Copper Bonding Pad Structure for Reliable Multi-Chip Packaging
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Solution Overview
Problem
Semiconductor packages face limitations in becoming compact, lightweight, and multifunctional due to challenges in stacking semiconductor chips using traditional methods, such as the chip on wafer (CoW) method, which struggles with thermal characteristics and reliability.
Innovation Solution
The semiconductor package employs a die to wafer (D2W) method for bonding semiconductor chips, utilizing copper-based bonding pads with a dielectric liner to enhance thermal characteristics and reliability, and integrates multiple chips to form a multi-chip package with improved thermal dissipation and reduced separation of metal layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the chip on wafer (CoW) method is used for stacking semiconductor chips, then the manufacturing process is simpler, but the thermal characteristics and reliability deteriorate
Solution Approach 1:
The patent introduces a dielectric liner as an intermediary layer between the copper bonding pad and the surrounding structures. This liner acts as a mediator that prevents direct contact between copper and other materials, thereby preventing galvanic corrosion and improving thermal characteristics while maintaining manufacturing feasibility through a controlled deposition process
Solution Approach 2:
The patent employs a composite structure consisting of multiple materials: copper for electrical conductivity and bonding, dielectric material for insulation and thermal management, and barrier layers for corrosion prevention. This composite approach optimizes both thermal characteristics and reliability while maintaining ease of manufacture through standardized multi-layer fabrication processes
2Device complexity
If traditional bonding methods are used, then the device structure is simpler, but metal layer separation occurs reducing reliability
Solution Approach 1:
The dielectric liner serves as a bonding intermediary between metal layers, enabling reliable adhesion without direct metal-to-metal contact. This intermediary layer prevents separation while the bonding process remains relatively simple, involving standard deposition and patterning steps followed by controlled bonding conditions
Solution Approach 2:
The patent modifies bonding parameters by introducing the dielectric liner and controlling its thickness and material properties. This parameter change enables reliable bonding at controlled conditions while preventing metal layer separation, balancing structural complexity with reliability enhancement
3Adaptability or versatility
If multiple semiconductor chips are integrated into one package, then the capacity and functionality increase, but the thermal management becomes more challenging
Solution Approach 1:
The dielectric liner acts as a thermal intermediary between the copper bonding pads and surrounding structures. It provides a controlled thermal interface that facilitates heat dissipation from multiple stacked chips, managing thermal accumulation in the compact multifunctional package while maintaining electrical connectivity
Solution Approach 2:
The composite structure with copper bonding pads and dielectric liners creates favorable thermal pathways. The copper provides high thermal conductivity for heat extraction, while the dielectric material provides thermal management through its controlled thermal properties, enabling effective heat dissipation in the multifunctional stacked package
Data Source
AI summary
A semiconductor package includes a substrate, a semiconductor layer on the substrate, a wiring structure on the semiconductor layer, a connection pad on and connected to the wiring structure, a test pad on and connected to the wiring structure, the test and connection pads being horizontally spaced from each other, a first liner film on the wiring structure and having a first bonding pad trench, a second liner film on the first liner film and having a second bonding pad trench, a first bonding pad including a barrier layer in contact with the first liner film and a metal layer on the barrier layer, and a second bonding pad filling an inner portion of the second bonding pad trench and in contact with the second liner film, wherein the second liner film integrally covers upper surfaces of the barrier layer and metal layer.