Yes, you can use a loop of #14 solid copper wire like found in house wiring or stripped from a piece of Romex in a Weller soldering gun. It will not heat evenly though. It gets hottest at the point furthest from the terminals. I used a loop of wire for the tip in my Weller gun since it is free.
Getting there with the 'tooth extraction'!
I tried a few solder pumps but the GOOT brand is by far the best so far. Plus using nice thick desolder wick 3.0mm helps clean out the PCB holes.
Then, isopropyl alcohol with a soft brush and a blow out out of any residue/dust and we are ready for soldering of the replacement sockets.
Hope this helps anyone with a similar problem!
I tried a few solder pumps but the GOOT brand is by far the best so far. Plus using nice thick desolder wick 3.0mm helps clean out the PCB holes.
Then, isopropyl alcohol with a soft brush and a blow out out of any residue/dust and we are ready for soldering of the replacement sockets.
Hope this helps anyone with a similar problem!
You should be proud of yourself. Desoldering can be really crappy work! I say that because even today, I struggled with the tiny holes that are so popular these days. Desoldering gun didn't work. Different solder wicks, even with a little extra fux didn't work. The cheapie manual solder sucker did best. And for what it's worth, the ChipQuik didn't do as well as usual. When the holes are small, all you can count on is damage. Next time, I will try to remember to use the pointed tip on the soldering iron.
Your work looks like new.
Your work looks like new.
Thanks mate - I forgot to mention for any newbies, practice on an old board first!
I grabbed an old preamp PCB (failed experiment) and desoldered that - which led to the discovery that thin braid and inferior pumps just didn't work as well.
Thank goodness these DIY forums exist, all the help in here is much appreciated! 😉
I grabbed an old preamp PCB (failed experiment) and desoldered that - which led to the discovery that thin braid and inferior pumps just didn't work as well.
Thank goodness these DIY forums exist, all the help in here is much appreciated! 😉
Having trouble finding George's orange-stench vapor-degreaser/flux-remover after going thru the login-to-post cycle.
I've seen citrus-based terpene strippers for circuit boards to remove certain soluble conformal coatings...but in an industry that wanted all components on PCB's databased for their sensitivity to solvent damage and absorption. Polymers, obviously need attention, but oddly (to me) plastic package vs. ceramic-frit-seal semiconductors (mostly about IC's) had different moisture-proofness (for lack of a word similar to hydrophilic but for the terpene solvent...terpenophilic?).
The chemicals in still-in-use vapor-phase flux removers for non-aqueous cleaner are usually updated to something ozone-layer friendly. I cannot remember the name of one of the solvents, but think Miller-Stephenson is one supplier.
Still stinks, but differently. At least exhaust ducting was added.
I guess medical and aerospace are the only outlier large (US) industries with waivers to still use tin-lead solder to a significant degree.
Fast forward from the 80's manually stuffed PTH board to today's SMD boards. Solder paste is screened onto the pads by a machine that works similar to the machine that puts logos on a T-shirt at the mall. The boards then travel down the conveyer belt to one or more "pick and place" machines where robotic tool heads pick small parts from a reel and place them in the solder. Then the fun begins. After the board is populated, it goes to an IR reflow oven where it gets heated by IR lamps according to a certain time / temp profile.
The solder paste is an emulsion of micro fine metallic solder balls and a thick sticky paste of flux. The flux is solvent based so the solder paste must be kept in a controlled environment from the time it's made until it is used. Old or improperly stored paste will not flow right when heated leading to poorly soldered parts or "tombstoning." This is where some of your parts are standing on one end after reflowing and a really bad board looks like a graveyard full of tombstones.
The plastic used in the manufacture of most SMD IC chips is somewhat hydrophilic and will absorb moisture. They come in sealed packages from the manufacturer and must be stored in a low humidity environment. The large square QFP's, QFN's and BGA's are worse case. We had a wall full of nitrogen filled "dry boxes" in the solder assembly lab. Leave a tray full of chips out on a workbench overnight and you will hear them popping like popcorn in the IR oven. Our factory was in south Florida where the humidity is somewhere between excessive and raining almost all year round.
I made prototypes which ran in the solder assembly lab, not the production lines. There was a check box on my request form that asked "regular or unleaded." "Regular" boards could not be exported.
The solder paste is an emulsion of micro fine metallic solder balls and a thick sticky paste of flux. The flux is solvent based so the solder paste must be kept in a controlled environment from the time it's made until it is used. Old or improperly stored paste will not flow right when heated leading to poorly soldered parts or "tombstoning." This is where some of your parts are standing on one end after reflowing and a really bad board looks like a graveyard full of tombstones.
The plastic used in the manufacture of most SMD IC chips is somewhat hydrophilic and will absorb moisture. They come in sealed packages from the manufacturer and must be stored in a low humidity environment. The large square QFP's, QFN's and BGA's are worse case. We had a wall full of nitrogen filled "dry boxes" in the solder assembly lab. Leave a tray full of chips out on a workbench overnight and you will hear them popping like popcorn in the IR oven. Our factory was in south Florida where the humidity is somewhere between excessive and raining almost all year round.
I made prototypes which ran in the solder assembly lab, not the production lines. There was a check box on my request form that asked "regular or unleaded." "Regular" boards could not be exported.
When I was at TI in the Seattle area (so not as wet as Florida but still pretty damp) we'd bake QFNs at 125 ºC for 48 hours before soldering them on a board that would go to a customer. This was for one-off eval boards.
My DIY SMT reflow has all been done in Calgary. The relative humidity in my house is usually around 30-40 %, dropping well below that during a deep freeze in the winter. I have a humidifier on my furnace to keep the RH from dropping into the teens.
No issues with popcorn parts here.
Tom
My DIY SMT reflow has all been done in Calgary. The relative humidity in my house is usually around 30-40 %, dropping well below that during a deep freeze in the winter. I have a humidifier on my furnace to keep the RH from dropping into the teens.
No issues with popcorn parts here. Sometimes they go as far as removing the lead-free solder balls from a BGA and applying their own leaded balls. It's pretty wild. No wonder aerospace and defence stuff is so expensive.
Tom
We had the capability to "reball" BGA chips in our solder assembly lab too, but it was usually for a different reason. I was usually working with one off, or one of a very few, prototype boards. Often these boards were EVB's for custom RF chips or other SMD parts that our group designed. These chips were in short supply and cost thousands of dollars each. They could get reused two or three times before becoming useless.
I forgot to mention something IMPORTANT in my last post. There are several "no cleanup" or "water cleanup" solders available today that use a water soluble flux. The residue left behind from the use and imperfect cleanup of this kind of solder IS hydroscopic and WILL absorb moisture from the air. This may be OK a typical "maker" board that runs on 5 or 12 volts. It is NOT OK on a vacuum tube amp or other PC board that operates at a high voltage level.
There have been two instances of residue from some Chip Quik water cleanup solder conducting enough current to fire up and burn a Tubelab PC board. There was a customer with a burnt TSE-II board who had used Chip Quick solder and then left the board in his garage for several days. After finishing the amp all worked well for a few days before the fireworks began. I sent the customer a new board and got his burnt one back. There was a spot where the board had carbonized and burned and a few other places where some stray current had obviously flowed. Application of 500 volts to other traces with flux residue did not produce fireworks, so I left the board in the garage for two weeks. Reapplication of voltage produced fireworks which usually just popped and died. In two instances the fireball grew until the board was burnt.
I purchased the exact same solder he had used and was able to duplicate the fireworks on a new board. If you use any solder that is no-clean, or water clean, use IPA to remove all residue from the board before applying power.
I made a "really sloppy solder job" board with the same solder, let it sit outside and in the garage for several days, then tested it for conductivity and got some fireworks. I then scrubbed the board down with some 91% IPA from Walmart, let it dry in the sun for about an hour then brought it inside. After a day or two I tested it to 550 volts (the limit of my old Fluke 407D) with no fireworks.
Walmart has 3 grades of IPA, 50%, 70% and 91%. The non alcohol component is water, so get the 91% stuff or but 100% from Amazon.
I forgot to mention something IMPORTANT in my last post. There are several "no cleanup" or "water cleanup" solders available today that use a water soluble flux. The residue left behind from the use and imperfect cleanup of this kind of solder IS hydroscopic and WILL absorb moisture from the air. This may be OK a typical "maker" board that runs on 5 or 12 volts. It is NOT OK on a vacuum tube amp or other PC board that operates at a high voltage level.
There have been two instances of residue from some Chip Quik water cleanup solder conducting enough current to fire up and burn a Tubelab PC board. There was a customer with a burnt TSE-II board who had used Chip Quick solder and then left the board in his garage for several days. After finishing the amp all worked well for a few days before the fireworks began. I sent the customer a new board and got his burnt one back. There was a spot where the board had carbonized and burned and a few other places where some stray current had obviously flowed. Application of 500 volts to other traces with flux residue did not produce fireworks, so I left the board in the garage for two weeks. Reapplication of voltage produced fireworks which usually just popped and died. In two instances the fireball grew until the board was burnt.
I purchased the exact same solder he had used and was able to duplicate the fireworks on a new board. If you use any solder that is no-clean, or water clean, use IPA to remove all residue from the board before applying power.
I made a "really sloppy solder job" board with the same solder, let it sit outside and in the garage for several days, then tested it for conductivity and got some fireworks. I then scrubbed the board down with some 91% IPA from Walmart, let it dry in the sun for about an hour then brought it inside. After a day or two I tested it to 550 volts (the limit of my old Fluke 407D) with no fireworks.
Walmart has 3 grades of IPA, 50%, 70% and 91%. The non alcohol component is water, so get the 91% stuff or but 100% from Amazon.