The first production step is deposition, where sputtering is used in order to cover the substrates with a thin layer over the entire surface. Depending on the type of sensor that is required, different materials, thicknesses and qualities can be chosen for the covering.
In this step, the substrates are coated with photosensitive lacquer by a centrifuge. All our sensor structures are sketched on so-called masks: through exposure, light is lead through the mask onto the photoresist. The covered parts are not reached by the light, leaving the coating unexposed. During the subsequent developing of the substrates, the coating on the exposed areas is washed away, the non-exposed area remains on the substrate.
During the etching process the part of the coating that is not required is removed through etching. Two different processes are used to etch the substrates: ion etching and wet-chemical etching.
IST AG uses laser trimming or laser calibration as a method of adjusting (trimming) components by laser induced material changes. Thereby the resistance value is increased continuously by decreasing the meander structure until the desired value is achieved.
During screen printing, the contact points are strengthened with a conductive paste. This enables a better connection between the contact point and the electrical contacts. Additionally, the substrate is covered with a non-conductive paste, which prevents scratches and damages of the sensor due to mechanical or chemical influences.
While dicing, the substrates are cut into individual strips, so that afterwards wires can be welded on the sensors.
对于焊接工艺，IST AG 提供了焊接到芯片上的各种线材、长度和直径的可能性。 我们区分裸线和绝缘线。 为了增强焊接点并保护其免受机械损坏，在焊接区域涂抹了一种浆料，可提供出色的拉力。
During the final electrical measurement, all sensors are checked with a 2-point calibration measurement. According to their accuracy they are sorted into different classes.
Dr. Florian Krogmann, Chief R&D Officer
Our versatile technological portfolio covers different substrate material choices, the use of thin- and thick-film technologies and patterning technologies as well as diverse test and assembly options.