Stacked Semiconductor Package Bonding With Dummy Support Die
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Solution Overview
Problem
As the number of stacked semiconductor chips increases, deformation accumulates, leading to curved surfaces in upper chips, making it difficult to bond the uppermost core die, resulting in voids and deteriorated interfacial bonding quality and heat dissipation.
Innovation Solution
A semiconductor package design that includes a buffer die with a dummy support die attached to the uppermost core die using an adhesive member, featuring an overhang portion and fillet portion to stabilize the bonding interface, and a sealing member for improved thermal conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the number of stacked semiconductor chips is increased, then the functionality and integration density are improved, but the accumulated deformation causes curved surfaces in upper chips, making bonding difficult and generating voids that deteriorate interfacial bonding quality
Solution Approach 1:
A dummy support die is introduced as an intermediary component attached to the uppermost core die. This dummy support die has a larger area than the core dies, providing additional support and stabilizing the bonding interface. The dummy support die acts as a mediator that compensates for the curved surface deformation, enabling void-free bonding even when stacking multiple chips together.
2Strength
If a thick uppermost core die is bonded to an underlying core die, then the structural strength is improved, but it becomes difficult to deform the uppermost core die, preventing void discharge and deteriorating bonding quality
Solution Approach 1:
The dummy support die is attached to the uppermost core die before the final bonding process. This preliminary attachment provides immediate structural support and stabilizes the bonding interface, preventing deformation issues before bonding occurs. The dummy support die's larger area creates a stable platform that facilitates proper alignment and bonding while preventing void formation.
3Quantity of substance
If multiple chips are stacked to improve integration density, then the device functionality is enhanced, but heat dissipation becomes more difficult due to accumulated deformation and bonding issues
Solution Approach 1:
The dummy support die serves as a thermal management intermediary by providing a stable, flat bonding interface that ensures good thermal contact between stacked chips. By preventing void formation and deformation at the bonding interfaces, the dummy support die enables efficient heat transfer pathways through the stacked structure, improving overall heat dissipation performance while maintaining high integration density.
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
Prevents delamination and bubble formation at the bonding interface, enhancing bonding quality and improving heat dissipation characteristics by using a thick dummy support die with excellent thermal conductivity.
Implementation Method 1
a dummy support die attached to an uppermost core die among the plurality of core dies by an adhesive member
Implementation Method 2
since the dummy support die has excellent thermal conductivity, the heat dissipation characteristics of the package may be improved
Data Source
AI summary
A semiconductor package includes a buffer die, a plurality of core dies sequentially stacked on the buffer die, a dummy support die attached to an uppermost core die among the plurality of core dies by an adhesive member, and a sealing member on outer side surfaces of the plurality of core dies and an outer side surface of the dummy support die. The dummy support die includes an overhang portion that protrudes from the outer side surface of the uppermost core die. The adhesive member includes a fillet portion that is in contact with the overhang portion and that is on at least a portion of the outer side surface of the uppermost core die.