Surface-mount device and terminal for surface-mount device
By introducing multiple bends and protrusions or holes into the conductive terminals of surface mount devices, the deformation and misalignment problems of the terminals during the overmolding process are solved, achieving higher resistance to deformation and misalignment, and reducing material usage and cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DONGGUAN LITTELFUSE ELECTRONICS CO LTD
- Filing Date
- 2025-04-30
- Publication Date
- 2026-07-21
AI Technical Summary
The conductive terminals of existing surface mount devices are prone to deformation and misalignment during the protective coating process, especially when mounted vertically. This can lead to severe device misalignment and rejection, resulting in waste and increased costs.
The conductive terminal structure is designed, including a support portion, a connection portion, and a middle portion. The middle portion has multiple bends and protrusions or holes to enhance its resistance to deformation and skewness. When a protective coating is formed through injection molding, the protrusions and holes reduce deformation forces, while the bends provide rigidity.
It improves the resistance to deformation and skewness of the terminals, reduces waste and cost of components, and allows for thinner terminal designs, reducing material usage.
Smart Images
Figure CN224537378U_ABST
Abstract
Description
Technical Field
[0001] This disclosure generally relates to the field of surface mount devices. More particularly, this disclosure relates to terminal structures for surface mount devices, wherein the terminal structure has improved resistance to deformation and skewness when a protective coating is overmolded thereon. Background Technology
[0002] Surface mount devices (SMDs) typically include conductive terminals that facilitate mechanical and electrical connections between electronic components (such as metal oxide varistors, fuses, etc.) and a circuit board. For example, a typical metal oxide varistor (MOV) includes an MOV chip having a first electrode and a second electrode disposed on opposite sides thereon. The conductive first and second terminals can be soldered to the first and second electrodes, respectively. The first and second terminals may include pads or leads capable of being soldered to corresponding contacts on a circuit board. A protective coating, typically formed of epoxy resin, can be overmolded onto the MOV and the first and second terminals (e.g., via injection molding) to provide protection against external contaminants and prevent arcing between the MOV and surrounding components.
[0003] A problem associated with constructions such as those described above is that when the protective coating is applied using injection molding or similar processes, the flow of the overmolding material can exert forces on the electronic components and coated terminals, causing the terminals to deform (e.g., bend or deflect), resulting in undesirable misalignment of the terminals and electronic components. This problem is particularly prevalent when electronic components are mounted vertically, where the maximum dimension of the electronic component extends perpendicular to the circuit board, such as for the purpose of minimizing the area occupied by the electronic component on the circuit board. Vertical mounting typically requires longer terminals, which are more prone to misalignment compared to shorter terminals. If such misalignment is severe, it may be necessary to reject the SMD as defective, resulting in waste and increased costs.
[0004] In view of the above, it is desirable to provide an SMD with a terminal that is resistant to deformation and skewness. Utility Model Content
[0005] This overview is provided to present, in a simplified form, the selection of concepts further described below in the detailed description. This overview is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter.
[0006] An embodiment of a surface mount device according to the present disclosure may include: an electronic component having a first electrode disposed on a first side thereon and a second electrode disposed on a second side thereon; a first terminal connected to the first electrode and a second terminal connected to the second electrode, wherein each of the first terminal and the second terminal includes: a leg portion adapted to be connected to a contact on a printed circuit board; a connection portion connected to a corresponding one of the first electrode and the second electrode; and an intermediate portion extending between the leg portion and the connection portion, the intermediate portion including: a plurality of bends formed therein and an embossment formed therein, wherein the embossment extends through at least one of the plurality of bends.
[0007] An embodiment of a terminal for a surface mount device according to the present disclosure may include a foot portion adapted to connect to a contact on a printed circuit board; a connection portion adapted to connect to an electrode of an electronic component; and an intermediate portion extending between the foot portion and the connection portion, the intermediate portion including a plurality of bends formed therein and a protrusion formed therein, wherein the protrusion extends through at least one of the plurality of bends. Attached Figure Description
[0008] Various embodiments of this disclosure will now be described by way of example with reference to the accompanying drawings, in which:
[0009] Figure 1A This is a perspective view illustrating a surface mount device according to an embodiment of the present disclosure;
[0010] Figure 1B It is shown Figure 1A Another perspective view of the surface mount device;
[0011] Figure 2 It is shown Figure 1A and Figure 1B A perspective view of a surface-mount device with a protective coating; and
[0012] Figure 3 This is a perspective view illustrating another surface mount device according to an embodiment of the present disclosure. Detailed Implementation
[0013] Exemplary embodiments of surface mount devices will now be described more fully below with reference to the accompanying drawings. However, surface mount devices can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will convey certain exemplary aspects of surface mount devices to those skilled in the art.
[0014] refer to Figure 1A and Figure 1BThis image shows a perspective view of a surface mount device 10 (hereinafter “SMD 10”) according to an embodiment of the present disclosure. The SMD 10 may include an electronic component 12 (hereinafter “component 12”) and conductive first terminals 14 and second terminals 16. Component 12 may be or may include any type of electronic component typically mounted on a printed circuit board (PCB). Figure 1A and Figure 1B In the exemplary embodiment shown, component 12 is a metal oxide rheostat (MOV). In other embodiments, component 12 may be a fuse, diode, thermistor, etc. This disclosure is not limited in this respect. Electronic component 12 may include a first electrode 18 and a second electrode located on opposite sides of electronic component 12 (the second electrode is not shown in the view but is generally the same as the first electrode 18). The term "electrode" is generally used herein to refer to any type of conductive contact, terminal, rod, or connection point of electronic component. The first and second electrodes may be generally planar and may be formed of a layer or film of metal (e.g., silver, gold, copper, tin, nickel, aluminum, etc.). This disclosure is not limited in this respect.
[0015] The first terminal 24 and the second terminal 26 of the SMD 10 facilitate electrical connections of the electronic component 12 within a circuit, as further described below. The first terminal 24 and the second terminal 26 can be formed of a metal with good electrical conductivity. Examples of such metals include, but are not limited to, copper, tin, aluminum, etc. The first terminal 24 can be electrically and mechanically connected to the first electrode 18 of the electronic component 12, and the second terminal 26 can be electrically and mechanically connected to the second electrode (not shown in the view) of the electronic component 12. The first terminal 24 and the second terminal 26, and their corresponding orientation and connection to the first and second electrodes, can be substantially the same. Therefore, this document will describe only the first terminal 24 and its orientation and connection to the first electrode 18 in more detail, and it will be understood that such a description will also apply to the second terminal 26 and its orientation and connection to the second electrode.
[0016] The first terminal 24 may be formed by cutting, pressing, or otherwise using a single piece of metal, and may include a planar support portion 30 suitable for soldering to contacts on a PCB. The first terminal 24 may also include a planar connection portion 32 for soldering to a first electrode 18 of the electronic component 12, as further described below. The first terminal 24 may also include an intermediate portion 34 extending between the support portion 30 and the connection portion 32. The support portion 30 may be located in a horizontal plane parallel to... Figure 1A and Figure 1B The XZ plane of the Cartesian coordinate system shown. Connecting portion 32 can be located in a vertical plane, which is parallel to... Figure 1A and Figure 1B The XY plane of the Cartesian coordinate system shown is perpendicular to the plane of the support portion 30. The intermediate portion 34 may include a plurality of bends or folds formed therein, which define a plurality of segments extending along the respective planes. For example, the intermediate portion 34 may include a first bend 36 from which a first segment 38 extends perpendicular to the support portion 30; a second bend 40 from which a second segment 42 extends from the first segment 38; a third bend 44 from which a third segment 46 extends from the second segment 42; a fourth bend 48 from which a fourth segment 50 extends from the third segment 46; and a fifth bend 52 from which a fifth segment 54 extends from the fourth segment 50; and a sixth bend 55 from which a connecting portion 32 extends from the fifth segment 54. The aforementioned bends and segments facilitate the necessary positioning and orientation of the leg portion 30 and the connecting portion 32 relative to each other, to allow connection to the PCB (not shown) and the first electrode 18 of the vertically oriented electronic component 12, respectively. It will be appreciated that the above description and... Figure 1A and Figure 1B The specific locations, orientations, and total number of bends and segments shown are not limiting and may be varied to suit specific applications without departing from the scope of this disclosure.
[0017] The intermediate portion 34 may also include corrugations or protrusions formed therein, extending through certain bends described above and between certain segments described above. For example, the intermediate portion 34 may include one or more protrusions 56 extending through the third bend 44, from the second segment 42 into the third segment 46. The intermediate portion 34 may also include one or more protrusions 58 extending through the fourth bend 48, the fifth bend 52, and the sixth bend 55, from the third segment 46 through the fourth segment 50 and into the fifth segment 54. The protrusions 56, 58 may provide enhanced strength and stiffness to the intermediate portion 34 at the third bend 44, the fourth bend 48, the fifth bend 52, and the sixth bend 55. Thus, when the protective coating 60 (see...) Figure 2When the protrusions are overmolded onto the electronic component 12 and the first terminal 24 and the second terminal 26 (e.g., via injection molding), the first terminal 24 and the second terminal 26 can exhibit improved resistance to bending, deflection, or deformation under the force applied to them by the overmolding material (e.g., epoxy resin). Undesirable misalignment of the first terminal 24 and the second terminal 26, and the electronic component 12, is thus mitigated, reducing waste and costs that would otherwise result from defective devices. Furthermore, the enhanced strength and stiffness provided by the protrusions allow the first terminal 24 and the second terminal 26 to be thinner than conventional terminals (i.e., terminals formed from metal sheets thinner than those used to manufacture conventional terminals), thereby reducing the cost of the first terminal 24 and the second terminal 26 relative to conventional terminals. For example, the first terminal 24 and the second terminal 26 can have a thickness ranging from 0.15 mm to 0.30 mm. This disclosure is not limited in this respect.
[0018] In various embodiments, the planar connection portion 32 of the first terminal 24 may include one or more protrusions formed therein. For example, as Figure 1A As shown, the connection portion 32 may include a U-shaped protrusion 60 that defines an underlying channel, recess, or pocket (hereinafter referred to as a "recess") facing the first electrode 18 of the electronic component 12 and at least partially surrounding the area of the connection portion 32 that is soldered to the first electrode 18. Therefore, when the connection portion 32 is soldered to the first electrode 18, the recess defined by the protrusion 60 can collect excess solder reflow that would otherwise leak or diffuse between the connection portion 32 and the first electrode 18. Defects and reliability problems associated with such solder reflow leakage are thus mitigated.
[0019] refer to Figure 3 The diagram shows a perspective view of a surface mount device 70 (hereinafter “SMD 70”) according to another embodiment of the present disclosure. The SMD 70 may be substantially similar to the SMD 70 described above and may similarly include electronic components 72 and a first terminal 74 and a second terminal 76. The first terminal 74 and the second terminal 76 may be substantially identical. Therefore, only the first terminal 74 is described in more detail herein, and it will be understood that such description will also apply to the second terminal 76.
[0020] The first terminal 74 may be substantially similar to the first terminal 24 of the SMD 10 described above and may similarly include a leg portion 80, a connecting portion 82, and an intermediate portion 84 extending between the leg portion 80 and the connecting portion 82. The intermediate portion 84 may include protrusions 86, 88 similar to the protrusions 56, 58 described above. The intermediate portion 84 may also include one or more apertures 90 formed therein. For example, as... Figure 3 As shown, the intermediate portion 84 may include three circular holes 90 formed therein. This disclosure is not limited in this respect, and the size, shape, location, and number of holes 90 may vary in alternative embodiments. When a protective coating is overmolded onto the electronic component 72 and the first terminal 74 and the second terminal 76 (e.g., via injection molding), the overmolding material (e.g., epoxy resin) can flow through the holes 90, thereby reducing the resistance of the first terminal 74 and the second terminal 76 to the forces exerted upon them by the flow of the overmolding material. Therefore, the holes 90 make the first terminal 74 and the second terminal 76 less prone to bending, deflection, or deformation under the forces of the overmolding material. Undesirable misalignment of the first terminal 74 and the second terminal 76 and the electronic component 72 is thus mitigated, reducing waste and costs that would otherwise result from defective devices. Furthermore, the improved resistance to deformation provided by the holes 90 allows the first terminal 74 and the second terminal 76 to be thinner than conventional terminals (i.e., formed from a metal sheet thinner than that used to manufacture conventional terminals), thereby reducing the cost of the first terminal 74 and the second terminal 76 relative to conventional terminals. In various embodiments, the protrusions 86, 88 in the intermediate portion 84 may be omitted when only the hole 90 is provided to enhance the resistance to deformation of the first terminal 74 and the second terminal 76. This disclosure is not limited in this respect.
[0021] As used herein, elements or steps described in the singular and beginning with the words “a” or “an” should be understood to not exclude elements or steps in the plural form, unless such exclusion is explicitly stated. Furthermore, references to “one embodiment” in this disclosure are not intended to exclude the existence of additional embodiments that also incorporate the described features.
[0022] While this disclosure refers to certain embodiments, numerous modifications, alterations, and variations of the described embodiments are possible without departing from the scope and domain of this disclosure, as defined in the appended claims. Therefore, this disclosure is intended to be limited to the described embodiments but has the full scope defined by the following claims and their equivalents.
Claims
1. A surface mount device, characterized in that, The surface mount device includes: An electronic component having a first electrode disposed on a first side thereon and a second electrode disposed on a second side thereon; A first terminal connected to the first electrode and a second terminal connected to the second electrode, wherein each of the first terminal and the second terminal includes: The support leg portion is adapted to connect to contacts on a printed circuit board; A connection portion, wherein the connection portion is connected to a corresponding one of the first electrode and the second electrode; and The intermediate portion extends between the support leg portion and the connecting portion, and the intermediate portion includes: Multiple bends are formed therein; and A protrusion formed therein, wherein the protrusion extends through at least one of the plurality of bends.
2. The surface mount device according to claim 1, characterized in that, The support leg portion is oriented perpendicular to the connecting portion.
3. The surface mount device according to claim 1, characterized in that, The intermediate portion includes: a first bend, from which a first segment extends perpendicularly to the leg portion; a second bend, from which a second segment extends from the first segment; a third bend, from which a third segment extends from the second segment; a fourth bend, from which a fourth segment extends from the third segment; a fifth bend, from which a fifth segment extends from the fourth segment; and a sixth bend, from which the connecting portion extends from the fifth segment.
4. The surface mount device according to claim 1, characterized in that, The connection portion of at least one of the first terminal and the second terminal includes a protrusion formed therein, wherein the protrusion in the connection portion defines a groove for collecting excess solder between the connection portion and a respective one of the first electrode and the second electrode.
5. The surface mount device according to claim 4, characterized in that, The protrusions in the connection portion at least partially surround the area of the connection portion that is welded to a corresponding one of the first electrode and the second electrode.
6. The surface mount device according to claim 5, characterized in that, The protrusions in the connecting portion are U-shaped.
7. The surface mount device according to claim 1, characterized in that, Also includes: A protective coating is overmolded onto the electronic components and the first and second terminals.
8. The surface mount device according to claim 1, characterized in that, The intermediate portion includes holes formed therein.
9. The surface mount device according to claim 1, characterized in that, The first terminal and the second terminal have a thickness ranging from 0.15 mm to 0.30 mm.
10. The surface mount device according to claim 1, characterized in that, Each of the first terminal and the second terminal is formed from a single piece of metal.
11. A terminal for surface mount devices, characterized in that, The terminals include: The support leg portion is adapted to connect to contacts on a printed circuit board; A connection portion, the connection portion being adapted to connect to the electrodes of an electronic component; and The intermediate portion extends between the support leg portion and the connecting portion, and the intermediate portion includes: Multiple bends are formed therein; and A protrusion formed therein, wherein the protrusion extends through at least one of the plurality of bends.
12. The terminal according to claim 11, characterized in that, The support leg portion is oriented perpendicular to the connecting portion.
13. The terminal according to claim 11, characterized in that, The intermediate portion includes: a first bend, from which a first segment extends perpendicularly to the leg portion; a second bend, from which a second segment extends from the first segment; a third bend, from which a third segment extends from the second segment; a fourth bend, from which a fourth segment extends from the third segment; a fifth bend, from which a fifth segment extends from the fourth segment; and a sixth bend, from which the connecting portion extends from the fifth segment.
14. The terminal according to claim 11, characterized in that, The connection portion includes protrusions formed therein, wherein the protrusions in the connection portion define grooves for collecting excess solder between the connection portion and the electrodes of the electronic component.
15. The terminal according to claim 14, characterized in that, The protrusions in the connecting portion are U-shaped.
16. The terminal according to claim 11, characterized in that, The intermediate portion includes holes formed therein.
17. The terminal according to claim 11, characterized in that, The terminal has a thickness ranging from 0.15 mm to 0.30 mm.
18. The terminal according to claim 11, characterized in that, The terminal is formed from a single piece of metal.