CN115348718A - PTC circuit protection device - Google Patents

PTC circuit protection device Download PDF

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Publication number
CN115348718A
CN115348718A CN202110525741.1A CN202110525741A CN115348718A CN 115348718 A CN115348718 A CN 115348718A CN 202110525741 A CN202110525741 A CN 202110525741A CN 115348718 A CN115348718 A CN 115348718A
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electrode
ptc
layer
protection device
circuit protection
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陈继圣
江长鸿
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Fuzetec Technology Co Ltd
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Fuzetec Technology Co Ltd
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/11—Printed elements for providing electric connections to or between printed circuits

Abstract

A PTC circuit protection device comprises a PTC polymer layer, a first conductive layer electrically connected to the PTC polymer layer, a second conductive layer electrically connected to the PTC polymer layer, an insulating layer unit arranged on the first conductive layer and the second conductive layer, a first electrode formed on the insulating layer unit and electrically connected to the first conductive layer, and a second electrode formed on the insulating layer unit and electrically connected to the second conductive layer, wherein a first groove is formed on the first electrode. The PTC circuit protection device has excellent bonding strength to a PCB.

Description

PTC circuit protection device
Technical Field
The present invention relates to a Positive Temperature Coefficient (PTC) circuit protection device, and more particularly, to a PTC circuit protection device formed with a groove.
Background
A Positive Temperature Coefficient (PTC) element has a PTC effect, making it useful as a circuit protection device (e.g., a resettable fuse). The PTC element includes a PTC polymer unit, and a first electrode and a second electrode formed on opposite surfaces of the PTC polymer unit. The PTC polymer unit comprises a polymer base material containing a crystalline region and an amorphous region, and a particulate conductive filler. The particulate conductive filler is dispersed in the amorphous regions of the polymer matrix and forms a continuous conductive path for electrically connecting the first and second electrodes. The PTC effect refers to a phenomenon in which when the polymer base material temperature of the crystalline region is raised to its melting point, the crystals in the crystalline region start to melt, thereby generating a new amorphous region. When the new amorphous region increases to the point where it merges into the original amorphous region, the conductive path of the particulate conductive filler transitions to a non-continuous state and the resistance of the PTC polymer unit increases sharply, causing electrical non-conduction between the first and second electrodes.
Referring to fig. 1, a conventional surface-mounted PTC circuit protection device 1 includes a PTC unit 14, a first insulating layer 15, a second insulating layer 16, a first electrode 17, and a second electrode 18. The PTC unit 14 includes a first conductive member 12, a second conductive member 13, and a polymer layer 11 laminated between the first conductive member 12 and the second conductive member 13. The polymer layer 11 exhibits PTC characteristics and comprises a polymer base material and a particulate conductive filler dispersed in the polymer base material. The first insulating layer 15 is disposed on the first conductive member 12, and the second insulating layer 16 is disposed on the second conductive member 13. The first electrode 17 is electrically connected to the first conductive member 12 and disposed on the first insulating layer 15, and further extends toward the second insulating layer 16. Similarly, the second electrode 18 is electrically connected to the second conductive member 13 and disposed on the second insulating layer 16, and further extends toward the first insulating layer 15.
The above-described conventional surface-mount PTC circuit protection device 1 is typically mounted to an electronic apparatus (e.g., a printed circuit board (not shown)) by solder. However, solderability (solderability) between the surface mount PTC circuit protection device 1 and the electronic equipment is not as desirable.
Disclosure of Invention
It is an object of the present invention to provide a PTC circuit protection device which overcomes at least one of the disadvantages of the background art described above.
The PTC circuit protection device comprises a PTC polymer layer, a first conductive layer, a second conductive layer, an insulating layer unit, a first electrode and a second electrode. The first conductive layer is electrically connected to the PTC polymer layer. The second conductive layer is electrically connected to the PTC polymer layer and spaced apart from the first conductive layer. The insulating layer unit is arranged on the first conducting layer and the second conducting layer. The first electrode is formed on the insulating layer unit, is electrically connected with the first conducting layer and is arranged at intervals with the second conducting layer. The second electrode is formed on the insulating layer unit, is electrically connected to the second conductive layer and is arranged at an interval with the first conductive layer and the first electrode. Wherein the first electrode is formed with a first groove recessed from a surface of the first electrode toward the PTC polymer layer.
In the PTC circuit protection device of the present invention, the second electrode is formed with a second groove which is recessed from the surface of the second electrode toward the PTC polymer layer.
In the PTC circuit protection device according to the present invention, the first electrode has a first recess-defining wall defining the first recess, the second electrode has a second recess-defining wall defining the second recess, and a surface area of the first recess-defining wall is not less than 10% of a surface area of the first electrode and a surface area of the second recess-defining wall is not less than 10% of a surface area of the second electrode.
In the PTC circuit protection device according to the present invention, the PTC polymer layer has an upper surface, a lower surface opposite to the upper surface, and a surrounding surface interconnected to the upper surface and the lower surface, the first conductive layer is disposed on the upper surface, and the second conductive layer is disposed on the lower surface; the insulating layer unit comprises a first insulating layer arranged on the first conducting layer and a second insulating layer arranged on the second conducting layer; the first electrode includes an upper first electrode portion disposed on the first insulating layer, a lower first electrode portion disposed on the second insulating layer, and a first electrode connection portion formed on the surrounding face of the PTC polymer layer, the first electrode connection portion being interconnected to the upper first electrode portion and the lower first electrode portion; and the second electrode includes an upper second electrode portion disposed on the first insulating layer, a lower second electrode portion disposed on the second insulating layer, and a second electrode connection portion formed on the surrounding surface of the PTC polymer layer, the second electrode connection portion being interconnected to the upper second electrode portion and the lower second electrode portion.
In the PTC circuit protection device according to the present invention, the first groove of the first electrode is formed in one of the upper first electrode portion and the lower first electrode portion.
In the PTC circuit protection device according to the present invention, the second groove of the second electrode is formed in one of the upper second electrode portion and the lower second electrode portion.
In the PTC circuit protection device according to the present invention, the PTC polymer layer has an upper surface, a lower surface opposite to the upper surface, and a surrounding surface interconnected to the upper surface and the lower surface, the first conductive layer is disposed on the upper surface, and the second conductive layer is disposed on the lower surface; the first conducting layer comprises an upper first conducting part arranged on the upper surface and a lower first conducting part arranged on the lower surface; the second conducting layer comprises an upper second conducting part arranged on the upper surface and a lower second conducting part arranged on the lower surface; the insulating layer unit comprises a first insulating layer arranged on the first conducting layer and a second insulating layer arranged on the second conducting layer, the first insulating layer comprises an upper first insulating part arranged on the upper first conducting part and a lower first insulating part arranged on the lower first conducting part, and the second insulating layer comprises an upper second insulating part arranged on the upper second conducting part and a lower second insulating part arranged on the lower second conducting part; the first electrode includes an upper first electrode portion disposed on the upper first insulating portion, a lower first electrode portion disposed on the lower first insulating portion, and a first electrode connection portion formed on the surrounding surface of the PTC polymer layer, the first electrode connection portion being interconnected to the upper first electrode portion and the lower first electrode portion; and the second electrode comprises an upper second electrode part arranged on the upper second insulating part, a lower second electrode part arranged on the lower second insulating part, and a second electrode connecting part formed on the surrounding surface of the PTC polymer layer, wherein the second electrode connecting part is interconnected with the upper second electrode part and the lower second electrode part.
In the PTC circuit protection device according to the present invention, the first groove of the first electrode is formed in one of the upper first electrode portion and the lower first electrode portion.
In the PTC circuit protection device according to the present invention, the first electrode is formed with two first grooves, which are formed on the upper first electrode part and the lower first electrode part, respectively.
In the PTC circuit protection device according to the present invention, the second electrode is formed with at least one second groove formed on one of the upper second electrode portion and the lower second electrode portion.
In the PTC circuit protection device according to the present invention, the upper first electrode portion has a first recess-defining wall defining the first recess, the upper second electrode portion has a second recess-defining wall defining the second recess, a surface area of the first recess-defining wall is not less than 10% of an upper surface area of the upper first electrode portion, and a surface area of the second recess-defining wall is not less than 10% of an upper surface area of the upper second electrode portion.
In the PTC circuit protection device according to the present invention, the surface area of the first recess defining wall is 10% to 80% of the upper surface area of the upper first electrode portion, and the surface area of the second recess defining wall is 10% to 80% of the upper surface area of the upper second electrode portion.
In the PTC circuit protection device of the present invention, the surface area of the first recess defining wall is 25% to 75% of the upper surface area of the upper first electrode portion, and the surface area of the second recess defining wall is 25% to 75% of the upper surface area of the upper second electrode portion.
The PTC circuit protection device of the present invention further comprises an insulating spacer disposed between the upper first conductive portion and the upper second conductive portion.
The PTC circuit protection device of the present invention further comprises a third conductive layer and a fourth conductive layer, wherein the third conductive layer comprises an upper third conductive part disposed between the upper first insulating part and the upper first electrode part, and a lower third conductive part disposed between the lower first insulating part and the lower first electrode part; and the fourth conducting layer comprises an upper fourth conducting part arranged between the upper second insulating part and the upper second electrode part and a lower fourth conducting part arranged between the lower second insulating part and the lower second electrode part.
In the PTC circuit protection device, each first conductive layer and each second conductive layer are nickel-plated copper foils.
In the PTC circuit protection device of the present invention, the insulating layer unit is made of epoxy resin.
The PTC circuit protection device comprises a PTC polymer layer, a polymer substrate and a granular conductive filler, wherein the granular conductive filler is dispersed in the polymer substrate, and the polymer substrate comprises a non-grafted olefin polymer.
The PTC circuit protection device of the present invention further comprises an olefin polymer grafted with a carboxylic acid anhydride.
In the PTC circuit protection device of the present invention, the particulate conductive filler is selected from carbon black powder, metal powder, conductive ceramic powder, or a combination thereof.
The invention has the beneficial effects that: the PTC circuit protection device has excellent bonding strength to a PCB.
Drawings
Other features and effects of the present invention will be apparent from the embodiments with reference to the accompanying drawings, in which:
fig. 1 is a schematic cross-sectional view of a conventional PTC circuit protection device;
fig. 2 is a schematic cross-sectional view of a first embodiment of the PTC circuit protection device of the present invention;
fig. 3 is a schematic cross-sectional view of a second embodiment of the PTC circuit protection device of the present invention; and
fig. 4 is a perspective view of the second embodiment.
Detailed Description
Before the present invention is described in detail, it should be noted that like elements are represented by like reference numerals throughout the following description.
Furthermore, directional terms (e.g., up and down) used in the description and claims of the present invention are simply intended to help describe relative positions of elements of the present invention, and are not intended to limit the actual positions of each element when the present invention is actually performed.
Referring to fig. 2, the first embodiment of the PTC circuit protection device 2 according to the present invention includes a PTC unit 21, an insulating layer unit 23, a first electrode 24, and a second electrode 25. The PTC unit 21 includes a PTC polymer layer 210, a first conductive layer 211, and a second conductive layer 212. The first conductive layer 211 is electrically connected to the PTC polymer layer 210. The second conductive layer 212 is electrically connected to the PTC polymer layer 210 and spaced apart from the first conductive layer 211. The insulating layer unit 23 is disposed on the first conductive layer 211 and the second conductive layer 212. The first electrode 24 is formed on the insulating layer unit 23, electrically connected to the first conductive layer 211 and spaced apart from the second conductive layer 212. The second electrode 25 is formed on the insulating layer unit 23, electrically connected to the second conductive layer 212, and spaced apart from the first conductive layer 211 and the first electrode 24. The first electrode 24 is formed with a first groove 244, and the first groove 244 is recessed from the surface of the first electrode 24 toward the PTC polymer layer 210. In some embodiments of the present invention, the second electrode 25 is formed with a second recess 254, the second recess 254 being recessed from the surface of the second electrode 25 toward the PTC polymer layer 210.
The first electrode 24 has a first recess-defining wall 245 defining the first recess 244 and the second electrode 25 has a second recess-defining wall 255 defining the second recess 254. In some embodiments of the invention, the surface area of the first recess-defining wall 245 is no less than 10% of the surface area of the first electrode 24. In some embodiments of the invention, the surface area of the second groove defining wall 255 is no less than 10% of the surface area of the second electrode 25. It should be noted that the surface areas of the first electrode 24 and the second electrode 25 refer to the surface areas of the first electrode 24 and the second electrode 25, which are not in contact with the PTC unit 21 and the insulating layer unit 23 and do not include portions extending to be electrically connected to the first conductive layer 211 and the second conductive layer 212, respectively.
In some embodiments of the present invention, the surface area of the first recess-defining wall 245 is 10% to 80% of the surface area of the first electrode 24, and the surface area of the second recess-defining wall 255 is 10% to 80% of the surface area of the second electrode 25.
In some embodiments of the present invention, the surface area of the first recess-defining wall 245 is 25% to 75% of the surface area of the first electrode 24, and the surface area of the second recess-defining wall 255 is 25% to 75% of the surface area of the second electrode 25.
In some embodiments of the present invention, the PTC polymer layer 210 includes an upper surface, a lower surface opposite to the upper surface, and a surrounding surface interconnecting the upper surface and the lower surface. In the present embodiment, the first conductive layer 211 is disposed on the upper surface, and the second conductive layer 212 is disposed on the lower surface. The insulating layer unit 23 includes a first insulating layer 231 disposed on the first conductive layer 211 and a second insulating layer 232 disposed on the second conductive layer 212. The first electrode 24 includes an upper first electrode portion 241 disposed on the first insulating layer 231, a lower first electrode portion 242 disposed on the second insulating layer 232, and a first electrode connecting portion 243 formed on a surrounding surface of the PTC polymer layer 210. The first electrode connecting portion 243 interconnects the upper first electrode portion 241 and the lower first electrode portion 242. The second electrode 25 includes an upper second electrode portion 251 disposed on the first insulating layer 231, a lower second electrode portion 252 disposed on the second insulating layer 232, and a second electrode connecting portion 253 formed on a surrounding surface of the PTC polymer layer 210. The second electrode connecting portion 253 interconnects the upper second electrode portion 251 and the lower second electrode portion 252.
In some embodiments of the present invention, the first groove 244 of the first electrode 24 is formed on one of the upper first electrode portion 241 and the lower first electrode portion 242. In some embodiments of the present invention, the first electrode 24 has two first grooves 244, and the first grooves 244 are formed on the upper first electrode portion 241 and the lower first electrode portion 242, respectively.
In some embodiments of the present invention, the second recess 254 of the second electrode 25 is formed on one of the upper second electrode portion 251 and the lower second electrode portion 252. In some embodiments of the present invention, the second electrode 25 has two second grooves 254, and the second grooves 254 are respectively formed on the upper second electrode portion 251 and the lower second electrode portion 252.
Referring to fig. 3 and 4, a second embodiment of the PTC circuit protection device 2 of the present invention is similar to the first embodiment, with the following differences.
Referring to fig. 3 and 4, the PTC polymer layer 210 includes an upper surface, a lower surface opposite to the upper surface, and a surrounding surface interconnecting the upper surface and the lower surface. In the present embodiment, the first conductive layer 211 includes an upper first conductive portion 2111 disposed on the upper surface and a lower first conductive portion 2112 disposed on the lower surface. The second conductive layer 212 includes an upper second conductive portion 2121 disposed on the upper surface and a lower second conductive portion 2122 disposed on the lower surface. The insulating layer unit 23 includes a first insulating layer 231 disposed on the first conductive layer 211 and a second insulating layer 232 disposed on the second conductive layer 212. The first insulating layer 231 includes an upper first insulating portion 2311 disposed on the upper first conductive portion 2111 and a lower first insulating portion 2312 disposed on the lower first conductive portion 2112. The second insulating layer 232 includes an upper second insulating portion 2321 disposed on the upper second conductive portion 2121 and a lower second insulating portion 2322 disposed on the lower second conductive portion 2122. The first electrode 24 includes an upper first electrode portion 241 disposed on the upper first insulating portion 2311, a lower first electrode portion 242 disposed on the lower first insulating portion 2312, and a first electrode connecting portion 243 formed on a surrounding surface of the PTC polymer layer 210. The first electrode connecting portion 243 is interconnected to the upper first electrode portion 241 and the lower first electrode portion 242. The second electrode 25 includes an upper second electrode part 251 disposed on the upper second insulating part 2321, a lower second electrode part 252 disposed on the lower second insulating part 2322, and a second electrode connecting part 253 formed on the surrounding surface of the PTC polymer layer 210. The second electrode connecting portion 253 is interconnected to the upper second electrode portion 251 and the lower second electrode portion 252.
In some embodiments of the present invention, the first groove 244 of the first electrode 24 is formed on one of the upper first electrode portion 241 and the lower first electrode portion 242. In some embodiments of the present invention, the first electrode 24 is formed with two first grooves 244, and the first grooves 244 are respectively formed on the upper first electrode portion 241 and the lower first electrode portion 242.
In some embodiments of the present invention, the second recess 254 of the second electrode 25 is formed on one of the upper second electrode portion 251 and the lower second electrode portion 252. In some embodiments of the present invention, the first electrode 24 is formed with two second grooves 254, and the second grooves 254 are respectively formed on the upper second electrode portion 251 and the lower second electrode portion 252.
In some embodiments of the present invention, the upper first electrode portion 241 has a first recess-defining wall 245 defining the first recess 244, the upper second electrode portion 251 has a second recess-defining wall 255 defining the second recess 254, the surface area of the first recess-defining wall 245 is no less than 10% of the upper surface area of the upper first electrode portion 241, and the surface area of the second recess-defining wall 255 is no less than 10% of the upper surface area of the upper second electrode portion 251. The upper surface area of the upper first electrode portion 241 refers to an area of a surface of the upper first electrode portion 241 opposite to the upper surface of the PTC polymer layer 210; the upper surface area of the upper second electrode portion 251 refers to an area of a surface of the upper second electrode portion 251 opposite to the upper surface of the PTC polymer layer 210.
In some embodiments of the present invention, the surface area of the first recess-defining wall 245 and the second recess-defining wall 255 is 10% to 80%, or 25% to 75%, of the upper surface area of the upper first electrode portion 241 and the upper second electrode portion 251.
In some embodiments of the present invention, the surface area of the first recess defining wall 245 is not less than 10% of the upper surface area of the upper first electrode portion 241, or 10% to 80% of the upper surface area of the upper first electrode portion 241, or 25% to 75%. In some embodiments of the invention, the surface area of the second groove defining wall 255 is not less than 10% of the upper surface area of the upper second electrode portion 251, or 10% to 80%, or 25% to 75% of the upper surface area of the upper second electrode portion 251. In some embodiments of the invention, an insulating spacer 28 is disposed between the upper first conductive portion 2111 and the upper second conductive portion 2121. The insulating spacer 28 may also be disposed between the lower first conductive portion 2112 and the lower second conductive portion 2122.
In some embodiments of the present invention, the PTC circuit protection device 2 further comprises a third conductive layer 26 and a fourth conductive layer 27. The third conductive layer 26 includes an upper third conductive portion 261 disposed between the upper first insulating portion 2311 and the upper first electrode portion 241, and a lower third conductive portion 262 disposed between the lower first insulating portion 2312 and the lower first electrode portion 242. The fourth conductive layer 27 includes an upper fourth conductive portion 271 disposed between the upper second insulating portion 2321 and the upper second electrode portion 251, and a lower fourth conductive portion 272 disposed between the lower second insulating portion 2322 and the lower second electrode portion 252.
In some embodiments of the present invention, each of the first conductive layers 211 and each of the second conductive layers 212 may be made of a metal material, such as a metal foil, a metal-plated foil (e.g., nickel-plated copper foil), and the like.
In some embodiments of the present invention, the insulating layer unit 23 is made of epoxy resin.
In the present invention, the PTC polymer layer 210 comprises a polymer base material and a particulate conductive filler dispersed in the polymer base material. The polymeric substrate can be made from a polymer composition that contains a non-grafted olefin-based polymer, such as High Density Polyethylene (HDPE). In some embodiments of the invention, the polymer composition further comprises a grafted olefin-based polymer. In some embodiments of the invention, the grafted olefin-based polymer comprises an olefin-based polymer grafted with a carboxylic acid anhydride. The olefin-based polymer grafted with carboxylic anhydride may be a high-density polyethylene grafted with carboxylic anhydride. In this example, the olefin-based polymer grafted with a carboxylic anhydride was HDPE grafted with maleic anhydride.
In the present invention, the particulate conductive filler may be made of carbon black, metal, conductive ceramic material, or a combination of the foregoing. In some embodiments of the invention, the particulate conductive filler is selected from carbon black powder, metal powder, conductive ceramic powder, or combinations thereof.
Examples of the particulate conductive filler include titanium carbide, zirconium carbide, vanadium carbide, niobium carbide, tantalum carbide, chromium carbide, molybdenum carbide, tungsten carbide, titanium nitride, zirconium nitride, vanadium nitride, niobium nitride, tantalum nitride, chromium nitride, titanium disilicide, zirconium disilicide, niobium disilicide, tungsten disilicide, gold, silver, copper, aluminum, nickel-metalized glass beads, nickel-metalized graphite, ti-Ta solid solution, W-Ti-Ta-Cr solid solution, W-Ta solid solution, W-Ti-Ta-Nb solid solution, W-Ti-Ta solid solution, W-Ti solid solution, ta-Nb solid solution, or a combination of the foregoing.
In certain embodiments of the present invention, the polymer base material may comprise 5wt% to 50wt% of the PTC polymer layer 210, and the particulate conductive filler may comprise 50wt% to 95wt% of the PTC polymer layer 210.
The method of manufacturing the PTC circuit protection device 2 comprises the steps of: (a) providing a PTC polymer layer 210; (b) Forming a first conductive layer 211 electrically connected on the PTC polymer layer 210; (c) A second conductive layer 212 formed on the PTC polymer layer 210 to be electrically connected and spaced apart from the first conductive layer 211; (d) Forming an insulating layer unit 23 over the first conductive layer 211 and the second conductive layer 212; (e) Hot-pressing the PTC polymer layer 210, the first conductive layer 211, the second conductive layer 212 and the insulating layer unit 23 to form a laminate; (f) Forming a first electrode 24 on the stack layer to be electrically connected to the first conductive layer 211; (g) Forming a second electrode 25 on the stack, electrically connected to the second conductive layer 212 and spaced apart from the first electrode 24; (h) A first groove 244 is formed on the first electrode 24, the first groove 244 being recessed from the surface of the first electrode 24 toward the PTC polymer layer 210. In certain embodiments of the present invention, the method further comprises the step of (i) forming a second recess 254 on the second electrode 25, the second recess 254 being recessed from the surface of the second electrode 25 toward the PTC polymer layer 210.
The invention will be further described in the following examples, but it should be understood that these examples are for illustrative purposes only and are not to be construed as limiting the practice of the invention.
Examples
< example 1 (E1) >
First, 10.5g of HDPE (available from Formosa Plastics, product number: HDPE 9002) as a non-grafted olefin-based polymer, 10.5g of HDPE grafted with maleic anhydride (available from DuPont, product number: MB 100D) as an olefin-based polymer grafted with carboxylic anhydride, and 29g of carbon black powder (available from Columbian Chemicals, product number: raven 430 UB) as a particulate conductive filler were used.
The above ingredients were mixed in a mixer (Brander), and the ingredients were mixed at a temperature of 200 ℃ and a stirring speed of 50rpm for 10min to obtain an ingredient mixture.
Placing the mixture in a mold, and hot pressing at 200 deg.C and 80kg/cm 2 Is hot pressed for 4min to form a plurality of PTC polymer embryo pellets. Taking out the embryo granules from the mold, and clamping the embryo granules in upper and lower pieces of nickel-plated copper foil at 200 deg.C and 80kg/cm 2 The next step is a hot pressing for 4min, and then Co-60 gamma rays are irradiated with a total radiation dose of 15Mrad, and then the upper and lower nickel-plated copper foils are etched to form an upper first conductive part and an upper second conductive part which are spaced from each other, and a lower first conductive part and a lower second conductive part which are spaced from each other, so as to obtain a PTC unit with a thickness of 0.32 mm. Referring to fig. 3 and 4, in a second embodiment, the upper first conductive portion and the lower first conductive portion are used together as the first conductive layer, and the upper second conductive portion and the lower second conductive portion are used together as the second conductive layer.
Next, epoxy resin layers are disposed on the exposed two opposite surfaces of the first conductive layer, the second conductive layer and the PTC polymer layer, and then hot-pressed to form the first insulating layer, the second insulating layer and an insulating spacer disposed between the first conductive layer and the second conductive layer (as shown in fig. 3 and 4).
A third conductive layer and a fourth conductive layer are provided on the first insulating layer and the second insulating layer, respectively, to obtain a laminate. The third conductive layer and the fourth conductive layer are formed in a manner similar to that of the first conductive layer and the second conductive layer. And plating a first electrode and a second electrode on the third conductive layer and the fourth conductive layer respectively, and plating the first electrode and the second electrode on the side surface of the laminated body so as to extend and connect the upper part and the lower part of the third conductive layer and the fourth conductive layer respectively. The first electrode includes an upper first electrode portion, a lower first electrode portion, and a first electrode connecting portion. The second electrode comprises an upper second electrode part, a lower second electrode part and a second electrode connecting part. A first groove and a second groove are respectively formed on the upper first electrode part and the upper second electrode part by a numerical control engraving machine (purchased from Shanghai Yidiao company, model YD 3040G). The first and second grooves are defined by first and second groove defining walls, respectively. In embodiment 1, the surface area of the first groove-defining wall is 10% of the upper surface area of the upper first electrode portion, and the surface area of the second groove-defining wall is 10% of the upper surface area of the upper second electrode portion. And finally obtaining the PTC circuit protection device of E1.
< examples 2 to 7 (E2-E7) >
The process conditions of the PTC circuit protection devices of E2-E7 are similar to those of E1, with the difference that the surface areas of the first recess defining wall and the second recess defining wall are based on the ratio of the upper surface areas of the upper first electrode portion and the upper second electrode portion, respectively (as shown in table 1).
< comparative example 1 (CE 1) >
The process conditions of the PTC circuit protection device of CE1 are similar to those of E1, with the difference that no grooves are formed on the first and second electrodes (as shown in table 1).
TABLE 1
Figure BDA0003065672760000111
Performance test
[ solderability test ]
The upper surfaces of the upper first electrode portion and the upper second electrode portion of the PTC circuit protection devices of E1 to E7 and CE1 are coated with tin-based solder, respectively. Subsequently, the PTC circuit protection devices of E1-E7 and CE1 were attached to a Printed Circuit Board (PCB) by the tin-based solder, respectively, to obtain test samples of E1-E7 and CE1, respectively. Next, each test sample was placed in a reflow oven (reflow oven) to perform reflow (reflow soldering). The peak temperature of the reflow oven was set to 285 ℃ to control the reflow interval to be above the liquid phase temperature of 260 ℃ for 20 seconds, with an overall reflow time of 4min. Next, solderability of each test sample was tested (with "the area of the covered solder occupies 90% or more of the upper surface area of the upper first electrode portion and the upper second electrode portion" as a criterion for successful soldering), and the ratio of the test samples for successful soldering was calculated, with the results shown in table 2.
TABLE 2
Figure BDA0003065672760000121
The results in table 2 show that the PTC circuit protection devices of E1-E7 (particularly the recess-defining walls of E1-E5 have a 10% to 80% surface area ratio) have good solderability to PCB compared to the PTC circuit protection device of CE1 (without the recess). In particular, when the ratio of the surface area of the recess defining wall of the PTC circuit protection device of the test sample is 25% to 75% (E2-E4), the rate of successful soldering is as high as 100%.
In summary, the PTC circuit protection device 2 of the present invention is capable of achieving the object of the present invention by forming the recess in the electrode thereof and controlling the ratio of the surface area of the wall defining the recess even further, since the PTC circuit protection device 2 has excellent bonding strength to the PCB.
The above description is only an example of the present invention, and the scope of the present invention should not be limited thereby, and the invention is still within the scope of the present invention by simple equivalent changes and modifications made according to the claims and the contents of the specification.

Claims (20)

1. A PTC circuit protection device characterized in that: the PTC circuit protection device comprises:
a PTC polymer layer;
a first conductive layer electrically connected to the PTC polymer layer;
a second conductive layer electrically connected to the PTC polymer layer and spaced apart from the first conductive layer;
an insulating layer unit disposed on the first conductive layer and the second conductive layer;
a first electrode formed on the insulating layer unit, electrically connected to the first conductive layer, and spaced apart from the second conductive layer; and
a second electrode formed on the insulating layer unit, electrically connected to the second conductive layer and spaced apart from the first conductive layer and the first electrode,
wherein, the first electrode is formed with a first groove, and the first groove is sunken from the surface of the first electrode towards the PTC polymer layer.
2. A PTC circuit protection device according to claim 1, wherein: the second electrode is formed with a second groove that is recessed from a surface of the second electrode toward the PTC polymer layer.
3. A PTC circuit protection device according to claim 2, wherein: the first electrode has a first recess-defining wall defining the first recess, the second electrode has a second recess-defining wall defining the second recess, a surface area of the first recess-defining wall is not less than 10% of a surface area of the first electrode and a surface area of the second recess-defining wall is not less than 10% of a surface area of the second electrode.
4. The PTC circuit protection device according to claim 1, wherein:
the PTC polymer layer has an upper surface, a lower surface opposite to the upper surface, and a surrounding surface interconnected with the upper surface and the lower surface, the first conductive layer is disposed on the upper surface, and the second conductive layer is disposed on the lower surface;
the insulating layer unit comprises a first insulating layer arranged on the first conducting layer and a second insulating layer arranged on the second conducting layer;
the first electrode includes an upper first electrode portion disposed on the first insulating layer, a lower first electrode portion disposed on the second insulating layer, and a first electrode connection portion formed on the surrounding face of the PTC polymer layer, the first electrode connection portion being interconnected to the upper first electrode portion and the lower first electrode portion; and
the second electrode includes an upper second electrode portion disposed on the first insulating layer, a lower second electrode portion disposed on the second insulating layer, and a second electrode connection portion formed on the surrounding surface of the PTC polymer layer, the second electrode connection portion being interconnected to the upper second electrode portion and the lower second electrode portion.
5. The PTC circuit protection device according to claim 4, wherein: the first groove of the first electrode is formed on one of the upper first electrode portion and the lower first electrode portion.
6. The PTC circuit protection device according to claim 5, wherein: the second groove of the second electrode is formed on one of the upper second electrode portion and the lower second electrode portion.
7. A PTC circuit protection device according to claim 1, wherein:
the PTC polymer layer has an upper surface, a lower surface opposite to the upper surface, and a surrounding surface interconnected with the upper surface and the lower surface, the first conductive layer is disposed on the upper surface, and the second conductive layer is disposed on the lower surface;
the first conducting layer comprises an upper first conducting part arranged on the upper surface and a lower first conducting part arranged on the lower surface;
the second conducting layer comprises an upper second conducting part arranged on the upper surface and a lower second conducting part arranged on the lower surface;
the insulating layer unit comprises a first insulating layer arranged on the first conducting layer and a second insulating layer arranged on the second conducting layer, the first insulating layer comprises an upper first insulating part arranged on the upper first conducting part and a lower first insulating part arranged on the lower first conducting part, and the second insulating layer comprises an upper second insulating part arranged on the upper second conducting part and a lower second insulating part arranged on the lower second conducting part;
the first electrode includes an upper first electrode portion disposed on the upper first insulating portion, a lower first electrode portion disposed on the lower first insulating portion, and a first electrode connection portion formed on the surrounding surface of the PTC polymer layer, the first electrode connection portion being interconnected to the upper first electrode portion and the lower first electrode portion; and
the second electrode includes an upper second electrode portion disposed on the upper second insulating portion, a lower second electrode portion disposed on the lower second insulating portion, and a second electrode connecting portion formed on the surrounding surface of the PTC polymer layer, the second electrode connecting portion being interconnected to the upper second electrode portion and the lower second electrode portion.
8. The PTC circuit protection device according to claim 7, wherein: the first groove of the first electrode is formed on one of the upper first electrode portion and the lower first electrode portion.
9. The PTC circuit protection device according to claim 7, wherein: the first electrode is formed with two first grooves formed on the upper and lower first electrode portions, respectively.
10. A PTC circuit protection device according to claim 9, wherein: the second electrode is formed with at least one second groove formed on one of the upper and lower second electrode portions.
11. A PTC circuit protection device according to claim 10, wherein: the upper first electrode portion has a first groove defining wall defining the first groove, the upper second electrode portion has a second groove defining wall defining the second groove, a surface area of the first groove defining wall is not less than 10% of an upper surface area of the upper first electrode portion and a surface area of the second groove defining wall is not less than 10% of an upper surface area of the upper second electrode portion.
12. A PTC circuit protection device according to claim 11, wherein: the surface area of the first recess defining wall is 10% to 80% of the upper surface area of the upper first electrode portion and the surface area of the second recess defining wall is 10% to 80% of the upper surface area of the upper second electrode portion.
13. A PTC circuit protection device according to claim 12, wherein: the surface area of the first recess defining wall is 25% to 75% of the upper surface area of the upper first electrode portion and the surface area of the second recess defining wall is 25% to 75% of the upper surface area of the upper second electrode portion.
14. The PTC circuit protection device according to claim 7, wherein: the PTC circuit protection device further comprises an insulating spacer disposed between the upper first conductive portion and the upper second conductive portion.
15. The PTC circuit protection device according to claim 7, wherein: the PTC circuit protection device further comprises a third conductive layer and a fourth conductive layer,
the third conductive layer comprises an upper third conductive part arranged between the upper first insulating part and the upper first electrode part and a lower third conductive part arranged between the lower first insulating part and the lower first electrode part; and
the fourth conductive layer includes an upper fourth conductive portion disposed between the upper second insulating portion and the upper second electrode portion, and a lower fourth conductive portion disposed between the lower second insulating portion and the lower second electrode portion.
16. A PTC circuit protection device according to claim 1, wherein: each first conductive layer and each second conductive layer are nickel-plated copper foils.
17. A PTC circuit protection device according to claim 1, wherein: the insulating layer unit is made of epoxy resin.
18. A PTC circuit protection device according to claim 1, wherein: the PTC polymer layer comprises a polymer substrate and granular conductive filler dispersed in the polymer substrate, wherein the polymer substrate comprises non-grafted olefin polymer.
19. A PTC circuit protection device according to claim 18, wherein: the polymeric substrate also includes an olefin-based polymer grafted with a carboxylic acid anhydride.
20. A PTC circuit protection device according to claim 18, wherein: the particulate conductive filler is selected from carbon black powder, metal powder, conductive ceramic powder, or a combination of the foregoing.
CN202110525741.1A 2021-05-14 2021-05-14 PTC circuit protection device Pending CN115348718A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110525741.1A CN115348718A (en) 2021-05-14 2021-05-14 PTC circuit protection device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110525741.1A CN115348718A (en) 2021-05-14 2021-05-14 PTC circuit protection device

Publications (1)

Publication Number Publication Date
CN115348718A true CN115348718A (en) 2022-11-15

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Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110525741.1A Pending CN115348718A (en) 2021-05-14 2021-05-14 PTC circuit protection device

Country Status (1)

Country Link
CN (1) CN115348718A (en)

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