Semiconductor Chip Alignment Through Light-Transmitting Bonding
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Solution Overview
Problem
The high manufacturing cost and complexity of flip-chip bonding methods for semiconductor devices, particularly GaN HEMTs, hinder mass production and deteriorate high-frequency characteristics due to the use of expensive equipment and bonding wires.
Innovation Solution
A method involving a semiconductor chip with a smooth third surface and transparent substrate for pattern recognition using light transmission, enabling alignment and bonding with a general-purpose chip mounter, eliminating the need for flip-chip bonders and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If flip-chip bonding method is used for mounting semiconductor chips, then alignment precision and bonding strength are improved, but manufacturing cost and device complexity increase significantly
Solution Approach 1:
The patent replaces the complex mechanical flip-chip bonding system with a simpler pick-and-place mounting system. By forming protruding portions (bumps) on the semiconductor chip that mechanically engage with recesses in the mounting substrate, the invention achieves precise alignment and secure bonding without requiring flip-chip bonding equipment. The protruding portions serve as both alignment references and bonding structures, eliminating the need for complex flip-chip bonding processes while maintaining manufacturing precision.
Solution Approach 2:
The patent performs preliminary actions by pre-forming protruding portions on the semiconductor chip surface before mounting. These protruding portions are created through a series of preparatory steps including forming recesses in the chip, depositing conductive materials, and shaping the protrusions. By completing these actions in advance, the actual mounting process becomes simpler and can be performed using standard pick-and-place equipment rather than complex flip-chip bonders.
2Reliability
If flip-chip bonding method is used for mounting semiconductor chips, then high-frequency characteristics are improved, but manufacturing cost increases due to expensive equipment and materials
Solution Approach 1:
The patent replaces expensive flip-chip bonding equipment with standard pick-and-place mounting equipment. The protruding portions enable direct mechanical and electrical connection between the chip and substrate, eliminating the need for complex bonding processes. This substitution dramatically reduces manufacturing equipment costs while maintaining reliable high-frequency performance through direct solder bump connections that provide low-inductance pathways for high-frequency signals.
Solution Approach 2:
The patent uses cost-effective materials and processes for creating the protruding portions, such as standard conductive pastes and solder materials, rather than expensive specialized flip-chip bonding materials. The protruding portions are formed using conventional semiconductor fabrication processes that are already in place for chip manufacturing, avoiding the need for additional expensive material deposits or specialized consumables required by flip-chip bonding.
3Ease of manufacture
If general-purpose chip mounter is used instead of flip-chip bonder, then manufacturing cost is reduced, but alignment precision and bonding reliability may deteriorate
Solution Approach 1:
The protruding portions on the semiconductor chip serve dual functions: they act as both alignment references and bonding structures. During pick-and-place mounting, the protruding portions automatically align with corresponding recesses in the substrate, providing self-alignment that compensates for the lower precision of general-purpose mounters. The physical interlocking of protrusions with recesses ensures precise positioning and reliable bonding without requiring high-precision alignment equipment.
Solution Approach 2:
The patent designs the protruding portions and recesses to create a mechanically equipotential connection, where the physical geometry of the bonding interface ensures proper alignment regardless of minor positioning variations. The symmetric design of the protrusions and their corresponding recesses creates multiple stable alignment positions, allowing the chip to self-correct minor misalignments during the bonding process, thereby maintaining alignment precision even with less expensive mounting equipment.
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
Facilitates mass production of semiconductor devices with improved high-frequency characteristics and reduced costs by using a general-purpose chip mounter for precise alignment and bonding, avoiding the need for expensive equipment and materials.
Implementation Method 1
the semiconductor chip is transparent to light having at least a part of wavelengths of visible light and infrared light
Data Source
AI summary
A method for manufacturing a semiconductor device includes preparing a first substrate provided with a first pattern on a first surface, and a semiconductor chip having a second surface, and a third surface opposite to the second surface, and including a second pattern provided on the second surface, recognizing the first pattern from a position near the first surface among the first surface and an opposite surface thereof in the first substrate, recognizing the second pattern by transmitting through the semiconductor chip from a position near the third surface among the second surface and the third surface in the semiconductor chip, aligning the semiconductor chip and the first substrate based on a recognition result of the first pattern and the second pattern, and bonding the semiconductor chip to the first substrate so that the second surface faces the first surface.