RDS_Lacktrockner_en - 第5页

5 Lacquer and casting hardening T o achieve the best drying results, it is important to precisely coordinate the process and material. W e differentiate between physically hardening lacquers, which harden very quickly pu…

Protective lacquer coatings increase the reliability and

service life of your products. They enhance the tracking

resistance of your components and provide protection

against environmental inuences such as moisture,

corrosion, chemicals and dust. Casting compounds reduce

mechanical stress, for example vibrations on the component.

These materials need to be hardened reliably so that they

can later work without any problems in end devices in the

automotive industry, medical technology or security-related

modules in aerospace technology. The lacquer determines

the process! Depending on the coating material, convection

(i.e. moving warm air) is used in the drying process, or infrared

radiation as an addition in the combination heating process

for particularly flexible proling. In the process, temperatures

up to a maximum of 250 °C are used for optimum hardening

of the components, depending on the product and process

requirements.

The perfect system for every application

Endless opportunities with the RDS

Industrial elds

Hardening and drying technologies for cleanroom

requirements in the semiconductor industry

Hardening of adhesives, lacquers, casting resins,

casting compounds, silicone gel etc.

Drying process for

protective lacquer coating

RDS areas of application

Glass | Glob top applications | Hardening of electropastes | Chip-scale packaging | Hardening of

protective lacquers| Burn-in of resistor pastes | Hardening of casting compounds | Hardening of

adhesive lacquers and adhesives | Hardening of green tape/ceramic blanks | Hardening of compo-

nent encapsulations | Flip-chip processes | Drying processes in hybrid metallisation | Cleanroom

requirements | Hardening processes in hybrid production | Hardening of resistor pastes in thick-lm

technology | Hardening of underll materials | Hardening of casting resins | Cavity ll for BGA housing

Lacquer and casting hardening

To achieve the best drying results, it is important to precisely

coordinate the process and material. We differentiate between

physically hardening lacquers, which harden very quickly pure-

ly with the release of solvents, oxidative-hardening lacquers,

which dry with atmospheric oxygen, chemically hardening

lacquers, often 2K materials and radiation-hardening

lacquers which harden with UV radiation, for example. A

separate UV dryer is required for the latter. The RDS systems

are perfect for hardening polyurethane resin, acrylic resin,

epoxy resins, acrylate resins and silicone-based casting

compounds.

A slow heating of the assembly is essential, particularly

when it comes to protective coatings that contain volatile

solvents, because an excessively high temperature gradient

during the heating phase can cause the top layer of the

coating to harden too quickly and the underlying solvent

will no longer be able to escape. For this reason, the drying

systems from Rehm Thermal Systems feature two short

zones at the inlet area which are regulated separately in

order to provide the optimum temperature gradient for the

corresponding paint.

Innovative procedures

adjusted to material and product

Optimum heat management

with IR radiation and convection

Thanks to our many years of experience, we

know precisely which actuators are needed to

set up a system that can be adapted simply and

individually to the various process requirements

and product landscapes of our customers.

The RDS systems are modularly structured.

The efcient upper and lower heaters work with

infrared radiation (IR) and/or convection to dry the

various materials reliably. By implementing these

two heat transfer processes, the systems are

optimally designed for the processing of lacquers

and castings containing solvents. The RDS drying

oven thus consists of several separately adjusta-

ble heating zones. In the warming-up phase, the

component and the protective lacquer are heated

up. Both the upper and lower IR radiators can be

controlled with different set-point temperatures.

Thus in the inlet area of the dryer, an increased

amount of IR radiation and a reduced convective

heat transfer is applied to the component. This

means that lacquers in particular are heated up

evenly and, thanks to the low convection, are not

dispersed onto the component.

In the drying phase, the temperature is main-

tained until the material has hardened completely.

A stronger convection is needed for this, as the

evaporating solvents need to be discharged. In the

subsequent cooling phase, the components are

cooled down gently.