CN212624987U

CN212624987U - Thermally protected piezoresistor

Info

Publication number: CN212624987U
Application number: CN202021665806.XU
Authority: CN
Inventors: 汪洋; 王维; 丛艳丽; 秦建华; 邹斌
Original assignee: Shanghai Sophie Electronic Technology Co ltd
Current assignee: Shanghai Sophie Electronic Technology Co ltd
Priority date: 2020-08-11
Filing date: 2020-08-11
Publication date: 2021-02-26
Anticipated expiration: 2030-08-11
Also published as: TWM622123U

Abstract

The utility model provides a thermal protection's piezoresistor, including first temperature fuse and varistor piece, still include an encapsulation shell: the first temperature fuse is attached to one side surface of the piezoresistor disc and then packaged in the packaging shell; the first fuse pin of the first temperature fuse is electrically connected to the voltage-sensitive resistor disc, and the second fuse pin extends out of the packaging shell; a first voltage-sensitive pin extending out of the packaging shell is further arranged on one side face, away from the first temperature fuse, of the voltage-sensitive resistance sheet. The first temperature fuse is attached to the piezoresistor disc, so that the temperature protection of the piezoresistor disc is directly and accurately carried out, and the problem that the piezoresistor is not effectively thermally protected is solved.

Description

Thermally protected piezoresistor

Technical Field

The utility model belongs to the technical field of electronic component, specificly relate to a piezoresistor with heat protect function.

Background

The existing piezoresistor does not have an overheat protection function, and in order to realize circuit overheat protection, a piezoresistor and a temperature fuse are generally connected in series, then a shell is additionally arranged, and then encapsulation is carried out. The piezoresistor is large in size and high in cost, and cannot directly and accurately carry out thermal protection on the piezoresistor, so that the actual use requirement cannot be met.

Disclosure of Invention

The utility model aims at providing a thermal protection's piezo-resistor to solve piezo-resistor and do not have the problem of effective thermal protection.

The specific scheme is as follows: a thermally protected varistor comprising a first temperature fuse and a varistor sheet, further comprising an encapsulating housing:

the first temperature fuse is attached to one side surface of the piezoresistor disc and then packaged in the packaging shell; the first fuse pin of the first temperature fuse is electrically connected to the voltage-sensitive resistor disc, and the second fuse pin extends out of the packaging shell; a first voltage-sensitive pin extending out of the packaging shell is further arranged on one side face, away from the first temperature fuse, of the voltage-sensitive resistance sheet.

The utility model discloses a further technical scheme does: the remote signaling fuse is arranged in the packaging shell and attached to the piezoresistor sheet.

The utility model discloses a further technical scheme does: the remote signaling fuse is a second temperature fuse, and two pins of the second temperature fuse protrude out of the packaging shell to be electrically connected with an external remote signaling circuit.

The utility model discloses a further technical scheme does: the second temperature fuse has the same fusing temperature as the first temperature fuse.

The utility model discloses a further technical scheme does: the second voltage-sensitive pin is arranged on one side of the piezoresistor sheet, on which the first temperature fuse is fixed, and is electrically connected to the first fuse pin.

The utility model discloses a further technical scheme does: the second fuse pin comprises a steel wire, a copper-clad layer and a tin-plated layer from inside to outside in sequence.

The utility model discloses a further technical scheme does: the upper end of the second fuse pin is further coated with an insulating layer.

Has the advantages that: the utility model provides a thermal protection's piezoresistor, including first temperature fuse and varistor piece, still include an encapsulation shell: the first temperature fuse is attached to one side surface of the piezoresistor disc and then packaged in the packaging shell; the first fuse pin of the first temperature fuse is electrically connected to the voltage-sensitive resistor disc, and the second fuse pin extends out of the packaging shell; a first voltage-sensitive pin extending out of the packaging shell is further arranged on one side face, away from the first temperature fuse, of the voltage-sensitive resistance sheet. The first temperature fuse is attached to the piezoresistor disc, so that the temperature protection of the piezoresistor disc is directly and accurately carried out, and the problem that the piezoresistor is not effectively thermally protected is solved.

Drawings

FIG. 1 illustrates a front view of a partially windowed package housing according to an embodiment of the present invention;

FIG. 2 shows the schematic structure of FIG. 1 with the package housing removed;

fig. 3 is a front view of a second package housing according to an embodiment of the present invention after being partially windowed;

fig. 4 shows a schematic structural view of fig. 2 with the package housing removed.

Detailed Description

To further illustrate the embodiments, the present invention provides the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the embodiments. With these references, one of ordinary skill in the art will appreciate other possible embodiments and advantages of the present invention. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.

The present invention will now be further described with reference to the accompanying drawings and detailed description.

Example one

As shown in fig. 1 and 2, this embodiment provides a thermally protected varistor including a first thermal fuse 2, a second thermal fuse 3, a varistor sheet 1, and an encapsulating case 10.

The varistor sheet 1 is a zinc oxide varistor sheet, a first varistor pin 11 is arranged on one side surface of the varistor sheet 1, and a first temperature fuse 2 and a second temperature fuse 3 are respectively attached to the other side surface of the varistor sheet 1.

The first temperature fuse 2 is used as a temperature fuse of the piezoresistor, and the main body part of the first temperature fuse 2 is attached to the side surface of the piezoresistor sheet 1 and then packaged in the packaging shell 10; meanwhile, the first fuse pin 20 of the first thermal fuse 2 is folded up in a U shape, attached to the side surface of the varistor 1 and electrically connected to the varistor, and the second fuse pin 21 extends out of the package housing for electrically connecting to an external circuit. Furthermore, the second fuse pin 21 is electrically connected to the first varistor pin 11 through the first thermal fuse 2, the first fuse pin 20 and the varistor sheet 1 in sequence, thereby forming a varistor main circuit.

The second temperature fuse 3 is used as a remote signaling fuse for detecting whether the main circuit of the piezoresistor is failed or not. The remote signaling fuse 3 is also arranged in the packaging shell 10 and is attached to the piezoresistor sheet 1; meanwhile, two pins of the second temperature fuse 3 protrude out of the packaging shell to be electrically connected with an external remote signaling circuit, and the second temperature fuse is used for driving elements such as an alarm or an LED lamp and the like to indicate whether the electronic device is over-temperature failure or not.

In this embodiment, the fusing temperatures of the second temperature fuse 3 and the first temperature fuse 2 are the same, that is, after the varistor sheet 1 is over-heated and fused for protection, a remote signaling signal can be input to indicate that the circuit is failed.

This embodiment has not only realized 1 direct detection temperature protect function of piezo-resistor piece through first temperature fuse 2, has still realized fault signal output through second temperature fuse 3, reminds the function immediately.

Example two

As shown in fig. 3 and 4, this embodiment also provides a thermally protected varistor, which is substantially the same as embodiment 1 and includes a package housing 10, and a first thermal fuse 2, a second thermal fuse 3, and a varistor sheet 1 packaged in the package housing 10.

The embodiment further includes a second voltage-sensitive pin 12, the second voltage-sensitive pin 12 and the first voltage-sensitive pin 11 are respectively attached to two opposite sides of the varistor sheet 1, and the second voltage-sensitive pin 12 fixes one side of the first temperature fuse 2 and is electrically connected to the first fuse pin 20. This setting of second pressure sensitive pin 12 has realized independent of piezo-resistor disc 1 with temperature protect function, even high temperature opens a way, and piezo-resistor disc 1 still can work temporarily, and it passes through the signal of second temperature fuse 3 output trouble telesignalling, and the suggestion is immediately changed bad damage component can, has improved equipment stability.

In this embodiment, the pins of the first thermal fuse 2 and the second thermal fuse 3 are made of tinned copper clad steel wires, so as to facilitate wave soldering and avoid the heat of the wave soldering process from damaging the temperature-sensitive alloy of the thermal fuse, i.e. taking the second fuse pin 21 as an example, the second fuse pin sequentially comprises a steel wire, a copper clad layer and a tin-plated layer from inside to outside. Meanwhile, in order to enhance the insulating effect and adjust the soldering height, the upper end of the second fuse pin 21 is further covered with an insulating layer, i.e., only the lower end portion is exposed for soldering and electrical connection. Of course, it can be seen that the two leads of the second thermal fuse 3 are also covered with the insulating layer.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A thermally protected varistor comprising a first thermal fuse and a varistor sheet, further comprising an encapsulating housing:

the first temperature fuse is attached to one side surface of the piezoresistor disc and then packaged in the packaging shell;

the first fuse pin of the first temperature fuse is electrically connected to the voltage-sensitive resistor disc, and the second fuse pin extends out of the packaging shell; a first voltage-sensitive pin extending out of the packaging shell is further arranged on one side face, away from the first temperature fuse, of the voltage-sensitive resistance sheet.

2. The varistor of claim 1, wherein: the remote signaling fuse is arranged in the packaging shell and attached to the piezoresistor sheet.

3. The varistor of claim 2, wherein: the remote signaling fuse is a second temperature fuse, and two pins of the second temperature fuse protrude out of the packaging shell to be electrically connected with an external remote signaling circuit.

4. A varistor according to claim 3, characterized in that: the second temperature fuse has the same fusing temperature as the first temperature fuse.

5. The varistor of claim 2, wherein: the second voltage-sensitive pin is arranged on one side of the piezoresistor sheet, on which the first temperature fuse is fixed, and is electrically connected to the first fuse pin.

6. A varistor according to any of claims 1-5, characterized in that: the second fuse pin comprises a steel wire, a copper-clad layer and a tin-plated layer from inside to outside in sequence.

7. A varistor according to any of claims 1-5, characterized in that: the upper end of the second fuse pin is further coated with an insulating layer.