TH45849B - Process accelerometer sensor Electro-Fabrication (E-Fab) and the process of manufacturing such equipment. - Google Patents

Abstract

DC60 accelerometer sensor built using process Electro-Fabrication (E-Fab) consists of a centrally located floating mass that is secured by one, two or four arms, depending on the design, the structure is protected by a silicone rubber sheet construction. For example, polydimethysiloxane (PDMS) will be created by plastic molding and plasma bonding on a glass substrate. The aerodynamic structure will be constructed with low-cost metal materials used in the process. electroplating such as nickel (Ni) or copper (Cu), on the floating mass there is a thin film layer of suitable electrical insulation such as Alumina (AI2O3), Silicon Nitride (Si3N4) or Silicon Dioxide (SiO2) followed by a thin film layer of piezoresistor A coating is placed on each arm and a suitable thin metal film such as Cu / Cr is coated on the tip for the electrode. When the arm is bent by force acting on the piezoresistor So, the amount of acceleration pressed can be measured by measuring the electrical resistance of the device by the piezoresistor. In this invention, a suitable material, such as indium tin oxide (ITO), was created by a specific process, ion-assisted electron beam evaporation. Is a process At low temperatures, the ideal ion-assisted deposition parameters can be controlled, resulting in a qualified ITO film. Good piezoresistivity suitable for highly sensitive accelerometer sensors. With a device that is small to make A sensor that can measure acceleration in the thousands of g (9.8m / s2) and most importantly, the process. It is much cheaper to manufacture than other mass-float accelerometers that use an integrated circuit manufacturing process. In applications, the accelerometer is often attached to the vehicle with the base plate mounted. In a way perpendicular to the direction of motion or acceleration Accelerometer sensor built using the process Electro-Fabrication (E-Fab) consists of a centrally located floating mass that is secured by one, two or four arms, depending on the design, the structure is protected by a silicone rubber sheet construction. For example, polydimethysiloxane (PDMS) will be created by plastic molding and plasma bonding on a glass substrate. The aerodynamic structure will be constructed with low-cost metal materials used in the process. electroplating such as nickel (Ni) or copper (Cu), on the float mass there is a thin film layer of suitable electrical insulation such as Alumina (AL2O3), Silicon Nitrde (Si3N4) or Silicon Dioxide (SiO2) followed by a thin film layer of piezoresistor A coating is placed on each arm and a suitable thin metal film such as Cu / Cr is coated on the tip for the electrode. When the arm is bent by force acting on the piezoresistor So, the amount of acceleration pressed can be measured by measuring the electrical resistance of the device by the piezoresistor. In this invention a suitable material, for example indium tin oxide (ITO), was created by a specific process, ion-assisted electron deam evaporation. Is a process At low temperatures, ideal ion-assised deposition parameters can be achieved at low temperatures, resulting in a qualified ITO film. Good piezoresistivity suitable for highly sensitive accelerometer sensors. With a device that is small to make A sensor that can measure acceleration in the thousands of g (9.8m / s2) and most importantly, the process. It will be cheaper to produce than other mass-float accelerometers. In the use of accelerometer sensors, it is often attached to the vehicle where the base plate is located. In a way perpendicular to the direction of motion or acceleration

Claims (3)

An acceleration sensor device comprising: - a base plate (3) consisting of a first and second surface, wherein said base plate (3) is made of an insulating material; - a floating mass (1) formed on one surface of said base plate (3) with an air gap (7) to which at least one mounting arm (2) is connected; - a thin film insulating layer (4) formed on said floating mass (1); - a thin film piezoresistor layer (5) formed on each of said mounting arms (2), such that the electrical resistance of the thin film piezoresistor layer (5) changes when a contact force to be measured is applied; - at least two electrodes (6) for each said piezoresistor (5) formed on the piezoresistor layer. (piezoresistor) (5) to act as the output terminal of said acceleration sensor device, and - a protective structure (8) mounted on a base plate (3) surrounding the floating mass structure and all others, wherein said acceleration sensor device has the characteristics of said base plate (3) having the properties of an insulating material that can withstand a heat of at least 250 °C and having a thin film layer of piezoresistor (5) which is indium tin oxide (lTO) material fabricated by ion-assisted electron beam evaporation process and having the characteristics of a protective structure (8) made of a silicone rubber material such as polydimethysiloxane (PDMS) to be fabricated by plastic molding and plasma bonding on a glass substrate, and said floating mass structure (1) having the characteristics of a smooth film with an extra thick center fabricated by electroplating process and having the said insulating layer (4) coated on top. 2. The acceleration sensor device of claim 1, wherein said base plate (3) is made of glass. 3. The acceleration sensor device of claim 1, wherein said base plate (3) is made of silica. 4. The acceleration sensor device of any one of claims 2-3, wherein said base plate (3) has a width and length between 1 and 100 millimeters and a thickness between 0.5 and 2 millimeters. 5. The acceleration sensor device of claim 1, wherein said floating mass (1) is made of copper metal and has a thickness in the range of 1 and 50 micrometers. 6. The acceleration sensor device of claim 1, wherein said floating mass (1) is made of Nickel metal and having a thickness in the range of 1-50 micrometers. 7. The acceleration sensor device in claim 1, wherein said thin film insulating layer (4) is made of alumina. 8. The acceleration sensor device in claim 1, wherein said thin film insulating layer (4) is made of silicon nitride. 9. The acceleration sensor device of claim 1, wherein said thin film insulating layer (4) is made of silicon dioxide. 1 0. The acceleration sensor device of any one of claims 8-10, wherein said thin film insulating layer (4) has a thickness of 300-2000 nm. 1 1. The acceleration sensor device of claim 1, wherein a layer of piezoresistive material (5), namely lndium tin oxide (lTO), is coated on each arm. 1 2. The acceleration sensor device of claim 1, wherein said thin film insulating layer (4) is made of silicon dioxide. (piezoresistive) (5) said having a U-shaped coil pattern 1 3. The acceleration sensor device according to claim 12, wherein said thin metal film electrodes (6) comprise a first chromium layer having a thickness of 20-40 nanometers and a subsequent copper layer having a thickness of 500-1000 nanometers 1 4. The acceleration sensor device according to claim 1 has a protective structure (8) consisting of a sheet of silicone rubber, namely polydimethysiloxane (PDMS), attached to a base plate (3), surrounding a floating mass structure, and all the other things said 1 5. The manufacturing process for the acceleration sensor device comprises: - providing a base plate (3) comprising a first and second face; - providing a floating mass (1) made of metal and partly floating above the surface; one of said base plates (3), having a space (7) in between, wherein said floating mass (1) further comprises at least two fastening strips (2) for fixing said floating mass (1) to said base plate (3); - providing a thin film insulating layer (4) formed on said floating mass (1) for electrical insulation; - providing a thin film layer of piezoresistor (5) formed on each of said mounting arms (2); - providing at least two terminals (6) for each piezoresistor (5) formed on said piezoresistor (5) to serve as the output terminals of said acceleration sensor device; and - providing a protective structure (8) fixed on said base plate (3) surrounding said floating mass structure, etc., wherein the manufacturing process of said acceleration sensor device It is characterized by the process of providing the said flotation mass (1) comprising the steps of - depositing a thin metal film as a base for the said retaining strip (2) on the base plate (3) by evaporation or sputtering process in combination with patterning by photolithography process; - creating a photoresist layer (9) by photolithography process with at least two openings for the formation of said retaining strip (2); - creating a retaining arm (2) in the said openings of the said photoresist layer (9) by electroplating process, where the said retaining strip (2) is of the same metal as the metal thin film as the base of said retaining strip (2); and - creating a flotation mass (1) with a thickness and a thick structure in the center by electroplating process, which will be connected through at least one retaining arm (2) structure; - removing the said photoresist layer (9). to create the said gap (7) between said floating mass (1) and said base layer (3), and - creating a protective structure (8) by means of plastic molding, whereby a suitable sized rectangular mold is made on a flat base plate, and then the PDMS liquid rubber is casted onto this simple mold, which is baked at a temperature of approximately 80 °C for 2 hours to allow the PDMS to dry completely, and then the PDMS is peeled off from the mold; - bonding the protective structure (8) to the base plate (3) by a plasma bonding process. 1 6. The manufacturing process for the acceleration sensor device of claim 15, wherein the thin metal film layer of said floating mass (1) has an initial thickness of 100-200 nm. 1 7. The manufacturing process for the acceleration sensor device of claim 15, wherein the step of creating said thin film insulating layer (4) is performed by an evaporation process. 1 8. The process of manufacturing the acceleration sensor device of claim 15, wherein the step of fabricating said thin film insulating layer (4) is performed by the sputtering process 1. 9. The process of manufacturing the acceleration sensor device of claim 15, wherein the step of fabricating said thin film of piezoresistor (5) is performed by the ion-assisted electron beam evaporation process 2. 0. The process of manufacturing the acceleration sensor device of claim 15, wherein the step of fabricating at least two electrodes (6) of said thin film of piezoresistor (5) on said thin film of piezoresistor (5) with metal is performed by the evaporation process 2. 1. The process of manufacturing the acceleration sensor device of claim 15, wherein the step of forming at least two electrodes (6) of a thin film of piezoresistor (5) on said thin film of piezoresistor (5) with metal is performed by a sputtering process 2. 2. The process for manufacturing the acceleration sensor device of claim 15, wherein the process for fabricating said protective structure (8) is performed by the plastic molding process 2. 3. The process for manufacturing the acceleration sensor device of claim 15, wherein the step of securing said protective structure (8) to the base plate (3) is performed by a plasma bonding process.