Nanoparticle Adhesion Layer for Semiconductor Packaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor packaging technologies face challenges in achieving strong and reliable adhesion between diverse materials, particularly as device miniaturization advances, leading to issues with mechanical stability, moisture ingress, and electrical reliability.
Innovation Solution
A method involving the formation of patterned nanoparticle adhesion layers with zones of electrical conductance and insulation is used, where nanoparticles are deposited and sintered onto a substrate, and then selectively oxidized or reduced to enhance adhesion, anchored within the substrate, and encapsulated with a polymeric compound to improve mechanical and electrical bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If general roughening of the leadframe surface is applied to improve adhesion, then adhesion between materials is enhanced, but wire bonding quality deteriorates and vision systems cannot detect the rough surface
Solution Approach 1:
The patent applies selective surface roughening only to specific regions where adhesion is needed, rather than general roughening of the entire leadframe surface. This localized approach preserves the smooth surfaces required for wire bonding while providing enhanced adhesion in designated areas through controlled chemical etching or mechanical abrasion.
Solution Approach 2:
The leadframe surface is divided into distinct functional zones: roughened areas for adhesion enhancement and smooth areas for wire bonding. This segmentation allows each region to have optimized surface properties for its specific function, resolving the conflict between adhesion requirements and wire bonding quality.
2Strength
If chemical etching is used to roughen the leadframe surface, then adhesion is improved, but manufacturing cost increases due to additional process steps
Solution Approach 1:
The patent combines the surface roughening process with existing leadframe manufacturing steps, such as integrating chemical etching into the standard fabrication sequence. By merging the adhesion enhancement process with routine manufacturing operations rather than adding separate dedicated steps, the cost increase is minimized while achieving the desired adhesion improvement.
3Strength
If the leadframe surface is roughened to enhance adhesion, then mechanical bonding is improved, but moisture ingress and chemical corrosion risks increase due to surface defects
Solution Approach 1:
The patent creates localized roughened regions with controlled morphology that provide mechanical interlocking for adhesion while maintaining overall surface integrity. The roughening is applied selectively rather than universally, and the surface structure is controlled to provide adhesion benefits without creating excessive defects that would compromise moisture barrier properties.
Solution Approach 2:
The patent employs composite surface structures combining roughened and smooth regions, or integrates additional protective coating layers over the roughened surfaces. This composite approach allows the roughened areas to provide mechanical bonding while the overall structure or protective layers maintain resistance to moisture ingress and chemical corrosion.
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 significantly enhances adhesion between metallic and polymeric materials, improving mechanical stability and electrical reliability by creating a strong anchor for the package, while allowing for selective electrical conductance for signal routing, resulting in improved device performance and longevity.
Implementation Method 1
nanoparticles are deposited and sintered onto a substrate
Implementation Method 2
selectively oxidized or reduced to enhance adhesion
Implementation Method 3
selectively oxidized or reduced to enhance adhesion
Implementation Method 4
A semi-viscous thermoset polymeric compound is pressured through runners across the leadframe strip to enter each cavity through a gate
Implementation Method 5
After filling the cavities, the compound is allowed to harden by polymerization
Implementation Method 6
An insulating material is added to contact the nanoparticle layer and fill pores/voids in the nanoparticle layer
Data Source
AI summary
A device comprises a substrate and an adhesive nanoparticle layer patterned into zones of electrical conductance and insulation on top of the substrate surface. A diffusion region adjoining the surface comprises an admixture of the nanoparticles in the substrate material. When the nanoparticle layer is patterned from originally all-conductive nanoparticles, the insulating zones are created by selective oxidation; when the nanoparticle layer is patterned from originally all-non-conductive nanoparticles, the conductive zones are created by depositing selectively a volatile reducing agent. A package of insulating material is in touch with the nanoparticle layer and fills any voids in the nanoparticle layer.