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Electronics => Electronics => Topic started by: macdad- on August 29, 2010, 08:51:01 PM

Title: Soldering small ICs
Post by: macdad- on August 29, 2010, 08:51:01 PM

I got a sample shipment from TI for some LED drivers for a LED counter circuit and made a stupid mistake of ordering the driver(TLC5904) in the wrong package a HTQFP 100 Pin. I don't want to order some more in the right packaging as I don't want to break the respect-the-sample-system rule. Any tips for soldering it?

Title: Re: Soldering small ICs
Post by: madsci1016 on August 29, 2010, 09:07:14 PM

Flux, the smallest tip they make for your soldering iron, flux, tweezers, flux, magnifying glass for inspections, and did i mention soldering flux?

Flux all the pads on your PCB and let it dry. Place the chip down in on the pads correctly aligned. The dried flux will be a little sticky, so it will hold it down some. If the alignment is right, carefully heat up one pin. Between the flux and the tin on the PCB and chip pin, it will be enough to 'solder' that one pin down. Then go through each pin, apply a little solder to the tip of your iron, then heat up the pin so the solder runs off the iron and onto the pin and pad. Repeat a few times till the pins look sufficiently soldered down.

I first taught myself the Sparkfun method of creating a solder blob over a row of pins, then I found out why that's the wrong way to do it. Learn from my mistakes.

Title: Re: Soldering small ICs
Post by: macdad- on August 30, 2010, 03:41:58 PM

Thanks, hopefully I can solder it without screwing up(100 Pins at 0.075 pitch!)

Title: Re: Soldering small ICs
Post by: paulstreats on August 30, 2010, 05:06:37 PM

PRACTICE PATIENCE REPETITION :P :P :P

Title: Re: Soldering small ICs
Post by: madsci1016 on August 30, 2010, 05:53:10 PM

Quote from: macdad- on August 30, 2010, 03:41:58 PM

Thanks, hopefully I can solder it without screwing up(100 Pins at 0.075 pitch!)

It really is easy. I have shaky hands and I can do it.