CN216212605U

CN216212605U - SMD thermistor

Info

Publication number: CN216212605U
Application number: CN202122465052.4U
Authority: CN
Inventors: 汪洋
Original assignee: Nanjing Shiheng Electronics Co ltd
Current assignee: Nanjing Shiheng Electronics Co ltd
Priority date: 2021-10-13
Filing date: 2021-10-13
Publication date: 2022-04-05
Anticipated expiration: 2031-10-13

Abstract

The utility model discloses a surface-mounted thermistor which comprises a resistor chip and leads, wherein the leads comprise upper leads and lower leads, the upper leads and the lower leads are respectively welded on the upper surface and the lower surface of the resistor chip, each lead extends in parallel along the surface of the resistor chip to form a leading-out part, the leading-out parts of the upper leads are bent downwards after extending beyond the surface range of the resistor chip from welding points to form downward folding parts, the leading-out parts of the lower leads extend in parallel along the lower surface for a section and then are folded downwards to form downward folding parts, the downward folding parts of the upper leads and the lower leads extend downwards for a section and then are folded backwards to form reverse folding parts, the tail ends of the reverse folding parts are folded upwards to form upward folding parts, and the reverse folding parts of the upper leads and the reverse folding parts of the lower leads are positioned on the same horizontal plane. The resistor ensures ventilation and heat dissipation of the thermistor during working through the folded structure of the lead wire, and simultaneously ensures the distance between the thermistor and a PCB, and the folded lead wire structure also ensures firm installation and stable support of the resistor and is convenient for automatic mounting.

Description

SMD thermistor

Technical Field

The utility model belongs to the field of electronic components, and particularly relates to a surface-mounted thermistor.

Background

Either a positive temperature coefficient thermistor or a negative temperature coefficient thermistor generates heat when in use, particularly when a large current is passed through the thermistor, and therefore, a sufficient heat dissipation space needs to be left for the thermistor when in use. The traditional thermistor is generally installed in a direct inserting mode, and although the traditional thermistor is good in heat dissipation performance, the traditional thermistor occupies a large space, is high in height and is inconvenient to install automatically. The traditional patch type thermistor occupies small space and has short height, but is not suitable for the thermistor, because the temperature of the resistor body is very high when the thermistor is used, the temperature can reach 200 ℃ or even higher, and the high-temperature PCB can not bear the high-temperature thermistor. There is therefore a need for improvements in existing thermistors to accommodate the trend towards miniaturization and production automation of modern electronic devices.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems, the utility model develops the thermistor with a novel structure, on one hand, the height of the thermistor can be reduced, the occupied space is reduced, the automatic mounting is convenient, the thermistor can better radiate heat like the traditional direct-insertion thermistor, and the damage to a PCB (printed circuit board) can be avoided.

Specifically, the utility model adopts the following technical scheme:

the utility model provides a SMD thermistor, including resistance chip and lead wire, the lead wire includes lead wire and lower lead wire, weld respectively at resistance chip's upper surface and lower surface, every lead wire extends along resistance chip's parallel surface and forms the extraction portion, the extraction portion of going up the lead wire extends from the solder joint and forms down the portion of folding down after surpassing resistance chip surface range, down lead wire extraction portion rolls over down and forms down the portion of folding down after extending one section along the parallel surface, go up the lead wire and form the back-folding portion after the down-folding portion of lead wire down extends one section, the end of back-folding portion is rolled over upwards and is formed the portion of folding up, wherein the back-folding portion of going up the lead wire and the back-folding portion of lead wire down are in same horizontal plane.

In a preferred embodiment, the end of the folded-up portion is further provided with an insulating portion.

In one embodiment, the lead-out portion of the lower lead extends for the same length as the lead-out portion of the upper lead.

In a preferred embodiment, the resistor is further covered with an encapsulating material, wherein the lower edge of the folded portion is exposed from the encapsulating material to form an exposed portion.

In one embodiment, the lead-out portions of the upper and lower leads are arranged to intersect.

In another embodiment, the leading-out parts of the upper lead and the lower lead are arranged in parallel, the extending directions of the leading-out parts are the same, and the downward folded parts of the upper lead and the lower lead are positioned on the same side of the resistor chip.

In still another embodiment, the lead-out portions of the upper and lower leads are arranged in parallel, the lead-out portions extend in opposite directions, and the folded-down portions of the upper and lower leads are located on opposite sides of the resistor chip.

The surface-mounted thermistor ensures ventilation and heat dissipation of the surface-mounted thermistor during working by utilizing the folded structure of the lead, ensures the distance between the surface-mounted thermistor and a PCB (printed circuit board), cannot damage the circuit board, ensures firm installation and stable support of the resistor by utilizing the folded lead structure, and is convenient for automatic surface mounting.

Drawings

FIG. 1 is a schematic structural diagram of a surface mount thermistor according to the present invention;

FIG. 2 is a bottom view of one embodiment of the present invention;

FIG. 3 is a bottom view of another embodiment of the present invention;

FIG. 4 is a schematic structural diagram of yet another embodiment of the present invention;

fig. 5 is a schematic structural diagram of yet another embodiment of the present invention.

In the figure: 1. a resistor chip; 2. a lead-out section; 3. a fold-down portion; 4. a folded-back portion; 5. an upward folded part; 6. an insulating section; 7. packaging the materials; 8. leading wires up; 9. a down lead; 10. an exposed portion.

Detailed Description

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Referring to fig. 1, a structure of the chip thermistor according to the present invention is shown. As shown in fig. 1, the chip thermistor of the present invention includes a resistor chip 1, an upper lead 8 and a lower lead 9, wherein the upper lead 8 and the lower lead 9 are respectively welded on the upper surface and the lower surface of the resistor chip 1, each lead extends in parallel along the surface of the resistor chip to form a lead-out portion 2, the lead-out portion 2 extends beyond the surface of the resistor chip and is bent downward to form a lower folded portion 3, the lower folded portion 3 extends downward for a section and is folded back to form a folded back portion 4, the end of the folded back portion 4 is folded back upward to form an upper folded portion 5, and the folded back portions 4 of the upper lead 8 and the lower lead 9 are located on the same horizontal plane to form a welding surface of the resistor and a PCB board. In general, since the resistor is encapsulated, the resistor further includes an encapsulating material 7, and in this case, the lower surface of the folded portion 4 is entirely or partially exposed from below the encapsulating material 7 to form an exposed portion 10 as a bonding surface.

The folded-up portion 5 can ensure the ventilation space below the resistor chip 1 and the distance between the resistor chip and the PCB to avoid damage to the PCB, and therefore, an insulating portion 6 is preferably further provided at the end of the folded-up portion to electrically insulate the end of the lead from the resistor chip.

In the solution of the present invention, the resistor chip may be a circular chip, as shown in fig. 2, a rectangular chip, or a square chip, as shown in fig. 3, or a chip with other various shapes, such as a circle, an ellipse, a polygon, and the like. The resistor may or may not be encapsulated, as shown in fig. 4 and 5. The leads may be arranged in parallel, as in fig. 2, or may be arranged in cross, as in fig. 3, although the figures show the crossing leads arranged on a square chip and the parallel leads arranged on a circular chip, it should be understood that these figures are merely used as examples, and the actual arrangement should be configured according to actual needs, for example, the crossing leads are more applied to a circular chip in actual cases.

The lengths of the lead-out portions 2 of the upper and lower leads may be the same or different, for example, as shown in fig. 1, the lead-out portions extend the same length, or as shown in fig. 5, the lead-out portions differ in length, the lower lead is bent downward earlier, so that the resistor can be used on a board with a tighter space.

The extending directions of the lead-out portions of the upper and lower leads may be the same, so that the folded-down portions of the upper and lower leads are located on the same side of the resistor chip. The extending directions of the lead-out parts can be opposite, so that the downward folding parts of the upper lead and the lower lead are positioned at the opposite sides of the resistor chip, as shown in fig. 4, the length of the lead-out parts can be shortened, more space is left below the resistor chip, and smoother ventilation can be ensured.

The utility model discloses a surface-mounted thermistor which comprises a resistor chip and leads, wherein the leads comprise upper leads and lower leads, the upper leads and the lower leads are respectively welded on the upper surface and the lower surface of the resistor chip, each lead extends in parallel along the surface of the resistor chip to form a leading-out part, the leading-out parts of the upper leads are bent downwards after extending beyond the surface range of the resistor chip from welding points to form downward folding parts, the leading-out parts of the lower leads extend in parallel along the lower surface for a section and then are folded downwards to form downward folding parts, the downward folding parts of the upper leads and the lower leads extend downwards for a section and then are folded backwards to form reverse folding parts, the tail ends of the reverse folding parts are folded upwards to form upward folding parts, and the reverse folding parts of the upper leads and the reverse folding parts of the lower leads are positioned on the same horizontal plane. The resistor ensures ventilation and heat dissipation of the thermistor during working through the folded lead structure of the lead, ensures the distance between the thermistor and a PCB (printed circuit board), cannot damage the circuit board, ensures firm installation and stable support of the resistor through the folded lead structure, and is convenient for automatic mounting.

While the embodiments of the present invention have been described in detail with reference to the drawings and the specific examples, the present invention is not limited to the embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art.

Claims

1. The utility model provides a SMD thermistor, including resistance chip and lead wire, a serial communication port, the lead wire includes lead wire and lower lead wire, weld respectively at resistance chip's upper surface and lower surface, every lead wire extends along resistance chip's surface parallel and forms the extraction portion, the extraction portion of going up the lead wire is followed the solder joint and is extended to be surpassed resistance chip surface scope and then bend downwards and form down-folded part, down lead wire extraction portion is followed and is rolled over down after one section of lower surface parallel extension and form down-folded part, go up the lead wire and form back-folded part after the down-folded part downwardly extending of lower lead wire one section, the end of back-folded part is rolled over upwards and is formed up-folded part, wherein the back-folded part of going up the lead wire and the back-folded part of lower lead wire are in same horizontal plane.

2. The chip thermistor according to claim 1, wherein the end of the folded-up portion is further provided with an insulating portion.

3. The chip thermistor according to claim 1, wherein the lead-out portion of the lower lead extends for the same length as the lead-out portion of the upper lead.

4. The chip thermistor according to claim 1, wherein an encapsulant is integrally coated outside the resistor, and wherein a lower edge of the folded-back portion is exposed from the encapsulant to form an exposed portion.

5. The chip thermistor according to claim 1, wherein the lead-out portions of the upper and lower leads are arranged crosswise.

6. The chip thermistor according to claim 1, wherein the lead-out portions of the upper and lower leads are arranged in parallel, the lead-out portions extend in the same direction, and the folded-down portions of the upper and lower leads are located on the same side of the resistor chip.

7. The chip thermistor according to claim 1, wherein the lead-out portions of the upper and lower leads are arranged in parallel, the lead-out portions extend in opposite directions, and the folded-down portions of the upper and lower leads are located on opposite sides of the resistor chip.