Intermetallic Compound Formation in 3DIC Package Bonding
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Solution Overview
Problem
The semiconductor industry faces manufacturing challenges in developing three-dimensional integrated circuit (3DIC) packages that are not entirely satisfactory in terms of integration density and functionality, particularly in forming reliable connections between semiconductor dies and package components.
Innovation Solution
A chip-on-wafer-on-substrate (CoWoS) package structure is formed by bonding an integrated circuit die to a package component using a solder joint with intermetallic compounds (IMCs) formed between connectors, and a thermal annealing treatment is performed to connect these IMCs, ensuring strong and reliable electrical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional bonding methods are used to connect semiconductor dies and package components, then the manufacturing process is simpler, but the reliability and electrical connection stability are insufficient
Solution Approach 1:
The patent applies preliminary action by performing a first annealing treatment before the actual bonding process. This pre-annealing step prepares the intermetallic compounds in advance, ensuring they have the proper crystal structure and electrical properties before bonding, which improves connection reliability without compromising the overall process feasibility
Solution Approach 2:
The patent utilizes parameter changes by controlling the annealing temperature and time to transform the intermetallic compound structure. By adjusting these thermal parameters, the patent optimizes the electrical and mechanical properties of the connection, achieving reliable electrical connections while managing the complexity of the process
2Strength
If multiple separate intermetallic compound layers are formed between connectors, then the connection structure is more robust, but the electrical circuitry may experience short circuits or high resistance
Solution Approach 1:
The patent applies merging by combining multiple separate intermetallic compound layers into a single continuous intermetallic compound structure through annealing treatment. This integration maintains the structural robustness of multiple layers while eliminating the electrical discontinuities and potential short circuits that would occur at the interfaces between separate layers
Solution Approach 2:
The patent utilizes phase transitions by heating the structure through annealing to transform the intermetallic compound layers from separate phases into a continuous phase. This thermal treatment causes diffusion and reorganization of atoms, merging the distinct layers into a unified structure with improved electrical conductivity and reduced resistance
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 solution enhances the reliability and lifetime of the package structure by preventing electrical circuitry problems such as short circuits and high resistance, and ensures durable connections between the connectors, improving the overall performance and integration density of semiconductor packages.
Implementation Method 1
a first intermetallic compound is formed between the solder joint and the first bump. A second intermetallic compound is formed between the solder joint and the second bump
Implementation Method 2
A thermal annealing treatment is performed before a qualification test is performed over the package structure. The solder joint reacts with the material of the first and second bumps so that more intermetallic compounds are formed
Data Source
AI summary
Package structures and methods for forming the same are provided. A package structure includes a package component including a first bump. The package structure also includes an intermetallic compound (IMC) on the first bump. The package structure further includes an integrated circuit die including a second bump on the IMC. The integrated circuit die and the package component are bonded together through the first bump and the second bump. The IMC extends from the first bump to the second bump to provide good physical and electrical connections between the first bump and the second bump.