Tools for assembly
Here are the tools and materials you will need for assembling your own ZeroPhone.
In case you don't have the suitable tools&materials, you're exceedingly likely to find all of these at a hackerspace - here's a list of hackerspaces for a start, and if you don't have a hackerspace nearby, a university's lab or someone's home workshop will likely be available. In the worst case, you should be able to obtain all the tools by yourself at a good price (<$50).
- 1 Kit assembly
- 2 Self-assembly
These are the tools/materials you when assembling a ZeroPhone from an SMD-ready kit - like the kits that will be available through the giveaway.
These are the tools&materials you will absolutely have to use - some of them (i.e. solder wick and solder) might be supplied together with your kit (depends on where you get the kit from).
There are plenty of soldering irons and soldering stations that will be suitable for ZeroPhone kit assembly. What are the things you need to know when looking for the tool you'll ultimately use during ZP assembly?
Soldering iron tip
Whether you're using a regulated soldering iron, an unregulated one, or one that comes with a soldering station, this is one thing that's universally true.
During soldering, one of the most important parts is the tip of the soldering iron. For the majority of regulated irons, the tips are changeable and can be swapped for tips of different size and shape. With unregulated irons, tips are usually not sold separately - if the tip is faulty, you are better off buying a new soldering iron.
- The tip needs to be clean in a way that solder can stick to it. If the solder doesn't stick to the tip and it's hard to melt solder with the tip of the soldering iron, the tip needs to be replaced - it will bring more frustration than results. Copper tips can be sanded to somewhat restore their function, however, tips made from other materials will only get destroyed further by sanding, so be careful before you apply Internet advice in hopes of making your soldering iron work better. - The tip needs to be wide enough to transfer heat quickly, but small enough to be usable while soldering 2.54mm (0.1in) pin headers. Simply put, "needle" tips usually supplied with cheap soldering irons will not work that well, neither will the huge tips on irons used for soldering high-thermal-capacity things (i.e. 60W soldering irons) - the sweet spot is in the middle. As a rule of thumb, a 2.5mm-wide chiseled tip will get you a long way.
Q: Why does tip width matter? Can't I just use one of these cool needle tips that come with cheap soldering irons by default, or a very wide tip to make sure I'm heating up everything to the max?
A: When soldering iron tip touches the PCB and the pin you're soldering, it starts heating them both - transferring energy to them. As a result of transferring the heat energy, the soldering tip's end cools down - and if the flow of heat energy from the iron's heating element to the tip is not good enough, the solder that the tip is touching will cool down and likely solidify again, or become viscous. In order to make heat energy flow quicker from the soldering iron's heater to the soldering iron's tip, you need to have the least thermal resistance on the path from the heater to the tip - and the wider the tip, the lower is its thermal resistance. In short, the soldering tip's "body" width controls how quickly the soldering iron's tip "replenishes" its energy from the iron's heating element, which severely impacts your solder joint quality and your soldering experience overall.
Unregulated vs regulated soldering irons
Usually, the cheapest soldering irons don't have any temperature regulation - which is one of the things that makes them so cheap. However, they're also less efficient when it comes to soldering - since 1) they're more likely to overheat the PCB pads, resulting in bad connections 2) they will burn flux quicker, which will require using some additional flux. While you absolutely can use a cheap (~$5) soldering iron, it's likely that it won't perform all that well and won't result in the kinds of soldering you'd like to rely on when it comes to a day-to-day use device. Nevertheless, it's absolutely possible to assemble a ZeroPhone with an unregulated soldering iron.
Soldering station vs soldering iron
Having explained the "regulated vs unregulated" choice, the next choice you might have to make is as follows - "having access to both a regulated soldering station and a regulated soldering iron, which one do I use?".
What if you have a lot of choice, i.e. you're looking for new soldering equipment to buy? Here are some options:
- A soldering station with a soldering iron that accepts one of these tips:
- 900M-T-2.4D tip - T12-D24 tip - A tip similar to one of the listed above
- TS100/TS80 soldering iron with a TS-D24 tip - it's on the more expensive side, but it's a perfect fit for soldering together something like a ZeroPhone
If you have an unregulated soldering iron, it's best if you use leaded solder. You can use lead-free solder, provided it's of good quality and your soldering iron is capable of melting it with the same efficiency that it can melt leaded solder. Usually, this requires a regulated soldering iron or soldering station.
In addition to all the tools/materials listed in the "Kit assembly" section, here are the tools you will need/want to use if you will be self-assembling a ZeroPhone - which includes soldering SMD parts.
Having a set of tweezers is imperative for soldering SMD parts. You will want fine tip (sharp) tweezers for that - finer than for the usual kit assembly.
Hot air gun
While ZeroPhone is designed so that it can be assembled using only a soldering iron, some parts of the assembly (i.e. ATMega328P and TPA2005 soldering) will be easier if you use a hot air gun.
Reflow oven, stencil and solder paste
If you plan to assemble more than one phone at a time, I strongly suggest you get some solder paste, a stencil and a reflow-capable oven. The best way to do this is to find a hackerspace near you which is capable of providing you with all of that, for a fair price - since solderpaste is kinda expensive when compared to i.e. solder. However, using these tools will dramatically speed up the SMD assembly of multiple ZeroPhones.