Page "Liquid crystal display" Paragraph 62

LCD panels are more likely to have defects than most ICs due to their larger size.

For example, a 300 mm SVGA LCD has 8 defects and a 150 mm wafer has only 3 defects.

However, 134 of the 137 dies on the wafer will be acceptable, whereas rejection of the whole LCD panel would be a 0 % yield.

In recent years, quality control has been improved.

An SVGA LCD panel with 4 defective pixels is usually considered defective and customers can request an exchange for a new one.

Some manufacturers, notably in South Korea where some of the largest LCD panel manufacturers, such as LG, are located, now have " zero defective pixel guarantee ", which is an extra screening process which can then determine " A " and " B " grade panels.

Many manufacturers would replace a product even with one defective pixel.

Even where such guarantees do not exist, the location of defective pixels is important.

A display with only a few defective pixels may be unacceptable if the defective pixels are near each other.