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WO-2026094449-A1 - PROTECTIVE ELEMENT AND BATTERY PACK

WO2026094449A1WO 2026094449 A1WO2026094449 A1WO 2026094449A1WO-2026094449-A1

Abstract

The present invention provides a protective element capable of ensuring insulation after fusing of a fuse element.　This protective element comprises an insulating substrate 2, a heating element 6 provided on the insulating substrate 2, an insulating layer 7 covering the heating element 6, an intermediate electrode 4 provided on the surface of the insulating substrate 2 and electrically connected to the heating element 6, a fuse element 3 mounted on the intermediate electrode 4, and a cap member 5 covering a surface 2a side of the insulating substrate 2. The cap member 5 is a molded article of a resin composition containing an insulating inorganic filler, the insulating inorganic filler is a glass fiber milled fiber, and the resin composition has a glass fiber milled fiber filling amount between 35 wt% and 45 wt%, inclusive.

Inventors

  • TOBATA, Marina
  • MUKAI, KOICHI

Assignees

  • デクセリアルズ株式会社

Dates

Publication Date
20260507
Application Date
20250912
Priority Date
20241028

Claims (6)

  1. Insulating substrate and A heating element provided on the insulating substrate, An insulating layer covering the aforementioned heating element, An intermediate electrode provided on the surface of the insulating substrate and electrically connected to the heating element, A fuse element mounted on the aforementioned intermediate electrode, The insulating substrate comprises a cap member that covers the surface side, The aforementioned cap member is a molded article of a resin composition containing an insulating inorganic filler, The insulating inorganic filler is glass fiber milled fiber, The resin composition has a filling amount of glass fiber milled fibers of 35% by weight or more and 45% by weight or less. Protective element.
  2. The protective element according to claim 1, wherein the resin composition contains 40% by weight or more and 45% by weight or less of the glass fiber milled fiber.
  3. Insulating substrate and A heating element provided on the insulating substrate, An insulating layer covering the aforementioned heating element, An intermediate electrode provided on the surface of the insulating substrate and electrically connected to the heating element, A fuse element mounted on the aforementioned intermediate electrode, The insulating substrate comprises a cap member that covers the surface side, The aforementioned cap member is a molded article of a resin composition containing an insulating inorganic filler, The insulating inorganic filler is glass fiber chopped fiber, The resin composition has a filling amount of glass fiber chopped fibers of 30% by weight or more and 40% by weight or less. Protective element.
  4. The heating element and the insulating layer are formed on the surface of the insulating substrate on which the fuse element is provided. The protective element according to any one of claims 1 to 3, wherein the intermediate electrode is laminated on the insulating layer.
  5. The protective element according to any one of claims 1 to 3, wherein the heating element and the insulating layer are formed on the back surface of the insulating substrate opposite to the surface on which the fuse element is provided.
  6. The system comprises one or more battery cells and a protective element connected to the charge/discharge path of the battery cells and blocking the charge/discharge path. The protective element is the protective element described in any one of claims 1 to 3. Battery pack.

Description

Protective elements and battery pack This technology relates to a protective element mounted on an electric current path that melts a fuse element by heating with a heating element, thereby interrupting the electric current path, and to a battery pack using the same. This application claims priority based on Japanese Patent Application No. 2024-188967, filed in Japan on October 28, 2024, which is incorporated herein by reference. Lithium-ion rechargeable batteries are high-power, high-energy-density batteries used in small mobile devices such as laptops, mobile phones, and smartphones. In recent years, their adoption has been increasing in devices requiring large capacities, high current, and high voltage, such as power tools, electric bicycles, electric motorcycles, electric vehicles, and home energy storage systems. However, because these batteries use organic solvents, there is a risk of fire and smoke if the operating temperature, input/output current, or charging voltage exceeds the specified range. Therefore, it is common to incorporate protection circuits and protective elements using electronic circuits. These protection circuits typically utilize FETs (Field-Effect Transistors) for electrical ON/OFF switching, thermistors for temperature sensing, and fuses for physical circuit interruption. Fuses with heating elements are frequently used. A protective element consisting of a fuse with a heating element, in addition to its function of cutting off in the event of overcurrent like a typical current fuse, can also cut off the fuse element by heating up when an abnormality is detected by the electronic circuit. Compared to a typical current fuse that only cuts off in the event of overcurrent, this protective element has advantages such as quicker cutting in the event of an abnormality, easier circuit-based setting of safety margins considering battery characteristics and usage conditions, and the ability to melt and cut the fuse element at the intended timing. Figure 8 shows an example configuration of a surface-mount type protective element; (A) is a plan view with the cap member omitted, (B) is a cross-sectional view, and (C) is a bottom view. The protective element 100 shown in Figure 8 comprises an insulating substrate 101, first and second electrodes 102 and 103 formed on the surface of the insulating substrate 101, a heating element 104 formed on the surface of the insulating substrate 101, an insulating layer 105 covering the heating element 104, an intermediate electrode 106 laminated on the insulating layer 105 and connected to the heating element 104, a fuse element 107 which is a fusible conductor mounted via a connecting material 110 made of various tin-based solder pastes across the first electrode 102, the intermediate electrode 106, and the second electrode 103, flux 111 applied to the fuse element 107, and a cap member 112 covering the surface of the insulating substrate 101 on which the fuse element 107 is mounted. The first and second electrodes 102 and 103 are terminals connected to the current path of the external circuit to which the protection element 100 is connected. They are connected via castellation to the first and second external connection electrodes 102a and 103a formed on the back surface of the insulating substrate 101, respectively. The protection element 100 is incorporated into a part of the current path formed on the external circuit board by the connection of the first and second external connection electrodes 102a and 103a to connection electrodes provided on the external circuit board to which the protection element 100 is mounted. The heating element 104 is a conductive material with relatively high resistance that generates heat when energized, and is made of materials such as nichrome, W, Mo, Ru, or materials containing these materials. The heating element 104 is connected to a heating electrode 108 formed on the surface of the insulating substrate 101. The heating electrode 108 is connected via castellation to a third external connection electrode 108a formed on the back surface of the insulating substrate 101. The protection element 100 is connected to an external power supply provided in the external circuit by the third external connection electrode 108a being connected to a connection electrode provided on the external circuit board on which the protection element 100 is mounted. The energization of the heating element 104 is constantly controlled by a switch element (not shown) or the like. The heating element 104 is covered with an insulating layer 105 made of glass or the like, and an intermediate electrode 106 is formed on the insulating layer 105, so that it is superimposed on the intermediate electrode 106 via the insulating layer 105. Furthermore, a fuse element 107, connected between the first and second electrodes 102 and 103, is connected to the intermediate electrode 106 via a connecting material 110. As a result, the protective element 100 is t