Wiring Substrate Adhesion via Segmented Composite Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wiring substrates face challenges in achieving sufficient adhesion strength between stacked substrates, which affects their reliability and performance.
Innovation Solution
A wiring substrate design that includes a first substrate with a conductive paste and a second substrate with protruding electrodes, where the electrodes are electrically connected to the conductive paste, and both substrates have adhesive layers that are bonded together to enhance adhesion strength, allowing for improved stacking and connection reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional wiring substrates use stacked substrates with conductive paste for interconnection, then electrical connections between layers are achieved, but adhesion strength between stacked substrates is insufficient
Solution Approach 1:
The adhesive layer is segmented into multiple regions with different properties: a first region with first adhesive material and a second region with second adhesive material having different glass transition temperatures. This segmentation allows different portions of the substrate stack to be bonded at different temperatures, optimizing adhesion strength across the entire structure while accommodating thermal expansion differences.
Solution Approach 2:
Different regions of the adhesive layer are assigned different local qualities through the use of adhesive materials with distinct glass transition temperatures. The first adhesive material (lower Tg) provides flexibility and adhesion at lower temperatures, while the second adhesive material (higher Tg) provides structural stability and strong bonding at higher temperatures, creating a gradient of adhesive properties throughout the layer.
2Reliability
If adhesive layers are used to bond stacked substrates, then substrates can be connected, but adhesion strength between substrates remains insufficient
Solution Approach 1:
The adhesive layer is constructed as a composite material system combining two different adhesive materials with complementary properties. The first adhesive material (e.g., polyimide-based with lower Tg) and second adhesive material (e.g., epoxy-based with higher Tg) work synergistically to provide both initial bonding and final structural strength, achieving superior adhesion reliability that neither material could achieve alone.
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 enhanced adhesion strength between substrates improves the reliability and performance of the wiring substrate, enabling better electrical connections and reduced lead time in manufacturing, while allowing for selective stacking and increased yield rates.
Implementation Method 1
a first adhesive layer and a second adhesive layer stacked in layers, the adhesive layers being bonded to each other
Data Source
AI summary
A wiring substrate includes a first substrate and a second substrate stacked on the first substrate. The first substrate includes a first adhesive layer and conductive paste. The first adhesive layer is on a surface of a first insulating layer. The conductive paste is in an opening in the first adhesive layer. The second substrate includes a second adhesive layer and a protruding electrode. The second adhesive layer is on a surface of a second insulating layer facing toward the first substrate, and is bonded to the first adhesive layer. The protruding electrode has an end uncovered by the second adhesive layer, and is electrically connected to the conductive paste.