Sealed small surface-mounted packaging device for devices and components realized by PCB (Printed Circuit Board)
Through the integrated molding and metallization of PCB process, combined with insulating coating treatment, a sealed small surface-mount packaging device for miniaturized, high-frequency, and high-power density switching power converters was designed, solving the difficulty of taking into account small sizes in the existing technology. The problems of transformation, surface finishing, sealing, full electromagnetic shielding efficiency, high reliability packaging and lightweighting achieve efficient and economical packaging effects.
Patent Information
- Application Number
- CN202421126717.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-22
- Publication Date
- 2025-02-07
- Estimated Expiration
- 2034-05-22
AI Technical Summary
When designing a switching power converter with miniaturization, high frequency and high power density, it is difficult to take into account both miniaturization, surface adjustment, sealing, full electromagnetic shielding performance, high reliability packaging and lightweighting.
The sealed small surface sealing packaging device for devices and components implemented using PCB, including PCB base plate, PCB frame and cover plate, is formed in one piece through the PCB process, combined with vacuum air phase deposition method, wet chemical deposition method or additive manufacturing 100% metallization and insulating coating on the inner surface.
It realizes the effects of miniaturization, surface mount, sealing, full electromagnetic shielding, high-reliability packaging and lightweighting, reducing costs and improving the voltage and insulation performance of the device.
Smart Images
Figure CN222441969U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of filter manufacturing, in particular to a sealed small surface-mount packaging device for components and assemblies implemented by PCB. Background Art
[0002] As switching power converters develop towards miniaturization, high frequency and high power density, electronic equipment has an urgent need for miniaturization, surface mounting, lightweight and high electromagnetic shielding efficiency of devices, components, LC filters (Passive Filter) and EMI filters (Electromagnetic Filter).
[0003] Among them, the use of baseboard-free substrate integrated packaging technology to design surface-mount components, devices, LC filters, and EMI filters is one of the directions of miniaturization development.
[0004] The surface mount, sealed, electromagnetically shielded components, devices, LC filters, and EMI filter packages designed with substrate integrated packaging technology are usually composed of substrates, frames, and covers. In the current mature technologies, the substrate can be realized by PCB (Printed Circuit Board), LTCC (Low Temperature Co-fired Ceramic), HTCC (High-temperature co-fired ceramics), beryllium oxide ceramics, etc., and the frames and covers are often made of metal materials. The components and the encapsulated frames of the devices and components are assembled on the front of the substrate, and the pads on the bottom are used as the lead-out terminals of the devices and components for assembly and welding at the user's location. The disadvantage is that the design of the flat bottom plate is prone to misalignment when assembling the frame, thereby affecting the air tightness and appearance; the frame and cover are made of metal materials. If the line-to-ground withstand voltage performance and line-to-ground insulation performance of the devices and components are required to be high, the safety distance must also be increased, which is not conducive to miniaturization. In addition, metal materials are relatively heavy, which is not conducive to lightweighting. Therefore, it is a technical problem that needs to be solved urgently to ensure that the packaging of devices and components can take into account miniaturization, surface mounting, sealing, full electromagnetic shielding effectiveness, high-reliability packaging, and lightweight. Utility Model Content
[0005] The technical problem to be solved by the utility model is to provide a sealed small surface mount packaging device for components and assemblies implemented by PCB, which effectively overcomes the defects of the prior art.
[0006] The technical solution of the utility model to solve the above technical problems is as follows:
[0007] A sealed small surface mount packaging device for PCB-implemented devices and components comprises a PCB base plate, a PCB frame and a cover plate. The PCB frame is arranged on the PCB base plate, and the two are integrally formed. The cover plate is packaged on the upper end of the PCB frame.
[0008] On the basis of the above technical solution, the present invention can also be improved as follows.
[0009] Furthermore, the outer surface of the PCB frame is 100% metallized by vacuum vapor deposition, wet chemical deposition or additive manufacturing.
[0010] Furthermore, the inner surface of the PCB frame is subjected to insulation coating treatment.
[0011] Furthermore, the top of the PCB frame is metallized.
[0012] Furthermore, a first middle groove for accommodating tall components is provided in the middle of the PCB bottom plate, and a second middle groove for accommodating tall components is provided in the middle of the cover plate.
[0013] Furthermore, the above-mentioned PCB base plate is a double-layer or multi-layer PCB printed circuit board, and the upper surface of the above-mentioned PCB base plate is provided with a first printed circuit microstrip for assembling components constituting devices, components and filters, such as capacitors, resistors, inductors and chokes; the lower surface of the above-mentioned PCB base plate is provided with a second printed circuit microstrip for assembling devices, components and filters at the user's site; the above-mentioned PCB base plate is provided with a via hole for connecting the first printed circuit microstrip and the second printed circuit microstrip, and the above-mentioned via hole is metallized and filled by plugging electroplating.
[0014] Furthermore, the cover plate is a metal cover plate or a PCB cover plate with double-sided metallization. If the cover plate is a PCB cover plate, it is assembled with the PCB frame by a hot melt sealing process, and the outer surface of the PCB cover plate is 100% metallized, and a printed microstrip matching the inner surface and the frame welding position is provided, and a suitable via hole is provided here, the via hole is metallized, and the hole is filled and leveled by electroplating, and the non-welding area of the inner surface of the PCB cover plate is subjected to insulation coating treatment; if the cover plate is a metal cover plate, it can be assembled with the PCB frame by a hot melt sealing process, or a parallel seam soldering process, or a parallel seam welding process, or a laser seam welding process, and when the insulation safety distance is tight, the inner side of the metal cover plate must be insulated, and the insulation treatment includes spraying an insulating film, bonding an insulating film or an insulating plate.
[0015] Further, the hot melt sealing process is implemented by using a first tool, which includes a welding tool bottom bracket for placing multiple cover plates, a welding tool fixing plate for fixing multiple enclosures, and a welding tool pressure cover for compacting the enclosures and the cover plates. The welding tool bottom bracket is a plate-shaped component, and the welding tool bottom bracket is provided with a plurality of first grooves adapted to the cover plates, and the depth of the first grooves is equal to the thickness of the cover plates. Both sides of the first grooves are provided with fixing bolts for fixing the welding tool fixing plate and the welding tool pressure cover, and the welding tool pressure cover is provided with a second groove adapted to the PCB bottom plate, and the depth of the second groove is equal to or slightly less than the thickness of the PCB bottom plate. The welding tool fixing plate is a plate-shaped component, and the welding tool fixing plate is provided with a plurality of first through grooves matched with the enclosure frames.
[0016] The assembly of the cover plate by parallel seam welding, parallel seam soldering or laser seam welding process is implemented by a second tooling, and the second tooling includes a seam welding tooling fixture, and the seam welding tooling fixture is provided with a third groove adapted to the part to be sealed.
[0017] The beneficial effects of the utility model are as follows: the above-mentioned PCB base plate is a dual-purpose item, eliminating the base plate for traditional component and device packaging, which not only meets the needs of miniaturization and surface mounting, but also reduces weight and saves costs. The above-mentioned PCB base plate and PCB frame are integrally formed using PCB technology, eliminating the assembly process of the frame and the substrate, or the substrate and the base plate in the process of preparing device and component packaging. The inner surface of the PCB frame is subjected to insulation coating treatment, and the required safety distance can be greatly reduced when the same insulation performance index is achieved, which is further conducive to miniaturization and lightweight; or under the condition of the same insulation safety distance, the line-to-ground insulation performance is better, and the line-to-ground voltage resistance capacity is stronger, and the effect is that the product reliability is higher. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is one of the schematic diagrams of the entire structure consisting of a PCB base plate and a PCB frame provided in an embodiment of the utility model.
[0019] Figure 2 for Figure 1 The structure shown is a schematic diagram of the structure cut along the section line AA.
[0020] Figure 3 for Figure 1 The structure shown is a schematic diagram of the structure cut along the section line BB.
[0021] Figure 4 for Figure 1 Bottom view of the structure shown.
[0022] Figure 5The second schematic diagram of the whole structure composed of the PCB bottom plate and the PCB surrounding frame provided in the embodiment of the utility model (with a metal sealing ring).
[0023] Figure 6 for Figure 5 The structure shown is a schematic diagram of the structure cut along the section line CC.
[0024] Figure 7 for Figure 5 The structure shown is a schematic diagram of the structure cut along the section line DD.
[0025] Figure 8 The third schematic diagram of the whole structure composed of the PCB base plate and the PCB frame provided in the embodiment of the utility model (sink platform thick copper with LDI electroplating).
[0026] Fig. 9 for Figure 8 The structure shown is a schematic diagram of the structure cut along section line EE.
[0027] Fig.10 for Figure 8 The structure shown is a schematic diagram of the structure cut along the section line FF.
[0028] Fig.11 The schematic diagram of the structure of the metal cover plate for parallel seam soldering and parallel seam welding.
[0029] Fig.12 for Fig.11 The structure shown is a schematic diagram of the structure cut along the section line GG.
[0030] Fig.13 for Fig.11 The structure shown is a schematic diagram of the structure cut along the section line HH.
[0031] Fig.14 Schematic diagram of the structure of the metal cover plate sealed by the laser seam welding process.
[0032] Fig.15 for Fig.14 The structure shown is a schematic diagram of the structure cut along section line II.
[0033] Fig.16 for Fig.14 The structure shown is a schematic diagram of the structure cut along the section line JJ.
[0034] Fig.17 Schematic diagram of the structure of the PCB cover sealed by the hot melt sealing process and the microstrip pattern printed on the inner surface.
[0035] Fig.18 for Fig.17 The structure shown is a schematic diagram of the structure cut along the section line KK.
[0036] Fig.19 for Fig.17 The structure shown is a schematic diagram of the structure cut along the section line LL.
[0037] Fig. 20 for Fig.17 The outer surface shown is printed with a microstrip pattern.
[0038] Fig.21 The structure of the metal sealing ring is shown in FIG.
[0039] Fig. 22 for Fig.21 The structure shown is a schematic diagram of the structure cut along the section line MM.
[0040] Fig.23 This is a schematic diagram of the welding tool support structure.
[0041] Fig.24 for Fig.23 The structure shown is a schematic diagram of the structure cut along section line NN.
[0042] Fig.25 for Fig.23 The structure shown is a schematic diagram of the structure cut along section line OO.
[0043] Fig.26 This is a schematic diagram of the welding tool fixing plate structure.
[0044] Fig. 27 for Fig.26 The structure shown is a schematic diagram of the structure cut along the section line PP.
[0045] Fig.28 for Fig.26 The structure shown is a schematic diagram of the structure cut along the section line QQ.
[0046] Fig.29 This is one of the schematic diagrams of the welding tooling cover structure (used to assemble the cover plate using the hot stage method to achieve the thermal sealing process).
[0047] Fig.30 for Fig.29 The structure shown is a schematic diagram of the structure cut along the section line RR.
[0048] Fig.31 for Fig.29 The structure shown is a schematic diagram of the structure cut along the section line SS.
[0049] Fig.32 This is the second schematic diagram of the welding tool cover structure.
[0050] Fig.33 for Fig.32 The structure shown is a schematic diagram of the structure cut along the section line TT.
[0051] Fig.34 for Fig.31 The structure shown is a schematic diagram of the structure cut along section line UU.
[0052] Fig.35 This is a schematic diagram of the seam welding fixture structure.
[0053] Fig.36 for Fig.32 The structure shown is a schematic diagram of the structure cut along section line VV.
[0054] In the accompanying drawings, the components represented by the reference numerals are listed as follows:
[0055] 1. PCB bottom plate; 2. PCB frame; 3. Cover plate; 4. Metal sealing ring; 5. Welding tool base; 6. Welding tool fixing plate; 7. Welding tool pressure cover; 8. Seam welding tool fixture; 12. First middle groove; 22. Sinking platform; 31. Second middle groove; 32. First edge boss; 51. First groove; 52. Fixing bolt; 61. First through groove; 62. First through hole; 71. Heat dissipation tooth; 72. Second through hole; 73. Second groove; 81. Third groove; 82. Fourth through hole. DETAILED DESCRIPTION
[0056] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.
[0057] Example
[0058] like Figures 1 to 36 As shown, the sealed small surface mount packaging device for devices and components implemented by the PCB of this embodiment includes a PCB base plate 1, a PCB frame 2 and a cover plate 3. The PCB frame 2 is arranged on the PCB base plate 1, and the two are integrally formed. The cover plate 3 is packaged at the upper end of the PCB frame 2.
[0059] In this embodiment, the PCB base plate 1 serves as both a functional substrate and a package base plate, serving two purposes. Compared with the traditional packaging of devices, components, and filters, the base plate of the housing is omitted, which is intended to meet the needs of miniaturization and surface mounting, while reducing weight and saving costs. Compared with the substrate-type surface mounting packaging of devices and components, the assembly of the metal frame can be omitted, and the weight is lighter and the volume is smaller.
[0060] In this embodiment, the outer surface of the PCB enclosure 2 is 100% metallized by vacuum vapor deposition, wet chemical deposition or additive manufacturing. Since the outer surface of the PCB enclosure 2 is metallized and the ground connection between the PCB enclosure 2 and the base plate is good, the electromagnetic shielding effect of full metal packaging can be achieved after the cover plate 3 is assembled, so the electromagnetic shielding performance of the finished product is guaranteed, and the weight is lighter and the cost is low.
[0061] In this embodiment, the inner surface of the PCB enclosure 2 is not provided with any printed circuit microstrip, and is subjected to insulation coating treatment, which can significantly reduce the insulation safety distance under the premise of ensuring insulation performance, and the effect is that the volume can be reduced. Or under the condition of the same insulation safety distance, the line-to-ground insulation performance is better, and the line-to-ground voltage withstand capacity is stronger, and the effect is that the product reliability is higher.
[0062] In summary, the technical solution of this embodiment solves the technical problem of realizing miniaturization, surface mounting, sealing, light weight, full electromagnetic shielding effectiveness, and high-reliability packaging at low cost in the art.
[0063] In this embodiment, Figures 1 to 36 As shown, the top of the PCB frame 2 is metallized. Specifically, a metal layer is plated on the top of the PCB frame 2, or thick copper is vertically electroplated by LDI, or a very thin metal sealing ring 4 is assembled by reflow soldering or vacuum eutectic soldering. More specifically, if the cover plate 3 is assembled by hot melt sealing or parallel seam soldering, the top surface of the PCB enclosure 2 only needs to be plated with a metal layer to ensure the weldability of the plated layer; if the cover plate 3 is assembled by parallel seam welding, a very thin metal sealing ring 4 needs to be welded by eutectic welding on the top of the PCB enclosure 2, and the material and surface coating of the metal sealing ring should also meet the requirements of the parallel seam welding process; if the cover plate 3 is assembled by laser seam welding, a thick copper plated by LDI vertical electroplating process needs to be used on the top surface of the PCB enclosure 2, or a very thin metal sealing ring 4 with a sinking platform needs to be assembled by reflow soldering or vacuum eutectic soldering. In order to meet the requirements of the laser seam welding process, the thick copper plated by LDI needs to be milled into a sinking platform 22, and the surface coating of the sinking platform and the material and surface coating of the metal sealing ring 4 should also meet the requirements of the laser seam welding process. In this solution, there are multiple process solutions available for realizing the PCB enclosure 2, and all of them can make the packaged finished product meet the requirements of air tightness and electromagnetic shielding performance, and can also meet the requirements of lightweight and low cost.
[0064] In this embodiment, Figure 1 , Figure 5 , Figure 8 The Cx1 / Cx2 printed in the silk screen indicates the pads for assembling the line-to-line capacitors of the EM I filter, the Cy1 / Cy2 indicates the pads for assembling the line-to-ground capacitors of the EM I filter, and the Ly indicates the pads for assembling the common-mode choke of the EM I filter.
[0065] In this embodiment, Figures 1 to 36 As shown, the middle of the PCB bottom plate 1 is provided with a first middle groove 12 for accommodating high components such as chokes and inductors, and the middle of the cover plate 3 is provided with a second middle groove 31 for accommodating high components such as chokes and inductors. This design can fully and effectively utilize the internal space, reduce the height of the package, and is conducive to miniaturization and lightweight.
[0066] In this embodiment, the PCB base plate 1 is a double-layer or multi-layer PCB printed circuit board. The upper surface of the PCB base plate 1 is provided with a first printed circuit microstrip for assembling components constituting devices, components and filters, such as capacitors, resistors, inductors and chokes; the lower surface of the PCB base plate 1 is provided with a second printed circuit microstrip for assembling devices, components and filters at the user's site; the PCB base plate 1 is provided with a via hole for connecting the first printed circuit microstrip and the second printed circuit microstrip, and the via hole is metallized and filled by plugging and electroplating.
[0067] In this embodiment, the cover plate 3 is a metal cover plate or a PCB cover plate with double-sided metallization. If the cover plate 3 is a PCB cover plate, it is assembled with the PCB frame 2 by using a hot melt sealing process, and the outer surface of the PCB cover plate is 100% metallized (the edge of the PCB cover plate can also be metal-wrapped), and a printed microstrip matching the welding position of the inner surface and the frame is provided, and a suitable via hole is provided here, the via hole is metallized, and the hole is filled and leveled by electroplating, the non-welding area is not provided with a printed microstrip, and the non-welding area of the inner surface of the PCB cover plate is subjected to an insulation coating treatment; if the cover plate 3 is a metal cover plate, the hot melt sealing process, the parallel seam soldering process, the parallel seam welding process or the laser seam welding process can all realize the assembly of the cover plate 3 and the PCB frame 2, and if the insulation safety distance is tight, the inner side of the metal cover plate must be subjected to insulation treatment, and the insulation treatment includes spraying an insulation film, bonding an insulation film or an insulation plate.
[0068] In this embodiment, Figures 1 to 36As shown, the hot melt sealing process is implemented by a first tool, which includes a welding tool base 5 for placing multiple cover plates 3, a welding tool fixing plate 6 for fixing multiple PCB enclosures 2, and a welding tool pressure cover 7 for compacting the PCB enclosure 2 and the cover plate 3. The welding tool base 5 is a plate-shaped component, and a plurality of first grooves 51 adapted to the cover plate 3 are provided on the welding tool base 5. The depth of the first groove 51 is equal to the thickness of the cover plate 3. Both sides of the first groove 51 are provided with fixing bolts 52 for fixing the welding tool fixing plate 6 and the welding tool pressure cover 7. The welding tool pressure cover 7 is provided with a second groove 73 adapted to the PCB bottom plate 1. The depth of the second groove 73 is equal to or slightly less than the thickness of the PCB bottom plate 1. The welding tool fixing plate 6 is a plate-shaped component, and a plurality of first through grooves 61 matched with the PCB enclosure 2 are provided on the welding tool fixing plate 6.
[0069] The assembly of the cover plate by parallel seam welding, parallel seam soldering or laser seam welding process is implemented by a second tooling, which includes a seam welding tooling fixture 8, on which a third groove 81 adapted to the above-mentioned sealed part and a fourth through hole 82 fixed on the equipment instrument are provided.
[0070] More specifically, if the welding fixture base 5 is used to assemble the cover plate, the depth of the first groove 51 is equal to the thickness of the cover plate 3. If the welding fixture base 5 is used to assemble the metal sealing ring 4, the depth of the first groove 51 is equal to the height of the metal sealing ring 4. The two sides of the first groove 51 are provided with fixing bolts 52 for fixing the welding fixture fixing plate 6 and the pressure cover 7. The welding fixture fixing plate 6 is a plate-like structure, with a plurality of first through grooves 61 adapted to the size of the PCB enclosure 2 and first through holes 62 for fixing. The thickness of the fixing plate is slightly smaller than the height of the PCB enclosure 2. The first through holes 62 are slid to cover the fixing bolts 52 and are installed on the welding fixture base 5. If the cover plate is assembled by the hot melt sealing process, the welding fixture fixing plate 6 is made of a material that is resistant to high temperatures and has good thermal insulation. If the metal sealing ring is assembled by vacuum welding, the welding fixture fixing plate 6 is made of a metal material with good thermal conductivity. The welding tool pressure cover 7 is a metal device with suitable weight, good heat transfer performance and a second groove 73 on the bottom surface. The second through hole 72 is slid to cover the fixing bolt 52 and is installed on the welding tool fixing plate 6. A second groove 73 is provided that matches the size of the PCB bottom plate 1. The depth of the second groove 73 is equal to or slightly less than the thickness of the PCB bottom plate 1 to ensure that the welding tool pressure cover 7 can compact the PCB bottom plate 1 when the cover plate and the surrounding frame are assembled. If the welding tool pressure cover 7 is used to assemble the cover plate by the hot stage method to realize the hot melt sealing process, a heat dissipation tooth 71 is also provided on the top. In this scheme, the hot melt sealing process requires the welding tool base 5, the welding tool fixing plate 6, and the welding tool pressure cover 7. The welding tool base 5 adopts a blind groove design. The length and width of the first groove 51 of the welding tool base 5 match well with the length and width of the cover plate 3 to achieve a tight fit and prevent the cover plate 3 from shifting; the depth of the first groove 51 is equal to the thickness of the cover plate 3, which can be used as a welding tool base and also as a solder paste coating tool, with two uses in one. The welding tool base 5 is made of a metal material with good heat conduction. The welding tool fixing plate 6 is provided with a first through groove 61 that matches well with the length and width of the PCB frame 2 to achieve a tight fit, preventing the PCB frame 2 and the cover plate 3 from being misaligned when assembled. The welding tool pressure cover 7 is made of a metal material with good thermal conductivity, and its top end is provided with or without heat dissipation teeth 71 as appropriate; its bottom end is provided with a groove 73 for clamping the PCB bottom plate of the part to be sealed. If the hot stage method is used to realize the hot melt sealing process to assemble the cover plate, the top of the welding tool pressure cover 7 needs to be provided with heat dissipation teeth 71; if the reflow soldering or vacuum eutectic soldering method is used to realize the hot melt sealing process to assemble the cover plate, the top of the welding tool pressure cover 7 is not provided with heat dissipation teeth. Each part to be sealed uses an independent welding tool pressure cover 7, and the weight of the welding tool pressure cover 7 is directly used to compact the frame and the cover plate instead of using screw locking method. The purpose is to better ensure that the four sides of each frame are evenly stressed and the force is appropriate. During welding, it is helpful to discharge the gas inside the weld between the frame and the cover plate, so as to achieve a dense weld without pores.The seam welding assembly cover plate used for laser seam welding, parallel seam welding and parallel seam soldering requires a seam welding fixture 8.
[0071] It should be supplemented that: if the parallel seam soldering process or the parallel seam welding process is used to assemble the cover plate, when the cover plate 3 is relatively thick, the edge must be designed as a boss (the first edge boss 32) to satisfy the parallel seam welding process.
[0072] If necessary, a groove (second middle groove 31) can be cut in the middle of the cover plate 3 for high components according to actual conditions, which can ensure strength and fully and effectively utilize the internal space, which is conducive to miniaturization and lightweight.
[0073] If a hot plate, reflow soldering or vacuum eutectic soldering method is used to realize the hot melt sealing process to assemble the cover plate, the cover plate 3 can be an all-metal cover plate or a PCB cover plate. If the solder is solder paste, the solder paste is applied to the cover plate 3 using a welding tool base and a steel mesh. The welding tool base 5 adopts a groove design. A cover plate 3 is placed in each groove (first groove 51), and the inner surface of the cover plate 3 faces upward. The length and width of the first groove 51 of the welding tool base 5 are tightly matched with the length and width of the cover plate 3, and the depth is the same as the thickness of the cover plate, which can avoid displacement during the coating of solder paste and welding, and facilitate the coating of solder paste. Placing a steel mesh on the welding tool base 5 for solder paste coating can ensure the quality, efficiency and coating rate of solder paste coating. Remove the steel mesh, there is no need to remove the cover plate, and directly place the welding tool fixing plate 6 on the welding tool base 5. If the solder is a solder sheet, after placing the cover plate 3 into the first groove 51 of the welding tool base 5, place the solder sheet on the cover plate 3, and place the welding tool fixing plate 6 on the welding tool base 5. Then place the part to be sealed into the first through groove 61 of the welding tool fixing plate 6, so that it is upside down on the solder, and buckle a welding tool pressure cover 7 for each part to be sealed, so that the second groove 73 covers the bottom plate of the part to be sealed. If the hot stage method is used to realize the hot melt sealing process to assemble the cover plate, the prepared welding tool and the part to be sealed are placed on the hot stage, and the heating stage is started to assemble the cover plate and the frame of the part to be sealed together. If the reflow soldering or vacuum eutectic soldering method is used to realize the hot melt sealing process to assemble the cover plate, the prepared welding tool and the part to be sealed are placed in the reflow soldering furnace or the vacuum eutectic soldering furnace, and the equipment is started to assemble the cover plate and the frame of the part to be sealed together.
[0074] If the parallel soldering process is used to assemble the cover plate, the cover plate 3 must be a metal cover plate. First, place the part to be sealed into the third groove 81 of the seam welding fixture 8, then place the solder sheet and the cover plate 3 on the top of the PCB frame 2 in sequence, and assemble the cover plate and the frame of the part to be sealed together using a parallel seam welding instrument.
[0075] If the parallel seam welding process is used to assemble the cover plate, the cover plate 3 must be a metal cover plate. First, place the metal sealing ring 4 in the first groove 51 of the welding tool base 5, place a solder sheet or use a steel mesh to coat the solder paste on the metal sealing ring 4, place the welding tool fixing plate 6 on the welding tool base 5, place the PCB enclosure in the first through groove 61 of the welding tool fixing plate 6, and put it upside down on the solder, then buckle the welding tool pressure cover 7, and use reflow soldering or vacuum eutectic welding to assemble the PCB enclosure 2 and the metal sealing ring 4 together. Put the part to be sealed into the third groove 81 of the seam welding tool fixture 8, then place the cover plate 3, and finally use the parallel seam welding instrument to assemble the cover plate.
[0076] If the cover plate is assembled by laser seam welding, the cover plate 3 must be a metal cover plate. The top of the PCB frame is vertically electroplated with thick copper by LD I, and a sinking platform for placing the cover plate 3 is milled on the edge; or a metal sealing ring 4 with a sinking platform is assembled on the top of the PCB frame 2 by reflow soldering or vacuum eutectic welding (the method is as described above). The part to be sealed is placed in the third groove 81 of the seam welding fixture 8, and then the cover plate 3 is placed, and finally the cover plate is assembled by parallel laser seam welding equipment.
[0077] It should be noted that the above-mentioned welding tool base 5 can be used as both a solder paste coating tool and a welding base. If it is used to assemble the cover plate 3, a groove (first groove 51) for placing the cover plate 3 is provided. In a specific example, the first groove 51 can be provided in a 3×3 rectangular array. The length and width of the first groove 51 are tightly matched with the length and width of the cover plate 3, and its depth is equal to the thickness of the cover plate 3. If it is used to assemble the metal sealing ring 4 and the PCB frame 2, a groove (first groove 51) for placing the metal sealing ring 4 is provided. The length and width of the first groove 51 are tightly matched with the length and width of the metal sealing ring 4, and its depth is equal to the height of the metal sealing ring 4.
[0078] It should be noted that the welding fixture fixing plate 6 is provided with a through slot (first through slot 61) for fixing the parts to be sealed. In a specific example, the first through slot 61 can be arranged in a 3×3 rectangular array. The length and width of the first through slot 61 match the length and width of the frame, and the depth can be slightly smaller than the height of the frame. If the hot stage method is used to implement the hot melt sealing process to assemble the cover plate, the welding fixture fixing plate 6 is made of high-temperature resistant material with good thermal insulation performance. It can play an insulating role when assembling the cover plate, so that the internal component solder joints are protected from secondary melting due to high temperature. If it is used for reflow soldering or vacuum eutectic soldering to assemble the PCB frame 2 and the metal sealing ring 4, it is made of high-temperature resistant metal material with good thermal conductivity. The purpose is to have good heat transfer during welding, which is conducive to ensuring excellent welding quality.
[0079] It should be supplemented that: the above-mentioned welding tooling cover 7 adopts a groove design and can be made of a high-temperature resistant metal material with good thermal conductivity. Each enclosure uses a welding tooling cover 7 separately. The length and width of the groove (second groove 73) match the length and width of the bottom plate 2. When in use, the second through hole 72 is sleeved on the fixing bolt 52 of the welding tooling base 5, which plays the role of positioning and fixing the welding tooling cover 7, and evenly transfers the weight pressure of the welding tooling cover 7 to each side of the enclosure, so as to achieve the effect of compacting the enclosure and the cover plate or metal sealing ring. In addition, if the hot stage method is used to realize the hot melt sealing process to assemble the cover plate, the top of the welding tooling cover 7 is provided with a heat dissipation tooth 71, the purpose of which is to avoid secondary melting of the internal solder joints of the device to be sealed due to high temperature during welding. If the reflow soldering or vacuum eutectic soldering method is used to realize the hot melt sealing process to assemble the cover plate or the sealing metal ring, the top of the welding tooling cover 7 is not provided with a heat dissipation tooth. In order to achieve the effect of compacting the frame and the cover plate or the metal sealing ring by utilizing the weight of the welding tooling cover itself, it is necessary to optimize the design of the dimensions of each part through mechanical simulation calculation.
[0080] In this embodiment, the packaging process of the sealed small surface mount packaging device for components and assemblies implemented by PCB is as follows:
[0081] Plan 1 is as follows:
[0082] Step 1: Use PCB process to make the PCB bottom plate and PCB frame into one piece, metallize the outer surface and top surface of the PCB frame (for example, copper plating, nickel plating, and gold plating), and connect the outer surface with the top surface as one piece. The purpose of the metallization layer on the outer surface and its connection with the top surface as one piece is to ensure electromagnetic shielding performance. The metallization layer on the top surface is for the subsequent assembly of the cover plate by the melting sealing process.
[0083] Step 2: Perform insulation coating treatment on the inner surface of the PCB frame;
[0084] Step 3: Apply solder paste to the printed circuit microstrip on the front of the base plate, place the components and perform reflow soldering to complete the assembly of internal components;
[0085] Step 4: After cleaning, debugging, internal three-proofing, gluing or potting, the parts become ready for sealing, and the capping is done after the glue is completely cured;
[0086] Step 5. If a metal cover is used, proceed directly to step 6. If a PCB cover is used, the outer surface of the PCB cover is 100% metallized (the edge of the PCB cover can also be metal-wrapped), and the inner surface of the PCB cover is provided with a matching printed microstrip only at the welding position with the PCB frame, and a suitable via hole is provided here. The via hole is metallized and filled with plugging electroplating, and the non-welding area on the inner surface of the PCB cover is subjected to insulation coating.
[0087] Step 6: If necessary, insulate the interior first, and then assemble the cover, as follows:
[0088] Assembling the cover plate by hot melt sealing process: the first tooling is required to be used, the metal cover plate or PCB cover plate is placed in the first groove, with the inner side of the cover plate facing upwards, and then solder paste is applied to the area to be soldered by screen printing, or a solder sheet is directly placed, and then a welding tooling fixing plate is placed on the welding tooling bottom bracket, and the part to be sealed is placed in the first through groove, so that it is inverted on the solder paste or solder sheet, and then the welding tooling pressure cover is assembled on the fixing bolt, and the PCB bottom plate is sunk into the second groove of the welding tooling pressure cover and compacted, and then the heating table, reflow soldering furnace or vacuum eutectic soldering furnace is started to complete the assembly of the cover plate;
[0089] Or the cover plate is assembled by parallel seam soldering process: the part to be sealed is placed in the third groove of the above-mentioned seam welding fixture, a solder sheet is placed on the top surface of the frame of the part to be sealed, and then the metal cover plate is placed on the solder sheet, and finally the parallel seam welding equipment is started to complete the assembly of the cover plate;
[0090] Step 7: Remove the finished product for laser marking;
[0091] Step 8: Coating the finished product with a protective agent (depending on the device application, coating with a thin film protective agent or a conformal coating, or a combination of thin film protective agent coating and conformal coating coating)
[0092] In this scheme, if the cover plate is assembled by hot melt sealing process, the cover plate can be a metal cover plate or a PCB cover plate with double-sided metallization. The middle of the inner side of the cover plate can be grooved for high components according to actual conditions. It can not only ensure strength, but also make full and effective use of the internal space, which is conducive to miniaturization. If the cover plate adopts a PCB cover plate with double-sided metallization, the outer surface is 100% metallized, and the inner surface is only provided with a printed circuit microstrip at the part that needs to be welded with the PCB frame, and the surface is plated with a metal layer to ensure solderability. The remaining parts are not provided with a printed circuit microstrip, and an insulation coating treatment is performed. Under the premise of ensuring insulation performance, the insulation safety distance can be greatly saved, which is conducive to miniaturization, or the insulation performance can be greatly improved under the original insulation safety distance conditions, and the reliability is improved; and a suitable conductive hole is provided, the conductive hole is metallized, and the plug hole is electroplated and filled. The suitable electrical conductive hole can ensure the electromagnetic shielding performance of the package, and the plug hole electroplating and filling can ensure the sealing performance of the package. With the metal treatment of the surface, the appearance is free of marks, and it is as flat and beautiful as a metal cover plate.
[0093] In this solution, the edge of the cover plate can be designed as a boss when necessary to solve the matching problem between the cover plate and the frame. If the cover plate is assembled by parallel seam soldering process, when the cover plate is thick, the edge must be designed as a boss to meet the requirements of parallel seam welding process.
[0094] Plan 2: Details are as follows:
[0095] Step 1: Use PCB technology to make the PCB bottom plate and PCB frame into one piece, metallize the outer surface and top surface of the PCB frame (for example, copper plating, nickel plating, and gold plating), and connect the outer surface and the top surface as one piece. The purpose of the metallization layer on the outer surface and its connection with the top surface as one piece is to ensure electromagnetic shielding performance. The metallization layer on the top surface is for the subsequent assembly of the metal sealing ring. The treatment of the metal sealing ring assembled on the top of the PCB frame is as follows:
[0096] According to the specific situation, a reflow soldering or vacuum eutectic soldering process is selected to assemble a very thin metal sealing ring on the top of the PCB frame. The first tooling is required for implementation. Specifically, the metal sealing ring is first placed in the first groove of the welding tooling base; then a solder sheet is placed on the metal sealing ring or solder paste is coated on the steel mesh; then a metal welding tooling fixing plate is placed; thereafter, a whole piece of the PCB bottom plate and the PCB frame formed in one piece is placed in the through groove of the welding tooling fixing plate; a welding tooling pressure cover is placed on each whole piece of the PCB bottom plate, and the above-mentioned PCB bottom plate is sunk into the second groove of the above-mentioned assembly welding tooling pressure cover and compacted; finally, the PCB frame and the metal sealing ring are placed in a reflow soldering furnace or a vacuum eutectic soldering furnace to complete the assembly;
[0097] Step 2: Perform insulation coating treatment on the inner surface of the PCB frame;
[0098] Step 3: Apply solder paste to the printed circuit microstrip on the front of the base plate, place the components and perform reflow soldering to complete the assembly of internal components;
[0099] Step 4: After cleaning, debugging, internal three-proofing, gluing or potting, the parts become ready for sealing, and the capping is done after the glue is completely cured;
[0100] Step 5: If necessary, insulate the interior first, and then assemble the cover, as follows:
[0101] Assemble the cover plate by using the parallel seam welding process: put the part to be sealed into the third groove of the above-mentioned seam welding fixture, place the metal cover plate on the top of the PCB frame, and then use the parallel seam welding equipment to complete the assembly of the cover plate;
[0102] Step 6: Remove the finished product for laser marking;
[0103] Step 7: Coating the finished product with a protective agent (depending on the device application, coating with a thin film protective agent or a conformal coating, or a combination of thin film protective agent coating and conformal coating coating)
[0104] In this solution, the edge of the cover plate is designed as a boss when necessary, and grooves can be cut in the middle for tall components according to actual conditions when necessary. This not only meets the parallel seam welding process requirements, but also ensures strength, fully and effectively utilizes the internal space, and is conducive to miniaturization and lightweight.
[0105] Option 3 is as follows:
[0106] Step 1: Use PCB technology to make the PCB bottom plate and PCB frame integrally formed, metallize the outer surface of the PCB frame (for example, copper plating, nickel plating, and gold plating), and metallize the top of the PCB frame. The top of the PCB frame is processed as follows:
[0107] The top surface of the PCB enclosure is plated with thick copper using LDI vertical electroplating, and a sink for placing the cover plate is milled out on the edge. The thick copper on the top of the enclosure is connected to the metal layer on the outer surface of the enclosure as a whole, and then the thick copper on the top of the enclosure is surface treated according to the laser seam welding process requirements;
[0108] Or assemble a thin metal sealing ring with a surface treatment and a recessed platform on the edge according to the method in step 1 of the above scheme 2;
[0109] Step 2: Perform insulation coating treatment on the inner surface of the PCB frame;
[0110] Step 3: Apply solder paste to the printed circuit microstrip on the front of the base plate, place the components and perform reflow soldering to complete the assembly of internal components;
[0111] Step 4: After cleaning, debugging, internal three-proofing, gluing or potting, the parts become ready for sealing, and the capping is done after the glue is completely cured;
[0112] Step 5: If necessary, insulate the interior first, and then assemble the cover, as follows:
[0113] Using laser seam welding process: put the part to be sealed into the third groove of the above-mentioned seam welding fixture, place the metal cover plate on the sink table on the top of the enclosure frame, and then use laser seam welding equipment to complete the assembly of the cover plate;
[0114] Step 6: Remove the finished product for laser marking;
[0115] Step 7: Coating the finished product with a protective agent (depending on the device application, coating with a thin film protective agent or a conformal coating, or a combination of thin film protective agent coating and conformal coating coating)
[0116] In this solution, the top surface of the PCB enclosure is vertically plated with thick copper using LDI, and the edge is milled into a groove platform, and then the surface is treated according to the laser seam welding process requirements to facilitate laser seam welding of the metal cover plate; or the top surface of the PCB enclosure is metallized, and then a surface-treated thin metal sealing ring with a groove platform is assembled. The metal layer on the outer surface of the PCB enclosure is connected to the sealing ring on the top of the PCB enclosure to achieve the same electromagnetic shielding effect as the metal enclosure. Although both laser seam welding and parallel seam welding can achieve a very high level of airtightness, compared with parallel seam welding, laser seam welding can also seam weld special-shaped covers with inner chamfers, which can meet applications with special requirements for packaging structure and appearance.
[0117] The sealed small surface mount packaging device and process for devices and components implemented by the PCB of this embodiment have the following advantages:
[0118] (1) The PCB base plate is a dual-purpose device, eliminating the base plate of traditional device, component and filter packaging; the PCB base plate and the PCB frame are integrally formed using the PCB process, eliminating the assembly process of the frame and the base plate, the base plate and the substrate, or the frame and the substrate in the traditional discrete surface mount sealed packaging design. It not only meets the needs of miniaturization, surface mounting, and sealing, but also reduces weight and saves costs. (2) The PCB base plate and the PCB frame are integrally formed using the PCB process, eliminating the assembly process of the frame and the substrate in the traditional surface mount sealed packaging without a base plate. (3) The outer surface of the PCB frame is 100% metallized using vacuum vapor deposition, wet chemical deposition or additive manufacturing, and its metal layer is well electrically connected to the ground of the PCB base plate. First, it is conducive to enhancing airtightness, and second, it can ensure electromagnetic shielding performance. (4) No printed circuit strip is set on the inside of the PCB enclosure, and only the printed circuit strip matching the welding part of the enclosure is set on the inside of the PCB cover. No printed circuit strip is set on the other parts, and the non-welding area on the inside of the PCB enclosure and the inside of the PCB cover is treated with insulation coating. Under the premise of ensuring the insulation performance and the line-to-ground withstand voltage performance, the insulation safety gap can be greatly reduced, thereby achieving miniaturization, or under the condition of the same insulation safety gap, the insulation performance is better, the line-to-ground withstand voltage capability is stronger, and the product reliability is higher. (5) There are four processes for cover assembly: Option 1 is to place a solder sheet on the top of the PCB frame and then use parallel seam welding to weld the metal cover. Compared with the traditional surface mount sealed package, it is unnecessary to assemble the metal frame or metal sealing ring. Option 2 is to use solder sheet or solder paste and use hot melt sealing process to assemble the metal cover or double-sided metallized PCB cover. Compared with the traditional surface mount sealed package, it is unnecessary to assemble the metal frame, metal sealing ring and metal cover, and the size and weight can be reduced. Option 3 is to use reflow soldering or eutectic soldering of a very thin metal sealing ring on the top surface of the above-mentioned PCB frame, and then use parallel seam welding or laser seam welding to weld the metal cover. Compared with the metal frame used in the traditional surface mount sealed package, the length and width can be appropriately reduced and the weight can be reduced. Option 4 is to use LD I vertically electroplated thick copper on the top surface of the above-mentioned PCB frame, milling a sink table and surface treatment, and then use laser seam welding to assemble the metal cover. IThe vertically plated copper has a strong adhesion to the PCB frame and good density, and the airtightness of the device package is guaranteed. Compared with the traditional surface mount sealed package using a metal frame, the volume can be appropriately reduced and the weight can be reduced. This utility model patent provides a low-cost solution for small surface mount, sealed, lightweight, and universal packaging.The beneficial effects are as follows: the metal cover plate cooperates with the PCB enclosure with 100% metallized outer surface to realize the assembly and device packaging, the ground of the PCB bottom plate is well electrically connected with the metal layer on the outer surface of the PCB enclosure, and the metal layer on the outer surface of the PCB enclosure is well electrically connected with the metal cover plate, so the full electromagnetic shielding performance of the product can be guaranteed; even if the PCB cover plate is used, since the outer surface of the PCB cover plate is 100% metallized, the inner side of the PCB cover plate and the welding position of the PCB enclosure are provided with a matching printed microstrip, and a suitable via hole is provided here, the via hole is metallized, and the via hole is filled and leveled by plugging and electroplating, so the double-sided metallized PCB cover plate cooperates with the PCB enclosure design with 100% metallized outer surface to realize the assembly and device packaging, the ground of the PCB bottom plate and The metal layer on the outer surface of the PCB frame is well electrically connected, and the metal layer on the outer surface of the PCB frame is well electrically connected to the metal layer on the outer surface of the PCB cover plate, so the electromagnetic shielding performance of the package is guaranteed, and the appearance of the package is also guaranteed, the volume can be reduced, the weight can be reduced, and the line-to-ground insulation performance and voltage resistance performance are good; in addition, the hot melt sealing process, parallel seam welding process, parallel seam soldering process, and laser seam welding process are very mature, low cost, and the air tightness of the finished product is guaranteed; furthermore, even if a thin metal sealing ring is assembled and then the metal cover plate is assembled by parallel seam welding or laser seam welding, since the main body of the PCB frame is made of non-metallic material, compared with the full metal frame and metal cover plate used in the traditional substrate-type surface mount sealed package, the weight can be reduced and the volume can be reduced.
[0119] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.
Claims
1. A sealed small surface mount packaging device for PCB-implemented devices and components, characterized in that: It includes a PCB base plate, a PCB frame and a cover plate. The PCB frame is arranged on the PCB base plate, and the two are integrally formed. The cover plate is packaged on the upper end of the PCB frame.
2. The sealed small surface mount packaging device for components and assemblies implemented by PCB according to claim 1, characterized in that: The outer surface of the PCB frame is 100% metallized by vacuum vapor deposition, wet chemical deposition or additive manufacturing.
3. The sealed small surface mount packaging device for components and assemblies implemented by PCB according to claim 2, characterized in that: The inner surface of the PCB frame is subjected to insulation coating treatment.
4. The sealed small surface mount packaging device for components and assemblies implemented by PCB according to claim 3, characterized in that: The top of the PCB frame is metallized.
5. The sealed small surface mount packaging device for components and assemblies implemented by PCB according to claim 4, characterized in that: A first middle groove for accommodating tall components is provided in the middle of the PCB bottom plate, and a second middle groove for accommodating tall components is provided in the middle of the cover plate.
6. The sealed small surface mount packaging device for components and assemblies implemented by PCB according to claim 5, characterized in that: The PCB base plate is a double-layer or multi-layer PCB printed circuit board. The upper surface of the PCB base plate is provided with a first printed circuit microstrip for assembling components constituting devices, components and filters; the lower surface of the PCB base plate is provided with a second printed circuit microstrip for assembling devices, components and filters at the user's site; the PCB base plate is provided with a via hole for connecting the first printed circuit microstrip and the second printed circuit microstrip, and the via hole is metallized and filled by plugging electroplating.
7. The sealed small surface mount packaging device for components and assemblies implemented by PCB according to claim 6, characterized in that: The cover plate is a metal cover plate or a PCB cover plate with double-sided metallization. If the cover plate is a PCB cover plate, it is assembled with the PCB frame by using a hot melt sealing process, and the outer surface of the PCB cover plate is 100% metallized, and a printed microstrip matching the welding position of the inner surface and the frame is provided, and a suitable via hole is provided here, the via hole is metallized, and the hole is filled and leveled by electroplating, and the non-welding area of the inner surface of the PCB cover plate is subjected to insulation coating treatment; if the cover plate is a metal cover plate, it can be assembled with the PCB frame by using a hot melt sealing process, or a parallel seam soldering process, or a parallel seam welding process, or a laser seam welding process, and when the insulation safety distance is tight, the inner side of the metal cover plate must be subjected to insulation treatment, and the insulation treatment includes spraying an insulation film, bonding an insulation film or an insulation plate.
8. The sealed small surface mount packaging device for components and assemblies implemented by PCB according to claim 7, characterized in that: The hot melt sealing process is implemented by using a first tool, which includes a welding tool bottom bracket for placing multiple cover plates, a welding tool fixing plate for fixing multiple enclosures, and a welding tool pressure cover for compacting the enclosures and the cover plates. The welding tool bottom bracket is a plate-shaped component, and a plurality of first grooves adapted to the cover plates are provided on the welding tool bottom bracket. The depth of the first groove is equal to the thickness of the cover plate. Both sides of the first groove are provided with fixing bolts for fixing the welding tool fixing plate and the welding tool pressure cover. The welding tool pressure cover is provided with a second groove adapted to the PCB bottom plate. The depth of the second groove is equal to or slightly less than the thickness of the PCB bottom plate. The welding tool fixing plate is a plate-shaped component, and a plurality of first through grooves matched with the enclosure frames are provided on the welding tool fixing plate. The assembly of the cover plate by parallel seam welding process, parallel seam soldering process or laser seam welding process is implemented by using a second tool, and the second tool includes a seam welding tool fixture, and the seam welding tool fixture is provided with a third groove adapted to the part to be sealed.