You have the pin numbering incorrect for 5- 8 , it should be 5 to 8 from bottom to top.
There are a couple of options:
You might be able to carefully scrape off the solder mask material (gentle scrapping with an exacto knife) covering some of the vias and traces, and make either repairs or new wired connections to them.
Do the vias of pins 3,4 and 5 go thru the board to the other side. If so then wrap the pin of the chip with a turn or two of some 30 AWG solid wire such as used for wire-wrap (stripped of insulation) and touch it with a hot iron and a tiny bit of solder to make a secure joint; then push the other end of the stripped wire thru the vias and solder on the other side. Only use the remaining solder pads on pins 1,2,8,7,6 to hold the chip to the board, don’t worry about the others as long as the connection to the via is made.
Pin 5 might be difficult in that you will have to insert the wire in the via first, then wrap and solder to the pin.
Another approach is to superglue the traces for 3 and 4 down to the board and solder to them from above after the chip is down and held with the other pins.
Pin 5 you may be able to create a “pad” and trace using the 30AWG wire laying it flat on the board and soldering to the via after removing the solder mask material.
Good luck to you, be sure to show us some pictures of the final result.
I need some help with tips and tricks for soldering specific things.
First when I need to replace a driver and driver is soldered inside, and of course I can’t do that like they do on machine, I must to solder from counter side, I always have problems to solder and secure a driver to the pill, simply a solder wont stick.
I use a very hot soldering iron and try with flux, paste, results are same, I cant solder this two things, other problem is that I can’t apply too more heat or I can damage the driver.
Second situation where I need some tips and trick is where connection points are too close for wire and enought away that I can bridge only solder from one point to another. If I put solder on one dot and on other and when I try to connect that points a solder only increase on that dots and dont want to melt together and connect.
1. More power and more thermal mass. Use a big tip and more than 60 W. Both parts are tinned which helps a lot. You only need to make it hot enough for the solder to melt. But heating up the pill needs some energy. Try to clamp it in something that doesn’t sucks the heat away.
2. Use a wire. A wire without insulation. Just put a long strip over both pads, solder them and cut off the excess.
I use 80w soldering iron 480 degrees and pill is damn too hot I’m afraid to damage the driver and LED, solder is melting but wont stick in that place where I want.
I already do that but it looks awful as you can see on the picture, and on other side you can see I managed to bridge some soldering points to one… which is pain in the ass and very hard to do, it is best solution but I can’t do it easily.
vidramon, does your soldering tip easily melt solder? Is your tip dirty or black in some areas?
I really think your problem is lack of heat. 480 degrees seems low. I work with nice Metcal soldering stations and at home I have a Hakko FX-951 and run them at 700 degrees (750 - 840 using lead-free junk). Try to up the temp if possible.
If he could pre-heat the pill on a warm hot plate (like ~170C) then he could use the soldering iron to just do the final melt. Problem when you use iron to heat entire pill to temp is the tip oxidizes and hard to clean off enough to make good joint. On top of that if the gap is too big the solder will not want to connect anyways, using thin solid wire to bridge gap is probably a good suggestion from above.
For second LED strip problem I’m not sure why you don’t just curl wire in a loop instead of using hard small piece. If you want very good visual finish there is 90 degree and 45 degree connectors made for clean LED strip installs I believe.
I’m using an Elsold Sn60/Pb40 which is German brand it is not probably top notch but it is neither bad.
Flux is Elsold Elflux 2001.
Yes I see Mat’s video about that, he also pre-heated a pill before do a soldering and in his case soldering was quite sucessefull. I don’t have any equipement to pre-heat pill, only ordinary hairdryer, but I think it don’t have enought temp to do that…
Yes I know about that LED connectors but they do not work in my case, it is complicated to explain but I can’t use them… And I need to use as little as possible conductor for two reasons, first is visual effect and second there is too many letters and a big drop of voltage and current will be since there is a lot of conductors.
I managed to do something, changed a top of soldering iron to the smallest one that I have and do a very very precise work and result is good as you can see on pictures, it need a lot of solder that can melt and connect two points but thats is it how is it.
Hhmm, I never use a pointy iron tip anymore - never. Smallest I'll use is a smaller chisel tip. I only use chisel tip and bevel tip, and only Hakko brand.
You need heat to get to where you want it and a wet flat surface works much better. By wet I mean wet the tip with solder - difference it makes is huge.
I haven't had much trouble bridging small gaps. Trick for drivers on brass pills is plenty of flux and hold the wet tip on the brass for a couple secs first - that's all you need to do to pre-heat it.
Electricians need a ton of effort when it comes to tidying up their work desk. Here, we fix components like Printed Circuit Boards (PCBs), diodes, transistors, inductors, and integrated circuits (IC), so we’ll naturally get a busy and messy environment. Has anyone used soldering mats like an excellent partner to serve as a protective layer and a tool keeper?
Yesterday I soldered 0402 NTC to Convoy’s pcb so that LD-A4’s thermal protection would work. 0402 is starting to be too small for hand soldering but I managed.
You can use regular pcb’s and LD-4A drivers external thermal protection. You need to scratch some insulation off from pcb’s positive path and solder NTC to that. Other end of the NTC is for the drivers thermal wire.
I slip a wafer of wood between the mcpcb and the heatsink/pill/shelf. Then solder with the biggest tip I can use safely and very hot, very quick. Pre-tin the pads on the mcpcb as well as pre-tinning the wires.
