How is my Soldering?

[n3tjm]

Did some SMD soldering practice tonight. Last night I soldered three more practice rows of resistors and capacitors. The practice exercises by soldering the itsy bitsy tiniest capacitors I have ever seen. After those were done I decided to do the inner center section which is part of the circuit that does something. It consists of a 555 ic and a 4017 ic, several resistors and capacitors, and a bunch of diodes in the form of LED's. This is where my experience with electronics kicks off because I had to reference the schematic to know what resistor goes where. Good thing I know how to read them.

No, the dots on the right are not specks of dirt. They are actually capacitors!


A couple of those itsy bitsy capacitors tacked into place


The practice rows and the center of the circuit is finished

 

[heada]

I've done that exact same kit. All the small stuff was difficult but those stupid glass diodes are a pain. Tweezers seem to just slip on them. Looks like you did a good job on it all

 

[KC3KNM]

Looks great! Don't see any cold joints. Are you using an iron or a hot air? If you're using an iron currently, I've found a touch of solder paste on the pads and hot air make SMD soldering much easier and cleaner. If you're going to solder more small stuff a cheap preheating station makes it even nicer, particularly for rework and sensitive components.

 

[OverTheTop]

How picky do you want me to get? Good effort for starters anyway. I have been doing SMT soldering for about 20 years and still evaluate each joint as to how close I get to target condition. It is the only way to keep improving .



Is the left side of the third column actually soldered? Looks clean in the pic (see ellipse)
Quite a few joints are tending to have too much solder (see red arrow for an example)
What you are looking for is a nice concave fillet, like shown by the green arrow. The light reflects in a nice crescent when you get it right.
There are a few components that are not flat on the PCB. See purple arrow for an example. This is usually tweezer technique, being able to pick up the component with the tweezer tips not limiting the component being flat on the PCB when placed.

Regarding the SOIC integrated circuits, it looks like you have about the right amount of solder there. Hard to tell in the pic but the solder must have a "heel fillet" where the legs start to go up vertical and curve away from the PCB pad. Note that the solder should not go all the way up the pin as the pin flexing provides mechanical stress relief for the assembly when temperatures change. FYI there is no requirement at all for a toe fillet (on the very ends of the pins).

If you are trying to get solder to go somewhere, it follows three things:

• Flux
• Heat
• Other Solder

Sometimes I also add gravity into that list.

BTW, the smaller the components the more difficult it is to get the right amount of solder and achieving target condition is more difficult. Using very thin solder, say 0.3mm diameter, helps with this.

Keep up the good work.

[edit] Forgot to mention. You can solder with or without magnification (I generally don't need it) but you MUST INSPECT with x10 OR GREATER magnification. This is very important!!! (note the three exclamation marks!)

[edit 2] Forgot to mention. If the joints are acceptable, don't rework them to be perfect. It actually creates a thicker intermetallic bond layer which is more brittle.

 

[n3tjm]

I was hoping for someone to be picky. Constructive Criticism is a good thing. I noticed the raised component at the purple arrow and fixed that already. I am using a Aoyue 888A Digital Soldering Station. I am using an AmScope SE400-Z Professional Binocular Stereo Microscope using the 10x lenses. All of this work was with the iron. I also used flux. I tried a few techniques. That row you mentioned I pre soldered the first side, soldered the one end down, and then soldered the other end. The result is a much cleaner solder joint on one side. I do need to get some thinner solder. The thinnest I got is .8mm. Money is a little tight right now but there are a few things I want to get to add to my soldering station eventually. For example, a Soldering Mat, Soldering Tape, and an Ultrasonic Cleaner.

I been soldering since I was a kid. Something my Dad taught me as soon as he felt I was old enough. (He worked on the C64 and C65 (his name is actually on the C65 motherboard)). I have put together several altimeters and even built my own timer for airstarts based on a 555 and Resistors to set the time. This is my first attempt to do surface mount soldering. I feel like it is a good job for a first try . Eventually when I feel like I am good enough at this, I will build that Egg Timmer Quantum I got during Secret Santa

 

[prfesser]

Did some SMD soldering practice tonight. Last night I soldered three more practice rows of resistors and capacitors. The practice exercises by soldering the itsy bitsy tiniest capacitors I have ever seen. After those were done I decided to do the inner center section which is part of the circuit that does something. It consists of a 555 ic and a 4017 ic, several resistors and capacitors, and a bunch of diodes in the form of LED's. This is where my experience with electronics kicks off because I had to reference the schematic to know what resistor goes where. Good thing I know how to read them.

No, the dots on the right are not specks of dirt. They are actually capacitors!

A couple of those itsy bitsy capacitors tacked into place

The practice rows and the center of the circuit is finished

Looks like a darned good job to me, quite a lot better than I was able to do on my Eggtimer. I put a Quark together over a year ago, before my hands got too shaky. It works but it ain't pretty.

Best -- Terry

 

[cerving]

Looks good to me. Wire solder and solder paste work a little differently with SMT parts. With solder paste, you're trying to bond the bottom of the leads to the pads. With wire solder, you're probably not going to get under the pads, so you need to get the edges (i.e. the "heel" for those SOIC chips). That's why we make the pads oversized... it makes doing that easier, at the expense of board space.

 

[FredA]

You've got hot air.
Get a paste dispenser (syringe) and use that.
Put paste on the pads and place parts onto the paste.
Hot air will allow surface tension to center the part as the paste turns to solder.
Once you get used to using hot air, you won't use a pencil iron for much....

 

[n3tjm]

ok. I'll add solder paste to my list.

 

[dr wogz]

picky:
Where applicable, ensure the text on the parts all face / read the same way. And ideally, oriented the same as the PCB text & lettering..

 

[Wayco]

My only experience with SMT parts is building Eggtimer kits. I'm glad "Over the Top" gave you constructive criticism, and I agree that some of your work could be better, but....
You could move on to building Eggtimer systems with what you have now. Cris has improved his boards to the point that most anyone with a soldering iron can do a competent job soldering them. You can play around with all these practice boards, using the paste Fred suggests, smaller solder and anything else you want to play with, or you can build an Eggtimer kit using the instructions that Cris wrote. That's what I did, and have dozens of operational Eggfinder TX kits in all my high flying rockets. It s not because I have superior soldering skills either, some of my stuff looks like your practice board.
If you want some smaller solder to practice with, send me your address, I have over a dozen rolls of really fine solder that Cris supplies with his kits. I can build three kits with each roll he supplies, so I have plenty to spare.

 

[Peartree]

Thank you for sharing your experiences. To be honest, I've looked at the Eggtimer kits. And, I have some limited experience soldering, and own a soldering station and several pencils and a gun for bigger work. That said, looking at this sort of thing, as impressive as it is, pretty much convinces me that I will probably never buy an Eggtimer product. Even though I own Z-gauge trains (1/220 scale) I have no desire to work on things this small.

 

[n3tjm]

picky:
Where applicable, ensure the text on the parts all face / read the same way. And ideally, oriented the same as the PCB text & lettering..

I already do that . Can't be done 100% of the time but if it can be done I do it

 

[FredA]

Note that the "other" common way for hobbyist to use solder paste is to apply paste everywhere (stencil maybe if doing it a lot) then place all the parts and pop into a toaster oven to flow-solder everthing at once.

 

[dr wogz]

Note that the "other" common way for hobbyist to use solder paste is to apply paste everywhere (stencil maybe if doing it a lot) then place all the parts and pop into a toaster oven to flow-solder everthing at once.

at what temp, and for how long?

 

[heada]

Thank you for sharing your experiences. To be honest, I've looked at the Eggtimer kits. And, I have some limited experience soldering, and own a soldering station and several pencils and a gun for bigger work. That said, looking at this sort of thing, as impressive as it is, pretty much convinces me that I will probably never buy an Eggtimer product. Even though I own Z-gauge trains (1/220 scale) I have no desire to work on things this small.

Most of the Eggtimer kits don't use the super tiny parts. For example, the Quantum is all 1206 parts (farthest left in the pic in this thread) and some chips like the chips in the pic. I'm 45 and nearsighted but probably need to go get bifocals I could probably solder the 1206 parts without any magnification. The chips I would need something to help me see. You can do it too if you give it a try. A Quark (0805 parts, second from the left) or Quantum (1206 parts, all the way to the left) isn't that much of an investment to try your skills on and if it works, you get a good deployment device.

If you don't already have it, get a lighted magnifying lamp. I got this one:
https://smile.amazon.com/gp/product/B07MMZ27QK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1This makes all the difference. When set at the proper distance, those small parts look the size of a pinky fingernail and aren't difficult to work with at all.

Get a 3rd hand setup to hold the board at just the right height. I got one similar to this:
https://smile.amazon.com/Helping-So...ld=1&keywords=3rd+hand&qid=1610047700&sr=8-11
To clean your iron between uses, get a tip cleaner. Lightyears beyond the damp sponge method and greatly extends the life of your iron tips. I got this one:
https://smile.amazon.com/gp/product/B00FZPGDLA/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Get a good set of tweezers to pickup and hold parts. I got this set:
https://smile.amazon.com/gp/product/B07F2L5F3H/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1Ceramic ones are better and so I'd get this one now:
https://smile.amazon.com/Eyech-Non-...=ceramic+tweezers&qid=1610047867&s=hi&sr=1-10
Get a flux pen. It makes the solder flow MUCH easier. I give each pad a quick swipe of flux and the pads of devices I'm mounting get a swipe too (like the wireless module or GPS module on Eggtimer devices) I got this one:
https://smile.amazon.com/Liquid-Flu...&s=hi&sprefix=no+clean+flux+,tools,218&sr=1-4
Cris includes lead based solder but not everyone does. I got a big spool of it and use that instead. I got this one:
https://smile.amazon.com/gp/product/B07C5ZNFD4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
With this setup, I've soldered almost all the different kits Eggtimer offers. TRS has some of the smallest parts (smaller than a grain of rice) and I just did 3 of them between Christmas and NewYears on a Saturday. You can do it if you try.

 

[boatgeek]

Thank you for sharing your experiences. To be honest, I've looked at the Eggtimer kits. And, I have some limited experience soldering, and own a soldering station and several pencils and a gun for bigger work. That said, looking at this sort of thing, as impressive as it is, pretty much convinces me that I will probably never buy an Eggtimer product. Even though I own Z-gauge trains (1/220 scale) I have no desire to work on things this small.

Cris is kind enough to make the Eggtimer components a little bigger than the grains of sand in the pictures above. If I can successfully build a kit, you can too.

 

[n3tjm]

Looking at my board, I did forget to solder all but one in that row. I fixed it. Yeah, those cylinder diodes where a pain.

 

[OverTheTop]

Those diodes are I think MELF (metal endcap leadless form) package. They are a pain when learning. Tweezer technique is king there, as it is with most SMT soldering. Hot end not so much IMHO. I found that the better my tweezer technique got the less important was the type of tweezer I was using.

FYI these are my favourite tweezers:

https://www.amazon.com/102ACAX-Stainless-Magnetic-Tweezer-Overall/dp/B004UN8MQW
The trick to using them (took me a couple of weeks to figure it out!) is to hold them at the crossover point. Roll fingers back to open, roll the closer to the tip to apply more pressure to the gripping.

 

[FredA]

For the toaster over - do some reading and experiment. Can't say I've done it myself, but know plenty who do.

For tweezers - invest in some with ceramic tips -- won't suck the heat away as you try to solder the part.

 

[n3tjm]

Good idea.

 

[Michael L]

picky:
Where applicable, ensure the text on the parts all face / read the same way. And ideally, oriented the same as the PCB text & lettering..

Beat me to it.

OverTheTop has some fantastic info. But, my biggest problem when I solder SMD components is getting too much solder. I have an oven and I've used paste but I'd rather hand solder 99% of what I do.

 

[Michael L]

Thank you for sharing your experiences. To be honest, I've looked at the Eggtimer kits. And, I have some limited experience soldering, and own a soldering station and several pencils and a gun for bigger work. That said, looking at this sort of thing, as impressive as it is, pretty much convinces me that I will probably never buy an Eggtimer product. Even though I own Z-gauge trains (1/220 scale) I have no desire to work on things this small.

The EggTimer kits are pretty easy to build.

 

[Michael L]

Note that the "other" common way for hobbyist to use solder paste is to apply paste everywhere (stencil maybe if doing it a lot) then place all the parts and pop into a toaster oven to flow-solder everything at once.

Ebay has some fairly "cost effective" reflow ovens. I have one that I occasionally use. I don't build a lot of any one thing or anything all that large so I haven't used at a lot. It comes with different ramp/soak/cool profiles. It seems to work pretty well.

 

[cerving]

Thank you for sharing your experiences. To be honest, I've looked at the Eggtimer kits. And, I have some limited experience soldering, and own a soldering station and several pencils and a gun for bigger work. That said, looking at this sort of thing, as impressive as it is, pretty much convinces me that I will probably never buy an Eggtimer product. Even though I own Z-gauge trains (1/220 scale) I have no desire to work on things this small.

Fair enough, we openly admit that our kits aren't for everybody. We have a lot of people asking us about providing assembled kits, we don't have the resources to do it and farming it out in small volumes is expensive. That's one reason why our kits have a better price/performance ratio than more traditional options. That being said, there are people that will assemble them for a fee; in many cases, you'll still come out way ahead after you pay them.

 

[KilroySmith]

at what temp, and for how long?

My reflow oven is a $10 toaster oven from Goodwill. I used a very nice Fluke thermometer with a fast probe to calibrate it; it turns out that I can closely follow the suggested reflow profile of the Kester solder I'm using by:
1. Put the board in the cold oven.
2. Turn it to 175C/345F.
3. When the oven reaches 175C/345F, wait for 60 seconds.
4. Turn the oven to max temp
5. When the inside reaches 220C/430F, turn it off and open the door.

This all takes just about 4 minutes with my oven.

This can often be improved with a small tap on the board when you open the oven (helps the surface tension of the solder align all the parts with the pads nicely). I suggest trying it with some practice boards first.

 

[n3tjm]

After doing another practice kit, I decided to attempt my egg timer quant um. I think it went well, but more importantly, it works.

 

[neil_w]

I need to buy some solder, and realized that I've never actually purchased it in my life.... always used what was available at work (I've never done significant amounts of soldering at home before).

What size is good? I won't be doing extremely fine work with it. Also don't need a huge quantity. There are as always a billion options on Amazon. Is lead-free good to use? I don't think I've worked with it before (although all our products are build lead-free).

 

[mbeels]

What size is good? I won't be doing extremely fine work with it.

Asking that question on an electronics forum is a bit like asking a "which glue..." question on a rocketry forum. Do you remember which size(s) you used at work that you liked? I have 3 different sizes at home, but I probably would be just fine with one size. What do you plan on soldering?

The downside of solder too small is that you have to feed a lot to solder a bigger joint. The downside of solder too big is that it may be harder to control the application for small work. And if you have a very small tip, it may be difficult to apply enough heat.

 

[neil_w]

Asking that question on an electronics forum is a bit like asking a "which glue..." question on a rocketry forum. Do you remember which size(s) you used at work that you liked? I have 3 different sizes at home, but I probably would be just fine with one size. What do you plan on soldering?

I have some right now that is extremely fine, but don't know the size. Right now I'm re-capping a subwoofer power supply, other times I need to tin wires, repair toys, occasionally do little modifications to things. No fine-pitch SMT work or anything like that (if I ever need to do that I'll buy some fine stuff as needed).

I'm thinking something in the .6-.8mm range.