Semiconductor Bump Pillar Design for Structural Strength
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Solution Overview
Problem
Conventional semiconductor devices with fine pitch technology face issues with structural strength during assembly, leading to bending and short circuits, which increases manufacturing costs and waste due to the fragile column-shaped bumps.
Innovation Solution
The semiconductor device design features bumps with a pillar part and a top part, where the pillar part has a dimension longer than 1.2 times the width of the bonding pad, providing structural strength, and the top part is composed of solder that melts under a specific temperature, while the pillar part remains intact, using materials like copper, gold, or nickel for the pillar and tin-lead or lead-free solder for the top part.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If column-shaped bumps are used in fine pitch technology, then the wire pitch can be miniaturized, but the structural strength deteriorates causing bending and short circuits
Solution Approach 1:
The bump is divided into two distinct parts: a pillar part made of high-strength material (copper, gold, or nickel) and a top part made of solder material. This segmentation allows each part to fulfill its specific function - the pillar part provides structural strength while the top part enables electrical connection and melting capability
Solution Approach 2:
The bump uses composite material construction with different materials for different parts. The pillar part uses materials with high melting points (copper, gold, or nickel) for structural integrity, while the top part uses solder materials (tin-lead or lead-free) that melt at lower temperatures. This composite approach resolves the contradiction between miniaturization and structural strength
2Reliability
If monitor and inspection systems are employed to avoid defective products, then the quality can be maintained, but the manufacturing cost increases
Solution Approach 1:
The bump structure is designed with inherent strength characteristics before the assembly process begins. The pillar part's extended dimensions and high-strength materials prevent bending during assembly operations, eliminating the need for expensive monitor and inspection systems to detect structural weaknesses
Solution Approach 2:
The design uses cost-effective materials for the top part (solder materials like tin-lead or lead-free solder) that perform their function and can be replaced if needed, while the critical structural pillar part uses durable materials. This approach reduces overall manufacturing cost compared to using expensive materials throughout or implementing extensive inspection systems
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 design enhances structural strength, improves yield rates by reducing defects, and lowers manufacturing costs by minimizing the need for extensive inspection and re-work processes.
Implementation Method 1
The top part is composed of solder that melts under a specific temperature, while the pillar part remains intact
Data Source
AI summary
A semiconductor device and a manufacturing method thereof are provided. The semiconductor device has an active surface. The semiconductor device includes at least a connecting element and at least a bump. The connecting element is disposed on the activate surface and has a minimum dimension smaller than 100 microns. The bump is disposed on the connecting element and is electrically connected to the active surface by the connecting element. The bump includes a pillar part disposed on the connecting element and a top part disposed at the top of the pillar part. The pillar part has a first dimension and a second dimension both parallel to the active surface. The first dimension is longer than 1.2 times the second dimension. The top part is composed of solder and will melt under the determined temperature. The pillar part will not melt under a determined temperature.