Regarding GND hatch pattern of 1 layer film sensor.

[YuMa_1534086]

Hello.

I have question about capsense GND hatch pattern.

Design guide(P.110) describes about GND hatch pattern of 2 layers and 4 layers.

=> http://www.cypress.com/file/46081/download

But this document does not describe about 1 layer film sensor.

How should users design GND hatch pattern around capsense button if they use 1 layer film sensor?

Best Regards.

Yutaka Matsubara

[RyanZhao]

Matsubara-san,

We don't recommend to use 1 layer sensor. If user touches on the sensor trace, the sensor will be active which is unexpected.

For the first layer hatch pattern, refer to Section 7.4.5 in the design guide: " The maximum recommended trace width is 7 mil (0.18 mm). You should surround the CapSense traces with a hatched ground or hatched shield with trace-tohatch clearance of 10 mil to 20 mil (0.25 mm to 0.51 mm)."   And refer to Section 7.4.13 about other rules checklist(clearance to ground hatch, e.g.).

Thanks,

Ryan

[YuMa_1534086]

Ryan-san.

I would like to know hatch fill percentage of 1 layer film sensor.

Below figure is a recommended hatch fill percentage of 2 layer and 4 layer.

Could you please let us know recommended hatch fill percentage of 1 layer film sensor?

=>  ???% on 1 layer film sensor  (???-mil line, ???-mil spacing)

Best Regards.

Yutaka Matsubara

[YuMa_1534086]

Dear Cypress.

Can you update this community.

Best Regards.

Yutaka Matsubara

[RyanZhao · Accepted solution]

Matsubara-san,

Sorry for my late!

Generally, 25% on 1 layer film sensor  (7-mil line, 45-mil spacing) is recommended.

Note: If users touched on the sensor trace, the sensor will be active which is unexpected. In this case, 1 layer film sensor is not recommended. But if the customer will use spring construction. 1 layer film design won't lead to false touch.

Thanks,

Ryan