Method of using laser routing to form a rigid/flex circuit board

A method of fabricating a multilayer circuit board having rigid and flexible sections, by Z-axis laser routing, comprising the steps of:

• forming a rigid superstructure having a laminating surface and an opposing surface, said laminating surface having at least one strip of laser reflective material disposed thereon, said strips defining a boundary between the rigid and flexible sections of said multilayer circuit board;
• providing a flexible substrate for lamination to said rigid superstructure;
• applying an adhesive material to selective areas intermediate said rigid superstructure and the flexible substrate, said selective areas corresponding to a section designated to be rigid on said multilayer circuit board;
• laminating said rigid superstructure to the flexible substrate forming a rigid laminate composite, wherein said strips of laser reflective material abut the flexible substrate;
• directing laser energy at said rigid superstructure in alignment with said strips of laser reflective material, forming a laser routed channel through said rigid superstructure terminating at said strip of laser reflective material, said channel defining an interface between said rigid and flexible sections on said multilayer circuit board;
• and
• removing selected sections of said rigid superstructure between said laser routed channels to expose selected sections of the flexible substrate, forming said multilayer circuit board having rigid and flexible sections.