Die Bonding Apparatus Optical Alignment via Bond Head Cavity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing die bonding processes face inaccuracies due to errors in die pick-up, calibration issues between optical systems, and thermal expansion, leading to placement inaccuracies, especially when handling large or long dice.
Innovation Solution
A die bonding apparatus with a bond head and pick-up tool that allows for visual alignment of the die after pick-up, using a dual or single optical assembly positioned to view the die and bonding site, eliminating motion errors and minimizing thermal expansion impacts by maintaining optical system stability during alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If visual alignment is performed before die pick-up using two separate optical systems, then alignment can be conducted, but errors introduced during die pick-up cannot be corrected and calibration errors affect placement accuracy
Solution Approach 1:
The patent performs visual alignment after die pick-up rather than before, allowing the system to capture and correct for any errors or movements that occur during the pick-up process. The optical system views the die while it is held by the pick-up tool, enabling real-time alignment adjustments that account for actual die position and orientation.
Solution Approach 2:
The patent uses a single optical assembly that can view both the die held by the pick-up tool and the bonding site, eliminating the need for calibration between two separate optical systems. This unified viewing approach ensures that all alignment measurements are made from the same reference frame, removing calibration errors entirely.
2Ease of operation
If two separate optical systems are used for viewing die and substrate, then visual alignment can be performed, but calibration errors and thermal expansion affect coordinate relationship accuracy
Solution Approach 1:
The patent employs a single optical assembly positioned to view both the die and the bonding site through the bond head cavity. This eliminates the need for calibration between two separate optical systems and removes the source of calibration errors. The single optical system provides a unified coordinate reference for all alignment operations.
Solution Approach 2:
The bond head cavity serves as an intermediary space that allows the optical assembly to view both the die held by the pick-up tool and the bonding site on the substrate. This intermediary viewing position enables simultaneous observation of both reference points without requiring physical movement of the optical system.
3Ease of operation
If optical systems are separated by large distance for viewing die and substrate, then both can be viewed, but thermal error and table motion error increase affecting placement accuracy
Solution Approach 1:
The patent positions the optical assembly in a vertical dimension above the bond head, allowing it to view both the die and bonding site through the bond head cavity without requiring large horizontal separation. This vertical positioning approach eliminates the need for long-distance horizontal movement of the optical system, reducing thermal and motion errors.
4Measurement precision
If bond head is made narrow to allow optical viewing, then optical assembly can view die, but bond head structure becomes more constrained
Solution Approach 1:
The patent designs the bond head with a cavity that accommodates the optical assembly within its structure. The optical system is nested inside the bond head, allowing the bond head to maintain its functional width while providing an internal viewing path for the optical assembly through the cavity.
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 approach enhances die bonding precision by allowing real-time alignment adjustments and reducing calibration and motion errors, improving placement accuracy and reducing cycle time without sacrificing precision.
Implementation Method 1
an optical assembly positioned for viewing an orientation of the die bonding site
Implementation Method 2
a bond head movable between a supply of semiconductor dice and a die bonding site; a pick-up tool attached to the bond head for holding a die
Data Source
AI summary
A die bonding apparatus and a bonding method are provided wherein the apparatus comprises a bond head movable between a supply of semiconductor dice and a die bonding site, a pick-up tool attached to the bond head for holding a die to be bonded at the die bonding site and an optical assembly positioned for viewing an orientation of the die bonding site. The bond head is configured such that an orientation of the die being held by the pick-up tool between the optical assembly and the die bonding site is viewable by the optical assembly, whereby the orientation of the die may be aligned with the orientation of the die bonding site.