharging of one or more batteries. The circuit board includes a wiring board having a first main surface, a plurality of electronic components mounted on the first main surface, and a continuous resin portion that is provided in contact with only a portion of the first main surface and covers the plurality of electronic components. The first main surface includes a continuous covered region that is covered by the resin portion and a continuous uncovered region that is not covered by the resin portion. The resin portion has an end portion that contacts the region of the first main surface where the plurality of electronic components are not mounted.

[0007] A method for manufacturing a circuit board according to a third aspect of the present technology is a method for manufacturing a circuit board including a wiring board having a first main surface, a plurality of electronic components mounted on the first main surface, and a continuous resin portion provided in contact with only a portion of the first main surface and covering the plurality of electronic components. This manufacturing method includes the following three steps: (1) placing a mold having a continuous recess in a portion of the first main surface facing the continuous coverage target region that is part of the first main surface and includes the plurality of electronic components, on the wiring board having the plurality of electronic components mounted on the first main surface, and pouring uncured resin into the recess; (2) cooling and solidifying the uncured resin poured into the recess within the mold to form the resin portion; and (3) removing the mold from the wiring board. Here, the recess in the mold has an end portion at a portion of the first main surface facing the non-mounted region of the plurality of electronic components when the mold is placed on the wiring board.

[0008] In a circuit board according to a first aspect of the present technology and a battery pack according to a second aspect of the present technology, a continuous resin portion covering a plurality of electronic components has an end portion of the first main surface of the wiring board that contacts a non-mounting area of ​​the plurality of electronic components. This allows, for example, during the manufacturing process of the circuit board, when the wiring board is sandwiched between molds and uncured resin, the raw material for the resin portion, is poured through the mold gate, to collect air bubbles that form in the uncured resin at a location corresponding to the end of the resin portion. Furthermore, during the process of pouring the uncured resin, the raw material for the resin portion, through the mold gate, pressure on the uncured resin tends to be high at a location corresponding to the end of the resin portion. Therefore, burrs that form during the process of curing the uncured resin are likely to occur at a location corresponding to the end of the resin portion. This makes it possible to limit the locations where air bubbles become voids as the resin hardens and the locations where burrs occur to locations facing the non-mounting area of ​​the electronic components. Therefore, since electronic components are not placed in the locations where burrs or voids occur, it is possible to suppress a decrease in waterproofness due to burrs or voids.

[0009] In a circuit board manufacturing method according to a third aspect of the present technology, a mold is used to form the resin portion. The mold has a recess having an edge at a portion of the first main surface of the wiring board that faces a non-mounted region of the plurality of electronic components when the mold is overlaid on the wiring board. This allows a mold having a continuous recess at a portion facing a continuous target region that is part of the first main surface and includes the plurality of electronic components to be overlaid on the wiring board with the plurality of electronic components actually mounted on the first main surface. When uncured resin is poured into the recess, air bubbles generated in the uncured resin can be collected at the edge of the recess. Furthermore, during the process of pouring the uncured resin, which is the raw material for the resin portion, from the gate of the mold, pressure on the uncured resin tends to be high at the edge of the recess. Therefore, burrs generated during the curing process of the uncured resin are likely to occur at the edge of the recess. This makes it possible to limit the areas where air bubbles become voids and burrs occur as the resin hardens to areas facing the non-mounted region of the electronic components. Therefore, since electronic components are not disposed in areas where burrs or voids have occurred, it is possible to suppress deterioration of waterproofing caused by burrs or voids.

[0010] FIG. 1 is a diagram illustrating an example of a planar configuration of a circuit board according to an embodiment of the present technology. FIG. 2 is a diagram illustrating an example of a planar configuration of the wiring board of FIG. 1. FIG. 3(A) is a diagram illustrating an example of a cross-sectional configuration of the circuit board of FIG. 1 taken along line A-A. FIG. 3(B) is a diagram illustrating an example of a planar configuration of the resin portion of FIG. 3(A). FIG. 4(A) is a diagram illustrating an example of a planar configuration of a lower mold. FIG. 4(B) is a diagram illustrating an example of a cross-sectional configuration of the lower mold of FIG. 4(A) taken along line A-A. FIG. 5(A) is a diagram illustrating an example of a planar configuration of an upper mold. FIG. 5(B) is a diagram illustrating an example of a cross-sectional configuration of the upper mold of FIG. 5(A) taken along line A-A. FIG. 5(C) is a diagram illustrating an example of a cross-sectional configuration of the upper mold of FIG. 5(A) taken along line B-B. FIG. 6 is a diagram illustrating an example of a manufacturing procedure for the circuit board of FIG. 1. FIG. 7(A) is a diagram illustrating a modified example of the cross-sectional configuration of the circuit board of FIG. 1 taken along line A-A. FIG. 7(B) is a diagram showing an example of the planar configuration of the resin portion of FIG. 7(A). FIG. 8(A) is a diagram showing a modified cross-sectional configuration of the circuit board of FIG. 1 taken along line A-A. FIG. 8(B) is a diagram showing an example of the planar configuration of the resin portion of FIG. 8(A). FIG. 9(A) is a diagram showing a modified cross-sectional configuration of the circuit board of FIG. 1 taken along line A-A. FIG. 9(B) is a diagram showing an example of the planar configuration of the resin portion of FIG. 9(A). FIG. 10 is a diagram showing a modified cross-sectional configuration of the circuit board of FIG. 1 taken along line A-A. FIG. 11 is a diagram showing an example of the cross-sectional configuration of an upper mold for forming the resin portion of FIG. 10. FIG. 12 is a diagram showing a modified planar configuration of the surface on the first main surface side of the circuit board of FIG. 1. FIG. 13 is a diagram showing an example of the planar configuration of the surface on the second main surface side of the circuit board of FIG. 12. FIG. 14 is a diagram showing an example of the side configuration of the circuit board of FIG. 12. FIG. 15 is a diagram showing an example of a cross-sectional configuration of the circuit board of FIGS. 12 and 13 taken along line A-A. FIG. 16(A) is a diagram showing a modified example of the planar configuration of the lower mold. FIG. 16(B) is a diagram showing an example of a cross-sectional configuration of the lower mold of FIG. 16(A) taken along line A-A. FIG. 17(A) is a diagram showing a modified example of the planar configuration of the upper mold. FIG. 17(B) is a diagram showing an example of a cross-sectional configuration of the upper mold of FIG. 17(A) taken along line A-A. FIG. 17(C) is a diagram showing an example of a cross-sectional configuration of the upper mold of FIG. 17(A) taken along line B-B. FIG. 18 is a diagram showing a modified example of the planar configuration of the surface on the first main surface side of the circuit board of FIG. 1. FIG. 19 is a diagram showing an example of a planar configuration of the surface on the second main surface side of the circuit board of FIG. 18.FIG. 20 is a diagram showing an example of the side configuration of the circuit board of FIG. 18. FIG. 21 is a diagram showing an example of the cross-sectional configuration of the circuit board of FIGS. 18 and 19 taken along line A-A. FIG. 22(A) is a diagram showing a modified planar configuration of the lower mold. FIG. 22(B) is a diagram showing an example of the cross-sectional configuration of the lower mold of FIG. 22(A) taken along line A-A. FIG. 23(A) is a diagram showing a modified planar configuration of the upper mold. FIG. 23(B) is a diagram showing an example of the cross-sectional configuration of the upper mold of FIG. 23(A) taken along line A-A. FIG. 23(C) is a diagram showing an example of the cross-sectional configuration of the upper mold of FIG. 23(A) taken along line B-B. FIG. 24 is a diagram showing a modified planar configuration of the surface of the first main surface of the circuit board of FIG. 1. FIG. 25 is a diagram showing an example of the planar configuration of the surface of the second main surface of the circuit board of FIG. 24. FIG. 26 is a diagram showing an example of the cross-sectional configuration of the circuit board of FIGS. 24 and 25 taken along line A-A. Fig. 27 is a perspective view showing an example of the configuration of a battery pack, Fig. 28 is a perspective view showing an example of the configuration of a battery module contained in the battery pack of Fig. 27, and Fig. 29 is an exploded perspective view showing an example of the configuration of the battery pack of Fig. 27.

[0011] Hereinafter, embodiments of the present technology will be described in detail with reference to the drawings.

[0012] (Embodiment) First, a circuit board 100 according to an embodiment of the present technology will be described. FIG. 1 illustrates an example of a planar configuration of the circuit board 100. For example, as illustrated in FIG. 1 , the circuit board 100 includes a wiring board 10 having a first main surface 11 and a plurality of electronic components 20 mounted on the first main surface 11. The plurality of electronic components 20 mounted on the first main surface 11 include, for example, at least one type of component selected from the group consisting of a microcontroller, an IC (integrated circuit), a fuse, a current-carrying bus bar, a resistor, and a capacitor. For example, at least one type of component selected from the group consisting of a microcontroller, an IC, a fuse, a current-carrying bus bar, a resistor, and a capacitor is mounted on the first main surface 11 as the plurality of electronic components 20. The wiring board 10 corresponds to a specific example of a "wiring board" according to an embodiment of the present technology. The plurality of electronic components 20 mounted on the first main surface 11 correspond to a specific example of a "plurality of electronic components" or a "plurality of first electronic components" according to an embodiment of the present technology.

[0013] The circuit board 100 further includes, for example, a resin portion 30 provided in contact with only a portion of the first main surface 11, rather than the entire first main surface 11, as shown in FIG. 1 . The resin portion 30 in contact with the first main surface 11 corresponds to a specific example of a "resin portion" or "first resin portion" according to an embodiment of the present technology. The resin portion 30 covers the multiple electronic components 20 and is continuous. The resin portion 30 is made of a waterproof resin material that can protect the multiple electronic components 20 from atmospheric moisture and submersion of the circuit board 100 in water. The resin portion 30 is made of, for example, at least one resin material selected from the group consisting of polyamide, polyester, and polyurethane.

[0014] The wiring board 10 is a plate-shaped component in which conductive metal is formed as wiring on an insulating substrate, and is a printed wiring board (PWB) in a state in which electronic components 20 are not attached. The wiring board 10 may be a plate-shaped component in which wiring is formed on the surface of a single insulating substrate, or a plate-shaped component in which wiring is formed on the surface and inside of a laminate in which multiple insulating substrates are stacked. As shown in FIG. 1 , the first main surface 11 of the wiring board 10 includes, for example, a continuous covered region S1 covered by a resin portion 30 and an uncovered region S2 not covered by the resin portion 30. As shown in FIG. 2 , the first main surface 11 of the wiring board 10 includes, for example, a mounting region S3 in which multiple electronic components 20 are mounted and an uncovered region S4 in which multiple electronic components 20 are not mounted. FIG. 2 illustrates an example of a planar configuration of the first main surface 11 of the wiring board 10. The covered region S1 corresponds to a specific example of a “covered region” according to an embodiment of the present technology. The uncovered area S2 corresponds to a specific example of an "uncovered area" according to an embodiment of the present technology. The non-mounting area S4 corresponds to a specific example of an "non-mounting area" according to an embodiment of the present technology.

[0015] The mounting region S3 is provided with a plurality of pad electrodes for electrically connecting the plurality of electronic components 20 to the wiring of the wiring substrate 10. The above-mentioned pad electrodes are not formed in the non-mounting region S4, and the surface of the insulating substrate or a thin film covering the surface of the insulating substrate is exposed. For example, as shown in FIG. 1 , the resin portion 30 extends from a gate portion 31 that contacts the edge of the wiring substrate 10 to an end portion 33 that contacts the non-mounting region S4.

[0016] The end 33 is disposed at a location spaced apart from the edge of the wiring substrate 10 and is surrounded on three sides by the uncoated region S2. The end 33 has, for example, a rectangular shape in a plan view. The end 33 has, for example, an area smaller than the area occupied by the largest electronic component 20 among the multiple electronic components 20 mounted on the wiring substrate 10. The end 33 has, for example, an area (1 mm or more × 1 mm or more) large enough to accommodate the largest air bubbles (e.g., bubbles with a diameter of approximately 1 mm) that may be generated during the manufacturing process described below. The end 33 is located at the farthest point along the contour of the resin portion 30 from the gate portion 31. The portion of the resin portion 30 between the gate portion 31 and the end 33 (intermediate portion 32) may have, for example, a strip-like shape extending from the gate portion 31 to the end 33, as shown in FIG. 1 , or a non-strip-like shape with varying widths depending on the location. 1, a portion of the intermediate portion 32 contacts the edge of the wiring substrate 10. The intermediate portion 32 may be disposed only at a location spaced apart from the edge of the wiring substrate 10.

[0017] The end portion 33 refers to a portion of the plurality of electronic components 20 covered by the intermediate portion 32 that is a predetermined distance dx away from the electronic component 20 that is closest to the end portion 33. The predetermined distance dx corresponds to the thickness of the resin portion 30 required to waterproof the electronic component 20. The predetermined distance dx is equal to the longest distance (e.g., d7 in FIG. 1 ) among the distances (e.g., d1 to d9 in FIG. 1 ) between the side surface of the resin portion 30 and the side surface of each electronic component 20 when the resin portion 30 is viewed in plan view.

[0018] FIG. 3A shows an example cross-sectional configuration of the circuit board 100 of FIG. 1 taken along line A-A. FIG. 3B shows an example planar configuration of the resin part 30 of FIG. 3A. The cross-sectional configuration of FIG. 3A corresponds to the cross-sectional configuration of FIG. 3B taken along line A-A. For example, as shown in FIG. 3A, the end part 33 has a portion (second part 33B) of the resin part 30 (intermediate part 32) that is thicker than the adjacent part 32A adjacent to the end part 33. Further, as shown in FIG. 3A, for example, the end part 33 has a shape in which the thickness of the end part 33 increases with increasing distance from the adjacent part 32A. The end part 33 has a shape in which the thickness of the end part 33 increases with increasing distance from the adjacent part 32A, at a portion (first part 33A) between the adjacent part 32A and the second part 33B. The resin part 30 is a resin mold formed by low-pressure molding using a metal mold, and has a three-dimensional shape corresponding to the shape of a recess 221 of an upper metal mold 220, which will be described later. Here, "low-pressure molding" refers to molding at a temperature of 90°C to 240°C under a pressure of 3 kgf / cm ２ ~50 kgf / cm ２ This refers to molding under the following conditions.

[0019] Next, a method for manufacturing the circuit board 100 will be described. First, the molds (lower mold 210, upper mold 220) used in the manufacturing process of the circuit board 100 will be described, and then a method for manufacturing the circuit board 100 using the molds (lower mold 210, upper mold 220) will be described.

[0020] Fig. 4(A) shows an example of a planar configuration of the lower mold 210. Fig. 4(B) shows an example of a cross-sectional configuration of the lower mold 210 of Fig. 4(A) taken along line A-A. Fig. 5(A) shows an example of a planar configuration of the upper mold 220. Fig. 5(B) shows an example of a cross-sectional configuration of the upper mold 220 of Fig. 5(A) taken along line A-A. Fig. 5(C) shows an example of a cross-sectional configuration of the upper mold 220 of Fig. 5(A) taken along line B-B.

[0021] The lower mold 210 has an accommodation portion 211 that accommodates the wiring substrate 10, as shown in Figures 4(A) and 4(B), for example. The upper mold 220 has a recess 221, as shown in Figures 5(A), 5(B), and 5(C), for example. The recess 221 is continuous with a portion of the first main surface 11 that faces a continuous coating target region that includes the plurality of electronic components 20 when the upper mold 220 is superimposed on the wiring substrate 10.

[0022] The recess 221 has a three-dimensional shape corresponding to the shape of the resin portion 30. A gate portion 222 is connected to one end of the recess 221. The gate portion 222 is a void that connects one end of the recess 221 to the outside and serves as an inlet for pouring uncured resin 300 (described below) into the upper mold 220. The other end of the recess 221 forms an end portion 223. The end portion 223 is provided at a location on the first main surface 11 that faces the non-mounting regions S4 of the multiple electronic components 20 when the upper mold 220 is superimposed on the wiring substrate 10. The end portion 223 is provided at a location along the contour of the recess 221 that is farthest from the gate portion 222. The portion of the recess 221 between the gate portion 222 and the end portion 223 may have a band-like shape extending from the gate portion 222 to the end portion 223, as shown in Figure 5 (A), or may have a non-band-like shape with a width that varies depending on the location.

[0023] 5(C), the end portion 223 has a portion (second portion 223B) in the recess 221 that is thicker than the thickness of an adjacent portion 224 adjacent to the end portion 223. Further, as shown in FIG. 5(C), the end portion 223 has a shape in which the thickness of the end portion 223 increases with increasing distance from the adjacent portion 224. The end portion 223 has a shape in which the thickness of the end portion 223 increases with increasing distance from the adjacent portion 224 at a portion (first portion 223A) between the adjacent portion 224 and the second portion 223B.

[0024] 6 shows an example of a manufacturing procedure for the circuit board 100. First, a wiring board 10 on which a plurality of electronic components 20 are mounted is prepared (step S101). Next, a lower mold 210 and an upper mold 220 are placed on the wiring board 10 (step S102). Next, uncured resin 300 is injected into the gate portion 222 of the upper mold 220, thereby flowing into the recess 221 through the gate portion 222 (step S103). The uncured resin 300 is the raw material of the resin portion 30 and is made of at least one thermoplastic resin selected from the group consisting of polyamide, polyester, and polyurethane.

[0025] As the uncured resin 300 flows into the recess 221, bubbles may be generated in the uncured resin 300 due to the three-dimensional structure of the electronic components 20 arranged in the recess 221. When bubbles are generated in the uncured resin 300, the bubbles move toward the end 223 and eventually accumulate at the end 223 (flow end). Furthermore, the pressure of the uncured resin 300 may become locally high at the end 223, which may cause the uncured resin 300 to leak from the end 223. As the uncured resin 300 flows into the recess 221, gas remaining in the recess 221 or gas generated in the recess 221 is discharged to the outside, for example, via a vent provided in the upper mold 220.

[0026] Next, the uncured resin 300 is cooled and solidified in the molds (lower mold 210, upper mold 220) (step S104). As a result, the resin part 30 is formed. At this time, air bubbles remaining in the end 223 become voids in the end 33. Furthermore, the uncured resin 300 leaking from the end 223 becomes burrs in the end 33. Finally, the molds (lower mold 210, upper mold 220) are removed from the wiring substrate 10. In this manner, the wiring substrate 100 is manufactured.

[0027] In the manufactured wiring board 100, voids and burrs are unlikely to occur in the resin part 30 in any locations other than the end part 33, but voids and burrs may occur in the end part 33. Since no electronic component 20 is present in the end part 33, the possibility that moisture in the atmosphere will reach the electronic component 20 due to the voids and burrs in the end part 33 is extremely low.

[0028] Next, the effects of the circuit board 100 will be described.

[0029] In this embodiment, the resin portion 33 has an end portion 33 abutting the non-mounting area S4. This allows voids and burrs that may occur in the resin portion 33 during the manufacturing process to be concentrated at the end portion 33. Because no electronic components 20 are present at the end portion 33, the possibility that moisture in the air will reach the electronic components 20 due to the voids and burrs at the end portion 33 is extremely low. Therefore, it is possible to suppress a decrease in waterproofing caused by burrs and voids.

[0030] In this embodiment, end 33 is disposed at a location spaced apart from the edge of wiring substrate 10 and is surrounded on three sides by uncoated region S2. This allows voids and burrs that may occur in resin portion 33 during the manufacturing process to be concentrated at end 33. Because no electronic components 20 are present at end 33, the possibility of atmospheric moisture reaching electronic components 20 due to voids and burrs at end 33 is extremely low. Therefore, it is possible to suppress a decrease in waterproofing caused by burrs and voids.

[0031] In this embodiment, the end 33 is provided at the farthest point along the contour of the resin part 30 from the gate part 31. This allows voids and burrs that may occur in the resin part 33 during the manufacturing process to be concentrated at the end 33. Because no electronic component 20 is present at the end 33, the possibility of moisture in the air reaching the electronic component 20 due to the voids and burrs at the end 33 is extremely low. Therefore, it is possible to suppress a decrease in waterproofing caused by burrs and voids.

[0032] In this embodiment, end 33 has a portion (second portion 33B) that is thicker than adjacent portion 32A. This allows uncured resin 300 to smoothly flow into the portion (second portion 223B) corresponding to second portion 33B during the manufacturing process, thereby concentrating voids and burrs that may occur in resin portion 33 at end 33. Because no electronic component 20 is present at end 33, the possibility of atmospheric moisture reaching electronic component 20 due to voids and burrs at end 33 is extremely low. Therefore, deterioration of waterproofing due to burrs and voids can be suppressed.

[0033] In this embodiment, the end 33 has a shape in which the thickness of the end 33 increases with increasing distance from the adjacent portion 32A. This allows the uncured resin 300 to smoothly flow into the portion corresponding to the second portion 33B (second portion 223B) during the manufacturing process, thereby concentrating voids and burrs that may occur in the resin portion 33 at the end 33. Because no electronic component 20 is present at the end 33, the possibility of atmospheric moisture reaching the electronic component 20 due to the voids and burrs at the end 33 is extremely low. Therefore, a decrease in waterproofing caused by burrs and voids can be suppressed.

[0034] Next, the effects of the manufacturing method of the circuit board 100 will be described.

[0035] In this embodiment, uncured resin 300 is poured into recesses 221 of an upper mold 220 that is superimposed on wiring substrate 10. When upper mold 220 is superimposed on wiring substrate 10, recesses 221 have edges 223 at locations on first main surface 11 that face non-mounting regions S4 of multiple electronic components 20. This allows air bubbles and leakage of uncured resin 300 that may occur during the manufacturing process to be concentrated at edges 223. As a result, voids and burrs that may occur in resin portion 33 can be concentrated at edges 33. Because electronic components 20 are not present at edges 33, the possibility of atmospheric moisture reaching electronic components 20 due to voids and burrs at edges 33 is extremely low. Therefore, a decrease in waterproofing due to burrs and voids can be suppressed.

[0036] In this embodiment, the end 223 is provided at the farthest point along the contour of the recess 221 from the gate portion 222. This allows air bubbles and leakage of uncured resin 300 that may occur during the manufacturing process to be concentrated at the end 223. As a result, voids and burrs that may occur in the resin portion 33 can be concentrated at the end 33. Because no electronic component 20 is present at the end 33, the possibility of moisture in the air reaching the electronic component 20 due to the voids and burrs at the end 33 is extremely low. Therefore, it is possible to suppress a decrease in waterproofing caused by burrs and voids.

[0037] In this embodiment, end 223 has a portion (second portion 223B) that is thicker than adjacent portion 224. This allows uncured resin 300 to smoothly flow into second portion 223B during the manufacturing process, so that air bubbles and leakage of uncured resin 300 that may occur during the manufacturing process can be concentrated at end 223. As a result, voids and burrs that may occur in resin portion 33 can be concentrated at end 33. Because electronic components 20 are not present at end 33, the possibility of atmospheric moisture reaching electronic components 20 due to voids and burrs at end 33 is extremely low. Therefore, deterioration of waterproofing due to burrs and voids can be suppressed.

[0038] In this embodiment, the end 223 is further shaped so that its thickness increases with increasing distance from the adjacent portion 224. This allows the uncured resin 300 to smoothly flow into the second portion 223B during the manufacturing process, so that air bubbles and leakage of the uncured resin 300 that may occur during the manufacturing process can be concentrated at the end 223. As a result, voids and burrs that may occur in the resin portion 33 can be concentrated at the end 33. Because no electronic component 20 is present at the end 33, the possibility of moisture in the air reaching the electronic component 20 due to the voids and burrs at the end 33 is extremely low. Therefore, a decrease in waterproofing caused by burrs and voids can be suppressed.

[0039] Next, modified examples of the circuit board 100 will be described.

[0040] (Variation A) In the above embodiment, the end portion 33 (first portion 33A) may have a tapered shape that widens with increasing distance from the adjacent portion 32A, as shown in FIGS. 7A and 7B . In this case, the end portion 223 also has a tapered shape that widens with increasing distance from the adjacent portion 224. In this case, the uncured resin 300 can be smoothly introduced into the second portion 223B during the manufacturing process, so that air bubbles and leakage of the uncured resin 300 that may occur during the manufacturing process can be concentrated at the end portion 223. As a result, voids and burrs that may occur in the resin portion 33 can be concentrated at the end portion 33. Because no electronic component 20 is present at the end portion 33, the possibility of atmospheric moisture reaching the electronic component 20 due to voids and burrs at the end portion 33 is extremely low. Therefore, deterioration of waterproofing due to burrs and voids can be suppressed.

[0041] (Variation B) In the above embodiment and Variation A, the end 33 may have a circular or elliptical shape in plan view, for example, as shown in Figures 8(A) and 8(B). In this case, the end 223 also has a circular or elliptical shape in plan view. In this case, it is possible to alleviate localized concentration of pressure at the end 223, thereby suppressing leakage of uncured resin 300 at the end 223. Therefore, it is possible to suppress deterioration of waterproofing due to voids.

[0042] (Variation C) In the above embodiment and Variation A, the end 33 may have a polygonal shape similar to a circle or an ellipse in plan view, as shown in Figures 9(A) and 9(B), for example. In this case, the end 223 also has a polygonal shape similar to a circle or an ellipse in plan view. In this case, it is possible to mitigate localized pressure concentration at the end 223, thereby suppressing leakage of the uncured resin 300 at the end 223. Therefore, it is possible to suppress deterioration of waterproofing due to voids.

[0043] (Variation D) In ​​the above embodiment and variations A, B, and C, for example, as shown in FIG. 10 , the thickness of the end portion 33 may be thinner at a portion (first portion 33A) of the end portion 33 closer to the adjacent portion 32A than at the adjacent portion 32A. In this case, for example, as shown in FIG. 11 , the thickness of the end portion 223 may be thinner at a portion (first portion 223A) of the end portion 223 closer to the adjacent portion 224 than at the adjacent portion 224. In this case, air bubbles can be temporarily accumulated in front of the first portion 223A during the manufacturing process, and then, when the filling pressure increases, the accumulated air bubbles can be rapidly introduced into the second portion 223B. As a result, voids and burrs that may occur in the resin portion 33 can be concentrated in the end portion 33. Because no electronic component 20 is present in the end portion 33, the possibility of atmospheric moisture reaching the electronic component 20 due to voids and burrs in the end portion 33 is extremely low. Therefore, a decrease in waterproofness caused by burrs and voids can be suppressed.

[0044] (Modification E) In the above-described embodiment and modifications A, B, C, and D, the wiring board 10 may have a through hole H1, for example, as shown in FIGS. 12, 13, and 15. The through hole H1 corresponds to a specific example of a "through hole" according to an embodiment of the present technology. FIG. 12 illustrates a modification of the planar configuration of the surface on the first main surface 11 side of the circuit board 100. FIG. 13 illustrates an example of the planar configuration of the surface on the second main surface 12 side of the circuit board 100. FIG. 15 illustrates an example of the cross-sectional configuration of the circuit board 100 taken along line A-A in FIGS. 12 and 13. The second main surface 12 corresponds to the surface of the wiring board 10 that faces the first main surface 11.

[0045] In this modification, a plurality of electronic components 20 are also mounted on the second main surface 12 of the wiring substrate 10, and the plurality of electronic components 20 mounted on the second main surface 12 are covered by a gate portion 22 and a portion of the intermediate portion 23 of the resin portion 30. The plurality of electronic components 20 mounted on the second main surface 12 include, for example, at least one type of component selected from the group consisting of a microcontroller, an IC, a fuse, a current-carrying bus bar, a resistor, and a capacitor. The plurality of electronic components 20 mounted on the second main surface 12 include, for example, at least one type of component selected from the group consisting of a microcontroller, an IC, a fuse, a current-carrying bus bar, a resistor, and a capacitor. The plurality of electronic components 20 mounted on the second main surface 12 corresponds to a specific example of a "second electronic component" according to an embodiment of the present technology. For example, as shown in FIG. 14 , the resin portion 30 has a portion contacting the first main surface 11 and a portion contacting the second main surface 12. The portion of the resin portion 30 that contacts the second main surface 12 corresponds to a specific example of a "second resin portion" according to an embodiment of the present technology. FIG. 14 illustrates an exemplary side configuration of the circuit board 100 of FIG. 12 . The resin portion 30 further includes a portion that fills the through hole H1 and connects the portion of the resin portion 30 that contacts the first main surface 11 and the portion of the resin portion 30 that contacts the second main surface 12, as shown in FIG. 15 , for example. On the second main surface 12, the resin portion 30 includes a covered region S5 that is covered by the resin portion 30 and is continuous, and an uncovered region S6 that is not covered by the resin portion 30, as shown in FIG. 13 , for example. The through hole H1 is provided in the covered regions S1 and S5. In this modification, the end portion 33 of the resin portion 30 has the configuration described in the above embodiment and modifications A, B, C, and D.

[0046] Fig. 16(A) shows a modified example of the planar configuration of the lower mold 210. Fig. 16(B) shows an example of the cross-sectional configuration of the lower mold 210 of Fig. 16(A) taken along line A-A. Fig. 17(A) shows a modified example of the planar configuration of the upper mold 220. Fig. 17(B) shows an example of the cross-sectional configuration of the upper mold 220 of Fig. 17(A) taken along line A-A. Fig. 17(C) shows an example of the cross-sectional configuration of the upper mold 220 of Fig. 17(A) taken along line B-B.

[0047] 16(A) and 16(B), for example, the lower mold 210 has an accommodation portion 211 that accommodates the wiring substrate 10, and a recess 212. The recess 212 is continuous with a portion of the second main surface 12 that faces the continuous coating target region that includes the plurality of electronic components 20 when the lower mold 210 is superimposed on the wiring substrate 10, as shown in FIG.

[0048] The recess 212 has a three-dimensional shape corresponding to the shape of the portion of the resin portion 30 that is provided on the second main surface 12 side. A gate portion 213 is connected to one end of the recess 212. The gate portion 213 is a void that connects one end of the recess 212 to the outside, and serves as an inlet for pouring the uncured resin 300 into the lower mold 210. The other end of the recess 212 is located at a position facing the through hole H1 of the wiring substrate 10 when the lower mold 210 is superimposed on the wiring substrate 10.

[0049] 17(A), 17(B), and 17(C), the upper mold 220 has a recess 221. The recess 221 is continuous with a portion of the first main surface 11 that faces the continuous coating target region including the plurality of electronic components 20 when the upper mold 220 is superimposed on the wiring substrate 10.

[0050] The recess 221 has a three-dimensional shape corresponding to the shape of the portion of the resin part 30 provided on the first main surface 11 side. One end of the recess 221 is disposed at a location (hereinafter referred to as the "facing location") that faces the through hole H1 of the wiring substrate 10 when the upper mold 220 is superimposed on the wiring substrate 10. The other end of the recess 221 forms an end 223. The end 223 is provided at a location on the first main surface 11 that faces the non-mounting region S4 of the plurality of electronic components 20 when the upper mold 220 is superimposed on the wiring substrate 10. The end 223 is provided at a location along the contour of the recess 221 that is farthest from the facing location. The portion of the recess 221 between the facing location and the end 223 may be, for example, a strip-like shape extending from the facing location to the end 223, as shown in FIG. 17A , or a non-strip-like shape whose width varies depending on the location.

[0051] 17(C), for example, the end portion 223 has a portion (second portion 223B) in the recess 221 that is thicker than the thickness of an adjacent portion 224 adjacent to the end portion 223. Further, for example, as shown in Fig. 17(C), the end portion 223 has a shape in which the thickness of the end portion 223 increases with increasing distance from the adjacent portion 224. The end portion 223 has a shape in which the thickness of the end portion 223 increases with increasing distance from the adjacent portion 224 at a portion (first portion 223A) between the adjacent portion 224 and the second portion 223B.

[0052] In this modified example, during the manufacturing process, uncured resin 300 is injected into gate portion 213 of lower mold 210, and thereby uncured resin 300 flows into recess 212 via gate portion 213. At this time, uncured resin 300 in recess 212 flows into recess 221 of upper mold 220 via through hole H1 of wiring substrate 10.

[0053] As the uncured resin 300 flows into the recesses 212 and 221, bubbles may be generated in the uncured resin 300 due to the three-dimensional structure of the electronic components 20 arranged in the recesses 212 and 221. If bubbles are generated in the uncured resin 300, the bubbles move toward the end 223 and eventually accumulate at the end 223 (flow end). Furthermore, the pressure of the uncured resin 300 may become locally high at the end 223, which may cause the uncured resin 300 to leak from the end 223. As the uncured resin 300 flows into the recesses 212 and 221, gas remaining in the recesses 212 and 221 or gas generated in the recesses 212 and 221 is discharged to the outside, for example, via a vent provided in the upper mold 220.

[0054] In this modification, the resin portion 33 has a portion that contacts the first main surface 11, a portion that contacts the second main surface 12, and a portion that fills the through-hole H1. In this configuration, air bubbles are more likely to occur in the uncured resin 300 than in the above embodiment. However, the portion of the resin portion 33 that contacts the first main surface 11 has an end portion 33 that contacts the non-mounting area S4. This allows voids and burrs that may occur in the resin portion 33 during the manufacturing process to be concentrated in the end portion 33. Because no electronic components 20 are present in the end portion 33, the possibility of atmospheric moisture reaching the electronic components 20 due to the voids and burrs in the end portion 33 is extremely low. Therefore, a decrease in waterproofing due to burrs and voids can be suppressed.

[0055] (Modification F) In the above-described embodiment and modifications A, B, C, and D, the resin portion 30 may have a connecting portion 34 connecting a portion of the resin portion 30 that contacts the first main surface 11 and a portion of the resin portion 30 that contacts the second main surface 12, at a position that contacts the side of the wiring board 10, as shown in, for example, FIGS. 18 , 19 , 20 , and 21 . The connecting portion 34 corresponds to a specific example of a “third resin portion” according to an embodiment of the present technology. FIG. 18 illustrates a modification of the planar configuration of the surface of the circuit board 100 on the first main surface 11 side. FIG. 19 illustrates an example of the planar configuration of the surface of the circuit board 100 on the second main surface 12 side. FIG. 20 illustrates an example of the side configuration of the circuit board 100 of FIG. 18 . FIG. 21 illustrates an example of a cross-sectional configuration of the circuit board 100 of FIGS. 18 and 19 taken along line A-A.

[0056] In this modification, a plurality of electronic components 20 are also mounted on the second main surface 12 of the wiring substrate 10, and the plurality of electronic components 20 mounted on the second main surface 12 are covered by a gate portion 22 and a part of the intermediate portion 23 of the resin portion 30. On the second main surface 12, the resin portion 30 includes, for example, as shown in Fig. 19, a continuously connected covered region S5 that is covered by the resin portion 30, and an uncovered region S6 that is not covered by the resin portion 30. In this modification, the end portion 33 of the resin portion 30 has the configuration described in the above embodiment and modifications A, B, C, and D.

[0057] Fig. 22(A) shows a modified example of the planar configuration of the lower mold 210. Fig. 22(B) shows an example of the cross-sectional configuration of the lower mold 210 of Fig. 22(A) taken along line A-A. Fig. 23(A) shows a modified example of the planar configuration of the upper mold 220. Fig. 23(B) shows an example of the cross-sectional configuration of the upper mold 220 of Fig. 23(A) taken along line A-A. Fig. 23(C) shows an example of the cross-sectional configuration of the upper mold 220 of Fig. 23(A) taken along line B-B.

[0058] 22(A) and 22(B), for example, the lower mold 210 has an accommodation portion 211 that accommodates the wiring substrate 10, and a recess 212. The recess 212 is continuous with a portion of the second main surface 12 that faces the continuous coating target region that includes the plurality of electronic components 20 when the lower mold 210 is superimposed on the wiring substrate 10, as shown in FIG.

[0059] The recess 212 has a three-dimensional shape that corresponds to the shape of the portion of the resin portion 30 that is provided on the second main surface 12 side and the shape of the portion of the resin portion 30 that is provided on the side surface side of the wiring substrate 10. A gate portion 213 is connected to one end of the recess 212. The gate portion 213 is a void that connects one end of the recess 212 to the outside, and serves as an inlet for pouring the uncured resin 300 into the lower mold 210. The other end of the recess 212 is positioned at a location that faces the through hole H1 of the wiring substrate 10 when the lower mold 210 is superimposed on the wiring substrate 10.

[0060] 23(A), 23(B), and 23(C), the upper mold 220 has a recess 221. The recess 221 is continuous with a portion of the first main surface 11 that faces the continuous coating target region including the plurality of electronic components 20 when the upper mold 220 is superimposed on the wiring substrate 10.

[0061] The recess 221 has a three-dimensional shape that corresponds to the shape of the portion of the resin part 30 that is provided on the first main surface 11 side and the shape of the portion of the resin part 30 that is provided on the side surface of the wiring substrate 10. One end of the recess 221 is disposed at a location that does not face the wiring substrate 10 (hereinafter referred to as the "non-facing location") when the upper mold 220 is superimposed on the wiring substrate 10. The other end of the recess 221 forms an end 223. The end 223 is disposed at a location on the first main surface 11 that faces the non-mounting regions S4 of the multiple electronic components 20 when the upper mold 220 is superimposed on the wiring substrate 10. The end 223 is disposed at the location that is furthest from the non-facing location along the contour of the recess 221. The portion of the recess 221 between the non-opposing portion and the end portion 223 may be, for example, as shown in Figure 23 (A), in a band-like shape extending from the non-opposing portion to the end portion 223, or may be a non-band-like shape whose width varies depending on the location.

[0062] 23(C), for example, the end portion 223 has a portion (second portion 223B) in the recess 221 that is thicker than the thickness of an adjacent portion 224 adjacent to the end portion 223. Further, for example, as shown in FIG. 23(C), the end portion 223 has a shape in which the thickness of the end portion 223 increases with increasing distance from the adjacent portion 224. The end portion 223 has a shape in which the thickness of the end portion 223 increases with increasing distance from the adjacent portion 224 at a portion (first portion 223A) between the adjacent portion 224 and the second portion 223B.

[0063] In this modified example, during the manufacturing process, uncured resin 300 is injected into the gate portion 213 of the lower mold 210, and the uncured resin 300 flows into the recess 212 via the gate portion 213. At this time, the uncured resin 300 in the recess 212 flows into the recess 221 of the upper mold 220 via the non-opposite portion described above.

[0064] As the uncured resin 300 flows into the recesses 212 and 221, bubbles may be generated in the uncured resin 300 due to the three-dimensional structure of the electronic components 20 arranged in the recesses 212 and 221. If bubbles are generated in the uncured resin 300, the bubbles move toward the end 223 and eventually accumulate at the end 223 (flow end). Furthermore, the pressure of the uncured resin 300 may become locally high at the end 223, which may cause the uncured resin 300 to leak from the end 223. As the uncured resin 300 flows into the recesses 212 and 221, gas remaining in the recesses 212 and 221 or gas generated in the recesses 212 and 221 is discharged to the outside, for example, via a vent provided in the upper mold 220.

[0065] In this modification, the resin portion 33 has a portion in contact with the first main surface 11, a portion in contact with the second main surface 12, and a portion (connecting portion 34) in contact with the side surface of the wiring substrate 10. In this configuration, air bubbles are more likely to form in the uncured resin 300 than in the above embodiment. However, the portion of the resin portion 33 in contact with the first main surface 11 has an end portion 33 in contact with the non-mounting area S4. This allows voids and burrs that may occur in the resin portion 33 during the manufacturing process to be concentrated in the end portion 33. Because no electronic components 20 are present in the end portion 33, the possibility of atmospheric moisture reaching the electronic components 20 due to the voids and burrs in the end portion 33 is extremely low. Therefore, a decrease in waterproofness caused by burrs and voids can be suppressed.

[0066] (Modification G) In the above-described modification F, the wiring substrate 10 may have a through hole H1, for example, as shown in FIGS. 24, 25, and 26. For example, as shown in FIG. 26, the resin portion 30 has a portion contacting the first main surface 11, a portion contacting the second main surface 12, a connecting portion 34, and a portion filling the through hole H1. The portion of the resin portion 30 filling the through hole H1 corresponds to a specific example of a "fourth resin portion" according to an embodiment of the present technology. FIG. 24 illustrates a modification of the planar configuration of the surface of the circuit board 100 on the first main surface 11 side. FIG. 25 illustrates an example of the planar configuration of the surface of the circuit board 100 on the second main surface 12 side. FIG. 26 illustrates an example of the cross-sectional configuration of the circuit board 100 taken along line A-A in FIGS. 24 and 25. In this case, it is possible to pour the uncured resin 300 up to the end 223 at a lower pressure during the manufacturing process.

[0067] Incidentally, when through holes H1 are provided in wiring substrate 10, air bubbles are more likely to occur in uncured resin 300 than in the case of modification F described above. However, the portion of resin portion 33 that contacts first main surface 11 has end portion 33 that contacts non-mounting area S4. This allows voids and burrs that may occur in resin portion 33 during the manufacturing process to be concentrated in end portion 33. Because electronic components 20 are not present in end portion 33, the possibility of atmospheric moisture reaching electronic components 20 due to voids and burrs in end portion 33 is extremely low. Therefore, deterioration of waterproofing caused by burrs and voids can be suppressed.

[0068] (Application Example) Fig. 27 shows a perspective configuration example of a battery pack 1000 including a circuit board 100 (hereinafter simply referred to as "circuit board 100") according to the above embodiment and modifications A to F. Fig. 28 shows a perspective configuration example of a battery module 300 and circuit board 100 contained in the battery pack 1000. Fig. 29 shows an exploded perspective configuration example of the battery pack 1000.

[0069] As shown in Figures 27 and 28, the battery pack 1000 includes an exterior case 400, a battery module 300 housed in the exterior case 400, and a circuit board 100. As shown in Figure 29, the battery module 300 includes one or more batteries 310, a plurality of battery holders 320, and a plurality of metal tabs 330. The circuit board 100 is connected to the plurality of metal tabs 330, for example, and functions as a control board that controls the charging and discharging of the one or more batteries 310. The circuit board 100 may include circuits that measure the voltage of the one or more batteries 310, detect the remaining capacity of the one or more batteries 310, and measure the current output from the one or more batteries 310 to detect the presence or absence of an overcurrent.

[0070] 29 , the exterior case 400 is composed of a lower case 420 and an upper case 430. The lower case 420 and the upper case 430 are stacked together to form a storage space for accommodating the battery module 300 and the circuit board 100. The exterior case 400 (e.g., the lower case 420) is provided with external terminals 410 connected to the circuit board 100. The battery module 300 is connected to the external terminals 410 via the circuit board 100.

[0071] In this application example, the circuit board 100 according to the above embodiment and modifications A to F is used in a battery pack 1000. This makes it possible to prevent the plurality of electronic components 20 on the circuit board 100 from deteriorating due to atmospheric moisture or the like, thereby providing a battery pack 1000 that is highly resistant to atmospheric moisture or the like.

[0072] Although the present technology has been described above using one embodiment, the present technology is not limited to the aspect described in the above embodiment, and various modifications are possible with respect to the present technology. The effects described in this specification are merely examples, and therefore the effects of the present technology are not limited to the effects described in this specification. Therefore, other effects may be obtained with respect to the present technology.

[0073] The present technology may also have the following configurations. <1> A circuit board comprising: a wiring board having a first main surface; a plurality of first electronic components mounted on the first main surface; and a first resin portion that is continuous and provided in contact with only a portion of the first main surface and covers the plurality of first electronic components, wherein the first main surface includes a continuous covered region that is covered by the first resin portion and an uncovered region that is not covered by the first resin portion, and the first resin portion has an end portion that contacts the unmounted region of the first main surface where the plurality of first electronic components are not mounted. <2> The circuit board according to <1>, wherein the end portion is located at a position separated from an edge of the wiring board and is surrounded on three sides by the uncovered region. <3> The circuit board according to <1> or <2>, wherein the first resin portion has a gate portion that contacts the edge of the wiring board, and the end portion is provided at a position farthest from the gate portion along the contour of the first resin portion. <4> The circuit board according to any one of <1> to <3>, wherein the end portion has a width wider than that of an adjacent portion of the first resin portion adjacent to the end portion. <5> The circuit board according to <4>, wherein the end portion has a tapered shape that widens with increasing distance from the adjacent portion. <6> The circuit board according to <4> or <5>, wherein the end portion has a portion that is thicker than the adjacent portion. <7> The circuit board according to <6>, wherein the end portion has a shape that increases in thickness with increasing distance from the adjacent portion. <8> The circuit board according to <6> or <7>, wherein the thickness of the end portion is thinner at a portion of the end portion closer to the adjacent portion than the thickness of the adjacent portion. <9> The circuit board according to any one of <4> to <8>, wherein the end portion has a polygonal shape similar to a circle or an ellipse in plan view. <10> The circuit board according to any one of <4> to <8>, wherein the end portion has a circular or elliptical shape in plan view. <11> The circuit board according to any one of <1> to <10>, wherein the end portion is made of at least one resin material selected from the group consisting of polyamide, polyester, and polyurethane.<12> The circuit board according to any one of <1> to <11>, further comprising: a plurality of second electronic components mounted on a second main surface opposite the first main surface; a second resin portion that is provided in contact with only a portion of the second main surface and covers the plurality of second electronic components, and that is continuous; and a third resin portion that is in contact with a side surface of the wiring board and is connected to the first resin portion and the second resin portion. <13> The circuit board according to <12>, wherein a through hole is formed in the wiring board, and the circuit board further comprises a fourth resin portion that fills the through hole and is connected to the first resin portion and the second resin portion. <14> A battery pack including the circuit board according to any one of <1> to <12> as a circuit board that controls charging and discharging of one or more batteries. <15> A method for manufacturing a circuit board including: a wiring board having a first main surface; a plurality of electronic components mounted on the first main surface; and a continuous resin portion provided in contact with only a portion of the first main surface and covering the plurality of electronic components, the method comprising: superimposing a mold having a continuous recess in a portion of the first main surface facing a continuous region to be covered that is a portion of the first main surface and includes the plurality of electronic components, on the wiring board having the plurality of electronic components mounted on the first main surface; pouring uncured resin into the recess; cooling and solidifying the uncured resin poured into the recess within the mold to form the resin portion; and removing the mold from the wiring board, wherein the recess has an end portion in a portion of the first main surface facing a non-mounting region of the plurality of electronic components when the mold is superimposed on the wiring board. <16> The method for manufacturing a circuit board according to <15>, wherein the mold has a gate portion connected to the recess, and the edge portion is provided at a point furthest from the gate portion along the contour of the recess. <17> The method for manufacturing a circuit board according to <15> or <16>, wherein the edge portion has a width wider than a width of an adjacent portion of the recess that is adjacent to the edge portion. <18> The method for manufacturing a circuit board according to <17>, wherein the edge portion has a tapered shape that becomes wider as it moves away from the adjacent portion.<19> The method for manufacturing a circuit board according to <17>, wherein the end has a portion that is thicker than the adjacent portion. <20> The method for manufacturing a circuit board according to <19>, wherein the end has a shape in which the thickness of the end increases with increasing distance from the adjacent portion. <21> The method for manufacturing a circuit board according to any one of <17> to <20>, wherein the end has a polygonal shape similar to a circle or an ellipse in plan view. <22> The method for manufacturing a circuit board according to any one of <17> to <20>, wherein the end has a circle or an ellipse in plan view.

Claims

1. A circuit board comprising: a wiring board having a first main surface; a plurality of first electronic components mounted on said first main surface; and a first resin portion that is provided in contact with only a portion of said first main surface and that is continuous and covers said plurality of first electronic components, wherein said first main surface includes a continuous covered region that is covered by said first resin portion and an uncovered region that is not covered by said first resin portion, and said first resin portion has an end portion of said first main surface that is in contact with the unmounted region of said plurality of first electronic components.

2. The circuit board according to claim 1, wherein the end portion is located at a position spaced apart from the edge of the wiring board and is surrounded on three sides by the uncovered area.

3. A circuit board as described in claim 1 or claim 2, wherein the first resin portion has a gate portion that contacts the edge of the wiring board, and the end portion is provided at the farthest point along the contour of the first resin portion from the gate portion.

4. A circuit board according to any one of claims 1 to 3, wherein the end portion has a width greater than the width of an adjacent portion of the first resin portion adjacent to the end portion.

5. The circuit board according to claim 4, wherein said end portion has a tapered shape that widens as it moves away from said adjacent portion.

6. The circuit board according to claim 4 or 5, wherein the end portion has a portion that is thicker than the thickness of the adjacent portion.

7. The circuit board according to claim 6, wherein the end portion has a shape in which the thickness of the end portion increases with increasing distance from the adjacent portion.

8. The circuit board according to claim 6 or 7, wherein the thickness of the end portion at a portion closer to the adjacent portion is thinner than the thickness of the adjacent portion.

9. The circuit board according to any one of claims 4 to 8, wherein the end portion has a polygonal shape similar to a circle or an ellipse in plan view.

10. The circuit board according to any one of claims 4 to 8, wherein the end portion has a circular or elliptical shape in a plan view.

11. The circuit board according to any one of claims 1 to 10, wherein the end portion is made of at least one resin material selected from the group consisting of polyamide, polyester, and polyurethane.

12. A circuit board as claimed in any one of claims 1 to 11, further comprising: a plurality of second electronic components mounted on a second main surface opposite the first main surface; a second resin portion that is provided in contact with only a portion of the second main surface and that covers the plurality of second electronic components, and a third resin portion that is in contact with a side surface of the wiring board and that is connected to the first resin portion and the second resin portion.

13. The circuit board according to claim 12, wherein a through hole is formed in the wiring board, and the circuit board further comprises a fourth resin portion that fills the through hole and connects the first resin portion and the second resin portion.

14. A battery pack comprising the circuit board according to any one of claims 1 to 10 as a circuit board for controlling the charging and discharging of one or more batteries.

15. A method for manufacturing a circuit board comprising: a wiring board having a first main surface; a plurality of electronic components mounted on the first main surface; and a continuous resin portion provided in contact with only a portion of the first main surface and covering the plurality of electronic components, the method comprising: superimposing a mold having a continuous recess at a location facing a continuous area to be covered that is a portion of the first main surface and includes the plurality of electronic components, on the wiring board with the plurality of electronic components mounted on the first main surface; pouring uncured resin into the recess; cooling and solidifying the uncured resin poured into the recess within the mold to form the resin portion; and removing the mold from the wiring board, wherein the recess has an end at a location on the first main surface that faces an area where the plurality of electronic components are not mounted, when the mold is superimposed on the wiring board.

Images