Rotating Shear Block for Semiconductor Die Testing
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Solution Overview
Problem
High-force shear testing of semiconductor dies on substrates poses challenges due to stress concentration at clamp and load application points, which existing technologies fail to adequately address, especially when testing at forces above 20kgf.
Innovation Solution
A shear testing system featuring a rotatable shear block with a bearing on a shaft and vacuum-held for self-alignment, allowing maximum contact and distributing the load to minimize stress, and a shear tool with controlled clearances to reduce tipping moment and facilitate access in tight applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high force shear testing is performed on semiconductor dies, then bond quality measurement is achieved, but stress concentration occurs at clamp and load application points
Solution Approach 1:
The shear block is segmented with multiple shear faces that can be independently positioned. This allows the load to be distributed across multiple contact points on the die rather than concentrated at a single point, reducing stress concentration while maintaining measurement capability
Solution Approach 2:
The shear block is made rotatable on the shaft, allowing dynamic adjustment of the shear face orientation. This enables the shear face to self-align with the die edge for optimal contact, distributing stress more evenly while maintaining measurement precision
2Manufacturing precision
If a fixed shear block is used for shear testing, then alignment is simple, but maximum contact with the die cannot be ensured
Solution Approach 1:
The shear block is designed to self-align through rotation on the shaft. The bearing facilitates this self-alignment process, allowing the shear face to automatically orient itself for maximum contact with the die edge without requiring complex external alignment mechanisms
Solution Approach 2:
The rotatable design allows the shear block to dynamically adjust its orientation during the testing process, ensuring optimal contact is achieved regardless of minor variations in die positioning or geometry
3Device complexity
If a non-rotatable shear block is used, then the structure is simple, but the block cannot adapt to different die configurations
Solution Approach 1:
The shear block is made rotatable on the shaft, allowing it to dynamically adjust its orientation to match different die configurations and edge angles. This provides adaptability without requiring multiple specialized blocks for different die types
Solution Approach 2:
The rotatable shear block with bearing can accommodate various die sizes, shapes, and orientations by simply rotating to the appropriate angle. This single multi-functional block replaces what would otherwise require multiple specialized fixed blocks
4Stability of the object's composition
If the shear block is held firmly without vacuum, then positioning is stable, but alignment adjustment is difficult
Solution Approach 1:
Vacuum suction is applied to the shear block to provide firm holding during the actual shear testing operation, ensuring positioning stability. The vacuum can be easily engaged and disengaged to facilitate alignment adjustments before and after testing
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 system effectively reduces stress concentrations and ensures accurate alignment, enabling reliable bond testing across various force ranges and complex die configurations, extending tool life through wear-resistant design and easy replacement of shear block faces.
Implementation Method 1
said block has a bearing in it that runs on the end of the shear tool shaft
Implementation Method 2
said shear tool has holes for porting vacuum for holding the shear block on the end of the shear tool
Data Source
Figure A1~A3
Figure B1~B4
Figure B5~B9
AI summary
A test device for shear testing semiconductor die (2) bonded to a substrate (1). Shear block (7) being self aligning and made from a soft material to minimise stresses on the die caused by the test load thereby reducing or eliminating any damage to the die. Different block designs can be made to suit different applications, shear face (12) being tailored to test either single die, die placed very closely to each other or stacked die. The depth of shear face (12) may be less than the die thickness ensuring that the bond surface is not damaged by block (7) during the test.