Surface Mount Soldering SD Card Connector Trouble [SOLVED!]

I can’t seem to eliminate shorts from the next to last pin on the SD card connector. I have tried chisel and pointy shaped soldering iron tips. I think I might have tried too hard on this pin, because it is almost gone now. I am open to suggestions. Surface mounting this component looked like an easy enough task looking at this step by step: I fear that I’ve wrecked this component of Ambika and will not have any preset or storage capabilities now.

Have you tried measuring for continuity and shorts on the pins?
It doesn’t look great but also looks like it could just work.

Hi Shiftr,

I have tried measuring. For, the next to last pin before the really tiny pins (the one that has gotten very small, now), I get a short (numbers show up on the multimeter display and change quickly) when I put a testing lead on either pin next to it. This is for both continuity and resistance at 20K. I also still get the SD card reader error still if I put in a card, power up and press the switch under LED 15. It could be that there isn’t enough pad left for the remainder of the pin to be solder on to. I think I underestimated the skill/touch required to successfully surface mount the SD connector.

You mean the 5th from the right? That pad should be connected to ground. It’s not strange to have some readings on that. If the pins next to each other don’t measure anything near 0 Ohm they don’t have shorts. Next you should check the connection of the pins to the other parts they connect to (IC’s, caps etc) You can check the traces on drawings of the Motherboard on the build page or in the schematic.
It could also be a problem with your SD card. Some SD cards don’t work well with the ambika, Did you try a different one?

based on the vapor trails coming off your solder points. I would say you are running your iron 100 degrees hotter that you should and you are burning away the flux before it can do what it’s supposed to. Get a flux pen matching the solder you use, turn the iron down a 100 degrees and go from there. Different tips heat up to different temperatures, that’s why any real temperature regulated soldering iron has a “calibrate” function where you can measure tip temperature and adjust the heater accordingly. Using a $15.99 soldering iron designed to solder guitar cables isnt going to cut it for modern surface mount components and you will probably do more damage than good

^- correct. Use SN60PB40 Solder and 303°Celsius (iconic Number!)

Possible that solder has run underneath? or you’ve toasted it that much that the plastic inside has frazzled and you need a new socket.

6581 Punk, I am loading a picture of the plastic on the socket. Does this look like it needs replacement?

Shiftr, this is the SD card I’ve got. It was the smallest I could find off the shelf. Has any one had trouble with this kind of card?

Frank, this is the solder I was using. Is this solder too high temperature for this application?

Altitude, I have also attached a picture of a syringe of flux paste I have in my kit as well as my soldering station, which I will dial down to 303… Will this syringe suffice or is a flux pen a smaller and more accurate way to go?

Thank you for your help!

Hard to say really. Personally I’d (very carefully so as to not lift pads) desolder it all and test it out of circuit.

Solder is fine - but you really don’t need silver in it - Ambika is not a Zombie

The left 3 Pins of the Connector in the Pic (big Version) look suspicious… and is this a splash of solder on the Board??

looks like you have the right tools for the job, just turn the heat down. With SMD stuff, the protocol is to flux the pad and the pin, then hit it with solder. I usually just get a bit of solder on the tip of the iron and then just touch the part, it should suck the solder on to the pad

Doesn’t solder with silver require a higher soldering temperature? If I remember correctly, it’s fine for cables and stuff, but not exactly recommended for components.

I agree with @6581punk that the solder might have run under the card reader component, causing a short there. If you can’t find it you might consider desoldering the reader component (you’ll probably break it in the process, so be ready to order a replacement), clean up, and resolder.

Silver solder is really a problem actually it needs a much higher temperature.

My take homes: roll the heat back on my iron to 303 celsius (Altitude was right, I am about 100 degrees too hot), don’t use silver bearing solder for component work (SN60PB40 is better) and add flux to pins and pads before soldering.

For troubleshooting the SD connector, I should consider carefully desoldering the SD connector, clean up and start over with the caveat that a replacement SD connector should be handy.

Thank you again, MI community. I am learning a lot. Hopefully, I can make this right.

Frank, I think that might be a surface burn, rather than a splash of solder and a trick of the light made it look silver. I’ll need to look at it after work to confirm.

Oh, is there anything I can do if the pads under the pins of the SD connector are damaged?

I missed the silver solder reference, you don’t want to use that on a PCB, or brazing and welding.

62% tin, 36% lead, 2% silver. It’s an ‘improved’ non-leadfree solder, not real silver solder. Melting point is 179°C, very slightly lower even than for traditional 60/40 solder. The solder should not be the issue - except when soldering gold plated pads. Are those on the SD reader gold plated?

“Sn62. Common in electronics. The strongest tin-lead solder. Appearance identical to Sn60Pb40 or Sn63Pb37. Crystals of Ag3Sn may be seen growing from the solder. Extended heat treatment leads to formation of crystals of binary alloys. Silver content decreases solubility of silver, making the alloy suitable for soldering silver-metallized surfaces, e.g. SMD capacitors and other silver-metallized ceramics.[8][23][27] Not recommended for gold.[16] General-purpose.”

I don’t remember now if the pads were gold or not. I can’t find an image of the bare pads of the motherboard.

Thank you, ByteFrenzy.