DLP® Pico Projection Mounting Concepts
Updated: 11 November 2020
Important considerations for mounting the DMD

Important considerations when mounting the DMD include optical alignment, ensuring a good electrical connection, and control of the mounting loads (forces) applied to the DMD electrical and thermal areas.    The DMD data sheet specifies the maximum loads for each of these areas. DMDs with pads require a continuous load on the DMD for a good electrical connection. The load applied to the DMD electrical area should be that which is needed to maintain a good electrical connection and general clamping to secure the DMD in place.
  • Good mounting practices include: 
    1. Use of the DMD defined Datums ‘A’, ‘B’, and ‘C’ for both optical and electrical alignment
      • DMD must be pushed against the interface Datums ‘B’ and ‘C’
    2. Control of part tolerances which contribute to changes in the loads applied to the DMD (gaps for springs, gaps between PCB and boss, etc…)
    3. Control part tolerances for features used to align the DMD, electrical interposer, and PCB
    4. A design that prevents interactions between loads applied to the thermal and electrical areas
    5. Preventing PCB from bending (clamp material and thickness)
    6. If additional loads are needed to secure the DMD they should be applied in a lateral direction to not apply additional loads to the DMD

  • Control mechanical forces on the DMD thermal and electrical interface areas to prevent them from exceeding those specified in the DMD data sheet (System Mounting Interface Loads section).
    1. Mechanical forces should be uniformly applied (even clamping pressure)
      • Partial tightening of fasteners, order of tightening fasteners, possible use of a fixture
    2. Design Method to control of forces    (Best method)
      • Forces controlled by design details rather than use of fastener torques or special procedures
      • Minimize force variations from part tolerances by use of coil springs, flat springs, shoulder screws
      • Minimum and maximum force range easily determined and controlled
    3. Assembly Process Method to control of forces
      • Forces controlled by use of fastener torque and special procedures
      • Greater variation and uncertainty of force applied than Design Method of control
      • Applied forces highly dependent on assembly person and process
      • Torque value determined for a specific design (set of materials and fasteners used)
      • Difficult to determine clamping forces from fasteners
These concepts can be modified to meet the specific requirements of the application and its environment.    In so doing ensure the modifications allow the DMD specifications to still be met

Series 312 DMD Mounting Concepts
(Select Figures below or Mounting Concept Title for detailed information)
web section view:

Series 312 Mounting Concept #1

  • TI Drawing 2513792
  • Mechanical loads on DMD thermal area are controlled by design (flat spring)
  • Mechanical loads on DMD electrical area are controlled by design (coil springs)
  • The control of mechanical loads on the thermal and electrical areas are independent of each other
  • Optional features allow for PCB to be mounted later than DMD
  • Important: Selection of coil springs, and design of flat spring are critical for control of mounting loads