Flip-Chip Semiconductor Detector With Low-Capacitance Underfill Layout
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Solution Overview
Problem
The existing silicon drift detectors face challenges in reducing parasitic capacitance and inductance when connecting the reading electrode and amplifier with a wire, which leads to noise interference and affects the sensitivity of electromagnetic wave energy measurement.
Innovation Solution
The semiconductor detector employs a flip-chip connection structure between the first semiconductor chip with the reading electrode and the second semiconductor chip with the amplifier, where an underfill is injected into the gap between the chips except for specific connection portions. These connection portions are designed to avoid being surrounded by the underfill, using guide portions to create spaces with lower permittivity, thereby reducing parasitic capacitance and inductance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a wire is used to connect the reading electrode and amplifier, then electrical connection is achieved, but parasitic capacitance and inductance increase causing noise interference
Solution Approach 1:
The harmful wire connection is completely removed from the system. Instead of using a wire to connect the reading electrode and amplifier, the patent extracts this problematic element and replaces it with a direct flip-chip bonding connection, eliminating the source of parasitic capacitance and inductance.
Solution Approach 2:
An underfill material is introduced as an intermediary substance between the first semiconductor chip (containing the reading electrode) and the second semiconductor chip (containing the amplifier). This underfill serves as a mediator that provides mechanical support and electrical isolation while allowing the creation of a low-permittivity space that reduces parasitic effects.
2Stability of the object's composition
If underfill is injected into the gap between chips, then mechanical support and filling are achieved, but parasitic capacitance increases around connection portions
Solution Approach 1:
The patent applies local quality by creating a specific low-permittivity space around the connection portions between the chips, while the rest of the gap is filled with underfill material. This localized modification ensures that the connection areas have optimized electrical characteristics (reduced parasitic capacitance) while the overall structure maintains mechanical stability through the underfill.
Solution Approach 2:
The gap between the chips is segmented into two functional zones: a low-permittivity space surrounding the connection portions for electrical performance, and the remaining gap filled with underfill for mechanical support. This segmentation allows each zone to fulfill its specific function without compromising the other.
3Ease of manufacture
If wire connection is used, then ease of manufacturing is improved, but measurement precision deteriorates due to noise from parasitic elements
Solution Approach 1:
The patent merges the reading electrode chip and amplifier chip into a single integrated flip-chip assembly with direct bonding. This merging eliminates the separate wire connection step while maintaining manufacturing feasibility through standardized flip-chip processes, thereby improving measurement precision by eliminating parasitic elements.
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 effectively suppresses noise interference caused by parasitic capacitance and inductance, enhancing the sensitivity of the semiconductor detector for measuring electromagnetic wave energy.
Implementation Method 1
the wire necessarily contains a parasitic capacitance and a parasitic inductance. Therefore, the noises due to the parasitic capacitance and the parasitic inductance are superimposed on the signal output from the reading electrode
Implementation Method 2
the wire necessarily contains a parasitic capacitance and a parasitic inductance
Data Source
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AI summary
A technique capable of improving a performance of a semiconductor detector is provided. The semiconductor detector is made based on injection of an underfill into a gap between a first semiconductor chip and a second semiconductor chip in a flip-chip connection state, but the underfill is not formed in periphery of a connection structure connecting a reading electrode pad and a gate terminal through a bump electrode.