Electroless plating method

Abstract

To provide an electroless plating method capable of simplifying a manufacturing process and reducing manufacturing cost.SOLUTION: An electroless plating method comprises: preparing a metal object to be plated; subjecting the object to be plated to washing to remove impurities on the surface of the object to be plated; subjecting the surface of the object to be plated to plasma processing to ionize metal on the surface of the object to be plated; and immersing the object to be plated subjected to the plasma processing in a chemical plating solution to deposit a plating layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a plating method, and more particularly to an electroless plating method. [Background technology]

[0002] Generally, prior to electroless plating coating, the surface of the object to be plated must be sensitized and activated to allow the catalyst to adhere to the surface of the object to be plated, and when the object to be plated is subsequently immersed in a chemical plating solution to react, the metal is promoted to precipitate and deposit on the catalyst layer to form a plating layer. Summary of the Invention [Problem to be solved by the invention]

[0003] The sensitization and activation processes require pretreatment of the object to be plated by selecting a chemical solution that corresponds to the metal to be plated, which lengthens the overall process time and increases costs. [Means for solving the problem]

[0004] The present invention provides an electroless plating method to simplify the manufacturing process and reduce manufacturing costs.

[0005] The electroless plating method of the present invention includes the following steps: preparing an object to be plated, where the object to be plated is made of metal; subjecting the object to a cleaning process to remove impurities on the surface of the object to be plated; subjecting the surface of the object to a plasma treatment process to ionize the metal on the surface of the object to be plated; and immersing the object to be plated that has undergone the plasma treatment process in a chemical plating solution to form a plating layer.

[0006] In one embodiment of the present invention, the object to be plated is immersed in a chemical plating solution immediately after the object has undergone a plasma treatment process.

[0007] In one embodiment of the present invention, the process gas of the plasma treatment process comprises oxygen and / or argon, and the surface of the object to be plated is exposed to a plasma environment generated by the process gas.

[0008] In one embodiment of the present invention, the surface of the object to be plated is not catalytically activated before the object to be plated is immersed in the chemical plating solution.

[0009] In one embodiment of the present invention, the material of the object to be plated includes gold, silver, platinum, palladium, rhodium, nickel, cobalt, or an alloy thereof.

[0010] In one embodiment of the present invention, the chemical plating solution contains a metal salt, and the metal salt includes nickel ions, chromium ions, gold ions, tin ions, or copper ions.

[0011] In one embodiment of the invention, the cleaning process comprises wet chemical cleaning or plasma cleaning.

[0012] In one embodiment of the present invention, the cleaning solution used in the wet chemical cleaning method includes hydrochloric acid, sulfuric acid, hydrogen peroxide, ammonia, dilute hydrofluoric acid, organic acid, sodium hydroxide, or a combination thereof.

[0013] In one embodiment of the present invention, the cleaning process is a plasma cleaning method, and the cleaning process and the plasma treatment process are performed within the same process step.

[0014] In one embodiment of the present invention, the object to be plated is formed on a substrate, and the material of the substrate includes quartz, glass, resin, or semiconductor. [Effects of the Invention]

[0015] Based on the above, the present invention can greatly simplify the process steps and reduce the manufacturing cost by replacing the surface catalytic activation treatment with the surface plasma treatment process. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a flowchart of an electroless plating method according to one embodiment of the present invention. [Figure 2A] 1A-1D are schematic cross-sectional views of various stages in an electroless plating method according to one embodiment of the present invention. [Figure 2B] 1A-1D are schematic cross-sectional views of various stages in an electroless plating method according to one embodiment of the present invention. [Figure 2C] 1A-1D are schematic cross-sectional views of various stages in an electroless plating method according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] Any directional terms such as "upper," "lower," "front," "rear," "left," "right," etc. referred to herein are used solely to refer to the orientation of the accompanying drawings, and therefore, any directional terminology used is exemplary and not limiting of the present invention.

[0018] In the drawings, each figure illustrates the general features of the methods, structures, and / or materials used in particular embodiments. However, these figures should not be construed as defining or limiting the scope or nature encompassed by these embodiments. For example, the relative dimensions, thicknesses, and positions of each film layer, region, and / or structure may be reduced or enlarged for clarity.

[0019] In the following embodiments, the same or similar elements are denoted by the same or similar reference numerals, and redundant descriptions are omitted. Furthermore, the features of different embodiments can be combined with each other without contradiction, and simple equivalent changes and modifications made according to the scope of this specification or patent application still fall within the scope of this patent.

[0020] Figure 1 is a flow chart of an electroless plating method according to one embodiment of the present invention, and Figures 2A to 2C are schematic cross-sectional views of various stages of an electroless plating method according to one embodiment of the present invention.

[0021] 1 and 2A, in step S10, an object 102 to be plated is provided, and the object 102 may be made of metal. For example, the material of the object 102 to be plated may include gold, silver, platinum, palladium, rhodium, nickel, cobalt, alloys thereof, or other suitable metal materials, which facilitate subsequent chemical plating on the surface 102s of the object 102 to be plated.

[0022] In some embodiments, the object to be plated 102 may be formed on the substrate 100. For example, the object to be plated 102 may be formed on the substrate 100 by physical vapor deposition, chemical vapor deposition, sputtering, electroplating, or other deposition methods. The material of the substrate 100 may include, but is not limited to, quartz, glass, resin, semiconductor, or other suitable substrate materials. Although detailed structures of the substrate 100 are omitted in FIG. 2A , it can be understood that the substrate 100 may include structures such as conductive layers, conductive vias, etc., and thus the object to be plated 102 may be electrically connected to corresponding conductive structures of the substrate 100.

[0023] Continuing with reference to FIGS. 1 and 2A, in step S20, a cleaning process is performed on the object 102 to remove impurities (e.g., oxides, organic matter, metal particles, etc.) on the surface 102s of the object 102. For example, the cleaning process may include wet chemical cleaning, plasma cleaning, or other suitable cleaning methods. Wet chemical cleaning uses a chemical reaction between a cleaning solution and impurities on the surface 102s of the object 102 to remove the impurities. The cleaning solution may include hydrochloric acid, sulfuric acid, hydrogen peroxide, ammonia, dilute hydrofluoric acid, organic acids, sodium hydroxide, combinations thereof, or other suitable cleaning solutions. In some embodiments, the cleaning solution may include hydrogen peroxide and ammonia to remove organic contaminants or particles on the surface 102s of the object 102. In some embodiments, the cleaning solution may include hydrogen peroxide and hydrochloric acid to remove metal or ionic contaminants on the surface 102s of the object 102. In some embodiments, the cleaning solution includes hydrogen peroxide and sulfuric acid and can remove organic contaminants from the surface 102s of the object to be plated 102. In some embodiments, the cleaning solution includes dilute hydrofluoric acid and can remove oxides from the surface 102s of the object to be plated 102. In some embodiments, the wet chemical cleaning method can be performed multiple times using different cleaning solutions, but the invention is not limited thereto. Plasma cleaning methods use plasma to chemically react with impurities on the surface 102s of the object to be plated 102 or to bombard the surface 102s of the object to be plated 102 with plasma to remove impurities. In some embodiments, the plasma cleaning method is performed in a plasma environment generated by a gas source including oxygen, hydrogen, argon, a combination thereof, or other suitable gas. In some embodiments, the object to be plated 102 can be cleaned by one or more wet chemical cleaning methods, one or more plasma cleaning methods, or a combination of wet chemical cleaning and plasma cleaning methods, but the invention is not limited thereto.

[0024] 1 and 2B, in step S30, a plasma treatment process T1 is performed on the surface 102s of the object 102 to be plated, to ionize the metal on the surface 102s of the object 102. For example, the process gas for the plasma treatment process T1 can include oxygen, argon, a combination thereof, and / or other suitable process gases, and the surface 102s of the object 102 to be plated is exposed to a plasma environment generated by the process gas, ionizing the metal on the surface, thereby improving the surface energy and hydrophilicity, and promoting the subsequent formation of a plating layer thereon, eliminating the need for sensitization and activation treatment of the surface 102s of the object 102 to be plated, thereby simplifying the process steps.

[0025] In some embodiments, when the cleaning process is a plasma cleaning method, the cleaning process and the plasma treatment process can be combined and performed in the same process step, although the invention is not limited thereto. In other embodiments, the cleaning process and the plasma treatment process can be performed in different process steps.

[0026] 1 and 3B, in step S40, the plating target 102 that has undergone the plasma treatment process T1 is immersed in a chemical plating solution (not shown), and the surface 102s of the plating target 102 undergoes a chemical reaction to form the plating layer 104. In some embodiments, the chemical plating solution includes a metal salt to provide a source of metal ions for the plating layer 104. For example, the metal salt may include nickel ions, chromium ions, gold ions, tin ions, copper ions, or other suitable metal ions, depending on the material of the plating layer 104 to be plated. In some embodiments, the metal salt may be, for example, a salt composed of a metal ion and sulfate ions, sulfite ions, chloride ions, or the like, but the present invention is not limited thereto. In some embodiments, the chemical plating solution also includes a reducing agent for reducing the metal ions to a metal deposit. For example, the reducing agent may be selected from the group consisting of sodium hypophosphite, sodium borohydride, amine boron, formic acid, formaldehyde, sodium formate, and hydroxylamine. In some embodiments, the chemical plating solution also includes a complexing agent and a buffering agent to stabilize the metal ions in the chemical plating solution. In some embodiments, the chemical plating solution can be heated to a working temperature to facilitate the chemical reaction.

[0027] In some embodiments, after the object to be plated 102 undergoes the plasma treatment process T1, the object to be plated 102 can be immediately immersed in a chemical plating solution to promote the progress of chemical reactions on the surface 102s of the object to be plated 102 and to uniformly form a plating layer 104 on the surface 102s of the object to be plated 102.

[0028] In this embodiment, the surface 102s of the object 102 to be plated is not catalytically activated before the object 102 to be plated is immersed in the chemical plating solution. In other words, a catalytic layer is not formed on the surface 102s of the object 102 to be plated before the object 102 to be plated is immersed in the chemical plating solution. Since the surface 102s of the object 102 to be plated in this embodiment does not require catalytic activity, it is possible to omit the complicated surface sensitization and activation treatment steps, thereby reducing manufacturing costs.

[0029] In some embodiments, the object to be plated 102 may be considered a seed layer for the plating layer 104. In some embodiments, the object to be plated 102 and the plating layer 104 may be considered pads for the substrate 100, through which the substrate 100 can be connected to the outside. In other embodiments, the object to be plated 102 and the plating layer 104 may be a barrier layer to protect subsequent processes.

[0030] In summary, the present invention can greatly simplify the step process and reduce the manufacturing cost by replacing the surface sensitization and activation treatment with the surface plasma treatment process.

[0031] Although the present invention has been disclosed through the above-mentioned embodiments, these are not intended to limit the present invention, and a person having ordinary knowledge in the relevant technical field can make some modifications and alterations without departing from the spirit and scope of the present invention, and the protection scope of the present invention shall be determined by the scope of the attached patent application. [Industrial Applicability]

[0032] The electroless plating method of the present application is suitable for applications involving the formation of layers of metallic materials. [Explanation of symbols]

[0033] 100: Substrate 102: Plating object 102s:Surface 104: Plating layer S10, S20, S30, S40: Step T1: Plasma treatment process

Claims

1. Preparing an object to be plated, the object being made of metal; subjecting the object to a cleaning process to remove impurities on the surface of the object; performing a plasma treatment process on the surface of the object to be plated to ionize metal on the surface of the object to be plated; and immersing the object to be plated that has undergone the plasma treatment process in a chemical plating solution to form a plating layer.

2. 2. The electroless plating method of claim 1, wherein the object to be plated is immersed in the chemical plating solution immediately after the object has undergone the plasma treatment process.

3. 2. The electroless plating method of claim 1, wherein a process gas of the plasma treatment process comprises oxygen and / or argon, and the surface of the object to be plated is exposed to a plasma environment generated by the process gas.

4. 2. The electroless plating method according to claim 1, wherein the surface of the object to be plated is not catalytically activated before the object to be plated is immersed in the chemical plating solution.

5. 2. The electroless plating method according to claim 1, wherein the material of the object to be plated includes gold, silver, platinum, palladium, rhodium, nickel, cobalt, or an alloy thereof.

6. 2. The electroless plating method according to claim 1, wherein the chemical plating solution contains a metal salt, and the metal salt contains nickel ions, chromium ions, gold ions, tin ions, or copper ions.

7. The electroless plating method of claim 1 , wherein the cleaning process comprises a wet chemical cleaning method or a plasma cleaning method.

8. 8. The electroless plating method of claim 7, wherein the cleaning solution used in the wet chemical cleaning method comprises hydrochloric acid, sulfuric acid, hydrogen peroxide, ammonia, dilute hydrofluoric acid, organic acid, sodium hydroxide, or a combination thereof.

9. 8. The electroless plating method of claim 7, wherein the cleaning process is a plasma cleaning process, and the cleaning process and the plasma treatment process occur within the same process step.

10. 2. The electroless plating method according to claim 1, wherein the object to be plated is formed on a substrate, and the material of the substrate includes quartz, glass, resin, or semiconductor.

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