Through-Via Substrate Structure for High-Current Void Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing through-via substrates face challenges in increasing the allowable current while minimizing defects such as voids in conductive and resin materials as the dimension of the through holes increases.
Innovation Solution
A through-via substrate design with a through hole having a minimum dimension and specific ratios of distances and thicknesses, including resin layers and conductive layers, is implemented to enhance current capacity and prevent defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the dimension of the through hole in the plane direction is increased to increase the allowable current, then the allowable current increases, but the conductive material or resin material is likely to have defects such as voids
Solution Approach 1:
The through via is divided into multiple portions (first portion, second portion, third portion) along the thickness direction, with each portion having different structural characteristics. The closed portion is segmented from the main through via body, creating a distinct sealing structure that prevents void formation while maintaining current-carrying capacity across different dimensional regions
Solution Approach 2:
The through via structure combines conductive material (for current conduction) with resin material (for filling and insulation), creating a composite structure. The closed portion acts as a sealing element that integrates both materials, preventing voids in the resin material while maintaining electrical continuity through the conductive material portions
2Reliability
If the dimension of the through hole is increased to increase the allowable current, then the allowable current increases, but the resin material filled in the through hole is likely to have defects such as voids
Solution Approach 1:
The closed portion acts as an intermediary structure between the conductive material and the resin material. It seals the interface regions where voids typically form, mediating the interaction between the two materials and preventing resin material defects while allowing the through hole dimension to be increased for higher current capacity
3Reliability
If the through hole dimension is increased, then the allowable current increases, but the uniformity and thermodynamic reliability deteriorate due to increased thermal stress
Solution Approach 1:
Different portions of the through via have different structural qualities optimized for their specific functions. The closed portion provides local sealing quality to prevent voids and manage thermal stress at critical interfaces, while the first and second portions maintain electrical conductivity. This local differentiation allows the overall structure to handle higher currents while maintaining uniformity and thermodynamic reliability
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A through via includes a closed portion that closes a through hole at least at a minimum portion of the through hole, a third portion that is located on a wall surface of the through hole between a first surface and the closed portion, and a fourth portion that is located on the wall surface of the through hole between a second surface and the closed portion. A resin layer includes a first resin layer that is located inside the third portion and a second resin layer that is located inside the fourth portion. The through via has a first distance that is a maximum value of a distance from the first surface to the closed portion in a thickness direction of a substrate and a second distance that is a maximum value of a distance from the second surface to the closed portion in the thickness direction of the substrate. A ratio of the first distance to a thickness of the substrate is 0.10 or more. A ratio of the second distance to the thickness of the substrate is 0.10 or more.