What Problems Will Occur in the Operation for Silicon Wafer Cutting?
From: Issued date 2019.07.18 Back
The silicon wafer cutting requirement is very high, and only excellent technological level from the cutter can create perfect production. The silicon wafer cutting itself is not an easy thing, therein various problems will appear. All of us should notice in the operation.
1. Impurity line trace: caused by the impurity in the polycrystalline silicon ingot, not able to be completely removed in the slicing process, resulting in the emergence of the related line trace on the silicon wafer.
2. Scratch line trace: caused by SIC large particles or mortar caking in the mortar. In the cutting process, SIC particles 'get stuck' between the steel wire and the silicon wafer, and cannot overbrim, resulting in the line trace.
Expressive form: including the whole line trace and the half line trace, concave, shiny line trace, narrower than other line traces.
3. Densely covered line trace (intensive line trace): due to not enough mortar grinding ability or the slicer mortar loop system problem, resulting in the intensive line trace area appearing on the silicon wafer.
4. Misplacement line trace: it is generated because there is mortar and other foreign matter on the hydraulic clamping device surface of the slicer or the residual glue on the supporting plate, resulting in that the hydraulic device and the supporting plate cannot entirely clamp and the supporting plate screw looses.
In the whole cutting process, the factors that play the leading role on the silicon wafer quality and the rate of finished products are the cutting fluid viscosity, silicon carbide micro powder particle type and particle size, mortar viscosity, mortar flow rate, steel wire speed, steel wire tension and workpiece feed speed, etc.
Line trace and TTV: The line trace and TTV are quite headache things encountered during silicon wafer processing, and may appear from time to time, impossible to be defended effectively. TTV appears at the time of knife entering, while the line trace is easy to appear at the time of line arch retracting.