# Can I solder SMD with these tools?

#### kam hagh

Joined Nov 7, 2015
60
Hi, I thought I should start making my own circuits and build some stuff instead of using a breadboard, but the problem is I don't have much money and resources, can I do SMD soldering with these? (is it worth it?)

the solder paste i found was from a brand called mechanic, that's all i know! I'm planning on keeping it in the fridge inside a glass container inside a plastic bag!

the flux was unknown

but the the only air station i found was this : GORDAK 952, is this a decent one? I'm worried it will die after few uses!
I have a cheap 4$iron which lights up my LEDs when soldering! and that doesn't sound good for smd! or even normal soldering I also added some 1206 components to my order I'll be printing my circuits with a laser printer and some acid! never done it before! Do i need anything else? Sorry if this question is stupid :| Thread Starter #### kam hagh Joined Nov 7, 2015 60 I'll be using a hotplate for reflowing! and maybe use hot air gun when i can't use a hotplate #### DickCappels Joined Aug 21, 2008 6,962 I found that adding a ground wire from the metal parts on the front of cheap soldering irons helps -but only if your soldering iron has an accessible screw head or other attach point that doesn't get so hot that it melts the wire's insulation. #### MrAl Joined Jun 17, 2014 7,965 Hi there, I've used a fair number of different kinds of soldering irons in my time and i've never seen one that would light up an LED when soldering it to say a board. The only conclusion is that there must be something wrong with the soldering iron. Not only that though, but when doing SMD work i find that a very very narrow pointy tip is best when the solder gets between pins, as you only have to reheat with the point tip starting nearer to the chip package edge and "draw" the solder along the pin length with the tip, and that 'pulls' the solder out from between the pins even without needing solder wick. That brings us to solder wick also, which some people use to pick up the excess solder that gets between the pins and bridges them so as to create an unwanted short between pins. If you have a point tip for your iron though you may not need this as outlined above. Before i tried SMD work with solder paste i always used wire solder, the very very thin type. After finally trying solder paste i can see it works pretty nice. You dont need much paste and you dont need much hot air flow either. The paste however comes with different nozzle sizes. You probably want the most narrow size nozzle you can get. I didnt know this the first time i ordered some, so i ened up with a nozzle that is too wide, which is about 1/16 inch diameter. For the smaller parts 1/32 inch diameter would have been much better for dispensing along the pin rows. With the 1/16 inch dia, i have to actually spread it out with a sewing pin (needle) to get it onto the pins in the right amount. There are a lot of videos on YouTube where you can see SMD soldering examples. The paste also comes with different kinds of dispenser tubes, which i didnt know either until after i bought mine. Some come with plungers that you can PULL out as well as PUSH in to dispense. If you can PULL it out you can draw the left over paste that fills the nozzle when you are done using it, so it wont be all stuck in the nozzle next time you go to use it. Mine only PUSHes in, so i cant do this. That means i might have to clean out the paste tube nozzle with something that i can slide down the center, like a stiff wire or something, in order to clean it out before storage. Since i am relatively new to this SMD soldering too i also have some questions such as: 1. Do you clean out your nozzle each time you use it, and if so, how? 2. Did you ever try FREEZING your paste instead of just refrigeration? (may not be recommended but never tried it myself) The goal with #2 is of course to keep it fresh for more than a year. My use will be very low, maybe once per month, so i'd like it to last as long as possible. Thread Starter #### kam hagh Joined Nov 7, 2015 60 I actually don't have ground in here, no house has it in my country ( I live in kind of a poor country ) and my soldering iron is a oxided 4$ iron from when I was a kid! (well still kind of am, I'm 16.5 years old) so i have to buy a new one anyway! it does act weird and make some noises which scares me!

I also found quick 700 on a website I don't trust! I also found GORDAK 983A which is just a soldering station and no hot air gun.(In here, people love brands none has never heard of... not sure if this is one.)

Do I really need a hot air station? It's not like I'm a professional, I'm planning on becoming an electric engineer but still... it sounds like that a solder like GORDKA 983A and a hot plate is enough for me. But if it is, are those good products?

and the only kind of paste I found wasn't syringe or anything like that, I guess I'll be using a toothpick!

and the solder i added was 0.8mm

I just want to see if it's possible to make my own SMD PCBs in here with these equipment or I'm just dreaming!

btw, the thing that made me really thing about this was that some ICs are only available in smd, and that i should move from theory to building actual stuff! I wanted to make automated plant watering so we don't have to tell anyone to water out plants when we go on a trip!

#### DickCappels

Joined Aug 21, 2008
6,962
When I lived in a cinder block house surrounded by rice paddies in an area in which NOTHING was grounded, I used the antenna mast for my cell phone as a ground (a section of the mast was buried in earth). I grounded the computer, soldering iron, my metal desk and my projects to that.

#### kam hagh

Joined Nov 7, 2015
60
When I lived in a cinder block house surrounded by rice paddies in an area in which NOTHING was grounded, I used the antenna mast for my cell phone as a ground (a section of the mast was buried in earth). I grounded the computer, soldering iron, my metal desk and my projects to that.
Will my radiator(warming my room) work? The water plumb is connected to ground i think! I tried that and my PC's case using a multimeter and it read something like 110v or 40v(I can read again), I also touched my pc while touching my radiator and i had a shock! + the wire connecting my pc's case to radiator got hot so i guess that does act as ground!

is the problem my solder? maybe a decent one will fix that! and what about the other part of my question:?

#### sirch2

Joined Jan 21, 2013
1,026
Look at some of the SMD soldering tutorials on Youtube. I only use the hot-air for desoldering and don't use paste at all. Get a flux pen, clean and flux the board hold the part accurately with some tweezers and tack a couple of corners with solder. Then run solder across all the pins, don't worry too much about bridges, now use solder wick to remove the bridges between pins and inspect carefully.

#### kam hagh

Joined Nov 7, 2015
60
Look at some of the SMD soldering tutorials on Youtube. I only use the hot-air for desoldering and don't use paste at all. Get a flux pen, clean and flux the board hold the part accurately with some tweezers and tack a couple of corners with solder. Then run solder across all the pins, don't worry too much about bridges, now use solder wick to remove the bridges between pins and inspect carefully.

And i've watched plenty already, but i also saw a couple of hotplate and reflow oven ones, they sounded insanely simple! the paste just soldered itself to the ic pins i also saw a video about drag method but it looks like that doesn't work with QFN or other types (I don't think I'll do anything other than QFN at worst) but it was so simple! i tried to do the same with my 5year old flux and my 4$iron and it worked! (on a burned already soldered board, the solder from my tip got to the ic and soldered itself! but after doing it another time i got bridge and no matter what i did i couldn't fix it with wick wire, it was not soaking solder at all, i did use a solder sucker and it worked however! It's not about choosing a soldering iron, these are my options: (sorry but i don't know anything about them so i can't choose!) http://eshop.eca.ir/ابزار-مونتاژ-تعميرات-و-لحیم-کاری/1272-هویه-35w-مخصوص-smd.html the review says this one doesn't have electricity so its good for smd(it says smd solder and nothing more) and is well.... 7$!

it has compatible tips like http://eshop.eca.ir/ابزار-مونتاژ-تعميرات-و-لحیم-کاری/3516-سر-هویه-best-900m-t-i-درجه-یک-طلائی.html

I also found the mentioned GORDAK 931A for 37\$ which is a station, but I'm not sure if the tip is compatible or if it is going to give my components a shock like my current one!

the links are persian but there is a picture and model number + specs!

#### dl324

Joined Mar 30, 2015
12,462
the solder paste i found was from a brand called mechanic, that's all i know! I'm planning on keeping it in the fridge inside a glass container inside a plastic bag!
Unless the solder paste is lead free, don't put it in the refrigerator if you also store food in it (the refrigerator).

I bought a few pounds of lead-based solder paste from a surplus store that was past it's expiration date. I've had it for years now and found that it still does it's job. I keep the container sealed and it hasn't dried out. If the small portion I'm actively starts drying out, I add flux to it. Sparkfun had a video on this.

#### kam hagh

Joined Nov 7, 2015
60
Unless the solder paste is lead free, don't put it in the refrigerator if you also store food in it (the refrigerator).

I bought a few pounds of lead-based solder paste from a surplus store that was past it's expiration date. I've had it for years now and found that it still does it's job. I keep the container sealed and it hasn't dried out. If the small portion I'm actively starts drying out, I add flux to it. Sparkfun had a video on this.
Thanks all

I cant wait I hope i don't do anything stupid with the chloride .... :| and my printer has scaling problems i should fix till it arrives!
and good to know

#### dl324

Joined Mar 30, 2015
12,462
I neglected to mention that I store my solder paste in a cool, dry location. Refrigeration is out of the question because it's lead-based and I'm not inclined to have a refrigerator just for solder paste.

#### kam hagh

Joined Nov 7, 2015
60
I neglected to mention that I store my solder paste in a cool, dry location. Refrigeration is out of the question because it's lead-based and I'm not inclined to have a refrigerator just for solder paste.
good think its coldoutside for now, but i'll have to think about something for the summer! maybe build one myself with a peltier, but that consumes tons of power!

#### Roderick Young

Joined Feb 22, 2015
408
If you cannot afford hot air, an alternative is to just use two fine tipped soldering irons. That's what I did when I was younger. For 1206, first melt a bit of solder onto each pad. Just barely melt it, so that the flux is still there. Then place the component on top (you may need tweezers), and heat both sides at the same time with soldering irons. The solder melts quickly, and the component will center itself. This actually goes fairly quickly when you're young and have good eyesight and dexterity, but not money to spend.

#### sirch2

Joined Jan 21, 2013
1,026
The difficulty in using paste as I see it is you need a mask or some way of accurately getting the paste on the pads and nowhere else. I don't do enough volume to make cutting masks worth while so I just use the drag technique. If the wick isn't working to clear the bridges it is oxidized, you need clean wick or put some flux on the wick.

#### ErnieM

Joined Apr 24, 2011
8,109
The Gordak looks very similar to the one I use for occasional use. Both the solder iron and air pencil are replaceable and they are available on Ebay. I've replaced my iron once, have backups for both on hand.

Hot air is very helpful for things like QFN packages as you can heat both the part and the board underneath.

Solder paste is best dispensed from a syringe. You can do that with a plunger but it will hurt your hand, I know from doing just that for a large board. There are mechanical plungers available that work well, but of course compressed air and a foot peddle controlled dispenser are the best (though expensive). On a budget I'd go mechanical, it's what I use now.

#### kam hagh

Joined Nov 7, 2015
60
After printing my PCB to a normal printing paper, I can see that it isn't going to be hard! bigger than other smd component's i've seen (like raspberry pi) but still PTH' have a really small pad for soldering and they're so close to the traces so that makes me worry a bit, but otheer than that it sounds ok even if i had to use solder paste (which i think i don't, only problem is my thick 0.8mm solder) i'll just apply it using a toothpick

#### ErnieM

Joined Apr 24, 2011
8,109
Yep. I've used a pin to apply paste, but it is very hard to control the exact amount you want, either too much or nearly none at all. Eventually you get something that works but always looks sloppy.

With towo lead things like R or C parts it is easy to use a spool of solder: make a blob on one pad, solder one end of the part there, then do the other side.

#### kam hagh

Joined Nov 7, 2015
60
Yep. I've used a pin to apply paste, but it is very hard to control the exact amount you want, either too much or nearly none at all. Eventually you get something that works but always looks sloppy.

With towo lead things like R or C parts it is easy to use a spool of solder: make a blob on one pad, solder one end of the part there, then do the other side.
I've watched some videos and yeah doesn't sound that hard! all i need now are tweezers!

I also bought a cheap paste (it was the only paste i could find) for experiments, I'll use the hot plate from my father's factory!

#### ErnieM

Joined Apr 24, 2011
8,109
When I use flux I use a flux pen which just puts a small amount just where I need it. I got several off EBay from China, takes a few weeks but the price is nice.

Tweezers are more of an issue then you may think. I need very fine tips for some parts, wide tips for larger parts like ICs. They need to stay very clean and non magnetic or the parts stick to them (very frustrating!).