TW202018977A - Illuminating device - Google Patents

Abstract

An illuminating device is provided, which includes a first conductive lead frame, a second conductive lead frame, a flip-chip LED die disposed on an upper surface of the first conductive lead frame and an upper surface of the second conductive lead frame, a photoluminescent sheet disposed on an upper surface of the flip-chip LED die, an inner reflective structure surrounding and covering a side surface of the flip-chip LED die, and an outer reflective structure surrounding and covering a side surface of the inner reflective structure. Therefore, the light emitted by the LED die can be reflected by the internal reflective structure and emitted out from the upper surface to enhance the central luminous intensity of the illuminating device.

Description

Light emitting device

The invention relates to a light-emitting device, in particular to a light-emitting device including an LED chip.

LED (Light Emitting Diode) chips are commonly used to provide light sources such as illumination and backlight, and LED chips are usually set in a reflective cup. The reflective cup can reflect the lateral light of the LED chip to the positive direction, so as to reduce the light emitting angle of the LED chip. However, for the requirement of small-angle light emission, the reduction of the light-emitting angle by the reflective cup is still not enough, so the secondary optical design (lens) needs to be used to further reduce the light-emitting angle.

On the other hand, after the LED chip is installed in the reflective cup, a fluorescent material can be formed in the reflective cup by molding or spraying process to cover the LED chip; the fluorescent material can convert the LED chip The color that emits light. However, the molding or spraying process consumes more fluorescent materials and is more unevenly distributed, which makes it difficult to control production costs and has poor color conversion effects.

In summary, there are still some problems to be improved in the technical field related to LED chips.

An object of the present invention is to provide a light-emitting device that concentrates light emitted from an LED chip in a forward direction, thereby increasing the central luminous intensity of the light-emitting device.

To achieve the above purpose, the light-emitting device provided by the present invention includes a first conductive Bracket; a second conductive bracket; a flip-chip LED chip, disposed on an upper surface of the first conductive bracket and an upper surface of the second conductive bracket; a fluorescent patch, disposed on the flip-chip An upper surface of the LED chip; an internal reflective structure surrounding and covering a side of the flip chip LED chip; an external reflective structure surrounding and covering a side of the internal reflective structure.

In one embodiment, the light emitting device further includes a light scattering structure disposed on an upper surface of the fluorescent patch and an upper surface of the internal reflection structure.

In one embodiment, the light scattering structure includes a light scattering material and a fluorescent material.

In one embodiment, the internal reflection structure further surrounds and covers a side of the fluorescent patch.

In one embodiment, the light-emitting device further includes an adhesive layer disposed between the fluorescent patch and the upper surface of the flip-chip LED chip.

In one embodiment, the adhesive layer includes a fluorescent material.

In one embodiment, the light emitting device further includes an electrostatic protection element, which is disposed on the upper surface of the first conductive support and is covered by the internal reflection structure.

In an embodiment, the external reflection structure includes an upper end portion, the upper end portion is higher than the internal reflection structure, and the upper end portion surrounds and covers a side of the light scattering structure.

In an embodiment, the upper surface of the internal reflection structure is a concave surface, a convex surface or a flat surface.

In one embodiment, a side surface of the first conductive support and a side surface of the second conductive support are coplanar with a side surface of the external reflective structure.

In an embodiment, one side of the first conductive support and the second conductive support One side of the frame and one side of the external reflection structure are non-coplanar.

In one embodiment, a refractive index of the internal reflection structure is the same as a refractive index of the external reflection structure.

In one embodiment, a refractive index of the internal reflection structure is different from a refractive index of the external reflection structure.

In one embodiment, the area of the upper surface of one of the fluorescent patches is not greater than 1.5 times the area of the upper surface of the flip-chip LED chip.

In one embodiment, the thickness of the fluorescent patch is between 60 microns and 300 microns.

In order to make the above purpose, technical features and advantages more comprehensible, the following is a detailed description with preferred embodiments and accompanying drawings.

1~4‧‧‧Lighting device

11‧‧‧The first conductive bracket

12‧‧‧Second conductive bracket

20‧‧‧ flip chip LED chip

30‧‧‧fluorescent patch

40‧‧‧Internal reflection structure

50‧‧‧External reflection structure

60‧‧‧Light scattering structure

70‧‧‧adhesive layer

80‧‧‧Static protection element

81‧‧‧Wire

110, 120, 200, 300, 400, 500, 600

111, 121, 201, 301, 401, 501, 601

502‧‧‧Upper end

L‧‧‧Light

D1, D2

Figure 1 is a top view of a light emitting device according to a first preferred embodiment of the present invention;

Figure 2 is a cross-sectional view of the light emitting device according to the first preferred embodiment of the present invention (along the cutting plane line A-A of Figure 1);

FIGS. 3A to 3C are another cross-sectional views of the light emitting device according to the first preferred embodiment of the present invention;

Figure 4 is a cross-sectional view of a light emitting device according to a second preferred embodiment of the present invention;

Figure 5 is a cross-sectional view of a light emitting device according to a third preferred embodiment of the present invention;

Figure 6 is a top view of a light emitting device according to a fourth preferred embodiment of the present invention; and

Figure 7 is a cross-sectional view of a light emitting device according to a fourth preferred embodiment of the present invention (along Figure 6) The cut line B-B).

The following will specifically describe specific embodiments according to the present invention; however, without departing from the spirit of the present invention, the present invention can still be practiced in many different forms of embodiments, and the scope of protection of the present invention should not be interpreted as being limited to the description. Narrator.

Unless the context clearly indicates otherwise, the singular form "a" as used herein also includes the plural form, and the orientations (such as front, back, up, down, both sides, inner, outer, etc.) are relative positions, It can be defined according to the use state of the light-emitting device, and does not indicate or imply that the wireless communication device needs to have a specific direction of construction or operation, nor can it be understood as a limitation to the present invention.

Please refer to FIG. 1 and FIG. 2, which are a top view and a cross-sectional view (along the cutting plane line A-A of FIG. 1) of the light emitting device 1 according to the first preferred embodiment of the present invention. The light-emitting device 1 can provide light with a smaller light-emitting angle (larger central light-emitting intensity), and is therefore suitable as a flash for electronic products such as mobile phones. The light emitting device 1 may include a first conductive support 11, a second conductive support 12, a flip chip LED chip 20, a fluorescent patch (photoluminescence patch) 30, an internal reflection structure 40 and an external reflection Structure 50, the technical content of each element will be explained in order as follows.

The shapes of the first conductive support 11 and the second conductive support 12 may be plate-shaped, and may have grooves or through holes, etc., and are usually made of metal materials, metal alloys, or metal plating layers with good conductivity. The flip-chip LED chip 20 (hereinafter referred to as LED chip 20) is disposed on an upper surface 110 of the first conductive support 11 and an upper surface 120 of the second conductive support 12, and two electrodes on the lower surface of the flip-chip LED chip 20 (Not shown) electrically connected to the first conductive support 11 and the second conductive support 12 respectively, receiving electric energy from the first conductive support 11 and the second conductive support 12 to emit light. The LED chip 20 is a multi-faceted light emitting type, for example, a 5-surface emitting type, and light L is emitted from both the upper surface 200 and the side surface 201 (including the four side surface portions). In one embodiment, the flip-chip LED chip 20 includes a substrate, an N-type semiconductor layer, an active layer, and a P-type semiconductor layer. The N-type semiconductor layer, the active layer, and the P-type semiconductor layer are sequentially arranged on the substrate. The above two electrodes are respectively disposed on the N-type semiconductor layer and the P-type semiconductor layer.

The fluorescent patch 30 is a pre-formed sheet-like (plate-like or film-like) structure, which can be formed of organic materials (such as silicone rubber) or inorganic materials (such as glass, ceramics, etc.); taking organic materials as an example, it can Fluorescent materials (such as fluorescent powder, quantum dot materials and other photoluminescent materials) are mixed and cured in silicone rubber, and taking inorganic materials as an example, the fluorescent material and ceramic powder (or glass powder) can be sintered together to make. The fluorescent patch 30 is disposed on an upper surface 200 of one of the LED chips 20 and covers all of the upper surface 200. Therefore, the light L emitted from the upper surface 200 of the LED chip 20 will pass through the fluorescent patch 30, and then the color (wavelength) of part of the light L will be converted by the fluorescent patch 30 (for example, from blue to yellow). The thicker the fluorescent patch 30 or the higher the ratio of the fluorescent material, the more light L should be converted into colors, and the thickness of the fluorescent patch 30 is preferably between 60 microns and 300 microns ( micrometer).

In this embodiment, the fluorescent patch 30 can be directly disposed on the upper surface 200 of the LED chip 20 without an additional adhesive material between the two. That is, when the raw material of the fluorescent patch 30 (such as silicone glue) is semi-cured (that is, the silicone glue is in the B-stage, which is still sticky), it is disposed on the upper surface 200 of the LED chip 20.

The internal reflective structure 40 surrounds and covers a side 201 of the LED chip 20, and the external reflective structure 50 surrounds and covers a side 401 of the internal reflective structure 40. Moreover, the internal reflective structure 40 and the external reflective structure 50 are also separately disposed on the upper surface 110 of the first conductive support 11 and the second conductive On the upper surface 120 of the electrical support 12, the two are not an integrally formed structure; in other words, there is an interface between the two. In addition, the internal reflective structure 40 and/or the external reflective structure 50 may partially cover the first conductive support 11 and the second conductive support 12 to enhance the bonding with the first conductive support 11 and the second conductive support 12. The internal reflection structure 40 may completely cover the side 201 (including four side portions) of the LED chip 20, and the external reflection structure 50 may completely cover the side 401 (including four side portions) of the internal reflection structure 40. The external reflective structure 50 and the internal reflective structure 40 may be of equal height (not shown), or the external reflective structure 50 is higher than the internal reflective structure 40. In other words, the external reflective structure 50 further includes an upper end 502, which is higher than the internal The reflective structure 40 upper surface 400.

Both the internal reflection structure 40 and the external reflection structure 50 have good light reflectivity (eg, greater than 90%), and can be formed from a thermosetting plastic or a thermoplastic as a base material, mixed with a higher proportion of light scattering materials; plastics include, for example, phenylpropanol Phenylpropanolamine (PPA), Polycyclohexylenedimethylene terephthalate (PCT), Sheet Molding Compound (SMC), Epoxy Molding Compound (EMC) , Unsaturated Polyester (UP), Polycarbonate (PC), Polyethylene (PE), Polyethylene Terephthalate (PET), Cycloolefin Copolymer ( Cyclic olefin copolymers (COC), etc., and the light scattering material includes, for example, titanium dioxide, silicon dioxide, zirconium dioxide, boron nitride, or the like.

By the arrangement of the internal reflection structure 40 and the external reflection structure 50, the light L emitted from the side surface 201 of the LED chip 20 will be reflected toward the upper surface 200 of the LED chip 20, and then emitted through the fluorescent patch 30 Outside the light emitting device 1. As a result, the light L generated in the LED chip 20 is collected at the center of the light-emitting device 1 to reduce the light emission of the light-emitting device 1 The angle increases the central luminous intensity of the light emitting device 1.

Preferably, the internal reflection structure 40 further surrounds and covers a side surface 301 (including four side portions) of the fluorescent patch 30 and exposes the upper surface 300 of the fluorescent patch 30. Therefore, when the light L enters the fluorescent patch 30, some of the light L may be directed toward the side 301 of the fluorescent patch 30, and the light L will also be reflected by the internal reflection structure 40, and then from the fluorescent patch The upper surface 300 of the sheet 30 is ejected. Thereby, the light-emitting angle of the light-emitting device 1 can be further reduced, and the central light-emitting intensity can be more increased.

On the other hand, depending on the process parameters, the upper surface 400 of the internal reflection structure 40 may be concave, convex, or flat, as shown in FIG. 2, FIG. 3A, and FIG. 3B, respectively. When the upper surface 400 is concave or convex, the upper surface 400 is slightly higher than the upper surface 200 of the LED chip 20 (or the upper surface 300 of the fluorescent patch 30), so as to achieve a better light reflection effect. In addition, the refractive index of the internal reflective structure 40 and the refractive index of the external reflective structure 50 may be the same or different depending on the process parameters or application requirements.

Furthermore, as shown in FIG. 2, a side surface 501 of the external reflective structure 50 may be flush with a side surface 111 of the first conductive support 11 and a side surface 121 of the second conductive support 12, thereby forming a coplanar structure. Or as shown in FIG. 3C, according to application requirements, the first conductive support 11 and the second conductive support 12 may also extend laterally on the side 501 of the external reflective structure 50, so that the side 111 and the first conductive support 11 The side surface 121 of the two conductive supports 12 and the side surface 501 of the external reflection structure 50 are not coplanar.

Next, as shown, the patch 30 over the lateral dimension of the first fluorescent FIG. 3A surface 300 (e.g., width or length, perpendicularly to the thickness _{persons). 1} D is not smaller than the transverse dimension of the LED chip 20 on the surface 200 of D _2, Preferably, the lateral dimension D _{1 of the} fluorescent patch 30 is not greater than 1.5 times the lateral dimension D ₂ of the LED chip 20 (that is, D ₂ ≦D ₁ ≦1.5 D ₂ ) to avoid the side of the fluorescent patch 30 301 is too close to the external reflective structure 50; thus, there is sufficient gap between the side surface 301 of the fluorescent patch 30 and the external reflective structure 50, so that the raw material of the internal reflective structure 40 can easily surround and cover the LED chip 20 through the gap One side 201.

The following will describe other preferred embodiments according to the present invention. The same part of the technical content of each embodiment will be omitted or simplified, and the different parts should be applicable to other embodiments.

Please refer to FIG. 4, which is a cross-sectional view of a light emitting device 2 according to a second preferred embodiment of the present invention. The light emitting device 2 further includes a light scattering structure 60 disposed on the upper surface 300 of the fluorescent patch 30 and the upper surface 400 of the internal reflection structure 40. The light scattering structure 60 is used to let the light L passing through the different colors of the fluorescent patch 30 (for example, including blue and yellow) include scattering and mix, so that the light emitted from the light emitting device 2 (the upper surface 600 of the light scattering structure 60) L has a more uniform color temperature or color distribution. The upper surface 600 of the light scattering structure 60 may be flush, lower or higher than the upper surface 500 of the outer reflective structure 50.

In addition, the upper end 502 of the outer reflective structure 50 may surround and cover the side surface 601 of the light scattering structure 60. As a result, the light L traveling toward the side surface 601 is reflected by the upper end portion 502 of the outer reflective structure 50 and is redirected toward the upper surface 600 to be emitted.

Similar to the internal reflection structure 40 and the external reflection structure 50, the light scattering structure 60 can also be formed from a thermosetting plastic or a thermoplastic plastic, mixed with a lower proportion of light scattering materials, that is, the light scattering structure 60 includes less light scattering materials Since the light scattering material included in the internal reflection structure 40 or the external reflection structure 50, the light scattering structure 60 will not block the light L from passing therethrough.

In addition to the light scattering material, the light scattering structure 60 may further include a fluorescent material, the same The light scattering material is uniformly distributed in the light scattering structure 60. Therefore, when the light L passes through the light scattering structure 60, part of the color of the light L will be converted by the fluorescent material of the light scattering structure 60 (for example, from blue to yellow, red, or green), and then from the light scattering structure 60 The upper surface 600 is shot. Therefore, the light L emitted from the upper surface 600 includes three parts: the part originally generated by the LED chip 20, the part converted by the fluorescent patch 30, and the part converted by the light scattering structure 60. The refractive index of the light scattering structure 60 can be set close to the refractive index of the fluorescent patch 30, so that when the light L enters the light scattering structure 60 from the fluorescent patch 30, the light energy caused by total internal reflection on the interface is reduced loss.

On the other hand, the light-scattering structure 60 can also be replaced by a light-transmitting structure 60, which does not include a light-scattering material or a fluorescent material, and is used to protect the fluorescent patch 30.

Next, please refer to FIG. 5, which is a cross-sectional view of a light emitting device 3 according to a third preferred embodiment of the present invention. The light-emitting device 3 further includes an adhesive layer 70 disposed between the fluorescent patch 30 and the upper surface 200 of the LED chip 20. More specifically, before the fluorescent patch 30 is placed on the upper surface 200, the fluorescent patch 30 itself is no longer viscous (or insufficiently viscous). For example, the fluorescent patch 30 is a glass or ceramic sheet, or a fully cured organic material (That is, silicone rubber at the C-stage), so the adhesive patch 70 is used to adhere the fluorescent patch 30 to the upper surface 200.

The adhesive layer 70 has a small thickness and is transparent. The adhesive layer 70 may be disposed on all or part of the upper surface 200. In addition, the adhesive layer 70 may also include a fluorescent material (for example, red phosphor, yellow phosphor, etc.) to change the wavelength of the light L.

Please refer to FIGS. 6 and 7, which are a top view and a cross-sectional view (along the cut line B-B of FIG. 6) of the light-emitting device 4 according to the fourth preferred embodiment of the present invention. The light-emitting device 4 further includes an electrostatic protection element 80 disposed on the upper surface 110 of the first conductive support 11 or the second The conductive support 12 is on the upper surface 120 and is covered by the internal reflection structure 40. More specifically, the electrostatic protection element 80 may be electrically connected to the LED chip 20 through the first conductive support 11, the wire 81, and the second conductive support 12, so as to stabilize the voltage applied to the LED chip 20 and prevent the LED from increasing current. The wafer 20 is damaged. The electrostatic protection element 80 may be a Zener diode or one of the following groups: varistor (Varistor), multilayer varistor (MLV), polymer ESD suppressor (PESD) ) And Transient Voltage Suppressor (TVS). Due to the presence of the electrostatic protection element 80, the LED chip 20 and the fluorescent patch 30 are not located in the center of the light emitting device 4, but are biased toward one side. In addition, since the ESD protection element 80 is covered by the internal reflection structure 40, the ESD protection element 80 cannot be directly seen from the perspective of the top view.

In summary, the light-emitting device of the present invention can reflect the lateral light emitted from the LED chip to the positive direction, thereby increasing the central luminous intensity of the light-emitting device. In addition, the light-emitting device can save production costs due to the use of conductive brackets and fluorescent patches. The fluorescent materials in the fluorescent patch can be more evenly distributed, so the color conversion effect is more uniform throughout the fluorescent patch.

In one embodiment, the fluorescent patch 30 has a first phosphor, but the internal reflection structure 40 does not have any phosphor.

In one embodiment, the fluorescent patch 30 has a first phosphor, and/or a second phosphor, and/or a third phosphor, but the internal reflection structure 40 and the light scattering structure 60 do not With any fluorescent powder.

In one embodiment, the fluorescent patch 30 has a first phosphor, and/or a second phosphor, and/or a third phosphor, and the internal reflection structure 40 has a first phosphor , And/or a second phosphor, and/or a third phosphor, but the light scattering structure 60 does not have any phosphor.

In an embodiment, the fluorescent patch 30 has a first phosphor, and/or a first phosphor Two phosphors, and/or a third phosphor, the light scattering structure 60 has a first phosphor, and/or a second phosphor, and/or a third phosphor, but internal reflection The structure 40 does not have any phosphor.

In one embodiment, the fluorescent patch 30 has a first phosphor, and/or a second phosphor, and/or a third phosphor, and the internal reflection structure 40 has a first phosphor , And/or a second phosphor, and/or a third phosphor, the light scattering structure 60 has a first phosphor, and/or a second phosphor, and/or a third phosphor Light pink.

The first phosphor, the second phosphor and the third phosphor may be any combination of yellow phosphor, green phosphor and red phosphor. The yellow phosphor can be Y ₃ Al ₅ O ₁₂ : Ce ³⁺ (YAG for short) and (Sr,Ba) ₂ SiO ₄ : Eu ²⁺ (the content of Sr ^{2+ is} high, Silicate for short), the green phosphor can It is Si _6-z Al _z O _z N _8-z : Eu ²⁺ (abbreviated as β-SiAlON) and Lu ₃ Al ₅ O ₁₂ : Ce ³⁺ (abbreviated as LuAG). The red phosphor can be CaAlSiN ₃ : Eu ^{2 +} (CASN or 1113 for short), Sr ₂ Si ₅ N ₈ : Eu ²⁺ (abbreviated as 258) and K ₂ SiF ₆ : Mn ⁴⁺ (abbreviated as KSF).

The above embodiments are only used to illustrate the technical solution of the present invention, not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, persons of ordinary skill in the art should understand that they can still implement the foregoing embodiments The technical solutions described in the examples are modified, or some or all of the technical features are equally replaced; and these modifications or replacements do not deviate from the scope of the technical solutions of the embodiments of the present invention.

1‧‧‧Lighting device

11‧‧‧The first conductive bracket

12‧‧‧Second conductive bracket

20‧‧‧ flip chip LED chip

30‧‧‧fluorescent patch

40‧‧‧Internal reflection structure

50‧‧‧External reflection structure

110, 120, 200, 300, 400 ‧‧‧ upper surface

111, 121, 201, 301, 401, 501

502‧‧‧Upper end

L‧‧‧Light

Claims (16)

A light-emitting device, including: A first conductive support; A second conductive support; A flip chip LED chip, disposed on an upper surface of the first conductive support and an upper surface of the second conductive support; A fluorescent patch is provided on the upper surface of one of the flip-chip LED chips; An internal reflection structure surrounding and covering one side of the flip chip LED chip; and An external reflection structure surrounds and covers one side of the internal reflection structure. The light emitting device according to claim 1, further comprising a light scattering structure disposed on an upper surface of the fluorescent patch and an upper surface of the internal reflection structure. The light emitting device according to claim 2, wherein the light scattering structure includes a light scattering material and a fluorescent material. The light emitting device according to claim 2, wherein the external reflection structure includes an upper end portion, the upper end portion is higher than the internal reflection structure, and the upper end portion surrounds and covers a side surface of the light scattering structure. The light-emitting device according to claim 1, wherein the internal reflection structure further surrounds and covers a side of the fluorescent patch. The light-emitting device according to claim 1, further comprising an adhesive layer disposed between the fluorescent patch and the upper surface of the flip-chip LED chip. The light-emitting device according to claim 6, wherein the adhesive layer includes a fluorescent material. The light-emitting device according to claim 1, further comprising an electrostatic protection element disposed on the upper surface of the first conductive support or the upper surface of the second conductive support, And covered by the internal reflection structure. The light-emitting device according to claim 1, wherein the external reflection structure includes an upper end portion, and the upper end portion is higher than the internal reflection structure. The light emitting device according to claim 1, wherein the upper surface of the internal reflection structure is a concave surface, a convex surface or a flat surface. The light emitting device according to claim 1, wherein a side surface of the first conductive support and a side surface of the second conductive support are coplanar with a side surface of the external reflection structure. The light emitting device according to claim 1, wherein a side surface of the first conductive support and a side surface of the second conductive support and a side surface of the external reflection structure are non-coplanar. The light emitting device according to claim 1, wherein a refractive index of the internal reflection structure and a refractive index of the external reflection structure are the same. The light emitting device according to claim 1, wherein a refractive index of the internal reflection structure is different from a refractive index of the external reflection structure. The light emitting device according to claim 1, wherein a lateral dimension of an upper surface of the fluorescent patch is not greater than 1.5 times a lateral dimension of the upper surface of the flip-chip LED chip. The light-emitting device according to claim 1, further comprising a light-transmitting structure disposed on an upper surface of the fluorescent patch and an upper surface of the internal reflection structure.

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