Promising materials for semiconductor-based chemical sensors are photocurable polymers that can be applied utilizing conventional photolithographic processes compatible with microelectronic technology. In this work different acrylate-based polymers curable under UV irradiation have been tested for their applicability as packaging materials. A mixture consisting of acrylate oligomer (epoxy, urethane, siloxane, polyester), reactive monomers and suitable photoinitiator is applied to a wirebonded sensor chip to form a thick (100-1000 μm) polymer layer. After exposure and development, a window is opened over the gate region. Results on polymer-layer adhesion, electrical resistivity, chemical resistance and lifetime of the encapsulated microsensors in various aqueous solutions are presented. © 1995.
- Photocurable polymers
- Sensor packaging