Stacked Optoelectronic Module for Compact ToF Optics
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Solution Overview
Problem
Current optoelectronic modules for mobile devices, such as Time of Flight camera modules, have limitations in minimum dimensions, spatial resolution, and robustness due to tolerance chains in barrel optics and the use of thermoplastic materials, which restrict their application and manufacturing processes.
Innovation Solution
An optoelectronic module design featuring a driver die with an optical sensor die and a preassembled optical stack mounted via an adhesive layer, encapsulated by a material that minimizes tolerance chains and allows for standard SMT processes, reducing the need for active alignment and enhancing reliability and thermal-mechanical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If barrel optics with threaded barrel and housing are used, then spatial resolution can be achieved, but the module dimensions become large (>10 mm lateral, >2 mm height)
Solution Approach 1:
The patent merges the optical components (lenses, apertures) and the sensor array into a single integrated optoelectronic module package, eliminating the need for separate threaded barrel and housing structures. This integration maintains optical alignment while dramatically reducing the lateral dimensions from >10 mm to a compact footprint suitable for mobile devices.
Solution Approach 2:
The patent transitions from a lateral extension architecture (barrel optics extending horizontally) to a vertical stacking architecture where optical components are arranged in layers above the sensor array. This dimensional reorganization reduces lateral footprint while maintaining optical path length and focal properties.
2Ease of manufacture
If thermoplastic materials (injection molded lenses) are used, then manufacturing is simplified, but maximum temperature is limited and standard reflow processes cannot be applied
Solution Approach 1:
The patent employs composite material construction where thermoplastic lenses are combined with metal or thermally stable housing components. This allows the optical elements to be injection molded (maintaining manufacturing simplicity) while the overall module can withstand reflow soldering temperatures through the thermal stability of the composite structure.
3Ease of operation
If threaded barrel with multiple components is used, then focal length adjustment is possible, but tolerance chain increases and active alignment is required
Solution Approach 1:
The patent implements self-aligning features where the optoelectronic module package automatically maintains proper optical alignment through precision molded features and mechanical interlocks. This eliminates the need for manual active alignment procedures and reduces the number of adjustable components while maintaining focal length precision.
4Adaptability or versatility
If multiple components with tolerances are used, then assembly flexibility is maintained, but tolerance chain increases and reliability decreases
Solution Approach 1:
The patent combines multiple discrete optical components into an integrated optoelectronic module package with fewer interfaces and connections. This reduction in component count directly reduces the tolerance chain accumulation and potential failure points, thereby improving reliability while maintaining assembly flexibility through the modular package design.
Data Source
AI summary
An optoelectronic module includes a driver die mounted on a substrate. The optoelectronic module also includes an optical sensor die mounted on an upper surface of the driver die. The optical sensor die includes at least one optical detector. The driver die is electrically connected to the optical sensor die. The optoelectronic module further includes an optical stack mounted via an adhesive layer to an upper surface of the optical sensor die above the at least one optical detector. The optoelectronic module additionally includes an encapsulant material that laterally encapsulates the optical stack.