Curved Image Sensor Fabrication via Tensioned Bending Substrate
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Solution Overview
Problem
Existing optical systems face design constraints with flat-surface image sensors, limiting their performance in achieving uniform light intensity and spatial frequency response, and there is a need for a method to bend image sensors without causing cracking or buckling.
Innovation Solution
A method involving a bending substrate bonded or deposited onto the image sensor, applying forces or torques to introduce tension and shape the image sensor into curved forms such as spherical or aspheric shapes, while maintaining the light-sensitive surface in tension to reduce dark current and avoid undesirable deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If forces or torques are applied to bend the image sensor, then the curved shape is achieved, but cracking or buckling may occur
Solution Approach 1:
A bending substrate is introduced as an intermediary element between the flat image sensor and the desired curved shape. The bending substrate is bonded to the image sensor and deformed into a curved configuration, thereby transferring the bending action indirectly through the substrate rather than applying force directly to the fragile image sensor, thus preventing cracking or buckling.
Solution Approach 2:
The patent changes the physical state or configuration parameter of the bending substrate (from flat to curved) to achieve the desired shape transformation. By controlling the curvature radius and deformation parameters of the bending substrate, the image sensor is gradually bent into the desired curved shape without exceeding its mechanical strength limits.
2Manufacturing precision
If the image sensor is bent into a curved shape, then uniform light intensity and spatial frequency response are achieved, but the manufacturing complexity increases
Solution Approach 1:
The manufacturing process is segmented into distinct stages: first fabricating the flat image sensor separately, then bonding the bending substrate to it, and finally deforming the substrate into the desired curved shape. This segmentation allows each component to be optimized and manufactured independently, reducing overall manufacturing complexity while achieving the precise curved configuration needed for uniform light intensity and spatial frequency response.
Solution Approach 2:
The patent applies curvature to the image sensor by bonding it to a bending substrate that is deformed into a spherical or aspherical shape. This curvature transformation enables the image sensor to achieve uniform light intensity and spatial frequency response across its surface, while the modular bending substrate approach keeps the manufacturing process manageable.
3Stability of the object's composition
If a bending substrate is bonded onto the image sensor, then the curved shape is maintained, but the device complexity increases
Solution Approach 1:
The bending substrate is permanently bonded to the image sensor, merging the two components into a single integrated curved structure. This merging maintains the curved shape stability while reducing the need for separate support structures or active control mechanisms, thereby limiting the increase in device complexity.
Solution Approach 2:
The bending substrate is designed as a thin, flexible layer that can be deformed into the desired curved shape and bonded to the image sensor. This thin-film approach maintains the curved shape effectively while adding minimal structural complexity and mass to the overall device.
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
The curved image sensor design enhances optical system performance by providing uniform light intensity and spatial frequency response, reduces dark current, and avoids cracking or buckling, allowing for more flexible integration into optical systems.
Implementation Method 1
Forces or torques are applied to the bending substrate so as to introduce tension to the image sensor. The tension leads to bending of the image sensor into any of a number of curved shapes.
Implementation Method 2
an image sensor fabricated on a relatively brittle substrate, such as silicon or germanium, for example, may be bent so that the light-sensitive surface of the image sensor is curved
Data Source
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AI summary
Techniques for fabricating an image sensor chip having a curved surface include placing a bending substrate on a first surface of an imaging sensor chip. The first surface of the imaging sensor chip includes light sensors to generate electrical signals in response to receiving light. Fabricating also includes bending the bending substrate so as to impart forces on the image sensor chip to produce a curved imaging sensor chip. A second surface of the curved imaging sensor chip may be adhered to a backside substrate. The second surface is opposite the first surface. The bending substrate may be removed from the first surface of the imaging sensor chip.