Jigit is a tool that generates 3D printable jigs that make it a breeze to solder through hole electronic components with perfect results. A 1 minute intro is here https://www.youtube.com/watch?v=OyDZIb-CLvM
SMD electronic components are now commonly used in electronic boards, including in DIY designs. These need to be soldered onto boards. Depending on the exact parts, this can take some work and some skill.
The need for soldering is undesirable in many scenarios. Firstly, not everyone has the equipment or skills for soldering. Second, changing the circuit also requires de-soldering components to replace replacements - making experimentation that bit harder.
The need for soldering is among the biggest barriers to getting more people doing electronics - be it workshops for beginners, or prototyping a new idea. What if we could do without soldering.... ? This hack will explore this idea and see what can be done. I will build upon the idea of using 3D printed jigs, but now specialized to SMD parts. This is a new feature for JigIt. Using components this way is not a new idea (e.g. see SolderlessPCB). However, there is a lack of automation and resources in this area, in open source software. JigIt works directly on KiCAD designs (open source electronics design software); thus is a generic toolkit to reduce need for soldering requirement in various scenarios. Unlike SolderlessPCB, which relies on pre-generated (hand crafted?) 3D models of cavities to hold electronics components, JigIt generates cavities based on 3D models of the components themselves.
Status during the hackathon:
JigIt was extended to support SMD components. It is able to generate 3D printable jigs that hold SMD components.
A basic level of functionality w.r.t using SMD components without soldering is achieved. That said, results are somewhat mixed and not very repeatable. These are tolerance and fitting issues that need tuning (i.e. not necessarily related to code)
I have tested small electronic components such as 1206 SMD LEDs and 1206 resistors with mixed results. I test functionality using continuity checks as well as diode check on multimeter for LEDs, which is sufficient to establish continuity and proof that component makes appropriate contact on the PCB with the 3D printed jig. Also tried with components such as TSSOP20 (CH32 series chip) on a breakout board. It seems fine but didn't find the time to check this as it needs additional connections.
There is (expected) dependence of tolerance on the material used for 3D printing. The small dimensions of the tested SMD components makes it difficult to tune things in this timeframe. I am testing with PLA and ColorFab nGen filaments. Ideally I would need to change over my 3D printer to use a fine nozzle (0.25mm) rather than the existing standard nozzle (0.4mm) to achieve better tolerances and results (printing with fine nozzle is much slower than standard nozzle).
These tests were done with off-the-shelf breakout boards for testing - one an Adafruit Perma Proto Board and one a TSSOP20 breakout board (see the demo directory). This approach is taken for testing as it is not feasible to make PCBs in this time frame. KiCAD designs are created to correspond to the components that are mounted for testing. The Adafruit Perma Proto Board has 9 LEDs and resistors, and the TSSOP20 breakout board has one chip.
With a custom PCB, SMD components would be placed in the 3D printed jig, then the PCB, and screws would be tightened (screws and nuts shown in video), thus achieving secure connection of component to the circuit. The circuit would then work as expected. It will be easy to swap out components (e.g. change LED color or change resistor value, or even pin compatible chips with different capabilities). This should be useful for prototyping, workshops (soldering in a workshop can be hard to manage). Could even be useful for doing things like LED/conference badges (this last thing is the actual motivation to build the SMD capability in the first place; larger LEDs will likely be used in such applications)
Please Note: The main video (demo link) has the LEDs turning ON in an area out of the video (towards the end of the video - during testing). Please see https://www.youtube.com/watch?v=4Yi2tmE0O04 - this shows the LEDs in the video while testing.
