3D Die-Stacking Package Structure Using Electroplated Through Holes
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Solution Overview
Problem
The high cost of expensive equipment required for chemical vapor deposition and uniquely designed electroplating stations limits the widespread adoption of three-dimensional die-stacking package structures, making them unaffordable for many packaging houses due to the need for costly metal seedlayer and via metalizing processes.
Innovation Solution
A three-dimensional die-stacking package structure is developed using a polymer insulating layer as an adhering layer between stacked dice, with an electroplating process utilizing a bottom electrode from a top substrate to form conductive contacts, eliminating the need for costly chemical vapor deposition and specialized electroplating equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chemical vapor deposition process is used to form metal seedlayer and silicon dioxide insulating layer, then the quality and reliability of through hole metalizing is improved, but the manufacturing cost and equipment investment increase significantly
Solution Approach 1:
The patent extracts and removes the expensive chemical vapor deposition process from the manufacturing flow. Instead of using CVD to form metal seedlayer and silicon dioxide insulating layer, the invention uses electroplating directly to form conductive plugs through holes, eliminating the need for CVD equipment and significantly reducing manufacturing costs while maintaining through hole metalizing quality
Solution Approach 2:
The patent replaces expensive, specialized equipment (CVD station and uniquely designed electroplating station) with standard, readily available electroplating equipment. This substitution uses common, affordable equipment to achieve the same functional outcome, making the process accessible to more manufacturers without compromising product quality
2Manufacturing precision
If uniquely designed electroplating station is used for high aspect ratio through hole plating, then the plating quality and fill completeness is improved, but the equipment cost and complexity increase
Solution Approach 1:
The patent makes standard electroplating equipment perform the specialized function of filling high aspect ratio through holes by using conductive adhesive material as both adhesive and conductive filler. This universal approach allows ordinary electroplating stations to achieve results previously requiring uniquely designed equipment, reducing device complexity while maintaining plating quality
Solution Approach 2:
The patent uses conductive adhesive material that combines adhesive properties and electrical conductivity in a single material. This composite material serves dual functions: bonding the stacked wafers together and providing electrical connection through the through holes, eliminating the need for separate metal seedlayer and insulating layer formation
3Reliability
If conventional through hole metalizing process is used, then the electrical connection reliability is improved, but the number of process steps and manufacturing time increase
Solution Approach 1:
The patent merges multiple process steps into a single electroplating operation. Instead of separate steps for forming metal seedlayer, silicon dioxide insulating layer, and through hole metalizing, the invention combines these functions into one electroplating step that directly forms conductive plugs, reducing manufacturing time and improving productivity while maintaining electrical connection reliability
Solution Approach 2:
The patent performs preliminary preparation by forming through holes and applying conductive adhesive material before stacking. This preliminary action ensures that when wafers are stacked, the conductive material is already in position to provide both bonding and electrical connection, streamlining the overall process and improving manufacturing efficiency
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 reduces manufacturing costs by allowing the use of existing electroplating stations and eliminates the need for expensive equipment, while maintaining high performance and compact size, enabling efficient electrical connections between stacked dice.
Implementation Method 1
perform an electroplating process in the through hole with the bottom electrode served as an electroplating electrode, and forming a conductive contact passing through the stacked dice
Data Source
AI summary
This invention provides a substrate having at least one bottom electrode formed therein. A plurality of dice each having at least one opening formed therein are vertically stacked together one by one by a polymer insulating layer acting as an adhering layer between them, along with the openings thereof aligned to each other to form a through hole passing through said dice. The stacked dice are joined to a bottom of the substrate with the polymer insulating layer acting as an adhering layer, making the bottom electrode of the substrate contact the through hole. An electroplating process is performed with the bottom electrode serving as an electroplating electrode to form a conductive contact passing through the dice.