Ultra-Slim Fingerprint Sensor Package Without Separate PCB
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Solution Overview
Problem
Existing finger print sensor packages and fabrication methods are inadequate, particularly in achieving ultra-slim thickness without using a separate printed circuit board (PCB).
Innovation Solution
A finger print sensor package is designed with a semiconductor die, encapsulant, first and second redistribution layers (RDLs), passivation layers, and land grid arrays (LGAs), which allows for the fabrication of an ultra-slim finger print sensor with a thickness of 500 μm or less without a separate PCB.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a separate printed circuit board (PCB) is used in the finger print sensor package, then the electrical connection and signal transmission are improved, but the overall thickness and size of the package increases
Solution Approach 1:
The patent merges the PCB function with the sensor package by integrating redistribution layers (RDLs) directly onto the sensor substrate. The first and second RDLs are formed on the same substrate as the sensor, eliminating the need for a separate PCB while maintaining electrical connection functionality. This integration reduces the overall package thickness to 500 μm or less.
Solution Approach 2:
The patent transitions from a three-dimensional stacked structure (sensor + separate PCB) to a planar integrated structure where multiple functional layers are arranged in two dimensions on a single substrate. The RDLs are distributed across the substrate surface in a planar configuration, reducing the vertical dimension (thickness) while maintaining electrical connectivity through lateral routing.
2Length of stationary object
If the finger print sensor package is made ultra-slim (500 μm or less), then the miniaturization and slimness are improved, but the manufacturing complexity and precision requirements increase
Solution Approach 1:
The patent segments the package into distinct functional layers (sensor layer, encapsulant layer, passivation layers, RDL layers) that can be manufactured and processed separately before integration. This layer-by-layer fabrication approach allows each layer to be optimized independently, reducing the cumulative precision requirements compared to manufacturing a monolithic ultra-thin structure.
Solution Approach 2:
The patent performs preliminary actions by pre-forming the RDL patterns, passivation layers, and encapsulant structures before final assembly. The first RDL is formed with preliminary patterning, followed by encapsulant deposition, then the second RDL is added. This sequential preliminary preparation of each layer simplifies the final integration process and reduces the precision demands on the ultimate assembly step.
Data Source
AI summary
Various aspects of the present disclosure provide a semiconductor device, for example comprising a finger print sensor, and a method for manufacturing thereof. Various aspects of the present disclosure may, for example, provide an ultra-slim finger print sensor having a thickness of 500 μm or less that does not include a separate printed circuit board (PCB), and a method for manufacturing thereof.