Methods for characterization of wafer-level encapsulation applied on silicon to LTCC anodic bonding

Abstract

This paper presents initial results on generic characterization methods for wafer-level encapsulation. The methods, developed specifically to evaluate anodic bonding of low-temperature cofired ceramics (LTCC) to Si, are generally applicable to wafer-level encapsulation. Different microelectromechanical system (MEMS) structures positioned over the whole wafer provide local information about the bond quality. The structures include (i) resonating cantilevers as pressure sensors for bond hermeticity, (ii) resonating bridges as stress sensors for measuring the stress induced by the bonding and (iii) frames/mesas for pull tests. These MEMS structures have been designed, fabricated and characterized indicating that local information can easily be obtained. Buried electrodes to enable localized bonding have been implemented and their effectiveness is indicated from first results of the novel Si to LTCC anodic bonding.

Microwave Technology for Hybrid Fabrication Processes

“…They performed a review of the work done by various researchers in the field of microwave joining especially targeting the joints that involved stainless steel as at least one of the specimen to be joined through microwave hybrid heating. Anodic bonding on silicon substrates is divided into bonding using a thin sheet of glass (a wafer) or a glass layer that is deposited onto the silicon using a technique such as sputtering [5,6]. The glass wafer is often sodium-containing Borofloat or Pyrex glasses.…”