A Method of MEMS Package Using Local Laser Bonding
The negative effect of the conventional laser bonding caused by high temperature has been analyzed in the Si-glass bonding process. A new method which is the combination of chip surface activated pre-bonding and laser bonding has been proposed. The method has been used for Micro Electro Mechanical System package experiment. The process is: firstly, a hydrophilic surface was formed by using a special chemical method. Secondly, Si and glass were pre-bonded at room temperature. Finally, the laser with the wavelength of 1.070 μm, spot diameter of 480 μm, power of 70 W was local heated by the laser. This method achieves low-temperature bonding without external press. And the tensile test also shows that the strength of sample bonding reaches 2.8 MPa~3.2 MPa. So it not only ensures the quality of MEMS chip, but also reduces the cost of the package.
Liangchi Zhang, Chunliang Zhang and Zichen Chen
L. Cheng et al., "A Method of MEMS Package Using Local Laser Bonding", Advanced Materials Research, Vols. 328-330, pp. 1313-1316, 2011