Etched lid for lid sealing for sealing applications

WinWay lids are composed of Kovar, steel and other alloys, and are used in the seam welding process to melt and fuse the thinner edges of the lids onto a metal seal ring. This concentrates the greatest heat at the perimeter of the lid to enable a weld onto the metal seal ring. 

The metal etching process works by ‘printing’ a component design onto photoresist which is laminated onto metal. The areas of photoresist which have not been printed are removed, exposing the metal, which is subsequently etched away.

A specific type of metal etching, photochemical machining—also known as photo etching—is the ideal way to economically produce complex parts with fine detail. Fundamentally, photo etching is similar to other types of metal etching. A coating is applied to a sheet metal surface, and acid is used to dissolve away exposed areas.

Unlike other etching methods, however, photo etching involves the use of hardened photographic film. The film shows the negative image of the part to be created, and two identical sheets are applied to the front and back of the sheet metal. That assembly is then laminated with a UV-sensitive photoresist, which hardens only around the clear areas of the film. The outlines of the parts are left unprotected by the resist, and when the assembly is bathed in an acidic solution, that outlining material is washed away, leaving only the parts of interest.

Metal etching first emerged as a sheet metalworking technology over 50 years ago. The earliest applications of the technique were rooted in the artisan space—examples of which include Rembrandt etchings and engravings for medieval swords.

While many people continue to view metal etching in this light, the use of the technology has grown rapidly in the last decade. Designers are now leveraging this highly precise corrosion process to solve a number of engineering challenges that are not possible to overcome or become too costly with the traditional route of stamping. This is paving the way for advanced aircraft, low to no emission vehicles and satellite communications, amongst other applications.