DLP® Concepts to Mount Series 460 DMDs and Support PC Board Updated: 24 October 2024

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 pins do not require a continuous load on the DMD for a good electrical connection (as DMDs with pads do). The only load that needs to be applied to the DMD (electrical area) is that which is needed to keep the PCB from moving after it is installed. Good mounting practices include: Use of the DMD defined Datums ‘A’, ‘B’, and ‘C’ for optical alignment Control of part tolerances which contribute to changes in the loads applied to the DMD (gaps for springs, gaps between PCB and boss, etc…) A design that prevents interactions between loads applied to the thermal and electrical areas Preventing PCB from bending Fixing PCB in place without applying 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). Mechanical forces should be uniformly applied (even clamping pressure) Partial tightening of fasteners, order of tightening fasteners, possible use of a fixture 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 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 (based on 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. The heat sinks included in the concepts are representative of the mechanical mounting features but not the thermal performance characteristics. The thermal characteristics of a heat sink or heat exchanger should be designed to ensure all the DMDs thermal specifications are met under all conditions.
Series 460 DMD Mounting Concepts
(Select Figures below or Mounting Concept Title for detailed information)
| Pin Guide Mounting Concept TI Drawing 2519123 Raised Pin on optical chassis and hole in PCBoard are to aid alignment when installing the DMD and PCB Distance between fasteners supports both ZIF and LIF style sockets Push Nut is to retain shoulder screws and coil springs to heat sink (optional) Mechanical loads on DMD thermal area are controlled by design (coil springs) Mechanical loads on DMD electrical area result from securing or fixing the PCB in place The control of mechanical loads on the thermal and electrical areas are independent of each other Important: Selection of coil springs is critical for control of mounting loads
| Edge Guide Mounting Concept TI Drawing 2519124 Raised areas on optical chassis provide alignment aid for edge of DMD cermaic when installing the DMD and PCB Other highlights are the same as the Pin Guide Mounting Concept above
| PC Board Support Concepts General ideas for securing PCB - ideas need to be modified for this specific DMD TI Drawing 2507519 includes: System - FS (Flat spring) System - W1 (Washer 1) System - W2 (Washer 2) System - C1 (Clip 1) System - C2 (Clip 2)