1 Reply Latest reply on Jan 24, 2019 12:25 AM by RuzheZ_36

    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,