Art of Soldering

[kaushik]

I thought of jotting down few things that may help starters . As I can mange time i will enter more details.


Which soldering iron?
Technically Rs.4k-6k weller or Hakko station is a good one time buy( for the guys constant diyers and willing to put cash ).

But for most guys who build max say 20 boards in a month i recommend the Soldron in 150/-
So get this :
**Aluminum tip** -1 , Soldron 1 , stand 1 , wet clean type sponge 1 ,
file -1 .


Which solder,flux :
WBT silver mini roll via ebay.com some 350/-, this will go min 10 boards for sure , most local solders here in bangalore are crap .
while in delhi you can manage with SINCON (local one flows nice , but you will prefer the WBT 3% silver solder )

get the AMTECH paste flux from mobile shop,it is the best in <100Rs

Cut the fluff:
Temperature control : you will not need unless it is an SMD device like dac chip , practically most amp and other ICs will survive for 15sec at 200Deg (Rough guess )

Damage during soldering:
Well it is like making an egg omelet..i recommend contact duration keep in 3 sec all will be good
===========================================
Notes : so far the guide is for thru-hole components
===========================================
Learning soldering :
Start with a small kit from Kits n Spares or vegakit , just let it be Simple alarm / op amp in < 200rs say !
there are many youtube vids and if you are the bookish type there is good read here .
Steps are simple :
1. pour water to the cleaning sponge. Just clean the tip with that .
aluminum tip dont need filing , so directly you can solder . but i recommended you make the tip little rough by file .
2. scratch the joint with blade like thing or clean with IP alcohol
3.take the solder wire to joint(important) and melt for 3-5secs ,release
continue this untill solder covers it.

dont melt the wire and take onthe tip and apply ..it was good for old 'Re-cord' type solderings,new rounded tips dont do well in this way....

--TBD

 

[nowwhat?]

Kaushik, Good article. Just what I wanted before I get my hands into solder (hopefully not!)

Could you address these as well?

• Which Soldron or other brand iron? What wattage for the iron works best for replacing a few capacitors and resistors and basic DIY. Should one get the variable temperature one?
• What is the flux for?
• I read somewhere about tinning the tip of the iron.
• Third hand/magnifying glass seems to be essential. Where does one get this?
• Are small pliers required?
• Lastly, Is the joint made by holding the tip at the junction of the PCB pad and component (e.g. resistor) leg and then applying the solder wire to it?

Thanks!

 

[kaushik]

a)
25 watt SOLDRON:for most thru hole work
keep 75 watt cheap iron if you have big solder points(7mm+) like copper foils,bigger diodes

willing to spend for station?
one option is in 2.5k:
Aoyue - Soldering Station [ 936 ]
Aoyue ? Lynx - The Computers , Portable Audio , Electronics Online Shopping Store In India

b)What is the flux for?
7.1.1 Soldering Basics
c)tinning the tip
not required for aluminum coated tip eliminates the sauna bath of tip time to time ,unless you love copper
d)better to have nose pliers ,must have is nipper,cuts legs at .5mm which is pain with all other tools

350Rs D00269 - DURATOOL - CLAMP TOOL, WITH MAGNIFIER | element14 India HH +magnifier

This is must for cable makers..otherwise will suffer burns.
Also normal soldering is easier with this.
(magnifier not needed for normal eyesight people)
e)yes,try hands on ,you will develop trick to have uniform joint

Tips:


Wipe the tip on a damp sponge and wet it with a small amount of solder at joint;
Apply the hot iron to one side of the joint and then feed in solder from the other;
Allow the flux to work on the surfaces and the solder to flow across the whole joint, this should take no more than a couple of seconds;
Remove the solder, then the iron;
Allow the joint to cool and solidify without any disturbance.


The solder needs to completely wet the component lead and the pad on the solder side of the PCB. A consistent, concave, meniscus should be formed with an angle of 40 and 70 from the horizontal.
If any of the components have moved during solidification of the joint this will show up as a dull, grainy, finish. This type of joint will be mechanically weak and unreliable.
Applying the iron for too long will cause spikes of solder to form which may bridge to other connections, causing a short circuit.
Black areas on the joint and signs of poor wetting indicate a "dry" joint. This is caused by dirt in the joint area and will result in an unacceptably high resistance.
If the profile of the joint is convex, rather than concave, then there is too much solder in place.

Kaushik, Good article. Just what I wanted before I get my hands into solder (hopefully not!)

Could you address these as well?

• Which Soldron or other brand iron? What wattage for the iron works best for replacing a few capacitors and resistors and basic DIY. Should one get the variable temperature one?
• What is the flux for?
• I read somewhere about tinning the tip of the iron.
• Third hand/magnifying glass seems to be essential. Where does one get this?
• Are small pliers required?
• Lastly, Is the joint made by holding the tip at the junction of the PCB pad and component (e.g. resistor) leg and then applying the solder wire to it?

Thanks!

 

[doors666]

an eye piece also helps, the kind that the watch repair guys use. i got the 4x one from sp road for less than 100.

Hybrid sells rosin flux (looked like pure rosin) for 60 bucks. no shoe polish box paste flux will come close to it. i hate those paste fluxes. will post a pic later.

 

[nowwhat?]

Thanks for a detailed reply, Kaushik!

What are the pros and cons of soldering iron vs. station?

Also rather than dig up old threads, can you name some reliable and haggle-free dealers on SP Road for this stuff? Am planning to go there this weekend or next.

 

[doors666]

helping hands with magnifier is available at the goodwill store on sp road.

pics of hybrid solder i got along with the eyepiece. its 63/37 eutectic solder with flux in the core.

 

[kaushik]

an eye piece also helps, the kind that the watch repair guys use. i got the 4x one from sp road for less than 100.

Hybrid sells rosin flux (looked like pure rosin) for 60 bucks. no shoe polish box paste flux will come close to it. i hate those paste fluxes. will post a pic later.

doors, AMTECH 'paste' flux

is one best flux for all your needs.
as you get in all mobile repair vendors.


dont get confused with the other paste flux types

i have done many smd work till 230pin chips this flux is damn clear and effective.
many other industrial grade flux packs are there,but you should know where to pick.

 

[lakshit]

Well that polish type solder flux looks very awful undoubtedly, but i have used it many times and it worked well. However I haven't use these bottle type flux so no idea about them.

 

[omishra]

Look at below soldering of SMD chip on tiny Blue PCBs which I did for one HFV FM. I will tell how I done it.

There is yet another same chip on the bottom side of tiny PCB.

After holding the PCB secured followed steps -

1. Apply thin layer of flux on PCB using ear buds (ear cleaner), of course new
2. Same way apply flux on chip terminal
3. Melt little metal on any two diagonal solder pads of chip on PCB
4. Place it on PCB by matching solder pads and orientation. Hold it there from top pressure using some wooden toothpick etc
5. Heat those diagonal solder pads with metal blobs, not pins of chip till solder melts and chip settle into place by submerging its pins into molten metal.
6. Now take used solder removing wick and put across all pins on one side. Make heating with soldering as if you are removing solder metal. But here it will be thinly applied on pad and pins. Do same thing for pins on other side.

You are done without short and without extra solder metal.

 

[captrajesh]

Found this informative link leading to a series of videos offering soldering lessons: https://www.youtube.com/playlist?list=PL926EC0F1F93C1837

 

[shafic]

I hope this will help too!!



http://mightyohm.com/files/soldercomic/FullSolderComic_EN.pdf