Light emitting diode and wafer level package method, wafer level bonding method thereof, and circuit structure for wafer level package

This invention discloses a light emitting diode, a wafer level package method, a wafer level bonding method, and a circuit structure for a wafer level package. The light emitting diode includes a package carrier, a conducting material, at least one light emitting diode structure and a package material. The package carrier has at least one package unit and two through holes on the package carrier and corresponding to the package unit. The conducting material is disposed in the through holes and formed at the bottom of the package unit. The light emitting diode structure is formed on a substrate. The substrate having a light emitting diode structure is flipped over in the package unit, and the electrodes of the light emitting diode structure are bonded with the conducting material. After the substrate is removed, a package material is stuffed in the package unit or on the light emitting diode structure.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a light emitting diode, and more particularly to a light emitting diode that grows a light emitting diode structure onto a substrate, and uses the substrate as a medium for bonding the light emitting diode structure onto a package carrier to achieve the purpose of producing a light emitting diode with a wafer level package.

2. Description of the Related Art

Referring toFIG. 1for a schematic view of a conventional surface mount device (SMD) type light emitting diode (LED) package, the SMD-type light emitting diode package structure1comprises a cup base12, a conductive lead frame13, a light emitting diode structure11, two conductive wires14and15, and an encapsulation16, wherein the light emitting diode structure11is a semiconductor component that luminesces by an external voltage and includes a p-electrode and an n-electrode and connects two conductive wires14and15to the conductive lead frame13. The conductive lead frame13is disposed in the base12, and extended to the external surface of the base12and serves as a contact point for the following surface mount process. Traditionally, epoxy, silicone, or light transmitting colloidal fluid is usually filled into the cup base12and stuffed onto the light emitting diode structure11and the conductive wire14,15, and cured into an encapsulation16having a protective function for protecting and fixing the light emitting diode structure11and the conductive wire14,15during the manufacturing process of the conventional SMD-type light emitting diode package structure1. However, such manufacturing process or assembly is more complicated, and erroneous alignments may occur easily.

At present, the high-performance, high-power and high-brightness light emitting diode produces a large heat source, and thus most manufacturers usually install a heat dissipating structure to a lead frame when the light emitting diode lead frame is produced, so that the heat produced by the light emitting diode can be dispersed to assure the lifetime of the light emitting diode.

Referring toFIG. 2for a schematic view of a heat dissipating structure of a conventional light emitting diode, the light emitting diode2is a SMD-type including a lead frame21,22having a cathode211and an anode221and formed by stamping a thin metal substrate. The lead frame21,22further includes a vertical connecting portion212,222separately coupled to the cathode211and the anode221, a solder portion213,223formed at an end of the connecting portion212,222and extended parallel to the cathode211and the anode221, wherein excessive materials of the lead frame21,22are cut away for extrusion, and a heat dissipating structure23integrally formed at the bottom of the cathode211, and the heat dissipating structure23is a square cylindrical body231having a plurality of equidistant heat dissipating fins232formed in the cylindrical body231and a heat dissipating passage233defined between any two adjacent heat dissipating fins232. A rack24is formed by injection to cover the cathode211and the anode221, such that the solder portion213,223of the lead frame21,22is disposed at the bottom of the rack24, and the light emitting diode structure25is installed at the top of the cathode211. The light emitting diode structure25is soldered and connected to the anode221through a conductive wire26. A light-transmitting mask27is packaged on the rack24of the corresponding light emitting diode structure25.

However, the aforementioned shortcomings of the prior art including the complicated manufacturing process and the increased cost of a heat dissipating structure and the occurrence of erroneous alignments still exist. In view of these shortcomings, the inventor of the present invention based on years of experience in the related industry to conduct extensive researches and experiments, and finally developed a light emitting diode in accordance with the present invention to overcome the shortcomings of the prior art.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to overcome the foregoing shortcomings of the prior art by providing a light emitting diode, and more particularly to a light emitting diode that grows a light emitting diode structure onto a substrate, and uses the substrate as a medium for bonding the light emitting diode structure onto a package carrier to achieve the purpose of producing a light emitting diode with a wafer level package.

To achieve the foregoing objective, the light emitting diode of the invention comprises a package carrier, a conducting material, at least one light emitting diode structure and a package material. The package carrier includes at least one package unit and at least two through holes disposed on the package carrier and corresponding to the package unit. The conducting material is disposed in the through holes and formed on the package unit. The light emitting diode structure is grown on a substrate, and installed into the package unit by flipping the substrate over, and the electrodes of the light emitting diode structure are bonded with the conducting material. After the substrate is removed, the package material is stuffed into the package unit or on the light emitting diode structure to complete manufacturing the light emitting diode having a wafer level package in accordance with the present invention. A single light emitting diode or a plurality of light emitting diodes can be obtained by an appropriate cutting process.

The present invention further provides a circuit structure of a wafer level package carrier, and the circuit structure comprises a package carrier and an integrated circuit structure. The package carrier includes at least one package unit and at least two conductive windows disposed on the package carrier and corresponding to the package unit. The integrated circuit structure is installed on the package carrier and corresponding to the package unit, and coupled to the conductive window. The integrated circuit structure includes an active component, a passive component or a combination of the above for controlling or driving the light emitting diode structure in the package unit.

The wafer level package method of a light emitting diode in accordance with the present invention comprises the steps of:(1) providing a substrate;(2) forming at least one light emitting diode structure on the substrate;(3) providing a package carrier that installs at least one package unit, and corresponding to the package unit at least two through holes disposed on the package carrier;(4) disposing a conducting material into the through holes and forming the conducting material on the package unit;(5) flipping a substrate having the light emitting diode structure over, such that the light emitting diode structure corresponds to the package unit of the package carrier;(6) performing a bonding process to bond two electrodes of the light emitting diode structure separately with the conducting material in the package units;(7) removing the substrate, such that the light emitting diode structure is disposed in the package unit of the package carrier; and(8) stuffing a package material in the package unit or on the light emitting diode structure.

With the aforementioned steps, a wafer level package method of the light emitting diode is achieved.

The wafer level bonding method of a light emitting diode in accordance with the present invention comprises the steps of:(1) providing a substrate;(2) forming at least one light emitting diode structure on the substrate;(3) providing a package carrier that installs at least one package unit, and corresponding to the package unit at least two through holes disposed on the package carrier;(4) disposing a conducting material into the through holes and forming the conducting material on the package unit;(5) flipping a substrate having the light emitting diode structure over, such that the light emitting diode structure corresponds to the package unit of the package carrier; and(6) performing a bonding process to bond two electrodes of the light emitting diode structure separately with the conducting material in the package units.

In summation of the description above, the light emitting diode of the present invention is packaged by the wafer level package method to give a precise alignment by the substrate (or wafer) and provide a miniaturized light emitting diode for the package process to improve the production yield rate and the light emitting performance of the light emitting diode. Further, a single light emitting diode structure or a plurality of light emitting diode structures can be obtained by cutting the light emitting diode structures with a wafer level package. In the meantime, the package carrier is preferably made of silicon (Si) for providing better heat dissipating performance, mechanical stress and supporting effect to simplify the complicated process of manufacturing a heat dissipating device on the light emitting diode.

To make it easier for our examiner to understand the technical characteristics and performance of the present invention, we use preferred embodiments with the attached drawings for the detailed description of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

For simplicity, like numerals are used for like elements for the description of the specification of the present invention as follows.

Referring toFIG. 3for a flow chart of a wafer level package method of a light emitting diode in accordance with the present invention, the method comprising the steps of:

Step S21: providing a substrate31;

Step S22: forming at least one light emitting diode structure32on the substrate31;

Step S23: providing a package carrier41that installs at least one package unit42, and at least two through holes44disposed on the package carrier41and corresponding to the package unit42;

Step S24: disposing a conducting material45into the through holes44, and forming the conducting material45on the package unit42;

Step S25: flipping the substrate31having the light emitting diode structure32over, such that the light emitting diode structure32corresponds to the package unit42of the package carrier41;

Step S26: performing a bonding process to bond two electrodes33,34of the light emitting diode structure32separately with the conducting material45in the package units42;

Step S27: removing the substrate31, and remaining the light emitting diode structures32in the package units42; and

Step S28: stuffing a package material in the package units42or on the light emitting diode structures32.

With the aforementioned steps, the wafer level package method of a light emitting diode is achieved.

The substrate is preferably made of LiTaO3, LiNBO3, Li2B4O3, La3Ga5SiO14, Al2O3, ZnO, GaAs, AlN, InAs or Si, and the plurality of light emitting diode structures disposed on the substrate emit at least one color light, and provide different color lights by a combination of color lights to meet the industrial requirements. The package carrier is preferably made of silicon (Si) to provide better heat dissipating performance, mechanical stress and supporting effect. The package carrier further includes different circuit structures, such as a through hole of an electrode of the same polarity, for connecting the electrodes in parallel, or installing a control circuit of the light emitting diode. The conducting material preferably includes copper, silver, gold or any conducting metal, and the bonding process preferably includes a direct bonding, an anodic bonding, an eutectic bonding, an adhesive bonding or a glass frit bonding, and the direct bonding is divided into a high-temperature bonding, a low-temperature bonding, a bonding with a dielectric layer or a bonding without a dielectric layer. Further the electrode is a p-electrode or an n-electrode, and the package material preferably includes a light emitting material, epoxy, silicone, other protective material or a combination of the above. The light emitting material preferably includes a phosphorescent light emitting material or a fluorescent light emitting material.

Referring toFIG. 4for a schematic view a wafer level package method of a light emitting diode in accordance with a preferred embodiment of the present invention, the wafer level package method comprises the steps of: providing a substrate31; and growing an LED structure32on the substrate31and then a p-electrode33and an n-electrode34on the LED structure32to complete manufacturing the substrate31having the LED structure32.

Referring toFIG. 5for a schematic view a wafer level package method of a light emitting diode in accordance with a preferred embodiment of the present invention, the wafer level package method comprises the steps of: providing a package carrier41; forming a package unit42on the package carrier41and two through holes44at the bottom of the package unit42; disposing a conducting material45into the through holes44, and forming the conducting material45at the bottom43of the package unit42to complete producing the package carrier41.

Referring toFIG. 6for a schematic view a wafer level package method of a light emitting diode in accordance with a preferred embodiment of the present invention, the wafer level package method comprises the steps of: flipping the substrate31having the LED structure32as shown inFIG. 4over and placing the substrate31on the package carrier41as shown inFIG. 6for aligning the LED structure32to the package unit42of the package carrier41, and bonding two electrodes33,34of the LED structure32separately with the conducting material45in the package unit42by an eutectic bonding technology, After the bonding is completed, the substrate31is removed, and the LED structure32is remained in the package unit42of the package carrier41.

Referring toFIG. 7for a schematic view of a wafer level package method of a light emitting diode in accordance with a preferred embodiment of the present invention, the package carrier41of the LED structure32as shown inFIG. 4coats a light emitting material61in the package unit42and a package material62on the LED structure32to complete producing a wafer level package of a light emitting diode.

Referring toFIG. 8for a schematic view of a light emitting diode of the present invention, the light emitting diode7comprises a package carrier41, a conducting material45, a light emitting diode structure32and a light emitting material61or a package material62. The package carrier41installs a package unit42, and its bottom43has two through holes44. The conducting material45is placed into the through hole44, such that the conducting material45is formed at the bottom43of the package unit42. The light emitting material61or package material62is stuffed in the package unit42or on the light emitting diode structure32.

The substrate is preferably made of LiTaO3, LiNBO3, Li2B4O3, La3Ga5SiO14, Al2O3, ZnO, GaAs, AlN, InAs or Si, and the package carrier is preferably made of silicon (Si) to provide better heat dissipating performance, mechanical stress and supporting effect. The package carrier further installs different circuit structures, such as a through hole of an electrode of the same polarity, for connecting the electrodes in parallel, or installing a control circuit of the light emitting diode. The conducting material preferably includes copper, silver, gold or any conducting metal, and the electrodes include a p-electrode and an n-electrode. Further, the package material preferably includes a light emitting material, epoxy, silicone, other protective material or a combination of the above. The light emitting material preferably includes a phosphorescent light emitting material or a fluorescent light emitting material.

Referring toFIG. 9for a schematic view of another light emitting diode of the present invention, the light emitting diode8comprises a package carrier41, a conducting material45, a plurality of light emitting diode structures32and a light emitting material61or a package material62. The package carrier41includes a plurality of package units42, and its bottom43has at least two through holes44, and the conducting material45is placed into the through holes44to form the conducting material45at the bottom43of the package unit42. The light emitting material61or package material62is stuffed in the package unit42or on the light emitting diode structure32to achieve the light emitting diode8having a plurality of light emitting diode structures32, or obtain a light emitting diode7of a single light emitting diode structure32by an appropriate cutting.

The substrate preferably includes LiTaO3, LiNBO3, Li2B4O3, La3Ga5SiO14, Al2O3, ZnO, GaAs, AlN, InAs or Si, and the package carrier is preferably made of silicon (Si) to provide better heat dissipating performance, mechanical stress and supporting effect. The package carrier further installs different circuit structures, such as a through hole of an electrode of the same polarity, for connecting the electrodes in parallel, or installing a control circuit of the light emitting diode. The conducting material preferably includes copper, silver, gold or any conducting metal, and the electrodes include a p-electrode and an n-electrode. Further, the package material preferably includes a light emitting material, epoxy, silicone, other protective material or a combination of the above. The light emitting material preferably includes a phosphorescent light emitting material or a fluorescent light emitting material.

Referring toFIG. 10for a flow chart of a wafer level bonding method of a light emitting diode in accordance with the present invention, the method comprises the steps of:

Step S91: providing a substrate31;

Step S92: forming at least one light emitting diode structure32on the substrate31;

Step S93: providing a package carrier41that installs at least one package unit42, and at least two through holes44disposed on the package carrier41and corresponding to the package unit42;

Step S94: disposing a conducting material45into the through holes44to form the conducting material45on the package unit42;

Step S95: flipping the substrate31having the light emitting diode structure32over, such that the light emitting diode structure32corresponds to the package unit42of the package carrier41; and

Step S96: performing a bonding process to bond two electrodes33,34of the light emitting diode structure32separately with the conducting material45in the package units42.

With the aforementioned steps, the wafer level bonding method of a light emitting diode is achieved.

The substrate is preferably made of LiTaO3, LiNBO3, Li2B4O3, La3Ga5SiO14, Al2O3, ZnO, GaAs, AlN, InAs or Si, and the substrate has a plurality of light emitting diode structures that emit at least one color light, and obtain different color lights by a combination of the light emitting diodes to meet the industrial requirements. The package carrier is preferably made of silicon (Si) to provide better heat dissipating performance, mechanical stress and supporting effect. The package carrier further installs different circuit structures, such as a through hole of an electrode of the same polarity, for connecting the electrodes in parallel, or installing a control circuit of the light emitting diode. The conducting material preferably includes copper, silver, gold or any conducting metal, and the bonding process preferably includes a direct bonding, an anodic bonding, an eutectic bonding, an adhesive bonding or a glass frit bonding, and the direct bonding is divided into a high-temperature bonding, a low-temperature bonding, a bonding with a dielectric layer or a bonding without a dielectric layer. Further, the electrodes include a p-electrode and an n-electrode.

Referring toFIG. 11for a schematic view of a circuit structure of a wafer level package carrier in accordance with the present invention the circuit structure A of the package carrier comprises a package carrier A1and an integrated circuit structure A2. The package carrier A1has at least one package unit A11disposed thereon, and at least two conductive windows A12disposed on the package carrier A1and corresponding to the package unit A11. The integrated circuit structure A2is disposed at the bottom of the package carrier A1and corresponding to the package unit A11, and coupled to the conductive window A12. The integrated circuit structure A2includes an active component, a passive component or a combination of the above.

The package carrier is preferably made of silicon (Si) to provide better heat dissipating performance, mechanical stress and supporting effect. The conductive window preferably includes a conducting material such as copper, silver, gold or any conducting metal. The active component of the integrated circuit structure is generally a component related to the direction of current, such as a transistor, a silicon controlled rectifier, a diode or a valve. The passive component is generally a component not related to the direction of current, such as a resistor, a capacitor, or an inductor. The active component, the passive component or their combination is provided for controlling or driving a light emitting diode structure installed in the package unit.

The description and its accompanied drawings are used for describing preferred embodiments of the present invention, and it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.