Are these components? - Page 1
Forum section: electronics / general

author: msuffidy
author_rank: Frequent Contributor
timestamp: May 23, 2023, 03:06:49 am
content: I have a PCIe card that does weird things it seems the more I use it, including disappear from the system.I was looking at the PCB and I noticed these gold bowties. They look kind of like spark gaps, but they are not gaps, are they fuses or something? Maybe they indicate where the spark gaps are sort of looks like (my camera magnified it so I can see).

author: helius
author_rank: Super Contributor
timestamp: May 23, 2023, 03:50:14 am
content: They could function as a PCB fuse; but also they control the thermal conductivity between different areas of copper fill, which can be useful for soldering for example. On old computers like the Apple II, "bowties" were used for circuit options the user could modify with an x-acto knife.

author: boB
author_rank: Frequent Contributor
timestamp: May 23, 2023, 04:05:21 am
content: Could they be modifiable areas where you might want to cut those connections for certain reasons ?Since it looks like one power plane to another, I'm thinking that is why there are so many.boB

author: thm_w
author_rank: Super Contributor
timestamp: May 23, 2023, 09:22:36 pm
content: Its a net tie to connect two nets electrically but allow you to automatically have a clearance gap on the copper pour.Since they have the exposed copper they could also work as a test point, or as previous say make it easier to cut with a knife.https://smtnet.com/library/files/upload/NetTies-and-How-to-Use-Them.pdf

author: Infraviolet
author_rank: Super Contributor
timestamp: May 25, 2023, 07:59:33 pm
content: How did those "bowties" remain as exposed copper during manufacture, and not end up with tin/HASL/ENIG/gold or whatever other plating was used covering over them? Most production processes have everything which isn't covered by solder mask plated with one of those covering to make them easier for parts to solder on to.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 25, 2023, 08:32:06 pm
content: OSP (organic solderability preservative) -- keeps the bare (unplated) board clean enough for production purposes (6 months or so shelf life, give or take?).Tim

author: trophosphere
author_rank: Frequent Contributor
timestamp: May 26, 2023, 03:06:15 am
content: Quote from: Infraviolet on May 25, 2023, 07:59:33 pmMaybe they addPeelable Soldermaskbefore the plating step and then remove afterwards?

author: ebastler
author_rank: Super Contributor
timestamp: May 26, 2023, 06:17:50 am
content: Quote from: Infraviolet on May 25, 2023, 07:59:33 pmPretty sure theyareENIG surfaces. The color may not come across clearly in the photo, but the OP describes them as "gold bowties".

author: strawberry
author_rank: Super Contributor
timestamp: May 26, 2023, 06:46:17 am
content: Quote from: ebastler on May 26, 2023, 06:17:50 amfools gold?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 26, 2023, 10:29:50 am
content: Have seen it before on a laptop motherboard, here mostly holes, but some solder jumpers appear on the bottom side. This was after like 10 years in use, so they've aged to a darker orange color, comparable to the tantalums -- which I think are tantalum polymer perhaps, not the regular yellow kind. It's not a camera trick, they are darker than usual, and no it's not a heat+age thing, at least I don't think it is; there are yellow ones elsewhere. As well as aluminum polymer chip, and either can poly or electrolytic elsewhere too. They certainly went for diversity in here...https://www.seventransistorlabs.com/Images/8510W_1.jpghttps://www.seventransistorlabs.com/Images/8510W_2.jpgTim

author: Whales
author_rank: Super Contributor
timestamp: May 26, 2023, 10:58:01 am
content: > I have a PCIe card that does weird things it seems the more I use it, including disappear from the system.Just as an aside: also be wary of PCIE switch chips on the motherboards themselves. Perhaps they only trigger problems for certain cards.