CN212782902U

CN212782902U - Paster type thermal protection type piezoresistor

Info

Publication number: CN212782902U
Application number: CN202022125282.1U
Authority: CN
Inventors: 陈色江; 彭少雄
Original assignee: Dongguan Delchuang Electronic Co ltd
Current assignee: Dongguan Delchuang Electronic Co ltd
Priority date: 2020-09-24
Filing date: 2020-09-24
Publication date: 2021-03-23
Anticipated expiration: 2030-09-24

Abstract

The utility model discloses a patch-type thermal protection type piezoresistor, which comprises a thermal protection device, a piezoresistor chip, a first sheet metal terminal, a second sheet metal terminal and an insulating layer; the thermal protection device comprises an insulating shell and a protection device positioned in the insulating shell; the insulating shell is fixed on the upper surface of the first electrode, one end of the second sheet metal terminal and the first electrode are both connected with the protection device, the other end of the second sheet metal terminal penetrates through the insulating layer and is attached to or separated from the insulating layer, one end of the first sheet metal terminal is welded with the second electrode, and the other end of the first sheet metal terminal penetrates through the insulating layer and is attached to or separated from the insulating layer. The utility model discloses avoided insulating layer high temperature to catch fire and arouse the fire incident.

Description

Paster type thermal protection type piezoresistor

Technical Field

The utility model relates to an electronic components field, the more specifically thermal protection type piezoresistor of paster type that says so.

Background

The voltage dependent resistor is an overvoltage protection type safety device connected with a protected circuit in parallel, and can absorb the surge when the surge voltage occurs in the circuit under the conditions of circuit switching, circuit switching or other conditions, so that the devices in the circuit are prevented from being damaged by the overvoltage impact. However, when the circuit voltage exceeds the working voltage of the piezoresistor, the piezoresistor can be quickly scalded to cause the insulation encapsulating layer of the piezoresistor to burn, and in case of serious accidents, the electrical appliance catches fire to cause fire.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome prior art's not enough, provide a thermal protection type piezoresistor of paster type.

In order to achieve the above purpose, the utility model adopts the following technical scheme: a patch-type thermal protection varistor comprises a thermal protection device, a varistor chip, a first sheet metal terminal, a second sheet metal terminal and an insulating layer; the piezoresistor chip and the thermal protection device are packaged in the insulating layer, the top of the piezoresistor chip is provided with a first electrode, and the bottom of the piezoresistor chip is provided with a second electrode; the thermal protection device comprises an insulating shell and a protection device positioned in the insulating shell; the insulating shell is fixed on the upper surface of the first electrode, one end of the second sheet metal terminal and the first electrode are both connected with the protective device, the other end of the second sheet metal terminal penetrates through the insulating layer and is attached to or separated from the insulating layer, one end of the first sheet metal terminal is welded with the second electrode, and the other end of the first sheet metal terminal penetrates through the insulating layer and is attached to or separated from the insulating layer.

The further technical scheme is as follows: the protection device is an elastic metal wire; one end of the elastic metal wire penetrates out of the top of the insulating shell and is welded with one end of the second sheet metal terminal, and the other end of the elastic metal wire penetrates out of the bottom of the insulating shell and is welded with the first electrode; and the solder adopted at the welding position of the other end of the elastic metal lead and the first electrode is less than 200 ℃.

The further technical scheme is as follows: the protection device is a thermal fuse; one end of the thermal fuse penetrates out of the top of the insulating shell and is welded with one end of the second sheet metal terminal, and the other end of the thermal fuse penetrates out of the bottom of the insulating shell and is welded with the first electrode; the melting point of the thermal fuse is less than 200 ℃.

The further technical scheme is as follows: the protection device is a self-recovery fuse; the self-recovery fuse comprises a first connecting line and a second connecting line; the first connecting wire penetrates out of the top of the insulating shell and is welded with one end of the second sheet metal terminal, and the second connecting wire penetrates out of the bottom of the insulating shell and is welded with the first electrode.

The further technical scheme is as follows: and the joint of the insulating shell and the first electrode is fixed by hot melt adhesive.

The further technical scheme is as follows: the first sheet metal terminal comprises a first inner welding sheet, a first outer welding sheet and a first connecting sheet connected between the first inner welding sheet and the first outer welding sheet; the first inner welding sheet is positioned in the insulating layer and welded with the second electrode, and the first outer welding sheet penetrates out of the insulating layer and is attached to or separated from the outer surface of the insulating layer; the second sheet metal terminal comprises a second inner welding sheet, a second outer welding sheet and a second connecting sheet connected between the second inner welding sheet and the second outer welding sheet; the second inner welding sheet is positioned in the insulating layer and welded with the first electrode, and the second outer welding sheet penetrates out of the insulating layer and is attached to or separated from the outer surface of the insulating layer.

The further technical scheme is as follows: the first connecting piece comprises an inclined part extending downwards along the left end of the first inner welding piece, a first transverse part extending leftwards along the lower end of the inclined part, a first vertical part extending upwards along the left end of the first transverse part, a second transverse part extending leftwards along the top end of the first vertical part, and a second vertical part extending downwards along the left end of the second transverse part; first outer welding lug horizontal connection in the lower extreme of second vertical portion and laminating or keep away from the surface in the insulating layer, welding lug horizontal connection in the upper end of slope.

The further technical scheme is as follows: the second connecting piece comprises a first vertical part extending downwards along the right end of the second inner welding piece, a horizontal part extending rightwards along the lower end of the first vertical part, and a second vertical part extending downwards along the right end of the horizontal part; the second outer welding sheet is horizontally connected to the lower end of the second vertical portion and attached to or far away from the outer surface of the insulating layer, and the second inner welding sheet is horizontally connected to the top of the first vertical portion.

Compared with the prior art, the utility model beneficial effect be: the utility model discloses a set up hot protection device, when piezoresistor reached or exceeded a certain upper limit value at the temperature, heat was taken off the device and is heated, and the solder joint of protection device and piezoresistor chip melts, and timely cuts off piezoresistor chip and circuit power supply, avoids the chip to generate heat to the insulating layer high temperature that has avoided catches fire and arouses the fire incident.

The foregoing is a summary of the present invention, and other objects, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments, which is provided for the purpose of illustration and understanding of the present invention.

Drawings

Fig. 1 is a schematic structural diagram of a first embodiment of a patch-type thermal protection type varistor of the present invention;

fig. 2 is a schematic structural diagram of a second embodiment of the patch-type thermal protection type varistor of the present invention.

Detailed Description

In order to more fully understand the technical content of the present invention, the technical solution of the present invention will be further described and illustrated with reference to the following specific embodiments, but not limited thereto.

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and to simplify the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "secured" are to be construed broadly and can, for example, be connected or detachably connected or integrated; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," some embodiments, "" an example, "" a specific example, "" or "some examples," or the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above should not be understood to necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples described in this specification can be combined and combined by one skilled in the art.

Example one

Referring to fig. 1, the present invention provides a chip-type thermal protection varistor, which includes a thermal protection device 3, a varistor chip 2, a first sheet metal terminal 4, a second sheet metal terminal 5, and an insulating layer 1 (the insulating layer 1 is made of epoxy resin); the piezoresistor chip 2 and the thermal protection device 3 are packaged in the insulating layer 1, the top of the piezoresistor chip 2 is provided with a first electrode 21, and the bottom of the piezoresistor chip 2 is provided with a second electrode 22; the thermal protection device 3 includes an insulating housing 31 (any housing capable of realizing insulation in the prior art), and an elastic metal wire 32 located in the insulating housing 31; the insulating shell 31 is fixed on the upper surface of the first electrode 21, one end of the elastic metal wire 32 penetrates through the top of the insulating shell 31 and is welded with one end of the second sheet metal terminal 5, the other end of the second sheet metal terminal 5 penetrates through the insulating layer 1 and is separated from the insulating layer 1, and the other end of the elastic metal wire 32 penetrates through the bottom of the insulating shell 31 and is welded with the first electrode 21; one end of the first sheet metal terminal 4 is welded to the second electrode 22, and the other end of the first sheet metal terminal 4 penetrates through the insulating layer 1 and is separated from the insulating layer 1. Specifically, the solder adopted at the welding position of the other end of the elastic metal lead and the first electrode is less than 200 ℃, and the solder can be Bi58Sn42 with a melting point of 138 ℃ or In52Sn48 with a melting point of 118 ℃. The joint of the insulating housing 31 and the first electrode 21 is fixed by hot melt adhesive.

The utility model discloses a set up thermal protection device 3, when piezoresistor reached or exceeded a certain upper limit value at the temperature, the heat was taken off the device and is heated, and elastic metal wire 32 melts with the solder joint of 2 chips on the piezoresistor chip, and elastic metal wire 32 returns and contracts, hangs on the terminal, in time cuts off 2 chips on the piezoresistor chip and circuit power supply, avoids the chip to generate heat to avoided 1 high temperature on the insulating layer to catch fire and arouse the fire incident.

Further, the first sheet-like metal terminal 4 includes a first inner bonding tab 41, a first outer bonding tab 47, and a first connecting tab connected between the first inner bonding tab 41 and the first outer bonding tab 47; the first inner welding sheet 41 is positioned in the insulating layer 1 and is welded with the second electrode 22, and the first outer welding sheet 47 penetrates out of the insulating layer 1 and is separated from the outer surface of the insulating layer 1; the second sheet metal terminal 5 includes a second inner bonding tab 51, a second outer bonding tab 55, and a second connecting piece connected between the second inner bonding tab 51 and the second outer bonding tab 55; the second inner bonding pad 51 is located in the insulating layer 1 and bonded to the first electrode 21, and the second outer bonding pad 55 penetrates the insulating layer 1 and is separated from the outer surface of the insulating layer 1.

Further, the first connecting piece includes an inclined portion 42 extending obliquely downward along the left end of the first inner welding piece 41, a first transverse portion 43 extending leftward along the lower end of the inclined portion 42, a first vertical portion 44 extending upward along the left end of the first transverse portion 43, a second transverse portion 45 extending leftward along the top end of the first vertical portion 44, and a second vertical portion 46 extending downward along the left end of the second transverse portion 45; the first outer bonding tab 47 is horizontally connected to the lower end of the second vertical portion 46 and away from the outer surface of the insulating layer 1, and the first inner bonding tab 41 is horizontally connected to the upper end of the inclined portion 42. The second connecting piece includes a first vertical portion 52 extending downward along a right end of the second inner welding piece 51, a horizontal portion 53 extending rightward along a lower end of the first vertical portion 52, and a second vertical portion 54 extending downward along a right end of the horizontal portion 53; the second outer bonding tab 55 is horizontally connected to the lower end of the second vertical portion 54 away from the outer surface of the insulating layer 1, and the second inner bonding tab 51 is horizontally connected to the top of the first vertical portion 52.

In certain embodiments, the protection device is a thermal fuse; one end of the thermal fuse penetrates out of the top of the insulating shell and is welded with one end of the second sheet metal terminal, and the other end of the thermal fuse penetrates out of the bottom of the insulating shell and is welded with the first electrode; the melting point of the thermal fuse is less than 200 ℃. When the voltage dependent resistor is operated, the voltage dependent resistor will rapidly generate high heat (greater than 200 c) when the supply voltage exceeds the operating voltage of the voltage dependent resistor. At this time, the thermal fuse is instantaneously fused by high heat generated from the varistor, and the power supply is cut off. The temperature of the piezoresistor can be rapidly reduced after the power supply is cut off, so that the ignition of the piezoresistor insulating layer is prevented, and the occurrence of fire accidents is prevented.

In some embodiments, the protection device is a self-healing fuse; the self-recovery fuse comprises a first connecting line and a second connecting line; the first connecting wire penetrates out of the top of the insulating shell and is welded with one end of the second sheet metal terminal, and the second connecting wire penetrates out of the bottom of the insulating shell and is welded with the first electrode. The self-recovery fuse is in a high-conductivity state at normal temperature and in a high-resistance state at high temperature. When the piezoresistor works normally (the circuit voltage does not exceed the working voltage of the piezoresistor), the self-recovery fuse is in a high-conductivity state, and the normal work of the piezoresistor is not influenced. However, when the circuit voltage exceeds the working voltage of the piezoresistor, the piezoresistor heats rapidly, when the temperature rises to a certain state, the polymer resin of the self-recovery fuse melts, the volume increases rapidly, and a high resistance state is formed, thereby cutting off the power supply of the piezoresistor, enabling the piezoresistor to stop working, rapidly reducing the temperature, and preventing the occurrence of firing accidents of the insulation layer of the piezoresistor. When the high-temperature state of the piezoresistor is released, the self-recovery fuse is cooled and crystallized again, the volume is shrunk, and the piezoresistor is recovered to be in a high-conductivity state, so that the piezoresistor can be recycled.

Example two

The present embodiment is different from the first embodiment in that the first outer bonding pad and the second outer bonding pad are bonded to the insulating layer, thereby reducing the occupied space of the varistor as a whole. Referring to fig. 2, the specific structure of this embodiment is as follows:

a chip-type thermal protection varistor comprises a thermal protection device 3A, a varistor chip 2A, a first sheet-like metal terminal 4A, a second sheet-like metal terminal 5A and an insulating layer 1A (the insulating layer 1A may be made of insulating varnish); the piezoresistor chip 2A and the thermal protection device 3A are packaged in the insulating layer 1, the top of the piezoresistor chip 2A is provided with a first electrode 21A, and the bottom of the piezoresistor chip 2A is provided with a second electrode 22A; the thermal protection device 3 comprises an insulating shell 31A and an elastic metal wire 32A positioned in the insulating shell 31A; the insulating shell 31A is fixed on the upper surface of the first electrode 21A, one end of the elastic metal wire 32A penetrates through the top of the insulating shell 31A and is welded with one end of the second sheet metal terminal 5, the other end of the second sheet metal terminal 5A penetrates through the insulating layer 1A and is attached to the insulating layer 1A, and the other end of the elastic metal wire 32A penetrates through the bottom of the insulating shell 31A and is welded with the first electrode 21A; one end of the first sheet-like metal terminal 4 is welded to the second electrode 22A, and the other end of the first sheet-like metal terminal 4A penetrates the insulating layer 1 and is bonded to the insulating layer 1A.

Further, the first sheet-like metal terminal 4A includes a first inner bonding tab 41A, a first outer bonding tab 47A, and a first bonding tab connected between the first inner bonding tab 41A and the first outer bonding tab 47A; the first inner welding sheet 41 is positioned in the insulating layer 1 and welded with the second electrode 22A, and the first outer welding sheet 47A penetrates through the insulating layer 1A and is attached to the outer surface of the insulating layer 1A; the second sheet metal terminal 5A includes a second inner bonding tab 51A, a second outer bonding tab 55A, and a second connecting piece connected between the second inner bonding tab 51A and the second outer bonding tab 55A; the second inner bonding pad 51A is located in the insulating layer 1A and is bonded to the first electrode 21A, and the second outer bonding pad 55A penetrates through the insulating layer 1A and is attached to the outer surface of the insulating layer 1A.

Further, the first connecting piece includes an inclined portion 42A extending obliquely downward along the left end of the first inner welding piece 41A, a first lateral portion 43A extending leftward along the lower end of the inclined portion 42A, a first vertical portion 44A extending upward along the left end of the first lateral portion 43A, a second lateral portion 45A extending leftward along the top end of the first vertical portion 44A, and a second vertical portion 46A extending downward along the left end of the second lateral portion 45A; the first outer bonding tab 47A is horizontally connected to the lower end of the second vertical portion 46A and attached to the outer surface of the insulating layer 1A, and the first inner bonding tab 41A is horizontally connected to the upper end of the inclined portion 42A. The second connecting piece includes a first vertical portion 52A extending downward along a right end of the second inner welding piece 51A, a horizontal portion 53A extending rightward along a lower end of the first vertical portion 52A, a second vertical portion 54A extending downward along a right end of the horizontal portion 53A; the second outer bonding tab 55A is horizontally connected to the lower end of the second vertical portion 54A and attached to the outer surface of the insulating layer 1A, and the second inner bonding tab 51A is horizontally connected to the top of the first vertical portion 52A.

The technical content of the present invention is further described by the embodiments only, so that the reader can understand it more easily, but the embodiments of the present invention are not limited thereto, and any technical extension or re-creation according to the present invention is protected by the present invention. The protection scope of the present invention is subject to the claims.

Claims

1. A patch-type thermal protection piezoresistor is characterized by comprising a thermal protection device, a piezoresistor chip, a first sheet metal terminal, a second sheet metal terminal and an insulating layer; the piezoresistor chip and the thermal protection device are packaged in the insulating layer, the top of the piezoresistor chip is provided with a first electrode, and the bottom of the piezoresistor chip is provided with a second electrode; the thermal protection device comprises an insulating shell and a protection device positioned in the insulating shell; the insulating shell is fixed on the upper surface of the first electrode, one end of the second sheet metal terminal and the first electrode are both connected with the protective device, the other end of the second sheet metal terminal penetrates through the insulating layer and is attached to or separated from the insulating layer, one end of the first sheet metal terminal is welded with the second electrode, and the other end of the first sheet metal terminal penetrates through the insulating layer and is attached to or separated from the insulating layer.

2. The chip-type thermal protection varistor as claimed in claim 1, wherein said protection device is an elastic metal wire; one end of the elastic metal wire penetrates out of the top of the insulating shell and is welded with one end of the second sheet metal terminal, and the other end of the elastic metal wire penetrates out of the bottom of the insulating shell and is welded with the first electrode; and the solder adopted at the welding position of the other end of the elastic metal lead and the first electrode is less than 200 ℃.

3. The chip-type thermal protection varistor as claimed in claim 1, wherein said protection device is a thermal fuse; one end of the thermal fuse penetrates out of the top of the insulating shell and is welded with one end of the second sheet metal terminal, and the other end of the thermal fuse penetrates out of the bottom of the insulating shell and is welded with the first electrode; the melting point of the thermal fuse is less than 200 ℃.

4. The chip-type thermal protection varistor as claimed in claim 1, wherein said protection device is a self-healing fuse; the self-recovery fuse comprises a first connecting line and a second connecting line; the first connecting wire penetrates out of the top of the insulating shell and is welded with one end of the second sheet metal terminal, and the second connecting wire penetrates out of the bottom of the insulating shell and is welded with the first electrode.

5. The chip-type thermal protection varistor as claimed in claim 1, wherein the junction of said insulating case and said first electrode is fixed by hot melt adhesive.

6. The chip-type thermal protection varistor as claimed in claim 1, wherein said first sheet-like metal terminal comprises a first inner bonding pad, a first outer bonding pad, and a first connecting pad connected between said first inner bonding pad and said first outer bonding pad; the first inner welding sheet is positioned in the insulating layer and welded with the second electrode, and the first outer welding sheet penetrates out of the insulating layer and is attached to or separated from the outer surface of the insulating layer; the second sheet metal terminal comprises a second inner welding sheet, a second outer welding sheet and a second connecting sheet connected between the second inner welding sheet and the second outer welding sheet; the second inner welding sheet is positioned in the insulating layer and welded with the first electrode, and the second outer welding sheet penetrates out of the insulating layer and is attached to or separated from the outer surface of the insulating layer.

7. The chip-type thermal protection varistor according to claim 6, wherein said first connection tab comprises an inclined portion extending obliquely downward along a left end of said first inner bonding tab, a first lateral portion extending leftward along a lower end of said inclined portion, a first vertical portion extending upward along a left end of said first lateral portion, a second lateral portion extending leftward along a top end of said first vertical portion, and a second vertical portion extending downward along a left end of said second lateral portion; first outer welding lug horizontal connection in the lower extreme of second vertical portion and laminating or keep away from the surface in the insulating layer, welding lug horizontal connection in the upper end of slope.

8. A patch type thermal protection type varistor according to claim 7, wherein said second connection pad comprises a first vertical portion extending downward along a right end of the second inner bonding pad, a horizontal portion extending rightward along a lower end of the first vertical portion, a second vertical portion extending downward along a right end of the horizontal portion; the second outer welding sheet is horizontally connected to the lower end of the second vertical portion and attached to or far away from the outer surface of the insulating layer, and the second inner welding sheet is horizontally connected to the top of the first vertical portion.