TWI385696B - Protective device - Google Patents

Description

Protective component

The present invention relates to a protection element for use in an electronic device, and more particularly to a protection element that prevents overcurrent and overvoltage.

In recent years, information technology has advanced by leaps and bounds. Information products such as mobile phones, computers and personal mobile assistants can be seen everywhere. With their help, they provide people with the needs of food, clothing, housing, transportation, education and music. Make people's dependence on information products grow with each passing day. However, there has been a recent news about the explosion of batteries in portable electronic products such as mobile phones during charging and discharging. Therefore, the industry began to strengthen the protection measures of the battery during charging and discharging to prevent the battery from exploding due to overvoltage or overcurrent during charging and discharging.

The protective element proposed by the prior art is protected by connecting a thermal fuse in the protective component to the circuit of the battery, and electrically connecting the thermal fuse and the heater in the protective component to the field effect transistor (FET) and the integrated circuit. Control unit such as (IC). In this way, when the integrated circuit measures that the field effect transistor is driven when the voltage is overvoltage, the current is heated by the heater in the protection element to melt the temperature fuse, thereby causing the circuit of the battery to be in an open state to reach an overvoltage. protection. In addition, when an overcurrent occurs, a large amount of current flows through the thermal fuse, which causes the thermal fuse to be heated and blown, thereby causing the circuit of the battery to be in an open state to achieve overcurrent protection.

1 is a schematic cross-sectional view of a conventional thermal fuse package. Referring to FIG. 1 , a conventional thermal fuse package 100 has a substrate 110 , a heater 120 , an insulating layer 130 , a metal layer 140 , and a flux 150 . The heater 120 is disposed on the substrate 110, and the insulating layer 130 covers the heater 120. The metal layer 140 is disposed on the insulating layer 130, and the flux 150 covers the metal layer 140. In this way, the heater 120 is heated to directly melt the metal layer 140 to melt the metal layer 140 and flow toward the electrode layer 160 on both sides of the heater 120.

However, since the surface of the insulating layer 130 is nearly flat, the maximum height H1 of the electrode layer 160 with respect to the substrate 110 is not much different from the maximum height H2 of the insulating layer 130 with respect to the substrate 110, and the molten metal layer 140 still has a certain Viscosity. Therefore, the molten metal layer 140 is less likely to flow, so that the heater 120 cannot effectively melt the metal layer 140, and the overvoltage protection requirement cannot be achieved.

The invention provides a protection element which can effectively prevent overcurrent and overvoltage.

The invention provides a protective element comprising a substrate, an upper electrode, a lower electrode, an end electrode, a heating element, a flux and a metal block. The substrate has a first surface and a second surface opposite to each other. The upper electrode is disposed on the first surface of the substrate, and has a first sub-electrode and a third sub-electrode and a fourth sub-electrode opposite to each other. The first sub-electrode has a first extension. The first extension portion is located between the third sub-electrode and the fourth sub-electrode, and one of the third sub-electrode and the fourth sub-electrode has a first protrusion. The lower electrode is disposed on the second surface of the substrate. The terminal electrode is connected to the upper electrode and the lower electrode. The heating element is disposed on the substrate, wherein the first extension extends above the heating element. The flux is disposed on the first surface of the substrate and between the first extension portion and the third sub-electrode, and between the first extension portion and the fourth sub-electrode. The metal block is disposed on the first surface of the substrate, and connects the third sub-electrode, the first extension portion and the fourth sub-electrode.

The invention provides a protective component comprising a substrate, an upper electrode, a lower electrode, an end electrode, a heating element, a metal block, a first solder layer and a second solder layer. The substrate has a first surface and a second surface opposite to each other. The upper electrode is disposed on the first surface of the substrate, and has a first sub-electrode and a third sub-electrode and a fourth sub-electrode opposite to each other. The first sub-electrode has a first extension, and the first extension is located between the third sub-electrode and the fourth sub-electrode. The lower electrode is disposed on the second surface of the substrate. The terminal electrode is connected to the upper electrode and the lower electrode. The heating element is disposed on the substrate, wherein the first extension extends above the heating element. The metal block is disposed on the first surface of the substrate, and connects the third sub-electrode, the first extension portion and the fourth sub-electrode. The first solder layer is disposed between the metal block and the first extension. The second solder layer is disposed between the metal block and the third sub-electrode and between the metal block and the fourth sub-electrode. The solid phase point of the metal block is greater than the soldering temperature of the second solder layer, and the soldering temperature of the second solder layer is greater than the assembly temperature of the protective element.

The invention provides a protective element comprising a substrate, an upper electrode, a lower electrode, an end electrode, a heating element, a metal block and a solder layer. The substrate has a first surface and a second surface opposite to each other. The upper electrode is disposed on the first surface of the substrate, and has a first sub-electrode and a third sub-electrode and a fourth sub-electrode opposite to each other. The first sub-electrode has a first extension, and the first extension is located between the third sub-electrode and the fourth sub-electrode. The lower electrode is disposed on the second surface of the substrate. The terminal electrode is connected to the upper electrode and the lower electrode. The heating element is disposed on the substrate and the first extension extends above the heating element. The metal block is disposed on the first surface of the substrate, and connects the third sub-electrode, the first extension portion and the fourth sub-electrode. The solder layer is disposed between the metal block and the first extension portion, disposed between the metal block and the third sub-electrode, and disposed between the metal block and the fourth sub-electrode. The ratio of the volume of the metal block to the area of the solder layer is less than 0.16.

Based on the above, the flux of the protective element of the present invention is located between the sub-electrode of the upper electrode and the extension, and the upper electrode of the protective element has a protrusion. Therefore, when the heating element is heated, the molten flux can effectively help the metal block to melt, and the molten metal flows to the protruding portion due to the surface tension, that is, the protruding portion can increase the flow space and adsorption of the molten metal. The area prevents the molten metal from conducting the extension and the sub-electrode to cause a short circuit problem.

The above described features and advantages of the present invention will be more apparent from the following description.

2A is a top plan view of a protective element in accordance with an embodiment of the present invention. 2B is a bottom view of the protection element of FIG. 2A. 2C is a cross-sectional view of the protection element of FIG. 2A taken along line I-I'. Referring to FIG. 2A, FIG. 2B and FIG. 2C, in the embodiment, the protection component 200a includes a substrate 210, an upper electrode 220, a lower electrode 230, an end electrode 240, a heating element 25, 0, a flux 260, and A metal block 270.

In detail, the substrate 210 has a first surface 212 and a second surface 214 opposite to each other and a side surface 216 connecting the first surface 212 and the second surface 214. The upper electrode 220 is disposed on the first surface 212 of the substrate 210 and has a first sub-electrode 222 and a second sub-electrode 224 opposite to each other and a third sub-electrode 226 and a fourth sub-electrode 228 opposite to each other. It should be noted that in other embodiments, the upper electrode 220 may not include the second sub-electrode 224 and does not affect the overcurrent and overvoltage protection effects. The first sub-electrode 222 has a first extension portion 222a, and the first extension portion 222a is located between the third sub-electrode 226 and the fourth sub-electrode 228. In particular, the ratio of the width of the first extension portion 222a to the width of the substrate 210 is less than 0.8.

The third sub-electrode 226 has a first protrusion 226a, and the fourth sub-electrode 228 has a second protrusion 228a. The first protrusion 226a and the second protrusion 228a are located between the first extension 222a and the second sub-electrode 224, and the first protrusion 226a and the second protrusion 228a are spaced apart by a distance D. In the present embodiment, the pitch D is preferably between 0.1 mm and 0.4 mm, and the third sub-electrode 226 and the fourth sub-electrode 228 can be prevented from being short-circuited. The lower electrode 230 is disposed on the second surface 214 of the substrate 210. The terminal electrode 240 connects the upper electrode 220 and the lower electrode 230 and covers the side surface 216 of the substrate 210.

The heating element 250 is disposed on the second surface 214 of the substrate 210 and is connected to the lower electrode 230. In this embodiment, the lower electrode 230 has a fifth sub-electrode 232 and a sixth sub-electrode 234 opposite to each other and a seventh sub-electrode 236 and an eighth sub-electrode 238 opposite to each other. The fifth sub-electrode 232, the sixth sub-electrode 234, the seventh sub-electrode 236, and the eighth sub-electrode 238 are sequentially disposed corresponding to the first sub-electrode 222, the second sub-electrode 224, the third sub-electrode 226, and the fourth sub-electrode 228. . The fifth sub-electrode 232 has a second extension 232a, and the sixth sub-electrode 234 has a third extension 234a. The second extension portion 232a and the third extension portion 234a are located between the seventh sub-electrode 236 and the eighth sub-electrode 238 and are parallel to each other and do not overlap, and the heating element 250 is connected to the second extension portion 232a and the third extension portion 234a. between. However, in other embodiments, the heating element 250 can also be directly connected between the fifth sub-electrode 232 and the sixth sub-electrode 234 without the second extension 232a and the third extension 234a.

The material of the substrate 210 includes ceramic (for example, alumina), glass epoxy resin, zirconium dioxide (ZrO 2 ), tantalum nitride (Si 3 N 4 ), aluminum nitride (AlN), boron nitride (BN) or other inorganic materials. The material of the upper electrode 220 and the lower electrode 230 is, for example, a material having good electrical conductivity such as silver paste, silver platinum alloy, nickel, nickel alloy, copper or gold. The material of the terminal electrode 240 is, for example, a material having good electrical conductivity such as nickel, gold, copper, or a combination thereof. The material of the heating element 250 includes ruthenium dioxide (RuO ₂ ), carbon black (which can be doped in an inorganic adhesive such as water glass or an organic adhesive such as a thermosetting resin), copper, nickel-chromium alloy, titanium and Nickel-copper alloy, etc. In addition, in order to protect the heating element 250 from external environment pollution or oxidation, an insulating layer 285 may be covered on the heating element 250, and the material thereof includes glass glue or epoxy resin.

The flux 260 is disposed on the first surface 212 of the substrate 210 and between the first extension portion 222a and the third sub-electrode 226 and between the first extension portion 222a and the fourth sub-electrode 228. Specifically, the flux 260 is filled in a first recess R1 composed of the third sub-electrode 226, the first extension portion 222a, and the substrate 210, and is filled in the fourth sub-electrode 228 and the first extension portion. 222a and a second recess R2 formed by the substrate 210. In addition, the flux 260 of the present embodiment is composed of rosin (about 50% to 80%), softener (about 5% to 20%), and active agent (about 0.5% to 4%). %) and synthetic rubber (about 5% to 20%).

The metal block 270 is disposed on the first surface 212 of the substrate 210 and connects the third sub-electrode 226, the first extension portion 222a and the fourth sub-electrode 228. Specifically, the metal block 270 covers a portion of the third sub-electrode 226, the flux 260, the first extension portion 222a, and the fourth sub-electrode 228. In the present embodiment, since the flux 260 and the first extension portion 222a are both located between the heating element 250 and the metal block 270, the flux 260 can effectively help the metal block 270 above it to blow when the heating element 250 is heated. And achieve effective prevention of overvoltage or overcurrent.

When the heating element 250 is heated to cause the flux 260 and the metal block 270 to be in a molten state, the flux 260 can prevent the metal block 270 from being oxidized by the surface on which the hot melt starts to flow, so that the effect of the metal block 270 being blown can be ensured. Since the third sub-electrode 226 and the fourth sub-electrode 228 of the upper electrode 220 of the embodiment have the first protruding portion 226a and the second protruding portion 228a, respectively, the molten metal may be moved to the first protruding portion due to the influence of the surface tension. The 226a flows with the second protrusion 228a. That is, the first protrusion 226a and the second protrusion 228b can increase the flow space and the adsorption area of the molten metal. As a result, the molten metal does not accumulate or stay between the third sub-electrode 226 and the first extension portion 222a and between the fourth sub-electrode 228 and the first extension portion 222a, so that a short circuit can be avoided. In addition, the material of the metal block 270 includes tin-lead alloy (tin 2.5%, lead 97.5%), tin-silver-lead alloy (tin 5%, silver 2.5%, lead 92.5%), tin-indium-bismuth-lead alloy, tin-bismuth alloy, tin Low melting point alloy such as silver copper alloy.

It should be noted that the width of the first extension portion 222a of the embodiment and the width of the substrate 210 are selected to be specific ranges, that is, the ratio of the width of the first extension portion 222a to the width of the substrate 210 is less than 0.8. Therefore, when the protection element 200a reduces its component volume in order to match the small-sized electronic product, the first sub-electrode 222, the second sub-electrode 224, the third sub-electrode 226, and the fourth sub-electrode 228 of the upper electrode 220 can also provide Corresponding electrode areas or spacing between each other to ensure that the metal block 270 can be quickly blown. In this way, in addition to increasing the range of application of the protection element 200a, the reliability of the protection element 200a can also be improved.

In addition, it should be noted that the present invention does not limit the types of the third sub-electrode 226 and the fourth sub-electrode 228, although the third sub-electrode 226 and the fourth sub-electrode 228 mentioned herein are embodied as The first protrusion 226a and the second protrusion 228a are respectively provided. However, in other embodiments not shown, the third sub-electrode 226 and the fourth sub-electrode 228 may have only one protrusion or multiple sizes. The protrusions are still within the scope of the invention as claimed.

3A is a top plan view of a protective element in accordance with another embodiment of the present invention. 3B is a bottom view of the protection element of FIG. 3A. Figure 3C is a cross-sectional view of the protective element of Figure 3A taken along line II-II'. Referring to FIG. 3A, FIG. 3B and FIG. 3C simultaneously, in the present embodiment, the protection component 200b of FIGS. 3A-3C is similar to the protection component 200a of FIGS. 2A-2C, but the main difference is that: FIG. 3A The protective component 200b of FIG. 3C further includes a solder layer 280 over the third sub-electrode 226, the fourth sub-electrode 228, and the first extension 222a.

In detail, a portion of the solder layer 280 is disposed between the metal block 270 and the third sub-electrode 226, between the metal block 270 and the fourth sub-electrode 228, and between the metal block 270 and the first extension portion 222a. . As a result, when the heating element 250 is heated to cause the flux 260, the metal block 270, and the solder layer 280 to be in a molten state, the molten metal has a wetting effect on the molten state of the solder layer 280 and the helper solvent 260, and at the same time The first protrusion 226a and the second protrusion 228a flow by the influence of the surface tension. That is, the molten state of the solder layer 280 and the co-solvent 260 may further such that the molten metal does not accumulate or remain between the third sub-electrode 226 and the first extension 222a and the fourth sub-electrode 228 and the first extension Between the portions 222a, the occurrence of a short circuit can be avoided. In other words, the reliability of the protection element 200b can be further improved. In addition, the material of the solder layer 280 includes tin-silver alloy (tin 96.5%, silver 3.5%), gold, silver, tin, lead, antimony, indium, gallium, palladium, nickel, copper and other metal materials, and the solder layer 280 can be more Contains flux.

Further, in order to further ensure that the metal block 270 can be effectively blown, the present embodiment conducts an experiment for the relationship between the volume of the metal block 270 and the area of the solder layer 280. As can be seen from Table 1, when the ratio of the volume of the metal block 270 to the area of the solder layer 280 is less than 0.16, the heating element 250 having a power of 7 watts can surely blow the metal block 270. In addition, since the molten solder layer 280 has better wettability, when the metal block 270 is blown, it will accumulate on the molten solder layer 280, and it is ensured that the molten metal does not allow the first extension portion 222a and the third sub-section. The electrode 226 or the fourth sub-electrode 228 generates a short circuit phenomenon. In this way, it can be further ensured that the metal block 270 can be effectively blown, thereby achieving effective prevention of overvoltage or overcurrent. In short, when the ratio of the volume of the metal block 270 to the area of the solder layer 280 is less than 0.16, the reliability of the effective melting of the metal block 270 can be improved.

4 is a cross-sectional view of a protective element in accordance with another embodiment of the present invention. Referring to FIG. 4, in the present embodiment, the protection component 200c of FIG. 4 is similar to the protection component 200b of FIGS. 3A-3C, but the main difference is that the protection component 200c of FIG. 4 includes a first solder layer. 282 is on the first extension portion 222a, and a second solder layer 284 is on the third sub-electrode 226 and the fourth sub-electrode 228.

In detail, a portion of the first solder layer 282 is disposed between the metal block 270 and the first extension portion 222a. A portion of the second solder layer 284 is disposed between the metal block 270 and the third sub-electrode 226 and between the metal block 270 and the fourth sub-electrode 228. In particular, in this embodiment, the solid phase point of the metal block 270 is greater than the soldering temperature of the second solder layer 284, and the soldering temperature of the second solder layer 284 is greater than when the assembled protective component 200c is on a circuit board (not shown). Temperature (ie assembly temperature). In addition, the solid phase point of the metal block 270 is greater than the soldering temperature of the second solder layer 284, and the soldering temperature of the second solder layer 284 is greater than the soldering temperature of the first solder layer 282. The liquidus point of the metal block 270 is also greater than the temperature at which the protective component 200c is assembled on a circuit board (not shown) (i.e., the assembly temperature).

In the present embodiment, the melting point of the first solder layer 282 is lower than the melting point of the second solder layer 284. In this way, when the heating element 250 is heated, the first solder layer 282 is first melt-bonded to the metal block 270 above it, thereby lowering the melting point of the metal block 270, and reducing the time during which the metal block 270 is blown. Further, when the melting point of the first solder layer 282 is smaller than the temperature at which the protective component 200c is assembled on the circuit board (not shown), the first solder layer 282 is first melted with the upper metal block 270 when the protective component is assembled. Bonding, which in turn lowers the melting point of the metal block 270, can further reduce the time during which the metal block 270 is blown. In addition, the second sub-electrode 226 and the fourth sub-electrode 228 are coated with the second solder layer 284 having a higher melting point, so that when the protective component 200a is assembled on the circuit board (not shown), the second solder layer 284 is melted and generated. The metal block 270 is displaced and does not affect the resistance after assembly.

In addition, in order to further ensure that the metal block 270 can be effectively blown, the ratio of the volume of the metal block 270 to the area of the solder layer (ie, the area of the first solder layer 282 plus the area of the second solder layer 284) may also be less than 0.16. The range can improve the reliability of the effective melting of the metal block 270. In other words, the design of the protection element 200c of the present embodiment has better reliability.

FIG. 5A is a top plan view of a protective element according to another embodiment of the present invention. FIG. 5B is a bottom view of the protection element of FIG. 5A. Figure 5C is a cross-sectional view of the protective element of Figure 5A taken along line III-III'. Referring to FIG. 5A, FIG. 5B and FIG. 5C simultaneously, in the present embodiment, the protection component 200d of FIGS. 5A to 5C is similar to the protection component 200a of FIGS. 2A to 2C, but the main difference between the two is that FIG. 5A The heating element 250, the second extending portion 322b, and the third extending portion 324a of the protective element 200d of FIG. 5C are disposed on the first surface 212 of the substrate 210.

In detail, in the embodiment, the first sub-electrode 322 of the upper electrode 320 further has a second extension portion 322b, and the second sub-electrode 324 has a third extension portion 324a. The second extension portion 322b and the third extension portion 324a are disposed between the third sub-electrode 326 and the fourth sub-electrode 328, and the heating element 250 is located on the first surface 212 of the substrate 210 and connects the second extension portion 322b and the third portion. Extension 324a. The insulating layer 285 is disposed between the first extending portion 322a and the second extending portion 322b and the third extending portion 324a, that is, the first extending portion 322a is located on a surface of the insulating layer 285, and the second extending portion 322b and the third portion The extensions 324a are located on the other opposing surface of the insulating layer 285. In particular, the orthographic projections of the first extension portion 322a, the second extension portion 322b, and the third extension portion 324a on the insulating layer 285 do not overlap each other.

In addition, the flux 260 is disposed on the insulating layer 285 and located between the first extension portion 322a and the third sub-electrode 326 and between the first extension portion 322a and the fourth sub-electrode 328. The metal block 270 covers a portion of the third sub-electrode 326, the flux 260, the first extension 322a, and the fourth sub-electrode 228 such that the flux 260 is between the metal layer 270 and the insulating layer 285. As such, when the heating element 250 is heated, the heat permeable insulating layer 285 is conducted to the flux 260 and the metal block 270 to melt the metal block 270. At this time, the flux 260 directly contacting the metal block 270 may also contribute to the melting of the metal block 270.

It should be noted that, in this embodiment, the lower electrode 330 of the protection element 200d has a fifth corresponding to the first sub-electrode 322, the second sub-electrode 324, the third sub-electrode 326, and the fourth sub-electrode 328. The sub-electrode 332, a sixth sub-electrode 334, a seventh sub-electrode 336 and an eighth sub-electrode 338. In another embodiment, the lower electrode 330 may also have no fifth sub-electrode 332 according to design requirements, so as to form an empty pin design on the second surface 214 of the substrate 210, and the protection component is assembled on the circuit board (not shown). ) The orientation is correct.

Figure 6 is a cross-sectional view of a protective element in accordance with another embodiment of the present invention. Referring to FIG. 6, in the present embodiment, the protection component 200e of FIG. 6 is similar to the protection component 200b of FIGS. 3A-3C, but the main difference is that the protection component 200e of FIG. 6 includes a housing 290. In detail, the housing 290 is disposed on the first surface 212 of the substrate 210 and covers the metal block 270 for protecting the metal block 270, and can prevent the molten metal, the flux 260, and the solder layer 280 from leaking out. Problems such as circuit interference occur. Further, the material of the casing 290 includes materials such as alumina, polydiether ketone (PEEK), nylon (nylon), thermoplastic resin, ultraviolet curable resin, or phenol formaldehyde resin.

It should be noted that the foregoing embodiments are merely illustrative. In other implementations not shown, those skilled in the art can refer to the foregoing embodiments to select the foregoing components or combinations according to actual needs. Achieve the desired technical effect.

In summary, the present invention has at least the following effects:

1. The flux of the protective element of the present invention is located between the sub-electrode of the upper electrode and the extension, and the flux is disposed between the metal block and the heating element. Thus, as the heating element heats up, the molten flux can be under the metal block, effectively helping the metal block melt.

2. The upper electrode of the protective element of the present invention has a protruding portion, so that when the heating element is heated, the protruding portion can increase the flow space and the adsorption area of the molten metal, and can prevent the molten metal from being electrically connected to the extension portion and the sub-electrode to cause a short circuit. problem.

3. The ratio of the width of the first extension of the protective element of the present invention to the width of the substrate is less than 0.8, so that when the protective element is reduced in size for matching the small-sized electronic product, it can also provide a corresponding electrode area or The spacing between each other ensures that the metal block can be quickly blown and has better reliability.

4. The ratio of the volume of the metal block of the protective element of the present invention to the area of the solder layer is less than 0.16, which ensures the reliability of the effective melting of the metal block.

5. The solid phase point of the metal block of the protective element of the present invention is greater than the soldering temperature of the second solder layer, and the soldering temperature of the second solder layer is greater than the temperature (ie, the assembly temperature) when the protective element is assembled on the circuit board. Therefore, it is possible to avoid a situation in which the metal block is displaced when the protective element is assembled, and the resistance is not affected after the assembly.

6. The solid phase point of the metal block of the protective element of the present invention is greater than the soldering temperature of the second solder layer, and the soldering temperature of the second solder layer is greater than the soldering temperature of the first solder layer. Therefore, when the heating element is heated, the first solder layer is first fused to the metal block above it, thereby lowering the melting point of the metal block, and reducing the time during which the metal block is blown.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

100. . . Thermal fuse package

110. . . Substrate

120. . . Heater

130. . . Insulation

140. . . Metal layer

150. . . Flux

160. . . Electrode layer

200a ~ 200e. . . Protective component

210. . . Substrate

212. . . First surface

214. . . Second surface

220, 320. . . Upper electrode

222, 322. . . First subelectrode

222a, 322a. . . First extension

224, 324. . . Second subelectrode

226, 326. . . Third subelectrode

226a, 326a. . . First protrusion

228, 328. . . Fourth subelectrode

228a, 328a. . . Second protrusion

230, 330. . . Lower electrode

232, 332. . . Fifth subelectrode

232a, 322b. . . Second extension

234, 334. . . Sixth subelectrode

234a, 324a. . . Third extension

236, 336. . . Seventh subelectrode

238, 338. . . Eighth subelectrode

240. . . Terminal electrode

250. . . Heating element

260. . . Flux

270. . . Metal block

280. . . Solder layer

282. . . First solder layer

284. . . Second solder layer

285. . . Insulation

290. . . case

D. . . spacing

H1, H2. . . maximum height

R1. . . First groove

R2. . . Second groove

1 is a schematic cross-sectional view of a conventional protective element.

2A is a top plan view of a protective element in accordance with an embodiment of the present invention.

2B is a bottom view of the protection element of FIG. 2A.

2C is a cross-sectional view of the protection element of FIG. 2A taken along line I-I'.

3A is a top plan view of a protective element in accordance with another embodiment of the present invention.

3B is a bottom view of the protection element of FIG. 3A.

Figure 3C is a cross-sectional view of the protective element of Figure 3A taken along line II-II'.

4 is a cross-sectional view of a protective element in accordance with another embodiment of the present invention.

FIG. 5A is a top plan view of a protective element according to another embodiment of the present invention.

FIG. 5B is a bottom view of the protection element of FIG. 5A.

Figure 5C is a cross-sectional view of the protective element of Figure 5A taken along line III-III'.

Figure 6 is a cross-sectional view of a protective element in accordance with another embodiment of the present invention.

200a. . . Protective component

210. . . Substrate

212. . . First surface

214. . . Second surface

216. . . Side surface

220. . . Upper electrode

222a. . . First extension

230. . . Lower electrode

232a. . . Second extension

234a. . . Third extension

240. . . Terminal electrode

250. . . Heating element

260. . . Flux

270. . . Metal block

285. . . Insulation

Claims (47)

A protective component comprising: a substrate having a first surface and a second surface opposite to each other; an upper electrode disposed on the first surface of the substrate, having a first sub-electrode and a first surface opposite to each other a third sub-electrode and a fourth sub-electrode, wherein the first sub-electrode has a first extension, the first extension is located between the third sub-electrode and the fourth sub-electrode, and the third sub-electrode One of the fourth sub-electrodes has a first protrusion; the lower electrode is disposed on the second surface of the substrate; one end electrode is connected to the upper electrode and the lower electrode; and a heating element is disposed on the substrate, wherein The first extension extends above the heating element; a flux disposed on the first surface of the substrate between the first extension and the third sub-electrode, and located at the first extension And the fourth sub-electrode; and a metal block disposed on the first surface of the substrate, and connecting the third sub-electrode, the first extension portion and the fourth sub-electrode. The protection element of claim 1, wherein the third sub-electrode and the fourth sub-electrode have a second protrusion, and the first protrusion and the second protrusion are spaced apart from each other. spacing. The protective element of claim 2, wherein the spacing is between 0.1 mm and 0.4 mm. The protection element of claim 2, wherein the upper electrode further has a second sub-electrode, and the first protrusion and the second protrusion are located at the first extension and the second sub-electrode between. The protective device according to claim 1, further comprising a solder layer disposed between the metal block and the third sub-electrode, disposed between the metal block and the fourth sub-electrode, and disposed on the Between the metal block and the first extension. The protective element of claim 5, wherein the ratio of the volume of the metal block to the area of the solder layer is less than 0.16. The protective element of claim 1, wherein a ratio of a width of the first extension to a width of the substrate is less than 0.8. The protection element of claim 1, further comprising a first solder layer and a second solder layer, wherein the first solder layer is disposed between the metal block and the first extension, the second A solder layer is disposed between the metal block and the third sub-electrode and between the metal block and the fourth sub-electrode. The protective component of claim 8, wherein the solid phase of the metal block is greater than the soldering temperature of the second solder layer, and the soldering temperature of the second solder layer is greater than the assembly temperature of the protective component. The protective component of claim 8, wherein the solid phase of the metal block is greater than the soldering temperature of the second solder layer, and the soldering temperature of the second solder layer is greater than the soldering temperature of the first solder layer. The protective element of claim 8, wherein a ratio of a volume of the metal block to an area of the first solder layer plus an area of the second solder layer is less than 0.16. The protective element of claim 1, wherein the heating element is located on the second surface and is connected to the lower electrode. The protection element of claim 12, wherein the lower electrode has a fifth sub-electrode and a sixth sub-electrode opposite to each other, the fifth sub-electrode corresponds to the first sub-electrode, and the heating element The fifth sub-electrode and the sixth sub-electrode are connected. The protection element of claim 13, wherein the fifth sub-electrode has a second extension, the sixth sub-electrode has a third extension, and the second extension is located at the third extension The seventh sub-electrode is interposed between the second sub-electrode and the eighth sub-electrode, and the heating element is connected between the second extension and the third extension. The protection element of claim 1, wherein the upper electrode further comprises a second sub-electrode, and the heating element is located on the first surface and connects the first sub-electrode and the second sub-electrode. The protection element of claim 15, wherein the first sub-electrode has a second extension, the second sub-electrode has a third extension, and the second extension and the third extension are configured The heating element connects the second extension portion and the third extension portion between the third sub-electrode and the fourth sub-electrode. The protective component of claim 16, further comprising an insulating layer disposed between the first extending portion and the second extending portion and the third extending portion, wherein the first extending portion and the first portion The two projections, the orthographic projections of the third extension on the insulating layer do not overlap each other. The protection element of claim 15, wherein the lower electrode has a sixth sub-electrode and a seventh sub-electrode and an eighth sub-electrode opposite to each other, the sixth sub-electrode and the seventh sub-electrode The eighth sub-electrode is sequentially disposed corresponding to the second sub-electrode, the third sub-electrode, and the fourth sub-electrode. The protective element according to claim 1 further comprises an insulating layer covering the heating element. The protective component of claim 1, further comprising a housing disposed on the first surface of the substrate and covering the metal block. A protective component comprising: a substrate having a first surface and a second surface opposite to each other; an upper electrode disposed on the first surface of the substrate, having a first sub-electrode and a first surface opposite to each other a third sub-electrode and a fourth sub-electrode, wherein the first sub-electrode has a first extension, and the first extension is located between the third sub-electrode and the fourth sub-electrode; On the second surface of the substrate; an end electrode connecting the upper electrode and the lower electrode; a heating element disposed on the substrate, wherein the first extension extends above the heating element; and a metal block is disposed on the substrate On the first surface of the substrate, and connecting the third sub-electrode, the first extension portion and the fourth sub-electrode; a first solder layer disposed between the metal block and the first extension portion; a second solder layer disposed between the metal block and the third sub-electrode and disposed between the metal block and the fourth sub-electrode, wherein a solid phase point of the metal block is greater than a fusion of the second solder layer Temperature and the second weld Fusion temperature of the layer is greater than the temperature of protection element is assembled. The protective component of claim 21, wherein a solid phase point of the metal block is greater than a soldering temperature of the second solder layer, and a soldering temperature of the second solder layer is greater than a soldering temperature of the first solder layer. The protective element of claim 21, wherein the liquidus point of the metal block is greater than the assembly temperature of the protective element. The protective element of claim 21, wherein a ratio of a volume of the metal block to an area of the first solder layer plus an area of the second solder layer is less than 0.16. The protection element of claim 21, wherein the third sub-electrode has a first protrusion, the fourth sub-electrode has a second protrusion, and the first protrusion and the second protrusion There is a gap between them. The protection element of claim 25, wherein the upper electrode further has a second sub-electrode, and the first protrusion and the second protrusion are located at the first extension and the second sub-electrode between. The protective element of claim 25, wherein the spacing is between 0.1 mm and 0.4 mm. The protective element of claim 21, wherein a ratio of a width of the first extension to a width of the substrate is less than 0.8. The protective element of claim 21, wherein the heating element is located on the second surface and is connected to the lower electrode. The protection element of claim 29, wherein the lower electrode has a fifth sub-electrode and a sixth sub-electrode opposite to each other, the fifth sub-electrode corresponding to the first sub-electrode, the heating element is connected Between the fifth sub-electrode and the sixth sub-electrode. The protection element of claim 29, wherein the fifth sub-electrode has a second extension, the sixth sub-electrode has a third extension, the second extension being located at the third extension The seventh sub-electrode is interposed between the second sub-electrode and the eighth sub-electrode, and the heating element is connected between the second extension and the third extension. The protection element of claim 21, wherein the upper electrode further comprises a second sub-electrode on the first surface, and the heating element is connected to the first sub-electrode and the second sub-electrode. The protective component of claim 21, further comprising a flux disposed on the first surface of the substrate between the first extension and the third sub-electrode, and located at the first The extension portion is between the fourth sub-electrode, and the metal block covers a portion of the flux. The protective element according to claim 21, further comprising an insulating layer covering the heating element. The protective component of claim 21, further comprising a housing disposed on the first surface of the substrate and covering the metal block. A protective component comprising: a substrate having a first surface and a second surface opposite to each other; an upper electrode disposed on the first surface of the substrate, having a first sub-electrode and a first surface opposite to each other a third sub-electrode and a fourth sub-electrode, wherein the first sub-electrode has a first extension, and the first extension is located between the third sub-electrode and the fourth sub-electrode; On the second surface of the substrate; an end electrode connecting the upper electrode and the lower electrode; a heating element disposed on the substrate, wherein the first extension extends above the heating element; a metal block disposed on the The first surface of the substrate is connected to the third sub-electrode, the first extension portion and the fourth sub-electrode; and a solder layer is disposed between the metal block and the first extension portion and disposed on the first surface The metal block and the third sub-electrode are disposed between the metal block and the fourth sub-electrode, wherein a ratio of a volume of the metal block to an area of the solder layer is less than 0.16. The protection element of claim 36, wherein the third sub-electrode has a first protrusion, the fourth sub-electrode has a second protrusion, and the first protrusion and the second protrusion There is a gap between them. The protective element of claim 37, wherein the spacing is between 0.1 mm and 0.4 mm. The protection element of claim 37, wherein the upper electrode further comprises a second sub-electrode, and the first protrusion and the second protrusion are located at the first extension and the second sub-electrode between, The protective element of claim 36, wherein a ratio of a width of the first extension to a width of the substrate is less than 0.8. The protective element of claim 36, wherein the heating element is located on the second surface and is connected to the lower electrode. The protection element of claim 41, wherein the lower electrode has a fifth sub-electrode and a sixth sub-electrode opposite to each other, the fifth sub-electrode corresponds to the first sub-electrode, and the heating element The fifth sub-electrode and the sixth sub-electrode are connected. The protection element of claim 42, wherein the fifth sub-electrode has a second extension, the sixth sub-electrode has a third extension, and the second extension is located at the third extension The seventh sub-electrode is interposed between the second sub-electrode and the eighth sub-electrode, and the heating element is connected between the second extension and the third extension. The protection element of claim 36, wherein the upper electrode further comprises a second sub-electrode on the first surface, and the heating element is connected to the first sub-electrode and the second sub-electrode. The protective component of claim 36, further comprising a flux disposed on the first surface of the substrate between the first extension and the third sub-electrode, and located at the first Between the extension and the fourth sub-electrode, and the metal block is located on the flux. The protective element according to claim 36 of the patent application further comprises an insulating layer covering the heating element. The protective component of claim 36, further comprising a housing disposed on the first surface of the substrate and covering the metal block.