Cut out short circuits and corrosion with conformal coating NZ
Advances in technology over the years and subsequent growth of the electronics industry has lead to a rise in the need for printed circuit boards (PCBs). Exposure to environmental fragments such as dust and humidity pose significant challenges to the lifespan of electronic parts and circuit boards are no exception. This is where conformal coating NZ comes in.
Conformal coating is a polymeric-based solution which is applied to electronic circuitry to protect against dust, moisture, chemicals and temperature extremes that would otherwise cause damage to the function of the electronic device.
The following are benefits of applying conformal coating:
- Transparent: Components are clearly discernible
- Improved lifespan: Added protection increases the durability of electrical appliances
- PCB conductor spacing efficiency: Insulating properties reduce the distance between adjacent edges of isolated conductive patterns in a conductor layer
- Reduced environmental stress on circuit board assembly
- Thermal and mechanical shock protection
This article explains the way conformal coating works, application and specialists in New Zealand.
How conformal coating works
There are five main types of conformal coatings, namely; acrylic, polyurethane, epoxy, silicone and parylene. A thin film (25-250 micrometers) is applied to the printed circuit board (PCB) and provides a breathing membrane that filters ionic substances such as fingerprint residues which reduce conduction.
Conformal coatings protect PCBs from assembly debris such as wire clippings, loose hardware and solder splatter. Furthermore, they help protect the PCB from vibration damage. Different chemistries repel contaminants at different levels. As a result, a material compatibility study is necessary to determine the correct type of coating for the application.
Acrylic conformal coating
Acrylic conformal coating or Acrylic Resin (AR) is a relatively hard material with a smooth, glossy finish. It is highly arc-resistant, meaning it has a high resistance to electrical arc voltage which can cause a material to become electrically conductive over time.
|✓ Strong dielectric properties allow it to withstand applied voltage||× High VOC potential depending on curing method|
|✓ Simple application and drying process||× Limited chemical resistance|
|✓ Good moisture resistance||× Sensitive to chipping and flaking|
|✓ Reasonably priced||× Not ideal for harsh environments|
|✓ Great for applications that will likely be exposed to water|
Polyurethane conformal coating
This type of coating can be either a single- or double-part substance. The coating surface is smooth, glossy and non-porous. Coating hardness ranges from extremely hard to relatively soft.
|✓ Strong chemical resistance||× Long complete curing time|
|✓ Resistant to mechanical wear||× High VOC potential during curing|
|✓ Low temperature flexibility||× Medium bond strength & tends to peel or flake off|
|✓ Superior protection in harsh environments||× Moisture-cured PU’s affected by presence of humidity|
|✓ Low reversion potential||× Complex removal and rework process|
|✓ Strong dielectric characteristics|
Epoxy conformal coating
Unlike acrylic conformal coatings, epoxy coatings are highly abrasion resistant. They are one of the hardest coatings and produce a hard, smooth finish that is chipping, peeling and cracking resistant.
|✓ Excellent chemical and abrasion resistance||× Can be difficult to remove for repairs|
|✓ Good dielectric properties||× Rigid; can crack in vibration or thermal cycling|
|✓ Relatively short cure time||× Can shrink, causing stress on components/diodes|
|✓ Useful to 150°|
Silicone conformal coating
This is a flexible overlay that protects PCB’s in typically high-temperature environments. Furthermore, they are easy to apply and flexible. Silicone coatings can be coated at a much thicker film build to compensate for the somewhat lower dielectric withstand.
|✓ Stable over wide temperature range (-40°C to 200°C)||× Low abrasion resistance|
|✓ Flexible; provides vibration dampening||× Potential for contamination with other processes|
|✓ Good moisture resistance||× Can have outgassing|
|✓ Good UV resistance||× Rework/repair is very difficult (only removable by abrasion)|
|✓ High dielectric strength|
|✓ Good chemical and heat resistance|
Parylene conformal coating
Parylene or Poly para xylylene is a thermopastic which can be deposited on various substances to form a nearly uniform, continuous layer. Additionally, it is very soft with an approximate hardness of human skin.
|✓ Excellent uniformity||× Requires special application of vapor deposition polymerization before applying|
|✓ Moisture, chemical and temperature resistant||× High cost|
|✓ High dielectric strength||× Sensitive to contaminants|
|× Easy to damage during routine handling|
|× Unsuitable for applications that are subject to friction, pressure or thermal cycling|
What is the best conformal coating?
Choosing the most appropriate conformal coating depends on the size and depth of your project. There are 10 basic factors to consider:
- The temperature operating range
- International, customer or national standards
- Environmental considerations of the circuit board
- Requirement to rework the conformal coating
- Conformal coating material type
- Application process consideration
- Curing the conformal coating
- National, state, regional legislation and insurance
- Supplier performance
The priority of each of these factors depends on where you are in the coating process. Evaluating each and applying a holistic approach to making the final decision will ensure you save costs and ultimately maximize protection for your PCB.
Find conformal coating in New Zealand
Are you looking to buy conformal coating in New Zealand? We are always on hand to connect you with suppliers. Below is a brief overview of possible companies for conformal coating in New Zealand where you can buy coatings or have it applied.
|Synergy Electronics||Importer and distributor||webstore (0800 347 045)|
|element14 Limited||Electrolube distributor||+64 (0) 800 90 80 80|
|RS Components Ltd||Electrolube distributor||Units 31-33 761 Great South Road, Penrose, Auckand 1061|
|Baskiville||Distributor||16 Methven Chertsey Road, Methven 7745|
|Regenisys||Restoration and application||29 Olive Rd, Penrose, Auckland 1061|
|Ambersil – CRC Industries NZ||Manufacturer||10 Highbrook Dr, East Tamaki, Auckland 2013|