Hybrid Glass Core Lamination for Uniform Through-Hole Packaging
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Solution Overview
Problem
Copper-clad laminates fail to meet the increasing demands of semiconductor packaging architectures for improved total thickness variation (TTV), lower coefficient of thermal expansion (CTE), lower shrinkage, and higher elastic modulus, leading to assembly difficulties and high costs due to challenges in patterning through-holes in thick glass cores.
Innovation Solution
A hybrid glass core is developed, comprising multiple thin glass layers laminated together with dielectric layers, allowing for cost-effective formation of through-holes with low aspect ratios, thereby achieving the desired mechanical properties without the processing limitations of monolithic glass cores.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If monolithic thick glass cores are used, then low TTV, low CTE, low shrinkage, and high modulus are achieved, but through-hole patterning becomes exceedingly difficult with severely tapered profiles
Solution Approach 1:
The patent divides the thick glass core into multiple thin glass layers (each approximately 50-150 μm thick) that are laminated together with dielectric layers. This segmentation allows through-holes to be formed in each thin layer with low aspect ratios, avoiding the severe tapering problem that occurs when drilling through thick monolithic glass cores. The through-holes pass through multiple layers sequentially, achieving the required thickness while maintaining profile uniformity.
Solution Approach 2:
The patent transitions from forming through-holes in a single thick glass layer to forming through-holes across multiple thin glass layers stacked in the vertical dimension. By distributing the through-hole formation across multiple layers, each with a small thickness-to-diameter ratio, the overall thick substrate requirement is met while maintaining manufacturable aspect ratios for each individual layer.
2Manufacturing precision
If CCL cores are used, then ease of manufacture is maintained, but TTV and shrinkage requirements are not satisfied
Solution Approach 1:
The patent creates a hybrid composite structure combining glass layers and dielectric layers. The glass layers provide the critical mechanical properties of low TTV, low CTE, low shrinkage, and high modulus, while the dielectric layers enable through-hole formation and provide electrical insulation. This composite approach allows the core to meet stringent mechanical requirements while remaining manufacturable.
3Manufacturing precision
If planarization processes are implemented to correct high incoming core TTV, then TTV requirements are met, but manufacturing cost becomes prohibitive
Solution Approach 1:
The patent performs preliminary action by controlling TTV at the core fabrication stage through the use of thin laminated glass layers with precise thickness control (approximately 50-150 μm each). By ensuring low TTV in the core before subsequent processing steps, the need for expensive planarization processes is eliminated, as the low incoming core TTV naturally carries through to the build-up and solder resist layers.
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
The hybrid glass core provides improved TTV, low CTE, low shrinkage, and high elastic modulus while enabling cost-effective manufacturing of thick substrates with uniform and efficient through-hole formation, reducing assembly costs and enhancing semiconductor packaging capabilities.
Implementation Method 1
A hybrid glass core is developed, comprising multiple thin glass layers laminated together with dielectric layers
Implementation Method 2
laser drilling of thick glass cores results in through glass vias with severely tapered profiles
Data Source
AI summary
Embodiments disclosed herein include hybrid cores for electronic packaging applications. In an embodiment, a package substrate comprises a plurality of glass layers and a plurality of dielectric layers. In an embodiment, the glass layers alternate with the dielectric layers. In an embodiment, a through-hole through the plurality of glass layers and the plurality of dielectric layers is provided. In an embodiment a conductive through-hole via is disposed in the through-hole.