Stress relieved flat frame for DMD window

A method for attaching a transparent piece to a substrate assembly comprising a substrate portion, a seal ring, and a micromirror array, the method comprising:

• providing a window frame comprising a substantially planar outer portion, an inner portion substantially perpendicular to the substantially planar outer portion, and a stress relieving means comprising first and second portions positioned between the inner portion and the outer portion of the window frame, wherein the inner portion and the first portion of the stress relieving means define a first partially enclosed space, and the first portion and the second portion of the contoured portion define a second partially enclosed space;
• mounting only a sidewall of the transparent piece to the inner portion of the widow frame using a process sufficient to form a seal between the window frame and the transparent piece;
• mounting the outer portion of the window frame to the seal ring of the substrate portion by seam welding the window frame to the seal ring of the substrate assembly;
• and
• wherein the step of providing a window frame further comprises stamping a unitary piece of sheet metal to form the stress-relieving means and the inner portion.