Flip Chip Alignment Using Bonding Arm CCD Imagers
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Solution Overview
Problem
The conventional flip chip bonding process for integrating circuit dies with substrates is hindered by complex and time-consuming alignment procedures, leading to reduced throughput and increased costs due to the need for multiple optical lenses and iterative alignment corrections.
Innovation Solution
The use of a bonding arm equipped with CCD imagers mounted outside the component, allowing for direct downward alignment and eliminating the need for fiducial mark identification and iterative alignment adjustments, combined with the option of laser transmitters for enhanced accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple optical lenses and iterative alignment corrections are used, then alignment precision is improved, but alignment time and process complexity increase
Solution Approach 1:
The patent extracts and eliminates the fiducial mark identification step from the alignment process. By using direct optical alignment between the integrated circuit die and substrate without requiring fiducial marks, the method removes an entire subsystem (fiducial mark detection and interpretation) that caused iterative corrections and time delays while maintaining alignment precision.
Solution Approach 2:
The patent inverts the traditional alignment approach by eliminating the need for fiducial marks and pattern recognition. Instead of using marks as intermediaries for alignment, the system directly aligns the functional elements (connector terminals with pads) through simplified optical detection, reversing the conventional sequence of mark detection → position calculation → alignment correction.
2Manufacturing precision
If multiple optical lenses and iterative alignment corrections are used, then alignment precision is improved, but device complexity increases
Solution Approach 1:
The patent removes the fiducial mark identification subsystem from the alignment system. This extraction eliminates the need for complex pattern recognition algorithms, mark detection optics, and iterative correction mechanisms, thereby reducing device complexity while preserving alignment precision through direct optical alignment methods.
Solution Approach 2:
The invention inverts the conventional alignment paradigm by eliminating fiducial marks entirely. Instead of adding complexity to detect and interpret marks, the system simplifies the alignment process by directly optically aligning functional elements, thereby reducing device complexity while maintaining manufacturing precision.
3Manufacturing precision
If iterative alignment corrections are performed, then alignment precision is improved, but throughput decreases
Solution Approach 1:
The patent applies preliminary action by pre-positioning the integrated circuit die and substrate using simplified optical alignment without iterative corrections. The alignment is achieved in a single step through direct optical detection of functional elements, eliminating the need for repeated positioning and correction cycles, thereby maintaining precision while maximizing throughput.
Solution Approach 2:
The invention skips the iterative alignment correction steps entirely by using direct optical alignment between functional elements. This allows the process to rush through the alignment phase in a single operation rather than repeatedly cycling through detection and correction, thereby improving throughput without sacrificing alignment precision.
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 significantly reduces alignment time, increases throughput, and lowers costs by streamlining the flip chip assembly process through precise and automatic alignment without reliance on fiducial marks or pattern recognition, minimizing errors caused by motor vibration.
Implementation Method 1
bonding arm having a plurality of charge coupled device (CCD) imagers mounted thereon and looking toward the integrated circuit and past the integrated circuit
Implementation Method 2
In further embodiments, a plurality of laser transmitters are mounted on the bonding arm
Data Source
AI summary
Methods and apparatus for alignment in a flip chip bonding. A method includes attaching an integrated circuit having connector terminals to a bonding arm, the bonding arm having a chuck for attaching the integrated circuit at the backside surface, the bonding arm having a plurality of CCD imagers mounted thereon; receiving a substrate having pads corresponding to the connector terminals; using the bonding arm, positioning the integrated circuit proximal to the substrate; aligning the integrated circuit connector terminals with the pads on the substrate using the CCD imagers on the bonding arm; positioning the connector terminals in contact with the pads on the substrate; and performing a solder reflow to attach the integrated circuit to the substrate. An apparatus includes a bonding arm with a chuck for carrying a component and CCD imagers mounted on the arm for alignment.