Polishing Head Adhesive Bonding Without Thermal Deformation
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Solution Overview
Problem
Conventional polishing heads using the rubber-chuck method suffer from degradation in uniformity and flatness of polished semiconductor wafers due to thermal deformation of the rubber film and template assembly during the adhesive bonding process, which requires skilled manual operation and increases equipment size and investment.
Innovation Solution
A method of producing a polishing head where the backing pad and template are stuck to a rigid body using a double-sided tape under reduced pressure without heating, preventing air entry and thermal deformation, and using a liquid or paste reaction curable adhesive to maintain flatness and adhesive strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heating is applied during adhesive bonding to ensure adhesive strength, then bonding reliability is improved, but thermal deformation occurs degrading wafer flatness
Solution Approach 1:
The patent changes the bonding parameters by using reduced pressure instead of heating to achieve adhesive bonding. This allows the adhesive to bond effectively without causing thermal deformation to the rubber film and template assembly, thereby maintaining wafer flatness while ensuring bonding reliability.
Solution Approach 2:
The patent creates a reduced pressure environment during the bonding process, which acts as an inert atmosphere that prevents air entry and thermal deformation. This environment allows adhesive bonding to occur without the harmful effects of heat, preserving the flatness of the polishing head components.
2Manufacturing precision
If manual operation is used for adhesive bonding to ensure precision, then bonding quality is improved, but production time increases and equipment complexity increases
Solution Approach 1:
The patent employs a self-service bonding mechanism where the reduced pressure environment automatically prevents air entry and enables consistent adhesive bonding without requiring skilled manual operation. This automated approach maintains bonding quality while reducing production time and equipment complexity.
3Strength
If heating is applied to activate adhesive, then adhesive strength is improved, but thermal deformation of rubber film and template occurs
Solution Approach 1:
The patent changes the bonding conditions by using reduced pressure instead of heating to activate the adhesive. This parameter change allows the adhesive to achieve sufficient strength without causing thermal deformation to the rubber film and template, preserving their flatness.
Solution Approach 2:
The patent replaces the thermal mechanism (heating) with a mechanical one (reduced pressure) to achieve adhesive bonding. This substitution eliminates thermal deformation while maintaining adhesive strength, as the reduced pressure environment facilitates bonding without heat application.
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 method ensures the backing pad and template remain flat, maintaining high wafer flatness and reducing production time and equipment costs, enabling the polishing of wafers with improved uniformity and precision.
Implementation Method 1
sticking the backing pad on the lower portion of the rigid body with a double-sided tape under a reduced pressure without heating the backing pad; and subsequently sticking the template on the backing pad with a double-sided tape or a liquid or paste reaction curable adhesive containing no solvent under a reduced pressure without heating the template
Implementation Method 2
sticking the backing pad on the lower portion of the rigid body with a double-sided tape under a reduced pressure without heating the backing pad
Data Source
AI summary
A method of producing a polishing head including: a backing pad, for holding a workpiece back surface, stuck on a lower portion of a rigid body; and a ring template, for holding a workpiece edge, disposed on a lower surface of the backing pad. This polishing head brings a front surface of the workpiece into sliding contact with a polishing pad attached on a turn table while holding the workpiece back surface on the lower surface of the backing pad. The method includes sticking the backing pad on the lower portion of the rigid body with a double-sided tape under a reduced pressure without heating; and sticking the template on the backing pad with a double-sided tape or a liquid or paste reaction curable adhesive containing no solvent under a reduced pressure without heating. This method can polish the workpiece into a very flat workpiece.