Semiconductor Chip Pad Layout for Warpage and Crack Relief
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Solution Overview
Problem
Semiconductor devices face challenges in maintaining reliability due to warpage and cracking of semiconductor chips caused by internal stress and thermal expansion, particularly in vertical MOSFETs, which affect the transport and performance of the devices.
Innovation Solution
The semiconductor device incorporates a first connector connected to at least one electrode pad, with additional electrode pads not connected to the first connector, and a sealing resin covering these unconnected pads, along with strategic electrode pad orientations to mitigate internal stress and thermal expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If all electrode pads are connected to connectors and wires, then electrical connectivity is ensured, but internal stress and warpage increase due to rigid constraints
Solution Approach 1:
The patent applies local quality by differentiating the treatment of electrode pads: some pads (first electrode pads) are connected to connectors via bonding materials for electrical connectivity, while other pads (second electrode pads) are intentionally left unconnected to serve as stress relief zones. This local differentiation allows the chip to maintain both electrical functionality and mechanical stability by releasing internal stress at specific locations without compromising overall connectivity.
2Reliability
If rigid connectors and wires are used for all electrode pads, then electrical connection is secure, but thermal expansion causes cracking and reduces reliability
Solution Approach 1:
The patent converts the harmful effect of thermal expansion into a beneficial stress relief mechanism. By leaving certain electrode pads unconnected, the design allows thermal expansion forces to be absorbed and released through these unconnected regions rather than transmitting cracking stresses through the entire chip structure. The unconnected pads act as sacrificial elements that protect the critical connected pads from thermal damage.
3Reliability
If multiple bonding materials are used for electrical connection, then connectivity is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent segments the electrode pad population into two distinct groups: connected pads for electrical functionality and unconnected pads for stress management. This segmentation simplifies the overall bonding structure by reducing the number of required bonding materials and connectors, while still achieving both electrical connectivity and mechanical stability. The segmented approach avoids the complexity of designing universal bonding solutions for all pads.
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
This configuration enhances the reliability of the semiconductor device by reducing warpage and cracking, ensuring stable transport and improved performance.
Implementation Method 1
warpage and cracking of semiconductor chips caused by internal stress and thermal expansion
Data Source
AI summary
A semiconductor device of an embodiment includes a lead frame; a first bonding material; a semiconductor chip including a lower surface, an upper surface, a first electrode connected to the first bonding material, a second electrode provided on the upper surface, and electrode pads connected to the second electrode; second bonding materials provided on each of the electrode pads; and a first connector connected to at least one of the second bonding materials, wherein the second bonding material which is not connected to the first connector is not connected to a connector or a wire.