Electronic Protection System
Urethane/Alkyd Thin Film Coating
Bectron® PL 4122-E BLF
Product description
Bectron® PL 4122 E BLF FLZ is a range of transparent
coating polyurethane varnishes based on established
urethane modified alkyd chemistry. The performance
of Bectron® PL 4122 E BLF FLZ meets the
latest requirements of electronics, low pin corrosion
and fast curing at room temperature or oven cure
conditions.
Bectron® PL 4122 E BLF FLZ is lead-free and has no
aromatic compounds in the solvent and satisfies the
requirements of the ROHS directive.
The varnish features superior performance in thermal
and dielectric properties which are maintained when
subjected to environmental stress.
The coating varnish is available in the following
grades:
• 3 solids/viscosity levels for each application system:
PL 4122-37 E BLF FLZ
PL 4122-40 E BLF FLZ
PL 4122-45 E BLF FLZ
Application
Coating of electronics:
• PCB’s subject aggressive environment
o automotive or marine navigation
o Industrial
o Corrosive gas
• hybrids
• SMD devices
• discrete components
• Suitable for safety critical systems
Main Properties of Bectron PL 4122E BLF
• High temperature index of 134°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
• Suitable for Inspection of coated areas under UV light
Resistance to Harsh Conditions
Components varnished with Bectron® PL 4122 E BLF
provide maximum protection against contaminants
such as moisture and dust and many chemicals. It is
resistant to corrosive gas atmosphere, weak acid
fuels, oils, glycols and many other fluids used in
automotive and shipping industry.
Bectron® PL 4122 E BLF can survive temperature
shock and temperature cycling resistance such as
-40 to +130°C for several cycles
The cured coating retains good adhesion but remains
flexible to withstand distortion of the PCB (Mandrel
bend test)
Processing
The coating varnish Bectron® PL 4122 E BLF is optimised
for mass production robotic application on all
major equipment systems including select coat, select
spray nozzles and automated dipping systems.
It can also be used with manual and simpler applications
equipment by dipping, brushing or hand-spray.
The Grades PL 4122-37 E BLF or 40E BLF are for
general applications. For dipping PL 4122-45 E BLF
is usually recommended with Thinner Bectron® 239
for dilution to the required viscosity.
Bectron® PL 4122 E BLF is flammable and good ventilation
is important in all processing areas.
Curing
For batch Curing:
• Air curing at 23°C for 16h
• Accelerated curing 80°C/0,5h
Continuous Oven Curing:
Very short cure times of about 10 minutes can be
achieved with the correct temperature profile in a well
regulated in-line oven. Caution is needed to limit the
rate of temperature increase to avoid bubbles in the
coating. Guidance on curing profiles is available on
request.
Re-work
If a component needs to be replaced in the in the
assembled printed circuits it is possible to solder
through the cured coating and the coating needs to
be replaced on the new solder joint. Cleaning Agent
AC 93 can be used to remove the PL 4122 up to 24
hours after curing and cleaning of equipment.
Table 1: Typical properties of coating varnish
Property Conditions Value Units
Non volatile content, ISO 3251 (Solids Content) 1,5 g, 2 h, 130°C
Bectron PL 4122-37 E BLF 37 ± 1 %
Bectron PL 4122-40 E BLF 40 ± 2 %
Bectron PL 4122-45 E BLF 45 ± 1 %
Viscosity - Flow Time -, DIN/EN/ISO 2431 cup
Bectron PL 4122-37 E BLF 4 mm-Cup, 23 °C 40 ± 3 ( 50) Seconds (mPas)
Bectron PL 4122-40 E BLF 4 mm-Cup, 23 °C 65 ± 5 ( 80) Seconds (mPas)
Bectron PL 4122-45 E BLF 6 mm-Cup, 23 °C 40 ± 3 ( 240) Seconds (mPas)
Density, DIN EN ISO 2811-2 23°C
Bectron PL 4122-37 E BLF 0,86 ± 0,01 g/cm³
Bectron PL 4122-40 E BLF 0,87 ± 0,01 g/cm³
Bectron PL 4122-45 E BLF 0,88 ± 0,01 g/cm³
Minimum shelf life 23 °C 6 months
Curing Time 23 °C, dust dry 0,25 h
23 °C, touch dry 1,00 h
23 °C, cured 16,00 h
80°C (batch oven) 0.5 h
Table 2 – Thermal Properties of cured coating
Property Condition Value Units
Temperature Resistance, IEC 60216 134 °C
Flammability File-No. E 211569 Vertical UL 94 V0
Table 3 - Mechanical properties of cured coating
Property Condition Value Units
Mandrel Bend Test, IEC 60464-2 3 mm, 0.06 mm film >180 °
Cross Cut Test, DIN EN ISO 2409 GT 0 - 1
Table 4 – Dielectric properties of cured coating
Property Condition Value Units
Permittivity, IEC 60250 23°C 10 KHz 3.5
Dielectric Dissipation Factor, IEC 60250 23°C 10 KHz 0.023
Dielectric Strength, IEC 60464 part 2
- After 23 hours water immersion 23°C
112
108
KV/mm
KV/mm
Volume Resistivity, IEC 60464 part 2 23°C 1 x 1015 W • cm
Tracking resistance, IEC 60112 600 CTI
Table 5 - Chemical properties of cured coating
Property Condition Value Units
Water absorption, ISO 62 23°, 24 hours
100°C, 0.5 hour
1.5
2.5
%
%
Our advice in application technology given verbally, in writing and by testing corresponds to the best of our knowledge and belief, but is intended
as information given without obligo, also with respect to any protective rights held by third parties. It does not relieve you from your own
responsibility to check the products for their suitability to the purposes and processes intended. The application, usage and processing of the
products are beyond our reasonable control and will completely fall into your scope of responsibility. Should there nevertheless be a case of
liability from our side, this will be limited to any damage to the value of the merchandise delivered by us. Naturally, we assume responsibility for
the unobjectionable quality of our products, as defined in our General Terms and Conditions
