To obtain the best casting results, we have published an extensive guide that is available upon request. In summary: use compounds in extremely dry surroudings (pay attention to possible condensation moist). Stir A-component before use. Mix A + B components slowly, but thoroughly and prevent air getting into the mixture. Make sure that the product to be casted is free of solvents, grease or silicone residues and use mixture well within it’s recommended potlife. Air can be avoided by heating, vibration and vacuum. For the best results, we recommend a very smooth, bright surface that pulls up at the edges. Our experienced staff is available for inquiries and/or advice.
Advantages and disadvantages of vacuum-casting:
Details based on experience with vacuum-casting of electronic components.
There are no fundamental research results available about advantages or disadvantages of vacuum casting of eletronic parts and components. It is generally accepeted that this field of expertise is based on experience and know-how. Being active in this field for more than 30 years, we at Intercol are able to offer this to our customers.
1) Using vacuum techniques, will provide several advantages which improve the quality of the final product. Creating a vacuum during the casting process, will prevent air and CO2 inside the compound and minimize difficult to control influences, such as humidity and air-bubbles. gieten geeft zo wie zo enkel voordelen inzake kwaliteit, de nadelen liggen op het gebied van investerings-, proceshandeling en onderhoudskosten.
2) Vacuum casting in combination with a heated product will improve the quality even further. Heating the compound will improve the escape of possible bubbles. Any bubble trapped inside the compound will disturb the thermal conductivity of the compound and therefor the performance of the electronic component. Bubbles may cause so called “hot-spots” (especially in high-voltage applications), which can cause the compound to become conductive.
3) A vacuum will improve the wetting of the casted surface, which improves the adhesion between compound and component.
4) We would recommend to create the largest surface possible to improve the chance for bubbles to escape.
5) A slowly increased vacuum (or alternating) will improve bubble escapement.
6) The vacuum should be applied before the compound has started to form a gel structure. Bubbles will more easily escape and the cross-link process will not be disturbed or weakened.
7) Large bubbles are more likely to escape than smaller bubbles.