A multi-chip module (MCM) is described. This MCM includes at least two substrates that are mechanically coupled and aligned by positive and negative features on facing surfaces of the substrates. These positive and negative features may mate and self-lock with each other. The positive features may be self-populated into the negative features on at least one of the substrates using a hydrophilic layer in the negative feature. This hydrophilic layer may be used in conjunction with a hydrophobic layer surrounding the negative features on a top surface of at least one of the substrates.