Tips on soldering pin headers on T3.2

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sherinkapotein

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Hello,

This sounds rudimentary (even to me asking) but is there a guide to getting started with soldering the Teensy's.

Background. I've had a T3.2 for a few months now and yesterday I finally decided that I need to get working on it. My first step was to solder some breakaway pin headers like here.

I am not a hardware guy (well can say a software one either ;) ), but in the last few months I'd had some exposure of getting items together on a prototype board (say soldering!!).
What I'd realised was that a decent scrap over the copper surface to remove oxide before soldering helps. But since I coudn't do that on the my teensy's through pin holes (a mild caress using a paperknife didn't help much and didn't apply force, afraid of damaging the pcb). What I ended up was a total mess with the solder refusing to hold. I'd tried with/ without solder flux, and different solder wires( with and without flux inside) but the result was similar mess indeed.

I understand there is something fundamental I'm missing here. Is there some tool required for it? Would the learned and experienced care to shed some light on it and possible measure to the recover my ill-soldered pins.

Help please!!

PS:On a totally unrelated issue that from the subject. Why on a capable and potent board like T3.2 should there be only 1 SPI controller!!:(
 
Soldering should just work, since the T3.2 has gold plated holes to prevent corrosion. It's hard to tell with something like soldering, but maybe you don't have the iron hot enough, or you have it way to hot, but don't apply it long enough for both surfaces to bond.

There are video tutorials but my 10c on things to check would be:

Find something other than a teensy with a through hole
If it's not a plated hole clean it up so it's shiny
Check your solder is intended for electronic use and the sort with resin inside and not more than a couple of years old (leaded is easy to work with but isn't good for you, pick your poison)
Strip a copper wire and thread it through
Touch the solder to the iron tip, it should melt quickly, but only make a thin trail of resin burning. If the blob of molten metal eveporates quickly then it's way to hot, if it's not melting in under a second it's probably too cold, or the tip is corroded.
Touch the soldering iron tip to a point where it's contacting both bits of metal
If things start to smoke straight away the iron is too hot, small blob of solder on the top should be transfering heat into both surfaces, if not move till it is.
Give it a couple of seconds and feed the solder into the join, not the iron
For two light weigh surfaces 2-3 seconds should be enough to get it hot enough.
If things are burning it's too hot, if it's not melting unless you give it 5-10 seconds things are too cold or the heat transfer is poor (iron internal contact may be rough) or iron is too small
Lift the solder and then the iron away and the join should be a nice curve and a shiny finish. If it's crusty then things didn't get hot enough, if it's not touching one or other surface that surface either has a coating that doesn't solder, or wasn't heated enough.
If tracks lift or the board discolours at all then iron is too hot.

The reason for not using a teensy here is the normal result for too much heat on the teensy tracks is lifting pads. and that's less annoying on a scrap board.

There are lots of words there and video may work better, but will hopefully give you some clues if it's equipment or technique that's causing problems.
 
sherinkapotein said:
PS:On a totally unrelated issue that from the subject. Why on a capable and potent board like T3.2 should there be only 1 SPI controller!!:(
Click to expand...

The underlying MK20DX256VLH7 microprocessor that is used for the Teensy 3.2 only has one SPI module. The Teensy 3.5 and 3.6 support 3 separate SPI buses, though only 2 of the buses are connected by the outer pins (the 3rd SPI bus is connected by soldering wires to the underneath pads).

As Frank B says, you can put multiple SPI devices on a SPI bus. You have to dedicate a CS (chip select) pin to each device. On some devices, you would need to also dedicate a DC (data/command) pin. However, you probably should check each of the SPI drivers to make sure that they have been modified to support SPI transactions to properly mediate between the separate displays.
 
Your tip must be wetted (coated) with shiny solder but no great blobs. If it won't, your tip has oxidized and may need to be resurfaced or replaced but try cleaning with emery cloth or fine steel wool.

Put headers into breadboard and Teensy on to the headers.

Heat the pad and the header with the tip for a second or two the touch with proper resin core solder 1mm or less not something for plumbing.

Lead free can be slightly more finicky. 63%Sn/37%Pb has the lowest melting point and thereby gives a noob a bit longer before toasting their baord.

The solder should flow or 'wet' to the heated parts almost immediately or you don't have the parts hot enough.

A dry tip will not transfer heat properly... trying to blob solder off the tip does not work.

look for info on 'tinning' a soldering tip. Get the brass shavings or a good sponge to clean your tip.

A clean properly tinned tip is key.

I still suck at it but that was the lesson I learned.

Oh.. and when you mess up... a desolder tool (solder sucker) and/or solder wick.

Plus a dab from a flux-pen to help with wetting on parts you've failed with before sometimes helps.
 
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I highly recommend Kester 44 solder. It's not terribly expensive and works so much better than the cheaper brands.

The reality of multiple SPI ports is not as wonderful as it might first seem. For fast SPI clock speed (where "fast" is 1/10th of the CPU clock or more) and small messages used by nearly all SPI chip, busy polling is by far the most efficient software implementation. So even if you have multiple ports, to actually have more than one transferring data simultaneously, you need a totally different software approach which is usually much, much slower. In the context of the way virtually SPI-based libraries are currently implemented, having extra SPI ports really isn't very useful, expect perhaps to avoid loading MOSI, MISO & SCK with too many chips and wires.

A separate fast SDIO port to avoid using SPI for SD cards is a huge win. Or will be in a distant but glorious future where the Arduino SD library supports better caching and leverages the SDIO port and DMA to pre-cache sectors while other non-SD code runs.

Perhaps in time we'll see some special SPI-based libraries make effective use of DMA on the other SPI ports. But the reality is very few SPI peripherals can really benefit from this approach, and least while we're dealing with 10 to 50 MHz SPI clock speeds and CPU speeds under 500 MHz. In a much more distant future when we get 1 GHz rate microcontrollers, the trade-offs will very likely look different. The silicon processes capable of such speeds will also provide far more advanced (and complex) peripherals than we have today.
 
Soldering should just work, since the T3.2 has gold plated holes to prevent corrosion. It's hard to tell with something like soldering, but maybe you don't have the iron hot enough, or you have it way to hot, but don't apply it long enough for both surfaces to bond.
Click to expand...
I did range temperatures between 300-350 in steps of 10 on different holes. I would confess being reluctant to make my iron contact for more time than to melt the solder in fear of damaging the components. May be I should have been more liberal (or not). But I sure will consider your tips on a few cheap STM32 clones heading my way this week.

Strip a copper wire and thread it through
Click to expand...
This sound novel. :) to my ears. Will definitely try it.

I highly recommend Kester 44 solder.
Click to expand...
Will definitely try it

Lead free can be slightly more finicky. 63%Sn/37%Pb has the lowest melting point and thereby gives a noob a bit longer before toasting their baord.
Click to expand...
Another one that I'll subect my other cheap boards to experiment on.

You know that you can attach more than one device to the SPI-Controller?
Click to expand...
Yes I do, but a possible use case follows, of which I wanted to explore the possibility, hence got to my teensy up and running in the first place
Possible use case: A NRF24l01+ on SPI 1, SD card on SPI2, the SDfat buffers increased to say 16K, when it fills up, DMA writes the buffer(FIFO) to SD card while the cpu (read NRF...) still available for listening/transmitting on separate SPI. But guess now I'll try to use some RTOS libraries to get what I need.

EDIT: After reading Paul's post which came up as I was typing mine. The entire premise of benefiting from multiple SPI ports in the use case above may be flawed and woudnt have succeeded anyway I guess.

Thank you all for your inputs
PS: It seems I shoudn't even waste days scrapping the web. This Right here seems to be much potent and concise source of knowledge. thanks y'all
 
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Is your 300 to 350 C or F?

if it's C you may have things too hot, and trying minimise contact time to compensate. That said I've never really trusted front panel reads and been more interested in how the joints work afterwards.
 
I got a decent temp controlled soldering iron from Sparkfun - probably not the same one offered now. Working well for my occasional untrained/unpracticed abuse. It came with the bronze wiping sponge that works well to keep the tip nice, though time to replace it with the spare I bought as it can come out with more crud than it went in with.

The cool thing I also got was Tip Tinner - it easily restores the nice shiny working tip noted above.

Flux is your friend - Also I had a rosin pen that was a pain to use - drained too fast in too few uses, suddenly dry - I got a tub of rosin paste similar to that. I just tapped the 8 legs of a SOIC8 flash chip in and soldered it with wire solder and all 8 pins look good - not powered it up yet. Having rosin to start with cold surfaces and a rosin free ball on the end of the solder seems to aid wetting and heat transfer and reduce cooking time.

Worthwhile to practice - and find a couple decent vids to watch. The last I watched was for SMD stuff - getting first pin anchored to start square stable is important. Same with through hole - worth it to spend time before getting things stable so it doesn't shift when the solder is flowing so you can focus on getting the right amount on the pin&pad and not keeping it in place under pressure.
 
Couple of thoughts:

1) Get a good soldering iron with a 'real' temperature controller, then dial it in for your particular solder.
2) Tip tinners and coarse brass to clean same are a must
3) Get a variety of tips. A fine tip for small holes like the CFS206 RTC crystal, a broader angled one for drag soldering, etc. They all have a purpose.
4) Flux in a dispenser of choice (I use syringes) is your friend, especially when it comes to de-soldering
5) Speaking of which, get appropriate copper braid, a solder sucker, and other tools for component removal (I like chip quick).
6) Appropriate alcohol wipes (99% Isopropyl) are important to use on PCBs prior to soldering. They may dry out your hands though.
7) Rigs to hold stuff are helpful (helping hands?)
8) Antistatic mats and grounding points before handling sensitive components saves hair (from getting pulled later).
9) I happen to use kester lead free solder, am happy with the solder paste also.

If you plan on putting a lot of feet on teensy's, it might make sense to build a jig where you insert all the pins, plop the teensy on top and then solder it all together, with all the pins lined up 100% parallel, equidistant, and so on. Not incredibly easy to achieve, especially if you attempt to put legs on bottom pads.

Technique will come with time. Youtube videos are very good starting points because they illustrate what you should see while soldering. Marrying the right tip to the task is an important first step. For small holes like on the Teensy, I firmly jam the tip of the tinned soldering iron against the pin and the hole, ensuring both a heated. Only then apply solder, which should get sucked in through capillary action, form a nice cone shape on the pad, cover it 100%. Beware of cold joints...
 
oric_dan said:
OP, now that you're getting into soldering, the next thing you will realize is boards and components jump around all over the place when trying to solder. I've often wished I had a 3rd hand. There are a number of pcb vises around, but I recently bought one of these, and it's by far the best thing I've found for holding circuit boards - and cheap too.
http://www.jameco.com/Jameco/Products/MakeImag/2237036.jpg
http://www.jameco.com/z/VTHH6-Velleman-Circuit-Board-Clamping-Kit_2237036.html
Click to expand...

I like that vice (from Vellman), but since Adafruit started reselling the Stickvise, the Stickvice has become my favorite soldering vice:

I like it because it doesn't tend to swing if I put the soldering iron on the board, like the above vice does (this is particularly when I'm desoldering, as I'm trying to melt all of the solder, and I tend to rest the de-soldering iron on the join until the whole solder blob is melted). I know I'm probably too heavy handed, but the Stickvice works better for me. I do use the Vellman vice when soldering a board underneath, and I have some attachments already on the board that are too tall for the Stickvise.

For desoldering, I never had much luck with the the simple solder suckers used in conjunction with a normal soldering iron. I like this electric version from Vellman that allows you to heat up the solder and then suck it up, rather than trying to use one hand with the soldering iron and the other with the solder sucker:
 
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I like it because it doesn't tend to swing if I put the soldering iron on the board, like the above vice does
Click to expand...
If you'll notice, there are 2 thumb screws at the top that keep the pcb from rotating when tightened.

I've used a panavise for years but the one indicated is far superior. Basically, instant mounting of different size pcbs, and allows the pcb to rotate around to any angle in pitch, top-bottom, or azimuth.

I also never do solder-sucking, but melt the solder and push through a stainless steel pin to open the pad hole.

EDIT: also, this sounds like a minor thing but it's not. I used to do fine dissections under a microscope. The real key to easy soldering/etc is to rest your wrists, or at least your forearms during soldering, on the table or something firm, and then the tip won't jiggle around. This is especially helpful when soldering headers onto the Teensy pcbs, where you have to be careful not to damage the components already attached to the pcb.
 
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MichaelMeissner said:
I like that vice (from Vellman), but since Adafruit started reselling the Stickvise, the Stickvice has become my favorite soldering vice:
...
I like it because it doesn't tend to swing if I put the soldering iron on the board
Click to expand...

I see @MM's point here - I got one and it cannot be as stable as the Adafruit Table top unit. The first is relatively stable - and very adjustable - but I end up in a compromised situation once off the centerline - the piece ends up 'swinging' the platform getting the iron in place - esp desoldering ...

The 30W heated solder sucker looks good too! I can get some holes clean but often cannot negotiate heating and placing the vacuum tip close/fast enough. Most of my soldering experience was watching my EE buddy - his solder sucker tips were always horribly deformed - he was practiced at forcing it the right way&place to get the job done - that takes pressure & practice. Last internal small JST hole I tried to clean I just repeatedly resoldered full until I gave up before I ruined the board - the stainless steel pin sounds like another tool for that.
 
but I end up in a compromised situation once off the centerline - the piece ends up 'swinging' the platform getting the iron in place
Click to expand...

Takes a bit of playing to get the Velleman optimally set. First align the pcb into a balanced position, like the first pic, and not the 2nd,
http://www.vellemanusa.com/images/products/1/vthh6_application.jpg
http://thumbs.ebaystatic.com/images/g/4scAAOSwJ7RYX60J/s-l225.jpg

Then, push the bottom slider in until the spring is about "half-way" compressed and tighten both slider and also thumb screws on top. Now the pcb is balanced and won't rotate easily. Takes about 10-sec to set it.

EDIT: the other thing is to orient the pcb vertically, then you can work on both sides and with both hands. I do this for special things, like after-the-fact mods, but for soldering up pcbs initially, I usually just lay them flat on the work bench [actually on top of several stacked books], stick in the parts and hold with electrical tape, then flip the pcb over and solder and snip. Works for me.
 
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It can be done - you only know it isn't quite right a couple hundred degrees into it :)

By centerline I meant of 'the component under the iron' - sometimes that is off to the edge of the board. And things (like the USB connector) keep from having full adjustability. Afraid the Adafruit vise might have issue with that as well as it has to hold somewhere - but without the center rotation it will sit solid.

Also the base thumbscrews are in plastic - I keep wondering how long before it breaks out in making it tight.

Odd the Adafruit comes with Nylon jaws then adds second buy to get more heat tolerant ones that I suppose would be needed for air solder unit. Air solder might toast the vellman unit in use.

Note: Indeed having Arm support seems essential and hard to find without a tested bench I suppose.
 
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defragster said:
It can be done - you only know it isn't quite right a couple hundred degrees into it :)

By centerline I meant of 'the component under the iron' - sometimes that is off to the edge of the board. And things (like the USB connector) keep from having full adjustability. Afraid the Adafruit vise might have issue with that as well as it has to hold somewhere - but without the center rotation it will sit solid.
Click to expand...

Yeah, both stickvise and the Vellman board have the problem that you really need a little bit of a lip to hold the boards.

defragster said:
Also the base thumbscrews are in plastic - I keep wondering how long before it breaks out in making it tight.
Click to expand...
Yes, and in my experience, you can't really tighten down the screws on the Vellman unit enough to prevent it from moving if you are heavy handed and press down with the soldering iron. I've had experience with other plastic screws that soon got stripped, that I try to be cautious in over-tightening the screws.

defragster said:
Odd the Adafruit comes with Nylon jaws then adds second buy to get more heat tolerant ones that I suppose would be needed for air solder unit. Air solder might toast the vellman unit in use.
Click to expand...
Note, Adafruit is only reselling the stickvise, they didn't design it.

Yeah, I don't really see the point of the standard headers, since I do a vice or two with burn marks from an errant soldering iron. So, when I bought my stickvise, I also bought the high heat plates, and immediately swapped them out. This discussion reminded me that I always want to raise the height of the plates, and I went out to the hardware store to get some 3mm x 20mm screws, and I put the old plate in between the base and the high temperature plate. I usually only think of this at 11pm when the store is closed.

Unfortunately my hardware store didn't have any longer screws nor 3mm tee joints. Sometimes I really want to attach the vice down to the table so it won't move. I'll have to go to a more specialty store (like McMaster) to get longer 3mm screws and tee joints.

defragster said:
The 30W heated solder sucker looks good too! I can get some holes clean but often cannot negotiate heating and placing the vacuum tip close/fast enough. Most of my soldering experience was watching my EE buddy - his solder sucker tips were always horribly deformed - he was practiced at forcing it the right way&place to get the job done - that takes pressure & practice. Last internal small JST hole I tried to clean I just repeatedly resoldered full until I gave up before I ruined the board - the stainless steel pin sounds like another tool for that.
Click to expand...
Note, I forgot to mention the electronic solder sucker has one big mis-design 'feature'. It doesn't have an off switch, and currently the plug takes force to remove it from the socket of the extension cord I have at my table. Instead you need to unplug it to turn it off. So, I plug it into an electrical strip that does have a plug, and plug that into the wall.

I do wish somebody would come up with a soldering iron (and de-soldering iron also), that has a motion sensor in it. If you haven't moved the iron for 5-10 minutes, it should shut off the iron. So far, I don't think I've managed to leave it on all night, but I can imagine it happening.
 
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Speaking of stripping out plastic, I never do that since my fingers are so well calibrated [right!!!], but I read that if you ever do such an evil thing, you can insert a short piece of smallest size nylon cable tie into the hole, and screw the screw back in, and it will hold. I've not tried it myself, since as you know, I never strip out screws, LOL.
 
@MM - you are right :: www.stickvise.com/#home sells on Amazon and hackaday at same price and same setup buy with nylon and add-on PTFE jaws. Amazon would ship faster and free. I suppose you saw their site with hack notes - with McMaster part #'s.

I've got a switch on my SFun iron - always wonder when I'll leave it on. Should put a timer plug there - sounds like the desolder iron would need at least that.
 
One way to deal with the forgetfulness problem is that I use a small hepa air filter next to the soldering space to suck up the solder fumes, and I can hear the fan running from the other room, whenever things are turned on.
https://www.overstock.com/Home-Garden/Holmes-HEPA-220-Air-Purifier/619216/product.html

For that matter, although it's common knowledge anymore, no one specifically mentioned to OP that leaded-solder is not the best material to handle with your fingers. so don't stick your fingers in your mouth or eat food without washing your hands after soldering. And don't let the little kids in the soldering room at all.
 
oric_dan said:
One way to deal with the forgetfulness problem is that I use a small hepa air filter next to the soldering space to suck up the solder fumes, and I can hear the fan running from the other room, whenever things are turned on.
https://www.overstock.com/Home-Garden/Holmes-HEPA-220-Air-Purifier/619216/product.html

For that matter, although it's common knowledge anymore, no one specifically mentioned to OP that leaded-solder is not the best material to handle with your fingers. so don't stick your fingers in your mouth or eat food without washing your hands after soldering. And don't let the little kids in the soldering room at all.
Click to expand...
I have a fan that goes, but it is a simple fan, and perhaps I should use a HEPA fan.

But in any case, I'm more worried about the dog knocking into the table when the iron is hot and hurting herself when I'm out of the room and potentially having a fire hazard if is left overnight.
 
But in any case, I'm more worried about the dog knocking into the table when the iron is hot and hurting herself when I'm out of the room and potentially having a fire hazard if is left overnight.
Click to expand...

Since you mention this .... I have a home automation system "almost" implemented that uses $3 Hope RFM radios and Arduino mega328 chips for remote nodes, so the nodes are cheap. I can distribute nodes to strategic places around the home for monitoring, eg kitchen stove, furnace/hot water heater closet, &etc. I might put a node at the soldering station as one of the monitor points. The central radio hub monitors all the remote nodes, and can signal any bad status.
 
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MichaelMeissner said:
I have a fan that goes, but it is a simple fan, and perhaps I should use a HEPA fan.

But in any case, I'm more worried about the dog knocking into the table when the iron is hot and hurting herself when I'm out of the room and potentially having a fire hazard if is left overnight.
Click to expand...

I use a master-slave power strip.
The master is my desktop-computer which goes to sleep after some time.
If I leave the room, even unplanned, the soldering-iron, hot-air, both displays and even the lamp are switched off after some time.
Simple and effective.
 
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