A method for bonding a first component to a second component includes placing the first and second components in a cavity. Each of the first and second components has a bonding portion, and the bonding portion of the first component faces the bonding portion of the second component. A supercritical fluid is then introduced into the cavity with a temperature of 40-400° C. and a pressure of 1,500-100,000 psi, and a pressure of 4-100,000 psi is applied on both the first and second components, assuring the bonding portion of the first component bond to the bonding portion of the second component. Moreover, a method for separating a first component from a second component includes placing a composite in a cavity. The composite includes the first component, the second component and a connecting layer by which the first component joins to the second component. The supercritical is then introduced into the cavity.