Flexible Interposer Absorbs Thermal Stress in Semiconductor Packaging
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Solution Overview
Problem
Conventional semiconductor die packaging methods, such as chip-scale packages (CSPs), face issues with thermal stress due to mismatched coefficients of thermal expansion between semiconductor dice, interposers, and carrier substrates, leading to potential electrical connection failures and manufacturing complexities, especially with rigid external electrode structures.
Innovation Solution
The development of an interposer with flexible solder pad elements that can accommodate thermal stresses and uneven surfaces, formed as a unitary part of a core material, simplifying the manufacturing process and improving compatibility with carrier substrates and semiconductor dice.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If rigid external electrode structures are used in conventional CSP packaging, then manufacturing precision and structural stability are improved, but thermal stress resistance and adaptability to uneven surfaces deteriorate
Solution Approach 1:
The patent applies this principle by using a flexible interposer substrate with flexible solder pad elements instead of rigid external electrodes. The flexible material allows the interposer to deform and accommodate thermal expansion differences between the semiconductor die, interposer, and carrier substrate, thereby reducing thermal stress while maintaining reliable electrical connections.
Solution Approach 2:
The patent changes the physical parameter of the interposer from rigid to flexible. This parameter change allows the interposer to dynamically adapt to thermal stresses and surface irregularities, resolving the contradiction between structural stability and thermal stress resistance.
2Stability of the object's composition
If rigid external electrode structures are used in conventional CSP packaging, then structural stability is improved, but ease of manufacture deteriorates due to additional processing steps
Solution Approach 1:
The patent merges the interposer substrate and the external electrode structures into a single flexible interposer component. The flexible solder pad elements are formed as an integrated part of the flexible interposer substrate, eliminating the need for separate attachment processes and simplifying manufacturing while maintaining structural stability.
Solution Approach 2:
By using a flexible substrate that inherently provides both structural support and electrode functionality, the patent eliminates complex assembly steps required for rigid electrode attachments, thereby improving ease of manufacture while maintaining structural integrity.
3Reliability
If flexible solder pad elements are used in the interposer, then thermal stress resistance and adaptability to uneven surfaces are improved, but manufacturing precision may deteriorate
Solution Approach 1:
The flexible solder pad elements can deform to accommodate misalignments and surface irregularities, providing a tolerance buffer that maintains reliable electrical connections even when manufacturing precision varies, thereby resolving the contradiction between thermal stress resistance and alignment accuracy.
Solution Approach 2:
By changing the mechanical property of the electrode structures from rigid to flexible, the patent creates a system that can dynamically adjust to manufacturing variations, maintaining reliable connections without requiring extremely tight manufacturing tolerances.
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 flexible interposer effectively absorbs thermal-induced stresses, reduces the risk of electrical connection failures, and simplifies production by eliminating the need for additional processing steps required for forming or attaching conventional external electrode structures.
Implementation Method 1
an interposer for a semiconductor die package... formed with flexible solder pad elements that overcome the drawbacks associated with prior art external electrode structures. Due to its flexible nature, the interposer of the present invention is more readily able to accommodate thermal induced stresses
Data Source
AI summary
Various embodiments of an interposer for mounting a semiconductor die, as well as methods for forming the interposer, are disclosed. The interposer includes flexible solder pad elements that are formed from a core material of the interposer, such that the interposer may absorb thermally induced stresses and conform to warped or uneven surfaces. Embodiments of electronic device packages including a semiconductor die mounted to and electrically connected to the interposer, as well as methods for forming the electronic device packages, are also disclosed. In one electronic device package, the semiconductor die is electrically connected to the interposer with wire bonds attached to a routing layer of the interposer. In another electronic device package, the semiconductor die is electrically connected to the interposer by bonding the semiconductor die to the flexible solder pad elements of the interposer in a flip-chip configuration. A computer system incorporating an electronic device package with an interposer according to the present invention is also disclosed.