A reflow-resistant laminated solid aluminum electrolytic capacitor and a preparation method thereof

Abstract

The present invention discloses a reflow soldering resistant laminated solid aluminum electrolytic capacitor and a preparation method thereof, comprising a resin shell and a ceramic base with a rectangular cross-section, a substrate being arranged on the upper surface of the ceramic base, a plurality of cores being stacked in sequence on the upper surface of the substrate, and a resin shell being fitted on the upper surface of the ceramic base. In the present invention, a plurality of capacitor cores are stacked on the substrate to achieve a first lead-out, and a semi-finished product encapsulated with resin is embedded and bonded to the ceramic base to achieve a second lead-out; the capacitor structure provided by the present invention has a longer and more tortuous water vapor channel than the traditional structure, which ensures the aging effect and can slow down the subsequent moisture absorption of the capacitor during the storage process between leaving the factory and being placed on a reflow soldering board, thereby improving the moisture resistance of the core package and preventing the core package structure after being damp from being damaged due to water vapor expansion during reflow soldering. In addition, the present invention uses a double substrate structure of a ceramic base and a substrate to improve the reflow soldering resistance of the capacitor.

Description

Technical Field

[0001] The present invention relates to the technical field of solid aluminum electrolytic capacitors, in particular to a reflow-resistant laminated solid aluminum electrolytic capacitor and a preparation method thereof. Background Art

[0002] Solid aluminum electrolytic capacitors include wound-type solid aluminum electrolytic capacitors and multilayer solid aluminum electrolytic capacitors. Both use conductive polymers as solid electrolytes. However, multilayer solid aluminum electrolytic capacitors use a multi-layer core stacked in parallel structure and a surface mount design. Compared with wound-type solid aluminum electrolytic capacitors, multilayer solid aluminum electrolytic capacitors are more suitable for the development of miniaturization and lightweight devices in the electronic information industry.

[0003] The mature industrial preparation process of the existing laminated solid aluminum electrolytic capacitor is as follows: the cut chemical foil is divided into the anode area and the cathode area with a barrier glue, and a conductive polymer solid electrolyte layer, a conductive carbon paste layer and a conductive silver paste layer are sequentially formed on the surface of the cathode area of ​​the foil to form a capacitor core; multiple capacitor cores are stacked in sequence on an external lead frame to form a capacitor core package, and the anode and cathode are led out. The capacitor core package is resin encapsulated, aged and the pins are formed to produce a solid aluminum electrolytic capacitor.

[0004] However, the structure and process of existing multilayer solid aluminum electrolytic capacitors have the following deficiencies:

[0005] In a structure where the lead frame is bonded to the core package, moisture in the environment can easily penetrate the core package through the gap between the lead frame and the resin encapsulation material, causing the capacitor to absorb moisture. During the reflow soldering process, the moisture-absorbed capacitor can easily cause the cathode material layer and the dielectric layer to peel off due to the thermal expansion of the internal moisture, causing the capacitor to fail.

[0006] The heat resistance of the organic resin package shell is poor, and due to the limitations of the injection molding process, the resin shell is prone to tiny pores and cracks that are difficult to detect with the naked eye. (Although increasing the injection molding pressure can help reduce the probability of pores and cracks in the resin shell, excessive injection molding pressure will damage the structure of the core package and deform the core, resulting in increased leakage current, decreased capacity, and even capacitor failure.) During the reflow soldering process, the high welding temperature can easily aggravate the cracking of the resin shell, causing the conductive polymer to be subjected to high temperature shock, dedoping, and decreased conductivity. This is manifested as an increase in the ESR (equivalent series resistance) of the finished capacitor and a decrease in performance. In severe cases, the capacitor will fail.

[0007] Based on this, the present invention designs a reflow-resistant laminated solid-state aluminum electrolytic capacitor and a preparation method thereof to solve the above problems. Summary of the Invention

[0008] The object of the present invention is to provide a reflow-resistant laminated solid-state aluminum electrolytic capacitor and a preparation method thereof, so as to solve the above-mentioned technical problems.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a reflow-resistant laminated solid-state aluminum electrolytic capacitor, comprising a resin housing and a ceramic base having a rectangular cross-section, a substrate being provided on the upper surface of the ceramic base, the substrate having a rectangular cross-section, a plurality of cores being stacked sequentially on the upper surface of the substrate, the resin housing being bonded to the upper surface of the ceramic base, and the resin housing covering the upper surface, surrounding side surfaces, and the plurality of cores;

[0010] A rectangular protrusion is provided in the middle of the upper surface of the ceramic base, and a rectangular recess is formed in the middle of the lower surface of the substrate toward the upper surface to cooperate with the rectangular protrusion.

[0011] A first anode lead-out portion and a first cathode lead-out portion are respectively provided at opposite ends of the rectangular recessed portion, and ends of the first anode lead-out portion and the first cathode lead-out portion that are away from each other extend out of two ends of the substrate respectively, and the anode portion of the core is electrically connected to the first anode lead-out portion, and the cathode portion of the core is electrically connected to the first cathode lead-out portion;

[0012] The ceramic base is provided with a second anode lead-out portion and a second cathode lead-out portion electrically connected to the first anode lead-out portion and the first cathode lead-out portion at opposite ends thereof, and both the second anode lead-out portion and the second cathode lead-out portion are exposed from the lower surface of the ceramic base.

[0013] Preferably, the length of the substrate is 100% to 120% of the length of the core, the width of the substrate is 100% to 120% of the width of the core, the length of the rectangular recess is 50% of the length of the substrate, the width of the rectangular recess is 50% to 80% of the width of the substrate; the depth of the rectangular recess is 50% of the thickness of the substrate.

[0014] Preferably, the length of the ceramic base is not less than 110% of the length of the substrate, and the width of the ceramic base is not less than 110% of the width of the substrate.

[0015] Preferably, the first anode lead-out portion includes a first anode horizontal portion having a rectangular cross-section and equal width, a first anode connecting portion, and a first anode pin, and the width of the first anode pin is equal to the width of the rectangular recessed portion; the first anode horizontal portion and the first anode pin are respectively arranged parallel to the upper and lower surfaces of the substrate, one end of the first anode horizontal portion and the first anode pin is flush with one end of the rectangular recessed portion, one end of the first anode pin extends beyond the edge of the substrate relative to the other end, the first anode horizontal portion and the first anode pin are connected at their mutually flush ends via the first anode connecting portion, and the first anode connecting portion is respectively perpendicularly connected to and electrically conductive with the first anode horizontal portion and the first anode pin;

[0016] The structure and shape of the first cathode lead-out portion are consistent with those of the first anode lead-out portion.

[0017] Preferably, the second anode lead-out portion includes a second anode horizontal portion having a rectangular cross-section, a second anode connecting portion, and a second anode pin, the second anode horizontal portion and the second anode pin being respectively arranged parallel to the upper and lower surfaces of the ceramic base, one end of the second anode horizontal portion and the second anode pin being flush with the edge of the rectangular raised portion, one end of the second anode pin being flush with the edge of the ceramic base relative to the other end, the second anode connecting portion being vertically connected between the second anode horizontal portion and the second anode pin, and the second anode horizontal portion and the second anode pin being electrically conductive via the second anode connecting portion, and the second anode horizontal portion being in contact with and electrically conductive to the first anode pin;

[0018] The structure and shape of the second cathode lead-out portion are consistent with those of the second anode lead-out portion.

[0019] Preferably, the length of the second anode pin is 20%-30% of the length of the ceramic base, and the width of the second anode pin is 50%-100% of the width of the ceramic base.

[0020] Preferably, surfaces of the second anode pin and the second cathode pin away from the ceramic base are both provided with a tin layer.

[0021] A method for preparing a reflow-resistant laminated solid-state aluminum electrolytic capacitor, the method comprising the following steps:

[0022] S1. Stacking a plurality of cores in sequence on an external substrate, with the anode portion and cathode portion of the core respectively attached to and electrically connected to the first anode horizontal portion and the first cathode horizontal portion, and the first anode pin and the first cathode pin on the substrate fixedly connected to the external frame, to obtain a core package assembly;

[0023] S2. Encapsulating the core package assembly with epoxy resin molding compound, forming a resin shell on the outside of the core package assembly, and manufacturing a semi-finished capacitor assembly, wherein the lower surface of the substrate, the first anode pin, and the first cathode pin are exposed outside the resin shell;

[0024] S3, absorbing moisture and aging the semi-finished capacitor assembly, and then punching the semi-finished capacitor from the external fixed frame along the boundary of the resin shell to obtain the semi-finished capacitor parts;

[0025] S4. Conduct electrical performance tests on the semi-finished capacitor parts to select the ones with qualified electrical performance;

[0026] S5. Connect the semi-finished capacitor parts with qualified electrical properties to the ceramic base of the peripheral device to produce a reflow-resistant laminated solid aluminum electrolytic capacitor.

[0027] Preferably, the method for connecting the semi-finished capacitor parts and the ceramic base of the peripheral device in step S5 is specifically as follows:

[0028] S51, coating the surfaces of the second anode horizontal portion and the second cathode horizontal portion of the ceramic base with conductive silver paste, and coating the remaining areas with insulating adhesive;

[0029] S52, bonding the first anode pin and the second anode horizontal portion, and bonding the first cathode pin and the second cathode horizontal portion, and fitting and bonding the rectangular recessed portion at the bottom of the semi-finished capacitor component and the rectangular raised portion of the ceramic base.

[0030] Preferably, the steps S3-S5 may also be:

[0031] S3, connecting the semi-finished capacitor assembly to the ceramic base to produce a second semi-finished capacitor assembly;

[0032] S4. Absorb moisture and age the second capacitor semi-finished product assembly, and then punch the second capacitor semi-finished product out from the external fixed frame along the boundary of the resin shell to obtain a finished capacitor;

[0033] S5. Conduct electrical performance testing and screening on the finished capacitors to produce reflow-resistant laminated solid aluminum electrolytic capacitors.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] In the present invention, several capacitor cores are stacked on a substrate to achieve the first lead-out, and the resin-encapsulated semi-finished product is embedded and bonded to the ceramic base to achieve the second lead-out. The first anode lead-out portion and the first cathode lead-out portion provided during the first lead-out reserve a certain water vapor channel for the moisture absorption requirement of the capacitor aging process, thereby ensuring the aging effect. At the same time, the water vapor channel of this structure is longer and more tortuous than that of the traditional structure, which can also slow down the subsequent moisture absorption of the capacitor during the storage process between leaving the factory and being placed on the reflow soldering board, thereby improving the moisture resistance of the core package and preventing the core package structure from being damaged by water vapor expansion during reflow soldering after being damp.

[0036] The ceramic base with lead-out components installed during the second lead-out process has a dual-substrate structure with a ceramic base and a base plate. While meeting the upper-board soldering requirements of client applications, the ceramic base's excellent heat resistance and crack resistance are combined with the FR-4 base plate, which has a low thermal conductivity and excellent thermal insulation properties, to effectively reduce damage to the core from high-temperature shocks and improve the capacitor's reflow resistance during the upper-board soldering process.

[0037] At the same time, when preparing the capacitor, the substrate is connected to the frame of the peripheral device, thereby combining the traditional lead frame lead-out method with the substrate support component. The existing component moisture absorption and aging production equipment can continue to be used in the moisture absorption and aging process of the capacitor component. The equipment has high compatibility and meets industrial practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 Schematic diagram of the structure of the solid aluminum electrolytic capacitor of the present invention;

[0040] Figure 2 Schematic diagram of the front cross-section structure of the solid aluminum electrolytic capacitor of the present invention;

[0041] Figure 3 Schematic diagram of the structure of the ceramic base in the solid aluminum electrolytic capacitor of the present invention;

[0042] Figure 4 Schematic diagram of the structure of the substrate in the solid aluminum electrolytic capacitor of the present invention;

[0043] Figure 5 Schematic diagram of the structure of the first anode lead-out portion of the solid-state aluminum electrolytic capacitor of the present invention;

[0044] Figure 6Schematic diagram of the structure of the second anode lead-out portion of the solid aluminum electrolytic capacitor of the present invention;

[0045] Figure 7 This is a schematic flow chart of a first method for preparing a solid-state aluminum electrolytic capacitor according to the present invention;

[0046] Figure 8 The figure is a schematic flow chart of a second method for preparing a solid aluminum electrolytic capacitor according to the present invention.

[0047] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0048] Resin shell; 2. Ceramic base; 21. Rectangular protrusion; 3. Substrate; 31. Rectangular recess; 4. Core; 5. First anode lead-out portion; 51. First anode horizontal portion; 52. First anode connecting portion; 53. First anode pin; 6. First cathode lead-out portion; 7. Second anode lead-out portion; 71. Second anode horizontal portion; 72. Second anode connecting portion; 73. Second anode pin; 8. Second cathode lead-out portion. Implementation Method

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0050] See also Figure 1-6 As shown, a technical solution provided by the present invention is:

[0051] A reflow-resistant laminated solid-state aluminum electrolytic capacitor includes a resin housing 1 and a ceramic base 2 having a rectangular cross-section. A substrate 3 having a rectangular cross-section is provided on the upper surface of the ceramic base 2. A plurality of cores 4 are stacked sequentially on the upper surface of the substrate 3. The resin housing 1 is attached to the upper surface of the ceramic base 2 and covers the upper surface, surrounding sides of the substrate 3, and the plurality of cores 4.

[0052] A rectangular protrusion 21 is provided in the middle of the upper surface of the ceramic base 2, and a rectangular recess 31 is formed in the middle of the lower surface of the substrate 3 so as to cooperate with the rectangular protrusion 21.

[0053] A first anode lead-out portion 5 and a first cathode lead-out portion 6 are respectively provided at opposite ends of the rectangular recessed portion 31. Ends of the first anode lead-out portion 5 and the first cathode lead-out portion 6 that are away from each other extend out of the two ends of the substrate 3. The anode portion of the core 4 is electrically connected to the first anode lead-out portion 5, and the cathode portion of the core 4 is electrically connected to the first cathode lead-out portion 6.

[0054] The ceramic base 2 has a second anode lead-out portion 7 and a second cathode lead-out portion 8 at opposite ends thereof, which are electrically connected to the first anode lead-out portion 5 and the first cathode lead-out portion 6 , respectively. Both the second anode lead-out portion and the second cathode lead-out portion are exposed from the lower surface of the ceramic base.

[0055] Specifically, the length of the substrate 3 is 100% to 120% of the length of the core 4, the width of the substrate 3 is 100% to 120% of the width of the core 4, the length of the rectangular recess 31 is 50% of the length of the substrate 3, the width of the rectangular recess 31 is 50% to 80% of the width of the substrate 3; the depth of the rectangular recess 31 is 50% of the thickness of the substrate 3.

[0056] Specifically, the length of the ceramic base 2 is not less than 110% of the length of the substrate 3 , and the width of the ceramic base 2 is not less than 110% of the width of the substrate 3 .

[0057] From the above description, it can be seen that the size of the substrate is limited to provide sufficient support for the core; the sizes of the substrate and the ceramic base are increased to match the wall thickness requirements of the resin shell; the sizes of the rectangular protrusions and rectangular recesses on the ceramic base and the substrate are limited to provide sufficient bonding area to ensure the firmness of the connection between the ceramic base and the substrate.

[0058] Specifically, the first anode lead-out portion 5 includes a first anode horizontal portion 51 having a rectangular cross-section and equal width, a first anode connecting portion 52, and a first anode pin 53. The width of the first anode pin 53 is equal to the width of the rectangular recessed portion 31. The first anode horizontal portion 51 and the first anode pin 53 are respectively arranged parallel to the upper and lower surfaces of the substrate 3. One end of the first anode horizontal portion 51 and the first anode pin 53 is flush with one end of the rectangular recessed portion 31. One end of the first anode pin 53 extends beyond the edge of the substrate 3 relative to the other end. The first anode connecting portion 52 connects the first anode horizontal portion 51 and the first anode pin 53 at their mutually flush ends. The first anode connecting portion 52 is also perpendicularly connected to the first anode horizontal portion 51 and the first anode pin 53 and electrically conductive therewith.

[0059] The structure and shape of the first cathode lead-out portion 6 are consistent with those of the first anode lead-out portion 5 .

[0060] Specifically, the second anode lead-out portion 7 includes a second anode horizontal portion 71 having a rectangular cross-sectional shape, a second anode connecting portion 72, and a second anode pin 73. The second anode horizontal portion 71 and the second anode pin 73 are respectively arranged parallel to the upper and lower surfaces of the ceramic base 2. One end of the second anode horizontal portion 71 and the second anode pin 73 is flush with the edge of the rectangular raised portion 21, and one end of the second anode pin 73 is flush with the edge of the ceramic base 2 relative to the other end. The second anode connecting portion 72 is vertically connected between the second anode horizontal portion 71 and the second anode pin 73, and the second anode horizontal portion 71 and the second anode pin 73 are electrically connected through the second anode connecting portion 72. The second anode horizontal portion 71 is in contact with and electrically connected to the first anode pin 53.

[0061] The structure and shape of the second cathode lead-out portion 8 are consistent with those of the second anode lead-out portion 7 .

[0062] Specifically, the length of the second anode pin 73 is 20%-30% of the length of the ceramic base 2 , and the width of the second anode pin 73 is 50%-100% of the width of the ceramic base 2 .

[0063] From the above description, it can be seen that the size of the second anode pin is limited to provide sufficient welding area to meet the client's upper board welding requirements, while maintaining a sufficient distance between the anode and cathode pins to avoid electrical conduction between the anode and cathode pins due to diffusion contact of solder paste during upper board welding, causing a short circuit in the capacitor.

[0064] Specifically, the surfaces of the second anode pin 73 and the second cathode pin away from the ceramic base 2 are both provided with a tin layer.

[0065] See also Figure 7-8 As shown, another technical solution provided by the present invention is:

[0066] A method for preparing a reflow-resistant laminated solid-state aluminum electrolytic capacitor, the method comprising the following steps:

[0067] S1. Stack several cores 4 in sequence on an external substrate 3, with the anode portion and cathode portion of the core 4 respectively attached to and electrically connected to the first anode horizontal portion 51 and the first cathode horizontal portion, and the first anode pin 53 and the first cathode pin on the substrate 3 fixedly connected to the external frame to obtain a core package assembly;

[0068] S2. Encapsulating the core package assembly with epoxy resin molding compound, forming a resin shell 1 on the outside of the core package assembly, and manufacturing a semi-finished capacitor assembly, wherein the lower surface of the substrate 3, the first anode pin 53, and the first cathode pin are exposed outside the resin shell 1;

[0069] S3, absorbing moisture and aging the semi-finished capacitor assembly, and then punching the semi-finished capacitor from the external fixed frame along the boundary of the resin shell 1 to obtain the semi-finished capacitor parts;

[0070] S4. Conduct electrical performance tests on the semi-finished capacitor parts to select the ones with qualified electrical performance;

[0071] S5. Connect the semi-finished capacitor parts with qualified electrical performance to the external ceramic base 2 to produce a reflow-resistant laminated solid aluminum electrolytic capacitor.

[0072] Specifically, the method for connecting the semi-finished capacitor parts and the peripheral ceramic base 2 in step S5 is as follows:

[0073] S51, coating the surfaces of the second anode horizontal portion 71 and the second cathode horizontal portion of the ceramic base 2 with conductive silver paste, and coating the remaining areas with insulating adhesive;

[0074] S52 , bonding the first anode pin 53 to the second anode horizontal portion 71 and the first cathode pin to the second cathode horizontal portion, and fitting and bonding the rectangular recessed portion 31 at the bottom of the semi-finished capacitor component to the rectangular raised portion 21 of the ceramic base 2 .

[0075] Specifically, steps S3-S5 may also be:

[0076] S3, connecting the semi-finished capacitor assembly to the ceramic base 2 to obtain a second semi-finished capacitor assembly;

[0077] S4. Absorb moisture and age the second capacitor semi-finished product assembly, and then punch the second capacitor semi-finished product out from the external fixed frame along the boundary of the resin housing 1 to obtain a finished capacitor;

[0078] S5. Conduct electrical performance testing and screening on the finished capacitors to produce reflow-resistant laminated solid aluminum electrolytic capacitors.

[0079] Embodiment 1 of the present invention is ( Figure 1-7 shown):

[0080] A reflow-resistant laminated solid-state aluminum electrolytic capacitor includes a resin housing 1 and a ceramic base 2 with a rectangular cross-section (the ceramic base 2 is made of alumina ceramic). A substrate 3 is provided on the upper surface of the ceramic base 2 (the substrate 3 is made of FR-4 epoxy glass cloth laminate). The substrate 3 has a rectangular cross-section and is stacked with a plurality of cores 4 on its upper surface. The resin housing 1 is attached to the upper surface of the ceramic base 2 and covers the upper surface, surrounding sides of the substrate 3, and the plurality of cores 4.

[0081] In this embodiment, the length of the ceramic base 2 is not less than 110% (preferably 110%) of the length of the substrate 3 , and the width of the ceramic base 2 is not less than 110% (preferably 110%) of the width of the substrate 3 ;

[0082] In this embodiment, the length of the substrate 3 is 100% to 120% (preferably 110%) of the length of the core 4 , and the width of the substrate 3 is 100% to 120% (preferably 110%) of the width of the core 4 ;

[0083] A rectangular protrusion 21 is provided in the middle of the upper surface of the ceramic base 2, and a rectangular recess 31 is formed in the middle of the lower surface of the substrate 3 so as to cooperate with the rectangular protrusion 21.

[0084] In this embodiment, the length of the rectangular recessed portion 31 is 50% of the length of the substrate 3 , the width of the rectangular recessed portion 31 is 50% to 80% (preferably 60%) of the width of the substrate 3 , and the depth of the rectangular recessed portion 31 is 50% of the thickness of the substrate 3 ;

[0085] A first anode lead-out portion 5 and a first cathode lead-out portion 6 are respectively provided at opposite ends of the rectangular recessed portion 31 (the first anode lead-out portion 5 and the first cathode lead-out portion 6 are both made of copper or a copper alloy). The ends of the first anode lead-out portion 5 and the first cathode lead-out portion 6 that are away from each other extend out of the two ends of the substrate 3. The anode portion of the core 4 is electrically connected to the first anode lead-out portion 5, and the cathode portion of the core 4 is electrically connected to the first cathode lead-out portion 6.

[0086] In this embodiment, the first anode lead-out portion 5 includes a first anode horizontal portion 51 having a rectangular cross-section and equal width, a first anode connecting portion 52, and a first anode pin 53. The width of the first anode pin 53 is equal to the width of the rectangular recessed portion 31. The first anode horizontal portion 51 and the first anode pin 53 are respectively arranged parallel to the upper and lower surfaces of the substrate 3. One end of the first anode horizontal portion 51 and the first anode pin 53 is flush with one end of the rectangular recessed portion 31. One end of the first anode pin 53 extends beyond the edge of the substrate 3 relative to the other end. The first anode connecting portion 52 connects the first anode horizontal portion 51 and the first anode pin 53 at their mutually flush ends. The first anode connecting portion 52 is also perpendicularly connected to the first anode horizontal portion 51 and the first anode pin 53 and electrically conductive therewith.

[0087] The structure and shape of the first cathode lead-out portion 6 are consistent with those of the first anode lead-out portion 5;

[0088] The ceramic base 2 is provided with a second anode lead-out portion 7 and a second cathode lead-out portion 8 electrically connected to the first anode lead-out portion 5 and the first cathode lead-out portion 6 at opposite ends thereof (the second anode lead-out portion 7 and the second cathode lead-out portion 8 are both made of copper or copper alloy);

[0089] In this embodiment, the second anode lead-out portion 7 includes a second anode horizontal portion 71 having a rectangular cross-section, a second anode connecting portion 72, and a second anode pin 73. The length of the second anode pin 73 is 20%-30% (preferably 25%) of the length of the ceramic base 2, and the width of the second anode pin 73 is 50%-100% (preferably 75%) of the width of the ceramic base 2. The second anode pins 73 are respectively arranged parallel to the upper and lower surfaces of the ceramic base 2. One end of the second anode horizontal portion 71 and the second anode pin 73 is flush with the edge of the rectangular raised portion 21, and one end of the second anode pin 73 is flush with the edge of the ceramic base 2 relative to the other end. The second anode connecting portion 72 is perpendicularly connected between the second anode horizontal portion 71 and the second anode pin 73, and the second anode horizontal portion 71 and the second anode pin 73 are electrically connected through the second anode connecting portion 72. The second anode horizontal portion 71 is in contact with and electrically connected to the first anode pin 53.

[0090] The structure and shape of the second cathode lead-out portion 8 are consistent with those of the second anode lead-out portion 7;

[0091] In this embodiment, a tin layer is provided on the surface of the second anode pin 73 and the second cathode pin away from the ceramic base 2 .

[0092] The specific preparation method of the above-mentioned reflow-resistant multilayer solid aluminum electrolytic capacitor is as follows:

[0093] S1. Stack several cores 4 in sequence on an external substrate 3, with the anode and cathode portions of the cores 4 respectively attached to and electrically connected to the first anode horizontal portion 51 and the first cathode horizontal portion, and the first anode pins 53 and the first cathode pins on the substrate 3 are fixedly connected to an external frame (when multiple groups of capacitors are to be prepared at one time, multiple substrates are connected to the external frame in an N*N matrix or strip-shaped evenly spaced arrangement to obtain a core package assembly;

[0094] In this embodiment, the core 4 is prepared by: cutting a chemically formed aluminum foil into rectangles to form a first aluminum foil; coating the first aluminum foil with a barrier adhesive to prepare an insulating barrier tape, dividing the anode region and the cathode region to form a second aluminum foil; performing a chemically formed repair treatment on the dielectric layer on the cathode region side of the second aluminum foil to obtain a third aluminum foil; forming a conductive polymer layer on the cathode region surface of the third aluminum foil to obtain a fourth aluminum foil; impregnating the cathode region of the fourth aluminum foil with a conductive graphite emulsion and then drying it to form a conductive carbon paste layer to obtain a fifth aluminum foil; impregnating the cathode region of the fifth aluminum foil with a conductive silver paste and then drying it to form a conductive silver paste layer to obtain the core 4.

[0095] In this embodiment, the specific stacking method of the plurality of cores 4 is as follows: the anode portion of the first core 4 and the first anode horizontal portion 51, as well as the anode portions of the plurality of cores 4, are connected and electrically conductive by welding; the cathode portion of the first capacitor core 4 and the first cathode horizontal portion, as well as the cathode portions of the plurality of capacitor cores 4, are bonded and electrically conductive by conductive silver glue;

[0096] S2. Encapsulating the core package assembly with epoxy resin molding compound, forming a resin shell 1 on the outside of the core package assembly, and manufacturing a semi-finished capacitor assembly, wherein the lower surface of the substrate 3, the first anode pin 53, and the first cathode pin are exposed outside the resin shell 1, that is, the resin shell 1 covers the plurality of core pieces 4, the upper surface of the substrate 3, and the surrounding side surfaces;

[0097] S3, absorbing moisture and aging the semi-finished capacitor assembly, and then punching the semi-finished capacitor from the external fixed frame along the boundary of the resin shell 1 to obtain the semi-finished capacitor parts;

[0098] In this embodiment, the specific punching method of the semi-finished capacitor assembly is as follows: cutting off the sides of the resin shell 1 at both ends, removing the first anode pin 53 and the first cathode pin to expose the portion outside the resin shell 1;

[0099] S4. Conduct electrical performance tests on the semi-finished capacitor parts to select the ones with qualified electrical performance;

[0100] S5, connecting the semi-finished capacitor parts with qualified electrical performance to the external ceramic base 2 to produce a reflow-resistant laminated solid aluminum electrolytic capacitor;

[0101] In this embodiment, the specific connection method between the semi-finished capacitor parts and the ceramic base 2 is:

[0102] S51, coating the surfaces of the second anode horizontal portion 71 and the second cathode horizontal portion of the ceramic base 2 with conductive silver paste, and coating the remaining areas with insulating adhesive;

[0103] S52 , bonding the first anode pin 53 to the second anode horizontal portion 71 and the first cathode pin to the second cathode horizontal portion, and fitting and bonding the rectangular recessed portion 31 at the bottom of the semi-finished capacitor component to the rectangular raised portion 21 of the ceramic base 2 .

[0104] The second embodiment of the present invention is ( Figure 1-6 and Figure 8 shown):

[0105] The difference between Example 2 and Example 1 lies in the different methods for preparing the capacitor, specifically:

[0106] S3, connecting the semi-finished capacitor assembly to the ceramic base 2 to obtain a second semi-finished capacitor assembly;

[0107] S4. Absorb moisture and age the second capacitor semi-finished product assembly, and then punch the second capacitor semi-finished product out from the external fixed frame along the boundary of the resin housing 1 to obtain a finished capacitor;

[0108] S5. Conduct electrical performance testing and screening on the finished capacitors to produce reflow-resistant laminated solid aluminum electrolytic capacitors.

[0109] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A reflow-resistant laminated solid aluminum electrolytic capacitor, characterized in that: It comprises a resin shell (1) and a ceramic base (2) with a rectangular cross-sectional shape, a substrate (3) is provided on the upper surface of the ceramic base (2), the cross-sectional shape of the substrate (3) is rectangular, a plurality of chip cores (4) are stacked in sequence on the upper surface of the substrate (3), the resin shell (1) is arranged on the upper surface of the ceramic base (2), and the resin shell (1) covers the upper surface, surrounding side surfaces and the plurality of chip cores (4) of the substrate (3); A rectangular protrusion (21) is provided in the middle of the upper surface of the ceramic base (2), and a rectangular recess (31) is formed in the middle of the lower surface of the substrate (3) so as to cooperate with the rectangular protrusion (21). A first anode lead-out portion (5) and a first cathode lead-out portion (6) are respectively provided at opposite ends of the rectangular recessed portion (31); the ends of the first anode lead-out portion (5) and the first cathode lead-out portion (6) that are away from each other respectively extend out of two ends of the substrate (3); the anode portion of the core (4) is electrically connected to the first anode lead-out portion (5); and the cathode portion of the core (4) is electrically connected to the first cathode lead-out portion (6); The ceramic base (2) is provided with a second anode lead-out portion (7) and a second cathode lead-out portion (8) respectively at opposite ends thereof, the second anode lead-out portion (7) and the second cathode lead-out portion (8) being electrically conductive with the first anode lead-out portion (5) and the first cathode lead-out portion (6), and the second anode lead-out portion (7) and the second cathode lead-out portion (8) are both exposed from the lower surface of the ceramic base (2).

2. The reflow-resistant laminated solid aluminum electrolytic capacitor according to claim 1, characterized in that: The length of the substrate (3) is 100% to 120% of the length of the core (4); the width of the substrate (3) is 100% to 120% of the width of the core (4); the length of the rectangular recessed portion (31) is 50% of the length of the substrate (3); the width of the rectangular recessed portion (31) is 50% to 80% of the width of the substrate (3); and the depth of the rectangular recessed portion (31) is 50% of the thickness of the substrate (3).

3. The reflow-resistant laminated solid aluminum electrolytic capacitor according to claim 1, characterized in that: The length of the ceramic base (2) is not less than 110% of the length of the substrate (3), and the width of the ceramic base (2) is not less than 110% of the width of the substrate (3).

4. The reflow-resistant laminated solid aluminum electrolytic capacitor according to claim 1, characterized in that: The first anode lead-out portion (5) comprises a first anode horizontal portion (51) having a rectangular cross-sectional shape and equal width, a first anode connecting portion (52) and a first anode pin (53), and the width of the first anode pin (53) is equal to the width of the rectangular recessed portion (31); the first anode horizontal portion (51) and the first anode pin (53) are respectively arranged in parallel on the upper and lower surfaces of the substrate (3); one end of the first anode horizontal portion (51) and the first anode pin (53) are flush with one end of the rectangular recessed portion (31); one end of the first anode pin (53) extends out of the edge of the substrate (3) relative to the other end; the first anode horizontal portion (51) and the first anode pin (53) are connected to each other at one end through the first anode connecting portion (52); and the first anode connecting portion (52) is respectively vertically connected to the first anode horizontal portion (51) and the first anode pin (53) and electrically conductive; The structure and shape of the first cathode lead-out portion (6) are consistent with those of the first anode lead-out portion (5).

5. The reflow-resistant laminated solid aluminum electrolytic capacitor according to claim 4, characterized in that: The second anode lead-out portion (7) comprises a second anode horizontal portion (71) having a rectangular cross-sectional shape, a second anode connecting portion (72) and a second anode pin (73); the second anode horizontal portion (71) and the second anode pin (73) are respectively arranged in parallel on the upper and lower surfaces of the ceramic base (2); one end of the second anode horizontal portion (71) and the second anode pin (73) are flush with the edge of the rectangular protrusion (21); one end of the second anode pin (73) is flush with the edge of the ceramic base (2) relative to the other end; the second anode connecting portion (72) is vertically connected between the second anode horizontal portion (71) and the second anode pin (73); the second anode horizontal portion (71) and the second anode pin (73) are electrically conductive via the second anode connecting portion (72); the second anode horizontal portion (71) and the first anode pin (53) are attached to and electrically conductive to each other; The structure and shape of the second cathode lead-out portion (8) are consistent with those of the second anode lead-out portion (7).

6. The reflow-resistant laminated solid aluminum electrolytic capacitor according to claim 5, characterized in that: The length of the second anode pin (73) is 20%-30% of the length of the ceramic base (2), and the width of the second anode pin (73) is 50%-100% of the width of the ceramic base (2).

7. The reflow-resistant laminated solid aluminum electrolytic capacitor according to claim 5, characterized in that: Surfaces of the second anode pin (73) and the second cathode pin away from the ceramic base (2) are both provided with a tin layer.

8. A method for preparing a reflow-resistant laminated solid aluminum electrolytic capacitor according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: S1, stacking a plurality of cores (4) in sequence on an external substrate (3), and the anode portion and cathode portion of the core (4) are respectively attached to and electrically connected to the first anode horizontal portion (51) and the first cathode horizontal portion, and the first anode pin (53) and the first cathode pin on the substrate (3) are fixedly connected to an external frame, thereby obtaining a core package assembly; S2, encapsulating the core package assembly with epoxy resin molding material, forming a resin shell (1) outside the core package assembly, and obtaining a capacitor semi-finished assembly, wherein the lower surface of the substrate (3), the first anode pin (53) and the first cathode pin are exposed outside the resin shell (1); S3, absorbing moisture and aging the capacitor semi-finished product assembly, and then punching the capacitor semi-finished product from the external fixed frame along the boundary of the resin shell (1) to obtain the capacitor semi-finished product loose parts; S4. Conduct electrical performance tests on the semi-finished capacitor parts to select the semi-finished capacitor parts with qualified electrical performance; S5. Connecting the capacitor semi-finished parts with qualified electrical properties to the external ceramic base (2) to obtain a reflow soldering resistant laminated solid aluminum electrolytic capacitor.

9. The method for preparing the reflow-resistant laminated solid aluminum electrolytic capacitor according to claim 8, characterized in that: The method for connecting the capacitor semi-finished parts and the ceramic base (2) of the peripheral device in step S5 is specifically as follows: S51, coating the surfaces of the second anode horizontal portion (71) and the second cathode horizontal portion of the ceramic base (2) with conductive silver glue, and coating the remaining areas with insulating adhesive; S52, bonding the first anode pin (53) to the second anode horizontal portion (71), and the first cathode pin to the second cathode horizontal portion, and fitting and bonding the rectangular recessed portion (31) at the bottom of the capacitor semi-finished component to the rectangular raised portion (21) of the ceramic base (2).

10. The method for preparing the reflow-resistant laminated solid aluminum electrolytic capacitor according to claim 8, characterized in that: The steps S3-S5 may also be: S3, connecting the capacitor semi-finished assembly to the ceramic base (2) to obtain a second capacitor semi-finished assembly; S4, absorbing moisture and aging the semi-finished component of the second capacitor, and then punching the semi-finished component of the second capacitor from the external fixed frame along the boundary of the resin shell (1) to obtain a finished capacitor; S5. Conduct electrical performance testing and screening on the finished capacitors to obtain reflow soldering resistant laminated solid aluminum electrolytic capacitors.

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