FLIR Thermal Camera for teardown - my latest patient, the E2 - Page 1
Forum section: electronics / general

author: Fraser
author_rank: Super Contributor
timestamp: May 09, 2015, 11:41:26 am
content: For all thermal camera fans out there, I have just aquirred a new patient in need of repair.It is a poorly FLIR E2 that will need a tear down to determine what is ailing itThis is just the introductory post and will be followed by a photographic record of its disassembly. I hope the journey will be interesting to the readership.Some background on the camera.The original FLIR Ex and Exx series were produced in the early 2000's and are not to be confused with the latest Ex and EXX cameras. How confusing of FLIR to use the same family nameThese cameras were intended to be a very portable, yet capable, handheld thermal camera that could be used like a kind of thermal 'torch'. Hence its shape. I tested one of these when they were first released and performance was pretty impressive at the time.The resolution is 160x120 with a thermal sensitivity of 0.12C and 30 frames per second. The removable standard lens is 24 degrees, but other lenses may be fitted. The lens material is Germanium and it is large in diameter.The menu structure is simple and all important functions are present. Namely, Auto and Manual modes with setting of centre temperature, span, emissivity, measurement areas etc.Connectivity options are either PC or direct composite video output. Power comes from a Li-Ion 7.2V 1.8Ah removable battery that is located in the handle. These batteries are available new for £20 on ebay.The 'patient' that I have just received is an E2 manufactured in 2002. It was being used by an electrician and this was the target market of the series i.e. preventative maintenance tasks. My camera has stood up to a long life in service very well, so build quality appears good.My cameras fault appeared to be 'failure to boot' in the auction description. On receipt and initial testing it is clear that the camera is booting just fine with no errors shown. The FFC shutter is activating as expected and with normal regularity BUT no thermal image is appearing on the screen. Almost as if the lens cap was fitted. A key symptom is the fact that the spot temperature reading is around -4 degrees ! Something is very wrong there ! I have also noted what appears to be fluid ingress witness marks between the LCD panel and its plastic protector. The LCD is working fine though. Overzealous cleaning with screen cleaner maybe ? That may be nothing to do with the fault but we shall see.I will be investigating the cause of these symptoms and will have to take the camera apart to do so. As such I thought I would start this topic so that I can add pictures and updates as I delve into this little camera. It is certainly worth the effort to repair it.I hope this will be an interesting and enjoyable thread for the readershipPictures of the patient attached and the cameras brochure.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: May 09, 2015, 12:35:11 pm
content: In case anyone is wondering why I have not torn into the casing as soon as the unit arrived....I always follow good practice and check all functionality and symptoms before opening the case.That is to say, check all menu options, look for obvious symptoms during these checks and then do a factory reset so that camera is running a known baseline configuration. Re test camera to see if symptoms have changed.During the testing I noted the following:1. Measured spot and area temperatures are always around -4C2. Setting span to its widest range and bringing centre temperature up to include ambient and 36C resulted in no thermal image data when my hand was waved in front of the camera with and without lens fitted. The camera is effectively blind.3. The camera information menu showed serial numbers and information for all modules fitted EXCEPT the lens. From experience, cameras with removable lenses take data from the lens which includes FOV and serial number. That appears to be missing in this case. Germanium lens element Temperature data is also provided by the lens and this is important to the cameras internal correction algorithms. Lens contact gently cleaned but this issue remains.I am suspicious of the very low -4C measurement but the camera is performing a FFC event without complaint. The absence of lens data is also of interest. I sjall be looking at the three main thermal data providers in the camera....namely, lens temperature, chassis temperatureand the microbolometer outputs. The microbolometer contains both image elements and die temperature monitors. The microbolometer in this camera is circa 2002 and so is likely a conventional (very expensive) hermetically sealed, gold plated, module. They are normally very robust so I do not expect microbolometer failure in this case.These cameras contain built in diagnostics so I am surprised taht no error messages occur at boot.I still need to carry out tests on all I/O ports to see what they are producing by way of image data but that will have to wait as duty calls elsewhere.I shall investigate this as and when time and my energy levels permitFor anyone interested, the auction I bought the camera from is here:http://www.ebay.co.uk/itm/331542226167?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AITNot a great description and the pictures with flash make the screen look awful but it is, in fact, not scratched at all. Just liquid ingress witness marksAurora

author: Fraser
author_rank: Super Contributor
timestamp: May 09, 2015, 06:52:44 pm
content: I have had a most enjoyable afternoon disassembling and inspecting my new patient.How many of you have bought a piece of equipment and had the nagging feeling that someone has been in it before you ? I had that feeling with this camera and I was correct.Thankfully no harm has been done but it is obvious that someone was looking for the easy fix etc. More on that later.This E2 came to me with the comment that it belonged to the sellers father who is an electrician by trade. He had apparently intended to repair it himself but lost interest long ago. Hence its was sold as part of a clear-out. ...... that pair of words send a shiver down my spine ...... my wife uses words like that when she see our garage contentsAnyway, I opened the camera knowing that some form of liquid has got between the LCD and its protective window. I could also see strands of cotton wool on the inside of the screen so someone had to have been in her before me. The worst case scenario was that the E2 had gone for a swim at some point in time. That would have been bad news, very bad newsWith some trepidation I removed all of the screws that appeared to be associated with the case. This camera does not have any concealed screws (unlike the new FLIR TG165)The case separates into three parts with the display and keyboard panel lifting off of the top. One screw fixing point was damaged in the display/keyboard panel, possibly the result of a fall impact cracking the plastic around the knurled brass insert.I was trained in forensic examination of electronics so enjoy analysing a 'crime scene' to ascertain what happened to a piece of equipment. This Camera is going to be subjected to a full inspection as I know there are fluid contamination issues that need to be addressed inside. The good news for the readership is that I have to strip the camera down to its component parts for inspection and lots of photos will ensue.I continued with the disassembly of the case and at each stage of a PCB removal I inspected the PCB and surrounding area for signs of fluid ingress and residue. I found the following:1. The rear of the LCD protection screen has been exposed to fluid of type unknown and then wiped with cotton wool. Poorly executed cleaning has left residue on the screen.2. The LCD surround is tin plated steel and is showing evidence of corrosion.3. The main PCB is fitted with an aluminium heat-sink and pink thermal transfer pads that cover two large IC's on the board. a layer of fluid was found between the thermal pads and the IC tops. This can sometimes be fluid coming from the pad as occurs with oil/silicone impregnated types. The fluid does not evaporate in warm temperatures so it is unlikely to be water. There is no fluid visible around the pins on the PCB below the heatsink.4. The microbolometer diaphragm and chassis temperature monitoring housing has evidence of a sticky residue between it and the microbolometer. The shape of the residue is circular yet the microbolometer is a rectangular shape. I have no explanation for this disparity yet.6. The micobolometer Germanium window was contaminated with a dried on layer of unknown origin. The layer was easily removed using IPA. There remains some minor marking on the window but this may be fine line corrosion which can occur on Germanium parts. They are not serious enough to effect a 160x120 pixel thermal camera image though.7. The microbolometer has pins arranged around its periphery. The microbolometer hermetic housing is steel with gold plated pins egressing via glass vacuum seals. On two sides of the microbolometer there is evidence of fluid damage in the form of corrosion of the steel adjacent to the pins (rust has formed). There would also appear to be rust contamination of the microbolometer inter pin spacing. This could seriously impair the data on the affected pins.8. The display/keyboard case is fitted with a metal finger gasket. This gasket is showing clear signs of corrosion and finger damage due to attempted cleaning using a inappropriate methodology.9. There is evidence of fluid accumulation around the lower screw mounting of the microbolometer housing where it fits into the lens mount and FFC shutter assembly10. There is fluid contamination residue on the laser protective window which is located directly above the microbolometer. This causes some distortion and spreading of the laser beam.Well that is the bad news...... now for some good bits.......1. The case shows no obvious physical damage due to a drop impact (except the brass bush retainer inside the display section.2. There is no evidence of fluid presence or accumulation in the lower case halves.3. There is no evidence of corrosion on any PCB or component pins (except on the microbolometer itself)4. There is no evidence of fluid ingress through the lens mount and the matt black coating inside is pristine. (fluid would 'watermark' this for sure)5. There is no evidence of component leakage on the PCB's and no fluid residue visible on them.Some readers may already be thinking this camera a lost cause ? Well the good news is that I have managed to get it to produce a thermal image, albeit a noisy one. The noise may be being caused by the contamination and rusting of the area around the microbolometer pins The contamination is of an unknown origin and I shall be asking the sellers father for any information that he might have on the incident that lead to such.This is turning out to be an interesting little project. I have proven that the camera and microbolometer are still capable of producing a thermal image so it is worth the effort to restore the unit to its full capabilities. Nothing I have seen today makes me think this camera is beyond my help.It LivesPictures to followAurora

author: Fraser
author_rank: Super Contributor
timestamp: May 09, 2015, 07:48:33 pm
content: OK here we go....internal pictures time

author: Fraser
author_rank: Super Contributor
timestamp: May 09, 2015, 07:52:17 pm
content: More.....

author: Fraser
author_rank: Super Contributor
timestamp: May 09, 2015, 07:56:55 pm
content: and more.......

author: Fraser
author_rank: Super Contributor
timestamp: May 09, 2015, 07:58:51 pm
content: and more......

author: tautech
author_rank: Super Contributor
timestamp: May 09, 2015, 08:17:15 pm
content: Very enjoyable commentary in reply #2.Good luck with your latest patient.

author: Fraser
author_rank: Super Contributor
timestamp: May 09, 2015, 08:37:26 pm
content: As I previously stated I noted that the temperature measurement was totally out of wack and that the lens data was missing. The lens data symptom was a very important clue as I knew the lens passes data and temperature to the main board. Without this data a thermal camera will behave very strangely indeed. My first checks were focussed on the lens contacts, PCB and its associated mating pogo stick contacts on the camera. All was well with these. Some quick continuity tests on the ribbon cable that connected the lens contacts to the camera display board. ...... aha no continuity on several lines. The ribbon cable was not correctly seated in its snap lock ribbon socket. It looked OK , but wasn't. refitting the cable correctly cured the temperature reading issue and the lens data now appeared in the camera information page.The thermal image appeared and responded to my hand in front of the lens and then to my cat sitting on the floor. Focus worked fine and the temperature readings seemed reasonable. The image had a lot of line noise and a poor flat field however so I knew that other issues are causing problems in the camera.It is my opinion that this camera has suffered an 'event' that caused degradation of the image. Someone, likely the electrician owner, opened the camera in the hope of finding an easy fix or to investigate how bad matters were inside. Having given up on the repair I believe that person reassembled the camera poorly. This lead to case seals being incorrectly positioned, ribbon cables being pinched and the incorrect insertion of the lens communications ribbon in its display PCB socket. The camera then failed to provide an image so the amateur repairer likely thought they had broken something, and gave up.Then the camera comes to me for some TLCI still need to clean away all corrosion and wash the PCB's in IPA to ensure no contamination remains t cause future issues. The microbolometer will receive lots of TLC to sanitise its case and remove all rust from areas where they may cause issues. The rusted areas will then be carefully painted with a rust stabiliser to prevent any worsening of the corrosion. Once I am sure all is clean, I will retest the camera to see if the symptoms remain.Note the OEM modifications in the pictures. They are very obvious but well executed. this is a first generation version of this camera as it is dated 2002, which is the year of first release. Hence the modifications.Once I have the camera working correctly I will carefully set about replacing the lithium button cell whilst maintaining power to its terminals. I doubt it protects the calibration data but I would rather not find out that it does the hard way !The camera will receive a full restoration of its case as well.I have a brand new battery on its way to me as well so I will not need to rely upon the somewhat decrepit original batteries that have already been rebuilt once in their lives.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: May 09, 2015, 08:59:55 pm
content: As some members know, I have a high resolution X-Ray capability if needed. In this case the patient did not need an X-Ray, but I have another 'helper' on hand if needed...... theCAT scanner, aka Oliver, or Ollie for short. Picture attached.When not scanning what I am doing, he sleepsAurora

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 09, 2015, 10:33:41 pm
content: I wonder why they have a TCXO in there

author: Fraser
author_rank: Super Contributor
timestamp: May 09, 2015, 10:43:23 pm
content: @Mike,I wondered about that as well. My higher spec PM series cameras use normal SMD crystal oscillator blocks and multi clock generators. Even the RTC is a normal 32kHz crystal.A TCXO seems overkillI'll see if I can work out what it serves.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: May 10, 2015, 11:24:17 am
content: Well I have heard back from the seller. He has yet to speak with his father but it would appear that the camera suddenly stopped working one day. His father is not the original purchaser of the unit (no great surprise there) so it may have suffered 'abuse' in a prior life.Sadly I was also advised that the poor camera has spent the past 2 years (since failure) in a damp workshop. This may explain the corrosion issues on ferrous parts.I have re-inspected all of the PCB's this morning and can confirm that there is absolutely no fluid contamination on them or the component leads. No corrosion evident on the leads either. It is possible that I am witnessing condensation corrosion on the microbolometer. This is a lesson to all thermal camera owners....keep your cameras warm and dry when in storage.I revisited the fluid that was found on the heat sinking pad and tops of the IC's. I can confirm that it is some sort of oil or silicone fluid that the thermal pad contains. Another smaller thermal pad in the lens mount is exhibiting the same sort of 'sweating'.It is looking more likely that this camera has suffered a drop event that dislodged parts within. The main large heat-sink has definitely moved since manufacture and is slightly bent. The broken brass insert retainer on the display casing also points to a drop event.When this happened, I may never know but I suspect someone went inside to 'fix' it. If they did, they made a poor job of re-assembly evidenced by poor seal positioning, trapped flex cables and poor cleaning hygiene on the LCD display protector. It is quite plausible that the thermal sensors cable was not correctly fitted at this time of this 'fix' and eventually lost connectivity with the connector contacts, causing the 'no image' fault.I have removed the temperature sensor cable and it has more than one set of pin contact marks on it so it has been poorly positioned in its life. I will detail the thermal monitoring of the camera in a separate message. It uses three DS1624S temperature sensors in the optical path. Quite comprehensive monitoring but this was not a cheap camera when new.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: May 10, 2015, 12:04:21 pm
content: Just remembered..... there is some very bad news regarding the microbolometer in this camera....... it has slight distortion above the knee on its pins down two sides. That is to say, the microbolometer capsule is suspended above the PCB on its pins alone and it is no longer parallel to the PCB. This is classic drop event damage and can be terminal for the microbolometer.The event plays out as follows...... the camera is dropped from approx 1m height and lands on its rear end. The kinetic energy stored in the relatively heavy microbolometer capsule means it tries to continue moving in the direction of gravity. The thin gold plated supporting leads absorb the energy but in the process bend at the weakest point, namely the horizontal area above the knee. The result is a microbolometer capsule that is no longer parallel to the pcb or perpendicular to the optical path. The other potential areas of concern in such an event are damage to the glass vacuum seals caused by the torque exerted by the leads, and the potential for separation of the thermoelectric cooler from the microbolometer die. Both of these failures would render the microbolometer scrap as it is not DIY repairableWhen I had the camera running, the image was noisy and there was a definite thermal cool sot in the middle of the image. This does not bode well for the microbolometer. Time will tell whether this camera has a future.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: May 10, 2015, 12:42:38 pm
content: Whilst sat looking at the patient considering the work I need to do on the microbolometer, I had a thought about this thread and where it is going. It will likely meander all over the place whilst I work on this camera, and that was my intention really.... a commentary on the investigation and hopefully repair of a piece of equipment that is of interest to many fellow techies these days. It is also a piece of equipment for which no official technical information may be distributed to the public (ITAR regulations).I am considering staring another thread entitled "Anatomy of a thermal camera" and using this E2 as the subject of the thread. The alternative would be to use one of my many PM5xx series thermal cameras as the subject under investigation. I already have good knowledge of that design. It is somewhat different to the more recent 'pistol grip' designs though. Such a thread may help others to better understand the technology and what lives inside the case of these clever bits of kit. I would have to stick to high level descriptions of the design and no schematics as any deep technical detail (even that learnt from reverse engineering) will place me in breach of ITAR. I could find myself in hot water if some official in the USA takes issue with what I have written.Anyway, its just a thought and may come to nothing. At least if the camera is scrap due to microbolometer damage, it will have served a useful purpose. We will see how the repair progresses in this thread.Expect me to flit around the camera in this thread as I am popping in and out of this repair as and when time and energy permits. You are witnessing my 'quick and dirty' approach to a repair at the moment ! Not my finest work but hey, needs must and I am having a ballAnd for anyone wondering.... yes I am doing the teardown and analysis work on a lap tray in our conservatory and not in my garden based lab. Why ? Well M.E limits what I can do and I can pop in and out of this little project easily if it is sat near me in my nice warm and bright conservatory. Not all work has to happen in a 'shed'Thankfully my wife is being very tolerant of my 'playing' at the moment.Aurora

author: bookaboo
author_rank: Frequent Contributor
timestamp: May 10, 2015, 01:11:12 pm
content: I do enjoy a good troubleshooting thread

author: Fraser
author_rank: Super Contributor
timestamp: May 10, 2015, 01:20:23 pm
content: Good,I'll try to keep it interesting and funAurora

author: Fraser
author_rank: Super Contributor
timestamp: May 10, 2015, 02:03:07 pm
content: OK, those who have been reading this thread up to this point will be aware that the FLIR E2 camera was not producing a thermal image but otherwise appeared to be functioning normally. Important symptoms were the incorrect spot temperature of approx -4C and the lack of any lens information in the camera information page.For those unaware, FLIR cameras normally have an information page in the camera menu that displays the serial and revision number of key elements within the camera, including the lens. The lens data packet also identifies the lens type to the camera for calibration purposes.The fact that the lens data was missing immediately told me that camera was not seeing the lens. I am also aware from previous work on FLIR professional cameras that they install a thermal sensor inside the removable lenses to provide Germanium element temperature as this is required for temperature compensation purposes. Germanium lens transmission decreases as its physical temperature increases.The removable lens communicates with the camera body via four contacts that mate with sprung loaded 'pogo stick' contact that protrude from the lens mount. Contamination can prevent correct contact performance and so cleaning may sometimes be necessary. This was not a solution for my E2.Upon opening the E2 for the inspection stage I focussed on the signal path between the lens mount contacts and the PCB within. A quick continuity check on the 4 conductors proved that three were not connected to the PCB socket contacts. Further inspection showed that the ribbon cable was not correctly seated in this socket and so had been the cause of the lens data loss.It does not end there however..... The 4 wire communications ribbon detailed above also carries thermal sensor data from three sensors in the optical path. DS1624S thermal sensors with built in flash memory are employed to monitor the temperature as follows:DS1624S IC from front back ->1st = Temperature and identity of lens2nd = Temperature of the FFC shutter3rd = Temperature of the Microbolometer capsule and front Germanium window.All three sets of temperature data were therefore absent when the camera was in fault. I am surprised that the camera did not display an error. Instead it tried to operate without a temperature reference from the optical path and did not produce an image. The lack of the required data appears to have totally befudled the image production process. Not that surprising.Pictures of the temperature sensors attached.The flex pcb fits either side of the diaphragm and the curved FR4 pcb is attached to the lens rear.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: May 10, 2015, 04:23:44 pm
content: I'm back againNext steps on the repair......1. Carefully clean the microbolometer to remove all loose ferrous material from capsule and between the pins.2. Attempt to lift the microbolometer capsule away from its PCB to straighten the distorted pins and correct the error introduced in the face angle.3. Straighten the bent aluminium heat-sink plate.4. Temporarily reassemble camera and check operation.5. Disassemble camera and carefully clean all parts and PCB's to remove any accumulated film on their surface.6. If camera is still displaying a noisy image, continue investigationThe noise in the image that I have referred to is not pixel noise but multiple random horizontal lines. These may be caused by the corrosion around the microbolometer pins or there could be a microbolometer related noisy DC-DC converter in the unit. We shall see.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: May 10, 2015, 04:41:59 pm
content: Aaaaah! major brain fadeThe distorted pins on the microbolometer will NOT cause an error in the face angle of the front window relative to the optical path. Why? because the face of the microbolometer is the mounting point to the diaphragm and lens mounts. The micobolometer PCB floats on the leads.This changes the drop event scenario. If such an event occurred, then the bent microbolometer pins may have been caused by either the kinetic energy of the PCB or by something impacting the PCB from the rear (another module) The impact point would also have been the opposite to that previously considered. Namely towards the front of the unit.Of course the microbolometer may have had distorted pins since manufactureIt will be interesting to see if any other evidence of a drop comes to light.Oh dear, time to take a rest, the old brain gets a bit befudled sometimesAurora

author: Fraser
author_rank: Super Contributor
timestamp: May 10, 2015, 05:02:54 pm
content: Pictures of the microbolometer. Note the two diagonally opposed mounting points on the front.Take a closer look and you will see the gap between the PCB and rear of the capsule is not constant. You may also see the bent leads above the knee, though it is not that clear in these pictures.Aurora

author: SeanB
author_rank: Super Contributor
timestamp: May 10, 2015, 05:05:28 pm
content: So it was dropped, and of course hit lens first. Wonder if that would have popped the microbolometer loose on the cooler, and as the front cover is opaque it would be difficult to see unless you use another high resolution camera as a close up to see inside.

author: Fraser
author_rank: Super Contributor
timestamp: May 10, 2015, 05:23:31 pm
content: Looks like a potential drop casualty. I have worked on several thermal cameras that have been dropped. A common hazard in industry. Always use a wrist or neck lanyard ! It can get enxpensive if you don't and a drop happens.I have a superb 'top of the line' NEC AVIO thermal camera that was dropped on its lens. The result was a wrecked lens filter riing (thankfully a replaceable part), a slightly bent lens chassis (aluminium so repairable) and the battery carrier chassis (aluminium) driving into the rear of the microbolometer PCB.I have got that camera working fine now but just have not had the time to sort out the bent metalwork yet. It will be a lovely camera when re-assembled though. It cost me £700 as a project and they sell used for around £8000 - £10.000Well worth the effort and why I am taking my time repairing it properly.Back to the E2. Its weight is at the front so it would naturally fall on its lens. However I can find no evidence of impact on the lens or lens mountThe microbolometer may have suffered damage, I will have to see once I have the unit back together for further testing. Brains a bit too tired to do that right now so watch this spaceI maybe able to X-Ray the microbolometer depending upon the thickness of the steel capsule walls. If the microbolometer die had moved forward away from the thermoelectric cooler I would have expected damage to it but my knowledge of the internal construction is limited to old HP documents and not this type of FLIR staring array.Aurora

author: SeanB
author_rank: Super Contributor
timestamp: May 10, 2015, 07:04:45 pm
content: Carpeted floor will show no damage, but will still have enough force applied to the innards.

author: Fraser
author_rank: Super Contributor
timestamp: May 10, 2015, 07:15:30 pm
content: For anyone interested in how I will be cleaning the microbolometer capsule area that sits between and behind the leads ....here is my secret ........TePe interdental brushes and a syringe full of IPA to flush away detritusI'll be using the special ESD safe TePe brushes designed for static sensitive teeth of courseTePe brushes come in many sizes from tiny to humungous ! Very useful to have in the workshop. They cost around £5 for a pack of 10. Available at all good grocery stores in the UK and from your dentistI also use other dental tools, piks etc as they are perfect for SMT workingAurora

author: robrenz
author_rank: Super Contributor
timestamp: May 10, 2015, 07:21:06 pm
content: Very interesting and well documented thread, keep up the good work!

author: Fraser
author_rank: Super Contributor
timestamp: May 10, 2015, 07:24:36 pm
content: @robrenz,Thanks.This is just me having fun.... you just don't usually get a blow by blow account on such things from me.I just hoped it might make an interesting little thread for some. It also helps my grey brain cells to write about the camera..... helps focus the mind and to spot errors in my thought processes.I have been asked to document fault finding on thermal cameras before but it is quite a task to do properly. I may yet do a more formal document on the topic.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: May 10, 2015, 10:15:39 pm
content: Cleaning of the microbolometer capsule has been completedIt took a little more aggressive cleaning action than just the TePe brushes but I am happy with the result. There was significant red rust between several pins which can't have been good for performance.I ended up using a combination of IPA washing, TePe brushing and surface abrasion using a blunt tipped dental pik. These removed all but the most stubborn corrosion and that is nowhere near the leads so is of little concern. I will be happy with 90% on this task'Before' and 'After' pictures attached.I then evaluated the risk of lifting the corner of the microbolometer that had been pressed closer to the PCB. There was the risk of lifting pads that were placed under tension, cracking the glass vacuum seals through torque action and the lesser risk of distorting the capsule case. In the end I elected to correct the lead distortion and lifted the capsule using careful leverage. All went well and the capsule now sits parallel to the PCB and the leads are correctly shapedAnother step closer to the retesting of the unit.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: May 11, 2015, 01:08:37 am
content: I have spoken a lot about the microbolometer in the E2 but have not explained its internal design or the purpose of its various external connections. Time to remedy that for those unfamiliar with this type of device. Don't worry, I am not going to go into any great depth here, just a high level overview.The microbolometer used in a staring array such as fitted in the E2 is basically a large matrix array of bolometers or thermistors in common terms. These bolometers are individually read by read out electronics and their values are used to build a thermal map of what the array is seeing. The thermal energy of a scene is projected onto the array by the thermal cameras optics and so the thermal scene is recreated on the surface of the bolometer array. All sounds simple until you consider how such an array will behave in the real world.Each bolometer in the array will have its own unique thermal response characteristics and the whole array will be subject to thermal drift due to localised heating of the die and ambient temperature changes. Untamed such an array would be next to useless for a thermal camera application.In order to tame the array of bolometers several techniques are often employed. Note that there are many ways to achieve the desired result, and this is just one. It is however the way the E2 operates.First of all the microbolometer die temperature is stabilised at a temperature usually around 30 Degrees Celcius. This is done using active heating and cooling in the form of a Peltier Element. Note that this is NOT a cooled array in thermal camera terms. They are very different beasts. This is a temperature stabilised array. In order to stabilise the die temperature a closed loop controller is employed. This has thermal sensors attached to the die feeding it with temperature readings. The controller then takes the appropriate action to heat or cool the die. This temperature stabilisation of the die does not counteract the changes in bolometer temperature due to scene illumination.Non Uniformity correction and flat field correction are also needed to tame the, now temperature stabilised, microbolometer, but that is a topic for another day.Sticking with the microbolometer, what would we find if we took one apart ?Well the first obvious component is the capsule in which the array is housed. The capsule is hermetically sealed and has a thermally transparent window at its front. The area inside the capsule is a vacuum which helps to prevent internal thermal currents and impurities that could degrade the arrays performance over time. Inside the capsule we would first see the staring array of bolometers mounted on the die. These are extraordinarily fragile and cannot be touched or cleaned with compressed air. On the rear of the die we would find the single stage Peltier element for temperature stabilisation. The Peltier element operates using the thermal mass of the metal capsule as its counterpoise. On the die we would normally find two temperature sensors that serve the closed loop temperature stabilisation controller. Some microbolometers also have highly complex processing power on the same die as the bolometers, others do not. The array of bolometers is read by read out electronics and either passed to the on board processing or sent to the capsules external I/O pins.When looking at the microbolometer capsule from the outside you will see that there are a large number of pins around its side. In the case of the E2 capsule, the pins are present on three sides. These pins are for input/output functionality and have glass seals insulating them from the metal capsule and retaining the vacuum within. On the fourth side of the E2 microbolometer you will see two larger pins and a crimped tube with paint at its tip. The two larger pins are the supply rails to the Peltier element and their size relates to the current that can be involved for temperature stabilisation. Low conductor losses are important here. There is a grounding pin on the capsule case. The crimped tube is the vacuum port through which the air inside the capsule was removed. It is crimped, soldered and then coated with a gas sealant paint to maintain the vacuum over decades. Microbolometers do not require renewal of the vacuum during their service life.The window that sits in front of the staring bolometer array is usually manufactured from Germanium. A very expensive material (metal) that has properties desirable in thermal imaging. The window seal to the capsule is achieved using specialist epoxy that is gas tight.Well that just about covers the basics of the microbolometer that you have seen in the E2 pictures. This type of microbolometer is expensive to manufacture and so some consumer grade modern thermal cameras have moved to cheaper designs that may be manufactured more easily. These do not require the metal vacuum capsule. The same basic design principles apply however, just in a different format.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: May 11, 2015, 02:54:45 am
content: The FLIR patent covering the Early Ex series provides some nice pictures of teh optical block and core.I have extracted one and attached it here.The key items of interest are:3b,3d & 3eare the DS1624S thermal sensors10is the microbolometer array10Ais the Peltier element10Bis the microbolometer capsule mounting clamp11is the lens shell11a & 11bare the Germanium lens elements13is the diaphragm19is the FFC shutterFor those wishing to read the Patent document. Search for Patent US6707044Patents US7157705 and US20040124359 also apply to the early Ex series cameras.Aurora

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 11, 2015, 04:40:48 am
content: Appreciate your work on this Aurora. Thorough methodology and simple explanation.For those that are curious, thermal stabilization partially solves some of the problems in getting usable information out of these arrays. Each bolometer sits in a delicate thermal balance. Heat comes in from the external scene, and goes out by radiating to the back of the array and by conduction through the leads that connect each bolometer to the readout circuitry. In a typical design these leads are the only mechanical support for each bolometer element, and are made as thin as possible to minimize conduction losses. When a uniform temperature scene is viewed each bolometer ideally would stabilize at the same temperature, somewhere between the scene temperature and the readout temperature. In reality the temperatures vary due to a variety of manufacturing variations in the individual bolometers, including lead dimensions, emissivity, bolometer dimensions and so on (in addition to variations from flux through the optics and other factors outside the bolometer array). Since the radiation balance part of the equation is a power law and the conduction portion is linear with temperature, operating at an unstabilized temperature changes the balance between conduction and radiation dramatically. Stabilization makes compensation for all of these variations between individual bolometers more tractable.In addition the slope of the thermistor response to temperature varies significantly with temperature, so the response of the array can be improved by heating it. The amount of heating is a trade between this response gain and a number of negative factors whose importance varies with application.

author: JBaughb
author_rank: Regular Contributor
timestamp: May 11, 2015, 05:04:30 am
content: This is a great read. Getting into the mind of someone performing equipment repair is always fascinating to me. I guess I am very much interested in other though process and how it differs from my own. Bravo, good sir.

author: Fraser
author_rank: Super Contributor
timestamp: May 11, 2015, 10:56:34 am
content: @CatalinaWOW,Nice descriptionI was surprised when I met my first non temperature stabilised microbolometer.....that found in the modern FLIR E4. When FLIR told me that they just let it stabilise at its own natural operating temperature I was puzzled as to how they tamed the thermal behaviour of the bolometer array.I understand that they did not botherIt relies upon die temperature monitoring and agenericcompensation table that FLIR produced. I say generic as FLIR have clearly stated that the camera is calibrated at a set ambient temperature and some cameras will work better than others at different ambient temperatures, even when in the same batch, depending upon how well the compensation table matches the microbolometer characteristicsI believe this comes under the heading of 'good enough' for the intended market.With regard to the pros and cons of the Peltier temperature stabilisation design, it may be considered a necessary evil in some cases. We already know the pros's but as to the cons......It is hungry on power at initial start up, but this diminishes as the operating temperature is reached. If a camera is sat in a very cold environment or operated in such, the Peltier element has to do a lot of work and so draws significant power form the hosts power supply.. In battery operated equipment this can be an issue. A more serious issue with the Peltier element is out-gassing. Peltier elements contain chemicals that can out-gas during the operational life of the microbolometer capsule. The capsule contains a vacuum and would normally be considered relatively inert in terms of an environment for the bolometers. The out-gassing of the Peltier element effectively contaminates the environment inside the capsule with some potentially negative effects in high performance microbolometers. I believe manufacturers do their best to deal with this issue but it remains a negative attribute of 'on die' Peltier temperature stabilisation that should be considered.Some may ask why the Peltier element is not external to the capsule. The answer is simple....thermal efficiency. When inside the capsule it is in a vacuum and is in close physical contact with the die that it is heating or cooling. It uses the metal capsule as its counterpoise against which to heat or cool and this is effectively sitting in free air to permit radiation and convection cooling if needed.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: May 11, 2015, 11:09:41 am
content: @JBaughB,You need to be careful getting into my mind....it can be a scary place full of all manner of weird and wonderful technical triviaOn a more serious note, I should warn that I am writing up this investigation purely for fun and hopefully the interest of the reader. I suffer from chronic fatigue syndrome at the moment and that can definitely blunt my thought processes when needing to concentrate for any significant length of time. It is one of the awful symptoms of CFS (M.E.) that upsets me most. I used to have a pin sharp analytical mind, but these days its a bit more like a rusty old 6 inch used nailSharp it is not !This is the first thermal camera investigation and repair that I have done in some time. I do not claim that my approach to this one has been the best or most efficient. I am just feeling may away around a camera that I have not worked on before. Its just a fun little adventure for me and I decided that I would extend the teardown thread to share my progress with the diagnostics and repair work. You could consider this thread to have become my 'notebook' or doodle pad for this repair. I am hopeful that those who read it may learn something, anything, from my meandering commentaryIf nothing else, readers can have a laugh at mistakes that I may/will make along the wayAurora

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 11, 2015, 11:44:01 am
content: There is an apparently unused pin in the image - I imagine this is probably for a getter to remove the last traces of gases from the envelope after pumping and sealing.

author: Fraser
author_rank: Super Contributor
timestamp: May 11, 2015, 02:20:42 pm
content: @Mike,I am honestly not sure about a Getter in microbolometers. The capsule is not a high voltage environment like a thermionic valve and is decidedly more delicate. a getter pan erupting inside a microbolometer capsule sounds like a nightmare ! I will take a close look at my photographs again. I thought that pin was a ground connection but I may be wrong.The E2 is now reassembled for its first test since cleaning.The good news is that it still works and is producing a thermal image.The bad news is that IMHO it has too much horizontal line noise at low spans and the spot temperature measurement seems to have serious issues with accuracy !The FFC correctly flattens the image so at least that is coping with any gradient across the microbolometer array. I did a quick and dirt test using a mug of boiling water. Pictures attached.Note in the pictures of the thermal core assembly the close proximity of the microbolometer pcb unused cream connector to the black sub-assembly that sits vertically behind it. One corner of that sub assembly points forwards and is almost touching the microbolometer connector. The sub-assembly is very poorly mounted and is only held in place by an aluminium 'arm' coming from the sub assembly heatsink ! Very poor design that allows the sub-assembly to rock on that single pivot point.It is my belief that this E2 was dropped, landed on its lens end and the sub-assembly travelled forward into the microbolometer pcb. The location of the cream connector on that PCB correlates with where the microbolometer leads were most distorted and that is where I applied leverage to correct the distortion.She's alive, but not out of the woods yet. I want to do some tests on the DC-DC converters looking for unexpected noise on the microbolometer supply rails. Some monitoring of the Peltier element drive is also warranted. I will also need to investigate the inaccuracy of the spot readings. In full AUTO mode the camera tends to select a narrow span and that produces noise in the image, which is to be expected. Manual mode allowed to to produce a less noisy image but I remain concerned that this camera still has some issues to be found and resolved. This could get interestingThe bad news is that I am knackered and will need to take a short break from this project. I also have chores to complete to keep my wife happy. Watch this space fr the next stage in diagnosing this patients ailmentsI'll be back !Aurora

author: Fraser
author_rank: Super Contributor
timestamp: May 11, 2015, 02:23:33 pm
content: The images that I was seeing when the camera was first fired up after re-assembly and being aimed at a cup of boiling water. Note the temperature spans that were in operation in the pictures. Spot temperature measurement seems way off the mark. Emmissivity was not the issue here.Tests with the lens cap on got really weird as the camera selected narrow spans and there was temperature drifting in the images. The FFC event did correct this though. Damaged Peltier thermal coupling to the microbolometer die ?Not sure yet. Tests using a lens cap are never a great idea though as there is thermal energy passing out of the microbolometer through the optical path. I will do a proper test with a Black Body thermal source later.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: May 11, 2015, 02:38:17 pm
content: @Mike,I can confirm that the large unused pin on the microbolometer is not a ground connection to the capsule as it passes through a glass seal like the Peltier element supply pins adjacent to it.Hmmm some more study is needed of the original Honeywell Microbolometer Patents on which this microbolometer is based. I have them filed somewhere.Time to rest now thoughAurora

author: Fraser
author_rank: Super Contributor
timestamp: May 11, 2015, 03:09:56 pm
content: One last comment from me today.....I was told by a service agent for FLIR that the cameras that followed the PM Series were not as well built or mechanically robust. I consider the E2 to be proof of this statement. It really is a pretty poor design inside.Ignoring the 'bodge' wires, which I might add have been executed very well, it is the whole feel of the case and PCB retention mechanisms. They all feel very much like a prototype rather than a production unit. The main PCB is secured to one half of the case using quality screws and plastic embedded brass ferrules. The microbolometer sub-assembly that sits vertically behind it is quite frankly an appalling piece of engineering. Truly a joke. The plastic chassis is supposed to sandwich a heat-sink and thermal pads between two PCB's (Main and sub)....it doesn't do this well and the PCB's pop out of their tiny retaining clips. The thermal pads are not able to do their job as they are no longer in contact with the IC's that they are supposed to help cool.The sub-assembly has not a single screw on it. The heat-sink is used as the mounting for the sub assembly and a single aluminium arm extends down to the cameras tripod mounting where it is retained by a single screw. It is fair to say that apart from this single mounting point and the connector that joins the assembly to the main PCB, this thing is floatingCrazy when you realise that the heat-sink cools the main processor in the camera ! The heat-sink should be screwed down onto the main PCB to ensure good thermal transfer.More poor design is to be found in the display section. The LCD panel is placed into a carrier and little plastic clips are glued on either side of it to roughly retain it. The whole LCD panel is floating with no proper impact absorption material present. It is eventually held in place by fingering around the clear plastic screen ... read on, it gets better (or should that be worse?)...... the LCD display carrier also contains the rubber keypad. The LCD carrier and keypad are clipped onto the display PCB. The display PCB is free to move up and down in the clips by at least 2mmThat is to say, if you try to press a rubber keypad button, the PCB moves down and away from the panel by around 2mm ! So how is the display PCB kept in place ?...... not a retaining screw to be seen. The display PCB mates with a large connector on the top edge of the main PCB. The display case retaining screws sandwich the display board between the display case and the main PCB edge connector. Great design ..... NOT !What can I say ? It is certainly not one of FLIR's finest designs, and considering how expensive they were when new, I would go as far as to say it is shoddy workmanship by the mechanical design team.TTFNAurora

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 11, 2015, 06:33:56 pm
content: Line noise of the type you are seeing seems unlikely to be a thermal contact to the Peltier issue. Seems more likely to be an electronics issue, perhaps a dodgy ground or unconnected shield due to the construction shortcuts you have noted.Get your rest and keep enjoying this. I sure am enjoying following along. While I don't have CFS, I have noted that as I get older I can't keep up the intense thinking sessions I once did. It's OK, just takes longer to get to the end.

author: Fraser
author_rank: Super Contributor
timestamp: May 11, 2015, 07:51:12 pm
content: @CatalinaWOW,I completely concur, the line noise is not what I would expect of a Peltier issue. It is the images that show a cool middle with graduated halo's radiating out to a warmer border to the image. But even this does not resemble what I would expect of a separated Peltier element.I have witnessed the cold finger in a cooled AGEMA 550 separating from the die and causing a similar graduated halo effect, but that is a completely different technology. I am not even certain that the Peltier element can separate or whether it is an integral part of the microbolometer die.I will be focussing on the noise lines for now as they are something I can investigate further.Time to break out the oscilloscopesAurora

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 11, 2015, 08:15:46 pm
content: I'm sure I've seen reference to a getter in some microbolometer info somewhere.Of course the chemistry may be different to that used in valves, for one it's a direct connection as opposed to an induction coupling, so temp could be well controlled.A quick search for microbometer getter found this very detailed article on packaging:http://accessengineeringlibrary.com/pdfdownload/?contentId=advanced-mems-packaging%2Fp200199219970327001

author: SeanB
author_rank: Super Contributor
timestamp: May 11, 2015, 08:33:37 pm
content: Phillips developed some non sputtering getters a while ago, mostly used in sodium and MH lamps as a getter that does not cause a thermal stress area on the outer glass. They are small, reasonably active and will not sputter material. That would be perfect in this application in a pocket inside the metal envelope provided you can get them hot enough during pump down to activate them.

author: Fraser
author_rank: Super Contributor
timestamp: May 11, 2015, 08:47:02 pm
content: @Mike,Great find, Thank youThat document is very helpful in understanding the internal construction of the microbolometer and the out-gassing issues of the Peltier element.They show the getter in the vacuum pump down port. I have now learnt about modern getters as well. ExcellentHaving seen that the Peltier element is soldered to the microbolometer, it is highly unlikely that my E2 has suffered Peltier separationHappy days.Many Thanks for finding this and sharing.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: May 11, 2015, 08:55:24 pm
content: @SeanB,I was unaware of getters in microbolometers or in proximity to sensitive electronics. I studied thermionic valves where the getters are brutal thingsToday was a good day.......I learnt something new.Aurora

author: SeanB
author_rank: Super Contributor
timestamp: May 11, 2015, 09:06:06 pm
content: PIc here, with a little info.http://www.lamptech.co.uk/Spec%20Sheets/Philips%20SOXPSG35.htmClose up of the PSG pellet.http://www.lighting-gallery.net/gallery/displayimage.php?album=2854&pos=21&pid=80275