An inner frame for a switching power supply

Abstract

This utility model discloses an inner frame for a switching power supply, mainly comprising a plastic base for use with the main circuit board and sub-circuit boards of the switching power supply. The main body of the base is a rectangular, perforated, "I"-shaped plate structure for assembling with the main circuit board body with a basically overlapping outer contour. Support ribs and bracket plates stand on both sides of the base. The support ribs support the main circuit board and sub-circuit boards, and the bracket plates limit and hold the main circuit board and sub-circuit boards in a pre-positioned manner. Compared with the prior art, the PCB circuit board assembly of this utility model enables the power supply to achieve high power and small size.

Description

Technical Field

[0001] This utility model relates to the field of AC / DC switching power supplies, and in particular to the internal frame of a high-power, high-power-density, small-volume AC / DC switching power supply. Background Technology

[0002] Switching power supply modules are power supplies that can be directly mounted on printed circuit boards. They can power application-specific integrated circuits, processors, memory, and digital or analog loads, and are widely used in industrial control, power instrumentation, and smart home applications where size requirements are stringent.

[0003] Switching power supply modules can be broadly categorized into AC / DC and DC / DC converters. DC / DC converters have achieved modularization, and their design technology and manufacturing processes are mature and standardized both domestically and internationally. However, the modularization of AC / DC converters, due to their inherent characteristics, encounters more complex technical and manufacturing challenges during the modularization process. The most prominent issue lies in the size constraint; a 30W AC / DC switching power supply module is 2.5 times the size of a comparable DC / DC converter.

[0004] As analyzed above, current AC / DC switching power supply modules on the market struggle to balance size, performance, and price. Conventional stacked structures have low production efficiency, are difficult to automate in terms of manufacturing processes, and suffer from poor stability, insufficient strength, and susceptibility to deformation. Utility Model Content

[0005] In view of the above problems, the present invention aims to overcome at least one of the shortcomings of the prior art and provide a new type of internal frame for switching power supplies, which can not only support the realization of all existing electrical performance, but also further improve the power density of the package structure, making the switching power supply product more miniaturized.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] An inner frame for a switching power supply mainly includes a plastic base for use with the main circuit board and sub-circuit board of the switching power supply. The main body of the base is a rectangular "I"-shaped plate structure. A first hole is opened between the two sides of the base to form a safety distance separating the magnetic core of the planar transformer from the secondary side. Support plates and / or support bones are erected on both sides of the first hole of the base. The support plates on the outer side of the first hole of the base extend at both ends in the vertical direction along the plate surface of the base.

[0008] Preferably, a support plate is erected on the outer side of the first hole of the base to form a retaining wall for the planar transformer.

[0009] Preferably, the support plate is a plate-shaped structure, integrally formed with the base, and its outer wall is flush with the edge side wall of the base.

[0010] Preferably, the top and bottom ends of the support plate are provided with protruding claws, and the top and / or bottom surfaces of the support plate that are lower than the protruding claws form a support surface.

[0011] Preferably, the supporting bone is a columnar structure that protrudes along the inner side of the support plate.

[0012] Preferably, the base further includes PIN pin holders, which are respectively disposed on both sides of the base and integrally formed with the base, and the outer wall of the PIN pin holders is flush with the side wall of the base; and / or the PIN pin holders are arranged in a single row along the edge of the base; and / or the PIN pin holders of the base are provided with PIN pins, which are metal leads.

[0013] Preferably, the upper end of the PIN holder has a notch to form a space for accommodating excess solder during PIN soldering.

[0014] Preferably, the inner frame has a flat overall shape, with the main body being a rectangular frame, and thin protrusions extending from both ends of the frame along the vertical direction of the edge.

[0015] Preferably, the base has a second hole for some components to protrude from the base plane.

[0016] Preferably, the base has thin raised strips along its edge to serve as reinforcing ribs for the base plate.

[0017] Compared with the prior art, the beneficial effects of the inner frame of the switching power supply of this utility model are as follows:

[0018] 1. The inner frame of the new switching power supply has PIN pins that are electrically connected on both sides, which are connected by injection molding plastic to form an inner frame. The PIN pin seats and the inner frame are provided with bosses to support the PCB. The PIN pin seats are designed with grooves to reserve space to store the solder after the product has been reflowed. In addition, the plastic inner frame is designed with several ribs to form pre-positioning with the PCB gaps, reducing the use of production jigs and fixtures and improving production efficiency. At the same time, in order to make the product miniaturize, the skeleton of tall components on the PCB is directly hollowed out to avoid them. The one-piece skeleton increases the strength of the product and ensures the spacing between the two PCBs.

[0019] 2. The inner frame of the new switching power supply can form a stacked combination structure in which the outer contours of the inner frame, sub-circuit board, and main circuit board are basically overlapped, which can increase the power density of the switching power supply product by more than 120% compared with the power density of existing products.

[0020] 3. The system optimization design adopts new packaging technology and optimized circuit. The inner frame can match the PCB circuit board assembly to carry the circuit that has been improved from the primary side feedback circuit to the secondary side feedback circuit, so that the miniaturized product structure of the switching power supply module can be applied to the power range of 30W to several hundred watts. Attached Figure Description

[0021] Figure 1 This is a three-dimensional exploded view of the inner frame of the switching power supply of this utility model;

[0022] Figure 2 This is an exploded perspective view of the inner frame of the switching power supply of this utility model.

[0023] Figure 3 This is a three-dimensional view of the assembled internal frame of the switching power supply of this utility model.

[0024] Figure 4 This is a perspective view of the assembled inner frame of the switching power supply of this utility model.

[0025] The reference numerals in the above figures are explained as follows:

[0026] Attached image labels:

[0027] 200 main circuit board

[0028] 300 sub-circuit boards

[0029] 400 planar transformer

[0030] 500 Inner frame, 510 Pin, 520 Base, 521 Support bone, 522 Bracket plate, 523 Raised bar, 524 PIN header, 525 Notch, 527 Claw, 528 Support surface, 530 Hole, 540 Hole Detailed Implementation

[0031] To meet the market's higher demand for high-power (e.g., above 30W) switching power supplies, it is necessary to improve the performance of primary-side feedback circuits, including voltage accuracy, load regulation, and voltage regulation. However, improving the electrical performance of existing primary-side feedback circuits at higher power requires high-performance components and a larger product size, significantly limiting the potential for miniaturization of the switching power supply package structure. Therefore, further miniaturization improvements require first modifying the circuit principle. Through systematic optimization analysis of the circuit topology, a secondary-side feedback method is preferred. However, this secondary-side feedback circuit requires the addition of optocouplers for isolation, which would inevitably increase the product's footprint if a traditional single-board design were used. Therefore, this invention proposes a two-layer structure, placing the optocouplers on a separate board, thus maintaining the overall footprint of the power supply product on the application board without increasing its size. This improves the electrical performance of the switching power supply while ensuring increased power density. Whether an electronic device meets electromagnetic compatibility (EMC) standards directly impacts its marketability; therefore, simultaneously considering EMC improvements during the miniaturization design of switching power supplies is crucial.

[0032] The present invention and its beneficial effects will be further described in detail below with reference to specific embodiments and accompanying drawings. However, the specific embodiments of the present invention are not limited thereto.

[0033] Please see Figures 1 to 3 The attached drawings show the inner frame of the switching power supply of this utility model. The inner frame 500 of the switching power supply mainly includes a plastic base 520, used to cooperate with the main circuit board 200 and sub-circuit board 300 of the switching power supply. The main body of the base is a rectangular "I"-shaped plate structure, used to assemble with the main circuit board body with its outer contour basically overlapping. Holes 530 are opened between the two sides of the base to form a safety distance separating the planar transformer core from the secondary side. During power supply product assembly, the core of the planar transformer 400 on the main circuit board 200 can be inserted into the holes 530. Whether a safety distance is maintained between the planar transformer core and the secondary side (i.e., the primary and secondary sides) can be determined by whether the power supply product meets the relevant safety certification requirements or has obtained relevant safety certifications. Because the required safety distance varies depending on the product performance according to relevant standards, the use of measurement methods to determine it is limited by the lack of uniform measurement standards. The interpretation of the measured safety distance may be inconsistent among different parties. However, power supply products generally need to meet the relevant requirements for safety certification. Power supply products that meet safety certification generally have a safety distance requirement for the separation between the primary and secondary sides, or in other words, an effective safety distance between the planar transformer core and the secondary side.

[0034] On both sides of the hole 530 of the base, there are support plates 522 and support bones 521. The support bones are used to support the main circuit board and the sub-circuit board, and the support plates are used to limit and hold the main circuit board and the sub-circuit board to form a pre-position, so as to reduce the use of production jigs and improve production efficiency. The support plates 522 on the outside of the hole 530 of the base extend out at both ends in the vertical direction of the base plate surface.

[0035] A support plate 522 is erected on the outer side of the hole 530 in the base to form a retaining wall for the planar transformer, thereby increasing the isolation performance of the planar transformer. Thin ridges 523 are provided along the edge of the base to serve as reinforcing ribs for the base plate.

[0036] The base also includes PIN holders 524, which are integrally formed with the base on both sides, and the outer wall of the PIN holders is flush with the side wall of the base. The PIN holders can be arranged in a single row along the edge of the base. A notch 525 is provided at the upper end of the PIN holder to create a reserved space for storing solder after reflow soldering of the power supply product; that is, a space to accommodate excess solder during PIN soldering. PINs, which are metal leads, can be provided on the PIN holders of the base to achieve electrical connection between the main circuit board and the sub-circuit board.

[0037] The support plate, a plate-like structure, is integrally formed with the base, and its outer wall is flush with the side wall of the base. The outer wall of the PIN holder of the base is flush with the side wall of the base. The overall outline of the base formed by the support plate 522 and the PIN holder 524 can substantially coincide with the outer outline of the main circuit board 200. The top and bottom ends of the support plate are provided with claws 527 for pre-positioning into the square slots on both sides of the main circuit board and the sub-circuit board, thereby reducing the use of production jigs and improving production efficiency. The top and bottom surfaces of the support plate, which are lower than the claws, form support surfaces 528 for supporting the main circuit board and the sub-circuit board.

[0038] The support bone 521 is a columnar structure that protrudes along the inner wall of the support plate. By stacking the support bone and the support plate, it makes the most efficient use of the narrow spaces between components on the circuit board. This saves internal space while providing effective support for both circuit boards, offering more possibilities for the design of key components in product miniaturization. In other embodiments, similar irregular columnar structures or reused support plate sections can be used to achieve the same or similar miniaturized support structure design functions.

[0039] The inner frame has a flat overall shape, with a rectangular main body and thin protrusions extending from both ends of the frame along the vertical direction of the edges. To further minimize the product's size, tall components on the PCB can be recessed into the inner frame to accommodate them. This integrated inner frame increases the power supply's strength while maintaining sufficient spacing between the two PCBs. Additionally, the base can have holes 540 for some components to protrude from the base surface.

[0040] Because the inner frame of this utility model's switching power supply can form a stacked combination structure where the outer contours of the inner frame, sub-circuit board, and main circuit board are basically overlapped, a novel double-layer packaging structure for the switching power supply can be realized, increasing the power density of the switching power supply product by more than 120% compared to existing products. When the switching power supply undergoes a systematic improvement design of its modular structure through the adoption of new packaging technology and optimized circuitry, the inner frame can match the PCB circuit board assembly to support circuits that have been improved from primary-side feedback circuits to secondary-side feedback circuits. Furthermore, the miniaturized and optimized structure of the switching power supply module structure can be extended to a power range from 30W to several hundred watts.

[0041] The embodiments of this utility model are not limited thereto. Based on the above content of this utility model, using common technical knowledge and conventional means in the field, without departing from the basic technical idea of ​​this utility model, the specific implementation circuit of this utility model can be modified, replaced or changed in many other forms, all of which fall within the protection scope of this utility model.

Claims

1. An inner frame for a switching power supply, mainly comprising a plastic base for use with the main circuit board and sub-circuit board of the switching power supply, characterized in that: The main body of the base is a rectangular "I"-shaped plate structure. A first hole is opened between the two sides of the base to form a safety distance separating the magnetic core and the secondary side of the planar transformer. Support plates and / or support bones are erected on both sides of the first hole of the base. The support plates on the outer side of the first hole of the base extend at both ends in the vertical direction along the plate surface of the base.

2. The inner frame of the switching power supply according to claim 1, characterized in that: A support plate is erected on the outside of the first hole of the base to form a retaining wall for the planar transformer.

3. The inner frame of the switching power supply according to claim 1, characterized in that: The support plate is a plate-shaped structure, integrally formed with the base, and its outer wall is flush with the edge side wall of the base.

4. The inner frame of the switching power supply according to claim 1, characterized in that: The top and bottom ends of the support plate are provided with protruding claws, and the top and / or bottom surfaces of the support plate that are lower than the protruding claws form a support surface.

5. The inner frame of the switching power supply according to claim 1, characterized in that: The supporting bone is a columnar structure that protrudes along the inner side of the support plate.

6. The inner frame of the switching power supply according to claim 1, characterized in that: The base also includes PIN pin holders, which are respectively disposed on both sides of the base and integrally formed with the base, and the outer wall of the PIN pin holders is flush with the side wall of the base; and / or the PIN pin holders are arranged in a single row along the edge of the base; and / or the PIN pin holders of the base are provided with PIN pins, which are metal leads.

7. The inner frame of the switching power supply according to claim 6, characterized in that: The upper end of the PIN holder has a notch to form a space for accommodating excess solder during PIN soldering.

8. The inner frame of the switching power supply according to claim 6, characterized in that: The inner frame has a flat overall shape, with the main body being a rectangular frame, and thin protrusions extending from both ends of the frame along the vertical direction of the edge.

9. The inner frame of the switching power supply according to claim 1, characterized in that: The base has a second hole for some components to protrude from the base plane.

10. The inner frame of the switching power supply according to claim 1, characterized in that: The base has thin raised strips along its edge to serve as reinforcing ribs for the base plate.

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