WO2010002206A2

WO2010002206A2 - Electrode material for aln substrate, method of forming electrode on aln substrate, and aln substrate

Info

Publication number: WO2010002206A2
Application number: PCT/KR2009/003622
Authority: WO
Inventors: 김성호
Original assignee: (주) 아모엘이디
Priority date: 2008-07-04
Filing date: 2009-07-02
Publication date: 2010-01-07
Also published as: KR20100004714A; KR100954722B1; WO2010002206A3

Abstract

Disclosed are an electrode material for an AlN substrate with which the adhesion of an electrode formed on the AlN substrate can be improved, a method in which an electrode is formed on the AlN substrate by utilizing electrode material that can improve the adhesion, and an AlN substrate having an electrode with improved adhesion. The electrode material of the AlN substrate is comprised of 50-80 wt% Ag, 10-40 wt% Bi glass, and 3-8 wt% Al as main materials and the remaining components as auxiliary material. The electrode material comprised of the main materials including 50-80 wt% Ag, 10-40 wt% Bi glass, and 3-8 wt% Al and the auxiliary material including the balance component is coated (printed) onto the AlN substrate and formed as an electrode in order to improve the adhesion between the AlN substrate and the electrode relative to existing techniques. When compared with existing sputtering techniques, the cost required for electrode formation can be reduced and productivity is also improved.

Description

A method for forming electrodes on electrode materials of Aln substrate and Aln substrate and Aln substrate

The present invention relates to an electrode material of an Al substrate and a method of forming an electrode on an Al substrate, and more specifically, to an electrode formed on an Al substrate of a flat plate and an electrode formed on the Al substrate. A method and an Al substrate having an electrode thereby.

AION has a thermal conductivity of approximately 170 W / mK. AION is a material that is frequently used in areas requiring high thermal conductivity due to its high thermal conductivity. The LED package is useful because the heat generated from the LED chip must be removed quickly.

However, since Al is an insulator, in order to use it as a board | substrate of an LED package, an electrode must be formed in an Al substrate.

In order to form the electrodes in the conventional Al structure, a process of simultaneously firing the electrodes during fabrication of the substrate was used. In this case, a tungsten (W) electrode mainly having an Al firing temperature of about 1500 ° C. or higher and capable of withstanding high firing temperatures was mainly used.

In this way, a nitrogen atmosphere furnace is required in order to co-fire the AA substrate and the electrode. Nitrogen atmosphere furnaces are expensive and expensive because they must be fired in an atmosphere. Therefore, companies that produce substrates by co-firing Al substrates and electrodes are rare, and it is also very difficult to set conditions for simultaneous firing. Also, even when co-firing, the thermal conductivity is lower than the theoretical value (about 170 W / mK).

For this reason, most of the companies that provide Aln substrates now offer Aln substrates without electrodes having a flat structure.

Therefore, a company that purchases and uses an Al substrate having a flat structure (that is, no electrode) has a problem of forming an electrode. In forming the electrodes, most of the electrodes were formed on the Al substrate by using a sputter method. Although the sputtering method is adopted and used by various companies, the sputtering equipment is expensive, the target used in the process is expensive, and the process time is very long, resulting in low productivity.

Accordingly, the inventors of the present invention tried to form the electrode on the Al substrate by printing without adopting the sputtering method while devising a way to improve the productivity at a lower cost.

1 is a printing method used by the applicant, and shows a process of forming an electrode on a flat Al substrate by a printing method.

According to Fig. 1, after dispensing a paste (e.g., paste of Ag component) 14 onto a flat Al substrate 10 fired as in (a), one side direction (e.g., right direction) is applied to the squeeze 12. Printing by pushing to form the electrode 16 as shown in (b). Then, when fired, the electrode 16 is formed. Thereafter, the first plating layer 18 of Ni is plated on the upper surface of the electrode 16, and then the second plating layer 20 of Ag or Au is plated thereon.

After the plating is completed, the reflow proceeds. After the reflow, most of the adhesion failure occurs as shown in FIG. 2. That is, as in " A " of FIG. 2, the case where the electrode 16 and the

plating layers

18 and 20 are separated from the Al substrate 10 is multireflective.

Accordingly, the Applicant has found that improving the components of the electrode material at the end of various experiments can solve the adhesion failure while searching for a way to solve the adhesion failure.

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above-mentioned conventional problems, and an object thereof is to provide an electrode material of an Al substrate which can improve the adhesion of the electrode to be formed on the Al substrate.

It is another object of the present invention to provide a method for forming an electrode on an Al substrate by using an electrode material capable of improving adhesion.

Still another object of the present invention is to provide an Al substrate having an electrode with improved adhesion.

In order to achieve the above object, the electrode material of the Al substrate according to the preferred embodiment of the present invention is an electrode material of the Al substrate,

A main material comprising 50 to 80% by weight of Ag, 10 to 40% by weight of Bi-based glass, and 3 to 8% by weight of Al, and a submaterial of the remaining components.

Substances include Mg. In this case, Mg is 1 to 5 weight%.

The submaterial further comprises one or more of Si, Cu, and Zn. In this case, Si is 4-10 weight%, Cu is 1-3 weight%, and Zn is 4-10 weight%.

On the other hand, the method for forming an electrode on the Al substrate according to an embodiment of the present invention, the preparation step of preparing a baked Al substrate; An application step of applying an electrode material comprising a main material comprising 50 to 80% by weight of Ag, 10 to 40% by weight of Bi-based glass, and 3 to 8% by weight of Al, and an ingredient of the remaining ingredients to an Al substrate; And a firing step of firing the applied electrode material.

On the other hand, the Al substrate according to the embodiment of the present invention, the main material containing 50 to 80% by weight of Ag, 10 to 40% by weight of Bi-based glass, and 3 to 8% by weight of Al and the subsidiary material of the remaining components And the electrode formed by baking after the electrode material is apply | coated to the surface.

According to the present invention having such a configuration, an electrode material comprising a main material containing 50 to 80% by weight of Ag, 10 to 40% by weight of Bi-based glass, and 3 to 8% by weight of Al and a component material of the remaining components is used. By coating (printing) and electrodelizing the substrate, an effect of improving adhesion between the Al substrate and the electrode can be obtained as compared with the conventional method.

In particular, compared with the conventional sputtering method, the cost required for electrode formation can be reduced and productivity is improved.

Since the electrode pattern is not shrunk by printing on the fired Al substrate, the accuracy of the electrode pattern can be maintained as compared with the simultaneous firing type.

Not only can it be applied to all fields using an aluminum substrate that requires an electrode, but also it can be usefully used for a large area LED package in the form of a single unit or an array employing a high power light emitting device.

Since the adhesion of the electrode formed on the Al substrate is strong, the adhesion failure can be eliminated, whereby the Al substrate on which the electrode is formed can be provided.

1 is a view for explaining the electrode forming process by a conventional printing method.

FIG. 2 is a view for explaining the poor adhesion after plating of the electrode formed by the method of FIG.

3 is a view showing the results of the test for the adhesion with the Al substrate after forming and plating the electrode on the Al substrate using the electrode material according to an embodiment of the present invention.

4 is a view showing a result of a wire pearl test after forming and plating an electrode on an Al substrate using an electrode material according to an embodiment of the present invention.

5 is a view showing the results of a lead heat test after forming and plating an electrode on an Al substrate using an electrode material according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described with respect to the electrode material of the Al substrate according to an embodiment of the present invention.

The electrode material of the Al substrate according to the embodiment of the present invention is in the form of a paste and printed on the Al substrate. In the embodiment of the present invention, the electrode paste is printed on the baked Al substrate.

The components of the paste constituting the electrode material are shown in the following table.

Table 1

ingredient	Example of optimal component content (% by weight)	Range of ingredient content (% by weight)
Mg	3.66	1 to 5
Al	5.43	3 to 8
Si	6.53	4 to 10
Cu	1.55	1 to 3
Zn	6.28	4 to 10
Ag	62.84	50 to 80
Bi	11.72	10 to 40

In the table, 50 to 80 wt% Ag, 10 to 40 wt% Bi-based glass, and 3 to 8 wt% Al are the main materials.

Ag accounts for most of the paste printed on the aluminum substrate. Bi-based glass is an element that improves adhesion with an Al substrate. Al, like Bi-based glass, is an element that improves adhesion with A-N substrate.

If the content of Bi-based glass exceeds 40% by weight, the effect of adhesion is great, but since the glass is exposed to the surface of the Al substrate during firing, the electrical resistance is increased, so that plating is not well performed during plating. When the content of Bi-based glass is less than 10% by weight, a problem arises in the adhesion, which makes it impossible to use as an electrode. Therefore, it is preferable that Bi type glass contains about 10 to 40 weight%.

When the Al content is outside the 3 to 8% by weight, the adhesion improvement effect is reduced.

In the table, Mg, Si, Cu, and Zn become subsidiary materials (additives). When the content of Mg exceeds 1 to 5% by weight, the effect of improving adhesion decreases. Si, Cu and Zn are low melting point materials. The electrode paste of the embodiment of the present invention is fired at a firing temperature of about 800 to 900 degrees. Accordingly, low melting point materials such as Si, Cu, Zn and the like are included as additives for viscosity maintenance and the like. In this case, Si is added at 4 to 10% by weight, Cu is added at 1 to 3% by weight, and Zn is preferably added at 4 to 10% by weight. Among the materials, Si, Cu, and Zn can be selectively used. That is, at least one of Si, Cu, and Zn is included as needed.

Referring to the process of forming and plating the electrode using the electrode material according to an embodiment of the present invention.

First, calcined Al substrate is prepared. An electrode pattern is formed by applying (including printing) a paste containing the components exemplified in the table (eg, Mg, Al, Si, Cu, Zn, Ag, Bi-based glass) to the prepared Al substrate. The paste must be printed on the fired Al substrate so that the electrode pattern does not shrink during subsequent firing, thereby maintaining the accuracy of the electrode pattern. The cofired type has a problem in the precision of the electrode pattern due to the shrinkage rate.

The electrode pattern thus formed is fired at a firing temperature of about 800 to 900 degrees. When fired, it becomes an electrode. After firing, the first plating layer of Ni and the second plating layer of Ag or Au are sequentially plated on the upper surface of the electrode. Ni prevents the electrode and the plating layer on the electrode from being peeled off by the reaction with the solder during the reflow process after SMT for mounting the LED package. As the plating method of the first plating layer, an electrolytic plating method or an electroless plating method is used. The reason for using Ag is that it can be wire bonded, serves as a reflector that reflects light, and has a good reaction with solder. The reason for using Au is because of excellent wire bonding and excellent reaction with solder. What is necessary is just to determine the plating material of a 2nd plating layer in consideration of each condition. As the plating method of the second plating layer, an electroplating method or an electroless plating method is used.

As described above, plating was performed after the formation of electrodes on the baked substrate, and various tests were conducted.

First, in order to test for adhesion with an Al substrate, reflow was performed at approximately 300 ° C. after plating. As a result, as shown in FIG. 3, it was found that the electrode was kept in close contact with the Al substrate. This shows that there is no problem in the adhesion between the electrode and the Al substrate after reflow.

Secondly, a wire pull test was performed after plating. Typically, the wire pearl test after plating is treated as bad if less than 5, when using the electrode material according to an embodiment of the present invention it can be seen that it is more than 5 as shown in FIG.

Third, the lead heat test was performed after plating. After plating, all lead electrodes should be present. Test conditions were that 90% or more of lead was formed in the electrode at 10sec / 250 ° C. As a result of the lead heat test after plating, all the electrodes were present as shown in FIG. 5 (b) is based on the conventional method, and the electrode does not exist conventionally.

Through such tests, when the electrode is formed on the Al substrate using the electrode material according to the embodiment of the present invention, it can be seen that the adhesion failure is removed after plating.

On the other hand, the present invention is not limited only to the above-described embodiment, but can be modified and modified within the scope not departing from the gist of the present invention, and the technical spirit to which such modifications and variations are applied also belong to the following claims Must see

Claims

As the electrode material of the Al substrate,

An electrode material of an Al substrate, comprising: a main material comprising 50 to 80% by weight of Ag, 10 to 40% by weight of Bi-based glass, and 3 to 8% by weight of Al;
The method according to claim 1,

The submaterial comprises Mg. An electrode material of an Al substrate.
The method according to claim 2,

Wherein Mg is 1 to 5% by weight of the electrode material of the Al substrate.
The method according to claim 2,

The electrode material of an Al substrate, further comprising at least one of Si, Cu, and Zn.
The method according to claim 4,

Si is 4 to 10% by weight of the electrode material of the Al substrate.
The method according to claim 4,

Cu is 1 to 3% by weight of the electrode material of the Al substrate.
The method according to claim 4,

Zn is 4 to 10% by weight of the electrode material of the EL substrate.
Preparing a calcined Al substrate;

An application step of applying an electrode material including a main material comprising 50 to 80% by weight of Ag, 10 to 40% by weight of Bi-based glass, and 3 to 8% by weight of Al, and an ingredient of the remaining ingredients to the Al substrate; And

And firing the calcined electrode material.
The method according to claim 8,

The method of forming an electrode on an Al substrate, characterized in that the material of the coating step comprises Mg.
The method according to claim 9,

Wherein the Mg is 1 to 5% by weight, the method of forming an electrode on an A substrate.
The method according to claim 9,

And said subsidiary material further comprises at least one of Si, Cu, and Zn.
The method according to claim 11,

The Si is a method for forming an electrode on an Al substrate, characterized in that 4 to 10% by weight.
The method according to claim 11,

The Cu is a method for forming an electrode on an Al substrate, characterized in that 1 to 3% by weight.
The method according to claim 11,

Wherein Zn is 4 to 10% by weight of the electrode to form an electrode, characterized in that the substrate.
50 to 80 wt% Ag, 10 to 40 wt% Bi-based glass, and an electrode material comprising the main material comprising 3 to 8 wt% Al and the subsidiary materials of the remaining components were formed by firing after application to the surface. An EL substrate comprising an electrode.
The method according to claim 15,

The substrate according to claim 1, wherein the submaterial comprises Mg.
The method according to claim 16,

The substrate further comprises at least one of Si, Cu, and Zn.