Wafer Grinding Thickness Control via Protective Component Measurement
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Solution Overview
Problem
The thickness of protective components used in wafer processing often changes due to heating and pressing conditions, affecting grinding conditions and potentially leading to defects, as the residual adhesive from protective tapes or glue layers can remain on electrode bumps.
Innovation Solution
A method involving a wafer processing technique that includes forming a protective component from a thermoplastic resin, measuring its thickness, and adjusting the grinding process by subtracting the protective component's thickness from the total wafer thickness to ensure accurate grinding to a finished thickness, using a protective component sticking apparatus and a grinding apparatus with integrated thickness measurement and control systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protective component with a glue layer is used to prevent wafer breakage and dust adhesion, then the wafer is protected during grinding, but residual adhesive remains on electrode bumps causing defects
Solution Approach 1:
The invention extracts and removes the harmful glue layer from the protective component, retaining only the protective resin layer. This eliminates the source of adhesive residue that causes electrode bump defects while preserving the protective function during grinding operations.
Solution Approach 2:
The protective component is designed as a single-use, disposable element made of thermoplastic resin without adhesive. It is applied to protect the wafer front surface during grinding, then removed and discarded, eliminating contamination risks from reusable adhesive-based protective tapes.
2Stability of the object's composition
If the protective component is pressed while heating to achieve close contact with the wafer surface, then adhesion is improved, but the thickness of the protective component decreases
Solution Approach 1:
The invention implements a feedback control system where the thickness of the protective component is measured before and after heating/pressing. The measured thickness change is fed back to adjust grinding parameters, ensuring the wafer achieves the correct finished thickness despite variations in protective component compression.
Solution Approach 2:
The invention changes the approach from maintaining constant protective component thickness to accounting for thickness changes. By measuring the actual thickness after heating/pressing and using this information to adjust grinding depth, the system adapts to parameter changes rather than resisting them.
3Shape
If the protective component thickness changes due to heating and pressing conditions, then close contact with wafer irregularities is achieved, but grinding precision is affected
Solution Approach 1:
The system measures the protective component thickness after heating/pressing and uses this feedback information to adjust grinding parameters. This closed-loop control maintains manufacturing precision despite the protective component's shape changes during application.
Solution Approach 2:
The thickness of the protective component is measured in advance before the grinding operation begins. This preliminary measurement allows the grinding parameters to be pre-adjusted based on the actual protective component thickness, ensuring precise finished thickness control from the start of grinding.
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 reduces the influence of protective component thickness changes on processing conditions, ensuring consistent and accurate grinding results even when the protective component's thickness varies, thereby minimizing defects and maintaining precise control over the wafer's finished thickness.
Implementation Method 1
a protective component formed of a resin that softens by heat is stuck to the front surface side of a wafer by pressing the protective component while heating the protective component
Data Source
AI summary
A wafer processing method in which a wafer including devices on a front surface side is processed. The method includes a wafer-with-protective-component forming step of forming the wafer with a protective component through sticking the protective component formed of a resin that softens by heat to the front surface side by pressing and heating the protective component, a thickness measurement step of measuring a thickness of the protective component in the wafer with the protective component, and a grinding step of holding the wafer with the protective component by a chuck table and grinding a back surface side of the wafer until a thickness of the wafer becomes an intended finished thickness. In the grinding step, the thickness of the protective component measured in the thickness measurement step is subtracted from a total thickness of the wafer with the protective component to calculate the thickness of the wafer.