MEP EP#262: Flex PCB Primers

MEP EP#262: Flex PCB Primers
Parker

Robert Feranec

Published a video about what to consider when selecting chips for your new board design.

Don’t want to steal Robert's content so go check him out.

Hardware design and PCB Layout online course

Comprehensive Power Supply System Designs for Harsh Automotive Environments Consume Minimal Space, Preserve Battery Charge, Feature Low EMI

Analog engineer Bin Wu and previous Linear Tech engineer Zhongming Ye writing an application note with linear tech devices.
‘An Ideal Diode Satisfies Automotive Immunity Norms’

LT8672

Active rectifier controller

Why is all this needed?

Car power is dirty

Load dumps
Cold cranking
Pulses

ISO 7632-2 is a negative spike whose peak voltage exceeds −220 V!

Reverse Polarity
AC Ripple

Stephen

Wurth Elektronik on Flex PCBs

Basically Polyimide foil with deposited copper
3 ways to create a system (from page 2)

Heterogeneous
Homogeneous
Partial Homogeneous

Full flex and Semiflex
Much Much easier way to create a 3d system design
Added benefit of having a full panelized system

Can test a full panel of designs all at once
Test points can technically be on the flex

Break and make

Take the rails off of the PCB

Flex-rigid boards

Can be bonded to external layers
Can be internal
Can be rigid on one side or both
Can be multiple layers

Layout and routing

Create a new layer in your EDA tool to define the Flex portion
No vias in flex portion
Use teardrops for added rigidity
Use wider tracks where possible for added strength
Do not change width in bend area
Distribute conductors evenly

Documentation

Do it... Do it a lot
In addition to the PCB gerber or ODB++ files include drawings
A fab drawing that defines the flex pcb is very helpful