I am new and just finishing my first ever board. Will send to PCB factory in a few days time.
To be on safe side, would like advises from the group.
For first prototype on SMD R and C, i use 0603 KiCad-build-in-hand-solder footprint for a big 100x100mm board. Will be 63% tin, 37% lead solder. Is that ok?
Next version will be 0402 to fit actual plastic case size and shape. Will be done by stencil and hot plate and may be manufacturing-proper non lead solder. For “specific chip” (non R, non C) Should I use KiCad non-hand-solder footprint OR the manufacturer supported footprint library downloaded from Mouser.
Below post say JLCPCB also has footprint library. Also, a few other from DigiKey, etc.
I have never used ‘hand-solder’ footprints.
When I wanted to find optimum capacitor values for RFID antenna the proces could be described as:
for 3 values of C1,C2,
for (C3,C4=10pF, C3,C4<40pF, C3,C4+=2pF),
find the C5 value giving optimum read distance.
This needed may be hundred times changing C5 value.
I have done it at PCB with standard 0603 footprints for all these capacitors hand de-soldering and soldering them.
Even PCB changed its color after this I can say that I see no special problems with soldering 0603 elements at standard footprint.
Of course I was using classic (not Pb-Free) solder to do that.
In the USA I personally do not even have any ROHS (unleaded) solder. I have been using leaded solder for 60 years and I think (??) I am OK so far. My little bit of experience elsewhere with ROHS solder indicates that it is significantly more difficult to use, but I suppose that would get better after a “learning curve.” For personal use, I would not recommend using ROHS solder unless you need to do so. One such reason is if you are working on boards which already have ROHS solder. In that case you may need to be sure that the alloys are compatible.
Back (maybe 40 years ago?) when environmental agencies pushed the electronics industry to switch to ROHS solder, I think it happened three times that the industry said “No we cannot find a way to do it.” Finally pressure built and our industry found a way. But I do believe it is more difficult to solder.
I use my own oversized footprints routinely. I do think it is likely to make work easier, especially on smaller chips such as 0603 and fine pitch ICs where I fatten the corner pads.
Not permitted in product you want to sell, but when doing your own experiments…
It can be only your opinion
But seriously there is difference between someone soldering one PCB per month and someone working in production doing it all the time or working with big wave soldering equipment.
We had a problem when ROHS was introduced.
This was the only one time (ever) when we were involved (not directly) in some (big for us) government order. We had to manufacture as many of one of our products as we normally did for 10 years.
As final decision of order was moved from 11.2005 to 04.2006 they said that the term to do is shifted from 06.2006 to 09.2006. But 1.07.2006 ROHS was coming. An year before we just started to use contract manufacturer and only thanks to that we were able to even think of complete the order. But our contract manufacturer said that they haven’t mastered lead-free technology yet and will not do it till 09.2006.
I thought of it as typical bureaucratic rudeness. We supposedly have a postponed deadline but we have to meet it in 2 months because if we sell after 1.07 we expose ourselves to penalties for breaking the law. It was a very hot time
It was microprocessor education tool and was sold via some company who since that moment kept selling it. Later they pressed us whether we would do something else for education because from their contacts with schools it appears that if we wrap shit in paper and sign that it is our product, they will buy it blindly. We even had a few interesting ideas, but our processing capacity is too small.
