ESS Rapid Temperature Change Stress Screening Machine
Environmental Stress Screening (ESS)
Stress screening is the use of acceleration techniques and environmental stress under the design strength limit, such as: burn in, temperature cycling, random vibration, power cycle... By accelerating the stress, the potential defects in the product emerge [potential parts material defects, design defects, process defects, process defects], and eliminate electronic or mechanical residual stress, as well as eliminate stray capacitors between multi-layer circuit boards, the early death stage of the product in the bath curve is removed and repaired in advance, so that the product through moderate screening, Save the normal period and decline period of the bathtub curve to avoid the product in the process of use, the test of environmental stress sometimes lead to failure, resulting in unnecessary losses. Although the use of ESS stress screening will increase the cost and time, for improving the product delivery yield and reduce the number of repairs, there is a significant effect, but for the total cost will be reduced. In addition, customer trust will also be improved, generally for electronic parts of the stress screening methods are pre-burning, temperature cycle, high temperature, low temperature, PCB printed circuit board stress screening method is temperature cycle, for the electronic cost of the stress screening is: Power pre-burning, temperature cycling, random vibration, in addition to the stress screen itself is a process stage, rather than a test, screening is 100% of the product procedure.
Product features of rapid temperature change stress screening machine:
1, It can set different stress screening temperature variation of 5°C/min, 10°C/min and 15°C/min.
2, It can perform rapid temperature change (stress screening), condensation test, high temperature and humidity, temperature and humidity cycle and other tests.
3, It meets the requirements of electronic equipment product stress screening test.
4, It can be switched between equal temperature and average temperature two test methods.
Specification requirements of rapid temperature change stress screening machine:
1, It can set a variety of stress screening (fast temperature variability) 5°C/min, 10°C/min and 15°C/min test conditions.
2, It meets the stress screening of electronic equipment products, lead free process, MIL-STD-2164, MIL-344A-4-16, MIL-2164A-19, NABMAT-9492, GJB-1032-90, GJB/Z34-5.1.6, IPC-9701 and other test requirement.
3, It can perform equal temperature and average temperature test mode.
4, It uses aluminum sheet to verify the load capacity of the machine (non-plastic load).
Vacuum High Temperature Test Chamber
Features of vacuum high temperature test chamber: special high temperature equipment for defoaming and anti-oxidation. And it meets the standards: GB/T2423.1 (IEC60068-2-1), GB/T2423.2 (IEC60068-2-2), ISO16750; JESD22, GB/T 14710, GB/T 13543.
First, product overview of vacuum high temperature test chamber:
New and simple design;
The program of automatic control of pressure and temperature control is easy to operate and advanced in function;
Observation window for easy observation of test material status (optional);
Dual structure in the chamber: the inside of the vacuum container has a dual structure of an inner slot, and a heater is set outside the inner chamber to reduce heat loss, improve temperature uniformity, greatly shorten the temperature rising time, and improve the operating rate of the equipment;
Widely used: can be used for defoaming, degassing, hardening, drying and so on;
Resin liquid mixing and silicone liquid when the defoaming treatment in LED production process, various resin molding degas treatment, IC injection of epoxy resin hardening treatment, drying for electronic parts after water cleaning, vacuum high temperature test chamber can be used in all these process;
Second, different models of vacuum high temperature test chamber:
Model number
Temperature range
Internal volume
Type
Internal size
(W*H*Dmm)
External size
(W*H*Dmm)
VAC-101P
+40～+200℃
91L
Atmospheric pressure range：933～1[*102Pa](abs)
450×450×450
902×1,392×780
VAC-201P
+40～+200℃
216L
Atmospheric pressure range：933～1[*102Pa](abs)
600×600×600
1,052×1,532×930
VAC-301P
+40～+200℃
512L
Atmospheric pressure range：933～1[*102Pa](abs)
800×800×800
1,252×1,772×1,130
Model number
Temperature/pressure range
Internal size
(W*H*Dmm)
LCV-234
(RT+20)°C~+200°C / 0-101kPa(Gauge)
450×450×450
LCV-244
550×550×550
New Energy Environment Test Solution
The problem of new energy reliability is still difficult, and the integrated detection system of electrical stress and environmental stress will provide the best means for research and development and manufacturing.
Industry
Test object
Use
Technology
Solution
New Energy
Battery (secondary battery)
Inspect
Charge and discharge test
High and low temperature (&humidity) test chamber
Rapid temperature (&humidity)change test chamber
Evaluate
Characteristic test
Rapid temperature (&humidity)change test chamber
Fuel cell
/
Temperature resistance
Small ultra-low temperature test chamber
High and low temperature (&humidity) test chamber
Rapid temperature (&humidity)change test chamber
Information Communication Environment Test Solution
The statistical analysis shows that the failure of electronic components accounts for 50% of the failure of electronic complete machine, and the reliability detection technology still faces many challenges.
Industry
Test object
Use
Technology
Solution
IT Communication
Transmission switching equipment
Inspect
High temperature placement test
High and low temperature (&humidity) test chamber
Aging test
High and low temperature (&humidity) test chamber
Evaluate
Thermal cycling test
High and low temperature (&humidity) test chamber
Tellcordia test
High and low temperature (&humidity) test chamber
Thermal cycling test
Rapid temperature (&humidity)change test chamber
Mobile communication terminal
Inspect
Finished operation test
High and low temperature (&humidity) test chamber
Finished operation test
Rapid temperature (&humidity)change test chamber
Evaluate
Temperature and humidity test
High and low temperature (&humidity) test chamber
Computer
Inspect
Finished product screening
Rapid temperature (&humidity)change test chamber
High temperature placement test
High and low temperature (&humidity) test chamber
Aging test
High and low temperature (&humidity) test chamber
External computer storage device
Inspect
Component screening
High and low temperature (&humidity) test chamber
Component screening
Rapid temperature (&humidity)change test chamber
Evaluate
Ensure operation test within temperature and humidity range
High and low temperature (&humidity) test chamber
Ensure operation test within temperature and humidity range
Rapid temperature (&humidity)change test chamber
Thermal Cycling Test(TC) & Thermal Shock Test(TS)
Thermal Cycling Test(TC):
In the life cycle of the product, it may face various environmental conditions, which makes the product appear in the vulnerable part, resulting in product damage or failure, and then affect the reliability of the product.
A series of high and low temperature cycling tests are done on the temperature change at the temperature variation rate of 5~15 degrees per minute, which is not a real simulation of the actual situation. Its purpose is to apply stress to the test piece, accelerate the aging factor of the test piece, so that the test piece may cause damage to the system equipment and components under environmental factors, in order to determine whether the test piece is correctly designed or manufactured.
Common ones are:
Electrical function of the product
The lubricant deteriorates and loses lubrication
Loss of mechanical strength, resulting in cracks and cracks
The deterioration of the material causes chemical action
Scope of application:
Module/system product environment simulation test
Module/System Product Strife test
PCB/PCBA/ Solder Joint Accelerated Stress Test (ALT/AST)...
Thermal Shock Test(TS):
In the life cycle of the product, it may face various environmental conditions, which makes the product appear in the vulnerable part, resulting in product damage or failure, and then affect the reliability of the product.
High and low temperature shock tests under extremely harsh conditions on rapid temperature changes at a temperature variability of 40 degrees per minute are not truly simulated. Its purpose is to apply severe stress to the test piece to accelerate the aging factor of the test piece, so that the test piece may cause potential damage to the system equipment and components under environmental factors, in order to determine whether the test piece is correctly designed or manufactured.
Common ones are:
Electrical function of the product
The product structure is damaged or the strength is reduced
Tin cracking of components
The deterioration of the material causes chemical action
Seal damage
Machine specifications:
Temperature range: -60 ° C to +150 ° C
Recovery time: < 5 minutes
Inside dimension: 370*350*330mm (D×W×H)
Scope of application:
PCB reliability acceleration test
Accelerated life test of vehicle electric module
LED parts accelerated test...
Effects of temperature changes on products:
The coating layer of components falls off, the potting materials and sealing compounds crack, even the sealing shell cracks, and the filling materials leak, which causes the electrical performance of components to decline.
Products composed of different materials, when the temperature changes, the product is not evenly heated, resulting in product deformation, sealing products cracking, glass or glassware and optics broken;
The large temperature difference makes the surface of the product condense or frost at low temperature, evaporates or melts at high temperature, and the result of such repeated action leads to and accelerates the corrosion of the product.
Environmental effects of temperature change:
Broken glass and optical equipment.
The movable part is stuck or loose.
Structure creates separation.
Electrical changes.
Electrical or mechanical failure due to rapid condensation or freezing.
Fracture in a granular or striated manner.
Different shrinkage or expansion characteristics of different materials.
The component is deformed or broken.
Cracks in surface coatings.
Air leak in the containment compartment.
Lab Companion-Rapid Temperature Cycling Test Chamber
Introduction of Lab Companion
With over 20 years of experience, Lab Companion is a world class manufacturer of environmental chambers and an accomplished supplier of turn-key test systems and equipment. All our chambers build on Lab Companion’s reputation for long life and exceptional reliability.
With a scope of design, manufacture and service, Lab Companion has established a quality management system that complies with the International Quality System Standard ISO 9001:2008. Lab Companion’s equipment calibration program is accredited to the International Standard ISO 17025 and the American National Standard ANSI/NCSL-Z-540-1 by A2LA. A2LA is a full member and signatory of the International Laboratory Accreditation Cooperation (ILAC), the Asia Pacific Laboratory Accreditation (APLAC) and the European Cooperation for Accreditation (EA).
Lab Companion’s SE-Series Environmental Test Chambers offer a significantly enhanced airflow system, which provides better gradients and improved product temperature change rates. These chambers utilize Thermotron’s flagship 8800 Programmer/Controller featuring a high resolution 12.1” flat panel display with touch screen user interface, expanded capabilities to graph, data log, edit, access on-screen help, and long term hard drive data storage.
Not only do we offer the highest quality products, we also provide ongoing support designed to keep you up and running long after the initial sale. We provide factory direct local service with an extensive inventory of the parts you might need.
Performance
Temperature range: -70°C to +180°C
Performance: With 23 Kg aluminum load (IEC60068-3-5), the rising rate from +85°C to -40°C is 15℃/min; the cooling rate from -40°C to +85°C is15℃/min too.
Temperature control：± 1°C Dry bulb temperatures from control point after stabilization at the control sensor
Performance is based on an ambient condition of 75°F (23.9°C) and 50% RH
Cooling/Heating Performance based on measurement at the control sensor in the supply air stream
Constructure
Interior
Nonmagnetic Series 300 stainless steel with a high nickel content
Internal seams heliarc welded for hermetic sealing of the liner
Corners and seams designed to allow for expansion and contraction under the temperature extremes encountered
Condensate drain located in the liner floor and under the conditioning plenum
Chamber base is fully welded
“Ultra-Lite” non-settling fiberglass insulation
One adjustable interior stainless steel shelf is standard
Exterior
Die-formed treated sheet steel
Metal access covers provided for easy opening doors to electrical components
Finish water-based, air dry lacquer, sprayed over a cleaned and primed surface
Easy lift-off hinged access doors for servicing the refrigeration system
One 12.5 cm diameter access port with interior weld and removable insulating plug mounted in right hand side wall accessories on hinged door for easy access
Features
Chamber Operation clearly displays helpful run-time information
Graphing Screen offers expanded capabilities, enhanced programming and reporting
System Status displays crucial refrigeration system parameters
Program Entry makes it easy to load, view and edit profiles
Set Up quick-step wizards make profile entry easy
Pop-up Refrigeration Charts for handy reference
Therm-Alarm® provides over & under temperature alarm protection
Activity Log Screen provides comprehensive equipment history
Web Server allows internet access to equipment via Ethernet
User-Friendly Pop-up Key Pad makes data entry quick and easy
Includes:
- Four USB Ports-two External & two Internal
- Ethernet
- RS-232
Technical specifications
1-4 independently programmable channels
Measuring Accuracy: 0.25% of span typical
Selectable °C or °F temperature scale
12.1” (30 cm) color flat panel touch screen display
Resolution: 0.1°C, 0.1%RH, 0.01 for other linear applications
Real time clock included
Sample Rate: Process variable sampled every 0.1 seconds
Proportional Band: Programmable 1.0° to 300°
Control Method: Digital
Intervals: Unlimited
Interval Resolution: 1 sec to 99 hrs,59 min with 1 second resolution
- RS-232
- 10+ Years Data Storage
- Product Temperature Control
- Event Relay Board
Operating Modes: Automatic or Manual
Program Storage: Unlimited
Program Loops:
- Up to 64 loops per program
Loops can be repeated up to 9,999 times program
- Up to 64 nested loops are allowed per
Drug Stability Test
The effectiveness and safety of drugs have attracted much attention, and it is also a livelihood issue that the country and the government attach great importance to. The stability of drugs will affect the efficacy and safety. In order to ensure the quality of drugs and storage containers, stability tests should be performed to determine their effective time and storage state. Stability test mainly studies whether the quality of drugs is affected by environmental factors such as temperature, humidity and light, and whether it changes with time and the correlation between them, and studies the degradation curve of drugs, according to which the effective period is presumed to ensure the effectiveness and safety of drugs when used. This article collects the standard information and test methods required for various stability tests for customers' reference.
First, drug stability test criteria
Storage conditions of drugs:
Storage conditions (Note 2)
Long-term experiment
25℃±2℃ / 60%±5%RH or
30℃±2℃ /65%±5% RH
Accelerated test
40℃±2℃ / 75%±5%RH
Middle test (Note 1)
30℃±2℃ / 65%±5%RH
Note 1: If the long-term test condition has been set at 30℃±2℃/65% ±5%RH, there is no middle test; if the long-term storage condition is 25℃±2℃/ 60% ±5%RH, and there is a significant change in the accelerated test, then middle test should be added. And should be assessed against the criteria of "significant change".
Note 2: Sealed impervious containers such as glass ampoules can be exempted from humidity conditions. Unless otherwise determined, all tests shall be carried out in accordance with the stability test plan in the interim test.
The accelerated test data should be available for six months. The minimum duration of the stability test is 12 months for the middle test and the long-term test.
Store in refrigerator:
Storage conditions
Long-term experiment
5℃±3℃
Accelerated test
25℃±2℃ / 60%±5%RH
Stored in freezer:
Storage conditions
Long-term experiment
-20℃±5℃
Accelerated test
5℃±3℃
If the product containing water or solvents that may be subject to solvent loss is packaged in a semi-permeable container, the stability assessment should be conducted under low relative humidity for a long period of time, or an middle test of 12 months, and an accelerated test of 6 months, in order to prove that the drug placed in the semi-permeable container can withstand the low relative humidity environment.
Containing water or solvents
Storage conditions
Long-term experiment
25℃±2℃ / 40%±5%RH or 30℃±2℃ /35%±5% RH
Accelerated test
40℃±2℃;≤25%RH
Middle test (Note 1)
30℃±2℃ / 35%RH±5%RH
Note 1: If the long-term test condition is 30℃±2℃ / 35%±5%RH, there is no middle test.
The calculation of the relative water loss rate at a constant temperature of 40℃ is as follows:
Substituted relative humidity (A)
Control relative humidity (R)
Water loss rate ratio ([1-R]/[1-A])
60%RH
25%RH
1.9
60%RH
40%RH
1.5
65%RH
35%RH
1.9
75%RH
25%RH
3.0
Illustration: For aqueous drugs placed in semi-permeable containers, the water loss rate at 25%RH is three times that of 75%RH.
Second, Drug stability solutions
Common drug stability test criteria
(Source: Food and Drug Administration, Ministry of Health and Welfare)
Item
Storage conditions
Long-term experiment
25°C /60% RH
Accelerated test
40°C /75%RH
Middle test
30°C/65%RH
(1) Wide temperature range test
Item
Storage conditions
Long-term experiment
Low or sub-zero temperature conditions
Accelerated test
Room temperature and humidity or low temperature conditions
(2) Test equipment
1. Constant temperature and humidity test chamber
2. Drug stability test chamber
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
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.
Reliability of Ceramic Substrate
Ceramic PCB (Ceramic Substrate) refers to a special process plate where copper foil is directly bonded to the surface (single or double) of alumina (Al2O3) or aluminum nitride (AlN) ceramic substrate at high temperature. The ultra-thin composite substrate has excellent electrical insulation performance, high thermal conductivity, excellent soldering and high adhesion strength, and can be etched into a variety of graphics like PCB board, with great current carrying capacity. Therefore, the ceramic substrate has become the basic material of high-power electronic circuit structure technology and interconnect technology, which is suitable for products with high caloric value (high-brightness LED, solar energy), and its excellent weather resistance can be applied to harsh outdoor environments.
Main application products: high power LED carrier board, LED lights, LED street lights, solar inverter
Ceramic substrate features:
Structure: Excellent mechanical strength, low warping, thermal expansion coefficient close to silicon wafer (aluminum nitride), high hardness, good processability, high dimensional accuracy
Climate: Suitable for high temperature and humidity environment, high thermal conductivity, good heat resistance, corrosion and wear resistance, UV& yellowing resistance
Chemistry: Lead-free, non-toxic, good chemical stability
Electrical: high insulation resistance, easy metallization, circuit graphics and strong adhesion
Market: Abundant materials (clay, aluminum), easy to manufacture, low price
PCB material thermal characteristics comparison (conductivity) :
Glass fiber board (traditional PCB) : 0.5W/mK, aluminum substrate: 1~2.2W/mK, ceramic substrate: 24[alumina]~170[aluminum nitride]W/mK
Material heat transfer coefficient (unit W/mK) :
Resin: 0.5, alumina: 20-40, silicon carbide: 160, aluminum: 170, aluminum nitride: 220, copper: 380, diamond: 600
Ceramic substrate process classification:
According to the line ceramic substrate process is divided into: thin film, thick film, low temperature co-fired multi-layer ceramic (LTCC)
Thin Film Process (DPC) : Precise control of component circuit design (line width and film thickness)
Thick film process (Thick film) : to provide heat dissipation and weather conditions
Low temperature co-fired multilayer ceramic (HTCC) : The use of glass ceramics with low sintering temperature, low melting point, high conductivity of precious metal co-fired characteristics, multi-layer ceramic substrate) and assembly.
Low temperature co-fired multilayer ceramics (LTCC) : Stack several ceramic substrates and embed passive components and other ics
Thin film ceramic substrate process:
· Pretreatment → sputtering → photoresistance coating → exposure development → line plating → film removal
· Lamination → hot pressing → degreasing → substrate firing → circuit pattern formation → circuit firing
· Lamination → surface printed circuit pattern → hot pressing → degreasing → co-firing
· Printed circuit graphics → lamination → hot pressing → degreasing → co-firing
Ceramic substrate reliability test conditions:
Ceramic substrate high temperature operation: 85℃
Ceramic substrate low temperature operation: -40℃
Ceramic substrate cold and thermal shock:
1. 155℃(15min)←→-55℃(15min)/300cycle
2. 85 ℃ (30 min) please - - 40 ℃ (30 min)/RAMP: 10 min (12.5 ℃ / min) / 5 cycle
Ceramic substrate adhesion: Stick to the surface of the board with 3M#600 tape. After 30 seconds, tear quickly in a 90° direction with the surface of the board.
Ceramic substrate red ink experiment: Boil for one hour, impermeable
Test equipment:
1.High and low temperature humid heat test chamber
2. Three-box gas type cold and heat shock test chamber
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㎏
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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