Processing scheme of sensor parts

Processing schemes for sensor components vary depending on the sensor type, material, and accuracy requirements. Here are some examples of common processing schemes and key points:

1. Linear Displacement Sensor Core Parts Processing Scheme

materials and characteristics

The core material is 1J50 iron-nickel soft magnetic alloy, which has high permeability and low coercivity. It needs to eliminate the processing stress by vacuum annealing heat treatment to ensure the magnetic properties.

Process Classification

According to the aspect ratio classification, parts with different aspect ratios adopt different processes:

Aspect ratio ≤ 5: processing on a small CNC lathe, one-time clamping to complete the processing of outer circle and inner hole, followed by vacuum annealing.

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Aspect ratio> 10: Ultrasonic vibration drilling technology is introduced to solve the problem of deep hole processing and improve efficiency and accuracy.

Critical Control Points

Tool selection: avoid chip adhesion, use coated tools and optimize chip breaking groove type.

Clamping method: slender shaft with two center clamping, deep hole processing pay attention to chip removal.

Protective measures: special parts box turnover, to avoid magnetic attenuation.

2. MEMS sensor processing scheme

bulk micro-machining technology

Wet etching: The silicon wafer is etched with tetramethylammonium hydroxide (TMH) solution to form a micro-mesa structure, and the solution formulation and etching conditions need to be optimized to improve the flatness.

Dry deep etching: using reactive ion etching (DRIE), can achieve high aspect ratio, vertical structure etching, commonly used in humidity sensors, nanoprobes and other processing.

surface micro-machining technology

The movable structure, such as a deformable mirror actuator, is constructed through the steps of film deposition, photolithography, sacrificial layer release, etc., and the film thickness and release process need to be precisely controlled.

3. semiconductor sensor processing scheme

Wafer Processing

Silicon is purified from silicon sand and made into wafers by ingot casting, cutting and polishing, and the surface shall be protected by oxide layer.

lithography and etching

The circuit pattern is defined by photolithography, and dry etching (such as reactive ion etching) realizes high-precision pattern transfer. Wet etching has low cost but limited accuracy.

Thin Film Deposition and Interconnection

Chemical vapor deposition (CVD), physical vapor deposition (PVD) and other techniques deposit metal or insulating film, aluminum or copper interconnect circuit connection.

Testing and Packaging

The electrical test selects qualified chips, and the packaging process includes wafer cutting, chip attachment, wire bonding, etc., to protect the chip and realize signal transmission.

4. Weighing Sensor Elastomer Processing Scheme

Material selection

Using 17-4PH stainless steel, it has good elasticity and hardness, and eliminates material defects through ultrasonic inspection.

Machining

After the bar is cut into a cylinder, it is turned to process the patch and the upper indenter structure, and the milling machine processes the cable connector socket and the wire hole. The dimensional accuracy and surface quality should be strictly controlled during the processing.

The above scheme needs to be optimized and adjusted according to the design requirements of specific sensors, mass production requirements and cost control. The actual processing should strictly follow the process specifications to ensure product quality and stable performance.