PMcoat AK 122-37 F

The Product

PMcoat AK 122-37 F is a transparent conformal coating, based on established urethane modified alkyd chemistry. It is designed for air less cross cut nozzle applications and spray, but it could also use for brush and dip applications.
PMcoat AK 122-37 F meets the latest requirements of electronics, e.g. low pin corrosion, fast curing at ambient temperatures or oven cure conditions.

PMcoat AK 122-37 F is lead-free and has no aromatic compounds in the solvent and satisfies the require-ments of RoHS directive.

The varnish features superior performance in thermal and dielectric properties which are maintained when subjected to environmental stress.

Application

Coating of electronics:
• PCB’s subject aggressive environment
– automotive or marine navigation
– Industrial
– Corrosive gas
– Hybrids

  • SMD devices
  • Discrete components
  • Suitable for safety critical systems
Main Properties
  • High temperature index of 135°C
  • Listed in UL 94 V0
  • Superior dielectric properties
  • High volume resistivity including humid conditions
  • Resists moisture, water, corrosive gas, chemicals
  • Excellent adhesion to most surfaces
  • All performance properties in very thin films
  • RoHS compliant
  • Eminently suitable for inspection under UV-light
  • Reworkable
Resistance to Harsh Conditions

Electronic components, covered with PMcoat AK 122-37 F, provide maximum resistance against conta-minants such as moisture, dust and many chemicals. It withstands corrosive gas atmosphere, weak acids, fuels, oils, glycols and many other fluids used in automotive and shipping industry.

The cured coating retains good adhesion, but remains flexible to withstand distortion of the PCB.
PCB’s, covered with PMcoat AK 122-37 F, can survive temperature shock and temperature cycling tests for more than 500 cycles (e.g. 40 to 125°C, IPC Test 2.6.7.1 Class 2).

Processing

PMcoat AK 122-37 F is optimized for mass produc-tion with automatic and semi-automatic applications. Especially for cross cut nozzle applications. It is ready to use, usually no diluting is needed.
The coating minimizes risk of blocking the nozzle.
It could also be used for dipping and brush coating, if the viscosity is suited to the PCB or electronic com-ponent. Thinner PMsolv 3001 is required for dilution.

PMcoat AK 122-37 F is a flammable liquid; good ven-tilation is important in all processing areas.
In order to achieve satisfactory wetting and fault-free adhesion with PMcoat AK 122-37 F, it is important to ensure compatibility with applied solder resist, paste and flux.
A cleaning process can optimize adhesion (e.g. plasma treatment or conventional washing of the PCB’s).

Curing

Batch curing:
Ambient Temperature, for 16 h
Accelerated cure at 80°C in 0.5 h

Continuous oven curing: Very short cure times of about 8 min can be achieved with correct temperature profile in a well regulated in-line oven. Caution is needed to limit the rate of temperature increase to avoid bubbles creation. Gui-dance on curing profiles is available on request.

Re-work and Cleaning

If a component needs to be replaced on a PCB, it is possible to solder though the cured coating. Brush away residues and cover with PMcoat AK 122-37 F. Thinner PMsolv 5000 can be used to remove the

varnish within 24 h after application. Thinner PMsolve 5000 is recommended for storage cups of automatic coating equipment and cleaning of equipment

To the data sheet