SIM Card Connectors and White PCBs Make Huge LED Snowflakes Happen

[Mike Harrison] talked about designing and building a huge scale LED lighting installation in which PCBs were used as both electrical and mechanical elements, and presented at Electromagnetic Field 2016. The project involved 84,000 RGBW LEDs, 14,000 microcontrollers and 25,000 PCBs. It had some different problems to solve compared to small jobs, but [Mike] shared techniques that could be equally applied to smaller scale projects or applications. He goes into detail on designing for manufacture and assembly, sourcing the parts, and building the units on-site.

The installation itself was a snowflake display for a high-end shopping mall in Hong Kong in the 2015 Christmas season. [Mike] wanted a small number of modular boards that could be connected together on-site to make up the right shapes. In an effort to minimize the kinds of manufacturing and parts needed, he ended up using modular white PCBs as structural elements as well as electrical. With the exception of some minor hardware like steel wire supports, no part of the huge snowflakes required anything outside of usual PCB manufacturing processes to make. The fewer suppliers, the fewer potential problems. [Mike] goes into design detail at 6:28 in the video.

For the connections between the boards, he ended up using SIM card connectors intended for cell phones. Some testing led to choosing a connector that matched up well with the thickness of a 1.6mm PCB used as a spacer. About 28,000 of them were used, and for a while in 2015 it was very hard to get a hold of that particular part, because they had cleaned everyone out! Continue reading “SIM Card Connectors and White PCBs Make Huge LED Snowflakes Happen”

Custom Case Made Entirely Out of PCBs

So you’ve finished your project. You’ve got a wonderful circuit, a beautiful PCB, and everything works perfectly. You’re done right? Well, maybe not. Sure, a bare PCB might be fine for a dev board, but what if you have a LCD to mount, a knob that needs turning, and buttons that need pressing. Yeah, that potentiometer hanging off the board by a few wires isn’t so pretty, is it? So it’s time for a case. Yuck. We all hate modifying cases.

[Electrodacus] came up with a clever solution in the form of stacking PCBs to form a case. In his project, he actually has the circuitry spread across 3 PCBs, and uses surface mount connectors to connect them in a stack. Along the edges are specifically shaped PCBs to complete the enclosure. This technique could be used with only one PCB containing all the circuitry, and the others acting as the case sides and top.

In this solar battery management project, the base layer has most of the power circuitry. This layer uses an aluminum metal core PCB for heat dissipation. The center layer is home for the micro controller and supporting components. And the top layer is the “front panel” with capacitive touch buttons and a cut out for a LCD. The top layer silk screen contains the logo, button markings, and the pin out of all the connectors.

If you hate drilling and filling cases (as much as we do), this technique might be right for your next project.

[via EEVBlog Forums]