Porous Rewiring Layer Structure for Thermal-Cycle-Resistant Modules
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing modules with a package-on-package (POP) structure experience degradation due to thermal cycling, as the relationship between the insulating layer and wiring conductor pores is not adequately considered, leading to potential separation and degradation.
Innovation Solution
A module design featuring a rewiring layer with a rewiring conductor and insulating layer, where the rewiring conductor has smaller pores than the insulating layer, reducing the thermal expansion coefficient difference and preventing separation, achieved through the use of specific particle size fillers and resins in the conductive and insulating layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a porous insulating layer is used as a rewiring layer, then the dielectric constant and dielectric loss are reduced, but degradation due to thermal cycling occurs because the relationship between insulating layer pores and wiring conductor pores is not considered
Solution Approach 1:
The patent applies porous materials in both the insulating layer and wiring conductor, with the insulating layer having pores of 0.5-5.0 μm and the wiring conductor having pores of 0.1-1.0 μm. This porous structure reduces dielectric loss while the coordinated pore size relationship prevents thermal cycling degradation by matching thermal expansion characteristics between layers.
Solution Approach 2:
The patent changes the pore size parameters of both the insulating layer and wiring conductor to achieve optimal performance. By controlling the pore diameter ratios and filling rates, the patent simultaneously achieves low dielectric loss and high reliability under thermal cycling conditions.
2Ease of manufacture
If the insulating layer and wiring conductor have different pore sizes without coordination, then manufacturing is simplified, but separation occurs due to thermal expansion mismatch
Solution Approach 1:
The patent employs coordinated porous structures in both the insulating layer and wiring conductor, where the pore size relationship (wiring conductor pores 0.1-1.0 μm, insulating layer pores 0.5-5.0 μm) reduces thermal expansion mismatch and prevents separation while maintaining manufacturing feasibility through screen printing processes.
Solution Approach 2:
The patent creates a composite structure where the wiring conductor and insulating layer are both porous materials with coordinated pore characteristics. This composite approach allows the two layers to work together harmoniously under thermal stress, preventing separation while maintaining ease of manufacture through compatible processing methods.
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 design effectively prevents or reduces degradation due to thermal cycling by minimizing thermal expansion mismatch, enhancing flexibility and bonding strength, thereby improving module reliability.
Implementation Method 1
the rewiring conductor and the insulating layer include first pores and second pores, respectively, each of the first pores having a smaller average diameter than each of the second pores
Data Source
AI summary
A module, including: a sealed body including a circuit board and an electronic component each sealed with a sealing resin, wherein a conductor is exposed from a part of a surface of the sealed body; and a rewiring layer disposed on a surface of the sealed body and including an insulating layer and a rewiring conductor connected to the conductor, wherein the rewiring conductor includes: a connecting conductor disposed in the insulating layer and connected to the conductor; and an input/output electrode disposed on a surface of the insulating layer on a side opposite to a side facing the sealed body and connected to the connecting conductor, and the rewiring conductor and the insulating layer include first pores and second pores, respectively, each of the first pores having a smaller average diameter than each of the second pores in the insulating layer.