Wafer Laminate Two-Layer Adhesive Light Shielding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wafer/glass laminates require cumbersome photolithography steps and high pressure for bonding, and the resin used can degrade when exposed to light, especially in the visible to near-infrared spectrum.
Innovation Solution
A two-layer adhesive system comprising a light-shielding first cured resin layer (A) with substantial absorption up to 500 nm and a thermosetting second cured resin layer (B) based on silicone or epoxy resin, applied in a specific order to prevent resin degradation and facilitate bonding under reduced pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a photosensitive resin layer is used for bonding wafer to glass, then the wafer/glass laminate can be formed with device function, but cumbersome photolithography steps are involved and high pressure is necessary for bonding
Solution Approach 1:
The adhesive layer is segmented into two distinct layers: a lower light-shielding layer (first cured resin layer) and an upper bonding layer (second cured resin layer). This segmentation allows each layer to perform its specific function independently - the lower layer blocks light to prevent resin degradation, while the upper layer provides bonding functionality, thereby eliminating the need for photolithography steps and high pressure bonding.
Solution Approach 2:
The invention uses a composite adhesive layer structure combining two different resin systems with complementary properties. The first cured resin layer provides light-shielding properties, while the second cured resin layer provides bonding properties. This composite structure resolves the contradiction by integrating multiple functions into a single adhesive system, simplifying the overall process while maintaining bonding reliability.
2Device complexity
If a single-layer adhesive is used for bonding, then the structure is simple, but the resin degrades when exposed to light in the visible to near-infrared spectrum
Solution Approach 1:
The adhesive is segmented into two layers with distinct functions. The lower light-shielding layer absorbs light in the visible to near-infrared spectrum, preventing it from reaching and degrading the upper bonding resin layer. This segmentation allows the bonding resin to maintain its stability while the structure remains relatively simple with just two layers.
Solution Approach 2:
The light-shielding layer acts as an intermediary between the light source and the bonding resin layer. It intercepts and absorbs harmful light wavelengths, protecting the bonding resin from degradation. This intermediary layer resolves the contradiction by shielding the resin from light exposure while maintaining the simplicity of the overall adhesive structure.
3Strength
If high pressure is applied for bonding, then strong adhesion is achieved, but the processing complexity and equipment requirements increase
Solution Approach 1:
The invention changes the chemical and physical parameters of the adhesive system by using a two-layer cured resin structure. This parameter change allows bonding to occur under reduced pressure conditions while maintaining strong adhesion, thereby reducing the complexity of bonding equipment and processing requirements while achieving the desired bonding strength.
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
The solution effectively shields light in the visible to near-infrared range, preventing resin degradation and allowing for reliable bonding of wafers to transparent substrates with reduced processing complexity and pressure, enhancing the reliability and fabrication of device wafers.
Implementation Method 1
a bonding layer of two layers, a cured resin layer (A) of a specific structure having substantial absorption at wavelength up to 500 nm and a cured resin layer (B) which is a cured product of a thermosetting resin composition having a bonding function
Data Source
Figure 1
AI summary
A wafer laminate has an adhesive layer (3) sandwiched between a transparent substrate (1) and a wafer (2), with a circuit forming surface of the wafer facing the adhesive layer. The adhesive layer (3) includes a first cured resin layer (3a) disposed adjacent the substrate and having light-shielding properties and a second cured resin layer (3b) disposed adjacent the wafer and comprising a cured product of a thermosetting resin composition.