Low quality solder, iron, and desoldering iron - burnt my PCB pads

User avatar
Menuhin

10 Dec 2018, 12:12

I just found out that good solder and good soldering iron make great difference, by this video.
No wonder I have been lifting pads, burning circuits with the 400°C solder & desolder tips and the solder didn't even melt yet.
All soldering wires I can find all came from China though.

Really want to know the settings of some of the forum members here, especially good ones that do not break the bank.

JBert

10 Dec 2018, 12:52

My decades-old 50W Weller soldering station is locked at 370°C and works sufficiently well for normal PCBs and joining wires. Only big solder pads ( > 2 cm²), grounding planes (basically a soldering pad spread out over the entire PCB) or thick wires form a problem.

The trick is to have a soldering iron which can give off just the right amount of heat very quickly. For that your iron needs to contain enough mass to "store" some heat, have enough heating power (i.e. 30-50W for starters) and proper temperature monitoring (soldering guns generally are 100W and can become way too hot for small solder work).

andrewjoy

10 Dec 2018, 13:09

The trick is to have an iron with a good thermal capacity. That way you can lower the temp but that heat will get into the to the pad better.

The problem with a cheap iron is you have to have the temp higher and if you spend too long on the pad the pad will heat up too much and lift.

I have a JBC HD-2B i got super cheap off ebay

https://www.jbctools.com/hd-2b-heavy-du ... ory-1.html

__red__

10 Dec 2018, 15:19

andrewjoy wrote: The trick is to have an iron with a good thermal capacity.
This.

I use a metcal clone (thermaltronics) where the temperature is fixed by the tip that you use. That thing can dump so much energy into my work it should be tagged a thermonuclear device.

Also - the type of end you use makes a massive difference too. Most people here should be using chisel.

As far as solder selection there are two things I look for:

1. Temperature.
2. Flux.

In the above video when soldering the thru-hole with the "quality solder" the only thing my brain was screaming was 'dry-joint'.

andrewjoy

10 Dec 2018, 16:10

__red__ wrote:
andrewjoy wrote: The trick is to have an iron with a good thermal capacity.
This.

I use a metcal clone (thermaltronics) where the temperature is fixed by the tip that you use. That thing can dump so much energy into my work it should be tagged a thermonuclear device.

Also - the type of end you use makes a massive difference too. Most people here should be using chisel.

As far as solder selection there are two things I look for:

1. Temperature.
2. Flux.

In the above video when soldering the thru-hole with the "quality solder" the only thing my brain was screaming was 'dry-joint'.

I almost got a cheap metcal on ebay before the JBC but i did not bother with a sniper service and got sniped :(

AS good as the JBC is i need a smaller tip / micro pencil for SMD work the HD-2B is a super high power station and is fine for keyboard work , but i would not re-work a chip on a phone / laptop with it. And sadly you cannot use the smaller hand-piece and tips with the HD ( stupid IMO).

Another tip is get a station where the heater IS the tip. Dont go for the old style hakko clones that have an element the tip sits over , they are useless.

Oh and never use lead free solder, not only is it crap and prone to cracking over time ( a big reason modern electronics fail) its much harder to use. A good brand to look for is multi-core , oh and get is as thin as you can.

User avatar
Menuhin

10 Dec 2018, 17:48

andrewjoy wrote:
__red__ wrote:
andrewjoy wrote: The trick is to have an iron with a good thermal capacity.
This.

I use a metcal clone (thermaltronics) where the temperature is fixed by the tip that you use. That thing can dump so much energy into my work it should be tagged a thermonuclear device.

Also - the type of end you use makes a massive difference too. Most people here should be using chisel.

As far as solder selection there are two things I look for:

1. Temperature.
2. Flux.

In the above video when soldering the thru-hole with the "quality solder" the only thing my brain was screaming was 'dry-joint'.

I almost got a cheap metcal on ebay before the JBC but i did not bother with a sniper service and got sniped :(

AS good as the JBC is i need a smaller tip / micro pencil for SMD work the HD-2B is a super high power station and is fine for keyboard work , but i would not re-work a chip on a phone / laptop with it. And sadly you cannot use the smaller hand-piece and tips with the HD ( stupid IMO).

Another tip is get a station where the heater IS the tip. Dont go for the old style hakko clones that have an element the tip sits over , they are useless.

Oh and never use lead free solder, not only is it crap and prone to cracking over time ( a big reason modern electronics fail) its much harder to use. A good brand to look for is multi-core , oh and get is as thin as you can.
What are some of the solder stations that use these heater-element-inside-tip design?
I know only Hakko 950 and 951 and they cost almost 400€ in Germany.

andrewjoy

10 Dec 2018, 18:43

Menuhin wrote: I know only Hakko 950 and 951 and they cost almost 400€ in Germany.

TS 80 and TS100

Or go second hand

https://www.ebay.co.uk/itm/METCAL-Solde ... SwfoJb0cWB

You would need a hand piece and tip for that tho.

Genuine https://uk.farnell.com/metcal/sp-hc1/so ... dp/4950460
good clone http://www.ams-electronics.co.uk/shop/d ... ndpiece-2/

And a tip

https://www.ebay.co.uk/sch/items/?_nkw= ... =&LH_CAds=

I would go for this tip , if your just starting out

https://www.ebay.co.uk/itm/OKI-METCAL-S ... :rk:5:pf:0

User avatar
abrahamstechnology

10 Dec 2018, 18:56

ALWAYS use leaded solder, but be aware that a lot of 60/40 solder from China is counterfeit.

andrewjoy

10 Dec 2018, 19:01

I dont even know why they banned leaded solder in products , the impact from broken electronics that 90% of people wont or cannot fix and the horrible toxic fumes from the special flux you need for the lead free type is way worse than a small amount of lead in a product that can simply be reclaimed when its recycled properly.

I guess Overpaid politicians with too much time on there hands!

User avatar
Muirium
µ

10 Dec 2018, 19:21

Our politicians are much too busy cramming themselves into a clown car for that.

Banning lead was a good idea. Because 100% of products get disposed. We are literally a rounding error. And all that lead was going somewhere. The less of it, the better.

andrewjoy

10 Dec 2018, 20:26

Muirium wrote: Our politicians are much too busy cramming themselves into a clown car for that.

Banning lead was a good idea. Because 100% of products get disposed. We are literally a rounding error. And all that lead was going somewhere. The less of it, the better.
Not if its recycled! And everything should be. Or it should be fixed and re-used, or used for parts.

But then not all companies are green and down with the recycling. Not going to name names or anything, but if you where to find a anti consumer tech company with a cult following you would be on the right lines :mrgreen: .

But ether way lead solder > lead free.

User avatar
vvp

10 Dec 2018, 21:41

Is there any country in EU where old/broken electronics is not collected for recycling? I think it is banned to dispose of it in an unsorted garbage bin in all EU countries.

__red__

10 Dec 2018, 23:42

andrewjoy wrote: I dont even know why they banned leaded solder in products[/url]
Lead goes into landfill.
Water goes into landfill.
Lead goes into water supply.

__red__

10 Dec 2018, 23:48

Menuhin wrote: What are some of the solder stations that use these heater-element-inside-tip design?
I know only Hakko 950 and 951 and they cost almost 400€ in Germany.
I love and adore the Metcal / Thermatronics method.

Reasons:
0. It is physically impossible for them to overheat.
1. It's not controlled by a 'thermocouple -> heater' feedback loop, but actual physics where the temperature is a property of the chemical composition of the tip.

See this video for a brief explaination:

https://www.youtube.com/watch?v=S9Wmqc9O24w

JBert

11 Dec 2018, 01:33

__red__ wrote:
Menuhin wrote: What are some of the solder stations that use these heater-element-inside-tip design?
I know only Hakko 950 and 951 and they cost almost 400€ in Germany.
I love and adore the Metcal / Thermatronics method.

Reasons:
0. It is physically impossible for them to overheat.
1. It's not controlled by a 'thermocouple -> heater' feedback loop, but actual physics where the temperature is a property of the chemical composition of the tip.

See this video for a brief explaination:

https://www.youtube.com/watch?v=S9Wmqc9O24w
That's nifty.

The Weller I spoke of above is based on a similar idea: it's a classic heater element but on the tip is a magnet which actuates a reed switch until the magnet reaches the Curie point and stops actuating the switch. There's no circuitry to monitor the temperature which can fail, it's all in that analog process.

I guess the Metcal / Thermathronics method is still better for longetivity though as there are no moving parts, but then again that Weller "Magnastat" has been holding out for quite some time. And even if the reed switch gets momentarily stuck, there's nothing some "percussive maintenance" can't fix (well, at least once - then you might have other problems).

Engicoder

11 Dec 2018, 02:20

@__red__ touched on two important factors that most beginners under appreciate: flux and tip selection. Flux does wonders for getting solder to behave nicely and the correct tip allows for quick work without over or under heating.

This old video covers from Pace the basics better than any other I have seen.
https://www.youtube.com/watch?v=vIT4ra6Mo0s

User avatar
JP!

11 Dec 2018, 02:31

This is such a great thread. I have yet to invest in all the tools I would like to have (metcal station, desoldering gun, etc) but maybe one of these days. I cringe when I think of work I did or attempted with a Radio Shack soldering iron without the use of flux and and improper tip. Also I learned a fare amount watching avionics level soldering tutorials from YouTube.

User avatar
vvp

11 Dec 2018, 10:50

__red__ wrote: I love and adore the Metcal / Thermatronics method.
How do you set different temperature with such an iron? It looks like it always sets it to the curie point. If so then it is rather useless. Well better than an iron without any temperature regulation at all but still ...

It is good if one can set different tip temperatures depending on the tip and kind of joints being soldered. Thermocouples work well to detect temperature and electronics will control power to keep the tip temperature at whatever user prefers.

Anakey

11 Dec 2018, 11:12

i would guess that if you needed to solder a larger area then that would act as a heatsink therefore the iron would need to heat up more due to the heat loss but as long as the iron is hot enough to melt the solder then does it really need to be any higher?

User avatar
vvp

11 Dec 2018, 13:12

The point is that the best soldering iron temperature depends on the parts being soldered and the thermal capacity and thermal conductivity of the tip. E.g. when you solder tiny SMD parts then you may want smaller temperature (lets say around 260°C). When soldering bigger through hole parts then you will want bigger temperature (lets say around 340°C). If you have a thick tip with bigger thermal capacity then you can use a bit smaller temperature than with a thin tip. You can somewhat compensate incorrect tip kind with temperature setting. And it is easier to change temperature than the tip.

It is good to have a knob on your iron which allows you to set temperature. The Metcal / Thermatronics method does not seem to allow it without changing the tip itself.

Anyway, proper flux use is the most important. If in doubt whether to use a small or a bigger tip then use the bigger one. Flux, solder mask an the surface tension will take care of tin settling on the proper places. The bigger tips have higher thermal capacity and conductivity which helps to solder more quickly which is good when you do not want to lift pads or thermally damage the part.

User avatar
Menuhin

11 Dec 2018, 16:20

__red__ wrote:
andrewjoy wrote: I dont even know why they banned leaded solder in products
Lead goes into landfill.
Water goes into landfill.
Lead goes into water supply.
Electronics and electrical appliances waste are processed differently and at least partially recycled in many European countries. Isn't it?

Is there anything that can replace lead and that is not as harmful to the environment?
Or is some of the lead-free solder flux indeed quite toxic? Or more toxic indeed?

My current desoldering iron from China is effective in desoldering - but as soon as the solder melt, the pad and the nearby area on the PCB would just turn to ash gray in color...

__red__

11 Dec 2018, 17:17

vvp wrote: How do you set different temperature with such an iron? It looks like it always sets it to the curie point. If so then it is rather useless. Well better than an iron without any temperature regulation at all but still ...
I'm going to answer your question with a different question and then answer it:

"Why do you need to set a different temperature?"

If you use a solder with a known melting point then the only real reason to increase the temperature is to make the iron dump more energy into a joint which has a larger volume of 'stuff' to heat.

If your bit is capable of continuously dumping massive amounts of heat energy into your joint without having the raise the temperature at all - why raise the temperature at all?

... and to answer your original question, you change the temperature of your iron by using a different bit.

Here's a link to thermaltronic's bitlist:

http://www.thermaltronics.com/tipcartridge.php

It's a different planet from your usual 'tips from ebay'

andrewjoy

11 Dec 2018, 17:19

Screw it , i am getting a metcal!

I will just the JBC for big jobs !

User avatar
vvp

11 Dec 2018, 21:54

__red__ wrote: "Why do you need to set a different temperature?"
To transfer the heat to the joint more quickly so that you do not dwell on the joint for too long.

But it is likely that metacal can react more quickly to the temperature changes of the iron tip. That would be a good feature. Maybe even worth the troubles with tip changing just to use a different temperature.

__red__

11 Dec 2018, 23:22

vvp wrote: Maybe even worth the troubles with tip changing just to use a different temperature.
It's worth it because I can switch tips and be at the new temperature faster than someone can change the temp of their adjustable iron.

They are literal 'hot swap'.

Post Reply

Return to “Workshop”