Photosensitive Polyimide Adhesive for Low-Temperature Semiconductor Packaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional photosensitive adhesives based on polyimide resins face challenges in forming patterns with alkali developer solutions and achieving sufficient re-adhesiveness and adhesive strength at low temperatures, leading to thermal damage and residual heat stress in semiconductor packaging.
Innovation Solution
A photosensitive adhesive composition comprising a polyimide with a carboxyl group, a photo-polymerizable compound, and a photopolymerization initiator, along with a thermosetting resin, which allows for pattern formation with an alkali developer solution and provides re-adhesiveness and high adhesive strength at low temperatures, using specific molecular weight ranges and chemical formulations to enhance solubility and thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional photosensitive adhesives based on polyimide resin are used, then the adhesive can be exposed to light for patterning, but the adhesive requires high temperature (300°C or more) for ring closure reaction or adhesion, causing severe thermal damage to surrounding material
Solution Approach 1:
The patent changes the chemical composition parameters of the adhesive by introducing a carboxyl group-containing polymer component alongside the polyimide resin. This compositional parameter change enables the adhesive to form patterns with alkali developer solutions at lower temperatures, eliminating the need for high-temperature ring closure reactions and thus preventing thermal damage to surrounding materials.
Solution Approach 2:
The patent creates a composite adhesive system combining polyimide resin with a carboxyl group-containing polymer. This composite material leverages the photosensitivity and adhesion properties of polyimide while the carboxyl group-containing polymer provides solubility in alkali developer solutions, enabling pattern formation without high-temperature processing.
2Reliability
If conventional photosensitive adhesives based on polyimide resin are used, then the adhesive can be exposed to light for patterning, but residual heat stress is easily generated
Solution Approach 1:
The patent modifies the adhesive composition by incorporating a carboxyl group-containing polymer, which changes the thermal and chemical properties of the system. This enables pattern formation through chemical etching with alkali developer solutions rather than thermal processes, thereby eliminating the generation of residual heat stress while maintaining pattern-forming capability.
3Manufacturing precision
If conventional photosensitive adhesives based on polyimide resin are used, then the adhesive can form patterns, but the adhesive does not easily have both pattern-forming properties with alkali developer solution and sticking property at low temperature
Solution Approach 1:
The patent develops a composite adhesive consisting of polyimide resin combined with a carboxyl group-containing polymer. The polyimide provides photosensitivity for pattern formation, while the carboxyl group-containing polymer provides solubility in alkali developer solutions and low-temperature adhesion properties. This composite structure simultaneously achieves pattern-forming precision and low-temperature sticking capability.
Solution Approach 2:
The patent assigns different functional properties to different components of the adhesive system: the polyimide resin component provides photosensitivity and structural integrity for pattern formation, while the carboxyl group-containing polymer component provides chemical reactivity with alkali developer solutions and low-temperature adhesion. This functional differentiation enables simultaneous achievement of pattern-forming properties and low-temperature sticking properties.
4Reliability
If conventional photosensitive adhesives based on polyimide resin are used, then the adhesive can be exposed to light, but it is difficult to impart re-adhesiveness which gives sufficiently high adhesive strength
Solution Approach 1:
The patent creates a composite adhesive system where polyimide resin provides photosensitivity for light exposure and patterning, while the carboxyl group-containing polymer provides reactive groups that form strong chemical bonds with substrates. This composite structure enables the adhesive to maintain high adhesive strength after light exposure by utilizing the bonding capabilities of the carboxyl groups.
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 composition achieves superior pattern-forming properties, re-adhesiveness, and high adhesive strength at low temperatures, reducing thermal damage and ensuring reliable semiconductor devices and electronic components with improved shear adhesive strength and thermal stability.
Implementation Method 1
a photopolymerization initiator, which initiates polymerization of the photo-polymerizable compound upon light exposure
Data Source
AI summary
A photosensitive adhesive composition comprising: (A) a polyimide having a carboxyl group as a side chain, whereof the acid value is 80 to 180 mg/KOH; (B) a photo-polymerizable compound; and (C) a photopolymerization initiator.