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Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
Athira seminar
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Athira seminar

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my seminar on moisture measurement ..it s unique

my seminar on moisture measurement ..it s unique

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  • 1. WELCOME8/3/2013 DEPT ECE,SNMIMT,Maliankara 1
  • 2. SEMINAR ONPRESENTED BYATHIRA M JOSHYROLL NO:14,S8 ECE8/3/2013 DEPT ECE,SNMIMT,Maliankara 2
  • 3. CONTENTS INTRODUCTION MOISTURE MEASUREMENT INSIDE ELECTRONIC DEVICES MOISTURE MEASUREMENT OF SKIN BLOCK DIAGRAM OVERVIEW MOISTURE MEASUREMENT IN PCB EXPERIMENTAL SETUP MODELLING PTH AND NON-PTH IN COPPER PLANES ADVANTAGES DISADVANTAGES FUTURE SCOPE CONCLUSION REFERENCE8/3/2013 DEPT ECE,SNMIMT,Maliankara 3Moisture Measurement
  • 4.  Moisture is the amount of water in any form in a material It is a component of molecular makeup for all material Excessive or deficient moisture adversely impact the physicalproperties of a materialINTRODUCTION8/3/2013 DEPT ECE,SNMIMT,Maliankara 4Moisture Measurement
  • 5. BLOCKDIAGRAM MeasurementPrimaryAir ovenSecondaryDestructive Non-DestructiveInterdigital capacitor Ultracapacitor8/3/2013 DEPT ECE,SNMIMT,Maliankara 5Moisture Measurement
  • 6. MOISTURE MEASUREMENT INSIDEELECTRONIC DEVICESUSING ULTRACAPACITOR Ultracapacitor:Electrochemical capacitor with relatively highenergy density Lack of dielectric permits packaging of plates with largesurface area into a given volume Formed of ordinary activated carbon electrodes8/3/2013 DEPT ECE,SNMIMT,Maliankara 6Moisture Measurement
  • 7. CONTD… No liquid electrolyte exists inside the device Electrodes are placed on both sides of a layer of poroussilicon Potassium hydroxide in powder form is embedded insideporous silicon Useful for monitoring moisture penetration inside smallelectronic devices8/3/2013 DEPT ECE,SNMIMT,Maliankara 7Moisture Measurement
  • 8. CONTD… As moisture penetrates the porous silicon layer, a liquidelectrolyte starts to form Presence of moisture causes:• Conductivity of electrolyte increases• Hence the capacitance of the ultracapacitor increases• Results in high capacitance8/3/2013 DEPT ECE,SNMIMT,Maliankara 8Moisture Measurement
  • 9. CONTD…Ultracapacitor (dry, without electrolyte) (with electrolyte)8/3/2013 DEPT ECE,SNMIMT,Maliankara 9Moisture Measurement
  • 10. CONTD…8/3/2013 DEPT ECE,SNMIMT,Maliankara10Capacitance with relative humidity (5-80)% of MC causes (0-17) μFMoisture Measurement
  • 11. MOISTURE MEASUREMENT OF SKIN Importance: Needed for the identification and prevention ofECZYMA Method adopted for skin moisture measurement:capacitancemethod(Interdigital Capacitor)Mild case of eczyma8/3/2013 DEPT ECE,SNMIMT,Maliankara 11Moisture Measurement
  • 12. CONTD… Stratum corneum is the outermost layer of the skin It is composed of dead skin cells, a protein calledKeratin, naturally secreted oils Dry skin exhibits a lack of oils results in cracking of thestratum corneum8/3/2013 DEPT ECE,SNMIMT,Maliankara 12Moisture Measurement
  • 13. CONTD…8/3/2013 DEPT ECE,SNMIMT,Maliankara 13Stratum corneumMoisture Measurement
  • 14. BLOCK DIAGRAM8/3/2013 DEPT ECE,SNMIMT,Maliankara 14INTERDIGITALCAPACITANCECAPACITANCEMEASURINGCIRCUITMICROCONTROLLERDISPLAYMoisture Measurement
  • 15. CONTD…INTERDIGITAL CAPACITOR: IDC is the core component in capacitance method It contains thin strips of copper Moisture is measured as proportional increase in capacitance8/3/2013 DEPT ECE,SNMIMT,Maliankara 15Moisture Measurement
  • 16. CONTD… SCATTERFIELD EFFECT:• Deviation of the linear path from one plate to the other• Important concept in the design of an IDC8/3/2013 DEPT ECE,SNMIMT,Maliankara 16Moisture MeasurementInterdigital capacitance
  • 17. CONTD…CAPACITANCE MEASURING CIRCUIT: Circuit to measure the increase in capacitance is required “Add on capacitance meter” is used for the purpose Add on capacitance circuit is used to identify capacitors of therange 1pF to 100pF8/3/2013 DEPT ECE,SNMIMT,Maliankara 17Moisture Measurement
  • 18. CONTD…8/3/2013 DEPT ECE,SNMIMT,Maliankara 18Add on capacitance circuitMoisture Measurement
  • 19. CONTD…8/3/2013 DEPT ECE,SNMIMT,Maliankara 19 Circuit charges the test capacitor via a resistor selected by therotary switch Circuit charges the largest capacitor (in the range) in exactly100 units of time Voltmeter works only when the pin 6 of 74c14 IC is low Voltmeter gives the reading corresponding to the testcapacitanceMoisture Measurement
  • 20. CONTD…MICROCONTROLLER : Project incoporates AVR butterfly microcontroller It has an ADC converter built in, labelled as Voltage V_in Microcontroller takes data from the ADC port (V_in) andperforms the conversion It produces a value of 0 on the display when the device isturned on and IDC is exposed to air8/3/2013 DEPT ECE,SNMIMT,Maliankara 20Moisture Measurement
  • 21. CONTD…8/3/2013 DEPT ECE,SNMIMT,Maliankara 21AVR butterfly microcontroller kitMoisture Measurement
  • 22. RESULTSKIN TYPE VALUE DISPLAYED ON LCDMoist skin 10-12Normal skin 4-9Dry skin 1-38/3/2013 DEPT ECE,SNMIMT,Maliankara 22
  • 23. CONTD…8/3/2013 DEPT ECE,SNMIMT,Maliankara 23Complete circuit of moisture sensorMoisture Measurement
  • 24. MOISTURE MEASUREMENT IN PCBEFFECTS OF MOISTURE IN PCB : Moisture reduces the quality of lamination and solder Excessive moisture increases dielectric constant leading tochanges in circuit switching speed Ionic corrosion causes electrical open circuit or short circuit High levels of residual moisture in PCBs causes delaminationduring soldering8/3/2013 DEPT ECE,SNMIMT,Maliankara 24Moisture Measurement
  • 25. CONTD… Moisture enters the PCB when the partial pressure of themoisture is greater to that inside the PCB Focused on capacitance measurements to follow theabsorption and desorption behaviour of moisture Capacitance is dependent on permitivity (which is dependenton moisture)8/3/2013 DEPT ECE,SNMIMT,Maliankara 25Moisture Measurement
  • 26. DELAMINATED PCB8/3/2013 DEPT ECE,SNMIMT,Maliankara 26Moisture Measurement
  • 27. EXPERIMENTAL SETUP Test boards are designed with capacitors situated on innerlayers between external copper planes It is placed in 85°C and 85 per cent relative humidity (RH)environment Moisture removal at bake temperatures of 80, 110 and 125°Cis monitered Capacitance is periodically measured at a frequency of 100kHz8/3/2013 DEPT ECE,SNMIMT,Maliankara 27Moisture Measurement
  • 28. 8/3/2013 DEPT ECE,SNMIMT,Maliankara 28(a)Test board showing plated and non-plated through holesat different densities (b) Illustration of the internal gridcapacitorsDimensioned capacitor designMoisture Measurement
  • 29. CAPACITANCE MEASURED8/3/2013 DEPT ECE,SNMIMT,Maliankara 29Effect of non-PTH hole density on average capacitance decrease for the test boards baked at (a)80°C, (b) 110°C and (c) 125°CMoisture Measurement
  • 30. CONTD…8/3/2013 DEPT ECE,SNMIMT,Maliankara 30Comparison of PTH and non-PTH on the capacitance decrease with bake time at 125°C forthree hole densitiesMoisture Measurement
  • 31. CONTD… Average capacitance decreases more quickly for higher holedensities due to the increase in surface area Capacitance decreases faster for boards with non-PTH suchboards require shorter bake time PTH boards have a smaller exposed surface area than non-PTH boards so moisture cannot escape so easily8/3/2013 DEPT ECE,SNMIMT,Maliankara 31Moisture Measurement
  • 32. MODELLING PTH AND NON-PTH INCOPPER PLANES Modelling is done to compare different moisture desorptioncapability of PTH and non-PTH boards during a baking Model boards are subjected to stimulated baking Model consisted of a PCB with a 0.4 mm hole repeatedinfinitely in both x and y directions and with a pitch of 4 mm Extra model was created to represent copper planes on innerlayers only8/3/2013 DEPT ECE,SNMIMT,Maliankara 32Moisture Measurement
  • 33. CONTD…8/3/2013 DEPT ECE,SNMIMT,Maliankara 33(a) Non-PTH with copper plane on outer layers, (b) PTH with copper plane on ouer layers and(c) PTH with internal copper planesMoisture Measurement
  • 34. MODELLED MOISTURE PROFILE :8/3/2013 DEPT ECE,SNMIMT,Maliankara 34Modelled moisture profile (a) non-PTH with copper plane on outerlayers, (b) PTH with copper plane on outer layers and (c) PTH withinternal copper planesMoisture MeasurementCONTD…
  • 35. CONTD… Dark blue colour represents saturation and light yellow as dryregions Moisture exits non-PTH PCB model more quickly as moisturecan escape more easily from the greater open surface area For PTH board, rate of moisture loss is slower as moisturemust diffuse a greater distance to find surface free fromcopper For boards with internal copper planes moisture rapidly existsfirst,then becomes slow8/3/2013 DEPT ECE,SNMIMT,Maliankara 35Moisture Measurement
  • 36. CONTD…8/3/2013 DEPT ECE,SNMIMT,Maliankara 36Modelled effect of bake time on the mean moisture content in the centralregion (1 mm off the copper plane) in boards PTH and non-PTH boards.Moisture Measurement
  • 37. ADVANTAGESULTRACAPACITOR SKIN MOISTURE SENSORLong life High accuracyLow cost portabilityExtremely low internal resistance inexpensiveHigh output power and Improved safety8/3/2013 DEPT ECE,SNMIMT,Maliankara 37Moisture Measurement
  • 38. DISADVANTAGESULTRACAPACITOR SKIN MOISTURE SENSORHighest dielectric absorption Difficulty in producing the deviceLow maximum voltage Not a handheld deviceHigh self discharge8/3/2013 DEPT ECE,SNMIMT,Maliankara 38Moisture Measurement
  • 39. FUTURE SCOPESCOPE OF ULTRACAPACITOR IN PACEMAKER: Pacemaker helps to monitor and control your heartbeat It consists of a battery, a computerized generator, and wireswith sensors at their tips Malfunction can occur if moisture happens to be inside thedevice Ultracapacitor can be used inside the device to check theamount of moisture8/3/2013 DEPT ECE,SNMIMT,Maliankara 39Moisture Measurement
  • 40. CONTD…8/3/2013 DEPT ECE,SNMIMT,Maliankara 40Pacemaker implanted inside human bodyMoisture Measurement
  • 41. CONCLUSION8/3/2013 DEPT ECE,SNMIMT,Maliankara 41FoodMedicineIndustryRELEVANCECONCLUSION7/2/2013 DEPTOF ECE,SNMIMT,Maliankara 42Moisture Measurement
  • 42. CONTD… A processed materials MC will define its physical properties atall stages of processing and final product existence Non-destructive methods are preferred andeach methoddiscussed has specific applications Moisture analysis means testing at the point ofprocessing, and making adjustments before product integrityis effected8/3/2013 DEPT ECE,SNMIMT,Maliankara 42Moisture Measurement
  • 43. REFERENCE Design of a handheld skin moisture measuring device for applicationtowards eczema, By Scott Truong Moisture measurements in pcbs and impact of design on desorptionbehaviour , Chris Hunt,, National Physical Laboratory, UK N.P. Avdelidis, P. I. Nicholson & P. Wallace, ”Pulsed thermography in theinvestigation of PCBs for defect detection & analysis”, www.wikipedia.org www.ecma-international.org8/3/2013 DEPT ECE,SNMIMT,Maliankara 43Moisture Measurement
  • 44. 8/3/2013 DEPT ECE,SNMIMT,Maliankara 44Moisture Measurement
  • 45. 8/3/2013 DEPT ECE,SNMIMT,Maliankara 45Moisture Measurement

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