Method for testing electroplating uniformity of fine circuit board

Abstract

The invention discloses a method for testing electroplating uniformity of a fine circuit board. The method comprises the following steps: S1, preparing a substrate; s2, forming a conductive layer on the substrate through sputtering by a magnetron sputtering process; s3, forming a photoresist layer on the substrate on which the conductive layer is formed; s4, removing the part, corresponding to the circuit area of the conductive layer, on the photoresist layer to expose the circuit area; s5, carrying out electroplating thickening operation on the circuit area so as to form a circuit layer in the circuit area through electroplating; s6, removing the remaining photoresist layer; and S7, measuring the thicknesses of the plurality of areas of the circuit layer through a white light interferometer, judging whether the circuit layer is qualified or not according to the difference value of the thicknesses of the plurality of areas of the circuit layer, and judging whether the circuit layer is qualified or not according to the difference value of the thicknesses of the plurality of areas of the circuit layer. The method can be used for detecting the electroplating uniformity of the fine circuit board, and the detection precision and accuracy can be improved.

Description

Technical Field

[0001] The invention relates to a method for testing the electroplating uniformity of a fine circuit board. Background Art

[0002] As AI progresses, traditional data processing capabilities and transmission speeds can no longer meet the growing demand, including the urgent pursuit of better performance, greater bandwidth, lower energy consumption and higher integration. In this context, small and efficient high-speed electronic products have emerged, directly promoting higher standards for PCB design and manufacturing, especially the requirements for fine circuit boards have leapt to a new height.

[0003] For fine circuit boards, circuit uniformity depends on the combined effect of electroplating uniformity and etching uniformity. The traditional electroplating uniformity test method only considers the electroplating uniformity of the bare board, which is far from the electroplating uniformity of the actual circuit. However, the precision and accuracy of the electroplating uniformity detection of fine circuit boards are poor and cannot meet industry requirements. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a method for testing the electroplating uniformity of a fine circuit board, which can be used to detect the electroplating uniformity of a fine circuit board and improve the precision and accuracy of the detection.

[0005] The purpose of the present invention is achieved by the following technical solutions: A method for testing the uniformity of electroplating of a fine circuit board comprises the following steps: Step S1: prepare a substrate; Step S2: sputtering a conductive layer on the substrate by a magnetron sputtering process; Step S3: forming a photoresist layer on the substrate having the conductive layer formed thereon; Step S4: removing the portion of the photoresist layer corresponding to the circuit area of ​​the conductive layer to expose the circuit area; Step S5: performing an electroplating thickening operation on the circuit area to form a circuit layer in the circuit area by electroplating; Step S6: removing the remaining photoresist layer; Step S7: measuring the thickness of multiple regions of the circuit layer by a white light interferometer, and judging whether the circuit layer is qualified according to the difference in thickness of the multiple regions of the circuit layer.

[0006] In step S4, the portion of the photoresist layer corresponding to the circuit area of ​​the conductive layer is removed by exposure and development processes.

[0007] A step S11 is further provided between step S1 and step S2: wiping the substrate and baking the substrate.

[0008] The thickness of the conductive layer is 550-600 nm.

[0009] The thickness of the conductive layer is 560 nm.

[0010] The substrate is a glass substrate, a silicon substrate, or an organic substrate.

[0011] The step S3 comprises the following sub-steps: Sub-step S31: uniformly coating photoresist on the conductive layer; Sub-step S32: curing the liquid photoresist coated on the conductive layer to form a photoresist layer.

[0012] In sub-step S32, the substrate coated with the photoresist is heated.

[0013] In sub-step S32, the substrate coated with the photoresist is heated at a temperature of 100°C.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a method for testing the electroplating uniformity of a fine circuit board. The method adopts steps S1 to S7, and in step S2, a conductive layer is formed on a substrate by a magnetron sputtering process, so as to improve the deposition uniformity of the conductive layer, cleverly avoid the interference of the conductive layer factor on the detection, and ensure the ultimate uniformity at the beginning of circuit production. On this basis, combined with steps S3 to S5, the circuit layer pattern is accurately constructed. This process directly measures the copper thickness of different areas of the circuit layer, which can be used to detect the electroplating uniformity of the fine circuit board, greatly improving the precision and accuracy of the measurement. Compared with traditional means, the scheme of the present invention has achieved a significant leap in practicality and data reliability, and provides a strong technical support for the high-quality manufacturing of fine circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a partial schematic diagram of a circuit layer electroplated on a circuit area of ​​the present invention; Among them, 10 is the line layer; 20 is the line isolation area; 30 is the line dense area. DETAILED DESCRIPTION

[0016] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0017] like Figure 1 As shown, a method for testing the uniformity of electroplating of a fine circuit board comprises the following steps: Step S1: prepare a substrate; Step S2: sputtering a conductive layer on the substrate by a magnetron sputtering process; Step S3: forming a photoresist layer on the substrate with the conductive layer; Step S4: removing the portion of the photoresist layer corresponding to the circuit area of ​​the conductive layer to expose the circuit area; Step S5: performing an electroplating thickening operation on the circuit area, and forming a circuit layer 10 by electroplating in the circuit area, that is, electroplating the circuit layer 10 on the circuit area by an electroplating process; Step S6: removing the remaining photoresist layer; Step S7: measuring the thickness of multiple regions of the circuit layer 10 by a white light interferometer, and judging whether the circuit layer 10 is qualified according to the difference in thickness of the multiple regions of the circuit layer 10.

[0018] The present invention provides a method for testing the electroplating uniformity of a fine circuit board. The method adopts steps S1 to S7. In step S2, a conductive layer is formed on a substrate by a magnetron sputtering process, so as to improve the deposition uniformity of the conductive layer, cleverly avoid the interference of the conductive layer factor on the test result of the electroplating uniformity, and ensure the initial extreme uniformity of the circuit production. On this basis, combined with steps S3 to S5, a photoresist layer is first formed on a substrate with a conductive layer, and then a portion of the circuit area corresponding to the conductive layer on the photoresist layer is removed, and then a circuit layer 10 is electroplated on the circuit area by an electroplating process, and a pattern of the circuit layer 10 is accurately constructed. Then, the thickness of multiple different areas of the circuit layer 10 is measured by a white light interferometer. The method can be used to detect the electroplating uniformity of the fine circuit board, and the measurement precision and accuracy are greatly improved. Compared with traditional means, the scheme of the present invention has achieved a significant leap in practicality and data reliability, and provides a strong technical support for the high-quality manufacturing of fine circuits.

[0019] In step S4, the portion of the photoresist layer corresponding to the circuit area of ​​the conductive layer is removed by exposure and development process. By adopting the above arrangement, it is convenient to remove the portion of the photoresist layer corresponding to the circuit area of ​​the conductive layer.

[0020] Preferably, the photoresist layer is exposed by a photolithography machine, and the exposed area is developed using a developer.

[0021] A step S11 is provided between step S1 and step S2: wiping the substrate and baking the substrate to remove impurities on the substrate surface, ensure the cleanliness of the substrate surface, and evaporate the organic solvent to avoid affecting the effect of forming the photoresist layer.

[0022] Preferably, in step S11, the substrate is baked in a vacuum oven for 30 minutes to improve the stability of the substrate.

[0023] Preferably, in step S11, the substrate is wiped with alcohol.

[0024] Preferably, the thickness of the conductive layer is 550-600 nm. As the most preferred embodiment of the present invention, the thickness of the conductive layer is 560 nm.

[0025] Preferably, the substrate is a glass substrate, a silicon substrate, or an organic substrate to further improve the effect of forming the conductive layer.

[0026] The step S3 comprises the following sub-steps: Sub-step S31: uniformly coating photoresist on the conductive layer; Sub-step S32: Curing the liquid photoresist coated on the conductive layer to form a solid photoresist layer.

[0027] Preferably, in sub-step S32, the conductive layer coated with the photoresist is heated. As the most preferred embodiment of the present invention, in sub-step S32, the conductive layer coated with the photoresist is heated at a temperature of 100° C. for 5 minutes to ensure the formation effect of the photoresist layer and the stability and accuracy of the circuit area.

[0028] In step S6, the remaining photoresist layer may be removed by using a photoresist stripping solution.

[0029] The circuit board in which the circuit layer 10 has the circuit isolation area 20 and the circuit dense area 30 is a fine circuit board.

[0030] Preferably, the circuit layer 10 includes an isolated circuit area 20 and a dense circuit area 30. In step S7: the thickness of multiple regions of the isolated circuit area 20 and the dense circuit area 30 of the circuit layer 10 is measured by a white light interferometer, and whether the circuit layer 10 is qualified is determined according to the difference in thickness of multiple regions of the isolated circuit area 20 and the dense circuit area 30 of the circuit layer 10, so that the copper thickness of multiple regions of the isolated circuit area 20 and the dense circuit area 30 is measured, and the measurement precision and accuracy are greatly improved.

[0031] In this embodiment, the line spacing in the line dense area 30 is less than or equal to 10 μm, and the line spacing in the line isolated area 20 is 800-1200 μm. As a more preferred embodiment, the line spacing in the line isolated area 20 is 900-1000 μm.

[0032] Preferably, in step S7, the thickness of multiple regions of the circuit layer 10 is measured by a white light interferometer, and whether the circuit layer 10 is qualified is determined according to the difference in thickness of the multiple regions of the circuit layer 10, If the electroplating thickness of the circuit layer 10 is 8 μm, and the difference between any two thicknesses of the plurality of regions of the circuit layer 10 is less than 1 μm, the circuit layer 10 is qualified; otherwise, the circuit layer 10 is judged to be unqualified; If the electroplating thickness of the circuit layer 10 is 15 μm, and the difference between any two thicknesses of the plurality of regions of the circuit layer 10 is less than 1.5 μm, the circuit layer 10 is qualified; otherwise, the circuit layer 10 is unqualified; If the electroplating thickness of the circuit layer 10 is 20 μm, and the difference between any two thicknesses of the plurality of regions of the circuit layer 10 is less than 2 μm, the circuit layer 10 is qualified; otherwise, the circuit layer 10 is unqualified.

[0033] By adopting the above-mentioned setting, the circuit layer 10 can be judged based on the electroplating thickness of the circuit layer 10 and the difference between any two thicknesses of the multiple regions of the circuit layer 10, which can further improve the accuracy and lay the foundation for high-quality manufacturing of fine circuits.

[0034] In actual operation, if the electroplating thickness of the circuit layer 10 is 8 μm, and the difference between any two of the thicknesses of the plurality of regions of the circuit layer 10 is 0.8 μm, 0.7 μm, 0.8 μm, 0.6 μm, 0.7 μm, 0.7 μm, 0.7 μm, 0.8 μm, 0.7 μm, 0.7 μm, 0.8 μm, 0.7 μm, 0.8 μm, then it is judged as passing; if the difference between any two of the thicknesses of the plurality of regions of the circuit layer 10 is greater than 1 μm, then it is judged as failing; In actual operation, if the electroplating thickness of the circuit layer 10 is 15μm, and the difference between any two of the thicknesses of the multiple regions of the circuit layer 10 is 1.2μm, 0.9μm, 1.1μm, 1.2μm, 1μm, 1μm, 0.9μm, 1.1μm, 1.2μm, 1μm, and 1.1μm respectively, it is judged as passing; if the difference between any two of the thicknesses of the multiple regions of the circuit layer 10 is greater than 1.5μm, it is judged as failing.

[0035] In actual operation, if the electroplating thickness of the circuit layer 10 is 20μm, and the difference between any two of the thicknesses of the multiple regions of the circuit layer 10 is 1.6μm, 1.5μm, 1.7μm, 1.6μm, 1.8μm, 1.8μm, 1.6μm, 1.6μm, 1.6μm, 1.6μm, 1.6μm, and 1.5μm respectively, it is judged as passing; if the difference between any two of the thicknesses of the multiple regions of the circuit layer 10 is greater than 2μm, it is judged as failing.

[0036] As a further preferred embodiment of the present invention, the method for testing the uniformity of electroplating of fine circuit boards further includes step S8 arranged after step S7: slicing the circuit layer to measure the thickness of the circuit layer 10 through slicing. On the basis of adopting step 7, combined with step 8, the comprehensiveness and accuracy of the measurement can be further improved.

[0037] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A method for testing the uniformity of electroplating of fine circuit boards, characterized in that: The following steps are involved: Step S1: prepare a substrate; Step S2: sputtering a conductive layer on the substrate by a magnetron sputtering process; Step S3: forming a photoresist layer on the substrate having the conductive layer formed thereon; Step S4: removing the portion of the photoresist layer corresponding to the circuit area of ​​the conductive layer to expose the circuit area; Step S5: performing an electroplating thickening operation on the circuit area to form a circuit layer in the circuit area by electroplating; Step S6: removing the remaining photoresist layer; Step S7: measuring the thickness of multiple regions of the circuit layer by a white light interferometer, and judging whether the circuit layer is qualified according to the difference in thickness of the multiple regions of the circuit layer.

2. The method for testing the uniformity of electroplating of a fine circuit board as claimed in claim 1, characterized in that: In step S4, the portion of the photoresist layer corresponding to the circuit area of ​​the conductive layer is removed by exposure and development processes.

3. The method for testing the uniformity of electroplating of a fine circuit board as claimed in claim 1, characterized in that: A step S11 is further provided between step S1 and step S2: wiping the substrate and baking the substrate.

4. The method for testing the uniformity of electroplating of a fine circuit board as claimed in claim 1, characterized in that: The thickness of the conductive layer is 550-600 nm.

5. The method for testing the uniformity of electroplating of a fine circuit board as claimed in claim 4, characterized in that: The thickness of the conductive layer is 560 nm.

6. The method for testing the uniformity of electroplating of a fine circuit board as claimed in claim 1, characterized in that: The substrate is a glass substrate, a silicon substrate, or an organic substrate.

7. The method for testing the uniformity of electroplating of a fine circuit board as claimed in claim 1, characterized in that: The step S3 comprises the following sub-steps: Sub-step S31: uniformly coating photoresist on the conductive layer; Sub-step S32: curing the liquid photoresist coated on the conductive layer to form a photoresist layer.

8. The method for testing the uniformity of electroplating of a fine circuit board as claimed in claim 7, characterized in that: In sub-step S32, the substrate coated with the photoresist is heated.

9. The method for testing the uniformity of electroplating of a fine circuit board as claimed in claim 8, characterized in that: In sub-step S32, the substrate coated with the photoresist is heated at a temperature of 100°C.

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