TWI627652B - Protection device and circuit protection apparatus containing the same - Google Patents

Abstract

The invention provides a protection element and a circuit protection device therefor. The protection element includes a first planar substrate, a second planar substrate, a heating member, a fuse, and an adsorbing member. The first planar substrate includes a first surface, the second planar substrate including a second surface facing the first surface. The heating member is disposed on the first surface, and the fuse member is disposed above the heating member. The absorbing member is disposed on the second surface and located above the fuse. When an overvoltage or an overtemperature occurs, the heating member generates heat to melt the fuse, and the adsorbing member adsorbs the molten metal of the fuse.

Description

Protection element and circuit protection device thereof

The present invention relates to a protection element applied to an electronic device and a circuit protection device including the same, and more particularly to a protection element having a function of preventing overvoltage, overcurrent or overtemperature and a circuit protection device thereof.

A current fuse having a low melting point metal such as lead, tin or antimony is widely known as a protective element for cutting off an overcurrent. Thereafter, in terms of preventing overcurrent and overvoltage, the protective element is continuously developed, which comprises sequentially laminating a heat generating layer and a low melting point metal layer on a planar substrate. When the overvoltage occurs, the heating element generates heat, and the heat is transferred upward from the bottom, and the electrode carrying the low melting point metal body is heated, and the low melting point metal body is blown, and the current flowing through is cut off to protect the related circuit or electronic device.

In recent years, mobile devices have become highly popular, and information products such as mobile phones, computers, and personal mobile assistants are everywhere, making people's dependence on information products increasing. However, from time to time, there has been news about the explosion of batteries in portable electronic products such as mobile phones during charging and discharging. Therefore, the manufacturer gradually improves the design of the aforementioned overcurrent and overvoltage protection components, and enhances 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 protection element proposed by the prior art is protected by connecting the fuse in the protection element in series with the circuit of the battery, and electrically connecting the low melting point metal layer and the heat generating layer in the protection element to the switch and the integrated circuit (IC). )element. In this way, when the IC component measures the overvoltage, the startup switch is turned on, and the current is passed through the heat generating layer in the protection component, so that the heat generating layer generates heat to blow the fuse, thereby causing the circuit of the battery to be in an open state. Overvoltage protection is achieved. Those skilled in the art can also fully understand that when an overcurrent occurs, a large amount of current flows through the fuse, which causes the fuse to heat up and fuse, thereby achieving overcurrent protection.

1 is a schematic cross-sectional view of a conventional protective element that implements the aforementioned protective mechanism. The protection element 100 has a planar substrate 110, a heating element 120, an insulating layer 130, a low melting point metal layer 140, a flux 150, and a cover 170. The outer edge of the outer cover 170 is disposed on the surface of the planar substrate 110, and provides an inner space for accommodating the heating member 120, the insulating layer 130, the low melting point metal layer 140, and the flux 150. The heating element 120 is disposed on the planar substrate 110 and electrically connects the two heating element electrodes 125. The low melting point metal layer 140 connects the electrode layers 160 on both sides and an intermediate electrode 165. The insulating layer 130 covers the heating member 120 and the heating member electrode 125. The low melting point metal layer 140 is disposed above the insulating layer 130 as a fuse, and the flux 150 completely covers the low melting point metal layer 140. In this way, when the heating element 120 generates heat, the low melting point metal layer 140 can be directly melted, so that the low melting point metal layer 140 is melted and flows to the electrode layers 160 and the intermediate electrode 165 on both sides, so the both side electrode layers 160 and the intermediate electrode 165 The three-electrode block is formed by the melting of the low-melting-point metal layer 140 to the three blocks, resulting in the low-melting-point metal layer 140 being separated from the original one piece of metal into three pieces, and the cut-off current is for protection purposes. In the prior art, since the three electrode blocks are all under the low melting point metal layer 140, but above the low melting point metal layer 140, even if there is a chemical protective film such as rosin, under high temperature heating, The chemical protective film also loses its protective effect due to loss or volatilization, and the surface of the low-melting-point metal layer 140 is easily oxidized to a different extent when heated and melted at a high temperature to form an oxide film, and the oxide film covers the low melting. On the surface of the melting point metal layer 140, the molten metal is prevented from accumulating to the three electrode blocks, resulting in the low melting point metal layer 140 being less likely to be blown, and having a problem that the fusing time is not accurate. The invention utilizes an innovative structural design that can break through this problem and make the fusing time more accurate.

At present, mobile devices tend to be miniaturized, and therefore components mounted therein are required to be thinner. The outer cover 170 of the above protective element 100 requires a certain height to accommodate the inner member. Since the outer cover 170 is usually formed by injection molding, it is not easy to further reduce the height of the outer cover 170 in the process, and does not meet the demand for thinning. . In addition, the injection molding requires mold opening, and the cost is high, so that the design of the protection member 100 has a problem that the cost is not easily further reduced.

The present invention provides a protection element and a circuit protection device including the same, which has the functions of overvoltage, overcurrent and/or overtemperature protection, and can be made thinner, conforming to the trend of miniaturization and thinning of electronic devices. demand.

According to a first aspect of the present invention, there is provided a protective member comprising a first planar substrate, a second planar substrate, a heating member, a fuse member, and an adsorbing member. The first planar substrate includes a first surface, the second planar substrate including a second surface facing the first surface. The heating member is disposed on the first surface, and the fuse member is disposed above the heating member. The absorbing member is disposed on the second surface and located above the fuse. When an overvoltage or an overtemperature occurs, the heating member generates heat to melt the fuse, and the adsorbing member adsorbs the molten metal of the fuse.

In one embodiment, the fuse member is in an upward and downward direction of adsorption when molten.

In one embodiment, the protective element further includes an insulating frame disposed on the second surface for collecting the flux over the fuse.

In one embodiment, the insulating frame includes an outer frame and an inner frame, the inner frame gathering the flux, the outer frame confining an adhesive or a guide post between the first planar substrate and the second planar substrate.

In one embodiment, there is a gap between the fuse member and the adsorbing member, and the gap is at a distance sufficient to produce an adsorption effect.

In one embodiment, the gap is filled with solder paste to connect the fuse and the adsorbing member.

In one embodiment, the protective element has a thickness of 0.2 to 2 mm.

In one embodiment, the protective element further includes an insulating layer disposed between the fuse and the heating member for isolation.

In one embodiment, the protection element further includes a first electrode and a second electrode disposed on the first surface, and the two ends of the fuse are respectively connected to the first electrode and the second electrode.

In one embodiment, the protection element further includes a third electrode and a fourth electrode disposed on the first surface, the third electrode and the fourth electrode being respectively connected to both ends of the heating member.

In one embodiment, the heating member is rectangular, and the third electrode and the fourth electrode are respectively connected to the longitudinal ends of the heating member.

In one embodiment, the protective element further includes an electrode layer connected to the middle of the fuse and electrically connected to the third electrode.

In one embodiment, the protective element forms an equivalent circuit in which the fuse comprises two fuses and the heater comprises one heater.

According to a second aspect of the present invention, a circuit protection device comprising the aforementioned protection component is provided with a detector and a switch. The detector is used to detect the voltage drop or temperature of a circuit to be protected. A switch is connected to the detector to receive its detection signal. When the detector detects a voltage drop or the temperature exceeds a preset value, the switch is turned on, so that a current flows through the heating member, so that the heating member generates heat to melt the fuse member, and the adsorption member adsorbs the melting of the fuse member. metal.

In one embodiment, the fuse member is in an upward and downward direction of adsorption when molten.

In one embodiment, the detector and the open relationship are disposed on the first surface.

Different from the prior art, the embodiment of the invention not only has three electrodes under the fuse member, but also can adsorb the molten low-melting metal, and the adsorbing member has the upper or upper adsorbing molten low-melting metal above the fuse member. Ability. Therefore, when the heating member starts heating, the low melting point metal contained in the fuse member starts to melt, and is adsorbed by the upper adsorbing member and the lower three electrodes, so that the oxide layer is not easily formed, and the low melting point metal is cut off. Therefore, the present invention overcomes the problem of inaccurate melting time of the low melting point metal of the prior art by adsorbing the molten low melting point metal from the upper adsorbing member and the lower electrode.

The protective element of the present invention can be fabricated using printing technology in a large scale, so that the protective element can be made relatively thin, meeting the requirements of miniaturization and thinning of the element. In addition, due to the injection molding technology not used in the process, it is not necessary to open the mold, which can reduce the production cost. In terms of the process, the protection element can be separately fabricated on the basis of the above planar substrate and the lower planar substrate at the initial stage of manufacture, so that the related processes can be simultaneously performed, and the components on the lower planar substrate and the upper planar substrate can be combined and combined. Complete the protection component. Because it can be produced at the same time, it can increase the throughput and increase the output. In addition, there is another advantage in separately producing separately. If the semi-finished products made by the above planar substrate and the lower planar substrate have defective products, they can be eliminated separately, and it is not necessary to wait until the finished protective component is finished and then eliminated, thereby reducing the loss of defective products. . Furthermore, compared with the conventional protection element structure design, the protection element of the present invention has a relatively concentrated fuse time (smaller standard deviation), and can withstand large voltage and power, and has superior quality stability.

The above and other technical contents, features and advantages of the present invention will become more apparent from the following description.

2 is a perspective structural view of the protective element 10 of the first embodiment of the present invention, FIG. 3A is an exploded perspective view of the protective element 10, and FIG. 4 is a cross-sectional view of the protective element 10 of FIG. 2 taken along line 1-1. The protection element 10 includes a first planar substrate 11, a second planar substrate 12, a fuse 13, a heating member 14, an insulating layer 15, an electrode layer 16, an insulating frame 17, a silver paste 18, a protective layer 19, an adsorbing member 20, and a first The electrode 21, the second electrode 22, the third electrode 23, the fourth electrode 24, the pad 25, the pad 26, and the pad 27. The structural integrity of Figures 2, 3A and 4 is slightly different for the sake of brevity and clarity of the drawings. For example, Figure 4 does not depict insulating layer 19, pads 25, 26 and 27, and the like. Preferably, the protective element of the present invention can use the first planar substrate 11 and the second planar substrate 12 as a basis, and separately fabricate various members, and then combine the two to form the protective member 10. The upper surface (first surface) of the first planar substrate 11 can be used to fabricate the first electrode 21, the second electrode 22, the third electrode 23, and the fourth electrode 24 by printing techniques, usually the four electrodes are simultaneously printed, and have Same height (thickness). The third electrode 23 and the fourth electrode 24 are similar in a T shape, and each includes an elongated portion and an end portion, wherein the elongated portion extends between the first electrode 21 and the second electrode 22. Next, a heating member 14 is formed, and the heating member 14 is connected at both ends to the third electrode 23 and the fourth electrode 24 to form a conductive path. In one embodiment, the heating element 14 is formed by printing and fills the gap between the third electrode 23 and the fourth electrode 24. The insulating layer 15 covers the third electrode 23, the fourth electrode 24, and the heating member 14 to provide insulation isolation. The electrode layer 16 is formed on the surface of the insulating layer 15 at a central portion, and then the solder paste is printed and the fuse 13 is attached. The fuse 13 is connected across the first electrode 21, the electrode layer 16, and the second electrode 22 to form a conductive path. The gap between the fuse member 13 and the insulating layer 15 may also be additionally filled with an insulating material to provide a supporting effect to avoid deformation of the fuse member 13. The elongated portion of the third electrode 23 is connected to one end of the heating member 14, and its end portion is electrically connected to the electrode layer 16. The position of the electrode layer 16 corresponds to the central portion of the fuse member 13 as the intermediate electrode of the fuse member 13. When the fuse member 13 is melted, the alloy is adsorbed to each other due to the high temperature, and the fuse member 13 is adsorbed downward toward the first electrode 21, the electrode layer 16, and the second electrode 22. In one embodiment, the fuse member 13 may be connected to the first electrode 21, the electrode layer 16, and the second electrode 22 by solder 31. The insulating frame 17 is disposed above the fuse 13 or, in particular, on the lower surface (second surface) of the second planar substrate 12, and includes an inner frame 171 and an outer frame 172 for collecting the flux above the fuse 13 . In this embodiment, the inner frame 171 and the outer frame 172 are rectangular (but not limited to rectangular), and the inner frame 171 is surrounded by the outer frame 172. The adsorbing member 20 may be disposed on the lower surface of the second planar substrate 12 by silver paste printing or by electroplating, and surrounded by the inner frame 171. The position of the adsorbing member 20 corresponds to the upper center of the fuse member 13, so that the fuse member 13 can be adsorbed upward when it is melted, and the fusing effect is enhanced. The first planar substrate 11 and the second planar substrate 12 may be bonded by a bonding agent or a pillar 32 made of a silver paste and a solder paste to form a support to increase the structural strength thereof. The elongated silver paste 18 is located on opposite sides of the lower surface of the second planar substrate 12 to assist in fixing and connecting the first planar substrate 11 and the second planar substrate 12. However, the silver paste 18 and the guide post 32 are not absolutely necessary, and may be omitted if structural strength permits. In particular, the inner frame 171 is used to collect the flux, and the outer frame 172 confines the adhesive or pillar 32 between the first planar substrate 11 and the second planar substrate 12. The inner frame 171 and the outer frame 172 can be printed, and a very thin thickness can be obtained. In particular, the inner frame 171 and the outer frame 172 have a thickness equal to or slightly larger than the thickness of the adsorbing member 20, and the inner frame 171 can be directly contacted and blown. The upper surface of the piece 13. The upper surface of the second planar substrate 12 may cover the protective layer 19, for example, using a glass or glaze material to provide protection and may be used to mark the mark of the protective element 10. A semicircular through hole is disposed at a position of a side surface of the first planar substrate 11 with respect to the first electrode 21, the second electrode 22, and the fourth electrode 24. The surface of the semicircular through hole may be plated with a conductive layer to form a conductive via 33. The conductive vias 33 are respectively located on three different sides of the first planar substrate 11. The pads 25, 26 and 27 are located on the lower surface of the first planar substrate 11 as an interface for soldering the protective element 10 to a circuit board (not shown). In detail, one conductive via 33 electrically connects the first electrode 21 and the pad 25, the other conductive via 33 electrically connects the second electrode 22 and the pad 26, and another conductive via 33 electrically connects the fourth electrode 24 and Solder pad 27.

The third electrode 23 and the fourth electrode 24 connected to the heating member may have different designs as shown in Figs. 3B and 3C. The portion in which the heating member 14 is connected to the third electrode 23 and the fourth electrode 24 in FIG. 3A is a longitudinal strip-like design, and the portion in FIG. 3B and FIG. 3C to which the heating member 14 is connected is designed in a lateral direction such that the third electrode 23 And the fourth electrode 24 is connected to both longitudinal ends of the heating member 14. Since the heating member 14 is rectangular in this embodiment, the design of Figs. 3B and 3C causes the electric resistance of the heating member 14 to become large (current flows in the longitudinal direction of the heating member, and the current path becomes long). Generally, as more cells are connected in series in the battery to be protected, a larger resistance heating element 14 is required to maintain power stability because of an increase in operating voltage. Therefore, the designs of Figures 3B and 3C are suitable for such applications. In addition, the heating element 14 can also use a lower resistance material to obtain a similar resistance value in response to a longer current path.

In summary, the main components of the protective member 10 include a first planar substrate 11, a second planar substrate 12, a heating member 14, a fuse member 13, and an adsorbing member 20. The upper surface (first surface) of the first planar substrate 11 faces the lower surface (second surface) of the second planar substrate 12. The heating element 14 is disposed on the first surface, and the fuse element 13 is disposed above the heating element 14. The adsorbing member 20 is disposed on the second surface and located above the fuse member 13. When an overvoltage or an overtemperature occurs, the heating member 14 generates heat to melt the fuse member 13, and at this time, the adsorbing member 20 adsorbs the molten metal of the fuse member 13 from above. Further, the first electrode 21 and the second electrode 22 located under the fuse member 13 also generate adsorption from the lower side, so that the fuse member 13 can simultaneously generate adsorption phenomena in the upward and downward directions when it is melted.

In one embodiment, the first planar substrate 11 and the second planar substrate 12 may be a square planar insulating planar substrate, and the material may be selected from, for example, alumina, aluminum nitride, zirconia or a heat resistant glass plate. The first electrode 21, the second electrode 22, the third electrode 23 and the fourth electrode 24 may comprise silver, gold, copper, tin, nickel or other conductive metal, having a thickness of about 0.005 to 1 mm, or particularly 0.01 mm, 0.05 mm. , 0.1mm, 0.3mm, 0.5mm. In addition to using printed electrodes, it can also be fabricated using sheet metal for high voltage applications. The material of the fuse member 13 may be selected from a low melting point metal or an alloy thereof such as Sn-Pb-Ag, Sn-Ag, Sn-Sb, Sn-Zn, Zn-Al, Sn-Ag-Cu, Sn, or the like. Depending on the amount of current required to pass, the length and width of the fuse member 13 can be adjusted, but not exceeding the length and width of the first planar substrate 11 and the second planar substrate 12, and the thickness thereof is between 0.005 mm and 1 mm. Preferably, the thickness is between 0.01 mm and 0.5 mm, and the optimum thickness is between 0.02 mm and 0.2 mm, or especially 0.05 mm, 0.1 mm, and 0.3 mm. The thicker fuse 13 is used in applications with high currents such as 30-100A. The material of the heating member 14 may include additives such as ruthenium oxide (RuO ₂ ) and silver (Ag), palladium (Pd), and platinum (Pt). As the material of the insulating layer 15 isolated between the heating member 14 and the fuse member 13, a glass, an epoxy, an alumina or a silicone or a glaze may be used. The adsorbing member 20 can be prepared by silver paste printing or by electroplating. The adsorbing member 20 may be represented by a single number or a plurality of strips, blocks, dots, curves, or other shapes, and the composition may be a metal or an alloy such as silver, gold, copper, nickel, tin, lead, antimony, or the like. Layer or multilayer metal composition.

As described above, on the first planar substrate 11, the heating member 14 and the members of the first to fourth electrodes 21, 22, 23, and 24 can be formed by thick film printing. Similarly, members such as the insulating frame 17 and the adsorbing member 20 can also be formed on the surface of the second planar substrate 12 by printing. After the members of the surfaces of the first planar substrate 11 and the second planar substrate 12 are respectively fabricated, the second planar substrate 12 is inverted and the two are combined to form the protective element 10. Since the main components can be produced by printing and have no cover design, the thinner design can be achieved. In addition, since some of the members are separately fabricated on different planar substrates, the complexity of fabrication can be reduced. The second planar substrate 12 can be slightly smaller than the first planar substrate 11, so that the second planar substrate 12 can be first mounted in the jig and then combined with the first planar substrate 11. Further, in the separately produced relationship, if the semi-finished products of the first planar substrate 11 and the second planar substrate 12 are defective, they can be individually screened, so that the yield of the final protective component 10 can be increased, and the manufacturing cost can be reduced. However, the present invention does not limit the components on the first planar substrate 11 and the second planar substrate 12 to be specific. If the final structure of the protective component 10 includes the technical features defined by the present invention, it will remain covered by the present invention.

In one embodiment, the surface of the adsorbing member 20 disposed above the fuse member 13 may directly contact or retain a gap with the fuse member 13, and the gap must have a distance to produce an adsorption effect. If there is a gap, the thickness of the gap is not more than 1.5 mm, preferably not more than 1 mm, preferably not more than 0.5 mm, and can be filled with a solder paste (not shown). The action of the adsorbing member 20 and the solder paste is to adsorb the metal at the time of melting the aggregated fuse 13 from above to prevent the flow of the fuse 13 from flowing around. The gap may also be filled with rosin or other soft metal or flux, but still needs to be adsorbed from above. The function of the molten metal of the fusion fuse 13 is collected. The position of the heating member 14 corresponds to the fuse member 13, so that heat generated by the heating member 14 can be efficiently transmitted to the fuse member 13 to melt the fuse member 13.

In some cases, when the fuse member 13 is blown, the second planar substrate 12 is likely to be cracked if overheated, and a heat conductive layer (for example, a silver metal layer or a thermal conductivity greater than 50 W) may be printed on the upper surface of the second planar substrate 12. /m·K or a material of 100 W/m·K) to enhance thermal runaway to prevent cracking of the second planar substrate 12. An insulating layer can then be formed over the silver metal layer while preventing the silver metal layer from causing undesired short circuit problems.

Since the main members can be fabricated by printing techniques, the thickness of the heating member 14 and the associated first to fourth electrodes 21, 22, 23, 24, etc. can be reduced such that the distance between the first planar substrate 11 and the second planar substrate 12 is only It is about 0.03~1.5mm, the preferred distance is 0.04~1mm, and the optimum distance is 0.05~0.5mm, or especially 0.1mm, 0.3mm, 0.7mm or 1.2mm. Therefore, even after the first planar substrate 11 and the second planar substrate 12 are added, the thickness of the protective element 10 is only about 0.2 to 2 mm, preferably 0.4 to 1.5 mm, and the optimum thickness is 0.5 to 1 mm, or particularly 0.3. Mm, 0.7mm, 1.3mm, can effectively achieve the effect of thinning. Further, the dimensional change of the fuse member 13 and the heating member 14 can affect the resistance value thereof, and accordingly, the low-resistance fuse member 13 and the high-resistance heater member 14 can be fabricated, that is, the high-efficiency protection member 10 can be produced.

The equivalent circuit diagram of the protection element 10 of the present invention can be as shown by the circuit of the dashed box in FIG. The first electrode 21 serves as an end point A1 to which a device to be protected (for example, a secondary battery or a motor) is connected, and the second electrode 22 is connected to an end point B1 such as a charger or the like. The third electrode 23 is connected to the heating member 14 and the electrode layer 16. The other end of the heating member 14 is connected to the fourth electrode 24. According to the circuit design of the protection element 10, the circuit formed by the fuse 13 comprises two fuses connected in series, and the heating element 14 forms a heater (shown by a resistance symbol). In one embodiment, the fourth electrode 24 is electrically coupled to the switch 52, which may be, for example, a field effect transistor (FET). A switch 52, such as a gate of the FET, is coupled to the detector 51 and is coupled to the other terminal A2 of the circuit to be protected, and to the other end B2 of the charger. The detector 51 can be an IC component and has a function of detecting a voltage drop or a temperature. When there is no overvoltage or overtemperature, the switch 52 is open and current flows through the fuse 13 but no current flows through the heater 14. If an overcurrent occurs at this time, the fuse 13 is blown to provide overcurrent protection. When the detector 51 detects that the voltage exceeds a predetermined value (overvoltage) or the temperature exceeds a preset value (over temperature), the switch 52 is switched to the on state, and the current is sourced from the source of the switch 52 to the 汲Drain and flow through the heating element 14. The heating member 14 generates heat to melt the fuse member 13, thereby providing protection against overvoltage or overtemperature. In summary, B1 to A1, B2 to A2 form two power lines provided to the circuit to be protected, and a combination of the protection element 10, the detector 51 and the switch 52 connects the two power lines to form a circuit protection device 50. . When the detector 51 detects that the voltage drop or temperature of the circuit to be protected exceeds a preset value, the starting heating member 14 blows the fuse member 13. In one embodiment, the first planar substrate 11 can be made larger, for example, the first planar substrate 11 of FIG. 4 is extended to the left and right, so that the upper surface of the first planar substrate 11 can provide the space-mounted detector 51 and the switch 52. And modular.

Hereinafter, the protective element 10 of the foregoing embodiment of the present invention and the conventional protective element 100 of the same specification shown in FIG. 1 are tested, wherein the resistance of the fuse is 0.0012 Ω, the resistance of the heating member is about 24 Ω, the supply voltage is 42 V, and the fuse is blown. The situation after the fuse is broken is shown in the photographs of Figures 6 and 7, respectively. Fig. 6 shows that the fuse member 61 of the protective member of the present invention has a considerable distance between the upper and lower portions which are divided after being broken, and the fuse member 61 can be completely broken after being melted. Viewed from above, the position of the adsorbing member 62 is substantially in the middle of the breaking distance of the fuse member 61. Referring to Fig. 7, although the fuse element 71 of the conventional protection element can be disconnected, the distance at which the fuse element 71 is broken is significantly smaller, indicating that the effect of disconnection is not as good as the design of the present invention. It can be seen that the present invention provides the adsorbing member 62 located above the fuse member 61, which can produce an adsorption effect when the fuse member 61 is melted, and helps the fuse member 61 to be disconnected in time and in a large area. In addition, in the same test condition and taking 10 samples of the fuse test, the protection component of the present invention is designed to have a standard deviation of the fuse time of 0.783 seconds, and the conventional protection element design has a standard deviation of the fuse time of 1.652 seconds, wherein The calculation of the standard deviation is based on the following formula (1). It is obvious that the fuse element of the present invention has a relatively concentrated fuse time and is superior to conventional designers. ...(1) where, For the blow time, For the sample average, and For the sample size.

The protection element 10 of the present invention performs a fuse test at different supply voltages of 18.4 to 60 V, and the current value, voltage value, and fuse time are recorded as shown in Table 1 below. When added to a supply voltage of 56V, its power can be up to about 132W. When the supply voltage is greater than 60V, it is found that the upper second planar substrate 12 is cracked during the test, and it is presumed that the heat generation is suddenly concentrated in a certain portion and cannot be effectively and uniformly conducted.

[Table 1]  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> Example</td><td> Heating element (Ω) </td><td> Fuse (Ω) </td><td> Supply Voltage (V) </td><td> Current (A) </td><td> Voltage (V) </td><td> Power (W) </td><td> Fuse time (s) </td><td> Substrate cracking</td></tr><tr><td> 1 </td><td> 23.74 </td><td > 0.0012 </td><td> 60.0 </td><td> - </td><td> - </td><td> - </td><td> - </td><td> Yes </td></tr><tr><td> 2 </td><td> 22.74 </td><td> 0.0012 </td><td> 56.0 </td><td> 2.34 </td ><td> 56.68 </td><td> 132.63 </td><td> 0.13 </td><td> No </td></tr><tr><td> 3 </td><td > 22.70 </td><td> 0.0012 </td><td> 56.0 </td><td> 2.30 </td><td> 55.69 </td><td> 128.09 </td><td> 0.12 </td><td> No </td></tr><tr><td> 4 </td><td> 24.77 </td><td> 0.0011 </td><td> 56.0 </td ><td> 2.10 </td><td> 56.09 </td><td> 117.79 </td><td> 0.22 </td><td> No </td></tr><tr><td > 5 </td><td> 22.80 </td><td> 0.0012 </td><td> 56.0 </td><td> 2.29 </td><td> 56.09 </td><td> 128.45 </td><td> 0.08 </td><td> No </td></tr><tr><td> 6 </td>< Td> 23.66 </td><td> 0.0012 </td><td> 46.0 </td><td> 1.81 </td><td> 45.44 </td><td> 82.25 </td><td> 0.34 </td><td> No </td></tr><tr><td> 7 </td><td> 23.31 </td><td> 0.0012 </td><td> 46.0 </ Td><td> 1.85 </td><td> 45.64 </td><td> 84.43 </td><td> 0.23 </td><td> No </td></tr><tr>< Td> 8 </td><td> 22.00 </td><td> 0.0012 </td><td> 46.0 </td><td> 1.91 </td><td> 45.59 </td><td> 87.08 </td><td> 0.23 </td><td> No </td></tr><tr><td> 9 </td><td> 24.07 </td><td> 0.0011 </ Td><td> 42.0 </td><td> 1.69 </td><td> 41.70 </td><td> 70.47 </td><td> 1.11 </td><td> No </td> </tr><tr><td> 10 </td><td> 23.66 </td><td> 0.0012 </td><td> 42.0 </td><td> 1.67 </td><td> 41.77 </td><td> 69.76 </td><td> 1.07 </td><td> No </td></tr><tr><td> 11 </td><td> 23.31 </ Td><td> 0.0012 </td><td> 42.0 </td><td> 1.69 </td><td> 41.70 </td><td> 70.47 </td><td> 1.03 </td> <td> No </td></tr><tr><td> 12 </td><td> 22.00 </td><td> 0.0011 </td><td> 20.4 </td><td> 0.96 </td><td> 20.22 </td><td> 19.41 </td><td> 9.48 </td><td> No </td></tr><tr><t d> 13 </td><td> 22.74 </td><td> 0.0011 </td><td> 20.4 </td><td> 0.91 </td><td> 20.24 </td><td> 18.42 </td><td> 9.10 </td><td> No </td></tr><tr><td> 14 </td><td> 22.70 </td><td> 0.0012 </ Td><td> 20.4 </td><td> 0.95 </td><td> 20.19 </td><td> 19.18 </td><td> 8.67 </td><td> No </td> </tr><tr><td> 15 </td><td> 22.77 </td><td> 0.0012 </td><td> 18.4 </td><td> 0.83 </td><td> 18.20 </td><td> 15.11 </td><td> 30.22 </td><td> No </td></tr><tr><td> 16 </td><td> 22.80 </ Td><td> 0.0012 </td><td> 18.4 </td><td> 0.81 </td><td> 18.19 </td><td> 14.73 </td><td> 29.13 </td> <td> No </td></tr><tr><td> 17 </td><td> 23.23 </td><td> 0.0012 </td><td> 18.4 </td><td> 0.80 </td><td> 18.12 </td><td> 14.50 </td><td> 27.21 </td><td> No </td></tr></TBODY></TABLE>

Similarly, the conventional protection device 100 performs a fuse test at different supply voltages of 18.4 to 56 V, wherein the current value, voltage value, and fuse time are recorded as shown in Table 2 below. The samples in Table 2 are subjected to a supply voltage of up to 46 V, at which point the component can withstand a power of approximately 77 W. When the supply voltage was 56V, the cover was found to be cracked during the test. Because the outer cover is a closed structure with respect to the planar substrate, the temperature is less likely to escape, so it is easy to be cracked due to overheating, and the voltage and power that can be withstood are not as good as the protective element design of the present invention.

[Table 2]  <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> Comparative example</td><td> Heating element (Ω) </td><td> Fuse (Ω) </td><td> Supply Voltage (V) </td><td> Current (A) </td><td> Voltage (V) </td><td> Power (W) </td><td> Fuse time (s) </td><td> Cover cracking</td></tr><tr><td> 1 </td><td> 22.56 </td><td > 0.0012 </td><td> 56.0 </td><td> - </td><td> - </td><td> - </td><td> - </td><td> Yes </td></tr><tr><td> 2 </td><td> 23.66 </td><td> 0.0012 </td><td> 46.0 </td><td> 1.71 </td ><td> 45.14 </td><td> 77.19 </td><td> 0.46 </td><td> No </td></tr><tr><td> 3 </td><td > 23.31 </td><td> 0.0012 </td><td> 46.0 </td><td> 1.75 </td><td> 45.31 </td><td> 79.29 </td><td> 0.38 </td><td> No </td></tr><tr><td> 4 </td><td> 22.00 </td><td> 0.0012 </td><td> 46.0 </td ><td> 1.76 </td><td> 45.29 </td><td> 79.71 </td><td> 0.43 </td><td> No </td></tr><tr><td > 5 </td><td> 24.85 </td><td> 0.0011 </td><td> 43.0 </td><td> 1.65 </td><td> 42.55 </td><td> 70.21 </td><td> 1.16 </td><td> No </td></tr><tr><td> 6 </td>< Td> 25.25 </td><td> 0.0011 </td><td> 42.0 </td><td> 1.56 </td><td> 41.66 </td><td> 64.99 </td><td> 1.28 </td><td> No </td></tr><tr><td> 7 </td><td> 24.49 </td><td> 0.0012 </td><td> 42.0 </ Td><td> 1.65 </td><td> 41.65 </td><td> 68.72 </td><td> 1.22 </td><td> No </td></tr><tr>< Td> 8 </td><td> 23.89 </td><td> 0.0011 </td><td> 42.0 </td><td> 1.69 </td><td> 41.70 </td><td> 70.47 </td><td> 1.21 </td><td> No </td></tr><tr><td> 9 </td><td> 23.97 </td><td> 0.0012 </ Td><td> 32.0 </td><td> 1.29 </td><td> 31.77 </td><td> 40.98 </td><td> 2.47 </td><td> No </td> </tr><tr><td> 10 </td><td> 23.34 </td><td> 0.0012 </td><td> 32.0 </td><td> 1.31 </td><td> 31.40 </td><td> 41.13 </td><td> 2.31 </td><td> No </td></tr><tr><td> 11 </td><td> 23.66 </ Td><td> 0.0011 </td><td> 20.0 </td><td> 0.84 </td><td> 20.40 </td><td> 17.14 </td><td> 13.83 </td> <td> No </td></tr><tr><td> 12 </td><td> 24.49 </td><td> 0.0011 </td><td> 20.0 </td><td> 0.82 </td><td> 20.48 </td><td> 16.79 </td><td> 16.19 </td><td> No </td></ Tr><tr><td> 13 </td><td> 24.38 </td><td> 0.0012 </td><td> 18.4 </td><td> 0.73 </td><td> 18.21 < /td><td> 13.29 </td><td> 43.98 </td><td> No </td></tr><tr><td> 14 </td><td> 24.32 </td> <td> 0.0012 </td><td> 18.4 </td><td> 0.73 </td><td> 18.20 </td><td> 13.29 </td><td> 48.52 </td><td > No </td></tr><tr><td> 15 </td><td> 24.14 </td><td> 0.0012 </td><td> 18.4 </td><td> 0.73 < /td><td> 18.19 </td><td> 13.28 </td><td> 31.60 </td><td> No </td></tr><tr><td> 16 </td> <td> 24.48 </td><td> 0.0011 </td><td> 18.4 </td><td> 0.72 </td><td> 18.12 </td><td> 13.05 </td><td > 34.45 </td><td> No </td></tr></TBODY></TABLE>

Tables 1 and 2 above are only comparisons of the fuse tests based on specific specifications, and do not limit the problem that the protective elements of the present invention are sure to cause substrate cracking at a supply voltage of 60V. In practical applications, the present invention can achieve a withstand voltage of more than 70V or higher in different protection elements, or is suitable for higher power applications.

The equivalent circuit of the protective element of the foregoing embodiment includes two fuses and one heater. However, it is also possible to fabricate circuit forms comprising, for example, two fuses and two heaters, or one fuse and one heater, using other different structural circuit designs, while still being covered by the innovative technology of the present invention. In still another embodiment, the fuse member electrically connects the two pads to form a conductive path, and the heating member connects the other two pads to form another conductive path, so that the current flowing through the heating member can be independently controlled to blow the fuse.

The invention can break through the problem that the traditional protection component is not easy to be blown and the fuse time is not accurate, and the fuse effect is enhanced. In addition to the ability of the protective element of the present invention to be adsorbed downward, by increasing the arrangement of the upper adsorbing members, the alloys are attracted to each other due to the high temperature, and the molten low melting point metal in the fuse member is also directed upward. Adsorption is carried out to prevent the formation of an oxide layer at a high temperature, so that the fuse can be smoothly blown.

The protective element of the present invention can make full use of the characteristics of the printing technology, so that the protective element can be made relatively thin, and meets the requirements of miniaturization and thinning of the component. The injection molding technology that is not used in the process not only simplifies the process, but also eliminates the cost of manufacturing the mold. In addition, compared with the conventional protective element structural design, the protective element of the present invention has a relatively concentrated fusing time (smaller standard deviation) and can withstand higher voltage and power, so that it has superior quality stability.

The technical contents and technical features of the present invention have been disclosed as above, and those skilled in the art can still make various substitutions and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the present invention should be construed as being limited by the scope of the appended claims

10‧‧‧Protection components

11‧‧‧ First planar substrate

12‧‧‧ Second planar substrate

13‧‧‧Fuse parts

14‧‧‧heating parts

15‧‧‧Insulation

16‧‧‧electrode layer

17‧‧‧Insulation frame

18‧‧‧Silver glue

19‧‧‧Protective layer

20‧‧‧Adsorbed parts

21‧‧‧First electrode

22‧‧‧second electrode

23‧‧‧ third electrode

24‧‧‧fourth electrode

25, 26, 27‧‧ ‧ pads

31‧‧‧ Solder

32‧‧‧ Guide column

33‧‧‧Electrical through holes

50‧‧‧Circuit protection device

51‧‧‧Detector

52‧‧‧ switch

61, 71‧‧‧Fuse parts

62‧‧‧Adsorbed parts

100‧‧‧protective components

110‧‧‧Flat substrate

120‧‧‧heating parts

125‧‧‧heating electrode

130‧‧‧Insulation

140‧‧‧low melting point metal layer

150‧‧‧flux

160‧‧‧electrode layer

165‧‧‧Intermediate electrode

170‧‧‧ Cover

Figure 1 shows a schematic view of the structure of a conventional protective element. 2 is a perspective view showing the three-dimensional structure of a protective element according to an embodiment of the present invention. 3A is a schematic exploded view showing the protection element of an embodiment of the present invention. 3B is a schematic exploded view showing the protection element of another embodiment of the present invention. 3C is a schematic view showing the exploded structure of a protective element according to still another embodiment of the present invention. Figure 4 is a cross-sectional view showing the structure of one embodiment taken along line 1-1 of Figure 2; FIG. 5 is a circuit diagram showing a circuit protection device according to an embodiment of the present invention. Fig. 6 shows a state in which the fuse member is blown in the protective member of the present invention. Figure 7 shows the appearance of a fuse in a conventional protective element after it has been blown.

Claims (16)

A protective element comprising: a first planar substrate comprising a first surface; a second planar substrate comprising a second surface facing the first surface; a heating member disposed on the first surface; a fuse member disposed Above the heating member; an adsorbing member disposed on the second surface and located above the center of the fuse; wherein when an overvoltage or an overtemperature occurs, the heating member generates heat to melt the fuse, and the adsorbing member adsorbs The fuse of the molten metal causes a vertical upward adsorption. The protective member according to claim 1, wherein the fuse member generates an adsorption phenomenon in the upward and downward directions when it is melted. A protective component according to claim 1, further comprising an insulating frame disposed on the second surface for collecting a flux over the fuse. The protective element according to claim 3, wherein the insulating frame comprises an outer frame and an inner frame, the inner frame collecting the flux, the outer frame confining an adhesive or a guide between the first planar substrate and the second planar substrate column. The protective member according to claim 1, wherein a gap is formed between the fuse member and the adsorbing member, and the gap is spaced apart to produce an adsorption effect. The protective member according to claim 5, wherein the gap is filled with a solder paste to connect the fuse member and the adsorbing member. The protective element according to claim 1, wherein the protective element has a thickness of 0.2 to 2 mm. The protective member according to claim 1, further comprising an insulating layer disposed between the fuse member and the heating member for isolation. The protection element according to claim 1, further comprising a first electrode and a second electrode disposed on the first surface, the fuse member being respectively connected to the first electrode and the second electrode. The protective element according to claim 9, further comprising a third electrode and a fourth electrode disposed on the first surface, the third electrode and the fourth electrode being respectively connected to both ends of the heating member. The protective member according to claim 10, wherein the heating member is rectangular, and the third electrode and the fourth electrode are respectively connected to longitudinal ends of the heating member. The protective element according to claim 10, further comprising an electrode layer connected to the middle of the fuse and electrically connected to the third electrode. A protective element according to claim 12, wherein the protective element forms an equivalent circuit in which the fuse comprises two fuses and the heater comprises one heater. A circuit protection device comprising: a protection component comprising: a first planar substrate comprising a first surface; a second planar substrate comprising a second surface facing the first surface; a heating element disposed on the first a fuse member disposed above the heating member; and an adsorbing member disposed on the second surface and located above the center of the fuse member; a detector for detecting a voltage drop or temperature of the circuit to be protected And a switch connected to the detector to receive the detection signal; wherein when the detector detects a voltage drop or the temperature exceeds a preset value, the switch is turned on, so that a current flows through the heating element, so that The heating member generates heat to melt the fuse member, and the adsorbing member adsorbs the molten metal of the fuse member to thereby generate vertical upward adsorption. A circuit protection device according to claim 14, wherein the fuse member is in an upward and downward direction of adsorption when it is melted. The circuit protection device of claim 14, wherein the detector and the open relationship are disposed on the first surface.