Investigations into packaging technology for membrane-based thermal flow sensors

Abstract

Abstract.A new packaging method to mount a membrane-based thermal flow sensor, flush with the surface, is presented. Therefore, a specific design for the housing is shown, which is also adaptable to other conditions. It has been experimentally shown that it is important to mount the sensor flush with the surface. In addition, the experimental results are discussed. If a membrane-based thermal flow sensor is not mounted flush with the surface, vortices can occur (depending on velocity and fluid properties) or the reduction in the channel cross section plus a decrease in sensitivity have to be taken into account.

Systematic study of packaging designs on the performance of CMOS thermoresistive micro calorimetric flow sensors

“…More detailed CFD simulations with the coupled fluid mechanics and heat transfer for the quantitative analysis of the performance changes in E-Type and S-Type will be studied in the future work. Considering the fluid flow over the surface ( y = 0 mm) of TMCF sensor, the separated flow can be determined by the condition of the negative velocity gradient, equation (6) [14]:…”

“…The reason for this inconsistency mainly comes from the overly simplified 2D simulation. In the experiments, the TMCF sensor is a kind of rectangular pillar stands in the center of the flow channel, which is different from Dumstorff et al [6] setup that the sensor span over the entire channel width. Therefore, more detailed 3D CFD simulations with the consideration of width difference between the flow channel and the sensor chip are necessary.…”

“…As shown in figure 10, the new criterion in equation (11) could successfully distinguish the cases of separated flow and attached flow with different d * and Ar. In addition, the reported experimental result of the step-up design (see the solid square symbol in figure 10) from the work of Dumstorff and the coworks [6]. is also plotted.…”

“…Comprehensive research studies of the flow sensor's packaging will be necessary to achieve accurate flow measurements. Otherwise, the improper packaging design of the flow sensor will lead to inaccurate flow measurements due to the leakage, or a dramatically reduced sensor performance caused by the flow separation or turbulence [6,7].…”

“…However, very few works have systematically studied the effect of packaging design on the performance of micro thermal flow sensors. Recently, Dumstorff et al [6] reported a sensor packaging design with a portion of sensor chip inside the flow channel and observed the decrease of sensitivity in the non-flushed sensor packaging compared to the flushmounted counterpart.…”