Glass Frit as a Hermetic Joining Layer in Laser Based Joining of Miniature Devices

Abstract

In this paper we investigate the feasibility of using a laser as the heat source to drive a hermetic joining process based on a glass frit intermediate layer. The laser allows the necessary heat energy to be provided in a localised manner; important either as part of a multi-stage process, or to allow thermally-sensitive materials to be used inside the package. Our study includes an investigation of the impact of rough and grooved surfaces on the hermeticity and strength of the join, demonstrating the robust nature of the process, and its ability to allow feed-throughs to the centre of package. Hermetic sealing is demonstrated, with leak rates of 10 -9 mbar l s -1 , satisfying the military standard MIL-STD-883G.

A Laser-Assisted Bonding Method Using a Liquid Crystal Polymer Film for MEMS and Sensor Packaging

“…To our knowledge, this is the first study of fine test in LCP-bonded microcavities. The results of fine leak test are comparable with that of the glass frit-bonded packages [23].…”

“…Alternatively, the intermediate layer-based approach has been investigated due to the advantages of low or moderate bonding temperature (<300°C) and better tolerance to surface nonuniformity (unevenness). A number of intermediate layer materials have been studied for substrate bonding, including Au, Al [20], Au/Sn solder [9], indium [21], Zn-based wire [22], glass frit [23], [24], and benzocyclobutene polymer [25], [26].…”

Laser assisted dye-sensitized solar cell sealing: From small to large cells areas

“…Thus, the use of a laser assisted glass sealing process, instead of using the traditional pressure/thermal processes, was identified as a potential route for overcoming this limitation. Actually, laser joining techniques have been developed to encapsulate miniature MEMS [13]. These techniques allow dissimilar materials to be joining together.…”

“…These techniques allow dissimilar materials to be joining together. However, they require surface treatments for turning the surfaces rough enough if a bonding material is used, [13] or for making the surfaces smooth and clean if no bonding material is used [14]. Moreover, those techniques are usually dependent on the glass-frit cord shape and they are not suitable for scaling up to large areas, as needed for BIPV applications.…”

Finite element analysis of laser bonding process on organic light-emitting device

“…[6,7] In this process, the laser energy penetrates the transparent layer and is absorbed by opaque layer, then is delivered to the nearby interfaces by conduction and radiation. It is known that the real laser bonding test is expensive and time-consuming.…”