TW201304199A - Light emitting diode chip packages - Google Patents

Abstract

A light emitting diode chip package is provided. The light emitting diode chip package includes a lead frame, having a cavity and a raised stage disposed in the cavity, wherein the cavity is divided into two areas by the raised stage. A light emitting diode chip is disposed on the raised stage and two kinds of phosphors are coated on the bottom surfaces of the two areas of the cavity respectively. The lead frame is filled with a packaging seal material to cover the light emitting diode chip and the phosphors.

Description

Light-emitting diode chip package

The present invention relates to a light emitting diode chip package, and more particularly to a light emitting diode chip package having a high color rendering index.

A light-emitting diode (LED) wafer is a composite semiconductor component that converts current into light by means of energy conversion, and a single light-emitting diode wafer can emit only light of a specific light color.

Conventionally, in order to achieve white light, light emitted by three kinds of light-emitting diode chips of red light, green light, and blue light can be mixed into white light. This white light has a high color rendering index (CRI), but the circuit design is troublesome.

Another way to form white light is to apply red and green mixed phosphor powder on the blue diode chip, blue light emitted by the blue diode chip, and red light emitted by the red and green phosphor powder. The green light is mixed into white light. Although the color rendering index of this white light can reach 80%, the red and green fluorescent powders have the problem of mutually absorbing light, and cannot achieve good luminous efficiency.

In addition, green phosphor powder can be directly coated on red and blue diode wafers to achieve white light. However, the green phosphor powder above the wafer is susceptible to light and heat, making the phosphor powder The reliability is not good.

Embodiments of the present invention provide a light emitting diode chip package that overcomes the above problems such that the emitted white light has a high color rendering index without the problem that the phosphor powder absorbs light from each other. In addition, it can also improve the reliability of the phosphor powder and extend the life of the phosphor powder.

According to an embodiment of the invention, a light emitting diode chip package includes: a bracket structure having a groove and a convex platform disposed in the groove, wherein the convex platform divides the groove into two regions; the light emitting diode chip The phosphor powder is respectively disposed on the bottom surface of the two regions of the groove; and the encapsulant is filled in the bracket structure to cover the LED chip and the phosphor powder.

In order to make the above objects, features, and advantages of the present invention more comprehensible, the following detailed description is made in conjunction with the accompanying drawings.

Referring to FIG. 1A, there is shown a plan view of a light emitting diode chip package in accordance with an embodiment of the present invention. The LED package includes a lead frame 10 having a recess 14 and a raised platform 12 disposed within the recess 14. One or more illuminations may be disposed on the raised platform 12. Polar body wafer 16. In Fig. 1A, the raised platform 12 divides the recess 14 into front and rear regions 14A and 14B, and two kinds of phosphors 18 and 20 are coated on the bottom surfaces of the two regions 14A and 14B, respectively. In one embodiment, the sidewalls of the recess 14 may be sloped sidewalls, thereby reducing the absorption of the phosphors 18 and 20, thereby increasing the luminous efficiency of the phosphors 18 and 20.

In one embodiment, the LED array 16 can be a blue LED wafer, and the phosphors 18 and 20 are red and green phosphors, respectively, forming a white LED package. In another embodiment, the LED array 16 can be a blue LED wafer, and the phosphors 18 and 20 are red and yellow phosphors, respectively, to form a light emitting diode chip that emits white or warm light. Package.

According to an embodiment of the present invention, the two phosphors 18 and 20 can be completely separated by the raised platform 12, and the phosphors 18 and 20 have no contact surface with each other, thereby avoiding or reducing the two types of fluorescence. The problem that the powders 18 and 20 absorb light from each other enhances the luminous efficiency of the phosphors 18 and 20 and improves the color rendering index of the LED package.

At the bottom end of the recess 14 of the bracket structure 10, there is also a conductive support 30. In one embodiment, two conductive pads (not shown) of the LED array 16 are, for example, n-contacts (n-contact, respectively). And a p-type contact (p-contact) is disposed at the top end of the wafer, and is electrically connected to the conductive holder 30 by wire bonding 28, respectively, and the light-emitting diode chip 16 is connected to the external circuit via the conductive holder 30 ( Not shown) Electrical connection.

1B is a plan view showing a light emitting diode package according to another embodiment of the present invention. The difference between FIG. 1B and FIG. 1A is that the conductive holder 30 is disposed above the raised platform 12, and the light emitting diode is The two conductive pads (not shown) of the wafer 16 are electrically connected to the conductive support 30 by wire bonding 28, respectively.

1C is a plan view showing a light emitting diode package according to another embodiment of the present invention. The difference between FIG. 1C and FIG. 1B is that the two conductive pads (not shown) of the LED wafer 16 are disposed. At the bottom end of the wafer, and the LED wafer 16 is directly electrically connected to the conductive support 30 disposed above the raised platform 12.

1D is a plan view showing a light emitting diode package according to another embodiment of the present invention. The difference between FIG. 1D and FIG. 1A-1C is that the bump platform 12 has a via 32 therein and is convex. An electrode 34 is disposed below the platform 12, and two conductive pads (not shown) of the LED array 16 are disposed at the bottom end of the wafer, and the LED wafer 16 is electrically connected to the electrode 34 via the via 32. Therefore, the LED wafer 16 can be electrically connected to an external circuit through the electrode 34.

Referring to Fig. 2A, there is shown a cross-sectional view of a light emitting diode package according to an embodiment of the present invention along section line 2-2' of Fig. 1A. As shown in FIG. 2A, the top end of the raised platform 12 is higher than the surfaces of the phosphors 18 and 20 such that the LED array 16 disposed on the raised platform 12 is completely separated from the phosphors 18 and 20. Since there is no contact surface, the phosphor powders 18 and 20 are not affected by the light emission and heat generation of the LED chip 16, and the reliability of the phosphor powders 18 and 20 can be improved, and the service life of the phosphor powders 18 and 20 can be prolonged.

As shown in FIG. 2A, the LED package further includes an encapsulant 22 filled in the recess 14 of the support structure 10, covering the LED wafer 16 and the phosphors 18 and 20, and in the encapsulant There is also a lens structure 24 above the material 22.

In this embodiment, the shape of the lens structure 24 is two continuous curved surfaces. For example, the lens structure 24 may be two continuous convex lenses having a function of reflecting and penetrating light. The junction of the two continuous curved surfaces of the lens structure 24 is aligned with the LED wafer 16 such that a portion of the light emitted by the LED wafer 16 penetrates from the junction of two continuous curved surfaces, and the other portion A continuous surface reflection. In one embodiment, the LED wafer 16 is, for example, a blue LED wafer, and the light emitted by the lens structure 24 has a light transmittance of about 15% to 30%, preferably 25%, and the lens. The light reflectance of structure 24 is about 70% to 85%, preferably 75%.

As shown in FIG. 2A, a portion of the light emitted from the LED wafer 16 is also irradiated onto the phosphors 18 and 20, so that the phosphors 18 and 20 are excited to emit light, and the phosphors 18 and 20 are irradiated. The emitted light passes through the encapsulant 22 and the lens structure 24, and is mixed with the light emitted from the LED 16 to form white light.

Referring to Fig. 2B, there is shown a cross-sectional view of a light emitting diode package according to another embodiment of the present invention along section line 2-2' of Fig. 1A. The difference between FIG. 2B and FIG. 2A is that the light-emitting diode wafer 16 of FIG. 2A has vertical sidewalls, and the light-emitting diode wafer 16 of FIG. 2B has inclined sidewalls, and thus the light-emitting diode of FIG. 2B. The side of the wafer 16 is preferably light-emitting, and the side-emitting light can be used to excite the phosphors 18 and 20.

Referring to Fig. 3A, there is shown a cross-sectional view of a light emitting diode package according to another embodiment of the present invention along section line 2-2' of Fig. 1A. The difference between the 3A and 2A is that the shape of the lens structure 24 is a curved surface, for example, a convex lens, and the LED package of FIG. 3A further includes a reflective layer 26 disposed in the lens structure 24, and a reflective layer. The material of 26 is, for example, a metallic material having a mirror effect or other material that reflects light. The reflective layer 26 is located at the interface of the lens structure 24 and the encapsulant 22, and the reflective layer 26 is aligned with the LED substrate 16.

In this embodiment, the combination of reflective layer 26 and lens structure 24 has the function of reflecting and penetrating light. In one embodiment, the LED wafer 16 is, for example, a blue LED wafer, and the light emitted by the combination of the lens structure 24 and the reflective layer 26 has a light transmittance of about 15% to 30%. It is 25%, and the light reflectance of the combination of the reflective layer 26 and the lens structure 24 is about 70% to 85%, preferably 75%.

As shown in FIG. 3A, a portion of the light emitted by the LED wafer 16 is reflected by the reflective layer 26 to be incident on the phosphors 18 and 20, and the other portion of the light passes through the lens structure 24. In addition, a part of the light emitted from the LED chip 16 is irradiated onto the phosphors 18 and 20, so that the phosphors 18 and 20 are excited to emit light, and the light emitted by the phosphors 18 and 20 passes through. The encapsulant 22 and the lens structure 24 are mixed with light emitted from the LED 16 to form white light.

Referring to Fig. 3B, there is shown a cross-sectional view of a light emitting diode package according to another embodiment of the present invention along section line 2-2' of Fig. 1A. The difference between FIG. 3B and FIG. 3A is that the reflective layer 26 of the LED package of FIG. 3B is disposed in the encapsulant 22 . Similarly, the reflective layer 26 of FIG. 3B is located at the interface of the lens structure 24 and the encapsulant 22, and the reflective layer 26 is aligned with the LED substrate 16. Therefore, the combination of the reflective layer 26 of FIG. 3B and the lens structure 24 also has the function of reflecting and penetrating light.

Referring to Fig. 4, there is shown a cross-sectional view of a light emitting diode package according to another embodiment of the present invention along section line 4-4' of Fig. 1D. The difference between FIG. 4 and FIG. 2A is that the LED package of FIG. 4 has vias 32 formed in the raised platform 12, and the vias 32 are penetrated from the top surface of the raised platform 12 to the bottom. A conductive material such as a metal is filled in the via hole 32. The conductive pad (not shown) of the LED chip 16 is electrically connected to the electrode 34 disposed under the bump platform 12 by the via hole 32. The polar body wafer 16 can be electrically connected to an external circuit (not shown) via the electrode 34. Therefore, in the light-emitting diode package of FIG. 4, the light-emitting diode chip 16 is electrically connected to an external circuit without wire bonding.

Further, the design of the via hole 32 and the electrode 34 of the embodiment of Fig. 4 can also be applied to the embodiment of Figs. 2B, 3A and 3B, in place of the wire bonding method.

In summary, the LED package of the embodiment of the present invention utilizes the design of the groove and the raised platform of the bracket structure, so that the two kinds of phosphor powder are completely separated by the convex platform without a contact surface, so Avoid or reduce the problem of the two kinds of phosphor powder absorbing each other, improve the luminous efficiency of the phosphor powder, and improve the color rendering index of the LED package.

In addition, according to the LED package of the embodiment of the invention, the phosphor powder is completely separated from the LED chip without a contact surface, so that the phosphor powder is not exposed to light and heat emitted by the LED chip. The effect can increase the reliability of the phosphor powder and extend the life of the phosphor powder.

Although the present invention has been disclosed in its preferred embodiments, it is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application attached.

10. . . Bracket structure

12. . . Raised platform

14. . . Groove

14A, 14B. . . Two areas of the groove

16. . . Light-emitting diode chip

18, 20. . . Fluorescent powder

twenty two. . . Packaging glue

twenty four. . . Lens structure

26. . . Reflective layer

28. . . Wire bonding

30. . . Conductive bracket

32. . . Via

34. . . electrode

1A-1D is a plan view showing a light emitting diode chip package in accordance with various embodiments of the present invention.

2A and 2B are cross-sectional views showing a light-emitting diode package along a section line 2-2' of FIG. 1A, in which the shape of the lens structure is two continuous curved surfaces, in accordance with various embodiments of the present invention. .

3A and 3B are cross-sectional views of the light emitting diode package taken along section line 2-2' of Fig. 1A, in which the shape of the lens structure is a curved surface, in accordance with various embodiments of the present invention.

Fig. 4 is a cross-sectional view showing a light emitting diode package according to a section line 4-4' of Fig. 1D, in accordance with an embodiment of the present invention.

10. . . Bracket structure

12. . . Raised platform

14. . . Groove

14A, 14B. . . Two areas of the groove

16. . . Light-emitting diode chip

18, 20. . . Fluorescent powder

twenty two. . . Packaging glue

twenty four. . . Lens structure

28. . . Wire bonding

30. . . Conductive bracket

Claims (18)

A light emitting diode chip package includes: a bracket structure having a recess and a raised platform disposed in the recess, wherein the raised platform divides the recess into two regions; a light emitting diode a body wafer disposed on the raised platform; two kinds of phosphor powder respectively coated on the bottom surface of the two regions of the groove; and a sealing material filled in the bracket structure to cover the light A diode chip and the phosphor powder. The illuminating diode package of claim 1, further comprising a lens structure disposed on the encapsulant. The light emitting diode chip package of claim 2, wherein the shape of the lens structure comprises a curved surface or two continuous curved surfaces, and wherein the connection of the two continuous curved surfaces is aligned with the light emitting diode Body wafer. The illuminating diode package of claim 2, wherein the lens structure is a convex lens, and further comprising a reflective layer disposed between the convex lens and the encapsulant. The illuminating diode package of claim 4, wherein the combination of the lens structure and the reflective layer has a light penetration and light reflection function, and a light reflectance of 70% to 85%. The light-emitting diode package of claim 5, wherein the light-emitting diode wafer is a blue-diode wafer and has a light transmittance of 15% to 30%. The LED package of claim 4, wherein the reflective layer is disposed in the convex lens or in the encapsulant, and the reflective layer is aligned with the LED. The light emitting diode chip package of claim 2, wherein the lens structure is two continuous convex lenses. The light-emitting diode package of claim 8, wherein the light-emitting diode wafer is a blue-diode wafer and has a light transmittance of 15% to 30%. The illuminating diode package of claim 1, wherein the illuminating diode chip is completely separated from the phosphor powder, and the illuminating diode chip comprises one or more illuminating diodes. Polar body wafer. The luminescent diode package of claim 1, wherein the two phosphors are completely separated by the raised platform. The light emitting diode chip package of claim 1, wherein the light emitting diode chip comprises a blue light diode chip, and the two phosphor powders comprise green phosphor powder and red phosphor powder. Or yellow fluorescent powder with red fluorescent powder. The light emitting diode chip package of claim 1, wherein the sidewall of the light emitting diode wafer comprises vertical sidewalls or inclined sidewalls. The illuminating diode package of claim 1, further comprising a conductive support disposed under the recess of the support structure, and the conductive diode is bonded to the conductive via a wire bonding manner. The bracket is electrically connected. The illuminating diode package of claim 1, further comprising a conductive support disposed above the raised platform of the support structure, and the LED is bonded via a wire bonding method. The conductive bracket is electrically connected. The illuminating diode package of claim 1, further comprising a conductive support disposed above the raised platform of the support structure, and the LED is directly electrically connected to the conductive support . The illuminating diode package of claim 1, further comprising a via hole disposed in the bump platform, and an electrode disposed under the bump platform, wherein the light emitting diode chip is via the light emitting diode chip The via hole is electrically connected to the electrode. The light emitting diode chip package of claim 1, wherein the sidewall of the recess of the bracket structure comprises a sloped sidewall.