7 Replies Latest reply on Dec 17, 2018 12:35 AM by ShanmathiN_06

    Cap touch button production test

    LiFi_1601451

      We are going to make a automatic test Jig in production line for cap touch button test. One of the possibility is to use a metal coins connected to ground to simulate the human figure. Please recommend the diameter of the metal coins. Are there any better method to simulate the human figure in production line?

        • 1. Re: Cap touch button production test
          ShanmathiN_06

          Hi,

           

          The average human finger diameter is 9 mm (Mentioned in pg 73 of AN64846 http://www.cypress.com/file/41076/download)

          So, you could use a metal coin of 9 mm diameter.

          You could use a metal coin/rod connected to ground to simulate the human figure. Ensure that the finger touches at the center of the button while testing.

           

          In addition, you could also check sensitivity/false triggers by having a 3/4 mm diameter metal coin (depends on size of buttons) and check if the buttons are responding or not.

           

          Thanks,
          Shanmathi

          • 2. Re: Cap touch button production test
            LiFi_1601451

            Dear Shanmathi,

            Can the test metal coin made by copper? If no, please recommend a proper metal type for the test coin.

             

            Fiske Lin

            Senior Electronic Engineer

            Corporate Engineering

            Defond Group

             

            T +852 31237674

            • 3. Re: Cap touch button production test
              ShanmathiN_06

              Hi, yes you can use Copper/any metal (conductive)

               

              Thanks,
              Shanmathi

              • 4. Re: Cap touch button production test
                LiFi_1601451

                Are there any thickness requirement on the copper test coins

                Besides, below is the design of our button. the button is on a 0.25mm thickness FPC. The button size is 10mm x 10mm. The guard ring is with 2mm thickness. The guard ring square is 19mm x 20mm. We also want to use a metal in production to test that the guard ring can protect the button under rain and snow environment or not. Please tell me the shape and size of the metal used to test the guard ring in mass production

                 

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                • 5. Re: Cap touch button production test
                  ShanmathiN_06

                  Hi Fiske Lin,

                   

                  We do not have any requirement for the thickness of copper coins. You could use a copper coin of a comparable thickness to the sensor.

                  We do not expect much variations in the testing for varied thickness.

                   

                  The guard sensor should be tested in an environment that is similar to the actual environment. So, in your case, you could spray water (for rain) and ice cubes/snow on the board and evaluate the performance of guard sensor.

                   

                  Thanks,

                  Shanmathi

                  • 6. Re: Cap touch button production test
                    LiFi_1601451

                    Dear Shanmathi,

                    In our mass production test, we expect to conduct guard sensor test on every unit. It is time consuming and impossible to do spray water test on very unit. It will be good if we can use a metal with special shape (similar to use 9mm coins on button test) to test a guard ring. Please recommend the metal shape and size for guard sensor test.

                     

                    Fiske Lin

                    Senior Electronic Engineer

                    Corporate Engineering

                    Defond Group

                     

                    T +852 31237674

                    • 7. Re: Cap touch button production test
                      ShanmathiN_06

                      Dear Lin,

                       

                      I understood your requirement. You could either of the following two methods:

                      Test 1 unit on the actual environmental conditions (rain/snow) to have an idea of the signal generated when guard sensor is triggered.

                       

                      1) Vary the size of copper coin and place it on the unit such that the signal generated is equivalent to the actual environmental conditions. (recommended)

                      2) Fix the coin size and place it on the unit at a proximity distance such that the signal matches. However, in this case, after deciding on the proximity distance, you should exactly place the coin at that distance.

                       

                      Thanks,

                      Shanmathi