PROBIMER® 77-9020 / Hardener 77-9002

• Halogen-free – exceeds JPCA Standard
• Green version
• High resolution
• Excellent small hole developability with high aspect ratio
• Wide drying window
• Long hold times after drying and exposure
• High comparative tracking index (CTI)
• High dielectric strength
• Excellent adhesion of legend inks and conformal coatings
• High resistance with aggressive post solder mask processes
• High resolution in bar code laser process
• Two-component-system, glossy surface
• Low sublimation
• High resolution
• Excellent small hole developability with high aspect ratio
• Optimized for long hold times between individual process steps
• Wide process windows offer high flexibility
• Excellent chemical, electrical and physical end properties
• Fulfills the requirements of IPC SM-840-C, classes H & T
• Corresponds to the requirements of well-known OEMs
• High comparative tracking index (CTI) and high dielectric strength
• Excellent adhesion of conformal coatings
• High resistance with aggressive post solder mask metal finishes

Room Requirements on Working Environment

In order to reach best results the following room requirements should be respected:

• Room Temperature: 20 - 24°C
• Relative Humidity: 45 - 55%
• Cleanroom: Class 100’000
• Overpressure Cleanroom: + 3 mm WS
• UV blocked light

Mixing

• Thoroughly mix the two components for 10-15 minutes. Mixing should be done with gentle mechanical stirring. High shear mixing must be avoided in order to prevent entrapment of large amounts of air, which can cause bubbles and poor levelling of the printed coating.
• Viscosity is then adjusted with the addition of approximately 1.7 kg of the diluent 1-Methoxy-2-propyl acetate (PMA).

Pot Life

At room temperature the ready-to-use mixture has a pot life of 3 days.

Pre-Cleaning

• For a good adhesion of the lacquer, we recommend chemical and/or mechanical pre-cleaning.
• Hold times prior to coating have to be minimized, since oxidation may impair the adhesion of the lacquer.
• Only completely dried boards should be coated, this has to be ensured especially for boards with small holes (microvia technology).

Coating

For PROBIMER® 77-9020 a pre-heating of the boards is not required. A wide process window of 20-50°C (68-122 °F) surface temperature facilitates a uniform coating of the boards.

¹⁾ Higher wet weights can be achieved if the respective processing parameters, e.g. drying time are adjusted.

Flash-off / Drying

PROBIMER® 77-9020 offers a wide drying window of 80-90°C (176-194 °F) between 30-70 minutes.

¹⁾ The recommended parameters are valid for CL-lines. For all other processing equipment, the optimum settings have to be defined.

¹⁾ The recommended parameters are valid for: Phase III and Phase IV. For all other processing equipment, the optimum settings have to be defined.
²⁾ Cycle time = 20 s.

Exposure

A hold time prior to exposure is not necessary. The spectral sensitivity is in the range of 350 - 420 nm. The exposure time depends on the parameters for the developing step.

Developing

The areas of unexposed Probimer 77 / 9020 lacquer should be developed in a continuous spray developing line. Developing is carried out in a 0.8-1.2 % aqueous alkaline solution.

Inspection and Stripping

In case of mishandling during exposure, such as mis-registration, boards can be stripped at 50°C (122 °F) with 10% NaOH solution.

Final Curing

Thermal curing is required to ensure optimal properties in the cured film. It can be done in a standard convection oven.

After curing Probimer lacquers exhibit extremely high chemical resistance and, thus, cannot be easily removed without damaging the board.

UV-Curing

After thermal curing, we recommend UV curing of 1000-2000 mJ/cm² for increased chemical resistance.

Legend Inks and Conformal Coatings

• In general, legend inks and conformal coatings exhibit good to excellent adhesion to boards coated with PROBIMER® 77-9020.
• However, due to the large variety of available products preliminary trials are strongly recommended.

Production Release Trials

• A variety of flow agents, soldering machines and soldering techniques as well as cleaning processes are used to mount components on circuit boards.
• Adjustment of the processing parameters and design guidelines to ensure optimal use of solder masks leads to the best overall results.
• Users should carry out their own tests prior to release for production runs.

Probimer products contain flammable solvents.

When the line is in operation no open flame or light is allowed in the vicinity.

Before carrying out maintenance or repair work the line should be cleaned and the work area thoroughly ventilated.

Probimer lacquers are complex chemical compounds. To ensure that these products exhibit consistent quality in application we recommend storage under the following conditions:

• PROBIMER® 77-9020 / 9002 in original container at 2-18°C
• PROBIMER® 77-9002 in original containers at 2-18°C
• Under ‘EXP’ on the package label, the expiry date is indicated. Within this period the product should be used.