Enhanced Bonding by Applied Current in Cu-to-Cu Joints Fabricated Using 20 μm Cu Microbumps
| Autor: | Chanho Shin, Young Ho Kim, Sung Woo Ma |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science Contact resistance 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Electromigration Computer Science Applications Electronic Optical and Magnetic Materials Mechanics of Materials 0103 physical sciences Shear strength Electrical and Electronic Engineering Composite material Current (fluid) 0210 nano-technology |
| Zdroj: | Journal of Electronic Packaging. 139 |
| ISSN: | 1528-9044 1043-7398 |
| DOI: | 10.1115/1.4037474 |
| Popis: | The effect of applied current in enhancing bonding was studied in Cu-to-Cu direct bonding using Cu microbumps. A daisy-chain structure of electroplated Cu microbumps (20 μm × 20 μm) was fabricated on Si wafer. Cu-to-Cu bonding was performed in ambient atmosphere at 200–300 °C for 10 min under 260 MPa, during which direct current of 0–10 A (2.5 × 106 A/cm2) was applied. With increasing applied current, the contact resistance decreased and the shear strength in the Cu-to-Cu joints increased. The enhanced bonding imparted by the application of current was ascribed to Joule heating and electromigration effects. Subsequently, the joint temperature was calibrated to isolate the electromigration effects for study. In Cu-to-Cu joints joined at the same adjusted temperature, increasing the current caused unbonded regions to decrease and regions of cohesive failure to increase. The enhanced diffusion across the Cu/Cu interfaces under the applied current was the main mechanism whereby the quality of the Cu-to-Cu joints was improved. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|