Key Stages of the Electrical Die Sorting Process


December 10, 2021

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The lengthy silicon wafer manufacturing process ensures that the semiconductor’s electronic elements are well-connected. For this reason, manufacturers conduct an electrical die sorting process or EDS to identify the chips that meet the processing center’s required quality level.  

Silicon Wafer Manufacturing Process

What Are the Key Steps of the Electrical Die Sorting Process?

Electrical Test and Wafer Burn-in

Manufacturers conduct an electrical test to examine specific attributes, including DC voltage and electric current parameters of individual semiconductor elements. These elements include the capacitor, transistor, resistance, and diode. Once they complete the electrical test, they’ll initiate the wafer burn-in process.  

The wafer burn-in procedure increases the final product’s reliability by reducing the defects at the first stage of production. Additionally, this process involves the application of heat to the wafer before applying AC/DC voltage to detect and identify the possible causes behind the defects.

Hot/Cold Pre-Laser

The hot/cold pre-laser process is the subsequent quality test that uses electrical signals to determine whether the chips on the wafer are faulty or functional.  It involves thermal testing to detect defects that may occur at specific temperatures. Repairable chips identified during this pre-laser process are tagged for repairs and stored for later processing.

Laser Repair and Post-laser

This process involves using laser beams to address the discrepancies identified in the repairable chips. Next, the post-laser process ensures appropriate repairs on these specific chips.

Tape Laminate and Backgrinding

Manufacturers use tape laminate and backgrinding processes to assemble extremely flat products such as IC cards used in passports or transit cards. They laminate UV tape on the front surface of the wafer to protect its patterned surface during the grinding process.  

Next, they use a grinding wheel made up of diamond particles to file down the backside of the wafer. The tape is peeled off as soon as the grinding process is completed.  


Defective chips are marked with special ink before they’re discarded. For this reason, the inking process helps manufacturers save time, materials, and manpower.

Quality Control in Silicon Wafer Manufacturing

Looking for the Best Silicon Wafer Manufacturing Company?

If you’re looking to find top-quality wafers for your next project, get in touch with Wafer World today.  

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