Semiconductor Bump Layout Around Lens Material for Wafer Bonding
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Solution Overview
Problem
Bonding of semiconductor chips is not performed easily due to the presence of lens materials on the light collection surface, which complicates the formation of bumps and alignment, leading to low bonding efficiency and increased heat load in existing methods.
Innovation Solution
A semiconductor device with bumps on a first semiconductor substrate where the distance between the bump and the lens material is greater than twice the bump's diameter, allowing for easy bonding by forming the lens material in a region other than the bumps, and a manufacturing method that includes forming bumps and lens material with specific spacing to facilitate efficient chip bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lens material is formed on the entire light collection surface including peripheral circuit region, then light collection efficiency is improved, but bump formation precision deteriorates due to increased opening depth
Solution Approach 1:
The light collection surface is segmented into pixel region and peripheral circuit region. The lens material is formed only in the pixel region, while the peripheral circuit region remains exposed for bump formation. This segmentation allows the lens material to cover areas where it is needed for light collection while leaving areas where it would interfere with manufacturing processes.
Solution Approach 2:
The lens material coverage is made non-uniform across the light collection surface. Instead of covering the entire surface, the lens material is applied selectively only to the pixel region, creating local quality differences that optimize both light collection in the pixel region and manufacturing accessibility in the peripheral circuit region.
2Measurement precision
If chip-on-chip bonding method is used, then alignment precision is maintained, but bonding efficiency deteriorates due to low productivity
Solution Approach 1:
Multiple chip bonding operations are merged into a single wafer-level bonding process. Instead of bonding chips individually in sequence, the invention enables simultaneous bonding of multiple chips to a wafer, combining what would be separate operations into one efficient process that maintains alignment precision while dramatically improving productivity.
Solution Approach 2:
The bonding process transitions from a one-dimensional sequential chip-by-chip approach to a two-dimensional wafer-level parallel processing approach. By utilizing the wafer surface area and arranging multiple chips in a matrix, the process exploits an additional spatial dimension to enable simultaneous bonding operations.
3Measurement precision
If multiple second semiconductor chips are bonded one by one to semiconductor wafer, then alignment precision is maintained, but bonding time increases in proportion to number of chips
Solution Approach 1:
Alignment marks are pre-formed on the semiconductor wafer before the bonding process. This preliminary action allows for rapid alignment of multiple chips during bonding, eliminating the need for time-consuming alignment procedures for each individual chip and enabling parallel processing of multiple chips simultaneously.
Solution Approach 2:
The alignment mark pattern is copied across the entire wafer surface, allowing each chip to be aligned using the same reference pattern. This copying approach enables consistent alignment precision across multiple chips while reducing the complexity of the alignment process, as the same alignment procedure can be applied to all chips in parallel.
Data Source
AI summary
There is provided a semiconductor device including: a plurality of bumps on a first semiconductor substrate; and a lens material in a region other than the plurality of bumps on the first semiconductor substrate, wherein a distance between a side of a bump closest to the lens material and a side of the lens material closest to the bump is greater than twice a diameter of the bump closest to the lens material, and wherein the distance between the side of the bump closest to the lens material and the side of the lens material closest to the bump is greater a minimum pitch of the bumps.