As automotive semiconductor market has expanded, the importance of measurement of temperature-dependent warpage (thermal warpage) has been increasing. For automobiles, high reliability is necessarily demanded because their failures are directly linked to people's life. Therefore automotive industry had established AEC qualification standards for automotive devices. The standard demands environmental tests that include not only high temperature test but also negative temperature test reaching -55 ℃. In view of this situation, we have developed a thermal warpage measurement system that has the ability to change sample temperature from -60 to 260 ℃ which can meet the demands of the standard. The following are some features of the system. <(1)Warpage measurement ability>Measurement is performed by confocal method which is well known as accurate optical metrology. Generally speaking, confocal method is time consuming method for measurement. But our technique we call non-scanning confocal method overcomes such a drawback maintaining advantages of confocal method and the non-scanning confocal method has already been used widely for in-line coplanarity inspection of flip-chip bumps. Conventional warpage measurement technique like Moire method needs sample preparation like de-ball and painting. But the non-scanning confocal method doesn”™t need any sample preparation. The method can measure not only substrate warpage accurately without de-ball but even ball height/coplanarity. Moreover the system can deal with even several tens of micron diameter bumps, because it has 8.0um pixel resolution regardless of sample size. Unlike conventional warpage measurement system, the field of view (FOV) size of 13x13mm is constant and bigger samples than the FOV can be measured by stitching FOVs using a XY translation stage up to 136x323mm (JEDEC tray size).<(2)Heating and cooling ability>The system has a big size chamber for heating and cooling so that a whole JEDEC tray can be measured. In order to heat all samples in the big chamber uniformly, convection heating is used as heating method. Convection heating has many advantages compared to radiation heating that is normally used by conventional systems. The advantages are as follows.

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