Sunk-Type Optical Sensor Package Cavity Integration
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Solution Overview
Problem
Existing optical sensor package structures in wearable and mobile devices are difficult to miniaturize without significant cost and performance degradation, as current methods require advanced fabrication processes and increased risk, making it challenging to reduce size while maintaining functionality.
Innovation Solution
A sunk-type package structure for optical sensors, where the optical sensing chip is disposed within a cavity of the substrate, reducing size by integrating the light source and sensing chips inside the cavity, and using a light-permeable housing to minimize electromagnetic interference and optical crosstalk, while maintaining effective light transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the optical sensing chip is disposed inside the cavity of the substrate, then the size of the optical sensor is decreased, but the fabrication complexity and tolerance requirements increase
Solution Approach 1:
The optical sensing chip is nested inside the cavity formed in the substrate, creating a compact integrated structure. The cavity is formed by etching or removing material from the substrate to create a recessed area that accommodates the optical sensing chip, allowing the chip to be positioned below the surface level of the substrate. This nesting approach reduces the overall package size while maintaining functional performance.
Solution Approach 2:
The invention transitions from a planar arrangement where all components are on the same surface to a three-dimensional arrangement utilizing vertical space. By creating a cavity in the substrate and placing the optical sensing chip within this cavity, the design exploits the third dimension (depth) to reduce the footprint area, effectively moving components from a two-dimensional layout to a three-dimensional configuration.
2Length of stationary object
If the optical sensing chip is disposed inside the cavity of the substrate, then the thickness of the optical sensor is decreased, but the manufacturing precision requirements increase
Solution Approach 1:
The cavity is formed in the substrate before the optical sensing chip is mounted. This preliminary formation of the cavity allows for precise control of the recess depth and dimensions, establishing a predetermined positioning structure that guides the subsequent placement of the optical sensing chip. The cavity acts as a pre-prepared receptacle that ensures proper alignment and depth control.
Solution Approach 2:
The invention uses a cost-effective approach by forming the cavity through standard substrate processing techniques rather than requiring expensive advanced fabrication processes. The cavity structure serves as a simple but effective solution to achieve thickness reduction without necessitating complex or costly manufacturing steps, making the approach economically viable.
3Volume of moving object
If conventional methods are used to reduce package size, then cost increases and performance degrades, but if the sunk-type structure is used, then size decreases while maintaining performance
Solution Approach 1:
The invention merges the substrate and optical sensing chip into a single integrated structure by embedding the chip within the substrate cavity. The housing then encapsulates both the substrate and embedded chip as a unified assembly. This merging eliminates the need for separate mounting structures and reduces the overall package volume while maintaining the functional performance of the optical sensing chip through proper light path management.
Solution Approach 2:
The invention extracts the optical sensing chip from the traditional surface-mounted position and relocates it into the cavity of the substrate. This extraction from the conventional packaging arrangement allows for reduced package size while the housing structure is designed to maintain the necessary optical pathways and protective functions, thereby preserving performance despite the changed configuration.
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 sunk-type package structure effectively decreases the size of optical sensors by integrating components within a cavity, reducing thickness and size, while enhancing sensing performance and minimizing interference, thus addressing the limitations of conventional methods.
Implementation Method 1
The housing includes a light-permeable area positioned above the first sensing area
Data Source
AI summary
A sunk-type package structure includes a substrate, an optical sensing chip, and a housing. The substrate has a cavity with a first depth. The optical sensing chip is disposed inside the cavity and electrically connected with the substrate. A surface of the optical sensing chip has a first sensing area for sensing light. The housing covers the substrate and the optical sensing chip. The housing has a light-permeable portion disposed above the first sensing area.