Wafer Dicing with Local UV Curing to Prevent Blade Adhesion
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Solution Overview
Problem
The adhesive layer of the adhesive tape clings to the cutting blade during wafer cutting, leading to quality issues and fine chipping of the chips due to the soft adhesive layer's vibration.
Innovation Solution
A cutting apparatus that applies ultraviolet light to cure the adhesive layer before cutting, using a UV laser oscillator positioned to pre-cure the adhesive tape region to be cut, ensuring the adhesive force is maintained without excessive reduction, thus preventing adhesion to the blade and vibration-induced chipping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If ultraviolet rays are applied to the entire adhesive tape to cure the adhesive layer before cutting, then the adhesive layer does not cling to the cutting blade and chip quality is improved, but the adhesive force of the adhesive layer is excessively lowered, causing chip scattering and breakage during cutting
Solution Approach 1:
The patent applies ultraviolet light only to the street regions (cutting lines) rather than the entire adhesive tape, creating locally cured adhesive layers only where cutting occurs. This selective curing maintains adhesive force in the chip regions while preventing adhesion to the blade at the cutting lines, resolving the contradiction between chip quality and adhesive force.
Solution Approach 2:
The adhesive tape is divided into different functional regions: cured regions at the streets (cutting lines) and uncured regions at the chip areas. This segmentation allows different properties in different locations - the cured regions prevent blade adhesion while the uncured regions maintain strong adhesive force for chip holding.
2Object-generated harmful factors
If the adhesive layer is cured by ultraviolet light irradiation, then the adhesive layer does not cling to the cutting blade, but the chips are scattered from the adhesive tape during cutting due to excessive reduction of adhesive force
Solution Approach 1:
The ultraviolet light is applied selectively to the street regions where cutting occurs, creating cured adhesive layers only at these locations. The chip regions remain uncured and maintain strong adhesive force, ensuring chips stay firmly attached to the tape during cutting while preventing blade adhesion at the cutting lines.
3Strength
If the adhesive layer is soft and uncured, then the adhesive force is strong for holding chips, but the chips are minutely vibrated during cutting, generating fine chipping at chip peripheries and lowering flexural strength
Solution Approach 1:
The adhesive layer is cured by ultraviolet light only at the street regions (cutting lines) where the cutting blade passes, while the chip regions remain uncured and soft. This localized curing provides rigidity at the cutting lines to prevent vibration and chipping, while maintaining adhesive strength in the chip regions.
4Manufacturing precision
If ultraviolet light is applied to cure the adhesive layer at the cutting region, then blade adhesion is prevented, but it is difficult to precisely control the light quantity and irradiation period according to tape kind and thickness
Solution Approach 1:
The patent replaces complex mechanical control systems with a simple optical approach. A transparent wafer table allows ultraviolet light to pass through and cure the adhesive layer uniformly without requiring complex adjustment mechanisms. The transparency of the wafer table simplifies the system while achieving precise curing control.
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
Prevents adhesive layer adhesion to the cutting blade and minimizes fine chipping, maintaining chip quality and flexural strength by accurately curing the adhesive layer before cutting.
Implementation Method 1
an adhesive tape in which the adhesive layer is cured by irradiation with ultraviolet light
Data Source
AI summary
A cutting apparatus for dividing a wafer that is stuck to an adhesive tape in which the adhesive layer is cured by ultraviolet light and that is supported by an annular frame through the adhesive tape, into individual chips, includes: a holding unit having a frame support section that supports the annular frame, and a wafer table that is formed of a transparent body and supports the wafer; a cutting unit including, in a rotatable manner, a cutting blade for cutting the wafer; and an ultraviolet light applying unit that applies ultraviolet light, the ultraviolet light applying unit being disposed facing the cutting blade in such a manner that the wafer table is interposed therebetween. The ultraviolet light applying unit applies ultraviolet light to a region where the wafer is to be cut by the cutting blade, to form a cured region where the adhesive layer is cured.