var10
Mechanical
- Apr 4, 2013
- 188
Hello all,
Lets see if I can explain this properly. I am trying to improve something that is already working (just want to hear what others do in similar situations). I have a pcb with piezo-electric sensor. On one side we have a machined fitting and on the other side we have a machined cover. The hoses are connected to the fitting during equipment operation to measure speed and altitude. Thus we need all faying faces to be perfectly sealed so that when there is suction or pressure the crystal can measure value properly. At the present we use dow corning grease stuff in between machined steel and pcbs. So far its all good. But the entire process of applying grease and assembling is very nasty and it gets acrylic conformal applied to it after assembly with the the back cover (no conformal on the front side).
That being said, once you assemble it; the grease is squeezed out and it comes in contact with its neighbors (components). Its hard to clean/wipe of the excess and it does not cause any harm to anything. So I am after anything that is easy to be used while having similar properties to vaccuum grease stuff. We also need them to be removed for repairs - so its a no for epoxy or permanent adhesives. Just thought I would ask if anyone out there have better compound/sealant/chemical/technique to achieve proper sealing. I have forgotten to mention this equipment will go through rigorous centrifugal, vibrational and temperature testings.
I am thinking of just having a epdm rubber o-ring that sits inside a groove. But open for other options too!
Cheers,
V.
Lets see if I can explain this properly. I am trying to improve something that is already working (just want to hear what others do in similar situations). I have a pcb with piezo-electric sensor. On one side we have a machined fitting and on the other side we have a machined cover. The hoses are connected to the fitting during equipment operation to measure speed and altitude. Thus we need all faying faces to be perfectly sealed so that when there is suction or pressure the crystal can measure value properly. At the present we use dow corning grease stuff in between machined steel and pcbs. So far its all good. But the entire process of applying grease and assembling is very nasty and it gets acrylic conformal applied to it after assembly with the the back cover (no conformal on the front side).
That being said, once you assemble it; the grease is squeezed out and it comes in contact with its neighbors (components). Its hard to clean/wipe of the excess and it does not cause any harm to anything. So I am after anything that is easy to be used while having similar properties to vaccuum grease stuff. We also need them to be removed for repairs - so its a no for epoxy or permanent adhesives. Just thought I would ask if anyone out there have better compound/sealant/chemical/technique to achieve proper sealing. I have forgotten to mention this equipment will go through rigorous centrifugal, vibrational and temperature testings.
I am thinking of just having a epdm rubber o-ring that sits inside a groove. But open for other options too!
Cheers,
V.
