Die-in-Die Semiconductor Layout With Cavity Interconnects
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Solution Overview
Problem
The increasing trend towards sophisticated semiconductor devices poses challenges in accommodating additional features and applications without compromising performance or increasing costs, as existing semiconductor device packages face limitations in configuration and interconnect efficiency.
Innovation Solution
A die-in-die semiconductor device configuration is developed, where a first semiconductor die has a cavity formed in its backside to accommodate a second semiconductor die, with additional cavities extending through the front end of line region to connect with the back end of line region, using thermal compression non-conductive paste and copper pillars for interconnects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a traditional semiconductor device package configuration is used, then the device structure is simple and manufacturing is easier, but the device cannot accommodate additional features and applications without compromising performance or increasing costs
Solution Approach 1:
The patent implements a die-in-die configuration where a second semiconductor die is mounted within a cavity formed in the backside of a first semiconductor die. This nesting approach allows multiple functional dies to be integrated in a compact stacked arrangement, enabling additional features and applications without increasing the overall package footprint or compromising performance
Solution Approach 2:
The invention transitions from a traditional planar device layout to a three-dimensional stacked configuration by forming cavities in the backside of the first die and mounting the second die within these cavities. This vertical stacking in the Z-dimension enables enhanced adaptability and feature integration while maintaining a low-profile package structure
2Adaptability or versatility
If more features and applications are added to semiconductor devices, then device functionality is enhanced, but performance may be compromised or costs increased
Solution Approach 1:
The patent divides the semiconductor device into separate functional modules, with different features and applications implemented on different semiconductor dies. The first die and second die each contain specific functional circuits, allowing independent optimization of each die for its intended function while maintaining overall system reliability through the modular die-in-die integration approach
3Volume of moving object
If a compact stacked die arrangement is implemented, then device profile is reduced and interconnect efficiency is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent performs preliminary actions by forming the cavities in the backside of the first semiconductor die before mounting the second die. These cavities are precisely formed with controlled depth and dimensions to accommodate the second die and establish proper interconnect alignment. Thermal compression non-conductive paste is also applied in advance to the bottom of the cavities, ensuring proper positioning and electrical connection when the second die is mounted, thereby achieving compact stacking with controlled manufacturing precision
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 configuration enables a compact, low-profile stacked die arrangement with efficient interconnects, minimizing performance impact and cost while accommodating additional features and applications.
Implementation Method 1
a thermal compression non-conductive paste material (e.g., commonly used in flip-chip packaging) is dispensed at the bottom side of the first cavity
Implementation Method 2
With the thermal compression non-conductive paste material cured, a hermetic seal is formed in the first cavity between the second semiconductor die and the first semiconductor die
Implementation Method 3
The second semiconductor die with copper pillars is inserted into the first cavity with a thermal compressive force such that the copper pillars are pushed into respective second cavities
Implementation Method 4
With the copper pillars pushed into respective cavities, the thermal compression non-conductive paste material is displaced, and conductive connections are formed with the respective die interconnect traces of the first semiconductor die
Data Source
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AI summary
A method of forming a die-in-die semiconductor device is provided. The method includes forming a first cavity in a backside of a first semiconductor die. The first semiconductor die has a back end of line (BEOL) region, a front end of line (FEOL) region, and a bulk region. A second semiconductor die is mounted in the first cavity. A bond pad of the second semiconductor die is interconnected through a bottom side of the first cavity with an embedded conductive trace of the BEOL region of the first semiconductor die.