Method for realizing selective electroplating of ceramic copper-clad substrate

Abstract

The invention discloses a method for realizing selective electroplating of a ceramic copper-clad substrate. The method comprises the following steps of: masking and electroplating for the first time: coating a photosensitive film, aligning and exposing through a positioning hole, developing to form an electroplating window, electroplating nickel and gold, and removing the film by using an alkaline solution; secondary masking and etching a secondary coating photosensitive film; reusing a positioning hole for alignment exposure; developing and covering a gold plating area and exposing a to-be-etched copper layer; etching the copper layer; by adopting the double-mask collaborative mechanism, the first mask focuses on electroplating pattern transfer and the second mask side re-etching protection, so that batch production can be realized, the production speed is high, and a complicated process of ink printing is not needed.

Description

Technical Field

[0001] The present invention relates to the technical field of electroplating, and in particular to a method for realizing selective electroplating of a ceramic copper-clad substrate. Background Art

[0002] Currently, after etching the circuit pattern, gold plating is performed. During etching, each copper island on the substrate that requires nickel-gold plating must be connected by pre-reserving copper strips to connect them. After etching, photosensitive ink is printed to fill the etched circuit grooves to avoid wasting gold material. After electroplating, the photosensitive ink needs to be stripped and then re-printed to fill the surface and circuit grooves. This process is designed to expose the pre-reserved conductive copper strips for etching. Extra-thick copper will result in poor exposure and development accuracy, which will further reduce the etching effect of the reserved copper strips. Etching the reserved copper strips will also result in incomplete patterns and gaps. Printing ink is inefficient and the ink will stick everywhere, contaminating other products. Ink stripping is time-consuming and difficult to mass produce. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides a method for achieving selective electroplating of a ceramic copper-clad substrate.

[0004] The purpose of the present invention can be achieved through the following technical solutions: A method for selective electroplating of a ceramic copper-clad substrate comprises the following steps: Step S1: After cleaning the ceramic copper-clad substrate, apply a 10-30 μm thick liquid photosensitive ink on its surface, and bake it in a hot air circulation oven at 75-80° C. for 30 minutes to form a rigid dry film; Step S2: Position the laminated substrate using pins, calibrate it using positioning holes, and then expose it under an exposure machine.

[0005] Step S3: After exposure, spray developing with a 1.5% by mass sodium carbonate developer for 50-60 seconds to form a plating window area; Step S4, electroplating nickel and gold to form a 3-5 μm nickel plating layer and a 0.05-0.1 μm gold plating layer; Step S5: using a 25% by mass sodium hydroxide solution to remove the rigid dry film, and then applying a 10-30 μm thick liquid photosensitive ink. After coating, the film is placed in a hot air circulation oven at 75-80° C. for 30 minutes to form a rigid dry film again; Step S6: Calibrate through the positioning holes and then expose under an exposure machine; Step S7, repeating steps S3 and S4, then removing the solder and forming a rigid dry film again, cleaning, and cutting.

[0006] First masking and plating Coating photosensitive film → Exposure through positioning holes → Development to form electroplating window → Electroplating nickel and gold → Alkaline solution stripping film.

[0007] Secondary masking and etching Secondary coating of photosensitive film → multiplexing positioning hole alignment exposure → development to cover the gold-plated area and expose the copper layer to be etched → etching the copper layer → alkaline solution to remove residual solder and form a rigid dry film again.

[0008] Furthermore, the ceramic copper clad substrate is manufactured by the following steps: The solder is applied to the S i3 After baking, drying and debinding treatment on N4 ceramic substrate, it is hot-pressed and brazed with copper material under vacuum at 900℃ to produce a ceramic copper-clad substrate.

[0009] Furthermore, the solid content of the liquid photosensitive ink in step S1 is 60%.

[0010] Furthermore, the resolution of the exposure machine in step S2 is less than 5 μm, and the ultraviolet light source with a wavelength of 436 nm and an energy density of 80 mj / cm is selected for exposure. 2 .

[0011] Furthermore, in step S3, the opening ratio of the electroplating window area is ≥85%.

[0012] Furthermore, in the nickel-gold electroplating process in step S4, the plating solution is a nickel sulfate / nickel chloride plating solution, wherein the nickel ion concentration is 300 g / L and the chloride ion concentration is 60 g / L.

[0013] Furthermore, in step S6, a UV light source with a wavelength of 365 nm and an energy density of 60 mj / cm 2 .

[0014] Beneficial effects of the present invention: The present invention discloses a method for realizing selective electroplating of a ceramic copper-clad substrate, which adopts a double-mask collaborative mechanism. The first mask focuses on transferring the electroplating pattern, and the second mask focuses on etching protection. It can realize mass production with fast production speed, does not require the cumbersome process of ink printing, and does not require etching of the reserved conductive copper strips, and will not cause notches on the copper edge to damage the integrity of the substrate circuit pattern. DETAILED DESCRIPTION

[0015] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0016] Example 1: A method for selective electroplating of a ceramic copper-clad substrate, comprising the following steps: Step S1: After cleaning the ceramic copper-clad substrate, apply a 10 μm thick liquid photosensitive ink (MA-201a, 60% solid content, from Shenzhen Qiangsheng Electronic Materials Co., Ltd.) on its surface. After coating, bake in a hot air circulation oven at 75° C. for 30 minutes to form a rigid dry film. Step S2: Position the laminated substrate using pins, calibrate it using positioning holes, and then expose it under an exposure machine.

[0017] The resolution of the exposure machine is less than 5μm. The exposure is carried out using a UV light source with a wavelength of 436nm and an energy density of 80mj / cm 2 .

[0018] Step S3: After exposure, spray developing with a 1.5% by mass sodium carbonate developer for 50 seconds to form a plating window area (opening ratio ≥ 85%); Step S4, electroplating nickel and gold to form a 3 μm nickel plating layer and a 0.05 μm gold plating layer; The plating solution in the nickel-gold electroplating process is a nickel sulfate / nickel chloride plating solution, in which the nickel ion concentration is 300 g / L and the chloride ion concentration is 60 g / L.

[0019] Step S5: using a 25% by mass sodium hydroxide solution to remove the rigid dry film, and then applying a 10 μm thick liquid photosensitive ink. After the coating is completed, the film is placed in a hot air circulation oven at 75° C. and baked for 30 minutes to form a rigid dry film again; Step S6: After calibration through the positioning holes, the film is exposed under an exposure machine. The UV light source with a wavelength of 365nm and an energy density of 60mj / cm 2 . ; Step S7, repeating steps S3 and S4, then removing the solder and forming a rigid dry film again, cleaning, and cutting.

[0020] The ceramic copper clad substrate is manufactured by the following steps: The solder is applied to the S i3 After baking, drying and debinding treatment on N4 ceramic substrate, it is hot-pressed and brazed with copper material under vacuum at 900℃ to produce a ceramic copper-clad substrate.

[0021] Example 2: A method for selective electroplating of a ceramic copper-clad substrate, comprising the following steps: Step S1: After cleaning the ceramic copper-clad substrate, a 20 μm thick liquid photosensitive ink (MA-201a, 60% solid content, from Shenzhen Qiangsheng Electronic Materials Co., Ltd.) was coated on its surface. After coating, the substrate was placed in a hot air circulation oven at 78° C. for 30 minutes to form a rigid dry film. Step S2: Position the laminated substrate using pins, calibrate it using positioning holes, and then expose it under an exposure machine.

[0022] The resolution of the exposure machine is less than 5μm. The exposure is carried out using a UV light source with a wavelength of 436nm and an energy density of 80mj / cm 2 .

[0023] Step S3: After exposure, spray developing with a 1.5% by mass sodium carbonate developer for 55 seconds to form a plating window area (opening ratio ≥ 85%); Step S4, electroplating nickel and gold to form a 4 μm nickel plating layer and a 0.08 μm gold plating layer; The plating solution in the nickel-gold electroplating process is a nickel sulfate / nickel chloride plating solution, in which the nickel ion concentration is 300 g / L and the chloride ion concentration is 60 g / L.

[0024] Step S5: using a 25% by mass sodium hydroxide solution to remove the rigid dry film, and then applying a 15 μm thick liquid photosensitive ink. After the coating is completed, the film is placed in a hot air circulation oven at 78° C. and baked for 30 minutes to form a rigid dry film again; Step S6: After calibration through the positioning holes, the film is exposed under an exposure machine. The UV light source with a wavelength of 365nm and an energy density of 60mj / cm 2 . ; Step S7, repeating steps S3 and S4, then removing the solder and forming a rigid dry film again, cleaning, and cutting.

[0025] The ceramic copper clad substrate is manufactured by the following steps: The solder is applied to the S i3 After baking, drying and debinding treatment on N4 ceramic substrate, it is hot-pressed and brazed with copper material under vacuum at 900℃ to produce a ceramic copper-clad substrate.

[0026] Example 3: A method for selective electroplating of a ceramic copper-clad substrate, comprising the following steps: Step S1: After cleaning the ceramic copper-clad substrate, apply a 25 μm thick liquid photosensitive ink (MA-201a, 60% solid content, from Shenzhen Qiangsheng Electronic Materials Co., Ltd.) on its surface. After coating, bake in a hot air circulation oven at 80° C. for 30 minutes to form a rigid dry film. Step S2: Position the laminated substrate using pins, calibrate it using positioning holes, and then expose it under an exposure machine.

[0027] The resolution of the exposure machine is less than 5μm. The exposure is carried out using a UV light source with a wavelength of 436nm and an energy density of 80mj / cm 2 .

[0028] Step S3: After exposure, spray developing with a 1.5% by mass sodium carbonate developer for 60 seconds to form a plating window area (opening ratio ≥ 85%); Step S4, electroplating nickel and gold to form a 4 μm nickel plating layer and a 0.08 μm gold plating layer; The plating solution in the nickel-gold electroplating process is a nickel sulfate / nickel chloride plating solution, in which the nickel ion concentration is 300 g / L and the chloride ion concentration is 60 g / L.

[0029] Step S5: using a 25% by mass sodium hydroxide solution to remove the rigid dry film, and then applying a 25 μm thick liquid photosensitive ink. After coating, the film is placed in an 80° C. hot air circulation oven for 30 minutes to form a rigid dry film again; Step S6: After calibration through the positioning holes, the film is exposed under an exposure machine. The UV light source with a wavelength of 365nm and an energy density of 60mj / cm 2 . ; Step S7, repeating steps S3 and S4, then removing the solder and forming a rigid dry film again, cleaning, and cutting.

[0030] The ceramic copper clad substrate is manufactured by the following steps: The solder is applied to the S i3 After baking, drying and debinding treatment on N4 ceramic substrate, it is hot-pressed and brazed with copper material under vacuum at 900℃ to produce a ceramic copper-clad substrate.

[0031] Example 4: A method for selective electroplating of a ceramic copper-clad substrate, comprising the following steps: Step S1: After cleaning the ceramic copper-clad substrate, a 30 μm thick liquid photosensitive ink (MA-201a, 60% solid content, manufactured by Shenzhen Qiangsheng Electronic Materials Co., Ltd.) was coated on its surface. After coating, the substrate was placed in an 80° C. hot air circulation oven and baked for 30 minutes to form a rigid dry film. Step S2: Position the laminated substrate using pins, calibrate it using positioning holes, and then expose it under an exposure machine.

[0032] The resolution of the exposure machine is less than 5μm. The exposure is carried out using a UV light source with a wavelength of 436nm and an energy density of 80mj / cm 2 .

[0033] Step S3: After exposure, spray developing with a 1.5% by mass sodium carbonate developer for 60 seconds to form a plating window area (opening ratio ≥ 85%); Step S4, electroplating nickel and gold to form a 5 μm nickel plating layer and a 0.1 μm gold plating layer; The plating solution in the nickel-gold electroplating process is a nickel sulfate / nickel chloride plating solution, in which the nickel ion concentration is 300 g / L and the chloride ion concentration is 60 g / L.

[0034] Step S5: using a 25% by mass sodium hydroxide solution to remove the rigid dry film, and then applying a 30 μm thick liquid photosensitive ink. After the coating is completed, the film is placed in an 80° C. hot air circulation oven for 30 minutes to form a rigid dry film again; Step S6: After calibration through the positioning holes, the film is exposed under an exposure machine. The UV light source with a wavelength of 365nm and an energy density of 60mj / cm 2 . ; Step S7, repeating steps S3 and S4, then removing the solder and forming a rigid dry film again, cleaning, and cutting.

[0035] The ceramic copper clad substrate is manufactured by the following steps: The solder is applied to the S i3 After baking, drying and debinding treatment on N4 ceramic substrate, it is hot-pressed and brazed with copper material under vacuum at 900℃ to produce a ceramic copper-clad substrate.

[0036] The above content is merely an example and explanation of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A method for selective electroplating of a ceramic copper-clad substrate, characterized in that: The steps include: Step S1: After cleaning the ceramic copper-clad substrate, apply a 10-30 μm thick liquid photosensitive ink on its surface, and bake it in a hot air circulation oven at 75-80° C. for 30 minutes to form a rigid dry film; Step S2: Positioning the laminated substrate using pins, calibrating it using positioning holes, and then exposing it under an exposure machine; Step S3: After exposure, spray developing with a 1.5% by mass sodium carbonate developer for 50-60 seconds to form a plating window area; Step S4, electroplating nickel and gold to form a 3-5 μm nickel plating layer and a 0.05-0.1 μm gold plating layer; Step S5: using a 25% by mass sodium hydroxide solution to remove the rigid dry film, and then applying a 10-30 μm thick liquid photosensitive ink. After coating, the film is placed in a hot air circulation oven at 75-80° C. for 30 minutes to form a rigid dry film again; Step S6: Calibrate through the positioning holes and then expose under an exposure machine; Step S7, repeating steps S3 and S4, then removing the solder in the ceramic copper clad substrate and forming a rigid dry film again, cleaning, and cutting.

2. The method for selective electroplating of a ceramic copper-clad substrate according to claim 1, wherein: The ceramic copper clad substrate is manufactured by the following steps: The solder is applied to the S i3 After baking, drying and debinding treatment on N4 ceramic substrate, it is hot-pressed and brazed with copper material under vacuum at 900℃ to produce a ceramic copper-clad substrate.

3. The method for selective electroplating of a ceramic copper-clad substrate according to claim 1, wherein: The solid content of the liquid photosensitive ink in step S1 is 60%.

4. The method for selective electroplating of a ceramic copper-clad substrate according to claim 1, wherein: The resolution of the exposure machine in step S2 is less than 5 μm, and the ultraviolet light source with a wavelength of 436 nm and an energy density of 80 mj / cm is used for exposure. 2 .

5. The method for selective electroplating of a ceramic copper-clad substrate according to claim 1, wherein: In step S3, the opening ratio of the electroplating window area is ≥85%.

6. The method for selective electroplating of a ceramic copper-clad substrate according to claim 1, wherein: In the nickel-gold electroplating process in step S4, the plating solution is a nickel sulfate / nickel chloride plating solution, wherein the nickel ion concentration is 300 g / L and the chloride ion concentration is 60 g / L.

7. The method for selective electroplating of a ceramic copper-clad substrate according to claim 1, wherein: In step S6, a UV light source with a wavelength of 365 nm and an energy density of 60 mj / cm is used for exposure. 2 .