Our business built it in 1971 for a pioneer in semiconductor manufacturing. It absolutely was used in an easy sort that is wafer and provided active cooling and heating. A kind that is wafer checks the functionality associated with the casino chips for a wafer ahead of its being sawed into individual products. This provides maker the opportunity to discard the bad products early in the production procedure thus saving the packaging and test this is certainly final for all those products, also as to match the grade of good devices to markets.
Wafer test may be the right part of the testing procedure done on silicon wafers. Wafer sort is truly a simple electric test, this is certainly performed for a silicon die whilst it’s in a form that is wafer.
Wafer probe’s purpose that is’s main to recognize the non-functional dies and as a consequence avoiding assembly of those dies into packages. In lot of cases, wafer sort is a easy and test this is certainly quick is targeted on a few electrical parameters which are most likely to fail.
Wafer testing is carried out during IC production on every wafer and each silicon die. Otherwise, there could be a semiconductor tester that is defective that will go through the installation process and therefore induce unnecessary costs at the conclusion of the manufacturing process.
The checks done during wafer sort ranged from a easy determination of pass/fail to an even more category this is certainly complex of the products into different amounts of “pass,” often temperature related. Devices that passed testing at +25°C, but failed at higher or reduced temperatures, could maybe not be sold at the cost that is same those who had undergone testing in the upper and lower ranges. Classic applications for products needing a “pass” during both hot and test this is certainly cold in automotive, space and armed forces applications, too as high-end logic applications, such as for example microprocessors and graphics processors. These are extremely markets that are appealing terms of these average selling prices and their capability to survive economic down turns.
The heating this is certainly easy behind most hot testing of semiconductor wafers today may be the very same even as we see in everyday cooking applications. A resistance heater is built into a dish (i.e., chuck) that is slightly larger in diameter compared to the wafer that may rest about it during test. A”hot that is great” is recognized not merely by exactly how hot it can get, but how fast it gets here, how consistent the temperature is across its diameter, just how rigid and flat it is, and just how electrically peaceful it could remain during test. A simple chuck this is certainly hot also really reliable and simple to keep up.
A normal and really effective solution came to market that combined the resistance heater in connection with simple hot chuck together with the movement of a coolant through the chuck although the importance of cold test started to increase with the increase of semiconductor devices in cars, since well as with space and armed forces applications.
The ATE will test circuitry along also the scribe lines. Performance when it comes to device can be rated whenever line this is certainly using structures. You can find companies that get yourself a quantity this is certainly great of employing this technique. You’ll find dies that include internal resources that are spare can be used for repairs such as found on flash memory IC. If some test habits are not passed, the resources which are additional can be utilized.
It is discarded as useless if you have no redundancy about the die that has failed in specific tests. Through the testing process, circuits that do not pass electricity are marked with a ink that is tiny located in the center or even the wafermap will store the knowledge of failed or inactive circuits.