3D Chip Bonding With Controlled Electrode Protrusion
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Solution Overview
Problem
In three-dimensional semiconductor chip mounting, the use of an organic insulating material for bonding interfaces can lead to bonding failures due to thermal expansion mismatch with metal electrodes, causing debris accumulation and hindering electrode bonding.
Innovation Solution
A method involving precise protrusion amounts and polishing of electrodes and insulating layers, aligned to minimize thermal expansion interference, using organic insulating materials with controlled expansion coefficients and surface roughness, followed by thermocompression bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an organic insulating material is used for the bonding interface, then debris can be absorbed and bonding failure is prevented, but thermal expansion mismatch causes the organic insulating layer to expand more than the metal electrode and inhibit bonding
Solution Approach 1:
The patent changes the physical parameters of the organic insulating layer by controlling its thickness and the protrusion amount of the electrode. Specifically, the electrode protrudes from the organic insulating layer surface by a controlled amount (0.1-10 μm) before bonding, and the organic insulating layer thickness is optimized (1-10 μm). These parameter adjustments ensure that even when the organic insulating layer expands thermally during bonding, the electrode maintains sufficient protrusion to achieve reliable bonding while the organic layer absorbs debris.
Solution Approach 2:
The patent performs preliminary polishing of the organic insulating layer and electrode surfaces before bonding to create a smooth surface with controlled roughness. This preliminary action ensures that when thermal expansion occurs during bonding, the surfaces are already optimized for contact, preventing the expanded organic layer from inhibiting bonding. The protrusion amount is also predetermined through prior polishing or formation processes.
2Reliability
If the organic insulating layer thickness is increased to absorb more debris, then bonding failure is reduced, but the thermal expansion of the thicker organic layer becomes more significant and hinders electrode bonding
Solution Approach 1:
The patent optimizes the organic insulating layer thickness to a specific range (1-10 μm) that balances debris absorption capability with thermal expansion control. This parameter optimization ensures the layer is thick enough to absorb cutting debris from dicing while remaining thin enough that its thermal expansion during bonding does not prevent electrode contact. The electrode protrusion amount (0.1-10 μm) is also optimized to compensate for the thermal expansion of this controlled thickness.
3Reliability
If the electrode protrusion amount is increased to ensure contact despite organic layer expansion, then bonding is improved, but the manufacturing precision requirement increases due to the need for precise protrusion control
Solution Approach 1:
The patent defines a practical protrusion amount range (0.1-10 μm) that balances bonding reliability with manufacturing feasibility. This parameter range is large enough to accommodate variations in manufacturing processes while small enough to maintain precise control. The patent also specifies the organic insulating layer thickness range (1-10 μm) to work in conjunction with the protrusion amount, creating a coordinated parameter set that achieves reliable bonding without requiring extreme 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
Enhances reliable bonding between electrodes by managing thermal expansion, ensuring consistent contact and adhesion despite organic insulating layer expansion, thereby improving the integrity of semiconductor devices.
Implementation Method 1
the organic insulating material has a linear expansion coefficient different from that of a metal material used for electrodes, and thus the organic insulating material may expand more than the metal material due to heating at the time of bonding
Implementation Method 2
bonding the first organic insulating layer and the insulating layer portion to each other, and bonding the first electrode and the second electrode to each other, by heating and pressurizing the first semiconductor substrate and the semiconductor chip
Data Source
AI summary
A method for manufacturing a semiconductor device includes preparing first and second semiconductor substrates, dividing the second semiconductor substrate into semiconductor chips, and bonding the first organic insulating layer and an insulating layer portion of the semiconductor chip to each other and bonding the first electrode and the second electrode to each other by heating and pressurizing them. Before heating, at least one of a first protrusion amount of the first electrode or a second protrusion amount of the second electrode is a protrusion amount within 130% of a protrusion amount ΔL represented by Formula (1). In Formula (1), D is a layer thickness of the organic insulating layer, ΔT is a temperature difference of a heating temperature, α1 is the linear expansion coefficient of the organic insulating layer, and α2 is the linear expansion coefficient of the electrode.[Formula 1]ΔL=D×ΔT×(α1-α2)1+ΔT×α2(1)