Self-Aligned Stacked-Die Microelectronics Package
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional stacked-die assemblies in microelectronics packages face challenges with poor alignment, leading to variability in magnetic coupling coefficients and reduced signal transfer performance, which requires expensive and complex alignment techniques, and result in a bulky package that does not meet low-profile requirements for modern portable devices.
Innovation Solution
A self-aligned stacked-die assembly is achieved by using a thinned flip chip die with a mold compound that provides vertical walls aligned with the die edges, allowing a second die to be stacked with precise alignment, eliminating the need for electrical connections and enabling stable magnetic coupling without significant variability, thus reducing the package thickness and improving signal transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional stacked-die assembly is used, then manufacturing cost is reduced, but alignment precision between stacked dies deteriorates
Solution Approach 1:
The mold compound is applied and cured before die stacking to pre-establish the alignment reference structure. The vertical walls are formed in advance to guide subsequent die placement, eliminating the need for complex real-time alignment procedures during assembly.
Solution Approach 2:
The mold compound acts as an intermediary element that provides vertical reference walls between the module substrate and the stacked dies. These walls serve as a mechanical guide that simplifies the alignment process without requiring expensive optical alignment equipment.
2Length of moving object
If die thickness is increased, then structural stability is improved, but package profile height increases
Solution Approach 1:
The patent utilizes thin film structures and flexible packaging materials that provide sufficient structural stability despite reduced thickness. The mold compound and encapsulant materials are formulated to maintain mechanical integrity while enabling low-profile packaging.
3Manufacturing precision
If horizontal alignment tolerance is relaxed, then manufacturing cost is reduced, but magnetic coupling coefficient variability increases
Solution Approach 1:
The vertical walls formed by the mold compound provide self-aligning features that guide the stacked dies into proper horizontal alignment automatically. This self-service alignment mechanism eliminates the need for expensive external alignment equipment and achieves tight coupling precision through the structure itself.
4Use of energy by moving object
If vertical distance between inductive coupling components is increased, then die thickness is reduced, but magnetic coupling efficiency deteriorates
Solution Approach 1:
The patent optimizes the vertical spacing parameter between inductive coupling components to achieve the desired balance. By carefully controlling the thickness parameters and vertical positioning, the design maintains adequate magnetic coupling efficiency while achieving reduced overall package thickness.
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 self-aligned stacked-die assembly enhances signal transferring performance, reduces the package thickness, and eliminates the need for expensive alignment techniques, achieving stable magnetic coupling coefficients and efficient energy transfer between dies.
Implementation Method 1
analog signals may be transferred from the first thinned flip chip die to the second die through magnetic coupling, which does not require such electrical connections
Implementation Method 2
The vertical walls of the first opening are well aligned with edges of the first thinned flip chip die in both X-direction and Y-direction
Data Source
AI summary
The present disclosure relates to a microelectronics package with a self-aligned stacked-die assembly and a process for making the same. The disclosed microelectronics package includes a module substrate, a first die with a first coupling component, a second die with a second coupling component, and a first mold compound. The first die is attached to the module substrate. The first mold compound resides over the module substrate, surrounds the first die, and extends above an upper surface of the first die to define a first opening. Herein, the first mold compound provides vertical walls of the first opening, which are aligned with edges of the first die in X-direction and Y-direction. The second die is stacked with the first die and in the first opening, such that the second coupling component is mirrored to the first coupling component.