Microphone Chip Arrangement with Adjustable Backside Volume
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Solution Overview
Problem
The manufacture of conventional silicon microphones is complex and difficult to optimize due to limited backside volume, which restricts the performance of the micro-electromechanical system (MEMS) chips, and requires numerous processing steps and specialized equipment.
Innovation Solution
A method involving bonding a microphone chip to a first carrier, depositing adhesive material laterally from the microphone structure, and arranging the microphone structure into a cavity of a second carrier to create a chip arrangement that allows for adjustable backside volume and acoustic sealing, using hot melt adhesive materials and flip chip bonding for robust interconnections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the backside volume is increased to optimize microphone performance, then the performance is improved, but the wafer thickness must be increased which complicates manufacturing
Solution Approach 1:
The device is divided into separate components: the MEMS chip and the housing are manufactured independently and then assembled together. The housing contains the backside volume cavity, which is formed separately from the MEMS chip fabrication process. This segmentation allows the backside volume to be optimized independently of the wafer thickness.
Solution Approach 2:
The housing acts as an intermediary structure that provides the backside volume cavity. Instead of forming the cavity directly in the wafer, the housing serves as a mediator that creates the required acoustic volume through its internal cavity structure, decoupling the volume requirement from the wafer thickness.
2Ease of manufacture
If conventional manufacturing methods are used, then the process is established, but numerous processing steps and specialized equipment are required increasing complexity
Solution Approach 1:
Multiple functions are merged into fewer manufacturing steps. The housing is formed using injection molding which simultaneously creates the cavity structure and the acoustic seal. The assembly process combines the MEMS chip mounting, acoustic sealing, and backside volume formation into a single integration step, reducing the total number of processing steps.
Solution Approach 2:
The patent employs standard injection molding technology, which is aĉç, cost-effective manufacturing process widely used in the industry. This replaces the need for specialized, expensive equipment while achieving the required precision and functionality through conventional manufacturing methods.
3Ease of manufacture
If the backside volume is limited by wafer thickness, then manufacturing is simpler, but the performance of the microphone is restricted
Solution Approach 1:
The solution moves from a two-dimensional constraint (wafer thickness) to a three-dimensional solution by creating a vertical cavity within the housing structure. The backside volume is no longer limited by the horizontal dimensions of the wafer but extends vertically within the housing, effectively adding a new dimensional space for volume optimization.
Solution Approach 2:
The MEMS chip is nested within the housing structure, which contains the backside volume cavity. This nested arrangement allows the smaller MEMS chip to be positioned within the larger housing that provides the acoustic volume, enabling performance optimization without increasing the overall device footprint or complicating the manufacturing process.
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 simplifies the manufacturing process, allows for adjustable backside volume, and provides a cost-effective method to form microphones with improved performance by enabling acoustic sealing and robust electrical interconnections, reducing the need for expensive dedicated equipment.
Implementation Method 1
the adhesive material fixes the microphone chip to the cavity of the second carrier
Data Source
AI summary
In various embodiments, a method for manufacturing a chip arrangement, the method including bonding a microphone chip to a first carrier, the microphone chip including a microphone structure, depositing adhesive material laterally disposed from the microphone structure, and arranging the microphone structure into a cavity of a second carrier such that the adhesive material fixes the microphone chip to the cavity of the second carrier.