Method for etching metal from a circuit board

Abstract

The metal etching method for a circuit board of the present invention includes: pre-processing the circuit board; using radio frequency plasma etching equipment to control the reaction chamber pressure, ion beam energy, and beam current density to etch metal patterns on the circuit board; and post-processing the circuit board. This method employs environmentally friendly and efficient plasma etching technology, enabling high-precision, low-damage etching of metal lines and patterns.

Description

Technical Field

[0001] This invention relates to the field of electronic manufacturing technology, and in particular to a method for metal etching of circuit boards. Background Technology

[0002] Circuit boards are a critical component of electronic devices, and the metal lines and patterns on them are formed through etching processes. Traditional etching methods typically use highly corrosive chemical reagents, such as acidic or alkaline solutions. These methods not only pose environmental pollution problems but also potential safety hazards to operators. Furthermore, traditional etching methods struggle to achieve high precision and complex patterning and cause significant damage to the substrate.

[0003] Therefore, developing an environmentally friendly, efficient, and low-damage metal etching method for circuit boards is an urgent need in the field of electronic manufacturing. Summary of the Invention

[0004] The purpose of this invention is to provide an improved metal etching method for circuit boards, which uses environmentally friendly and efficient plasma etching technology to achieve high-precision, low-damage etching of metal lines and patterns.

[0005] To achieve the above objectives, the metal etching method for the circuit board of the present invention includes the following steps:

[0006] Pre-process the circuit board;

[0007] Radio frequency plasma etching equipment is used to control the reaction chamber pressure, ion beam energy, and beam current density to etch metal patterns on the circuit board; and

[0008] The circuit board is then post-processed.

[0009] Compared with existing technologies, this invention uses radio frequency plasma etching equipment to etch metal patterns on circuit boards by controlling the reaction chamber pressure, ion beam energy, and beam current density, thus avoiding the generation of chemical waste. The ion beam has strong directionality, allowing for precise control of etching depth and sidewall contours. The optimized ion beam energy and beam current density minimize damage to the circuit board substrate. Moreover, this invention has wide applicability and is suitable for etching various types of metals, including copper, aluminum, and gold.

[0010] Preferably, the pressure in the reaction chamber is controlled at 50-200 mTorr.

[0011] Preferably, the ion beam energy is controlled to be 50-200 eV.

[0012] Preferably, the beam current density is controlled at 0.5-1.0 mA / cm². 2 .

[0013] Preferably, a mixture of argon and oxygen is used as the etching gas.

[0014] Preferably, the pretreatment includes cleaning the circuit board and performing photolithography on the circuit board.

[0015] Preferably, the surface of the circuit board is cleaned using an ultrasonic cleaner and deionized water or an organic solvent.

[0016] Preferably, the photolithography process includes forming a photolithographic protective layer on the circuit board and a curing process.

[0017] Preferably, the post-processing includes removing residues and performing surface analysis on the circuit board. Detailed Implementation

[0018] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific implementation methods of this application are described in detail below with reference to some embodiments. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0019] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0020] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0021] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0022] The metal etching method for circuit boards of the present invention will be further described below with reference to embodiments, but this does not limit the present invention. The method of the present invention aims to provide an improved metal etching method for circuit boards, which adopts environmentally friendly and efficient plasma etching technology, and can achieve high-precision, low-damage etching of metal lines and patterns.

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

[0024] Pre-process the circuit board;

[0025] Radio frequency plasma etching equipment is used to control the reaction chamber pressure, ion beam energy, and beam current density to etch metal patterns on the circuit board; and

[0026] The circuit board is then post-processed.

[0027] This invention utilizes radio frequency plasma etching equipment to etch metal patterns onto circuit boards by controlling the reaction chamber pressure, ion beam energy, and beam current density, thus avoiding the generation of chemical waste. The ion beam has strong directionality, allowing for precise control of the etching depth and sidewall contours. Optimized ion beam energy and beam current density minimize damage to the circuit board substrate. Furthermore, this invention has broad applicability, suitable for etching various types of metals, including copper, aluminum, and gold.

[0028] Specifically, in one embodiment, the circuit board is first pre-treated, including cleaning and photolithography. Specifically, the circuit board is cleaned using an ultrasonic cleaner and an organic solvent to remove impurities such as oil and dust. The organic solvent may be isopropanol to improve the cleaning effect. Preferably, the photolithography process includes forming a photolithographic protective layer on the circuit board and a curing process. Specifically, the circuit board is subjected to photolithography or other patterning processes to form a photolithographic protective layer for the areas to be etched. During the photolithography process, ultraviolet light curing technology is introduced to enhance the adhesion and etching resistance of the protective layer.

[0029] Specifically, this invention employs a radio frequency plasma etching apparatus for etching. As a specific embodiment, a 13.56 MHz radio frequency plasma generator is used. Of course, higher frequency radio frequency plasma generators, such as 27.12 MHz, can also be used to achieve more efficient etching.

[0030] The pretreated circuit board is placed in a plasma reaction chamber. A gas with high chemical reactivity and low sputtering rate is selected as the etching gas, such as argon or oxygen, or a mixture of both. Optionally, an inert gas (such as helium or neon) can also be used as an auxiliary gas to optimize the etching process. Radio frequency power is applied to the plasma gas to generate an ion beam. Optimized etching results are achieved by setting and controlling the reaction chamber pressure, ion beam energy, and beam current density. As an example, the reaction chamber pressure is preferably controlled at 50-200 mTorr, for example, 100 mTorr. In another example, the ion beam energy is preferably controlled at 50-200 eV, for example, 150 eV. In yet another example, the beam current density is controlled at 0.5-1.0 mA / cm². 2 For example, 0.7 mA / cm 2 Ideally, the etching time should be adjusted according to the thickness of the metal to be etched and the required etching depth.

[0031] In an alternative embodiment, a magnetic field-assisted device, such as magnetron sputtering, is added within the plasma reaction chamber to improve etching efficiency and uniformity.

[0032] After etching, the circuit board undergoes post-processing, including residue removal and surface analysis. Specifically, the reaction chamber is purged with nitrogen to remove residual gases; the protective layer on the circuit board is peeled off to expose the etched metal lines and patterns; and surface analysis is performed on the etched circuit board to confirm the etching quality. Surface analysis may include etching depth, etched pattern roughness, etc., for example, using a scanning electron microscope (SEM) and an optical profilometer to analyze the surface of the etched circuit board and confirm the etching quality.

[0033] As a preferred embodiment, after the protective layer is stripped, a plasma cleaning step is introduced to remove residual organic matter and etching byproducts.

[0034] As a preferred embodiment, the etched circuit board is subjected to surface modification treatment, such as chemical plating or ion implantation, to enhance the corrosion resistance and conductivity of the metal lines.

[0035] After the above process, the etched metal lines and patterns have clear sidewall contours, uniform etching depth, and no obvious surface damage, meeting the requirements of high-performance circuit boards.

[0036] In summary, this invention utilizes radio frequency plasma etching equipment to etch metal patterns onto circuit boards by controlling the reaction chamber pressure, ion beam energy, and beam current density, thus avoiding the generation of chemical waste. The ion beam exhibits strong directionality, allowing for precise control of the etching depth and sidewall contours. Optimized ion beam energy and beam current density minimize damage to the circuit board substrate. Furthermore, this invention is highly adaptable and suitable for etching various types of metals, including copper, aluminum, and gold.

[0037] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for etching metal onto a circuit board, characterized in that, Includes the following steps: Pre-process the circuit board; Radio frequency plasma etching equipment is used to control the reaction chamber pressure, ion beam energy and beam density to etch metal patterns on the circuit board; as well as The circuit board is then post-processed.

2. The metal etching method for a circuit board as described in claim 1, characterized in that, The pressure in the reaction chamber is controlled at 50-200 mTorr.

3. The metal etching method for a circuit board as described in claim 1, characterized in that, The ion beam energy is controlled to be 50-200 eV.

4. The metal etching method for a circuit board as described in claim 1, characterized in that, Control the beam current density to 0.5-1.0 mA / cm² 2 .

5. The metal etching method for a circuit board as described in claim 1, characterized in that, A mixture of argon and oxygen was used as the etching gas.

6. The metal etching method for a circuit board as described in claim 1, characterized in that, The pretreatment includes cleaning the circuit board and performing photolithography on the circuit board.

7. The metal etching method for a circuit board as described in claim 6, characterized in that: The surface of the circuit board is cleaned using an ultrasonic cleaner and deionized water or organic solvent.

8. The metal etching method for a circuit board as described in claim 6, characterized in that: The photolithography process includes forming a photolithographic protective layer on the circuit board and a curing process.

9. The metal etching method for a circuit board as described in claim 1, characterized in that: The post-processing includes removing residues and performing surface analysis on the circuit board.