PI 640i Microscope optics

The PI 640i infrared microscope kit is ideal for engineers who need accurate temperature data on small electronic devices or Micro-Electro-Mechanical Systems (MEMS). The ability to see thermal variations and make measurements on small targets depends on the detector resolution, and the optics focus the heat energy from the device onto the IR camera’s detector elements. This ensures precise and reliable temperature measurements, essential for detailed thermal analysis of miniature components.

Many engineers find that temperature measurements made with contact thermocouples on small electronic devices do not correlate with measurements made using a properly equipped infrared camera. This discrepancy is common when the target size is small, as the connection with the thermocouple can act as a thermal bridge, conducting heat away from the target. In such cases, measurements with a non-contact infrared camera are more accurate, as they avoid the heat conduction issues associated with contact methods.

As with microscopes that operate in the visible spectrum, choosing the right optic for any application involves a trade-off between the total observable field of view and the smallest target that needs to be observed and measured. The PI 640i microscope objective can detect temperature changes on targets as small as 28 µm within a total field of view of 18.2 mm x 13.8 mm (.72 in x .54 in). A high-resolution IR camera with standard wide field of view optics will only deliver accurate measurements of microelectronic targets with the right infrared microscope optics. The PI 640i microscope packages combine a high-resolution infrared camera with German-designed infrared microscope objectives and a precision mounting stage for working distance adjustment, ensuring precise thermal measurement and analysis of small targets.

Most IR camera manufacturers will quote a single pixel size or IFOV (Instantaneous Field of View) to promote a camera’s ability to resolve small targets. However, accurately measuring temperature with an infrared camera always requires more than one pixel. Infrared cameras with small detector pitch or pixel element size can require as many as 7 x 7 pixels to deliver a temperature measurement within the camera’s accuracy specification. The MFOV (Measurement Field of View) specification is crucial for obtaining correct temperature measurements, as it accounts for the necessary number of pixels to ensure accurate readings.

In addition to low thermal noise, the optimal pixel pitch size of 17 µm for long-wavelength infrared radiation allows a small Measurement Field of View (MFOV) of just 3 x 3 pixels, unlike other infrared cameras with smaller pixels. The superior quality and larger size of the optics also guarantee high image quality, minimizing image distortion and ensuring uniform attenuation across the entire image. A wide variety of interchangeable lens optics are available to properly frame and maximize pixel count on the target to be measured. The infrared camera supports a frame rate of 32 Hz in standard mode or 125 Hz in high-speed subframe mode, allowing for the monitoring of fast manufacturing processes.

The PI 640i works with Optris PIX Connect software, available as a free download with free updates. The PIX Connect package includes tools for locating hot and cold spots, histograms, temperature profiling, image subtraction, and other thermal image processing features. For researchers and process engineers, the PC-based PIX Connect platform offers powerful thermal image processing capabilities, enabling users to extract and document fully calibrated temperature measurements from any pixel in the scene.

Time-versus-temperature data can be extracted from live thermal video feeds and recorded thermal video files containing stored temperature data. Engineers can utilize the data collection capabilities to extract the highest, lowest, and average temperatures from areas of any size or shape, along with complex alarm signals. Additionally, the system supports replaying stored thermal video frame by frame, allowing engineers to capture and store radiometric images and trigger snapshots during temperature changes.

Many engineers will take data on several locations on electric devices over a long period using the Temperature/Time feature, which logs data at user-specified intervals and stores it in .csv files. Some engineers prefer capturing the full image and use calibrated sequence files or calibrated .tiff images, which can be recorded at user-specified intervals. The Snapshot sequence storage routine also supports CSV file storage of the complete temperature matrix at user-specified intervals, providing comprehensive data for analysis.

Thermography software optris PIX Connect is included and license-free.All infrared cameras are delivered with the thermography software optris PIX Connect, developed specifically for the extensive documentation and analysis of thermal images. The Windows-based PIX Connect software enables users to tailor the infrared cameras to meet specific requirements. It analyses live and recorded temperature data and triggers alarm signals for process integration.The key to leveraging the Optris infrared camera is a correct configuration. This includes detailed device-specific configurations such as frame rate, measurement range adjustments, external communication settings, and USB/Ethernet configurations. Moreover, PIX Connect facilitates firmware updates and the download of configuration files over the Internet. PIX Connect Optris offers several different SDKs for our Xi and PI thermal imaging cameras. Depending on the operating platform, the infrared camera, the coding language, and the hardware platform, different software interfaces can be utilized: SDK The Optris IRmobile allows users to set up and commission an Optris infrared pyrometer or infrared camera with an Android smartphone or tablet. This tool becomes handy for commissioning and aligning the infrared camera’s field of view or adjusting the configuration. The app analyzes the connected infrared camera’s live infrared image stream with auto hot and cold spot detection. For pyrometers, a temperature-time diagram or the video signal is displayed. This app works on most Android devices running 5.0+ with a USB port supporting USB-OTG (On The Go). Google Play

Can I switch between MO2X and MO44 optics?

Yes. Optics can be changed in the field and deliver calibrated temperature measurements, provided both optics are calibrated with the specific PI 640i they are mated with. For correct calibration, make sure to select the optic attached to the camera from the pull-down optics box in the Device tab of the Configuration menu. All optics that have been calibrated with your serial number camera will be visible in this box if the PC hosting PIX Connect software is online.

Can I use non-microscopic field-of-view optics for larger targets such as printed circuit boards?

Yes. Four additional optics are available for the PI 640i and can be calibrated for use with the camera. This dramatically extends the PI 640i’s application potential, enabling thermal imaging and temperature measurement of full-size printed circuit boards or the products that host them. As with microscope optics, make sure to select the correct calibration file when switching optics.

I have my microscope optics. Can I use these?

Microscope optics developed with visible light cameras will not transmit infrared radiation emitted in the spectral region where the PI 640i is responsive and cannot be used with an infrared camera. Infrared optics not calibrated with the PI 640i could potentially deliver magnified thermal images but will not deliver calibrated temperature measurements.

Why do I need a microscope stage?

Macro focus can be performed using the knurled ring on the outside of the microscope objective but minute adjustments in working distance can dramatically improve image clarity and temperature measurement accuracy. Each microscope package’s stages facilitate this minute working distance adjustment. If the image is not in optimal focus, the temperature measurements will not be accurate.

Can I measure the temperature of the leads connected to my small electronic devices?

Small leads can be seen with powerful infrared microscope optics but are most often made of low-emissivity metals that reflect heat energy. Leads need to be coated with carbon black or flat black paint to be accurately measured with an infrared camera. The same is true for a component (can) made from metal. If a metal lead cannot be treated with a high emissivity coating, the high emissivity connection point of the lead to a device can often serve as an indication that the lead in question is running hotter than desired.

Can I see through the layers on a printed circuit board?

FR-4 and Teflon (PTFE) are common materials used as substrate layers in printing circuit boards. They are not transmissive in the infrared region so you cannot see through them with an IR camera. However, heat from a specific region may conduct up through the various printed circuit board layers to the top board, presenting any conducted heat to an infrared camera targeted at that region on the board surface. The camera settings may need to be optimized to enhance sensitivity so that small shorts from inner layers can be seen. Copper foil inserted in between PCB layers can mute or entirely prevent the flow of heat from the inner layers to the top surface of the board.

Can an infrared camera validate chip and substrate temperatures during PCB manufacturing?

Any infrared measurement requires a clear line of sight between the camera optics and the surface to be measured. Infrared temperature measurements in a reflow oven would be impossible without an access port and mounting and camera cooling provisions. Although there is no system actively marketed now with this capability there is one forced-convection SMT reflow system in development using Optris IR cameras in line scan mode to measure temperatures and create full infrared images through small slits in the oven in four locations.

• Infrared Camera PI 640i with Microscope optics
• USB cable (1m / 3.28 ft)
• Cable for output/input (1 m / 3.28 ft) incl. terminal block
• Rugged outdoor transport case (IP67)
• Microscope stand
• Base plate with ESD pad
• Software package optris PIX Connect
• Quick Start Guide