ote:
ll's "fat
was not
not as
wonder
(does it
ig
eak of
orrected)
ower
too ;)
ignores
ver,
forgot
I'd
10/2.age in
ald number.
. No
,ou've
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to
ia
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nif
C.
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I've done a few big SoCs in a previous job, and that is kinda how it works with both inhouse and purchased IP, and for every new design the blocks get a few tweaks to meet some new requirement and in the end no one really know how they should work
-Lasse
wrote
"fat
it
corrected)
number.
I just got one that had *every* power/current value listed as TBD. Nice. It's fun designing the power system with such a complete spec.
wrote
"fat
not
as
it
corrected)
forgot
number.
I know that IC mfgs provide lib parts at times. But I use a CAD that is not so popular out here. It has its downsides such as this, but it has an upside that wipes out any and all downsides: No crashes.
That's in fact how most people want schematics. Including myself.
On alumina and other higher tech material, yes. On FR4 I simply will not do it. If the client insists, ok, but then the result is their responsibility.
Well, I am quite flooded with work despite the fact that I do not use BGA. Simulating right now to see whether I can use an MSOP sans thermal pad instead of a leadless QFN with pad. Nothing beats the gentle compliance of leads on a package.
If it goes on like this through winter I won't need to heat the office, the computer does that.
wrote
"fat
not
as
wonder
(does it
of
corrected)
;)
ignores
forgot
10/2.in
number.
Actually I do like buses a lot. Especially the ones with comfy seats and WiFi on board :-) ... Just kidding, I do like buses on schematics.
Ever dealt with Asian-style schematics? Oh, there is still some white on the page, let's cram the preamp in there. Then you start following a line clear across the page and it goes to ... ground!
wrote
"fat
not
as
wonder
(does it
of
corrected)
;)
ignores
forgot
10/2.in
number.
It can't import data from any other format? Ours can't but I don't expect much from it (and I'm always disappointed).
in
on
Most? GOt a cite for that? None of the companies I've worked for wanted anything that ugly. It makes the schematic unreadable.
BGAs.
Nope. FR4. The is *no* problem. In fact, they're more reliable than other packages. They do have to be done right, of course. Actually, at the PPoE (small company) they had far fewer problems with BGAs than they did with any other package. They didn't have an XRAY machine, either.
You do tiny stuff. Without big DSPs, I don't have a job.
Global warming is finally coming to CA?
wrote
"fat
not
as
wonder
(does it
of
corrected)
;)
ignores
forgot
10/2.in
number.
It can import but let's put it that way: My experience with that is very mixed. I wouldn't trust it.
in
on
to
Most as in pretty much all my clients. I don't think there is any opinion poll data for that available.
I don't know what's ugly about it. Look at the schematics on the web, they usually have opamps split out, same for 74HC14 inverters and such, but the uC or DSP is one big block.
BGAs.
As you tend to say, I do not buy it.
Does this mean lots of laptop manufacturers including your former employer do it wrong? This is how it looks when BGA solder joints on their laptops give up:
Just for giggles, someone came up with a real low-tech repair method:
paycheck.
Then I do not want your job :-)
I sure hope so. However, since I do not trust that we bought the record qty of five cords of almond again for this year. Blew through the complete stack the last two seasons already, literally done to the last sticks. In 2000 I thought that was impossible, back then two cords was fine.
wrote
"fat
not
as
wonder
(does it
of
corrected)
;)
ignores
forgot
10/2.in
number.
Our in-house BGA placement success rate has been 100%. We have had a couple of problems after multiple rework/replacements. BGAs seem to be a lot more reliable than fine-pitch leaded chips.
Most of all, I do
Another virtue of BGAs!
I agree that on the whole they are reliable, but they have a reputation in some circles through some manufacturers cutting corners. You only have to look at the reliability of Xboxes!
wrote
"fat
not
as
wonder
(does it
of
corrected)
;)
ignores
forgot
10/2.in
number.
But your stuff probably doesn't occasionally get nailed to the runway with a loud ker-crunch sound and several tires blowing out.
Hmm, I don't see that one. I want to be able to inspect. It doesn't protect against reverse engineering since those guys have every tool imaginable at their disposal.
wrote
Dell's "fat
not
not as
wonder
(does it
of
corrected)
power
;)
ignores
driver,
forgot
10/2.in
number.
No
built
Very few Gs.
XRAY, if you must. We have one in our lab but it's never used.
wrote
"fat
not
as
wonder
(does it
of
corrected)
;)
ignores
forgot
10/2.in
number.
Busses where the contents are not similarly named (not Bus[0:11], rather BusWr, BusRd, BusEn,...)?
I work for an Asian company. I think their schematics *suck*. No hierarchy, even.
It can't be cutting corners, rather incompetence. My experience with BGAs is the same as JL's - far more reliable than other fine-pitched packages. Even the .5mm BGA went flawlessly, even though the process guy didn't think they could do it.
wrote
Dell's "fat
not
not as
wonder
(does it
of
corrected)
power
;)
ignores
driver,
forgot
10/2.in
number.
No
built
Trust, but verify. ;-)
in
on
to
Sorta my point, though if I'd shown up with a schematic like that, no one would have hired me. They want their documentation to describe how the widget works.
Nothing else fits on the page with the "big block". Might just as well have a netlist.
BGAs.
Of course you don't. It's a fact, though. BGAs are a far superior package. There are some problems with thick boards and fine-pitched BGAs but I try to stay at .8mm or above. .5mm can be done but it gets dicey with more than six layers or so. The boards get pretty thin, too (1mm and less).
Probably. Nothing would surprise me from the PC Co.
Sorry can't watch videos. My laptop will blow up. ;-)
paycheck.
Different strokes.
I thought you bought five cords last year? I've got two houses with heat pumps now. No more wood stoves for me (we do have a gas fireplace in the old house and I'll probably put gas logs in this one).
wrote
Dell's "fat
not
not as
wonder
(does it
of
corrected)
power
;)
ignores
driver,
forgot
10/2.in
number.
No
built
You don't have to inspect them!
We actually do inspect the 2 or 3 outer rows of balls, with a little optical prism camera thing. But that's just to get an idea of how things went, not to literally inspect every joint. But our yield is
100%, so the inspection is kind of a ritual.
This is cool:
If you need to replace a BGA, pull the old one off, and then stick that orange (kapton) thing down on the board. Squeegee paste onto it (with a tiny x-acto knife squeegee) and scrape off the excess. Place the new BGA and reflow the whole board. The kapton thing stays.
We have one board where we replaced a 780-ball FPGA three times.
[...]
:-)
Then it doesn't save time. If I have to verify all names, pin numbers and ERC pin functions I might as well roll my own from scratch.
nuts in
exhaust on
to
My schematics do describe how it works. Analog guys live that way.
That's perfectly fine. There will be a net name saying, for example, PULSECNT and the two letters uC underneath. Then everyone with enough smarts will know that this goes to sheet 7 where the big fat uC lives. It is not necessary and would be rather confusing to whack out timer #2 and then place it on sheet 2 where this net is. You'd be looking at sheet 7 and ask your self "There's pins missing here. Where the heck did all the timers go?".
BGAs.
The real fact is that whole small businesses have sprung up because of all the BGA failures. Usually one-man shops. In our area their are mobile, they often buy retired ambulances, put in a work bench, then drive to the customers with the BGA problems.
It's an IBM T40 with BGA failure. Lots of other brands have the same issues.
packages.
paycheck.
That's why I wrote "again". We bought five cords also last year, and blew through all of that. Lots of people in CA also have heat pumps but that was a major mistake. Because the state government became hardcore leftist so now they tax the dickens out of these poor folks, via reverse tiers on the power bill. A meager baseline quantity costs around
15c/kWh. With a heatpump or A/C you exceed that within days and then prices quickly shoot up to something like 35c/kWh. I knew an old lady who was very skinny, so needed it warm in the house in her 90's. She paid north of $1000/month in winter. That's insane, I won't do that.
wrote
Dell's "fat
not
not as
wonder
(does it
of
corrected)
power
;)
ignores
driver,
forgot
10/2.in
number.
No
built
busses,
If it's clear what the bus does I am ok with that. But I prefer BUSWR[0:11], BUSRD[0:11], BUSEN[0:3], and so on. Consistency is important in schematics.
You have my sympathies :-)
wrote
"fat
not
as
wonder
(does it
of
corrected)
;)
ignores
forgot
10/2.in
number.
Done. But we'll have to interleave the story and the beer, or else the curves will get wigglier as we go on. ;)
Cheers
Phil Hobbs
wrote
"fat
not
as
wonder
(does it
of
corrected)
;)
ignores
forgot
10/2.in
number.
"You've
A LPTM can out-drink a SETM every time.
Did I ever show you my pen-and-cocktail-napkin-and-beer chromatography thing?
wrote
Dell's "fat
not
not as
wonder
(does it
of
corrected)
power
;)
ignores
driver,
forgot
10/2.in
number.
No
"You've
I don't think so. Another one of those experiments that becomes less quantitative as the evening progresses.
Cheers
Phil Hobbs
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