CN116092760A - Overcurrent protection element capable of preventing cold and hot impact failure - Google Patents
Overcurrent protection element capable of preventing cold and hot impact failure Download PDFInfo
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- CN116092760A CN116092760A CN202211719488.4A CN202211719488A CN116092760A CN 116092760 A CN116092760 A CN 116092760A CN 202211719488 A CN202211719488 A CN 202211719488A CN 116092760 A CN116092760 A CN 116092760A
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- ptc
- ptc chip
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- overcurrent protection
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- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 claims abstract description 27
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 25
- 239000006229 carbon black Substances 0.000 claims abstract description 24
- 239000002245 particle Substances 0.000 claims abstract description 22
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 24
- 239000011889 copper foil Substances 0.000 claims description 16
- 238000005516 engineering process Methods 0.000 claims description 10
- 238000003466 welding Methods 0.000 claims description 5
- 238000003475 lamination Methods 0.000 claims description 2
- 239000012792 core layer Substances 0.000 abstract description 13
- 239000000463 material Substances 0.000 abstract description 12
- 230000007613 environmental effect Effects 0.000 abstract description 11
- 230000002159 abnormal effect Effects 0.000 abstract description 4
- 230000032683 aging Effects 0.000 abstract description 4
- 239000010410 layer Substances 0.000 abstract description 4
- 230000002265 prevention Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 4
- 230000035939 shock Effects 0.000 description 3
- 101000669528 Homo sapiens Tachykinin-4 Proteins 0.000 description 2
- OKUGPJPKMAEJOE-UHFFFAOYSA-N S-propyl dipropylcarbamothioate Chemical compound CCCSC(=O)N(CCC)CCC OKUGPJPKMAEJOE-UHFFFAOYSA-N 0.000 description 2
- 102100039365 Tachykinin-4 Human genes 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 238000004891 communication Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
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Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
- H01C7/02—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having positive temperature coefficient
- H01C7/027—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having positive temperature coefficient consisting of conducting or semi-conducting material dispersed in a non-conductive organic material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C1/00—Details
- H01C1/14—Terminals or tapping points or electrodes specially adapted for resistors; Arrangements of terminals or tapping points or electrodes on resistors
- H01C1/1406—Terminals or electrodes formed on resistive elements having positive temperature coefficient
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C13/00—Resistors not provided for elsewhere
- H01C13/02—Structural combinations of resistors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
- H01C7/13—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material current responsive
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- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Ceramic Engineering (AREA)
- Thermistors And Varistors (AREA)
Abstract
The invention discloses an overcurrent protection element for preventing cold and hot impact failure, which comprises two PTC core layers made of different materials, wherein conductive particles of a first PTC core layer are tungsten carbide or nickel powder, and conductive particles of a second PTC core layer are carbon black. The first PTC core layer and the second PTC core layer form an integrated element with a parallel structure, and the integrated element is finally connected in series into a circuit. The invention has the advantages that: the PTC element is connected with the carbon black PTC core layer in parallel, so that the problem of environment reliability of abnormal resistance rise of the PTC element made of tungsten carbide or nickel powder under the condition of cold and hot impact is effectively solved. Under normal environment, through-flow and overcurrent protection of heavy current is realized through the PTC sandwich layer I of tungsten carbide or nickel powder material with lower resistance, and after environmental aging and cold and hot impact, the PTC sandwich layer I becomes high resistance, and through the carbon black based PTC sandwich layer II under the parallel structure, the through-flow and overcurrent protection function is continuously maintained, so that the condition that the circuit fails due to cold and hot impact prevention is avoided.
Description
Technical Field
The invention relates to a PTC protection element, in particular to an overcurrent protection element capable of preventing cold and hot impact failure.
Background
The high polymer positive temperature coefficient thermistor (PTC) has low resistance in low temperature environment, increases with the increase of temperature, and rapidly increases when reaching a certain temperature point, thus being a self-recovery fuse. In a normal state, the current in the circuit is relatively small, the temperature of the PPTC is low, and when the overcurrent or the overtemperature phenomenon occurs, the resistance value of the PPTC becomes very large instantaneously, and the current in the circuit is cut off, so that the circuit is in an approximate open circuit state, and the overcurrent protection effect is achieved on other elements in the circuit. This also makes PTC widely used as a secondary protection in overcurrent protection in many fields of communication, computers, automobiles, industrial control, home appliances, and the like.
The PTC is obtained by blending polymer and conductive particles, and the conductive particles currently used for mass production mainly comprise low-resistance materials of tungsten carbide or nickel powder materials and conventional carbon black materials. Tungsten carbide or nickel powder materials are limited by the material characteristics, and have poor performance under the environment reliability such as cold and hot impact temperature cycle, and exponential rise resistance can occur. This causes the application side to be in an open failure state due to an abnormal rise in loop resistance. The service life of the tungsten carbide or nickel powder material becomes very short, and the market application range cannot be widened.
The PTC element made of carbon black performs well under the temperature cycle of cold and hot impact and does not cause resistance rise. However, the resistance of the alloy is slightly higher than that of tungsten carbide or nickel powder, and the alloy cannot be applied to a high-current environment.
With the development of the market, the requirements of application ends are gradually increased, and the requirements of environmental reliability of various devices are higher.
For heavy current overcurrent protection, the initial resistance is reduced by adopting a technical scheme of reducing initial current, such as adopting parallel PTC chips, and the application range of the protection element is increased, but the protection element is usually made of PTC materials with the same material, so that the protection element is convenient to process.
Disclosure of Invention
The invention aims to provide an overcurrent protection element capable of preventing cold and hot impact failure.
The invention aims at realizing the following technical scheme: the utility model provides an overcurrent protection element of cold and hot impact failure that prevents, includes PTC chip and conductive connection terminal, PTC chip include the PTC chip of two kinds of different materials, PTC chip one adopts tungsten carbide or nickel powder to be the low resistance sandwich layer of conductive particle, PTC chip two adopts carbon black to be the relative high resistance chip of conductive particle, PTC chip one and PTC chip two form the integrated component of parallel structure, establish ties with external circuit through connection terminal.
Further, the parallel connection mode includes: the parallel structure of the two lamination sheets of the first PTC core layer and the second PTC core layer is realized by the PCB technology or the welding technology; or, the second PTC chip taking carbon black as the conductive particle is hollowed out, the first PTC chip is built in, and then a parallel structure is formed by a blind hole technology or a welding technology.
And the first PTC core layer and the second PTC core layer form a parallel structure through a PCB processing technology or a combination welding technology.
Under normal environment, through-flow and overcurrent protection of large current is realized through the PTC chip made of tungsten carbide or nickel powder with lower resistance, and after environmental aging and cold and hot impact, the PTC chip I becomes high resistance, and through the carbon black-based PTC chip II under the parallel structure, the through-flow and overcurrent protection function is continuously maintained, so that the circuit is prevented from being directly in an open circuit failure state due to the high resistance of the PTC chip I.
The principle of the invention is as follows:
based on a low-resistance PTC chip I with tungsten carbide or nickel powder as conductive particles, the low-resistance large-current capacity of the chip I is utilized in a large-current loop, and the PTC characteristic of the chip I is used for overcurrent protection.
The overcurrent protection element with the cold and hot impact failure prevention function is mainly applied to circuit designs with high current and high environmental reliability requirements, and has the advantages that:
(1) compared with the traditional PTC element made of tungsten carbide or nickel powder, the PTC element made of tungsten carbide or nickel powder effectively solves the problem of environment reliability of abnormal resistance rise of the PTC element made of tungsten carbide or nickel powder under the condition of cold and hot impact by connecting the PTC chip with carbon black in parallel. Under normal environment, through-flow and overcurrent protection of large current are realized through a first PTC chip made of tungsten carbide or nickel powder with low resistance, after environmental aging and cold and hot impact, the first PTC chip becomes high resistance, and through a second PTC chip with carbon black base under a parallel structure, the through-flow and overcurrent protection function is continuously maintained, so that the circuit is prevented from being directly in an open circuit state due to the high resistance;
(2) the integrated element has a simple structure and can be manufactured into a lead type, a strip type or a patch type element according to the application conditions of clients.
Drawings
Fig. 1 is a schematic structural diagram of an overcurrent protection element with a cold-hot impact failure protection function in embodiment 1;
FIG. 2 is a schematic diagram of an overcurrent protection device with cold and hot impact failure protection in embodiment 2;
FIG. 3 is a circuit diagram of a component protection scheme;
description of the reference numerals:
1. PTC chip I with tungsten carbide or nickel powder as conductive particles;
2. -PTC chip two with carbon black as conductive particles;
3', 3—upper, lower, right terminal;
4', 4—upper, lower left terminals;
5', 5—left and right conductive vias;
6. 6' — upper and lower conductive blind holes;
A. a power supply terminal;
B. a power supply terminal;
C. a signal end;
D. and an overcurrent protection element for preventing cold and hot impact failure.
Detailed Description
The present invention will be described in further detail with reference to specific examples.
Example 1
An overcurrent protection element for preventing cold and hot impact failure has upper and lower terminals, as shown in figure 1, comprising a PTC chip 1 using tungsten carbide or nickel powder as conductive particles and a PTC chip 2 using carbon black as conductive particles, wherein,
the inside of the PTC chip II 2 is hollowed, the PTC chip I implanted with tungsten carbide or nickel powder is connected to the upper copper foil 11 and the lower copper foil 12 of the PTC chip II 2 through the upper conductive blind holes 6 and the lower conductive blind holes 6', so that an internal parallel structure is realized;
the upper copper foil 21 of the PTC chip II 2 is conducted to the upper and lower right terminals 3', 3 through the right conductive through holes 5;
the lower copper foil 22 of the PTC chip II 2 is conducted to the upper and lower left surface terminals 4', 4 through the left conductive through hole 5'; finally, the left and right terminals 3, 4 are connected to an external circuit and connected in series to the circuit.
As shown in fig. 3, a circuit diagram of a protection scheme of the overcurrent protection D for preventing cold-hot impact failure according to the invention is shown.
Under normal environment, the PTC chip 1 of tungsten carbide or nickel powder has relatively low resistance, and under the parallel structure, the PTC chip 1 is mainly used for carrying out through-flow and overcurrent protection of large current according to ohm law; after environmental aging and cold and hot impact, the PTC chip 1 is aged to become high resistance, and the resistance of the carbon black-based PTC chip 2 is unchanged, so that the original state is maintained. According to ohm's law, at this time, because the resistance of the carbon black PTC core layer 2 is low, the through-flow and overcurrent protection functions are mainly performed by means of the carbon black PTC core layer 2, so that the line is prevented from being directly in an open circuit state failure due to the high resistance of the PTC element 1.
Example 2
An overcurrent protection element for preventing cold and hot impact failure has an upper terminal and a lower terminal, which are commonly used laminated parallel structure as shown in figure 2, wherein,
the second PTC chip 2 taking carbon black as conductive particles is respectively connected into the left conductive through holes 5' through the upper copper foil 21; the right conductive through holes 5 are respectively connected through the lower copper foil 22;
the internal parallel structure is realized, and finally, the upper and lower left terminals 4', 4 are respectively conducted through the left conductive through holes 5'; the upper and lower right terminals 3', 3 are connected to an external circuit through the right conductive vias 5, and are connected in series into the circuit.
The principle of operation is the same as in example 1.
Comparative column
A conventional single material PTC element, a tungsten carbide PTC element, and a carbon black based PTC element are used.
The initial resistance, the resistance after 1000 cold and hot shocks, and the resistance rise are measured under cold and hot shock conditions (20 min at 0 ℃ to 20min at 100 ℃ for 1000 times). See table 1:
the PTC element of tungsten carbide can achieve ultra-low resistance and high current through-flow capability. However, the problem of environmental reliability exists, abnormal rise resistance is presented, the rise is exponentially increased, the rise amplitude is more than 1000 times, and the rise is increased from the mΩ level to the hundred Ω level.
The carbon black-based PTC element has a stable resistance under cold and hot shock, substantially maintains an initial level, and does not rise in resistance. Therefore, the PTC element with the carbon black and the PTC core layer connected in parallel can effectively solve the problem of the environmental reliability that the resistance of the PTC element made of tungsten carbide or nickel powder is abnormally increased under the condition of cold and hot impact.
Results and discussion: the invention fully utilizes the characteristics of low initial resistance and suitability for large-current protection of the PTC chip taking tungsten carbide or nickel powder as conductive particles, and simultaneously ensures the high environmental reliability of the element by being connected with the carbon black-based PTC chip with good environmental reliability.
The element of the invention is suitable for circuits with high environmental reliability requirements but high current through-flow capability.
The foregoing disclosure and features of the invention have been disclosed as illustrative only and not as restrictive of the invention, it may be possible to devise various arrangements which, however, are more than disclosed herein. Accordingly, the scope of the present invention should not be limited to the disclosure of the embodiments, but should include all combinations of what is presented in the different sections, as well as various alternatives and modifications without departing from the invention, and is intended to be covered by the claims of the present invention.
Claims (4)
1. The utility model provides an overcurrent protection element of cold and hot impact failure that prevents, includes PTC chip and conductive connection terminal, its characterized in that: the PTC chip I (1) is a low-resistance chip with tungsten carbide or nickel powder as conductive particles, the PTC chip II (2) is a relatively high-resistance chip with carbon black as conductive particles, the PTC chip I (1) and the PTC chip II (2) form an integrated element with a parallel structure, and the integrated element is connected with an external circuit in series through a connecting terminal.
2. The overcurrent protection element for preventing cold and hot impact failure according to claim 1, wherein the parallel connection mode comprises: through PCB technology or welding technology, the double-layer lamination type parallel structure of the first PTC chip (1) and the second PTC chip (2) is adopted; or, the PTC chip (2) taking carbon black as conductive particles is hollowed out, and the built-in PTC chip (1) is formed into a parallel structure by a blind hole technology or a welding technology.
3. The overcurrent protection element for preventing cold and hot impact failure according to claim 1 or 2, wherein: the PTC chip comprises a PTC chip I (1) taking tungsten carbide or nickel powder as conductive particles and a PTC chip II (2) taking carbon black as conductive particles, wherein,
the inside of the PTC chip II (2) is hollowed out, the PTC chip I (1) implanted with tungsten carbide or nickel powder is respectively communicated with the upper copper foil (11) and the lower copper foil (12) of the PTC chip II (2) through the upper conductive blind holes (6) and the lower conductive blind holes (6'), so that an internal parallel structure is realized;
the upper copper foil (21) of the PTC chip II (2) is communicated with the upper right terminal (3 ', 3) and the lower right terminal (3') through the right conductive through hole (5);
the lower copper foil (22) of the PTC chip II (2) is communicated with the upper left surface terminal (4 ', 4) and the lower left surface terminal (4 ') through the left conductive through hole (5 '); finally, the left and right terminals (3, 4) are connected with an external circuit and are connected in series into the circuit.
4. The overcurrent protection element for preventing cold and hot impact failure according to claim 1 or 2, wherein: has upper and lower terminals, wherein,
PTC chip I (1) using tungsten carbide or nickel powder as conductive particles is connected into the right conductive through hole (5) through the upper copper foil (11); the left conductive through hole (5') is accessed through the lower copper foil (12);
PTC chip II (2) using carbon black as conductive particles is respectively connected with left conductive through holes (5') through upper copper foil (21); the right conductive through holes (5) are respectively connected through the lower copper foil (22);
the internal parallel structure is realized, and finally, the upper and lower left terminals (4 ', 4) are respectively conducted through the left conductive through holes (5'); and the upper right terminal (3 ', 3) and the lower right terminal (3', 3) are communicated through the right conductive through hole (5), are connected with an external circuit through the terminals and are connected in series into the circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211719488.4A CN116092760A (en) | 2022-12-30 | 2022-12-30 | Overcurrent protection element capable of preventing cold and hot impact failure |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202211719488.4A CN116092760A (en) | 2022-12-30 | 2022-12-30 | Overcurrent protection element capable of preventing cold and hot impact failure |
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| CN116092760A true CN116092760A (en) | 2023-05-09 |
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| CN112786268A (en) * | 2021-02-03 | 2021-05-11 | 上海维安电子有限公司 | Double contact surface PTC overcurrent protection element |
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2022
- 2022-12-30 CN CN202211719488.4A patent/CN116092760A/en active Pending
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