Redistribution Interconnect for Microbeamformer Pitch Mismatch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional flip-chip architecture for microbeamformer ICs in ultrasound transducers faces challenges with high-frequency arrays and curved arrays, requiring unique ICs, limiting re-use and increasing development costs and time-to-market, and struggles with alignment accuracy and tolerance requirements in chip tiling.
Innovation Solution
A redistribution interconnect system that decouples microbeamformer ICs from transducer array spatial constraints, using flip-chip bumps to connect ICs with different pitch sets to transducer elements, allowing for geometrical remapping and pitch matching in both azimuth and elevation directions, enabling flexible interconnect designs for flat and curved arrays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flip-chip architecture is used to couple microbeamformer ICs to transducer arrays, then electrical connection reliability is improved, but spatial constraint flexibility deteriorates due to pitch-matching requirements
Solution Approach 1:
A redistribution interconnect layer is introduced as an intermediary between the microbeamformer IC and the transducer array. This redistribution layer acts as a mediator that receives signals from IC bond pads at one pitch and redistributes them to transducer elements at a different pitch, thereby decoupling the spatial constraints of the IC from those of the array while maintaining reliable electrical connections through flip-chip bumps
2Ease of manufacture
If pitch-matched transducer arrays and microbeamformer ICs are used, then manufacturing simplicity is improved, but re-use opportunities are reduced and development costs increase
Solution Approach 1:
The redistribution interconnect layer provides universal adaptability that allows a single microbeamformer IC design to interface with multiple transducer array configurations having different pitches. This multi-functional capability enables the same IC to be reused across different array designs, increasing re-use opportunities while the standardized flip-chip process maintains manufacturing simplicity
3Reliability
If flip-chip architecture with pitch-matching is used, then interconnection reliability is improved, but development time increases due to limited re-use opportunities
Solution Approach 1:
The redistribution interconnect serves as a flexible intermediary that maintains reliable flip-chip interconnections while enabling design re-use. By decoupling the pitch constraints, existing IC designs can be reused with different arrays through the redistribution layer, significantly reducing development time without compromising interconnection reliability
4Manufacturing precision
If microbeamformer ICs are designed with specific pitch constraints, then manufacturing precision is improved, but adaptability to different array configurations deteriorates
Solution Approach 1:
The interconnection system is segmented into two independent parts: the microbeamformer IC with its fixed pitch bond pads, and the transducer array with its fixed pitch elements. The redistribution interconnect layer bridges these segmented parts, allowing each to maintain its own manufacturing precision requirements while adapting to different configurations through the flexible redistribution network
Data Source
AI summary
An ultrasound transducer includes one or more microbeamformer integrated circuit chips, an array of acoustic elements, and a redistribution interconnect coupled via conductive elements between the one or more integrated circuit chips and the array of acoustic elements. The one or more microbeamformer integrated circuit chips each include a plurality of bond pads separated from adjacent ones thereof by a first pitch set. The acoustic elements of the array are separated from adjacent ones thereof by a second pitch set, the second pitch set being different from the first pitch set. In addition, the redistribution interconnect couples on a first side of the redistribution interconnect to the one or more microbeamformer integrated circuit chips via conductive elements. The redistribution interconnect couples on a second side to the array of transducer elements via conductive elements. The redistribution interconnect provides an interconnection between the bond pads of the one or more microbeamformer integrated circuit chips with the first pitch set with corresponding ones of the acoustic elements of the array with the second pitch set.