Fastener system

Abstract

Generally speaking, one or more aspects of the present disclosure relate to a screwless fastener system and its components, wherein the screwless fastener system comprises a fastener washer comprising a conical spring, one or more washer center ribs, and a retaining cup comprising an attachment pin, a fastener washer configured to be press-fitted to an interface surface of the attachment pin, and a conical spring configured to create a joint preload between the fastener washer and the attachment pin clamp surface.

Description

Technology Field

[0001] This application claims priority to U.S. Patent Application No. 19 / 048,282, filed on February 7, 2025, titled “FASTENER SYSTEM,” the entirety of which is incorporated herein by reference for all purposes.

[0002] The present disclosure relates to a fastener system. More specifically, the present disclosure relates to a self-retaining fastening washer and a system thereof. The fastener system can be used to attach a printed circuit board assembly to a heatsink. Background Technology

[0004] Many types of fasteners can structurally, thermally, and electrically connect printed circuit board assemblies to heat sinks. However, these fasteners can be time-consuming to install. These fasteners may also be supplied as individual components, which can introduce additional difficulties during the assembly process. Furthermore, these fasteners may have a high failure rate during installation, such as falling off, screws crossing or being incorrectly tightened, or loosening due to joint preload variability. Consequently, the use of such fastening systems can result in low process yields and / or high failure rates during assembly. means of solving the problem

[0006] For the purpose of summarizing the advantages achieved with respect to the prior art and the invention, specific objects and advantages of the invention are described in the specification. Not all such objects or advantages may be achieved in any specific embodiment of the invention. Accordingly, for example, a person skilled in the art will recognize that the invention may be practiced or performed in a manner that achieves or optimizes one advantage or group of advantages taught in the specification, without necessarily achieving other objects or advantages that may be taught or implied in the specification.

[0007] In some aspects, a threadless fastener system for securing a printed circuit board assembly (PCBA) to an attachment pin is disclosed, wherein the attachment pin includes a clamping surface extending from a heat sink and spaced from the heat sink. The clamping surface is configured to support the PCBA. The screwless fastener system comprises a fastening washer comprising a conical spring and a plurality of interference petals—the plurality of interference petals are sized and shaped to clamp to an attachment pin—and a retaining cup sized and shaped to accommodate the fastening washer—wherein when the plurality of interference petals are clamped to the attachment pin, a portion of the retaining cup is positioned between the fastening washer and the PCBA—wherein when the plurality of interference petals are clamped to the attachment pin, the conical spring generates a thermally stable clamping force on the PCBA located between the clamping surface and a portion of the retaining cup.

[0008] In some aspects, a fastening washer configured to be fastened to an attachment pin is described. The fastening washer comprises a conical spring including an inner edge and an outer edge, a flat outer rim extending from the outer edge of the conical spring, an integrated press surface extending inward from the inner edge, and a plurality of interference petals disposed on the inside of the integrated press surface.

[0009] In some embodiments, the fastener washer additionally includes an opening at the center of a plurality of interference petals. In some embodiments, the inner and outer edges are circular and concentric. In some embodiments, the fastener washer additionally includes one or more gaps extending radially through a portion of a conical spring. In some embodiments, the integral pressure surface is substantially parallel to the flat outer rim. In some embodiments, the plurality of interference petals are configured to mechanically grip the attachment pin. In some embodiments, the fastener washer is additionally constructed of stainless steel. In some embodiments, the fastener washer additionally includes a height from the flat outer rim to the plurality of interference petals, and the height is about 2 mm. In some embodiments, the outer diameter of the flat outer rim is about 13 mm. In some embodiments, the diameter of the opening is about 2.75 mm.

[0010] In some aspects, a screwless fastener system is described. The screwless fastener system comprises a retaining cup having a cup clamping surface, a fastening washer including a conical spring located within the retaining cup, and an attachment pin having an interface surface and a pin clamping surface, wherein the end of the attachment pin is configured to be attached to a first item, the fastening washer is configured to be clamped to the interface surface, and the conical spring is configured to generate a clamping force on a second item located between the cup clamping surface and the pin clamping surface.

[0011] In some embodiments, the cup clamping surface is positioned at a certain distance from the end of the attachment pin. In some embodiments, the interface surface is electrically conductive. In some embodiments, the retaining cup further includes one or more washer centering wedges. In some embodiments, the clamping force is at least 300 N. In some embodiments, the retaining cup further includes a washer press distance limiting feature. In some embodiments, the retaining cup further includes one or more snap retainers. In some embodiments, the first component is a heat sink, and the heat sink is fixedly attached to the attachment pin. In some embodiments, the second component is a PCBA. Brief explanation of the drawing

[0013] The inventions are described with respect to the attached drawings, and similar reference characters refer to similar elements; Figure 1 is a conceptual diagram of a screwless fastener system according to the disclosure. FIG. 2 is a front cross-sectional view of the screwless fastener system of FIG. 1 including a retaining cup, a fastener washer, and an attachment pin. Figure 3 is a conceptual diagram of the fastener washer of Figure 1. Figure 4 is a conceptual diagram of the retaining cup of Figure 1. Fig. 5 is a front view of the attachment pin of Fig. 1. Specific details for implementing the invention

[0014] The detailed description of specific embodiments to be set forth below provides various descriptions of specific embodiments. However, the innovations described in this disclosure may be practiced in different ways, for example, as defined and covered by the claims. In this description, similar reference numerals and / or terms refer to drawings that may represent identical or functionally similar components. It should be understood that the components depicted in the drawings are not necessarily drawn to scale. It should also be understood that specific embodiments may include more components than those depicted in the drawings, or may include a subset of the components depicted in the drawings. Furthermore, some embodiments may include any combination of suitable features from two or more drawings. Headings are provided for convenience only and do not affect the scope or meaning of the claims.

[0015] Generally speaking, one or more aspects of the present disclosure relate to a screwless fastener system that may include a self-retaining fastener washer. The screwless fastener system may attach a printed circuit board assembly (PCBA) to a heat sink while positioning a PCBA spaced apart from the heat sink. The screwless fastener system may secure the PCBA to attachment pins. The screwless fastener system may advantageously maintain a gap between the PCBA and the heat sink. The screwless fastener system may include a self-retaining fastener washer comprising a conical spring. The screwless fastener system may advantageously improve the speed and accuracy of assembling the PCBA to the heat sink because multiple fastener washers can be compressed simultaneously to attach one or more PCBAs to the heat sink. Although the screwless fastener system described herein is described as attaching a PCBA to a heat sink, it should be understood that the screwless fastener system may be used to attach a first component to a second component using the embodiments or sub-combinations of the embodiments described herein.

[0016] FIGS. 1 and 2 illustrate a threadless fastener system (100) according to the disclosure. As shown in FIG. 1, the threadless fastener system (100) comprises a retaining cup (110), a fastening washer (130), and an attachment pin (150). In a feature embodiment, the fastening washer (130) is located within the retaining cup (110). In a feature embodiment, the attachment pin (150) passes through the center of the fastening washer (130) during assembly. The threadless fastener system (100) can structurally, thermally, and electrically connect a printed circuit board assembly (170) to a heatsink (180).

[0017] In some embodiments, as shown in FIG. 2, the screwless fastener system (100) can attach the PCBA (170) to the heat sink (180). As shown in FIG. 2, the attachment pin (150) extends proximally from the distal surface of the heat sink (180). In some embodiments, the attachment pin (150) is fixedly attached to the heat sink (180). The attachment pin (150) may include a circular or substantially circular perimeter and have a central axis A. The attachment pin (150) may include a clamping surface (162). The clamping surface (162) may be located at a distance B from the heat sink (180). In some examples, the distance B may be between 0 mm and 30 mm. In some examples, distance B is about 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3.0mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, It may be 28 mm, 29 mm, 30 mm, or any range between these values. In a particular embodiment, the clamping surface (162) may be substantially perpendicular to the central axis A and substantially parallel to the distal surface of the heat sink (180). In a feature embodiment, the clamping surface (162) may include a rectangular, triangular, or part of the perimeter of the attachment pin (150). In a particular embodiment, the PCBA (170) may be positioned on the clamping surface (162).The retaining cup (110) may be located distal from the clamping surface (162) and on the opposite side of the PCBA (170) from the clamping surface (162). A fastener washer (130) may be located within the retaining cup (110).

[0018] The fastener washer (130) can mechanically grip the interface surface (154) of the attachment pin (150) (e.g., clamping via friction and / or interference fit). In certain embodiments, the interface surface (154) may be a cylindrical surface extending from the clamping surface (162). In a feature embodiment, the interface surface (154) may be smooth. In a feature embodiment, part or all of the interface surface (154) may be textured, knurled, ribbed, or stepped. The fastener washer (130) may be positioned on the retaining cup washer surface (124) of the retaining cup (110). A press force may be applied proximally to the fastener washer (130) parallel to the axis of the attachment pin (150). This pressure can cause the fastener washer (130) to bend by a press distance, resulting in it being clamped to the interface surface (154). The pressure creates a clamp load on the fastener washer (130), causing the fastener washer (130) to apply pressure to the retaining cup (110) and to fasten the PCBA (170) between the clamping surface (162) and the cup clamping surface (118) in contact with the PCBA (170). Advantageously, the attachment pin (150) supports the PCBA after being fixed together. In some embodiments, the retaining cup washer surface (124) is spaced apart from the cup clamping surface (118) by a distance C. In some examples, the distance C is between 0.5 mm and 10 mm. In some examples, the distance C is at least 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.It may be 4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, or any range between these values.

[0019] Advantageously, the screwless fastener system (100) provides electrical creepage and clearance separation for adjacent high voltage electrical components and traces on the PCBA (170) because the retaining cup (110) may be an electrical insulator and the fastener washer (130) may have clearance with respect to the surface of the PCBA (170). The retaining cup (110) may include a creepage surface between the fastener washer (130) and the surface of the PCBA (170). The screwless fastener system (100) may also maintain a thermally stable clamping force so that the clamping force can be maintained through thermal cycling conditions and various thermal conditions (e.g., extremely high temperatures, extremely low temperatures and sudden transitions between these).

[0020] In some examples, the clamping force may be between 10 N and 1500 N, and the pressing distance may be between 0.5 mm and 1.0 mm. In some examples, the pressing distance may be at least 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, or any range between these values. In some examples, the generated clamping force is at least 10 N, 50 N, 100 N, 150 N, 200 N, 210 N, 220 N, 230 N, 240 N, 250 N, 260 N, 270 N, 280 N, 290 N, 300 N, 310 N, 320 N, 330 N, 340 N, 350 N, 360 N, 370 N, 380 N, 390 N, 400 N, 410 N, 420 N, 430 N, 440 N, 450 N, 460 N, 470 N, 480 N, 490 N, 500 N, 550 N, 600 N, 650 N, 700 N, 750 N, 800 N, 850 N, 900 N, 950 N, 1000 N, 1050 N, 1100 N, 1150 N, 1200 N, 1250 N, 1300 N, 1350 N, 1400 N, 1450 N, 1500 N, or any range between these values. In some examples, the fastener washer (130) can withstand a height change between 0.01 mm and 0.75 mm before a loss of clamping force occurs. In some examples, the height loss in the proximal or distal direction before the loss of clamping force occurs may be at least or approximately at least 0.01 mm, 0.1 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.60 mm, 0.65 mm, 0.70 mm, 0.75 mm, or any value between these values.

[0021] In some examples, a plurality of screwless fastener systems (100) may be used to fully attach the PCBA (170) to the heat sink (180). The plurality of screwless fastener assemblies may be spaced evenly around the surfaces of the PCBA (170) and the heat sink (180) to form a stable connection between the PCBA (170) and the heat sink (180). The PCBA (170) may be assembled to be attached to the heat sink (180) in a manner that may include the following steps. An adhesive material may be distributed at each location where the retaining cup (110) is to be installed. In a specific embodiment, the retaining cup (110) may include a metal function and may be soldered to the PCBA (170). A washer assembly comprising a retaining cup (110) equipped with a pre-installed fastener washer (130) can be installed on a PCBA (170) via a pick-and-place machine from a tape and reel package to place the washer assembly on an adhesive material. The PCBA (170) can pass through a reflow oven to cure the adhesive material. In certain embodiments, the adhesive material may be cured separately. A manufacturing line may be provided with a PCBA (170) with the washer assembly installed. One or more PCBA (170) assemblies may be placed on a heat sink (180) having an attachment pin (150) corresponding to each washer assembly. The attachment pin (150) may be formed integrally with the heat sink (180). The retaining cup (110) of the washer assembly can transmit an external pressure to press the PCBA (170) against the clamping surface (162) of the attachment pin (150) before mounting the fastener washer (130). This pressure can be used to wet-out the thermal interface material placed between the PCBA (170) and the heat sink (180). Pressure is supplied to each fastener washer (130).The applied pressure attaches each fastener washer (130) to the attachment pin (150). This assembly method has the advantage of reducing assembly time by allowing each fastener washer (130) to be fastened to the attachment pin (150) simultaneously. The shape and tolerances of the screwless fastener system (100) described herein advantageously improve robustness against tolerance stack-up between components. The washer assembly can accommodate multiple attachment pins (150) across the heat sink (180). In certain embodiments, different attachment pins may have varying heights across the heat sink (180). The fastener washer (130) may float relative to the retaining cup (110), thereby allowing the fastener washer (130) to move freely within the retaining cup (110) relative to the attachment pin (150), reducing the possibility of misalignment between components of the screwless fastener system (100).

[0022] FIG. 3 illustrates a conceptual diagram of a fastener washer (130) according to the disclosure. As described, the fastener washer (130) may include a conical spring (140), which may have a surface in the shape of a cross-section of a cone. In a specific embodiment, the surface forms a circular inner edge and a circular outer edge. An outer rim (132) may extend outward from the outer edge of the conical spring (140). In a specific embodiment, the outer rim (132) may extend outward perpendicular to the axis of the fastener washer (130). In a specific embodiment, the outer rim (132) may be substantially a planar ring. The conical spring (140) may extend inwardly at an angle from the outer rim (132). For example, the conical spring (140) can be extended from the outer rim (132) at an angle between 15 and 40 degrees.

[0023] The integrated press surface (138) may extend inward from the inner edge of the conical spring (140). In a specific embodiment, the press surface (138) may extend inward perpendicular to the axis of the fastener washer (130). In a specific embodiment, the integrated press surface (138) may be substantially a flat ring. The integrated press surface (138) may be parallel to the outer rim (132). In a specific embodiment, a plurality of interference petals (142) may be disposed inside the integrated press surface (138). A plurality of interference petals (142) may extend obliquely from the integrated press surface (138). In some examples, the fastener washer (130) may include 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or more interference petals (142) or any range between these values. An opening (144) may be located at the center of the multiple interference petals (142). The opening (144) may be a central opening and may have a diameter approximately equal to or smaller than the interface surface (154) of the attachment pin (150) described herein. In some embodiments, the fastener washer (130) may have a height between 0.5 mm and 10 mm. In some examples, fastener washers 130 have a size of approximately 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3.0mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm or these values It can have an arbitrary range between them.In some embodiments, the fastener washer (130) may have an outer diameter between 8 mm and 35 mm. In some examples, the fastener washer (130) may have an outer diameter of approximately 8 mm, 9 mm, 10 mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, or any range between these values. In some embodiments, the fastener washer (130) may have an inner diameter between 1 mm and 15 mm. In some examples, fastener washers 130 have a size about 1.0 mm, 1.1 mm, 1.2 mm, 1.25 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.75 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.25 mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.75mm, 2.8mm, 2.9mm, 3.0mm, 3.1mm, 3.2mm, 3.25mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.75mm, 3.8mm, 3.9mm, 4.0mm, The fastener washer (130) may have a thickness of approximately 0.5 mm, 1.0 mm, 1.25 mm, 1.5 mm, 1.75 mm, 2.0 mm, 2.25 mm, 2.5 mm, 2.75 mm, 3.0 mm, 3.25 mm, 3.5 mm, 3.75 mm, 4 mm, 4.25 mm, 4.5 mm, 4.75 mm, 5.0 mm, or any range between these values. The fastener washer (130) may have a variable thickness.The fastener washer (130) may include a petal thickness and an outer spring thickness. The petal thickness may be the thickness of the fixed washer (130) near the interference petal (142). The outer spring thickness may be the thickness near the outer radius of the fixed washer (130). In some examples, the petal thickness may differ from the outer spring thickness. In some examples, the petal thickness may be thicker than the outer spring thickness. In some examples, the petal thickness may be thinner than the outer spring thickness. In some examples, the conical spring (140) may have a variable thickness. In some examples, the conical spring (140) may have the same thickness as the outer spring thickness. The thickness of the fastener washer (130) may affect the press-force required to clamp the fastener washer (130) and apply a pre-load.

[0024] The outer rim (132) can advantageously reduce the pressure required to clamp and preload the fastener washer (130). The outer rim (132) can be angled slightly further to form a smooth surface when the width of the fastener washer (130) expands during installation. The inclined outer rim (132) advantageously prevents the outer edge of the outer rim (132) from digging into the retaining cup (110). The outer rim (132) can advantageously improve the pre-load retention of the fastening system (100) over time by increasing the contact area between the fastener washer (130) and the retaining cup (110) and reducing the pressure applied to the retaining cup (110). The reduced pressure in this way can reduce creep or stress relaxation of the retaining cup (110).

[0025] The integral pressure surface (138) can advantageously limit or reduce the lateral load received by the fastener washer (130) when a pressure is applied to the fastener washer (130). The integral pressure surface (138) also advantageously provides separation between the multiple interference petals (142) and the conical spring (140). This can advantageously reduce deformation of the multiple interference petals (142) due to pre-loading of the conical spring (140).

[0026] The fastener washer (130) may include a plurality of spring gaps (136) located in the conical spring (140). The spring gaps (136) can advantageously reduce the stiffness of the conical spring (140), which can control the clamp load generated by the fastener washer (130). The spring gaps (136) can prevent small pressure distance variations from causing large clamp load variations. The spring gaps (136) may be located adjacent to the outer rim (132) and may extend radially across part or most of the width of the conical spring (140). In some examples, the width to which the spring gaps (136) extend radially can adjust the stiffness of the conical spring (140). For example, the longer the spring gaps (136) extend radially, the lower the stiffness of the conical spring (140). The small gap (134) may extend radially across the outer rim (132) at each spring gap (136) in a particular embodiment. The narrow width of the small gap (134) can advantageously reduce or prevent some or all of the fastener washers (130) from getting tangled with each other during the assembly process, for example, in a bowl feeding apparatus.

[0027] In some examples, the fastener washer (130) may be made of aluminum, stainless steel (e.g., 301 SST, 304 SST, or 316 SST), titanium, or steel. In some examples, the fastener washer (130) may be magnetic. In some embodiments, the fastener washer (130) may be work-hardened or heat-treated. In certain embodiments, the fastener washer (130) may be surface-treated (e.g., passivation, electroplating, painting, or anodizing).

[0028] FIG. 4 illustrates a conceptual diagram of a retaining cup (110) according to the disclosure. The retaining cup (110) generally has a cylindrical shape and includes a cup clamping surface (118) located at the proximal end of the retaining cup (110). A retaining cup washer surface (124) is located distally from the cup clamping surface (118). The retaining cup washer surface (124) may be substantially flat with a circular wall (122) extending distally from the retaining cup washer surface (124). The circular wall (122) may have an inner diameter so that a fastener washer (130) can be positioned inside the circular wall (122), and a clearance fit is possible. In some embodiments, the circular wall (122) may have an inner diameter between 9 mm and 40 mm. In some examples, the circular wall (122) may have a range of about 9 mm, 10 mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm, 16 mm, 16.5 mm, 17 mm, 17.5 mm, 18 mm, 20 mm, 22 mm, 24 mm, 26 mm, 28 mm, 30 mm, 32 mm, 34 mm, 36 mm, 38 mm, 40 mm, or any range between these values. In some examples, the distal edge of the circular wall (122) may serve as a hard stop for a clamping tool for installing a fastener washer (130).

[0029] The height of the circular wall (122) can be defined so that the maximum displacement is not exceeded when the fastener washer (130) is installed, thereby limiting the force generated at the joint. The height of the circular wall (122) can define a preload force between the fastener washer (130) and the attachment pin (150) by limiting the displacement of the compression surface. The preload force between the fastener washer (130) and the attachment pin (150) may also be limited by force feedback of a press apparatus. The central opening (120) may extend through the center of the retaining cup washer surface (124).

[0030] Multiple snap retainers (114) may hold a fastener washer (130) inside a circular wall (122). In certain embodiments, the multiple snap retainers (114) may be spaced evenly around the inner circumference of the circular wall (122). The snap retainers (114) are sized so that the fastener washer (130) can be pressed from the proximal side to the distal side of the snap retainers (114), thereby preventing the fastener washer (130) from shaking or falling out of the retaining cup (110). In some examples, the snap retainers (114) may each include a slanted proximal surface and a blunt distal surface. The snap retainers (114) may be spaced evenly near the distal edge of the circular wall (122) so as not to come into contact with the fastener washer (130) when the fastener washer (130) is pressed into the retaining cup (110). In some examples, the retaining cup may include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more snap retainers (114), or any range of numbers between these values. In a feature embodiment, the fastener washer (130) is retained in the cup by applying heat and pressure to deform the circular wall (122). In a feature embodiment, the fastener washer (130) is retained using a complex path formed within the circular wall (122). In a feature embodiment, the fastener washer (130) is retained by a snap ring inserted into a groove within the circular wall (122).

[0031] The retaining cup (110) may also include a plurality of centering wedges (116). The plurality of centering wedges (116) may be located proximal to the retaining cup washer surface (124) and distal to the distal surface of the snap retainer (114). In certain embodiments, the centering wedges (116) may be spaced evenly around the inner perimeter of the circular wall (122). The centering wedges (116) may position the fastener washer (130) so that the opening (144) is substantially concentric with the center opening (120) of the retaining cup (110). The centering wedges (116) may be formed integrally with the retaining cup (110). The centering wedges (116) may be flexibly attached to the circular wall (122). In some examples, the retaining cup (110) may include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more center wedges (116), or may include any range of these values. Advantageously, the center wedges (116) may allow for tolerance variations between the retaining cup (110), fastener washer (130), PCBA (170), and attachment pin (150) during assembly of the screwless fastener system (100) by positioning the opening (144) of the fastener washer (130) relative to the center opening (120) of the retaining cup (110) while providing a gap between the outer edge of the fastener washer (130) and the circular wall (122) of the retaining cup (110).

[0032] In some examples, the retaining cup (110) may be formed from a non-conductive moldable material capable of withstanding high and low temperatures. For example, it is a flame-retardant polymer such as PBT, PP, silicone, or nylon (e.g., PA 66, PA 6, recycled PA 66).

[0033] FIG. 5 illustrates an attachment pin (150) according to the disclosed content. The attachment pin (150) generally has a circular circumference and includes a lead-in tip (158) located at the proximal end in a specific embodiment. In some examples, the lead-in tip (158) has a round or flat tip. In some examples, the lead-in tip (158) has a pointed tip. In some examples, the lead-in tip (158) is inclined at an angle between 15 and 75 degrees. For example, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, or any range between these values.

[0034] At the distal end from the lead-in tip (158), the attachment pin (150) may include a plurality of cylindrical portions having different diameters while having a common central axis. Each cylindrical portion may extend over a portion of the length of the attachment pin (150). This stepped cylindrical shape can advantageously prevent the attachment pin (150) from bending. The lead-in tip (158) may pass through the central opening (120) of the retaining cup (110) and the opening (144) of the fastener washer (130).

[0035] As illustrated in FIG. 5, a centering surface (156) may be located on the distal side of the lead-in tip (158) of the attachment pin (150). The diameter of the centering surface (156) may be sized to have a clearance fit with the center opening (120) of the retaining cup (110) and the opening (144) of the fastener washer (130). The centering surface (156) can align and center the fastener washer (130) with respect to the axis of the attachment pin (150).

[0036] From the center surface (156) at the distal side, the attachment pin (150) may include an interface surface (154). The diameter of the interface surface (154) may be sized to have an interference fit with the opening (144) of the fastener washer (130). In some embodiments, the diameter of the interface surface (154) may be between 1 mm and 20 mm. In some examples, the diameter of the interface surface (154) is approximately 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, 3.0 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, 4.0 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, It may have 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, or any range between these values. The interface surface (154) may be configured to move a plurality of interference petals (142) of the fastener washer (130). In some embodiments, the interface surface (154) may include a surface treatment to increase surface roughness and increase the grip force between the interface surface (154) and the interference petals (142). In some embodiments, the interface surface (154) may include a machined ridge or uneven surface to increase the grip force between the interface surface (154) and the interference petals (142).

[0037] The attachment pin (150) may include a transition surface between the center surface (156) and the interface surface (154), thereby preventing abrupt transition from the small diameter of the center surface (156) to the large diameter of the interface surface (154).

[0038] The attachment pin (150) may include a pass-through surface (152) distal from the interface surface (154). The pass-through surface (152) may extend through the PCBA (170) to the retaining cup (110). The diameter of the pass-through surface (152) may be sized to have a clearance fit through the opening of the PCBA (170) and the center opening (120) of the retaining cup (110). The diameter of the pass-through surface (152) may be sized to have a larger interference fit than the interface surface (154). Advantageously, the larger diameter pass-through surface (152) may be used to permanently deform the interference petal (142) around the opening (144) of the fastener washer (130) during an over-press operation. The excessive compression operation can eliminate interference alignment between the washer center opening (144) and the pin interface surface (154), thereby making it possible to separate the fastener washer (130) from the previously fastened connection state.

[0039] At the distal end of the pass surface (152), the attachment pin (150) may include a clamping surface (162). In certain embodiments, the clamping surface (162) may be perpendicular to the center axis of the attachment pin (150). The diameter of the clamping surface (162) is sufficiently wide so that the PCBA (170) can be positioned on the clamping surface (162) when the pass surface (152) passes through the PCBA (170). In some examples, the clamping surface (162) may be conductive.

[0040] The attachment pin (150) may include an attachment element (160) at the far end of the attachment pin (150). The attachment element (160) may be attached to the heat sink (180). In some examples, the attachment pin (150) may be integrally formed with the heat sink (180). In some examples, the attachment element (160) may be co-molded with the heat sink (180). In some examples, the attachment element (160) may be clinched to the heat sink. In some examples, the attachment element (160) may be press-fitted into the heat sink in an interference fit manner. In some embodiments, the attachment element (160) may be bonded to the heat sink using an adhesive, or may be bonded to the heat sink using any known metal joining technique such as soldering, brazing, and welding (e.g., resistance welding, spin welding, or friction stir welding).

[0041] In some examples, the pass-through surface (152) may include one or more parallel fastening surfaces. The fastening surface may be a flat parallel surface that can be fastened by a tool. The fastening surface may be fastened to assist in the assembly of the attachment element (160) to the heat sink (180). For example, when screwing the attachment element (160) to the heat sink (180). In some examples, the clamping surface (162) may be integrally formed with a clinch nut, which is a component of the heat sink (180). The attachment element (160) of the attachment pin (150) may be attached to the clinch nut. In some examples, the attachment element (160) may be screwed into the clinch nut or press-fitted.

[0042] The foregoing disclosure is not intended to limit the present disclosure to the embodiments or exact formations disclosed in the specification. As such, it is considered that modifications and / or various other formations and embodiments of the present disclosure are possible from the perspective of the disclosure, whether explicitly described or implied in the specification. Accordingly, having described embodiments of the present disclosure, those skilled in the art will recognize that changes in form and detail may be made without departing from the scope of the present disclosure.

[0043] In the specification above, the disclosure is described with reference to specific embodiments. However, as will be recognized by those skilled in the art, the various embodiments disclosed herein may be modified or otherwise implemented in various other ways without departing from the spirit and scope of the disclosure. Accordingly, this description should be considered illustrative and is intended to instruct those skilled in the art in the manner of making and using various aspects of the disclosed fastening system. It should be understood that the forms of the disclosure shown and described herein should be considered as representative embodiments. Equivalent elements or materials may be substituted for elements that are representatively exemplified and described herein. Furthermore, specific features of the disclosure may be used independently of the use of other features, all of which will be obvious to those skilled in the art after benefiting from the description of the disclosure. Expressions such as “including,” “comprising,” “incorporating,” “consisting of,” “have,” and “is” used to describe and assert the present disclosure are intended to be interpreted in a non-exclusive manner, that is, they allow for the non-exclusive existence of the described items, components, or elements. References to the singular form should also be interpreted in relation to the plural form.

[0044] Furthermore, the various aspects disclosed herein should be accepted as illustrative and descriptive and should not be interpreted as limiting the content of the disclosure. All combinator references (e.g., connected, associated, combined, etc.) are used solely to aid the reader's understanding of the content of the disclosure and may not form any limitations, such as the use, location, or orientation of the elements disclosed herein. Accordingly, where combinator references are present, they should be interpreted broadly. Moreover, such combinator references do not necessitate inferring that two elements are directly connected to each other.

[0045] Additionally, numeric terms such as “first,” “second,” “one,” “other,” or other general and numeric terms, but not limiting, should also be taken only as identifiers to help readers understand the various elements, embodiments, changes and / or modifications of the present disclosure and may not form limitations, such as the order or preference of elements, embodiments, changes and / or modifications, with respect to other elements, embodiments, changes and / or modifications.

[0046] Additionally, it will be understood that one or more elements depicted in the drawings / drawings may be implemented in a more separated or integrated manner, and may also be removed in certain cases as useful depending on the specific application.

[0047] For illustrative purposes, the term "horizontal" as used herein is defined as a plane parallel to the plane or surface of the floor of the area where the device being described is used, regardless of its direction. The term "floor" may be used interchangeably with the term "ground." The term "vertical" indicates a direction perpendicular to the horizontal just defined. Terms such as "up," "down," "bottom," "top," "side," "front," "back," "side," "higher," "lower," "upper," "upper," and "lower" are defined with respect to the horizontal plane in use.

[0048] Terms such as "comprising," "including," and "having" are synonyms and are used in an open-ended fashion, without excluding additional elements, features, acts, or actions. Furthermore, the term "or" is used in an inclusive sense (rather than an exclusive one); for example, when used to link a list of elements, "or" refers to one, some, or all of the elements.

[0049] Although specific embodiments and examples have been described herein, those skilled in the art will understand that many aspects of the system described herein may be combined or modified differently to still form additional embodiments or acceptable examples. All such variations and modifications are intended to be included within the scope of this disclosure. Various designs and approaches are possible. No function, structure, or step disclosed herein is essential or indispensable.

[0050] For the purposes of this disclosure, specific aspects, advantages, and new features are described herein. It should be understood that not all advantages are necessarily achieved according to specific embodiments. Accordingly, for example, a person skilled in the art will recognize that this disclosure may be practiced or performed in a manner that achieves one advantage or a group of advantages taught in the specification without necessarily achieving other advantages that may be taught or implied in the specification.

[0051] Furthermore, while exemplary embodiments have been described herein, the scope of the invention includes all embodiments including equivalent elements that are obvious to those skilled in the art based on this disclosure, as well as modifications, omissions, combinations (e.g., combinations of configurations between different embodiments), adaptations, and / or changes. The limitations set forth in the claims should be interpreted broadly based on the wording used in the claims and should not be limited by the embodiments described in this specification or during the filing process, and such embodiments should be interpreted as non-exclusive. Additionally, the operation of the disclosed processes and methods may be modified in any way, such as by changing the order of operations, inserting additional operations, or deleting operations. Accordingly, this specification and the embodiments are merely illustrative examples, and the true scope and spirit of the invention are defined by the full scope of the claims and their equivalents.

[0052] Conditional language used herein, such as "can," "might," "may," "eg," and similar terms, is generally intended to convey that certain features, elements, and / or states are included in some embodiments while other embodiments do not, unless otherwise specifically stated or otherwise understood within the context in which they are used. Accordingly, such conditional language is not generally intended to imply that features, elements, and / or states are required for one or more embodiments in any way, or that one or more embodiments must necessarily include logic for determining, by the presence or absence of drafter input or prompting, whether these features, elements, blocks, and / or states can be included in or performed in any particular embodiment.

[0053] The scopes disclosed in this disclosure also include all overlaps, sub-scopes, and combinations thereof. Language such as “up to,” “at least,” “greater than,” “less than,” “between,” etc. includes the mentioned numbers.

Claims

Claim 1 A screwless fastener system for securing a printed circuit board assembly (PCBA) to an attachment pin, wherein the attachment pin extending from a heat sink comprises a clamping surface spaced apart from the heat sink configured to support the PCBA, and the system comprises a fastener washer comprising a conical spring and a plurality of interference petals, wherein the plurality of interference petals are sized and shaped to clamp to the attachment pin, and a retaining cup sized and shaped to accommodate the fastener washer, wherein when the plurality of interference petals are clamped to the attachment pin, a portion of the retaining cup is positioned between the fastener washer and the PCBA, and when the plurality of interference petals are clamped to the attachment pin, the conical spring generates a thermally stable clamping force on the PCBA positioned between the clamping surface and a portion of the retaining cup. Claim 2 A fastener washer configured to be fastened to an attachment pin, wherein the fastener washer comprises a conical spring having an inner edge and an outer edge, a flat outer rim extending from the outer edge of the conical spring, an integral pressure surface extending inward from the inner edge, and a plurality of interference petals disposed inward from the integral pressure surface. Claim 3 A fastener washer according to paragraph 2, further comprising an opening at the center of the plurality of interference petals. Claim 4 A fastener washer according to paragraph 2, wherein the inner edge and the outer edge are circular and concentric. Claim 5 A fastener washer according to paragraph 2, further comprising one or more gaps extending radially through a portion of the conical spring. Claim 6 In paragraph 2, the integrated pressure surface is a fastener washer substantially parallel to the flat outer rim. Claim 7 In paragraph 2, the plurality of interference petals are fastener washers configured to mechanically grip the attachment pin. Claim 8 In paragraph 2, the fastener washer is a fastener washer further comprising stainless steel. Claim 9 A fastener washer according to paragraph 2, wherein the fastener washer further comprises a height from the flat outer rim to the plurality of interference petals, and the height is about 2 mm. Claim 10 A fastener washer according to paragraph 2, wherein the outer diameter of the flat outer rim is approximately 13 mm. Claim 11 In paragraph 3, the diameter of the opening is approximately 2.75 mm, a fastener washer. Claim 12 A screwless fastener system comprising a retaining cup having a cup clamping surface, a fastener washer including a conical spring positioned within the retaining cup, and an attachment pin having an interface surface and a pin clamping surface, wherein the end of the attachment pin is configured to be attached to a first component, the fastener washer is configured to clamp to the interface surface, and the conical spring is configured to generate a clamping force on a second component positioned between the cup clamping surface and the pin clamping surface. Claim 13 In Clause 12, the cup clamping surface is a system that is spaced at a certain distance from the end of the attachment pin. Claim 14 In Clause 12, the interface surface is an electrically conductive system. Claim 15 In paragraph 12, the retaining cup further comprises one or more washer center wedges, a system. Claim 16 In claim 12, the clamping force is at least 300 N, in the system. Claim 17 In Clause 12, the retaining cup further comprises a washer pressure distance limiting function, in a system. Claim 18 In paragraph 12, the retaining cup further comprises one or more snap retainers, in a system. Claim 19 In paragraph 12, the above-mentioned first component is a heat sink, and the heat sink is fixedly attached to the attachment pin, a system. Claim 20 In Clause 12, the above-mentioned second component is a system that is a PCBA.

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