Vacuum Deposition Collimator for 2-Micron Indium Bump Arrays
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Solution Overview
Problem
Conventional deposition techniques for indium solder bumps are inadequate for producing smaller sizes, particularly in the microLED field, where improved systems and methods are needed to achieve smaller bump arrays.
Innovation Solution
A vacuum deposition system comprising a high-vacuum chamber with a cleaning apparatus, a carrier assembly, an evaporator for indium, and a collimator to direct and deposit indium onto a substrate, allowing for precise control and deposition of indium bumps as small as 2 microns or less.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional deposition techniques are used, then existing bump arrays can be produced, but smaller bump sizes (2 microns or less) cannot be achieved
Solution Approach 1:
The deposition system is segmented into distinct functional modules: a cleaning apparatus with ion source, a carrier assembly with substrate holder, an evaporator with indium supply, and a collimator with aperture. Each module independently contributes to achieving small bump sizes, allowing precise control without requiring complete system redesign.
Solution Approach 2:
The collimator creates a localized deposition zone by defining a specific aperture through which indium atoms are directed. This localizes the material flux to a precise area on the substrate, enabling formation of small 2-micron bumps with controlled spatial distribution and high manufacturing precision.
2Productivity
If multiple wafers are processed sequentially with chamber evacuation between depositions, then each wafer can be cleaned and coated, but production efficiency is reduced
Solution Approach 1:
The system maintains continuous high vacuum throughout the processing sequence. Multiple wafers are cleaned, coated, and removed without breaking vacuum or evacuating the chamber between steps. The carrier assembly allows sequential wafer processing while the indium supply remains ready for immediate deposition, eliminating idle time and maximizing productivity.
Solution Approach 2:
The cleaning apparatus prepares multiple wafers in advance within the vacuum chamber before deposition begins. Substrates are pre-cleaned with ion bombardment while the chamber remains sealed, so when indium deposition is ready, clean substrates are immediately available for coating without requiring intermediate vacuum breaks.
3Manufacturing precision
If the substrate is not cleaned under vacuum before deposition, then processing time is reduced, but contamination affects bump formation quality
Solution Approach 1:
The cleaning and deposition processes occur in a high vacuum environment that acts as an inert atmosphere, preventing oxidation and contamination of both the substrate surface and the indium material. This inert environment maintains bump formation quality while the continuous vacuum process minimizes additional processing time.
Solution Approach 2:
Substrates are pre-cleaned in the vacuum chamber using ion bombardment before indium deposition begins. This preliminary cleaning action removes contaminants from the substrate surface while the chamber remains sealed, ensuring high bump formation quality without requiring separate cleaning steps that would extend processing time.
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
Enables the formation of indium bump arrays with diameters as small as 2 microns or smaller, and allows for efficient processing of multiple wafers without chamber evacuation between depositions, enhancing production efficiency.
Implementation Method 1
an evaporator adapted to hold a supply of the substance in the chamber and to evaporate and produce a discharge of the substance
Implementation Method 2
a collimator disposed within the chamber between the supply of the substance and the carrier assembly, the collimator being configured to define an aperture proximal to the substrate and to capture the discharge but for that which is directed through the aperture
Implementation Method 3
an apparatus for receiving and cleaning the substrate to produce a clean substrate and for delivering the clean substrate to a coating position in the chamber under high vacuum
Data Source
AI summary
A system and method are provided for depositing a substance onto a substrate, the system comprising: a chamber adapted to operate under high vacuum; an apparatus for receiving and cleaning the substrate to produce a clean substrate and for delivering the clean substrate to a coating position in the chamber under high vacuum; a carrier assembly for receiving the clean substrate from the apparatus and for retaining the substrate at the coating position; an evaporator adapted to hold a supply of the substance in the chamber and to evaporate and produce a discharge of the substance; and a collimator disposed within the chamber between the supply of the substance and the carrier assembly, the collimator being configured to define an aperture proximal to the substrate and to capture the discharge but for that which is directed through the aperture.