Hollow Particles with Crosslinked Shell for Low CTE Electronic Materials
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Solution Overview
Problem
Existing hollow particles do not achieve a sufficient decrease in thermal expansion coefficient for electronic material applications, which is necessary for improving the performance of insulation resin layers in electronic circuits.
Innovation Solution
The development of hollow particles with a shell containing a polymer with a high content of crosslinkable monomer units, a void ratio of 50% or more, and a thermal expansion coefficient of 10.0×10−5/°C or less, achieved by adjusting the composition and production method of the shell to prevent acetone permeation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the amount of inorganic filler is increased to decrease CTE of insulation resin layer, then CTE decreases, but physical properties deteriorate (cracking occurs) and sufficient decrease in relative permittivity and dielectric dissipation factor cannot be achieved
Solution Approach 1:
The patent changes the type and amount of filler materials from conventional inorganic fillers to a specific combination of hollow particles (70-90 wt%) and inorganic filler (10-30 wt%). This parameter change allows achieving low CTE (close to copper plate) while maintaining physical properties and electrical characteristics, as the hollow particles provide low CTE without the cracking issues of high inorganic filler content
Solution Approach 2:
The patent creates a composite filler system combining hollow particles with specific inorganic fillers (silica, alumina, titania) in optimized ratios. This composite approach leverages the low CTE of hollow particles while using inorganic fillers to enhance mechanical strength and control electrical properties, avoiding the drawbacks of using only inorganic fillers
2Reliability
If hollow particles are incorporated to decrease permittivity and dielectric dissipation factor, then electrical properties improve, but CTE control becomes insufficient for electronic material applications
Solution Approach 1:
The patent optimizes the void ratio of hollow particles to 50-80% and the shell thickness to achieve the desired balance between electrical and thermal properties. By controlling these parameters, the hollow particles provide both low permittivity/dielectric loss and sufficiently low CTE when combined with inorganic fillers
3Stability of the object's composition
If conventional hollow particles are used to decrease CTE, then some CTE reduction is achieved, but the thermal expansion coefficient is still not sufficiently decreased for electronic material applications
Solution Approach 1:
The patent combines hollow particles with specific inorganic fillers (silica, alumina, titania) in a optimized ratio of 70-90 wt% hollow particles and 10-30 wt% inorganic filler. This composite filler system achieves CTE close to that of copper plates, providing sufficient CTE control for electronic material applications that conventional hollow particles alone cannot achieve
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
These hollow particles exhibit a decreased thermal expansion coefficient, reduced relative permittivity, and dielectric dissipation factor, while maintaining excellent heat resistance and mechanical strength, making them suitable for use in electronic material applications.
Implementation Method 1
hollow particles can scatter light well and can reduce light transmissivity as compared to solid particles
Implementation Method 2
the CTE of hollow particles is generally low compared to that of an insulation resin
Implementation Method 3
a polymer in which from 70 parts by mass to 100 parts by mass of a crosslinkable monomer unit is contained in 100 parts by mass of all monomer units
Data Source
AI summary
Hollow particles which comprise a shell containing a resin and a hollow portion surrounded by the shell, wherein a void ratio is 50% or more; wherein a volume average particle diameter is 1.0 μm or more; wherein the shell contains, as the resin, a polymer in which 70 parts by mass to 100 parts by mass of a crosslinkable monomer unit is contained in 100 parts by mass of all monomer units; wherein a thermal expansion coefficient at 80° C. to 200° C. is 10.0×10−5/° C. or less; and wherein, in a hollow particle immersion test in which a mixture obtained by adding 0.1 mg of the hollow particles to 4 mL of acetone and shaking them for 10 minutes at a shaking rate of 100 rpm, is left to stand for 48 hours in an environment at 25° C., less than 10% by mass of the hollow particles submerge in the acetone.