Method for making a three-dimensional liquid crystal polymer multilayer circuit board including membrane switch including air

A method for making an electronic device comprising:

• forming a multilayer circuit board having a non-planar three-dimensional shape defining a membrane switch recess therein filled with air, the multilayer circuit board comprising at least one liquid crystal polymer (LCP) layer, and at least one electrically conductive pattern layer thereon defining at least one membrane switch electrode adjacent the membrane switch recess filled with air to define a membrane switch;
• wherein forming the multilayer circuit board comprises
• forming a stacked arrangement comprising at least one pair of LCP layers with a bonding layer therebetween, and
• heating the stacked arrangement to shape the stacked arrangement into the non-planar three-dimensional shape and concurrently causing the bonding layer to bond together the adjacent LCP layers of the stacked arrangement.