Chip level package of light-emitting diode

The application discloses a light-emitting diode chip level package structure including: a permanent substrate having a first surface and a second surface; a first electrode on the first surface; a second electrode on the second surface; an adhesive layer on where the first surface of the permanent substrate is not covered by the first electrode; a growth substrate on the adhesive layer; a patterned semiconductor structure on the growth substrate; a third electrode and a fourth electrode on the patterned semiconductor structure and electrically connect with the patterned semiconductor structure; an electrical connecting structure on the sidewall of the patterned semiconductor structure electrically connecting the third electrode and the fourth electrode with the first electrode; and an insulation layer located on the side wall of the patterned semiconductor structure and between the electrical connecting structure for electrically insulating the patterned semiconductor structure.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the right of priority based on Taiwan Patent Application No. 097151602 entitled “A Chip Level Package of Light-emitting Diode”, filed Dec. 30, 2008, which is incorporated herein by reference and assigned to the assignee herein.

TECHNICAL FIELD

The present application generally relates to a light-emitting device, and more particularly to a light-emitting device with a chip level package.

BACKGROUND

The LED industry has developed vigorously, and the package sector has become the main battlefield. From the experience, how to develop a light, thin, short, small, low cost, and high efficiency package is an invariable design benchmark. Currently, a light-emitting apparatus must be formed with other devices.FIG. 11is a diagram of a known light-emitting apparatus structure. AsFIG. 11shows, a light-emitting apparatus600includes at least a sub-mount64with a circuit and a solder62on the sub-mount64. A light-emitting diode chip400includes at least one substrate58on the sub-mount64, a semiconductor epitaxial stack layer54on the substrate58, an electrode56on the semiconductor epitaxial stack layer54, and an electrical connecting structure66. The light-emitting diode chip400is adhered on the sub-mount64, and the substrate58of the light-emitting diode chip400is electrically connected with the circuit of the sub-mount64by the solder62. Furthermore, an electrical connecting structure66is electrically connected the electrode56of the light-emitting diode chip400with the circuit on the sub-mount64. The sub-mount64can be a lead frame or a large scale mounting substrate convenient for the circuit design of the light-emitting apparatus600and the heat dissipation. The lead frame and the plastic cup by injection molding may have become the history. The wafer level package, chip level package, and 3-D package are now replacement. From the saving cost and light, thin, short, and small points of view, the chip level package is a practicable method.

SUMMARY

The present application provides a chip level package technology to reduce the size of the light-emitting device and simplify the manufacturing process. Furthermore, the light extraction efficiency of the light-emitting device is enhanced.

One embodiment of the present application provides a permanent substrate embedded with a passive device, and the passive device can connect electrically with the semiconductor epitaxial stack layer in series or parallel.

One embodiment of the present application provides a permanent substrate wherein the material of the permanent substrate can be an insulating material composited with a high thermally-conductive material. The material of the insulating material can be ceramic material, glass, or polymer material. The material of the high thermally-conductive material can be silver, cupper, graphite, silicon carbide, or gold. The high thermally-conductive material region includes a plurality of thermal conduction through-holes to dissipate the heat effectively.

One embodiment of the present application provides a light extraction microstructure on the semiconductor epitaxial stack layer wherein the shape of the light extraction microstructure can be column, Fresnel lens, or saw.

One embodiment of the present application provides a photonic crystal structure wherein the photonic crystal structure is formed by the nanoimprint technology. The photonic crystal structure assures the light emitted from the light-emitting diode not to emit randomly and to increase the chance for the light to emit upwards. The scatter angle of the light-emitting diode is therefore reduced and the efficiency is enhanced.

One embodiment of the present application provides an optical-electrical device operated by alternating current comprising a plurality of light-emitting devices connecting electrically in series.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A manufacturing process flow of forming a light-emitting diode device100in accordance with the first embodiment of the present application is illustrated inFIG. 1AtoFIG. 1L. Referring toFIG. 1A, a growth substrate101with a first surface101aand a second surface101bis provided, and the material of the growth substrate can be sapphire. An epitaxial structure116is formed on the first surface101aof the growth substrate101by epitaxial process such as MOCVD, LPE, or MBE. The epitaxial structure116includes at least a first conductivity type semiconductor layer110, such as n-type (AlxGa1-x)yIn1-yN layer; an active layer112, such as a multiple quantum wells structure of (AlaGa1-a)bIn1-bN; and a second conductivity type semiconductor layer114, such as p-type (AlxGa1-x)yIn1-yN layer. Besides, the active layer112in this embodiment can be formed as a homostructure, single heterostructure, or double heterostructure. Referring toFIG. 1B, a patterned semiconductor structure118is formed by etching the epitaxial structure116on the growth substrate101. Referring toFIG. 1C, a third electrode120aand a fourth electrode120bare formed on the first conductivity type semiconductor layer110and the second conductivity type semiconductor layer114respectively. Referring toFIG. 1D, a connecting layer122is provided to connect a temporary substrate102with the patterned semiconductor structure118. Referring toFIG. 1E, a portion of the growth substrate101is removed by polishing or etching so the remaining of the growth substrate has a thickness of about 10 μm. Referring toFIG. 1F, a reflective layer124and a metal adhesive layer126are formed in sequence on the second surface101bof the growth substrate101. Next, cutting the metal adhesive layer126, the reflective layer124, and the growth substrate101asFIG. 1Gindicates. An insulation layer127is then formed on the sidewall of the patterned semiconductor structure118, the growth substrate101and the reflective layer124as shown inFIG. 1H.

Referring toFIG. 1I, a permanent substrate103with a first surface103aand a second surface103bis provided, and the material of the permanent substrate can be ceramic material, glass, composite material, or polymer material. A plurality of through-holes is formed on the permanent substrate103and penetrated through the permanent substrate103, and is filled with electrically conductive material130. A first electrode132aand a second electrode132bare formed on the first surface103aof the permanent substrate and the second surface103bof that respectively. The structure shown inFIG. 1His adhered with the permanent substrate shown inFIG. 11by the metal adhesive layer126, and the temporary substrate102and the connecting layer122are removed asFIG. 1Jshows. An electrical connecting structure134is formed by electro-plating or film deposition process to electrically connect the third electrode120aand the fourth electrode120bwith the first electrode132aof the permanent substrate as shown inFIG. 1K. A light-emitting diode device100shown inFIG. 1Lis formed after dicing. The light-emitting diode device100electrically connects with the circuit board of the light-emitting by the second electrode132bof the permanent substrate so there is no need of the sub-mount for heat dissipation.

Referring toFIG. 2, the permanent substrate of the light-emitting diode device100can be composited with insulating material and high thermally-conductive material. The insulating material can be ceramic material, glass, or polymer material; the high thermally-conductive material can be silver, copper, graphic, silicon carbide, or gold. A plurality of thermal conduction through-holes140are included the high thermally-conductive material region for heat dissipation.

Referring toFIG. 3, a light extraction microstructure136is formed on where the top surface of the first conductivity type semiconductor layer110is not covered by the electrode and on where the top surface of the second conductivity type semiconductor layer114is not covered by the electrode of the light-emitting diode device100respectively, and the shape of the light extraction microstructure can be column, Fresnel lens, and saw. The purpose of the light extraction microstructure is to increase the light extraction efficiency. Referring toFIG. 4, a photonic crystal structure137can also be formed on where the top surface of the first conductivity type semiconductor layer110is not covered by the electrode and on where the top surface of the second conductivity type semiconductor layer114is not covered by the electrode of the light-emitting diode device100respectively. The photonic crystal structure assures the light emitted from the light-emitting diode not to emit randomly and to increase the chance for the light to emit upwards. The scatter angle of the light-emitting diode is therefore reduced and the efficiency is enhanced.

A former manufacturing process flow of forming a light-emitting diode device200in accordance with the second embodiment of the present application is the same as that of the first embodiment as shown inFIG. 1AtoFIG. 1D. Referring toFIG. 5A, the growth substrate101is removed by the chemical selection etching or polishing method. Referring toFIG. 5B, a reflective layer124and a metal adhesive layer126are formed in sequence under the first conductivity type semiconductor layer110. Next, cutting the metal adhesive layer126and the reflective layer124asFIG.5Cindicates. An insulation layer127is then formed on the sidewall of the patterned semiconductor structure118and the insulating reflective layer124as shown inFIG.5D.

Referring toFIG. 5E, a permanent substrate103with a first surface103aand a second surface103bis provided, and the material of the permanent substrate can be ceramic material, glass, composite material, or polymer material. A plurality of holes is formed on the permanent substrate103and penetrated through the permanent substrate103, and is filled with electrically conductive material130. A first electrode132aand a second electrode132bare formed on the first surface103aof the permanent substrate and on the second surface103bof that respectively. The structure shown inFIG. 5Dis adhered with the permanent substrate shown inFIG. 5Eby the metal adhesive layer126, and the temporary substrate102and the connecting layer122are removed asFIG. 5Fshows. An electrical connecting structure134is formed by electro-plating or film deposition process to electrically connect the third electrode120aand the fourth electrode120bwith the first electrode132aof the permanent substrate as shown inFIG. 5G. A light-emitting diode device200shown inFIG. 5His formed after dicing. The light-emitting diode device200electrically connects with the circuit board of the light-emitting apparatus by the second electrode132bof the permanent substrate so there is no need of the sub-mount for heat dissipation.

Referring toFIG. 6, a light extraction microstructure136is formed on where the top surface of the first conductivity type semiconductor layer110is not covered by the electrode and on where the top surface of the second conductivity type semiconductor layer114is not covered by the electrode of the light-emitting diode device200respectively, and the shape of the light extraction microstructure can be column, Fresnel lens, and saw. The purpose of the light extraction microstructure is to increase the light extraction efficiency. Referring toFIG. 7, a photonic crystal structure137can also be formed on where the top surface of the first conductivity type semiconductor layer110is not covered by the electrode and on where the top surface of the second conductivity type semiconductor layer114is not covered by the electrode of the light-emitting diode device200respectively. The photonic crystal structure assures the light emitted from the light-emitting diode not to emit randomly and to increase the chance for the light to emit upwards. The scatter angle of the light-emitting diode is therefore reduced and the efficiency is enhanced.

A manufacturing process flow of forming a light-emitting diode device300in accordance with the third embodiment of the present application is illustrated inFIG. 8AtoFIG. 8G. Referring toFIG. 8A, a growth substrate101with a first surface101aand a second surface101bis provided, and the material of the growth substrate can be GaAs. An epitaxial structure116is formed on the first surface101aof the growth substrate101by epitaxial process such as MOCVD, LPE, or MBE. The epitaxial structure116includes at least a first conductivity type semiconductor layer110, such as n-type (AlxGa1-x)yIn1-yP layer; an active layer112, such as a multiple quantum wells structure of (AlaGa1-a)bIn1-bP; and a second conductivity type semiconductor layer114, such as p-type (AlxGa1-x)yIn1-yP layer. Besides, the active layer112in this embodiment can be formed as a homostructure, single hetero structure, or double heterostructure. Next, a transparent adhesive layer138is formed on the epitaxial structure116.

Referring toFIG. 8B, a permanent substrate103with a first surface103aand a second surface103bis provided, and the material of the permanent substrate can be ceramic material, glass, composite material, or polymer material. A plurality of through-holes is formed on the permanent substrate103and penetrated through the permanent substrate, and is filled with the electrically conductive material130. A first electrode132aand a second electrode132bare formed on the first surface103aof the permanent substrate and the second surface103bof that respectively. Then, a transparent adhesive layer138is formed on where the first surface103aof the permanent substrate is not covered by the first electrode132a.The structure shown inFIG. 8Ais adhered with the permanent substrate shown inFIG. 8Bby the transparent adhesive layer138asFIG. 8Cshows. Referring toFIG. 8D, the growth substrate101is removed by chemical selection etching or polishing method. A patterned semiconductor structure118is formed by etching the epitaxial structure116and the transparent adhesive layer138. Referring toFIG. 8E, a third electrode120aand a fourth electrode120bare formed on the first conductivity type semiconductor layer110and the second conductivity type semiconductor layer114respectively. Next, an insulation layer127is formed on the sidewall of the patterned semiconductor structure118. An electrical connecting structure134is formed by electro-plating or film deposition process to electrically connect the third electrode120aand the fourth electrode120bwith the first electrode132aof the permanent substrate as shown inFIG. 8F. A light-emitting diode device300shown inFIG. 8Gis formed after dicing. The light-emitting diode device300electrically connects with the circuit board of the light-emitting apparatus by the second electrode132bof the permanent substrate so there is no need of the sub-mount for heat dissipation.

Referring toFIG. 9, a light extraction microstructure136is formed on where the top surface of the first conductivity type semiconductor layer110is not covered by the electrode and on where the top surface of the second conductivity type semiconductor layer114is not covered by the electrode of the light-emitting diode device300respectively, and the shape of the light extraction microstructure can be column, Fresnel lens, and saw. The purpose of the light extraction microstructure is to increase the light extraction efficiency. Referring toFIG. 10, a photonic crystal structure137can also be formed on where the top surface of the first conductivity type semiconductor layer110is not covered by the electrode and on where the top surface of the second conductivity type semiconductor layer114is not covered by the electrode of the light-emitting diode device300respectively. The photonic crystal structure assures the light emitted from the light-emitting diode not to emit randomly and to increase the chance for the light to emit upwards. The scatter angle of the light-emitting diode is therefore reduced and the efficiency is enhanced.

The multiple electrodes in series connection in the chip layout design is also adopted to achieve the requirement of the operation under alternating current, and the permanent substrate can be embedded with passive devices such as resistors or capacitors to save the space.