Segmented Stiffener Ring Warpage Control
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Solution Overview
Problem
Electronic component packages experience warpage due to thermal coefficient of expansion differences between package components, and existing stiffener rings also warp, contributing to overall warpage, which complicates temperature control.
Innovation Solution
A segmented stiffener ring design with 'L' shaped segments and gaps between them is used, allowing for reduced thermal stress and warpage, with a higher thermal coefficient of expansion than the substrate to minimize warpage by expanding and contracting differently than the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If stiffener rings are incorporated into the electronic component package to control warpage, then the support and structural stability are improved, but the stiffener rings themselves warp due to thermal expansion differences, contributing to overall package warpage
Solution Approach 1:
The stiffener ring is divided into multiple discrete segments rather than being a continuous structure. Each segment is separated by gaps, allowing independent thermal expansion and contraction. This segmentation enables the stiffener to maintain structural support while accommodating thermal stresses without warping, directly resolving the contradiction between providing structural stability and preventing shape distortion.
2Strength
If a continuous stiffener ring is used to provide support, then the structural strength is improved, but the thermal stress applied to the substrate increases due to uniform expansion and contraction
Solution Approach 1:
By dividing the continuous stiffener ring into discrete segments with gaps between them, the structure maintains overall structural strength while allowing each segment to independently accommodate thermal expansion. This reduces the cumulative thermal stress transmitted to the substrate compared to a continuous ring that would uniformly expand and contract, thus resolving the contradiction between strength and stress.
Solution Approach 2:
The stiffener segments are strategically positioned and dimensioned to provide localized support where needed while leaving gaps in regions where thermal expansion occurs. This non-uniform distribution of stiffening elements allows the structure to maintain strength in critical areas while reducing thermal stress in regions prone to expansion, resolving the contradiction between strength and stress.
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 segmented stiffener ring effectively reduces its own warpage and the thermal stress it applies to the substrate, maintaining planarity of the package by contracting faster than the substrate upon cooling, thus minimizing warpage and maintaining package flatness.
Implementation Method 1
A segmented stiffener ring design with 'L' shaped segments and gaps between them is used, allowing for reduced thermal stress and warpage, with a higher thermal coefficient of expansion than the substrate to minimize warpage by expanding and contracting differently than the substrate
Implementation Method 2
maintaining planarity of the package by contracting faster than the substrate upon cooling, thus minimizing warpage and maintaining package flatness
Data Source
AI summary
A warpage control stiffener ring package includes a substrate having an upper surface and corners. A segmented stiffener ring is formed of “L” shaped segments, each segment being mounted to the upper surface at a corner of the substrate, wherein a gap exists between each of the segments. By forming the segmented stiffener ring of segments having gaps therebetween, warpage of the segmented stiffener ring itself, and thus the thermal stress applied by the segmented stiffener ring on to the substrate, is reduced as compared to a continuous stiffener ring. This allows the segmented stiffener ring to be designed to minimize warpage of the warpage control stiffener ring package.