Don't touch any soldering system that is not fully user temperature variable.
If you have to change the tip to change temperature, avoid.
Great for production use, hopeless for general lab/electronics use
QuoteDon't touch any soldering system that is not fully user temperature variable.
If you have to change the tip to change temperature, avoid.
Great for production use, hopeless for general lab/electronics use
Sorry Dave but I have to violently disagree here. 'Hopeless' is just bollocks.
As long as the iron has enough power and good thermal coupling to maintain a constant temp with varying loads without overshoot there is really no need for temperature adjustment.
The Metcal STSSS/MX systems are without doubt the best iron you can buy. I have no experience of their lower-end irons.
I do everything from 0.5mm QFNs and TQFPs to soldering M4 screw terminals into heavy-copper boards to carry 30 amps with the same tip temperature - in about 20 years of owning Metcals in a development environment I've never felt any need to have a temperature adjustment.
Can you explain exactly why you think you need temperature adjustment on a good iron? Except maybe for melting plastic.
I used to use a Pace rework station (ST75 I think) in my last job. It was a good tool but was only a single channel so I had to keep swapping over the PS-90 with the SX-80 desoldering pump/iron every time I was repairing anything. Another problem with pace is you can only buy bits in packs of 5. Great if you use 1 size bit all the time but not if you need many different sizes (for SMT one minute and then removing metal sheilding the next etc) and on a limited budget. I've been looking at Metcal SP-200 and one complaint is that they do not have enough power for larger jobs. Bits seem quite hard to find now that the SP-200 is discontinued. Bits can be had on Ebay I suppose but you cant always find what you want quickly and this can delay a job. The MX-500 is way too expensive for me. Now that Metcal is owned by OKI the prices seem to have come down and I'm looking at the OKI Metcal PS-900 (£139 +vat @ Farnell). I'm still not convinced about the merits of Smartheat vs conventional temperature control irons yet. The hakko 936 is also discontinued and replaced with a new funky model that cant be stacked. Suppose I'll have to keep looking.
David.
The MX-500 is way too expensive for me. .... I'm looking at the OKI Metcal PS-900 (£139 +vat @ Farnell).
Good iron still needs temp adjustment for me. I need to change the temp when I need to solder/desolder something with leadfree (everything mass produced is Pb free in EU and Pb free needs higher temps) and when desoldering using wick - the wick itself is like a radiator and probably makes the termal connection between joint and tip weaker, ramping up the temp gives great results.
Its actually very hard for someone who has not used a Metcal
soldering station to understand that bumping soldering temperature is
NOT necessary when soldering large-mass joints. Really hard.
I'll give you an example, though. This was with one of the early
Metcal stations - maybe a RFG-30 or PS2E - I don't recall. This blew
away the guys in my shop when I showed it to them for the first time.
Take an ordinary copper penny (a real penny - one that can be
soldered). Place it in the middle of a piece of single-sided or
double-sided PCB material that has been cleaned enough to be soldered
- perhaps 6" square.
Take the smallest Metcal tip that you have. I think that for me, it
was either a sttc-138 or a sttc-125. The '125 has a very tiny tip,
suitable for SMT work.
Add flux all around the penny, touch the soldering tip to the edge of
the penny and add a bit of solder to promote thermal
conductivity. Wait, then start adding solder so that the entire
penny is soldered to the PCB material. Total time - about 1 minute.
Observe that the tip temperature does NOT go above the set-point of 700F.
Now go and solder a SMT device to a PCB without damaging it.
None of the other soldering stations that we have (had) here could
solder that penny to the PCB material unless we installed a really
big tip - maybe even having to go to an 800F tip in the case of the
Weller station.
Like I said - its REALLY hard for someone who hasn't used that type
of soldering station to understand the difference.
dwayne
Lead-free just means you use the right temp tip to start with, which is also fine for leaded work.
QuoteDon't touch any soldering system that is not fully user temperature variable.
If you have to change the tip to change temperature, avoid.
Great for production use, hopeless for general lab/electronics use
Sorry Dave but I have to violently disagree here. 'Hopeless' is just bollocks.
As long as the iron has enough power and good thermal coupling to maintain a constant temp with varying loads without overshoot there is really no need for temperature adjustment.
The Metcal STSSS/MX systems are without doubt the best iron you can buy. I have no experience of their lower-end irons.
I do everything from 0.5mm QFNs and TQFPs to soldering M4 screw terminals into heavy-copper boards to carry 30 amps with the same tip temperature - in about 20 years of owning Metcals in a development environment I've never felt any need to have a temperature adjustment.
Can you explain exactly why you think you need temperature adjustment on a good iron? Except maybe for melting plastic.
There are plenty of reasons, which is why they make different temp fixed iron tips. Metcal have anywhere from 500F to 800F tips. Why do you think typical tip temperatures are well above the usual melting point of solder?
Which temp tip do you use, and why?
There are all sorts of theory like being able to deliver heat quicker without applying as much pressure for shorter periods, different solder and flux material types, thermal capacities of the parts etc etc.
So a variable temp iron is a more versatile and convenient tool, simple as that.
If you don't have different temp tips in your soldering kit then I'd have to say you are not properly equipped. Yes, you can "make do" with one temp, but it's not ideal for all purposes.
Dave.
If you do proper Pb-free soldering, then you can never use the same tip (or desoldering braid) for anything with leaded solder. Even tiny residue of Pb will result a lead contaminated joints, thus no longer Pb-free, and the tip is "poisoned" permanently. So much for "one tip" tactics...
If you do proper Pb-free soldering, then you can never use the same tip (or desoldering braid) for anything with leaded solder. Even tiny residue of Pb will result a lead contaminated joints, thus no longer Pb-free, and the tip is "poisoned" permanently. So much for "one tip" tactics...
Regards,
Janne