• Single-sided flex circuits

       Single-sided flexible circuits have a single conductor layer made of either a metal or conductive (metal filled) polymer        on a flexible dielectric film. Component termination features are accessible only from one side.

• Double access or back bared flex circuits

       Double access flex, also known as back bared flex, are flexible circuits having a single conductor layer but which is                      processed so as to allow access to selected features of the  conductor pattern from both sides.

• Sculptured flex circuits

  
  Sculptured flex circuits are a novel subset of normal flexible circuit structures. The manufacturing process involves a special flex circuit multi-step etching method which yields a flexible circuit having finished copper conductors wherein the thickness of the conductor differs at various places along their length.

• Double-sided flex circuits

  
  Double-sided flex circuits are flex circuits having two conductor layers. Theses flex circuits can be fabricated with or without plated through holes, though the plated through hole variation is much more common. 

• Multilayer flex circuits
  
  Flex circuits having three or more layers of conductors are known as multilayer flex circuits. Commonly the layers are interconnected by means of plated through holes, though this is not a requirement of the definition for it is possible to provide openings to access lower circuit level features. 

• Rigid-flex circuits
  
  

  Rigid-flex circuits are a hybrid construction flex circuit consisting of rigid and flexible substrates which are laminated together into a single structure. Rigid-flex circuits should not be confused with rigidized flex constructions are simply flex circuits to which a stiffener is attached to support the weight of the electronic components locally. 

    Flex Materials

  - Shin-Etsu (UL approved)-Epoxy adhesive system

  - Rogers (UL approved)-Epoxy adhesive system

  - Dupont FR (UL approved)-FR acrylic adhesive system

  - Dupont LF (Not UL approved) LF acrylic adhesive system

  - Adhesiveless base materials