Underfill Material Voidless Packaging Solder Bonding
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Solution Overview
Problem
Existing semiconductor packaging methods using pre-applied underfill films face challenges in achieving voidless mounting and maintaining favorable solder bonding properties, as current curing agents either introduce voids or degrade solder bonding.
Innovation Solution
An underfill material comprising a film-forming resin, epoxy resin, curing agent, curing accelerator, and inorganic filler, where the curing reaction reaches 20% conversion in 2.0 seconds or less and 60% conversion in 3.0 seconds or more, with specific viscosity ranges at these conversion points, ensuring voidless packaging and excellent solder bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If peroxide curing agent is used and curing speed is increased to prevent voids, then voidless packaging is achieved, but solder bonding properties are degraded
Solution Approach 1:
The patent changes the chemical parameters of the curing system by selecting specific curing agents (acid anhydride or amine type) with controlled reactivity, and adjusts the curing accelerator content to 1-10 parts by mass per 100 parts of epoxy resin. This parameter optimization enables the curing reaction to proceed at a controlled rate that prevents void formation while preserving solder bonding properties, resolving the contradiction between voidless packaging and solder bonding quality
Solution Approach 2:
The patent creates a composite curing system combining epoxy resin with specific curing agents (acid anhydride or amine type) and curing accelerators in optimized proportions. This composite material formulation achieves synergistic effects where the combination of components provides both rapid curing capability for voidless packaging and controlled reaction kinetics to maintain solder bonding properties, thus resolving the technical contradiction
2Productivity
If curing speed is increased to achieve voidless mounting, then void formation is prevented, but solder bonding properties are degraded
Solution Approach 1:
The patent optimizes the curing reaction parameters by selecting curing agents with appropriate reactivity and controlling the curing accelerator content within 1-10 parts by mass per 100 parts of epoxy resin. This parameter control enables the curing reaction to proceed at an optimized speed that achieves voidless mounting while maintaining favorable solder bonding properties, resolving the contradiction between curing speed and solder bonding quality
3Strength
If epoxy resin with phenol, acid anhydride or amine curing agent is used, then adhesive bonding is achieved, but voidless packaging and solder bonding properties cannot be simultaneously optimized
Solution Approach 1:
The patent formulates a composite adhesive material consisting of epoxy resin combined with specific curing agents (acid anhydride or amine type) and curing accelerators in optimized ratios. This composite material simultaneously provides strong adhesive bonding strength and controlled curing characteristics that enable voidless packaging, resolving the contradiction between adhesive bonding strength and voidless packaging achievement
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 underfill material achieves voidless packaging and superior solder bonding properties by controlling the curing reaction kinetics and viscosities, preventing void formation and ensuring strong electrical and mechanical connections.
Implementation Method 1
the semiconductor chip and substrate are thermally compressed together, electrical conduction is ensured using metallic bonding of solder bumps, and the semiconductor chip is bonded to the substrate by curing of the underfill film
Implementation Method 2
a time for a degree of conversion to reach 20% at 240°C calculated by Ozawa method using a differential scanning calorimeter
Data Source
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AI summary
An underfill material enabling voidless packaging and excellent solder bonding properties, and a method for manufacturing a semiconductor device using the same are provided. An underfill material is used which contains an epoxy resin and a curing agent, and a time for a reaction rate to reach 20% at 240°C calculated by Ozawa method using a differential scanning calorimeter is 2.0 sec or less and a time for the reaction rate to reach 60% is 3.0 sec or more. This enables voidless packaging and excellent solder connection properties.