Some implementations provide a substrate that includes several traces, a solder resist layer covering the several traces, and a testing pad coupled to a trace from the several traces. The testing pad is at least partially exposed and at least partially free of the solder resist layer when a chip is coupled to the substrate. In some implementations, the several traces have a pitch that is 100 microns (μm) or less. In some implementations, the substrate is a package substrate. In some implementations, the package substrate is a package substrate on which a thermal compression flip chip is mounted during an assembly process. In some implementations, the testing pad is free of a direct connection with a bonding component of the chip when the chip is coupled to the substrate. In some implementations, the bonding component is one of a solder ball.