VK Logger Ham Radio Forum Archive

I have just a limited experience in soldering SMD comp. I managed with my old Weller (WECP 50 Watts) to solder 1206 comps...but those 0805...
I went downtown to a Weller dealer shop and discovered that my tip is the smallest available for that model. Smaller tips come with new models whose prices are well over 200€ or 260 AU$!!!
And moreover the guy told me that the new leadless alloys need more heat and my 50 Watts are not enough...GASP

You don't need the world's smallest tip.

What works for me is:

1. Tin ONE pad.
2. Holding component in place using tweezers, with a tinned iron tip, let the solder flow to grip the component.
3. Remove tweezers and just solder the remaining side.

Another tool I have here are 'Thermotweezers' - like tweezers, but both sides are 35W soldering irons. Solder paste each pad, drop component on, hold down with a toothpick, and flow both pads at once.

73 - Rob VK2GOM / G0MOH

Thermotweezers?
Something like this one? http://www.chipdip.ru/en/video.aspx?vid=ID000289114

I second Rob's reply. I will add that I like to dip the SMD component in alcohol-based liquid resin flux prior to soldering it into place. This really makes the solder flow beautifully. I use a good old Weller soledering iron, usually with a 700 deg. F, 2mm chisel tip. It gets the heat into the joint really quickly. I have tried a pointy conical tip but for me it's nowhere near as good. I guess it's also a case of gaining confidence through practice.

Chas
VK3PY

I've found solder paste works well and gives a neat result (if you use a light touch on the syringe to put down a small dab). It does mean that you can then use one hand to place the component and keep it in place and the other to hold the soldering iron. I haven't needed to use flux as well.

With a little practice, SMD is much easier and faster than through-hole components.

Dave

Hi all

I have used most of the above techniques...the SMD arsenal includes:

Sharp pointed tip Weller and very fine solder
Solder Paste
Flux pens
Stainless steel dental instruments (for holding/moving components)
Bright lights over the bench!!
Magnifiers and a jeweler's loupe

and for tiny ICs and related close spaced pin devices I have an SMD rework station with various tip sizes.
Actually the rework station can do it all but it is not always convenient to heat up larger areas of the boards.

Cheers

Tim VK5ZT

I use a device called an "apprentice".

They come with a less degraded vision system and better vibration dampeners on their digital manipulators...

I use a "toaster oven" for single sided boards.Cheap-$20-30 from most supermarkets.
Place solder paste using a toothpick on each pad, place components as you go.
Put board in centre of oven.Place temp probe of digital multimeter on edge of board.
Turn oven on until temp gets to 110-120.Turn off,wait till temp drops back to 100.
Turn oven back on and watch till paste both melts AND attaches nicely to components ,Turn oven off.
After one minute open door-let cool.

On some boards the odd component changes position due to surface tension /heating differences.
This is easily fixed using an iron.On some occasions with close pitched ICs a bit of solder wick and a hot iron are needed
for a bit of clean-up.

This has worked well for me down to 0402 components.In more than 20 boards I have NEVER cooked a component.
Cheers,
Chris.

Not an 0805, but the principle remains the same, as W2AEW demonstrates.
Tack one leg down, align part, and solder legs.



And no matter how many times I hear it, I cannot get used to the way Americans pronounce "solder".

When still images and text no longer cut it

VK4GHZ wrote:And no matter how many times I hear it, I cannot get used to the way Americans pronounce "solder".

Yup - "Make mine a Whiskey and Solder, please"...

73,
Barry
VK3BJM

Before investing in a hot air workstation, I used a DSE Temperature Controlled Soldering Station with great results on 0603 and 0805 components for several years. I managed to build several Softrock kits and a VNWA.

The recipe for success is a temperature controlled iron with a clean tip - medium or fine sized.

Avoid the temptation to use a ultra fine conical tip - there is very little heat transfer with the small contact area. You will get good results from a 2 or 3mm chisel tip.

Removal of components without hot air is a difficult task. Once trick is to use 2 irons - one on each side of the component and lift it off....

...or the thermotweezers again. Brilliant for SMD removal. I have various tips; can remove all sorts of SOIC and even QFP's in one go. Recommended.

I also saw an iron tip a while ago from PACE, that would be of interest to SMD'ers. It was a conical 45deg shaved tip, with a hollow pool in the end. The idea was you filled it with molten solder, and then simply swiped it across a SOIC that was already fluxed up, and just the right amount of solder would flow and solder each leg perfectly. The results, when done correctly (and it took a bit of practice) were like machine reflowed. Perfect.

I was fortunate that back in the late 90's I was teaching SMT rework techniques to the RAF, so got to try out all sorts of nice kit

73 - Rob VK2GOM / GW0MOH

From 2:00 - 5:00, this new video from W2AEW demonstrates how easy it is to soder (!) SMT parts.



Posted in the interests of demonstrating that still pictures, text, and dead trees are so last century.

Thanks for the link, Adam. I need to practice my SMD skills very soon..

I must learn to soder like the W's Adam [emoji21]


Scott
VK4CZ

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Got to love the soddering

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