Multi-core group pulse capacitor and preparation method thereof

Abstract

A multi-core pulse capacitor and its manufacturing method are disclosed. The multi-core pulse capacitor includes a frame, multiple capacitor bodies, and a protective shell. The frame includes a first frame, a second frame, and multiple pad assemblies. The first frame includes a first lead and multiple first phase connection rods spaced apart on the first lead. The second frame includes a second lead opposite to the first lead and multiple second phase connection rods spaced apart on the second lead. The multiple first phase connection rods and multiple second phase connection rods are alternately arranged. Multiple pad assemblies are disposed between adjacent first and second phase connection rods. This application, by defining the structure of the multi-core pulse capacitor, uses several large-size capacitor chips and a frame to assemble and weld the product before molding. After molding, a protective shell is added as a structural reinforcement, effectively improving the mechanical properties of the product and giving it strong shock resistance and environmental adaptability.

Description

Technical Field

[0001] This invention belongs to the field of pulse capacitor manufacturing, specifically relating to a multi-core pulse capacitor and its manufacturing method. Background Technology

[0002] Currently, existing pulse power capacitors typically use multiple capacitors connected in parallel as energy storage units to increase capacitance and energy storage capacity. During fabrication, multiple capacitors are stacked between two opposing frames, with leads on the frames. However, existing large-size chip-molded pulse capacitors are limited by the properties of the molding material. When the size and chip size reach a certain level, cracking and delamination are prone to occur, requiring further improvement. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a multi-core pulse capacitor and its preparation method.

[0004] The present invention adopts the following technical solution:

[0005] A multi-core pulse capacitor includes a frame, multiple capacitor bodies, and a protective housing. The frame includes a first frame, a second frame, and multiple pad assemblies.

[0006] The first frame includes a first lead-out end and a plurality of first connecting rods spaced apart on the first lead-out end;

[0007] The second frame includes a second lead-out end opposite to the first lead-out end and a plurality of second connecting rods spaced apart on the second lead-out end, wherein the plurality of first connecting rods and the plurality of second connecting rods are spaced apart and alternately arranged;

[0008] Multiple welding pad assemblies are disposed between adjacent first phase connecting rods and second phase connecting rods. The welding pad assembly includes multiple first welding pads spaced apart on the first phase connecting rods and multiple second welding pads disposed on adjacent second phase connecting rods opposite to the multiple first welding pads, or multiple first welding pads spaced apart on the second phase connecting rods and multiple second welding pads disposed on adjacent first phase connecting rods opposite to the multiple first welding pads.

[0009] Multiple capacitor bodies are respectively disposed between opposite first and second welding pads. Each capacitor body includes two capacitor chips stacked on the top and bottom surfaces of the first and second welding pads, and a molded shell covering the outer periphery of the two capacitor chips.

[0010] A protective casing is provided around the periphery of multiple capacitor bodies.

[0011] Furthermore, the protective housing includes a first housing and a second housing arranged vertically opposite each other, a positioning mechanism disposed between the first housing and the second housing, and a plurality of mounting grooves for mounting a plurality of capacitor bodies are formed on the top surface of the second housing.

[0012] Furthermore, the positioning mechanism includes two elastic protective strips disposed opposite to each other between the first housing and the second housing, and two positioning components disposed between the two elastic protective strips and the first housing and the second housing, respectively. The positioning components include a plurality of first positioning holes disposed on the first housing, a plurality of second positioning holes disposed on the second housing opposite to the plurality of first positioning holes, a plurality of third positioning holes disposed on the elastic protective strips opposite to the first positioning holes, and a plurality of positioning bolts passing through the plurality of first positioning holes and third positioning holes and engaging with the opposite second positioning holes.

[0013] Furthermore, the two elastic protective strips are respectively formed with pin holes for the first lead-out end and the second lead-out end to extend out.

[0014] Furthermore, the first housing is provided with a plurality of first exhaust holes, and the second housing is provided with second exhaust holes opposite to the plurality of first exhaust holes, and the plurality of exhaust holes are respectively opposite to the plurality of mounting slots.

[0015] Furthermore, the first solder pad includes a first contact segment connected to the first contact rod or the second contact rod and a first solder pad disposed on one side of the first contact segment extending in a direction close to the adjacent second contact rod or the first contact rod. The second solder pad includes a second contact segment connected to the first contact rod or the second contact rod and a second solder pad disposed on one side of the second contact segment extending in a direction close to the adjacent second contact rod or the first contact rod. The second solder pad is disposed opposite to the first solder pad between the first contact rod and the second contact rod. The capacitor chip is disposed between the first solder pad and the second solder pad.

[0016] Furthermore, the first connecting segment has a first connecting groove extending downward from its top surface for embedding the first connecting rod or the second connecting rod, and the second connecting segment has a second connecting groove extending upward from its bottom surface for embedding the first connecting rod or the second connecting rod. A gap is formed between the side of the first connecting groove and the first connecting rod or the second connecting rod, and a gap is formed between the side of the second connecting groove and the first connecting rod or the second connecting rod.

[0017] Furthermore, the second connecting segment is engaged with the first connecting segment located on the same first connecting rod or second connecting rod, and is located on both sides of the first connecting rod or second connecting rod respectively.

[0018] A method for fabricating a multi-core pulse capacitor includes the following steps:

[0019] Step 1: Place multiple capacitor chips one by one on the soldering base and apply solder paste to the ends of the capacitor chips.

[0020] Step 2: Place the frame on multiple capacitor chips, so that the first and second solder pads are in contact with the two ends of the capacitor chips respectively. Then, stack multiple capacitor chips on the multiple capacitor chips respectively, so that the top and bottom surfaces of the first and second solder pads are respectively equipped with capacitor chips.

[0021] Step 3: On the welding base, the mold welding pressure block is closed to limit and fix multiple capacitor chips and the frame, and then sent into the reflow soldering for welding.

[0022] Step 4: After welding is completed, the welding pressure block and welding base are removed to obtain the capacitor group. Then, the capacitor group is sent into the molding equipment to form a molded shell of the two stacked capacitor chips. Then, a protective shell is put on the outer periphery of the multiple capacitor bodies to obtain the multi-core pulse capacitor.

[0023] Furthermore, the welding base includes multiple product slots for placing capacitor chips and multiple first horizontal venting slots and first vertical venting slots spaced apart. The welding block includes multiple limiting slots opposite to the multiple product slots and multiple second horizontal venting slots and second vertical venting slots spaced apart. The multiple first horizontal venting slots are opposite to the multiple second horizontal venting slots, and the multiple first vertical venting slots are opposite to the second vertical venting slots. The multiple capacitor chips located on the upper layer are limited in the multiple limiting slots.

[0024] 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 multi-core pulse capacitor, the present application uses several large-size capacitor chips and frames to assemble and weld the product before molding, and then adds a protective shell after molding as a structural reinforcement, which effectively improves the mechanical properties of the product and has extremely strong shock resistance and environmental adaptability. Specifically, the structure of the frame is defined, and the structure of the welding pad assembly is further defined, so that after the frame is assembled with several large-size capacitor chips, it can be molded to form a capacitor group, ensuring that the prepared multi-core pulse capacitor is not prone to cracking and delamination during subsequent use, and has high reliability. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a multi-core pulse capacitor;

[0026] Figure 2 This is an exploded view of a multi-core pulse capacitor.

[0027] Figure 3 This is a schematic diagram of the first shell structure;

[0028] Figure 4 A partial structural diagram of a multi-core pulse capacitor. Figure 1 ;

[0029] Figure 5 A partial structural diagram of a multi-core pulse capacitor. Figure 2 ;

[0030] Figure 6 This is a schematic diagram of the framework structure;

[0031] Figure 7 for Figure 6 Enlarged view of some of the structures in the image;

[0032] Figure 8 This is a schematic diagram showing the mating state of the welding base and the welding pressure block.

[0033] Figure 9 Schematic diagram of the welding base and welding pressure block Figure 1 ;

[0034] Figure 10 Schematic diagram of the welding base and welding pressure block Figure 2 ;

[0035] In the diagram, 1-frame, 2-capacitor body, 3-protective shell, 4-first frame, 5-second frame, 6-pad assembly, 7-welding base, 8-welding block, 21-capacitor chip, 22-molded shell, 31-first housing, 311-positioning groove, 312-first vent, 32-second housing, 321-mounting groove, 322-second vent, 33-positioning mechanism, 331-elastic protective strip, 332-positioning assembly, 333-first positioning hole, 334-second positioning hole, 335-third positioning hole, 336-positioning bolt, 337-pin hole, 41-first lead-out end, 42-first connecting rod, 43-first pin, 44-first connector Connecting rod, 441-First connecting part, 442-Connecting groove, 51-Second lead-out end, 52-Second connecting rod, 53-Second pin, 54-Second connecting rod, 61-First welding pad, 611-First connecting segment, 612-First welding pad, 613-First connecting groove, 614-First vertical segment, 615-Second vertical segment, 616-Horizontal segment, 62-Second welding pad, 621-Second connecting segment, 622-Second welding pad, 623-Second connecting groove, 71-Product groove, 72-First horizontal vent groove, 73-First vertical vent groove, 74-Guide hole, 81-Second horizontal vent groove, 82-Second vertical vent groove, 83-Guide post, 84-Limiting groove. Detailed Implementation

[0036] The present invention will be further described below through specific embodiments.

[0037] Reference Figures 1 to 10 As shown, a multi-core pulse capacitor includes a frame 1, multiple capacitor bodies 2, and a protective shell 3.

[0038] Frame 1 includes a first frame 4, a second frame 5, and multiple pad assemblies 6.

[0039] The first frame 4 includes a first lead-out end 41 and a plurality of first connecting rods 42 spaced apart on the first lead-out end 41. The first lead-out end 41 includes a first pin 43 and a first connecting rod 44 connected to the first pin 43. The plurality of first connecting rods 42 are connected to the first connecting rod 44. Specifically, the first connecting rod 44 forms a plurality of first connecting portions 441 connected to the plurality of first connecting rods 42. The first connecting portion 441 includes a connecting groove 442 extending upward from its bottom surface for insertion into the relative first connecting rod 42. Further, the first connecting rod 42 is a copper rod.

[0040] The second frame 5 includes a second lead-out end 51 opposite to the first lead-out end 41 and a plurality of second connecting rods 52 spaced apart from the second lead-out end 51, wherein the plurality of first connecting rods 42 and the plurality of second connecting rods 52 are alternately arranged. Specifically, the second lead-out end 51 includes a second pin 53 and a second connecting rod 54 connected to the second pin 53. The plurality of second connecting rods 52 are connected to the second connecting rods 54 in the same way as the connection between the first connecting rod 44 and the first connecting rod 42, which will not be described here. To elaborate further, the first pin 43 and the second pin 53 are staggered; furthermore, the number of first connecting rods 42 is greater than the number of second connecting rods 52, and the number of second connecting rods 52 is odd while the number of first connecting rods 42 is plural, so that the two sides of the frame 1 are exactly the first connecting rods 42, and the multiple second connecting rods 52 and the remaining first connecting rods are alternately arranged between the two first connecting rods 42 located at the ends; furthermore, the second connecting rods 52 are copper rods.

[0041] Multiple pad assemblies 6 are disposed between adjacent first phase connectors 42 and second phase connectors 52. Each pad assembly 6 includes multiple first solder pads 61 spaced apart on the first phase connectors 42 and multiple second solder pads 62 disposed on adjacent second phase connectors 52 opposite to the multiple first solder pads 61, or multiple first solder pads 61 spaced apart on the second phase connectors 52 and multiple second solder pads 62 disposed on adjacent first phase connectors 42 opposite to the multiple first solder pads 61.

[0042] The first welding pad 61 includes a first connection segment 611 that connects to the first connection rod 42 or the second connection rod 52, and a first welding pad 612 extending along a direction close to the adjacent second connection rod 52 or the first connection rod 42 on one side of the first connection segment 611. The first connection segment 611 forms a first connection groove 613 extending downward from its top surface for the first connection rod 42 or the second connection rod 52 to be inserted. Specifically, the first connection segment 611 includes a first vertical segment 614 and a second vertical segment 615 disposed opposite to each other, and a first vertical segment 615 disposed on the first vertical segment 614. A horizontal segment 616 is formed between the straight segment 614 and the second vertical segment 615, wherein the height of the first vertical segment 614 is lower than the height of the second vertical segment 615, a first connection groove 613 is formed between the first vertical segment 614 and the second vertical segment 615, and a first pad 612 is connected to the top of the first vertical segment 614; furthermore, a gap is formed between the side of the first connection groove 613 and the first connection rod 42 or the second connection rod 52, allowing the first pad 61 to deform appropriately, and its connection strength remains unchanged during the deformation process.

[0043] The second solder pad 62 includes a second contact segment 621 that connects to the first contact rod 42 or the second contact rod 52, and a second solder pad 622 extending along a direction close to the adjacent second contact rod 52 or the first contact rod 42, disposed on one side of the second contact segment 621. The second solder pad 622 is disposed opposite to the first solder pad 612 between the first contact rod 42 and the second contact rod 52. Specifically, the second contact segment 621 forms a second contact groove 623 extending upward from its bottom surface for the first contact rod 42 or the second contact rod 52 to be inserted, and a gap is formed between the side of the second contact groove 623 and the first contact rod 42 or the second contact rod 52. Further, the second contact segment 621 and the first contact rod 52 are located on the same side of the first contact rod 42 or the second contact rod 52. The first connecting segment 611 on the first connecting rod 42 or the second connecting rod 52 is engaged vertically and located on both sides of the first connecting rod 42 or the second connecting rod 52, so that the second vertical segment 615 of the first connecting segment 611 can extend into the second connecting groove 623 that is vertically opposite to it, and the end of the second connecting segment 621 can extend into the opposite first connecting groove 613. At this time, a gap is formed between the outer side of the second vertical segment 615 and the side wall of the second connecting groove 623, and a gap is formed between the outer side of the end of the second connecting segment 621 and the side wall of the first connecting groove 613, thereby allowing the first welding plate 61 and the second welding plate 62 located on the same connecting rod to have appropriate deformation, and their connection strength remains unchanged during the deformation process.

[0044] Multiple capacitor bodies 2 are respectively disposed between opposite first pads 612 and second pads 622. Each capacitor body 2 includes two capacitor chips 21 stacked on the top and bottom surfaces of the first pads 612 and the second pads 622, and a molded outer shell 22 covering the outer periphery of the two capacitor chips 21.

[0045] A protective outer shell 3 is disposed around the periphery of multiple capacitor bodies 2, including a first shell 31 and a second shell 32 disposed vertically opposite each other, and a positioning mechanism 33 disposed between the first shell 31 and the second shell 32. The top surface of the second shell 32 has multiple mounting grooves 321 for mounting multiple capacitor bodies 2 and multiple second vent holes 322 respectively disposed in the multiple mounting grooves 321. The bottom surface of the first shell 31 has multiple positioning grooves 311 opposite to the multiple mounting grooves 321 and multiple first vent holes 312 opposite to the multiple second vent holes 322. By defining the structure of the protective outer shell 3, the first shell 31 and the second shell 32 form external protection for the multiple capacitor bodies 2, thereby improving their impact resistance and preventing the frame 1 from deforming and bending, which would affect the use of the pulse capacitor. Furthermore, the first shell 313 and the second shell 2 are respectively provided with first vent holes 312 and second vent holes 322, which can prevent moisture residue in the sealed structure and improve the stability of the pulse capacitor.

[0046] The positioning mechanism 33 includes two elastic protective strips 331 disposed opposite to each other between the first housing 31 and the second housing 32, and two positioning components 332 disposed between the two elastic protective strips 331 and the first housing 31 and the second housing 32, respectively. The positioning components 332 include a plurality of first positioning holes 333 disposed on the first housing 31, a plurality of second positioning holes 334 disposed on the second housing 32 opposite to the plurality of first positioning holes 333, a plurality of third positioning holes 335 disposed on the elastic protective strips 331 opposite to the first positioning holes 333, and a plurality of positioning bolts 336 passing through the plurality of first positioning holes 333, third positioning holes 335 and cooperating with the relative second positioning holes 334. The elastic protective strips 331 disposed between the first housing 31 and the second housing 32 can rebound after the protective housing 3 is squeezed and deformed, thereby improving the mechanical properties and environmental adaptability of the product. Specifically, the two elastic protective strips 331 respectively form pin holes 337 for the first pin 43 and the second pin 53 to extend out.

[0047] Its preparation method specifically includes the following steps:

[0048] Step 1: Place multiple capacitor chips 21 one by one on the soldering base 7, and apply solder paste to the ends of the capacitor chips 21.

[0049] Step 2: Place the frame 1 on multiple capacitor chips 21, so that the opposite first solder pad 61 and second solder pad 62 are in contact with the two ends of the capacitor chip 21 respectively. Then, stack multiple capacitor chips on the multiple capacitor chips 21 respectively, so that the top and bottom surfaces of the opposite first solder pad 61 and second solder pad 62 are respectively equipped with capacitor chips 21.

[0050] Step 3: On the welding base 7, the mold welding block 8 is closed and fixed to limit and fix multiple capacitor chips 21 to the frame 1, and then sent into the reflow soldering for welding.

[0051] Step 4: After welding is completed, remove the welding pressure block 8 and the welding base 7 to obtain the capacitor group. Then, send the capacitor group into the molding equipment to form the two stacked capacitor chips 21 into the molding shell 22.

[0052] Step 5: A protective shell 3 is fitted around the outer periphery of multiple capacitor bodies 2. The capacitor group is placed on the top surface of the second shell 32 so that the lower ends of the multiple capacitor bodies 2 are embedded in the corresponding mounting grooves 321. Then, two elastic protective strips 331 are placed on the top surface of the second shell 32 so that the third positioning hole 335 on the elastic protective strip 331 is aligned with the corresponding first positioning hole 333. Next, the first shell 31 is placed on top of the capacitor group so that the top of the capacitor body 2 is embedded in the corresponding positioning groove 311. Then, the positioning bolts 336 are tightened to fix the capacitor group in the protective shell 3, thus forming a multi-core pulse capacitor.

[0053] The welding base 7 includes multiple product slots 71 for placing capacitor chips 21 and multiple first horizontal venting slots 72 and first vertical venting slots 73 spaced apart. The welding block 8 includes multiple limiting slots 84 opposite to the multiple product slots 71 and multiple second horizontal venting slots 84 and second vertical venting slots 82 spaced apart. The multiple first horizontal venting slots 72 are opposite to the multiple second horizontal venting slots 81, and the multiple first vertical venting slots 73 are opposite to the second vertical venting slots 82. During reflow soldering, the multiple capacitor chips located on the upper layer are respectively limited in the multiple limiting slots 84. Specifically, guide posts 83 are respectively provided at both ends of the bottom surface of the welding block 8, and two guide holes 74 are formed on the top surface of the welding base 7 to cooperate with the two positioning posts 83. Through the cooperation of the guide posts 83 and the guide holes 74, the welding block 8 can be quickly molded with the welding base 7.

[0054] This application defines the structure of a multi-core pulse capacitor by using several large-size capacitor chips and a frame 21 to assemble and weld the product before molding. After molding, a protective shell 3 is added as a structural reinforcement, which effectively improves the mechanical properties of the product and gives it strong shock resistance and environmental adaptability. Specifically, the structure of the frame 1 is defined, and the structure of the welding pad assembly 6 is further defined, so that after the frame is assembled with several large-size capacitor chips, it can be molded to form a capacitor bank. This ensures that the multi-core pulse capacitor prepared is not prone to cracking or delamination during subsequent use, and has high reliability.

[0055] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the present invention and the contents of the specification should still fall within the scope of the present invention.

Claims

1. A multi-core pulse capacitor, characterized in that: It includes a frame, multiple capacitor bodies, and a protective housing, wherein the frame includes a first frame, a second frame, and multiple pad assemblies; The first frame includes a first lead-out end and a plurality of first connecting rods spaced apart on the first lead-out end; The second frame includes a second lead-out end opposite to the first lead-out end and a plurality of second connecting rods spaced apart on the second lead-out end, wherein the plurality of first connecting rods and the plurality of second connecting rods are spaced apart and alternately arranged; Multiple welding pad assemblies are disposed between adjacent first phase connecting rods and second phase connecting rods. The welding pad assembly includes multiple first welding pads spaced apart on the first phase connecting rods and multiple second welding pads disposed on adjacent second phase connecting rods opposite to the multiple first welding pads, or multiple first welding pads spaced apart on the second phase connecting rods and multiple second welding pads disposed on adjacent first phase connecting rods opposite to the multiple first welding pads. Multiple capacitor bodies are respectively disposed between opposite first and second welding pads. Each capacitor body includes two capacitor chips stacked on the top and bottom surfaces of the first and second welding pads, and a molded shell covering the outer periphery of the two capacitor chips. A protective outer casing is disposed around the periphery of multiple capacitor bodies; The protective housing includes a first housing and a second housing arranged vertically opposite each other, and a positioning mechanism disposed between the first housing and the second housing. The top surface of the second housing has multiple mounting slots for mounting multiple capacitor bodies.

2. The multi-core pulse capacitor according to claim 1, characterized in that: The positioning mechanism includes two elastic protective strips disposed opposite to each other between the first housing and the second housing, and two positioning components disposed between the two elastic protective strips and the first housing and the second housing, respectively. The positioning components include a plurality of first positioning holes disposed on the first housing, a plurality of second positioning holes disposed on the second housing opposite to the plurality of first positioning holes, a plurality of third positioning holes disposed on the elastic protective strips opposite to the first positioning holes, and a plurality of positioning bolts passing through the plurality of first positioning holes, the third positioning holes and engaging with the opposite second positioning holes, respectively.

3. A multi-core pulse capacitor according to claim 2, characterized in that: The two elastic protective strips are respectively formed with pin holes for the first lead-out end and the second lead-out end to extend out.

4. A multi-core pulse capacitor according to claim 1, characterized in that: The first housing is provided with a plurality of first vent holes, and the second housing is provided with second vent holes that are opposite to the plurality of first vent holes. The plurality of vent holes are respectively opposite to the plurality of mounting slots.

5. A multi-core pulse capacitor according to claim 1, characterized in that: The first solder pad includes a first contact segment connected to a first contact rod or a second contact rod, and a first solder pad extending along a direction close to the adjacent second contact rod or first contact rod on one side of the first contact segment. The second solder pad includes a second contact segment connected to the first contact rod or second contact rod, and a second solder pad extending along a direction close to the adjacent second contact rod or first contact rod on one side of the second contact segment. The second solder pad is disposed opposite to the first solder pad between the first contact rod and the second contact rod. The capacitor chip is disposed between the first solder pad and the second solder pad.

6. A multi-core pulse capacitor according to claim 5, characterized in that: The first connecting segment has a first connecting groove extending downward from its top surface for embedding a first connecting rod or a second connecting rod. The second connecting segment has a second connecting groove extending upward from its bottom surface for embedding a first connecting rod or a second connecting rod. A gap is formed between the side of the first connecting groove and the first connecting rod or the second connecting rod, and a gap is formed between the side of the second connecting groove and the first connecting rod or the second connecting rod.

7. A multi-core pulse capacitor according to claim 5, characterized in that: The second connecting segment is engaged with the first connecting segment located on the same first connecting rod or second connecting rod, and is located on both sides of the first connecting rod or second connecting rod respectively.

8. The method for preparing a multi-core pulse capacitor according to claim 1, characterized in that: Includes the following steps: Step 1: Place multiple capacitor chips one by one on the soldering base and apply solder paste to the ends of the capacitor chips. Step 2: Place the frame on multiple capacitor chips, so that the first and second solder pads are in contact with the two ends of the capacitor chips respectively. Then, stack multiple capacitor chips on the multiple capacitor chips respectively, so that the top and bottom surfaces of the first and second solder pads are respectively equipped with capacitor chips. Step 3: On the welding base, the mold welding pressure block is closed to limit and fix multiple capacitor chips and the frame, and then sent into the reflow soldering for welding. Step 4: After welding is completed, the welding pressure block and welding base are removed to obtain the capacitor group. Then, the capacitor group is sent into the molding equipment to form a molded shell of the two stacked capacitor chips. Then, a protective shell is put on the outer periphery of the multiple capacitor bodies to obtain the multi-core pulse capacitor.

9. The method for preparing a multi-core pulse capacitor according to claim 8, characterized in that: The welding base includes multiple product slots for placing capacitor chips and multiple first horizontal venting slots and first vertical venting slots spaced apart. The welding block includes multiple limiting slots opposite to the multiple product slots and multiple second horizontal venting slots and second vertical venting slots spaced apart. The multiple first horizontal venting slots are opposite to the multiple second horizontal venting slots, and the multiple first vertical venting slots are opposite to the second vertical venting slots. The multiple capacitor chips located on the upper layer are limited in the multiple limiting slots.

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