Electro-optical Module Interposer Flip-Chip Signal Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electro-optical modules using wire bonding for connecting VCSEL diodes to substrates suffer from signal losses and electromagnetic interference during high frequency signal transmission due to limitations in loop length and height of bonding wires.
Innovation Solution
The electro-optical module employs an interposer for flip-chip electrical connection between the electro-optical element and the substrate, reducing signal transmission distance, and incorporates metal support members for EMI shielding and a heat sink for thermal dissipation, while maintaining precise alignment with a transparent plate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wire bonding is used to connect VCSEL diodes to substrates, then electrical connection is achieved, but signal losses and electromagnetic interference occur during high frequency signal transmission
Solution Approach 1:
The patent introduces an interposer as an intermediary component between the VCSEL diode and the substrate. The interposer provides a direct electrical connection path through its conductive structure, eliminating the need for bonding wires and their associated loop lengths. This intermediary structure resolves the contradiction by providing reliable high-frequency signal transmission without the harmful effects of long bonding wire loops.
Solution Approach 2:
The patent replaces the mechanical wire bonding system with a direct flip-chip mounting approach. Instead of using bonding wires to create electrical connections, the VCSEL diode is directly mounted to the interposer with its bonding pads contacting the interposer's contact pads. This substitution eliminates the mechanical loop structure that causes electromagnetic interference and signal loss.
2Reliability
If bonding wires are used for electrical connection, then electrical connectivity is established, but electromagnetic interference occurs during high frequency transmission
Solution Approach 1:
The interposer serves as a mediator that provides a controlled impedance path for electrical signals. By routing signals through the interposer's internal conductive structures rather than through bonding wires, the system maintains electrical connectivity while minimizing electromagnetic interference. The interposer acts as an intermediary that transforms the connection architecture to eliminate EMI sources.
Solution Approach 2:
The patent extracts and removes the bonding wires from the system entirely. By eliminating the bonding wire component, the source of electromagnetic interference is removed. The electrical connection function is extracted from the wire bonding process and transferred to the direct flip-chip mounting interface between the VCSEL diode and the interposer.
3Reliability
If wire bonding is used to connect electro-optical elements, then electrical connection is achieved, but signal losses occur during high frequency transmission
Solution Approach 1:
The patent substitutes the wire bonding mechanical system with a direct contact system. The VCSEL diode's bonding pads are directly contacted by the interposer's contact pads through flip-chip mounting, eliminating the bonding wire loop. This substitution reduces signal loss by providing a shorter, more direct electrical path with fewer interfaces and lower impedance discontinuities.
Solution Approach 2:
The interposer acts as an intermediary that provides a low-loss transmission path for high-frequency signals. Its controlled impedance structure and direct connection architecture minimize signal attenuation and reflection, resolving the contradiction between maintaining electrical connection and reducing signal loss.
4Reliability
If conventional wire bonding architecture is used, then electrical connection is established, but module size remains large
Solution Approach 1:
The patent extracts and removes the bonding wires and their associated loop structures from the module architecture. By eliminating these space-consuming components, the module footprint and height are reduced. The electrical connection function is maintained through the compact interposer structure, achieving miniaturization without sacrificing connectivity.
Solution Approach 2:
The patent transitions from a planar wire bonding architecture to a three-dimensional flip-chip mounting approach. The VCSEL diode is mounted face-down on the interposer, utilizing the vertical dimension for electrical connection. This dimensional change allows for more compact integration and reduces the overall module size while maintaining reliable electrical connections.
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 configuration reduces signal losses, enhances EMI shielding, and improves thermal dissipation, making the module suitable for high frequency signal transmission with improved accuracy and reduced size.
Implementation Method 1
an interposer disposed on the first surface of the substrate and the electro-optical element for electrically connecting the electro-optical element to the substrate
Implementation Method 2
incorporates metal support members for EMI shielding
Implementation Method 3
incorporates metal support members for EMI shielding and a heat sink for thermal dissipation
Implementation Method 4
a transparent plate disposed over the first surface of the substrate and the interposer through the support members and having a lens portion corresponding in position to the through hole of the interposer
Data Source
AI summary
An electro-optical module is provided, which includes: a substrate having a first surface with a groove and an opposite second surface; a plurality of support members disposed on the first surface of the substrate; at least an electro-optical element having opposite active and non-active surfaces and disposed in the groove of the substrate via the non-active surface thereof; an interposer disposed on the first surface of the substrate and the electro-optical element for electrically connecting the electro-optical element to the substrate, wherein the interposer has a through hole corresponding in position to the active surface of the electro-optical element; and a transparent plate disposed over the first surface of the substrate and the interposer through the support members and having a lens portion corresponding in position to the through hole of the interposer, thereby reducing signal losses, improving alignment precision, and achieving preferred thermal dissipation and EMI shielding effects.