Single-layer Copper-Clad Laminate (CCL) Production Process

1. Cutting: Based on the engineering design and layout, the raw material is cut to the specified dimensions for production.
2. Grinding: The copper foil surface is cleaned, and a silicon dioxide brush wheel is used to roughen the surface, enhancing ink adhesion.
3. Circuit Printing: Ink is applied to the surfaces where circuits are needed, protecting them during the etching process.
4. UV Curing: The ink is cured using ultraviolet light.
5. Etching: Unwanted copper (non-circuit areas not protected by ink) is etched away.
6. Ink Stripping: An alkaline solution (NaOH) is used to strip the ink from the circuit surfaces.
7. Grinding: Silicon dioxide brush wheels are used to provide a dry, clean, and rough surface for solder mask printing, preventing bubbling and ink detachment.
8. Solder Mask Printing: A layer of solder mask is printed using a screen printing method on areas where soldering is not needed.
9. UV Curing: The solder mask is cured using ultraviolet light.
10. Bottom Legend Printing: Customer-specified text, logos, or component symbols are screen-printed on the bottom side.
11. UV Curing: The printed legend is cured using ultraviolet light.
12. Top Legend Printing: Similar to the bottom side, customer-specified information is screen-printed on the top side.
13. UV Curing: The top-side legend is cured using ultraviolet light.
14. Drilling and Shaping: The large layout is separated into individual mold layouts, and holes are drilled for punching and other necessary processes.
15. Punching: Through-hole points specified by the customer are punched out.
16. Pressing: Correcting any bending that occurred during the process.
17. V-cutting: V-grooves are cut for separating panels after components are inserted.
18. Grinding: Removing dust, burrs, and contaminants from preceding processes.
19. Testing: Checking for open circuits, short circuits, and defects to prevent faulty products from reaching customers.
20. Surface Resin Coating: Applying a transparent resin coating to the soldering surface to isolate it from air and prevent oxidation.
21. Final Inspection: A comprehensive final inspection covering appearance, circuits, and other aspects.
22. Packaging and Shipment: Packaging the boards according to customer specifications, including vacuum sealing and external packaging for transportation and protection against damage and oxidation.

Multilayer Copper-Clad Laminate (CCL) Production Process

1. Cutting: According to the engineering design and layout, the raw material is cut to the specified dimensions for production.
2. Drilling: Holes are drilled on the board surface to establish connections between layers.
3. Grinding: The copper foil surface is cleaned, and a silicon dioxide brush wheel is used to roughen the surface, enhancing ink adhesion.
4. Copper Plating: A thin layer of copper is deposited on the entire printed board surface, especially on the hole walls, to establish conductivity between layers for subsequent electroplating.
5. Electroplating for Copper Thickness: Using electrochemical principles, the thickness of the copper layer inside the holes and on hole walls is increased to approximately 20-40 micrometers, ensuring reliable interlayer connections and preventing hole breakage in subsequent processes.
6. Grinding: The copper foil surface is cleaned, and a silicon dioxide brush wheel is used to roughen the surface, enhancing ink adhesion.
7. Dry Film Lamination: Dry film (photosensitive film) is tightly laminated onto the copper surface using heat and pressure.
8. Exposure: The desired circuit pattern is exposed on the dry film using image transfer technology.
9. Developing: Unexposed areas (circuits) of the dry film are washed away with a developing solution (Na2CO3); areas that underwent photosensitive reactions (non-circuits) remain on the copper surface as the etching or electroplating resist.
10. Secondary Copper Plating: The exposed copper areas are electroplated to achieve the desired copper thickness specified by the customer.
11. Tin Plating: A layer of tin is plated on the surface of the secondary copper-plated circuits as a protective layer for the etching process.
12. Film Stripping: Using an NaOH solution, the non-circuit areas’ dry film is removed, exposing the copper surface.
13. Etching: Using an etchant (ammonium water) that reacts with copper but not with tin, the unwanted copper in non-circuit areas is etched away, creating the desired circuit pattern.
14. Tin Stripping: Using a tin stripping solution (HNO3 + copper inhibitor), the tin layer on the circuit surface (protective layer for the etching process) is removed, exposing the solderable copper surface.
15. Automated Optical Inspection / Visual Inspection: Inspection after etching to ensure the lines meet requirements, check for anomalies in the holes, inspect for residual copper on the surface, and ensure clean etching.
16. Grinding: The copper foil surface is cleaned, and a silicon dioxide brush wheel is used to roughen the surface, enhancing ink adhesion.
17. Solder Mask Printing: A layer of solder mask is screen-printed on the board surface, acting as long-term insulation and providing chemical protection.
18. Pre-baking: Low-temperature evaporation of solvents in the ink to prevent it from sticking to the film during exposure and to dissolve evenly in non-exposed areas during development.
19. Exposure: Exposing the ink on the transparent areas of the film to ultraviolet light, allowing a reaction to occur. The substance generated won’t be washed away by the developing solution.
20. Developing: Unexposed areas (circuits) of the dry film are washed away with a developing solution (Na2CO3); areas that underwent photosensitive reactions (non-circuits) remain on the copper surface as the etching or electroplating resist.
21. Baking and Curing: Achieving the required hardness and adhesion of the solder mask through baking.
22. Legend Printing: Characters’ ink is screen-printed on the circuit surface, aiding component identification, insertion, and providing production information.
23. Baking and Curing: Achieving the required hardness and adhesion of the solder mask through baking.
24. V-cutting: Machining V-shaped grooves on the PCB as requested by the customer, facilitating panel separation into individual boards after components are installed.
25. Shaping and Cutting: Using a shaping machine to cut the boards into the required outer dimensions.
26. Cleaning: Removing dust left on the board surface by V-cutting and shaping processes, ensuring a clean board surface.
27. Testing: Conducting continuity tests under a specified voltage to ensure the electrical performance of the product meets design and usage requirements.
28. Surface Finish with Organic Solderability Preservatives (OSP): Applying a layer of transparent OSP film to the soldering surface, isolating it from air and providing customers with a good soldering surface.
29. Final Inspection: Inspecting the finished product for appearance, ensuring the quality of circuits meets customer requirements.
30. Packaging and Shipment: Packaging the boards according to customer specifications, including vacuum sealing and external packaging for transportation and protection against damage and oxidation.