Etched multi-layer sheets

Abstract

A method includes creating an opening in a first outer layer of a multilayer sheet of material, the sheet of material having three or more layers of material, including the first outer layer and a second outer layer. A selective etchant is introduced through the opening, where the etchant selectively etches an interior metal layer of the multilayer sheet of material compared with the first and second outer layers. The selective etchant is permitted to etch material of the interior metal layer under the first outer layer.

What is claimed is: 
     
         1 . A method comprising:
 creating an opening in a first outer layer of a multilayer sheet of material, the sheet of material having three or more layers of material, including the first outer layer and a second outer layer;   introducing a selective etchant through the opening, wherein the etchant selectively etches an interior metal layer of the multilayer sheet of material compared with the first and second outer layers; and   permitting the selective etchant to etch material of the interior metal layer under the first outer layer.   
     
     
         2 . The method of  claim 1 , wherein the first outer layer includes stainless steel. 
     
     
         3 . The method of  claim 1 , wherein the first outer layer includes a glass-reinforced epoxy laminate. 
     
     
         4 . The method of  claim 1 , wherein the interior metal layer includes aluminum. 
     
     
         5 . The method of  claim 1 , wherein creating the opening includes:
 applying a layer of photoresist to the first outer layer;   exposing the layer of photoresist to a pattern of radiation;   developing the photoresist;   selectively removing photoresist material from the first outer layer to leave the pattern of the radiation in the photoresist on the first outer layer; and   applying a chemical to the first outer layer, wherein the chemical selectively attacks the exposed material of the first outer layer compared with the resist material and compared with the first outer layer under the pattern of resist material.   
     
     
         6 . The method of  claim 1 , wherein the selective etchant etches the interior metal layer at a rate more than 100 times faster than the selective etchant etches the first outer layer. 
     
     
         7 . The method of  claim 1 , wherein permitting the selective etchant to etch material of the interior metal layer under the first outer layer includes forming a cavity in the interior metal layer; and further comprising:
 placing an electrical component of a computing device within the cavity.   
     
     
         8 . The method of  claim 1 , further comprising:
 creating a pattern of openings in the first outer layer;   introducing the selective etchant through the pattern of openings; and   permitting the selective etchant to etch material of the interior metal layer in a plurality of locations under the first outer layer.   
     
     
         9 . The method of  claim 8 , further comprising adding a phase change material to the multilayer sheet to replace at least some of the material from the interior metal layer that is removed by the selective etchant. 
     
     
         10 . The method of  claim 1 , wherein the sheet of material has an area that is greater than about 30 in 2  and a thickness that is less than about 2 mm.