CN216212606U

CN216212606U - Safety patch type thermistor

Info

Publication number: CN216212606U
Application number: CN202122578104.9U
Authority: CN
Inventors: 汪洋
Original assignee: Nanjing Shiheng Electronics Co ltd
Current assignee: Nanjing Shiheng Electronics Co ltd
Priority date: 2021-10-26
Filing date: 2021-10-26
Publication date: 2022-04-05
Anticipated expiration: 2031-10-26

Abstract

The utility model discloses a safe patch type thermistor which comprises a resistor chip and conducting strips, wherein the conducting strips comprise an upper conducting strip and a lower conducting strip which are respectively welded on the upper surface and the lower surface of the resistor chip through welding parts, each welding part is provided with one or more than two welding holes, each conducting strip extends in parallel along the surface of the resistor chip to form an extending part, the extending part extends from the welding part to exceed the surface range of the resistor chip and then is bent downwards to form a downward bending part, and the tail end of each conducting strip forms an installation part. According to the thermistor, the welding holes are formed in the welding part, so that the welding strength and the uniform distribution of soldering tin during welding are ensured, the heat generated by the thermistor during working cannot influence the welding strength and firmness, the bending structure of the conducting sheet ensures the distance between the resistor chip and the PCB, the ventilation and heat dissipation of the thermistor during working are ensured, and meanwhile, the automatic mounting of the thermistor is facilitated.

Description

Safety patch type thermistor

Technical Field

The utility model belongs to the field of electronic components, and particularly relates to a safe patch type thermistor.

Background

Some thermistors generate heat when being used, especially when being used in situations where a large current passes, such as surge current suppression power type NTC thermistors or over-current protection PTC thermistors, etc., a large amount of heat is generated during operation, which may have a large effect on the thermistors themselves and the use environment of the thermistors, for example, when a conductive sheet is welded on a resistance chip, more or less air gaps and holes may be generated at the welding position, the alternating of cold and heat generated by the thermistors during use may affect the firmness of the welding position, the heat generated by the thermistors may be transmitted to a PCB board to damage the PCB board, etc., so the firmness of the welding between the conductive sheet and the resistance chip is very important, and a sufficient heat dissipation space needs to be left for the thermistor during use. The traditional thermistor is generally installed in a straight-inserting manner, although the heat dissipation performance is good, the traditional thermistor is large in occupied space, high in height and inconvenient to automatically install, and the use of the straight-inserting type structure is greatly limited under the conditions that the installation space is limited and the installation height is limited; on the other hand, the traditional chip thermistor occupies a small space and has a short height, but is not suitable for the thermistor, because the temperature of the resistor body of the thermistor is very high when the thermistor is used, and can reach 200 ℃ or even higher, and the PCB cannot bear the high temperature. 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 structure of the thermistor needs to be improved, so that the thermistor cannot be damaged by self heat, on the other 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 type thermistor, and the thermistor and a PCB (printed circuit board) cannot be damaged.

Specifically, the utility model adopts the following technical scheme:

the utility model provides a SMD thermistor of safe type, includes resistance chip, conducting strip, and the conducting strip includes conducting strip and lower conducting strip, welds the upper surface and the lower surface at resistance chip through the weld part respectively, and every weld part has one or two above welding holes, and every conducting strip extends along the parallel extension in surface of resistance chip and forms the extension, and the extension is bent downwards after extending beyond resistance chip surface scope from the weld part and is formed the inflection portion, and the end of conducting strip forms the installation department.

In one aspect, the mounting portion is a section of the conductive sheet folded in a horizontal direction. Further, the mounting portion is folded back toward the resistor chip in the horizontal direction, and the end is folded up to form an up-folded portion.

On the other hand, the resistor chip is externally provided with an encapsulating material, one end of the encapsulating material bulges downwards to form a bulge part, the mounting part is a section of conducting strip bent from the tail end of the downward-folded part to the horizontal direction, and the lower edge of the mounting part and the lower edge of the bulge part are positioned on the same horizontal plane.

In another aspect, the thermistor is externally covered with a case, and a space between the case and the thermistor is filled with a thermally conductive paste.

Further, a gasket is arranged below the thermistor, and the lower edge of the mounting part extends out of the lower edge of the gasket or is parallel to the lower edge of the gasket, so that the heat insulation performance is good, and the influence of heat generation of the thermistor on the PCB is reduced.

Further, the thermistor can have a housing and a spacer at the same time, so that the thermistor has an integral structure, is more convenient to use, improves the stability of installation, has better heat dissipation, and isolates the influence of heat on the PCB.

The welding holes are formed in the welding part of the thermistor, so that the welding strength and the uniform distribution of soldering tin during welding are ensured, the heat generated by the thermistor during working cannot influence the welding strength, the bending structure of the conducting plate ensures the distance between the resistor chip and the PCB, the ventilation and heat dissipation of the thermistor during working are ensured, and meanwhile, the automatic mounting of the thermistor is facilitated.

Drawings

FIG. 1 is a schematic diagram of the construction of one embodiment of a thermistor of the present invention;

FIG. 2 is a schematic structural diagram of another embodiment of a thermistor according to the present invention;

FIG. 3 is a schematic structural diagram of yet another embodiment of the present invention;

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

FIG. 5 is a schematic structural view of an embodiment of the present invention including a housing;

FIG. 6 is a schematic structural view of another embodiment of the present invention including a housing;

FIG. 7 is a schematic structural view of an embodiment of the present invention including two weld holes;

FIG. 8 is a schematic structural view of an embodiment of the present invention including a gasket;

FIG. 9 is a schematic structural view of another embodiment of the present invention including a gasket.

In the figure: 1. a resistor chip; 2. a conductive sheet; 3. welding the part; 4. welding the hole; 5. an extension portion; 6. a fold-down portion; 7. an installation part; 8. packaging the materials; 9. a bulge part; 10. an upward folded part; 11. soldering tin; 12. a housing; 13. and (7) a gasket.

Detailed Description

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

Referring to fig. 1, there is shown a schematic structural view of the safety thermistor of the present invention. The chip thermistor comprises a resistor chip 1 and a conducting strip 2, wherein the conducting strip comprises an upper conducting strip and a lower conducting strip which are respectively welded on the upper surface and the lower surface of the resistor chip through a welding part 3, and the welding part is provided with a welding hole 4 which can help soldering tin 11 to be uniformly distributed between the surface of the resistor chip and the welding part during welding, so that the formation of air gaps in the welding part is reduced, and the firmness of the welding part during use is ensured. The welding hole is provided in one or more according to the necessity and the size of the welding portion, as shown in fig. 1 and 7. Although only one or two are shown in the drawings, it is understood that the number of the welding holes may be set to be more, for example, 3, 4 or more, according to design.

The conducting strip extends from the welding part and extends in parallel along the surface of the resistance chip to form an extension part 5, the extension parts of the upper conducting strip and the lower conducting strip extend from the welding part and exceed the surface range of the resistance chip and then are bent downwards to form a downward folding part 6, and the tail end of the conducting strip forms an installation part 7. The mounting portion may be a section of the fold-down portion extending downwardly for in-line mounting. Or the mounting part is a part horizontally bent from the lower folding part and horizontally extended and used for mounting in a patch mode. The horizontally extending mounting portion may be bent outwardly as shown in fig. 2 and 5, or inwardly as shown in fig. 3, 4, 6, 8 and 9. Meanwhile, as shown in fig. 4, in the case of inward bending, the end of the mounting portion may also be bent upward to form an upward bending portion 10, so as to ensure a space between the resistor chip and the PCB and provide a certain supporting function when mounting.

In one embodiment, the resistor chip 1 is wrapped by the encapsulant 8, and the opposite side of the encapsulant with respect to the leading direction of the conductive sheet passes through the accumulation of the encapsulant to form a bulge portion 9, as shown in fig. 2 and 3. The lower edge of the knob portion is in contact with the PCB board to which the thermistor is mounted and is lower than the lower edge of the other portion of the encapsulant. The lower edge of the bulge part is in contact with the PCB where the thermistor is to be installed and is lower than the lower edge of the other part of the encapsulating material, so that a ventilation space below the resistor chip 1 and a distance between the resistor chip and the PCB can be ensured, and the damage to the PCB is avoided.

In one embodiment, the mounting portion is a downwardly extending length of conductive strip and the distal end of the strip is lower than the lower edge of the knob portion, which is adapted for in-line mounting.

In another scheme, as shown in fig. 2 and 3, the mounting part is a conductive sheet bent from the end of the downward-folded part to the horizontal direction, and the lower edge of the mounting part and the lower edge of the bulge part are on the same horizontal plane. In this case, the mounting portion of the upper conductive sheet and the mounting portion of the lower conductive sheet are bent in the same direction or in different directions. The installation part of the upper conducting plate and the installation part of the lower conducting plate can be outwards or inwards bent, or respectively bent towards different directions of a horizontal plane, and of course, the installation parts can also be bent towards other directions according to the requirements of installation positions, so that the automatic mounting of the thermistor is facilitated.

In the solution of the present invention, the resistor chip may be a circular chip, as shown in fig. 1, or a rectangular chip, a square chip, or the like, as shown in fig. 7, or may be a chip with other various shapes, such as an oval shape, a polygon shape, or the like. The conducting strips can be arranged in parallel or in a crossed manner. Although specific configurations of conductive strips arranged are shown in the figures, it should be understood that these figures are only used as examples and that the actual arrangement should be configured according to actual needs, for example, in the actual case, conductive strips arranged crosswise on a circular chip and parallel on a rectangular chip are more applied, and those skilled in the art can easily make corresponding changes based on the contents of the present invention.

The lengths of the extending portions 6 of the upper conductive sheet and the lower conductive sheet may be the same or different, for example, in the case shown in fig. 2, the upper conductive sheet adopts a Z-shaped structure, a longer extending portion is required, the folded-down portion of the lower conductive sheet is bent obliquely, and the conductive sheet starts to be bent after extending out of the lower surface range of the resistor chip or the encapsulating material range, even not extending out of the lower surface range of the resistor chip. The extension portions may also extend for the same length, as shown in fig. 3, the space occupied by the conductive sheet is smaller overall, so that the overall structure of the thermistor is more compact.

In one embodiment, the resistive chip is externally covered with a housing 12, as shown in fig. 5 and 6. The shell can adopt ceramic package or metal casing, has good heat conduction effect and also plays the guard action, has filled heat-conducting glue between resistance chip and shell for the heat that resistance chip produced distributes away in time, has increased heat radiating area. In another embodiment, even a heat sink may be mounted on the housing to further improve the heat dissipation effect.

In another embodiment, a spacer 13 is added below the resistor chip, and the mounting surface of the mounting part can be exposed from the spacer or parallel to the lower edge of the spacer as required, as shown in fig. 8 and 9. The gasket can isolate the contact between the resistance chip and the PCB, and provides more integral packaging and more stable mounting surface, thereby being more beneficial to the mounting of the thermistor.

The thermistor can have both the spacer and the housing, thereby providing a more integral structure, more convenient use and better mounting, and better heat dissipation.

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 of safe type, includes resistance chip, conducting strip, its characterized in that, conducting strip include conducting strip and lower conducting strip, weld the upper surface and the lower surface at resistance chip through the weld part respectively, every weld part has one or two above welding holes, and every conducting strip extends along the parallel extension in surface of resistance chip and forms the extension, and the extension is bent downwards after extending beyond resistance chip surface scope from the weld part and is formed the inflection portion, and the end of conducting strip forms the installation department.

2. The secure surface mount thermistor according to claim 1, wherein the mounting part is a section of the conductive sheet folded in a horizontal direction.

3. The secure surface mount thermistor according to claim 2, wherein the mounting portion is folded back in a horizontal direction toward the resistor chip.

4. The secure surface-mount thermistor according to claim 3, wherein the mounting portion is folded back toward the resistor chip in a horizontal direction, and the end is folded up to form an upper folded portion.

5. The safety patch thermistor according to claim 1, wherein the resistor chip has an encapsulant on its exterior, one end of the encapsulant bulges downward to form a bulge, the mounting portion is a conductive strip bent from the end of the downward folded portion in a horizontal direction, and a lower edge of the mounting portion is located on a same horizontal plane as a lower edge of the bulge.

6. The secure patch thermistor according to claim 1, wherein the thermistor is externally covered with a case, and a space between the case and the thermistor is filled with a thermally conductive paste.

7. The safety patch thermistor according to any of claims 1 to 5, wherein a pad is disposed below the thermistor, and a lower edge of the mounting portion extends beyond or is parallel to a lower edge of the pad.