Dongguan Precision Test Equipment Co., Ltd.

Maintaining Your Environmental Test Chamber: Ensuring Longevity and Reliable Results  At Dongguan Precision Test Equipment Co., Ltd., we understand that your environmental test chamber is a crucial investment for ensuring the quality and reliability of your products. To maximize its lifespan, maintain testing accuracy, and prevent costly downtime, regular and proper maintenance is essential. This guide outlines key maintenance procedures for your environmental test chamber: 1. Dedicated and Professional Management: For optimal care, we strongly recommend assigning dedicated, trained personnel to manage and maintain your test chamber. Where feasible, investing in professional training from the equipment supplier will equip your team with the specialized knowledge and skills needed for effective maintenance and troubleshooting. 2. Quarterly Condenser Cleaning: Air-Cooled Systems: Regularly (every three months) inspect and clean the condenser fan. Remove any dust or debris buildup on the condenser fins to ensure proper airflow and efficient heat exchange for the compressor. Water-Cooled Systems: In addition to maintaining the correct inlet water pressure and temperature, ensure the specified water flow rate is consistently provided. Crucially, schedule quarterly descaling and cleaning of the condenser's internal components to prevent scale buildup and maintain optimal heat transfer. 3. Quarterly Evaporator (Dehumidifier) Cleaning: Due to the forced air circulation within the test chamber and the varying cleanliness levels of test samples, dust and particulate matter can accumulate on the evaporator (dehumidifier coils). A regular cleaning schedule (every three months) is vital to maintain efficient heat exchange for cooling and dehumidification. 4. Circulation Fan Blades and Condenser Fan Cleaning & Balancing: Similar to the evaporator, the circulation fan blades and condenser fan blades can accumulate dust and debris depending on the chamber's operating environment. Regular cleaning is necessary to ensure proper airflow. Additionally, periodically check for any imbalance in the fan blades, which can lead to vibration and potential damage. 5. Maintaining an Optimal Ambient Environment: Environmental test chambers are precision instruments and often represent a significant investment. To promote their longevity and stable operation, we recommend placing them in a controlled ambient temperature environment, ideally between 8℃ and 23℃. For laboratories that cannot meet these conditions, installing appropriate air conditioning (for air-cooled units) or a cooling tower (for water-cooled units) is strongly advised. 6. Water Circuit and Humidifier Cleaning: A restricted water flow or scale buildup in the humidifier can lead to dry-burning and potential damage to the heating element. Therefore, it is imperative to regularly clean the water lines and the humidifier to ensure unobstructed water supply and efficient humidification. 7. Post-Test Routine: Adopting a consistent post-test procedure is a simple yet effective maintenance practice. After each test completion, set the chamber temperature to near ambient conditions and allow it to run for approximately 30 minutes before powering it off. Finally, wipe down the interior walls of the workspace to remove any residual moisture or contaminants. 8. Troubleshooting Principles: Environmental test chambers are complex systems comprising electrical, refrigeration, and mechanical components. When a malfunction occurs, a systematic and comprehensive approach to troubleshooting is essential. External to Internal: Begin by eliminating external factors such as cooling water supply and power supply issues. Systematic Analysis: Once external factors are ruled out, adopt a system-based approach. Start with a high-level system breakdown and then delve into more specific components. Logical Deduction: A reverse troubleshooting method can be effective. Begin by checking the electrical wiring diagrams for potential electrical system faults and then investigate the refrigeration system. Caution Before Disassembly: Never attempt to blindly disassemble or replace components without a clear understanding of the fault. This can lead to further complications and unnecessary expenses. 9. Long-Term Inactivity Protocol: If the test chamber is to be taken out of service for an extended period, we recommend powering it on for at least one hour every two weeks. This helps to circulate the internal fluids and prevent potential issues arising from prolonged inactivity. 10. Safe Relocation: Relocating an environmental test chamber should ideally be performed under the guidance of our qualified technical personnel. This will minimize the risk of accidental damage or malfunction during the moving process. By adhering to these maintenance guidelines, you can significantly extend the lifespan of your Dongguan Precision environmental test chamber, ensure the accuracy and reliability of your testing results, and ultimately protect your investment. For any specific maintenance inquiries or to schedule professional servicing, please do not hesitate to contact our dedicated support team.

At Dongguan Precision Test Equipment Co., Ltd., we understand the paramount importance of product safety and reliability across various industries. To help manufacturers ensure their products meet stringent quality standards and withstand real-world conditions, we offer a comprehensive range of environmental test chambers designed to comply with a multitude of international and national testing standards. This document serves as a guide to the key testing standards our equipment is built to meet, particularly focusing on the critical area of New Energy Battery Testing and other essential environmental simulations.   I. Powering the Future Safely: New Energy Battery Testing Standards   The safety and performance of new energy batteries are critical. Our test chambers are designed to facilitate testing according to the following key standards: Mechanical Impact Testing: UL 1642: Standard for Lithium Batteries - Mechanical Tests - Impact Test UL 2054-2005: Household and Commercial Batteries - Mechanical Tests - Impact Test UN 38.3: Recommendations on the Transport of Dangerous Goods - Manual of Tests and Criteria - Section 38.3 - Impact Test GB/T 18287-2000: General Specification for Lithium-ion Batteries for Cellular Telephones - Heavy Object Impact Test SJ/T 11169-1998: Standard for Lithium Batteries - Impact Test YD 1268-2003: Safety Requirements and Test Methods for Lithium Batteries and Chargers for Mobile Communication Handsets - Impact Test SJ/T 11170-1998: Safety Standard for Household and Commercial Batteries - Mechanical Tests - Impact Test Crush (Squeeze) Testing: GB/T 2900.11-1988: Safety Performance Inspection Specification for Lithium-ion Batteries for Miner's Lamps - Crushing YD 1268-2003: Safety Requirements and Test Methods for Lithium Batteries and Chargers for Mobile Communication Handsets - Crush Resistance Performance SJ/T 11169-1998: Standard for Lithium Batteries - Crush Test UL 1642: Standard for Lithium Batteries - Compression Test GB/T 8897.4-2002: Primary Batteries - Part 4: Safety of Lithium Batteries - Crushing SJ/T 11170-1998: Safety Standard for Household and Commercial Batteries - Crushing YDB 032-2009: Backup Lithium-ion Battery Packs for Communication Use - Resistance to Extrusion UL 2054: Standard for Household and Commercial Batteries - Compression Test QB/T 2502-2000: General Specification for Lithium-ion Rechargeable Batteries - Crushing (Internal Short Circuit) Test Puncture (Nail Penetration) Testing: GB/T 18332.2-2001: Nickel-metal Hydride Rechargeable Batteries for Electric Road Vehicles - Puncture Test MT/T 1051-2007: Lithium-ion Batteries for Miner's Lamps - Nail Penetration Test II. Simulating Diverse Climatic Conditions: High & Low Temperature and Humidity Testing Our High and Low Temperature Test Chambers, Constant Temperature and Humidity Test Chambers, and High and Low Temperature Humidity Test Chambers are engineered to meet the requirements of the following standards, ensuring reliable performance evaluation under various climatic stresses: GB/T 5170.5-2008 GB/T 10586-2006 GB/T 2423.1-2008 (Test A: Cold) GB/T 2423.2-2008 (Test B: Dry Heat) GB/T 2423.3-2006 (Test Ca: Steady State Damp Heat) GB/T 2423.4-2008 (Test Db: Alternating Damp Heat) III. Withstanding Rapid Temperature Changes: Thermal Shock Testing Our Thermal Shock Test Chambers are designed to subject products to rapid and extreme temperature variations, adhering to and satisfying the requirements of the following standards: GB/T 2423.1-2001: Environmental testing for electric and electronic products - Part 2: Test methods - Test A: Cold GB/T 2423.2-2001: Environmental testing for electric and electronic products - Part 2: Test methods - Test B: Dry heat GB/T 2423.22-1989: Environmental testing for electric and electronic products - Part 2: Test methods - Test N: Change of temperature GJB 150.3-86: Environmental test methods for military equipment - Low temperature test GJB 150.4-86: Environmental test methods for military equipment - High temperature test GJB 150.5-86: Environmental test methods for military equipment - Temperature shock test GJB 360.7-87: Test methods for electronic components - Method 405: Temperature shock test GJB 367.2-87: Test methods for electronic equipment - 405 Temperature shock test SJ/T 10187-91: Y73 series temperature cycling test chambers - Single chamber type SJ/T 10186-91: Y73 series temperature cycling test chambers - Two chamber type IEC 68-2-14: Environmental testing - Part 2: Tests - Test N: Change of temperature GB/T 2424.13-2002: Environmental testing for electric and electronic products - Part 2: Test methods - Guidance for temperature cycling tests GB/T 2423.22-2002: Environmental testing - Part 2: Test methods - Test N: Change of temperature QC/T 17-92: General rules for weathering test of automotive parts EIA 364-32: Thermal Shock (Temperature Cycling) Test Procedure for Electrical Connectors and Sockets Environmental Effects Assessment IV. Accelerating Failure Analysis: Highly Accelerated Life Testing (HAST) Chambers Our Highly Accelerated Life Testing (HAST) Chambers are designed to accelerate the aging process of products under controlled high temperature and high humidity conditions, complying with: GB/T 5170.2-1996: Environmental testing equipment for electric and electronic products - Part 2: Temperature chambers IEC 60068-2-66-1994: Environmental testing - Part 2-66: Tests - Test Cy: Damp heat, steady state, accelerated test primarily intended for components V. Evaluating Resistance to Sunlight: Ultraviolet Weathering Test Chambers Our Ultraviolet Weathering Test Chambers simulate the damaging effects of sunlight, rain, and dew to assess the durability of materials exposed to outdoor environments, meeting the requirements of standards such as: ASTM G154: Standard Practice for Operating Fluorescent Ultraviolet (UV) Lamp Apparatus for Exposure of Nonmetallic Materials ASTM D4587-91:   ISO 11507/4892-3: Plastics - Laboratory sources of light - Part 3: Fluorescent UV lamps NE 927-6 ASTM G 153: Standard Practice for Operating Enclosed Carbon Arc Light Apparatus for Exposure of Nonmetallic Materials ASTM D 4329: Standard Practice for Fluorescent UV Exposure of Plastics   ASTM D 4799: Standard Practice for Accelerated Weathering Test Conditions and Procedures for Bituminous Materials (Xenon Arc Method) ASTM D 4587: Standard Practice for Conducting Determinations of Resistance to Industrial Fluids   SAE J 2020: Accelerated Exposure of Automotive Exterior Materials Using a Fluorescent UV and Condensation Apparatus ISO 4892: VI. Your Partner in Compliance and Reliability: Dongguan Precision At Dongguan Precision Test Equipment Co., Ltd., we are committed to providing high-quality, reliable environmental test chambers that empower manufacturers to meet the stringent demands of various industries. Our equipment is designed with precision engineering and adheres to a wide array of national and international testing standards, ensuring the safety, performance, and longevity of your products. Contact us today to discuss your specific testing requirements and discover how our comprehensive solutions can help you achieve compliance and build greater confidence in the reliability of your products.

I. Understanding Thermal Shock Testing for PCBs Concept: Thermal shock testing, also known as temperature cycling or thermal resistance testing, simulates the rapid temperature changes or alternating high and low temperature environments that a product might experience during its lifecycle.     Principle: During these abrupt temperature shifts or alternating extremes, the various materials comprising a PCB – including the substrate, prepreg (PP), copper plating, and solder mask – undergo expansion and contraction. The resulting stress and differences in the Coefficient of Thermal Expansion (CTE) of these materials can lead to physical damage, degradation, and changes in electrical resistance within the PCB.   II. The Importance of Thermal Shock Testing for PCBs Thermal shock testing plays a vital role throughout the lifecycle of a PCB: Early Design Flaw Detection (R&D Stage): Identifying and rectifying design weaknesses in the PCB at the research and development stage prevents costly issues later. This shortens the development cycle and reduces overall expenses. Quality Control in Manufacturing: Assessing whether the quality of manufactured PCBs meets customer requirements. Detecting manufacturing process defects early allows for timely investigation and improvement, ensuring the safety and quality of shipped products.   Material and Process Validation: Evaluating the reliability of base materials, solder masks, prepregs, and manufacturing processes to determine their suitability for the product's intended environment. Material and Process Comparison: Comparing the thermal shock resistance of PCBs fabricated with different materials and processes to identify superior options. III. Equipment Parameters Our thermal shock chambers at Dongguan Precision are designed to deliver precise and reliable testing:   Parameter Specification Nominal Internal Volume 300L Test Temperature Range -70℃ ~ 200℃ Temperature Fluctuation ≤ 1℃ Temperature Deviation ±2℃ (≤150℃) / ±3℃ (>150℃) Heating Rate (High Temp. Chamber) ≥ 11℃/min Cooling Rate (Low Temp. Chamber) ≥ 5℃/min Max. Sample Weight 10kg   IV. Case Studies: Real-World PCB Thermal Shock Testing   Case Study 1: High-Layer Count Test Board   A high-layer count test board underwent online thermal shock testing to verify the performance of the selected substrate material against customer specifications. The testing conditions and requirements were as follows:   Test Item Test Conditions Test Requirements Thermal Shock (Online) -55℃/15min, 125℃/15min, 1000 Cycles 1. Resistance Change Rate ≤ 5% 2. No delamination, board cracking, orbarrel cracking observed in cross-section analysis                                         Resistance change rate curve chart Sectional view of Test Position 1                            Sectional view of Test Position 3 Outcome: Post-testing, the resistance change rate at certain test points exceeded 5%. Cross-sectional analysis revealed through-hole copper barrel cracking. This indicated a potential weakness in the substrate material's ability to withstand the stress induced by repeated temperature extremes. The findings prompted a re-evaluation of the substrate material selection for this high-layer count application.   Case Study 2: Automotive Test Board An automotive test board was subjected to thermal shock testing to validate the performance of the solder mask material against customer requirements. The testing conditions and requirements were as follows:   Test Item Test Conditions Test Requirements Thermal Shock Test -40℃/15min, 125℃/15min, 500 Cycles No solder mask blistering, delamination, or cracking observed 1. IPC-TM-650 2.6.7.1A Conformal Coating Thermal Shock Resistance 2. IPC-TM-650 2.6.7.2C Thermal Shock, Thermal Cycling and Continuity 3. IPC-TM-650 2.6.7.3 Solder Mask Thermal Shock Resistance Observation diagram after the test   V. Common Thermal Shock Test Conditions The specific test conditions for thermal shock testing vary depending on the application and industry standards. Here are some common examples:   Sample Type Low Temperature (°C) High Temperature (°C) Dwell Time (min) Cycles Automotive -40 125 15 / 30 500 -55 140 1000 -65 150 1500 High-Layer Count -40 125 15 / 30 250 -55 125 500 High-Frequency -40 125 15 500 Package Substrate -55 150 30 1000   VI. Reference Standard Conditions (Printed Boards)     Item Qualification Quality Conformance/Acceptance Testing Baking Conditions (105~125)℃ / 6h Reflow Soldering 6 times IR Test Temperature (Low) Negotiated between supplier and buyer -40℃, -55℃ (default), -65℃ Test Temperature (High) Negotiated between supplier and buyer Min: Tg-10℃ (TMA) / Reflow Peak Temp -25℃ / 210℃ Sample Temperature Change Rate > 10℃/min (both hot and cold transition) > 1℃/S (both hot and cold transition) Test Cycles Negotiated between supplier and buyer 100 Resistance Change Rate Negotiated between supplier and buyer 5%     VII. Reference Standard Conditions (Conformal Coating & Solder Mask)     Level Low Temperature (°C) High Temperature (°C) Dwell Time (min) Cycles Remarks 1 -40 125 15 100 Default test condition when no requirement specified 2 -65 125 15 100 3 -65 250 15 100   Outcome: Microscopic examination after the test revealed cracking in the solder mask at the corners of the pads. This indicated insufficient flexibility or adhesion of the solder mask material to withstand the thermal stresses encountered in the automotive environment. The results led to an investigation into alternative solder mask materials with improved thermal shock resistance for this automotive application.     VIII. Conclusion: Partnering with Dongguan Precision for Reliable Thermal Shock Testing   The case studies highlight the critical role of thermal shock testing in identifying potential weaknesses in PCB materials and designs. At Dongguan Precision Test Equipment Co., Ltd., we are committed to providing high-performance thermal shock chambers and expert support to help our customers thoroughly evaluate the reliability of their PCBs. Our equipment is designed for accuracy, repeatability, and adherence to industry standards. By understanding the principles of thermal shock testing and utilizing reliable equipment, manufacturers can proactively address potential issues, ensuring the long-term performance and durability of their electronic products. Contact Dongguan Precision today to discuss your specific PCB testing needs and discover how our solutions can benefit your quality assurance processes.