TWM635306U - Protection element - 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.

Description

protection element

The present invention relates to a protection element, in particular, relates to a protection element which fuses a fusible conductor and blocks a current path by heating a heating body.

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

One embodiment of the present invention relates to a protection 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 The heating element is arranged between the first electrode and the second electrode. The protection element also includes a fusible conductor connected between the first electrode and the second electrode. The fusible conductor is configured to be fused by the heating of the heating element. At least a part of the first extension portion of the first electrode is located between the heating element and the substrate and contacts the heating element.

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

The protection element 1 may include a substrate 10, an electrode 11 (or called a first electrode 11), an electrode 12 (or called a second electrode 12), an electrode 13 (or called a third electrode 13), an insulating layer 14 (or called is the first insulating layer 14), heating element (such as heating element 15 shown in Figure 1B), insulating layer 16 (or called second insulating layer 16), solder resist layer 17a, solder resist layer 17b, soluble conductor 18 And cover body 19. In some embodiments, the heating element can be enclosed between the insulating layer 14 and the insulating layer 16 .

The protection element 1 can be applied in a protection circuit of an electronic device (such as a lithium ion battery or other secondary batteries). The electrodes 11 and the electrodes 12 can be disposed on opposite ends or two sides of the substrate 10 . The electrode 11 and the electrode 12 can be electrically connected through a meltable conductor 18 . The soluble conductor 18 can be electrically connected to the circuit substrate of an external circuit (such as a protection circuit) through the electrodes 11 and 12 to form a part of the electrical path of the external circuit. When a current exceeding a rated value flows through the fusible conductor 18 , the fusible conductor 18 is fused due to heat generated by the current (that is, Joule heat).

The electrode 13 can be disposed on 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 board 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 meltable conductor 18 to fuse to protect the electronics. effect of the device.

FIG. 1B is a top view of a protection element according to some embodiments of the present invention. In some embodiments, FIG. 1B is a top view of the protection element 1 in FIG. 1A . For the sake of brevity, only the substrate 10 , the electrode 11 , the electrode 12 , the electrode 13 , the insulating layer 14 and the heating element 15 are depicted in FIG. 1B .

Referring to FIG. 1B , the substrate 10 may include an insulating substrate such as a ceramic substrate, a glass substrate, a resin substrate, an insulation-treated metal substrate, or the like. In some embodiments, the substrate 10 may include (but not limited to) borosilicate glass (borophosphosilicate glass, BPSG), doped silicate glass (undoped silicate glass, USG), silicon (silicon), silicon oxide ( silicon oxide), silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, polyimide (PI), ABF substrate (Ajinomoto build-up film (ABF), molding compounds, pre-impregnated composite fibers (eg, pre-impregnated 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 prepregs may include, but are not limited to, multilayer structures formed by stacking or laminating multiple prepregs and/or sheets. In some embodiments, the substrate 10 may include (but not limited to) a circuit board (eg, FR4). The substrate 10 may include a surface 103 . In some embodiments, the surface 103 may include a side, side, periphery or border of the protection element 1 .

In some embodiments, the substrate 10 may include a through hole 10v1 (or called a first through hole 10v1 ), a through hole 10v2 (or called a second through hole 10v2 ), and a through hole 10v3 (or called a third through hole 10v3 ). ). Viewed from a top view, the through hole 10v1 , the through hole 10v2 and the through hole 10v3 can be respectively located under the electrode 11 , the electrode 12 and the electrode 13 to be covered, so they are indicated 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 can be respectively located within the surface 103 of the substrate 10 . The through hole 10v1 , the through hole 10v2 and the through hole 10v3 may be respectively located within the boundary of the substrate 10 . 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 may be electrically connected to the electrode 11 , the electrode 12 and the electrode 13 respectively. In some embodiments, vias 10v1, 10v2, and 10v3 can electrically connect electrode 11, electrode 12, and electrode 13 to an external terminal (for example, external terminal 11b, external terminal 12b and FIG. 1E shown external terminal 13b).

In some embodiments, the vias 10v1, 10v2, and 10v3 may include, but are 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, alloys may include nickel-chromium alloys (eg, nickel-chromium-aluminum, nickel-chromium-silicon), nickel-copper alloys (eg, nickel-copper-manganese), and the like. In some embodiments, the electrode 11 and the electrode 12 can be respectively connected to two through holes, and the electrode 13 can be connected to one through hole. In some embodiments, the size, quantity and position of the through holes can be adjusted according to the rated current of the protection element 1 . For example, the electrodes 11 and 12 may be respectively connected to three or more through holes. For example, the electrode 13 may connect two or more through holes.

As shown in FIG. 1B , the electrodes 11 , 12 and 13 may be adjacent to three adjacent sides or sides of the substrate 10 . For example, the electrode 12 is close to the left side of the substrate 10 , the electrode 13 is close to the lower side of the substrate 10 , and the electrode 11 is close to the right side and the upper side of the substrate 10 .

In some embodiments, electrode 11 may comprise a composite electrode. For example, the electrode 11 may be close to two adjacent sides (eg, the right side and the upper side) of the substrate 10 . The electrodes 11 can extend along two adjacent sides of the substrate 10 . The electrodes 11 may extend from one side of the substrate 10 to the other adjacent side.

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

A portion of the extension portion 11 e may be located between the insulating layer 14 and the heating element 15 . For example, the extension portion 11 e may have a part in contact with (for example, in direct contact with) the insulating layer 14 and the heat generating body 15 . For example, the extension portion 11 e may have a part extending below the heating element 15 and have an end exposed from the heating element 15 . In some embodiments, the width of the part 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 extending direction of the extending portion 11e may include a long side of a rectangle.

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

A part of the extension part 13 e may be located between the insulating layer 14 and the heating element 15 . For example, the extension part 13 e may have a part that contacts (for example, directly contacts) the insulating layer 14 and the heat generating body 15 . For example, a portion of the extension portion 13 e may extend below the heating element 15 and have an end portion exposed from the heating element 15 . In some embodiments, the width of the part of the extension part 13e located below the heating element 15 may be constant or uniform. For example, the part of the extension part 13e located below the heating element 15 may be a rectangle. The extending direction of the extending portion 13e may include the long sides of the rectangle.

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

In some embodiments, electrode 11, electrode 12, and electrode 13 may respectively 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 steps shown in FIG. 2J , the electrodes 11, 12 and 13 can be coated with nickel/gold (Ni/Au), nickel/lead/gold (Ni/Pb/Au ), or nickel/lead (Ni/Pb) and other coating films to prevent electrode oxidation and avoid changes in rated current or rated voltage due to electrode oxidation. As shown in FIG. 2J , portions where the extension portion 11 e and the extension portion 13 e are covered with the insulating layer 16 are not coated with a coating film.

Continuing to refer to FIG. 1B , the insulating layer 14 may be located above the substrate 10 and between the substrate 10 and the heating element 15 . A portion of the extension portion 11 e and a portion of the extension portion 13 e 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 suitable for substrate materials such as ceramics, glass, and resin. In some embodiments, the insulating layer 14 may have heat resistance, for example, it may withstand the heat when the fusible conductor 18 is melted. In some embodiments, the insulating layer 14 can separate the heating element 15 from the substrate 10 . In some embodiments, the insulating layer 14 can separate the electrode 11 , the electrode 12 and the electrode 13 to avoid micro-short circuit and improve device stability. In some embodiments, the insulating layer 14 can block or reduce heat dissipation through the substrate 10, ensuring that when the voltage exceeds the rated value, the heating element 15 can be heated to instantly fuse the fusible conductor 18, so as to protect the circuit and reduce the cost of the electronic device. risk of damage.

The heating element 15 can be located above the insulating layer 14 . The heat generating body 15 may contact (for example, directly contact) the insulating layer 14 . The heating element 15 may cover a part of the extension part 11e and a part of the extension part 13e. The heat generating body 15 may include a material that can generate heat when energized. In some embodiments, the heating element 15 may include (but 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.

FIG. 1C is an equivalent circuit diagram of a protection device according to some embodiments of the present invention. In some embodiments, FIG. 1C is an equivalent circuit diagram of the protection element 1 in FIG. 1A . For the sake of brevity, only electrode 11, electrode 12, electrode 13 and meltable conductor 18 are depicted in FIG. 1B.

Referring to FIG. 1B and FIG. 1C , the electrodes 11 , 12 , and 13 respectively have terminals or terminals electrically connected to a circuit substrate of an external circuit. The electrode 13 can be electrically connected to the electrode 11 through the extension part 13e, the heating element 15 and the extension part 11e. A heating element resistance can be formed between the electrode 13 and the electrode 11, and when the voltage exceeds a rated value, the fusible conductor 18 can be heated by the heating element resistance and be fused. In some embodiments, the meltable conductor 18 may not be directly electrically connected to the heating element resistor. For example, the meltable conductor 18 may not directly contact the heating element resistor. For example, the soluble conductor 18 may be indirectly connected to the heating element resistance via the electrode 11 .

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

Referring to FIG. 1D and FIG. 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 through the substrate 10 . The through hole 10v1 , the through hole 10v2 and the through hole 10v3 may extend between the surface 101 and the surface 102 respectively. The through hole 10v1 , the through hole 10v2 and the through hole 10v3 can be exposed from the surface 101 and the surface 102 respectively.

The electrodes 11 , 12 and 13 can be disposed or located on the surface 101 of the substrate 10 . The electrode 11 can be electrically connected to the external terminal 11b (or referred to as the first external terminal 11b ) through the through hole 10v1 . The electrode 12 can be electrically connected to the external terminal 12b (or referred to as the second external terminal 12b ) through the through hole 10v2 . The electrode 13 can be electrically connected to the external terminal 13b (or referred to as the third external terminal 13b ) through the through hole 10v3 . The external terminals 11 b , the external terminals 12 b and the external terminals 13 b can be located on the surface 102 of the substrate 10 . The external terminal 11b, the external terminal 12b, and the external terminal 13b can be used as terminals or terminals electrically connected to a circuit substrate of an external circuit.

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

In some embodiments, the extension portion 11 e may have a side that is coplanar with the side of the heating element 15 . Side surfaces of the extension part 11 e may be in contact with or covered by the insulating layer 16 . In some embodiments, the extension portion 11 e may have a bottom surface that is coplanar with the bottom surface of the heating element 15 . The bottom surface of the extension part 11 e 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 13 e may have a side surface that is coplanar with the side surface of the heating element 15 . Side surfaces of the extension part 13 e may be in contact with or covered by the insulating layer 16 . In some embodiments, the extension portion 13 e may have a bottom surface that is coplanar with the bottom surface of the heating element 15 . The bottom surface of the extension portion 13 e and the bottom surface of the heating element 15 may be in contact with the top surface of the insulating layer 14 .

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

The meltable conductor 18 can be connected between the electrode 11 and the electrode 12 . In some embodiments, the contact area of the meltable conductor 18 and the electrode 11 is substantially equal to the contact area of the meltable 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 heat generating body 15 may have a part located between the meltable conductor 18 and the extension portion 11e. The heating element 15 may have a part located between the soluble conductor 18 and the extension part 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 ), there may be no other conductive layer or conductive member between the heating element 15 and the meltable conductor 18 .

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

The solder resist layer 17 a (or referred to as the first solder resist layer 17 a ) and the solder resist layer 17 b (or referred to as the second solder resist layer 17 b ) can be disposed or located between the insulating layer 16 and the soluble conductor 18 . The solder resist layer 17 a and the solder resist layer 17 b can be disposed or located under the soluble conductor 18 . The solder resist layer 17 a and the solder resist layer 17 b may contact (eg, directly contact) the meltable conductor 18 . The solder resist layer 17a and the solder resist layer 17b may be covered by the soluble conductor 18 . The solder resist layer 17 a may be disposed adjacent to the electrode 11 . The solder resist layer 17 b may be disposed adjacent to the electrode 12 . In some embodiments, the solder resist layer 17a and the solder resist layer 17b may be separated or spaced apart from each other.

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 solder resist layer 17 a may not overlap with the extension portion 13 e. However, in other embodiments, the solder resist layer 17a and the extension portion 13e may at least partially overlap.

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

In some embodiments, the solder resist layer 17a and the solder resist layer 17b can be configured to segment or separate the melted meltable conductor 18 to reliably cut off the circuit, so that the fusing characteristics of the meltable conductor 18 are more stable . For example, the solder resist layer 17a and the solder resist layer 17b can divide the meltable conductor 18 into three sections. In other embodiments, there may be only one solder resist layer, for example only the solder resist layer 17a or the solder resist layer 17b, and the meltable conductor 18 may be divided into two sections. In other embodiments, there may be only one solder mask adjacent to electrode 11 , adjacent to electrode 12 , or substantially equidistant from both electrode 11 and electrode 12 . In other embodiments, there may be only one solder resist layer, the centerline of which may be substantially aligned with the centerline of the fusible conductor 18 .

In some embodiments, since the meltable conductor 18 can have a single melting point, the solder resist layer 17 a and the solder resist layer 17 b can simultaneously divide the meltable conductor 18 into three segments. For example, the electrode 11 and the electrode 12 can form an open circuit with the meltable conductor 18 at the same time.

In some embodiments, the solder resist layer 17a and the solder resist layer 17b may respectively include (but not limited to) epoxy resin (epoxy), urethane (urethane), acrylic (acrylic), organic and inorganic fillers, photoinitiated Agent (photoinitiator) and other materials.

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

2A to 2M show the manufacturing method of the protective device according to some embodiments of the present invention. According to some embodiments of the present invention, the manufacturing method disclosed in FIGS. 2A to 2M can be used to manufacture the protection device 1 shown in FIG. 1A .

Referring to FIG. 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, dicing lines (not shown) may be formed in the substrate 10 by laser dicing. In some embodiments, the depth of the scribe line may account for about 20% to about 60% of the thickness of the substrate 10 .

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

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

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

Referring to FIG. 2F , electrodes 11 , electrodes 12 and electrodes 13 are formed on the surface 101 of the substrate 10 and the insulating layer 14 . In some embodiments, the electrode 11 , the electrode 12 and the electrode 13 can be formed by sputtering, electroless plating, electroplating, printing, lithography 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 undergo laser etching, dry etching, ion bumping, or other methods. Possible ways are to remove part of the conductive layer or to pattern the conductive layer.

Referring to FIG. 2G , the heating element 15 is formed on the insulating layer 14 , the extension portion 11 e and the extension portion 13 e. In some embodiments, the heating element 15 can be formed by electroplating, vapor deposition, or sputtering. In some embodiments, the heating element 15 can be formed by mixing metal powder (such as ruthenium (Ru)) with a binder (such as 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.

Referring to FIG. 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.

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

2J and 2K, the 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 nickel/gold (Ni/Au), nickel/lead/gold (Ni/Pb/Au), or nickel/lead (Ni/Pb). The part where the extension part 11e and the extension part 13e are covered with the insulating layer 16 is not coated with the coating film 11p.

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

Referring to FIG. 2M , a cover body 19 is formed. In some embodiments, the substrate 10 can be separated into a plurality of independent components along the dicing lines formed by laser scribing, so as to expose the side surface of the substrate 10 (such as the surface 103 shown in FIG. 1A ). In some embodiments, the overcurrent protection device formed by the method shown in FIGS. 2A to 2M may be the same as the protection device 1 shown in FIG. 1A .

It will be appreciated that the methods and apparatus embodiments 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 can be practiced or carried out in various ways. Examples of particular implementations are provided herein for purposes of illustration only and are not meant to be limiting. In particular, acts, 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.

Also, the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. Any reference to an embodiment or element or act of the systems and methods herein referred to in the singular may also include embodiments including a plural of such elements, and any reference to any embodiment or element or act herein in the plural Any reference may also include an embodiment comprising only a single element. References in singular or plural are not intended to limit the presently disclosed systems or methods, components, acts or elements thereof. The use of "comprising", "including", "having", "comprising", "involving" and variations thereof herein is intended to cover the items listed thereafter and equivalents thereof as well as additional items. References to "or" may be considered inclusive such that any item using "or" may indicate any one, more than one, and all of the described items. Any references to front and rear, left and right, top and bottom, upper and lower, and vertical and horizontal are intended for convenience of description and do not limit the systems and methods, or components thereof, to any one position or spatial orientation.

Having thus described several aspects of at least one embodiment, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this invention and are intended to be within the scope of this invention. Therefore, the above description and drawings are by way of example only, and the scope of the present invention should be judged from the correct construction of the appended claims and their equivalents.

1: Protection element 10: Substrate 10v1: Via/First Via 10v2: Via/Second Via 10v3: Via/Third Via 11: Electrode/first electrode 11b: External terminal/first external terminal 11e: extension/first extension 11p: coated 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: heating element 16: Insulation layer/Second insulation layer 17a: Solder mask/first solder mask 17b: Solder mask/Second solder mask 18: Fusible conductor 19: cover body 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 the drawings, embodiments or any claims are accompanied by element symbols, such element symbols have been included for the sole purpose of increasing intelligibility in the drawings, embodiments or claims. Accordingly, the presence or absence of an element number is not intended to have a limiting effect on the scope of any claim element. In the figures, each identical or nearly identical component that is depicted in various figures is represented by a same numeral. For purposes of clarity, not every component is labeled in every figure. These figures are provided for the purpose of illustration and explanation and are not considered as a definition of the limitations of the present invention. In the picture:

Figure 1A is a perspective view of a protective element according to some embodiments of the present invention;

Figure 1B is a top view of a protection element according to some embodiments of the present invention;

Fig. 1C shows an equivalent circuit diagram of a protection element according to some embodiments of the present invention;

Figure 1D is a side view of a protective element according to some embodiments of the present invention;

Figure 1E is a side view of a protective element according to some embodiments of the present invention; and

2A to 2M show the manufacturing method of the protective device according to some embodiments of the present invention.

1: Protection 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 body

AA': tangent

BB': tangent

X: axis

Y: axis

Z: axis

Claims (10)

A protective element comprising: a substrate; a first electrode, which is arranged on the substrate and has a first extension; 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 is connected between the first electrode and the second electrode, and is configured to be fused by the heating of the heating element, Wherein the first extension portion of the first electrode has at least a part located between the heating element and the substrate and contacts the heating element. The protection element as claimed in claim 1, wherein the first electrode is connected to a first external terminal through a first through hole penetrating the substrate, and the second electrode is connected to a first external terminal through a second through hole penetrating the substrate a second external terminal. The protective element as described in Claim 1 further includes: a first insulating layer, which is arranged between the heating element and the substrate and separates the heating element from the substrate; and A second insulating layer is arranged between the heating element and the soluble conductor and separates the heating element from the soluble conductor. The protection device as claimed in claim 3, wherein the first electrode has an edge located between the first insulating layer and the second insulating layer. The protective element as described in claim 3 further includes: The first solder resist layer is disposed between the second insulating layer and the soluble conductor and contacts the soluble conductor. The protective element as described in claim 5 further includes: A second solder resist layer is disposed between the second insulating layer and the meltable conductor and contacts the meltable conductor, wherein the first solder resist layer is separated from the second solder resist layer. The protective element as described in Claim 1 further includes: A third electrode, which is arranged on the substrate and has a second extension, wherein at least a part of the second extension of the third electrode is located between the heating element and the substrate and contacts the heating element. The protection element according to claim 7, wherein an extending direction of the first extending portion is opposite to an extending direction of the second extending portion. The protection element according to claim 7, wherein the first electrode and the third electrode are configured to heat the heating element. The protection element as claimed in claim 1, wherein the first extending portion has a side surface that is coplanar with a side surface of the heating element.

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