An improved plastic-encapsulated surface-mount thermistor

Abstract

The present invention provides an improved plastic-sealed patch thermal varistor, comprising a thermistor chip, a varistor chip is arranged on one side of the thermistor chip, and a connecting piece is electrically connected to the lower part of the varistor chip and the thermistor chip, wherein the middle part of the right part of the connecting piece is integrally connected with a first pin; the upper part of the thermistor chip is electrically connected with a second pin; the upper part of the varistor chip is electrically connected with a third pin; and the outer sides of the thermistor chip and the varistor chip are provided with a plastic sealing layer. The present invention can inject solder paste into a paste storage conductive box through a tin injection port, so that the solder paste can be individually isolated through the paste storage conductive box, thereby avoiding the problem of bridging of the solder paste, and then avoiding the problem of short circuit after the thermal varistor is welded, and achieving the effect of paste storage welding.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermosensitive varistors, and particularly relates to an improved plastic-encapsulated surface-mounted thermosensitive varistor. Background Art

[0002] A thermosensitive varistor is an electronic component used on an electric energy meter. For example, the plastic-encapsulated surface-mounted thermosensitive varistor with the publication number CN207993596U includes a thermistor chip and a varistor chip. The thermistor chip and the varistor chip are arranged side by side in the same position. The bottoms of the thermistor chip and the varistor chip are respectively connected through the right end head of the lower connecting body and the left end head of the lower connecting body. There are still some problems in the actual use of this thermosensitive varistor. For example, when performing manual soldering on it, the operator needs to apply solder paste on the circuit board. Since the size of the thermosensitive varistor is small and the soldering position on the circuit board is small, the problem of solder paste bridging may occur during the process of applying solder paste. Furthermore, there may be a short-circuit phenomenon after the thermosensitive varistor is soldered. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides an improved plastic-encapsulated surface-mounted thermosensitive varistor, which can achieve the effect of solder paste storage soldering, effectively avoid the problem of solder paste bridging, and further avoid the problem of short-circuit phenomenon after the thermosensitive varistor is soldered.

[0004] Its technical solution is as follows: An improved plastic-encapsulated surface-mounted thermosensitive varistor includes a thermistor chip. A varistor chip is arranged on one side of the thermistor chip, and a connecting piece is electrically connected to the lower part between the varistor chip and the thermistor chip. The middle part of the right part of the connecting piece is integrally connected with a first lead; the upper part of the thermistor chip is electrically connected with a second lead; the upper part of the varistor chip is electrically connected with a third lead; a plastic encapsulation layer is arranged outside the thermistor chip and the varistor chip; the lower horizontal sections of the first lead, the second lead and the third lead all expose from the inside of the plastic encapsulation layer. It is characterized in that the lower parts of the lower horizontal sections of the first lead, the second lead and the third lead are respectively integrally connected with solder paste storage connection components; a limiting tweezering component is integrally connected to the top of the plastic encapsulation layer.

[0005] Preferably, each of the solder paste storage connection components includes a solder paste storage conductive box. Tin discharging ports are sequentially arranged from left to right on the lower side inside the solder paste storage conductive box; a tin injection port is arranged in the middle of one side of the solder paste storage conductive box.

[0006] Preferably, L-shaped support blocks are respectively integrally connected to the four corner parts of the lower part of the solder paste storage conductive box.

[0007] Preferably, the limiting tweezering component includes a first tweezing plate, a second tweezing plate is cross - arranged in the middle of the first tweezing plate, and second limiting grooves are respectively opened on the upper left and right sides of the front and rear parts of the first tweezing plate; first limiting grooves are respectively opened on the upper front and rear sides of the left and right parts of the second tweezing plate; the first tweezing plate and the second tweezing plate are arranged in a cross shape.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0009] 1. The present invention can inject solder paste into the solder paste storage and conductive box through the solder injection port, so that the solder paste can be separately isolated by the solder paste storage and conductive box, and further the problem of solder paste bridging can be avoided, and then the problem of short - circuit phenomenon after the hot - sensitive resistor is welded can be avoided, realizing the effect of solder paste storage welding.

[0010] 2. In the present invention, the L - shaped support block can make the welding part of the solder paste storage and conductive box and the circuit board have a certain distance, so that the melted solder paste can be fully combined with the welding part of the circuit board, and further the problem of false soldering can be avoided. Description of the Drawings

[0011] Figure 1 is the structural schematic diagram of the present invention.

[0012] Figure 2 is the internal structural schematic diagram of the present invention.

[0013] Figure 3 is the internal structural schematic diagram of the present invention from another perspective.

[0014] Figure 4 is the partial structural schematic diagram of the present invention.

[0015] Figure 5 is the structural schematic diagram of the solder paste connection component of the present invention.

[0016] Figure 6 is the structural schematic diagram of the limiting tweezering component of the present invention.

[0017] In the figure:

[0018] 1. Thermistor chip; 2. Varistor chip; 3. Connecting piece; 4. First pin; 5. Second pin; 6. Third pin; 7. Plastic sealing layer; 8. Solder paste connection component; 81. Solder paste storage and conductive box; 82. Solder discharge port; 83. L - shaped support block; 84. Solder injection port; 9. Limiting tweezering component; 91. First tweezing plate; 92. Second tweezing plate; 93. First limiting groove; 94. Second limiting groove. Detailed Embodiments

[0019] The present invention will be specifically described below with reference to the drawings. As shown in Figure 1 toFigure 4 As shown in the figure, an improved plastic-encapsulated chip thermosensitive varistor includes a thermistor chip 1. On one side of the thermistor chip 1, a varistor chip 2 is provided. A connecting piece 3 is electrically connected to the lower part between the varistor chip 2 and the thermistor chip 1. In the middle of the right part of the connecting piece 3, a first lead 4 is integrally connected; the upper part of the thermistor chip 1 is electrically connected to a second lead 5; the upper part of the varistor chip 2 is electrically connected to a third lead 6; a plastic encapsulation layer 7 is provided outside the thermistor chip 1 and the varistor chip 2; the lower horizontal sections of the first lead 4, the second lead 5 and the third lead 6 all protrude from the inside of the plastic encapsulation layer 7; the connecting piece 3 is made of a copper sheet; the first lead 4, the second lead 5 and the third lead 6 are respectively made of Z-shaped copper leads.

[0020] One of the improved plastic-encapsulated chip thermosensitive varistors further includes a solder paste storage connecting component 8, and the solder paste storage connecting component 8 is integrally connected to the lower parts of the lower horizontal sections of the first lead 4, the second lead 5 and the third lead 6 respectively; a limiting tweezering component 9 is integrally connected to the top of the plastic encapsulation layer 7, which is beneficial to achieving the effect of solder paste welding, can effectively avoid the problem of solder paste bridging, and further can avoid the problem of short circuit after the thermosensitive varistor is welded.

[0021] Combined with the attached Figure 5 As shown in the figure, the solder paste storage connecting component 8 respectively includes a solder paste storage conductive box 81. Solder discharge ports 82 are sequentially arranged from left to right on the lower side inside the solder paste storage conductive box 81; a solder injection port 84 is arranged in the middle of one side of the solder paste storage conductive box 81; the upper part of the solder paste storage conductive box 81 is integrally connected to the lower parts of the lower horizontal sections of the first lead 4, the second lead 5 and the third lead 6 respectively; the solder paste storage conductive box 81 is made of a copper box;

[0022] In order to make the lower part of the solder paste storage conductive box 81 have a certain distance from the welding position, L-shaped support blocks 83 are integrally connected to the four corners of the lower part of the solder paste storage conductive box 81. Through the L-shaped support blocks 83, the solder paste storage conductive box 81 can be spaced a certain distance from the welding part of the circuit board, so that the melted solder paste can be fully combined with the welding part of the circuit board, and further the problem of false soldering can be avoided; the L-shaped support blocks 83 are made of L-shaped copper blocks;

[0023] When manual soldering of this thermosensitive resistor is required, first inject solder paste into the solder paste storage and conductive box 81 through the solder injection port 84. Since the fluidity of the solder paste is poor, the solder paste will not flow out in large quantities through the solder discharge port 82. After the injection of the solder paste is completed, flux can also be injected into the solder paste storage and conductive box 81 through the solder injection port 84. Subsequently, place this thermosensitive resistor at the designated position on the circuit board and heat the thermosensitive resistor with a hot air gun. At this time, the solder paste in the solder paste storage and conductive box 81 will be heated and melted. Subsequently, part of the solder paste will flow to the soldering position on the circuit board through the solder discharge port 82, while the other part of the solder paste will remain in the solder paste storage and conductive box 81. Then remove the hot air gun to solidify the melted solder paste, thus completing the soldering of the thermosensitive resistor.

[0024] In this embodiment, as shown in the attached Figure 6 figures, the limiting tweezers component 9 includes a first tweezers plate 91. A second tweezers plate 92 is cross - arranged in the middle of the first tweezers plate 91. Second limiting grooves 94 are respectively formed on the upper left and right sides of the front and rear parts of the first tweezers plate 91. First limiting grooves 93 are respectively formed on the upper front and rear sides of the left and right parts of the second tweezers plate 92. The first tweezers plate 91 and the second tweezers plate 92 are arranged in a cross shape. The first limiting grooves 93 and the second limiting grooves 94 are respectively triangular grooves. The lower parts of the first tweezers plate 91 and the second tweezers plate 92 are integrally connected to the upper part of the plastic sealing layer 7. The first tweezers plate 91 and the second tweezers plate 92 are respectively made of silicone plastic plates;

[0025] When this thermosensitive resistor needs to be moved, the operator can pick up the first tweezers plate 91 or the second tweezers plate 92 with tweezers and place the tweezers in the first limiting groove 93 or the second limiting groove 94. Since the tweezers are in the first limiting groove 93 or the second limiting groove 94, the tweezers can only move within a small range in the first limiting groove 93 or the second limiting groove 94, thereby avoiding the problem of large - range relative movement between this thermosensitive resistor and the tweezers during the process of picking up this thermosensitive resistor.

[0026] When the present invention is in use, first, solder paste is injected into the solder paste storage and conductive box 81 through the solder injection port 84. Since the fluidity of the solder paste is poor, the solder paste will not flow out in large quantities through the solder discharge port 82. After the injection of the solder paste is completed, flux can also be injected into the solder paste storage and conductive box 81 through the solder injection port 84. Subsequently, the present thermosensitive resistor is placed at the designated position on the circuit board, and a hot air gun is used to heat the thermosensitive resistor. At this time, the solder paste in the solder paste storage and conductive box 81 will be heated and melted. Subsequently, part of the solder paste will flow to the welding position on the circuit board through the solder discharge port 82, and the other part of the solder paste will remain in the solder paste storage and conductive box 81. Then, the hot air gun is removed to solidify the melted solder paste, thus completing the welding of the thermosensitive resistor. Compared with the prior art, the present invention can inject solder paste into the solder paste storage and conductive box 81 through the solder injection port 84, so that the solder paste can be separately isolated by the solder paste storage and conductive box 81, thereby avoiding the problem of solder paste bridging, and then avoiding the problem of short circuit after the welding of the thermosensitive resistor, achieving the effect of solder paste storage welding; when it is necessary to move the present thermosensitive resistor, the operator can pick up the first picking plate 91 or the second picking plate 92 with tweezers and place the tweezers in the first limiting groove 93 or the second limiting groove 94. Since the tweezers are located in the first limiting groove 93 or the second limiting groove 94, the tweezers can only move within a small range in the first limiting groove 93 or the second limiting groove 94, thereby avoiding the problem of large-range relative movement between the thermosensitive resistor and the tweezers during the picking process of the thermosensitive resistor.

[0027] Any technical solution using the technical solution of the present invention, or designed by those skilled in the art inspired by the technical solution of the present invention to achieve the above technical effects, shall fall within the protection scope of the present invention.

Claims

1. An improved plastic-encapsulated patch thermal varistor, comprising a thermistor chip (1), a varistor chip (2) being arranged on one side of the thermistor chip (1), and a connecting piece (3) being electrically connected at the lower part between the varistor chip (2) and the thermistor chip (1), wherein a first pin (4) is integrally connected to the middle part of the right part of the connecting piece (3); a second pin (5) is electrically connected to the upper part of the thermistor chip (1); a third pin (6) is electrically connected to the upper part of the varistor chip (2); a plastic encapsulation layer (7) is arranged on the outer side of the thermistor chip (1) and the varistor chip (2); the lower horizontal sections of the first pin (4), the second pin (5) and the third pin (6) are all exposed from the inside of the plastic encapsulation layer (7), characterized in that: The lower parts of the lower horizontal sections of the first pin (4), the second pin (5) and the third pin (6) are respectively connected with a paste storage connection assembly (8); the top of the plastic sealing layer (7) is connected with a limited position tweezer assembly (9); the paste storage connection assembly (8) comprises a paste storage conductive box (81), the lower side of the inner part of the paste storage conductive box (81) is provided with tin discharge openings (82) from left to right; a tin injection opening (84) is provided in the middle of one side of the paste storage conductive box (81); the limited position tweezer assembly (9) comprises a first tweezer plate (91), a second tweezer plate (92) is cross-arranged in the middle of the first tweezer plate (91), and the upper left and right sides of the front and rear parts of the first tweezer plate (91) are respectively provided with second limiting grooves (94); the upper left and right sides of the left and right parts of the second tweezer plate (92) are respectively provided with first limiting grooves (93); the first tweezer plate (91) and the second tweezer plate (92) are arranged in a cross shape.

2. The improved plastic-encapsulated chip thermal varistor as claimed in claim 1, characterized in that: The four corners of the lower part of the paste storage conductive box (81) are respectively integrally connected with L-shaped support blocks (83).

3. The improved plastic-encapsulated chip thermal varistor as claimed in claim 1, characterized in that: The upper portion of the paste storage conductive box (81) is integrally connected to the lower portion of the lower horizontal section of the first pin (4), the second pin (5) and the third pin (6).

4. The improved plastic-encapsulated chip thermal varistor as claimed in claim 1, characterized in that: The first limiting groove (93) and the second limiting groove (94) are respectively triangular grooves.

5. The improved plastic-encapsulated chip thermal varistor as claimed in claim 1, characterized in that: The lower parts of the first tweezer plate (91) and the second tweezer plate (92) are respectively connected to the upper part of the plastic sealing layer (7) in an integrated manner.

6. The improved plastic-encapsulated chip thermal varistor as claimed in claim 1, characterized in that: The paste storage conductive box (81) is a copper box.

7. The improved plastic-encapsulated chip thermal varistor as claimed in claim 2, characterized in that: The L-shaped support block (83) is an L-shaped copper block.

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