MLCC laminations parallel or perpendicular to board - Page 1
Forum section: electronics / projects

author: slugrustle
author_rank: Frequent Contributor
timestamp: September 27, 2023, 10:53:07 pm
content: I was just hand soldering some MLCCs to a board and it occurred to me: Is there any electrical difference (maybe ESL or ESR) if the laminations of the MLCC are parallel to the board vs. perpendicular to the board?This probably doesn't come up with a pick & place machine; you get what you get. But I'm pulling the plastic film off the tape carrier and dumping the little parts out, so I'm getting random alignment. If there is a difference, I doubt it matters for the function of this particular circuit. I'm simply curious.

author: ataradov
author_rank: Super Contributor
timestamp: September 27, 2023, 11:00:38 pm
content: Capacitors are packaged in a random orientation, nobody keeps track of it through the manufacturing process. So, even with a PnP you get random orientation.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: September 28, 2023, 03:48:48 am
content: There is some consideration regarding how the board may flex under a MLCC. Can't remember much. Here's some info though. Basically, orient the caps in a manner that the board may flex lesshttps://product.tdk.com/en/techlibrary/solutionguide/mlcc_flex-crack.html

author: ataradov
author_rank: Super Contributor
timestamp: September 28, 2023, 04:10:50 am
content: You don't get to pick how you orient them, there are no visible markers and most of the time they have a square profile. If the profile is rectangular, then it is just extra work to have them on the side when placing them manually, so I don't see that happening.

author: Someone
author_rank: Super Contributor
timestamp: September 28, 2023, 04:28:26 am
content: Quote from: ataradov on September 28, 2023, 04:10:50 amThat link above from TDK talks about a design with a single "correct" orientation, probably just enforced by tape packaging.

author: ataradov
author_rank: Super Contributor
timestamp: September 28, 2023, 04:36:35 am
content: I don't see where it talks about orientation at all. It just shows failure mode in the "intuitive" horizontal orientation, but the failure mode would be the same for either of them.There is no way tape has correct orientation. Look at how they are made and packaged. They are cut from a sheet, then baked, then tumbled to smooth the corners, then packaged using vibratory sorting machines. They are processed in bulk in a huge pile.Here is a video from Kemet showing the processUnless capacitor has a clearly rectangular cross section, orientation would be totally random.

author: Someone
author_rank: Super Contributor
timestamp: September 28, 2023, 05:17:44 am
content: Quote from: ataradov on September 28, 2023, 04:36:35 amhttps://www.tdk-electronics.tdk.com/en/374108/tech-library/articles/products-technologies/products-technologies/tdk-expands-mlcc-lineup-with-new-low-resistance-soft-termination/3021044

author: ataradov
author_rank: Super Contributor
timestamp: September 28, 2023, 05:28:27 am
content: That is not the "link above".Ok, sure, if you have specialty capacitors that clearly indicate the orientation, mount it in the correct orientation. If you are like 99.99% of other people and use regular capacitors available from multiple vendors, there is no way to tell what orientation they are in from the tape.There are also automotive capacitors in metal SMD leads. Don't mount those sideways either.Surprisingly, those capacitors are not that much more expensive. But in the end, there are just 4 of them. So, if you need any other size or capacitance, you are still stuck with a random orientation.

author: Someone
author_rank: Super Contributor
timestamp: September 28, 2023, 07:34:53 am
content: Quote from: ataradov on September 28, 2023, 05:28:27 amThere is an entire "chapter" about those directional capacitors in the first link. But do keep insisting what I say is incorrect!EVEN MOR OBVIUS LINK FOR PEOPLE WHO CANT BE BOTHERERD:https://product.tdk.com/en/techlibrary/solutionguide/mlcc_flex-crack.html#anc04