Copper Pillar Sintering with Pressure Plate to Prevent Adhesion
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Solution Overview
Problem
Conventional methods for fabricating copper pillars in semiconductor components face issues such as voids in plating, incomplete sintering, and the inability to achieve desired volume and structural integrity due to lack of effective force-providing means during the sintering process, leading to poor performance.
Innovation Solution
A system and method utilizing a sinter unit with a thermal-pressure module and plate handler to apply force and heat, ensuring complete sintering of copper pillars on a substrate by using a plate as an intermediary layer to prevent adhesion to the presser, maintaining structural integrity and volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional electrolytic or electroless plating processes are used to fabricate copper pillars, then copper pillars can be formed on contacts, but voids are created within the pillars and they are not fully solid
Solution Approach 1:
The patent changes the material state from plated copper to sintered copper particles. By controlling particle size, packing density, and sintering parameters (temperature, pressure, time), the process achieves fully solid pillars without voids. The sintering process transforms loose particles into dense, void-free structures through diffusion bonding.
Solution Approach 2:
The sintering process utilizes phase transitions of copper particles from discrete particles to fused solid structure. By applying heat and pressure, the copper particles undergo diffusion and bonding, transitioning from a loose particulate state to a dense solid state, eliminating voids in the process.
2Productivity
If sintering is performed with the mask remaining on the substrate, then the sintering process can be completed, but the sintered conductive pillars join to the mask and material is removed when the mask is removed
Solution Approach 1:
The patent introduces a plate as an intermediary layer between the presser and the sintered pillars during the sintering process. This plate prevents direct contact between the presser and the conductive pillars, stopping the pillars from adhering to the presser. The plate acts as a mediator that allows force transmission while preventing material loss.
3Ease of manufacture
If conventional plating processes are used, then copper pillars can be formed, but they are loosely plated and cause poor electronic component performance
Solution Approach 1:
The patent changes the fabrication approach from electrochemical plating to thermal sintering of particles. By controlling sintering parameters (temperature, pressure, time), the process produces densely packed, strongly bonded copper pillars with superior mechanical and electrical properties, eliminating the loose plating structure.
Solution Approach 2:
The patent uses copper particles as the base material for pillar formation, creating a composite structure that is then sintered into a dense solid. This particle-based approach followed by sintering creates a more reliable structure compared to conventional plating, as the sintering process ensures complete bonding without voids or loose attachments.
4Manufacturing precision
If a force-providing means is added to enable compact sintering, then particles can be necked in a more compact manner, but the device complexity increases
Solution Approach 1:
The patent employs a presser that serves multiple functions: it applies compressive force for sintering, provides mechanical support, and works in conjunction with the plate to prevent adhesion. This multi-functional design achieves compact sintering without requiring separate complex force-providing mechanisms, as the presser integrates force application with the sintering process.
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 enhances the sintering process, improving cycle time and reducing capital expenditure while providing cost-effective copper pillars with desired structural integrity and adhesion to the substrate.
Implementation Method 1
a sinter unit, configured to sinter the structures on the base, wherein the sinter unit is further configured to apply force and provide heat to the structures on the base for the structures to sinter
Implementation Method 2
a thermal-pressure module, which comprises a presser, which is configured to apply the force via its press surface, which is further attached with the plate, a platform, in which the base rests thereupon, and a heating sub-module, which is configured to provide heat to any one or both the presser and the platform
Data Source
AI summary
A system and a method for sintering one or more structures on a base use a sinter unit. The sinter unit is configured to sinter the structures on the base. More specifically, the sinter unit applies force and provides heat to the structures on the base for the structures to sinter, in which a plate is made to be adjacent to the structures on the base.