PCB golden finger etching process
An optimized etching process with a specialized etching solution and controlled parameters addresses etching inaccuracies, enhancing gold finger precision and uniformity, meeting high electronic equipment standards.
Patent Information
- Application Number
- CN202411523768.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2024-12-31
AI Technical Summary
Traditional PCB board gold finger etching processes face challenges with etching accuracy, uniformity, and side etching issues, which affect the precision and performance of gold fingers, failing to meet the high standards required by modern electronic equipment.
An optimized etching process using a customized etching solution comprising cupric chloride, hydrochloric acid, hydrogen peroxide, and additives, along with controlled process parameters, ensures precise and uniform etching by applying resist and adjusting etching temperature, time, and stirring speed.
The process significantly reduces size deviations, prevents local over-etching or under-etching, and enhances etching uniformity, improving the quality and reliability of gold fingers for various electronic equipment.
Smart Images
Figure CN119233544A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of electronic technology, and in particular relates to a PCB board gold finger etching process. Background Art
[0002] In the rapid development of modern electronic technology, the quality and performance of printed circuit boards (PCBs) as one of the core components of electronic equipment are crucial. The gold fingers on PCBs are the key parts connecting electronic components and external devices, and their quality directly affects the reliability and stability of electronic equipment.
[0003] The traditional PCB board gold finger etching process usually uses a single etching solution and a simple etching method, which has many problems. On the one hand, the etching accuracy is difficult to guarantee, and it is easy to have large deviations in the size of the gold finger, which affects the accuracy of subsequent electronic component installation and connection. For example, in some high-precision electronic equipment, the dimensional accuracy requirements of the gold finger are extremely high, which is often difficult to meet with traditional processes. On the other hand, the etching uniformity is poor, which may cause local over-etching or under-etching on the surface of the gold finger, affecting its electrical performance and service life. In addition, the traditional process is also prone to side etching problems, which makes the edges of the gold finger uneven, increases the contact resistance, and reduces the quality of signal transmission.
[0004] With the continuous miniaturization, high performance and high reliability requirements of electronic equipment, the quality requirements for PCB gold fingers are getting higher and higher. It can no longer meet the needs of modern electronic manufacturing, and a new and efficient PCB gold finger etching process is urgently needed to solve these problems. Summary of the invention
[0005] The purpose of the present invention is to improve a PCB board gold finger etching process and solve the problems of the PCB board gold finger etching process. The present invention can accurately control the etching process by optimizing the etching liquid formula and process parameters, so that the size deviation of the gold finger is significantly reduced; at the same time, the use of the new etching process can make the etching liquid evenly distributed and act on the gold finger area of the PCB board, avoiding the phenomenon of local over-etching or under-etching; the etching process of the present invention is suitable for PCB boards of different types and specifications, as well as various complex electronic equipment manufacturing requirements; the optimized etching liquid formula of the present invention reduces the pollution to the environment while ensuring the etching effect.
[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows: a PCB board gold finger etching process, the process comprising the following steps:
[0007] (1) Prepare the etching liquid raw materials, clean, degrease, micro-etch and other pre-treatments on the PCB board to remove the oil, oxides and impurities on the surface and improve the contact performance between the gold finger and the etching liquid;
[0008] (2) Apply resist to the non-gold finger area of the PCB;
[0009] (3) Expose and develop the PCB board coated with the resist so that the resist in the gold finger area is removed to expose the copper foil;
[0010] (4) Place the exposed and developed PCB board into the etching solution for etching, and control the etching temperature, time, stirring speed and other parameters to ensure etching accuracy and uniformity;
[0011] (5) After etching, the PCB board is cleaned, film-removed and dried to remove residual etching solution and resist and improve the surface quality of the PCB board.
[0012] Furthermore, the etching solution raw materials are made of cupric chloride, hydrochloric acid, hydrogen peroxide and etching solution additives.
[0013] Furthermore, the etching solution additive is one or more of polyethylene glycol, ethylenediamine and ethylenediaminetetraacetic acid.
[0014] Furthermore, the etching solution raw material comprises the following components in parts by weight: 50-100 parts of cupric chloride, 20-50 parts of hydrochloric acid, 10-30 parts of hydrogen peroxide and 1-20 parts of etching solution additives.
[0015] Preferably, the etching solution raw material comprises the following components in parts by weight: 60-80 parts, 25-35 parts of cupric chloride, 15-20 parts of hydrogen peroxide and 3-5 parts of etching solution additives.
[0016] Preferably, the concentration of cupric chloride is 100-120 g / L; the concentration of hydrochloric acid is 50-60 ml / L; the concentration of hydrogen peroxide is 25-30 ml / L; and the concentration of the additive is 4-5 g / L.
[0017] Furthermore, the resist in step (2) is a dry film resist or a wet film resist.
[0018] Furthermore, the drying temperature in step (5) is 70-80°C.
[0019] The beneficial effects achieved by the present invention using the above structure are as follows: (1) The present invention can accurately control the etching process by optimizing the etching solution formula and process parameters, so that the size deviation of the gold finger is significantly reduced; (2) The present invention uses a new etching process to make the etching solution evenly distributed and act on the gold finger area of the PCB board, avoiding the phenomenon of local over-etching or under-etching; (3) The etching process of the present invention is suitable for PCB boards of different types and specifications, as well as various complex electronic equipment manufacturing needs; (4) The optimized etching solution formula of the present invention reduces pollution to the environment while ensuring the etching effect. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 A method for measuring etching width of a gold finger etching process for a PCB board.
[0021] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION
[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0023] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention. The preferred implementation methods and materials described herein are for demonstration purposes only and are not intended to limit the content of this application.
[0024] The experimental methods in the following examples are conventional methods unless otherwise specified; the experimental materials and test strains used in the following examples are purchased from commercial channels unless otherwise specified.
[0025] Example 1
[0026] A PCB board gold finger etching process
[0027] The process comprises the following steps:
[0028] (1) Prepare the etching liquid raw materials, clean, degrease, micro-etch and other pre-treatments on the PCB board to remove the oil, oxides and impurities on the surface and improve the contact performance between the gold finger and the etching liquid;
[0029] (2) Apply resist to the non-gold finger area of the PCB;
[0030] (3) Expose and develop the PCB board coated with the resist so that the resist in the gold finger area is removed to expose the copper foil;
[0031] (4) Place the exposed and developed PCB board into the etching solution for etching, and control the etching temperature to 40°C, the time to 20 minutes, and the stirring speed to 200 rpm to ensure the etching accuracy and uniformity;
[0032] (5) After etching, the PCB board is cleaned, film-removed and dried to remove residual etching solution and resist and improve the surface quality of the PCB board.
[0033] Wherein, the etching solution raw materials are made of cupric chloride, hydrochloric acid, hydrogen peroxide and etching solution additives.
[0034] Wherein, the etching solution additive is polyethylene glycol.
[0035] The etching solution raw materials include the following components in parts by weight: 60 parts, 25 parts of cupric chloride, 15 parts of hydrogen peroxide and 3 parts of etching solution additives.
[0036] Wherein, the concentration of cupric chloride is 100 g / L; the concentration of hydrochloric acid is 50 ml / L; the concentration of hydrogen peroxide is 30 ml / L; and the concentration of the additive is 4 g / L.
[0037] Wherein, the resist in step (2) is a dry film resist.
[0038] Wherein, the drying temperature in step (5) is 75°C.
[0039] Example 2
[0040] A PCB board gold finger etching process
[0041] The process comprises the following steps:
[0042] (1) Prepare the etching liquid raw materials, clean, degrease, micro-etch and other pre-treatments on the PCB board to remove the oil, oxides and impurities on the surface and improve the contact performance between the gold finger and the etching liquid;
[0043] (2) Apply resist to the non-gold finger area of the PCB;
[0044] (3) Expose and develop the PCB board coated with the resist so that the resist in the gold finger area is removed to expose the copper foil;
[0045] (4) Place the exposed and developed PCB board into the etching solution for etching, and control the etching temperature to 50°C, the time to 20 minutes, and the stirring speed to 180rpm to ensure the etching accuracy and uniformity;
[0046] (5) After etching, the PCB board is cleaned, film-removed and dried to remove residual etching solution and resist and improve the surface quality of the PCB board.
[0047] Wherein, the etching solution raw materials are made of cupric chloride, hydrochloric acid, hydrogen peroxide and etching solution additives.
[0048] Wherein, the etching solution additive is polyethylene glycol.
[0049] The etching solution raw materials include the following components in parts by weight: 70 parts, 30 parts of cupric chloride, 18 parts of hydrogen peroxide and 4 parts of etching solution additives.
[0050] Wherein, the concentration of cupric chloride is 110 g / L; the concentration of hydrochloric acid is 50 ml / L; the concentration of hydrogen peroxide is 25 ml / L; and the concentration of the additive is 4 g / L.
[0051] Wherein, the resist in step (2) is a dry film resist.
[0052] Wherein, the drying temperature in step (5) is 75°C.
[0053] Example 3
[0054] A PCB board gold finger etching process
[0055] The process comprises the following steps:
[0056] (1) Prepare the etching liquid raw materials, clean, degrease, micro-etch and other pre-treatments on the PCB board to remove the oil, oxides and impurities on the surface and improve the contact performance between the gold finger and the etching liquid;
[0057] (2) Apply resist to the non-gold finger area of the PCB;
[0058] (3) Expose and develop the PCB board coated with the resist so that the resist in the gold finger area is removed to expose the copper foil;
[0059] (4) Place the exposed and developed PCB board into the etching solution for etching, and control the etching temperature to 60°C, the time to 20 minutes, and the stirring speed to 220rpm to ensure the etching accuracy and uniformity;
[0060] (5) After etching, the PCB board is cleaned, film-removed and dried to remove residual etching solution and resist and improve the surface quality of the PCB board.
[0061] Wherein, the etching solution raw materials are made of cupric chloride, hydrochloric acid, hydrogen peroxide and etching solution additives.
[0062] Wherein, the etching solution additive is polyethylene glycol.
[0063] The etching solution raw materials include the following components in parts by weight: 80 parts, 35 parts of cupric chloride, 20 parts of hydrogen peroxide and 5 parts of etching solution additives.
[0064] Wherein, the concentration of cupric chloride is 120g / L; the concentration of hydrochloric acid is 60ml / L; the concentration of hydrogen peroxide is 30ml / L; and the concentration of additives is 5g / L.
[0065] Wherein, the resist in step (2) is a dry film resist.
[0066] Wherein, the drying temperature in step (5) is 75°C.
[0067] Experimental Example 1
[0068] The influence of a PCB gold finger etching process on the side etching
[0069] The PCB board was etched by the processes provided in Example 1, Example 2 and Example 3 of the present invention, and the obtained samples were divided into Example 1 group, Example 2 group and Example 3 group, with 3 samples in each group, and the initial state of the PCB board was kept consistent, and the side etching width of the edge of the gold finger was measured.
[0070] Result analysis: Figure 1 As shown, the side erosion width of Example 3 group is the smallest, followed by Example 2 group and Example 1 group.
[0071] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
[0072] The present invention and its embodiments are described above, and such description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design a structure and embodiment similar to the technical solution without creativity, which should belong to the protection scope of the present invention.
Claims
1. A PCB board gold finger etching process, characterized in that: The process comprises the following steps: (1) Prepare the etching liquid raw materials, clean, degrease, micro-etch and other pre-treatments on the PCB board to remove the oil, oxides and impurities on the surface and improve the contact performance between the gold finger and the etching liquid; (2) Apply resist to the non-gold finger area of the PCB; (3) Expose and develop the PCB board coated with the resist so that the resist in the gold finger area is removed to expose the copper foil; (4) Place the exposed and developed PCB board into the etching solution for etching, and control the etching temperature, time, stirring speed and other parameters to ensure etching accuracy and uniformity; (5) The etched PCB board is cleaned, film-removed and dried to remove residual etching solution and resist and improve the surface quality of the PCB board.
2. A PCB board gold finger etching process according to claim 1, characterized in that: The etching solution raw materials are made of cupric chloride, hydrochloric acid, hydrogen peroxide and etching solution additives.
3. A PCB board gold finger etching process according to claim 2, characterized in that: The etching solution additive is one or more of polyethylene glycol, ethylenediamine and ethylenediaminetetraacetic acid.
4. A PCB board gold finger etching process according to claim 3, characterized in that: The etching solution raw materials include the following components in parts by weight: 50-100 parts of cupric chloride, 20-50 parts of hydrochloric acid, 10-30 parts of hydrogen peroxide and 1-20 parts of etching solution additives.
5. A PCB board gold finger etching process according to claim 4, characterized in that: The etching solution raw materials include the following components in parts by weight: 60-80 parts, 25-35 parts of cupric chloride, 15-20 parts of hydrogen peroxide and 3-5 parts of etching solution additives.
6. A PCB board gold finger etching process according to claim 5, characterized in that: The concentration of the cupric chloride is 100-120 g / L; the concentration of the hydrochloric acid is 50-60 ml / L; the concentration of the hydrogen peroxide is 25-30 ml / L; and the concentration of the additive is 4-5 g / L.
7. A PCB board gold finger etching process according to claim 6, characterized in that: The resist in step (2) is a dry film resist or a wet film resist.
8. A PCB board gold finger etching process according to claim 7, characterized in that: The drying temperature in step (5) is 70-80°C.