CN115835618A - Self-leaded SMD package - Google Patents

Abstract

The invention discloses a self-leaded SMD package. The surface mount device assembly includes an electronic component and a package. The electronic assembly has a body and two leads extending from the body. The first lead has a first surface mounting portion and the second lead has a second surface mounting portion. The package has a top surface and four side surfaces arranged as an open box. The package also has two openings adapted to receive two leads.

Description

Self-Leaded SMD Packages

technical field

Embodiments of the present disclosure relate to surface mount technology (SMT), and more particularly, to automated SMT processes such as pick-and-place.

Background technique

Electronic components may be added to a printed circuit board (PCB) using through-hole technology (THT), surface mount technology (SMT), or a combination of THT and SMT. Each type of technology has its advantages and disadvantages. In order to connect a component to a PCB using THT, holes need to be drilled in the PCB, and device leads are inserted into the holes and soldered to copper pads on the other side of the PCB. Therefore, the THT connection parts use some space on both sides of the PCB. In some cases, the THT method cannot be automated (such as pick and place) to populate the PCB with components.

Populating a PCB with SMT involves placing surface mount devices (SMDs) on designated copper pads on one surface of the PCB. SMDs include conductive material on their surface for connection to copper pads. No holes were drilled for this component placement. Automated methods such as pick and place are well suited for use with SMT processes.

Many different types of electronic components have leads or wires, usually at least two, extending from the body of the component. For example, resistors, capacitors and diodes have two leads connected to the PCB using THT. A transistor can have three or more leads connected to a PCB using THT. Other devices, such as metal oxide varistors (MOVs), positive temperature coefficient (PTC) devices, negative temperature coefficient (NTC) devices, and thyristors, can be packaged with a body connected to two or more leads. Such devices are not suitable for pick-and-place SMT technology.

With regard to these and other considerations, the present improvement may be useful.

Contents of the invention

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be an aid in determining the scope of the claimed subject matter.

Exemplary embodiments of surface mount device assemblies according to the present disclosure may include electronic assemblies and packages. The electronic assembly has a main body and two leads extending from the main body. The first lead has a first surface mount portion, and the second lead has a second surface mount portion. The enclosure has a top surface and four sides arranged as an open box. The package also has two openings for receiving two leads.

An exemplary embodiment of a method of assembling a through hole technology (THT) component into a surface mount technology (SMT) component according to the present disclosure may include: bending a first lead and a second lead of a THT component, the THT component also having a body, The first lead is inserted into the first hole of the package, wherein the package includes a top surface, a first side and a second side, arranged as a lidless box. The first and second sides will be placed on the printed circuit board such that the top surface is parallel to the printed circuit board. The package also includes a first pair of package ears and a second pair of package ears. A first pair of package ears are disposed on the first side at a predetermined distance from the first side. A second pair of package ears is disposed on the second side at a predetermined distance from the second side. The method also includes inserting a second lead into the second hole of the package, wrapping the first lead around the first pair of package ears, and wrapping the second lead around the second pair of package ears.

Another exemplary embodiment of a surface mount device assembly according to the present disclosure may include an enclosure for housing electronic components. The enclosure has a top surface, a first side and a second side, arranged as a lidless box. The first side and the second side will be placed on the printed circuit board such that the top surface is parallel to the printed circuit board. The package also includes a first package ear and a second pair of package ears. A first pair of package ears are disposed on the first side at a predetermined distance from the first side. A second pair of package ears is disposed on the second side at a predetermined distance from the second side. The first side is parallel to the second side. The electronic component has a main body and first and second leads extending from the main body. The body fits into the lidless case.

Description of drawings

FIG. 1 is a diagram showing an SMD assembly (horizontal) according to an exemplary embodiment;

2A-2C are diagrams illustrating the SMD assembly of FIG. 1 according to an exemplary embodiment;

3A-3C are diagrams illustrating the SMD assembly of FIG. 1 according to an exemplary embodiment;

Figure 4 is a diagram showing an SMD assembly (vertical) according to an exemplary embodiment;

5A-5C are diagrams illustrating the SMD assembly of FIG. 4 according to an exemplary embodiment;

6A-6C are diagrams illustrating the SMD assembly of FIG. 4 according to an exemplary embodiment;

7A-7D are diagrams illustrating the SMD assembly of FIG. 1 according to an exemplary embodiment;

8A-8D are diagrams illustrating the SMD assembly of FIG. 4 according to an exemplary embodiment;

9A-9B are diagrams illustrating an SMD assembly for supporting a plurality of two-lead electronic devices according to an exemplary embodiment;

10A-10B are diagrams illustrating the SMD assembly of FIGS. 9A-9B according to an exemplary embodiment;

11A-11B are diagrams illustrating lead shapes for the SMD assemblies of FIGS. 1 and 4, respectively, according to an exemplary embodiment;

12 is a diagram illustrating a lead shape for the SMD assembly of FIGS. 9A and 9B according to an exemplary embodiment;

FIG. 13 is a flow diagram illustrating the process steps for manufacturing the SMD assembly of FIGS. 1 , 4 and 9A according to an exemplary embodiment;

14A-D are diagrams illustrating some of the process steps of FIG. 13 according to an exemplary embodiment.

Detailed ways

A surface mount device (SMD) assembly is disclosed herein. Each SMD assembly consists of two-lead electronics housed in a package. The package has two openings through which the leads of the electronic device are inserted, allowing the leads to be located substantially outside the package while the body remains inside. The sides of the package include pairs of ears around which the leads wrap once softened. A portion of each lead is located between a pair of ears, at a location on the bottom of the package to allow soldering of the SMD assembly to a printed circuit board (PCB). Portions of each lead may remain cylindrical or may be flattened for increased surface area and coplanarity with the PCB's pad. SMD assemblies are able to use leads that already exist on through-hole technology (THT) electronics. Additionally, electronic devices can be attached to PCBs using automated techniques such as pick and place.

For convenience and clarity, terms such as "top", "bottom", "upper", "lower", "vertical", "horizontal", "side", "transverse", "radial", " The terms "inner," "outer," "left," and "right" are used to describe the relative placement and orientation of features and components of the electrical box, each relative to the geometry and orientation of other features and components of the electrical box provided herein Appears in perspective, exploded perspective, and cross-section views. The terminology is not intended to be limiting and includes the words specifically mentioned, derivatives thereof and words of similar import.

Embodiments shown and described herein feature a metal oxide varistor (MOV) as a two-lead electronic device for use with a novel SMD assembly. The illustrated MOV has a specific size and shape. The principles of SMD assembly can be applied to MOVs of many different sizes and shapes. For example, some MOVs are characterized by a relatively flat, circular body, while others have a more cylindrical body. As another example, some MOV bodies may be flat rectangles or rectangular cubes. The SMD assembly is designed to support MOV bodies of any shape. Furthermore, SMD assemblies can be used with any two-lead electronic device that will fit into the housing, not just MOV devices. Finally, SMD assemblies can be scaled to support any size two-lead electronics without limitation.

FIG. 1 is a representative view of an SMD assembly 100 for housing two-lead electronic devices according to an exemplary embodiment. In the exemplary embodiment, SMD assembly 100 is also referred to as a horizontal SMD assembly, in contrast to the vertical SMD assembly shown and described below. The two-lead electronic component is a metal oxide varistor (MOV), shown in its original configuration, also known as a through-hole technology (THT) configuration 104a, and in a novel configuration, also known as a surface mount technology (SMT) configuration 104b( Hereinafter referred to as "MOV104"). Also shown is package 102 for housing MOV 104 (composed of MOV body 122 and leads 106a-b). In an exemplary embodiment, as shown, leads 106a-b of MOV 104 are softened and bent to accommodate package 102 (collectively "leads 106"). 11A is an illustration of leads 106a and 106b for an SMT configuration of MOV 104b in accordance with some embodiments.

MOV 104 is placed in package 102 to form SMD assembly 100 . SMD assemblies 100A and 100B are opposite views: SMD assembly 100A shows the device to be placed on a printed circuit board (PCB), while SMD assembly 100B shows the device with MOV 104 exposed. The SMD assembly 100 is self-leading because the leads 106 of the MOV 104 are used for new surface mount devices in its THT configuration. Therefore, additional leads need not be part of package 102 .

In an exemplary embodiment, the SMD assembly 100 converts any two-lead electronic device from a THT device to an SMT device. Since the THT device is inserted through a hole in the PCB and soldered to the other side, the THT device takes up space on both sides of the PCB, whereas the same device using an SMD assembly package would consume space on one side of the PCB. Additionally, PCBs do not require holes to be drilled into them like through-hole devices. The SMD assembly 100 is also suitable for pick and place automation techniques that have become common for SMT assemblies. In an exemplary embodiment, the SMD assembly 100 improves PCB manufacturing by allowing high speed assembly and low cost.

2A-2C are representative views of an SMD assembly 100 according to an exemplary embodiment. 2A is a perspective view of the SMD assembly 100; FIG. 2B is a side view of the SMD assembly; and FIG. 2C is a detailed view of one side of the SMD assembly. In Figures 2A and 2B, MOV 104 is exposed. SMD assembly 100 features package 102 , MOV 104 and leads 106 from FIG. 1 . In the exemplary embodiment, enclosure 102 is made of a rigid plastic material. In an exemplary embodiment, the package 102 provides a surface structure for surface mount automation, such as pick and place, the package provides a structure for positioning the leads 106 of the THT MOV 104a, and the package is flexible enough to support MOV, covering low-end to high-end MOV.

As shown in FIG. 1 , leads 106 of MOV 104 are arranged in an SMT configuration. Lead 106 is cylindrical and made of conductive material. In an exemplary embodiment, once the SMD assembly 100 is placed on the designated pads on the surface of the PCB (such as using pick and place or some other automated method), the leads 106 will be soldered to the designated pads on the surface of the PCB. Once so connected and power applied to the resulting circuit, the MOV 104 will be electrically connected to other components that are also soldered on the PCB.

In the exemplary embodiment, package 102 is a circular rectangular structure with five surfaces: a top surface 214 and four sides 212a-d (collectively "sides 212"). Essentially a rectangular cuboid lacking a surface opposite top surface 214, enclosure 102 may be considered an open box or a lidless box. When the SMD assembly 100 is placed on the PCB, the top surface 214 is normal to the sides 212a-d and parallel to the PCB. Opposing sides 212a and 212c are parallel to each other, as are opposing sides 212b and 212d. The opposite sides 212a and 212c are perpendicular to the opposite sides 212b and 212d, wherein the sides 212a, 212b, 212c and 212d are arranged in a rectangular shape.

Package 102 includes two openings 210a and 210b (collectively "openings 210"). Opening 210a is partially on top surface 214 and partially on side 212b; opening 210b is partially on the top surface and partially on side 212d. Furthermore, both openings 210a and 210b are on the same side of top surface 214 . In the exemplary embodiment, opening 210 enables body 122 of MOV 104 to be disposed inside package 102 while leads 106 are substantially outside the package.

On the outer surface of package 102 are package ears 208a-d (collectively "package ears 208"). Package ears 208 enable leads 106 to be strategically placed to allow soldering to corresponding pads on the PCB. Thus, package ears 208 provide a surface structure to hold leads 106 in position against the exterior of package 102 , thereby facilitating surface mount automation, such as pick and place, for the interior of MOV 104 . In an exemplary embodiment, as shown in FIG. 2B , package ears 208 are rectangular in shape and extend laterally outward from respective sides 212 at a distance d. In an exemplary embodiment, the distance d is slightly greater than the width w of the lead 106 .

Figure 2C shows side 212b of SMD assembly 100, and package ears 208b and 208a. In some embodiments, not visible in the side and perspective views of SMD assembly 100 are ear connectors 216a and 216b (collectively "ear connectors 216"), which themselves are rectangular in shape. Ear connectors 216 ensure that package ears 208 are spaced a distance d from corresponding sides 212 such that leads 106 of width w can be wrapped around the ear connectors. In the exemplary embodiment, package 102, four ear connectors 216, and four package ears 208 are formed as a unitary structure, such as by injection molding or similar techniques.

3A-3C are representative views of an SMD assembly 300 according to an exemplary embodiment. 3A is a perspective view of an SMD assembly 300; FIG. 3B is a side view of the SMD assembly; and FIG. 3C is a detailed view of one side of the SMD assembly. Like SMD assembly 100 , SMD assembly 300 is also referred to as a horizontal SMD assembly. Compared to SMD assembly 100 , SMD assembly 300 is characterized by flat leads. In other respects, the two SMD assemblies 100 and 300 are identical.

In Figures 3A and 3B, leads 306a and 306b (collectively "leads 306") are shown. In the exemplary embodiment, a portion of each lead 306 is flattened to facilitate placement of the lead on a designated pad of the PCB. As with lead 306a, lead portion 318a disposed between package ears 208a-b and side 212b is flat. Likewise, for leads 306b, lead portions 318b (collectively "lead portions 318") disposed between package ears 208c-d and side 212d are flat. In the exemplary embodiment, flattened lead portions 318 increase the surface area of leads 306 , which facilitates successful attachment of SMD assembly 300 to designated pads of the PCB. Furthermore, in the exemplary embodiment, by having flat leads, the SMD assembly 300 is coplanar with the PCB, which also facilitates successful attachment of the SMD assembly to designated pads of the PCB.

As shown in Figure 3B, there is a distance d between package ears 208c-d and side 212d. In an exemplary embodiment, the distance d is slightly greater than the width w of the lead 106 . Furthermore, in some embodiments, the width w ₂ of the lead portion 318 of the lead 306 is slightly wider than the width w between the package ear 208 and the corresponding side 212 .

The detailed view of Figure 3C shows why the difference in width w and _w2 is not a problem. Flat lead portion 318b is disposed slightly below bottom surface 320 of side 212d. Therefore, in the exemplary embodiment, the lead portion 318 is disposed slightly below the bottom surface of the overall SMD assembly 300 . Furthermore, package ears 208c-d do not reach the bottom surface of side 212d. In the exemplary embodiment, there is some overlap between the lead 306 and the width w ₂ of the package ear 208 .

For SMD assembly 100 (FIGS. 2A-2C), although leads 106 are cylindrical and not flat, portions of leads 106a between package ears 208a-b and sides 212b and between package ears 208c- A portion of lead 106b between d and side 212d is also disposed below the bottom surface of the SMD assembly. Thus, in the exemplary embodiment, the SMD assembly 100 can be successfully soldered to the designated pads of the PCB despite the slightly smaller surface area of the leads 106 to be used than the flat leads.

FIG. 4 is a representative view of an SMD assembly 400 for housing a two-lead electronics assembly, according to an exemplary embodiment. In an exemplary embodiment, the SMD assembly 400 is also referred to as a vertical SMD assembly in comparison with the horizontal SMD assemblies 100 and 300 described above. The two-lead electronic component is a metal oxide varistor (MOV), shown in its original configuration, also known as a through-hole technology (THT) configuration 404a, and in a new configuration, also known as a surface mount technology (SMT) configuration 404b (hereinafter called "MOV 404"). Also shown is a package 402 for housing an MOV 404 (composed of a MOV body 422 and leads 406a-b). In an exemplary embodiment, as shown, leads 406a-b of MOV 404 are softened and bent to fit package 402 (collectively "leads 406"). 11B is an illustration of leads 406a and 406b for an SMT configuration of MOV 404b in accordance with some embodiments.

In an exemplary embodiment, leads 406 are arranged at a different location relative to MOV body 422 than leads 106 ( FIG. 1 ). Where leads 106a and 106b are adjacent to the circumferential surface of the cylindrical MOV body, lead 406 is adjacent to the planar surface of MOV body 422 .

MOV 404 is placed in package 402 to form SMD assembly 400 . SMD assemblies 400A and 400B are opposite views: SMD assembly 400A shows the device to be placed on a printed circuit board (PCB), while SMD assembly 400B shows the device with MOV 404 exposed. The SMD assembly 400 is self-leading because the leads 406 of the MOV 404 are used for new surface mount devices in its THT configuration. Therefore, no additional leads need to be added to package 402 .

In an exemplary embodiment, the SMD assembly 400 converts any two-lead electronic device from a THT device to an SMT device. Since the THT device is inserted through a hole in the PCB and soldered to the other side, the THT device takes up space on both sides of the PCB, whereas the same device using an SMD assembly package would consume space on one side of the PCB. Additionally, PCBs do not require holes to be drilled into them like through-hole devices. The SMD assembly 400 is also adapted for the pick and place automation techniques that have become common for SMT assemblies. In an exemplary embodiment, SMD assembly 400 improves PCB manufacturing by allowing high speed assembly and low cost.

In an exemplary embodiment, horizontal SMD assemblies 100 and 300 and vertical SMD assembly 400 (and vertical SMD assembly 600 shown and described below) are available in response to customer requests. In an exemplary embodiment, a horizontal SMD assembly has a slightly larger footprint than a vertical SMD assembly, and thus consumes more surface space when placed on a PCB. In contrast, a vertical SMD assembly is slightly taller in a direction perpendicular to the PCB surface (eg, vertically) compared to a horizontal SMD assembly. Especially for circuits constrained by size and space, the availability of alternatives provides flexibility to customers. Therefore, horizontal and vertical SMD assemblies give customers options when designing circuits.

5A-5C are representative views of an SMD assembly 400 according to an exemplary embodiment. 5A is a perspective view of the SMD assembly 400; FIG. 5B is a side view of the SMD assembly; and FIG. 5C is a detailed view of one side of the SMD assembly. In Figures 5A and 5B, MOV 404 is exposed. SMD assembly 400 features package 402 , MOV 404 and leads 406 from FIG. 4 . In an exemplary embodiment, enclosure 402 is made of a rigid plastic material. In one embodiment, encapsulation 402 is thermoplastic, such as polyamide.

As shown in FIG. 4 , leads 406 of MOV 404 are arranged in an SMT configuration. Lead 406 is cylindrical and made of a conductive material. In an exemplary embodiment, once the SMD assembly 400 is placed on the designated pads on the surface of the PCB (such as using pick and place or some other automated method), the leads 406 will be soldered to the designated pads on the surface of the PCB. Once so connected and power applied to the resulting circuit, MOV 404 will be electrically connected to other components that are also soldered on the PCB.

In the exemplary embodiment, package 402 is a circular rectangular structure having five sides, a top surface 514 and four sides 512a-d (collectively "sides 512"). Essentially a rectangular cuboid lacking a surface opposite top surface 214, enclosure 402 may be considered an open box or a lidless box. When the SMD assembly 400 is placed on the PCB, the top surface 514 is normal to the sides 512a-d and parallel to the PCB. Opposing sides 512a and 512c are parallel to each other, as are opposing sides 512b and 512d. The opposite sides 512a and 512c are perpendicular to the opposite sides 512b and 512d, wherein the sides 512a, 512b, 512c and 512d are arranged in a rectangular shape.

Package 402 includes two openings 510a and 510b (collectively "openings 510"). As shown in FIG. 1 , leads 106 of MOV 104 are arranged in an SMT configuration. Opening 510a is partially on top surface 514 and partially on side 512d; opening 510b is partially on the top surface and partially on side 512b. Openings 510a and 510b are located on opposite sides of top surface 514 compared to openings 210a and 210b. In the exemplary embodiment, opening 510 enables body 422 of MOV 404 to be disposed inside package 402 while leads 406 are located substantially outside the package.

On the outer surface of package 402 are package ears 508a-d (collectively "package ears 508"). Package ears 508 enable leads 406 to be strategically placed to allow soldering to corresponding pads on the PCB. In an exemplary embodiment, as shown in FIG. 5 , package ears 508 are rectangular in shape and extend outwardly from respective sides 512 at a distance d from the sides. In an exemplary embodiment, distance d is slightly greater than width w of lead 406 .

FIG. 5C shows side 512d of SMD assembly 400 and package ears 508c and 508d. In some embodiments, not visible in the side and perspective views of SMD assembly 400 are ear connectors 516a and 516b (collectively "ear connectors 516"), which themselves are rectangular in shape. Ear connectors 516 ensure that package ears 508 are spaced a distance d from corresponding sides 512 such that leads 406 of width w can be wrapped around the ear connectors. In the exemplary embodiment, package 402, four ear connectors 516, and four package ears 508 are formed as a unitary structure, such as by injection molding or similar techniques.

6A-6C are representative views of an SMD assembly 600 according to an exemplary embodiment. Figure 6A is a perspective view of the SMD assembly 600; Figure 6B is a side view of the SMD assembly; Figure 6C is a detailed view of one side of the SMD assembly. Compared to SMD assembly 500 , SMD assembly 600 is characterized by flat leads. In other respects, the two SMD assemblies 500 and 600 are identical.

In Figures 6A and 6B, leads 606a and 606b (collectively "leads 606") are shown. In the exemplary embodiment, a portion of each lead 606 is flattened to facilitate placement of the lead on a designated pad of the PCB. As with lead 606a, lead portion 618a disposed between package ears 508a-b and side 512b is flat. Likewise, for leads 606b, lead portions 618b (collectively "lead portions 618") disposed between package ears 508c-d and side 512d are flat. In the exemplary embodiment, flattened lead portions 618 increase the surface area of leads 606 , which facilitates successful attachment of SMD assembly 600 to designated pads of the PCB. Additionally, in the exemplary embodiment, by having flat leads, the SMD assembly 600 is coplanar with the PCB, which also facilitates successful attachment of the SMD assembly to designated pads of the PCB.

As shown in Figure 6B, there is a distance d between package ears 508a-b and side 512b. In an exemplary embodiment, the distance d is slightly greater than the width w of the lead 606 . Furthermore, in some embodiments, the width w ₂ of the lead portion 618 of the lead 606 is slightly wider than the width w between the package ear 508 and the corresponding side 512 .

The detailed view of Figure 6C shows why the difference in width w and _w2 is not a problem. Flat lead portion 618b is disposed slightly below bottom surface 620 of side 512b. Therefore, in the exemplary embodiment, the lead portion 618 is disposed slightly below the bottom surface of the overall SMD assembly 600 . Additionally, package ears 508a-b do not reach the bottom surface of side 512b. In the exemplary embodiment, there is some overlap between the width w ₂ of the lead 606 and the package ear 508 .

For SMD assembly 500 (FIGS. 5A-5C), although lead 406 is cylindrical and not flat, part of lead 406a between package ears 508a-b and side 512b and between package ears 508c-d A portion of lead 406b between side 512d is also disposed below the bottom surface of the SMD assembly. Thus, in the exemplary embodiment, the SMD assembly 400 can be successfully soldered to the designated pads of the PCB despite the slightly smaller surface area of the leads 406 that can be used compared to flat leads.

7A-7D are representative views of package 102 for horizontal SMD assembly 100/300, according to an exemplary embodiment. 7A is a top view of package 102; FIG. 7B is a side view of the package; FIG. 7C is a suggested package and pad layout 702 on a PCB; and FIG. 7D is a second side view of the package. The dimensions of package 102 and package and pad layout 702 are given in millimeters and are not meant to be limiting. In an exemplary embodiment, the SMD assembly 100/300 supports MOV chip diameters of 5mm, 7mm, 10mm, 14mm, 20mm, 25mm, D7mm, D14mm, and D20mm, to name a few. Accordingly, the package 102 of the SMD assembly 100/300 is scalable to support multiple MOV sizes. The dimensions of FIGS. 7A-7D are illustrative of package 102 and package and pad layout 702 in accordance with some embodiments. However, for each size of package 102 of SMD assembly 100/300, a number of different MOVs may fit therein. Thus, in an exemplary embodiment, the SMD assembly 100/300 features a "one-size-fits-most" package.

In addition to providing dimensional information according to an exemplary embodiment, package placement 704 and pad locations 706a and 706b (collectively "pad locations 706") are shown, such as for a PCB layout (FIG. 7C). FIG. 7B also shows a flat lead specification 708 that would apply to SMD assembly 300 but not to SMD assembly 100 . Regardless of whether non-flat (cylindrical) leads 106 or flat leads 306 are used, the coplanarity of the soldered surfaces of the leads can be controlled to be less than 0.1 mm, where the diameter of the wire leads is typically 0.8 mm to 1 mm.

8A-8D are representative views of a package 402 for a vertical SMD assembly 400/600 according to an exemplary embodiment. 8A is a top view of package 402; FIG. 8B is a side view of the package; FIG. 8C is a suggested package and pad layout 802 on a PCB; and FIG. 8D is a second side view of the package. The dimensions of package 402 and package and pad layout 802 are given in millimeters and are not meant to be limiting. In an exemplary embodiment, the SMD assembly 400/600 supports MOV chip diameters of 5mm, 7mm, 10mm, 14mm, 20mm, 25mm, D7mm, D14mm, and D20mm, to name a few. Like SMD assembly 100/300, package 402 of SMD assembly 400/600 is scalable to support multiple MOV sizes. The dimensions of FIGS. 8A-8D are illustrative of package 402 and package and pad layout 802 in accordance with some embodiments. However, for each size of package 402 of SMD assembly 400/600, a number of different MOVs may fit therein. Thus, in an exemplary embodiment, the SMD assembly 400/600 features a "universal size" package.

In addition to providing dimensional information according to an exemplary embodiment, package placement 804 and pad locations 806a and 806b (collectively "pad locations 806") are shown, such as for a PCB layout (FIG. 8C). FIG. 8B also shows a flat lead specification 808 that would apply to SMD assembly 600 but not to SMD assembly 400 . Regardless of whether non-flat (cylindrical) leads 406 or flat leads 606 are used, the coplanarity of the soldered surfaces of the leads can be controlled to be less than 0.1 mm, where the diameter of the leads is typically 0.8 mm to 1 mm.

In some embodiments, looking at package and pad layout 702 ( FIG. 7C ) and package and pad layout 802 ( FIG. 8C ), horizontal SMD assembly 100 / 300 has a larger footprint on the PCB than vertical SMD assembly 400 /600 coverage area. The height of the horizontal SMD assembly 100/300 (FIG. 7B) is smaller than the height of the vertical SMD assembly 400/600 (FIG. 8B). Therefore, customers can flexibly choose between horizontal SMD assemblies and vertical SMD assemblies according to a given circuit design.

9A-9B are representative views of an SMD assembly 900 for housing a plurality of two-lead electronic components, according to an exemplary embodiment. Figure 9A is a perspective view of the SMD assembly 900; Figure 9B is a side view of the SMD assembly. In an exemplary embodiment, SMD assembly 900 is also referred to as a horizontal SMD assembly. A vertical SMD assembly for housing multiple two-lead electronic components is not shown here, although it may share features of SMD assembly 900 as well as vertical SMD assemblies 300/600. The three two-lead electronic components contained in package 902 of SMD assembly 900 are MOVs 904, although they are mostly obscured from view. Four leads 906a-d (collectively "leads 906") of MOV 104 are visible. In an exemplary embodiment, leads 906 are softened and bent to fit into package 902 .

Like the other SMD assemblies shown and described herein, the leads 906 of the SMD assembly 900 are cylindrical and made of a conductive material. In an exemplary embodiment, once SMD assembly 900 is placed on designated pads on PCB surface 916 (such as using pick and place or some other automated method), leads 906 will be soldered to designated pads on PCB surface 916 ( FIG. 9B ). pad. Once so connected and power applied to the resulting circuit, MOV 904 will be electrically connected to other components that are also soldered on PCB 916 .

In the exemplary embodiment, package 902 is a round rectangular structure with five sides, a top surface 914 and four sides 912a-d (collectively "sides 912"). Essentially a rectangular cuboid lacking a surface opposite top surface 814, enclosure 902 may be considered an open box or a lidless box. When the SMD assembly 900 is placed on the PCB, the top surface 914 is normal to the sides 912a-d and parallel to the PCB. Opposing sides 912a and 912c are parallel to each other, as are opposing sides 912b and 912d. The opposite sides 912a and 912c are perpendicular to the opposite sides 912b and 912d, wherein the sides 912a, 912b, 912c and 912d are arranged in a rectangular shape.

Package 902 includes six openings 910a-f (collectively "openings 910"). Openings 910a-c are located partially on top surface 914 and partially on side 912d; openings 910d-f are located partially on the top surface and partially on side 912b. In the exemplary embodiment, openings 910 enable the bodies of three MOVs 904 to be disposed inside package 902 while leads 906 are substantially outside the package.

On the outer surface of package 902 are package ears 908a-f (collectively "package ears 908"), which are visible on side 912b and which are not visible on side 912d. . Package ears 908 enable leads 906 to be strategically placed to allow soldering to corresponding pads on PCB 916 . In the exemplary embodiment, package ears 908 are rectangular in shape and extend outward from respective sides 912 . In contrast to package ears 208 and 508 , package ears 908 are provided in a pair. On side 912b, package ears 908a and 908b hold lead 906a; package ears 908c and 908d hold lead 906b; and package ears 908e and 908f hold lead 906c, and a similar arrangement occurs on side 912d.

In some embodiments, configurations can be exchanged so that any of the SMD assemblies 100, 300, 400, and 600 use a two-part package ear (eg, FIG. 9A ), while the SMD assembly 900 uses a one-part package. Ears 208 or 508 (eg, FIG. 2A ). In an exemplary embodiment, although not visible, SMD assembly 900 features ear connectors (eg, FIG. 2C ). In an exemplary embodiment, enclosure 902, ear connectors, and enclosure ears 908 are formed as a unitary structure, such as by injection molding or similar techniques. In some embodiments, although SMD assembly 900 supports three MOVs, the principles shown and described herein can be applied to SMD assemblies housing any number of two-lead electronic components.

10A and 10B are representative diagrams for dimensions of an SMD assembly 900 according to an exemplary embodiment. Figure 10A is a side view of the SMD assembly 900; and Figure 10B is a second side view of the SMD assembly. The dimensions of the SMD assembly 900 are given in millimeters and are not meant to be limiting. In an exemplary embodiment, SMD assembly 900 is scalable to support multiple MOV sizes. Thus, in the exemplary embodiment, SMD assembly 900 features a "universal size" package.

In an exemplary embodiment, the height of the sides 912a-d of the SMD assembly 900 is between 13.5mm and 14mm (FIG. 10A), and the width of the sides 912a and 912c is 18.0mm, including the total of the package ears 908. The width is between 20.9mm and 21.5mm (Fig. 10B). Figure 10A also shows a flat lead illustration 1002, although the SMD assembly 900 may have cylindrical leads or flat leads. Regardless of whether non-flat (cylindrical) leads 406 or flat leads 606 are used, the coplanarity of the soldered surfaces of the leads can be controlled to be less than 0.1 mm, where the diameter of the leads is typically 0.8 mm to 1 mm.

11A and 11B are representative diagrams of leads of the respective SMT MOVs of FIGS. 1 and 4, according to an exemplary embodiment. FIG. 11A features leads 106a and 106b for the SMT configuration of MOV 104b. Figure 1 IB features leads 406a and 406b for the SMT configuration of MOV 404b. Leads 106a and 106b are shown in positions relative to each other on either side of MOV 104 (not shown). Similarly, leads 406a and 406b are shown in positions relative to each other on either side of MOV 404 (not shown).

Each lead 106 / 406 includes an inner portion 1102 , a surface mount portion 1104 , and a package ear portion 1106 . The inner portion 1102 is the part of the leads 106/406 that remains inside the package 102/402 of the SMD assembly; the surface mount portion 1104 is the part of the leads that are to be soldered to the pads on the PCB; and the package ear portion Part 1106 is a portion of the leads that surround or otherwise connect to the package ears 208/508 of the SMD assembly. The lead configurations shown in FIGS. 11A and 11B are not meant to be limiting, as different shaped leads may be used with the SMD assemblies described herein.

FIG. 12 is a representative view of the leads of the SMD assembly 900 ( FIGS. 9A and 9B ) according to an exemplary embodiment. Leads 906 are shown in positions relative to each other on either side of MOV 904 (not shown).

Each lead 906 includes an inner portion 1202 , a surface mount portion 1204 and a package ear portion 1206 . The inner part 1202 is the part of the lead 906 that remains inside the package 902 of the SMD assembly 900; the surface mount part 1204 is the part of the lead that is to be soldered to the pad on the PCB; and the package ear part 1206 is around or A portion of the lead that is otherwise connected to the package ear 908 of the SMD assembly. The lead configuration shown in FIG. 12 is not meant to be limiting, as different shaped leads may be used with the SMD assemblies described herein.

When placed on a PCB, the self-leaded SMD assembly shown and described herein offers several advantages over THT type electronic assemblies. The use of SMD assembly packaging enables efficient and low-cost automated electronic component assembly lines. The package supports a wide range of voltages, from low voltage to high voltage electronic components. The package also supports electronic components of different sizes. Provide horizontal and vertical type SMD assembly for best customer choice.

manufacturing process

FIG. 13 is a representative flowchart for fabricating self-leaded SMD assemblies 100 , 400 , and 900 according to an exemplary embodiment, and FIGS. 14A-D are representative diagrams used to illustrate some of the process steps depicted in FIG. 13 . In an exemplary embodiment, leads of a plurality of electronic components are flat (block 1302). Alternatively, parts of the leads are flat, ie parts of the leads are to be soldered to the PCB. This is an optional step because self-leaded assemblies 100, 400, and 900 can also be soldered to a PCB without a flat lead.

In an exemplary embodiment, the electronic assembly is assembled in tape and reel packaging (block 1304). Tape and Reel is a manufacturing method consisting of a carrier tape with individual cavities for holding each electronic component. A sequential array of electronic components is thus arranged in the carrier tape. Cover tape is then used to secure the electronic assembly within the cavity, forming a reel, much like a movie reel. The tape and reel method allows for easy storage and transportation of electronic assemblies. The spool is attached to the spool of the SMD assembly machine where the electronic components are individually removed from their cavities and soldered to the printed circuit board. Figure 14A is an illustration of a tape and reel assembly of an MOV device.

The tape and reel of electronic assemblies are then fed into the SMD assembly machine (block 1306). There, the leads of each electronic component are optionally cut and bent (block 1308). Recall that the packages 102, 402, and 902 of the respective SMD assemblies 100, 400, and 900 are designed to support electronic components having different sizes. For example, a small MOV that is bent to fit the package would not have its leads cut, whereas a larger MOV might have its leads cut. Therefore, cutting of the leads is optional in this step. However, to fit the package, all leads are bent. Figure 14B is an illustration of a MOV 104/404/904 with bent leads.

Once the leads are bent, each electronic component is assembled into a corresponding package (block 1310). FIG. 14C shows MOV 104/404/904 placed in plastic package 102/402/902. The leads now protruding from the package are next wrapped around the package ears of the package 102/402/902 (block 1312). Also, in some embodiments, because the packages shown and described herein support electronic devices of various sizes and shapes, the number of turns of the leads is varied. Also, the wrapping of the leads will depend on whether the package ears are separated (as in SMD assembly 100 (FIG. 1)) or close together (as in SMD assemblies 400 (FIG. 4) and 900 (FIG. 9A)). And change. Figure 14D shows the leads wrapped around the ears of the package. In some embodiments, an adhesive is added to secure the body of the electronic device to the package (block 1314).

Once the electronic device is fully assembled, functional testing is performed on each self-leaded assembly to ensure that the device works (block 1316). A flatness check is also performed so that the self-leaded assembly can be soldered to the PCB as a surface mount device (block 1318). In an exemplary embodiment, the self-leaded components are then assembled into dedicated cavities of the tape and reel package, forming a new reel of SMD assemblies for the self-leaded components (block 1320).

As used herein, an element or step recited in the singular and proceeded with the word "a" or "an" should be understood as not excluding plural elements or steps, unless such exclusion is explicitly recited. Furthermore, references to "one embodiment" of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

Although this disclosure refers to certain embodiments, various modifications, substitutions and changes to the described embodiments are possible without departing from the sphere and scope of the disclosure as defined in the appended claims. Accordingly, it is intended that the disclosure not be limited to the described embodiments, but that it have the full scope defined by the language of the following claims and their equivalents.

Claims (20)

1. A surface mount device assembly comprising: Electronic components, including: main body; a first lead extending from the body, the first lead including a first surface mount portion; and a second lead extending from the body, the second lead comprising a second surface mount portion; packages, including: the top surface, the first side, the second side, the third side and the fourth side are arranged as an open box; a first opening adapted to receive said first lead; and The second opening is adapted to receive the second lead. 2. The surface mount device assembly of claim 1, wherein the first surface mount portion and the second surface mount portion are to be soldered to a printed circuit board. 3. The surface mount device assembly of claim 1, said package further comprising: a first pair of package ears disposed on the first side; and A second pair of package ears is disposed on the third side. 4. The surface mount device assembly of claim 3, the first lead further comprising a first package ear portion, and the second lead comprising a second package ear portion. 5. The surface mount device assembly of claim 4, wherein the first package ear portion is wrapped around the first pair of package ears and the second package ear portion is wrapped Wrapped around the second pair of enclosure ears. 6. The surface mount device assembly of claim 2, wherein the first surface mount portion and the second surface mount portion are flat. 7. The surface mount device assembly of claim 3, said package further comprising: a first pair of ear connectors disposed between the first pair of enclosure ears and the first side; and A second pair of ear connectors disposed between the second pair of enclosure ears and the third side. 8. The surface mount device assembly of claim 7, wherein said top surface, said first side, said second side, said third side, said fourth side, said first The pair of package ears, the first pair of ear connectors, the second pair of package ears and the second pair of ear connectors are formed as a unitary structure. 9. A method of assembling a through hole technology (THT) component into a surface mount technology (SMT) component, the method comprising: bending a first lead and a second lead of a THT assembly, the THT assembly further comprising a body; inserting the first lead into a first hole of a package comprising: arranged as a top surface, a first side and a second side of a lidless box, the first side and the second side being placed on a printed circuit board, wherein the top surface is parallel to the printed circuit board plate; a first pair of package ears disposed on the first side at a predetermined distance from the first side; and a second pair of package ears disposed on the second side at a predetermined distance from the second side, wherein the first side is parallel to the second side; inserting the second lead into a second hole of the package; wrapping the first lead around the first pair of package ears; and Wrapping the second lead around the second pair of package ears. 10. The method of claim 9, further comprising: Adhesive is added to secure the body to the enclosure. 11. The method of claim 9, wherein the first lead comprises a first surface mount portion disposed between the first pair of package ears, and the second lead comprises a first surface mount portion disposed between A second surface mount portion between the second pair of package ears. 12. The method of claim 11, wherein the first surface mount portion and the second surface mount portion are to be soldered to first and second pads on the printed circuit board. 13. The method of claim 12, wherein the first surface mount portion and the second surface mount portion are flat. 14. The method of claim 9, further comprising assembling the THT assembly in a tape and reel package. 15. The method of claim 9, further comprising assembling the SMT assembly in a tape and reel package. 16. A surface mount device assembly comprising: An enclosure adapted to house electronic components, the enclosure comprising: arranged as a top surface, a first side and a second side of a lidless box, the first side and the second side being placed on a printed circuit board, wherein the top surface is parallel to the printed circuit board plate; a first pair of package ears disposed on the first side at a predetermined distance from the first side; and a second pair of package ears disposed on said second side at a predetermined distance from said second side, wherein said first side is parallel to said second side, and An electronic assembly includes a main body, a first lead and a second lead extending from the main body, wherein the main body fits into the lidless case. 17. The surface mount device assembly of claim 16, wherein the first leads are wrapped around the ears of the first pair of packages and the second leads are wrapped around the ears of the second pair of packages. around the ears. 18. The surface mount device assembly of claim 17, wherein the first lead includes a first surface mount portion disposed between the first pair of package ears, and the second lead A second surface mount portion disposed between the second pair of package ears is included. 19. The surface mount device assembly of claim 18, wherein the first surface mount portion and the second surface mount portion are flat. 20. The surface mount device assembly of claim 17, said package further comprising: a first opening through which the first lead is disposed; and a second opening through which the second lead is disposed.

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