MEMS device having a rugged package and fabrication process thereof

Abstract

A MEMS device formed by a substrate, having a surface; a MEMS structure arranged on the surface; a first coating region having a first Young's modulus, surrounding the MEMS structure at the top and at the sides and in contact with the surface of the substrate; and a second coating region having a second Young's modulus, surrounding the first coating region at the top and at the sides and in contact with the surface of the substrate. The first Young's modulus is higher than the second Young's modulus.

Description

BACKGROUNDTechnical Field[0001]The present disclosure relates to a MEMS (Micro Electro-Mechanical System) device and the fabrication process thereof.Description of the Related Art[0002]As is known, electronic apparatuses comprising MEMS devices, such as MEMS movement sensors, are increasingly widespread. For the correct operation of such apparatuses, it is desired that MEMS devices are capable of detecting movement variations in an accurate and precise way in all operating conditions. Consequently, it is desirable for MEMS devices to be sufficiently sturdy so as not to break even when they are subjected to abrupt movements (for example, as a result of the apparatus being dropped or undergoing mechanical shock). Furthermore, it is desirable that their performance not to be significantly affected by the above abrupt movements.[0003]In most cases, it is not desirable to increase the robustness of MEMS devices by increasing their dimensions. In fact, MEMS movement sensors may be modelle...

AI Technical Summary

Benefits of technology

The patent is about a MEMS device and a way to make it. The device has a rugged package and uses an injection molding system. It includes a MEMS sensor that can detect movement. The device has two layers of coating, with the first layer having a higher stiffness than the second layer. The MEMS structure is connected to the substrate. The technical effect is that this design provides better protection and reliability for the MEMS sensor.

Problems solved by technology

In most cases, it is not desirable to increase the robustness of MEMS devices by increasing their dimensions.

Since the resonance frequency is an important parameter for determining the performance of the MEMS device, it is not desirable to improve the robustness of the MEMS device by modifying its dimensions since this would have an undesired impact on performance.

However, known solutions have some disadvantages.

In fact, if subjected to repeated mechanical shocks with high accelerations, mechanical stoppers of a MEMS movement sensor undergo gradual damage and failure, causing failure of the mechanical stoppers in the long run, which thus no longer protect the MEMS movement sensor.

These repeated accelerations may lead to malfunctioning or failure of the MEMS device, thus rendering it unusable.

This problem is particularly felt when handling the MEMS device before assembling the package (in particular, fixing the MEMS device to a supporting structure).

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