Galvanic effect test board for OSP (organic solderability preservative) micro-etching liquid
By designing a standardized OSP micro-etching solution galvanic effect test board, the problem of the galvanic effect of OSP micro-etching solution when connected to different active metals was solved, realizing a scientific and unified evaluation method and improving product reliability and testing efficiency.
Patent Information
- Application Number
- CN202423299736.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2026-02-03
- Estimated Expiration
- 2034-12-31
AI Technical Summary
Existing OSP micro-etching solutions are prone to the Giovanni effect when processing connections with different active metals, resulting in defects such as shrinkage of pads, absence of copper in orifices, and open circuits, which affect product reliability and finished product yield. Furthermore, the lack of uniformity and standardization in test boards leads to inaccurate evaluation and increased management difficulty.
A Giovanni effect test board for OSP micro-etching solution was designed, comprising 168 modules, each with a different gold-copper ratio pattern, connected by copper wires, covered with an ink layer, and made of copper-clad laminate material. The standardized and normalized test board design meets product quality requirements.
This approach enables the scientific evaluation of the Giaviani effect, avoids the quality and cost risks associated with substandard test boards, improves the standardization and consistency of testing, and reduces management difficulty.
Smart Images
Figure CN223872457U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of printed circuit technology, and in particular to a test board for testing the Giovanni effect in OSP preprocessing. Background Technology
[0002] As electronic products evolve towards miniaturization, intelligence, security, and multifunctionality, PCBs face demands for smaller size, more environmentally friendly materials, and higher wiring density. PCB surface treatment processes are trending towards halogen-free, lead-free, high solderability, and high stability. Traditional single surface treatment methods are no longer sufficient, and composite surface treatments, combining the advantages of multiple processes, are widely used. In some high-end PCB manufacturing processes, chemical nickel-gold etching combined with OSP (Optical Separation Process) is frequently used as the final surface treatment. However, this process suffers from a significant problem: the Giovanni Effect, also known as the Raw Cell Effect. When two or more different active metals (such as copper (Cu) and gold (Au)) are bonded together and pass through an OSP micro-etching solution (electrolyte), an electrochemical reaction occurs due to the difference in electromotive force (potential difference). The more active metal loses electrons and undergoes oxidation, resulting in defects such as shrinking pads, missing copper in vias, and open circuits, severely impacting product reliability and yield.
[0003] To address the above issues, the laboratory has specifically developed an OSP micro-etching solution with strong galvanic resistance. During the development process, a test board specifically designed to test galvanic resistance was created. This test board can be used for laboratory testing as well as client-side engineering testing. It features standardization, normalization, and uniformity, allowing for quantitative and scientific evaluation of the OSP micro-etching solution. This meets the company's product quality requirements and avoids the quality risks, cost risks, and management difficulties caused by selecting unqualified or unsuitable galvanic-resistant test boards. Utility Model Content
[0004] The technical problem to be solved by this utility model is to provide a galvanic effect test plate for OSP micro-etching solution, which has the characteristics of standardization, normalization and unification, and is used to scientifically evaluate the galvanic effect of OSP micro-etching solution and meet product quality requirements.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a Giovanni effect test board for OSP micro-etching solution, comprising a test board body; the test board body is provided with 168 modules; each module includes three patterns with different gold-copper ratios: pattern A, pattern B, and pattern C. Pattern A, pattern B, and pattern C each include an upper gold circle and a lower copper circle A, the gold circle and the copper circle A being connected by copper wires; two independent copper circles B are provided on both sides of each copper circle A; the area between the gold circle and the copper circle A is covered with an ink layer, and the copper wires are located below the ink layer.
[0006] Furthermore, the test board body is a copper-clad laminate; the copper-clad laminate has dimensions of 61cm × 53cm.
[0007] Furthermore, the copper-clad laminate is made by laminating a filler material layer impregnated with PP resin and copper foil together, with a copper thickness of 18 μm.
[0008] Furthermore, the 168 modules are arranged in 12 rows and 14 columns.
[0009] Furthermore, the middle part of the test board body is a module arrangement area, the distance between the module arrangement area and the edge of the copper-clad laminate is 2cm, and the spacing between adjacent modules in the module arrangement area is 1cm; the size of the module is 3cm×3cm.
[0010] Furthermore, the gold-copper ratio (diameter ratio) of the aforementioned patterns A, B, and C are 1:100, 1:300, and 1:500, respectively.
[0011] Furthermore, the gold circle is formed by applying 0.05 μm of gold to a copper layer with a thickness of 18 μm; the diameter of the gold circle in pattern A is 4000 μm, the diameter of the gold circle in pattern B is 6928.2 μm, and the diameter of the gold circle in pattern C is 8944 μm.
[0012] Furthermore, both copper circles A and B have a copper thickness of 18 μm and a diameter of 400 μm; in each pattern, the two copper circles B are equidistant from copper circle A, with a spacing of 600 μm.
[0013] Furthermore, below the green ink layer, the copper lines are 100µm wide and 18µm thick; the distance between the first and second copper lines is 8.5mm, and the distance between the second and third copper lines is 11mm.
[0014] Furthermore, the ink layer is 3000µm long and 7000µm wide.
[0015] The beneficial effects of this utility model are as follows:
[0016] The test board of this invention is characterized by standardization and uniformity. It is used to scientifically evaluate the galvanic effect of OSP micro-etching solution, meet product quality requirements, and avoid the quality risks, cost risks, and management difficulties caused by selecting unqualified or unsuitable galvanic test boards for testing. Attached Figure Description
[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0018] Figure 1 This is a schematic diagram of the structure of this utility model.
[0019] Figure 2 Design diagrams for each module.
[0020] Figure 3 This is a schematic diagram of the copper diameter loss ratio due to the Giaviani effect. Detailed Implementation
[0021] The technical solution of this utility model will be clearly and completely described below through specific embodiments.
[0022] The existing testing methods have the following drawbacks: 1. There is no unified standard for test boards, which leads to unreasonable evaluation; 2. The selection of test boards is unreasonable and cannot guarantee that they are fully suitable for the customer's product process requirements; 3. Because conventional PCB boards only have one gold-copper ratio, multiple PCB boards need to be tested to evaluate the Giavani effect, resulting in low work efficiency and a great waste of labor and material costs.
[0023] refer to Figure 1 and Figure 2 This utility model provides a galvanic effect test board for OSP micro-etching solution, which features standardization, normalization, and uniformity. It can quantitatively and scientifically evaluate the galvanic resistance, meet the company's product quality requirements, and avoid the quality risks, cost risks, and management difficulties caused by selecting unqualified or unsuitable galvanic resistance test boards for testing.
[0024] The Giovanni effect test board for OSP micro-etching solution in this embodiment includes a test board body. The test board body 1 is a copper-clad laminate; the copper-clad laminate has dimensions of 61cm × 53cm. The copper-clad laminate is made by laminating a filler material layer impregnated with PP resin and copper foil together, with a copper thickness of 18µm.
[0025] The test board body 1 is equipped with 168 modules 2 (such as...) produced through processes such as dry film lamination, development, etching, film removal, green paint application, exposure, and electroless gold plating. Figure 1 The 168 modules are arranged in 12 rows and 14 columns. Each module has three different gold-copper ratios connected by copper wires.
[0026] The middle part of the test board body is the module layout area. The distance between the module layout area and the edge of the copper-clad laminate is 2cm. The spacing between adjacent modules in the module layout area is 1cm. The size of the module is 3cm×3cm.
[0027] Specifically, the module includes three graphics with different gold-copper ratios: Graphic A, Graphic B, and Graphic C. The gold-copper ratios for Graphic A, Graphic B, and Graphic C are 1:100, 1:300, and 1:500, respectively.
[0028] Graphics A3, B4, and C5 all include an upper gold circle 31 and a lower copper circle A32, connected by a copper wire 33. Two independent copper circles B34 are positioned on either side of each copper circle A33. The area between the gold circle and the copper circle A is covered by an ink layer 6, with the copper wire located below the ink layer. Copper circles A and B have the same copper thickness and diameter, both 18µm thick and 400µm in diameter. In each graphic, the two copper circles B are equidistant from copper circle A, with a spacing of 600µm. The main purpose is to provide a more intuitive and accurate display of the anti-Gialvani effect by comparing it with the diameter of the central circle.
[0029] The copper wires connecting the gold and copper layers are located below the green ink layer. The copper wires are 100µm wide and 18µm thick. The distance between the first and second copper wires is 8.5mm, and the distance between the second and third copper wires is 11mm. The ink layer is 3000µm long and 7000µm wide.
[0030] The gold circle above the ink is a 0.05µm gold plating on a 18µm thick copper substrate; the diameter of the gold circle in pattern A is 4000µm, the diameter of the gold circle in pattern B is 6928.2µm, and the diameter of the gold circle in pattern C is 8944µm. (e.g.) Figure 2 )
[0031] The formula for calculating the copper diameter loss ratio due to the Giavian effect is as follows (e.g.) Figure 3 ):
[0032] Copper diameter loss ratio = (copper diameter before micro-etching - copper diameter after micro-etching) / copper diameter before micro-etching * 100. The smaller the loss ratio, the better the resistance to the Gabriel effect.
[0033] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Those skilled in the art can make various modifications or equivalent substitutions to the present utility model within its substance and protection scope, and such modifications or equivalent substitutions should also be considered to fall within the protection scope of the present utility model's technical solution.
Claims
1. A Giovanni effect test plate for OSP micro-etching solution, characterized in that: The test board includes a main body; the main body has 168 modules; each module includes three patterns with different gold-copper ratios: pattern A, pattern B, and pattern C. Patterns A, B, and C each include an upper gold circle and a lower copper circle A, which are connected by copper wires; each copper circle A has two independent copper circles B on both sides; the area between the gold circle and the copper circle A is covered with an ink layer, and the copper wires are located below the ink layer.
2. The Giovanni effect test plate for OSP micro-etching solution according to claim 1, characterized in that: The test board body is a copper-clad laminate; the copper-clad laminate has a size of 61cm × 53cm.
3. The Giovanni effect test plate for OSP micro-etching solution according to claim 2, characterized in that: The copper-clad laminate is made by laminating a filler layer impregnated with PP resin and copper foil together, with a copper thickness of 18 μm.
4. The Giovanni effect test plate for OSP micro-etching solution according to claim 1, characterized in that: The 168 modules are arranged in 12 rows and 14 columns.
5. A Giovanni effect test plate for OSP micro-etching solution according to claim 1, characterized in that: The middle part of the test board body is the module arrangement area. The distance between the module arrangement area and the edge of the copper-clad laminate is 2cm. The spacing between adjacent modules in the module arrangement area is 1cm. The size of the module is 3cm×3cm.
6. A Giovanni effect test plate for OSP micro-etching solution according to claim 1, characterized in that: The gold-copper ratios of the aforementioned patterns A, B, and C are 1:100, 1:300, and 1:500, respectively.
7. The Giovanni effect test plate for OSP micro-etching solution according to claim 1, characterized in that: The gold circle is formed by applying 0.05 μm of gold to a copper substrate with a thickness of 18 μm; the diameter of the gold circle in pattern A is 4000 μm, the diameter of the gold circle in pattern B is 6928.2 μm, and the diameter of the gold circle in pattern C is 8944 μm.
8. A Giovanni effect test plate for OSP micro-etching solution according to claim 1, characterized in that: Both copper round A and copper round B have a copper thickness of 18 μm and a diameter of 400 μm; in each pattern, the two copper rounds B are equidistant from copper round A, with a spacing of 600 μm.
9. A Giovanni effect test plate for OSP micro-etching solution according to claim 1, characterized in that: Below the green ink layer, the copper lines are 100µm wide and 18µm thick; the distance between the first and second copper lines is 8.5mm, and the distance between the second and third copper lines is 11mm.
10. A Giovanni effect test plate for OSP micro-etching solution according to claim 1, characterized in that: The ink layer is 3000µm long and 7000µm wide.