Are there design rules for the conformal coating dip application?


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There are design guidelines that can be used to help make conformal coating of circuit boards using the dip process a lot easier.

Having these specific design rules for dipping conformal coating can help save a lot of time, money and trouble on the production line.

Here are a list of rules and guidelines that could be considered.

  • Design the board so the masking components are at one end of the circuit. This allows the board to be dipped to a depth before the connectors are coated.
  • Design to hold the board correctly. Make it easy to hold the circuit easily.
  • Design the fixture correctly to avoid coating contamination. Don’t let the fixture get coated.
  • Match the coating material to the dip process. Ensure compatibility.
  • Design the board to drain to a corner. It ensures less build up is found on the board.
  • Avoid using components that can hold conformal coating. When the board drains ensure the component can too.
  • Use the correct components. Use components that are easy to mask.

To find out more click dipping design rules for conformal coating.


Why use conformal coating design rules?

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Circuit board design rules and guidelines, when using conformal coating, can save you money, time and problems.

Nexus, the independent conformal coating resource, have split the conformal coating into sections.

They include:

  • General design
  • Selective Robot
  • Dipping
  • Batch Spraying
  • Parylene

Each has overlapping rules and guidelines that also can be very specific to the application process.


Why it all can go wrong in the design stage for conformal coating

Most companies have successfully adopted Design for Manufacture (DFM) principles.

They have increased the level of communication between design teams and those required to manufacture the product, to eliminate or reduce the number and variety of production challenges.

However, this is not always the case.

Conformal coating is not simply a consumable material.

Unfortunately, for too many designers, conformal coating is simply a part number, to be applied to circuit boards.

For companies embracing lean philosophies and applying coatings, this failure to appreciate the subtleties of the application process can result in an un-coatable (at least as specified) assembly process.

The design rules for conformal coating are straightforward.

Follow them and you can save money and time in your application process.

However, if the rules are not followed, the resultant circuit board design can challenge even the most sophisticated conformal coating system and its operator to achieve the finish desired.

It is almost certain that the majority of these ‘nightmare’ scenarios could have been headed off during the design and or prototyping stages of development.


Find out how we can help you with your conformal coating application selection now.

Contact us to discuss your needs and let us explain how our coating equipment could work for you.

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How do I correctly dip coat my circuit board in conformal coating?


Dip coating is a traditional conformal coating application method that has been used to conformal coat circuit boards for a very long time.

The process in its simplest form is as follows:

  • The printed circuit board (PCB) is dipped into a tank of conformal coating liquid.
  • This can be complete submersion or partial dip.
  • The board can be dipped vertically, horizontally or at another angle.
  • The board can be dipped manually or automatically.
  • The board is removed from the coating and the excess coating drains away.

This process is highly effective in applying a conformal coating to a printed circuit board (PCB).


What equipment may you need for dipping circuit boards in conformal coating?

A simple process is a board dipped by hand into a container of conformal coating. This can give some reasonable results.

However, normally dip coating equipment is used. This is especially true if medium and high volume processing is required.

The reason for using dipping machines is because the process has variables that are critical to film integrity and they are controlled by the machine system.

The variables that are critical for film quality and thickness are:

  • The speed of immersion
  • Dwell time in the coating
  • The withdrawal speed of the board

These factors, plus the viscosity of the conformal coating, are important to create a high quality finish and reduce costs.

A simple process is a board dipped by hand into a container of conformal coating. This can give some reasonable results. However, normally dip coating equipment is used. This is especially true if medium and high volume processing is required.
A simple process is a board dipped by hand into a container of conformal coating. This can give some reasonable results. However, normally dip coating equipment is used. This is especially true if medium and high volume processing is required.

 


How cost effective is the dip process for conformal coating?

The conformal coating process itself can be extremely low cost.

The cost of a dip system can be low compared to many other processes and when balanced against the speed of application.

However, if the circuit board demands a lot of components be masked before processing then the overall coating process can be expensive.

Masking for dipping can be very demanding and very difficult to complete successfully.


Need to know more about using a conformal coating in your application process?

Contact us now and we can discuss how we can help you.

Give us a call at (+44) 1226 249019 or email your inquiries at sales@schservices.com