This paper will discuss the bendability design of flexible circuit.
Two factors related to the bendability design of flexible circuit.
One is how many times it will be binding.
And the secondly is what it can be bend.
A statics flexible circuit board
First factor determines whether the flexible circuit will be a static or dynamic PCB board.
If a flexible circuit definition static board, it’s an assembly process will be bend-to-install.
And the bending number also will be limited, usually a static flexible circuit bending flex less than 100 times in its lifetime.
By the way there were different from statics flexible circuit with rigid PCB.
A dynamic flexible circuit
To design a dynamic flexible circuit board is not easy.
Because dynamic, flexible circuit requires flexing will be bent on a regular basis.
This is hard to a static flexible circuit board, but there is another consider.
Also need to withstand tens of thousands of bends.
Design a right bend radius of flexible circuit
What is the bend radius definition?
In a static flexible circuit or a dynamic, flexible circuit, the minimum amount of bending for the flexing area.
This flexing area must be properly identified early in the design.
The second reason is that bend flexing may damage circuit copper.
So it’s important to ensure flexible circuit has the good area for flexible bending.
Three flexible circuit design suggestion is avoiding, 90 degree bend.
You know 90 degree bend may damage circuit copper.
Also cannot design a good bend flexible circuit copper area.
During the flexible circuit design process should avoided plated through holes in the bend area.
For greater effectiveness, rich, flexible circuit designer suggests conductors should be staggered in multilayered circuits.
Some flexible circuit companies even suggest conductors smaller than 10 mils should be placed within neutral bend axis.
Because there is no tension or compression during flexing in flexible circuit.
