Ceramic capacitor with double L-shaped pins

Abstract

A ceramic capacitor with double L-shaped pins comprises two supports arranged oppositely, one or more ceramic chips arranged between the two supports and two first solder layers respectively arranged between the end portions of the one or more ceramic chips and the opposite supports, and each support comprises two frames arranged symmetrically and a second solder layer arranged between the two frames. According to the invention, the structure of the ceramic capacitor is limited, and the two symmetrically arranged frames are mutually welded through the welding flux to serve as the support, so that the welding area of the prepared support and the PCB is doubled, the welding strength of the prepared ceramic capacitor is improved, the bonding strength of the ceramic capacitor and the PCB is better, and the service life of the ceramic capacitor is prolonged. Compared with a single-frame ceramic capacitor, the ceramic capacitor can resist higher-strength vibration, improves the reliability of a product, and can be applied to high-reliability occasions such as space flight and aviation.

Description

Technical Field

[0001] The utility model belongs to the field of ceramic capacitor preparation, and in particular relates to a double L-shaped pin ceramic capacitor. Background Art

[0002] With the rapid and continuous development of science and technology, the demand for small-size, large-capacity, and high-power capacitors in fields such as power supply, industry, automobile, military industry, and aerospace is increasing. Traditional chip ceramic capacitors are difficult to meet the demand for large capacity. Therefore, multiple ceramic capacitors are assembled in parallel to meet the demand for large capacity capacitors.

[0003] In harsh environments such as aerospace, more reliable components are needed. The characteristic of ceramic chips is that they are resistant to compression but not tension. Single chips are directly welded on PCB boards and are easily affected by board bending stress. Therefore, by welding the chip together through leads, the board bending stress will act on the leads without affecting the ceramic chip, thus solving the board bending stress problem; however, the existing L-shaped pin structure is not strong enough, the contact area with the PCB board is small, and it cannot adapt to higher-intensity vibration tests, which greatly limits its application occasions and needs further improvement. Utility Model Content

[0004] The utility model aims to overcome the shortcomings of the prior art and provide a double L-shaped pin ceramic capacitor.

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

[0006] A double L-shaped pin ceramic capacitor comprises two brackets arranged opposite to each other, one or more ceramic chips arranged between the two brackets, and two first solder layers respectively arranged between the ends of the one or more ceramic chips and the opposite brackets. The bracket comprises two symmetrically arranged frames and a second solder layer arranged between the two frames.

[0007] Furthermore, the frame includes a frame body and a plurality of L-shaped pins spaced apart at the bottom of the frame body, and the plurality of L-shaped pins of the two frames are symmetrically arranged at the lower end of the bracket.

[0008] Furthermore, a plurality of evenly arranged exhaust holes are formed on the frame body.

[0009] Furthermore, the frame also includes a plurality of support plates arranged between two adjacent L-shaped pins.

[0010] Furthermore, the ceramic chip includes a capacitor chip body and two outer electrode layers relatively arranged at two ends of the capacitor chip body. The capacitor chip body is formed by stacking and firing multiple dielectric layers. The dielectric layer includes a dielectric layer and an inner electrode group printed on the dielectric layer.

[0011] Further, the inner electrode group includes a plurality of first inner electrode layers and second inner electrode layers which are alternately arranged at intervals up and down.

[0012] Further, the first inner electrode layer includes a first long inner electrode and a first short inner electrode which are arranged at intervals left and right, the second inner electrode layer includes a second short inner electrode and a second long inner electrode which are arranged at intervals left and right, and the first long inner electrode and the second long inner electrode are arranged up and down in a staggered manner.

[0013] Further, the outer electrode layer includes a first outer electrode, a second outer electrode and a third outer electrode which are arranged in sequence from inside to outside. The first outer electrode on the left is connected to the second short inner electrode, and the first outer electrode on the right is connected to the first short inner electrode.

[0014] Further, the first solder layer is a tin-antimony alloy solder layer.

[0015] Further, the second solder layer is a tin-lead alloy solder layer.

[0016] As can be seen from the above description of the present invention, compared with the prior art, the beneficial effects of the present invention are as follows: By defining the structure of the ceramic capacitor, two symmetrically arranged frames are welded to each other with solder as the bracket, so that the welding area between the prepared bracket and the PCB board is doubled, the welding strength of the prepared ceramic capacitor is improved, the bonding strength between the ceramic capacitor and the PCB board is better, the ceramic capacitor with a single frame can withstand higher-intensity vibration, the reliability of the product is improved, and it can be applied to high-reliability occasions such as aerospace. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of a ceramic capacitor Figure 1 ;

[0018] Figure 2 is a schematic structural diagram of a ceramic capacitor Figure 2 ;

[0019] Figure 3 is a schematic structural diagram of a bracket Figure 1 ;

[0020] Figure 4 is a schematic structural diagram of a bracket Figure 2 ;

[0021] Figure 5 is a schematic structural diagram of a frame welding jig Figure 1 ;

[0022] Figure 6 is a schematic structural diagram of a frame welding jig Figure 2 ;

[0023] Figure 7Structural schematic of the frame welding fixture Figure 3 ;

[0024] Figure 8 Structural schematic of the finished product welding fixture Figure 1 ;

[0025] Figure 9 Structural schematic of the finished product welding fixture Figure 2 ;

[0026] Figure 10 Structural schematic of the finished product welding fixture Figure 3 ;

[0027] Figure 11 Structural schematic of the finished product welding fixture Figure 4 ;

[0028] Figure 12 Structural schematic of the finished product welding fixture Figure 5 ;

[0029] Figure 13 Internal structure cross-sectional view of the ceramic chip;

[0030] In the figure, 1 - bracket, 2 - ceramic chip, 3 - first solder layer, 4 - frame, 5 - second solder layer, 6 - frame welding fixture, 7 - finished product welding fixture, 21 - capacitor chip body, 22 - outer electrode layer, 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, 41 - frame body, 42 - L-shaped pin, 421 - vertical section, 422 - horizontal section, 43 - support plate, 44 - exhaust hole, 45 - relief area, 61 - base, 611 - welding groove, 62 - pressing block, 621 - positioning part, 622 - heat dissipation hole, 63 - positioning mechanism, 631 - positioning column, 632 - positioning hole, 71 - upper die base, 711 - upper mounting groove, 712 - first upper mounting groove ', 713 - second upper mounting groove, '72 - lower die base, 721 - lower mounting groove, 722 - first lower mounting groove, 723 - second lower mounting groove, 73 - limiting mechanism, 731 - limiting column, 732 - limiting hole. Specific embodiments

[0031] The following further describes the present utility model through specific embodiments.

[0032] Refer to Figures 1 to 13As shown, a double L-shaped pin ceramic capacitor includes two brackets 1 arranged opposite to each other, one or more ceramic chips 2 arranged between the two brackets 1, and a first solder layer 3 respectively arranged at the end of one or more ceramic chips 2 and the brackets 1 opposite to each other.

[0033] The bracket 1 includes two symmetrically arranged frames 4 and a second solder layer 5 arranged between the two frames 4, wherein the melting point of the second solder layer 5 is higher than the melting point of the first solder layer 3, so that during the secondary reflow soldering, the second solder layer 5 will not melt and cause the risk of the bracket 1 falling apart; specifically, the second solder layer 5 uses tin-lead alloy solder, whose composition is Sn10Pb90, and the melting point of the solder after welding is 287°C; the first solder layer 3 uses tin-antimony alloy solder, whose composition is Sn90Sb10, and the melting point of the solder after welding is 240°C.

[0034] The frame 4 includes a frame body 41, a plurality of L-shaped pins 42 spaced apart at the bottom of the frame body 41, a plurality of support plates 43 disposed between two adjacent L-shaped pins 42, and a plurality of exhaust holes 44 evenly arranged on the frame body 41. The plurality of L-shaped pins 42 of the two frames 4 are symmetrically disposed at the lower end of the bracket 1. By arranging a plurality of exhaust holes 44 on the frame body 41, during the welding process of the bracket 1, not only heat can be dissipated, but also the evaporated flux in the solder can be discharged through the exhaust holes 44, so that the second solder layer 5 is more compact; specifically, a clearance area 45 is formed between the two L-shaped pins 42, and the support plate 43 is disposed in the clearance area 45; further, the double L-shaped pins 42 include a vertical section 421 connected to the frame body 41 and a horizontal section 422 disposed perpendicular to the vertical section 421, and the support plate 43 is disposed in the same direction as the horizontal section 422 and is disposed higher than the horizontal section 422.

[0035] The ceramic chip 2 includes a capacitor chip body 21 and two outer electrode layers 22 arranged at both ends of the capacitor chip body 21, wherein the capacitor chip body 21 is formed by stacking and firing a plurality of dielectric layers, the dielectric layer includes a dielectric layer 23 and an inner electrode group printed on the dielectric layer 23, the inner electrode group includes a plurality of first inner electrode layers 24 and a second inner electrode layer 25 alternately arranged at intervals in the upper and lower parts, specifically, the first inner electrode layer 24 includes a first long inner electrode 241 and a first short inner electrode 242 arranged at intervals in the left and right parts, the second inner electrode layer 25 includes a second short inner electrode 251 and a second long inner electrode 252 arranged at intervals in the left and right parts, and the first long inner electrode 241 and the second long inner electrode 252 are alternately arranged in the upper and lower parts; further, the dielectric layer 23 is made of barium titanate ceramic, and the inner electrode group is made of palladium silver metal.

[0036] The outer electrode layer 22 includes a first outer electrode 221, a second outer electrode 222, and a third outer electrode 223 arranged in sequence from the inside to the outside. The first outer electrode on the left is connected to the second short inner electrode 251, and the first outer electrode on the right is connected to the first short inner electrode 242.

[0037] A method for preparing a double L-shaped pin ceramic capacitor includes the following steps:

[0038] Step 1: First, place a frame 4 in a frame welding jig 6 with the L-shaped pins 42 facing downwards. Then, apply a second solder on the opposite surface thereof to another frame, and then place another frame to fit with the second solder and make its L-shaped pins face upwards. Then, assemble the frame welding jig 5 and send it into a reflow soldering furnace for soldering at 290 - 310 °C to obtain the bracket 1.

[0039] Step 2: Place the welded bracket 1 in a finished product welding jig 7, and apply a first solder on the opposite surface of the bracket 1 to another bracket. Then, stack one or more ceramic chips 2 according to requirements. Next, apply the first solder at the ends of the stacked one or more ceramic chips 2 and place another bracket. Then, assemble the finished product welding jig 7, and at the same time, place the multiple L-shaped pins 42 of the bracket upwards, and send it into a reflow soldering furnace for soldering at 250 - 270 °C to obtain the double L-shaped pin ceramic capacitor.

[0040] Among them, the frame welding jig 6 includes a base 61, a pressing block 62 arranged on the base 61, and a positioning mechanism 63 arranged between the base 61 and the pressing block 62. Specifically, a welding groove 611 for installing the frame 4 is arranged on the base 61; a positioning portion 621 that can be embedded in the welding groove 611 and abuts against the frame 4 is formed on the opposite surface of the pressing block 62 and the base 61; the positioning mechanism 63 includes two positioning columns 631 arranged oppositely on the base 61 and extending upwards, and two positioning holes 632 arranged on the pressing block 62 for the two positioning columns 631 to be respectively embedded. Further, heat dissipation holes 622 extending inwards from the top surface of the pressing block 62 and opposite to the welding groove 611 are arranged on the pressing block 62. The heat dissipation holes 622 can not only dissipate heat but also allow the flux evaporated from the solder to be discharged through the heat dissipation holes 622. When welding the frame 4, first place a frame 4 in the welding groove 611, then apply the second solder and stack another frame to make it fit with the second solder. Then, through the cooperation of the positioning column 631 and the positioning hole 632, the positioning portion 621 on the pressing block 62 is embedded in the welding groove 611 to abut against the frame located above, so as to press the two frames 4 tightly. Ensure that after reflow soldering, a stable connection can be formed between the two frames 4.

[0041] The finished product welding jig 7 includes an upper die base 71 and a lower die base 72 which are oppositely arranged, and a limiting mechanism 73 arranged between the upper die base 71 and the lower die base 72. Among them, upwardly extending upper mounting grooves 711 for mounting opposite brackets and the ends of multiple ceramic chips are formed on the opposite surfaces of the upper die base 71 and the lower die base 72; downwardly extending lower mounting grooves 721 for mounting opposite brackets and the ends of ceramic chips are formed on the opposite surfaces of the lower die base 72 and the upper die base 71; the limiting mechanism 73 includes two limiting posts 731 oppositely arranged on the upper die base 71 and two limiting holes 732 arranged on the upper die base 71 for the opposite limiting posts 731 to be inserted into; specifically, the upper mounting groove 711 includes a first upper mounting groove 712 and a second upper mounting groove 713 which are arranged in sequence from top to bottom, and the length of the second upper mounting groove 713 is longer than that of the first upper mounting groove 712. The bracket opposite to the upper die base 71 is arranged in the first upper mounting groove 712, and the ends of the ceramic chips opposite to the upper die base 71 are arranged in the second upper mounting groove 713; the lower mounting groove 721 includes a first lower mounting groove 722 and a second lower mounting groove 723 which are arranged in sequence from top to bottom, and the length of the first lower mounting groove 722 is longer than that of the second lower mounting groove 723. The bracket opposite to the lower die base 72 is arranged in the second lower mounting groove 723, and the ends of the ceramic chips opposite to the lower die base are arranged in the first lower mounting groove 722; when welding the finished product, first place a bracket 1 in the second lower mounting groove 721, after applying the first solder, stack one or more ceramic chips 2 on the first solder according to requirements; then apply the first solder to the ends of the one or more ceramic chips 2, and attach the other bracket to the applied first solder; then press the upper die base 71 and the lower die base 72 tightly through the cooperation of the limiting posts 731 and the limiting holes 732, and at the same time place the multiple L-shaped pins 42 of the bracket 1 upward, send them into a reflow soldering furnace, and perform soldering at 250 - 270 °C to obtain a double L-shaped pin ceramic capacitor; during reflow soldering, the multiple L-shaped pins 42 are placed upward to avoid the phenomenon of solder climbing during the soldering process, prevent the first solder from melting and accumulating at the bottom of the bracket pins, on the one hand, affecting the appearance of the product, and on the other hand, also reducing the anti-bending performance of the product.

[0042] Using a single frame as the bracket, preparing a ceramic capacitor according to the method defined in this application, as a comparative example, and then conducting a vibration finite element simulation test on the double L-shaped pin ceramic capacitor prepared in this application and the comparative example. Among them, the experimental conditions and steps are as follows:

[0043] (a) Set the test parameters before the test (as shown in Table 1). Under the standard atmospheric conditions of the test, conduct an appearance inspection and function and performance detection on the test product before the test, and conduct an appearance inspection and record the results.

[0044] (b) Conduct a 36-hour vibration test on the test product under the specified test conditions. After the vibration function test, conduct function and performance detection, and detect and record the function and performance of the test product after the vibration test.

[0045] (c) After the test, the appearance inspection and function and performance detection of the test item are carried out under the standard atmospheric conditions of the test, and the appearance inspection results are recorded.

[0046] For the specific results, see Table 1 and Table 2.

[0047] Table 1 Vibration Experiment Spectrum Value Conditions

[0048]

[0049]

[0050] Table 2 Simulation Results Table

[0051]

[0052] It can be seen from the data in Table 2 that after 36 hours of vibration, the root mean square stresses at the bracket and solder joint positions of the double-L frame structure are 98.25 MPa and 10.14 MPa respectively, and the root mean square stresses at the bracket and solder joint positions of the single-L frame structure are 315.2 MPa and 56.71 MPa respectively. The double-L structure is much smaller in data than the single-L structure, so the double-L structure has stronger anti-vibration ability than the single-L structure.

[0053] In this application, by defining the structure of the ceramic capacitor, two symmetrically arranged frames 4 are welded to each other by solder as the bracket 1, so that the welding area between the prepared bracket 1 and the PCB board is doubled, the welding strength of the prepared ceramic capacitor is improved, the bonding strength between the ceramic capacitor and the PCB board is better, and compared with the ceramic capacitor with a single frame, it can withstand higher-intensity vibration, improving the reliability of the product, and can be applied to high-reliability occasions such as aerospace.

[0054] The above is only the preferred embodiment of the present utility model, so the scope of implementation of the present utility model cannot be limited thereby. That is, equivalent changes and modifications made according to the scope of the present utility model application and the content of the specification should still fall within the scope covered by the present utility model application.

Claims

1. A double L-shaped lead ceramic capacitor, characterized in that: It includes two brackets arranged opposite to each other, one or more ceramic chips arranged between the two brackets, and two first solder layers respectively arranged between the ends of one or more ceramic chips and the opposite brackets. The bracket includes two symmetrically arranged frames and a second solder layer arranged between the two frames.

2. A double L-shaped lead ceramic capacitor according to claim 1, characterized in that: The frame comprises a frame body and a plurality of L-shaped pins arranged at intervals at the bottom of the frame body, and the plurality of L-shaped pins of the two frames are symmetrically arranged at the lower end of the bracket.

3. A double L-shaped lead ceramic capacitor according to claim 2, characterized in that: The frame body is formed with a plurality of evenly arranged exhaust holes.

4. The double L-shaped lead ceramic capacitor according to claim 2, characterized in that: The frame also includes a plurality of support plates arranged between two adjacent L-shaped pins.

5. The double L-shaped lead ceramic capacitor according to claim 1, characterized in that: The ceramic chip comprises a capacitor chip body and two outer electrode layers arranged oppositely at two ends of the capacitor chip body. The capacitor chip body is formed by stacking and firing a plurality of dielectric layers. The dielectric layer comprises a dielectric layer and an inner electrode group printed on the dielectric layer.

6. A double L-shaped lead ceramic capacitor according to claim 5, characterized in that: The internal electrode group includes a plurality of first internal electrode layers and second internal electrode layers which are alternately arranged in an upper and lower manner.

7. The double L-shaped lead ceramic capacitor according to claim 6, characterized in that: The first inner electrode layer includes a first long inner electrode and a first short inner electrode spaced apart from each other, the second inner electrode layer includes a second short inner electrode and a second long inner electrode spaced apart from each other, and the first long inner electrode and the second long inner electrode are staggered up and down.

8. The double L-shaped lead ceramic capacitor according to claim 5, characterized in that: The outer electrode layer includes a first outer electrode, a second outer electrode and a third outer electrode arranged in sequence from the inside to the outside, the first outer electrode on the left is connected to the second short inner electrode, and the first outer electrode on the right is connected to the first short inner electrode.

9. The double L-shaped lead ceramic capacitor according to claim 1, characterized in that: The first solder layer is a tin-antimony alloy solder layer.

10. The double L-shaped lead ceramic capacitor according to claim 1, characterized in that: The second solder layer is a tin-lead alloy solder layer.

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