JP2018049962A - Electrode construction of light emission diode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode construction capable of reducing a used amount of gold, and reducing the cost.SOLUTION: In an electrode construction of a light emission diode, an adhesion layer 10 accumulated on the light emission diode and a bond pad layer 20 accumulated on the adhesion layer are packaged. The bond pad layer includes: at least two first metal layers 22 that are alternately sequentially accumulated; at least two second metal layers 21; and a gold layer 23 set to the outermost side. The first metal layer is any one of a group consisting of aluminium and an aluminium alloy. The second metal layer is any one of a group formed by titanium, nickel, chromium, platinum, palladium, titanium nitride, titanium tungsten, tungsten, rhodium, and copper. A main construction of the bond pad layer is a lamination construction of the first and second metal layers. A material of low cost is used for the first metal layer, and a material of high hardness is used for the second metal layer.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a light emitting diode, and more particularly to an electrode configuration of a light emitting diode.

  Taking a blue light-emitting diode as an example, the light-emitting diode (Light Emitting Diode, LED) is made of multiple epitaxials, which are semiconductor materials that emit light. A light emitting main body formed mainly from a gallium nitride-based (GaN-based) epitaxial layer, wherein the main structure is formed so as to deposit a sandwich structure including an N-type semiconductor layer, a light-emitting layer, and a P-type semiconductor layer. Can be divided into horizontal type, vertical type, flip type light emitting diodes, and the like from its configuration, and the main configuration includes an N type semiconductor layer, a light emitting layer, and a P type semiconductor layer.

  Referring to FIG. 1, the electrode structure of a known light emitting diode mainly including an adhesion layer 1 and a bond pad layer 2, wherein the adhesion layer 1 includes a chromium layer 1A (18 Å), a first metal layer. 1B (2500 angstroms) and a second metal layer 1C (500 angstroms), and the bond pad layer 2 includes a platinum layer 2A (400 angstroms) and a gold layer 2B (18000 angstroms), and performs wire bonding. In order to satisfy the demand for hardness during wire bonding and the demand for reduced electromigration, the thickness of the gold layer 2B must reach 18000 angstroms, obviously gold The amount used is extremely large. This is because, since aluminum has a low hardness, wire bonding is difficult to perform, and electromigration occurs when operated with a large current. Since the cost of gold is much higher than that of aluminum, its manufacturing cost is extremely high.

  In order to reduce the manufacturing cost, the use of other materials instead of gold on the premise that the photoelectric characteristics of the light emitting diode or the effect similar thereto is not changed is the current development direction of the field, for example, patents Reference 1 uses an aluminum alloy instead of aluminum to solve the phenomenon of electromigration occurring when operated at a large current, but the characteristics of aluminum alloy are very similar to aluminum. After all, the demand for hardness during wire bonding cannot be satisfied, and the phenomenon that electromigration occurs cannot be solved in a true sense.

Taiwan Patent No. I497767

  A main object of the present invention is to provide an electrode configuration capable of reducing the amount of gold used and reducing the cost.

  The present invention is applied to a light emitting diode, and is an electrode configuration of a light emitting diode including an adhesion layer deposited on the light emitting diode and a bond pad layer deposited on the adhesion layer, wherein the bond pad layer includes: And at least two first metal layers deposited alternately, at least two second metal layers, and an outermost gold layer, wherein the first metal layer is made of aluminum or an aluminum alloy. The second metal layer of any one of the group consisting of titanium, nickel, chromium, platinum, palladium, titanium nitride, titanium tungsten, tungsten, rhodium, copper (Ti, Ni, Cr, Pt, Pd, TiN, TiW , W, Rh, Cu).

  As a result, the present invention has a main configuration of the bond pad layer, the first metal layer being one of the group consisting of low-cost aluminum and aluminum alloy, and high hardness titanium, nickel, chromium, platinum, By adopting a laminated configuration with the second metal layer that is one of the group consisting of palladium, titanium nitride, titanium tungsten, tungsten, rhodium, and copper, the first metal layer is too soft and wire bonding is difficult to perform. Since the problem of electromigration can be improved and the amount of gold used can be greatly reduced, the manufacturing cost can be reduced and the manufacturing demand can be satisfied as compared with the conventional configuration.

It is a schematic diagram which shows the electrode structure of the conventional light emitting diode. It is a schematic diagram which shows the electrode structure of the light emitting diode which concerns on this invention. It is the comparison figure which compared the power consumption of the electrode structure which concerns on this invention, and the power consumption of the conventional electrode structure. It is the comparison figure which compared the forward voltage of the electrode structure which concerns on this invention, and the forward voltage of the conventional electrode structure. It is the comparison figure which compared the conversion efficiency of the electrode structure which concerns on this invention, and the conversion efficiency of the conventional electrode structure.

  In the following, detailed contents and technical description according to the present invention will be described in detail using examples, but these examples are only used for explanation and limit the implementation of the present invention. It is not a thing.

  Referring to FIG. 2, the present invention is applied to a light emitting diode, and includes an electrode configuration of a light emitting diode including an adhesion layer 10 deposited on the light emitting diode and a bond pad layer 20 deposited on the adhesion layer 10. The bond pad layer 20 includes at least two first metal layers 21 that are alternately deposited, at least two second metal layers 22, and an outermost gold layer 23, The first metal layer 21 is one of a group consisting of aluminum and an aluminum alloy, and the second metal layer 22 is titanium, nickel, chromium, platinum, palladium, titanium nitride, titanium tungsten, tungsten, rhodium, One of the group consisting of copper (Ti, Ni, Cr, Pt, Pd, TiN, TiW, W, Rh, Cu).

  The bond pad layer 20 further includes a platinum layer 24 interposed between the second metal layer 22 and the gold layer 23. The adhesion layer 10 may include a chromium layer 11, and the adhesion layer 10 may further include an aluminum layer 12 and a titanium layer 13 that are sequentially deposited on the chromium layer 11. The adhesion layer 10 is used to prevent the electrode configuration from falling off by sticking on the semiconductor layer or the P-type semiconductor layer. Further, it can be used as an N-type electrode or a P-type electrode of a light emitting diode.

  Next, referring to FIGS. 3, 4, and 5, each is a comparative diagram comparing the effect of the electrode configuration according to the present invention and the effect of the conventional electrode configuration, and of these, the electrode configuration according to the present invention is compared. The certain adhesion layer 10 and the bond pad layer 20 are configured as shown in FIG. 2. In the embodiment according to the present invention, the thickness and material of each layer are the chromium layer 11 of the adhesion layer 10. The thickness of the aluminum layer 12 is 2500 angstroms, the thickness of the titanium layer 13 is 500 angstroms, and the materials of the first metal layer 21 and the second metal layer 22 are: Aluminum and titanium, respectively, of which aluminum has a thickness of 10,000 angstroms and titanium has a thickness of 500 angstroms. The platinum layer 24 of Dopaddo layer 20 has a thickness of 400 angstroms, the gold layer 23 has a thickness is in the 2000 angstrom.

  In contrast, in the case of the conventional configuration as shown in FIG. 1, the thickness of each layer is 18 angstroms for the chromium layer, 2500 angstroms for the aluminum layer, 500 angstroms for the titanium layer, 400 angstroms for the platinum layer, and 400 angstroms for the gold layer. It is 18000 angstroms.

  The present invention uses the above-described electrode configuration according to the present invention and the conventional electrode configuration as an N-type electrode and a P-type electrode, respectively, and further consumes power under the respective forward currents (Power). A curve comparison diagram measuring forward voltage (Forward Voltage) and conversion efficiency (Walfilliness, WPE) was prepared, and the curves of the electrode configuration according to the present invention are represented by A1, A2, and A3. The curves are represented by B1, B2, and B3.

  Regarding the power consumption, as can be seen from FIG. 3, the curve A1 representing the electrode configuration according to the present invention is substantially the same as the curve B1 representing the conventional electrode configuration at the time of the low forward current, and as the forward current increases, Although the power consumption increases slightly, the difference is very limited.

  Regarding the forward voltage, as can be seen from FIG. 4, the curve A2 representing the electrode configuration according to the present invention is substantially the same as the curve B2 representing the conventional electrode configuration at the time of the low forward current, and as the forward current increases. Although the forward voltage is slightly increased, the difference is still very limited.

  Regarding the conversion efficiency, as can be seen from FIG. 5, the curve A3 representing the electrode configuration according to the present invention is almost the same as the curve B3 representing the conventional electrode configuration.

  From the above, the present invention is such that the main structure of the bond pad layer is a laminated structure of the first metal layer and the second metal layer, so that the first metal layer is too soft and wire bonding is difficult to perform. Since the problem of migration can be improved and the amount of gold used can be greatly reduced, there is no significant difference in photoelectric characteristics as shown in FIGS. In an embodiment according to the invention, a relatively high cost gold layer can save 13000 angstroms in thickness, while a relatively low cost titanium and aluminum layer are 1000 angstroms and 20000 angstroms, respectively. This is clearly an increase, which can be said to reduce manufacturing costs and meet manufacturing demands.

  In addition, what was mentioned above is only a preferable Example of this invention, and does not limit the range which this invention implements. Any changes and modifications made based on the scope claimed by the present invention shall fall within the scope claimed by the present invention.

DESCRIPTION OF SYMBOLS 1 Adhesion layer 1A Chromium layer 1B Aluminum layer 1C Titanium layer 2 Bond pad layer 2A Platinum layer 2B Gold layer A1, A2, A3, B1, B2, B3 Curve 10 representing electrode configuration Adhesion layer 11 Chrome layer 12 Aluminum layer 13 Titanium layer 20 Bond pad layer 21 First metal layer 22 Second metal layer 23 Gold layer 24 Platinum layer

Claims (7)

An electrode configuration of a light emitting diode, which is applied on a light emitting diode and includes an adhesion layer deposited on the light emitting diode and a bond pad layer deposited on the adhesion layer,
The bond pad layer has at least two first metal layers deposited alternately in sequence, at least two second metal layers, and an outermost gold layer, and the first metal layer is made of aluminum. The second metal layer is any one of the group consisting of titanium, nickel, chromium, platinum, palladium, titanium nitride, titanium tungsten, tungsten, rhodium, and copper. The electrode structure of the light emitting diode characterized by this.   The electrode structure of the light emitting diode according to claim 1, wherein the bond pad layer further includes a platinum layer interposed between the second metal layer and the gold layer.   The electrode structure of the light emitting diode according to claim 1, wherein the adhesion layer includes a chromium layer.   The electrode structure of the light emitting diode according to claim 3, wherein the adhesion layer further includes an aluminum layer and a titanium layer sequentially deposited on the chromium layer.   The electrode of claim 4, wherein the chromium layer of the adhesion layer has a thickness of 18 angstroms, the aluminum layer has a thickness of 2500 angstroms, and the titanium layer has a thickness of 500 angstroms. Constitution.   The material of the first metal layer and the second metal layer is aluminum and titanium, respectively, wherein the aluminum has a thickness of 10,000 angstroms and the titanium has a thickness of 500 angstroms. The electrode structure of the described light emitting diode.   The electrode structure of a light emitting diode according to claim 2, wherein the platinum layer of the bond pad layer has a thickness of 400 angstroms, and the gold layer has a thickness of 2000 angstroms.