High resolution AFM scanning Moiré method and its application to the micro-deformation in the BGA electronic package

The formation mechanism of atomic force microscope (AFM) Moir e is explained using the transmittance function. The technique for preparing the AFM Moir e specimen grating is described. The sensitivity and accuracy of this method is analyzed. AFM Moir e method is used to measure the thermal deformation ball grid array (BGA) electronic package. The shear strain at the different solders in the BGA package is measured. The result is compared with that from electron beam Moir e method. The consistent comparison result verifies the AFM Moir e method is reliable and effective in the micro-deformation measurement in the electronic package. 2002 Elsevier Science Ltd. All rights reserved.