Fabrication and test of a hermetic miniature implant package with 360 electrical feedthroughs

Abstract

A fabrication technology for small hermetic implant packages with large numbers of electrical feedthroughs is presented. First prototypes were fabricated on a ceramic substrate of 25·25 mm area, having a metal cup of 5 mm height soldered to it. These prototypes provide 360 feedthroughs. The electrical properties of the feedthroughs are characterized and the leakage rate of the packages is determined using helium fine leak tests. The amount of water sealed inside the packages is investigated. Based on maximum allowable water vapour concentrations inside hermetic packages reported in literature and applying a commonly accepted mathematical model, we predicted a minimum lifetime to water-induced failure of a few hundred years.

Materials considerations of implantable neuroengineering devices for clinical use

“…Schuettler et al [23] evaluated a hermetic package design based on a screen-printed alumina substrate onto which two Pt/Au layers separated by a dielectric were printed. The lower metal layer formed a total of 360 feedthrough traces.…”

The Influence of Flux on the Reliability of Solder-Sealed Hermetic Packages for Active Implantable Medical Devices

“…The packaging concept is realized in conventional thick-film technology, implementing solderable metallization layers and leadfree solder materials. However in comparison to the small packages in [2] the relatively large size of the BCI package introduced new problems when it came to the process of solder sealing. This paper deals with some practical issues for the choice of applicable soldering methods and materials to create highly reliable solder seals for hermetic implants.…”

“…For a recently introduced Brain-Computer-Interface (BCI) which is capable of cortical stimulation and recording such a hermetic housing was developed [1]. The package is sealed by means of manual soldering since former hermeticity investigations where promising for this method [2]. The packaging concept is realized in conventional thick-film technology, implementing solderable metallization layers and leadfree solder materials.…”

Hermetic glass soldered micro-packages for a vision prosthesis

“…Packages using Ti casing are known from pacemakers, deep- brain stimulators and cochlear implants. Another method for ceramic/metal combinations was presented by the authors in [4], where a brass lid is soldered onto a screen-printed ceramic substrate. However, the horizontal fabrication of the hermetic feedthroughs increases the size of the device with increasing number of electrical contacts.. Wireless power transmission is complicated when metallic packages are used, as the induced electric currents in the package's casing hinder the wireless transmission.…”