Multicolor light source and manufacturing method

Abstract

Methods, devices, and systems are described herein. A light source includes a first light-emitting diode (LED) die configured to emit a first die color and a second LED die configured to emit a second die color. A first filler is disposed over the first LED die. The first filler has a convex surface and includes a first phosphor such that the color of the first die is converted to a first emission color. A second filler is disposed over the second LED die. The second filler includes a second phosphor such that the color of the second die is converted to a second emission color having a higher absorption energy than the illumination energy of the first emission color.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 025,645, filed May 15, 2020, and European Patent Application No. 20186732.2, filed July 20, 2020, the contents of which are incorporated herein by reference. [Background technology]

[0002] Daytime running lamps (DRLs) may be mandatory lighting devices that can be automatically switched on when a vehicle is traveling on a road. For example, European Union (EU) regulations require DRL lights to remain on while the vehicle is moving, which may require the development of multi-function lighting modules to be equipped on vehicles. Common lighting function combinations include, for example, DRL / turn combinations and backup / turn combinations. To achieve such combinations, multi-color light sources may be employed. For example, a bi-color light source may be required for a DRL / turn module. Summary of the Invention

[0003] Methods, devices, and systems are described herein. A light source includes a first light-emitting diode (LED) die configured to emit a first die color and a second LED die configured to emit a second die color. A first filling is disposed over the first LED die. The first filling has a convex surface and includes a first phosphor that converts the color of the first die to a first illuminous color. A second filling is disposed over the second LED die. The second filling includes a second phosphor that converts the color of the second die to a second illuminous color that has a higher absorption energy than the illumination energy of the first illuminating color. [Brief explanation of the drawings]

[0004] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, in which:

[0005] [Figure 1] FIG. 1 is a diagram showing the emitted light colors perceived by an observer for various color combinations of two-color light sources.

[0006] [Figure 2] 1 is a diagram of the color space of the visible light spectrum.

[0007] [Figure 3] 1A and 1B are cross-sectional views of two polychromatic light sources with two different arrangements of phosphors.

[0008] [Figure 4] 1A and 1B show three embodiments of a multi-color light source.

[0009] [Figure 5] FIG. 2 is a diagram of a light source workpiece used to fabricate multiple light sources.

[0010] [Figure 6] FIG. 1 is a flow diagram of a method for manufacturing a light source workpiece.

[0011] [Figure 7] 1 is a diagram of an exemplary vehicle headlamp system.

[0012] [Figure 8] FIG. 2 is a diagram of another exemplary vehicle headlamp system. DETAILED DESCRIPTION OF THE INVENTION

[0013] Examples of different lighting system and / or light emitting diode ("LED") implementations are described in more detail below with reference to the accompanying drawings. These examples are not mutually exclusive, and features found in one example can be combined with features found in one or more other examples to achieve additional implementations. Accordingly, it will be understood that the examples shown in the accompanying drawings are provided for illustrative purposes only and are not intended to limit the disclosure in any manner. Like numbers refer to like elements throughout.

[0014] In this specification, terms such as first, second, and third may be used to describe various elements, but it is understood that these elements should not be limited by these terms. These terms may be used to distinguish one element from another. For example, a first element may be termed a second element, and a second element may be termed the first element, without departing from the scope of the present invention. As used herein, the term "and / or" may include any and all combinations of one or more of the associated listed items.

[0015] When an element, such as a layer, region, or substrate, is referred to as being "on" or extending "on" another element, it is understood that it is directly on or extending directly onto the other element, or that intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or extending "directly onto" another element, there may be no intervening elements present. Also, when an element is referred to as being "connected" or "coupled" to another element, it is understood that the element may be directly connected or coupled to the other element and / or connected or coupled to the other element via one or more intervening elements. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements between the element and the other element. It is understood that these terms are intended to encompass different orientations of the elements in addition to the orientation depicted in the figures.

[0016] Relative terms such as "below," "above," "upper," "below," "horizontal," or "vertical" may be used herein to describe the relationship of one element, layer, or region to another element, layer, or region as shown in the figures. It is understood that these terms are intended to encompass different orientations of the device in addition to the orientation shown in the figures.

[0017] For the manufacture of multicolor light sources, it may be most cost-effective to use chip-on-board (CoB) technology. Instead of packaging individual semiconductor devices containing each light-emitting diode (LED), CoB technology allows multiple LED chips (or dies) to be directly bonded to a substrate, such as a printed circuit board (PCB), resulting in a single module containing several LED chips. This can reduce the device's space and weight, as well as costs during the manufacturing process. More specifically, for the manufacture of a two-color light source, multiple strings of LED dies are mounted on a substrate, and then one portion of the LED die ring is covered with a fill containing a particular type of color-converting phosphor, while another portion of the LED die ring is covered with a different fill containing a different type of color-converting phosphor. The two portions of the LED die ring may use blue LED dies so that the light emitted by the two portions, after being converted by the respective fills, is perceived by an observer as a different color (e.g., white and red). However, the proximity of the two portions of the LED die ring increases the likelihood of light mixing, resulting in an observer perceiving a mixed color.

[0018] Figure 1 illustrates the emitted color perceived by an observer for various color combinations of two-color light sources. As shown in Figure 1A, the color of a blue LED die without a phosphor may appear blue to an observer. As shown in Figure 1B, a white phosphor may convert the color of the blue LED die to white, and a red phosphor may convert the color of the blue LED die to red. As mentioned above, two different phosphors may be required to render two different colors. However, if the blue emitted by the LED die first passes through the white phosphor and then the red phosphor, some color mixing may occur. For example, as shown in Figure 1C, what is rendered is a mixture of white and red (and therefore pink), not two different colors. This is because, for example, the blue portion of the white is converted by the red phosphor. Therefore, for different colors, the phosphors may need to be placed next to each other. This is usually done by placing a dam between the two phosphors.

[0019] Therefore, it may be desirable for multi-color light source products to efficiently avoid color mixing, and it may also be desirable for multi-color light source products to be more compact, less expensive, and produced by more efficient manufacturing processes.

[0020] Returning to Figure 1C, the red color point in the color space is farther away from the blue color point than the white color point, which can result in color mixing of the emitted colors. Now, let's turn to Figure 2. Figure 2 is a diagram of the color space of the visible light spectrum, showing the red, amber, green, cyan, blue, and white color points. Figure 2 shows that the distance between the blue and red color points is greater than the distance between the blue and white. Therefore, as shown in Figure 1D, if a blue color first encounters a red phosphor and then a white phosphor, the emitted light from the white phosphor will remain red. This is because the converted red color may not be converted again when it passes through the white phosphor.

[0021] FIG. 3 shows cross-sectional views of two multicolor light sources with two different phosphor arrangements. Referring to FIG. 3A, an LED die 10 may be covered by a fill 50 containing a white phosphor, and another LED die 30 may be covered by another fill 70 containing a red phosphor. Similar to fill 70, there may be a fill 71 containing a red phosphor and covering another LED die (not shown in FIG. 3A). Thus, the color of the first die and the color of the second die may each be converted to their respective emission colors by passing through their respective phosphors. As shown in FIG. 3A, the white emission color 15 from the white phosphor may still be converted by the red phosphor in fill 71, potentially resulting in an undesirable mixture of white and red emission colors.

[0022] In the two examples shown in Figure 3, a blue LED die is used as an example, but this is not intended to limit the present invention. As mentioned above, white can be a mixture of at least two wavelengths (e.g., blue (~450 nm) and yellow (~560 nm)). Therefore, according to the color region shown in Figure 2, since white contains light with higher energy (shorter wavelength), undesirable mixing may occur due to re-absorption of white in the red phosphor. Therefore, the white emission color 15 may still be converted to a red emission color when encountering the red phosphor.

[0023] In contrast, Figure 3B illustrates that such undesirable mixing can be avoided in accordance with embodiments described herein. In the example shown in Figure 3B, the first LED die 20 is covered by a first fill 60 including a first phosphor, which may be a red phosphor, and the second LED die 40 is covered by a second fill 80, 81 including a second phosphor, which may be a white phosphor. In embodiments, the light source may include more than one first LED die 20 and more than one second LED die 40. In embodiments, the first LED die and the second LED die may be separated by a distance. The distance may be, for example, less than 50 mm, less than 20 mm, or even less than 10 mm.

[0024] The colors of the first and second die may each be converted to their respective emission colors by passing through the respective phosphors. Also, the second fill 80 is positioned to the left of the first fill 60 in FIG. 3B , while another portion of the second fill (81) is positioned to the right of the first fill 60. However, in some embodiments, the fill 81 may cover another LED die (not shown in FIG. 3B ). In the example shown in FIG. 3B , the first die is blue and has already been converted to the first red emission color 26 by the first phosphor. Therefore, further encounter of the first emission color 26 with the second fill 81 may no longer induce color conversion. Therefore, the arrangement of the first LED die with the first fill and the second LED die with the second fill may ensure that the first emission color is not converted even when it encounters the second phosphor.

[0025] The first die color and the second die color may refer to the respective colors that can be directly emitted by the first and second LED dies. In the example described herein, both the first and second die colors are blue. Because blue provides enough energy to shift to almost any other color point, blue may be a desirable choice for the first and second die colors. However, it is clear that those skilled in the art will understand that the LED dies can be the same or different colors, and may further be other colors such as, but not limited to, red, green, and cyan. The second die color can be equal to or approximately equal to the first die color. Thus, for example, if the first and second die colors are blue, and the second emission color is white, the first emission color can also be amber. Furthermore, the first emission color can be white, red, or amber, and the second emission color can be cyan. Those skilled in the art will understand that different color combinations can be selected within their expertise based on the color regions shown in FIG. 2.

[0026] Referring further to FIG. 3B , the first fill 60 is shown to be waterdrop-shaped and have a convex surface. This can be advantageous in that the second emitting color 48 encounters the first fill 60 further along its three-dimensional propagation path, resulting in a portion of the second emitting color 48 being further converted to the first emitting color red by the first phosphor. Thus, by configuring the first fill 60 with a convex surface, light rays of the second emitting color 48 that would otherwise be converted can preferentially pass over the convex surface of the first fill 60 and thus cannot pass through the first fill 60. As previously mentioned, the portion of the second emitting color 48 that transmits from the right side of the second LED die 40 toward the lower-left portion of the surface of the first fill 60 (this portion of the second emitting color 48 is not shown in FIG. 3B ) may transmit through the first fill 60, but this is negligible. What the observing eye perceives is a clear color separation.

[0027] It is clear that the specific radius of curvature or waterdrop shape of the convex surface of first filler 60 can be selected by one skilled in the art according to the distance between first LED die 20 and second LED die 40 and the diameter of the sphere formed by first filler 60, which may also be related to the properties of the material applied to first filler 60, such as the thickness of the filler and / or phosphor material. For example, the surface tension of the applied filler can be adapted to control the shape of the convex surface. This description is not intended to limit one skilled in the art to the selection of filler material or specific parameters for the LED dies during a specific manufacturing process, which can be adapted according to different manufacturing and lighting requirements.

[0028] In summary, as shown in FIG. 3B, the configuration of the first LED die, the second LED die, and the first fill as well as the second fill can ensure that the first emission color is not converted by the second phosphor contained in the second fill. Furthermore, the first emission color, which has a lower energy than the absorption energy of the second phosphor, can ensure that color conversion no longer occurs, such that the first emission color and the second emission color are separated, even if the first emission color must physically pass through the second phosphor. This arrangement can mean that the observer's eye can perceive distinct multicolor light patterns in which the colors are distinguished as separate or spatially separated from each other. For example, different distinct colors can be seen in different locations. The second emission color may pass over the first fill and therefore not penetrate the first fill, such that no or little color conversion occurs in the first fill. In particular, the eye observing from outside the light source, or often from above, can distinguish the two-color light pattern. For example, a portion of the second emission color transmitted from the underside of the second LED die may transmit through the first fill, and the amount of such side transmission may be negligible compared to that of non-side transmission, so that two separate and distinct colors distinguishable by the eye may not interfere. In other words, because the second emission color preferentially passes over the first fill, separation between the first emission color and the second emission color may be improved.

[0029] When the illumination energy of the first emission color is lower than the absorption energy of the second phosphor, the wavelength λ (shown at the edge of the color diagram in Figure 2) is related to the energy E via E = (hc) / λ, where h is Planck's constant and c is the speed of light. As shown in Figure 2, color conversion from one color point to another requires a certain amount of energy consumption. Therefore, a lower energy of the first emission color than the absorption energy of the second fill can ensure that the first emission color is not converted by the second phosphor contained in the second fill when the first emission color passes through the second fill. In other words, when the first emission color passes through the second phosphor, color conversion may no longer occur in the second phosphor. This can further enhance the separation between the first emission color and the second emission color.

[0030] Furthermore, the convex surface of the droplet-shaped first filler may ensure that light rays of the second emitting color may preferentially pass over its convex surface without passing through the first filler to avoid being converted into the second emitting color, for example by forming a tangent to the convex surface of the first filler, thereby reducing or even eliminating undesirable color mixing between the first and second emitting colors.

[0031] FIG. 4 illustrates three embodiments of a multicolor light source. FIG. 4A illustrates a so-called sunny side up configuration of a multicolor light source. In the example shown in FIG. 4A, the light source includes a first LED die 20 covered by a first fill 60 containing a red phosphor and two second LED dies 40, 41, each covered by two second fills 80, 81, both containing a white phosphor. Due to the circular emission pattern, the top view shown in FIG. 4A appears in the shape of a fried egg, with the first emission color 26, which is red, forming a full circle in the center and the second emission color 48, which is white, present in the outer region surrounding the first emission color 26. Furthermore, the radius of the region containing the perceived first emission color 26 may differ from the radius of the second fill 60 because part of the side-transmitted second emission color 48 may penetrate the first fill 60 and thus be converted. In particular, the radius of the area of ​​the first emitting color 26 compared to the radius of the fried egg area perceived by the viewer may depend on, for example, the particular parameters of the convex surface of the first filling 60 .

[0032] FIG. 4B shows an example similar to FIG. 4A . In the example shown in FIG. 4B , the light source includes two first LED dies 20, 21, which may be located to the left and right of the second LED die 40, respectively. The first LED dies 20, 21 and the second LED die 40 may be covered by respective fillers, which may include two first fillers 60, 61 and a second filler 80. The first fillers 60, 61 may each include a red phosphor, and the second filler 80 may include a white phosphor. In the top view of this embodiment, the second emission color 48 is shown in the center of a so-called inverted fried egg configuration, while the first emission color 26 may be present in the outer region. Thus, according to FIGS. 4A and 4B , different color patterns are provided, which may include two separate colors and meet the general requirements of automobiles.

[0033] It is also noted that in Figures 4A and 4B, two dams 90 are provided at each end of the two embodiments. These dams 90 may be configured to further avoid interference between adjacent light sources. In the case of Figures 4A and 4B, only one light source including a total of three LED dies is shown. However, as will be described below, manufacturing processes may be performed on substrates that may include multiple light sources, and therefore, this may require the use of dams configured between adjacent light sources to avoid interference.

[0034] Nevertheless, referring to FIG. 4C , which shows another embodiment, the use of the dam 90 can be avoided. FIG. 4C shows an embodiment similar to FIG. 4B , in which the dam 90 is not used because the two first LED dies 20, 21 are in the shape of full hemispheres (water drops). More specifically, FIG. 4C shows full hemispheres for the first fills 60, 61, whereas in FIG. 4B , the first fills 60, 61 are only half hemispherical in shape. Thus, in the case of FIG. 4C , the convex surfaces of the first fills 60, 61 automatically reduce or even eliminate interference between adjacent light sources, because any light rays propagating from adjacent light sources toward the surfaces of the first fills 60, 61 form tangents on the convex surface and therefore simply pass over the surface without passing through the first fills 60, 61. Thus, apart from providing a variety of multi-colored lighting with reduced mixing of different emission colors, the embodiments described herein may also provide a flexible way of specific configuration depending, for example, on the materials used for the filling and the specific parameters induced during the specific manufacturing process to meet the lighting requirements expected in an automobile.

[0035] FIG. 4D, compared to FIGS. 4A-4C, illustrates another embodiment in which, in addition to a first LED die (not shown) and a second LED die (not shown), a third LED die 42 covered with a third filler 83 is included. The plan view shown in FIG. 4D shows a first filler 60 and multiple second fillers 80, 81, and 82. The arrangement of the first filler 60 and the second fillers 80-82 may be similar to the previous arrangement, except that in FIG. 4D, instead of simply one complete second filler, multiple second fillers may be provided, each covering a respective second LED die. Of course, the colors of the phosphors contained in the multiple second fillers may be the same or different depending on the specific multicolor pattern required. Separation of the second LED die can be achieved by using multiple dams. In particular, according to FIG. 4D, a third emission color may be provided after light transmission through the third filler 83. Similar to the second emitting color, the third emitting color passes over the first filling 60 such that the third emitting color is physically / spatially separated from at least the first emitting color.

[0036] Furthermore, the third emission color also passes over the third fill 80 and / or 82 to be further separated from the respective third fills. Therefore, a waterdrop shape can be adopted for the first fill 60 and / or the second fills 80-82. Multiple dams can be applied between the first fill 60, the second fills 80-82, and / or the third fill 83. Furthermore, for example, undesirable color conversion may be avoided by having the first emission color be red (or amber), the second emission color(s) be white, and the third emission color be blue or cyan. Therefore, further improvement in color separation can be achieved by ensuring that the energy of the first emission color and / or the second emission color(s) is lower than the absorption energy of the third fill 83 (which may optionally contain a third phosphor). Furthermore, when a blue third LED die 42 is used, the third fill 83 can be transparent. In the case of a cyan third die color, a UV-plus phosphor can be used in the third LED die 42 to achieve the cyan color. Thus, providing three-color separation can be achieved by the present invention. Alternatively, any light emitted by a phosphor with a higher energy than the absorbed energy of any other phosphor can be arranged not to pass through the other phosphors, for example, by separating the fill with one or more dams.

[0037] As previously mentioned, the third emission color can be blue. In such or similar embodiments, the third emission color can be the same as the color of the third die. Here, the third filler can be transparent and contain a phosphor to prevent color conversion when the color of the third die passes through the third filler. Therefore, the third filler can ensure that the first emission color and the second emission color are not converted. Thus, the multi-color separation provided by the embodiments described herein not only provides separation of two colors, but also the possibility of avoiding mixing between three different colors. Alternatively, the third filler can contain a third phosphor to convert the color of the third die to a third emission color different from the first emission color and / or the second emission color.

[0038] In embodiments, the color of the third die may be the same as or different from the color of the first die and / or the color of the second die. For example, the color of the first die and the color of the second die may be blue, and the color of the third die may be blue or cyan. If the color of the third die is cyan, the third emission color may be cyan either directly by the color of the die (without conversion by the phosphor material in the third filler being transparent) or by the color of the die converted by the phosphor in the third filler. In embodiments, one or more of the first, second, and third fillers may be silicone.

[0039] FIG. 5 is a diagram of a light source workpiece 100 used to fabricate multiple light sources. In an embodiment, the light source workpiece may be a CoB light source workpiece. In the example shown in FIG. 5, multiple first LED dies 201-208 and 211-214 are disposed on a substrate 1000. FIG. 5 further illustrates that there are three strings of first LED dies: one string including the first LED dies 201-204, another string including the first LED dies 205-208, and a third string including the first LED dies 211-214; the three strings of LED dies may be arranged parallel to one another. Additionally, multiple second LED dies 401-408 may be disposed on the substrate 1000; the first string of second LED dies including the second LED dies 401-404 may be arranged parallel to the second string of second LED dies including the second LED dies 405-408. FIG. 5 further illustrates that the rows of LED dies may also be parallel to one another. The parallel configuration of this embodiment helps simplify the manufacturing process, so that, for example, dicing of separate light sources as well as deposition of fill material can be facilitated with reduced complexity and cost. Thus, as shown in FIG. 5 , multiple light sources 1001-1008 are provided. Here, light sources 1001-1004 may each include a first LED die and a second LED die, and light sources 1005-1008 may each include two of the first LED dies and one second LED die. Furthermore, dams 90 may also be disposed on substrate 1000 to avoid interference between adjacent light sources, e.g., light source 1001 and light source 1005.

[0040] In some embodiments, the workpiece may also include a plurality of third LED dies, which may be disposed on a substrate and covered with a third filler. In this case, each light source may further include at least one-third of the LED dies, thereby providing multicolor illumination without interference between the three colors.

[0041] In embodiments, multiple dams may be placed on the substrate between adjacent light sources so that the polychromatic light emitted by each light source does not interfere with the adjacent light source.

[0042] The use of CoB technology may enable the construction of multiple light sources on a substrate containing multiple LED dies. Therefore, the deposition of the first and second fills may be applied to a batch of light sources, which may significantly improve manufacturing efficiency and reduce costs. In other words, it may no longer be necessary to individually place fills on single LEDs or to individually package LEDs. Therefore, the use of CoB technology may have the advantages of being space-saving, requiring low cost, while still allowing for the efficient production of light sources that exhibit effective color separation of at least two colors.

[0043] FIG. 6 is a flow diagram illustrating an exemplary method for fabricating a light source workpiece. In the example shown in FIG. 6, the method includes providing a substrate (602). A plurality of LED dies may be attached to the substrate (604). As previously described, the plurality of LED dies may be attached such that the rows of LED dies are parallel to one another and the columns of LED dies are similarly parallel to one another. It is within the expertise of one skilled in the art to then arrange the plurality of light sources according to the specific requirements of the lighting being manufactured. For example, according to FIG. 5, the LED dies 201-204 may be evenly arranged in a single row, which may be to the right of the plurality of second LED dies 401-404, such that four light sources 1001-1004 of the same configuration may be formed. Another plurality of light sources 1005-1008 may be formed in a similar manner, with the first LED dies 205-208 arranged to the right thereof and the first LED dies 211-214 arranged to the left thereof, while the plurality of second LED dies 405-408 may be arranged in the middle row.

[0044] Electrical connections within the plurality of LED dies may be configured (606). A fill material may be deposited on each of the plurality of LED dies on the substrate. In particular, a first fill material may be deposited on the first plurality of LED dies (608). In an embodiment, the first plurality of LED dies may be, for example, the plurality of first LED dies 201-204, 205-208, and 211-214 shown in FIG. 5. Therefore, it is clear that the configuration shown in FIG. 5 may facilitate the deposition of the first fill material. Similarly, a second fill material may be deposited on the second plurality of LED dies (610).

[0045] In an embodiment, the second plurality of LED dies may be, for example, the plurality of second LED dies 401-404 and 405-408 shown in FIG. 5. Also, if a plurality of third LED dies are present on the substrate for forming three-color light, a third filler (not shown in FIG. 6) may also be deposited in a manner similar to that described above. If necessary, electrical connections may be arranged between all of the plurality of LED dies and the substrate.

[0046] In embodiments, the electrical connections (606) within the multiple LED dies may be configured simultaneously with depositing the fill (608 / 610) or before or after depositing the fill (608 / 610).

[0047] In practice, each fill may need to be cured. More specifically, each cure may be applied to the first fill, the second fill, and the third fill. It is within the expertise of those skilled in the art to determine whether each, some, or all of the fills need to be cured. Furthermore, curing materials and related techniques are known to those skilled in the art, and therefore, the embodiments described herein are not limited to any particular material or technique. For example, in some embodiments, curing may be performed using an oven or by ultraviolet (UV) radiation.

[0048] Furthermore, in some embodiments, multiple dams 90 can be deposited between adjacent light sources. Taking FIG. 5 as an example, assuming that light sources 1001-1004 all show the same sunny side up red-white light, while light sources 1005-1008 all show inverted sunny side up red-white light, dams 90 can be deposited between light sources 1001-1004 and light sources 1005-1008 (see FIG. 4B for a similar diagram). This also avoids interference between adjacent light sources in a manner that reduces complexity and cost.

[0049] In summary, multiple LED dies can be arranged on a light source workpiece to form multiple light sources. Each light source can include at least one first LED die and at least one second LED die, so that at least two-color patterns with effective color separation can be achieved. Each light source can also include at least one-third of the LED dies, so that three-color illumination can be achieved. Therefore, multiple multicolor light sources can be easily manufactured, significantly reducing the number, complexity, and cost of the manufacturing process. Meanwhile, each light source can exhibit clearly defined color separation between different emission colors, and interference between adjacent light sources during the manufacturing process can be avoided without increasing the manufacturing complexity and cost. Therefore, a highly efficient manufacturing process for manufacturing multiple versatile multicolor light sources can be provided, and multiple multicolor light sources can be easily manufactured, significantly reducing the number, complexity, and cost of the manufacturing process. Meanwhile, each light source can exhibit clearly defined color separation between different emission colors, and interference between adjacent light sources during the manufacturing process can be avoided without increasing the manufacturing complexity and cost.

[0050] 7 is a diagram of an example vehicle headlamp system 700 that may incorporate one or more of the embodiments and examples described herein. The example vehicle headlamp system 700 shown in FIG. 7 includes a power line 702, a data bus 704, an input filter and protection module 706, a bus transceiver 708, a sensor module 710, an LED direct current-to-direct current (DC / DC) module 712, a logic low-dropout (LDO) module 714, a microcontroller 716, and an active headlamp 718. In an embodiment, the active headlamp 718 may be a signal lamp, which may be configured to implement multiple lighting functions simultaneously or at different times, potentially in combination with other components of the vehicle headlamp system 700 and / or automotive components external to the vehicle headlamp system 700, and may be used in some embodiments to ensure that various safety regulations can be met.

[0051] The power line 702 may have an input for receiving power from the vehicle, and the data bus 704 may have an input / output through which data may be exchanged between the vehicle and the vehicle headlamp system 700. For example, the vehicle headlamp system 700 may receive instructions from elsewhere in the vehicle, such as instructions to turn on turn signaling or turn on headlamps, and may transmit feedback to other locations in the vehicle as needed. In an embodiment, the active headlamp 718 may include one or more multi-color light sources, for example, as described above with respect to FIGS. 1-4. The corresponding instructions may include instructions to turn on one of multiple functions implemented by the multi-color light source of the signal lamp, such as, for example, an instruction to turn on daytime running lamps (DRLs), a turn signal instruction, or a backup instruction. In such an embodiment, at least the microcontroller 716, the LED DC / DC module 712, and the sensor module 710 may be activated to control and drive specific emitters within the multi-color light source, such that one multi-color light source may be used to implement one of multiple functions. In embodiments, a signal lamp, multi-color light source, or other vehicle light source may be configured to implement two or more functions, such as a DRL and a turn light, a position lamp and a turn light, or a DRL, a turn light, and a position lamp, etc. The instructions may direct modules within vehicle lighting system 700 to implement one of the two or more functions that the lamp and / or light source is configured to implement.

[0052] The sensor module 710 may be communicatively coupled to the data bus 704 and may provide additional data to the vehicle headlamp system 700 or elsewhere in the vehicle, for example, regarding environmental conditions (e.g., time of day, rain, fog, or ambient light levels), vehicle status (e.g., parked, moving, speed, or direction of movement), and the presence / location of other objects (e.g., vehicles or pedestrians). A headlamp controller separate from the vehicle controller communicatively coupled to the vehicle data bus may also be included in the vehicle headlamp system 700. In FIG. 7, the headlamp controller may be a microcontroller, such as microcontroller (μc) 716. The microcontroller 716 may be communicatively coupled to the data bus 704.

[0053] An input filter and protection module 706 may be electrically coupled to the power line 702 and may support various filters to, for example, reduce conducted emissions and provide power immunity. Additionally, the input filter and protection module 706 may provide electrostatic discharge (ESD) protection, load dump protection, alternator field decay protection, and / or reverse polarity protection.

[0054] An LED DC / DC module 712 may be coupled between the input filter and protection module 706 and the active headlamp 718 to receive the filtered power and provide a drive current that powers the LEDs in the LED array of the active headlamp 718. The LED DC / DC module 712 may have an input voltage of between 7 and 18 volts, with a nominal voltage of approximately 13.2 volts, and an output voltage that is slightly higher (e.g., 0.3 volts) than the maximum voltage of the LED array (e.g., determined by coefficients or local calibration and adjustments for operating conditions due to load, temperature, or other factors).

[0055] A logic LDO module 714 may be coupled to the input filter and protection module 706 to receive filtered power. The logic LDO module 714 may also be coupled to the microcontroller 716 and the active headlamp 718 to power electronics within the microcontroller 716 and / or the active headlamp 718, such as CMOS logic.

[0056] The bus transceiver 708 may have, for example, a universal asynchronous receiver transmitter (UART) or a serial peripheral interface (SPI) interface and may be coupled to a microcontroller 716. The microcontroller 716 may convert vehicle inputs based on or include data from the sensor module 710. The converted vehicle inputs may include a video signal that can be transferred to an image buffer within the active headlamp 718. Additionally, the microcontroller 716 may load a default image frame and test for open / short pixels during startup. In embodiments, the SPI interface may load a CMOS image buffer. The image frame may be a full frame, a differential frame, or a partial frame. Other functions of the microcontroller 716 may include a control interface monitoring CMOS status, including die temperature, as well as logic LDO outputs. In embodiments, the LED DC / DC output may be dynamically controlled to minimize headroom. In addition to providing image frame data, other headlamp functions may also be controlled, such as complementary use in combination with side marker or turn signal lights and / or activation of daytime running lights.

[0057] Figure 8 is a diagram of another example vehicle headlamp system 800. The example vehicle headlamp system 800 shown in Figure 8 includes an application platform 802, two LED lighting systems 806 and 808, and secondary optics 810 and 812.

[0058] LED lighting system 808 may emit light beam 814 (shown between arrows 814a and 814b in FIG. 8 ). LED lighting system 806 may emit light beam 816 (shown between arrows 816a and 816b in FIG. 8 ). In the embodiment shown in FIG. 8 , secondary optics 810 is adjacent to LED lighting system 808, and light emitted from LED lighting system 808 passes through secondary optics 810. Similarly, secondary optics 812 is adjacent to LED lighting system 806, and light emitted from LED lighting system 806 passes through secondary optics 812. In an alternative embodiment, secondary optics 810 / 812 are not provided in the vehicle headlamp system.

[0059] If included, the secondary optics 810 / 812 may be or include one or more light guides or reflectors, which allow the multicolored pattern emitted by the light source to be reflected, thereby allowing drivers and pedestrians to better recognize the vehicle even in low light levels and / or providing flexible, designated lighting with multiple colors. One or more light guides may be edge-lit or may have internal openings that define the interior edges of the light guides. LED lighting systems 808 and 806 may be inserted into the internal openings of one or more light guides to inject light into the interior edges (internal-opening light guides) or exterior edges (edge-lit light guides) of the one or more light guides. In embodiments, one or more light guides may shape the light emitted by the LED lighting systems 808 and 806 in a desired manner, such as, for example, a gradient, a chamfered distribution, a narrow distribution, a wide distribution, or an angular distribution.

[0060] Application platform 802 may provide power and / or data to LED lighting systems 806 and / or 808 via lines 804, which may include one or more or portions of power lines 702 and data bus 704 of FIG. 7. One or more sensors (such as those in vehicle headlamp system 800 or other additional sensors) may be internal or external to the housing of application platform 802. Alternatively, or additionally, as shown in example vehicle headlamp system 700 of FIG. 7, each LED lighting system 808 and 806 may include its own sensor module, connection and control module, power supply module, and / or LED array.

[0061] In an embodiment, vehicle headlamp system 800 may represent an automobile with a steerable light beam in which LEDs can be selectively activated to provide steerable light. For example, an array of LEDs or emitters may be used to define or project a shape or pattern or to illuminate only selected sections of a road. In one exemplary embodiment, infrared cameras or detector pixels in LED lighting systems 806 and 808 may be sensors (e.g., similar to the sensors in sensor module 710 of FIG. 7) that identify portions of a scene (e.g., a road or crosswalk) that require illumination.

[0062] Although the embodiments have been described in detail, those skilled in the art will appreciate, upon consideration of this description, that modifications may be made to the embodiments described herein without departing from the spirit of the inventive concept. Accordingly, it is not intended that the scope of the invention be limited to the specific embodiments illustrated and described.

Claims

1. a substrate; a first light emitting diode (LED) die having a bottom surface on the substrate and configured to emit light having a color of the first die when turned on; a first hemispherical-shaped filler completely surrounding all surfaces of the first LED die except the bottom surface, the first hemispherical-shaped filler including a first phosphor such that when the first LED die is turned on, the light having the color of the first die is converted to light having a first emission color; a second LED die spaced apart from the first LED die, having a bottom surface on the substrate, and configured to emit light having a color of the second die when the second LED die is turned on; a second fill completely surrounding all surfaces of the second LED die except the bottom surface and extending into the first hemispherical fill, the second fill including a second phosphor such that when the second LED die is turned on, the light having the color of the second die is converted to light having a second emitted color; when the first and second LED dies are turned on, the light having the first emission color has an illumination energy lower than an absorption energy of the second phosphor, and the light having the second emission color passes over the first hemispherical-shaped fill and is not converted by the first hemispherical-shaped fill. light source.

2. the color of the first die is blue or the color of the second die is blue; The light source of claim 1 .

3. the first luminous color is either red or amber, and the second luminous color is white; The light source of claim 2 .

4. the first emitting color is one of white, red, or amber, and the second emitting color is cyan; The light source of claim 2 .

5. a third LED die configured to emit a third die color; a third fill over the third LED die such that a third emission color is provided. The light source of claim 1 .

6. at least one of the third luminous color passing over the first hemispherical shaped fill or the third luminous color passing over the second fill such that the third luminous color is at least one of separated from the first luminous color or separated from the second luminous color; 6. The light source of claim 5.

7. the first luminous color is one of red or amber, the second luminous color is white, and the third luminous color is one of blue or cyan; 6. The light source of claim 5.

8. the first hemispherical filler, the second filler, and the third filler further comprise silicone; 6. The light source of claim 5.

9. A polychromatic light source comprising: a substrate; a plurality of first light emitting diode (LED) dies having bottom surfaces on the substrate and configured to emit light having a first die color when turned on; a first hemispherical-shaped filler completely surrounding all surfaces of the plurality of first LED dies except for the bottom surface, the first hemispherical-shaped filler including a first phosphor such that when at least one of the plurality of first LED dies is turned on, the light having a color of the first die is converted to light having a first emission color; a plurality of second LED dies spaced apart from the plurality of first LED dies, the second LED dies having bottom surfaces on the substrate and configured to emit a second die color; a second fill completely surrounding all surfaces of the plurality of first LED dies except for the bottom surface and extending into the first hemispherical fill, the second fill including a second phosphor such that when the plurality of second LED dies are turned on, the light having the color of the second dies is converted to light having a second emitted color; when the first and second LED dies are turned on, the light having the first emission color has an illumination energy lower than an absorption energy of the second phosphor, and the light having the second emission color passes over the first hemispherical-shaped fill and is not converted by the first hemispherical-shaped fill. a polychromatic light source; and a controller that receives a command to activate one of a plurality of lighting functions of the multicolor light source, and controls the multicolor light source in response to the command to turn on at least two of the plurality of first LED dies or at least two of the plurality of second LED dies in a predetermined pattern. Multifunction signal lamp.

10. the plurality of lighting functions include at least two of daytime running lamps, turning lights, and position lamps; 10. The multi-function signal lamp according to claim 9.

11. A light source workpiece comprising a plurality of light sources, the light source workpiece comprising: a substrate; a plurality of first LED dies having bottom surfaces on the substrate, configured to emit light having a first die color when at least one of the plurality of first LED dies is turned on, and covered by a first hemispherical-shaped filler on all surfaces except the bottom surface, the first hemispherical-shaped filler including a first phosphor such that when at least one of the plurality of first LED dies is turned on, the light having the first die color is converted to light having a first emission color; a plurality of second LED dies having bottom surfaces on the substrate, configured to emit light having a second die color when at least one of the plurality of second LED dies is turned on, and covered by a second fill, the second fill extending into the first hemispherical shaped fill, and including a second phosphor such that when the plurality of second LED dies are turned on, the light having the second die color is converted to light having a second emission color; the light having the first emission color has an illumination energy lower than an absorption energy of the second phosphor, and the light having the second emission color passes over the first hemispherical filling and is not converted by the first hemispherical filling; each light source of the light source workpiece includes at least one of the plurality of first LED dies and at least one of the plurality of second LED dies; Light source workpiece.

12. a plurality of third LED dies disposed on the substrate and covered by a third filler, each light source of the light source workpiece further including at least one of the plurality of third LED dies; The light source workpiece of claim 11 .

13. At least one of the plurality of first LED dies, the plurality of second LED dies, or the plurality of third LED dies is arranged in parallel. The light source workpiece of claim 12 .

14. and a plurality of dams disposed on the substrate between adjacent light sources so that the polychromatic illumination emitted by each light source does not interfere with the adjacent light source. The light source workpiece of claim 11 .

15. 1. A method of manufacturing a light source workpiece, comprising: providing a substrate; mounting a plurality of LED dies with bottom surfaces of the plurality of LED dies on the substrate, the plurality of LED dies being divided into at least a plurality of first LED dies and a plurality of second LED dies, the plurality of first LED dies being configured to emit light having a color of the first dies when turned on, and the plurality of second LED dies being configured to emit light having a color of the second dies when turned on; forming electrical connections within the plurality of LED dies; depositing a first hemispherical-shaped fill over the plurality of first LED dies such that the first hemispherical-shaped fill completely surrounds all surfaces of the plurality of first LED dies except for the bottom surfaces, the first hemispherical-shaped fill including a first phosphor such that the light having a color of the first die is converted to a first emission color when at least one of the plurality of first LED dies is turned on; depositing a second fill such that the second fill completely surrounds all surfaces of the plurality of second LED dies except for the bottom surface and extends into the first hemispherical fill, the second fill including a second phosphor such that when the plurality of second LED dies are turned on, the light having a color of the second dies is converted to light having a second emission color; the light having the first emission color has an illumination energy lower than an absorption energy of the second phosphor, and the light having the second emission color passes over the first hemispherical filling and is not converted by the first hemispherical filling. method.

16. The plurality of LED dies further includes a plurality of third LED dies, and the method further comprises: depositing a third fill over the plurality of third LED dies.

16. The method of claim 15.

17. further comprising curing the first hemispherical filler and the second filler.

16. The method of claim 15.

18. Mounting the plurality of LED dies on the substrate further includes arranging the plurality of LED dies to form a plurality of light sources, each of the plurality of light sources including at least one first LED die and at least one second LED die, and the method further includes: depositing a plurality of dams between adjacent light sources such that the polychromatic illumination emitted by each light source does not interfere with said adjacent light sources; 16. The method of claim 15.

19. at least one of the plurality of first LED dies, the plurality of second LED dies, or the plurality of third LED dies is arranged in parallel; 17. The method of claim 16.

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