Light emitting semiconductor bonding structure and method of manufacturing the same

A light emitting semiconductor bonding structure includes a structure formed by bonding a substrate onto a light emitting semiconductor. The substrate is a structure containing electric circuits. The ohmic contact N electrode layer and P electrode layer are formed on the N-type contact layer and the P-type contact layer of the light emitting semiconductor respectively. A first metallic layer and a second metallic layer are formed on the surface of the substrate by means of immersion plating or deposition. The metallic layers are connected electrically to the corresponding electric signal input/output nodes of the electric circuit of the substrate. The first metallic layer and the second metallic layer are bonded onto the N electrode layer and the P electrode layer respectively through supersonic welding, and as such the light emitting semiconductor is bonded onto the substrate, and thus realizing the electric connection in-between.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a light emitting semiconductor bonding structure and its manufacturing method, and in particular to a light emitting semiconductor structure bonded on a substrate for creation of electric connection therebetween.

2. The Prior Arts

In the conventional method of producing light emitting semiconductor bonding structures, a light emitting semiconductor is bonded onto an electrically controlled substrate through the ordinary flip chip process.FIG. 3of the attached drawings shows a conventional light emitting semiconductor bonding structure, which is obtained by bonding a substrate301to a light emitting semiconductor302. The substrate301is a structure containing electric circuits, and the light emitting semiconductor302is a light emitting diode. Taking the gallium-nitride (GaN) based light emitting diode as an example, the light emitting semiconductor302comprises an N-type contact layer303and a P-type contact layer304. The N type contact layer303is made of N-type gallium-nitride, and an ohmic contact N electrode layer303ais formed on one exposed side, and a first metallic bump303bis formed on the N electrode layer303a. The P type contact layer304is made of P-type gallium-nitride, an ohmic contact P electrode layer304ais formed on one exposed side, and a second metallic bump304bis formed on the P electrode layer304a. Therefore, the light emitting semiconductor302can be welded on the substrate301through the first metallic bump303band the second metallic bump304bby means of the Flip Chip Bonder, and as thus accommodating the input/output of the electric signals between the substrate301and the light emitting semiconductor302. However, if the metallic bump is made of solder, it is not suitable for the high temperature manufacturing process and the application of the high power light emitting diode (LED) because the melting point of the solder is too low. Besides, although the gold bump process can be used for the metallic bump to overcome the shortcomings of using the solder, yet by doing so, it would require the additional Au Bump Process. In addition, in the application of Gold Bump Process, the number of gold bumps will determine the effectiveness of heat dissipation, and resulting in the increase of its production cost due to the gold bump process required for the high power light emitting diode, and thus reducing its production yield.

Therefore, the development and realization of the present invention is based on the effort to overcome the shortcomings and disadvantages of the conventional light emitting semiconductor bonding structure.

SUMMARY OF THE INVENTION

The present invention relates to a light emitting semiconductor bonding structure and its manufacturing method, and it practically solves one or even several shortcomings and restrictions of the aforementioned related prior art.

The purpose of the present invention is to adopt the entire surface metallic layer bonding rather than the partial surface bonding at the junction of the light emitting semiconductor and the substrate, such that in the bonding process, it needs only to cooperate with the Flip Chip Bonder, and there is no need to produce the Au bumps. Therefore, this kind of entire surface bonding can not only provide the solid and strong bonding, more even current distribution, better heat dissipation, increased reliability, but can also further reduce its production cost and raise its production yield.

To achieve the aforementioned purpose, the present invention provides a light emitting semiconductor bonding structure and its manufacturing method, and the realization of the present invention is achieved mainly through the structure obtained by bonding the substrate onto the light emitting semiconductor. In addition, the substrate is a structure containing electric circuits, and an ohmic contact N electrode layer and P electrode layer are formed on the N-type contact layer and P-type contact layer in the light emitting semiconductor respectively; and the first metallic layer and the second metallic layer are formed on the surface of the substrate through the immersion-plating or deposition. The metallic layers are connected electrically to the corresponding electric signal input/output nodes of the substrate electric circuit respectively. The first metallic layer and the second metallic layer are in cooperation with the N electrode layer and P electrode layer of the light emitting semiconductor respectively so that the first metallic layer and the second metallic layer correspond to and are bonded onto the N electrode layer and P electrode layer respectively through ultra-sonic welding, so that the light emitting semiconductor is bonded onto the substrate, and thus realizing the electric connection in-between.

The purpose and functions of the present invention can be understood more thoroughly through the following detailed description together with the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A preferred embodiment of the present invention will be described in more detail further together with the attached drawings, wherein certain scales and the related scales of other portions are exaggeratedly enlarged to provide more clear description, so as to facilitate the people familiar with this technology to have a better understanding of the present invention.

FIG. 1is the schematic section view of the light emitting semiconductor bonding structure according to the preferred embodiment of the present invention.FIG. 2is the flowchart of the method of realizing the structure inFIG. 1according to the preferred embodiment of the present invention.

First, please refer toFIG. 1, which indicates the preferred embodiment of the light emitting semiconductor bonding structure of the present invention. This structure is realized through bonding the substrate101onto the light emitting semiconductor102.

The substrate101is a structure containing electric circuits, and at least a first metallic layer101aand a second metallic layer101bare formed on its surface. The first metallic layer101aand second metallic layer101bare connected electrically to the corresponding electric signal input/output nodes of the electric circuit of the substrate101, and thus accommodating the input/output of the electric signals between the substrate101and light emitting semiconductor102.

A lead frame is provided on the substrate101, which is used to connect electrically to the light emitting semiconductor102, so as to accommodate the input/output of electric signal from/to the light emitting semiconductor102.

In addition, the light emitting semiconductor102in reality is a light emitting diode, for example, a gallium-nitride (GaN) based light emitting diode. The light emitting semiconductor102includes an N-type contact layer103and a P-type contact layer104. The N-type contact layer103is made of N-type gallium-nitride, and an ohmic contact N electrode layer103ais formed on one of its exposed sides; and the P-type contact layer104is made of P-type gallium-nitride, and an ohmic contact P electrode layer104ais formed on one of its exposed sides.

The first metallic layer101aand the second metallic layer101bof the substrate101are bonded to N electrode layer103aand P electrode layer104aof the light emitting semiconductor102respectively so that the light emitting semiconductor102is bonded onto the substrate101, and thus realizing the electric connection in-between. The areas of said first metallic layer101aand the second metallic layer101bcorrespond to those of the N electrode layer103aand P electrode layer104arespectively so as to form the contact areas of approximately the same size.

Next, please refer toFIG. 2.FIG. 2is the flowchart of the method used in realizing the light emitting semiconductor bonding structure ofFIG. 1according to the preferred embodiment of the present invention, comprising the following steps:

Step201: forming the first metallic layer101aand the second metallic layer101bon the corresponding positions of the substrate101so that the areas and positions of the first metallic layer101aand the second metallic layer101bcorrespond to those of the N electrode layer103aand the P electrode layer104a.

Step202: flip-placing the light emitting semiconductor102on the substrate101so that the N-electrode103aand P-electrode104acorrespond to and are stacked on the first metallic layer101aand the second metallic layer101b, and then through the ultra-sonic welding, bonding the N electrode layer103aonto the first metallic layer101a, and bonding the P electrode layer104aonto the second metallic layer101b. As such, the light emitting semiconductor102can be bonded onto the substrate101, and thus realizing the electric connection in-between.

In the aforementioned steps, the first metallic layer101aand the second metallic layer101bare formed on the substrate101, this is achieved by means of the ordinary metal deposition method in addition to the immersion plating method. Its major essence is to form the first metallic layer101aand the second metallic layer101bon the substrate101so that the areas and positions of the first metallic layer101aand the second metallic layer101bcorrespond to those of the N electrode layer103aand the P electrode layer104a.

The deposition of the first metallic layer101aand the second metallic layer101bcan also be achieved by means of the ordinary metallic deposition, such as the physical vapor deposition (PVD), chemical vapor deposition (CVD), and electroplating.

The first metallic layer101aand the second metallic layer101bof the present invention connect the electric circuit of substrate101to the N electrode layer103aand P electrode layer104aof the light emitting semiconductor102. They form the junction interface between the electric signal input/output node in the electric circuit of the substrate101and the N electrode layer103aand the P electrode layer104aof the light emitting semiconductor102. Therefore, the invention is not restricted to depositing the first metallic layer101aand the second metallic layer101bon the substrate101, and the metallic layers can also be deposited on the surface of the N electrode layer103aand the P electrode layer104a.

The preferred Embodiment described above is only illustrative, and it is not intended to be construed as to be any restrictions to the present invention. Therefore, any variations or modifications made within the spirit and scope of the present invention can be included in the scope of protection of the present invention.