Ultra flat wafers have distinct properties which make it the perfect type of wafer for applications, like electronics, automotive, and microfabrication. But how do wafer manufacturers produce wafers that are durable enough for further processing? Here is the wafer thinning process for ultra flat wafers:
Back grinding is one of the most common methods for thinning wafers that are appropriate for final packaging of die after dicing. This method is fast with very minimal abnormalities and excellent surface finish.
Wafers are rotated on a vacuum chuck as the grinding wheel is rotating at the backside of the wafer at a controlled grinding rate. Graded diamond abrasives are fixed in binders on the edge of the grinding wheels. This produces wafers that are 150 μm thin from 750 μm. The loss from grinding and downstream processes have made it very challenging to thin wafers below 150 μm during production.
Sometimes, back grinding causes flaws on the surfaces of wafers. In order to get rid of the grinding damage and better the final surface finish it must go through these 3 methods:Traditional loose-abrasive polishing – This method combines the polishing and grinding techniques, which allow the removal of damage to be integrated into the grinder tool for an efficient wafer grinding and polishing.Wet Etching- This process is used to remove surface damage but it also is considered to be one of the most common wafer thinning techniques.Dry Plasma Etching- This method employs atmospheric dry plasma to get rid of surface damage. This method also improves the wafer edges by rounding them and controls the surface roughness.
Get the ultra flat wafers you need from a wafer manufacturing company you can trust. At Wafer World, we aim to provide all our clients uncompromised wafer quality and customer service. Call us today for inquiries or purchase wafers online!