TW202129664A - Composite electric circuit protection device characterized in that the composite electric circuit protection device has excellent tolerance and reliability and in the presence of overcurrent and overvoltage, the PTC component can protect the voltage-dependent resistor from burning - Google Patents

Abstract

Disclosed is a composite electric circuit protection device including a positive temperature coefficient (PTC) component, a voltage-dependent resistor, a first conductive lead and a second conductive lead. The PTC component includes a PTC layer, a first electrode layer and a second electrode layer. The PTC layer is provided with two opposite surfaces. The first electrode layer and the second electrode layer are respectively disposed on the two opposite surfaces of the PTC layer. The voltage-dependent resistor is connected to the second electrode layer. The first conductive lead is connected to the first electrode layer, and the second conductive lead is connected to the voltage-dependent resistor. The PTC component is provided with a rated voltage that is between 40% and 200% of the voltage-dependent voltage measured by the voltage-dependent resistor at 1 mA. The present composite electric circuit protection device has excellent tolerance. In the presence of overcurrent and overvoltage, the PTC component can protect the voltage-dependent resistor from burning.

Description

Composite circuit protection device

The present invention relates to a composite circuit protection device, in particular to a voltage-dependent resistor (voltage-dependent resistor, VDR, or varistor) is a composite circuit protection device for varistor voltage measured at 1 mA.

United States Patent US 8,508,328 B1 describes a plug-in polymer positive temperature coefficient (PPTC) over-current (PPTC) over-current protection device. See Figure 1. The PPTC over-current protection device includes two electrodes 30, one Solder material, conductive leads 50, 60 respectively connected to the electrodes 30, and a PTC polymer substrate 20 laminated between the electrodes 30. A hole 40 is formed in the PTC polymer substrate 20, and the hole 40 has an effective volume capable of accommodating the thermal expansion of the PTC polymer substrate 20 when the temperature rises.

Electrical characteristics [such as operating current and high-voltage surge endurability] are important factors that affect the occurrence of power surges in PPTC overcurrent protection devices. When the working current of the PPTC overcurrent protection device is increased by increasing the thickness or area of the PTC polymer substrate 20, it is more susceptible to damage from power surges. On the other hand, when the high voltage tolerance of the PPTC overcurrent protection device is increased by reducing the thickness or area of the PTC polymer substrate 20, the PPTC overcurrent protection device may not be less susceptible to damage from power surges.

Although a voltage-dependent resistor (VDR) can be combined with the PPTC over-current protection device to provide over-current and over-voltage (over-voltage) protection to the combined composite circuit protection device, the VDR is still only Can withstand short-term power surges (for example, 0.001 seconds). In other words, if the surge time exceeds a cut-off time interval, the VDR will be burned or damaged due to overcurrent or overvoltage, causing the composite circuit protection device to permanently lose its function.

Therefore, the purpose of the present invention is to provide a composite circuit protection device that can overcome at least one of the above-mentioned shortcomings of the prior art.

Therefore, the composite circuit protection device of the present invention includes a positive temperature coefficient (PTC) element, a varistor, a first conductive lead, and a second conductive lead. The PTC element includes a PTC layer, a first electrode layer and a second electrode layer. The PTC layer has two opposite surfaces. The first electrode layer and the second electrode layer are respectively disposed on the two opposite surfaces of the PTC layer. The varistor is connected to the second electrode layer. The first conductive lead is connected to the first electrode layer. The second conductive lead is connected to the varistor. The PTC element has a rated voltage, and the rated voltage is between 40% and 200% of the varistor voltage measured by the varistor at 1 mA.

The effect of the present invention is that the composite circuit protection device of the present invention has excellent tolerance and reliability. In the presence of overcurrent and overvoltage, the PTC element can protect the varistor from burning.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same numbers.

2 and 3, the first embodiment of the composite circuit protection device of the present invention includes a positive temperature coefficient (PTC) element 2, a varistor 3, a first conductive lead 4, and a second conductive lead 5.

The PTC element 2 includes a PTC layer 21, a first electrode layer 22, and a second electrode layer 23. The PTC layer 21 has two opposite surfaces 211. The first electrode layer 22 and the second electrode layer 23 are respectively disposed on the Two opposite surfaces 211 of the PTC layer 21.

The varistor 3 is connected to the second electrode layer 23 by a solder.

The first conductive lead 4 is connected to the first electrode layer 22. The second conductive lead 5 is connected to the varistor 3.

The PTC element 2 has a rated voltage that is between 40% and 200% of the varistor voltage measured by the varistor 3 at 1 mA. In some embodiments of the present invention, the rated voltage of the PTC element 2 is between 45% and 100% of the varistor voltage measured by the varistor 3 at 1 mA. In some specific embodiments of the present invention, the rated voltage of the PTC element 2 is between 45% and 70% of the varistor voltage measured by the varistor 3 at 1 mA.

According to the present invention, the PTC element 2 is under an overcurrent and a voltage greater than the varistor voltage of the varistor 3 and trips before the varistor 3 burns. In other words, in the presence of the overcurrent and the voltage greater than the varistor voltage of the varistor 3, the PTC element 2 quickly trips to a high resistance state, so that the overcurrent is restricted from flowing through The varistor 3 therefore protects the varistor 3 from burning, and the composite circuit protection device can be reused.

In this article, the terms "burnt", "sparking" and "fire" can be used interchangeably and refer to the loss of function of the varistor, which usually occurs above 180°C.

In some embodiments of the present invention, the PTC element 2 is at an overcurrent greater than 0.1 A and a voltage greater than the varistor voltage of the varistor 3 and trips within 1 μs to 100 s. . In some specific embodiments of the present invention, the PTC element 2 is under an overcurrent greater than 0.1 A and a voltage greater than the varistor voltage of the varistor 3 and trips within 10 μs to 10 s. . In some specific embodiments of the present invention, the PTC element 2 is under an overcurrent greater than 0.1 A and a voltage greater than the varistor voltage of the varistor 3 and trips within 0.1 ms to 1 s .

In some embodiments of the present invention, the PTC element 2 is under an overcurrent greater than 0.5 A and a voltage greater than the varistor voltage of the varistor 3 and trips within 1 ms to 10 s . In some specific embodiments of the present invention, the PTC element 2 is under an overcurrent greater than 0.5 A and a voltage greater than the varistor voltage of the varistor 3 and trips within 1 ms to 1 s .

In some embodiments of the present invention, the PTC element 2 is under an overcurrent greater than 10 A and a voltage greater than the varistor voltage of the varistor 3 and trips within 1 ms to 1 s . In some specific embodiments of the present invention, the PTC element 2 is under an overcurrent greater than 10 A and a voltage greater than the varistor voltage of the varistor 3 and trips within 1 ms to 0.1 s .

The PTC element 2 can be formed with a first hole 210. In this embodiment, the first hole 210 is formed in the PTC layer 21. The PTC layer 21 of the PTC element 2 has a peripheral edge 212 that defines the boundary of the PTC layer 21 and is interconnected with two opposite surfaces 211 of the PTC layer 21. The first hole 210 is spaced from the periphery 212 of the PTC layer 21 and has an effective volume capable of accommodating the thermal expansion of the PTC layer 21 when the temperature increases, so as to prevent the PTC layer 21 from undesired structural deformation.

In some embodiments of the present invention, the first hole 210 penetrates at least one of the two opposite surfaces 211 of the PTC layer 21. In some embodiments of the present invention, the first hole 210 also penetrates at least one of the first electrode layer 22 and the second electrode layer 23. In this embodiment, the first hole 210 penetrates two opposite surfaces 211 of the PTC layer 21 and the first electrode layer 22 and the second electrode layer 23 to form a through hole. In some embodiments of the present invention, the first hole 210 extends along a line passing through the geometric center of the PTC layer 21 and across the two opposite surfaces 211. The first hole 210 is defined by a hole defining wall, and the hole defining wall has a cross section parallel to the surface 211 of the PTC layer 21. The cross-section of the hole-defining wall can be round, square, oval, triangle, cross, etc.

According to the present invention, the PTC device 2 may be a polymer PTC (PPTC) device, and the PTC layer 21 may be a PTC polymer layer. The PTC polymer layer includes a polymer substrate and a conductive filler dispersed in the polymer substrate. The polymer substrate can be made of a polymer composition containing a non-grafted olefin-based polymer. In some specific embodiments of the present invention, the non-grafted olefin-based polymer is high-density polyethylene (HDPE). In some specific embodiments of the present invention, the polymer composition further includes a grafted olefin-based polymer. In some specific embodiments of the present invention, the grafted olefin-based polymer is an olefin-based polymer grafted with carboxylic anhydride. The conductive filler suitable for the present invention is selected from carbon black powder, metal powder, conductive ceramic powder or a combination of the foregoing, but is not limited thereto.

According to the present invention, the varistor 3 may include a varistor layer 31, a third electrode layer 32 and a fourth electrode layer 33. The varistor layer 31 has two opposite surfaces 311. The second conductive lead 5 is connected to one of the third electrode layer 32 and the fourth electrode layer 33 of the varistor 3. In some specific embodiments of the present invention, the varistor layer 31 is made of a metal oxide material.

In this embodiment, the third electrode layer 32 is disposed on one of the two opposite surfaces 311 of the varistor layer 31, and is connected to the second electrode layer 23 of the PTC element 2; the fourth electrode layer 33 is provided on the other of the two opposite surfaces 311 of the varistor layer 31. The second conductive lead 5 is connected and disposed between the second electrode layer 23 and the third electrode layer 32.

The varistor 3 may have a second hole 310 formed in the varistor layer 31. In this embodiment, the piezoresistor layer 31 of the piezoresistor 3 has a peripheral edge 312 that defines the boundary of the piezoresistor layer 31 and is opposite to two of the piezoresistor layer 31 The surfaces 311 are interconnected. The second hole 310 is spaced apart from the periphery 312 of the varistor layer 31.

In some embodiments of the present invention, the second hole 310 penetrates at least one of the two opposite surfaces 311 of the varistor layer 31. In some embodiments of the present invention, the second hole 310 also penetrates at least one of the third electrode layer 32 and the fourth electrode layer 33. In this embodiment, the second hole 310 penetrates two opposite surfaces 311 of the varistor layer 31 and the third electrode layer 32 and the fourth electrode layer 33 to form a through hole.

According to the present invention, the first conductive lead 4 has a connecting portion 41 and a free portion 42, and the second conductive lead 5 has a connecting portion 51 and a free portion 52. The connecting portion 41 of the first conductive lead 4 is connected to the outer surface of the first electrode layer 22 by a solder, and the free portion 42 of the first conductive lead 4 extends from the connecting portion 41 to the first electrode layer 22 For inserting into a circuit board or a pin hole of a circuit device (not shown). In this embodiment, the connecting portion 51 of the second conductive lead 5 is connected by a solder and is arranged between the second electrode layer 23 and the third electrode layer 32, and the free portion of the second conductive lead 5 52 extends from the connecting portion 51 to the second electrode layer 23 and the third electrode layer 32 to be inserted into the pin holes of a circuit board or a circuit device (not shown).

4 and 5, the second embodiment of the composite circuit protection device of the present invention is similar to the first embodiment, the difference is that in the second embodiment, the connecting portion 51 of the second conductive lead 5 is A solder is connected to the outer surface of the fourth electrode layer 33, and the free portion 52 of the second conductive lead 5 extends from the connection portion 51 out of the fourth electrode layer 33 for insertion into a circuit board or a circuit device. Foot hole (not shown). In addition, the second embodiment further includes a packaging material 7 that packages the PTC element 2, the varistor 3, a part of the first conductive lead 4 and a part of the second conductive lead 5. The free portion 42 of the first conductive lead 4 and the free portion 52 of the second conductive lead 5 are exposed outside the packaging material 7. In some specific embodiments of the present invention, the packaging material 7 is made of epoxy resin.

6 and 7, the third embodiment of the composite circuit protection device of the present invention is similar to the second embodiment, the difference is that the third embodiment also includes a third conductive lead 6, the third conductive lead 6 It is connected and arranged between the second electrode layer 23 and the third electrode layer 32. The third conductive lead 6 has a connecting portion 61 and a free portion 62. The connecting portion 61 of the third conductive lead 6 is connected to the second electrode layer 23 and the third electrode layer 32, and the free portion 62 of the third conductive lead 6 extends from the connecting portion 61 to the second electrode layer 23 and The third electrode layer 32 is for inserting into a pin hole of a circuit board or a circuit device (not shown).

In this embodiment, the packaging material 7 packages the PTC element 2, the varistor 3, a part of the first conductive lead 4, a part of the second conductive lead 5 and a part of the third conductive lead 6. The free portion 42 of the first conductive lead 4, the free portion 52 of the second conductive lead 5 and a part of the free portion 62 of the third conductive lead 6 are exposed outside the packaging material 7.

The present invention will be further described with reference to the following examples, but it should be understood that these examples are for illustrative purposes only and should not be construed as limitations to the implementation of the present invention.

Example

＜Example 1 (E1) ＞

21 g HDPE (purchased from Taiwan Plastics Industry Co., Ltd., product model: HDPE9002) as a non-grafted olefin polymer, 21 g of HDPE grafted with maleic anhydride (purchased from DuPont, product model: MB100D) as An olefin-based polymer grafted with carboxylic anhydride, 58 g of carbon black powder (purchased from Columbian Chemicals, product model: Raven 430UB) was used as a conductive filler.

The above three ingredients were mixed in a mixer (brand: Brabender), and the ingredients were mixed for 10 minutes under the conditions of a temperature of 200°C and a stirring speed of 30 rpm.

The above-obtained ingredient mixture is placed in a mold, and hot-pressed for 4 minutes under the conditions of a hot- ^{pressing temperature of 200° C. and a hot-pressing pressure of 80 kg/cm 2 to form a PTC polymer layer sheet.} The sheet was taken out of the mold and placed between two pieces of copper foil (respectively as the first electrode layer and the second electrode layer), and ^{hot-pressed at 200 ℃ and 80 kg/cm 2} for 4 min to form a thickness of 0.42 mm PPTC element. After cutting the PPTC element into multiple 9.5 mm × 11 mm chips (hereinafter referred to as PPTC-1), each chip was irradiated with Co-60 γ rays with a total radiation dose of 150 kGy. Weld the first conductive lead and the second conductive lead on the two copper foils of each small piece respectively, and then weld a metal oxide varistor (MOV, purchased from Ceramate Technical Company, product model: 07D270K, hereinafter referred to as MOV) -1) To one of the two copper foils to form an E1 composite circuit protection device.

According to Underwriter Laboratories' safety standard UL 1434 for thermistor-type device (thermistor-type device), the holding current (hold current, the maximum current value during normal operation) and trip current (trip current) of the PPTC chip are measured The minimum current value required for the PPTC element to reach a high resistance state), the rated voltage (that is, the voltage applicable to the PPTC element when it works), and the withstand voltage (that is, the maximum voltage that will not cause the PPTC element to malfunction or damage). In addition, according to Underwriter Laboratories' safety standard UL 1449 for transient voltage surge suppressors, the varistor voltage (ie, the voltage at which the MOV triggers the work) and the clamping voltage (MOV can provide Limited maximum voltage). The property measurement results of PPTC-1 and MOV-1 are shown in Table 1, respectively. 【Table 1】 Hold current Trip current Rated voltage Withstand voltage PPTC-1 5.00 A 8.50 A 16 V 16 V Varistor voltage ^a Clamping voltage ^b MOV-1 27 V 53 V a: Measured at 1 mA. b: Measured at pulse waveform (t _p ) 8/20 μs and pulse current (I _p ) 2.5 A.

＜Example 2 To 4 (E2-E4) ＞

The process conditions of the E2-E4 composite circuit protection device are similar to those of E1. The difference is that the PPTC chip is formed with a first perforation and/or the MOV is formed with a second perforation (as shown in Table 3). Each first perforation and Each second perforation is defined by a hole-defining wall with a circular cross-section (diameter of 1.5 mm and circular area of 1.77 mm ^{2 ).}

In E2, after γ-ray irradiation, the first perforation is drilled in the central part of the PPTC chip. In E3, before soldering the copper foil, a second hole is drilled in the center of the MOV. In E4, the first perforation is drilled in the central part of the PPTC chip and the second perforation is drilled in the central part of the MOV (as shown in Figure 3).

＜Comparative example 1 To 4 (CE1-CE4) ＞

The process conditions of CE1-CE4 composite circuit protection devices are similar to those of E1-E4. The difference is that CE1 and CE2 do not contain small PPTC chips, and CE3 and CE4 do not contain MOV.

＜Example 5 To 8 (E5-E8) ＞

The process conditions of the E5-E8 composite circuit protection device are similar to those of E1-E4, but the difference is that the ingredients for forming the PTC polymer layer sheet of E5-E8 are 10 g HDPE and 10 g HDPE grafted with maleic anhydride. , 15 g of carbon black powder and 15 g of magnesium hydroxide (purchased from MagChem company, product model: MH 10), and E5-E8 PPTC small pieces (hereinafter referred to as PPTC-2) are cut into a circle with a thickness of 2.2 mm Shape (3.1 mm in diameter). In addition, the MOV of E5-E8 is purchased from Ceramate Technical Company, product model: 20D361K (hereinafter referred to as MOV-2). The property measurement results of PPTC-2 and MOV-2 are shown in Table 2, respectively. 【Table 2】 Hold current Trip current Rated voltage Withstand voltage PPTC-2 0.08 A 0.16 A 250 V 250 V Varistor voltage ^a Clamping voltage ^b MOV-2 360 V 595 V a: Measured at 1 mA. b: Measured at pulse waveform (t _p ) 8/20 μs and pulse current (I _p ) 2.5 A.

＜Comparative example 5 To 8 (CE5-CE8) ＞

The process conditions of CE5-CE8 composite circuit protection devices are similar to those of E5-E8. The difference is that CE5 and CE6 do not contain PPTC chips, and CE7 and CE8 do not contain MOV.

＜Example 9 To 12 (E9-E12) ＞

The process conditions of the E9-E12 composite circuit protection device are similar to those of the E5-E8, but the difference is that the MOV forming the E9-E12 is purchased from Ceramate Technical Company, product model: 20D511K (hereinafter referred to as MOV-3). The varistor voltage of MOV-3 is 510 V (measured at 1 mA), and its clamping voltage is 845 V [measured at pulse waveform (t _p ) 8/20 μs and pulse current (I _p ) 2.5 A Measurement].

＜Comparative Example 9 To 12 (CE9-CE12) ＞

The process conditions of the CE9-CE12 composite circuit protection device are similar to those of E9-E12. The difference is that CE9 and CE10 do not contain PPTC chips, and CE11 and CE12 do not contain MOV. 【table 3】 Composite circuit protection device PPTC small piece First perforation MOV Second perforation E1 PPTC-1 - MOV-1 - E2 PPTC-1 Have MOV-1 - E3 PPTC-1 - MOV-1 Have E4 PPTC-1 Have MOV-1 Have CE1 - - MOV-1 - CE2 - - MOV-1 Have CE3 PPTC-1 - - - CE4 PPTC-1 Have - - E5 PPTC-2 - MOV-2 - E6 PPTC-2 Have MOV-2 - E7 PPTC-2 - MOV-2 Have E8 PPTC-2 Have MOV-2 Have CE5 - - MOV-2 - CE6 - - MOV-2 Have CE7 PPTC-2 - - - CE8 PPTC-2 Have - - E9 PPTC-2 - MOV-3 - E10 PPTC-2 Have MOV-3 - E11 PPTC-2 - MOV-3 Have E12 PPTC-2 Have MOV-3 Have CE9 - - MOV-3 - CE10 - - MOV-3 Have CE11 PPTC-2 - - - CE12 PPTC-2 Have - - "--" means there is no such component.

Performance Testing

[ Surge immunity test (Surge immunity test)]

Take 10 of E1-E12 and CE1-CE12 composite circuit protection devices as test samples for surge immunity test.

For E1-E4 and CE1-CE4 composite circuit protection devices, the surge immunity test of each test sample is at a voltage greater than MOV-1 varistor voltage (including 38 V and 44 V) and 0.5 A, PPTC Under the current of -1 overcurrent (ie 10 A), the test is performed by turning on for 60 seconds and then turning off. If neither the PPTC chip nor the MOV is burnt or damaged, the test sample has passed the surge immunity test, and the average value of the time for the PPTC chip to escape (if any) is recorded. If one of the PPTC chip and the MOV is burned, the test sample is burned, and the average of the burning time is recorded. The results are shown in Table 4, respectively. 【Table 4】 38 V/0.5 A 38 V/10 A 44 V/0.5 A 44 V/10 A result Time(s) result Time(s) result Time(s) result Time(s) E1 pass through 2.438 pass through 0.551 pass through 2.255 pass through 0.146 E2 pass through 2.425 pass through 0.532 pass through 2.200 pass through 0.134 E3 pass through 2.372 pass through 0.530 pass through 2.180 pass through 0.130 E4 pass through 2.345 pass through 0.525 pass through 2.165 pass through 0.125 CE1 MOV burned 4.706 MOV burned 2.264 MOV burned 4.319 MOV burned 1.033 CE2 MOV burned 4.432 MOV burned 2.055 MOV burned 3.887 MOV burned 1.018 CE3 pass through No jump PPTC burned 0.922 pass through No jump PPTC burned 0.922 CE4 pass through No jump PPTC burned 0.918 pass through No jump PPTC burned 0.913

The results in Table 4 show that the test samples of CE1 and CE2 containing only MOV-1 burned within 5 s at a current of 0.5 A and a voltage of at least 1.4 times the varistor voltage of MOV-1 (generally, MOV can withstand 1.2 times the voltage. The voltage of the varistor voltage), or it burns within 2.5 s under an overcurrent and overvoltage of 10 A, and the damage cannot be repaired. The test samples of CE3 and CE4 that only contained PPTC-1 burned down at an overcurrent of 10 A. On the contrary, all test samples containing a combination of PPTC-1 and MOV-1 in E1-E4 (where the rated voltage of PPTC-1 is about 59% of the varistor voltage of MOV-1) have passed the surge immunity test without burning . In addition, compared with E1, E2-E4 PPTC-1 and/or MOV-1 formed with perforated test samples, the heat transfer is improved, which can further shorten the time of PPTC-1 tripping and prevent overcurrent from flowing through the MOV. -1, so protect its MOV-1 from burning. In other words, in the test samples of E1-E4, PPTC-1 was at an overcurrent and a voltage greater than MOV-1 and tripped before MOV-1 burned.

For E5-E8 and CE5-CE8 composite circuit protection devices, the surge immunity test of each test sample is similar to the above. The difference is that the applied voltage is a varistor voltage greater than MOV-2 (including 400 V and 500 V). V) and the applied current is the overcurrent of PPTC-2 (ie 0.5A or 10 A). The results are shown in Table 5, respectively. 【table 5】 400 V/0.5 A 400 V/10 A 500 V/0.5 A 500 V/10 A result Time(s) result Time(s) result Time(s) result Time(s) E5 pass through 4.464 pass through 0.058 pass through 0.864 pass through 0.056 E6 pass through 4.400 pass through 0.058 pass through 0.860 pass through 0.055 E7 pass through 4.355 pass through 0.056 pass through 0.852 pass through 0.050 E8 pass through 4.350 pass through 0.055 pass through 0.834 pass through 0.048 CE5 MOV burned 19.575 MOV burned 1.396 MOV burned 10.585 MOV burned 0.463 CE6 MOV burned 19.422 MOV burned 1.375 MOV burned 10.440 MOV burned 0.455 CE7 PPTC burned 0.113 PPTC burned 0.060 PPTC burned 0.105 PPTC burned 0.058 CE8 PPTC burned 0.1100 PPTC burned 0.058 PPTC burned 0.102 PPTC burned 0.056

The results in Table 5 show that the test samples of CE5 and CE6 containing only MOV-2 burned within 20 s at an overcurrent of 0.5 A and an overvoltage of a varistor voltage greater than MOV-2, or were at an overcurrent of 10 A. It burns within 1.5 s under overvoltage, and the damage cannot be repaired. The CE7 and CE8 test samples containing only PPTC-2 burned down at 0.5 A and 10 A overcurrent. On the contrary, all test samples containing a combination of PPTC-2 and MOV-2 in E5-E8 (where the rated voltage of PPTC-2 is about 69% of the varistor voltage of MOV-2) have passed the surge immunity test without burning . In addition, compared to E5, E6-E8’s PPTC-2 and/or MOV-2 are formed with perforated test samples to improve heat transfer, which can further shorten the time for PPTC-2 to trip and prevent overcurrent from flowing through the MOV. -2, so protect its MOV-2 from burning. In other words, in the test samples of E5-E8, PPTC-2 was at an overcurrent and a voltage greater than MOV-2's varistor voltage and tripped before MOV-2 burned.

For the E9-E12 and CE9-CE12 composite circuit protection devices, the surge immunity test of each test sample is similar to the above. The difference is that the applied voltage is a varistor voltage greater than MOV-3 (including 600 V and 700 V). V). The results are shown in Table 6, respectively. 【Table 6】 600 V/0.5 A 600 V/10 A 700 V/0.5 A 700 V/10 A result Time(s) result Time(s) result Time(s) result Time(s) E9 pass through 1.244 pass through 0.055 pass through 0.856 pass through 0.050 E10 pass through 1.230 pass through 0.054 pass through 0.845 pass through 0.048 E11 pass through 1.225 pass through 0.050 pass through 0.834 pass through 0.046 E12 pass through 1.198 pass through 0.047 pass through 0.827 pass through 0.045 CE9 MOV burned 17.881 MOV burned 0.975 MOV burned 9.875 MOV burned 0.385 CE10 MOV burned 17.650 MOV burned 0.968 MOV burned 9.762 MOV burned 0.376 CE11 PPTC burned 0.100 PPTC burned 0.058 PPTC burned 0.098 PPTC burned 0.055 CE12 PPTC burned 0.985 PPTC burned 0.056 PPTC burned 0.095 PPTC burned 0.054

The results in Table 6 show that the test samples of CE9 and CE10 containing only MOV-3 burned within 18 s at an overcurrent of 0.5 A and an overvoltage of a varistor voltage greater than MOV-3, or were at an overcurrent of 10 A. It burns within 1 s under overvoltage, and the damage cannot be repaired. The test samples of CE11 and CE12 containing only PPTC-2 burned down at 0.5 A and 10 A overcurrent. On the contrary, all test samples of E9-E12 containing a combination of PPTC-2 and MOV-3 (where the rated voltage of PPTC-2 is about 49% of the varistor voltage of MOV-3) all passed the surge immunity test without burning . In addition, compared to E9, E10-E12’s PPTC-2 and/or MOV-3 are formed with perforated test samples to improve heat transfer, which can further shorten the time for PPTC-2 to trip and prevent overcurrent from flowing through the MOV. -3, so protect its MOV-3 from burning. In other words, in the test samples of E9-E12, PPTC-2 was at an overcurrent and a voltage greater than MOV-3 and tripped before MOV-3 burned.

To sum up, by including a PTC element with a desired rated voltage (for example, 40% to 200% of the varistor voltage measured at 1 mA), in the presence of the overcurrent and the overvoltage , The PTC element quickly trips to a high resistance state to protect the varistor from being burnt due to overcurrent. The composite circuit protection device of the present invention can therefore be used repeatedly, and exhibits its excellent endurance and performance. Reliability, so it can indeed achieve the purpose of the invention.

However, the above are only examples of the present invention. When the scope of implementation of the present invention cannot be limited by this, all simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the content of the patent specification still belong to This invention patent covers the scope.

20: PTC polymer substrate 30: Electrode 40: Hole 50: Conductive lead pin 60: Conductive lead pin 2: PTC component 21: PTC layer 210: first hole 211: Surface 212: Perimeter 22: The first electrode layer 23: second electrode layer 3: Varistor 31: Varistor layer 310: second hole 311: Surface 312: Perimeter 32: third electrode layer 33: Fourth electrode layer 4: The first conductive lead 41: Connection part 42: Ministry of Freedom 5: The second conductive lead 51: connecting part 52: Ministry of Freedom 6: The third conductive lead 61: Connection part 62: Ministry of Freedom 7: Packaging material

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: [Figure 1] is a schematic diagram of an existing plug-in PPTC overcurrent protection device; [Figure 2] is a schematic diagram of the first specific embodiment of the composite circuit protection device of the present invention; [Figure 3] is a schematic cross-sectional view of the first specific embodiment; [Figure 4] is a schematic diagram of the second specific embodiment of the composite circuit protection device of the present invention; [Figure 5] is a schematic cross-sectional view of the second specific embodiment; [Figure 6] is a schematic diagram of the third specific embodiment of the composite circuit protection device of the present invention; [Figure 7] is a schematic cross-sectional view of the third embodiment.

2: PTC components

21: PTC layer

210: first hole

211: Surface

22: The first electrode layer

23: second electrode layer

3: Varistor

31: Varistor layer

310: second hole

311: Surface

32: third electrode layer

33: Fourth electrode layer

4: The first conductive lead

41: Connection part

42: Ministry of Freedom

5: The second conductive lead

51: connecting part

52: Ministry of Freedom

Claims (20)

A composite circuit protection device, including: A PTC component, including: A PTC layer with two opposite surfaces, and The first electrode layer and the second electrode layer respectively disposed on two opposite surfaces of the PTC layer; A varistor connected to the second electrode layer; A first conductive lead connected to the first electrode layer; and A second conductive lead connected to the varistor, The PTC component has a rated voltage, and the rated voltage is between 40% and 200% of the varistor voltage measured by the varistor at 1 mA. The composite circuit protection device according to claim 1, wherein the rated voltage of the PTC element is between 45% and 100% of the varistor voltage measured by the varistor at 1 mA. The composite circuit protection device according to claim 1, wherein the rated voltage of the PTC element is between 45% and 70% of the varistor voltage measured by the varistor at 1 mA. The composite circuit protection device of claim 1, wherein the PTC element is under an overcurrent and a voltage greater than the varistor voltage and trips before the varistor burns. The composite circuit protection device of claim 4, wherein the PTC element is under an overcurrent greater than 0.1 A and a voltage greater than the varistor voltage within 1 μs to 100 s Jump off. The composite circuit protection device according to claim 4, wherein the PTC element is under an overcurrent greater than 0.5 A and a voltage greater than the varistor voltage within 1 ms to 10 s Jump off. The composite circuit protection device according to claim 4, wherein the PTC element is under an overcurrent greater than 10 A and a voltage greater than the varistor voltage within 1 ms to 1 s Jump off. The composite circuit protection device according to claim 1, wherein the PTC element has a first hole formed in the PTC layer. The composite circuit protection device according to claim 8, wherein the PTC layer of the PTC element has a peripheral edge, the peripheral edge defines the boundary of the PTC layer and is interconnected with two opposite surfaces of the PTC layer, and the first hole Spaced from the periphery of the PTC layer. The composite circuit protection device according to claim 8, wherein the first hole penetrates at least one of the two opposite surfaces of the PTC layer. The composite circuit protection device according to claim 10, wherein the first hole further penetrates at least one of the first electrode layer and the second electrode layer. The composite circuit protection device according to claim 1, wherein the varistor is formed with a second hole. The composite circuit protection device according to claim 1, wherein the varistor includes: A varistor layer with two opposite surfaces; A third electrode layer disposed on one of the two opposite surfaces of the varistor layer and connected to the second electrode layer of the PTC element; and A fourth electrode layer provided on the other of the two opposite surfaces of the varistor layer, The second conductive lead is connected to one of the third electrode layer and the fourth electrode layer of the varistor. The composite circuit protection device according to claim 13, further comprising a third conductive lead, the second conductive lead is connected to the fourth electrode layer, and the third conductive lead is connected and disposed on the second electrode layer and the Between the third electrode layer. The composite circuit protection device according to claim 13, wherein the varistor has a second hole formed in the varistor layer. The composite circuit protection device according to claim 15, wherein the piezoresistor layer of the piezoresistor has a peripheral edge that defines the boundary of the piezoresistor layer and is connected to the piezoresistor layer. The two opposite surfaces are interconnected, and the second hole is spaced from the periphery of the varistor layer. The composite circuit protection device according to claim 15, wherein the second hole penetrates at least one of the two opposite surfaces of the varistor layer. The composite circuit protection device according to claim 17, wherein the second hole further penetrates at least one of the third electrode layer and the fourth electrode layer. The composite circuit protection device according to claim 1, wherein the PTC element is a polymer PTC element, and the PTC layer is a PTC polymer layer. The composite circuit protection device according to claim 1, further comprising a packaging material packaging the PTC element, the varistor, a part of the first conductive lead and a part of the second conductive lead.

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