Stacked Lens Structure Direct Bonding Resin Elimination
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Solution Overview
Problem
The existing wafer-level lens process faces challenges in achieving shape and position accuracy, particularly when stacking multiple layers, as deformation and positional shifts occur due to adhesive resin shrinkage and thermal expansion in stacked lens structures.
Innovation Solution
A stacked lens structure is formed by directly bonding substrates with lenses through inorganic material layers, eliminating the need for adhesive resins and thereby reducing deformation and positional shifts, using techniques like dehydration condensation between oxide or nitride surface layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If adhesive resin is used to bond wafer substrates, then the substrates can be stacked, but deformation and positional shift occur due to resin shrinkage and thermal expansion
Solution Approach 1:
The patent extracts and removes the adhesive resin from the bonding process. By eliminating the resin layer entirely, the source of shrinkage and thermal expansion problems is removed. The substrates are bonded directly to each other through surface treatment and direct contact, preventing deformation and positional shift while maintaining stacking capability.
Solution Approach 2:
The patent introduces surface treatment layers (such as oxide or nitride films) as intermediaries between substrates. These treatment layers enable direct bonding by providing compatible bonding surfaces without requiring adhesive resin, thus achieving both stacking capability and high precision.
2Adaptability or versatility
If multiple layers are stacked using adhesive resin, then complex lens structures can be formed, but deformation increases with each additional layer
Solution Approach 1:
By removing the adhesive resin from between multiple substrate layers, the patent eliminates the cumulative shrinkage and thermal expansion effects that would occur with each resin layer. This enables stable stacking of three or more layers without increasing deformation, maintaining structural stability while achieving complex multi-layer lens structures.
3Ease of manufacture
If lens material is used as adhesive resin, then wafer substrates can be bonded, but shrinkage during curing causes positional shift
Solution Approach 1:
The patent completely removes the lens material adhesive resin from the bonding process. Instead, substrates are bonded through direct contact with surface treatment, eliminating curing shrinkage and its associated positional shift problems while maintaining the bonding function needed for substrate attachment.
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 the accuracy and stability of stacked lens structures by preventing resin-related deformations and thermal expansions, enabling the successful stacking of multiple layers without curing shrinkage or thermal expansion issues.
Implementation Method 1
using techniques like dehydration condensation between oxide or nitride surface layers
Data Source
AI summary
A deformation of a stacked lens is suppressed.A stacked lens structure has a configuration in which substrates with lenses having a lens disposed on an inner side of a through-hole formed in the substrate are bonded and stacked by direct bonding. The present technique can be applied to a camera module or the like in which a stacked lens structure in which at least three substrates with lenses including first to third substrates with lenses which are substrates with lenses in which a through-hole is formed in the substrate and a lens is formed on an inner side of the through-hole is integrated with a light receiving element, for example.