Design keypad on pcb
saeednowroozi , 09-09-2016, 08:14 AM
Hi all
I must design a keypad on pcb but I do not any standard about it(size,...). I upload a picture maybe help for my question.
I must design a keypad on pcb but I do not any standard about it(size,...). I upload a picture maybe help for my question.
robertferanec , 09-09-2016, 10:03 AM
Design it based on the rubber keypad you are using. Or, if it needs to be exactly the same as on the PCB, you can measure it's dimensions.
I have done this in past and I don't think there are some special requirements. You can just draw tracks close to each other (as two opposite combs) and the tracks will be shorted when a key is pressed. What you may want to consider is to add carbon surface on the tracks (make a note in the manufacturing notes layer) or make the PCB finish gold (do not use tin finish, that will oxidize and lose contact).
PS: Make a schematic symbol for the button and create a footprint for it (the "two combs" footprint). Then you can simply place as many buttons as you need.
I have done this in past and I don't think there are some special requirements. You can just draw tracks close to each other (as two opposite combs) and the tracks will be shorted when a key is pressed. What you may want to consider is to add carbon surface on the tracks (make a note in the manufacturing notes layer) or make the PCB finish gold (do not use tin finish, that will oxidize and lose contact).
PS: Make a schematic symbol for the button and create a footprint for it (the "two combs" footprint). Then you can simply place as many buttons as you need.
saeednowroozi , 09-09-2016, 11:06 AM
Think you
answer was perfect.
answer was perfect.
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