Bonding Arm Oblique Trajectory for Wide Semiconductor Chip Alignment
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Solution Overview
Problem
Conventional bonding apparatuses face challenges in achieving high-speed and high-accuracy bonding with a wide bonding area due to misalignment issues between the motion trajectory of the bonding tool and the optical axis, especially when the rotation center of the bonding arm is not aligned with the reference plane, leading to significant position measurement errors and limitations in supporting larger semiconductor chips.
Innovation Solution
A bonding apparatus with a rotation center positioned separately above the reference plane, where the bonding arm moves obliquely and the optical position detection means has an angle matching the motion trajectory, allowing for height adjustment of the bonding stage to align the reference plane between the chip's surfaces, ensuring accurate positioning and reducing misalignment errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the rotation center of the bonding arm is positioned at the same height as the reference plane to achieve perpendicular motion trajectory, then measurement precision is improved, but the bonding area is limited and cannot support larger semiconductor chips
Solution Approach 1:
The patent positions the rotation center in a different vertical dimension (above the reference plane) rather than at the same height, transforming the motion trajectory from a perpendicular circular arc to an oblique circular arc. This dimensional change allows the bonding arm to cover a larger bonding area while maintaining measurement precision through optical correction
2Area of stationary object
If the bonding arm length is increased to expand the bonding area, then the bonding area is improved, but the weight and moment of inertia increase, reducing bonding speed
Solution Approach 1:
By positioning the rotation center above the reference plane, the patent creates an oblique motion trajectory that expands the effective bonding area without requiring an increase in bonding arm length. The shorter arm maintains lower weight and moment of inertia, preserving high bonding speed while achieving wider bonding coverage through geometric configuration
3Area of stationary object
If the rotation center is positioned above the reference plane to enable wider bonding area, then the bonding area is improved, but misalignment errors between motion trajectory and optical axis increase
Solution Approach 1:
The patent makes the optical axis of the imaging device adjustable rather than fixed, allowing it to dynamically align with the oblique motion trajectory of the bonding tool tip. This dynamic adjustment capability enables the system to maintain measurement precision despite the rotation center being positioned above the reference plane for expanded bonding area
Solution Approach 2:
The patent changes the angular parameter of the optical axis to match the angle of the motion trajectory. By adjusting the optical axis angle to be equal to the trajectory angle, the system compensates for the misalignment that would otherwise occur when the rotation center is positioned above the reference plane, maintaining measurement accuracy while enabling wider bonding area
Data Source
AI summary
A bonding apparatus includes: a reference plane; a bonding arm configured to be rotated about a rotation center that is arranged separately from the reference plane and to move a capillary attached at a tip end thereof obliquely toward and away from the reference plane; and an imaging device for optically detecting bonding positions on a semiconductor chip and/or a lead frame, in which an angle between an optical axis being heading for the imaging device from the reference plane and the reference plane is approximately equal to an angle between a motion trajectory of a tip end of the capillary and the reference plane, and thereby the bonding apparatus can have a wide bonding area with a simple mechanism as well as perform high-speed and high-accuracy bonding.