Stacked Semiconductor Package with Selectable IPD Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor devices with integrated passive devices (IPDs) experience undesirable mutual inductive coupling when stacked, which is problematic for high-frequency applications like RF wireless communications, as it degrades signal integrity and increases footprint size.
Innovation Solution
The semiconductor package allows for selectable vertical and lateral separation between IPDs or inductor coils, minimizing mutual inductive coupling by adjusting the distance between stacked semiconductor die, thereby maintaining a small footprint while reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If semiconductor devices are stacked to reduce footprint, then area is reduced, but mutual inductive coupling between IPDs increases
Solution Approach 1:
The patent transitions from a two-dimensional side-by-side arrangement to a three-dimensional stacked arrangement, utilizing the vertical dimension to reduce footprint area. Multiple semiconductor devices are stacked vertically with their active sides facing the same direction, allowing efficient use of board space while maintaining device functionality.
Solution Approach 2:
The patent introduces non-uniform spacing between stacked devices, with different vertical distances between adjacent devices. By providing greater separation between devices containing inductively coupled IPDs and smaller separation between other devices, the patent locally optimizes the magnetic coupling characteristics while maintaining overall compactness.
2Reliability
If semiconductor devices are placed side-by-side to reduce mutual inductive coupling, then signal integrity is improved, but footprint area increases
Solution Approach 1:
The patent utilizes the vertical dimension to achieve device separation, stacking multiple semiconductor devices vertically rather than placing them side-by-side in the horizontal plane. This dimensional transition reduces footprint area while maintaining signal integrity through vertical isolation of inductively coupled IPDs.
Solution Approach 2:
The patent changes the spatial arrangement parameter from horizontal side-by-side placement to vertical stacking with controlled inter-device spacing. By adjusting the vertical distance between stacked devices, the patent optimizes both signal integrity (reducing mutual inductive coupling) and footprint area simultaneously.
3Reliability
If vertical separation between stacked IPDs is increased to reduce mutual inductive coupling, then signal integrity is improved, but device height increases
Solution Approach 1:
The patent implements non-uniform vertical spacing between stacked semiconductor devices, providing greater separation only between devices containing inductively coupled IPDs while maintaining smaller spacing between other devices. This localized approach reduces mutual inductive coupling and device height simultaneously by avoiding uniform excessive spacing throughout the stack.
Solution Approach 2:
The patent employs adjustable and selectable vertical and lateral separation distances between stacked IPDs, allowing dynamic optimization of the spacing parameters. This enables the system to adapt the separation distances to minimize mutual inductive coupling while constraining the overall device height within acceptable limits.
4Reliability
If lateral separation between stacked IPDs is increased to reduce mutual inductive coupling, then signal integrity is improved, but horizontal space consumption increases
Solution Approach 1:
The patent primarily utilizes vertical separation rather than lateral separation to reduce mutual inductive coupling between IPDs. By stacking devices vertically and adjusting vertical spacing, the patent avoids increasing horizontal space consumption while maintaining signal integrity through vertical isolation of inductively coupled components.
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
This approach effectively minimizes mutual inductive coupling, enhancing signal integrity and reducing the footprint of semiconductor devices, even in high-frequency applications, by allowing for precise control of the separation between IPDs or inductor coils.
Implementation Method 1
undesirable mutual inductive coupling or interference between the stacked IPD devices
Data Source
AI summary
A semiconductor package has first and second semiconductor die mounted to a substrate. The first semiconductor die includes a first inductor coil electrically coupled to the substrate. The second semiconductor die is mounted over the first semiconductor die. The second semiconductor die includes a second inductor coil electrically coupled to the substrate. A center of the second inductor coil has a vertical and lateral separation with respect to a center of the first inductor coil which are each selectable to minimize mutual inductive coupling between the first and second inductor coils. A spacer is disposed between the first and second semiconductor die to adjust the vertical separation. The center of the second inductor is positioned laterally within the second semiconductor die with respect to the center of the first inductor to adjust the lateral separation. The mutual inductive coupling decreases with increasing vertical and lateral separation.