Potting compounds and protective coatings from Henkel for the protection of printed circuit boards
In electronic applications, special potting compounds and conformal coatings from Henkel are used to protect sensitive electronic components such as printed circuit boards, as well as masking compounds to exclude certain areas from the conformal coating.
Potting materials from Henkel – Potting Compounds
Potting compounds from Henkel are used, among other things, to protect electronic components from environmental influences such as moisture and chemicals, to improve mechanical strength, to achieve high electrical insulation, for heat dissipation, to make the components vibration and shock resistant, for corrosion protection and to conceal intellectual property.
Specifically, these potting compounds are curable liquids. They are poured into a housing, for example, in which a circuit board is installed. After curing, the potting compound forms a fixed component of the PCB and the other components in the housing, for example to protect the electronics on the PCB.
A distinction is made between one-component potting (1-component potting) and two-component potting (2-component potting). Both types consist of the main components resin and hardener and may also contain filler and additives. The difference between the two types of potting is that in 1C potting, the resin and hardener are already mixed together and are therefore ready for immediate use, whereas in 2C potting, the resin and hardener are not yet mixed together, which prevents these components from reacting prematurely.
The advantages and disadvantages of one-component potting compounds compared to two-component potting compounds can be seen in the following table:
One-component potting compounds
| Ready for immediate use |
| Curing by heat required |
| Cool storage and defrosting required |
| Limited shelf life |
| Hardening agent mostly solid due to higher viscosity |
Two-component potting compounds
| Ingredients must be weighed and mixed |
| Curing at room temperature or by heat |
| Storage at room temperature |
| Long shelf life |
| Hardening agent mostly liquid; wide selection of hardening agents |
Handling potting compounds
The following points should be borne in mind when handling potting compounds:
- Keep container closed; cover urethane potting compounds with dry nitrogen before sealing
- Allow one-component casting compounds to thaw to room temperature before processing
- Only use non-porous materials for mixing
- Use plastic containers for mixing
- Use plastic or metal mixing tools
- Protect parts from moisture before encapsulation, especially when using urethane potting compounds
- check that the shelf life of the material has not yet been exceeded
- check whether the filler has settled; if the settled material is soft, it can be stirred up; disposal is necessary if the settled material is solid
- check whether the resin has crystallized; crystallization of the resin can be reversed by heating it (honey trick).
Types of potting compounds
Henkel offers various types of potting compounds, each of which is suitable for different electronic applications. The potting compounds differ according to the material they are made of. For example, there are epoxy potting compounds, silicone potting compounds, urethane potting compounds, polyacrylate potting compounds and electronic gel potting compounds. To show you the variety of hardeners for epoxy potting compounds, we present the four hardeners LOCTITE CAT 24LV, LOCTITE CAT 9, LOCTITE CAT 27-1 and LOCTITE CAT 17 in the following table:
| LOCTITE CAT 24LV | LOCTITE CAT 9 | LOCTITE CAT 27-1 | LOCTITE CAT 17 | |
| Processing time (100 g at 25 °C) | 30 min. | 45 min. | 2 hrs. | 24 hrs. |
| Curing schedule | 16 to 24 hours at room temperature; 2 hours at 65 °C | 16 to 24 hours at room temperature; 2 hours at 65 °C | 4 hours at 120 °C | 3 hours at 120 °C plus 3 hours at 150 °C |
| Operating temperature | Continuous: 105 °C Interrupted: 120 °C | Continuous: 130 °C Interrupted: 150 °C | Continuous: 175 °C Interrupted: 200 °C | Continuous: 230 °C Interrupted: 260 °C |
| Viscosity | 30 – 40 cPs | 80 – 100 cPs | 250 – 300 cPs | Paste |
Application range of Henkel potting compounds
Henkel’s potting compounds are used in the following industries, among others:
- Consumer electronics industry
- Automotive industry
- Aerospace industry
How to find the right potting compound
To find the right potting compound from Henkel for your own application, you should consider the following factors, among others:
- One-component potting or two-component potting
- Viscosity (flow behavior)
- Duration of workability
- Curing temperature
- Maximum operating temperature
- Chemical resistance
- Thermal conductivity
- flame-retardant properties
- Hardness of the material
To help you choose the right potting compound for your application, Henkel has put a Potting Selector online.
In addition, there are other special online selection tools from Henkel for other Henkel materials, as you can find out in our article “Henkel Selectors: Simply find the right Henkel Electronic Material online“.
Conformal Coatings from Henkel – Protective coating for PCB protection
If you only want to protect the electronic components with a thin coating, you do not use the potting compounds from Henkel, but rather special conformal coatings from Henkel. These are thinly applied protective coatings that are used in particular for printed circuit boards. Areas that you want to leave free of the conformal coating can be protected with a special masking compound before painting, which can then be removed again.
Protective effect of conformal coatings from Henkel
The protective effect of Henkel’s LOCTITE brand conformal coatings is wide-ranging. These protective coatings protect printed circuit boards against the following adverse environmental conditions, among others:
- Temperature shocks
- Moisture
- corrosive liquids
In addition, conformal coatings can inhibit leakage current and strengthen the solder joints between individual components and the printed circuit board. Thanks to the protective coatings from Henkel, long product life cycles can be achieved for the electronic components treated with them.
Properties and application of Henkel protective coatings
Conformal Coatings from Henkel are very thinly applied protective coatings. The coatings are transparent. Conformal coatings are applied to printed circuit boards, for example, either on the entire circuit board or only on certain areas.
LOCTITE conformal coatings can be applied to the respective parts in various ways. It is possible to spray, brush or dip the respective parts in protective coatings. If a conformal coating spray is used, it can be applied either manually or automatically.
Henkel’s conformal coatings have particularly fast curing properties, which enables rapid processing. And as far as environmental friendliness is concerned, Henkel’s LOCTITE conformal coatings are solvent-free.
Application range of protective coatings from Henkel
While conformal coatings were initially used in the aerospace industry, these protective coatings are now also used in other sectors.
Today, conformal coatings are also used in the automotive industry, the shipping industry, the medical industry and the consumer electronics industry.
Questions about potting compounds and LOCTITE conformal coatings
Abovo has been an authorized distributor of Henkel Electronic Materials for more than 15 years. Do not hesitate to take advantage of abovo’s expertise.
If you have any questions about Henkel’s potting compounds, the use of protective coatings or Henkel’s covering compounds, simply contact our experts at abovo by e-mail or telephone – without obligation, of course. Our telephone number is: +41 32 552 44 44. You can reach us by e-mail at info@abovo.ch.
