In wet film etching process and dry film etching process. How do I choose?

Choosing between wet film etching and dry film etching depends on several factors, including your specific project requirements, the materials you’re working with, and your manufacturing capabilities. Here are some considerations to help you decide which process to use:

1. Material Compatibility:

• Consider the type of metal or substrate you are working with. Both wet film and dry film etching can be used with various materials, but certain metals may be better suited to one method over the other. Ensure that your chosen process is compatible with your substrate.

2. Etching Depth and Feature Size:

• Determine the required etching depth and feature size for your project. If you need to etch fine, intricate patterns with high aspect ratios or very shallow features, wet film etching may be more suitable due to its precise control over etching rates.

3. Surface Finish and Quality:

• Consider the surface finish and quality requirements of your components. Wet film etching can provide a highly uniform surface finish, making it suitable for applications where surface quality is critical.

4. Production Volume:

• Assess your production volume needs. If you’re producing components in small quantities or for rapid prototyping, both wet and dry film etching can work, but wet film etching may offer quicker turnaround times.

5. Complexity of Design:

• Evaluate the complexity of your design and any design changes you anticipate. Wet film etching allows for more flexibility in modifying the mask pattern, making it preferable for designs that may evolve during production.

6. Cost Considerations:

• Analyze your budget and cost considerations. Wet film etching may be more cost-effective for small production runs and prototypes, while dry film etching can be more economical for larger volumes due to reduced setup time and material waste.

7. Process Control:

• Consider your ability to control and monitor the etching process. Wet film etching may require more precise control of etching parameters, such as temperature and agitation, to achieve the desired results.

8. Environmental Impact:

• Take into account environmental considerations. Both processes can be environmentally friendly if proper disposal procedures and environmentally friendly chemicals are used. However, if environmental concerns are a priority, verify the chemicals and waste management associated with each process.

9. Equipment and Expertise:

• Assess your available equipment and expertise. Wet film etching may require specific equipment for handling liquid photoresists, while dry film etching relies on the precise application of dry film resists. Ensure you have the necessary equipment and trained personnel.

10. Application-Specific Requirements: – Some applications may have unique requirements that favor one method over the other. For instance, in microfabrication or MEMS applications, wet film etching may be preferred for its ability to create high-aspect-ratio structures.

• PCB Etching Machine: From Dragon Etching
  • Purpose: PCB etching machines are used to selectively remove unwanted copper from the surface of a copper-clad board to create the desired circuit pattern.
  • Process:
    • The PCB is first cleaned to remove any contaminants.
    • A layer of photoresist is applied to the board’s surface.
    • A photomask, containing the desired circuit pattern, is aligned and placed on the board.
    • The board is exposed to UV light, which hardens the photoresist in areas not covered by the mask.
    • The etching machine sprays an etchant (e.g., ferric chloride) onto the board, which dissolves the exposed copper, leaving behind the circuit traces.
    • After etching, the remaining photoresist is stripped to reveal the clean copper traces.
  • Key Components: The machine includes a conveyor system for transporting boards, nozzles for uniform etchant distribution, and chemical control systems to monitor and control the etching process parameters like temperature, flow rate, and immersion time.
  • Recommended URL: PCB Etching Machine

• PCB Cleaning Machine: From Dragon Etching
  • Purpose: PCB cleaning machines are essential for removing various contaminants and residues from the surface of printed circuit boards.
  • Process:
    • The PCB is placed on a conveyor system that passes it through a series of cleaning stages.
    • Typically, the first stage involves a pre-cleaning step to remove heavy contaminants.
    • Subsequent stages employ ultrasonic cleaning baths, chemical cleaning agents, and brushes or nozzles to thoroughly clean the board’s surface.
    • Rinse cycles follow to remove cleaning agents and residues.
    • Drying mechanisms, such as hot air or infrared heating, ensure the board is completely dry.
  • Key Components: These machines consist of conveyor belts, cleaning tanks, brushes or nozzles for cleaning agents, drying mechanisms, and filtration systems to maintain the cleanliness of cleaning solutions.

• PCB Developing Machine: From Dragon Etching
  • Purpose: PCB developing machines are used to develop the exposed photoresist on a PCB, revealing the circuit pattern.
  • Process:
    • The PCB is loaded onto a conveyor or rack system.
    • It is then passed through a developer bath that contains a developer solution (typically alkaline) which removes the unexposed photoresist.
    • The time of immersion and the temperature of the developer solution are carefully controlled to achieve the desired development.
    • After developing, the board is rinsed to remove any residual developer.
  • Key Components: Key components include developer baths, conveyor systems, and temperature control units for precise process control.

• PCB Stripping Machine: From Dragon Etching
  • Purpose: PCB stripping machines are used in semiconductor manufacturing to remove photoresist or other unwanted layers from wafers.
  • Process:
    • The machine can use chemical processes, such as wet etching or solvent stripping, or mechanical methods, like abrasive brushing, to remove the unwanted layers.
    • The choice of method depends on the specific application and material to be stripped.
  • Key Components: Components may include chemical tanks, spray nozzles, and mechanical components for stripping, as well as exhaust systems to handle chemicals safely.

• PCB Grinding Machine: From Dragon Etching
  • Purpose: PCB grinding machines are used in semiconductor manufacturing to grind and polish silicon wafers for flatness and smoothness.
  • Process:
    • Wafers are mounted on a rotating chuck.
    • Abrasive materials (such as diamond grinding wheels) are used to remove material from the wafer’s surface.
    • Precision control systems ensure uniform grinding and polishing.
  • Key Components: Key components include the rotating chuck, abrasive materials, and precision control systems for grinding parameters.

• PCB Through-Hole Plating: From Dragon Etching
  • Purpose: Through-hole plating machines are used in PCB manufacturing to add a metal layer to through-holes in a printed circuit board, creating a conductive path.
  • Process:
    • The PCB is first cleaned and prepared.
    • It is then immersed in an electroplating bath containing a metal solution (typically copper).
    • An electrical current is applied to deposit the metal layer inside the through-holes.
    • After plating, the board is rinsed and dried.
  • Key Components: Components include electroplating baths, cathodes, anodes, and control systems for regulating plating parameters, as well as rinse and drying stations.

• PCB Drilling Machine: From Dragon Etching
  • Purpose: PCB drilling machines create holes for component leads and vias in printed circuit boards.
  • Detailed Workflow:
    1. Load the PCB onto the machine’s worktable.
    2. Program the CNC control system with coordinates for the holes to be drilled.
    3. Select the appropriate drill bits based on hole size requirements.
    4. The machine’s high-speed spindle begins drilling holes according to the programmed coordinates.
    5. Automatic tool changes may occur if different hole sizes are needed.
    6. Once all holes are drilled, the PCB is removed from the machine.
  • Key Components: Precision drill bits, CNC control system, worktable.

• PCB Routing Machine (PCB Router):
  • Purpose: PCB routing machines trim excess PCB material and separate individual boards from a larger panel.
  • Detailed Workflow:
    1. Load the PCB onto the routing machine.
    2. Program the CNC control system with the desired cutting paths.
    3. The machine’s rotating routing bits follow the programmed paths, precisely cutting the PCB.
    4. As each PCB is cut from the panel, it is moved to a separate collection area.
  • Key Components: Routing bits, CNC control software, worktable.
  • Recommended URL: PCB Routing Techniques

• Solder Paste Printing Machine:
  • Purpose: Solder paste printing machines deposit solder paste onto PCBs before component placement.
  • Detailed Workflow:
    1. Place a stencil over the PCB with openings corresponding to solder pad locations.
    2. Apply solder paste over the stencil.
    3. A squeegee spreads the solder paste evenly across the stencil.
    4. Excess solder paste is scraped away, leaving only paste in the stencil openings.
    5. Remove the stencil, leaving solder paste on the PCB.
  • Key Components: Stencils, squeegees, alignment systems.
  • Recommended URL: Solder Paste Printing Overview

• Pick and Place Machine:
  • Purpose: Pick and place machines automatically position surface-mount components onto PCBs.
  • Detailed Workflow:
    1. The vision system identifies component positions on feeders.
    2. Robotic arms with vacuum nozzles pick up components from the feeders.
    3. The machine accurately places components onto the PCB based on programmed coordinates.
    4. Components are placed at high speeds, with vision systems ensuring precision.
    5. PCBs move through the machine, and components are placed in the desired locations.
  • Key Components: Robotic arms, vision systems, feeders.
  • Recommended URL: Pick and Place Machines

• Reflow Oven:
  • Purpose: Reflow ovens melt solder paste to create solder joints between components and PCBs.
  • Detailed Workflow:
    1. PCBs with solder paste and components enter the oven on a conveyor belt.
    2. The oven has multiple temperature-controlled zones.
    3. In the preheat zone, the temperature gradually rises to activate the flux in the solder paste.
    4. In the reflow zone, the solder paste reflows, forming solder joints.
    5. Cooling zones gradually reduce the temperature to solidify the solder joints.
    6. PCBs exit the oven with properly formed solder joints.