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KR-20260064527-A - ARC QUENCHING AND FLAME RETARDING COATING FOR ELECTRONIC DEVICES

KR20260064527AKR 20260064527 AKR20260064527 AKR 20260064527AKR-20260064527-A

Abstract

A metal oxide varistor (MOV) device comprises an MOV chip, electrically conductive first and second electrodes disposed on opposite sides of the MOV chip, electrically conductive first and second leads connected to the first and second electrodes, respectively, and an arc-mitigating, flame-retardant coating covering portions of the MOV chip, the first and second electrodes, and the first and second leads, wherein the arc-mitigating, flame-retardant coating comprises a silicon composition formed of a filler suspended in a silicon resin, and the filler comprises one or more of melamine, guanidine, guanine, hydantoin, allantoin, urea, melamine-formaldehyde, melamine-cyanurate polymer, and boric acid.

Inventors

  • 첸 젠화
  • 장 춘-관
  • 디치 고든 티.

Assignees

  • 리텔퓨즈 인코퍼레이티드

Dates

Publication Date
20260507
Application Date
20251014
Priority Date
20241030

Claims (19)

  1. In a metal oxide varistor (MOV) device, MOV chip; Electrically conductive first and second electrodes disposed on opposite sides of the above MOV chip; Each, electrically conductive first and second leads connected to the first and second electrodes; and An MOV device comprising the above MOV chip, the above first and second electrodes, and an arc-mitigating, flame-retardant coating covering portions of the above first and second leads, wherein the arc-mitigating, flame-retardant coating comprises a silicone composition formed of a filler suspended in a silicone resin.
  2. The MOV device according to claim 1, wherein the filler comprises one or more of melamine, guanidine, guanine, hydantoin, allantoin, urea, melamine-formaldehyde, melamine-cyanurate polymer, and boric acid.
  3. An MOV device according to claim 1, wherein the filler comprises 3% to 70% by weight of the silicone composition.
  4. The MOV device according to claim 1, further comprising the arc mitigation, protection applied over the flame-retardant coating, and dielectric shell.
  5. In paragraph 4, the above protection, dielectric shell is formed of epoxy, MOV device.
  6. In a thermal protection metal oxide varistor (TMOV) device, MOV chip; Electrically conductive first and second electrodes disposed on opposite sides of the above MOV chip; An electrically conductive first lead connected to the first electrode; An electrically conductive second lead connected to a dielectric barrier disposed on the second electrode; A thermal cut-off (TCO) element having a first end electrically connected to the second lead on the dielectric barrier and a second end electrically connected to the second electrode; and A TMOV device comprising an arc-mitigating, flame-retardant coating covering the connection portion of the above TCO element and the above second electrode, wherein the arc-mitigating, flame-retardant coating comprises a silicone composition formed of a filler suspended in a silicone resin.
  7. In claim 6, the TMOV device, wherein the TCO element is formed of an electrically conductive material and adjusted to melt and separate when a predetermined temperature is reached.
  8. A TMOV device according to claim 6, wherein the filler comprises one or more of melamine, guanidine, guanine, hydantoin, allantoin, urea, melamine-formaldehyde, melamine-cyanurate polymer, and boric acid.
  9. A TMOV device according to claim 6, wherein the filler comprises 3% to 70% by weight of the silicone composition.
  10. In a positive temperature coefficient (PTC) device, A PTC element comprising electrically conductive particles suspended in a non-conductive medium; Electrically conductive first and second electrodes disposed on opposite sides of the above-mentioned PTC element; Each, electrically conductive first and second leads connected to the first and second electrodes; and A PTC device comprising the above PTC element, the above first and second electrodes, and an arc-mitigating, flame-retardant coating covering portions of the above first and second leads, wherein the arc-mitigating, flame-retardant coating comprises a silicone composition formed of a filler suspended in a silicone resin.
  11. A PTC device according to claim 10, wherein the filler comprises one or more of melamine, guanidine, guanine, hydantoin, allantoin, urea, melamine-formaldehyde, melamine-cyanurate polymer, and boric acid.
  12. A PTC device according to claim 10, wherein the filler comprises 3% to 70% by weight of the silicone composition.
  13. A PTC device according to claim 10, further comprising the arc mitigation, protection applied over the flame-retardant coating, and dielectric shell.
  14. In claim 11, the above protection, dielectric shell is formed of epoxy, a PTC device.
  15. Regarding fuses, Genome fuse body; Electrically conductive first and second end caps disposed on ends opposite to the fuse body; A usable element extending through the fuse body and electrically connected to the first and second end caps; and A fuse comprising an arc-mitigating, flame-retardant coating covering the fuse body, wherein the arc-mitigating, flame-retardant coating comprises a silicone composition formed of a filler suspended in a silicone resin.
  16. A fuse according to claim 15, comprising one or more of melamine, guanidine, guanine, hydantoin, allantoin, urea, melamine-formaldehyde, melamine-cyanurate polymer, and boric acid.
  17. A fuse according to claim 15, wherein the filler comprises 3% to 70% by weight of the silicone composition.
  18. A fuse comprising, in paragraph 15, arc mitigation, protection applied over a flame-retardant coating, and a dielectric shell.
  19. In Clause 11, the above protection, dielectric shell is formed of epoxy, fuse.

Description

Arc Quenching and Flame Retarding Coating for Electronic Devices The present invention generally relates to the field of electronic devices. More specifically, the present invention relates to an arc quenching, flame-retardant silicone composition for coating electronic devices prone to electric arc and/or combustion under extreme failure conditions. Various types of electronic devices are prone to electric arcing and/or burning when exposed to overcurrent, overvoltage, or overheating conditions (collectively referred to as “fault conditions”). These devices include metal oxide varistors (MOVs), thermal protection MOVs (TMOVs), fuses, and positive temperature coefficient (PTC) devices (e.g., PTC fuses and PTC heaters). In the case of MOV and PTC devices, fault conditions can cause the MOV or PTC elements within the device to overheat and burn, damaging the device and potentially damaging surrounding components. In the case of fuses and TMOVs, fault conditions can melt or disconnect the fusible elements within the device, obstructing the flow of current through the device. When the fusible element is disconnected, an electric arc can propagate between the disconnected parts of the fusible element (e.g., through vaporized particles remaining between the disconnected parts). If the electric arc is not extinguished, a significant subsequent current will flow through the device, potentially damaging connected components even though the fusible element is physically open. Additionally, the heat generated by the electric arc can burn or rupture the body of the device, potentially causing damage to surrounding components. Therefore, it is desirable to extinguish the electric arc as quickly as possible to prevent or mitigate potential damage to connected and surrounding components. This improvement may be useful in relation to these and other considerations. This summary is provided to briefly introduce concepts that are explained in more detail in the detailed description below. This summary is not intended to identify the primary or essential features of the claimed subject matter, nor is it intended to assist in determining the scope of the claimed subject matter. A metal oxide varistor (MOV) device according to an embodiment of the present disclosure may comprise an MOV chip, electrically conductive first and second electrodes disposed on opposite sides of the MOV chip, electrically conductive first and second leads connected to the first and second electrodes, respectively, and an arc-mitigating, flame-retardant coating covering portions of the MOV chip, the first and second electrodes, and the arc-mitigating, flame-retardant coating comprises a silicon composition formed of a filler suspended in a silicon resin. A thermal protection metal oxide varistor (TMOV) device according to an embodiment of the present disclosure may comprise an MOV chip, electrically conductive first and second electrodes disposed on opposite sides of the MOV chip, an electrically conductive first lead connected to the first electrode, an electrically conductive second lead connected to a dielectric barrier disposed on the second electrode, a thermal cut-off (TCO) element having a first end electrically connected to the second lead on the dielectric barrier and a second end electrically connected to the second electrode, and an arc-mitigating, flame-retardant coating covering a connection between the TCO element and the second electrode, wherein the arc-mitigating, flame-retardant coating comprises a silicon composition formed of a filler suspended in a silicon resin. A positive temperature coefficient (PTC) device according to an embodiment of the present disclosure may comprise a PTC element comprising electrically conductive particles suspended in a non-conductive medium, electrically conductive first and second electrodes disposed on opposite sides of the PTC element, electrically conductive first and second leads connected to the first and second electrodes, respectively, and an arc-mitigating, flame-retardant coating covering portions of the PTC element, the first and second electrodes, and the arc-mitigating, flame-retardant coating comprises a silicone composition formed of a filler suspended in a silicone resin. A fuse according to an embodiment of the present disclosure may comprise a dielectric fuse body, electrically conductive first and second end caps disposed on ends opposite to the fuse body, a movable element extending through the fuse body and electrically connected to the first and second end caps, and an arc-mitigating, flame-retardant coating covering the fuse body, wherein the arc-mitigating, flame-retardant coating comprises a silicone composition formed of a filler suspended in a silicone resin. FIGS. 1a-1c is a series of perspective views illustrating a metal oxide varistor device according to an embodiment of the present disclosure. FIGS. 2a-2c is a series of perspective views illustrating a thermal protection