Can someone say what is normally used for HAL please , i always thought it was solder but i have some oldish boards which have become unsolderable.
They do not appear to be tin coated.
If there is a very thin layer of tin it will dissolve into solid solution on a timescale of a few years, leaving
red copper surface I think. Yes its pure tin normally. For fine-pitch SMT like BGA packages you need
a very flat solder-wettable surface, just dipping in solder or tin is not good enough, hence electroplated
or air-leveled films are used. Gold is best of course.
Boardburner2:
Can someone say what is normally used for HAL please , i always thought it was solder but i have some oldish boards which have become unsolderable.
They do not appear to be tin coated.
Some details of what HAL is normally used for are here;
Oi!
No selfies
HAL/HASL is tin (or tin/lead solder for non-lead-free boards) - I have seen no sign of degradation on HASL boards over a couple of years.
Immersion tin (commonly used on home-made boards) is much thinner and less durable - it stops being readily solderable within months, IME.
Ah, now I undertand.
HAL is an acronym for HASL with out the S
Personally, I was wondering how the OP made the jump from talking about a Hardware Abstraction Layer to solder...
MarkT:
or air-leveled films are used. Gold is best of course.
I had some boards made as carriers to enable to mount smt chips on to through hole for use on breadboard.
Many patterns each board which were chaap from china , (i have a board shear).
I had some which were ENIG which have also become difficiult after 2 years or so.
Gold would seem to be the best long term option but i do not know of any supplier who offers this at a reasosnable price(my usal supplier does not offer gold , only ENIG).
Best would be to buy a carrier for the chip i require online.
Do not know the relevant search terms to use though.
I can never find the right carrier for the chip i need.
Current requriement it is for TI 4 port USB chip. I realise that it is going to be useless on a breadboard but just need a carrier to plug in to a custom PCB.
avr_fred:
Personally, I was wondering how the OP made the jump from talking about a Hardware Abstraction Layer to solder...
I do not understand.
I have some old boards which are no longer solderaable.
DrAzzy:
Immersion tin (commonly used on home-made boards) is much thinner and less durable - it stops being readily solderable within months, IME.
This is my experience also.
The boards i have i thought to be hot air levelled with solder, not sure though now.
I clean oxidised boards with a slightly abrasive household cleaner (like Jif) on a damp cloth.
Wipe a few times untill you see some difference.
Rinse with warm water, and let dry thoroughly.
Leo..
Ok.
I get it, One slily spooling error . 
Wawa:
I clean oxidised boards with a slightly abrasive household cleaner (like Jif) on a damp cloth.
Wipe a few times untill you see some difference.
Rinse with warm water, and let dry thoroughly.
Leo..
I do the same and works well on copper.
Whatever these boards are though i cannot solder with a blowlamp.
Boardburner2:
Whatever these boards are though i cannot solder with a blowlamp.
Uh, have you tried using a soldering iron? I've found that blow-torch based soldering implements are pretty much garbage.
DrAzzy:
Uh, have you tried using a soldering iron? I've found that blow-torch based soldering implements are pretty much garbage.
The blowlamp did not work. But it made me feel better.
I think the fault is with the boards but not sure why.
New boards on order, they are cheap , just have to wait 3 weeks.
Post a pic of the boards (the ones you haven't turned the blow-lamp on yet) if you could? I'm curious about what these cursed boards look like.
Sorry already binned them but the pads all had a slight bump at the same side which i assume was the downstream end of the air knife.
From memory this was typical of HASL which i thought i had ordered.
Slightly discoloured mottled surface compared to a new tinned one.
Hi
Slightly discoloured mottled surface compared to a new tinned one.
Are you sure they were Sn Tin, tinned?
They weren't lead free soldered/tinned were they?
Horrible stuff, will not mix with the good decent solder.
Even if used to tin, will make a joint look like crap.
Tom...
TomGeorge:
They weren't lead free soldered/tinned were they?
Horrible stuff, will not mix with the good decent solder.
Even if used to tin, will make a joint look like crap.Tom...
Quite possibly, i did not know there was a problem with these.
Thinking on though i know tinned copper is a problem with age and with lead free solder being a mix of copper tin perhaps i should not be surprised.
I have 5 year old boards with lead solder finish that are fine.
I have a board from the same order which solders fine but that was 4 layer so probably went through a different process line.