I know ROV manufacturers submerge all circuit boards and motor drives in an oil bath, and then expose the electronics to the surrounding subsea pressure. At 10000 ft, this is about 4500 psi. What I don't know, is what specific components would have problems with the 4500 psi.
- ICs should manage the pressure OK as they are reasonably encapsulated without air trapped inside.
- I spoke with a circuit board manufacturer and they thought some surface mount component boards might have a problem, as ball grid arrays may have air trapped within the vias. Anything with trapped air would be subject to mechanical stress as the air is compressed. Any thoughts on circuit board design for high pressure applications?
- Clocks? I don't know much about what sort of clock packaging would survive OK under pressure. Help!
- Capacitors? What type of capacitors would be OK and which ones may have a problem? What if the packaging is surface mount?
- Connectors? The pressure may be OK for most connectors, but the insulating oil bath may cause a problem. I'm sure solder connections are better than pluggable headers, but I'd like to have as much off-the-shelf products as possible. COTS!
- The equipment I would like to package for a subsea application is PC104 based processors and I/O, and a 30hp VFD. Any thoughts on typical VFDs under pressure? Could be IGBT or back-to-back thyristors
- motor would probably be a brushless DC motor or 3 phase induction.
- What else?
Temperature should be above freezing, so temperature should be a managable problem and heat dissipation is definately a simplified issue.
Anyone who has any experience with such an application can email me at snipped-for-privacy@myway.com. Any info or past experience stories would be appreciated!
OJ