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Re: Amateur electronics in danger due to lack of DIP ICs
On a sunny day (Tue, 02 Mar 2021 09:13:31 -0800) it happened
snipped-for-privacy@highlandsniptechnology.com wrote in

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What happens over the years?
I have a nice supply now of thin 60/40 for hobby work..
Some things I build in the eighties are still 100% functional and the soldering looks great.
 
http://www.panteltje.com/pub/8052AH_BASIC_computer/8052AH_BASIC_computer_wiring_img_1756.jpg
 
http://www.panteltje.com/pub/8052AH_BASIC_computer/8052AH_BASIC_computer_inside2_img_1757.jpg

Powered it up a year or 2 ago, only needed charging of the nicad SRAM backup, took a few minutes.


Re: Amateur electronics in danger due to lack of DIP ICs
On Wed, 03 Mar 2021 07:11:56 GMT, Jan Panteltje

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The only hazard is tin whiskers, and I think our alloy takes care of
that.

We have been doing many products lead-free for years, and they seem
OK.



--  

John Larkin      Highland Technology, Inc

The best designs are necessarily accidental.


  

Re: Amateur electronics in danger due to lack of DIP ICs
snipped-for-privacy@highlandsniptechnology.com wrote:
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With a water clean, iirc.  What sort of paste are you using?

(We may have to do the same eventually, but ionic contamination is death  
for low level circuitry.)

Cheers

Phil Hobbs


--  
Dr Philip C D Hobbs
Principal Consultant
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Re: Amateur electronics in danger due to lack of DIP ICs
On Wed, 3 Mar 2021 11:53:55 -0500, Phil Hobbs

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We're using a Delta/Qualitek paste for both water and solvent wash.

https://www.dropbox.com/s/tqzlmtbwrxy1shn/Delta_Paste.jpg?raw=1

I think the water wash involves a saponifier step.

Some parts (like relays) hate water and some hate solvent. I've been
using thru-hole relays lately, so the boards can be water washed and
the relays hand-soldered later.

I guess the thru-holes add a little capacitance. Not sure what that
tradeoff is.


Re: Amateur electronics in danger due to lack of DIP ICs
John Larkin wrote:
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Interesting--PbF with RMA flux.  Thanks!

Cheers

Phil Hobbs

--  
Dr Philip C D Hobbs
Principal Consultant
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Re: Amateur electronics in danger due to lack of DIP ICs
snipped-for-privacy@highlandsniptechnology.com wrote in  

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snip

  All of your military / Gov contracts are RoHS (lead) exempt and you  
could have used 63/37 on those, and you can use it on repairs as well.

Re: Amateur electronics in danger due to lack of DIP ICs
torsdag den 4. marts 2021 kl. 00.32.43 UTC+1 skrev snipped-for-privacy@decadence.org:
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but many components are now lead free and some require a lead free soldering profile
no matter what solder you use

Re: Amateur electronics in danger due to lack of DIP ICs
On Wed, 3 Mar 2021 15:46:32 -0800 (PST), Lasse Langwadt Christensen

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Using 63/37 on lead-free parts works great. But some fraction of our
customers insist on lead-free, so it's easier to go totally ROHS on
everything.

The temperature profile is lower for 63/37, which all parts should
like.


Re: Amateur electronics in danger due to lack of DIP ICs
torsdag den 4. marts 2021 kl. 01.24.15 UTC+1 skrev John Larkin:
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sure, but it my understanding that something things like that balls on
ROHS  BGAs need the higher temperature to probably melt and wet


Re: Amateur electronics in danger due to lack of DIP ICs
On Wed, 3 Mar 2021 16:41:07 -0800 (PST), Lasse Langwadt Christensen

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Some chips need extreme temps to fully collapse the balls. But just
soldering the balls to the PCB pads seems to work fine. The
temperature profile to fully collapse the balls can do more harm than
good.


Re: Amateur electronics in danger due to lack of DIP ICs
Lasse Langwadt Christensen wrote:
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Nah, the amount of tin on the pins is negligible.  They solder fine with  
63/37.

Cheers

Phil Hobbs

--  
Dr Philip C D Hobbs
Principal Consultant
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Re: Amateur electronics in danger due to lack of DIP ICs
torsdag den 4. marts 2021 kl. 03.01.49 UTC+1 skrev Phil Hobbs:
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sure, but not all parts have pins, some have balls that are ~96% tin


Re: Amateur electronics in danger due to lack of DIP ICs
On Thu, 4 Mar 2021 03:12:00 -0800 (PST), Lasse Langwadt Christensen

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They solder fine too. We've done millions.

Solder sticks all sorts of metals together.



--  

John Larkin      Highland Technology, Inc

The best designs are necessarily accidental.


  

Re: Amateur electronics in danger due to lack of DIP ICs
Lasse Langwadt Christensen wrote:
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I've yet to use my first BGA, and am in no hurry.  It'll be one of those  
EPC GaN FETs, probably.

Cheers

Phil Hobbs

--  
Dr Philip C D Hobbs
Principal Consultant
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Re: Amateur electronics in danger due to lack of DIP ICs
Am 04.03.21 um 19:25 schrieb Phil Hobbs:

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That worked surprisingly easy for me, 4 bumps on a square mm.
Jut a _very_ little bit of hot air, I didn't even need the vapor phase  
machine.

The proposed decal has some solder mask ON the pads.
That triggered an email from JLBpcb for confirmation, but
it's OK.

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Gerhard

Re: Amateur electronics in danger due to lack of DIP ICs
Jan Panteltje wrote:
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I use solid metal bulkhead-mount BNCs, which pass the stomp test.  (You  
hold the box in a vise, hang a dead BNC cable on it, and stomp on the  
cable.  If the cable comes out by the roots and the connectors survive,  
it passes the stomp test.

The main issue with this is that the connectors become the main  
mechanical reference for the board, which isn't always what you want.
Recently in protos and POC systems we've been moving to U.FL jacks on  
the board (10 cents) and U.FL to SMA bulkhead cables ($4).

Cheers

Phil Hobbs

--  
Dr Philip C D Hobbs
Principal Consultant
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Re: Amateur electronics in danger due to lack of DIP ICs
On Tue, 2 Mar 2021 12:51:59 -0500, Phil Hobbs

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Or you could have one of your kids sit on the box.

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I like Vbite BNCs that pass through a clearance hole in the panel.

https://www.dropbox.com/s/j3fycoyhpus0vpc/a4.jpg?raw=1

The panel takes the outside forces, especially up-down, but there is
no static force between the PCB and the enclosure.

https://www.dropbox.com/s/69qf4ixvra4xtfp/P5_pcb_Vbites.jpg?raw=1



--  

John Larkin      Highland Technology, Inc

The best designs are necessarily accidental.


  

Re: Amateur electronics in danger due to lack of DIP ICs
snipped-for-privacy@highlandsniptechnology.com wrote:
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When doing picosecond stuff, I'm much more concerned with signal  
integrity too.  I haven't done a lot of stuff faster than 100 ps or so,  
and so far that's mostly samplers.

Those U.FL things are sure cheap and convenient though--we sprinkle  
footprints for them all over the place, because it's a cheap and simple  
way to ensure good probing during debug, and hardly costs any  
capacitance if it's not populated.  (Especially if there's a 450-ohm  
0402 resistor in series.)

Cheers

Phil Hobbs


--  
Dr Philip C D Hobbs
Principal Consultant
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Re: Amateur electronics in danger due to lack of DIP ICs
On 3/3/21 10:52 am, Phil Hobbs wrote:
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I assume there is some impact if it is populated though, which would  
mean results during debugging will be different than production. Have  
you needed to quantify the difference? Or are there enough other  
parasitics to calibrate out that it doesn't matter?

Clifford Heath

Re: Amateur electronics in danger due to lack of DIP ICs
Clifford Heath wrote:
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It's a small fraction of a picofarad.  With a series resistor, it's a  
nit even in the gigahertz.

Cheers

Phil Hobbs

--  
Dr Philip C D Hobbs
Principal Consultant
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