Tin climbing prevention capacitor

Abstract

An anti-tin-climbing capacitor comprises two supports arranged oppositely, a plurality of capacitor chips arranged between the two supports in a vertically stacked mode and two first anti-tin-climbing coatings arranged on the inner sides of the two supports respectively, each support comprises a welding section and a pin section arranged at the lower end of the welding section, and the capacitor chips are stacked between the two opposite welding sections. The first anti-tin-climbing coating is arranged on the inner side of the pin section; according to the anti-tin-climbing capacitor, the tin stacking effect on the inner side of the support can be restrained, soldering tin is not prone to being stacked on the inner side of the pin section under the condition that the height of a product is reduced, and therefore under the same voltage and capacity, the product is lower in height and smaller in size, the requirement for miniaturization is met, and the reliability of the product is also improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to capacitor preparation field, concretely relates to a kind of anti-tin climbing capacitor. BACKGROUND

[0002] With the development of science and technology, such as power, industry, automobile, military and aerospace fields, the demand for large capacity, large power capacitor is increasing, and the traditional chip ceramic capacitor is difficult to meet the demand of large capacity, so the parallel assembly mode of multiple ceramic capacitors is used to realize the demand of capacitor.

[0003] In integrated circuits, the requirement of electronic components integration and miniaturization is higher and higher, so the size of the product is smaller and smaller under the condition of ensuring product function, especially the height direction of the product, due to the limitation of packaging, the height of the product is required to be as small as possible. However, while reducing the overhanging height of the frame, solder is easy to accumulate in the inner side of the frame pin during use, stress concentration is easy to occur, leading to chip cracking failure, which needs to be further improved. UTILITY MODEL CONTENT

[0004] The utility model aims at overcoming the shortcomings of prior art, and provides an anti-tin climbing capacitor.

[0005] The utility model adopts the following technical scheme:

[0006] An anti-tin climbing capacitor comprises two brackets arranged oppositely, a plurality of capacitor chips stacked between the two brackets and two first anti-tin climbing coatings arranged on the inner sides of the two brackets, the bracket comprises a welding section and a pin section arranged at the lower end of the welding section, the plurality of capacitor chips are stacked between the two opposite welding sections, and the first anti-tin climbing coating is arranged on the inner side of the pin section.

[0007] Further, it further comprises two second anti-tin climbing coatings arranged vertically on the top of the two first anti-tin climbing coatings, the capacitor chip comprises a chip body and two end electrodes arranged oppositely at the two ends of the chip body, and the second anti-tin climbing coating is coated on the bottom surface of the end electrode at the lower end and connected with the first anti-tin climbing coating.

[0008] Further, it further comprises a plurality of adhesive layers arranged between adjacent two capacitor chips, the adhesive layer comprises two adhesive sheets arranged oppositely, one end of the adhesive sheet is connected with the end electrode, and the other end is connected with the chip body.

[0009] Further, the chip body is formed by stacking and firing a plurality of dielectric layers, the dielectric layer comprises a dielectric layer and an internal electrode group printed on the dielectric layer, and the internal electrode group comprises a plurality of first internal electrode layers and second internal electrode layers arranged alternately in the up-down direction.

[0010] Further, the first inner electrode layer comprises a first long inner electrode and a first short inner electrode arranged at left and right sides, and the second inner electrode layer comprises a second short inner electrode and a second long inner electrode arranged at left and right sides, and the first long inner electrode and the second long inner electrode are arranged in an up-and-down staggered manner.

[0011] Further, the end electrode comprises a first outer electrode, a second outer electrode and a third outer electrode arranged in sequence from inside to outside, the first outer electrode at the left side is connected with the second short inner electrode, and the first outer electrode at the right side is connected with the first short inner electrode.

[0012] Further, the coating thickness of the first anti-creeping tin coating layer and the second anti-creeping tin coating layer is 5 um.

[0013] Further, the welding section is formed with an exhaust groove extending downward from the top surface thereof.

[0014] Further, the exhaust groove is arranged in a U-shaped manner.

[0015] Further, the pin section is arranged in an L-shaped manner.

[0016] From the above description of the utility model, compared with the prior art, the utility model has the beneficial effects that: by limiting the structure of the anti-creeping tin capacitor, the first anti-creeping tin coating layer is arranged on the inner side of the pin section of the support, so that the wettability of the outer surface of the support is better than that of the inner surface, and in the welding process of the product, the high-temperature solder after melting will creep to the side with good wettability, i.e. the outer surface of the support, and the inner surface will not have the tin stacking phenomenon;

[0017] The anti-creeping tin capacitor defined in the application can inhibit the tin stacking effect on the inner side of the support, and in the case of reducing the height of the product, the tin is not easy to accumulate on the inner side of the pin section, so that the product has a lower height and a smaller size under the same voltage and capacity, meets the miniaturization requirement, and improves the reliability of the product. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structure diagram of a creeping tin capacitor Figure 1 ;

[0019] Figure 2 is a structure diagram of a creeping tin capacitor Figure 2 ;

[0020] Figure 3 is a partial structure enlarged view in Figure 1 ;

[0021] Figure 4 is a structure sectional view of a capacitor chip

[0022] In the figure, 1 - support, 2 - capacitor chip, 3 - first anti-creep tin coating, 4 - second anti-creep tin coating, 5 - adhesive layer, 6 - high-temperature solder, 11 - welding section, 12 - pin section, 13 - exhaust groove, 21 - chip body, 22 - end electrode, 221 - first outer electrode, 222 - second outer electrode, 223 - third outer electrode, 23 - dielectric layer, 24 - first inner electrode layer, 241 - first long inner electrode, 242 - first short inner electrode, 25 - second inner electrode layer, 251 - second short inner electrode, 252 - second long inner electrode. DETAILED DESCRIPTION

[0023] The utility model will be further described below through the specific implementation.

[0024] Referring to Figures 1 to 4 As shown in the figure, an anti-creep tin capacitor includes two supports 1 arranged oppositely, a plurality of capacitor chips 2 stacked up and down between the two supports 1, two first anti-creep tin coatings 3 arranged respectively on the inner sides of the two supports 1, two second anti-creep tin coatings 4 arranged vertically on the top of the two first anti-creep tin coatings 3 respectively, and a plurality of adhesive layers 5 arranged between adjacent two capacitor chips 2, wherein the two second anti-creep tin coatings 4 are respectively coated on the bottom surface of the capacitor chip at the lower end of the stack and the opposite first anti-creep tin coating 3.

[0025] The support 1 includes a welding section 11 and a pin section 12 arranged at the lower end of the welding section 11. Specifically, the welding section 11 is formed with an exhaust groove 13 extending downward from the top surface thereof. Further, the exhaust groove 13 is arranged in a U shape, and the pin section 12 is arranged in an L shape. The support 1 is made of 4J42 Kovar alloy material, which is a series of fixed expansion alloys obtained by adjusting the nickel content to match the soft glass and ceramic with different expansion coefficients within a given temperature range. The expansion coefficient and Curie point of the support 1 increase with the increase of the nickel content.

[0026] The capacitor chip 2 is stacked between the two opposite welding sections 11 and includes a chip body 21 and two end electrodes 22 arranged oppositely at both ends of the chip body 21. Specifically, the chip body 21 is obtained by stacking and firing a plurality of dielectric layers. The dielectric layers include a dielectric layer 23 and an inner electrode group printed on the dielectric layer 23. Further, the inner electrode group includes a plurality of first inner electrode layers 24 and second inner electrode layers 25 arranged alternately in an up-down interval. The first inner electrode layer 24 includes a first long inner electrode 241 and a first short inner electrode 242 arranged in a left-right interval. The second inner electrode layer 25 includes a second short inner electrode 251 and a second long inner electrode 252 arranged in a left-right interval. The first long inner electrode 241 and the second long inner electrode 252 are arranged in an up-down staggered manner. Further, the dielectric layer 23 is barium titanate ceramic, and the first inner electrode layer 24 and the second inner electrode layer 25 are arranged on the dielectric layer 23 by coating process.

[0027] The end electrode 22 comprises a first outer electrode 221, a second outer electrode 222 and a third outer electrode 223 arranged in sequence from inside to outside, wherein the first outer electrode on the left side is connected with the second short inner electrode 251, and the first outer electrode on the right side is connected with the first short inner electrode 242; specifically, the welding section 11 of the support 1 is welded with the end electrode 22 through high-temperature solder 6, and the high-temperature solder 6 is composed of Sn10Pb90, the melting point of the solder after welding is 280℃, which can prevent the risk of the support 1 and the capacitor chip 2 from being scattered during use, and the U-shaped exhaust groove 13 plays a role in exhaust, in the process of reflow soldering of the support 1 and the capacitor chip 2, the high-temperature solder 6 will produce waste gas and resist, which can be discharged through the exhaust groove 13, so that the solder between the end electrode 22 and the support 1 is more dense.

[0028] The coating thickness of the first anti-creeping tin coating layer 3 and the second anti-creeping tin coating layer 4 is 5um, wherein the second anti-creeping tin coating layer 4 is arranged at the bottom of the end electrode and is connected with the first anti-creeping tin coating layer 3; specifically, the first anti-creeping tin coating layer 3 and the second anti-creeping tin coating layer 4 are phenolic epoxy acrylic resins, which can insulate and resist soldering for electronic components, so that the wettability of the outer surface of the support 1 is better than that of the inner surface, and in the process of product welding, the high-temperature solder 6 after melting will creep to the side with good wettability, that is, to the outer surface of the support, and the inner surface will not appear tin stacking phenomenon; and it is cured by ultraviolet irradiation to form on the inside of the pin section, in order to prevent tin stacking on the inside of the support 1, which causes tin stacking on the inside of the support 1, the overhanging height of the pin section 12 is designed to be more than 1.5mm; however, with the demand for miniaturization of products, it is required to reduce the height of the product, therefore, the anti-creeping tin coating layer is arranged on the inside of the pin section 12, so that the overhanging height of the pin section 12 can be reduced to below 0.7mm, and tin stacking phenomenon will not occur; in addition, the arrangement of the second anti-creeping tin coating layer 4 can effectively prevent solder overflow to the bottom of the capacitor chip at the lower end.

[0029] The adhesive layer 5 comprises two adhesive pieces arranged oppositely, wherein one end of the adhesive piece is connected with the end electrode 22 and the other end is connected with the chip body 21; specifically, the adhesive layer 5 uses red glue to stack multiple capacitor chips 21 into a whole, and the number of stacked capacitor chips can be selected according to actual use requirements.

[0030] The assembly process is as follows:

[0031] Step one, use the adhesive layer 5 to stack multiple capacitor chips 2 into a whole, and coat the resin on the bottom surface of the end electrode of the capacitor chip at the bottom to form the second anti-creeping tin coating layer 4;

[0032] Step two, shape the support 1, and coat the resin on the inside of the pin section 12 of the support 1 to form the first anti-creeping tin coating layer 3;

[0033] Step three, the stacked plurality of capacitor chips 2 and the bracket 1 are placed in a soldering fixture by high-temperature solder 6, and are welded into the anti-creeping tin capacitor by reflow soldering.

[0034] The application limits the structure of the anti-creeping tin capacitor, sets the first anti-creeping tin coating 3 on the inside of the pin section 12 of the bracket 1, so that the wettability of the outer surface of the bracket 1 is better than that of the inner surface, in the product use soldering process, the high-temperature solder after melting will creep to the side with good wettability, that is, to the outer surface of the bracket 1, and the inner surface will not appear tin stacking phenomenon; the anti-creeping tin capacitor limited by the application can inhibit the tin stacking effect on the inside of the bracket 1, in the case of reducing the product height, the solder tin is not easy to accumulate on the inside of the pin section 12, so that the product height is lower under the same voltage and capacity, the size is smaller, meets the miniaturization demand, and improves the reliability of the product.

[0035] The above is only a preferred embodiment of the application, and therefore cannot limit the range of the application, that is, equivalent changes and modifications made according to the application range and content of the specification should still be within the scope of the application.

Claims

1. A creepage-preventing tin capacitor, characterized by: The capacitor chip includes a chip body and two end electrodes oppositely arranged at two ends of the chip body, the second anti-creepage tin coating is coated on the bottom surface of the end electrode at the lower end and is in contact with the first anti-creepage tin coating.

2. A non-creeping tinned capacitor as defined in claim 1, wherein: The chip body is formed by stacking and firing a plurality of dielectric layers, the dielectric layer includes a dielectric layer and an inner electrode group printed on the dielectric layer, the inner electrode group includes a plurality of first inner electrode layers and second inner electrode layers alternately arranged at intervals.

3. A non-creeptin capacitor according to claim 2, wherein: The first inner electrode layer includes a first long inner electrode and a first short inner electrode arranged at intervals, the second inner electrode layer includes a second short inner electrode and a second long inner electrode arranged at intervals, and the first long inner electrode and the second long inner electrode are arranged alternately.

4. A non-creeping tinned capacitor as defined in claim 2, wherein: The end electrode includes a first outer electrode, a second outer electrode and a third outer electrode arranged in sequence from inside to outside, the first outer electrode on the left is connected with the second short inner electrode, and the first outer electrode on the right is connected with the first short inner electrode.

5. A non-creeping tin capacitor as defined in claim 4, wherein: The coating thickness of the first anti-creepage tin coating and the second anti-creepage tin coating is 5um.

6. A non-creeping tin capacitor as defined in claim 5, wherein: The welding section is formed with an exhaust groove extending downward from the top surface thereof.

7. A non-creeping tin capacitor as defined in claim 2, wherein: The exhaust groove is arranged in a U shape.

8. A non-creeping tin capacitor as defined in claim 1, wherein: The pin section is arranged in an L shape.

9. A non-creeping tinned capacitor as defined in claim 8, wherein: ​ 10. The creep resistant tin capacitor of claim 1, wherein: ​

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