Semiconductor Package Adhesive Structure for Thermal Shock Reliability
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Solution Overview
Problem
The increasing demand for miniaturized and lightweight electronic components in portable devices necessitates improved integration and reliability of semiconductor packages, particularly in addressing thermal shock issues during mounting on main boards.
Innovation Solution
A semiconductor package design featuring a two-layer adhesive structure, where a lower adhesive layer with an expanded area disperses vertical stress, and a thinner upper adhesive layer, enhancing thermal shock reliability by increasing the overall thickness of the adhesive structure without altering the package structure significantly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-layer adhesive structure is used to attach the semiconductor chip, then the package structure remains simple, but thermal shock reliability is insufficient due to concentrated stress
Solution Approach 1:
The adhesive structure is divided into two separate adhesive layers: a first adhesive layer attached to the lower surface of the semiconductor chip, and a second adhesive layer attached to the upper surface of the package substrate. This segmentation allows each layer to independently manage stress, with the first layer providing primary attachment and the second layer dispersing thermal stress, thereby improving thermal shock reliability while maintaining reasonable structural complexity.
2Reliability
If the adhesive layer area is expanded to disperse stress, then thermal shock reliability improves, but the package area and overall size increase
Solution Approach 1:
Instead of expanding the adhesive area in the horizontal plane, the solution extends the adhesive structure in the vertical dimension by adding a second adhesive layer on the package substrate surface. This layer has a larger area than the chip footprint, dispersing stress vertically and horizontally without increasing the overall package footprint, thus improving thermal shock reliability while maintaining compact package dimensions.
3Reliability
If the adhesive structure thickness is increased to improve thermal shock resistance, then reliability improves, but the package height increases
Solution Approach 1:
The second adhesive layer is strategically positioned and sized to extend beyond the chip boundaries on the package substrate surface, creating a local stress-dispersing structure. This localized extension provides enhanced thermal shock resistance through increased adhesive volume and stress distribution area, while the overall package height increase is minimized by confining the adhesive layers to specific regions rather than uniformly thickening the entire package structure.
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 significantly increases thermal shock reliability by dispersing concentrated stress and alleviating thermal shock, as demonstrated by reduced defect occurrence in semiconductor packages under repeated temperature changes.
Implementation Method 1
a first adhesive film attached to a lower surface of the semiconductor chip; a second adhesive film attached to an upper surface of the package substrate, wherein the second adhesive film is joined to the first adhesive film
Data Source
AI summary
A semiconductor package includes a package substrate, where a plurality of bonding pads are arranged on an upper surface of the package substrate; a semiconductor chip mounted on the upper surface of the package substrate, where a plurality of chip pads are arranged on an upper surface of the semiconductor chip; a first adhesive film attached to a lower surface of the semiconductor chip, wherein the first adhesive film having a first area corresponding to an area of the semiconductor chip; a second adhesive film attached to the upper surface of the package substrate, where the second adhesive film is joined to the first adhesive film, and the second adhesive film has a second area larger than the first area; a plurality of bonding wires; and a molding portion disposed on the upper surface of the package substrate.