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Advanced Soldering: Fast and Easy Soldering of Surface Mount Components

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Picture of Advanced Soldering: Fast and Easy Soldering of Surface Mount Components
Easily solder surface mount components like the tiniest LEDs and SOIC sized ICs. Make your own break out boards.

As more and more DIP ICs are being fazed out, some of them are now only available as surface mount devices. Creating a custom printed circuit board for each one is impractical for the amateur robot builder or electronics experimenter. Pre-etched Breakout boards which adapt a surface mount IC to the standard .1" spacing of breadboards are available. Unfortunately, they often cost more than the IC itself.

In this instructable are some techniques for making your own breakout board using standard copper traced strip board or perfboard. Also included are some techniques for easily mounting other ridiculously small surface mount components.

The first pic shows a breakout board for a SOIC-8 sized surface mount IC.

 
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Step 1: Materials

Picture of Materials

.015" diameter Kester 44 solder from: http://www.mouser.com/

30 gauge heat strippable magnet wire from Mouser

Heavy duty aluminum foil from WalMart

Loctite mounting putty from WalMart

Soldering iron with 1/32" tip

Brass shavings tip cleaner available from: http://www.jameco.com/

.055" spring wire or music wire to make a surface mount clamp

Step 2: Using Magnet Wire and Special Solder

Picture of Using Magnet Wire and Special Solder
There are two main difficulties with soldering very small components-- avoiding too large a solder joint which can short nearby contacts and soldering fast enough that you do not damage the component.

This Breakout board (intro pic) works well with SOIC sized ICs. This technique can also be used to mount several SOICs or other surface mount components on a project perfboard for more complex circuits. To make it easy requires two specialty items--special solder and magnet wire.


Thin Solder
When components are very close together, it can be difficult to solder them without blobbing over and shorting nearby pads and wires. The best solution i have found is to use a small tipped adjustable heat soldering iron (1/32") and the thinnest solder you can find. Standard solder and low temp solder is usually .032" in diameter which works fine for most things. Using thinner .015" diameter solder allows you to easily control the amount of solder on the joint.

If you use the least amount of solder necessary, it not only takes up the smallest volume, but it also allows you to solder a joint as quickly as possible. This reduces the chance of overheating and damaging delicate components like ICs and surface mount LED s. You can find the .015" solder at: Mouser.com
 
Magnet Wire
Instead of attempting to solder a SOIC IC to thin copper traces on a circuit board I have found it easier to solder magnet wire to the IC pins. I use 30 AWG heat strippable magnet wire available at: Mouser.com. You can use regular magnet wire, but it does not strip as easily, so I prefer the heat strippable magnet wire. This wire has a coating that can be stripped by soldering it with enough heat to melt the insulation. I let a large blob of solder hang from the soldering iron in contact with the wire for 5 or ten seconds while sliding the iron back and forth. In this way I strip the insulation and pre-tin the end before attempting to solder it to an IC or other surface mount component.

Step 3: Solder to SOICs

Picture of Solder to SOICs
soic-ic.jpg
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Solder Wire to IC
Insert the edge of a small square of heavy duty aluminum foil underneath the pin you are going to solder and over the pins on either side (pic4). This will prevent the solder from flowing on to the adjacent pins. It will also act as a heat sink. Clamp the IC onto a sheet of FR-4 fiberglass or perfboard. Put a piece of the Loctite mounting putty over one end of the foil to hold it in place. The magnet wire can then be held in place with the putty and in contact with the IC pin.

Strip and tin enough magnet wire to go to all the pins. You can then clamp one wire to the board holding the IC and aluminum foil shield and use the thin solder to solder the end of the wire to the IC pin. Move the foil and repeat the process for the rest of the pins. When you're done, you should have something which looks about like pic5.


Make a Breakout Board
Solder some .1" header pins to the perfboard that has the traces drilled out where the IC goes. Glue the IC to the perfboard. When the glue is dry, bend and solder the pre tinned wires to the header pins. Try to avoid getting the wires to close to each other as that can cause crosstalk or stray capacitance in some circuits.

You could of course forget the magnet wire and simply use shorter pieces of #30 uninsulated tinned wire. The advantage of leaving the magnet wire long and insulated is that it allows you to solder to the header pins without reheating the solder joints on the IC pins. This reduces the chance of damaging the joint or the IC. After you have tested the circuit, it is probably a good idea to coat the wires with epoxy or liquid tape to increase their insulation value, reduce the chance of crosstalk, and protect them from accidental damage from handling.

Pic5b shows a Picaxe 20x-2 SOIC breakout board module. It gives you the best of both worlds--a powerful microcontroller in a small package and an easy to use plug in module.


Step 4: Soldering to the Smallest Surface Mount LED, Resistor or Capacitor

Picture of Soldering to the Smallest Surface Mount LED, Resistor or Capacitor
putty.jpg
Pic 6 shows a 0603 sized LED unlit and lit which has been soldered to magnet wire.

Pic 7 shows how it was held in the putty before soldering to the pre-tinned wire.


Step 5: Make a Clamp for Holding Surface Mount Components.

Picture of Make a Clamp for Holding Surface Mount Components.
clamp2.jpg
remote-ring.jpg
Pic8 shows a clamp I made that works well to hold down small flat surface mount components when soldering them directly to a circuit board. It was made with spring wire that is sharpened to a point on one end and then bent to the form shown.

Pic9 shows the clamp in use.

pic10 shows how tight you can solder in a Picaxe 08 microcontroller in a remote control ring:

http://www.instructables.com/id/Make-A-Remote-Control-Ring/
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russ_hensel4 months ago

Just a note to let you know I have added this ( a year ago ) to the instructable:

Comprehensive Guide to Electronic Breadboards: A Meta Instructable

>> http://www.instructables.com/id/Comprehensive-Gui...

Take a look at a bunch of ideas for using breadboards.

rpotts28 months ago
I never thought of using foil when I tried deadbugging an ATTiny85. That's neat!
achand81 year ago

Nice Idea! But I think it's worth the time to etch a board

I have been looking for this after spending 3 hours ruining two (of 12) SMs i accidentally ordered.

The foil is BRILLIANT and this info is not so easy to find onlin- although now it seems obvious!

Thankyou
What did you use to remove the copper from the stripboard?
looks like a drill bit..
I really enjoyed your instructable, I wish I had come across it sooner as I have been soldering IC's from above still connected to the PCB. Yours is definitely more work but you get such a fantastic result - thanks
orksecurity5 years ago
Nicely illustrated. One thing to remember, when using the dead-bug technique or otherwise mounting a chip "upside down" -- The circuitry is often mounted close to the official top of the housing, to allow best heat transfer. Mounting it upside down can interfere with that, so if you do flip the chip you may want to flip it onto something that will act as a heat-sink.

(Look up descriptions of IBM's old Thermal Conduction Modules for an illustration of the extremes they went to in order to remove heat from face-down bipolar chips. I believe a description of TCMs was published in one of the IBM Journals in the late 1970's or early 1980's.)
Most chips made in more recent years have the circuitry mounted on the bottom because it means shorter traces, because it means shorter thermal path to traces and when the chip has higher thermal density there is a heatsink pad under it and exposed metal plate on the bottom. The one big exception to this is chips that create so much heat they must wear a sizable *real* heatsink instead of 'sinking to the PCB copper, for example CPUs, GPUs and chipsets found in computers.
bigjeff5 ac-dc4 years ago
You can tell immediately when you have one of these chips because it will have a metal plate on the bottom and the datasheet will specify soldering the pad to a copper pad on the PCB.
taurus1234 years ago
So you have taken an SMD chip and converted into a through hole chip. So what? Most SMDs come in through hole format and vice versa. What is the purpose of this, other than wasting time to re-invent the soup dish?
There are literally thousands of very useful IC's that only come in various forms of SMD.

DIP is deprecated tech, so it's kind of amazing there is still a decent subset of components that can still be found in that format. I think it's pretty much only the hobby electronics that have kept the format alive, so you can generally expect anything that wasn't targeted at hobbyists to not have a DIP package version.
That's not really true. Many types of chips are not available in DIP or are much more expensive in through-hole packaging than SMT. This is a very useful way to still be able to breadboard or through-hole solder those chips. Good instructable!
i agree with FaxJaxton on this one it can also save space on a thru-hole board if you are pressed for space
ouss764 years ago
sorry to say that but your solder is horrible: you added too much tin. a little less and it'll be perfect regards
agreed with this, less tin will make it perfect.
dhopper1224 years ago
I work soldering smaller components by hand. And let me tell you that is a pain in the orifice. I would not use the putty, as it might melt and contaminate the solder joint. I use a tooth pick to hold the item down while soldering. YES, it takes a good deal of consintration to work both tooth pick and iron, at the same time. Plus, what I see here is that the "coated" wire wasnt cleaned prior to soldering. I needs to be, as the coating will contaminate the solder joint also. Please understand this isnt a beat-down, but professional, "been there done that", experience.
MaXoR4 years ago
I like your wire holder, I built one for myself using an old metal coat hanger... works like a charm!

Also, I agree with dagenius when he said "if you have time to surf random ible's, you have time for a hobby". Also why surf here if you don't have time for the things you see.... Isn't that just wasting more of your precious time carlo$?
3366carlos5 years ago
Very nice, too bad I don't have time to mess with electronics anymore.
If you have time to surf random instructables, then I'm sure you can put aside some time for hobby.
endolith4 years ago
gsionek4 years ago
Thanks for all those tips! Very very useful!
I have over thirty years of professional experience with a soldering iron. This is the best article I have ever seen on surface mount hint and tips, especially for DIY applications. The aluminum foil trick to protect adjacent contacts should also prove handy for assembling high density connectors. First rate, A+, and many thanks.
Loki-me5 years ago

well done! I like the aluminum foil to prevent surface tension bonding between contacts.   
I find that designing and etching PCBs is much easier of a process than doing something like this, but I don't like magnet wire very much. This is a good idea, but people, please consider making your own custom boards. I am SOOOO glad that I learned Eagle. With my custom boards, I find that SMD is easier than through-hole.
Designing custom boards is more aesthetically pleasing, often more durable, and sometimes necessary to keep fast chips stable, but it also takes a LOT more time to do it. Something modular like pictured can at least be done in batches so you make a few dozen boards at a time but for most DIY work you wouldn't be making the same thing that many times.
If it works for you, then more power to you! However, I have had problems using protoboard and breadboard methods for some SMD chips. For the binary watch that I am building, I needed a boost/buck converter. Every time I used a breakout board with my breadboard, the chip failed. When I took the time to make a custom board, all the problems went away. (chip was MAX1724, but I am now using REG711)
juanangel5 years ago
My comment is related to soldering the SMT components. Something you should add to save the components is that the soldering tip must not be in contact with the component for more than 3 (three) seconds or damage to the internal electronics will happen instantly or later in use. If having problem with applying solder to the component, verify it is not Pb Free(lead free) which requires higher temperatures. No needs to add excess solder to terminals or cables (just check a board and familiarize with the amount of solder applied). Never move or verify the solder by moving the cable or connections while it is hot / warm. Use a magnifying glass to verify it, it should be smooth and shinny. Amount of solder should not be a reference to decide if connection is wrong. Hope this helps you.
bill20095 years ago
thank you. good tips generally for fine soldering. and the pic-on-a-stick with color coded header pins is cute.
spas995 years ago
will forgive, but it is ugly ....... so you can not make a PCB as it should?
mooseo5 years ago
Nice instructable. I'd like to add that a cheap dissecting microscope can make the actual soldering much easier. Suddenly the pins look huge and you can see how little bits of solder and wire might bridge between gaps. They're often available on ebay. A well lighted workspace is super helpful, too.
Wire wrap wire works as well as magnet wire for this type of soldering, as long as you have the right-sized stripper
wkuace5 years ago
Great Instructable and great soldering job, I'm an Electrical Engineering student and i've seen some awful soldering jobs even from junior and senior students. I'll bet even this would be impossible on a SOT-323, they are about the size of a small freckle lol. I don't like to use anything smaller then 0805's with the pick and place at school. so far i've stayed away from smt in my hobby work but i'll defiantly try this if i ever have to convert
I recommend designing custom boards if you switch to SMD. They are easier than through-hole on perfboard.
I remove a lot of stuff even SM with a pen torch and use the same method to solder SM components, just check the data sheet for temp and times almost all SM components are meant to be soldered in a oven. if you move the pen torch fast in a circle with the blue tip a inch or so off the pcb "really small flame" it will work every time. you may encounter a learning curve... I like this best for sm cmos and through hole fets
Calorie5 years ago
Well executed. I like that you reused a scarce resource, and that you were clever about it.
sageserver5 years ago
Nice macro shots! Does the blue-tac melt? If it does, wouldnt it stick to the led and make it messy?
ironsmiter5 years ago
Beautiful write-up on this technique.
I especially like the blue-tac for holding the led.
Since it'll melt if you get it too warm, it would probably work to let you know when you're putting the chip at risk of overheating too. :-)


Deadbug is your friend.

Flip the chip upside-down. Mark pin one. Glue onto the adapter board(superglue= permanent. hotglue=semi-permanent). now solder the wires.

If you use circuit planning software, just remember the change in pin locations. if you wirewrap the circuit, no worries. :-)

Cannot stress enough how much a good, small, clean solder tip is needed. A really good "fine" solder iron makes it about 80% easier.
possibly one of the most useful instructables iv'e ever seen, very nice!
marc.cryan5 years ago
Thanks for the tips!

Well done.
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