“I need to find a UL-listed conformal coating. Can you tell
me a little bit about the UL designation and do you have any conformal coating materials with this rating?”
Underwriters Laboratories® (UL) is a global independent safety science company offering expertise across five key strategic businesses: Product Safety, Environment, Life & Health, University, and Verification Services. UL has been working for a safer world since 1894 and partners with manufacturers to provide safe products to consumers through UL testing, certification, and follow-up audits.
DYMAX has many conformal coatings that are UL recognized; they can be found on the DYMAX website and are denoted with the UL marking. To retrieve the most up-to- date information on DYMAX conformal coatings, log onto the Underwriter Laboratories website www.ul.com, click on Certifications, and input DYMAX’s UL File Number, QMJU2.E140512.
Conformal Coatings, Electronic
“Do you have an FDA-approved adhesive for artificial hearts (structural and non-structural adhesive)? Which standard is more relevant and which standard applies - ISO 10993, USP Class VI, or another standard?”
If you are referring to implantable artificial hearts, we have to pass. DYMAX adhesives have not been tested for prolonged or permanent implantation and are only intended for use in short-term (<29 days) or single-use disposable device applications. DYMAX does not authorize their use in long-term implant applications.
Polymerized DYMAX MD® Medical Device adhesives are biocompatibility tested in accordance with ISO 10993 and/or USP Class VI. ISO 10993 is a newer, internationally accepted standard. The current DYMAX test protocol for medical adhesives contains the following studies:
- ISO 10993-4 Hemolysis
- ISO 10993-5 Cytotoxicity
- ISO 10993-6 Implantation 14 Days
- ISO 10993-10 Intracutaneous
- ISO 10993-11 Systemic Toxicity
Older DYMAX adhesives have been tested in accordance with USP Class VI, which consists of Systemic Toxicity, Intracutaneous and a 7-days Implantation Test. When comparing both standards, USP Class VI is included in and covered by ISO 10993.
“Can oxygen inhibition be removed from cured parts without damage to the fully-cured substrate area? We are looking to change our process to include a nitrogen blanket, but have many components that cannot be completed due to the tackiness on the outer surface.
We tried CRC Brakleen which effected the cured surface area as well as the tacky coating.”
First of all, I would like to refer to an older reply made regarding the inhibition of cure: http://mpmn.canon-experts.com/2009/03/
CRC Brakleen is a very strong cleaning agent that contains tetrachloroethylene and dichloromethane or ketone (depending on the packaging used). As you already noticed, these are chemicals that easily remove the tacky layer, but also dissolve the cured adhesive. If oxygen inhibition cannot be avoided, the tacky layer should be removed with an isopropyl alcohol (IPA) wipe. IPA is less aggressive and is commonly used for this purpose. We would always recommend a wipe rather than a soak.
“What is Micro Coating?”
Micro coating is a process in which durable coatings are selectively applied to small areas on an electronic assembly that require protection from elements in their operating environment, which commonly include moisture and liquids. Micro coating was first adopted by consumer devices to reduce device thickness. It is now beginning to catch on in other markets including aerospace and automotive. Micro coating applications are often very similar to encapsulation, but the materials are typically applied over the surface of leads with a high-accuracy automated application system. Many of DYMAX’s conformal coatings and encapsulation materials can be used as micro coatings.
“We need to bond a silicone insulator between two gold-plated electrodes. All materials need to be medically approved for non-implatable use. Can you recommend options to explore?”
I would recommend a silicone adhesive to bond the silicone insulator to the gold-plated electrodes. Two possible candidates are: Dow Corning Medical Adhesive Type A (acetoxy cure system), or NuSil Med1-4213 (2-part platinum cure system). Both materials are insulators themselves.