Rotary Bond Head with Tilted Camera for Wire Alignment
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Solution Overview
Problem
Existing wire bonding techniques require additional motion for pattern recognition alignment, increasing the overall bonding time due to the misalignment between the bonding wedge center and the PR optical center, necessitating separate movements in the XY and theta directions.
Innovation Solution
A method using a rotary bond head with a tilted remote camera system that aligns the optical center with the bonding wedge center, allowing for direct image capture and bonding without the need for additional motion, by positioning the camera system at an oblique angle relative to the bond head and incorporating a PR optics system for coaxial lighting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the PR optics assembly is mounted separately from the bonding wedge center, then the optical center can be positioned for optimal imaging, but additional XY and theta motion is required for alignment, increasing bonding time
Solution Approach 1:
The patent merges the PR optics assembly with the bonding wedge center by mounting the PR camera on the bond head such that the optical center coincides with the bonding wedge center. This integration eliminates the need for separate XY and theta motion operations, allowing pattern recognition and bonding alignment to occur simultaneously, thereby resolving the contradiction between alignment precision and bonding speed
2Manufacturing precision
If the bond head rotates to a predetermined angle for PR alignment before bonding, then accurate bonding points can be identified, but the overall bonding time increases due to additional motion steps
Solution Approach 1:
The patent implements preliminary action by performing pattern recognition and determining bonding point positions during the approach phase before the bonding operation. The PR camera captures images and identifies bonding points in advance, so that when the bond head reaches the bonding position, the alignment is already complete, eliminating the need for additional rotation and positioning steps during the bonding cycle
3Adaptability or versatility
If the PR optics assembly is located at a distance from the bonding wedge center, then the optical system can be independently positioned, but the bond head must perform additional XY and theta movements, reducing bonding efficiency
Solution Approach 1:
The patent merges the PR optics assembly with the bonding wedge center by mounting the PR camera on the bond head such that the optical center coincides with the bonding wedge center. This integration eliminates the need for separate XY and theta motion operations, allowing pattern recognition and bonding alignment to occur simultaneously, thereby resolving the contradiction between alignment precision and bonding speed
Data Source
AI summary
A wire is bonded to a target surface using a rotary bond head by positioning a wedge bonding tool of the bond head over the target surface. A camera system is tilted at an oblique angle relative to an arrangement of the bond head to conduct pattern recognition of bonding points on the target surface for determining actual positions of the bonding points and an orientation between the actual positions of first and second bonding points. The bond head is moved to the actual position of the first bonding point and rotated to the determined orientation. Thereafter, the wire is bonded to the target surface at the first bonding point with the bond head.