Dear Khun Thanakorn and Khun Nattakarn,
I hope you had a very nice long weekend. It was a pleasure meeting you and your team. Thank you for this opportunity to present ourselves at Western Digital. I would like to follow up with a few questions raised in the meeting:
1. epcoat-5300 can save the two water rinses after the chrome-free passivation because it has two components:
A) Polymer and complex fluoride based
B) Zirconium based
Any other chrome-free passivation on the market is zirconium based only which causes salt residue after passivation- thus needing the rinse. As epcoat-5300 is polymer based after passivation there will be no salt residue- saving the water rinse.
2. The epcoat-5300 passivation layer weight is in the range of 50 - 150 mg/m2
3. To measure the layer weight of the passivated layer an Analytical Balance analysis may be done. This is done with an analytical balance and 2 N oxalic acid:
i. Weighing the part with an analytical balance (=M1)
ii. Remove the passivation layer in 2 N oxalic acid 4 minutes at room temperature
iii. Rinse with DI water and wipe off loose components with a soft towel
iv. Rinse again with DI water and dry
v. Weigh the part again (=M2)
(M1 - M2) / surface = layer weight in g/m2
If there are any further questions please do not hesitate to contact us. Now we know to contact MMi. May I request for an SQE contact for MMi?
Many thanks,