MEMS Device Integration via Through Molding Vias
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrating MEMS pressure sensor, motion sensor, and gyroscope sensor devices into a single integrated circuit manufacturing process poses challenges due to unique electrically interconnecting requirements.
Innovation Solution
A method involving the formation of MEMS devices with a substrate, dielectric layers, polysilicon layers, and bonding material layers, where MEMS structures are patterned and bonded with a cap wafer to create sealed cavities with varying pressures, and electrical connectors are formed for interconnection, allowing for the integration of known good dies and reducing costs through the use of through molding vias instead of through substrate vias.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If MEMS devices with different pressure cavity requirements are integrated into a single manufacturing process, then device functionality and versatility are improved, but manufacturing complexity and process difficulty increase
Solution Approach 1:
The patent divides the manufacturing process into separate stages: first forming MEMS structures with first pressure cavity requirements, then bonding cap wafers to create second pressure cavities with different requirements. This segmentation allows each stage to be optimized independently for its specific pressure requirements, enabling integration of diverse MEMS devices while managing manufacturing complexity.
Solution Approach 2:
The patent performs preliminary actions by first forming the MEMS structures and their pressure cavities before bonding the cap wafers. This preliminary formation of pressure cavities with specific requirements allows subsequent cap wafer bonding to create additional cavities with different pressure characteristics, enabling versatile device functionality through staged manufacturing.
2Reliability
If through substrate vias are used for electrical interconnection, then connectivity is achieved, but manufacturing cost and process difficulty increase
Solution Approach 1:
The patent extracts the electrical interconnection function from the substrate itself by using through molding vias formed in the molding compound rather than through substrate vias. This extraction simplifies the manufacturing process and reduces costs while maintaining reliable electrical connectivity between MEMS devices and external circuits.
Solution Approach 2:
The patent introduces molding compound as an intermediary material that contains through molding vias for electrical interconnection. This intermediary approach replaces complex through substrate via formation with a simpler process of forming vias in the molding compound after device assembly, reducing manufacturing difficulty and cost while achieving reliable connectivity.
3Productivity
If all MEMS dies are integrated regardless of quality, then productivity is improved, but device reliability decreases
Solution Approach 1:
The patent performs preliminary quality assessment and selection of MEMS dies before integration into the final device. This preliminary action ensures that only known good dies are selected and integrated, maintaining high device reliability and yield while preserving productivity by preventing defective dies from consuming integration resources.
Solution Approach 2:
The patent implements a self-service quality control mechanism where MEMS dies are evaluated and selected based on their own performance characteristics before integration. This self-service approach to quality assurance ensures that only functioning dies are integrated, maintaining high reliability while efficiently utilizing manufacturing capacity.
Data Source
AI summary
An embodiment is a MEMS device including a first MEMS die having a first cavity at a first pressure, a second MEMS die having a second cavity at a second pressure, the second pressure being different from the first pressure, and a molding material surrounding the first MEMS die and the second MEMS die, the molding material having a first surface over the first and the second MEMS dies. The device further includes a first set of electrical connectors in the molding material, each of the first set of electrical connectors coupling at least one of the first and the second MEMS dies to the first surface of the molding material, and a second set of electrical connectors over the first surface of the molding material, each of the second set of electrical connectors being coupled to at least one of the first set of electrical connectors.