Method of fabricating bonding structure

A method of fabricating a bonding structure comprising a plurality of compliant bumps, the method comprising:

• providing a first substrate and a second substrate, wherein the first substrate comprises a plurality of first bonding pads, and the second substrate is disposed on one side of the first substrate and comprises a plurality of second bonding pads and the compliant bumps disposed thereon, the second bonding pads being opposite to the first bonding pads;
• forming a non-conductive adhesive layer and a plurality of ball-shaped spacers between the first and the second substrates;
• and
• compressing the first substrate, the non-conductive adhesive layer and the second substrate, such that the compliant bumps on the second bonding pads of the second substrate pass through the non-conductive adhesive layer and are electrically connected to the first bonding pads of the first substrate, wherein the ball-shaped spacers are distributed in the non-conductive adhesive layer sandwiched between the first and the second substrates for keeping the gap therebetween.