Semiconductor Bonding Structure With Elastic Gap Fill for Thin-Die Cracking
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Solution Overview
Problem
The reliability of system on integrated chip (SoIC) devices is compromised due to chipping and stress-induced cracking in thin semiconductor dies during manufacturing, particularly in 3D packaging, which affects the integrity and performance of the devices.
Innovation Solution
A method involving the use of elastic polymeric-based dielectric materials to fill gaps between semiconductor dies, reducing stress and enhancing the reliability of the bonding structure by minimizing cracking and maintaining structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If thin semiconductor dies are used in 3D packaging, then device integration and system performance are improved, but reliability deteriorates due to chipping and stress-induced cracking
Solution Approach 1:
The patent applies beforehand cushioning by introducing a compliant underfill material between the thin semiconductor die and the substrate before final assembly. This underfill material acts as a stress buffer that absorbs thermal expansion mismatches and mechanical stresses, preventing stress-induced cracking in the thin die during subsequent manufacturing and operation. The cushioning effect is established in advance to protect the vulnerable thin die structure.
Solution Approach 2:
The patent employs composite materials by combining the thin semiconductor die with a compliant underfill material and rigid substrate in a layered structure. This composite construction allows each material to perform its optimal function: the thin die provides high integration, the compliant underfill absorbs stress, and the rigid substrate provides structural support. The composite structure resolves the contradiction by distributing mechanical stresses away from the thin die.
2Length of moving object
If thin semiconductor dies are used, then bond pad pitch is reduced and system performance is enhanced, but structural integrity deteriorates leading to cracking
Solution Approach 1:
The patent applies flexible shells and thin films by using a compliant underfill material that acts as a flexible buffer layer between the thin die and substrate. This flexible layer accommodates thermal expansion and mechanical stresses without transmitting them to the thin die, thereby maintaining structural integrity despite the reduced die thickness required for small bond pad pitch.
Solution Approach 2:
The compliant underfill material serves as an intermediary between the thin semiconductor die and the rigid substrate. It mediates the mechanical and thermal stresses that would otherwise directly affect the thin die, protecting it from cracking while allowing the die to maintain its thin profile for reduced bond pad pitch.
3Ease of manufacture
If conventional rigid materials are used to fill gaps between dies, then manufacturing is simplified, but stress on thin dies increases causing cracking
Solution Approach 1:
The patent applies parameter changes by selecting a compliant underfill material with specific mechanical properties (higher elasticity, lower modulus) different from conventional rigid materials. This parameter change in material stiffness allows the underfill to absorb stresses through elastic deformation rather than transmitting them to the thin die, preventing cracking while remaining manufacturable through standard dispensing and curing processes.
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 proposed method improves the reliability of 3D packaging by reducing stress on thin semiconductor dies, thereby enhancing the structural integrity and reducing the likelihood of cracking, thus ensuring consistent device performance.
Implementation Method 1
A first gap between the first semiconductor dies is filled with a second dielectric material, wherein the second dielectric material has a different material property than the first dielectric material. At least one of the second and third dielectric materials is an elastic polymeric-based dielectric material.
Data Source
AI summary
A semiconductor structure and a method of manufacturing a semiconductor structure are provided. First semiconductor dies are formed from a first substrate, each of the first semiconductor dies including an interconnect structure having a first dielectric material. A first thinning operation is performed on each of the first semiconductor dies. Second semiconductor dies are formed from a second substrate. The first semiconductor dies are bonded to a third substrate. A first gap between the first semiconductor dies is filled with a second dielectric material. The second semiconductor dies are bonded to the first semiconductor dies through a second bonding film, each of the first semiconductor dies electrically connected to each of the corresponding second semiconductor dies. A second gap between the second semiconductor dies is filled with a third dielectric material, at least one of the second and third dielectric materials different from the first dielectric material.