Conformal Coating Application Techniques All of the facts for installation and use in production for today’s conformal coatings

Coating Application A close look at all coating techniques What the process is? How they impact on production? Their typical capital and running costs ? How processes integrate with the new conformal coating materials?

Coating Application

A close look at all coating techniques

What the process is?

How they impact on production?

Their typical capital and running costs ?

How processes integrate with the new conformal coating materials?

Possible coating application methods!

Possible coating application methods!

Coating Application Techniques Dip Spray – Aerosol / hand spray Brush Selective Spray Vapour Deposition

Coating Application Techniques

Dip

Spray – Aerosol / hand spray

Brush

Selective Spray

Vapour Deposition

Dip Coating Typical System

Dip Coating

Typical System

Dip Coating Process PCBs hung on arm Boards lowered into dip tank containing coating Immersion <12” min. Minimises entrapment Dwell time. For penetration. Withdrawal 3-6”/min. Controls thickness. Can dip horizontal or vertical

Dip Coating

Process

PCBs hung on arm

Boards lowered into dip tank containing coating

Immersion <12” min. Minimises entrapment

Dwell time. For penetration.

Withdrawal 3-6”/min. Controls thickness.

Can dip horizontal or vertical

Dip Coating Advantages Coating penetrates under components Coating is applied to both sides Coating thickness is assured Can be extremely fast process Low skilled process in application

Dip Coating

Advantages

Coating penetrates under components

Coating is applied to both sides

Coating thickness is assured

Can be extremely fast process

Low skilled process in application

Dip Coating Disadvantages Where intensive masking can be skilled process Inflexible for coating change Thin tip coverage is an issue (see next slide)

Dip Coating

Disadvantages

Where intensive masking can be skilled process

Inflexible for coating change

Thin tip coverage is an issue (see next slide)

Dip Coating Thin Tip Coverage

Dip Coating

Thin Tip Coverage

Dip Coating Capital Costs & Process Capability Capital investment low Running costs low Masking costs may be significant Low skilled process

Dip Coating

Capital Costs & Process Capability

Capital investment low

Running costs low

Masking costs may be significant

Low skilled process

Dip Coating Compatibility Suitable for all solvent & water based coatings Unsuitable for UV cure Can handle some moisture cure products Can be suitable for silicone coatings

Dip Coating

Compatibility

Suitable for all solvent & water based coatings

Unsuitable for UV cure

Can handle some moisture cure products

Can be suitable for silicone coatings

Spray Coating Typical System

Spray Coating

Typical System

Spray Coating Process Aerosol or spray gun Material is diluted and sprayed Multiple passes each at 90 degrees and multiple coats Spray assembly horizontally with spray gun at around 45 degrees Keep humidity >40% and <60%

Spray Coating

Process

Aerosol or spray gun

Material is diluted and sprayed

Multiple passes each at 90 degrees and multiple coats

Spray assembly horizontally with spray gun at around 45 degrees

Keep humidity >40% and <60%

Spray Coating Advantages Two-part Materials may be used Flexibility for alternate materials Reduced masking: shield v barrier Easier/Better tip and edge coverage

Spray Coating

Advantages

Two-part Materials may be used

Flexibility for alternate materials

Reduced masking: shield v barrier

Easier/Better tip and edge coverage

Good Sharp Edge Coverage Atomised Spray

Spray Coating Disadvantages Less penetration under components 3D shadow effects can limit Multiple layers required Semi-skilled process

Spray Coating

Disadvantages

Less penetration under components

3D shadow effects can limit

Multiple layers required

Semi-skilled process

Spray Coating Capital Costs & Process Capability Capital investment low Running costs low Masking costs could be significant Semi-skilled process Capable of >1000 PCBs / week.

Spray Coating

Capital Costs & Process Capability

Capital investment low

Running costs low

Masking costs could be significant

Semi-skilled process

Capable of >1000 PCBs / week.

Spray Coating Compatibility Suitable for all conformal coatings if viscosity can be lowered to a suitable level (<300 cps)

Spray Coating

Compatibility

Suitable for all conformal coatings if viscosity can be lowered to a suitable level (<300 cps)

Brush Coating Process Keep the brush “loaded” from pot Thin coating (10%) for levelling Flow the coating - DO NOT PAINT! Use high quality solvent resistant brushes

Brush Coating

Process

Keep the brush “loaded” from pot

Thin coating (10%) for levelling

Flow the coating - DO NOT PAINT!

Use high quality solvent resistant brushes

Brush Coating Advantages Suited for low volume Excellent for repair & rework Extremely low cost!

Brush Coating

Advantages

Suited for low volume

Excellent for repair & rework

Extremely low cost!

Brush Coating Disadvantages Volume work very expensive! Can be slow on large boards Quality of finish can be questionable Thick coating applied

Brush Coating

Disadvantages

Volume work very expensive!

Can be slow on large boards

Quality of finish can be questionable

Thick coating applied

Brush Coating Capital Costs & Process Capability Capital investment very low! Running costs low Labour costs could be significant Repeatability may be an issue Semi-skilled process Capacity staff dependent!!!

Brush Coating

Capital Costs & Process Capability

Capital investment very low!

Running costs low

Labour costs could be significant

Repeatability may be an issue

Semi-skilled process

Capacity staff dependent!!!

Brush Coating Compatibility Suitable for all conformal coatings if viscosity can be lowered to a suitable level (<100 cps)

Brush Coating

Compatibility

Suitable for all conformal coatings if viscosity can be lowered to a suitable level (<100 cps)

Selective Coating Typical System

Selective Coating

Typical System

Selective Spray Process XYZ & Φ platform Spray valve(s) of various designs Program valves through software

Selective Spray

Process

XYZ & Φ platform

Spray valve(s) of various designs

Program valves through software

Selective Spray Advantages Maximises throughput Minimises masking Automates and conveyorises the production Minimises Labour costs Highly controlled process

Selective Spray

Advantages

Maximises throughput

Minimises masking

Automates and conveyorises the production

Minimises Labour costs

Highly controlled process

Selective Spray Disadvantages May require masking Limitations on coating application (connectors) Skilled Process to operate & program Limitations in 3D spraying

Selective Spray

Disadvantages

May require masking

Limitations on coating application (connectors)

Skilled Process to operate & program

Limitations in 3D spraying

Selective Spray Capital Costs & Process Capability Capital investment high Running costs low Skilled process in programming High volume capacity dependent on valve

Selective Spray

Capital Costs & Process Capability

Capital investment high

Running costs low

Skilled process in programming

High volume capacity dependent on valve

Selective Spray Compatibility Suitable for all conformal coatings if viscosity can be lowered to a suitable level (<250 cps)

Selective Spray

Compatibility

Suitable for all conformal coatings if viscosity can be lowered to a suitable level (<250 cps)

Vapour Deposition Process Material is applied under a vacuum and is converted from gaseous monomers to a layer of dimerised material

Vapour Deposition

Process

Material is applied under a vacuum and is converted from gaseous monomers to a layer of dimerised material

Vapour Deposition Advantages Extremely good protection Uniform coverage

Vapour Deposition

Advantages

Extremely good protection

Uniform coverage

Vapour Deposition Disadvantages By nature it is a batch process Masking MUST be 100% Extremely costly

Vapour Deposition

Disadvantages

By nature it is a batch process

Masking MUST be 100%

Extremely costly

Vapour Deposition Capital Costs & Process Capability Capital investment very high Running costs high Skilled process in masking Low volume capacity

Vapour Deposition

Capital Costs & Process Capability

Capital investment very high

Running costs high

Skilled process in masking

Low volume capacity

Vapour Deposition Compatibility Unsuitable for all conformal coatings

Vapour Deposition

Compatibility

Unsuitable for all conformal coatings

Summary of Results Method Process Skill Capital Costs Throughput Compatibility Dip Low Low High Most Spray Semi Low Medium All Brush Semi Very Low Low All Selective Spray Low High High All Vapour Deposition High Very High Low None

Summary of Results

Whatever issues you currently have we can certainly help and are available to offer advice however complex. SCH Technologies www.conformalcoating.co.uk

Whatever issues you currently have we can certainly help and are available to offer advice however complex.

SCH Technologies

www.conformalcoating.co.uk