Known Good Die
Known Good Die (KGD)
Die Houses as well as expensive packaging often drive the desire to test the die again after wafer saw. One reason for re-testing is because saw induced failures can occur and it is possible that some die that were originally electrically good at 100% probe may now be bad after saw (cracks, chip outs, ESD damage could induce electrical failures). Another reason for testing again is because the die is being mounted into an expensive package or housing that can’t be re-worked, is difficult to re-work or is expensive. Another is because the parts are being used in a Hi-Rel (High Reliability) application (medical, military, satellite and more). In all cases the additional testing increases the average selling price (ASP) of the die due to the enhanced screening required but still less in comparison to the packaging costs.
Die Houses purchase whole wafers, partial wafers, wafers mounted on frames and sawn as well as individual die placed in waffle packs or Gel pack containers from wafer foundries. Die Houses add value to their customers with additional services provided – sawing, electrical testing, visual inspection, documentation, and the willingness to sell in small quantities. Die Houses, foundries and other companies often provide die that are referred to as Known Good Die or KGD.
SemiProbe has a family of probe systems – manual, semiautomatic and fully automatic with a complete line of accessories that can test whole wafers, partial wafers, wafers sawn and stretched on frames as well as individual die in trays at ambient or over temperature (hot and cold). Automated systems, with the addition of a dual end-effector can handle wafers, frames and trays of die with the same system.
