Thin Film Process to Fabricate a Conformable Thermal Printhead to Print on Most Types of Paper
Original Publication Date: 1987-May-01
Included in the Prior Art Database: 2005-Feb-01
Using dry etching of a polyester plastic substrate, to allow each heater to sit atop a pedestal, gives compliance to a thermal printer sufficient for printing on rough paper. Thermal print heads fabricated on ridges of substrates print only on the very smoothest papers; this design, with the heater elements sitting on pedestals, allows each element to conform to the surface below it. Fig. 1 shows the substrate 1 for both the cable and print head, which is 3- to 5-mil polyester onto which is deposited 4 to 6 microns of copper. This film 2 of copper forms both the electrical leads which connect the heaters to the plug connector pads and a heat conductor, taking the excess heat away from below the heaters. The area 3, where the heaters will be, has to be masked so as not to deposit any copper there.