The top layer of the PCAP touch panel is usually the cover glass, and the bottom layer is the conductive sensing layer. Depending on the core architecture of the touch controller, there are two detection modes:

Mutual Capacitance

The mutual capacitance detection method uses one axis as the input terminal and the other axis as the output terminal. The controller will calculate the signal amount of each node from the output terminal. When a finger touches the touch panel, firmware detects node capacitance changes, and touch position can be located. However, when there is water on the surface of the touch panel, the channels will affect each other, and false signals may be generated.

Self-Capacitance

The self-capacitive detection method scans each vertical and parallel channel. When a finger touches the touch panel, a capacitance change occurs in the channel. The controller knows the touch position by the vertical and parallel axis arrangement of the channel. Although self-capacitance detection can only support a single finger, the measurement is performed in all channels simultaneously, and there will be no potential difference between the channels. When there is water on the surface of the touch panel, the channels will not affect each other and will not produce false signals.

PenMount K1 series touch controllers support both mutual capacitance and self-capacitance detection. Under normal conditions, mutual capacitance is the default detection mode, and the finger signal is used as the detection threshold. If there is water in the operating environment, the customer can turn on the Water Mode in PenMount PCIUtility. When the water area exceeds the preset threshold, the waterproof mode is activated, and self-capacitance detection is used to confirm the touch signal, so that the user can have a better touch experience when drawing or clicking with a single finger in the water mist.

To prevent water from affecting the PCAP touch panel, please try to place the mechanism upright or at an angle to prevent water from accumulating on the touch surface. In addition, if the touch device is a metal frame that is connected to the ground, the water signal will look more like a finger signal. When water touches the metal frame from the inner edge, the false signal may be generated. All in all, if there is water in the environment of your PCAP touch device, you are welcome to contact us for discussion, and we will provide you with the most professional suggestions to optimize the performance of your PCAP products.

The PenMount research team continues to incorporate novel technologies to provide quality total solutions. Our core value is to shorten your product development cycle and offer a practical operation interface to streamline your product launch processes. Feel free to download all of PenMount’s standard product data and drivers from our website at: www.amtouch.com.tw or www.penmount.com. If you have any suggestions or comments please don’t hesitate to contact us at penmount_service@amtouch.com.tw or amt1@amtouch.com.tw. We look forward to hearing from you!