CapTIvate : Is there any effect when we design CapTIvate on FPC?

Yuji Kuroki

Intellectual 550 points

Hi,

Is there any effect when we design circuits on FPC(Flexible printed circuit) ?

Or, is there any points to be noted when we design circuit for CapTIvate on FPC?

Thanks,

Yuji

over 9 years ago

0 Chris Sterzik over 9 years ago

TI__Guru 64491 points

Yuji,
The biggest consideration of FPC is the impact of parasitic capacitance because the conductive layers are so close together compared with traditional rigid pcb. It is highly recommended to use very aggressive hatching or no ground plane at all directly below the electrode.

Regards,
Chris

0 Yuji Kuroki over 9 years ago in reply to Chris Sterzik

Intellectual 550 points

Hi Chris,

Thank you for your reply.

Please let me confirm, does 'hatching' means removing unnecessary copper on the circuit ? And, does 'no ground plane at all directly below the electrode' means 'no placing ground plane on adjacent layer of pattern layer' ? Sorry for basically question. Please teach me.

Regards,

Yuji

0 Chris Sterzik over 9 years ago in reply to Yuji Kuroki

TI__Guru 64491 points

Yuji,
Yes you are correct. The hatching removes a percentage of the copper to reduce surface area and completely removing the ground plane from the adjacent layer will reduce parasitic coupling even more.

software-dl.ti.com/.../ch_design.html

Best Regards,
Chris

0 Chris Sterzik over 9 years ago in reply to Chris Sterzik

TI__Guru 64491 points

Yuji,

I found another picture that I thought might be helpful. Please note top and bottom layers (2-layer configuration).

Regards,

Chris

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CapTIvate : Is there any effect when we design CapTIvate on FPC?