Pin terminal of switching device, tin pick-up terminal structure and relay

Abstract

The invention discloses a pin terminal of a switching device, a tin pick-up terminal structure and a relay. The pin terminal is provided with a tail end suitable for tin pick-up processing. At least one groove with an opening in the end face is formed in the tail end, and the groove is suitable for gathering and keeping tin materials after tin pick-up; the tin pick-up terminal structure comprises the pin terminal of the switching device, and the relay comprises the pin terminal of the switching device or the tin pick-up terminal structure. The pin terminal provided by the invention can realize controllable appearance size, good quality control and low cost through tinning treatment, and is easily matched with a PCB (Printed Circuit Board).

Description

Technical Field

[0001] This invention relates to the field of relays, and more specifically to a pin terminal, soldered terminal structure, and relay of a switching device. Background Technology

[0002] In existing relays, the pins need to be mounted to the PCB board by soldering. To ensure the reliability of the soldering, the pins of the product generally need to undergo tin plating or tinning surface treatment. Tin plating can be done as a whole or in a partial manner. Whole tin plating involves tin plating the entire relay and then sealing it with sealant. However, the heat during soldering can cause the plating to melt, and the originally sealed area will no longer be sealed due to the plating peeling off. This cannot meet the requirements of products with high sealing requirements. Partial tin plating is more complicated, more expensive, and the tinning area is difficult to control. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned defects or problems in the prior art and to provide a pin terminal, a soldered terminal structure and a relay for a switching device. The pin terminals of this application can be soldered and can ensure that the appearance and size are controllable, the quality control is good, the cost is low and it is easy to adapt to the PCB board.

[0004] To achieve the above objectives, the present invention and its preferred embodiments employ the following technical solutions, but the embodiments are not limited to the following solutions: Technical solution one relates to a pin terminal of a switching device, the pin terminal having an end suitable for tinning; the end is provided with at least one groove opening on its end face, the groove being suitable for allowing solder to gather and be retained after tinning.

[0005] Based on technical solution one, there is also technical solution two. In technical solution two and its related embodiments, the groove is located in the middle of the width direction of the pin terminal.

[0006] Based on technical solution one, there is also technical solution three. In technical solution three and its related embodiments, along the length direction of the pin terminal, at least a portion of the cross-sectional area of ​​the end of the pin terminal gradually decreases toward its end face.

[0007] Based on technical solution three, there is also technical solution four. In technical solution four and its related embodiments, along the length direction of the pin terminal, the cross-sectional area of ​​the groove gradually decreases and increases towards its opening.

[0008] Based on technical solution three or four, technical solution five is also provided. In technical solution five and its related embodiments, the end has a first inclined surface extending to the end face on at least one side along the thickness direction of the pin terminal, so that the size of at least part of the end in the thickness direction gradually decreases toward the end face, and / or, the end has a second inclined surface extending to the end face on at least one side along the width direction of the pin terminal, so that the size of at least part of the end in the width direction gradually decreases toward the end face.

[0009] Based on technical solution five, technical solution six is ​​also provided. In technical solution six and its related embodiments, when the end is provided with a first inclined surface, the vertical height of the first inclined surface along the length direction of the pin terminal is greater than or equal to the depth of the groove; when the end is provided with a second inclined surface, the vertical height of the second inclined surface along the length direction of the pin terminal is greater than or equal to the depth of the groove.

[0010] Based on technical solution five, technical solution seven is also provided. In technical solution seven and its related embodiments, when the end has a first inclined surface, the first inclined surface is a plane or an arc surface; when the end has a second inclined surface, the second inclined surface is a plane or an arc surface.

[0011] Based on technical solution four, there is also technical solution eight. In technical solution eight and its related embodiments, along the length direction of the pin terminal, the size of the groove along the width direction of the pin terminal gradually increases toward the opening.

[0012] Based on technical solution eight, there is also technical solution nine. In technical solution nine and its related embodiments, the groove is provided with a third inclined surface on both sides along the width direction of the pin terminal, so that the size of the groove in the width direction gradually increases towards the end face.

[0013] Based on technical solution nine, there is also technical solution ten. In technical solution ten and its related embodiments, the third inclined surface is a curved surface or a plane.

[0014] Based on technical solution nine, there is also technical solution eleven. In technical solution eleven and its related embodiments, the two third inclined surfaces are connected to the bottom of the groove by a circular arc surface or a plane transition.

[0015] Based on technical solution eight, there is also technical solution twelve. In technical solution twelve and its related embodiments, the groove is one of arc shape, trapezoidal shape or V shape.

[0016] Based on technical solution one, there is also technical solution thirteen. In technical solution thirteen and its related embodiments, the number of grooves is two or more, and each groove is arranged along the width direction of the pin terminal.

[0017] Based on technical solution one, there is also technical solution fourteen. In technical solution fourteen and its related embodiments, along the thickness direction of the pin terminal, at least one side of the groove extends to the side of the pin terminal, or the two sides of the groove extend to the two sides of the pin terminal respectively.

[0018] Based on technical solution one, there is also technical solution fifteen. In technical solution fifteen and its related embodiments, the end face of the pin terminal is provided with at least two grooves discretely.

[0019] Technical solution sixteen relates to a soldering terminal structure, including a pin terminal of a switching device as described in any one of technical solutions one to fifteen and solder; the solder is contained in the groove, and is formed by the surface tension of the pin terminal after being lifted from the molten solder and then accumulated in the groove and cooled.

[0020] Technical solution seventeen relates to a relay that adopts the pin terminals of the switching device as described in any one of technical solutions one to fifteen or has a tinned terminal structure as described in technical solution seventeen.

[0021] As can be seen from the above description of the present invention and its preferred embodiments, compared with the prior art, the technical solution of the present invention and its preferred embodiments have the following beneficial effects due to the adoption of the following technical means: In technical solution one, the pin terminals are soldered using a tin-dip method. This soldering method can solve the problems of poor sealing performance, complex process, high cost, and difficulty in controlling the tin-plated area caused by tin-plated soldering. However, in practice, this soldering method is prone to problems such as uncontrollable relay appearance dimensions, poor quality control, need for additional rework processes, and high costs. Through continuous observation, experimentation, and research, the applicant has found that the reason for the technical problems such as "uncontrollable relay appearance dimensions, poor quality control, need for additional rework processes, and high costs" is that tin has a melting point of 230℃ and is in a liquid state at high temperatures. After tinning, the pin terminals leave the molten tin, and the molten tin begins to cool and solidify. During the cooling process, the molten tin will flow downwards due to gravity, which can be approximately in the shape of a water droplet. After the molten tin cools and solidifies, it forms tin tips, which makes it impossible to accurately control the length of the pin terminals and cannot guarantee that all pin terminals can reliably adapt to the PCB board. Therefore, an additional process is required to remove the tin tips after tinning, which is costly.

[0022] In the first technical solution and its preferred embodiment, the groove structure provides an ideal space for the convergence and containment of residual molten solder after soldering. During the soldering process, when the pin is lifted from the molten solder, the molten solder will actively shrink and fill the groove under the action of its own surface tension, thereby avoiding the disorderly accumulation of molten solder on the flat end face and the protrusion of solder tips, which would affect the length and appearance of the pin terminal. It also eliminates the need for subsequent solder tip removal process, which not only reduces processing costs but also allows for precise control of the pin terminal length, ensuring reliable adaptation with the PCB board. At the same time, the overall appearance of the relay becomes uniform and controllable.

[0023] In the second technical solution and its preferred embodiment, the groove is located in the middle of the width direction of the pin terminal. This makes it easier for the molten solder to converge into the groove in the middle under the action of gravity, and the distribution is more symmetrical and balanced. This helps to prevent the molten solder from generating lateral pulling force when filling due to the skewed position of the groove, which would affect the flatness of the soldering between the pin terminal and the PCB board. This further reduces the risk of solder spikes and improves the consistency of the product appearance and the structural stability after soldering.

[0024] In the third technical solution and the preferred embodiment, the cross-sectional area of ​​at least a portion of the end of the pin terminal gradually decreases towards its end face. This guides the molten solder remaining on the outer peripheral wall of the pin terminal to the end face groove, reduces the adhesion of molten solder on the outer peripheral sidewall, promotes the convergence of molten solder into the groove, further prevents the formation of solder spikes and irregular solder lumps on the end sidewall, thereby avoiding the solder lumps from increasing the size of the pin terminal in the width or thickness direction, which is more conducive to ensuring reliable adaptation between the pin terminal and the PCB board.

[0025] In technical solution four and its preferred embodiments, along the length direction of the pin terminal, the cross-sectional area of ​​the groove gradually decreases and increases towards its opening. This helps the molten solder to "climb the wall" and fill the groove under the action of surface tension, avoiding gaps in the groove and ensuring that the molten solder is firmly locked in the groove, preventing it from falling off under the action of gravity due to its small contact area with the pin and weak bonding force. At the same time, it avoids the groove being too large and leaving too much molten solder, reducing the probability of the molten solder in the groove being too heavy and falling out of the groove, as well as the probability of the molten solder in the groove forming solder spikes.

[0026] In technical solution five and its preferred embodiments, the design of the first inclined surface and / or the design of the second inclined surface both result in a convergent structure at the end. This convergent structure further enhances the effect of guiding the peripheral solder towards the central area, improving the accuracy of solder control. The design of the first inclined surface primarily acts on the side of the end in the thickness direction, helping to reduce solder adhesion on this side and guiding the solder in the thickness direction towards the groove. It is also more suitable for wide-pin scenarios, improving adaptability and reliability. When both sides of the end are provided with the first inclined surface, the first inclined surface on both outer sides guides the solder from both sides of the pin thickness direction, ensuring symmetry, avoiding soldering problems caused by skewing, and enhancing appearance controllability and soldering consistency. The design of the second inclined surface primarily acts on the side of the end in the width direction, helping to reduce solder adhesion on this side and guiding the solder in the width direction towards the groove. When both sides of the end are provided with the second inclined surface, the second inclined surface on both outer sides guides the solder from both sides of the pin terminal in the width direction, ensuring symmetry, avoiding soldering problems caused by skewing, and enhancing appearance controllability and soldering consistency.

[0027] In technical solution six and its preferred embodiments, when the end is provided with a first inclined surface, the vertical height of the first inclined surface along the length direction of the pin terminal is greater than or equal to the depth of the groove; when the end is provided with a second inclined surface, the vertical height of the second inclined surface along the length direction of the pin terminal is greater than or equal to the depth of the groove. These designs ensure that the molten solder at the end is easily affected by gravity and flows downward and gathers at the groove; the groove has enough space to accommodate the molten solder, while preventing the end structure of the pin terminal from becoming fragile or the molten solder from being insufficiently filled or excessively filled due to excessive groove depth, which could easily cause it to fall off and form solder spikes.

[0028] In technical solution seven and its preferred embodiments, when the end has a first inclined surface, the first inclined surface is a plane or an arc surface; when the end has a second inclined surface, the second inclined surface is a plane or an arc surface. The smooth design of the plane or arc surface optimizes the flow path of the molten solder, ensuring that the molten solder efficiently flows into the groove. Compared with sharp edges, the arc surface is more conducive to the continuous spreading of the molten solder and reduces the separation of solder beads caused by sudden changes in surface tension; the plane provides a stable guiding angle.

[0029] In technical solution eight and its preferred embodiments, along the length of the lead terminal, the groove gradually increases in size towards the opening along the width of the lead terminal. The flared design of the groove expands the inlet cross-section of the molten solder. This structure guides the molten solder to naturally fill the groove from bottom to top, avoiding voids at the bottom, while increasing the contact area between the solder and the groove, thus improving the bonding strength. The flared shape also helps to resist the downward pull of gravity, making the solder more stably locked in the groove and preventing dripping during cooling.

[0030] In technical solution nine and its preferred embodiments, the double-sided third inclined surfaces form a funnel-shaped solder guiding structure, which can actively absorb molten solder through geometric expansion. The third inclined surfaces guide the molten solder to spread evenly along the inclined surfaces, accelerating the filling process and reducing air bubble residue. This design is particularly beneficial for the flow of high-viscosity solder, ensuring that the corners of the groove are completely wetted and eliminating the risk of cold solder joints caused by unfilled areas. In technical solution ten and its preferred embodiments, the smooth design of the third inclined surface as a plane or curved surface optimizes the flow path of the molten solder, ensuring that the molten solder efficiently flows into the groove. Compared with sharp edges, the arc surface is more conducive to the continuous spreading of the molten solder and reduces the separation of solder beads caused by sudden changes in surface tension; the plane provides a stable guiding angle.

[0031] In technical solution eleven and its preferred embodiments, the arc / plane transition at the bottom of the tank can eliminate sharp corner structures, reduce the difficulty of molten solder climbing, and ensure that the groove is filled with molten solder.

[0032] In the twelve technical solutions and their preferred embodiments, the arc shape is easy to process and form, the mold insert transition is natural and not easy to break, and the molten solder is easier to climb up the wall under its own surface tension and easier to fill the arc-shaped groove; the trapezoidal shape may provide a larger slot to facilitate the initial flow of molten solder and is easy to process and form.

[0033] In technical solution thirteen and its preferred embodiments, multiple grooves are spaced apart along the width direction of the pin terminal. This distributes the solder volume by setting multiple smaller convergence points, avoiding waste caused by excessive solder from a single large convergence point, reducing the weight of the converged solder, and making it easier to retain the solder within the grooves. It also prevents solder spikes from forming after solidification at the grooves and solves the problem that excessively large groove sizes may not allow sufficient solder to be stored within the grooves due to tension. Furthermore, multiple grooves are advantageous for use with pin terminals that have high current carrying capacity and large width.

[0034] In technical solution fourteen and its preferred embodiments, at least one side of the groove extends to the side of the pin terminal along the thickness direction, or both sides of the groove extend to the two sides of the pin terminal respectively. In the thickness direction, at least one side of the groove is in communication with air, which facilitates the removal of gas when molten solder enters and prevents obstruction of molten solder filling the groove. When both sides of the groove extend to the two sides of the pin terminal respectively in the thickness direction, the groove can be formed by cutting. Compared with the case of forming the groove on the end face, this helps to prevent pin terminal deformation, ensure that the pin terminal size meets expectations, and guarantee the uniformity of the dimensions of each pin terminal.

[0035] In technical solution fifteen and its preferred embodiments, discrete distribution refers to an irregular distribution. The discrete groove layout adapts to asymmetric molten solder flow scenarios. This means that by setting multiple smaller convergence points, the amount of molten solder is distributed, avoiding waste caused by a single large convergence point attracting too much molten solder, reducing the weight of the converged molten solder, and making it easier to retain the molten solder within the groove. It also prevents solder spikes from forming after solidification at the groove, and solves the problem that excessively large groove sizes may not be sufficient to store the molten solder within the groove due to tension. Furthermore, setting multiple grooves is also beneficial for use with pins and terminals with high current carrying capacity and large width.

[0036] Technical solution sixteen has the technical advantages of any one of technical solutions one through fifteen.

[0037] Technical solution seventeen has the technical advantages of any one of technical solutions one through fifteen, or the technical advantages of technical solution sixteen. Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments are briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a front view of the pin terminals of Embodiment 1 of this application; Figure 2 This is a bottom view of the pin terminals of Embodiment 1 of this application; Figure 3 This is a front view of the pin terminals of Embodiment 2 of this application; Figure 4 This is a bottom view of the pin terminals of Embodiment 2 of this application; Figure 5 This is a front view of the pin terminals of Embodiment 3 of this application; Figure 6 This is a bottom view of the pin terminals of Embodiment 3 of this application; Figure 7 This is a front view of the pin terminals of Embodiment 4 of this application; Figure 8 This is a bottom view of the pin terminals of Embodiment 4 of this application; Figure 9 This is a front view of the pin terminals of Embodiment 5 of this application; Explanation of key figure labels: Pin terminal 10; end 11; end face 111; groove 12; first inclined surface 13; second inclined surface 14; third inclined surface 15. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are preferred embodiments of the present invention and should not be considered as excluding other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0041] Unless otherwise expressly defined, the use of terms such as "first," "second," or "third" in the claims, description, and accompanying drawings of this invention is for distinguishing different objects and not for describing a specific order.

[0042] Unless otherwise expressly defined, in the claims, description, and accompanying drawings of this invention, the use of directional terms such as "center," "lateral," "longitudinal," "horizontal," "vertical," "top," "bottom," "inner," "outer," "upper," "lower," "front," "rear," "left," "right," "clockwise," and "counterclockwise" to indicate orientation or positional relationships is based on the orientation and positional relationships shown in the accompanying drawings and is only for the convenience of describing the invention and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the specific scope of protection of this invention.

[0043] Unless otherwise expressly defined, the terms "fixed connection" or "fixed connection" used in the claims, description and drawings of this invention should be interpreted broadly to refer to any connection in which there is no displacement or relative rotation relationship between the two parties, including non-removable fixed connection, detachable fixed connection, integral connection and fixed connection by other means or components.

[0044] In the claims, description and accompanying drawings of this invention, the terms "comprising," "having," and variations thereof are used to mean "including but not limited to."

[0045] Example 1 See Figure 1-2 , Figure 1-2 The diagram shows a pin terminal 10 of a switching device according to Embodiment 1. The pin terminal 10 has an end 11 adapted for tinning. The end 11 is provided with at least one groove 12 opening on its end face 111, the groove 12 being adapted for the collection and retention of solder after tinning.

[0046] The groove 12 is located in the middle of the width direction W of the pin terminal 10. In this embodiment, there is one groove 12. In other embodiments, when there are multiple grooves 12, each groove 12 can be arranged according to a certain pattern (such as along the width direction W of the pin terminal 10) and is generally arranged in the middle of the width direction W of the pin terminal 10. Along the length direction L of the pin terminal 10, at least a portion of the cross-sectional area of ​​the end 11 of the pin terminal 10 gradually decreases towards its end face 111. Along the length direction L of the pin terminal 10, the cross-sectional area of ​​the groove 12 gradually increases towards its opening. In the example provided in this embodiment, along the length direction L of the pin terminal 10, the size of the groove 12 gradually increases towards the opening along the width direction W of the pin terminal 10.

[0047] The end 11 has a first inclined surface 13 extending to the end face 111 on at least one side along the thickness direction T of the pin terminal 10, so that the dimension of at least a portion of the end 11 in the thickness direction T gradually decreases toward the end face 111, and / or, the end 11 has a second inclined surface 14 extending to the end face 111 on at least one side along the width direction W of the pin terminal 10, so that the dimension of at least a portion of the end 11 in the width direction W gradually decreases toward the end face 111. When the end 11 has the first inclined surface 13, the vertical height of the first inclined surface 13 along the length direction L of the pin terminal 10 is greater than or equal to the depth of the groove 12, and the first inclined surface 13 is a plane or an arc surface; when the end 11 has the second inclined surface 14, the vertical height of the second inclined surface 14 along the length direction L of the pin terminal 10 is greater than or equal to the depth of the groove 12, and the second inclined surface 14 is a plane or an arc surface. Specifically, in the example provided in this embodiment, the end 11 is provided with a first inclined surface 13 extending to the end face 111 on both sides along the thickness direction T of the pin terminal 10, and a second inclined surface 14 extending to the end face 111 on both sides along the width direction W of the pin terminal 10. The first inclined surface 13 and the second inclined surface 14 are both planes, and along the length direction L of the pin terminal 10, the vertical height of the first inclined surface 13 is greater than the depth of the groove 12, and the vertical height of the second inclined surface 14 is also greater than the depth of the groove 12.

[0048] The groove 12 has a third inclined surface 15 on both sides along the width direction W of the pin terminal 10, so that the size of the groove 12 in the width direction W gradually increases towards the end face 111. The third inclined surface 15 is a curved surface or a plane. The two third inclined surfaces 15 are connected to the bottom of the groove 12 by an arc surface or a plane. It is worth noting that the bottom of the groove 12 refers to the part located on the side of the groove 12 away from its opening along the depth direction of the groove 12. The groove 12 is arc-shaped, trapezoidal, or V-shaped. In this embodiment, the third inclined surface 15 is a curved surface, and the two third inclined surfaces 15 are connected to the bottom of the groove 12 by an arc surface, making the groove 12 arc-shaped.

[0049] Along the thickness direction T of the pin terminal 10, at least one side of the groove 12 extends to the side of the pin terminal 10, or both sides of the groove 12 extend to the two sides of the pin terminal 10, respectively. In this embodiment, both sides of the groove 12 extend to the two sides of the pin terminal 10, respectively.

[0050] This embodiment also provides a soldering terminal structure, including the lead terminal 10 of the above-mentioned switching device and solder; the solder is contained in the groove 12, and is formed by the lead terminal 10 being lifted from the molten solder by the end 11 and then accumulating in the groove 12 based on surface tension and cooling.

[0051] This embodiment also provides a relay that uses the pin terminal 10 of the above-described switching device or has the above-described tinned terminal structure.

[0052] In this embodiment, the groove 12 structure provides an ideal space for the gathering and containment of residual molten solder after soldering. During the soldering process, when the pin is lifted from the molten solder, the molten solder will actively shrink and fill the groove 12 under the action of its own surface tension. This avoids the disorderly accumulation of molten solder on the flat end face and the protrusion of solder tips, which would affect the length and appearance of the pin terminal 10. It also eliminates the need for subsequent solder tip removal processes, which not only reduces processing costs but also allows for precise control of the length of the pin terminal 10, ensuring reliable adaptation with the PCB board. At the same time, the overall appearance of the relay becomes uniform and controllable.

[0053] In this embodiment, the groove 12 is located in the middle of the width direction W of the pin terminal 10. This makes it easier for the molten solder to converge into the groove 12 in the middle under the action of gravity, and the distribution is more symmetrical and balanced. This helps to prevent the molten solder from generating lateral pulling force when filling due to the skewed position of the groove 12, which would affect the soldering flatness between the pin terminal 10 and the PCB board. This further reduces the risk of solder spikes and improves the consistency of the product appearance and the structural stability after soldering.

[0054] In this embodiment, at least a portion of the cross-sectional area of ​​the end 11 of the pin terminal 10 gradually decreases toward its end face 111. This guides the molten solder remaining on the outer peripheral wall of the pin terminal 10 to the groove 12 of the end face 111, reducing the adhesion of molten solder on the outer peripheral sidewall and promoting the convergence of molten solder into the groove 12. This further prevents the formation of solder spikes and irregular solder lumps on the sidewall of the end 11, thereby avoiding the increase of the size of the pin terminal 10 in the width direction W or thickness direction T by solder lumps, which is more conducive to ensuring reliable fit between the pin terminal 10 and the PCB board.

[0055] In this embodiment, along the length L of the pin terminal 10, the cross-sectional area of ​​the groove 12 gradually decreases and increases towards its opening. This helps the molten solder to "climb the wall" and fill the groove 12 under the action of surface tension, avoiding gaps in the groove and ensuring that the molten solder is firmly locked in the groove 12, preventing it from falling off under gravity due to its small contact area with the pin and weak bonding force. At the same time, it avoids the groove 12 being too large and leaving too much molten solder, reducing the probability of the molten solder in the groove 12 being too heavy and falling out of the groove 12, and the probability of the molten solder in the groove 12 forming solder spikes.

[0056] In this embodiment, the design of the first inclined surface 13 and / or the design of the second inclined surface 14 both enable the end 11 to form a convergent structure. This convergent structure further enhances the effect of guiding the peripheral solder liquid towards the central region, improving the accuracy of solder liquid control. The design of the first inclined surface 13 mainly acts on the side of the end 11 in the thickness direction T, which helps to reduce the solder liquid adhesion on this side and guides the solder liquid in the thickness direction T to flow into the groove 12. It is also more suitable for wide pin scenarios, improving adaptability and reliability. When both sides of the end 11 are provided with a first inclined surface 13, the first inclined surface 13 on both outer sides guides the solder liquid from both sides of the pin thickness direction T, ensuring symmetry, avoiding soldering problems caused by skewing, and enhancing appearance controllability and soldering consistency. The design of the second inclined surface 14 mainly acts on the side of the width direction W of the end 11, which helps to reduce the solder liquid adhesion on this side and guides the solder liquid in the width direction W to the groove 12. When both sides of the end 11 are provided with a second inclined surface 14, the second inclined surface 14 on both outer sides guides the solder liquid from both sides of the pin terminal 10 in the width direction W, ensuring symmetry, avoiding soldering problems caused by skewing, and enhancing appearance controllability and soldering consistency.

[0057] In this embodiment, when the end 11 is provided with a first inclined surface 13, the vertical height of the first inclined surface 13 along the length direction L of the pin terminal 10 is greater than or equal to the depth of the groove 12; when the end 11 is provided with a second inclined surface 14, the vertical height of the second inclined surface 14 along the length direction L of the pin terminal 10 is greater than or equal to the depth of the groove 12. These designs ensure that the molten solder at the end 11 is easily affected by gravity and flows downward and gathers at the groove 12; the groove 12 has enough space to accommodate the molten solder, while preventing the end 11 of the pin terminal 10 from becoming fragile due to excessive groove depth, or from being poorly filled with molten solder or being filled with too much molten solder, which could easily cause it to fall off and form solder spikes.

[0058] In this embodiment, when the end 11 is provided with a first inclined surface 13, the first inclined surface 13 is a plane or an arc surface; when the end 11 is provided with a second inclined surface 14, the second inclined surface 14 is a plane or an arc surface. The smooth design of the plane or arc surface optimizes the flow path of the molten solder, ensuring that the molten solder efficiently flows into the groove 12. Compared with sharp edges, the arc surface is more conducive to the continuous spreading of the molten solder and reduces the separation of solder beads caused by sudden changes in surface tension; the plane provides a stable guiding angle.

[0059] In this embodiment, along the length L of the pin terminal 10, the groove 12 gradually increases in size towards the opening along the width W of the pin terminal 10. The flared design of the groove 12 enlarges the inlet cross-section of the molten solder. This structure guides the molten solder to naturally fill the groove 12 from bottom to top, avoiding voids at the bottom. At the same time, it increases the contact area between the solder and the groove 12, improving the bonding strength. The flared shape also helps to resist the downward pull of gravity, making the solder more stably locked in the groove 12 and preventing dripping during cooling.

[0060] In this embodiment, the double-sided third inclined surfaces 15 form a funnel-shaped solder guiding structure, which can actively absorb molten solder through geometric expansion. The third inclined surfaces 15 guide the molten solder to spread evenly along the inclined surfaces, accelerating the filling process and reducing air bubble residue. This design is particularly beneficial for the flow of high-viscosity solder, ensuring that the corners of the groove 12 are completely wetted, eliminating the risk of cold solder joints caused by unfilled areas. In this embodiment, the smooth design of the third inclined surface 15, whether planar or curved, optimizes the flow path of the molten solder, ensuring efficient flow of the molten solder into the groove 12. Compared to sharp edges, the rounded surface is more conducive to the continuous spreading of the molten solder, reducing solder bead separation caused by sudden changes in surface tension.

[0061] In this embodiment, the arc / flat transition at the bottom of the tank can eliminate sharp corner structures, reduce the difficulty of molten solder climbing, and ensure that the groove 12 is filled with molten solder.

[0062] In this embodiment, the arc shape is easy to process and form, the mold insert transition is natural and not easy to break, and the molten solder is easier to climb up the wall under its own surface tension and easier to fill the arc-shaped groove 12.

[0063] In this embodiment, along the thickness direction T of the lead terminal 10, at least one side of the groove 12 extends to the side of the lead terminal 10, or both sides of the groove 12 extend to the two sides of the lead terminal 10 respectively. In the thickness direction T, at least one side of the groove 12 is in communication with air, which facilitates the removal of gas when molten solder enters and prevents the molten solder from being obstructed from filling the groove 12. When both sides of the groove 12 extend to the two sides of the lead terminal 10 in the thickness direction T, the groove 12 can be formed by cutting. Compared to the case of forming the groove 12 on the end face 111, this helps prevent deformation of the lead terminal 10, ensuring that the size of the lead terminal 10 meets expectations and that the size of each lead terminal 10 is consistent.

[0064] Tinned terminal structures also possess the aforementioned technical advantages.

[0065] Relays possess the aforementioned technical advantages.

[0066] Example 2 Example 2 has a structure that is basically the same as that of Example 1, except that, see [link to example]. Figure 3-4 The third inclined surface 15 is a plane, and the two third inclined surfaces 15 are connected to the bottom of the groove 12 by a plane transition, making the groove 12 trapezoidal.

[0067] The third inclined surface 15 provides a stable flow angle for the smooth design of the plane. The trapezoidal groove 12 can provide a larger opening to facilitate the initial flow of molten solder and is easy to process and shape.

[0068] Example 3 Example 3 has a structure that is basically the same as that of Example 1, except that, see [link to example]. Figure 5-6 The two third inclined surfaces 15 are planes, and the two third inclined surfaces 15 are connected to the bottom of the groove 12 by a circular arc, making the groove 12 approximately V-shaped.

[0069] Example 4 Example 4 has a structure that is basically the same as that of Example 1, except that, see [link to example]. Figure 7-8 The number of grooves 12 is two or more, and each groove 12 is arranged along the width direction W of the pin terminal 10. Specifically, in the example provided in this embodiment, the number of grooves 12 is three.

[0070] In this embodiment, multiple grooves 12 are spaced apart along the width direction W of the pin terminal 10. This means that multiple smaller convergence points are used to distribute the solder volume, avoiding waste caused by excessive solder at a single large convergence point, reducing the weight of the converged solder, and making it easier to retain the solder within the grooves 12. It also prevents solder spikes from forming after solidification at the grooves 12. Furthermore, it solves the problem that excessively large grooves 12 may not be sufficient to allow the solder to be stored within them by tension. In addition, providing multiple grooves 12 is advantageous for use with pin terminals 10 that have high current carrying capacity and large width.

[0071] Example 5 Example 5 has a structure that is basically the same as that of Example 4, except that, see [link to example]. Figure 9 The end face 111 of the pin terminal 10 is provided with at least two grooves 12 in a discrete manner. Discrete distribution means irregular distribution.

[0072] In this embodiment, the discrete groove layout 12 is adapted to asymmetric molten solder flow scenarios. By setting multiple smaller convergence points, the amount of molten solder is distributed, avoiding waste caused by a single large convergence point attracting too much molten solder. This reduces the weight of the converged molten solder, making it easier to retain the molten solder within the groove 12. It also prevents solder spikes from forming after solidification at the groove 12. Furthermore, it solves the problem that a groove 12 that is too large might not be able to hold the molten solder within it due to tension. In addition, setting multiple grooves 12 is also beneficial for use with pin terminals 10 that have high current carrying capacity and large width.

[0073] The foregoing description of the specifications and embodiments is intended to explain the scope of protection of this invention, but does not constitute a limitation on the scope of protection of this invention. Modifications, equivalent substitutions, or other improvements to the embodiments of this invention or a portion thereof that can be obtained by those skilled in the art through logical analysis, reasoning, or limited experimentation, based on the teachings of this invention or the foregoing embodiments, in conjunction with common knowledge, general technical knowledge, and / or existing technology, should all be included within the scope of protection of this invention.

Claims

1. A pin terminal (10) of a switching device, characterized in that, The pin terminal (10) has an end (11) suitable for tinning; the end (11) is provided with at least one groove (12) opening on its end face (111), the groove (12) being suitable for allowing solder to gather and be retained after tinning.

2. The pin terminal (10) of the switching device as described in claim 1, characterized in that, The groove (12) is located in the middle of the width direction of the pin terminal (10).

3. The pin terminal (10) of the switching device as described in claim 1, characterized in that, Along the length direction of the pin terminal (10), at least a portion of the cross-sectional area of ​​the end (11) of the pin terminal (10) gradually decreases toward its end face (111).

4. The pin terminal (10) of the switching device as described in claim 3, characterized in that, Along the length of the pin terminal (10), the cross-sectional area of ​​the groove (12) gradually decreases and increases in the direction close to its opening.

5. The pin terminal (10) of a switching device as described in claim 3 or 4, characterized in that, The end (11) has a first inclined surface (13) extending to the end face (111) on at least one side along the thickness direction of the pin terminal (10), so that at least a portion of the end (11) gradually decreases in size in the thickness direction toward the end face (111), and / or, the end (11) has a second inclined surface (14) extending to the end face (111) on at least one side along the width direction of the pin terminal (10), so that at least a portion of the end (11) gradually decreases in size in the width direction toward the end face (111).

6. The pin terminal (10) of a switching device as described in claim 5, characterized in that, When the end (11) is provided with a first inclined surface (13), the vertical height of the first inclined surface (13) along the length direction of the pin terminal (10) is greater than or equal to the depth of the groove (12); when the end (11) is provided with a second inclined surface (14), the vertical height of the second inclined surface (14) along the length direction of the pin terminal (10) is greater than or equal to the depth of the groove (12).

7. The pin terminal (10) of a switching device as described in claim 5, characterized in that, When the end (11) is provided with a first inclined surface (13), the first inclined surface (13) is a plane or an arc surface; when the end (11) is provided with a second inclined surface (14), the second inclined surface (14) is a plane or an arc surface.

8. The pin terminal (10) of a switching device as described in claim 4, characterized in that, Along the length direction of the pin terminal (10), the size of the groove (12) gradually increases toward the opening along the width direction of the pin terminal (10).

9. The pin terminal (10) of a switching device as described in claim 8, characterized in that, The groove (12) has a third inclined surface (15) on both sides along the width direction of the pin terminal (10) so that the size of the groove (12) in the width direction gradually increases toward the end face (111).

10. The pin terminal (10) of a switching device as described in claim 9, characterized in that, The third inclined surface (15) is a curved surface or a plane.

11. The pin terminal (10) of a switching device as described in claim 9, characterized in that, The two third inclined surfaces (15) are connected to the bottom of the groove (12) by a circular arc or a flat transition.

12. The pin terminal (10) of a switching device as described in claim 8, characterized in that, The groove (12) is one of the following: arc-shaped, trapezoidal, or V-shaped.

13. The pin terminal (10) of a switching device as described in claim 1, characterized in that, The number of grooves (12) is two or more, and each groove (12) is arranged along the width direction of the pin terminal (10).

14. The pin terminal (10) of a switching device as described in claim 1, characterized in that, Along the thickness direction of the pin terminal (10), at least one side of the groove (12) extends to the side of the pin terminal (10), or the two sides of the groove (12) extend to the two sides of the pin terminal (10), respectively.

15. The pin terminal (10) of a switching device as described in claim 1, characterized in that, The end face (111) of the pin terminal (10) is provided with at least two grooves (12) in a discrete manner.

16. A solder-dip terminal structure, characterized in that, Includes a pin terminal (10) of a switching device as described in any one of claims 1-15 and solder; the solder is contained in the groove (12), which is formed by the surface tension of the pin terminal (11) after being lifted from the molten solder and then enriched in the groove (12) and cooled.

17. A relay, characterized in that, It employs the pin terminal (10) of the switching device as described in any one of claims 1-15 or has the tinned terminal structure as described in claim 17.

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