Vibrational Verification for Functionality(VVF)
In the vibration generated during transportation, freight boxes are susceptible to complex dynamic pressures, and the resonant response generated is violent, which may cause packaging or product failure. Identifying the critical frequency and the type of pressure on the package will minimize this failure. Vibration testing is the assessment of the vibration resistance of components, components and complete machines in the expected transport, installation and use environment.
Common vibration modes can be divided into sinusoidal vibration and random vibration. Sinusoidal vibration is a test method often used in the laboratory, which mainly simulates the vibration generated by rotation, pulsation and oscillation, as well as the resonance frequency analysis and resonance point residence verification of the product structure. It is divided into sweep frequency vibration and fixed frequency vibration, and its severity depends on the frequency range, amplitude value and test duration. Random vibration is used to simulate the overall structural seismic strength assessment of the product and the shipping environment in the packaged state, with the severity depending on the frequency range, GRMS, test duration and axial orientation.
Vibration can not only loosen the lamp components, so that the internal relative displacement, resulting in de-welding, poor contact, poor working performance, but also make the components produce noise, wear, physical failure and even component fatigue.
To this end, Lab Companion launched a professional "LED lamp vibration test" business to simulate the vibration or mechanical shock that may occur in the actual transportation, installation and use environment of the lamp, evaluate the vibration resistance of the LED lamp and the stability of its related performance indicators, and find the weak link that may cause damage or failure. Improve the overall reliability of LED products and improve the failure status of the industry due to transportation or other mechanical shocks.
Service customers: LED lighting factory, lighting agents, lighting dealers, decoration companies
Test method:
1, the LED lamp sample packaging placed on the vibration test bench;
2, the vibration speed of the vibration tester is set to 300 RPM, the amplitude is set to 2.54 cm, start the vibration meter;
3, the lamp according to the above method in the upper and lower, left and right, front and back three directions respectively test for 30 minutes.
Results evaluation: After the vibration test, the lamp can not occur parts falling off, structural damage, lighting and other abnormal phenomena.
Double 85 Constant Temperature And Humidity Reliability Environmental Test (THB)
First, high temperature and humidity test
WHTOL (Wet High Temperature Operating Life) is a common environmental stress acceleration test, usually 85℃ and 85% relative humidity, which is generally carried out in accordance with the standard IEC 60068-2-67-2019. The test conditions are shown in the chart.
Second, the test principle
"Double 85 test" is one of the reliability environmental tests, mainly used for constant temperature and humidity box, that is, the temperature of the box is set to 85℃, the relative humidity is set to 85%RH conditions, to accelerate the aging of the test product. Although the test process is simple, the test is an important method to evaluate many characteristics of the test product, so it has become an indispensable reliability environmental test condition in various industries.
After aging the product under the condition of 85℃/85%RH, compare the performance changes of the product before and after aging, such as the photoelectric performance parameters of the lamp, the mechanical properties of the material, yellow index, etc., the smaller the difference, the better, so as to test the heat and moisture resistance of the product.
The product may have thermal failure when working in a continuous high temperature environment, and some moisture sensitive devices will fail in a high humidity environment. The dual 85 test can test the thermal stress generated by the product under high humidity and its ability to resist long-term moisture penetration. For example, the frequent failure of various products in the humid weather period in the south is mainly due to the poor temperature and humidity resistance of the products.
3. Experimental factors
In the LED lighting industry, many manufacturers have used the double 85 test results as an important means to judge the quality of lamps. Various possible reasons why LED lamps fail the dual 85 test are:
1. Lamp power supply: poor heat resistance of shell, danger of short circuit in circuit, failure of protection mechanism, etc.
2. Lamp structure: unreasonable design of heat dissipation body, installation problems, materials are not resistant to high temperature.
3. Lamp light source: poor moisture resistance, packaging adhesive aging, high temperature resistance.
If you encounter a special use environment, such as the working environment temperature is severe, you need to test its high and low temperature resistance, the test method can refer to the high and low temperature test project.
4. Serve customers
01. Customer group
LED lighting factory, LED power plant, LED packaging factory
02. Means of detection
Constant temperature and humidity test chamber
03. Reference standards
Constant temperature and humidity tests for electrical and electronic products -- Environmental testing -- Part 2: Test methods -- Test Cab: Constant temperature and humidity test GB/T 2423.3-2006.
04. Service content
4.1 Refer to the standard, conduct double 85 test on the product, and provide the third party's test results report.
4.2 Provide the analysis and improvement plan of the product through the double 85 test.
High Temperature Furnace Inspection Index
What is the high temperature furnace test standard? What metrics are tested? How long is the detection cycle? Which items are tested?
Test items (reference) :
Temperature uniformity test, system accuracy test, temperature, system accuracy, temperature uniformity, high temperature furnace verification and calibration, high temperature furnace (tube furnace) verification and calibration, box resistance furnace (high temperature furnace, heat treatment furnace) verification and calibration, high temperature furnace (box resistance furnace, dry furnace, heat treatment furnace) verification and calibration, silica
List of testing standards:
1, NCS/ CJ M61; SAE AMS 2750; JJF1376 High temperature furnace calibration specification NCS/ CJ M61, high temperature furnace calibration method SAE AMS 2750E, box type resistance furnace calibration specification JJF1376
2, AMS 2750F High temperature measurement AMS 2750F
3, GB 25576-2010 Food safety national standard Food additive silica (high temperature furnace method)
4, JJF 1184 thermocouple verification furnace temperature field test technical specification
5, AMS 2750E high temperature measurement AMS 2750E
6, AMS 2750F high temperature determination method 3.5
7, AMS 2750G high temperature measurement AMS 2750G
8, AMS 2750E high temperature determination method 1
9. JJF 1376; AMS 2750; JJG 276 Calibration specification for box type resistance furnace JJF 1376, high temperature measurement method AMS 2750E, high temperature creep, durable strength testing machine verification regulation JJG 276
10, JJF 1376 box type resistance furnace calibration specification
11, GB/T 9452-2012 heat treatment furnace effective heating zone determination method 1
12. SAE AMS 2750 high-temperature calibration method F
Reliability Testing Acceleration Testing
Most semiconductor devices have lifetimes that extend over many years at normal use. However, we cannot wait years to study a device; we have to increase the applied stress. Applied stresses enhance or accelerate potential fail mechanisms, help identify the root cause, and help labcompanion take actions to prevent the failure mode.
In semiconductor devices, some common accelerants are temperature, humidity, voltage, and current. In most cases, the accelerated testing does not change the physics of the failure, but it does shift the time for observation. The shift between accelerated and use condition is known as ‘derating.’
Highly accelerated testing is a key part of JEDEC based qualification tests. The tests below reflect highly accelerated conditions based on JEDEC spec JESD47. If the product passes these tests, the devices are acceptable for most use cases.
Temperature Cycle
Per the JESD22-A104 standard, temperature cycling (TC) subjects the units to extreme high and low temperatures transitions between the two. The test is performed by cycling the unit's exposure to these conditions for a predetermined number of cycles.
High Temperature Operating Life (HTOL)
HTOL is used to determine the reliability of a device at high temperature while under operating conditions. The test is usually run over an extended period of time according to the JESD22-A108 standard.
Temperature Humidity Bias/Biased Highly Accelerated Stress Test (BHAST)
According to the JESD22-A110 standard, THB and BHAST subject a device to high temperature and high humidity conditions while under a voltage bias with the goal of accelerating corrosion within the device. THB and BHAST serve the same purpose, but BHAST conditions and testing procedures enable the reliability team to test much faster than THB.
Autoclave/Unbiased HAST
Autoclave and Unbiased HAST determine the reliability of a device under high temperature and high humidity conditions. Like THB and BHAST, it is performed to accelerate corrosion. Unlike those tests, however, the units are not stressed under a bias.
High Temperature Storage
HTS (also called Bake or HTSL) serves to determine long-term reliability of a device under high temperatures. Unlike HTOL, the device is not under operating conditions for the duration of the test.
Electrostatic Discharge (ESD)
Static charge is an unbalanced electrical charge at rest. Typically, it is created by insulator surfaces rubbing together or pulling apart; one surface gains electrons, while the other surface loses electrons. The result is an unbalanced electrical condition known as static charge.
When a static charge moves from one surface to another, it becomes Electrostatic Discharge (ESD) and moves between the two surfaces in a form of a miniature lightning bolt.
When a static charge moves, it becomes a current that can damage or destroy gate oxide, metal layers, and junctions.
JEDEC tests ESD in two different ways:
1. Human Body Mode (HBM)
A component level stress developed to simulate the action of a human body discharging accumulated static charge through a device to ground.
2. Charged Device Model (CDM)
A component level stress that simulates charging and discharging events that occur in production equipment and processes, per the JEDEC JESD22-C101 specification.
Conversion Between Accelerated Aging of Xenon Lamp Aging Test Chamber And Outdoor Aging
Generally speaking, it is difficult to have a detailed positioning and conversion formula for the conversion between accelerated aging of xenon lamp aging test chamber and outdoor aging. The biggest problem is the variability and complexity of the outdoor environment. The variables that determine the relationship between xenon lamp aging test chamber exposure and outdoor exposure include:
1. Geographical latitude of outdoor aging exposure sites (closer to the equator means more UV).
2. Altitude (Higher altitude means more UV).
3. Local geographical characteristics, such as the wind can dry the test sample or close to water will produce condensation.
4. Random changes in climate from year to year can lead to a 2:1 change in aging at the same location.
5. Seasonal changes (e.g., winter exposure may be 1/7 of summer exposure).
6. Direction of the sample (5° south vs. vertical facing north)
7. Sample insulation (outdoor samples with insulated backing age 50% faster than uninsulated samples).
8. Working cycle of xenon lamp aging box (light time and wet time).
9. The working temperature of the test chamber (the higher the temperature, the faster the aging).
10. Test the uniqueness of the sample.
11. Spectral Intensity Distribution (SPD) of laboratory light sources
Objectively speaking, accelerated aging and outdoor aging have no convertibility, one is a variable, one is a fixed value, the only thing to do is to obtain a relative value, rather than an absolute value. Of course, it is not to say that relative values have no effect; on the contrary, relative values can also be very effective. For example, you will find that a slight change in design may double the durability of standard materials. Or you may find the same looking material from multiple suppliers, some of which age quickly, most of which take a moderate amount of time to age, and a smaller amount that ages after longer exposure. Or you may find that less expensive designs have the same durability against standard materials that have satisfactory performance over actual service life, such as 5 years.
How Long Is the Xenon Lamp Weathering Test Chamber Equivalent to a Year of Outdoor Exposure?
How long is the xenon lamp weathering test chamber equivalent to a year of outdoor exposure? How to test out its durability? This is a technical problem, but also a lot of users are concerned about the problem. Today's engineers of Lab Companion are going to explain this problem.
This problem looks very simple, in fact, it is a complex problem.We can not just get a simple number, let this number and the test time of the xenon lamp weathering test chamber to multiply, so as to get the outdoor exposure time, nor is the quality of our xenon lamp weathering test chamber not good enough! No matter how good the quality of the xenon lamp weathering test chamber is, how advanced it is, it is still impossible to find only a number to solve the problem. The most important thing is that the outdoor exposure environment is complex and changeable, affected by many factors, what are the specific?
1. The influence of geographical latitude
2. The influence of altitude
3. The influence of geographical environment when testing, such as wind speed.
4. The impact of the season, winter and summer will be different, summer exposure is 7 times the damage of winter exposure.
5. Direction of the test sample
6. Is the sample insulated or uninsulated? Samples placed on insulators will generally age much faster than those not placed on insulators.
7. Test cycle of xenon lamp weathering test chamber
8. Xenon lamp weathering test chamber operating temperature, the higher the temperature, the faster the aging
9. Testing of special materials
10. Spectrum distribution in the laboratory
LED Traffic Light Test
Light-emitting Diode, referred to as LED, is the abbreviation of the English name Light Emitting Diode, through the combination of electrons and holes to release energy light, can efficiently convert electrical energy into light energy, has a wide range of uses in modern society, such as lighting, flat panel display and medical devices. With the continuous progress of technology, this electronic component from the early can only emit low-light red light to develop other monochromatic light, has been widely used in visible light, infrared and ultraviolet light, is widely used in indicators and display boards, and then extended to traffic lights. It is known as a new light source in the 21st century, with high efficiency, long life, material is not easily affected by the environment and relatively stable, with the advantages of traditional light sources can not be comparable.
The traffic on the zebra crossing is heavy every day, as the guide of the traffic rules - the traffic light is also working hard every day, because it is placed outdoors all year round, so it must accept the strict reliability test before it can work. The test conditions include: Voltage electric, failure protection, electromagnetic noise, dust and waterproof, high temperature test, vibration test, salt spray test, insulation voltage, insulation resistance test...
Note: Before other tests, LED traffic lights need to undergo dry heat tests before other tests can be carried out.
Lamp surface test: dry heat test: 60℃/24 hours/applied voltage
Failure judgment: no deformation, loosening, falling off
Temperature resistance test: 70℃(16 hours)→-15℃(16 hours)→R.T., RAMP:≦1℃/min, 2cycle, power supply
Temperature and humidity test: 40℃→RAMP:≦1℃/min→40℃/95%(24 hours), power on
Continuous switching action: 40℃/60~80%, ON(1sec)←→OFF(1sec), 10000 times
Voltage electric: 80 ~ 135V(AC), 170 ~ 270V(AC)
Failure judgment: Light intensity drift ≦20%(110V, 220V light intensity as the benchmark)
Waterproof and dustproof meet IP54 class requirements
Insulation resistance test:
Insulation resistance: 500V
Failure determination: not less than 2MΩ
Insulation withstand voltage test: 1000V/60Hz/1min(after insulation resistance test)
Light chamber test:
High temperature test: 130℃/1 hour
Failure judgment: no deformation, loosening, falling off, cracking... Etc.
Vibration test: XYZ three-way, each 12min for 36min, 10 ~ 35 ~ 10Hz sine wave, each cycle for 3min, total vibration of 2mm
Failure judgment: no deformation, loosening, falling off, cracking, and the LED light surface can be normally lit and operated
Wind tunnel test: Wind speed 16 (51.5-56.4m /s), forward (0 degrees) and side (45 degrees), each blowing for 2 hours
Failure judgment: no deformation, loosening, falling off, cracking
Salt spray test: 96 hours
Failure determination: less than 8 embroider points on the area of 10,000mm^2, LED signal light surface insulation resistance >2MΩ, voltage 1000V/1min, no abnormality
Recommended model 1: high temperature and high humidity test chamber
High temperature and high humidity test chamber is suitable for electrical, electronic, instruments and other products, parts and materials in high and low temperature alternating wet and hot environment storage, transportation, use adaptability test; It is a reliability test equipment for all kinds of electronic, electrical, electrical, plastic and other raw materials and devices to carry out cold resistance, heat resistance, wet resistance, dry resistance test and quality control engineering; Especially suitable for fiber, LCD, crystal, inductance, PCB, battery, computer, mobile phone and other products of high temperature resistance, low temperature resistance, moisture resistance cycle test.
Recommended model 2: vibration of the comprehensive chamber
Vibration of the comprehensive chamber combined with temperature, humidity, vibration function in one, suitable for aerospace products, information electronic instruments, materials, electrical, electronic products, all kinds of electronic components in a comprehensive harsh environment to test their performance indicators. Vibration of the comprehensive chamber mainly for aerospace, aviation, petroleum, chemical, electronics, communications and other scientific research and production units to provide temperature and humidity change environment, at the same time in the test chamber will be electric vibration stress according to the specified period of the test on the test, for the user of the whole machine (or components), electrical appliances, instruments, materials for temperature and humidity, vibration comprehensive stress screening test. In order to assess the adaptability of the test product or to evaluate the behavior of the test product. Compared with the effect of a single factor, it can more truly reflect the adaptability of electrical and electronic products to temperature, humidity and vibration complex environment changes in transportation and actual use, and expose product defects, which is an essential and important test means for the whole process of new product development, prototype test and product qualification test.
Recommended model 3: salt spray test chamber
The salt spray test chamber is suitable for all kinds of communication electronic products, electronic appliances, hardware parts to do neutral salt spray test (NSS) and corrosion test (AASS, CASS), omplied with CNS, ASTM, JIS, ISO and other standards. The salt spray test is to test the corrosion resistance of the products on the surface of various materials after anti-corrosion treatment such as coating, electroplating, anodic treatment and anti-rust oil.
Recommended model 4: waterproof and dustproof test chamber
Waterproof and dustproof test chamber is suitable for outdoor terminals such as metering automation terminals and distribution network automation terminals to carry out rain and dust tests to ensure that the tested products can withstand the impact of harsh environmental changes, so that the products can operate safely and reliably, and are suitable for external lighting and signal devices and automotive lamp shell protection. It can provide realistic simulation of various environments such as water, spray and dust tests that electronic products and their components may be subjected to during transportation and use. In order to detect the waterproof and dustproof performance of various products.
Heat Pipe Reliability Test
Heat pipe technology is a heat transfer element called "heat pipe" invented by G.M. rover of Los Alamos National Laboratory in 1963, which makes full use of the principle of heat conduction and the rapid heat transfer properties of the refrigeration medium, and transfers the heat of the heating object quickly to the heat source through the heat pipe. Its thermal conductivity exceeds that of any known metal. Heat pipe technology has been widely used in aerospace, military and other industries, since it has been introduced into the radiator manufacturing industry, making people change the design idea of the traditional radiator, and get rid of the single heat dissipation mode that simply relies on high air volume motor to obtain better heat dissipation effect. The use of heat pipe technology makes the radiator even if the use of low speed, low air volume motor, can also get satisfactory results, so that the noise problem plagued by air cooling heat has been well solved, opening up a new world in the heat dissipation industry.
Heat pipe reliability test conditions:
High temperature stress screening test: 150℃/24 hours
Temperature cycling test:
120℃(10min)←→-30℃(10min), Ramp: 0.5℃, 10cycles 125℃(60min)←→-40℃(60min), Ramp: 2.75℃, 10cycles
Thermal shock test:
120℃(2min)←→-30℃(2min), 250 cycles
125℃(5min)←→-40℃(5min), 250 cycles
100℃(5min)←→-50℃(5min), 2000 cycles(check once after 200 cycles)
High temperature and high humidity test:
85℃/85%R.H./1000 hours
Accelerated aging test:
110℃/85%RH/264h
Other heat pipe test items:
Salt spray test, strength (blasting) test, leakage rate test, vibration test, random vibration test, mechanical shock test, helium combustion test, performance test, wind tunnel test
Bicycle Lamp Reliability Test
Bicycles are in the social environment of high oil prices and environmental protection, with environmental protection, fitness, slow living... Such as multi-functional recreational sports equipment, and bicycle lights are an indispensable and important part of bicycle night riding, if the purchase of low-cost and not after reliability test of bicycle lights, riding at night or through the tunnel failure, not only for the rider has a serious threat to life safety, For driving, collision accidents can occur because the driver cannot see the cyclist, so it is important to have bicycle lights that pass the reliability test.
Reasons for bicycle lamp failure:
a. Deformation, embrittlement and fading of lamp shell caused by high temperature of lamp
b. yellowing and embrittlement of lamp shell caused by outdoor ultraviolet exposure
c. Riding up and down the hill due to high and low temperature changes in the environment caused by lamp failure
d. Abnormal power consumption of car lights
e. Lights fail after a long time of rain
f. Hot failure occurs when the lights are lit for a long time
g. During riding, the lamp fixture drags loose, causing the lamp to fall
h. Lamp circuit failure caused by road vibration and slope
Bicycle lamp test classification:
Environmental test, mechanical test, radiation test, electrical test
Initial characteristic test:
Take any 30, light the lamp with DC power supply according to the rated voltage, after the characteristics are stable, measure the distance between the current and the optical center, less than 10 defective products are qualified, more than 22 are unqualified, if the number of defective products is between 11 and 22, another 100 samples are collected for testing, and the number of defective products under the original inspection is qualified when the number is less than 22. If the number exceeds 22, it is disqualified.
Life test: 10 bulbs passed the initial characteristic test, and 8 of them met the requirements.
Bicycle test speed: simulated 15 km/h environment
High temperature test (temperature test) : 80℃, 85℃, 90℃
Low temperature test: -20℃
Temperature cycle: 50℃(60min)→ normal temperature (30min)→20(60min)→ normal temperature (30min), 2cycle
Wet heat test: 30℃/95%R.H/48 hours
Stress screening test: High temperature: 85℃←→ Low temperature: -25℃, dwell time: 30min, cycle: 5cycles, power on, time: ≧24h
Shell salt spray test: 20℃/15% salt concentration/spray for 6 hours, determination method: the surface of the shell should not occur obvious rust
Waterproof test:
Description: The IPX rating of rainproof lamps needs to be at least IPX3 or above
IPX3(Water resistance) : Drop 10 liters of water vertically from a height of 200CM at 60˚ (test time: 10 minutes)
IPX4(anti-water, anti-splash) : 10 liters of water drops from 30 ~ 50CM in any direction (test time: 10 minutes)
IPX5:3m 12.5L of water from any direction [weak water](test time: 3 minutes)
IPX6:3m Strong spray 30 liters from any direction [strong water, pressure: 100KPa](test time: 3 minutes)
IPX7(Life waterproof) : It can be used for 30 minutes under 1m in water
Vibration test: vibration number 11.7 ~ 20Hz/amplitude: 11 ~ 4mm/ time: up and down 2h, about 2h, 2h before and after 2h/acceleration 4 ~ 5g
Drop test: 1 meter (hand drop), 2 meters (bicycle fall, fall from the frame)/ concrete floor/four times/four sides
Impact test: 10mm flat wooden platform/Distance: 1 m/diameter 20mm mass 36g steel ball free fall/top surface and side once
Low temperature impact: When the sample is cold to -5℃, maintain this temperature for three hours and then carry out the impact test
Irradiation test: long time irradiation brightness test, low voltage irradiation test, light brightness, light color
Bicycle lamp noun sorting:
Natural Convection Test (No Wind Circulation Temperature Test) and Specification
Home entertainment audio-visual equipment and automotive electronics are one of the key products of many manufacturers, and the product in the development process must simulate the adaptability of the product to temperature and electronic characteristics at different temperatures. However, when the general oven or constant temperature and humidity test chamber is used to simulate the temperature environment, both the oven and constant temperature and humidity test chamber have a test area equipped with a circulating fan, so there will be wind speed problems in the test area. During the test, the temperature uniformity is balanced by rotating the circulating fan. Although the temperature uniformity of the test area can be achieved through the wind circulation, the heat of the product to be tested will also be taken away by the circulating air, which will be significantly inconsistent with the actual product in the wind-free use environment (such as the living room, indoor). Because of the relationship of wind circulation, the temperature difference of the product to be tested will be nearly 10 ° C, in order to simulate the actual use of environmental conditions, many people will misunderstand that only the test machine can produce temperature (such as: oven, constant temperature and humidity test chamber) can carry out natural convection test, in fact, this is not the case. In the specification, there are special requirements for wind speed, and a test environment without wind speed is required. Through the natural convection test equipment (no forced wind circulation test), the temperature environment without fan is generated (natural convection test), and then the test integration test is carried out to detect the temperature of the product under test. This solution can be applied to the actual ambient temperature test of household related electronic products or confined Spaces (such as: Large LCD TV, car cockpit, car electronics, laptop, desktop computer, game console, stereo... Etc.).
The difference of the test environment with or without wind circulation for the test of the product to be tested:
If the product to be tested is not energized, the product to be tested will not heat itself, its heat source only absorbs the air heat in the test furnace, and if the product to be tested is energized and heated, the wind circulation in the test furnace will take away the heat of the product to be tested. Every 1 meter increase in wind speed, its heat will be reduced by about 10%. Suppose to simulate the temperature characteristics of electronic products in an indoor environment without air conditioning, if an oven or a constant temperature and humidity test chamber is used to simulate 35 ° C, although the environment in the test area can be controlled within 35 ° C through electric heating and freezing, the wind circulation of the oven and the constant temperature and humidity test chamber will take away the heat of the product to be tested, making the actual temperature of the product to be tested lower than the temperature in the real state of no wind. Therefore, it is necessary to use a natural convection testing machine without wind speed to effectively simulate the actual windless environment (such as: indoor, non-starting car cockpit, instrument chassis, outdoor waterproof box... Such environment).
Indoor environment without wind circulation and solar radiant heat irradiation:
Through the natural convection tester, simulate the client's actual use of the real air conditioning convection environment, hot spot analysis and heat dissipation characteristics of the product evaluation, such as the LCD TV in the photo not only to consider its own heat dissipation, but also to evaluate the impact of thermal radiation outside the window, thermal radiation for the product may produce additional radiant heat above 35 ° C.
Comparison table of wind speed and IC product to be tested:
When the ambient wind speed is faster, the IC surface temperature will also take away the IC surface heat due to the wind cycle, resulting in faster wind speed and lower temperature, when the wind speed is 0, the temperature is 100℃, but when the wind speed reaches 5m/s, the IC surface temperature has been below 80℃.
Unforced air circulation test:
According to the specification requirements of IEC60068-2-2, in the high temperature test process, it is necessary to carry out the test conditions without forced air circulation, the test process needs to be maintained under the wind-free circulation component, and the high temperature test is carried out in the test furnace, so the test cannot be carried out through the constant temperature and humidity test chamber or oven, and the natural convection tester can be used to simulate the free air conditions.
Description of test conditions:
Test specification for unforced air circulation: IEC-68-2-2, GB2423.2, GB2423.2-89 3.3.1
Unforced air circulation test: The test condition of unforced air circulation can simulate the free air condition well
GB2423.2-89 3.1.1:
When measuring under free air conditions, when the temperature of the test sample is stable, the temperature of the most hot spot on the surface is more than 5℃ higher than the temperature of the surrounding large device, it is a heat dissipation test sample, otherwise it is a non-heat dissipation test sample.
GB2423.2-8 10(Test heat dissipation test sample temperature gradient test) :
A standard test procedure is provided to determine the adaptability of thermal electronic products (including components, equipment level other products) to use at high temperatures.
Test requirements:
a. Testing machine without forced air circulation (equipped with a fan or blower)
b. Single test sample
c. The heating rate is not greater than 1℃/min
d. After the temperature of the test sample reaches stability, the test sample is energized or the home electrical load is carried out to detect the electrical performance
Natural convection test chamber features:
1. Can evaluate the heat output of the product to be tested after power, to provide the best distribution uniformity;
2. Combined with digital data collector, effectively measure the relevant temperature information of the product to be tested for synchronous multi-track analysis;
3. Record the information of more than 20 rails (synchronous record the temperature distribution inside the test furnace, multi-track temperature of the product to be tested, average temperature... Etc.).
4. The controller can directly display the multi-track temperature record value and record curve; Multi-track test curves can be stored on a USB drive via the controller;
5. The curve analysis software can intuitively display the multi-track temperature curve and output EXCEL reports, and the controller has three kinds of display [Complex English];
6. Multi-type thermocouple temperature sensor selection (B, E, J, K, N, R, S, T);
7. Scalable to increase heating rate & control stability planning.
Laptop Test Conditions
Notebook computer from the early 12-inch screen evolution to the current LED backlit screen, its computing efficiency and 3D processing, will not be lost to the general desktop computer, and the weight is becoming less and less burden, the relative reliability test requirements for the entire notebook computer is becoming more and more stringent, from the early packaging to the current boot down, the traditional high temperature and high humidity to the current condensation test. From the temperature and humidity range of the general environment to the desert test as a common condition, these are the parts that need to be considered in the production of notebook computer related components and design, the test conditions of the relevant environmental tests collected so far are organized and shared with you.
Keyboard tapping test:
Test one:
GB:1 million times
Key pressure :0.3~0.8(N)
Button stroke :0.3~1.5(mm)
Test 2: Key pressure: 75g(±10g) Test 10 keys for 14 days, 240 times per minute, a total of about 4.83 million times, once every 1 million times
Japanese manufacturers :2 to 5 million times
Taiwan manufacturer 1: more than 8 million times
Taiwan Manufacturer 2:10 million times
Power switch and connector plug pull test:
This test model simulates the lateral forces that each connector can withstand under abnormal usage. General laptop test items: USB, 1394, PS2, RJ45, Modem, VGA... Equal application force 5kg(50 times), up and down left and right pull and plug.
Power switch and connector plug test:
4000 times (Power supply)
Screen cover opening and closing test:
Taiwanese manufacturers: open and close 20,000 times
Japanese manufacturer 1: opening and closing test 85,000 times
Japanese manufacturer 2: opening and closing 30,000 times
System standby and recovery switch test:
General note type: interval 10sec, 1000cycles
Japanese manufacturer: System standby and recovery switch test 2000 times
Common causes of laptop failure:
☆ Foreign objects fall on the notebook
☆ Falls off the table while in use
☆ Tuck the notebook in a handbag or trolley case
☆ Extremely high temperature or low temperature ☆ Normal use (overuse)
☆ Wrong use in tourist destinations
☆PCMCIA inserted incorrectly
☆ Place foreign objects on the keyboard
Shutdown drop test:
General notebook type :76 cm
GB package drop: 100cm
Us Army and Japanese notebook computers: The height of the computer is 90 cm from all sides, sides, corners, a total of 26 sides
Platform :74 cm (packing required)
Land: 90cm (packing required)
TOSHIBA&BENQ 100 cm
Boot drop test:
Japanese :10 cm boot fall
Taiwan :74 cm boot fall
Laptop main board temperature shock:
Slope 20℃/min
Number of cycles 50cycles(no operation during impact)
The U.S. military's technical standards and test conditions for laptop procurement are as follows:
Impact test: Drop the computer 26 times from all sides, sides and corners at a height of 90 cm
Earthquake resistance test :20Hz~1000Hz, 1000Hz~2000Hz frequency once an hour X, Y and Z axis continuous vibration
Temperature test :0℃~60℃ 72 hours of aging oven
Waterproof test: Spray water on the computer for 10 minutes in all directions, and the water spray rate is 1mm per minute
Dust test: Spray the concentration of 60,000 mg/ per cubic meter of dust for 2 seconds (interval of 10 minutes, 10 consecutive times, time 1 hour)
Meets MIL-STD-810 military specifications
Waterproof test:
Us Army notebook :protection class:IP54(dust & rain) Sprayed the computer with water in all directions for 10 minutes at a rate of 1mm per minute.
Dust proof test:
Us Army notebook: Spray a concentration of 60,000 mg/ m3 of dust for 2 seconds (10 minute intervals, 10 consecutive times, time 1 hour)
Temperature and Humidity Terms
Dew Point temperature Td, in the air water vapor content unchanged, maintain a certain pressure, so that the air cooling to reach saturation temperature called dew point temperature, referred to as dew point, the unit is expressed in ° C or ℉. It's actually the temperature at which water vapor and water are in equilibrium. The difference between the actual temperature (t) and the dew point temperature (Td) indicates how far the air is saturated. When t>Td, it means that the air is not saturated, when t=Td, it is saturated, and when t<Td, it is supersaturated.
dew is the liquid water in the air that condenses on the ground. In the evening or at night, due to the radiation cooling of the ground or ground objects, the air layer close to the surface will also cool down. When the temperature drops below the dew point, that is, when the water vapor content in the air is susaturated, there will be condensation of water vapor on the surface of the ground or ground objects. If the dew point temperature is above 0 ° C at this time, tiny water droplets appear on the ground or ground objects, which are called dew.
frost refers to the white ice crystals formed on the ground or objects after the air close to the ground is cooled to the frost point (meaning the dew point is below 0) under the influence of radiation cooling on the ground.
fog refers to the condensation of water vapor suspended in the atmosphere near the Earth's surface, composed of small water droplets or ice crystals. When the temperature reaches the dew point temperature (or is close to the dew point), the water vapor in the air condenses to form fog.
snow is solid water in the form of snowflakes that falls to the ground from mixed clouds. Precipitation consisting of a large number of white opaque ice crystals (snow crystals) and their polymers (snow masses). Snow is the natural phenomenon of water condensing and falling in the air, or falling snow;
There is a limit to the amount of water vapor that can be contained in a unit volume of air under a certain pressure and a certain temperature. If the water vapor contained in the volume of air exceeds this limit, the water vapor will condense and produce precipitation, and the actual value of water vapor in the volume of air. In terms of absolute humidity. The more water vapor there is, the higher the absolute humidity of the air.
Relative Humidity refers to the percentage of water vapor pressure in the air and saturated water vapor pressure at the same temperature, or the ratio of the absolute humidity of wet air to the maximum absolute humidity that can be reached at the same temperature, and can also be expressed as the ratio of the partial pressure of water vapor in wet air to the saturation pressure of water at the same temperature.
Humidity: wet and dry bulb measurement
The dry and wet bulb thermometer is used to detect the [relative humidity] in the air, the dry bulb temperature is the temperature measured by the general temperature sensor, and the wet bulb temperature is tied on the temperature sensor with a wet cloth, and then soaked in a small cup of water, so that the water is wrapped in the whole sensor, because the relative humidity in the air must be less than or equal to 100% (the water vapor in the air is not saturated). Therefore, the moisture of the wet bulb will be evaporated, and the heat will be taken away during evaporation, resulting in a drop in the wet bulb temperature (the dry bulb temperature is the real air temperature), which means that the greater the difference in the readings of the dry and wet bulb thermometer, the more vigorous the evaporation of water, and the smaller the relative humidity in the air, as long as the temperature of the dry and wet bulb is measured, Then compare [relative humidity table] you can know the relative humidity of the environment at that time.
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IPv6 network supported