TWI609508B - Miniature surface mount device with large pin pads - Google Patents

Description

Miniature surface mount component with large pin spacer Related application

This application is a continuation-in-part application of US Application No. 12/321,059, filed on January 14, 2009, and filed on November 3, 2010, and is filed in The consecutive applications of International Application No. PCT/CN2011/000335, filed on March 2, the entire contents of each of which are hereby incorporated by reference.

Field of invention

The present invention relates generally to surface mount components and, more particularly, to a plastic leaded wafer carrier housing light emitting diode component and a light emitting diode display including the same.

background

In recent years, significant advances have been made in the field of light-emitting diode (LED) technology, and light-emitting diodes having higher brightness and color fidelity have been proposed. Due to these improved light-emitting diodes and improved image processing techniques, large-size, full-color LED video screens are available and are currently in common use. Large-size light-emitting diode displays typically include a combination of a plurality of individual light-emitting diode panels that provide image resolution, and such image resolution is determined by the distance or "pixel pitch" between adjacent pixels.

Outdoor displays that are intended to be viewed from a large distance have a relatively large pixel pitch and often contain a plurality of separate pixel arrays. In the separate pixel arrays, a group of independently mounted red, green, and blue light emitting diodes are driven to form a full color pixel for the viewer. On the other hand, indoor screens require shorter pixel pitches, such as 3 mm, and include panels that carry red, green, and blue light emitting diodes that are mounted, for example, on a surface mount component ( SMD) A single electronic package on the package. Each surface mount component often defines a pixel. The relatively small surface mount components are attached to a drive printed circuit board (PCB) that controls the output of each surface mount component.

While both indoor and outdoor displays can be viewed over a wide range of off-axis angles, color distortion is often seen as the viewing angle increases. In addition, the material of each of the light-emitting diode packages and/or the material for mounting the light-emitting diodes may have reflective properties, which may further reduce color fidelity due to unnecessary light reflection and/or glare.

It is well known that surface mount components and many other types of electronic packages containing integrated circuits or separate components such as diodes or power transistors are dissipated enough to require heat management. In addition, too much heat can also cause the LED to fail. One of the considerations for designing a light-emitting diode system is effective thermal management. In the design of electronic packages, one of the purposes of effective thermal management is to maintain the operating temperatures of the light-emitting diodes and other active circuit components at a value that is low enough to prevent premature component failure. Various cooling methods including conductive heat transfer are commonly used. One conventional method of implementing conductive heat transfer for dissipating heat in an electronic package is to allow heat to be conducted away along the leads of the element. However, such leads often do not have sufficient mass or exposed surface area to provide effective heat dissipation. For example, high intensity light emitting diodes that are primarily emitted in the visible portion of the electromagnetic spectrum can produce a significant amount of heat that is difficult to dissipate using these conventional techniques.

The design goals of increasing the viewing angle, maintaining a relatively low operating temperature, and reducing the size of the surface mount component package are somewhat competing. It would be desirable to develop a surface mount component package that achieves all of these design goals at a lower cost.

summary

An embodiment of a surface mount light emitting diode package includes a lead frame and a plastic housing at least partially surrounding the lead frame. The leadframe includes a plurality of electrically conductive wafer carriers. A light emitting diode is disposed on each of the conductive wafer carriers of the plurality of conductive wafer carriers. The surface mount light emitting diode package has a profile height of less than about 1.0 mm.

Another embodiment discloses a surface mount LED package that includes a housing and a lead frame that is at least partially surrounded by the housing. The housing includes opposing first and second major surfaces, opposing side surfaces, and opposing end surfaces. The housing defines a cavity extending from the first major surface into the interior of the housing. The leadframe includes a plurality of electrically conductive wafer carriers. A single light emitting diode is disposed on each of the wafer carrying pads of each of the conductive wafer carriers. Each of the light emitting diodes has a first electrical terminal and a second electrical terminal. A first electrical terminal of each of the light emitting diodes is electrically coupled to a corresponding conductive wafer carrier. A second electrical terminal of each of the light emitting diodes is electrically coupled to a connection pad of the one of the plurality of electrically conductive connections. One of the cavities has a depth of less than about 0.6 mm. In certain embodiments, the depth is less than about 0.55 mm. In other embodiments, the depth is less than about 0.5 mm. In other embodiments, the depth is less than about 0.45 mm, and in still other embodiments less than about 0.4 mm. In some embodiments, the profile height is less than 1 mm. In some embodiments, the profile height is less than about 0.95 mm. In other embodiments, the profile height is less than about 0.90 mm, and in still other embodiments, the profile height is less than about 0.85 mm.

Other embodiments disclose a light emitting diode display that includes a substrate that carries an array of surface mount elements (SMDs) configured in a plurality of vertical rows and a plurality of horizontal rows. Each surface mount component includes a housing and a plurality of light emitting diodes that are configured to be energized to collectively produce a substantial full range of colors and define one of the pixels of the display. The LED display further includes a signal processing and LED driver circuit electrically coupled to selectively energize the array of surface mount components to display an image on the LED display. Each pixel of the display has a size that is approximately equal to or less than 2.8 mm by approximately equal to or less than 2.8 mm.

Simple illustration

1 is a perspective view of a surface mount component according to an embodiment of the present invention; FIG. 2 is a top plan view of the embodiment shown in FIG. 1; and FIG. 3 is a basis for use in a surface mount component. FIG. 4 is a perspective view of the embodiment shown in FIG. 1; FIG. 5 is a plan view of the lead frame in FIG. 3; and FIG. 6 is a cross-sectional line 6-6. A cross-sectional view of an embodiment of the second embodiment taken; FIG. 7 is a plan view of an embodiment of a surface mount component; and FIG. 8 is a light emitting diode having a surface mount component in accordance with an embodiment of the present invention A front plan view of one part of the body monitor screen.

Detailed description

The following description is directed to a preferred embodiment of the present invention, which is intended to represent the best mode of the invention. This is not meant to be limiting, but merely to illustrate the general principles of the invention, the scope of which is defined by the scope of the appended claims.

Embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings in which FIG. However, the invention may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and the scope of the invention will be fully conveyed by those of ordinary skill in the art. Like numbers indicate all similar components.

It should be understood that although the terms first, second, etc. may be used herein to describe various components, these components should not be limited to these terms. These terms are only used to distinguish one component from another. Without departing from the scope of the invention, for example, a first member may be referred to as a second member, and similarly, a second member may be referred to as a first member. The term "and/or" used herein includes any and all combinations of one or more of the associated listed items.

It should be understood that when a member such as a layer, region or substrate is referred to as being "on" or "extending" another member, it can be directly on the other member or directly to the other member. Or there may be a majority of intermediate components. Conversely, when a component is referred to as being "directly on" or extending "directly on" another component, there is no intermediate component. It will also be appreciated that when "coupled" or "coupled" to another member, it can be directly connected or coupled to another member or a plurality of intermediate members can be present. In contrast, when "directly connected" or "directly coupled" to another component, there is no intermediate component.

Relative terms such as "below" or "above" or "above" or "below" or "horizontal" or "vertical" may be used herein to describe one component, layer or region and another component as shown. The relationship between layers. It should be understood that these terms are intended to encompass different orientations of the components and the orientation shown in the figures.

The words used herein are for the purpose of illustration and description and are not intended to As used herein, the singular and " It is to be understood that the terms "comprising" and "comprising", "the" One or more other features, integers, steps, operations, components, components, and/or groups thereof are added.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning meaning It should be understood that the terms used herein are to be interpreted as having a meaning consistent with their meaning in the context of the specification and the related art, and should not be an ideal unless explicitly defined herein. Interpretation of the way or the excessive form of judgment.

In some embodiments, a light emitting diode package has a plurality of light emitting diodes, and each of the light emitting diodes is electrically coupled to another input terminal and an output terminal. Therefore, the light emitting diode dies can be independently controlled and can operate more efficiently. In some embodiments, the LED package includes a leadframe having a housing such as a plastic polymer that is molded around the leadframe. The polymer housing includes opposite first and second major surfaces with a height distance therebetween, with opposite side surfaces having a width distance therebetween, and an opposite end surface having a length distance therebetween, wherein the width distance and the length distance Less than about 2.6 mm. In some embodiments, the equidistant system is approximately equal to or less than 2.5 mm and the other embodiments are approximately equal to or less than 2.35 mm. In some embodiments, the housing at least partially surrounds the lead frame and defines a cavity extending from the first major surface into the interior of the housing, at least a portion of the conductive wafer carrier being The bottom of the cavity is exposed. The ratio of the area of the bottom of the cavity to the area of the major surface is at least 35%. In certain embodiments, it is greater than 40%. In other embodiments, the ratio is greater than 50%.

In some embodiments, the LED package includes a plurality of light emitting diode crystal grains, for example, a red light emitting diode crystal grain, a green light emitting diode crystal grain, and a blue light emitting diode crystal. And the lead frame comprises a conductive wafer carrier for each of the light emitting diodes. In some embodiments, each of the electrically conductive wafer carriers has a length that extends at least 1/2 of the length of the bottom of the cavity. The shared mounting gasket will have a larger area to improve heat dissipation.

Figures 1-4 show a surface mount LED package 10 and components thereof in accordance with a particular exemplary embodiment for use with a light emitting diode display such as an indoor and/or outdoor light emitting diode screen. The LED package 10 includes a plastic housing 12 that at least partially surrounds a lead frame 14. The lead frame 14 includes first, second, and third conductive wafer carriers 142, 143 and 144 and first, second, and third conductive connecting portions 146, 147 and 148 separated from the conductive wafer carrier, such as Figure 3 shows. The electrically conductive wafer carriers 142-144 have a profile height in the range of from about 0.42 mm to about 0.48 mm. In other words, the profile height is the height of the curved lead frame. For example, in FIG. 3, the profile height represents the distance between the lower surface 82 of the conductive wafer carrier 142 and the upper surface 102 of the conductive wafer carrier 142. In certain embodiments, the profile height is less than about 1.0 mm. In other embodiments, the profile height is less than about 0.95 mm. In other embodiments, the profile height is from about 0.85 mm to about 0.95 mm. The leadframe metal sheet may have a sheet thickness of less than about 0.15 mm prior to bending. Further, the conductive wafer carrier adjacent to a center line of the surface mount light emitting diode package (i.e., surface mount component) may have a width of about 0.47 mm to 0.53 mm.

The first, second and third conductive wafer carriers each have an upper surface comprising a connection pad. For example, the first conductive wafer carrier 144 has an upper surface 104 that includes a connection pad 124. A light emitting diode 44 is disposed on the connection pad 124 on the upper surface 104 of the conductive wafer carrier 144. A light emitting diode 46 is disposed on the connection pad 123 of the upper surface 103. A light emitting diode 48 is disposed on the connection pad 122 of the upper surface 102. Each of the light emitting diodes has a first electrical terminal and a second electrical terminal. The first electrical terminal is defined as an anode. For example, the first light emitting diode 44 has an anode electrically coupled to the first conductive connection portion 146. The second and

The first, second and third conductive wafer connection pads each have an upper surface, a lower surface, and a connection pad on the upper surface. Each of the conductive wafer carriers has an upper surface, a lower surface, and a wafer carrying spacer on the upper surface. Each of the conductive connecting portions has an upper surface, a lower surface, and a connecting spacer on the upper surface. For example, in FIG. 3, the first conductive connection portion 146 has an upper surface 106, a lower surface 86, and a connection pad 126 on the upper surface 106. The second conductive connecting portion 147 has an upper surface 107, a lower surface 87, and a connecting spacer 127 on the upper surface 107. The third conductive connection portion 148 has an upper surface 108, a lower surface 88, and a connection pad 128 on the upper surface 108. The first conductive wafer carrier 142 has an upper surface 102, a lower surface 82, and a connection pad 122 on the upper surface 102. The second conductive wafer carrier 143 has an upper surface 103, a lower surface 83, and a connecting spacer 123 on the upper surface 103. The third conductive wafer carrier 144 has an upper surface 104, a lower surface 84, and a connection pad 124 on the upper surface 104. The lower surface of the conductive wafer carrier and the connection pad may also be referred to as a pin spacer. For example, the lower surface 86-88 of each of the conductive wafer carriers 146-148 and the lower surfaces 82-84 of each of the conductive wafer carriers 142-144 can each have a gasket area of about 0.4 mm by about 0.7 mm.

The first and second conductive wafer carriers 142 and 143 are adjacent to each other and the second and third conductive wafer carriers 143 and 144 are adjacent to each other. The adjacent conductive wafer carriers are separated by a carrier gap and have an upper surface profile that is asymmetrical with respect to a centerline in the carrier gap. The first and second conductive connections 146 and 147 are adjacent to each other. The second and third conductive connecting portions 147 and 148 are adjacent to each other. The adjacent conductive connections are separated by a connection gap and have an upper surface profile that is asymmetrical with respect to a centerline in the connection gap.

The housing 12 can be generally rectangular, including first and second major surfaces 24 and 26, opposite respective side surfaces 28 and 30, and end surfaces 32 and 34, respectively. The first and second surfaces may also be referred to as upper and lower surfaces. In one embodiment, the distance between the upper and lower surfaces 24 and 26, or the package contour height is less than about 1.0 mm. Preferably, the distance h between the upper and lower major surfaces 24 and 26 is from about 0.90 mm to about 1.00 mm. More preferably, the distance h between the upper and lower major surfaces 24 and 26 is about 0.95 mm. The distance w between the side surfaces 28 and 30 and the distance I between the end surfaces 32 and 34 are preferably less than about 2.6 mm. Preferably, the distance w between the side surfaces 28 and 30 is from about 2.40 mm to about 2.60 mm, and the distance I between the end surfaces 32 and 34 is also from about 2.40 mm to about 2.60 mm. Within the range. More preferably, the distance w between the side surfaces 28 and 30 is about 2.50 mm, and the distance I between the end surfaces 32 and 34 is about 2.50 mm.

By way of example and not limitation, the surface mount LED package 10 can have a full length L of approximately 2.5 mm, a full width W of approximately 2.5 mm, and a height H of 0.95 mm.

The plastic housing 12 further defines a recess or cavity 36 extending from the upper surface 24 into the plastic housing 12. In some embodiments, a reflective insert or ring 38 can be positioned and secured along one side of the cavity 36 or at least a portion of the wall 40. Additionally, the reflective insert or ring 38 can also be integrally formed with the plastic housing 12 and can be made of the same material as the plastic housing 12. The effectiveness of the reflectivity of the ring 38 can be enhanced by tapering the cavity 36 and ring 38 carried therein inwardly toward the interior of the housing. The preferred shape of the cavity 36 is a square or rectangular cavity. The square shape produces a surface mount light emitting diode package 10 having a more uniform wall thickness on each of the side surfaces 28 and 30 and the end surfaces 32 and 34. Thus, in accordance with one aspect of the invention, the size of the cavity increases as compared to, for example, a circular cavity.

The housing 12 is made of a material that is electrically insulating and thermally conductive. In an embodiment, the housing is a thermoplastic polycondensate. A particularly preferred thermoplastic polycondensate is polyphthalamide (PPA). In a preferred embodiment, the housing 12 can be formed from black polyphthalamide or white polyphthalamide. It has been discovered that the use of a black material in, for example, an image-generating surface mount component having surface mount components for use in a video display can improve contrast. Other housing materials include ceramics, resins, epoxies, and glass.

In the embodiment shown in FIGS. 1 and 2, the three light-emitting diodes 44, 46, 48 in the surface mount LED package 10 preferably emit red, green, and blue, respectively. The light emitting diodes in combination produce a substantially full range of colors when properly energized. In addition, two or more of the light emitting diodes may emit the same color, including white. For example, the light-emitting diode 44 and the light-emitting diode 46 may both emit red light. The light emitting diode wafers have a square-like or rectangular size. For example, the square-like light emitting diode wafer has a profile height of less than about 0.11 mm, or in the range of from about 0.09 mm to about 0.11 mm, or less than about 0.1 mm, or in the range of from about 0.08 to 0.10 mm. The square-like light emitting diode wafer can have a profile width of less than about 0.32 mm, or in the range of 0.265 mm to 0.315 mm. The square-like light emitting diode wafer can have a profile width of less than about 0.38 mm, or in the range of 0.33 mm to 0.38 mm. The rectangular-like light emitting diode wafer has a profile height of less than about 0.13 mm, or in the range of from about 0.10 mm to about 0.13 mm. The rectangular-like light emitting diode wafer has a profile width of less than about 0.28 mm, or in the range of from about 0.20 mm to about 0.28 mm. The rectangular-like light-emitting diode wafer has a profile width of less than about 0.36 mm, or in the range of from about 0.28 mm to about 0.36 mm.

In the illustrated embodiment, the red LEDs 44 are disposed on the first conductive wafer carrier 142. The green LED 46 is disposed on the second conductive wafer carrier 143 near the center of the cavity 36. The blue light emitting diode 48 is disposed on the third conductive wafer carrier 144. In order to dissipate heat from the light-emitting diodes, it is preferred to increase the surface area above the surface of the conductive wafer carriers so that they can dissipate heat more efficiently. For example, the surface area above each of the conductive wafer carriers is approximately twice the surface area above the corresponding connections.

The LED chips 44, 46, 48 extend in a transverse direction along a first axis 62, i.e., in a direction perpendicular to one of the side surfaces 28 and 30. The leads 50, 52, 54, 56 are parallel to each other and extend in a direction perpendicular to the direction 62 along a second axis 62a. The first axis and the second axis intersect each other near the second LED body 46.

In this embodiment, the conductive connections are provided by the application of the adhesive gasket, the mold flow, the heat dissipation, and the wafer positioning design, as compared to, for example, U.S. Patent Application Serial No. 12/321,059, the disclosure of which is incorporated herein by reference. The conventional disclosure disclosed therein is improved by the heat dissipation of the red light-emitting diode 44. Referring to Figures 1-4, the preferred heat dissipation is achieved by a larger surface area of each of the pin spacers. For example, each of the lower surfaces 86-88 of the electrically conductive connections 146-148 is increased by more than 10%. The surface area of each of the lower surfaces 82-84 of the electrically conductive wafer carriers also increases by more than 10%. More specifically, the surface areas of the lower surfaces 83 and 87 are increased by about 40%.

At the same time, in order to ensure that the polyphthalamide fluid flows uniformly in all directions as the housing 12 is formed, the contours 112 and 116 of the upper surfaces 104 and 104 are asymmetrical with respect to the second shaft 62a. Similarly, the contours 116 and 117 of the adjacent upper surfaces of the first and second electrically conductive connections 146 and 147 are asymmetrical with respect to the gap between the connections 146 and 147. The contours 117 and 118 of the adjacent upper surfaces of the second and third electrically conductive connections 147 and 148 are asymmetrical with respect to the gap between the connections 147 and 148. Similarly, the profile of adjacent wafer carriers is also asymmetrical with respect to the gap between adjacent wafer carriers such as 122-123 and 123-124.

The electrically conductive connections 146, 147, and 148 include electrical connection pads 126, 127, 128, respectively, that are positioned in the central region 58 and carried on components of the wafer carriers. Surfaces 102-104 are adjacent but separate. In a preferred form of the surface mount LED package 10, the leads 52, 54, 56, 58 are curved and extend along the respective end surfaces 32 and 34 of the housing to the outside thereof, and then bent again The lower surface 82-84 of the lead extends along the lower surface 26 of the plastic housing 12. The outer surfaces of the lower surfaces 82-84 and 86-88 of the leads are substantially flush with the bottom surface of a heat conductor to facilitate connection to a lower substrate. The lower surface 82-84 and 86-88 of the leads are electrically connected or joined to the wires or pads on the substrate using any of a variety of conventional joining techniques including soldering.

In a preferred embodiment, the solder pads are included on the bottom of the ends such that no solder is visible when viewing the individual surface mount components from above. This is advantageous because it helps prevent glare and improve contrast, especially when viewed during the day. As shown in Figures 1 and 6, the cavity 36 extends into the housing a depth sufficient to expose the connector pads 122-124 and 126-128.

The particular dimensions of the lower surfaces 82-84 and 86-88 of the leads 52-54 and 56-88 extending inwardly from the end surfaces 32 and 34 of the housing may depend on the desired surface mount LED package. Embodiments, the light-emitting diode to be used, the material of the housing 12, the size of the surface mount component, and/or other such factors and/or combinations of factors are determined. In some embodiments, the leads of the leads 50-52, 54-56 outside the housing may be separated by a gap 92 between the plurality of pads to electrically insulate the connections from each other.

The plurality of conductive wafer carriers 142, 143 and 144 and the plurality of conductive connections 146, 147 and 148 may be made of, for example, copper, a copper alloy, a conductive metal or a metal alloy, such as copper, a copper alloy, other suitable low resistance. Rate, corrosion resistant material, or a combination of these materials. Because the light emitting diode chips are disposed on the conductive wafer carriers 142-144, the large surface area of the upper surfaces 102-104 can contribute to heat dissipation.

Each of the LEDs 44, 46, and 48 can be electrically conductive by one of a solder, an adhesive, a coating, a film, a cladding, a paste, a grease, and/or other suitable material, and the thermal interface 100 is independent of the different connection pads. Geoelectric coupling. In a preferred embodiment, the LEDs 44, 46 and 48 can be electrically coupled and fixed to the connection pads 122-124 by using a solder pad on the bottom of the LED. The solder cannot be seen from above. It is advantageous to prevent the solder from being seen from above in order to reduce reflection and provide a better contrast, especially during the day.

In some manufacturing methods in accordance with the present invention, the light emitting diodes 44, 46 and 48 may be coupled to the connecting pads 122 prior to molding and/or assembling the housing 12 around the connecting pads. -124 coupling. Alternatively, the light emitting diodes can be coupled to the connection pads 122-124 after the connections have been partially enclosed within the housing. The cavity 36 extending into the housing can be configured such that a sufficient portion of the spacers 122-124 and 126-128 are exposed to receive the light emitting diodes and associated wires.

Referring now to Figures 6-7, certain examples of various components for a surface mount component package 10 for a light emitting diode are shown. By way of example and not limitation, the dimensions described below in connection with the embodiments illustrated in Figures 6-7 can also be applied to surface mount packages in Figures 1-5.

In the embodiment illustrated in Figure 6, the surface mount component package 10 has a width or length of less than about 2.6 mm. Preferably, the surface mount component has a width or length of from about 2.4 mm to about 2.6 mm. More preferably, the width or length of the surface mount component is about 2.5 mm. The surface mount component package 10 has a profile height of less than about 1.0 mm. Preferably, the surface mount component has a profile height in the range of from about 0.9 mm to about 1.0 mm. More preferably, the surface mount component has a profile height of about 0.95 mm. The cavity 36 has an opening width of from about 1.86 mm to about 1.96 mm in the upper surface and a width in the range of from about 1.59 to about 1.69 mm in the lower surface. Preferably, the cavity 36 has an opening width of about 1.91 mm in the upper surface and a width of about 1.64 mm in the lower surface. The angle θ between the two side surfaces of the cavity is from about 25.0° to about 35.00°, preferably about 30.0°. One of the widths of the cavity opening 36 in the first major surface 24 is in the range of from about 1.4 mm to about 1.55 mm. The opening of the cavity 36 in the first major surface has an area greater than about 55% and less than about 61% of the total area of the first major surface 24. The housing surrounding the cavity has a wall thickness in the range of from about 0.3 mm to about 0.45 mm. In detail, the wall thickness of the housing is thinner near the first major surface 24 than the wall thickness of the housing near the attachment spacer 60.

In Fig. 7, the three light-emitting diodes 46, 47 and 48 have a distance P1 or P2 of between about 0.3 mm and about 0.4 mm. Each of the light emitting diodes 44, 46 and 48 can have a contour width of from about 0.3 mm to about 0.4 mm. Each of the light emitting diodes 44, 46 and 48 can have a contour length of from about 0.3 mm to about 0.4 mm. In some embodiments, the pitch is less than about 0.3 mm and the profile width is less than about 0.3 mm. The gaps 92 can have a width of from about 0.13 to about 0.17 mm. The ratio of the area of the bottom portion 36a of the cavity to the area of the major surface 24 is at least 35%. In certain embodiments, the ratio is greater than 40%. In other embodiments, the ratio is greater than 50%.

Figure 8 is a schematic illustration of a portion of a light-emitting diode display screen 300, such as an indoor screen. Generally, the indoor screen includes a printed circuit board 302 carrying a plurality of surface mount components 304, such surface mount components. 304 is arranged in a plurality of rows and columns, and each surface mount component defines a pixel. Each pixel of the display has a size of about 2.8 mm by about 2.8 mm. Each of the light emitting diode chips can be driven at different voltage levels. For example, the red light emitting diode can be driven by a 2.2V power supply, and the blue and green light emitting diodes can be driven by a power supply of approximately 3.1V. The surface mount components 304 can include elements such as those described above and illustrated in Figures 1-7. The surface mount components 304 are electrically coupled to pads and pads on the printed circuit board 302 that are coupled to the pads in response to appropriate electrical signal processing and drive circuitry (not shown).

As noted above, each surface mount component carries a linear array 306 of vertical orientations of red, green, and blue light emitting diodes. This linear orientation of the light-emitting diodes has been found to improve color fidelity over a wide range of viewing angles. A plurality of through holes 308 may also be provided to allow for better and shorter contact of the ceramic surface mount component bodies with the printed circuit board. The through holes 308 also provide better heat dissipation.

It has been previously understood that these embodiments provide a mini surface mount light emitting diode package including a plurality of light emitting diodes on a lead frame partially surrounded by a plastic housing. The leadframe includes a plurality of electrically conductive wafer carriers and a plurality of electrically conductive connections. The pair of adjacent conductive wafer carriers or the upper surface of the adjacent connecting portion has an asymmetrical profile with respect to a centerline of a gap between the adjacent conductive wafer carriers or adjacent connecting portions. Compared to the conventional disclosure, the disclosed mini surface mount LED package has relatively large pin spacers, lower operating temperature, and lower manufacturing cost.

It is intended that the foregoing detailed description of the invention be construed as

10. . . Light-emitting diode package

12. . . case

14. . . Lead frame

twenty four. . . First major surface; upper major surface

26. . . Second major surface; lower major surface

28,30. . . Side surface

32,34. . . End surface

36. . . Cavity

36a. . . Bottom of the cavity

38. . . ring

40. . . wall

44. . . First light emitting diode

46. . . Second light emitting diode

48. . . Third light emitting diode

50,52,53,54,56,57,58. . . lead

58. . . Central area

60. . . Connection gasket

62. . . First axis

62a. . . Second axis

82,83,84,86,87,88. . . lower surface

92. . . gap

100. . . interface

102,103,104,106,107,108. . . Upper surface

112,116,117,118. . . profile

122,123,124,126,127,128. . . Connection gasket

142. . . First conductive wafer carrier

143. . . Second conductive wafer carrier

144. . . Third conductive wafer carrier

146. . . First conductive connection

147. . . Second conductive connection

148. . . Third conductive connection

300. . . LED display

302. . . A printed circuit board

304. . . Surface mount component

306. . . Array

308. . . Through hole

H. . . height

h. . . Distance between major surfaces

I. . . Distance between end surfaces

L. . . full length

P1, P2. . . spacing

W. . . Full width

w. . . Distance between side surfaces

θ. . . angle

1 is a perspective view of a surface mount component in accordance with an embodiment of the present invention;

Figure 2 is a top plan view of the embodiment shown in Figure 1;

Figure 3 is a perspective view of a lead frame in accordance with an embodiment of a surface mount component;

Figure 4 is a perspective bottom view of the embodiment shown in Figure 1;

Figure 5 is a plan view of the lead frame in Figure 3;

Figure 6 is a cross-sectional view of the embodiment of Figure 2 taken along section line 6-6;

Figure 7 is a plan view of an embodiment of a surface mount component; and

Figure 8 is a front plan view of a portion of a screen of a light-emitting diode display having a surface mount component in accordance with an embodiment of the present invention.

10. . . Light-emitting diode package

12. . . case

twenty four. . . First major surface; upper major surface

26. . . Second major surface; lower major surface

28,30. . . Side surface

32,34. . . End surface

36. . . Cavity

38. . . ring

40. . . wall

44. . . First light emitting diode

46. . . Second light emitting diode

48. . . Third light emitting diode

52,53,54. . . lead

122,123,124,126,127,128. . . Connection gasket

Claims (24)

A light emitting diode (LED) package comprising: a lead frame oriented on a first axis and a second axis perpendicular to the first axis, comprising a plurality of conductive wafer carriers and a plurality of conductive connections, wherein a first gap extending parallel to the first axis is a portion of the plurality of conductive wafer carriers and the plurality of conductive connections, wherein each of the conductive wafer carriers comprises an upper surface having a contour, wherein adjacent conductive The wafer carrier is separated by a carrier gap extending parallel to the second axis, and wherein the contours of the adjacent conductive wafer carriers are asymmetric with respect to a centerline of the carrier gap; a plurality of light emitting diodes Each of the plurality of conductive wafer carriers is disposed on each of the plurality of conductive wafer carriers; and a plastic housing at least partially surrounding the lead frame, wherein a height of the outline of the light emitting diode package is less than about 1.0 mm . The light emitting diode package of claim 1, wherein the light emitting diode package has a width of less than about 2.6 mm, and wherein the light emitting diode package has a length of less than about 2.6 mm. The light-emitting diode package of claim 1, wherein each of the light-emitting diodes has a first electrical terminal and a second electrical terminal, and the first electrical terminal of each of the light-emitting diodes and the corresponding conductive wafer carrier Coupling, wherein the first and second electrical terminals of each of the plurality of light-emitting diodes respectively comprise a cathode and an anode, wherein the second electrical terminals of each of the light-emitting diodes are electrically connected to the plurality of conductive terminals One of the parts corresponds to a conductive connection One of the connecting pads is electrically coupled. The luminescent diode package of claim 1, wherein the plastic housing comprises a square-like or rectangular cavity having a depth of about 0.5 mm. The light-emitting diode package of claim 1, wherein each of the conductive wafer carriers supports a single light-emitting diode that independently emits red, green or blue light. The illuminating diode package of claim 1, wherein each of the conductive wafer carriers further has a lower surface and a wafer carrying spacer on the upper surface, each conductive connecting portion having an upper surface, a lower surface, and And a connecting pad on the upper surface, wherein the second electrical terminals of the light emitting diodes of the plurality of light emitting diodes are electrically coupled to the connecting pads of the corresponding conductive connecting portions by a single wire. The illuminating diode package of claim 6, wherein each of the conductive connecting portion and the lower surface of the conductive wafer carrier has a shimming area of about 0.4 mm by about 0.7 mm. The illuminating diode package of claim 1, wherein the plastic housing comprises a thermoplastic material. The light-emitting diode package of claim 8, wherein the plastic case comprises one of white polyphthalamide or a black polyphthalamide. A surface mount component comprising: a housing including opposing first and second major surfaces, opposing side surfaces, and opposite end surfaces, the housing defining a first major surface a cavity extending into the interior of the housing; and a lead frame at least partially surrounded by the housing and oriented on a first axis and a second axis perpendicular to the first axis, the lead frame comprising a majority a conductive wafer carrier and a plurality of conductive connections, wherein a first gap extending parallel to the first axis is a portion of the plurality of conductive wafer carriers and the plurality of conductive connections, wherein each of the conductive wafer carriers comprises a contour An upper surface, wherein adjacent conductive wafer carriers are separated by a carrier gap extending parallel to the second axis, and wherein the contours of the adjacent conductive wafer carriers are relative to a centerline of the carrier gap Is asymmetrical; a single light-emitting diode on each of the wafer carrying pads of each of the conductive wafer carriers, each of the light-emitting diodes has a first electrical terminal and a second electrical terminal, wherein each of the light-emitting diodes The first electrical terminal is electrically coupled to the corresponding conductive wafer carrier; and wherein the second electrical terminal of each of the light emitting diodes is electrically coupled to one of the plurality of conductive connecting portions and the one of the conductive connecting portions, and In one of the cavity surface depth of less than 0.6mm and the mounting member profile height of less than one 1.00mm. The component of claim 10, wherein the first and second electrical terminals of each of the light emitting diodes comprise a cathode and an anode, respectively. The component of claim 10, wherein each of the conductive wafer carriers further has a lower surface and a wafer carrying spacer on the upper surface, each of the conductive connecting portions having an upper surface, a lower surface, and an upper surface a connection pad, wherein the conductive wafer carrier and the conductive connections Contains sheet metal. The component of claim 12, wherein the first and second electrical terminals of each of the light-emitting diodes respectively comprise a cathode and an anode, and wherein each of the light-emitting diodes emits red, green or blue light. The component of claim 13 , wherein the second electrical terminal of each of the light-emitting diodes and the connection pad of the corresponding conductive connection are electrically coupled by a single wire. The element of claim 12, wherein a surface area of one of the upper surfaces of each of the conductive connecting portions is less than about one-half of a surface area of a surface of each of the conductive wafer carriers. The component of claim 12, wherein each of the conductive connecting portion and the lower surface of the conductive wafer carrier has a gasket area of about 0.4 mm by about 0.7 mm. The element of claim 10, wherein the cavity has an opening angle of about 30 in a horizontal direction and a vertical direction. The element of claim 10, wherein the light emitting diodes extend in a first direction along one of the central axes of the surface mounting component. The element of claim 10, wherein the electrically conductive wafer carrier adjacent to a centerline of the surface mount component has a width of between about 0.47 mm and 0.53 mm. A light emitting diode display comprising: a substrate carrying an array of surface mount components (SMD) configured in a plurality of vertical rows and a plurality of horizontal columns, such surfaced components as claimed in claims 10-19 One of the components described, each surface mount element The device includes a housing and includes a plurality of light emitting diodes, the light emitting diode systems being configured to be energized to collectively produce a substantially full range of colors and defining one of the pixels of the display; and signal processing and light emitting diodes a drive circuit electrically coupled to selectively energize the array of surface mount components to display an image on the LED display, wherein each pixel of the display has an approximately equal to or less than 2.8 mm by approximately equal to or less than 2.8mm size. A light emitting diode (LED) package includes: a lead frame oriented on a first axis and a second axis perpendicular to the first axis, comprising a plurality of conductive wafer carriers and a plurality of conductive connections, wherein a first gap extending parallel to the first axis is a portion of the plurality of conductive wafer carriers and the plurality of conductive connections, wherein each of the conductive wafer carriers comprises an upper surface having a contour, wherein adjacent conductive The wafer carrier is separated by a carrier gap extending parallel to the second axis, and wherein the contours of the adjacent conductive wafer carriers are asymmetric with respect to a centerline of the carrier gap; a plurality of light emitting diodes Each of which is disposed on each of the plurality of electrically conductive wafer carriers; and a polymeric housing at least partially surrounding the lead frame, the polymeric housing having a relative distance therebetween having a height distance therebetween And a second major surface having an opposite side surface with a width distance therebetween and an opposite end surface having a length distance therebetween, wherein the height distance, the width distance and the length distance are less than 2.6mm. The illuminating diode package of claim 21, wherein the housing at least partially surrounds the lead frame and defines a cavity extending from the first major surface into the interior of the housing to The bottom of one of the cavities, and the ratio of the area of the bottom of the cavity to the area of the major surface is at least 35%. The light emitting diode package of claim 21, comprising a red light emitting diode die, a green light emitting diode die and a blue light emitting diode die. The illuminating diode package of claim 21, wherein the housing at least partially surrounds the lead frame and defines a cavity extending from the first major surface into the interior of the housing to One of the bottoms of the cavity, and each of the conductive wafer carriers has a length that extends at least 1/2 of the length of the bottom of the cavity.