3M tape with anisotropic z-axis electrical conductivity • Hacker News Board

Re: 3M tape with anisotropic z-axis electrical conductivity

#71

Post by bee_rider » Tue, Apr 19, 2022, 3:35 AM UTC

Rebelgecko wrote: post #68

bee_rider wrote: post #40

Earlier quoted context omitted.

I'm surprised they didn't do well during the pandemic. Their Aura masks were, like, weirdly better than every other mask I tried (at least in terms of comfort).

Agreed, they're the most comfortable ones I found without an exhalation valve. Conveniently they also fold flat. Only downside is that they go behind the head instead of using ear loops.

I can't stand ear loops anyway, they hurt my ears. It helps that my hair has grew out during the whole "don't get close to people" thing. Ponytail + around-head straps is a great combo for maximum snugness (you can loop the top one under and the bottom one over).

Re: 3M tape with anisotropic z-axis electrical conductivity

#72

Post by mlindner » Tue, Apr 19, 2022, 3:37 AM UTC

markdown wrote: post #27

loxias wrote: post #4

The prowess of materials science in companies like 3M and Dupont never ceases to amaze me. Just when I think I've seen it all with fiberglass tape and kapton tape...

Their "prowess" saw DuPont give cigarettes laced with new toxic chemicals they made to their employees to test the chemicals effects. Every human on earth has Dupont chemicals in their blood that will never go away, but accumulate over the course of our lives. These are "forever chemicals" that never break down. When you die you pass them on. They are in the animals you eat, in the beverages and water you drink, they…

Your post comes across as being written by someone who is unhinged rather than someone trying to make a convincing argument.

> This is the result of American capitalism and the worlds most corrupt banana republic legislature where bribery is so bad they made it legal.

And things like that just sound silly and trying to string a bunch of buzz words together.

Re: 3M tape with anisotropic z-axis electrical conductivity

#73

Post by mlindner » Tue, Apr 19, 2022, 3:37 AM UTC

bialpio wrote: post #56

dxuh wrote: post #44

Earlier quoted context omitted.

That Netflix link is not available everywhere and also quite time-consuming to review. Obviously it is also a dramatic piece rather than a (semi-)scientific. I had a brief look at the PFAS wikipedia page ( https://en.wikipedia.org/wiki/Per-_and_polyfluoroalkyl_subst... ), which is what that Netflix movie seems to be about, but it's also quite wordy and the claims you make can not be found on there as-is. Maybe you wa…

Not sure if you'll consider this a more scientific source, but John Oliver also did a piece about PFAS: https://m.youtube.com/watch?v=9W74aeuqsiU . The list of issues that the wiki article claims are "high certainty" is also quite concerning to me: https://en.m.wikipedia.org/wiki/Per-_and_polyfluoroalkyl_sub... At the very least, seems that the production is being ramped down - quick skim of the article yielded this…

John Oliver is a comedian, so also not a very good source. It's written for entertainment rather than being informative.

Re: 3M tape with anisotropic z-axis electrical conductivity

#74

Post by terplkwjpl24 » Tue, Apr 19, 2022, 3:45 AM UTC

markdown wrote: post #27

loxias wrote: post #4

The prowess of materials science in companies like 3M and Dupont never ceases to amaze me. Just when I think I've seen it all with fiberglass tape and kapton tape...

Their "prowess" saw DuPont give cigarettes laced with new toxic chemicals they made to their employees to test the chemicals effects. Every human on earth has Dupont chemicals in their blood that will never go away, but accumulate over the course of our lives. These are "forever chemicals" that never break down. When you die you pass them on. They are in the animals you eat, in the beverages and water you drink, they…

DuPont is now also the owner of Union Carbide whose carelessness caused one of the biggest industrial disasters in Bhopal in '84, killing over 3k people, and causing lasting injuries for many 10s of thousands. IIRC, some IITs even disallowed DuPont from participating in their campus-placements for this reason.

India's craven political dispensation accepted the pittance of damages paid by UC, but it barely covered anything. Such disgrace.

Re: 3M tape with anisotropic z-axis electrical conductivity

#75

Post by teraflop » Tue, Apr 19, 2022, 3:46 AM UTC

magicalhippo wrote: post #53

n4bz0r wrote: post #42

Could this be used for CPU (or some other truckload-of-pins chip) "reballing"? Does it do well under a bolted-on radiator / pressure plate? For instance, many old Playstation 3 systems go faulty because of the poor quality solder on the CPU/GPU that tends to crack over time. Being a normie, it's really hard to fix something like that at home. But this tape seems like it could save the day.

> Could this be used for CPU (or some other truckload-of-pins chip) "reballing"? The datasheet[1] says the minimum gap between conductors is 0.4mm, so based on that it should work for 0.5/0.65mm BGA. Also would clearly affect the speed you can run things at due to introducing parasitics. But would certainly be fun to try. [1]: https://multimedia.3m.com/mws/media/66235O/3m-electrically-c...

Getting the chip lined up accurately enough might be a bit trickier. With soldering, you can normally rely on the solder's surface tension to pull the pads into alignment.

Re: 3M tape with anisotropic z-axis electrical conductivity

#76

Post by loxias » Tue, Apr 19, 2022, 3:56 AM UTC

markdown wrote: post #27

loxias wrote: post #4

The prowess of materials science in companies like 3M and Dupont never ceases to amaze me. Just when I think I've seen it all with fiberglass tape and kapton tape...

Their "prowess" saw DuPont give cigarettes laced with new toxic chemicals they made to their employees to test the chemicals effects. Every human on earth has Dupont chemicals in their blood that will never go away, but accumulate over the course of our lives. These are "forever chemicals" that never break down. When you die you pass them on. They are in the animals you eat, in the beverages and water you drink, they…

(like I said..) I'm impressed with the prowess of the MATERIALS SCIENCE in companies like 3M and DuPont, certainly not the business ethics.

Please don't conflate admiration for the fascinating engineering work with endorsement of an entire company's impact on the world!

Re: 3M tape with anisotropic z-axis electrical conductivity

#77

Post by singlow » Tue, Apr 19, 2022, 3:57 AM UTC

derefr wrote: post #66

jlebar wrote: post #39

Earlier quoted context omitted.

> A while back I invested in 3M because it's a company that makes so many amazing and industry leading products and I thought they'd do well. A couple years later and the stock is just lagging. The relevant question isn't whether they make great products, but whether their stock is undervalued. We in the tech world are used to "great products" -> "stock price always goes up", but in the "real world" there's no reason…

New great products, in blue-ocean markets, creating new revenue sources, aren’t enough? For companies the size of 3M that “do everything”, do market traders just price in a certain stable rate of predicted innovation leading to geometric revenue growth / monopoly positioning / etc?

The current price is based on the predicted earnings growth. Everyone expects 3M to have earnings growth and that expectation is already baked in. The price is only going to spike if something unexpected happens. Growth would have to exceed expectations.

Re: 3M tape with anisotropic z-axis electrical conductivity

#78

Post by rallison » Tue, Apr 19, 2022, 4:04 AM UTC

bee_rider wrote: post #40

01100011 wrote: post #12

A while back I invested in 3M because it's a company that makes so many amazing and industry leading products and I thought they'd do well. A couple years later and the stock is just lagging. I guess they're dragged down by their environmental lawsuits these days. As a human, I'm appalled at their environmental track record but as an engineer, wow they really do so many things so well.

I'm surprised they didn't do well during the pandemic. Their Aura masks were, like, weirdly better than every other mask I tried (at least in terms of comfort).

Auras are great. I gave some to family and friends, and they became the go-to good masks for a decent portion of them.

My personal favorite is the 3M V-Flex N95. Super comfortable, great seal, and relatively large interior volume (great breathability). It's pretty close to a perfect mask. I also gave some of these away, and they were similarly popular.

In general, Aura seemed to be liked more for smaller faces, and V-Flex for larger faces. So, nowadays, my go-to recommendations are V-Flexes and Auras.

Re: 3M tape with anisotropic z-axis electrical conductivity

#79

Post by kevan » Tue, Apr 19, 2022, 4:15 AM UTC

systemvoltage wrote: post #23

01100011 wrote: post #12

A while back I invested in 3M because it's a company that makes so many amazing and industry leading products and I thought they'd do well. A couple years later and the stock is just lagging. I guess they're dragged down by their environmental lawsuits these days. As a human, I'm appalled at their environmental track record but as an engineer, wow they really do so many things so well.

3M is an awesome company. I've worked with them to produce custom adhesives for us ($MM orders). Their products have exceptional quality, reliability and performance. What you see in a datasheet is what you're going to get (or better). 3M's consumer products (Scotch, etc.) are also excellent. Anytime you use 3M products, you don't need to worry. I like that consistency and it brings peace to the mind. I'll pay more f…

The product quality is awesome. The company has some bad history with chemical dumping and caused at least one superfund site. And used the standard tobacco playbook after finding health concerns with PFAS chemicals in the 1970s to delay the rest of the world from finding out how bad it was. They only started phasing them out in 2000 and paid off at least one academic researcher for another decade to prevent or slow the release of studies showing negative affects.[1]

[1] https://www.smh.com.au/lifestyle/health-and-wellness/toxic-s...

Re: 3M tape with anisotropic z-axis electrical conductivity

#80

Post by mNovak » Tue, Apr 19, 2022, 5:26 AM UTC

Years ago I had the idea to use this tape to make solder-free PCB kits to teach electric circuits (the tape would connect the chip pins to the board, without shorting sideways). I bought a roll, and printed some boards for LEDs and 555 timers and such.

Unfortunately it didn't make reliable contact for the chip pins unless you were constantly pushing down on it. As I recall the datasheet states as much. That seems like a solvable material science problem, but alas perhaps not valuable enough.