There’re three major different types of raw material in polydome manufacturing , and each of them will be used in different layers, see polydome stack up bellowing.

polydome with rubber glue stack up

And here are details and datasheet of each type of polyester dome material.

PET (Polyester):

There’re two different colors: White and Transparent/Clear
And according to different function, PET can be divided into two different names:
Mylar: on top of polydome, normal color is Transparent/Clear and thickness will be 0.10mm or 0.125mm.
Spacer: on the bottom of polydome, normal color is Transparent/Clear, but white also available. Thickness 0.15mm, 0.175mm, 0.20mm.
For normal stack up, there’s only one side glue on Spacer so that it can be adhered to Mylar. If people want Polydome to be stick on circuit board, then there’ll be double sided glue on Spacer.

Transparent PET on both Mylar and Spacer

(Transparent PET on both Mylar and Spacer)

Click to download the normal popular PET we used in polydome.

  1. PET-without-glue
  2. PET75-Transparent-single-sided-glue
  3. Double-sided-glue-PET
Conductive Ink: Carbon ink, Silver ink

Carbon ink will be printed firstly on PET and has bigger contact resistance;
Normally silver ink will be printed in 2nd times and on carbon ink layer, and has much lower contact resistance so it will be contacting point with the PAD of circuit board.
When looking from top of polydome, you will see the black color that belongs to carbon ink, while view from bottom side of polydome, you will see the silver-grey color which belong to silver ink.

(top view (black color of carbon)               (bottom view: silver-grey color)

Click to download datasheet of conductive ink for polyester dome (Polydome)

  1. Carbon ink
  2. Silver ink
Rubber glue:

That type of glue has excellent stickiness while stick to rubber key, it’ll adhered firmly on rubber. Normal color is green and thickness 0.125mm.

rubber glue on top of Mylar of Mylar 
(rubber glue on top of Mylar of Mylar)

Click to download datasheet of rubber glue for polyester dome (Polydome)

  1. Rubber glue

Above mentioned are normal material for polyester dome, but we are always developing new material and find material according to customers’ request. If you have good material can be used in polydome, or want to know more information about polyester dome material, please contact us immediately!