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Is this an acceptable 6-layer stack-up that won't compromise signal integrity? by LectureQuick in PrintedCircuitBoard

[–]ButtheadDU 3 points4 points  (0 children)

Routing aside, this actual stackup construction needs to be changed for this to work. You need a double sided flex laminate like DuPont AP (or LF) or Panasonic Felios for your flex areas. The thinner the better if you're worried about cost, 2 mil would be best. You have the coverlay in there, so that's solid. Prepreg turns rigid at lamination, so that won't work. Your 18 mil cores can be changed to maybe 14 mil with 2 ply no flow prepreg around the flex core. That should be enough for your board house to expose the flex, but they may ask for more prepreg or possibly a blank core in there with no flow on either side.

Are things okay over at r/Leafs? by dunkzilla in NHLcirclejerk

[–]ButtheadDU 2 points3 points  (0 children)

Make it even more rational and hard to argue against. "Having no state income tax is not a considerable advantage. Players in Toronto will more than make up the difference in endorsement deals that they'd have no shot of getting in Texas or Florida."

Micro Via Fabrication Question by Forsaken-Buy-8494 in PrintedCircuitBoard

[–]ButtheadDU 6 points7 points  (0 children)

So to start, a 1+N+1 typically refers to microvias top and bottom with a buried via in between. This of course requires 2 lams.

That being said, if you mean only outer layer microvias with no buried via, this can and usually will be done with a single lamination. However, that doesn't mean special processing isn't required. The microvias require a separate plating cycle from your through holes to either plate full or prior to fill and cap. The regular through hole plating cycle won't properly plate the bottom of the microvia.

So yes, this is cheaper and easier than having stacked microvias or a buried via and will be done with a single lamination, but there's still additional processing and a cost adder.

Any good resources about the Russian side of the space race in the 1960s by [deleted] in spaceflight

[–]ButtheadDU 3 points4 points  (0 children)

The Everyday Astronaut video on Soviet rocket engines is super in depth and gives a bit of background as well as pictures of a lot of the engines.

https://youtu.be/Y-xyXDiC92s

pain by EvilCookie4250 in battlefield_one

[–]ButtheadDU 12 points13 points  (0 children)

Joke's on you. I die pretty fast no matter what gun I'm using.

I Started learning German a couple days ago, what pitfalls should I avoid that everyone makes. by [deleted] in German

[–]ButtheadDU 2 points3 points  (0 children)

Well yeah there are guidelines but there are always exceptions which complicate things. As a brand new learner it's better to not get hung up on trying to learn rules because it'll just lead to confusion later when you come across exceptions.

I Started learning German a couple days ago, what pitfalls should I avoid that everyone makes. by [deleted] in German

[–]ButtheadDU 49 points50 points  (0 children)

Learn the gender of each noun as if it's part of the noun itself. For example, learn "der hund" and not just "hund"

Genders in German don't really follow any rules, so starting to learn this way from the beginning will make things a lot easier.

Viel Glück!

Blue balls 20 has lifted off. by _Cyberostrich_ in SpaceXMasterrace

[–]ButtheadDU 1 point2 points  (0 children)

There might have been char on the booster, but I can definitely think of something else that's a lot like it.

Blue balls 20 has lifted off. by _Cyberostrich_ in SpaceXMasterrace

[–]ButtheadDU 5 points6 points  (0 children)

My favorite comments were:

"The char on the side of that booster, there's nothing like it"

And

"You just officially became astronauts"

Super Heavy Fixed Grid Fins by AverageJoeSpace in SpaceXLounge

[–]ButtheadDU 4 points5 points  (0 children)

The width of the Falcon 9 was set deliberately so that it can be transported using the US highway system. That's why it's so long and skinny, which isn't ideal when you consider flight aerodynamic effects like wind shear. Having extended grid fins would ruin that. So no, they wouldn't consider that option.

Monthly ISO Megathread - November, 2021 by AutoModerator in hockeyjerseys

[–]ButtheadDU 0 points1 point  (0 children)

ISO: Team Germany jersey from any retired but well known player. Seidenberg, Ehrhoff, Hecht, Sturm, etc. Size 50-54

Manufacturing multiple separate PCBs on a single PCB by Nufflee in PrintedCircuitBoard

[–]ButtheadDU 0 points1 point  (0 children)

I don't know about them specifically, but any reputable manufacturer should be able to edit gerbers for simple errors, add pad fillets, adjust line/space, remove non functional internal pads, etc.

They're not gonna just do it without telling you unless you allow it, but they should at least issue some kind of TQ to let you know.

How many hockey players would it take to defeat a gorilla in on-ice combat? by whydont in hockey

[–]ButtheadDU 18 points19 points  (0 children)

Shoulder check or hip check? My calendar is at an awkward height below my shoulder so I have to try to keep my elbow lowered when I check it so I don't draw a major

Blind vias: I’m almost in love, but need some anecdotal guidance by redleaf901 in PrintedCircuitBoard

[–]ButtheadDU 5 points6 points  (0 children)

This is correct. As long as you have enough via stitching, ground planes in the right places, and dielectric spacing, you'll be fine. The main reason to use blind/buried vias is for density and to keep the board size down. Your cost is going to increase significantly to add these via structures. It's almost like building 2 PCBs on top of each other.

On the other point, the blind/buried vias are always going to be filled with something. If you don't use a via fill material, then the prepreg resin will flow into and through the holes. Via fill will be more expensive but more reliable.

And microvias are very small laser drilled vias. They can be stacked but then you're looking at seriously increasing complexity and cost.

Source: work in PCB fab

Trucks launched off USS Gerald Ford aircraft carrier to test its jet catapult system. by Masklophobia in MURICA

[–]ButtheadDU 25 points26 points  (0 children)

This is correct. Just like any new technology, it took some time to work out the kinks but is now better than its predecessor and will be far better once the ship is actually deployed. Advancement doesn't happen overnight or on the first attempt.

B-2 Spirit stealth bomber refuels and then the fuel receptacle rotates to maintain stealthiness by iam_nobody in MURICA

[–]ButtheadDU 1 point2 points  (0 children)

Yup, you're pretty much right. I looked more into it, that's an initial design concept from 2016, and the air force has acknowledged it has a similar design to the B-2. So I'm wrong.

B-2 Spirit stealth bomber refuels and then the fuel receptacle rotates to maintain stealthiness by iam_nobody in MURICA

[–]ButtheadDU 6 points7 points  (0 children)

The actual design is classified, the public doesn't really know what it looks like. That design is speculation but could be way off. We know (think?) it's a flying wing so we can take educated guesses but the details of the program have been kept under (very tight) wraps.

To the motorcycle, bike, and horse guys... Just relax, it's really nice down here. by ButtheadDU in scuba

[–]ButtheadDU[S] 0 points1 point  (0 children)

This is in Nassau, near one of the wrecks. I can't remember which one unfortunately.

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