I bought one of these boards from you and after watching this video I now understand that you are not doing this for the money. Thank you for this labor of love. I am looking forward to going to Video #1 and starting the series.
👍👍 Best method is to avoid these bridges is to extend the footprint pad length to double or more. Apply solder pase on the outer edge of the pad. When we heated up the board. Paste flows towards the chip. Because of this longer pad, solder bridges will be very less. But only problem the board width will increase.
I only came here to learn more about ARM, but I am pleasantly surprised by the expert soldering demonstration. Wow, so at 8:55 you remove the excess solder, but you don't have to worry about the (small tiny) pins still having solder between them?
if I can recommend something. I'd suggest making a rotary switch system for continuity / shorts and have a socket you shove this into and then turn the switch one by one with the VOM connected to that. Plus such diagnostics could also be done with a semiconductor diagnosing it within seconds. This would further automate your manufacturing and confidence for delivery. Let's say you used an arduino or another programmable chip, you could have a program built in that measures the typical tolerances and anything pins that have that transistor / diode continuity could be set as a bias so the diagnostic block simply gives an ok on the entire board with those shorts.
Yes, I do this with pogo pins currently. The video is meant as a response to viewers telling me that soldering chips are hard to do. I wanted to provide some inspiration with how I did it back then. Interestingly, When I did this similar series a few years ago, I made a breadboard with about 60 LEDs and created a program to cycle through the LEDs. Not a good idea when there could be shorts, but it worked for the most part.
I failed to mention during the process of dragging the solder is that I use the iron to remove many of the bridges. If you remove the excess solder from the iron tip using a soldering iron sponge or the metal wool, you can go over those bridges and suck up the solder on the bridged pins with surface tension. I use the solder wick as a last resort.
That gave me new respect for small volume makers. That was a fair bit of labor for a relatively low price product. I was surprised that the small amount of solder paste was more than enough. Applying it in the middle of a row of pins makes it obvious why you need to drag in both directions. I'm still intimidated by the thought of doing SMD soldering.
Thanks. The process in the video was long because of all of the explaining and setup, but it only takes about 5 minutes for each board to get the SMD chip on the board and soldered correctly.
If I remember when I was soldering chips at work I used the same principle like soldering 2 corners pins, put some "liquid" flux and then right away used the soldering pan to drag over each pin moving in one pass. And there was no bridges at all at the end. It was like magic!
@@glewiss6696 Yes, I often do this for "looser" pin pitches. I like using solder paste as it gives you the freedom to align the chip perfectly and doesn't move around. A while back, when trying the soldering a single pin method, I would start by using clamping tweezers to keep the chip in place, but the chip would always slip off the pads since they were so small. It would take a good 10 minutes to play with the alignment. With the solder paste method, I just lay the chip, nudge it, and hot air freezes it in place. I did 20 boards after the video, all of them done within 1 hour.
Thanks for sharing the process. I personally use a hot plate or a reflow oven with a PID controller depending on the complexity of the board. One thing I also considered but never try was an ultrasonic bath to clean the flux mess. Have you tried that? Again thanks for sharing :-)
Oh and another question if I may ask. How would you test if there was any bridges in a non breakout board. I mean a real board. Are you adding in your PCB design specific test points? Would be great to see a video just on that. I always find difficult and risky to assess a good working board before plugging in on my laptop without the risk of breaking everything up 😅
I have considered an ultrasonic cleaner; I just never made the plunge. The solder left over by the through-hole soldering is easy to remove, just by scraping and then an alcohol wipe, but I'm sure the ultrasonic cleaner would be better. I saw Louis Rossman's technique that I would like to try, but it is costly. Most of the demonstrations here will be cost-sensitive as I want anyone with basic tools to succeed.
@@mic03311 Never stop asking questions. I enjoy them. Pogo pins are your friend when testing boards for products. That would be a really fun video to make. But, the process is a bit different. You can't just test for solder bridges in an economical setup that I know of. When assembling a board, the solder is applied with a stencil, then all of the components are placed and then reflowed. Now, you have all of those components giving you varying test results, so you will need to determine the proper voltages, resistances, etc., for each line and make a jig/setup for testing that particular board after assembly. You can use pogo pins for this, and the pogo pins can provide the measurements using another microcontroller to test these. You wouldn't want to do the "walking" to find shorts in production as they would be too slow. Alternatively, you could just have China assemble the boards, and they do the tests.
Please share what magnifying headband you're using. I'm looking for something good and like that. Would be nice if you could take a picture in to the lens so I can see how it looks with the PCB and components with the magnification. Maybe hard to do.. :)
