TW202105428A - Overcurrent protection device capable of immediately recognizing a non-power state when the overcurrent protection device is in a tripping state - Google Patents

Abstract

An overcurrent protection device includes a positive temperature coefficient (PTC) polymer element, two electrodes and a non-power trip indicator. The positive temperature coefficient polymer element has two opposite surfaces. The two electrodes are respectively connected to the two surfaces. The non-power trip indicator is formed on at least one of the electrodes to sense the temperature of the overcurrent protection device. When the overcurrent protection device of the present invention is in a tripping state, it can be immediately recognized, and the overall production cost and manufacturing process of the overcurrent protection device can be greatly reduced. Moreover, the non-power trip indicator is in direct contact with the at least one electrode, and the non-power trip indicator includes a thermo-chromic material.

Description

Overcurrent protection device

The present invention relates to an overcurrent protection device, in particular to an overcurrent protection device that includes a non-power trip indicator to sense its temperature.

The positive temperature coefficient (PTC) element has a PTC effect, making it useful as a circuit protection device (such as a fuse).

1, the existing circuit protection device includes a PTC polymer material 8 and two electrodes 9 respectively connected to two opposite surfaces 81 of the PTC polymer material 8. The PTC polymer material 8 includes a region containing a crystal and a The polymer substrate in the amorphous region, and a particulate conductive filler, which is dispersed in the amorphous region of the polymer matrix, and forms a continuous conductive path for electrically connecting the electrodes 9. The PTC effect refers to a phenomenon in which when the temperature of the crystalline region is increased to its melting point, the crystals in the crystalline region begin to melt, thereby generating a new amorphous region. When the new amorphous region is increased to the extent that it merges into the original amorphous region, the conductive path of the particulate conductive filler will become discontinuous and the resistance of the PTC polymer material 8 will increase sharply, causing the There is no electrical conduction between the electrodes 9.

The Republic of China Patent No. TW 424929 records an electronic fuse, which includes a housing, a filler filled in the housing, conductive particles contained in the filler, two conductive sheets extending into the housing, and a jumper The light-emitting diodes (LEDs) of the conductive sheets. The filler can expand to increase the reaction temperature. The conductive sheets are connected to the filler and are spaced apart from each other at appropriate intervals. The light emitting diode is connected in parallel with the filler. When the circuit is short-circuited, the filler will expand due to temperature rise, and the conductive particles will be separated from each other. Therefore, the current does not pass through the filler but passes through the light-emitting diode, causing the light-emitting diode to emit light.

However, the configuration of the above-mentioned electronic fuse increases complexity and manufacturing cost. Therefore, an overcurrent protection device that can be easily produced and meets industrial requirements is still to be developed.

Therefore, the purpose of the present invention is to provide an overcurrent protection device that can overcome at least one of the disadvantages of the prior art.

Therefore, the overcurrent protection device of the present invention includes a positive temperature coefficient (PTC) polymer element, two electrodes and a non-power trip indicator. The positive temperature coefficient polymer element has two opposite surfaces. The two electrodes are respectively connected to the two surfaces. The non-power trip indicator is formed on at least one of the electrodes to sense the temperature of the overcurrent protection device.

The effect of the present invention is that when the overcurrent protection device of the present invention is in a trip state, it can be immediately recognized, and the overall production cost and manufacturing process of the overcurrent protection device of the present invention can be greatly reduced.

The content of the present invention will be described in detail below:

In some specific embodiments of the present invention, the non-power trip indicator is in direct contact with the at least one electrode.

Preferably, the non-power trip indicator includes a thermochromic material. More preferably, the overcurrent protection device has a trip surface temperature, and the trip surface temperature is equal to or higher than the discoloration temperature of the non-power trip indicator. More preferably, the trip surface temperature of the overcurrent protection device is higher than 70°C.

Preferably, the discoloration temperature of the non-power trip indicator is higher than 60°C. More preferably, the discoloration temperature of the non-power trip indicator is higher than 60°C and not higher than 200°C.

In some specific embodiments of the present invention, the overcurrent protection device further includes a covering layer arranged between the no-power trip indicator and the at least one electrode. Preferably, the non-power trip indicator is in indirect contact with the at least one electrode through the covering layer. Optionally, the covering layer surrounds the positive temperature coefficient polymer element and the electrodes, and is made of a thermally conductive insulating material.

Preferably, the positive temperature coefficient polymer element includes a polymer substrate and a particulate conductive filler dispersed in the polymer substrate. More preferably, the particulate conductive filler is selected from carbon black powder, metal powder, conductive ceramic powder or a combination thereof. Still more preferably, the particulate conductive filler is carbon black powder.

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.

Referring to FIG. 2, a first embodiment of the overcurrent protection device of the present invention includes a positive temperature coefficient (PTC) polymer element 2, two electrodes 3 and a non-power trip indicator 4. The positive temperature coefficient polymer element 2 has two opposite surfaces 21. The two electrodes 3 are connected to the two surfaces 21 respectively. The non-power trip indicator 4 is formed on at least one of the electrodes 3 to sense the temperature of the overcurrent protection device. In the first embodiment, the non-power trip indicator 4 is in direct contact with the at least one electrode 3.

The positive temperature coefficient polymer element 2 includes a polymer substrate and a particulate conductive filler dispersed in the polymer substrate. In some embodiments of the present invention, the polymer substrate is made of polyvinylidene fluoride (PVDF). In other specific embodiments, the polymer substrate is made of a polymer composition containing crystalline polyolefin selected from non-grafted polyolefins [for example: non-grafted high-density polyethylene (HDPE), non-grafted low density polyethylene (LDPE), non-grafted ultra-low density polyethylene (ULDPE), non-grafted medium density polyethylene (MDPE), non-grafted polypropylene (PP) ], grafted polyolefin (for example: polyethylene grafted by carboxylic anhydride) or a combination thereof, or copolymer of olefin monomer and acid anhydride [for example: ethylene/maleic anhydride copolymer (PE/MA), ethylene /Butyl acrylate/maleic anhydride terpolymer (PE/BA/MA)].

The particulate conductive filler is selected from carbon black powder, metal powder, conductive ceramic powder or a combination thereof. In some specific embodiments of the present invention, the particulate conductive filler is carbon black powder.

The non-power trip indicator 4 includes a thermochromic material, which can be, but not limited to, Chroma Life Technology Ltd. or New Prismatic Enterprise Co., Ltd. ., Ltd.).

As used herein, the term "thermochromic material" refers to a substance that reacts to changes in temperature by changing its ability to absorb, penetrate, or reflect light. Therefore, in this document, the term “thermochromic” and “color” change based on thermochromic refers to any visual change of the non-power trip indicator 4. The visual change includes strictly defined visible color change, fluorescence change, luminescence change, phosphorescence change, and can indicate the occurrence of color or visual phenomenon, the disappearance of color or visual phenomenon, change to another color or other vision Phenomenon and similar phenomena change. The change is visualized. In other words, it is any apparent change of the no-power trip indicator 4 when viewed with the naked eye, regardless of whether it transmits filtered light or whether it transmits light stimuli (for example: ambient lighting or specific Wavelength of light exposure).

According to the present invention, the thermochromic material can be scattered all over the non-powered trip indicator 4, or concentrated in one area or multiple discrete regions of the non-powered trip indicator 4. When the thermochromic material is concentrated in the area of the non-power trip indicator 4, the area may be a specific shape or arranged in a predetermined shape, pattern or pattern.

In some specific embodiments of the present invention, the non-power trip indicator 4 has a color change temperature (T _cc ). The discoloration temperature can be higher than 60°C. The discoloration temperature may not be higher than 200°C.

According to the present invention, the overcurrent protection device has a trip surface temperature, and the trip surface temperature is equal to or higher than the discoloration temperature of the trip indicator 4 without power. In other words, the thermochromic material of the non-power trip indicator 4 can change color to reflect a trip state (see FIG. 3). In detail, when in a normal state, the surface temperature of the overcurrent protection device is usually between 25-50° C., which is lower than the discoloration temperature of the non-power trip indicator 4. However, when the overcurrent protection device trips, the surface temperature of the overcurrent protection device sharply increases to its trip surface temperature, which exceeds the discoloration temperature of the non-power trip indicator 4. Therefore, the temperature change of the thermochromic material of the non-power trip indicator 4 can be observed, and the trip state is indicated.

In some specific embodiments of the present invention, the trip surface temperature of the overcurrent protection device is higher than 70°C.

4, a second embodiment of the overcurrent protection device of the present invention is similar to the first embodiment, the difference is that the second embodiment further includes a non-power trip indicator 4 and the at least A covering layer 5 between the electrodes 3. In the second embodiment, the non-power trip indicator 4 indirectly contacts the at least one electrode 3 through the covering layer 5. In addition, the covering layer 5 surrounds the positive temperature coefficient polymer element 2 and the electrodes 3.

The covering layer 5 can be made of a thermally conductive and insulating material. Examples of thermally conductive insulating materials may include, but are not limited to, solder mask, tape, epoxy, or silicone. The covering layer 5 can protect the positive temperature coefficient polymer element 2 and the electrodes 3 from being damaged by external forces or environmental factors.

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

Preparation of polymer blend composition (polymer blend composition)

Preparation of carbon black powder (purchased from Columbian Chemicals Company, product model: Raven 430UB, DBP/D of 0.95, and bulk density of 0.53 g/cm ³ ) of three polymer blending compositions (ie formula 1, formula 2, formula 3) And the polymer substrate are as follows. In formula 1, the polymer substrate is ethylene/butyl acrylate/maleic anhydride terpolymer (PE/BA/MA) (purchased from Arkema company, product model: Lotader® 3410, BA content 18.0 wt%, The MA content is 3.1 wt%, and the melting point is 91°C). In formula 2, the polymer substrate includes HDPE (purchased from Taiwan Plastics Industry Co., Ltd., product model: HDPE9002, melting point 130°C) as a non-grafted polyolefin, and HDPE grafted with maleic anhydride (MA -g-HDPE, purchased from DuPont, product model: MB100D, melting point 134°C) as a polyolefin grafted with unsaturated carboxylic anhydride. In formula 3, the polymer substrate is polyvinylidene fluoride (PVDF) (purchased from Arkema, product model: Kynar® 761, melting point 170°C). The proportions of the polymer substrate and carbon black powder composed of the above three polymer blends are shown in Table 1, respectively.

The above three polymer substrates were mixed with carbon black powder in a mixer (brand: Brabender), and the ingredients were mixed at a temperature of 200°C and a stirring speed of 30 rpm for 10 minutes to obtain three types of polymerization. Compound composition (ie formula 1, formula 2, formula 3).

Preparation of small chips (chip)

The above-mentioned three polymer blending compositions were placed in a mold, and hot-pressed under ^{the conditions of a hot-pressing temperature of 200° C. and a hot-pressing pressure of 80 kg/cm 2} for 4 minutes to form three kinds of sheets with a thickness of 0.33 mm. Take the three kinds of sheets out of the mold, put each sheet in two pieces of nickel-plated copper foil (as electrodes), and ^{heat-press them at 200°C and 80 kg/cm 2} for 4 min to form a thickness of 0.4 mm laminates. After cutting the same layer board into multiple pieces of 8 mm × 8 mm, each piece was irradiated with Co-60 gamma rays with a total radiation dose of 150 kGy. The initial resistance of each chip was measured with a micro-ohm meter at 25°C. The average value of the initial resistance (n=100) and the calculated average volume resistivity of the three kinds of chips are shown in Table 1, respectively. 【Table 1】 formula Polymer blend composition Electricity of small pieces Polymer substrate Carbon black powder (wt%) Initial resistance (Ω) Volume resistivity (Ω-cm) PE/BA/MA (wt%) HDPE (wt%) MA-g-HDPE (wt%) PVDF (wt%) 1 42.0 - - - 58.0 0.016 0.256 2 - 21.0 21.0 - 58.0 0.020 0.320 3 - - - 60.0 40.0 0.050 0.800 "–" means that it has not been added.

Preparation of overcurrent protection device

＜Example 1 (E1) ＞

The two metal conductor pins are respectively connected to two nickel-plated copper foils of each small piece made of polymer blending composition of the above formula 1, and then the small pieces are covered with a covering layer made of epoxy resin. Blue when presenting H810Kb70P40, color temperature (T _cc) is 70 ℃, the temperature is below T _cc appear white when the temperature is higher than T _cc: will a thermochromic material [purchased from Jiurong Shuofeng life Technology Co., Ltd., Model Color] is screen-printed on the cover layer and dried for about 2 minutes to prepare an overcurrent protection device of E1 with a trip indicator.

＜Example 2 And 3 (E2 And E3) ＞

The process conditions of the overcurrent protection devices of E2 and E3 are similar to those of Example 1, except that the polymer blending composition and the thermochromic material are changed as shown in Table 2.

＜Example 4 To 6 (E4-E6) ＞

The process conditions of the over-current protection devices of E4-E6 are similar to those of Examples 1 to 3, and the difference is that the thermochromic material is changed as shown in Table 2.

＜Comparative example 1 To 3 (CE1-CE3) ＞

The process conditions of the CE1-CE3 overcurrent protection devices are similar to those of Examples 1 to 3, but the difference is that the CE1-CE3 trip indicator is made of a non-thermochromic (non-thermochromic, that is, does not change with temperature). Change the color) black marking ink (as shown in Table 2). 【Table 2】 Polymer blend composition Material to escape the indicator formula Label model T _cc (℃) Color below T _cc Color when higher than T _cc E1 1 Jiurong Shuofeng Life Technology Co., Ltd. H810Kb70P40 70 white blue E2 2 H810Kb110P40 110 E3 3 H810Kb150P40 150 E4 1 Chongyu Technology Co., Ltd. TM-ISI 70-3529 70 white green E5 2 TM-ISI 110-3529 110 E6 3 TM-ISI 150-3529 150 CE1 1 Markem- imaje 5751E-4 N/A black black CE2 2 CE3 3 "N/A" means unavailable.

Performance Testing

[ Room temperature color observation (Color observation at room temperatur)]

Observe the initial colors of the trip indicators of the overcurrent protection devices of E1-E6 and CE1-CE3 at 25°C (non-trip state), and the results are shown in Table 3, respectively.

[ Trip test (Trip test)]

For the over-current protection devices of E1-E6 and CE1-CE3, conduct a trip test with a constant voltage of 16 Vdc and a constant current of 10 A for 60 s. Use a thermocouple to measure the trip surface temperature of the over-current protection device at the moment of tripping, and Observe the color of the trip indicator when the overcurrent protection device is in the trip state, and the results are shown in Table 3. 【table 3】 The initial color of the escape indicator Trip test Trip surface temperature (℃) The color of the escape indicator when in the escape state E1 white 79.4 blue E2 white 114.8 blue E3 white 154.8 blue E4 white 80.2 green E5 white 115.3 green E6 white 154.6 green CE1 black 80.1 black CE2 black 114.9 black CE3 black 155.3 black

The results in Table 3 show that when the overcurrent protection devices of E1-E6 are in the trip state (the trip surface temperature is higher than the T _{cc of the} thermochromic material), the color of the trip indicator is different from its original color, while CE1 -When the CE3 overcurrent protection device is in the trip state, the trip indicator does not change its initial color, which means that the user can immediately identify the E1-E6 overcurrent protection device with the naked eye (that is, without any detection equipment) In a state of tripping.

In summary, by including the trip indicator with the reaction temperature, when the overcurrent protection device of the present invention is in the trip state, it can be immediately recognized by the color change of the trip indicator, and the present invention has The overall production cost and manufacturing process of the current protection device can be greatly reduced, 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.

2:Positive temperature coefficient polymer element 21: Surface 3: electrode 4: No power trip indicator 5: Covering layer 8: Positive temperature coefficient material 81: Surface 9: Electrode

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 over-current protection device; [Figure 2] is a schematic diagram of the first specific embodiment of the overcurrent protection device of the present invention in a normal (non-trip) state; [Figure 3] is a schematic diagram of the first embodiment in a tripped state; and [Figure 4] is a schematic diagram of the second specific embodiment of the overcurrent protection device of the present invention.

2:Positive temperature coefficient polymer element

21: Surface

3: electrode

4: No power trip indicator

Claims (13)

An overcurrent protection device, including: A positive temperature coefficient polymer element with two opposite surfaces; Two electrodes, respectively connected to the two surfaces; and A non-power trip indicator is formed on at least one of the electrodes to sense the temperature of the overcurrent protection device. The overcurrent protection device according to claim 1, wherein the no-power trip indicator is in direct contact with the at least one electrode. The overcurrent protection device according to claim 1, wherein the non-power trip indicator includes a thermochromic material. The overcurrent protection device according to claim 3, wherein the overcurrent protection device has a trip surface temperature, and the trip surface temperature is equal to or higher than the color change temperature of the non-power trip indicator. The overcurrent protection device according to claim 4, wherein the trip surface temperature of the overcurrent protection device is higher than 70°C. The overcurrent protection device according to claim 1, wherein the discoloration temperature of the non-power trip indicator is higher than 60°C. The overcurrent protection device according to claim 6, wherein the discoloration temperature of the non-power trip indicator is higher than 60°C and not higher than 200°C. The overcurrent protection device according to claim 1, further comprising a covering layer arranged between the no-power trip indicator and the at least one electrode. The overcurrent protection device according to claim 8, wherein the non-power trip indicator is in indirect contact with the at least one electrode through the covering layer. The overcurrent protection device according to claim 8, wherein the covering layer surrounds the positive temperature coefficient polymer element and the electrodes, and is made of a thermally conductive insulating material. The overcurrent protection device according to claim 1, wherein the positive temperature coefficient polymer element includes a polymer substrate and a particulate conductive filler dispersed in the polymer substrate. The overcurrent protection device according to claim 11, wherein the particulate conductive filler is selected from carbon black powder, metal powder, conductive ceramic powder, or a combination thereof. The overcurrent protection device according to claim 12, wherein the particulate conductive filler is carbon black powder.

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