OK.... part 2 of my general comments on PCBA inspection thermal cameras......
So far we have considered the camera head and the needs of the user where ergonomics are concerned. Basically a manufacturer needs to produce a versatile imaging solution that may easily be adapted to various roles found in both hobby and industrial use scenarios. Users have always had the option to mount a conventional thermal camera on a tripod or other mount to view a PCBA. Such is often a compromise solution however. The lens type and focus distance can be far from ideal for PCBA inspections and thermal profiling, but with little choice, the user make the best use of what they have available. A dedicated PCBA inspection camera offers those with a need for such with a ‘one stop’ ergonomically and technically refined solution to their PCBA thermal imaging needs. A hobbyist may elect to continue use of a generic thermal camera for such tasks due to cost but a PCBA inspection camera is still a viable product line as the electronics repair and research industries need such imaging equipment. High end thermal imaging equipment for PCBA work has traditionally been extremely expensive due to its specialist nature. The availability of more affordable imaging cores has the potential to change that situation.
As previously stated, I see a thermal camera based PCBA inspection system as comprising the camera head and a host that is running sophisticated image analysis software. Whilst a stand alone camera remains an effective tool, the added power of a host running analysis software adds much to the system, including the option for larger displays etc. The host system needs to be generic in nature fir broadest appeal in the market so I would expect to see support for PC, MAC, Linux, Android and iOS systems. The user may then select the host that most suits their needs. As a bare minimum, PC support is required.
The image analysis software is an area where a product can shine or fail. This applies to both all-in-one cameras and those using an external host fir image analysis. In its most basic firm, a hosts software will provide the user with the controls usually found on an all-in-one camera solution. Examples are....
Temperature Centre
Temperature Span
Auto Centre and Span mode
Emissivity
Ambient temperature
Distance to target
Colour Palette (LUT) selection
Spot temperature measurement
Image save
E-Zoom
Manual FFC activation
These are just the basics and image analysis software needs to offer a lot more to the user... examples are....
Spot and multi spot temperature measurement
Region of Interest
Highest and lowest temperature highlighting and measurement.
ISOTEMP capability
Scene Temperature alarm threshold and highlighting
Straight line temperature measurement plot
Image histogram view
Image stacking
Image annotation
Noise reduction algorithms with user selectable levels of effect
Mapping of temperature across the scene as a ‘heat map’
Temperature monitoring waterfall display
Electronic zoom with image enhancement through interpolation
Long term temperature logging of selected spots in scene
Camera measurement calibration the by user using reference Black Body sources (an advanced feature)
Video Recording function of display as seen by the user (spot temps, histograms etc.)
Time lapse image collection
Image saving options that include the RAW data, ‘As displayed’ frame grab, Radiometric JPEG and RGB JPEG.
Image overlay option for the semi transparent overlay of a reference PCBA board component layout (CAD image)
Image verification option for comparison of a DUT PCBA with a known good reference thermal image. Differences highlighted for user investigation and ‘alert’ differential values set by the user.
Option for a MSX style edge overlay using a visible light image of the PCBA taken with a separate camera.
PASS/FAIL PCBA test beaded upon preset permissible temperatures measures at specific points on the PCB. Many measurement points may be employed in such a test and thermal issues quickly identified.
Direct contact temperature measurement compatibility option where a thermocouple may be used to pass accurate temperature data to the software for use in its reporting. This would require a USB based thermocouple or PT100 thermometer as the data source. Such a data input could help with measurement accuracy and offset calculations by comparing the reported direct temperature measurement of an area with that reported by the thermal camera.
Well I think that is enough from me for now
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If DYT wish me to review their new product I would need ‘hands on’ experience of it for testing. I would be happy to carry out such a ‘Real World’ test.
Fraser