Implantable pacemaker/defibrillator teardown

[mikeselectricstuff]

[amyk]

That x-ray machine would've been really useful right about now...

[mikeselectricstuff]

That x-ray machine would've been really useful right about now...

Not enough resolution.

[G7PSK]

That black potting compound, I have come across something similar on AVR boards on large alternators, next to impossible to remove and will even pull though hole components of the board, I have removed it in the past with a hot air gun of the paint stripping type, when the black stuff is heated to about 200 deg C it becomes brittle and will crumble when prised up with a screwdriver or some other instrument. 

[free_electron]

That black potting compound, I have come across something similar on AVR boards on large alternators, next to impossible to remove and will even pull though hole components of the board, I have removed it in the past with a hot air gun of the paint stripping type, when the black stuff is heated to about 200 deg C it becomes brittle and will crumble when prised up with a screwdriver or some other instrument.

Soak in methyl ethylene ketone for 24 hours. Falls off without problems. No damage to parts.

[mikeselectricstuff]

That black potting compound, I have come across something similar on AVR boards on large alternators, next to impossible to remove and will even pull though hole components of the board, I have removed it in the past with a hot air gun of the paint stripping type, when the black stuff is heated to about 200 deg C it becomes brittle and will crumble when prised up with a screwdriver or some other instrument.

Soak in methyl ethylene ketone for 24 hours. Falls off without problems. No damage to parts.

This stuff was unusually tough - dichloromethane will usually soften and swell normal potting compounds in a day or two, but this stuff had a total of about a month and the only impact was that the softened PCB allowed it to flex and crack some of the epoxy off

[sotos]

Black potting compound is Polyurethane or epoxy, which is stronger between them?

[SeanB]

Chip encapsulating epoxy, thermosetting stuff that probably will only dissolve in HF and red fuming nitric acid........

Will leave nice shiny very clean chips, nothing else other than ceramics though.