Tablet Reliability Test
A Tablet Computer, also known as a Tablet Personal Computer (Tablet PC), is a small, portable personal computer that uses a touch screen as its basic input device. It is an electronic product with strong mobility, and it can be seen everywhere in life (such as waiting stations, trains, high-speed trains, cafes, restaurants, meeting rooms, suburbs, etc.). People carry only simple coat protection or even no, in order to facilitate use, the design reduces the size, so that it can be directly placed in the pocket or handbag, backpack, but the tablet computer in the process of moving will also experience many environmental physical changes (such as temperature, humidity, vibration, impact, extrusion, etc.). Etc.) and natural damage (such as ultraviolet light, sunlight, dust, salt spray, water droplets... It will also cause artificial unintentional injury or abnormal operation and misoperation, and even cause failure and damage (such as: household chemicals, hand sweating, falling, terminal insertion and removal too much, pocket friction, crystal nails... These will shorten the life of the tablet computer, in order to ensure the reliability of the product and extend the service life to improve, we must carry out a number of environmental reliability test projects on the tablet computer, the following relevant tests for your reference.
Environmental test project description:
Simulate various harsh environments and reliability assessments used by tablet computers to test whether their performance meets the requirements; It mainly includes high and low temperature operation and high and low temperature storage, temperature and condensation, temperature cycle and shock, wet and heat combination test, ultraviolet, sunlight, drip, dust, salt spray and other tests.
Operating temperature range: 0℃ ~ 35℃/5% ~ 95%RH
Storage temperature range: -10℃ ~ 50℃/10% ~ 90%RH
Operating low temperature test: -10℃/2h/ power operation
Operating high temperature test: 40℃/8h/ all running
Storage low temperature test: -20℃/96h/ shutdown
Storage high temperature test: 60℃/96h/ shutdown
High temperature test of vehicle storage: 85℃/96h/ shutdown
Temperature shock: -40℃(30min)←→80℃(30min)/10cycle
Wet heat test: 40℃/95%R.H./48h/ power standby
Hot and humid cycle test: 40℃/95%R.H./1h→ramp:1℃/min→-10℃/1h, 20cycles, power standby
Wet heat test: 40℃/95%R.H./48h/ power standby
Hot and humid cycle test: 40℃/95%R.H./1h→ramp:1℃/min→-10℃/1h, 20cycles, power standby
Weather resistance test:
Simulation of the most severe natural conditions, solar thermal effect test, each cycle of 24 hours, 8 hours of continuous exposure, 16 hours to keep dark, each cycle radiation amount of 8.96 kWh/m2, a total of 10cycles.
Salt spray test:
5% sodium chloride solution/Water temperature 35°C/PH 6.5~7.2/24h/ Shutdown → Pure water wipe shell →55°C/0.5h→ Function test: after 2 hours, after 40/80%R.H./168h.
Dripping test: According to IEC60529, in line with IPX2 waterproof rating, can prevent water droplets falling at an Angle of less than 15 degrees from entering the tablet computer and causing damage. Test conditions: water flow rate 3mm/min, 2.5min at each position, checkpoint: after test, 24 hours later, standby for 1 week.
Dust Test:
According to IEC60529, in line with the IP5X dust class, can not completely prevent the entry of dust but does not affect the device should be the action and anquan, in addition to tablet computers are currently many personal mobile portable 3C products commonly used dust standards, such as: mobile phones, digital cameras, MP3, MP4... Let's wait.
Conditions:
Dust sample 110mm/3 ~ 8h/ test for dynamic operation
After the test, a microscope is used to detect whether dust particles will enter the interior space of the tablet.
Chemical staining test:
Confirm the external components related to the tablet, confirm the chemical resistance of household chemicals, chemicals: sunscreen, lipstick, hand cream, mosquito repellent, cooking oil (salad oil, sunflower oil, olive oil... Etc.), the test time is 24 hours, check the color, gloss, surface smoothness... Etc., and confirm whether there are bubbles or cracks.
Mechanical test:
Test the strength of the mechanical structure of the tablet computer and the wear resistance of the key components; Mainly includes vibration test, drop test, impact test, plug test, and wear test... Etc.
Fall test: The height of 130cm, free fall on the smooth soil surface, each side fell 7 times, 2 sides a total of 14 times, tablet computer in standby state, each fall, the function of the test product is checked.
Repeated drop test: the height of 30cm, free drop on the smooth dense surface of 2cm thickness, each side fell 100 times, each interval of 2s, 7 sides a total of 700 times, every 20 times, check the function of the experimental product, tablet computer is in the state of power.
Random vibration test: frequency 30 ~ 100Hz, 2G, axial: three axial. Time: 1 hour in each direction, for a total of three hours, the tablet is in standby mode.
Screen impact resistance test: 11φ/5.5g copper ball fell on the center surface of 1m object at 1.8m height and 3ψ/9g stainless steel ball fell at 30cm height
Screen writing durability: more than 100,000 words (width R0.8mm, pressure 250g)
Screen touch durability: 1 million, 10 million, 160 million, 200 million times or more (width R8mm, hardness 60°, pressure 250g, 2 times per second)
Screen flat press test: the diameter of the rubber block is 8mm, the pressure speed is 1.2mm/min, the vertical direction is 5kg force flat press the window 3 times, each time for 5 seconds, the screen should display normally.
Screen front flat press test: The entire contact area, the direction of the vertical 25kg force front flat press each side of the tablet computer, for 10 seconds, flat press 3 times, there should be no abnormal.
Earphone plug and remove test: Insert the earphone vertically into the earphone hole, and then pull it out vertically. Repeat this for more than 5000 times
I/O plug and pull test: The tablet is in standby state, and the plug terminal connector is pulled out, a total of more than 5000 times
Pocket friction test: Simulate various materials pocket or backpack, the tablet is repeatedly rubbed in the pocket 2,000 times (friction test will also add some mixed dust particles, including dust particles, yan grass particles, fluff and paper particles for mixing test).
Screen hardness test: hardness greater than class 7 (ASTM D 3363, JIS 5400)
Screen impact test: hit the most vulnerable sides and center of the panel with a force of more than 5㎏
Concentrator Solar Cell
A concentrating solar cell is a combination of [Concentrator Photovoltaic]+[Fresnel Lenes]+[Sun Tracker]. Its solar energy conversion efficiency can reach 31% ~ 40.7%, although the conversion efficiency is high, but due to the long sunward time, it has been used in the space industry in the past, and now it can be used in the power generation industry with sunlight tracker, which is not suitable for general families. The main material of concentrating solar cells is gallium arsenide (GaAs), that is, the three five group (III-V) materials. General silicon crystal materials can only absorb the energy of 400 ~ 1,100nm wavelength in the solar spectrum, and the concentrator is different from silicon wafer solar technology, through the multi-junction compound semiconductor can absorb a wider range of solar spectrum energy, and the current development of three-junction InGaP/GaAs/Ge concentrator solar cells can greatly improve the conversion efficiency. The three-junction concentrating solar cell can absorb energy of 300 ~ 1900nm wavelength relative to its conversion efficiency can be greatly improved, and the heat resistance of concentrating solar cells is higher than that of general wafer-type solar cells.
Conduction Zone of Heat
Thermal conductivity
It is the thermal conductivity of a substance, passing from high temperature to low temperature within the same substance. Also known as: thermal conductivity, thermal conductivity, thermal conductivity, heat transfer coefficient, heat transfer, thermal conductivity, thermal conductivity, thermal conductivity, thermal conductivity.
Thermal conductivity formula
k = (Q/t) *L/(A*T) k: thermal conductivity, Q: heat, t: time, L: length, A: area, T: temperature difference in SI units, the unit of thermal conductivity is W/(m*K), in imperial units, is Btu · ft/(h · ft2 · °F)
Heat transfer coefficient
In thermodynamics, mechanical engineering and chemical engineering, the heat conductivity is used to calculate the heat conduction, mainly the heat conduction of convection or the phase transformation between fluid and solid, which is defined as the heat through the unit area per unit time under the unit temperature difference, called the heat conduction coefficient of the substance, if the thickness of the mass of L, the measurement value to be multiplied by L, The resulting value is the coefficient of thermal conductivity, usually denoted as k.
Unit conversion of heat conduction coefficient
1 (CAL) = 4.186 (j), 1 (CAL/s) = 4.186 (j/s) = 4.186 (W).
The impact of high temperature on electronic products:
The rise in temperature will cause the resistance value of the resistor to decrease, but also shorten the service life of the capacitor, in addition, the high temperature will cause the transformer, the performance of the related insulation materials to decrease, the temperature is too high will also cause the solder joint alloy structure on the PCB board to change: IMC thickens, solder joints become brittle, tin whisker increases, mechanical strength decreases, junction temperature increases, the current amplification ratio of transistor increases rapidly, resulting in collector current increases, junction temperature further increases, and finally component failure.
Explanation of proper terms:
Junction Temperature: The actual temperature of a semiconductor in an electronic device. In operation, it is usually higher than the Case Temperature of the package, and the temperature difference is equal to the heat flow multiplied by the thermal resistance. Free convection (natural convection) : Radiation (radiation) : Forced Air(gas cooling) : Forced Liquid (gas cooling) : Liquid Evaporation: Surface Surroundings Surroundings
Common simple considerations for thermal design:
1 Simple and reliable cooling methods such as heat conduction, natural convection and radiation should be used to reduce costs and failures.
2 Shorten the heat transfer path as much as possible, and increase the heat exchange area.
3 When installing components, the influence of radiation heat exchange of peripheral components should be fully considered, and the thermal sensitive devices should be kept away from the heat source or find a way to use the protective measures of the heat shield to isolate the components from the heat source.
4 There should be sufficient distance between the air inlet and the exhaust port to avoid hot air reflux.
5 The temperature difference between the incoming air and the outgoing air should be less than 14 ° C.
6 It should be noted that the direction of forced ventilation and natural ventilation should be consistent as far as possible.
7 Devices with large heat should be installed as close as possible to the surface that is easy to dissipate heat (such as the inner surface of the metal casing, metal base and metal bracket, etc.), and there is good contact heat conduction between the surface.
8 Power supply part of the high-power tube and rectifier bridge pile belong to the heating device, it is best to install directly on the housing to increase the heat dissipation area. In the layout of the printed board, more copper layers should be left on the board surface around the larger power transistor to improve the heat dissipation capacity of the bottom plate.
9 When using free convection, avoid using heat sinks that are too dense.
10 The thermal design should be considered to ensure that the current carrying capacity of the wire, the diameter of the selected wire must be suitable for the conduction of the current, without causing more than the allowable temperature rise and pressure drop.
11 If the heat distribution is uniform, the spacing of the components should be uniform to make the wind flow evenly through each heat source.
12 When using forced convection cooling (fans), place the temperature-sensitive components closest to the air intake.
13 The use of free convection cooling equipment to avoid arranging other parts above the high power consumption parts, the correct approach should be uneven horizontal arrangement.
14 If the heat distribution is not uniform, the components should be sparsely arranged in the area with large heat generation, and the component layout in the area with small heat generation should be slightly denser, or add a diversion bar, so that the wind energy can effectively flow to the key heating devices.
15 The structural design principle of the air inlet: on the one hand, try to minimize its resistance to the air flow, on the other hand, consider dust prevention, and comprehensively consider the impact of the two.
16 Power consumption components should be spaced as far apart as possible.
17 Avoid crowding temperature sensitive parts together or arranging them next to high power consuming parts or hot spots.
18 The use of free convection cooling equipment to avoid arranging other parts above the high power consumption parts, the correct practice should be uneven horizontal arrangement.
AEC-Q100- Failure Mechanism Based on Integrated Circuit Stress Test Certification
With the progress of automotive electronic technology, there are many complicated data management control systems in today's cars, and through many independent circuits, to transmit the required signals between each module, the system inside the car is like the "master-slave architecture" of the computer network, in the main control unit and each peripheral module, automotive electronic parts are divided into three categories. Including IC, discrete semiconductor, passive components three categories, in order to ensure that these automotive electronic components meet the highest standards of automotive anquan, the American Automotive Electronics Association (AEC, The Automotive Electronics Council is a set of standards [AEC-Q100] designed for active parts [microcontrollers and integrated circuits...] and [[AEC-Q200] designed for passive components, which specifies the product quality and reliability that must be achieved for passive parts. Aec-q100 is the vehicle reliability test standard formulated by the AEC organization, which is an important entry for 3C and IC manufacturers into the international auto factory module, and also an important technology to improve the reliability quality of Taiwan IC. In addition, the international auto factory has passed the anquan standard (ISO-26262). AEC-Q100 is the basic requirement to pass this standard.
List of automotive electronic parts required to pass AECQ-100:
Automotive disposable memory, Power Supply step-down regulator, Automotive photocoupler, three-axis accelerometer sensor, video jiema device, rectifier, ambient light sensor, non-volatile ferroelectric memory, power management IC, embedded flash memory, DC/DC regulator, Vehicle gauge network communication device, LCD driver IC, Single power Supply differential Amplifier, Capacitive proximity switch Off, high brightness LED driver, asynchronous switcher, 600V IC, GPS IC, ADAS Advanced Driver Assistance System Chip, GNSS Receiver, GNSS front-end amplifier... Let's wait.
AEC-Q100 Categories and Tests:
Description: AEC-Q100 specification 7 major categories a total of 41 tests
Group A- ACCELERATED ENVIRONMENT STRESS TESTS consists of 6 tests: PC, THB, HAST, AC, UHST, TH, TC, PTC, HTSL
Group B- ACCELERATED LIFETIME SIMULATION TESTS consists of three tests: HTOL, ELFR, and EDR
PACKAGE ASSEMBLY INTEGRITY TESTS consists of 6 tests: WBS, WBP, SD, PD, SBS, LI
Group D- DIE FABRICATION RELIABILITY Test consists of 5 TESTS: EM, TDDB, HCI, NBTI, SM
The group ELECTRICAL VERIFICATION TESTS consist of 11 tests, including TEST, FG, HBM/MM, CDM, LU, ED, CHAR, GL, EMC, SC and SER
Cluster F-Defect SCREENING TESTS: 11 tests, including: PAT, SBA
The CAVITY PACKAGE INTEGRITY TESTS consist of 8 tests, including: MS, VFV, CA, GFL, DROP, LT, DS, IWV
Short description of test items:
AC: Pressure cooker
CA: constant acceleration
CDM: electrostatic discharge charged device mode
CHAR: indicates the feature description
DROP: The package falls
DS: chip shear test
ED: Electrical distribution
EDR: non-failure-prone storage durability, data retention, working life
ELFR: Early life failure rate
EM: electromigration
EMC: Electromagnetic compatibility
FG: fault level
GFL: Coarse/fine air leakage test
GL: Gate leakage caused by thermoelectric effect
HBM: indicates the human mode of electrostatic discharge
HTSL: High temperature storage life
HTOL: High temperature working life
HCL: hot carrier injection effect
IWV: Internal hygroscopic test
LI: Pin integrity
LT: Cover plate torque test
LU: Latching effect
MM: indicates the mechanical mode of electrostatic discharge
MS: Mechanical shock
NBTI: rich bias temperature instability
PAT: Process average test
PC: Preprocessing
PD: physical size
PTC: power temperature cycle
SBA: Statistical yield analysis
SBS: tin ball shearing
SC: Short circuit feature
SD: weldability
SER: Soft error rate
SM: Stress migration
TC: temperature cycle
TDDB: Time through dielectric breakdown
TEST: Function parameters before and after stress test
TH: damp and heat without bias
THB, HAST: Temperature, humidity or high accelerated stress tests with applied bias
UHST: High acceleration stress test without bias
VFV: random vibration
WBS: welding wire cutting
WBP: welding wire tension
Temperature and humidity test conditions finishing:
THB(temperature and humidity with applied bias, according to JESD22 A101) : 85℃/85%R.H./1000h/bias
HAST(High Accelerated stress test according to JESD22 A110) : 130℃/85%R.H./96h/bias, 110℃/85%R.H./264h/bias
AC pressure cooker, according to JEDS22-A102:121 ℃/100%R.H./96h
UHST High acceleration stress test without bias, according to JEDS22-A118, equipment: HAST-S) : 110℃/85%R.H./264h
TH no bias damp heat, according to JEDS22-A101, equipment: THS) : 85℃/85%R.H./1000h
TC(temperature cycle, according to JEDS22-A104, equipment: TSK, TC) :
Level 0: -50℃←→150℃/2000cycles
Level 1: -50℃←→150℃/1000cycles
Level 2: -50℃←→150℃/500cycles
Level 3: -50℃←→125℃/500cycles
Level 4: -10℃←→105℃/500cycles
PTC(power temperature cycle, according to JEDS22-A105, equipment: TSK) :
Level 0: -40℃←→150℃/1000cycles
Level 1: -65℃←→125℃/1000cycles
Level 2 to 4: -65℃←→105℃/500cycles
HTSL(High temperature storage life, JEDS22-A103, device: OVEN) :
Plastic package parts: Grade 0:150 ℃/2000h
Grade 1:150 ℃/1000h
Grade 2 to 4:125 ℃/1000h or 150℃/5000h
Ceramic package parts: 200℃/72h
HTOL(High temperature working life, JEDS22-A108, equipment: OVEN) :
Grade 0:150 ℃/1000h
Class 1:150℃/408h or 125℃/1000h
Grade 2:125℃/408h or 105℃/1000h
Grade 3:105℃/408h or 85℃/1000h
Class 4:90℃/408h or 70℃/1000h
ELFR(Early Life failure Rate, AEC-Q100-008) : Devices that pass this stress test can be used for other stress tests, general data can be used, and tests before and after ELFR are performed under mild and high temperature conditions.
Equipo de prueba ambiental de confiabilidad combinado con aplicaciones de detección y control de temperatura de múltiples pistasEl equipo de prueba ambiental incluye una cámara de prueba de temperatura y humedad constante, una cámara de prueba de choque frío y caliente, una cámara de prueba de ciclo de temperatura, un horno sin viento... Todos estos equipos de prueba se encuentran en un entorno simulado de temperatura y humedad que impactan en el producto, para averiguarlo. El proceso de diseño, producción, almacenamiento, transporte y uso puede aparecer defectos del producto, anteriormente solo se simulaba la temperatura del aire del área de prueba, pero en los nuevos estándares internacionales y las nuevas condiciones de prueba de la fábrica internacional, el comienzo de los requisitos basados en la temperatura del aire. no lo es. Es la temperatura de la superficie del producto de prueba. Además, la temperatura de la superficie también debe medirse y registrarse sincrónicamente durante el proceso de prueba para el análisis posterior a la prueba. El equipo de prueba ambiental relevante debe combinarse con el control de la temperatura de la superficie y la aplicación de la medición de la temperatura de la superficie se resume a continuación. Aplicación de detección de temperatura de la mesa de prueba de la cámara de prueba de temperatura y humedad constantes: Descripción: Cámara de prueba de temperatura y humedad constantes en el proceso de prueba, combinada con detección de temperatura multipista, alta temperatura y humedad, condensación (condensación), temperatura y humedad combinadas, ciclo de temperatura lento... Durante el proceso de prueba, el sensor fijado a la superficie del producto de prueba, que se puede utilizar para medir la temperatura de la superficie o la temperatura interna del producto de prueba. A través de este módulo de detección de temperatura de múltiples pistas, las condiciones establecidas, la temperatura y humedad reales, la temperatura de la superficie del producto de prueba y la misma medición y registro se pueden integrar en un archivo de curva sincrónico para su posterior almacenamiento y análisis.Aplicaciones de detección y control de temperatura de la superficie de la cámara de prueba de choque térmico: [tiempo de permanencia basado en el control de la temperatura de la superficie], [registro de medición de la temperatura de la superficie del proceso de choque de temperatura] Descripción: El sensor de temperatura de 8 rieles se fija a la superficie del producto de prueba y se aplica al proceso de choque de temperatura. El tiempo de permanencia se puede contar hacia atrás según la llegada de la temperatura superficial. Durante el proceso de impacto, las condiciones de fraguado, la temperatura de prueba, la temperatura de la superficie del producto de prueba y la misma medición y registro se pueden integrar en una curva sincrónica.Aplicación de detección y control de temperatura de la superficie de la cámara de prueba del ciclo de temperatura: [La variabilidad de la temperatura del ciclo de temperatura y el tiempo de permanencia se controlan de acuerdo con la temperatura de la superficie del producto de prueba] Descripción: La prueba del ciclo de temperatura es diferente de la prueba de choque de temperatura. La prueba de choque de temperatura utiliza la energía máxima del sistema para realizar cambios de temperatura entre temperaturas altas y bajas, y su tasa de cambio de temperatura es tan alta como 30 ~ 40 ℃ /min. La prueba del ciclo de temperatura requiere un proceso de cambios de temperatura alta y baja, y su variabilidad de temperatura se puede configurar y controlar. Sin embargo, las nuevas especificaciones y las condiciones de prueba de los fabricantes internacionales han comenzado a exigir que la variabilidad de la temperatura se refiera a la temperatura de la superficie del producto de prueba, no a la temperatura del aire, y el control de variabilidad de la temperatura de la especificación del ciclo de temperatura actual. Según las especificaciones de la superficie del producto de prueba son [JEDEC-22A-104F, IEC60749-25, IPC9701, ISO16750, AEC-Q100, LV124, GMW3172]... Además, el tiempo de residencia de temperaturas altas y bajas también puede basarse en la superficie de prueba, en lugar de la temperatura del aire.Aplicaciones de detección y control de temperatura de la superficie de la cámara de prueba de detección de estrés cíclico de temperatura: Instrucciones: Máquina de prueba de detección de tensión por ciclo de temperatura, combinada con medición de temperatura de múltiples rieles, en la variabilidad de temperatura de la detección de tensión, puede optar por usar [temperatura del aire] o [temperatura de la superficie del producto de prueba] para controlar la variabilidad de la temperatura, además, En el proceso residente de alta y baja temperatura, el tiempo recíproco también se puede controlar según la superficie del producto de prueba. De acuerdo con las especificaciones pertinentes (GJB1032, IEST) y los requisitos de las organizaciones internacionales, de acuerdo con la definición de GJB1032 en el punto de medición de temperatura y tiempo de residencia de detección de tensión, 1. El número de termopares fijados en el producto no será inferior a 3, y el punto de medición de temperatura del sistema de enfriamiento no deberá ser inferior a 6, 2. Asegúrese de que la temperatura de 2/3 de los termopares del producto esté establecida en ±10 ℃, además, de acuerdo con los requisitos de IEST (Internacional Association for Environmental Science and Technology), el tiempo de residencia debe alcanzar el tiempo de estabilización de temperatura más 5 minutos o el tiempo de prueba de rendimiento. Aplicación de detección de temperatura de superficie sin horno de aire (cámara de prueba de convección natural): Descripción: Mediante la combinación de un horno sin viento (cámara de prueba de convección natural) y un módulo de detección de temperatura multipista, se genera la temperatura ambiente sin ventilador (convección natural) y se integra la prueba de detección de temperatura relevante. Esta solución se puede aplicar a la prueba de temperatura ambiente real de productos electrónicos (como: servidor en la nube, 5G, interior de vehículos eléctricos, ambiente interior sin aire acondicionado, inversor solar, televisor LCD grande, compartidor de Internet en el hogar, oficina 3C, computadora portátil, computadora de escritorio). , consola de juegos....... Etc.).
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