Title :
Laser assisted polymer bonding technology for advanced MEMS packaging
Author :
Zeng, J. ; Wang, C.H.
Author_Institution :
Sch. of Eng. & Phys. Sci., Heriot-Watt Univ., Edinburgh
Abstract :
This paper presents the development of a laser assisted polymer bonding process using benzocyclobutene (BCB) for encapsulation of MEMS and other microscale sensor devices. The polymer rings were fabricated on capping substrates using the photosensitive BCB resin and photolithography and then bonded onto device substrates to form microcavities for MEMS packaging. A high-power fibre-coupled diode laser at the wavelength of 970 nm was used as the heat source for BCB bonding/curing in conjunction with novel beam forming optics that allows selective illumination of the substrates to be joined. Defect free bonding was realised in 10 seconds using laser power of order 50 W and 1 kgf of bonding force. The quality of the laser produced polymer bond was assessed using optical inspection and leak test and it was shown that it is as good as that formed using conventional hotplate based approach, but reducing the bonding time by a factor of ~100.
Keywords :
bonding processes; curing; laser beam applications; micromechanical devices; photolithography; MEMS packaging; benzocyclobutene; capping substrates; curing; defect free bonding; heat source; high-power fibre-coupled diode laser; illumination; laser assisted polymer bonding process; laser power; microcavities; microscale sensor devices; optical inspection; photolithography; photosensitive resin; polymer rings; time 10 s; wavelength 970 nm; Bonding forces; Bonding processes; Encapsulation; Fiber lasers; Micromechanical devices; Optical beams; Optical polymers; Optical sensors; Packaging; Ring lasers;
Conference_Titel :
Electronics System-Integration Technology Conference, 2008. ESTC 2008. 2nd
Conference_Location :
Greenwich
Print_ISBN :
978-1-4244-2813-7
Electronic_ISBN :
978-1-4244-2814-4
DOI :
10.1109/ESTC.2008.4684528