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Introduction to glass-sealed thermistor AOI equipment

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Glass-sealed thermistors are compact temperature-sensing components, but their production involves more than checking appearance alone. Product presence, glass dimensions, lead condition, thermistor position, electrical resistance, insulation performance, and final appearance can all affect downstream quality. For manufacturers handling these checks at scale, separating each inspection step into isolated manual stations can increase handling, slow production, and make quality data harder to manage.

PTC's Glass-Sealed Thermistor Inspection Equipment is designed as a fully automated inspection line for temperature sensor production. Rather than functioning only as a standalone visual AOI station, the system combines multiple inspection and cleaning processes into one connected production workflow, from sintering inspection through final visual inspection and AGV unloading.

In this introduction, we explain how the system works, what it inspects, and how its automation, AI-assisted inspection, production data management, and MES connectivity support glass-sealed thermistor manufacturing.

What Is Glass-Sealed Thermistor AOI Equipment?

Glass-sealed thermistor AOI equipment is an automated inspection solution used to verify the quality of thermistor products during production. In PTC's configuration, optical inspection is only one part of a broader integrated process. The complete line combines product inspection, electrical testing, cleaning, visual inspection, production data management, and automated material transfer.

The standard process flow includes:

  1. Sintering inspection

  2. Oxide film cleaning

  3. Resistance testing

  4. Degreasing cleaning

  5. Insulation testing

  6. Overall visual inspection

  7. AGV docking for unloading

By connecting these stations into one automated line, the equipment can interface with upstream production equipment, complete multiple inspection tasks continuously, and transfer finished products to the next production stage with less manual intervention. For other automated inspection applications, you can also explore PTC's automated inspection solutions.

What Does the Equipment Inspect?

The inspection requirements of glass-sealed thermistors extend beyond surface defects. PTC's equipment combines several inspection functions so that mechanical, electrical, and appearance-related conditions can be evaluated within the same production line.

1. Sintering Inspection

The sintering inspection station checks key structural characteristics of the product before subsequent production stages. Inspection items include:

  • Product presence

  • Glass section length

  • Glass section diameter

  • Lead presence

  • Lead diameter

  • Thermistor element presence

  • Exposed thermistor element conditions

These checks help identify structural or assembly abnormalities early in the production process instead of waiting until final inspection.

2. Resistance Testing

Electrical resistance is one of the essential characteristics of a thermistor. According to the configured inspection requirements, the system can distinguish different resistance conditions, including high resistance, low resistance, and normal resistance.

Integrating resistance testing directly into the automated line allows electrical inspection to be completed as part of the production flow rather than as a separate offline operation.

3. Insulation Testing

The line also includes insulation testing to determine the insulation performance result of each product. Combining electrical and visual inspection within one automated system gives production teams a more complete view of product quality before unloading.

4. Overall Visual Inspection

The visual inspection station identifies appearance and positional abnormalities that may occur during glass-sealed thermistor production. Typical inspection items include:

  • Horizontal position deviation

  • Vertical position deviation

  • Thermistor chip shift

  • Lead bending

  • Other configured appearance defects

Automating these checks helps establish consistent inspection criteria while reducing dependence on repeated manual visual judgment.

glass-sealed thermistor AOI machine.png

Why Combine Inspection and Cleaning in One Line?

A notable feature of PTC's Glass-Sealed Thermistor Inspection Equipment is that inspection is integrated with cleaning and material handling instead of being treated as an isolated AOI process.

The line includes both oxide film cleaning and degreasing cleaning between different inspection stages. This creates a continuous workflow in which products move through inspection, cleaning, electrical testing, and final appearance inspection without repeatedly leaving the automated process.

For production environments with multiple process stations, this integrated architecture can simplify material transfer and reduce the number of manual interfaces between operations. It also makes it easier to connect quality results with the corresponding production batch.

AI-Assisted Defect Detection and Model Training

PTC integrates AI functions into the inspection software to support defect identification and inspection model optimization. The software can automatically mark detected defects and support model training based on production inspection data.

One important purpose of this AI-assisted workflow is to help filter false defects. In automated visual inspection, excessive false calls can cause acceptable products to be unnecessarily rejected or sent for additional review. By continuously refining the inspection model, the system is designed to improve first-pass yield while maintaining consistent inspection standards.

PTC applies machine vision, AI, automation, and other inspection technologies across multiple industrial applications. More related equipment can be found in our inspection and automation equipment range.

Production Data and MES Integration

Modern automated inspection is not limited to making a pass-or-fail decision. Production teams also need inspection records that can be reviewed and analyzed.

The Glass-Sealed Thermistor Inspection Equipment provides software functions for monitoring the real-time inspection process and final inspection results. The system can also manage:

  • Production data

  • Product batch information

  • Production yield statistics

  • Data storage and query

  • Data export to Excel

  • Production data analysis

The software also supports connection with MES systems. This enables inspection information to become part of the factory's broader manufacturing data environment instead of remaining inside an individual inspection station.

Automation and AGV Integration

The equipment is designed for full-line automation. It can automatically interface with upstream equipment for incoming material and connect the individual inspection and process stations into a continuous line.

At the end of the process, unloading can be connected with an AGV through a trolley docking configuration. This provides a path for integrating thermistor inspection with automated factory material logistics.

For manufacturers planning to incorporate inspection equipment into an existing production environment, PTC also provides engineering, integration, and technical support for customized automated inspection projects.

Key Technical Parameters

Item

Specification

Application

Fully automated inspection of glass-sealed thermistors / temperature sensors

Standard Process

Sintering inspection → oxide film cleaning → resistance testing → degreasing cleaning → insulation testing → visual inspection → AGV unloading

Inspection Efficiency

3600 pcs/h

Line Size

23000 × 1800 × 2000 mm (L × W × H)

Unloading Method

Trolley docking with AGV

Overkill Rate

5%

Utilization Rate

≥98%

Data Functions

Real-time inspection display, batch management, yield statistics, data storage, query, analysis, and Excel export

System Integration

MES connectivity and AGV docking support

High Compatibility for Different Production Requirements

Thermistor manufacturers may produce different product types or change inspection requirements between production programs. The PTC line is designed with compatibility in mind and can be configured according to different production and inspection requirements within this product category.

This flexibility is particularly important for manufacturers that do not want an automated line limited to only one fixed inspection recipe. Inspection configurations can instead be adapted around actual product and process requirements.

Benefits of an Integrated Thermistor Inspection Line

The main value of glass-sealed thermistor inspection equipment comes from bringing several previously separate quality-control operations together. For production teams, the integrated line provides several practical advantages:

  • Reduced manual handling: Inspection, cleaning, testing, and unloading are linked through an automated production sequence.

  • Broader inspection coverage: The system checks structural dimensions, electrical resistance, insulation performance, position, lead condition, and overall appearance.

  • Consistent inspection logic: Automated inspection and AI-assisted defect recognition reduce dependence on repetitive manual judgment.

  • Production traceability: Batch data, yield information, and inspection results can be stored, queried, exported, and connected with MES.

  • Automated factory integration: Upstream equipment interfacing and AGV unloading support integration with larger automated production environments.

  • High-throughput operation: The line is designed for an inspection efficiency of up to 3600 pcs/h under the specified configuration.

How to Evaluate a Glass-Sealed Thermistor Inspection Project

Selecting thermistor inspection equipment should begin with the actual product and production process rather than with a generic AOI specification. Different thermistor types can involve different dimensions, resistance requirements, defect criteria, and upstream or downstream interfaces.

Before defining the final equipment configuration, it is useful to clarify:

  • Thermistor type and product dimensions

  • Required sintering and appearance inspection items

  • Resistance testing criteria

  • Insulation testing requirements

  • Target production capacity

  • Required defect classification standards

  • MES or production data integration requirements

  • Upstream equipment interface requirements

  • AGV or other unloading requirements

These inputs allow the inspection process and automation layout to be designed around actual production conditions instead of forcing different products into a fixed inspection configuration.

Conclusion

Glass-sealed thermistor AOI equipment should not be viewed only as a camera-based appearance inspection machine. In an integrated production environment, quality control may involve structural inspection, electrical resistance testing, insulation testing, cleaning, appearance inspection, data management, and material transfer.

PTC's Glass-Sealed Thermistor Inspection Equipment combines these functions into a fully automated line with a standard process covering sintering inspection, oxide film cleaning, resistance testing, degreasing cleaning, insulation testing, overall visual inspection, and AGV unloading. AI-assisted defect processing, production data management, MES connectivity, and flexible production configuration further support automated sensor inspection.

If you are planning a new glass-sealed thermistor inspection line or want to integrate automated inspection into an existing sensor production process, contact PTC with your product specifications, inspection requirements, and production capacity so our engineering team can evaluate the appropriate configuration.

FAQ

What does glass-sealed thermistor inspection equipment check?

PTC's system can perform sintering inspection, resistance testing, insulation testing, and overall visual inspection. Inspection items include glass section dimensions, lead presence and diameter, thermistor presence, exposed thermistor conditions, resistance status, insulation results, positional deviation, thermistor chip shift, and lead bending.

Is the equipment only used for visual AOI?

No. Visual inspection is one part of the integrated line. The standard process also includes sintering inspection, oxide film cleaning, resistance testing, degreasing cleaning, insulation testing, and automated unloading.

What is the inspection efficiency?

The specified efficiency of the Glass-Sealed Thermistor Inspection Equipment is 3600 pcs/h under the stated equipment configuration.

Can the system connect to MES?

Yes. The software supports production data query, export, analysis, batch and yield statistics, and connection with MES systems for production data management.

Can the line connect with an AGV?

Yes. The standard configuration supports trolley docking with an AGV for automated unloading at the end of the production line.

Can the equipment support different thermistor products?

The line is designed with high compatibility and can be configured around different product types and inspection requirements. The final configuration should be determined according to the actual thermistor specifications, defect criteria, process requirements, and production capacity.

Contact Info

Telephone: +86-512-5792-3620 
 Email: info@ptcstress.com
 Address: No.581, Hengchangjing Road, Zhoushi Town, Kunshan City, Jiangsu Province, 215337, China

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