Glass Interposer CCL Structure for Plating Vias Below Cavities
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in assembling glass interposers for optoelectronic systems lies in plating vias below cavities, which is a complex process, and existing technologies face issues with power and signal integrity due to the distance between ASIC modules and optical transceivers.
Innovation Solution
The use of glass interposers with vias below cavities, where copper clad laminate provides a continuous seed layer for electrolytic plating, enabling true 3D interconnect architectures, and the incorporation of adhesion promoting layers like silicon nitride improves mechanical reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a PCB is used to interface ASIC with optical transceivers, then the assembly is simpler, but power and signal integrity losses increase due to distance
Solution Approach 1:
The patent transitions from a planar PCB interface to a three-dimensional glass interposer structure. The glass interposer with cavities and vias enables vertical stacking and direct coupling of ASIC modules and optical transceivers in the Z-dimension, reducing horizontal distance and improving signal integrity while maintaining manufacturing feasibility through advanced packaging techniques.
Solution Approach 2:
The glass interposer acts as an intermediary substrate between the ASIC module and optical transceiver. It provides mechanical support, electrical interconnection through vias, and optical pathways, enabling direct coupling while simplifying the overall assembly process compared to traditional PCB-based solutions.
2Adaptability or versatility
If vias are plated below cavities in glass interposers, then true 3D interconnect architectures are enabled, but the plating process becomes complex
Solution Approach 1:
The patent applies preliminary actions by forming seed layers and adhesion promoters on the glass substrate surface before creating cavities and vias. The copper clad laminate is applied and patterned in advance, providing a continuous seed layer that simplifies subsequent electrolytic plating of vias below cavities, reducing the complexity of the overall plating process.
Solution Approach 2:
The patent replaces traditional mechanical drilling and plating methods with a combination of laser drilling for via formation and electrolytic plating using continuous seed layers. This substitution enables more precise and complex 3D interconnect architectures while managing process complexity through advanced material deposition techniques.
3Ease of manufacture
If copper clad laminate provides continuous seed layer for electrolytic plating, then via plating is enabled, but adhesion and mechanical reliability challenges arise
Solution Approach 1:
The patent uses composite material structures with multiple layers including adhesion promoters (such as silicon nitride), seed layers, and copper clad laminate. This composite approach ensures strong adhesion between the glass substrate and metallic interconnects, maintaining mechanical reliability while enabling electrolytic plating of vias through the continuous seed layer.
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 solution facilitates efficient signaling and assembly, reducing power and signal losses by enabling direct coupling of dies and improving mechanical reliability in optoelectronic systems.
Implementation Method 1
The copper foil of the CCL provides a continuous seed layer that can then be used in order to electrolytically plate up the vias in the via openings
Implementation Method 2
the incorporation of adhesion promoting layers like silicon nitride improves mechanical reliability
Data Source
AI summary
Embodiments disclosed herein include interposers and methods of forming interposers. In an embodiment, an interposer comprises a substrate with a first surface and a second surface opposite from the first surface, where the substrate comprises glass. In an embodiment, the interposer further comprises a cavity into the first surface of the substrate, a via through the substrate below the cavity, a first pad in the cavity over the via, and a second pad on the second surface of the substrate under the via.