Patent attributes
A test structure including an array of microbumps electrically connecting a chip and a substrate, wherein a width of each microbump of the array of microbumps is equal to or less than about 50 microns (μm). The test structure further includes an interconnect structure connected to the array of microbumps. The test structure further includes an array of test pads around a periphery of the array of microbumps, wherein a test pad of the array of test pads is connected to a corresponding microbump of the array of microbumps through the interconnect structure. A width of the test pad is greater than a width of the corresponding microbump, and the test pad is adapted to be covered after circuit probing by a passivation material to prevent particle and corrosion issues.