madbeanpedals::forum

Projects => General Questions => Topic started by: jonnygreentrees on September 21, 2016, 11:32:18 AM

Title: Lifted pads
Post by: jonnygreentrees on September 21, 2016, 11:32:18 AM
Whenever I make a pedal on single-sided copper etch I always seem to get a couple of lifted pads. Is there a better way to repair these than just use jumpers/solder bridges to the next component along?
Title: Re: Lifted pads
Post by: Govmnt_Lacky on September 21, 2016, 05:36:42 PM
Not really a better way to repair... more like good advice to avoid them all together.

I have found that the most common reason for a pad lifting is excessive heat. Try to avoid keeping the soldering iron on the solder point for longer than needed. Maybe use a smaller/lower wattage iron. Decrease your heat a bit.

Sometimes the quality of FR4 is to blame as well. I have found the Tayda single-sided is notorious for pad lifting.

Food for thought...  ;)
Title: Re: Lifted pads
Post by: warriorpoet on September 22, 2016, 01:42:53 PM
To piggyback on this, make sure your tip is as small as is practical, too. You don't want to use a pencil tip on PCBs at all, but especially not on single-side.
Title: Re: Lifted pads
Post by: jonnygreentrees on September 23, 2016, 01:11:07 PM
Oh really!?

I was given a nice ERSA soldering station and I'm using this tip which is the smallest I could find that would fit it

https://www.amazon.co.uk/gp/product/B000UX9VMK/ref=oh_aui_detailpage_o01_s01?ie=UTF8&psc=1

Is this not ideal?
Title: Re: Lifted pads
Post by: warriorpoet on September 23, 2016, 02:18:07 PM
Not ideal; it delivers too much heat to your pads. Use something like this: https://www.amazon.co.uk/LF-ERSADUR-solder-tip-832/dp/B0024TECY0/ref=sr_1_10?s=industrial&ie=UTF8&qid=1474640114&sr=1-10&keywords=ersa+solder+tip

For reference, I run my Hakko at 440f (~227C) with 63/37 solder and a needle point tip. Congrats on the free iron!
Title: Re: Lifted pads
Post by: jonnygreentrees on September 23, 2016, 02:25:04 PM
Oh wow! I solder at 400 degrees Celsius is that too hot? Will look into getting a smaller tip
Title: Re: Lifted pads
Post by: Govmnt_Lacky on September 23, 2016, 02:51:12 PM
Quote from: jonnygreentrees on September 23, 2016, 02:25:04 PM
Oh wow! I solder at 400 degrees Celsius is that too hot? Will look into getting a smaller tip

I typically run at between 650 and 700F so you appear to be a bit high. I would go down to 350-375C and see how that goes.

Good Luck  ;)
Title: Re: Lifted pads
Post by: warriorpoet on September 23, 2016, 06:46:45 PM
Keep in mind: different irons will measure heat differently. My old iron wouldn't melt solder below 575f, this new one lifts pads at that temp. You don't want to be so cool it takes several seconds to heat the pad, but you don't want it so hot pads lift consistently. It's a balancing act!
Title: Re: Lifted pads
Post by: jtaormina on September 23, 2016, 07:46:37 PM
Getting crazy with solderwick can cause lifted pads.
Title: Re: Lifted pads
Post by: m-Kresol on September 23, 2016, 07:57:10 PM
I run my iron at 330 °C and did all of my soldering at 300 °C  until a few month back without problems. Now I'm in and out faster, but it takes some training to get to this point.

I use a chisel shaped tip for all my soldering.