Resin-Impregnated Copper TSVs for Conductivity and Thermal Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing through-silicon vias suffer from low productivity due to the need for extended plating times to control copper film precipitation, and substrates with through-silicon vias lack sufficient electrical conductivity and connection reliability, especially under temperature changes.
Innovation Solution
A method involving the formation of a copper sintered body with a porous structure in through-holes of a silicon substrate, followed by impregnation with a curable resin composition and curing to create an electric conductor with a resin-filled copper sintered body, ensuring high productivity and excellent connection reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electroplating is used to form copper films in through-silicon vias, then electrical conductivity is improved, but productivity deteriorates due to extended plating times required to control copper film precipitation
Solution Approach 1:
The invention changes the formation method from electroplating to sintering process, using copper paste with controlled particle size distribution (D10, D50, D90 values) and sintering temperature (900-1100°C) to achieve both high conductivity and productivity. The paste composition parameters are optimized to control copper particle densification during sintering.
Solution Approach 2:
The invention uses a composite structure combining copper particles with glass particles in the paste formulation. The glass particles fill voids between copper particles and provide binding, creating a composite material that achieves good electrical conductivity after sintering while maintaining process efficiency.
2Productivity
If copper paste sintering is used to form through-silicon vias, then productivity is improved, but electrical conductivity and connection reliability may deteriorate compared to electroplating
Solution Approach 1:
The invention optimizes sintering parameters including temperature (900-1100°C), atmosphere (nitrogen or hydrogen), and time to achieve dense copper structures with low porosity. The copper paste particle size distribution is specifically controlled to facilitate complete densification during sintering, ensuring electrical conductivity comparable to electroplating.
Solution Approach 2:
The invention initially creates a porous copper structure through sintering of copper paste particles, then uses resin impregnation to fill the pores. This two-step process maintains the productivity advantage of sintering while achieving the density and conductivity of electroplating through pore filling.
3Reliability
If traditional copper filling methods are used, then electrical conductivity is achieved, but connection reliability deteriorates under temperature changes
Solution Approach 1:
The invention creates a composite structure of copper sintered body with resin-impregnated pores. The resin component (epoxy or phenolic) has thermal expansion properties that complement copper, reducing thermal stress during temperature cycling. This composite structure improves connection reliability under thermal conditions while maintaining electrical conductivity.
Solution Approach 2:
The invention uses a porous copper sintered body structure that is subsequently impregnated with resin. The porous structure allows complete resin penetration, creating strong adhesion between copper and resin. This bonded composite structure resists delamination under thermal cycling, improving connection reliability.
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 method produces substrates with through-silicon vias that have low initial resistance and maintain stable resistance values during temperature cycles, providing high electrical conductivity and reliable connections.
Implementation Method 1
a copper paste sintering step of sintering the copper paste to form a copper sintered body
Implementation Method 2
a resin impregnation step of impregnating the copper sintered body with a curable resin composition
Implementation Method 3
a resin curing step of curing the curable resin composition impregnated into the copper sintered body
Data Source
AI summary
An aspect of the invention is a method for producing a substrate having through-silicon vias, the method including a preparation step of preparing a silicon substrate provided with through-holes, in which the through-holes communicate with both principal surfaces; a copper sintered body formation step of forming a copper sintered body having a porous structure such that the copper sintered body fills at least the through-holes; a resin impregnation step of impregnating the copper sintered body with a curable resin composition; and a resin curing step of curing the curable resin composition impregnated into the copper sintered body to form an electric conductor that includes the copper sintered body having pores filled with a resin cured product, and providing through-silicon vias in the through-holes.