WO2013118076A1

WO2013118076A1 - Low cost encapsulated light-emitting device

Info

Publication number: WO2013118076A1
Application number: PCT/IB2013/051020
Authority: WO
Inventors: Serge Joel Armand BIERHUIZEN
Original assignee: Koninklijke Philips N.V.
Priority date: 2012-02-10
Filing date: 2013-02-07
Publication date: 2013-08-15

Abstract

Light-emitting elements are situated on a film and then surrounded by reflective cups placed or formed on the film. The reflective cups are filled with encapsulants, affixing the light-emitting elements to the reflective cups. The film may then be removed, exposing the bottom contacts of the light-emitting elements. The encapsulated light-emitting elements within the reflective cups are singulated to provide individual light-emitting devices. The encapsulants may be molded or otherwise shaped to provide a desired optical function.

Description

Low cost encapsulated light-emitting device

Cross refrence to related application

This application is related to U.S. Patent Application No. 61/433,306, attorney docket no. 2011P00012US, entitled "Low Cost Encapsulated Light Emitting Device," filed on January 17, 201 1, which is commonly assigned and incorporated herein by reference.

Field of the invention

The present disclosure relates to the field of light-emitting devices, and in particular to a light-emitting device with one or more light-emitting elements encapsulated in a reflective cup.

Background

Solid state light-emitting devices (LEDs) are being used in an ever increasing variety of applications, and with increased market volume, the cost per device becomes increasingly more important. In like manner, with increased market competition, the relative performance of competing products also becomes increasingly important.

To improve light output efficiency, light-emitting devices often include reflective elements that serve to reflect stray light in the intended direction. Figs. 1A and IB illustrate example light-emitting devices with reflective elements.

In Fig. 1A, the light-emitting element 110 is placed in a reflective cup 120, which often also serves as a contact for coupling the element to an external power source. The element 110 will typically include a sandwich configuration of light emitting material between two electrodes, a lower electrode being connected to the contact 130A via the reflective cup 120, and an upper electrode being wire bonded to the other contact 130B. The light-emitting element 110, the reflective cup 120, and the electrodes 130A, 130B are subsequently encapsulated in an encapsulation material 170, such as an epoxy that is molded in the shape of a lens.

In Fig. IB, the light-emitting element 110 is mounted on a substrate 160, and the area surrounding the element 110 is coated with a reflective layer 125, such as a white dielectric. In this example, circuit traces 140 (shown in phantom) are coupled to the element 110, and through-hole vias 145A, 145B (shown in phantom) couple the traces 140 to electrodes 135A, 135B at the lower surface of the substrate 160. In this manner, the light-emitting device can be mounted directly upon a printed circuit board or other mounting surface.

The example device of Fig. 1A advantageously includes a reflective cup that is shaped to direct the light output in a concentrated beam, but the manufacturing process requires support of the cup 120 while the light-emitting element 110 is mounted and wire bonded, and subsequently encapsulated. The manufacture of example device of Fig. IB, on the other hand, may be simpler than the manufacture of the device of Fig. 1 A, but the encapsulant 150 generally needs to be substantially large and curved for high extraction efficiency and the reflective surface 125 does not direct the light as well as the reflective cup 120.

Summary

It would be advantageous to provide a simpler means of manufacturing a light- emitting device with a reflective structure that enhances the light output and directs the light forward.

In one or more embodiments of the present disclosure, advantages may be realized by a manufacturing process that includes mounting light-emitting elements on a film and disposing reflective cups around the light-emitting elements on the film. The reflective cups are filled with encapsulants, affixing the light-emitting elements to the reflective cups. The film may then be removed, exposing bottom contacts on the light-emitting elements. The encapsulated light-emitting elements within the reflective cups are then singulated to provide the individual light-emitting devices. The encapsulants may be molded or otherwise shaped to provide a desired optical function.

In some embodiments of the present disclosure, the light-emitting elements are arranged in groups that each includes light-emitting elements of different colors. A reflective cup is disposed around each group. In some embodiements wavelength converting elements are disposed over the encapsulants so each individual light-emitting device outputs white light.

Brief description of the drawings

In the drawings:

Figs. 1A and IB illustrate example prior art light-emitting devices;

Figs. 2A, 2B, 2C, and 2D illustrate an example manufacture of light-emitting devices having integral reflective structures;

Figs. 3 A, 3B, and 3C illustrate example alternative features of light-emitting devices having integral reflective structures;

. 4 illustrates an example flow diagram for providing light-emitting devices having integral reflective structures;

Figs. 5A and 5B illustrate example structures for light-emitting devices with multiple light-emitting elements; Fig. 6 illustrates an example flow diagram for providing light-emitting devices having integral reflective structures;

Figs. 7, 8, 9, 10, 11, 12, 13, 14, 15, and 16 illustrate an example manufacture of light-emitting devices; and

Fig. 17 illustrates an example light-emitting device attached to a waveguide, all arranged in accordance with embodiments of the invention.

Use of the same reference numbers in different figures indicates similar or identical elements.

Detailed description

In the following description, for purposes of explanation rather than limitation, specific details are set forth such as the particular architecture, interfaces, techniques, etc., in order to provide a thorough understanding of the concepts of the invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments, which depart from these specific details. In like manner, the text of this description is directed to the example embodiments as illustrated in the Figures, and is not intended to limit the claimed invention beyond the limits expressly included in the claims. For purposes of simplicity and clarity, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

Figs. 2 A to 2D illustrate an example steps to manufacture light-emitting devices with an integral reflective structure.

Fig. 2A illustrates the placement of multiple light-emitting elements 110 on a film 210. In a preferred embodiment, the light-emitting elements 110 are structured to each have contacts 23 OA and 23 OB on their lower surface, to facilitate coupling to an external power source upon removal of the film 210. The elements 110 may be placed on the film 210 using a conventional pick and place process. Alternatively, a block of elements 110 may be placed on an elastic film that is subsequently stretched to separate the elements 110 to situate the elements 110 appropriately. The term "film" is used herein in a general sense to distinguish it from a "substrate" in that the film is not necessarily required to provide structural support per se. A flexible film is particularly well suited for this process, due to its lower cost compared to a rigid film, but a rigid film may be well suited for repeated use of the film. Instead of film 210, light-emitting elements 110 may be mounted on individual leadframes. The leadframes may be placed on film 210 for subsequent processing.

At Fig. 2B, reflective structures 250 (e.g., reflective cups) are situated on the film 210, surrounding each light-emitting element 110. A top view of an example frame of light- emitting devices is illustrated in Fig. 2C. In this example, the structure 250 includes a set of planes or sidewalls that are angled with respect to the corresponding light-emitting element 110. Alternatively the sidewalls may be oriented vertically or they may be curved in any suitable manner. The sidewalls serve to efficiently reflect, scatter, or otherwise manipulate the light to extract additional light forward from the light-emitting element 110.

The structure 250 may be added to the film 210 in a number of ways. A preformed frame of reflective material, with openings for the light-emitting elements 110, may simply be placed upon the film 210. Alternatively the structure 250 may be molded directly upon the film 210 or injection molded with leadframes using a mold that is patterned to avoid placing the reflective material at the locations of the elements 110. A slurry of white dielectric material, for example, may be injection molded upon the film 210 or the leadframes using techniques common in the art of semiconductor fabrication. Alternatively, a reflective coating may be applied atop a shaped structure to form the reflective structure 250.

Also alternatively, instead of providing or forming a frame that includes multiple reflective structures, individual reflective structures 250 may be placed on the film 210 using a conventional pick and place process. Other techniques for placing or forming reflective structures that surround the light-emitting elements 110 on the film will be evident to one of ordinary skill in the art in view of this disclosure.

In some embodiments the reflective structures 250 are placed on the film 210 prior to the placement of light-emitting elements 110 while in other embodiments the light-emitting elements 110 are placed on the film 210 prior to the placement of the reflective structures 250.

After situating the light-emitting elements 110 and reflective structures 250 on the film 210, an encapsulant 270 is applied, filling the reflective structures 250 and affixing the light-emitting elements 110 to these reflective structures 250, as illustrated in FIG. 2D. Once the encapsulant affixes the light-emitting elements 110 to the reflective structures 250, the film 210 may be removed, exposing the contacts 23 OA and 230B for coupling to an external power source.

To further facilitate coupling to the contacts 230A and 230B, a lower layer of the reflective structure 250 may comprise an easily removable material, so that upon removal, the contacts 230A and 230B will extend slightly below the remaining surface of the structure 250. Such a sacrificial removable layer applied to the reflective structure and/or the bottom contacts of the LED chip may also be used to remove any excess material from the film 210 after removal of the light-emitting elements 110 and the reflective structures 250.

As illustrated in Fig. 2D, the upper surface of the encapsulant may be fiat. In many applications, the light-emitting device is coupled to a rectilinear waveguide or other structure having a relatively flat light input surface. For example, edge lit waveguides are increasingly being used to provide backlighting to displays, and surface lit waveguides are increasingly being used to provide high intensity edge-emitting lamps. By providing a flat surface on the LED that corresponds to a flat surface on a transmitting element, the light coupling efficiency into the waveguide is increased. By providing a reflective structure about the light-emitting element, the size and shape of the output surface of light-emitting device may be customized to conform to the transmitting element, substantially independent of the size and shape of the light-emitting element.

One of ordinary skill in the art will recognize that any of a variety of shapes may be used to form the reflective structures. Fig. 3A, for example, illustrates a reflective surface 350 that is curved, as compared to the planar surface 250 of Fig. 2A. In like manner, Fig. 3B illustrates a structure 360 that is circular, viewed from the top.

The encapsulant may also be formed in a variety of shapes to achieve a desired optical effect. For example, the encapsulant may be domed, similar to the domed shape of the encapsulant 170 in Fig. 1 that serves to spread the light output across a wide output angle. Fig. 3C, on the other hand, illustrates a more complex shape 370 that serves to extract light in combination with the reflector and provides a directed light output.

Fig. 4 illustrates an example flow diagram to facilitate the manufacture of a light- emitting device with integral reflective structure. At 410, the light-emitting elements are placed on a film, and at 420, reflective structures, with apertures for the light-emitting elements are placed or formed on the film. As described above, the light-emitting elements may also be mounted on leadframes, which may be placed on the film.

One of ordinary skill in the art will recognize that the order of this placement and/or formation may be reversed, in that the structures may be provided or formed on the film, and light-emitting elements may be placed within apertures provided for receiving the light- emitting elements. In like manner, the placement of the structures on the film may be effected by applying the film to a lower surface of a frame of reflective structures. In an embodiment wherein a shape of the lower end of the aperture corresponds to the shape of the light-emitting element, the aperture can provide the reference datum for placing each light-emitting element, thereby facilitating an accurate placement of each light-emitting element in a conventional pick-and-place process.

With the reflective structures and light-emitting elements situated at their desired relative locations on the film, an encapsulant is placed within the reflective structures, at 430. Generally, the encapsulant will fill the reflective structures, but the desired light output characteristics may call for a partial fill of the reflective structures. At 440, the encapsulant may be molded to a desired shape, again dependent upon the desired light output

characteristics. Optionally, other elements may be added to the structure, before, during, or after encapsulation. For example, a wavelength converter, such as a phosphor in a binder, may be added as a discrete element that is situated atop the light-emitting element or atop the encapsulant, or layered/sandwiched by the encapsulant, or the phosphor may be embedded within the encapsulant. With the light-emitting elements affixed to the reflective structures, the film may be removed, at 450, typically to expose the contacts on the light-emitting elements or the leadframes. Alternatively, the film may include conductive traces that serve to provide connections to the light-emitting elements, and in such an embodiment, the film would not be removed. It may then be affixed to a metal strip that serves as a heat sink. Light-emitting elements can be soldered, attached using silver paste to the traces on the film, or electrically connected using microsprings or microbumps.

At 460, the plurality of reflective structures and light-emitting elements are separated, or "singulated," into individual light-emitting devices. This singulation will depend upon the nature of the reflective structures. If, at 420, the structures are placed individually upon the film, or formed on the film as individual structures, the removal of the film at 450 will effect this singulation. Alternatively, if a frame of structures is formed or placed on the film, this singulation is effected by appropriately slicing/dicing the frame. One of ordinary skill in the art will recognize that this slicing/dicing of the frame can be facilitated by forming separation features on the frame, such as score lines or grooves.

Of particular note, if the material used as the reflective structure is suitable to exposure to the intended operational environment for the singulated light-emitting devices, there are no further processes required to further "package" the device. Even though the example embodiments illustrate a frame of structures that is designed to minimize the space between the reflective structures, one of ordinary skill in the art will recognize that the shape of the structures may be made to conform to a desired overall package shape of the singulated light-emitting devices. That is, the size and shape of the cavity of each reflective structure in which the light-emitting element may be based on the desired light output characteristics, while the exterior size and shape of each reflective surface may be based on the desired package characteristics.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments.

For example, although the example embodiments have included a one-to-one correspondence between light-emitting elements and reflective structures, and symmetric reflective structures, one of ordinary skill in the art will recognize that these are not limiting features. Fig. 5A illustrates, for example, a "light bar" embodiment wherein a rectangular reflective structure 530 encloses a plurality of light-emitting elements 110. In like manner, Fig. 5B illustrates a circular reflective structure 535 that encloses a plurality of light-emitting elements 110. Optionally, the bottom side of the reflective material may be patterned for ease of solderability, with features that facilitate self-alignment.

In either of the examples of Fig. 5 A or 5B, the plurality of light-emitting elements 110 may be situated on a common substrate with contacts that are commonly coupled to multiple elements 110. Alternatively, each element 110 may be situated directly on the film to facilitate independent coupling to an external power source. Other methods of accommodating multiple light-emitting elements within a reflective structure will be evident to one of ordinary skill in the art in view of this disclosure.

Fig. 6 illustrates an example flow diagram of a method 600 to facilitate the manufacture of a light-emitting device with integral reflective structures in one or more embodiments of the present disclosure. Method 600 may include one or more operations, functions, or actions as illustrated by one or more blocks. Although the blocks are illustrated in a sequential order, these blocks may also be performed in parallel, and/or in a different order than those described herein. Also, the various blocks may be combined into fewer blocks, divided into additional blocks, and/or eliminated based upon the desired

implementation. Method 600 is explained with the help of Figs. 7 to 16 showing progression in the construction of devices by through method 600.

Method 600 may begin in a block 602. At the block 602 as shown in Figs. 7 and 8, groups 702A-H of light-emitting elements are placed on a film 704. As described above, the light-emitting elements may also be mounted on leadframes (not shown), which may be placed on the film 704. The light-emitting elements may be a combination of two or more types of indium gallium nitride (InGaN) light-emitting diodes that emit blue light, InGaN light-emitting diodes that emit green light, aluminum indium gallium phosphide (AlInGaP) light-emitting diodes that emit red light, and phosphor-based InGaN light-emitting diodes that emit magenta light (blue light and red phosphor). The light-emitting diodes may be fabricated on sapphire substrates that are patterned for light extraction so the patterned sapphire substrates are not removed but remains with the elements at the end of the light- emitting element fabrication process. In one embodiment, each group 702 (e.g., group 702A) includes one or more light-emitting elements 706A, 706B that emit blue light, and one or more light-emitting elements 708A, 708B that emit green, red, or magenta light. The block 602 may be followed by an optional block 604. Each group 702 may have the same configuration of light-emitting elements or distinctly different configurations of light- emitting elements. At the optional block 604 as shown in Fig. 9, a wavelength converter 902 (shown in phantom) that generates light of a third color may be disposed atop the light-emitting elements 706A, 706B and 708A, 708B. The wavelength converter 902 may be one or more types of phosphor in a binder or a ceramic phosphor plate that emits red or green light. The optional block 604 may be followed by an optional block 606. In the optional block 606, the wavelength converter 902 may be molded to form non- planar emitting surfaces depending on the desired light output characteristics. The optional block 606 may be followed by a block 608. Alternatively the optional blocks 604 and 606 may precede the block 602, which may then be followed by the block 608.

In the block 608 as shown in Figs. 10 and 11, the reflective cups 1002A-H are placed or formed on the film 704. As described above, the reflective cups 1002A-H may be individually placed or formed, or collectively placed or formed. Each reflective cup 1002 defines a first aperture on the surface of the reflective cup that is placed on the film 704 (e.g., a bottom aperture on a bottom surface). The first aperture preferably fits closely around a corresponding group 702 of light-emitting elements on the film 704. Each reflective cup 1002 further includes reflective sidewalls that extend from the first aperture to a second aperture on the outward facing surface of the reflective cup (e.g., an exit window on a top surface) opposite the surface placed on the film 704.

Although the reflective cups 1002A-H are shown with four angled sidewalls, the reflective cups 1002A-H may be formed with other reflective surfaces depending on the desired light output characteristics. Furthermore, the order of the placement and/or formation of the light-emitting elements 706A, 706B, 708 A, 708B and the reflective cups 1002A-H may be reversed, in that the reflective cups 1002A-H may be provided or formed on the film 704, and the light-emitting elements 706A, 706B, 708A, 708B may be placed within the bottom apertures or soldered on leads provided for receiving the light-emitting elements 706A, 706B, 708A, 708B.

The block 608 may be followed by a block 610.

In the block 610 as illustrated in Fig. 12, an encapsulant 1202 is placed within the reflective cups 1002A-H (only the reflective cups 1002A-D are visible). Generally, the encapsulant 1202 fills the reflective cups 1002A-H, but the desired light output

characteristics may call for a partial fill of the reflective cups 1002A-H as illustrated in Fig. 13 (only the reflective cups 1002A-D are visible), or an overfill of the reflective cups 1002. The block 610 may be followed by a block 612.

In the block 612 as shown in Fig. 12, the encapsulant 1202 may be molded to form non-planar emitting surfaces 1204A-H (only the emitting surfaces 1204A-D are visible in phantom), over corresponding groups 702A-H of light-emitting elements (only the groups 702A-D are visible), depending on the desired light output characteristics. The block 612 may be followed by a block 614. In the block 614 as shown in Fig. 14, a wavelength converter 1402 is disposed atop the encapsulant 1202. The wavelength converter 1402 may be one or more types of phosphor in a binder or a ceramic phosphor plate that emits red or green light. The colors emitted by the light-emitting elements 706, 708 and the wavelength converter 1402 combine to generate white light. As discussed above, the encapsulant 1202 may partially fill the reflective cups

1002A-H. Fig. 15 illustrates the wavelength converter 1402 disposed over the encapsulant 1202 that partially fills the reflective cups 1002A-H (only the reflective cups 1002A-D are visible). The wavelength converter 1402 conforms to the contour of the encapsulant 1202 over the reflective cups 1002A-H. This leaves gaps 1502 between the wavelength converter 1402 and the second apertures (the exit windows) of the reflective cups 1002A-H. As Fig. 17 shows, a gap 1502 allows a light-emitting device 1702 singulated from the structure in Fig. 15 to have good coupling efficiency into a waveguide 1704 with a flat light input surface 1706. Specifically, the light refracts towards normal when it enters the waveguide 1704 so the light stays within waveguide. The block 614 may be followed by an optional block 616.

In the optional block 616 as illustrated in Fig. 14, the wavelength converter 1402 may be molded to form non-planar emitting surfaces 1404A-H (only the non-planar emitting surfaces 1404A-D are visible in phantom), over corresponding groups 702A-H of light- emitting elements, depending on the desired light output characteristics. The optional block 616 may be followed by a block 618.

In the block 618, the film 704 may be removed, typically to expose the bottom contacts on the light-emitting elements 706 and 708 or the leadframes. Alternatively, the film may include conductive traces that serve to provide connections to the light-emitting elements 706, 708, and in such an embodiment, the film would not be removed. The block 618 may be followed by a block 620.

In the block 620 as shown in Fig. 16, the reflective cups 1002A-H and the groups 702A-H of light-emitting elements are singulated into individual light-emitting devices 1602A-H. As described above, this singulation will depend upon the nature of the reflective structures. If the reflective cups 1002A-H are placed individually upon the film 704, or formed on the film 704 as individual structures, the removal of the film 704 at the block 618 will effect this singulation. Alternatively, if a frame of reflective cups 1002A-H is formed or placed on the film 704, this singulation is effected by appropriately slicing/dicing the frame along streets 1604 (shown in phantom). Some embodiments of the light-emitting device 1702 may generate white light without the use of green-emitting phosphor. Green-emitting phosphor is not preferred for some applications such as LCD backlighting as it tends to leak light into the red range and therefore degrades the color of the LCD display. Instead, these embodiments of the light- emitting device 1702 use blue and green-emitting InGaN light-emitting diodes 706, 708 and red-emitting phosphor in the wavelength converter 1402 to generate white light.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. For example, although the reflective structures in the example embodiments include a larger light output area than the light input area, one of ordinary skill in the art will recognize that the size and shape of the reflective structures will generally depend upon the desired light output characteristics from the particular light- emitting elements, and may take any of a variety of forms.

In interpreting these claims, it should be understood that: a) the word "comprising" does not exclude the presence of other elements or acts than those listed in a given claim; b) the word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements; c) any reference signs in the claims do not limit their scope; d) several "means" may be represented by the same item or hardware or software implemented structure or function; e) each of the disclosed elements may be comprised of hardware portions (e.g., including discrete and integrated electronic circuitry), software portions (e.g., computer programming), and any combination thereof; f) hardware portions may include a processor, and software portions may be stored on a non-transient computer-readable medium, and may be configured to cause the processor to perform some or all of the functions of one or more of the disclosed elements; g) hardware portions may be comprised of one or both of analog and digital portions; h) any of the disclosed devices or portions thereof may be combined together or separated into further portions unless specifically stated otherwise; i) no specific sequence of acts is intended to be required unless specifically indicated; and j) the term "plurality of an element includes two or more of the claimed element, and does not imply any particular range of number of elements; that is, a plurality of elements can be as few as two elements, and can include an immeasurable number of elements.

Claims

Claims:

Claim 1 : A method, comprising: providing a support, the support being selected from the group consisting of a film, a leadframe, and a leadframe on the film; adding groups of light-emitting elements on the support, each group comprising: one or more first light-emitting elements emitting light of a first color; and one or more second light-emitting elements emitting light of a second color; adding reflective cups on the support, each reflective cup surrounding a

corresponding group of light-emitting elements; adding an encapsulant in the reflective cups to affix each reflective cup to the corresponding group of light-emitting elements; and adding a wavelength converter over the groups of light-emitting elements, the wavelength converter emitting light of a third color, the first, the second, and the third primary colors combining to form white light. Claim 2: The method of claim 1, wherein the wavelength converter is disposed on the encapsulant.

Claim 3: The method of claim 2, wherein each group of light-emitting elements comprises: blue InGaN light-emitting diodes; and another type of light-emitting diodes selected from the group consisting of green InGaN light-emitting diodes, magenta InGaN light-emitting diodes, and red AlInGaP light-emitting diodes.

Claim 4: The method of claim 3, wherein the wavelength converter is selected from the group consisting of a phosphor in a binder, a first ceramic phosphor plate emitting red, and a second ceramic phospro plate emitting green light. Claim 5 : The method of claim 4, wherein the support is the film, the method further comprising removing the film after adding the encapsulant.

Claim 6: The method of claim 5, further comprising singulating the reflective cups to provide individual light-emitting devices each comprising a reflective cup fixed to a group of light- emitting elements. Claim 7: The method of claim 2, further comprising shaping the wavelength converter to form non-planar emitting surfaces over corresponding groups of light-emitting elements.

Claim 8: The method of claim 2, wherein adding the encapsulant comprises partially filling the reflective cups with the encapsulant, and the wavelength converter conforms to the encapsulant to leave gaps between the wavelength converter and exit windows of the reflective cups.

Claim 9: The method of claim 4, further comprising shaping the encapsulant to form non- planar emitting surfaces over corresponding groups of light-emitting elements, wherein the wavelength converter conforms to the non-planar emitting surfaces of the encapsulant.

Claim 10: The method of claim 1, wherein the wavelength converter is disposed on the light- emitting elements.

Claim 11 : A device, comprising: a reflective cup, comprising: a bottom aperture; and one or more reflective sidewalls extending from the bottom aperture; a group of light-emitting elements situated in the bottom aperture, comprising: one or more first light-emitting elements emitting light of a first color; and one or more second light-emitting elements emitting light of a second color; an encapsulant in the reflective cup that affixes the group of light-emitting elements to the reflective cup; and a wavelength converter over the group of light-emitting elements, the wavelength converting element emitting light of a third color, the first, the second, and the third primary colors combining to form white light.

Claim 12: The device of claim 11, wherein the wavelength converter is disposed on the encapsulant.

Claim 13: The device of claim 12, wherein the group of light-emitting elements comprises: blue InGaN light-emitting diodes; and another type of light-emitting diodes selected from the group consistine of green

InGaN light-emitting diodes, magenta InGaN light-emitting diodes, and red AlInGaP light-emitting diodes.

Claim 14: The device of claim 13, wherein the wavelength converter is selected from the group consisting of a phosphor in a binder, a first ceramic phosphor plate emitting red light, and a second ceramic phosphor plate emitting green light. Claim 15: The device of claim 12, wherein the wavelength converter comprises a non-planar emitting surface.

Claim 16: The device of claim 12, wherein the encapsulant partially fills the reflective cup, and the wavelength converter conforms to the encapsulant to leave a gap between the wavelength converter and an exit window of the reflective cup.

Claim 17: The device of claim 16, further comprising a waveguide with a flat input surface against the exit window of the reflective cup.

Claim 18: The device of claim 12, wherein the encapsulant comprises a non-planar emitting surface, wherein the wavelength converter conforms to the non-planar emitting surface of the encapsulant.

Claim 19: The device of claim 11, wherein the wavelength converter is disposed on the light- emitting element.

Claim 20: The device of claim 11, wherein the group of light-emitting elements and the reflective cup are placed on a leadframe.