Film coating method of circuit board

Abstract

The coating method of the circuit board disclosed by the invention comprises the following steps: exposing a target area of the circuit board and protecting parts, except the target area, of the circuit board; preparing a plating solution, wherein the plating solution comprises copper salt and a reducing agent; and soaking the circuit board in the plating solution for a preset time, taking out the circuit board, filtering, and drying to form a copper film on the target area of the circuit board. The circuit setting freedom degree of the circuit board can be greatly improved, and the plating solution is simple in composition and low in process difficulty, so that the manufacturing cost is reduced, batch operation is easy to achieve through the simple process, and the manufacturing efficiency and quality of the circuit board are improved.

Description

Technical Field

[0001] The invention relates to the field of semiconductor manufacturing, and in particular to a coating method for a circuit board. Background Art

[0002] When manufacturing integrated circuits, it is usually necessary to plate a layer of metal or alloy material on the surface of the circuit board to protect the circuit board and improve circuit performance. In the existing circuit board manufacturing process, it is generally necessary to form a copper layer on the substrate by chemical plating, electroplating or physical vapor deposition. The formed copper layer can be further made into a graphic circuit. However, these methods generally require high-cost equipment and materials, a long manufacturing cycle, and are not easy to achieve consistency in large-scale production.

[0003] Therefore, it is urgent to provide an improved circuit board coating method to overcome the above defects. Summary of the invention

[0004] The object of the present invention is to provide an improved coating method for a circuit board, which is simple, efficient and low-cost, and improves the manufacturing efficiency and quality of the circuit board.

[0005] To achieve the above object, the coating method of the circuit board of the present invention comprises the following steps:

[0006] exposing a target area of ​​a circuit board and protecting a portion of the circuit board other than the target area;

[0007] preparing a plating solution comprising a copper salt and a reducing agent; and

[0008] The circuit board is immersed in the plating solution for a predetermined time, and then taken out, the solution is filtered and dried to form a copper film on the target area of ​​the circuit board.

[0009] Compared with the prior art, the present invention adopts a chemical plating method and uses a suitable plating solution to treat the surface of the circuit board. The copper ions in the plating solution are reduced and deposited on the target area of ​​the circuit board, thereby depositing a copper film. This can greatly improve the circuit setting freedom of the circuit board. Moreover, the plating solution of the present invention has a simple composition and low process difficulty, thereby reducing the manufacturing cost. The simple process can easily realize batch operation and improve the manufacturing efficiency and quality of the circuit board.

[0010] Preferably, the copper salt is one or more of copper sulfate, copper chloride, copper oxide, basic copper carbonate and copper nitrate.

[0011] Preferably, the reducing agent is one or more of formaldehyde, hypophosphite, amine borane and sodium borohydride.

[0012] Preferably, the drying is carried out at room temperature, and the drying time is 10-30 minutes.

[0013] Preferably, the soaking time is 10-20 minutes.

[0014] Preferably, after the copper film is formed, the circuit board is cleaned.

[0015] Preferably, the method further comprises: during the immersion, controlling the temperature of the plating solution to be 50-60°C. DETAILED DESCRIPTION

[0016] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with some embodiments. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0017] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0018] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0019] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0020] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0021] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0022] The coating method of the circuit board of the present invention is further described below in conjunction with the embodiments, but the present invention is not limited thereby. The method of the present invention aims to provide an improved coating method of the circuit board, which is simple, efficient, and low-cost, and improves the manufacturing efficiency and quality of the circuit board.

[0023] In one embodiment of the coating method of the circuit board of the present invention, the following steps are included:

[0024] exposing a target area of ​​a circuit board and protecting a portion of the circuit board other than the target area;

[0025] preparing a plating solution comprising a copper salt and a reducing agent; and

[0026] The circuit board is immersed in the plating solution for a predetermined time, and then taken out, the solution is filtered and dried to form a copper film on the target area of ​​the circuit board.

[0027] The present invention adopts a chemical plating method, and uses a suitable plating solution to treat the surface of the circuit board. The copper ions in the plating solution are reduced and deposited on the target area of ​​the circuit board, thereby depositing and forming a copper film, which can greatly improve the circuit setting freedom of the circuit board. Moreover, the plating solution of the present invention has a simple composition and low process difficulty, thereby reducing the manufacturing cost. The simple process is easy to realize batch operation, and the manufacturing efficiency and quality of the circuit board are improved.

[0028] In a specific embodiment, first, prepare a circuit board, expose the target area and protect the circuit board except the target area. For example, the circuit board size is 10mm×10mm, the protection part is coated with an anti-corrosion film, and only the target area is exposed.

[0029] Next, a plating solution is prepared. Preferably, the plating solution contains a water-soluble copper salt and a soluble reducing agent. As an embodiment, the copper salt is one or more of copper sulfate, copper chloride, copper oxide, basic copper carbonate and copper nitrate. The reducing agent is one or more of formaldehyde, hypophosphite, amine borane and sodium borohydride. For example, in this embodiment, copper sulfate is used as the copper salt and formaldehyde is used as the reducing agent, and the plating solution is formed after mixing and stirring. A plating solution with a simple composition simplifies the process on the one hand and saves costs on the other.

[0030] Then, immerse the circuit board in the plating solution for 10-20 minutes. In order to obtain a more ideal plating effect, the temperature of the plating solution is controlled to be 50-60°C. Take it out after immersion, and place the circuit board in a funnel so that its bottom is exposed to the outside so that the liquid can be filtered out. Then, it can be dried at room temperature, for example, the drying time is 10-30 minutes, so that a metal film, that is, a copper film in this embodiment, is deposited on the target area of ​​the circuit board. In this embodiment, the copper ions in the plating solution are reduced to copper by a reduction reaction with the help of a reducing agent and are deposited on the surface of the circuit board. After this step, obvious copper-colored areas and uncovered areas appear on the surface of the circuit board.

[0031] Finally, the circuit board can be placed in clean water or other cleaning fluid to remove remaining impurities on the surface.

[0032] Therefore, the present invention adopts a chemical plating method to treat the surface of the circuit board with an appropriate plating solution, and the copper ions in the plating solution are reduced and deposited on the target area of ​​the circuit board, thereby depositing and forming a copper film, which can greatly improve the circuit setting freedom of the circuit board. Moreover, the plating solution of the present invention has a simple composition and low process difficulty, thereby reducing the manufacturing cost. The simple process can easily realize batch operation, thereby improving the manufacturing efficiency and quality of the circuit board.

[0033] The above disclosure is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A coating method for a circuit board, characterized in that: The following steps are involved: exposing a target area of ​​a circuit board and protecting a portion of the circuit board other than the target area; preparing a plating solution, wherein the plating solution includes a copper salt and a reducing agent; as well as The circuit board is immersed in the plating solution for a predetermined time, and then taken out, the solution is filtered and dried to form a copper film on the target area of ​​the circuit board.

2. The coating method for a circuit board according to claim 1, wherein: The copper salt is one or more of copper sulfate, copper chloride, copper oxide, basic copper carbonate and copper nitrate.

3. The coating method for a circuit board according to claim 1, wherein: The reducing agent is one or more of formaldehyde, hypophosphite, amine borane and sodium borohydride.

4. The coating method for a circuit board as claimed in claim 1, characterized in that: The drying is carried out at room temperature, and the drying time is 10-30 minutes.

5. The coating method for a circuit board as claimed in claim 1, characterized in that: The soaking time is 10-20 minutes.

6. The coating method for a circuit board as claimed in claim 1, characterized in that: After the copper film is formed, the circuit board is cleaned.

7. The coating method for a circuit board as claimed in claim 1, characterized in that: Also includes: During the soaking, the temperature of the plating solution is controlled to be 50-60°C.