20230413 JLCPCB Does flexible PCBs!!!

I had a wonderful surprise today. And to be honest, I am so grateful that my finalisation of the Main Control Board PCB was delayed. It was supposed to be done before April but I was too busy with re-drawing the circuit to accommodate the new LED lights. And so, with a difference of one week, suddenly JLCPCB has a new feature!

FLEXIBLE PCB

A normal PCB nowadays uses a sheet of fiberglass (FR4) as the medium. The advantage is that the FR4 board is robust and does not crack when dropped compared to the traditional brittle SRPB. It is also (to me) quite forgiving on beginners where soldering is concerned (i.e. track delamination due to excess heat). When I send my designs to JLCPCB, I have the option of choosing various board thickness from the usual 1.6mm down to 0.8mm for a minimal fee. Of course different board thickness, board colours and so on will influence the pricing.

The flexible PCB is a different matter altogether. Instead of the tough FR4 fibreglass, it uses a flexible polymer. For more than a decade (OK, decades) I was chasing after this technology but it was only affordable to manufacturers. The reason is that this ‘new’ technology is expensive and if I insist on using it to manufacture one of the boards, I could be looking at a four figure solution. (For Malaysia, just multiply that figure with 4.5 and you’d be vomiting blood too).

Originally, the reason for the search of the flexi-PCB was for the MkVII Playmates toy Tricorder where this solution would be ideal for the following reasons:
1. It allows the circuit to follow the inner shell’s curves and saves a lot of space, and
2. It would minimise the PCB count to either one board or two instead of three or so.

There is a reason why the flexi-PCB is so desired for this model. The first issue is that there is not much space or gap between the Cargo Bay walls and the outer fuselage. If I were to go for the 0.4mm option, the user would still have to carve out 0.4mm template for the board to fit into that gap. Secondly, the most obvious issue is that the rear of the Cargo Bay Walls curve inwards. Bending a tough FR4 fibreglass PCB would compromise its structure. And even if by some feat of ingenuity, you did get it to bend, the copper tracks could have problems.

So, this flexi-PCB solves both my problems of thickness and flexibility. But it created a new problem: money.