Grooved Columnar Electrode for Semiconductor Solder Ball Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor devices with wafer-level CSP structures experience weak bonding between solder balls and columnar electrodes, leading to solder ball detachment and potential packaging failures due to limited contact area and mechanical strength.
Innovation Solution
The semiconductor device incorporates a columnar electrode with a main body and grooves, where the solder ball includes a metal bump on the top surface and a filling part within the grooves, creating a bolt-like structure that increases contact area and bonding force by connecting at multiple planes rather than a single plane, and the grooves are designed to maintain mechanical strength and prevent gap formation during soldering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a conventional columnar electrode structure is used, then the device structure is simple, but the bonding force between solder ball and columnar electrode is weak
Solution Approach 1:
The columnar electrode is segmented by introducing grooves that divide the electrode body into multiple regions. This segmentation increases the surface area for solder ball contact and creates multiple bonding interfaces, thereby enhancing the bonding force between the solder ball and the columnar electrode without significantly complicating the overall device structure.
Solution Approach 2:
The invention transitions from a conventional single-plane contact structure to a multi-dimensional bonding structure by adding grooves that create bonding interfaces at different depths and positions. This dimensional change allows the solder ball to contact the columnar electrode at multiple planes simultaneously, significantly improving bonding strength.
2Area of stationary object
If the contact area between solder ball and columnar electrode is increased, then the bonding force is improved, but the manufacturing complexity increases
Solution Approach 1:
The grooves are designed as simple segmented features that can be easily formed using conventional manufacturing techniques such as etching or mechanical machining. These segmented grooves increase the contact area between the solder ball and columnar electrode while maintaining manufacturing simplicity through standardized geometric patterns.
Solution Approach 2:
The grooves create a porous-like structure within the columnar electrode that increases the effective contact area. This porous structure can be formed using simple etching processes or by incorporating sacrificial materials during electrode fabrication, thereby increasing bonding area without significantly increasing manufacturing complexity.
3Strength
If grooves are added to the columnar electrode, then the bonding force is enhanced, but the structural integrity may be compromised
Solution Approach 1:
The grooves are designed and positioned in advance during the electrode fabrication process, allowing the electrode material to be deposited or formed around the groove structures. This preliminary action ensures that the electrode maintains its structural integrity while incorporating the bonding-enhancing grooves, as the material flow and structural support are pre-planned during manufacturing.
Solution Approach 2:
The columnar electrode with grooves can be viewed as a composite structure where the electrode material and the groove regions work together to provide both structural support and enhanced bonding. The grooves may be filled with different materials or left as voids, creating a composite structure that maintains integrity while improving bonding force through the multi-plane contact capability.
Data Source
AI summary
A semiconductor device and a manufacturing method thereof. The semiconductor device includes a semiconductor substrate (300) provided with a plurality of pads (301), columnar electrodes on the pads (301) and a solder ball (321) provided on the columnar electrode. The columnar electrode comprises a main body (307) and a groove in the main body (307), and an opening of the groove is overlapped with the top surface of the columnar electrode. The solder ball (321) comprises a metal bump (320) arranged on the top of the columnar electrode and a filling part (319) filled in the groove. The solder ball and the columnar electrode form a structure similar to a bolt; thus the binding force between the solder ball and the columnar electrode is improved.