Roll Your Own 64GB SD Card From An EMMC Chip

It’s well-known that buying Flash storage devices from cheap online retailers is fraught with danger. Stories abound of multi-gigabyte drives that turn out to be multi-megabyte ones engineered to falsely report their capacity. So when [Jason Gin] found a source of 64GB Toshiba eMMC chips for only $6 per device he bought a few, but was prepared for disappointment.

To test them, he decided to use an SD card interface. There are minor differences between eMMC and SD, but the interfaces are electrically the same and in most cases an SD controller will happily do business with an eMMC. It was not however an easy task to connect the two — these eMMCs were in BGA packages, hardly the easiest ones to work with. He resorted to dead-bug soldering the relevant interface wires to SD lines, and connecting up his computer.

His first attempt was something of a failure, wiring the chip to the PCB of a cheap USB-to-SD adaptor. This did not put him off though, he followed it up by cracking open a very old 2GB SD card that contained a PCB instead of being potted, and soldering his eMMC in place of its Flash and controller. This even fit in the original SD housing, and met with success when plugged into more reliable SD card readers. He was thus able to confirm the capacity of his chips.

His blog post is worth a read for more than just the very fine soldering involved. He takes us through some of the intricacies of SD interfacing, as well as talking at length about the decoupling and termination required to make a reliable connection. We particularly like his use of an area of unconnected BGA balls as prototyping space for decouplers.

If you marvel at the exceptional dexterity required for hand BGA work, we’ve a couple of other treats for you. There is this TI infra-red sensor BGA soldered to a piece of stripboard, and this wafer-level chip package soldered to an SOIC prototyping board.

DIYing Huge BGA Packages

One day [Andy] was cruising around eBay and spotted something interesting. Forty Virtex-E FPGAs for two quid each. These are the big boys of the FPGA world, with 512 user IO pins, almost 200,000 logic gates, packed into a 676-ball BGA package. These are not chips designed for the hobbyist. These chips are not designed for boards with less than six layers. These chips aren’t even designed for boards with 6/6mil tolerances from the usual suspects in China. By any account, a 676-ball package is not like a big keep out sign for hobbyists. You don’t turn down a £2 class in advanced PCB design, though, leading to one of the most impressive ‘I just bought some crap on eBay’ projects we’ve seen.

halfbuiltThe project [Andy] had in mind for these chips was a generic dev board, which meant breaking out the IO pins and connecting some SRAM, SDRAM, and Flash memory. The first issue with this project is escape routing all the balls. Xilinx published a handy application note that recommends specific design parameters for the traces of copper under the chip. Unfortunately, this was a six-layer board, and the design rules in the application note were for 5/5mil traces. [Andy]’s board house can’t do six-layer boards, and their design rules are for 6/6mil traces. To solve this problem, [Andy] just didn’t route the inner balls, and hoped the 5mil traces would work out.

With 676 tiny little pads on a PCB, the clocks routed, power supply implemented, too many decoupling caps on the back, differential pairs, static RAM, a few LEDs placed just for fun, [Andy] had to solder this thing up. Since the FPGA was oddly one of the less expensive items on the BOM, he soldered that first, just to see if it would work. It did, which meant it was time to place the RAM, Flash, and dozens of decoupling caps. Everything went relatively smoothly – the only problem was the tiny 0402 decoupling caps on the back of the board. This was, by far, the hardest part of the board to solder. [Andy] only managed to get most of the decoupling caps on with a hot air gun. That was good enough to bring the board up, but he’ll have to figure some other way of soldering those caps for the other 30 or so boards.

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Upgrading a Nexus 5 eMMC to 64GB

Sometimes we feel confident in our soldering skills (but only sometimes) — and then we see something like this done.

IMG_20160324_205427Someone over on the XDA developers forum managed to upgrade his Nexus 5 from 16gb to 64gb — and not only that, upgraded the eMMC type from 4.5 to 5.0 so it writes and reads much faster.

While the details on the actual conversion are a bit vague, we did manage to dig up another video of someone replacing an eMMC chip from a Samsung Note 2.

It most certainly is possible… but would you look at the size of that chip!

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IR Rework Station

Modern surface mount components often need special tools for rework. However, those tools can be expensive. [Michael Skrepsky] wanted an infrared rework station, but didn’t like the price. So he built his own.

According to [Michael] he used a lot of scrap in the construction. . He used K-type thermocouples, optotriacs, triacs, a 20×4 display and, of course, an Arduino. An old bathroom heater, along with a 600W and 100W halogen bulb work as heaters.

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Hacklet 99 – Soldering Tools

If there is one tool every hardware hacker needs, it’s a good soldering setup. Soldering irons, heat guns, reflow ovens and the like make up the tools of the trade for building electronic circuits. Spend enough time working with a tool, and you’ll find a way to improve it. It’s no surprise that hackers, makers, and engineers have been hacking their soldering tools for decades. This week’s Hacklet features some of the best soldering tool projects on Hackaday.io!

hakkoWe start with  [Kuro] a Hakko 907 based Soldering Station. Hakko 907 and 936 soldering station clones from the Far East are available all over the internet. While the heaters work, none of them have very good temperature controllers. [Kuro] turned a problem into a project by building his own soldering station. These irons are rated for 24 V. 24 volt power supplies are not very common, but it’s easy to find old 19 volt supplies from discarded laptops. [Kuro] found that the lower voltage works just fine. An Arduino nano controls the show, with user output displayed on a 2 line LCD. The finished controller works better than the original, and probably would give a real Hakko model a run for its money.

reflowNext up is [Sukasa] with Reflow Oven. When MakerSpace Nanaimo needed a reflow oven, [Sukasa] jumped in with this design. The idea was to create an oven that looked unmodified – just think of it as the toaster oven of the future, or the reflow oven of today. A Netduino plus 2 is the main controller. User information is displayed on a color TFT LCD. This oven is even internet connected, with an internally hosted web page and JSON data feed. The Netduino controls two beefy Solid State Relays (SSRs). The SSRs handle the dirty work of switching the oven’s heating elements. Two fans keep air moving to avoid hot spots. Precision temperature sensing is achieved through a pair of Adafruit MAX31855 breakout boards reading thermocouples.

plateNext we have [Jaromir Sukuba] with Soldering preheat plate. When soldering surface mount components, like QFN or BGA parts, it helps to pre-heat the whole board. There are commercial products to do this using hot air and other techniques, but it really comes down to making a hotplate. [Jaromir] figured he could do a pretty good job at this, so he built his own with a 3mm aluminum plate. Heat comes from 6 resistors in TO-220 cases. A Microchip PIC18 monitors a thermocouple and keeps things from getting too hot. For power, [Jaromir] had the same idea as [Kuro] did, and used a 19V power brick from an old laptop.

gooseFinally we have [Alex Rich] with Locking ball and socket gooseneck system. [Alex] came up with the Stickvise, so it’s fitting that he comes up with an awesome upgrade for it. We’ve all fought with “helping hands” while soldering. You never get them at quite the right angle. This system fixes that with a simple ball and gooseneck setup. [Alex] saw a similar design and printed it out. While it worked, the pieces popped apart too easily. [Alex] redesigned the system, adding a threaded locking ring. These new goosenecks stay put, holding your work exactly where you want it.

If you want to see more soldering tool projects, check out our brand new soldering tools list! If I missed your project, don’t be shy! Just drop me a message on Hackaday.io. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

BGA Hand Soldering Video

By 2016, most people have got the hang of doing SMD soldering in the garage–at least for standard packaging. Ball Grid Array or BGA, however, remains one of the more difficult packages to work with [Colin O’Flynn] has an excellent video (almost 30-minutes, including some parts that are sped up) that shows exactly how he does a board with BGA.

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Fail of the Week: OpenMV Kickstarter Project Hits Manufacturing Snag

Making stuff is hard, especially when you are making lots of stuff. The OpenMV Cam project knows this, because it has hit a problem while putting together their cheap machine vision module. The problem is with the BGA solder balls that connect the image sensor to the main board.

openmv-thumbWe’ve covered this intriguing project before: the aim is to build a small, cheap module that can run image processing algorithms to easily give robots sight. The sensor is a Ball Grid Array (BGA) package, which means there are a grid of small solder balls on the back that form the electrical connections. It seems that some of these solder balls are oxidized, preventing them from melting and fusing properly with the board. This is called a head-in-pillow defect, because the ball behaves like your head when you lie down in bed. Your head squishes the pillow, but doesn’t merge into it. There are 38 balls on the OV26040 image sensor and even a single bad link means a failure.

The makers of the project have tried a number of solutions, but it seems that they may have to remake the ball links on the back of each sensor. That’s an expensive process: they say it will cost $7 for each, more than the actual sensor cost initially.

A few people have been posting suggestions in the comments for the project, including using solvents and changing the way the sensors are processed before mounting. We’d like to see them overcome this hurdle. Anybody have any suggestions to quickly and cost effectively move the manufacturing process forward?

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