Best Technique For Soldering & Inspecting BGA Chips – Voltlog #352

Welcome to a new Voltlog, in this video I’m gonna show you my method of soldering BGA chips because in the previous video where I showed the eMMC to microSD card adapter PCB I mentioned I don’t use any stencil for soldering the WFBGA153 package. I’m also gonna be showing you a method for easily checking if the BGA chip is soldered correctly or not.

So let’s start by talking about the BGA package that I used in this project, it’s the WFBGA153, this package has 153 lead-free balls, each is 0.3mm diameter and the pitch between balls is 0.5mm. Now the footprint that I used has 0.35mm pads for each of these balls, which means that when you consider the 0.5mm pitch, in between pads you are left with just 0.15mm which is roughly 6 mil, you basically can’t route any tracks in there using any of the standard PCB services.

PCB Solder Trainer | Voltlog #328

Welcome to a new Voltlog, the title probably gave it away already, this video is about a pcb solder trainer that I designed to measure ones soldering skills. This is not a new idea they have been around for a long time and there have been different designs around but you can join me in this video to see how I designed mine. 

I remember how soldering felt back when I was just starting tinkering with electronics, I think I was about 7-8 years old and I had this big communist soldering iron that I got from my father, this was about 100W rated, it had a small flashlight incandescent bulb and it used this thick copper wire as the soldering tip. It was great for soldering big stuff due to the power rating and the ability to transfer that heat efficiently. I remember I was using too much solder, I was making these huge solder blobs.

So back to the board design, let’s take a closer look at what I have in here. On the left we start with 01005 passives, these are 5 resistors in series and at the end of the string there is an LED. The LED has to be bigger because you can’t get them that small so the LED starts at 0402, imperial size. If you get all 5 resistors and the LED soldered right and you apply 5V to this header, the LED should light up and that’s your indication that you’ve at least electrically got everything connected right.

And the size of the components then goes up to 0204, 0402, 0603, 0805, 1203 then we have some resistor networks which I believe are 4×0603. Then we have some SOT23 devices these can be dual diodes also connected in series that will light up an LED.

Depending on the type of LED you choose and it’s forward voltage you can calculate what resistor values you need so the LED will light-up. In general a green LED with 47ohms resistor should work for this and the pads for each of these passive components are the hand solder type which makes them wider so that’s something to help you out.