Soldering SSOP to its mounting

SSOP? I do these all the time. I use a WSL iron with the WMP soldering pencil, and the sharply pointed micro tip. I run the iron usually at 700 F I use a stereo zoom microscope at 8 power (I could actually use less, but that's as low as it goes). I use 6" tweezers with curved tips to hold the chips.

I have 2 ways to do them. For small chips, I use .010" solder (really hard to get, usually .015" is as small as it comes.) I put solder on one corner pad, and solder the chip to that pad. I then check alignment of all pins, and twist the chip slightly if the opposite side is a little off, then solder the diagonal corner pin. If it is still out of line, I can melt the solder at one corner at a time and reposition. I then solder the rest of the pins.

For larger pins, I use some solder paste in a syringe. You are supposed to keep it in the fridge, but that is too much hassle. I have to stick a paper clip in the syringe every 6 months to re-mix the suspension. I put a #18 needle with a 45 degree angle ground on it on the syringe, and deposit a thin thread of paste along the pads. I place the chip with tweezers, and do the corner pins as above. When the chip is properly positioned, I then gently wipe the iron down the rows of pins, soldering them all.

I've done hundreds of 144-pin, 0.5mm chips this way. If I apply too much solder, then I need the wick to remove it. I have trained several people to do this, and they all got the hang of it. The microscope is pretty necessary. Some people can do a few with the naked eye, but they soon get eyestrain.

Jon

Reply to
Jon Elson
Loading thread data ...

They're not so bad-- 0.65mm pitch. Liquid flux, fine solder, fine tip and some braid to get rid of any bridges.

Best regards, Spehro Pefhany

--
"it\'s the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
Reply to
Spehro Pefhany

Where do you get 0.01" organic core solder? I am starting to flood some small parts with .015"

Regards,

Boris Mohar

Got Knock? - see: Viatrack Printed Circuit Designs (among other things)

formatting link

void _-void-_ in the obvious place

Reply to
Boris Mohar

Two chips that I will use -- IR22141SS -- are in form of SSOP. I got them for free actually. I also had to buy two mounting bases that are SSOP to DIP converters.

The question is not the heck do I solder these chips to the mounting bases. They are so small.

i
Reply to
Ignoramus5275

Thanks, Jon and Spehro. I feel less intimidated now.

i
Reply to
Ignoramus5275

I have a short writeup about how I deal with these type chips at

formatting link
There have been some DNS issues lately, so if that doesn't work: http://207.210.77.46/solder/smd.html

I personally use 0.020" solder (Kester 331), and use a fat tip that covers about 3 to 5 leads.

Darrell Harmon

formatting link

Reply to
dlharmon

I have Metcal and stereo zoom microscope. I use the same flux as you which can work miracles but I need some 0.01" solder for some really fine work. BTW that water soluble flux can promote rusting of hand tools that are in proximity of it.

Regards,

Boris Mohar

Got Knock? - see: Viatrack Printed Circuit Designs (among other things)

formatting link

void _-void-_ in the obvious place

Reply to
Boris Mohar

I've in the past reduced the diameter of commercial solder with a draw-plate. Ebay?

Reply to
Ian Stirling

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.