What are these shiny metal-like components in the images below?
Is that kapton tape covering for ESD protection?
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\$\begingroup\$ Looks like chip inductors? Bit hard to tell from the picture. \$\endgroup\$– LundinOct 3 at 6:40
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\$\begingroup\$ The pictures could be bigger. \$\endgroup\$– MiNiMeOct 3 at 8:41
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2\$\begingroup\$ I have added few more pictures of the same. You may check now. \$\endgroup\$– courageouslywinOct 3 at 10:26
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\$\begingroup\$ Do they all have 3 terminals? \$\endgroup\$– JensOct 3 at 10:48
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1\$\begingroup\$ SMD film capacitors, definitely. Pretty rare, but very distinctive. \$\endgroup\$– HearthOct 3 at 13:21
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2 Answers
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Hard to tell from the photo, but to me they look like SMD metalized film capacitors.
Lots of different film plastics can be used, including:
Polyphenylene Sulfide (PPS)
Polyethylene Terephthalate (PET)
and Polyethylene Naphthalate (PEN).
They are generally stable and low-loss, and often used in timing or converters circuits.
As shown by the PPS photo above, the electrode plates are sometimes visible, and I think this matches what is shown in the questioner's photo.
Some versions have a Kapton (or similar) film on top to provide some physical protection to the very thin capacitor plates. Edit:
(When extra photos were added, it initially looked like the devices had 3 terminals, but careful inspection suggests the "middle" terminal is just silkscreen marking.)
(Images from respective linked datasheets.)
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\$\begingroup\$ Thanks for the answer. I am new to this, so I have few more questions. What is that covering then? What is its purpose? \$\endgroup\$ Oct 3 at 10:25
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2\$\begingroup\$ Probably these are silkscreen markings and not 3rd terminal. Also they look like metallized acrylic type, for example ECPU series from panasonic \$\endgroup\$– RoktaOct 3 at 12:41
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1\$\begingroup\$ For reference, here's a screenshot of how the footprints may have been drawn: i.stack.imgur.com/muRdY.png \$\endgroup\$ Oct 3 at 21:00
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Could also be high reliability capacitors, which are constructed from two series connected stacks of plates, so that cracking and short circuiting which happens quite often, does not stop the capacitor from functioning. Often used in safety, automotive and other applications.
