Gap control for die or layer bonding using intermediate layers

A method of accurately controlling the dimensions of a gap provided between a portion of two layers joined together, the method comprising:

• providing a first layer with an element formed within a first surface;
• providing a second layer with a second surface;
• forming a recess in one of the first surface or the second surface, the recess having a predetermined depth;
• forming a groove in one of the first surface or the second surface, the groove defining a boundary for surrounding the element;
• providing sealing material on at least one of the first surface or the second surface;
• and
• joining the first layer and the second layer together such that the second surface is adjacent to and in direct contact with at least a portion of the first surface on all sides of the element, thereby completely enclosing the element,
• wherein the sealing material is arranged to be deformedly retained completely within the groove such that the recess defines the gap.