Monolithic Sun Sensor Integration for Alignment Error Reduction
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Solution Overview
Problem
Existing sun sensors are costly, complex to manufacture, large in size, power-intensive, and prone to alignment errors due to mechanical assembly and calibration requirements.
Innovation Solution
The development of monolithic sun sensors, where all components are integrated into a single unit using materials processing techniques, eliminating the need for mechanical assembly and allowing for batch processing, reduced size, and simplified calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional mechanical assembly methods are used to construct sun sensors with separate components (aperture plate, mechanical spacer, photosensor), then the sensor can be assembled and calibrated, but the manufacturing process becomes complex, time-consuming, and expensive
Solution Approach 1:
The patent merges the aperture plate, mechanical spacer, and photosensor into a single monolithic structure formed by depositing transparent material over the photosensor and patterning it to create the aperture and spacer functions in one integrated component, eliminating mechanical assembly steps
Solution Approach 2:
The transparent material layer serves multiple functions simultaneously: it acts as the spacer providing the required distance between aperture and photosensor, as the aperture plate when patterned with the aperture opening, and as a protective and structural element, replacing multiple separate components
2Volume of moving object
If traditional mechanical assembly with multiple separate components is used, then the sensor can be constructed, but the size and mass of the sensor increase
Solution Approach 1:
The patent combines multiple separate components (aperture plate, spacer, mounting structure) into a single monolithic component formed by depositing and patterning transparent material directly over the photosensor, dramatically reducing the number of parts and overall volume
Solution Approach 2:
The aperture and spacer structures are formed by patterning and layering the transparent material in a nested configuration where the aperture opening is defined within the patterned material layer that also provides the spacer function, creating a compact integrated structure
3Manufacturing precision
If mechanical spacers and aperture plates are assembled separately, then the components can be positioned, but alignment errors occur and calibration becomes necessary
Solution Approach 1:
The patent forms the aperture and spacer as an integrated monolithic structure deposited directly over the photosensor in a single fabrication process, eliminating relative alignment between separate mechanical components and removing the need for post-assembly calibration
Solution Approach 2:
The aperture pattern and spacer thickness are precisely controlled during the material deposition and patterning process itself, establishing the correct geometric relationships before the sensor is assembled or used, eliminating the need for subsequent alignment adjustments
4Ease of manufacture
If traditional sun sensors are manufactured individually with mechanical assembly, then each sensor can be calibrated, but the manufacturing cost increases to thousands of dollars per sensor
Solution Approach 1:
The patent enables batch fabrication of multiple sun sensors on a single substrate through semiconductor-compatible deposition and patterning processes, allowing simultaneous manufacturing of many sensors that can then be diced into individual units, dramatically reducing per-unit cost
Solution Approach 2:
The patent transitions from mechanical manufacturing methods to materials processing methods (deposition, patterning) that are compatible with high-volume semiconductor fabrication, enabling precise control of geometric parameters (aperture size, spacer thickness) through process parameters rather than mechanical tolerances
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in sun sensors that are more affordable, compact, consume less power, and are less susceptible to alignment errors, with the potential for per-sensor costs under $1 and suitability for various applications including spacecraft and terrestrial use.
Implementation Method 1
The spacer material has a thickness selected such that the patterned mask casts a shadow onto the photosensor that varies as a function of the monolithic sun sensor's angle relative to the sun
Implementation Method 2
aperture plate 130 transmits sunlight 150 onto different regions of photosensor 110
Data Source
AI summary
Under one aspect of the present invention, a monolithic sun sensor includes a photosensor; a spacer material disposed over the photosensor; and a patterned mask disposed over the spacer material and defining an aperture over the photosensor. The spacer material has a thickness selected such that the patterned mask casts a shadow onto the photosensor that varies as a function of the monolithic sun sensor's angle relative to the sun. The sun sensor may further include a substrate in which the photosensor is embedded or on which the photosensor is disposed. The spacer material may be transparent, and may include a layer of inorganic oxide, or a plurality of layers of inorganic oxide. The patterned mask may include a conductive material, such as a metal. The aperture may be lithographically defined, and may be square. The sun sensor may further include a transparent overlayer disposed over the patterned mask.