What are these shiny metal-like components in the images below?

Is that kapton tape covering for ESD protection?

enter image description here

enter image description here enter image description here

enter image description here enter image description here enter image description here

  • \$\begingroup\$ Looks like chip inductors? Bit hard to tell from the picture. \$\endgroup\$
    – Lundin
    Oct 3 at 6:40
  • \$\begingroup\$ The pictures could be bigger. \$\endgroup\$
    – MiNiMe
    Oct 3 at 8:41
  • 2
    \$\begingroup\$ I have added few more pictures of the same. You may check now. \$\endgroup\$ Oct 3 at 10:26
  • \$\begingroup\$ Do they all have 3 terminals? \$\endgroup\$
    – Jens
    Oct 3 at 10:48
  • 1
    \$\begingroup\$ SMD film capacitors, definitely. Pretty rare, but very distinctive. \$\endgroup\$
    – Hearth
    Oct 3 at 13:21

2 Answers 2


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)

enter image description here

Polyethylene Terephthalate (PET)

enter image description here

and Polyethylene Naphthalate (PEN).

enter image description here

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.)

  • \$\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
  • 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\$
    – Rokta
    Oct 3 at 12:41
  • 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

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.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.