TWI842008B - Protection element and method of manufacturing the same - Google Patents

Abstract

The present disclosure relates to a protection element. The protection element includes a substrate, a first electrode disposed on the substrate and having a first extending portion, a second electrode disposed on the substrate and spaced apart from the first electrode, and a heating element disposed between the first electrode and the second electrode. The protection element also includes a fusible conductor connecting between the first electrode and the second electrode. The fusible conductor is configured to be fused and cut off by heat from the heating element. At least a part of the first extending portion of the first electrode is disposed between the substrate and the heating element and contacting the heating element. The present disclosure also relates to a method of manufacturing a protection element.

Description

Protection element and manufacturing method thereof

The present invention relates to a protection element and a manufacturing method thereof, and more particularly, to a protection element that blocks a current path by melting a fusible conductor through heating of a heating element.

In the protection circuit of electronic devices (such as lithium-ion batteries or other secondary batteries), protection components with overcurrent and overvoltage protection functions can be used. The fusible conductor of the protection component can be melted when the current exceeds the rated value; and when the voltage exceeds the rated value, the fusible conductor can be melted by heating its heating element, thereby achieving the effect of protecting the electronic device.

One embodiment of the present disclosure is related to a protective element, including a substrate, a first electrode disposed on the substrate and having a first extension, a second electrode disposed on the substrate and spaced apart from the first electrode, and a heating element disposed between the first electrode and the second electrode. The protective element also includes a fusible conductor connected between the first electrode and the second electrode. The fusible conductor is configured to be melted by the heat generated by the heating element. The first extension of the first electrode has at least a portion located between the heating element and the substrate and in contact with the heating element.

One embodiment of the present disclosure is related to a manufacturing method of a protection element, including providing a substrate; and forming a first electrode, a second electrode and a third electrode on the substrate. The first electrode has a first extension portion and the third electrode has a second extension portion. The manufacturing method also includes forming a heating element to cover the first extension portion and the second extension portion; and forming a fusible conductor connected between the first electrode and the second electrode.

FIG. 1A is a perspective view of a protection element 1 according to some embodiments of the present disclosure.

The protection element 1 may include a substrate 10, an electrode 11 (or referred to as a first electrode 11), an electrode 12 (or referred to as a second electrode 12), an electrode 13 (or referred to as a third electrode 13), an insulating layer 14 (or referred to as a first insulating layer 14), a heating element (such as the heating element 15 shown in FIG. 1B ), an insulating layer 16 (or referred to as a second insulating layer 16), a solder mask 17a, a solder mask 17b, a fusible conductor 18, and a cover 19. In some embodiments, the heating element may be enclosed between the insulating layer 14 and the insulating layer 16.

The protection element 1 can be applied to the protection circuit of an electronic device (such as a lithium ion battery or other secondary battery). The electrode 11 and the electrode 12 can be arranged at opposite ends or sides of the substrate 10. The electrode 11 and the electrode 12 can be electrically connected through the fusible conductor 18. The fusible conductor 18 can be electrically connected to the circuit substrate of an external circuit (such as a protection circuit) through the electrode 11 and the electrode 12, and constitute a part of the current path of the external circuit. When a current exceeding the rated value flows through the fusible conductor 18, the fusible conductor 18 is melted due to the heat (i.e., Joule heat) generated by the current.

The electrode 13 can be disposed at one end or one side of the substrate 10 and is separated from the electrode 11 and the electrode 12. The electrode 13 can electrically connect the heating element to the circuit substrate of the external circuit. When the voltage exceeds the rated value (for example, when the lithium ion battery is overcharged), the heating of the heating element can cause the fusible conductor 18 to melt, thereby achieving the effect of protecting the electronic device.

FIG1B is a top view of a protection element according to some embodiments of the present disclosure. In some embodiments, FIG1B is a top view of the protection element 1 of FIG1A. For the sake of simplicity, FIG1B only depicts the substrate 10, the electrode 11, the electrode 12, the electrode 13, the insulating layer 14 and the heating element 15.

1B , the substrate 10 may include an insulating substrate, such as a ceramic substrate, a glass substrate, a resin substrate, an insulating metal substrate, etc. In some embodiments, the substrate 10 may include, but is not limited to, borophosphosilicate glass (BPSG), undoped silicate glass (USG), silicon, silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, polyimide (PI), Ajinomoto build-up film (ABF), molding compounds, pre-impregnated composite fibers (e.g., prepreg materials), combinations thereof, or the like. Examples of molding compounds may include, but are not limited to, epoxy resins (including fillers dispersed therein). Examples of prepreg materials may include, but are not limited to, a multi-layer structure formed by stacking or laminating a plurality of prepreg materials and/or sheets. In some embodiments, substrate 10 may include, but is not limited to, a circuit board (such as FR4). Substrate 10 may include surface 103. In some embodiments, surface 103 may include a side, side, periphery, or border of protective element 1.

In some embodiments, the substrate 10 may include a through hole 10v1 (or referred to as a first through hole 10v1), a through hole 10v2 (or referred to as a second through hole 10v2), and a through hole 10v3 (or referred to as a third through hole 10v3). When viewed from a top view, the through hole 10v1, the through hole 10v2, and the through hole 10v3 may be respectively located below the electrode 11, the electrode 12, and the electrode 13 and be shielded, and are therefore represented by dotted lines.

In some embodiments, the through-hole 10v1, the through-hole 10v2, and the through-hole 10v3 may be spaced apart from the surface 103, respectively. The through-hole 10v1, the through-hole 10v2, and the through-hole 10v3 may be located within the surface 103 of the substrate 10, respectively. The through-hole 10v1, the through-hole 10v2, and the through-hole 10v3 may be located within the boundary of the substrate 10, respectively. For example, the through-hole 10v1, the through-hole 10v2, and the through-hole 10v3 may not be exposed from the surface 103 of the substrate 10, respectively.

In some embodiments, the through-hole 10v1, the through-hole 10v2 and the through-hole 10v3 can be electrically connected to the electrode 11, the electrode 12 and the electrode 13, respectively. In some embodiments, the through-hole 10v1, the through-hole 10v2 and the through-hole 10v3 can electrically connect the electrode 11, the electrode 12 and the electrode 13 to an external terminal (e.g., the external terminal 11b shown in FIG. 1D, the external terminal 12b and the external terminal 13b shown in FIG. 1E), respectively.

In some embodiments, the through hole 10v1, the through hole 10v2 and the through hole 10v3 may include (but not limited to) copper (Cu), gold (Au), silver (Ag), aluminum (Al), nickel (Ni), titanium (Ti), tungsten (W), chromium (Cr), tin (Sn), or other metals or alloys. For example, in some embodiments, the alloy may include nickel-chromium alloy (such as nickel-chromium-aluminum, nickel-chromium-silicon), nickel-copper alloy (such as nickel-copper-manganese), etc. In some embodiments, the electrode 11 and the electrode 12 may be connected to two through holes respectively, and the electrode 13 may be connected to one through hole. In some embodiments, the size, number and position of the through hole can be adjusted according to the rated current size of the protection element 1. For example, the electrodes 11 and 12 may be connected to three or more through holes, respectively. For example, the electrode 13 may be connected to two or more through holes.

1B , electrodes 11, 12, and 13 may be close to three adjacent sides or surfaces of substrate 10. For example, electrode 12 is close to the left side of substrate 10, electrode 13 is close to the bottom side of substrate 10, and electrode 11 is close to the right side and top side of substrate 10.

In some embodiments, the electrode 11 may include a composite electrode. For example, the electrode 11 may be close to two adjacent sides (e.g., the right side and the upper side) of the substrate 10. The electrode 11 may extend along two adjacent sides of the substrate 10. The electrode 11 may extend from one side of the substrate 10 to another adjacent side.

The electrode 11 may have an extension portion 11e (or referred to as a first extension portion 11e). The extension portion 11e may extend from the electrode 11 toward the electrode 12 (e.g., toward the X-axis direction in FIG. 1B ), and toward the electrode 13 (e.g., in the opposite direction of the Y-axis in FIG. 1B ). The extension portion 11e may have a corner. The extension portion 11e may have two extension directions.

The extension portion 11e may have a portion located between the insulating layer 14 and the heating element 15. For example, the extension portion 11e may have a portion that contacts (e.g., directly contacts) the insulating layer 14 and the heating element 15. For example, the extension portion 11e may have a portion that extends below the heating element 15 and has an end exposed from the heating element 15. In some embodiments, the width of the portion of the extension portion 11e located below the heating element 15 may be constant or uniform. For example, the portion of the extension portion 11e located below the heating element 15 may be a rectangle. The extension direction of the extension portion 11e may include the long side of the rectangle.

The electrode 13 may have an extension portion 13e (or referred to as a second extension portion 13e). The extension portion 13e may extend from the electrode 13 toward the electrode 11 (eg, toward the Y-axis direction in FIG. 1B ).

The extension portion 13e may have a portion located between the insulating layer 14 and the heating element 15. For example, the extension portion 13e may have a portion contacting (e.g., directly contacting) the insulating layer 14 and the heating element 15. For example, the extension portion 13e may have a portion extending below the heating element 15 and having an end exposed from the heating element 15. In some embodiments, the width of the portion of the extension portion 13e located below the heating element 15 may be constant or uniform. For example, the portion of the extension portion 13e located below the heating element 15 may be a rectangle. The extension direction of the extension portion 13e may include the long side of the rectangle.

In some embodiments, the extension portion 11e and the extension portion 13e may extend in opposite directions. In some embodiments, the extension portion 11e and the extension portion 13e may be located at opposite ends or sides of the heating element 15. In some embodiments, the extension portion 11e and the extension portion 13e may not have an end exposed from the heating element 15. For example, the extension portion 11e and the extension portion 13e may extend below the heating element 15 and have an edge covered by the heating element 15 or aligned with the heating element 15. In some embodiments, the extension portion 11e and the extension portion 13e may be configured to heat the heating element 15. In some embodiments, the electrode 11 and the electrode 13 may heat the heating element 15 through the extension portion 11e and the extension portion 13e.

In some embodiments, the electrode 11, the electrode 12 and the electrode 13 may include (but not limited to) copper (Cu), gold (Au), silver (Ag), aluminum (Al), nickel (Ni), titanium (Ti), tungsten (W), chromium (Cr), tin (Sn), or other metals or alloys. In some embodiments, for example, in the process step shown in FIG. 2J, the electrode 11, the electrode 12 and the electrode 13 may be coated with a coating film such as nickel/gold (Ni/Au), nickel/lead/gold (Ni/Pb/Au), or nickel/lead (Ni/Pb) to prevent electrode oxidation and avoid changes in the rated current value or rated voltage value due to electrode oxidation. As shown in FIG. 2J , the portions of the extension portion 11e and the extension portion 13e covered by the insulating layer 16 are not coated with a coating film.

1B , the insulating layer 14 may be located above the substrate 10 and between the substrate 10 and the heat generating element 15 . A portion of the extending portion 11e and a portion of the extending portion 13e may extend above the insulating layer 14 .

In some embodiments, the insulating layer 14 may include (but not limited to) epoxy resin (including fillers dispersed therein), film plastic, silicon, or other materials applicable to substrate materials such as ceramics, glass, and resins. In some embodiments, the insulating layer 14 may have heat resistance, for example, it may withstand the heat when the fusible conductor 18 melts. In some embodiments, the insulating layer 14 may separate the heating element 15 from the substrate 10. In some embodiments, the insulating layer 14 may separate the electrodes 11, 12, and 13 to avoid micro short circuits and improve device stability. In some embodiments, the insulating layer 14 can block or reduce the heat dissipation through the substrate 10, ensuring that when the voltage exceeds the rated value, the heating element 15 can be heated to cause the fusible conductor 18 to melt immediately, thereby protecting the circuit and reducing the risk of damage to the electronic device.

The heat generating body 15 may be located above the insulating layer 14. The heat generating body 15 may contact (e.g., directly contact) the insulating layer 14. The heat generating body 15 may cover a portion of the extension portion 11e and a portion of the extension portion 13e. The heat generating body 15 may include a material that can generate heat when electricity is applied. In some embodiments, the heat generating body 15 may include (but is not limited to) tungsten (W), molybdenum (Mo), ruthenium (Ru), chromium (Cr), silver (Ag), ruthenium oxide (RuO or RuO ₂ ) or other metals, alloys, or metal oxides.

FIG1C is an equivalent circuit diagram of a protection element according to some embodiments of the present disclosure. In some embodiments, FIG1C is an equivalent circuit diagram of the protection element 1 of FIG1A. For the sake of simplicity, FIG1B only depicts the electrode 11, the electrode 12, the electrode 13 and the fusible conductor 18.

Referring to FIG. 1B and FIG. 1C , electrode 11, electrode 12, and electrode 13 each have a terminal or end point electrically connected to a circuit substrate of an external circuit. Electrode 13 can be electrically connected to electrode 11 through extension portion 13e, heating element 15, and extension portion 11e. A heating element resistor can be formed between electrode 13 and electrode 11, and when the voltage exceeds a rated value, fusible conductor 18 can be heated and melted by the heating element resistor. In some embodiments, fusible conductor 18 may not be directly electrically connected to the heating element resistor. For example, fusible conductor 18 may not be directly in contact with the heating element resistor. For example, fusible conductor 18 may be indirectly connected to the heating element resistor via electrode 11.

Figures 1D and 1E are side views of the protection element according to some embodiments of the present disclosure. In some embodiments, Figures 1D and 1E are cross-sectional views of the protection element 1 of Figure 1A cut along the tangent line AA' and the tangent line BB', respectively.

1D and 1E , the substrate 10 has a surface 101, a surface 102 opposite to the surface 101, and a surface 103 extending between the surface 101 and the surface 102. In some embodiments, the through hole 10v1, the through hole 10v2, and the through hole 10v3 may respectively penetrate the substrate 10. The through hole 10v1, the through hole 10v2, and the through hole 10v3 may respectively extend between the surface 101 and the surface 102. The through hole 10v1, the through hole 10v2, and the through hole 10v3 may respectively be exposed from the surface 101 and the surface 102.

Electrode 11, electrode 12 and electrode 13 may be disposed or located on surface 101 of substrate 10. Electrode 11 may be electrically connected to external terminal 11b (or referred to as first external terminal 11b) through through hole 10v1. Electrode 12 may be electrically connected to external terminal 12b (or referred to as second external terminal 12b) through through hole 10v2. Electrode 13 may be electrically connected to external terminal 13b (or referred to as third external terminal 13b) through through hole 10v3. External terminal 11b, external terminal 12b and external terminal 13b may be located on surface 102 of substrate 10. External terminal 11b, external terminal 12b and external terminal 13b may serve as a terminal or end point electrically connected to a circuit substrate of an external circuit.

The insulating layer 14 may be disposed on or located on the surface 101 of the substrate 10. The insulating layer 14 may be located between the electrode 11 and the electrode 12. The insulating layer 14 may have two opposite ends respectively covered by the electrode 11 and the electrode 12. The extension portion 11e and the extension portion 13e may be disposed on or located on the insulating layer 14. The extension portion 11e and the extension portion 13e may be covered by and in contact with the heat generating body 15.

In some embodiments, the extension portion 11e may have a side surface coplanar with the side surface of the heating element 15. The side surface of the extension portion 11e may contact with or be covered by the insulating layer 16. In some embodiments, the extension portion 11e may have a bottom surface coplanar with the bottom surface of the heating element 15. The bottom surface of the extension portion 11e and the bottom surface of the heating element 15 may contact the top surface of the insulating layer 14.

In some embodiments, the extension portion 13e may have a side surface coplanar with the side surface of the heating element 15. The side surface of the extension portion 13e may contact with or be covered by the insulating layer 16. In some embodiments, the extension portion 13e may have a bottom surface coplanar with the bottom surface of the heating element 15. The bottom surface of the extension portion 13e and the bottom surface of the heating element 15 may contact the top surface of the insulating layer 14.

The insulating layer 16 may be disposed on or located on the insulating layer 14 and cover the heating element 15. For example, the heating element 15 may be enclosed by the insulating layer 14 and the insulating layer 16. In some embodiments, the insulating layer 16 may separate the heating element 15 from the fusible conductor 18. In some embodiments, the insulating layer 16 may contact or cover one edge of the electrode 11 and one edge of the electrode 12. In some embodiments, the insulating layer 16 may include (but is not limited to) the materials listed above for the insulating layer 14, which will not be repeated here.

The fusible conductor 18 may be connected between the electrode 11 and the electrode 12. In some embodiments, the contact area between the fusible conductor 18 and the electrode 11 is substantially equal to the contact area between the fusible conductor 18 and the electrode 12.

In some embodiments, as shown in FIG. 1D , in the Z-axis direction (or the direction perpendicular to the surface 101 of the substrate 10), the heating element 15 may have a portion located between the fusible conductor 18 and the extension portion 11e. The heating element 15 may have a portion located between the fusible conductor 18 and the extension portion 13e. In some embodiments, as shown in FIG. 1D , in the Z-axis direction (or the direction perpendicular to the surface 101 of the substrate 10), no other conductive layer or conductive member may be included between the heating element 15 and the fusible conductor 18.

In some embodiments, the fusible conductor 18 may include (but not limited to) copper (Cu), tin (Sn), bismuth (Bi), silver (Ag), or other metals or alloys. In some embodiments, the fusible conductor 18 may be configured to be melted by the heat generated by the heating element 15. In some embodiments, the fusible conductor 18 may include a plurality of metal layers, for example, a copper metal layer and a tin metal layer. In some embodiments, the fusible conductor 18 may include a single metal layer or a single metal block. In some embodiments, the fusible conductor 18 may include a single alloy layer or a single alloy block. In some embodiments, the fusible conductor 18 may include a single melting point metal layer or a single melting point metal block. In some embodiments, the weight percentage of copper in the fusible conductor 18 may be 50%, 60%, 70%, 80%, 90% or more. In some embodiments, the fusible conductor 18 may include pure copper. For example, the copper of the fusible conductor 18 may directly contact the electrodes 11 and 12.

The solder mask 17a (or first solder mask 17a) and the solder mask 17b (or second solder mask 17b) may be disposed or located between the insulating layer 16 and the fusible conductor 18. The solder mask 17a and the solder mask 17b may be disposed or located below the fusible conductor 18. The solder mask 17a and the solder mask 17b may contact (e.g., directly contact) the fusible conductor 18. The solder mask 17a and the solder mask 17b may be covered by the fusible conductor 18. The solder mask 17a may be disposed adjacent to the electrode 11. The solder mask 17b may be disposed adjacent to the electrode 12. In some embodiments, the solder mask layer 17a and the solder mask layer 17b may be separated or spaced apart from each other.

In some embodiments, as shown in FIG. 1D , the solder mask layer 17 a and the extension portion 13 e may not overlap in the Z-axis direction (or a direction perpendicular to the surface 101 of the substrate 10 ). However, in other embodiments, the solder mask layer 17 a and the extension portion 13 e may at least partially overlap.

In some embodiments, the solder mask 17a and the solder mask 17b may have a rectangular shape. For example, as shown in FIG. 1A , the solder mask 17a and the solder mask 17b extend in the Y-axis direction. In some embodiments, the solder mask 17a and the solder mask 17b may extend beyond one side of the fusible conductor 18. For example, both ends of the solder mask 17a may be exposed from the fusible conductor 18. For example, both ends of the solder mask 17b may be exposed from the fusible conductor 18.

In some embodiments, the solder mask 17a and the solder mask 17b can be configured to segment or separate the molten fusible conductor 18, effectively interrupt the circuit, and make the fusing characteristics of the fusible conductor 18 more stable. For example, the solder mask 17a and the solder mask 17b can divide the fusible conductor 18 into three sections. In other embodiments, there may be only one solder mask, for example, only the solder mask 17a or the solder mask 17b can divide the fusible conductor 18 into two sections. In other embodiments, there may be only one solder mask adjacent to the electrode 11, adjacent to the electrode 12, or substantially equidistant from the electrode 11 and the electrode 12. In other embodiments, there may be only one solder mask layer, whose centerline may be substantially aligned with the centerline of the fusible conductor 18.

In some embodiments, since the fusible conductor 18 may have a single melting point, the solder resist layer 17a and the solder resist layer 17b may simultaneously divide the fusible conductor 18 into three sections. For example, the electrode 11 and the electrode 12 may simultaneously form a short circuit with the fusible conductor 18.

In some embodiments, the solder mask layer 17 a and the solder mask layer 17 b may include (but not limited to) materials such as epoxy, urethane, acrylic, organic and inorganic fillers, and photoinitiators.

The cover 19 may be disposed or located on the surface 101 of the substrate 10. In some embodiments, when viewed from the side view of FIG. 1D and FIG. 1E, the middle portion of the cover 19 may be thinner than the surrounding portion thereof. In some embodiments, when viewed from the side view of FIG. 1D and FIG. 1E, the middle portion of the cover 19 may have a substantially flat inner surface. In some embodiments, when viewed from the side view of FIG. 1D and FIG. 1E, the cover 19 may have a substantially flat upper surface.

2A to 2M show a manufacturing method of a protection element according to some embodiments of the present disclosure. According to some embodiments of the present disclosure, the manufacturing method disclosed in FIG. 2A to 2M can be used to manufacture the protection element 1 shown in FIG. 1A.

2A , a substrate 10 is provided. The substrate 10 has a surface 101 and a surface 102 opposite to the surface 101. In some embodiments, a cutting path (not shown) can be formed in the substrate 10 by laser cutting. In some embodiments, the depth of the cutting path can account for a ratio of about 20% to about 60% of the thickness of the substrate 10.

2B , a drill hole 10h is formed in the substrate 10. In some embodiments, the drill hole 10h can be formed by laser drilling or other feasible methods. The size, number and position of the drill hole 10h can be designed according to device specifications (such as rated current size) or process requirements.

2C, through holes 10v1, 10v2 and 10v3 are formed. In some embodiments, a conductive material may be formed in the drill hole 10h by sputtering, electroless plating, plating, printing, photolithography or other feasible methods.

Referring to FIG. 2D , with the surface 102 facing upward, external terminals 11b, 12b, and 13b are formed on the surface 102 of the substrate 10. In some embodiments, the external terminals 11b, 12b, and 13b can be formed by sputtering, electroless plating, electroplating, printing, photolithography, or other feasible methods. The positions of the external terminals 11b, 12b, and 13b correspond to the positions of the through holes 10v1, 10v2, and 10v3.

2E , the surface 101 faces upward, and an insulating layer 14 is formed on the surface 101 of the substrate 10. In some embodiments, the insulating layer 14 can be formed by coating, lamination or other feasible methods.

Referring to FIG. 2F , electrodes 11, 12, and 13 are formed on the surface 101 of the substrate 10 and the insulating layer 14. In some embodiments, the electrodes 11, 12, and 13 may be formed by sputtering, electroless plating, electroplating, printing, photolithography, or other feasible methods. The electrode 11 may have an extension 11e and the electrode 13 may have an extension 13e. In other embodiments, a conductive layer may be conformally formed on the surface 101 of the substrate 10 and the insulating layer 14, and then a portion of the conductive layer may be removed or the conductive layer may be patterned by laser etching, dry etching, ion bumping, or other feasible methods.

Referring to FIG. 2G , a heating element 15 is formed on the insulating layer 14, the extension 11e, and the extension 13e. In some embodiments, the heating element 15 can be formed by electroplating, evaporation, or sputtering. In some embodiments, the heating element 15 can be formed by mixing a metal (e.g., ruthenium (Ru)) powder with a binder (e.g., resin), forming a pattern by screen printing, and then sintering. In other embodiments, the heating element 15 can be formed by attaching a metal film.

2H , an insulating layer 16 is formed on the heat generating body 15. In some embodiments, the insulating layer 16 can be formed by coating, lamination or other feasible methods.

2I , solder resist layers 17a and 17b are formed on the insulating layer 16. In some embodiments, the solder resist layers 17a and 17b may be formed by coating, printing, photolithography or other feasible methods.

2J and 2K , a coating film 11p is formed on the electrode 11, the electrode 12, the electrode 13, the external terminal 11b, the external terminal 12b, and the external terminal 13b. In some embodiments, the coating film 11p can be formed by coating a metal such as nickel/gold (Ni/Au), nickel/lead/gold (Ni/Pb/Au), or nickel/lead (Ni/Pb). The portions of the extension 11e and the extension 13e covered by the insulating layer 16 are not coated with the coating film 11p.

2L , a fusible conductor 18 is formed on the electrode 11 and the electrode 12. In some embodiments, the fusible conductor 18 can be formed by sputtering, electroless plating, electroplating, printing, photolithography or other feasible methods. In other embodiments, the fusible conductor 18 can be formed by attaching a metal sheet or film (such as a copper alloy sheet or a pure copper metal sheet).

Referring to FIG. 2M , a cover 19 is formed. In some embodiments, the substrate 10 may be separated into a plurality of independent components along the cutting paths formed by laser scribing to expose the side surface of the substrate 10 (e.g., the surface 103 shown in FIG. 1A ). In some embodiments, the overcurrent protection device formed by the method shown in FIG. 2A to FIG. 2M may be the same as the protection component 1 shown in FIG. 1A .

It will be understood that the embodiments of the methods and apparatus discussed herein are not limited in application to the details of construction and arrangement of components set forth in the following description or illustrated in the accompanying drawings. The methods and apparatus can be implemented in other embodiments and may be practiced or performed in a variety of ways. Examples of specific embodiments are provided herein for illustrative purposes only and are not intended to be limiting. In particular, actions, elements, and features discussed in conjunction with any one or more embodiments are not intended to be excluded from a similar role in any other embodiment.

Furthermore, the words and terms used herein are for descriptive purposes and should not be construed as limiting. Any reference to an embodiment or element or action of the systems and methods herein referred to in the singular may also include embodiments that include a plurality of such elements, and any reference to any embodiment or element or action herein in the plural may also include embodiments that include only a single element. References in the singular or plural are not intended to limit the presently disclosed systems or methods, their components, actions, or elements. The use of "comprising," "including," "having," "containing," "involving," and variations thereof herein is intended to encompass the items listed thereafter and their equivalents as well as additional items. References to "or" may be construed as inclusive such that any term using "or" may indicate any of a single, more than one, and all of the items described. Any references to front and back, left and right, top and bottom, upper and lower, and vertical and horizontal are intended for convenience of description and do not limit the present systems and methods or their components to any one positional or spatial orientation.

Thus, having described several aspects of at least one embodiment, it should be understood that various changes, modifications, and improvements will readily occur to those skilled in the art. Such changes, modifications, and improvements are intended to be part of the present invention and are intended to be within the scope of the present invention. Therefore, the above description and drawings are by way of example only, and the scope of the present invention should be determined from the correct construction of the appended claims and their equivalents.

1: Protective element 10: Substrate 10v1: Through hole/first through hole 10v2: Through hole/second through hole 10v3: Through hole/third through hole 11: Electrode/first electrode 11b: External terminal/first external terminal 11e: Extension/first extension 11p: Coating film 12: Electrode/second electrode 12b: External terminal/second external terminal 13: Electrode/third electrode 13b: External terminal/third external terminal 13e: Extension/second extension 14: Insulation layer/first insulation layer 15: Heat generating element 16: Insulation layer/second insulation layer 17a: Solder resist/first solder resist 17b: solder mask/second solder mask 18: fusible conductor 19: cover 101: surface 102: surface 103: surface AA’: tangent BB’: tangent X: axis Y: axis Z: axis

Various aspects of at least one embodiment are discussed below with reference to the accompanying drawings, which are not intended to be drawn to scale. Where technical features in a figure, embodiment, or any claim are accompanied by element symbols, such element symbols have been included for the sole purpose of increasing the understandability of the figure, embodiment, or patent scope. Therefore, the presence or absence of element symbols is not intended to have a limiting effect on the scope of any patent scope element. In the figures, each identical or nearly identical component shown in various figures is represented by an identical number. For clarity, not every component is labeled in every figure. These figures are provided for the purpose of illustration and explanation and are not to be regarded as a definition of limitations of the present invention. In the figures:

FIG. 1A is a perspective view of a protection element according to some embodiments of the present disclosure;

FIG. 1B is a top view of a protection element according to some embodiments of the present disclosure;

FIG. 1C is an equivalent circuit diagram of a protection element according to some embodiments of the present disclosure;

FIG. 1D is a side view of a protection element according to some embodiments of the present disclosure;

FIG. 1E is a side view of a protective element according to some embodiments of the present disclosure; and

2A to 2M show a method for manufacturing a protection element according to some embodiments of the present disclosure.

1: Protective element 10: Substrate 11: Electrode/First electrode 11e: Extension/First extension 12: Electrode/Second electrode 13: Electrode/Third electrode 14: Insulation layer/First insulation layer 16: Insulation layer/Second insulation layer 17a: Solder mask/First solder mask 17b: Solder mask/Second solder mask 18: Fusible conductor 19: Cover AA’: Tangent BB’: Tangent X: Axis Y: Axis Z: Axis

Claims (12)

A protective element comprises: a substrate; a first electrode disposed on the substrate and having a first extension portion; a second electrode disposed on the substrate and spaced apart from the first electrode; a heating element disposed between the first electrode and the second electrode; a fusible conductor connected between the first electrode and the second electrode and configured to be fusible by heat generated by the heating element. and melted; a first insulating layer disposed between the heating element and the substrate; and a second insulating layer disposed between the heating element and the fusible conductor, wherein the first extension portion of the first electrode has at least a portion located between the heating element and the substrate and in contact with the heating element, and wherein the first electrode has an edge located between the first insulating layer and the second insulating layer. A protection element as described in claim 1, wherein the first electrode is connected to a first external terminal via a first through hole penetrating the substrate, and the second electrode is connected to a second external terminal via a second through hole penetrating the substrate. The protective element as described in claim 1 further includes: a first solder resist layer disposed between the second insulating layer and the fusible conductor and in contact with the fusible conductor. The protection element as described in claim 3 further includes: a second solder mask layer, which is disposed between the second insulating layer and the fusible conductor and contacts the fusible conductor, wherein the first solder mask layer is separated from the second solder mask layer. The protection element as described in claim 1 further includes: a third electrode, which is disposed on the substrate and has a second extension portion, wherein at least a portion of the second extension portion of the third electrode is located between the heating element and the substrate and contacts the heating element. A protective element as described in claim 5, wherein an extension direction of the first extension portion and an extension direction of the second extension portion are opposite. A protection element as described in claim 5, wherein the first electrode and the third electrode are configured to heat the heating element. A protective element as described in claim 1, wherein the first extension portion has a side surface coplanar with a side surface of the heating element. A method for manufacturing a protective element, comprising: providing a substrate; forming a first electrode on the substrate, wherein the first electrode has a first extension portion; forming a second electrode on the substrate and spaced apart from the first electrode; forming a heating element between the first electrode and the second electrode; forming a fusible conductor connected between the first electrode and the second electrode, wherein the fusible conductor is configured to The heat source is heated and melted; a first insulating layer is formed between the heat source and the substrate; and a second insulating layer is formed between the heat source and the fusible conductor, wherein the first extension of the first electrode has at least a portion located between the heat source and the substrate and in contact with the heat source, and wherein the first electrode has an edge located between the first insulating layer and the second insulating layer. The manufacturing method as described in claim 9 further includes: forming a first through hole, a second through hole and a third through hole penetrating the substrate. The manufacturing method as described in claim 9 further includes: forming a third electrode on the substrate, wherein the third electrode has a second extension portion, and the second extension portion has at least a portion located between the heating element and the substrate and in contact with the heating element. The manufacturing method as described in claim 9 further includes: forming a solder mask layer on the second insulating layer, wherein the fusible conductor contacts the solder mask layer.

Images