| Electronics > Beginners |
| Soldered 0805 vs 0603 vs 0402 vs 0201 vs 01005 vs 008004 today :) |
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| Pedro147:
--- Quote from: TheDane on October 05, 2017, 08:00:59 am ---A quick question - your tweezers are non-magnetic, right? --- End quote --- Yes they are, thanks though :) It is just the flux sticking to them. |
| analogo:
--- Quote from: Mr. Scram on October 05, 2017, 08:26:25 am ---Hol' up. There are two 0603s, depending on which side of the pond you are? --- End quote --- There are also two 0402 and two 1005 :) https://en.wikipedia.org/wiki/File:SMT_sizes,_based_on_original_by_Zureks.svg |
| khs:
If you want to use tiny (ceramic) capacitors, take into account the capacity decreases with increasing voltage. This effect increases with decreasing size, so very small capacitors may not work. https://www.maximintegrated.com/en/app-notes/index.mvp/id/5527 shows the effect for 1812 vs. 0603. 0603 is not very small. |
| alexg:
Hi All, just accidentally found out today that this post has been replied recently, I did that experiment back in February and not it is October, I am still learning, however I've been hand soldering under microscope every couple days day since then and now looking back I'm thinking it is not as scary as it seems all the way down to 01005, 008004 would still require individual attention but also very doable. If I had to give an advise to anyone doing exactly same experiment for fun, I'd say you need: - Good tweezers, that one on the picture I bought 2 years ago for about $6 - $7, I also have couple sets of those relatively cheap ones, the one you can buy off ebay for like few dollars for bunch, those are good for nothing, they flex too much, they look sharp at first glance but under 10x you can see that tips are uneven, no feedback at all, I only use them to pick dried silicone glue off a tip of nozzle. Those that I have in the picture have nice sharp even tips, non magnetic, made from some kind of nice steel, I think all small footprint SMD rework starts with good tweezers. - Do not drink coffee, lift any weights, move lawn, or do any physical labor before this project, this will make your hands shaky and won't get anything right, you can pick a component from the tray, etc, but once you place it on board and need to hold it steady or nudge it a little your movements won't be as precise as needed. - Get PCB pads size right, as you can see in my experiment pads for 01005 and 008004 spread apart more than they suppose to so those components we constantly pulled to one side more than the other so I had to constantly correct it into place bumping off center, etc. I think with right pad sizes it would have been much simpler. - Do not heat it with hot air from the top, even at slowest airspeed it will blow those 01005 and 008004 right off, apply heat from the bottom under components. - Do not try applying solder paste to 01005 and 008004 pads, its just too small, apply flux, then drag some solder with iron over pads it will make a solder bump on each pad, then place your component there and when you reheat solder from the bottom it will grab your component. - And of course you need a microscope, non of those head mountable magnification glasses will do the job in my opinion, I used SE400Z with 20x for this project and that was just right. My three favorite sizes now are 0603, 0402 and 0201 with most favorite being 0402 0603 is nice and juicy package with, resistors have printed values, capacitors have nice large values, easy to grab, easy to place, easy to flip if its upside down right on the spot, pad is big enough so applying solder paste is easy, etc 0402 is my favorite, easy to maneuver under microscope, pad is still big enough to apply solder paste, it is very space saving, so when I design circuits I can fit more parts per square inch so to speak, love it. 0201 I like very much too for its space saving abilities, but unfortunately moving it from tray to board, grabbing with tweezers, etc, is more challenging when you need to do bunch of them, one or two, okay, but when you need to populate a full board it will be annoying, also flipping them right way is a nightmare, they stick to tweezers etc, Those are my personal thoughts and observations, it may or may not work for others but hopefully it can help you a little. I have to redo this experiment again now as a skills refresher :) --- Quote from: ebastler on October 01, 2017, 07:24:44 am --- --- Quote from: alexg on February 11, 2017, 08:10:38 pm ---Hi All, just wanted to share cool experiment I did today, I soldered few capacitors today on same board starting from 0805 down to 008004 --- End quote --- Just curious: What size of tip, and what diameter of solder did you use? Did you add extra flux? --- End quote --- |
| Howardlong:
I was intending to do a video of making something useful at the WLCSP close pitch, 0201 and 01005 level, but haven't got around to it. In the meantime here's a couple of pics of how to flash an LED from a single 1.5v cell. There are some design considerations here; first you need something off the shelf that will work with 1.5v, and preferably down to about 1v. Second, your LED needs 1.6v to show any signs of life. This design uses some 0.8V logic, two schmitt trigger inverters in a single package. One oscillates at about 2Hz to flash the LED, but to get enough voltage to light the LED you need to up the game a bit, so the second schmitt trigger runs at around 10kHz and operates a single stage charge pump. This won't work properly above about 1.9v input or so as the schmitt trigger's output clamp diodes will start to conduct so you'll get dim/bright rather than on/off. Even the diodes are very carefully chosen for minimum Vf and Ir. Now the dual Schmitt trigger, an SN74AUP2G14, is available in a number of package sizes, but the smallest is a 0.4mm pitch BGA, so I went for that. None of this SC70 rubbish. The LED still flashes (just) down to 0.95v. Board is BusBoard SP3T-50x50-G. I found out a while back when soldering BGA/WLCSP packages in this way is that you need to use lead free solder, the connections become very brittle and fragile otherwise. Also for these reasonably high impedances you need to put the board in an ultrasonic bath: when I was debugging this board, and couldn't get it to work, I could see the ionic reactions bubbling away under the microscope. At that point I chose to put it in the bath, rinsed and dried it off, and ten minutes later it worked perfectly. As soon as you apply any flux again though, you need to re-clean. For normal stuff, 0402 and 0603 are my typical targets: 0201 and smaller are typically more expensive, so for volume production it doesn't make sense unless size is a key design parameter. Note this is the package top view, when flipped on the board to break out, pinout is mirrored. Penny, SOT23 and 8 pin DIP for comparison FWIW, a few months ago I did do a video soldering a 0.5mm 20 pin WLCSP to a breakout board. https://youtu.be/e9mdGqu1aZ0 |
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