Power supply module and assembly method

Abstract

A method for assembling a power module, in which a plurality of spacers are positioned between planes of different potential on at least a high-voltage end of a printed circuit board (PCB). The plurality of spacers have a creepage electric field greater than 0.4 kV / mm and are configured to mechanically support the PCB during assembly and curing of the encapsulant, which is an insulating material configured to provide electrical and thermomechanical insulation for the power module. The plurality of spacers can be fitted into one or more receiving openings in the PCB.

Description

[Technical Field]

[0001] Claiming priority under 35 U.S.C. § 120 This patent application claims priority to U.S. Provisional Patent Application No. 18 / 108,094, entitled "A POWER SUPPLY MODULE AND METHOD OF ASSEMBLY," filed February 10, 2023, and assigned to the assignee hereof, and is hereby expressly incorporated by reference herein.

[0002] background Field The present disclosure relates generally to power supplies, and more particularly to an encapsulated spacer for use in high voltage power supply modules. [Background technology]

[0003] background High-voltage power supply modules typically comprise encapsulated electrical components and are commonly used to generate direct current (DC) and alternating current (AC) outputs. These increasingly complex systems are typically assembled using rigid spacers, which often result in problematic warping of printed circuit board assemblies (PCBAs) that expediently accept lower-than-desired standards, compromising clearance distances to ground, premature failure of encapsulation materials, and bulky housings that increase the clearance distance of PCBAs from ground. Therefore, there is a need for more efficient and compact high-voltage power supply modules. Summary of the Invention [Means for solving the problem]

[0004] overview One aspect can be characterized as a method of assembling a power module, the method including: positioning a plurality of spacers between planes of different potential on at least a high voltage end of a printed circuit board (PCB), the plurality of spacers having a creepage electric field greater than 0.4 kV / mm and configured to at least structurally support the PCB during assembly; and encasing the PCB and the plurality of spacers in an encapsulant including an insulating material configured to thermally and electrically insulate the PCB.

[0005] Another aspect can be characterized as an electronic system including one or more power modules, each power module including a printed circuit board (PCB), an encapsulant having thermal and electrical insulating properties and configured to encase the PCB, and a plurality of spacers having a creepage electric field greater than 0.4 kV / mm and positioned within the encapsulant at least at a high voltage end of the PCB.

[0006] Yet another embodiment can be characterized as a power supply module, the power supply module including: an electronic assembly including a plurality of spacers having an electric field with a creepage distance greater than 0.4 kV / mm and one or more electrical components coupled to the electronic assembly; an encapsulant including an insulating material and configured to encase the electronic assembly; and at least one housing configured to define a region for containing the electronic assembly and enclosing the encapsulant. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is an exemplary power module having multiple encapsulated spacers according to the assembly methodology described herein.

[0008] [Figure 2] FIG. 2 depicts a spacer that can be positioned on a power module and operated in accordance with the assembly methodology described herein.

[0009] [Figure 3]FIG. 3 is a front view of the spacer shown in FIG.

[0010] [Figure 4] FIG. 4 is a bottom perspective view of the spacer shown in FIG.

[0011] [Figure 5] FIG. 5 is a top view of the spacer shown in FIG.

[0012] [Figure 6A] FIG. 6A is a second view of an exemplary power module having multiple encapsulated spacers in accordance with the assembly methodology described herein.

[0013] [Figure 6B] FIG. 6B is a diagram of an exemplary PCB having multiple receiving openings.

[0014] [Figure 7] FIG. 7 illustrates an exemplary power module having at least one encapsulated spacer secured to a PCB on a high-voltage end of the PCB and a plurality of rigid spacers secured to a PCB on a low-voltage end of the PCB in accordance with the assembly methodology described herein.

[0015] [Figure 8] FIG. 8 depicts an exemplary power module having at least one encapsulated spacer secured to at least one electrical component on a PCB at the high voltage end of the PCB in accordance with the assembly methodology described herein.

[0016] [Figure 9] FIG. 9 depicts exemplary spacers positioned in planes of different potential on a PCB and encased in encapsulant according to the assembly methodology described herein.

[0017] [Figure 10] FIG. 10 is a second view of the encapsulated spacer depicted in FIG.

[0018] [Figure 11] FIG. 11 is a third view of the encapsulated spacer of FIG. 9 illustrating the creepage distance of the encapsulated spacer between planes of different potential.

[0019] [Figure 12] FIG. 12 shows a flowchart illustrating a method that may be elaborated in connection with embodiments disclosed herein. DETAILED DESCRIPTION OF THE INVENTION

[0020] Detailed Description High-voltage power modules increasingly rely on sophisticated material compositions and variations in structural assemblies to provide sufficient clearance. Conventional electrical components in high-voltage power modules are encapsulated within solid polymer insulators, which provide electrical isolation from surfaces with varying electrical potentials. Encapsulating electrical components within high-voltage power modules allows for more compact designs, as the withstand voltage of the encapsulating material is much greater than that of air.

[0021] High-voltage assemblies, such as PCBAs, vary in length and width. Some PCBAs are approximately 700 mm long and 400 mm wide and typically include rigid spacers positioned exclusively at the high-voltage and low-voltage ends of the assembly. However, these rigid spacers often increase the PCBA's variability, resulting in an assembly that is highly susceptible to twisting and bending, particularly at its high-voltage ends. Twisting and bending are undesirable because the high-voltage ends of a PCBA typically approach a shorter distance to ground as they bend, reducing the overall voltage-withstand capability of the high-voltage assembly, often resulting in compromised clearance distances to ground. Furthermore, as the voltage-withstand capability of a high-voltage power module decreases, the susceptibility of the encapsulant also increases, often leading to premature failure of the encapsulant. Some conventional systems have attempted to reduce this undesirable outcome by increasing the PCBA's clearance, but this solution exclusively utilizes rigid spacers fixed to both ends of the PCBA, resulting in a larger and bulkier assembly. Therefore, there is currently a need for a more compact power module that is configured to maintain clearance from the PCBA to the grounds on both ends of the PCBA during assembly of the power module and during curing of the encapsulant.

[0022] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0023] Terms such as first, second, and third may be used herein to describe various elements, components, regions, layers, and / or sections, but it should be understood that these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer, or section from another region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be referred to as a second element, component, region, layer, or section without departing from the teachings of the present disclosure.

[0024] Spatially relative terms such as "beneath," "below," "lower," "under," "above," and "upper" may be used herein for ease of description to describe the relationship of one element or feature to another, as shown in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, elements described as "below" or "beneath" or "under" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary terms "below" and "under" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or to other orientations), and the spatially relative descriptors used herein would be interpreted accordingly. Additionally, when a layer is referred to as being between two layers, it will be understood that it may be the only layer between the two layers, or that one or more intervening layers may also be present.

[0025] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. It will be further understood that the terms "comprises" and / or "comprising," as used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items and may be abbreviated as " / ."

[0026] Embodiments of the present disclosure are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the present disclosure. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and / or tolerances, are expected. Thus, embodiments of the present disclosure should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shape that result, for example, from manufacturing. Accordingly, the regions illustrated in the figures are schematic in nature and their shapes are not intended to represent the actual shape of a region of a device and are not intended to limit the scope of the present disclosure.

[0027] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Terms such as those defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning in the context of the relevant art and / or this specification, and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0028] Referring to FIG. 1 , an exemplary power module (electronic assembly or electronic system) 100 according to aspects of the present disclosure is shown. As shown, the power module 100 may include at least two planes, e.g., a first plane 102 having a first potential (e.g., voltage withstand capability) and a second plane 106 having a second potential that is the same as or different from the first plane 102. The first plane 102 and the second plane 106 can be constructed of conductive or non-conductive materials. In some non-limiting embodiments, the first plane 102 defines an upper surface 104 of a housing (e.g., a potting box) (see, e.g., housing 638 described with reference to FIGS. 7-8 ), and the second plane 106 defines a lower surface 108 of the housing (e.g., potting box) (see, e.g., housing 638 described with reference to FIGS. 7-8 ). The housing 638 may further include a first side (see, for example, first side 640 described with reference to FIG. 6A ), a second side (see, for example, second side 642 described with reference to FIG. 6A ), a third side (see, for example, third side 644 described with reference to FIG. 6A ), and a fourth side (see, for example, fourth side 646 described with reference to FIG. 6A ), collectively considered as sides. The first flat surface 102, the second flat surface 106, and the sides can together define an interior 110 of the power module 100. The interior 110 can function to define a region that surrounds the encapsulant 126 and limits the volume of the encapsulant 126 that can be introduced into the power module 100.

[0029] 1 also shows a printed circuit board (PCB) 112 positioned within the interior 110 of the power module 100. The PCB 112 may include one or more electrical components 114 secured to at least one surface of the PCB 112 that function as part of the power module 100. The illustrated PCB 112 may further include one or more openings (see, for example, opening 611 described with reference to FIG. 6B ) that function to receive and fasten a plurality of spacers 116 to the PCB 112.

[0030] The plurality of spacers 116 may further include a first end 118 and a second end 120, where the first end 118 engages with an opening (not shown) formed in the first flat surface 102 of the power supply module 100 and the second end 120 engages with a second opening (not shown) formed in the second flat surface 106 of the power supply module 100. In some cases, the plurality of spacers 116 may be fitted or secured to the PCB 112 by other means at the high-voltage end 122 and the low-voltage end 124 of the PCB 112. In other embodiments, the plurality of spacers 116 may be fitted or secured to only the high-voltage end 122 of the PCB 112 by other means, while a conventional rigid spacer (see, for example, rigid spacer 636 described with reference to FIG. 6A ) is fitted or secured to the low-voltage end 124 of the PCB 112 by other means. In still other embodiments, the plurality of spacers 116 may be fitted or secured to both the high-voltage end 122 and the low-voltage end 124 of the PCB 112 by other means, and may be fitted or secured to the PCB 112 by other means at other mounting locations configured to provide mechanical support for the PCB 112 during assembly. Additionally or alternatively, the plurality of spacers 116 may be fitted or secured to one or more electrical components 114 on the PCB 112 by other means. The plurality of spacers 116 may extend vertically from the second plane 106 through the PCB 112 to the first plane 102, or may extend from the second plane 106 and terminate at the PCB 112. Alternatively, the plurality of spacers 116 may extend vertically from the first plane 102 through the PCB 112 to the second plane 106, or may extend from the first plane 102 and terminate at the PCB 112.

[0031] Also shown in FIG. 1 is an encapsulant 126 that completely encapsulates (also referred to as encasing) the various components contained within power module 100. In some embodiments, encapsulant 126 functions to provide electrical insulation for the encapsulated components in both low and high voltage environments. The illustrated encapsulant 126 may be composed of a polymeric insulating material such as epoxy, silicone, or polyurethane, but is not limited to that composition. In some examples, encapsulant 126 can cure at ambient temperature, while in other examples, the encapsulant can cure at 6° C. and, once cured, can function to withstand electrical and thermo-mechanical loads during operation of power module 100.

[0032] In some embodiments, the encapsulant 126 is injected or applied to the interior 110 of the housing (e.g., see housing 638 described with reference to FIG. 6A ) after the plurality of spacers 116 are positioned or secured on the PCB 112 or one or more electrical components 114. In yet other embodiments, the encapsulant 126 is injected or applied to a first half of the interior 110 of the housing and allowed to fully or partially harden or solidify before being injected or applied to a second half of the interior 110. Additionally or alternatively, after the encapsulant 126 is injected or applied to the interior 110 of the housing, the power module may be placed in a vacuum chamber configured to remove trapped air or gas within the encapsulant 126. A jig or other compression means (not shown) may then be implemented to apply pressure inwardly to the first planar surface 102 relative to the PCB 112 and second planar surface 106 and / or inwardly to the second planar surface 106 relative to the PCB 112 and first planar surface 102. The pressure from the compression means can act to ensure that the PCB 112 and the plurality of spacers 116 within the power module 100 remain in place while the encapsulant 126 hardens.

[0033] In some cases, a first end 118 of the spacer 116 extends through the top surface 104 of the power module 100, and a second end 120 of the spacer 116 extends through the bottom surface 108 of the power module 100, with the first end 118 and the second end 120 forming one or more coupling members configured to removably couple the power module 100 to one or more second power modules (not shown). Alternatively, the coupling members may extend from the PCB 112 through the top surface 104 and bottom surface 108 of the power module 100, or may be formed, bonded, or otherwise secured directly to the top surface 104 and bottom surface 108 of the power module 100.

[0034] 2-5, which illustrate a single spacer 116 according to one embodiment of the present disclosure. In the illustrated embodiment, the spacer 116 includes a core 228, a plurality of sheds 230, a first end 218 having a first diameter, and a second end 220 having a second diameter. The spacer 116 may be constructed from the same insulating material as the encapsulant 126. In other examples, the spacer 116 may be constructed from an insulating material dissimilar to the insulating material of the encapsulant 126, so long as the insulating material has similar electrical and mechanical properties to the insulating material of the encapsulant. In some embodiments, the spacer 116 may be constructed from an insulating material with a modified mix ratio that includes a greater amount of hardener or curing agent than the insulating material used in the encapsulant 126. In some cases, the hardness of the spacer 116 may be between 65-70 (Shore A), while the hardness of the encapsulant 126 may be between 45-50 (Shore A). The insulating material with the additional hardener functions to provide sufficient mechanical support for the PCB (e.g., PCB 112 of FIG. 1) during assembly and curing of the encapsulant 126 to prevent bending, flexing, or warping of the PCB 112. Being formed from the same insulating material reduces the risk of mechanical seizure at the interface or contact points between the spacer 116 and the surrounding encapsulant 126. Furthermore, because the insulating material has a matching coefficient of thermal expansion (CTE), tracking and dielectric breakdown are also reduced.

[0035] 2-4, the first end 218 of the spacer 116 may have a dissimilar diameter than the second end 220 of the spacer 116. In these examples, the variable diameter may function to aid in the placement and orientation of the spacer 116 within a plane of the power module (see, e.g., power module 100 in FIG. 1), with the first end 218 configured to engage with the first plane (see, e.g., first plane 102 in FIG. 1) and the second end 220 configured to engage with the second plane 106. This configuration is non-limiting, and the first diameter of the first end 218 and the second end 220 may be the same and therefore interchangeable within the power module 100.

[0036] 6A-6B, which illustrate top views of a power module 100 having a plurality of spacers 116 according to another embodiment of the present disclosure. As illustrated, the power module 100 includes a PCB 112 having a high-voltage end 122 and a low-voltage end 124, one or more electrical components 114 secured to its surface, and a rigid spacer 636. As shown in FIG. 6A, the power module 100 is contained within a housing 638 having a first side 640, a second side 642, a third side 644, and a fourth side 646. The illustrated embodiment further represents the power module 100 prior to injection or addition of an encapsulant (e.g., see the encapsulant 126 described with reference to FIG. 1) to the system. As shown, the PCB 112 may further include one or more openings 611 (also referred to as receiving openings 611) that function to receive and fasten the plurality of spacers 116 to the PCB 112. The openings may include tracks for fitting the spacers 116 into the PCB, or may be formed to allow other means of fitting the spacers 116 to the PCB 112.

[0037] 7-8, which show elevational views of a power module 100 filled with an encapsulant 126 and including at least one encapsulated spacer 116. Also shown are a plurality of rigid spacers 636 secured to the PCB 112 on the low-voltage end 124 of the PCB 112, as well as one or more electrical components 114 secured to the PCB 112. FIG. 7 shows the spacer 116 secured to or by other means on the high-voltage end 122 of the PCB 112, while FIG. 8 depicts the spacer 116 secured to or by other means directly on one or more electrical components 114 secured to the PCB 112. In some embodiments, the spacer 116 may be formed of two halves, with a first half configured to secure to one or more electrical components 114, while a second half configured to bond to or secure to the PCB 112.

[0038] 9-11, which illustrate an exemplary spacer 116 secured to PCB 112 and encapsulated within power module 100, as referenced in FIG. 1. As shown in FIG. 2, shed 230 is a disk-shaped component of spacer 116 that is designed with respect to geometry and relative positioning to enhance the electrical withstand performance of the dielectric interface formed by spacer 116 and encapsulant 126. To minimize the electric field of shed 230 and spacer 116, the geometry of shed 230 is rounded at the outer and inner edges. The spacer 116 of FIG. 11 has a creepage distance d of spacer 116 within power module 100. 沿面 and clearance distance d クリアランス As shown, d 沿面 is at least d クリアランス greater than d 沿面 and d クリアランス can vary, but in many embodiments, d 沿面 In some embodiments, the electric field at the creepage distance is at least 2 kV / mm. Furthermore, in some embodiments, the spacer 116 is ディスク / シェッド (disc diameter) smaller than the core diameter d コアIn some embodiments, the power module 100 comprises a plurality of sheds 230, each having a disk diameter d ディスク / シェッド is the creepage distance d along the surface of each shed 230 沿面 Furthermore, d 間隙 the distance between the two sheds 230 of the spacer 116 represented by d ディスク厚さ The thickness of each of the disks or sheds 230 is shown, represented by .

[0039] Reference is now made to FIG. 12 , which illustrates a flowchart depicting a method 1200 that may be traversed in connection with embodiments disclosed herein. In step 1202, a plurality of spacers 116 having electrical and thermal insulating properties may be formed from an insulating material. In step 1204, the plurality of spacers 116 may be positioned between the planes 102, 106 of different potentials on the PCB 112. In step 1206, the PCB 112 with the plurality of spacers 116 may be positioned within the housing 638 in a predetermined orientation. Finally, in step 1208, the PCB 112 with the plurality of spacers 116 may be encapsulated by an encapsulant 126, which may be composed of the same insulating material as the plurality of spacers 116.

[0040] The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. 1. A method of assembling a power module, the method comprising: Positioning a plurality of spacers between planes of different potential on at least a high voltage end of a printed circuit board (PCB), the plurality of spacers having a creepage electric field greater than 0.4 kV / mm and configured to at least mechanically support the PCB during assembly; encapsulating the PCB and the plurality of spacers in an encapsulant made of an insulating material; A method comprising:

2. The method of claim 1 , wherein the PCB includes one or more receiving openings, and the plurality of spacers fit within the one or more receiving openings of the PCB.

3. The method of claim 1 , wherein the PCB comprises one or more electrical components, and the plurality of spacers are secured to the one or more electrical components of the PCB.

4. forming a housing, the housing configured to contain the PCB, the plurality of spacers, and the encapsulant; Positioning the PCB and the plurality of spacers within the housing prior to encapsulation; applying pressure to the encapsulant during curing; The method of claim 1 further comprising:

5. 5. The method of claim 4, wherein the encapsulating includes applying an encapsulant to an interior of the housing to immerse a first side of the PCB in the encapsulant, and subsequently immersing a second side of the PCB opposite the first side.

6. The method of claim 1 , further comprising forming the spacers from the insulating material using a greater amount of curing agent than is used in the encapsulant.

7. The method of claim 1 , wherein the electric field in the creepage distance is at least 2 kV / mm.

8. The method of claim 1 , further comprising forming one or more coupling members configured to removably couple the power supply module to one or more second power supply modules.

9. 1. An electronic system comprising: one or more power supply modules, each power supply module comprising: a housing having at least two planar surfaces, a first planar surface defining an upper surface and a second planar surface defining a lower surface of the housing; a printed circuit board (PCB) positioned between at least the upper surface and the lower surface; a plurality of spacers positioned on at least a high voltage end of the PCB and configured to engage at least one of the at least two flat surfaces, each spacer of the plurality of spacers having a creepage electric field greater than 0.4 kV / mm; an encapsulant made of an insulating material and configured to encapsulate the PCB and the plurality of spacers; 1. An electronic system comprising one or more power supply modules comprising:

10. Each spacer of the plurality of spacers is a plurality of disks having disk diameters defining the creepage distance along a surface of each disk; a core having a core diameter smaller than the disk diameter; a first end configured to engage the top surface of the housing; a second end configured to engage the lower surface of the housing; and The electronic system of claim 9, comprising:

11. 11. The electronic system of claim 10, wherein the electric field in the creepage distance is 2 kV / mm.

12. The housing includes: The method further includes the step of: a first side of the housing; a second side of the housing; and a third side of the housing; and a fourth side of the housing; and The electronic system of claim 10, comprising:

13. 13. The electronic system of claim 12, wherein the plurality of spacers further comprise a proportion of a hardener that is greater than a proportion of a hardener in the electrically insulating material of the encapsulant to prevent warping of the PCB at least at the high voltage end.

14. 1. A power supply module, comprising: a housing having at least two planar surfaces, a first planar surface defining an upper surface and a second planar surface defining a lower surface of the housing; an electronic assembly comprising one or more electrical components coupled to at least one surface of the electronic assembly; a plurality of spacers positioned on the electronic assembly, the plurality of spacers comprising: a plurality of disks having a disk diameter defining a creepage distance along a surface of each disk; a core having a core diameter smaller than the disk diameter; a first end configured to engage the top surface of the housing; a second end configured to engage the lower surface of the housing; and an electric field at the creepage distance greater than 0.4 kV / mm; the plurality of spacers comprising: an encapsulant made of an insulating material and configured to encapsulate the electronic assembly and the plurality of spacers; A power supply module comprising:

15. 15. The power module of claim 14, wherein the electric field in the creepage distance is 2 kV / mm.

16. 15. The power module of claim 14, wherein the plurality of spacers are comprised of the insulating material with a greater amount of hardener than that used in the encapsulant.

17. 17. The power module of claim 16, wherein the plurality of spacers are secured to the one or more electrical components of the electronic assembly.

18. The power module of claim 14 , further comprising one or more coupling members configured to removably couple the power module to one or more second power modules.

19. 15. The power module of claim 14, wherein the insulating material is configured to prevent breakdown of the encapsulant at an interface between the plurality of spacers and the encapsulant when a voltage is introduced across the interface of the plurality of spacers.

20. 20. The power module of claim 19, wherein the electronic assembly is a printed circuit board (PCB), the plurality of spacers are positioned on the PCB at least at a high voltage end of the PCB, and the plurality of spacers are further configured to prevent warping of the PCB during assembly and curing of the encapsulant.

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