MEMS Transducer Package with Integrated Die and Wafer-Level Cap
Solution Overview
Problem
Conventional MEMS transducer packages are complex and costly due to their multi-part assemblies and require physical clearance for connections, which increases size and material costs.
Innovation Solution
A MEMS transducer package design featuring a semiconductor die portion with integrated electronic circuitry and a cap portion that acoustically connects with a stepped back volume, allowing for efficient packaging and reduced size, with the cap portion formed using wafer-level processing techniques to match thermal expansion coefficients and minimize stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional multi-part assemblies are used for MEMS transducer packages, then environmental protection and electrical connections are provided, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the package substrate, cover, and acoustic port functions into a single integrated semiconductor die structure. The die itself forms the package substrate with integrated circuitry, while the cap portion integrated directly onto the die eliminates the need for separate cover and substrate components, thereby reducing device complexity while maintaining environmental protection
Solution Approach 2:
The semiconductor die serves multiple functions simultaneously: it acts as the package substrate, provides environmental protection, integrates electronic circuitry for signal processing, and forms part of the acoustic path. This multi-functionality eliminates the need for separate dedicated components for each function, reducing overall package complexity
2Ease of operation
If physical clearance is provided for connections in MEMS transducer packages, then wire bonding and electrical connections are enabled, but package size increases
Solution Approach 1:
The patent merges the electrical connection function directly into the semiconductor die by integrating the electronic circuitry within the die structure. Bond pads are formed directly on the die surface, eliminating the need for separate connection clearance zones and reducing overall package footprint
Solution Approach 2:
The patent transitions from planar wire bonding requiring lateral clearance to vertical through-silicon via connections that route signals through the die thickness. This dimensional change allows electrical connections to be made in the vertical dimension rather than requiring lateral space, thereby reducing package footprint
3Ease of manufacture
If conventional package substrates are used, then transducer attachment and electrical pathways are provided, but manufacturing cost and complexity increase
Solution Approach 1:
The patent merges the package substrate function directly into the semiconductor die structure. The die serves as both the transducer mounting platform and the electronic circuitry carrier, eliminating the need for separate package substrates and reducing manufacturing steps
Solution Approach 2:
The semiconductor die is self-sufficient, providing both the mechanical platform for transducer attachment and the electronic circuitry for signal processing within a single component. This self-service capability eliminates the need for additional package substrate layers and associated manufacturing complexity
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 design results in a smaller, more cost-effective MEMS transducer package with reduced footprint and enhanced acoustic performance by integrating circuitry and using wafer-level processing for the cap portion, enabling efficient acoustic coupling and thermal stress management.
Implementation Method 1
cap portion formed using wafer-level processing techniques to match thermal expansion coefficients and minimize stress
Implementation Method 2
The die back volume and the cap back volume may acoustically connect
Implementation Method 3
the electrical output signal is usually obtained by measuring a signal related to the capacitance between the electrodes
Implementation Method 4
cap portion formed using wafer-level processing techniques to match thermal expansion coefficients and minimize stress
Data Source
AI summary
A MEMS transducer package is provided having a semiconductor die portion with a thickness bounded by a first surface and an opposite second surface. The package further has a transducer element incorporated in the second surface and a die back volume that extends through the thickness of the semiconductor die portion between the first surface and the transducer element. The package is completed by a cap portion that abuts the semiconductor die portion at the first surface.