Lead free solder in laptops - Page 1
Forum section: electronics / beginners

author: cswilsn
author_rank: Contributor
timestamp: September 11, 2013, 03:35:59 am
content: Hey Everyone,I'm having an issue with a laptop i'm trying to remove a few components from, this darn lead free solder is just plain horrible to work with.I have a pretty decent hakko station, but cant seem to get the solder to break free long enough to suck it up with my solder pump. I have also tried wick with no luck, tinning, etc, all the way up to 500 degrees Celsius.Does anyone have any tips/tricks they use, besides just a damn hot iron with a quick rise time?Thanks!CSW

author: c4757p
author_rank: Super Contributor
timestamp: September 11, 2013, 03:40:32 am
content: I doubt the problem is that it's lead-free solder. The vast ground and power planes in the board are soaking up the heat. You're basically trying to desolder from a large copper sheet. Good luck

author: cswilsn
author_rank: Contributor
timestamp: September 11, 2013, 04:19:55 am
content: I figured that had a lot to do with it.I got one out, not sure how. What about hitting it quick and hot with suction, like a high end desoldering gun/pump?i'm assuming drilling it out might cause damage to the board...I'm got a really small precision drill press but i'm not really sure =-)It'd be nice to know a bit more about it, I get a lot of these dead laptops dropped off and it seems to be a waste.CSW

author: Rick Law
author_rank: Super Contributor
timestamp: September 11, 2013, 04:33:55 am
content: Quote from: cswilsn on September 11, 2013, 04:19:55 amI posted a similar question not realizing the ground plate was my problem then. The solutions proposed byDavid_AVDlooks good -"Chip Quik"-- check out that thread.https://www.eevblog.com/forum/beginners/best-way-to-remove-a-3296-trimpot/msg221210/#msg221210ps: thanks again, David_AVDRick

author: nanofrog
author_rank: Super Contributor
timestamp: September 11, 2013, 04:42:49 am
content: Asc4757pstated, power & ground planes really pull the heat down. And if you continue to try to desolder the part/s, you'll end up damaging the PCB itself.To solve this, you'll need to get some heat to it from the bottom side of the board (i.e. electric skillet; used for pre-heating, not hot enough to actually melt the solder). This brings the entire board's temp up enough you'll be able to use your iron successfully, and not damage the board in the process (get board to ~150C).You can even use a skillet on the stove, but I wouldn't use a pan that's also used for food (lead or not, the flux has some nasty chemistry I wouldn't want anywhere near something I'm going to eat).There are also inexpensive pre-heaters available if you're interested in that route, or if you buy an electric skillet solely for this purpose (no food use), it can also be used for reflow soldering (need solder paste). You could even add temp control if you want.Might be of interest:https://www.sparkfun.com/tutorials/59#Skillet

author: cswilsn
author_rank: Contributor
timestamp: September 11, 2013, 06:25:39 am
content: I was able to have some success with the hot air gun, I put the board in a PCB Vise with the connector against gravity and it fell right off after a few minutes, I heated the board slightly under the infrared heater to prevent anything from cracking/getting damaged.I also used some thermally insulated foil tape around the other items I was blowing hot air near to keep them from coming off with a slight bend in the outer edge of the tape to kind of force the air away from the rest of the components (well as much as it could, kind of like a mickey mouse hot air attachment).I've had to remove chips before, and other SMD items but these power jacks in laptops are hard as hell!Thanks for the tips! It got me started in the direction I need to go. I already ordered a few pieces of chipquik and will have it here in a day or two, i'm going to use it for the replacement, and probably will in this case from now on (if it works like it does for everyone on youtube!).CSW

author: ablacon64
author_rank: Frequent Contributor
timestamp: September 11, 2013, 11:04:09 am
content: I always preheat the board and add new leaded solder to the joints. It helps a lot. Laptop DC Jack is really a pain. I guess that Hakko 808 desoldering pump must be a great tool for that, I'm thinking about getting one.

author: dfmischler
author_rank: Frequent Contributor
timestamp: September 11, 2013, 12:59:20 pm
content: I didn't notice that anyone else mentioned that either with or without pre-heat a 3.2mm tip can move a lot more heat than a 1.2mm...

author: G7PSK
author_rank: Super Contributor
timestamp: September 11, 2013, 02:30:05 pm
content: The other problem with laptop power jacks is the tightness of the pins in the holes, very often they seem to be a press fit and as soon as you then get any solder into the holes they are jammed in, the best way of removal is often to cut the pins from the jack body and remove each pin in turn or even solder onto the cut pins.I think from my own personal experience that lead free solder being almost pure tin absorbs so much copper from the through hole plating that it forms some form of bronze, I have had the solder become so unmeltable that I could not extract the pins using a 250 watt iron that quite easily will solder a truck size radiator.