When selecting a potting compound for electronics, it’s crucial to understand their role. They provide long-term protection and performance for devices. This article will help you understand the variety of available hermetisation products. With this knowledge, you can choose the best potting compound for your electronics.
Silicone potting compound for electronics – flexibility and versatility
Condensation silicone potting compounds cure into solid rubber with hardness ranging from 25 to 63 Shore A. They are particularly useful for hermetising electronic and electrical systems, where matching hardness to application requirements is important. Notably, some compounds, such as 021 and 029, have thermal conductivity in the range of 1.2-2 W/mK, which is a key feature for devices requiring efficient heat dissipation.
WARNING! During curing, by-products (white residue) are released, so ventilation is recommended until fully cured. Condensation potting compounds also shrink after curing, which can affect delicate system components.
| Potting Compound | 011 | 019 | 021 | 029 |
|---|---|---|---|---|
| Type | Silicone | Silicone | Silicone | Silicone |
| Curing | Condensation | Condensation | Condensation | Condensation |
| Color | Transparent | Milky | White | Grey |
| Consistency after Curing | Solid Rubber | Solid Rubber | Solid Rubber | Solid Rubber |
| Shore Hardness [A] after Curing | 25 | 58 | 53 | 63 |
| Consistency before Curing (cP) | 2,000 (+/- 500) | 45,000 | 1,125 | 1,455 |
| Thermal Conductivity | No | No | Yes (~1.2 W/mK) | Yes (~2 W/mK) |
Additive silicone potting compounds are perfectly suited for hermetisation and protection against various environmental conditions. This makes them particularly useful in the electronics and telecommunications industries. If your system generates a lot of heat, choose 047, which cures into white rubber with a thermal conductivity of ~1.5 W/mK. For LED applications, we recommend 031 and 037, which are transparent and do not scatter light after curing. Notably, additive compounds cure without by-products.
| Potting Compound | 031 | 037 | 047 |
|---|---|---|---|
| Type | Silicone | Silicone | Silicone |
| Curing | Additive | Additive | Additive |
| Color | Transparent | Transparent | White |
| Consistency after Curing | Soft Gel | Solid Rubber | Solid Rubber |
| Shore Hardness [A] after Curing | – | 12 | 20 |
| Consistency before Curing (cP) | 3,000 | 2,500 (+/- 500) | A= 2,500 (+/- 500) B= 3,500 (+/- 500) |
| Thermal Conductivity | No | No | Yes (~1.5 W/mK) |
| LED Application | Yes | Yes | No |
Epoxy potting compound for electronics – durability and stability
Epoxy potting compounds are characterized by very high hardness (95-97 Shore A). After curing, they become hard and stable, making them ideal for creating protective casts and hermetising electrical devices. Compound 141 is particularly recommended for potting entire electronic components, such as coils, transformers, and capacitors. It is important to note that these compounds do not conduct heat.
WARNING! Do not use compound 141 on styrofoam, as the included modifier dissolves polystyrene.
| Potting Compound | 141 | 149 |
|---|---|---|
| Type | Epoxy | Epoxy |
| Curing | Condensation | Condensation |
| Color | Light Yellow | Light Yellow |
| Consistency after Curing | Hard Solid | Hard Solid |
| Shore Hardness [A] after Curing | 95 | 97 |
| Consistency before Curing (cP) | 900 – 1,500 | 20,000 – 30,000 |
| Thermal Conductivity | No | No |
Selection criteria
Choosing the right potting compound requires analyzing specific project requirements and considering their properties. For heat-generating devices, we recommend silicone compounds (021, 029, 047), which are effective thermal conductors, preventing overheating. These are essential in high-performance electronic systems. When flexibility is important, silicone compounds are an excellent solution, as they absorb vibrations and protect against mechanical stresses. For durable and hard protection, epoxy compounds are the best choice, providing long-term protection and stability, particularly in static environments. Epoxy compounds are preferred in situations requiring high hardness and durability but should not be used with polystyrene.
Summary
When choosing the right potting compound, understanding the project’s specifics and functional and environmental requirements is crucial. Silicone compounds offer flexibility and versatility in applications, while epoxy compounds are characterized by durability and hardness. Balancing these features according to the specific needs of the project is crucial. Consider thermal conductivity, hardness, flexibility, environmental resistance, aesthetics, and special requirements. This approach will help you make the best choice for your project, ensuring optimal results and long-term performance.
More about electronic protection can be found on the website.
