False touch - 4 layer design - PCB revision

[jobic_1363266]

Hey there,

The case is that I'm having False touch on prototype being triggered. Are there problems with my layout? ( Gerber is attached and also board picture )

How frequently does it happens?

Once in a while.

Board details:

Number of layers: 4

Liquid tolerance: NO

layer 1 ( TOP - Sensors) :

• Hatch pattern 7mil/45mil ( Connected to Ground)
• Sensor size 10mmx10mm (rounded corners)
• Backlight leds

layer 2 :

• Hatch pattern 7mil/70mil (Connected to ground)
• All sensor tracks

layer 3 :

• VDD

Layer 4:

• Components and tracks
• surrounded by hatched plane ( connected to GND )

Layer 1 ( TOP - Sensors)

--------------------------------------------------------

Layer 2

--------------------------------------------------------

Layer 3

--------------------------------------------------------

Layer 4 (BOTTOM - Components)

Case structure:

Below I show how the PCB and other elements are stacked.

Touch Surface ( Air )

--------------------------------------------------------

0.75 mm polycarbonate adhesive

--------------------------------------------------------

2.4mm to 3mm Acrylic

--------------------------------------------------------

1.4mm PCB

--------------------------------------------------------

Thanks,

[RyanZhao · Accepted solution]

Hi Joao,

The description is not very clear for me, and I don't have a CAD tool to open the gerber file.

The KBA about CapSense troubleshooting is FYI.

PSoC® 4 CapSense® Troubleshooting Guide - KBA219217

How about rawcount, baseline waveform in the whole process? If there are more log can be shared with us, please share. for example, rawcount, baseline waveform, PSoC Creator project.

Thanks,

Ryan