Know thy enemy: Open vias in BGA footprints

[Andrew Zonenberg] has crossed a line in his electronic hobby projects. The Ball Grid Array (BGA) is a type of chip footprint which most hobbyists leave to the professionals. But he’s learned the skills necessary to use them in his projects. Recently he ran a test batch to show off his soldering process and illustrate one of the errors a novice might make.

For those that are unfamiliar, the BGA footprint is notoriously difficult to accurately solder because it consists of a large grid of tiny points covering the bottom of the chip. There’s no way to get in there with an iron, so soldering depends on accurate placement of solder paste and chip, as well as a near-perfect reflow cycle. Often times it’s difficult for the professionals too. Many blame the heat-failure of Xbox 360 on the complications of the BGA connects for one of the console’s chips.

For this experiment [Andrew] wanted to show what happens if you include vias in the BGA footprint. It’s fine to do so, as long as they’re capped. But if a standard via is included, capillary action ends up pulling the solder down into the via instead of making a connection with the chip. The image above is a cross-section of one such uncapped via, seen on the far right.

[Thanks George]

DIY battery powered soldering iron

When it’s time to get started on a project and put our irons in the fire, we usually reach for a nice Weller or Hakko soldering iron. Unfortunately, that isn’t possible when we’re soldering something away from a wall outlet. Portable soldering irons usually range from slightly to completely terrible, and [Adam] thought he could do better. He put together an Instructable for a portable battery-powered soldering iron that’s extremely easy to build.

[Adam]‘s project mounts a standard Radio Shack soldering iron tip in an E-10 flashlight bulb socket. Power is provided by 6 Volts of AA batteries, with a small switch added for the obvious safety concerns. Although [Adam] could have added a small project box, he chose to build his entire project around a piece of wood. This is an excellent choice in our humble opinion; wood doesn’t melt, has very low thermal conductivity, and anyone using this iron should be smart enough to turn it off if the handle starts smoking.

While this isn’t the best possible portable soldering iron (we’re partial to the disposable-lighter-fueled torches with a soldering iron attachment), it’s much better than the ColdHeat soldering iron that received consistently bad reviews.

Edit: [Adam] updated his build to be a little safer after this story was posted. We changed the original title pic to reflect this; here’s the old one.

Hackaday Links: January 24, 2012

Open source engraving

[Scott] wanted to do some v-carving with a CNC router, but couldn’t find software to generate GCode that didn’t cost hundreds of dollars. He ended up doing the sensible thing and wrote his own that will generate tool paths from CXF fonts. We’ll be bookmarking this for when our router project is done.

Improving Genesis sound output

Dissatisfied with the sound output on his Sega Genesis, [Drakon] installed a few mods into his console. How much could it really affect the sound? Listen to the video. The changeover happens at 0:50. Impressive. Now if only the chiptune scene would get into Segas.

Yes, we did, and now we’re seeding

Here’s an alternative to Thingiverse: The Pirate Bay has a new category for 3D-printable objects. The best file so far? A 1970 Chevelle. US Copyright law does not protect (most) physical objects, so it’s not illegal. Honestly, we can’t wait for somebody to take this to the courts; It’s sure to be an interesting case. Somebody upload a ship hull design and give the EFF a buzz.

Just be glad it’s not a QFN

[Mikey] was pulling a PDIP ATMega8 out of a socket with pliers and a screwdriver and broke the RESET pin. Ouch. He fixed it by soldering on a lead from a resistor. We’ve all done this before, but [Mikey]‘s results look really good. Here’s the gallery.

This might be fake

If you want a second analog stick for your 3DS, you could wait a month and buy a Circle Pad Pro, or install a PSP analog stick. We’re not sure how this would work – the Circle Pad Pro works over IR, and we’re not seeing an IR transmitter on this build. Here’s the source if anyone wants to give this a shot.

A very detailed reflow oven build

smd-solder-reflow-oven

If you do a lot of SMD soldering, a reflow oven is the fastest and most efficient way to get all those tiny components attached to your PCB. [Frank Zhao] saw the reflow ovens we featured here over the last few weeks and figured he might as well show off his rig as well. We’re certainly glad he did, because his very thorough writeup is a great stepping stone for anyone looking to construct a reflow oven of their own.

Like many others, he started off with a used toaster oven, modifying it to be controlled directly via the power cable rather than the oven’s dials. He built a small PCB to regulate the oven, which features an ATmega32u4 and thermocouple to keep the temperature in check. Control of the heating element is done using a solid state relay, for which he built his own heatsink.

He studied the reflow profile of the solder he would be using, programming the microcontroller to regulate the heating/cooling process without requiring any user input, aside from turning the oven on.

Check out the video below to see a brief overview of his system, and be sure to swing by his writeup to take a look at all the build details. There are a handful of additional videos along with plenty of pictures there, walking through each step of the process.

Continue reading “A very detailed reflow oven build”

Video: Soldering our PIC development board

For those of you who followed along with our Eagle CAD series, here is the final payoff where we assemble the circuit board that was designed. In this video, [Jack] explains where things will go on the board and then shows you how to solder the parts. For the advanced folks out there who haven’t moved to solely surface mount parts when you can get away with it, he shows an easy way to solder the processor, which is a TQFP-44 part. This can seem like a daunting task but it really isn’t.

If you would like to make your own board like this, you can find the files here. Please note that although this board shouldn’t have any issues, we haven’t tested it ourselves yet. [Jack] is going to do some videos about a different topic for a few weeks but will pick back up with this board again when they are done.

Video is after the break. Continue reading “Video: Soldering our PIC development board”

One-man SMD assembly line shares a lot of tips about doing it right

Need to use that antiquated hardware that can only be connected via a parallel port? It might take you some time to find a computer that still has one of those, or you could try out this USB to Parallel port converter. It’s not limited to working with printers, as the driver builds a virtual parallel port that you should be able to use for any purpose. But what we’re really interested in here isn’t the converter itself, but the build process. [Henrik Haftmann] posted a three-part series of videos on the assembly process, which you can watch after the break.

The build is mostly surface mount soldering with just a handful of components that need to be hand soldered. The first of his videos shows him stenciling solder paste onto the boards. From what we can see it looks like he built a nice jig for this using scrap pieces of copper-clad which match the thickness of the PCB, and hold it and the stencil securely in place. There’s a bunch of other tips you can glean from the videos, like the image seen above. It’s a clamp that holds the PCB and USB jack together while they are soldered.

If you’re ever thinking of assembling a bunch of boards you should set aside thirty minutes to watch them all.

Continue reading “One-man SMD assembly line shares a lot of tips about doing it right”

How to add modular tools to your soldering platform

[Patenomics] has had some trouble finding a suitable place to work on projects in his tiny apartment. Lately he’s taken to using the stove top as a soldering platform and was looking for ways to protect the stove while adding functionality. He built this soldering platform from a couple chunks of pegboard and some hardware store parts. He’s in for under $15 and has a really functional platform that may be worth adding to your solder station.

The two pegboard pieces are held in place by threaded rod and some nuts. This hardware also lends itself to adjustable feet so that you can make the platform level and stable. The holes in the top and bottom sheets line up to receive and securely position some additional tools. Here you can see that bendable copper pipe keeps some alligator clips right where they’re needed, but future plans include adding lights, clamps, and lasers.

This makes a nice work platform to go along with your other portable electronic bench tools. But if you’ve really got the itch, you’ll eventually outgrow all of this and then it might be time to find yourself a hackerspace to join.