Direct bonding of silicon nitride to copper via laser surface modification.

[Display omitted] • The direct bonding of Si 3 N 4 and copper was achieved via laser surface modification. • Si with intergranular glass contained were formed on Si 3 N 4 via laser modification. • A robust bonding was obtained through mechanical locking and metallurgical bonding. • The facile bonding approach has great potential in developing high-power devices. A convenient and efficient approach for direct bonding of Si 3 N 4 ceramic to copper via laser surface modification is introduced in this work. Laser irradiation was capable of dissociating Si 3 N 4 to create a silicon metalloid layer that attained the metallurgical bonding with copper facilitated by the copper-silicon eutectic reaction. The analytical test results show that a strong Si 3 N 4 /copper bonded pair with the shear strength of 18.3 MPa, along with a low bonding defect density (0.4%) was obtained. The validity and reliability of the as-prepared Si 3 N 4 /copper structure were verified given ca. 99.4% bonded area maintained after 1000 cycles of thermal cycling testing. This proof-of-concept study on the Si 3 N 4 /copper bonding approach with laser modification provides insights to fabricate the metalized ceramic substrate. [ABSTRACT FROM AUTHOR]