HALT is a rigorous methodology designed to push aerospace products beyond their operational limits, identifying potential weaknesses and failure modes that traditional testing methods might miss. By subjecting aerospace products to extreme stress conditions—far beyond what they would encounter in their normal life span—HALT provides invaluable insights into the inherent durability and reliability of aerospace components.

The beauty of HALT lies in its ability to reveal the unknown. It accelerates the aging process, simulating years of wear and tear in a fraction of the time, thereby uncovering latent defects and vulnerabilities. This preemptive identification allows for critical design modifications and enhancements, significantly reducing the risk of costly failures and recalls post-launch.

For aerospace manufacturers, the implications of HALT are profound. It signifies a commitment to excellence and represents a strategic investment in the product’s lifecycle. By integrating HALT into the development process, aerospace companies can confidently navigate the complex landscape of product reliability, ensuring that their products are not just fit for purpose but are built to last.

Aerospace Testing Laboratory: Advancing Product Reliability with HALT

In the quest for unparalleled aerospace product reliability, our aerospace testing laboratory offers organizations the use of Highly Accelerated Life Testing (HALT) methodologies. HALT represents a commitment to excellence and a testament to our dedication to advancing aerospace technology.

The HALT process within our aerospace testing laboratory involves a series of accelerated stress tests, including rapid temperature cycling, 6 degrees of freedom random vibration tests at varying frequencies, and combined environment tests. These tests are designed to expose products to conditions far more severe than they would ever encounter in service. By doing so, Delserro Engineering Solutions can identify potential failure points and address them long before they become real-world issues.

Key Advantages of HALT in Our Aerospace Testing Laboratory:

• Early Detection of Design Flaws: By applying stressors that exceed the normal operational limits, HALT helps uncover hidden weaknesses in product designs.
• Cost-Efficiency: Identifying and rectifying potential failures before products hit the market significantly reduces the risk of costly recalls and brand damage.
• Reduced Time to Market: Accelerated testing means faster validation of product robustness, enabling quicker transitions from design to production.
• Customized Testing Strategies: Our aerospace testing laboratory tailors HALT protocols to match the specific requirements and challenges of each aerospace product.

Through the strategic application of HALT, our aerospace testing laboratory supports the industry’s continuous drive toward innovation and reliability. We help our clients achieve the highest standards of performance and dependability in their aerospace endeavors.

Embrace the future of aerospace product testing with us. Discover how our HALT methodologies can elevate your products’ reliability to new heights.

The Impact of HALT on Aerospace Testing and Product Integrity

Highly Accelerated Life Testing (HALT) has significantly influenced aerospace testing practices, leading to more resilient and reliable aerospace products. HALT extends beyond traditional testing methods by focusing on identifying potential failure modes early in the product development cycle.

The practical benefits of integrating HALT into aerospace testing include:

• Early Detection and Rectification of Flaws: By pushing components beyond their operational limits, HALT helps uncover hidden weaknesses in the design and materials, allowing for early modifications.
• Comprehensive Stress Testing: HALT subjects aerospace products to a variety of stressors, including extreme temperatures and vibrations, to ensure they can withstand a broad range of operational environments.
• Support for Innovation: The rigorous demands of HALT encourage the exploration of new materials, designs, and manufacturing techniques, driving innovation in aerospace technology.
• Risk Mitigation: Identifying potential issues before products reach the market minimizes the risk of costly recalls and enhances the overall safety of aerospace missions.
• Streamlined Product Development: HALT can reduce the time required for product testing and validation.
• Stakeholder Confidence: Demonstrating a commitment to thorough testing and product reliability helps build trust among manufacturers, regulatory agencies, and users.

HALT’s role in aerospace testing is to provide a practical, systematic approach to improving product reliability and integrity. It’s about making informed decisions based on comprehensive data. Through the application of HALT, the aerospace industry can achieve a balance between innovation and reliability.

Improve Your Aerospace Products with HALT

Adopting Highly Accelerated Life Testing (HALT) for your aerospace products is a strategic move toward securing a competitive edge in the aerospace industry. By incorporating HALT into your product development process, you’re committing to the highest standards of safety, durability, and performance.

Our aerospace testing laboratory is equipped with state-of-the-art HALT technology and a team of experienced engineers dedicated to helping you achieve excellence in product development. Our aerospace testing laboratory’s ISO/IEC 17025 and ISTA accreditation are a testament to our capability to execute tests that are both precise and reliable. We understand the unique challenges of the aerospace sector and are committed to providing tailored testing solutions that meet your specific needs.

In the dynamic field of aerospace, staying ahead means continually pushing the boundaries of what’s possible. Partner with Delserro Engineering Solutions to harness the power of HALT and take your aerospace products to new heights.

Contact us today to learn more about how we can support your journey toward unparalleled reliability and success in the aerospace industry.

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In the fast-evolving medical device industry, the pathway to market success is marked by stringent standards. Delserro Engineering Solutions (DES) plays a pivotal role in this journey, offering expert testing services for both medical devices and their packaging. Recognizing that each product—from intricate surgical instruments to complex diagnostic machinery—requires rigorous scrutiny, DES employs cutting-edge environmental, vibration, HALT, and shock testing in its state-of-the-art facilities.

The comprehensive range of tests at DES is designed to address the specific challenges faced by medical devices in real-world conditions. By simulating various environmental factors and stressors, DES ensures that both the device and its packaging maintain integrity and functionality throughout their lifecycle. This attention to detail is crucial in the medical device industry where precision is paramount, and the smallest oversight can have significant consequences.

Our team delves into the nuances of each project, partnering with manufacturers to understand their unique needs and challenges. This collaborative approach allows for customized testing solutions that cater to the diverse requirements of the medical device sector.

Medical Device Testing: Meeting Rigorous Standards with DES

The field of medical device testing necessitates strict adherence to a variety of industry standards to ensure compliance. At Delserro Engineering Solutions (DES), we pride ourselves on aligning our testing services with these critical standards, assuring that medical device packaging meets the highest benchmarks of quality and reliability.

1. ISTA Compliance for Transportation Durability: As a certified testing laboratory, we conduct packaging tests that comply with International Safe Transit Association (ISTA) standards. These tests simulate the stress that packaging undergoes during transportation, ensuring that it can protect medical devices from damage due to shock, vibration, and other environmental factors.
2. ASTM Standards for Material Quality: Adhering to ASTM D7386 and other ASTM standards, we evaluate the material quality of packaging, assessing its durability and resilience under various conditions. These tests are crucial for determining if the packaging can maintain the sterility and integrity of medical devices.
3. ISO/IEC 17025 Accredited Testing: Our ISO/IEC 17025 accreditation signifies our technical competence in conducting standardized tests. This includes ensuring that medical device packaging meets specific environmental testing requirements crucial for maintaining product reliability throughout its lifecycle.
4. MIL-STD Compliance for Military-Grade Assurance: For products that require a higher level of robustness, such as those used in military applications, we ensure compliance with Military Standards like MIL-STD-810 and MIL-STD-202. This ensures that products can withstand extreme environmental conditions and rough handling.
5. Customized Testing Protocols: Beyond standard compliance, we offer customized testing solutions tailored to unique client specifications. Whether it’s assessing the resilience of packaging or devices under specific temperature conditions or evaluating its performance under unique mechanical stresses, our state-of-the-art facilities are equipped to handle diverse testing needs.

Navigating Challenges in Medical Device Package Testing

The journey from conception to market for medical devices is fraught with challenges, particularly when it comes to packaging. At Delserro Engineering Solutions (DES), we understand that the package is a crucial component that ensures device safety and efficacy during transit and storage.

With the medical device industry facing ever-tightening regulations, manufacturers must ensure their packaging can withstand a range of environmental stresses. DES’s medical device package testing services are designed to address these exacting standards, from simulating transportation conditions to mimicking the rigors of handling and storage.

Moreover, DES’s commitment to staying ahead in an evolving industry landscape means continuously updating our medical device package testing processes in line with the latest regulations and standards. Our laboratory’s ISO/IEC 17025 and ISTA accreditation are a testament to our capability to execute tests that are both precise and reliable. We engage with the latest industry practices, ensuring that our clients’ medical device packaging is robust, compliant, and above all, safe for the end-user.

Recognizing that off-the-shelf solutions do not fit all, our engineers work closely with clients to develop specialized medical device package testing plans that match the unique needs of their products. Whether it’s fine-tuning temperature cycles to match specific geographic journeys or tailoring shock tests for delicate components, DES ensures that every aspect of packaging is scrutinized and optimized for peak performance. This meticulous attention to detail ensures that when a medical device reaches its destination, it does so with its integrity unblemished and its functionality assured.

DES embraces the challenges of medical device package testing with a blend of accredited procedures, advanced technology, and customized service. By doing so, we ensure that our clients’ products are not only compliant but exemplify the highest standards of the medical device industry. Contact us to learn more about how we can address the specific testing needs for your medical device packaging.

Proven Expertise in the Medical Device Industry at DES

At Delserro Engineering Solutions (DES), our expertise in the medical device industry is more than just a claim—it’s a commitment. With over three decades of experience, DES has established itself as a leader in providing comprehensive testing solutions for both medical devices and their packaging. Our deep understanding of medical device industry standards positions us uniquely to help our clients navigate the complexities of product testing and compliance.

Our team of skilled engineers and technicians is dedicated to delivering results that surpass expectations. At DES, we understand that the medical device industry is rapidly evolving, and staying ahead means being equipped to adapt to new challenges. We offer personalized service, working closely with our clients to understand their specific needs and providing tailored solutions that align with their goals. This partnership approach has made us a trusted name among industry giants.

In the medical device industry, where precision, quality, and reliability are non-negotiable, DES stands as a beacon of excellence. We invite you to experience the DES difference—where quality testing leads to quality products.

Contact us today to learn how our expertise can enhance the reliability and market success of your medical devices.

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HALT Testing can be a competitive advantage for companies when performed correctly and at the right time. 

The best time to begin HALT testing during the product development process is when prototypes first become available. HALT is designed to expose product flaws and weaknesses, therefore, a successful test will produce areas for product improvement.  A lot of designers and manufacturers tend to wait until the product design is mature.  At that time, further process improvements or design changes become too costly or timely.  Ideally, HALT should be performed while the product is still fluid and moderate changes don’t become setbacks.  This allows product design to move much more rapidly and efficiently, saving the company time and money.  HALT testing can also eliminate the need for further verification if the product has proven reliable at the much more extreme conditions exposed to in HALT. 

Delserro Engineering Solutions, Inc. (DES) has the knowledge and experience to provide HALT testing services for your product.  We offer both standard and customized test solutions depending on your testing needs.  For more information on HASS, HALT or other testing services, contact DES or call 610.253.6637.

The post HALT Testing: When Should You Perform It? appeared first on Delserro Engineering Solutions.

• What is HALT (Highly Accelerated Life Testing) and Why Perform HALT?
• What Kind of Failures Occur During HALT?
• What Equipment is Used for HALT?
• What is a Typical HALT Procedure?

Number of Samples

It is recommended to HASS as many samples as possible per batch.  This will keep the screening cost per part to a minimum.  The number of samples will depend on the fixtures needed to attach the units to the chamber table, monitoring requirements, and power requirements.  The HASS setup should be optimized to work efficiently in a production environment.

Fixtures

The HASS fixtures should be manufactured for fast and efficient loading and removal of product.  They should hold as many products as possible.  The fixtures must be designed to support both vibration and thermal loading.  They must be durable in order to withstand the fatigue damage caused by the repeated stresses that will occur over the fixture’s lifetime.  The fixture needs to be lightweight, rigid, and have low thermal mass.

Functional Test Protocol

A Functional Test Protocol (FTP) must be performed on each sample undergoing HASS.  The FTP must check that the product functions within predetermined specifications.  The FTP coverage should be as comprehensive as possible for each sample under test.  The FTP equipment will be located outside of the chamber.

Proof of Screen

Before starting a HASS program, a Proof of Screen must be performed first to demonstrate that the product has sufficient life after the HASS and to demonstrate that the screen does find product defects.  After the Proof of Screen has been validated, production screening can begin.

It may be possible to determine the effectiveness of the HASS by seeding samples of the product with known defects.  The seeded defects could include solder defects or typical manufacturing process issues based upon past history of similar products.  Since, it is often very difficult to create a realistic seeded defect, mixed results may be obtained and judgment may need to be exercised as to whether the seeded defects are realistic.  Field returned units may be good candidates for seeded samples.

The main objective of the Proof of Screen is to prove that the screen has not removed significant life from the products during HASS.  The HASS profile should be repeated a minimum of 20 times, without failure occurrences. This shows that production units exposed to only one pass of the HASS profile, will still have at least 95% of their useful life remaining, or a maximum of 5% of their life was removed during one HASS screen.

Removing 5% of the life sounds like a lot, but in reality, the units would probably be able to withstand many more than 20 HASS cycles if a good job was done ruggedizing the product during HALT.  Also, ‘life” is an accelerated life.  The stresses in HASS are usually higher than normal use.  To prove that they still have sufficient life remaining after HASS, it is recommended to run the same Proof of Screen units through qual testing or reliability demonstration testing after the Proof of Screen.  If no failures show up, then it is not likely that the HASS would cause some long-term failure mode.

The Proof of Screen should be performed using the production HASS fixtures and the FTP equipment.  During the Proof of Screen, the products should be instrumented with thermocouples and accelerometers to check that a sufficient temperature rate of change/uniformity has been achieved and that sufficient vibration levels are being transmitted to the product.

Production HASS

A specific production HASS procedure should be developed for each product.  This is because the results from each HALT on dissimilar products may be different.  Typical general requirements are listed below.

General Requirements

The HASS should be conducted by qualified engineers or technicians who are familiar with how to use the HALT/HASS chambers and the support equipment.  All gauges, instruments, test equipment and measuring tools should have a current calibration status.

ESD Protection

Good ESD precautions should be used on any electronic product.  At a minimum, an ESD gown and wrist strap should be worn when handling any product with exposed circuit boards.  FTP test Fixtures shall be on a grounded stand.  Connections to product shall be carried out using ESD precautions.

Report

The reporting depends upon each product and upon each customer’s requirements.  Typically, a Pass/Fail report or certificate would be issued with each product or batch of products.  The pass/fail report or certificate should list the product serial number, a pass or fail status, and a summary of the failure mode if applicable at a minimum.

Disposition

The disposition depends upon each product and upon each customer’s requirements.  DES’s typical disposition procedure is as follows:

• All products are tagged with a Green Passed HASS label or a Red Failed HASS label as appropriate.  This may be stuck on the product or the outside of its packing.
• A HASS certificate will be inserted with each unit inside of its packing.

Corrective Action

Finally, a system to determine root cause of problems, develop corrective actions and verify corrective actions should be instituted.  Typically, a formal system such as FRACAS is implemented.  FRACAS stands for Failure Reporting, Analysis and Corrective Action System.  FRACAS is sometimes implemented using computer software and provides a process for reporting, classifying, analyzing failures, and planning corrective actions in response to those failures.

DES has over 20 years of experience performing HALT/HASS testing on a variety of medical, commercial, industrial and military products.  For more information on HASS, HALT or other testing services, contact DES or call 610.253.6637.

The post How to Implement a HASS Program appeared first on Delserro Engineering Solutions.

Two very important concepts to be applied in HASS are:

1. HALT must be performed before HASS to produce a robust product design before you enter into a HASS screening program. To learn more about Highly Accelerated Life Testing (HALT), please read our blogs:

What Is HALT (Highly Accelerated Life Testing) And Why Perform HALT?

What Is A Typical HALT Procedure?

What Equipment Is Used For HALT?

What Kind Of Failures Occur During HALT?

Circuit Board HALT Testing Case Study

Rapid HALT – A Cost Effective Alternative to HALT

An Informational Guide to HALT and HASS

2. A Proof of Screen (POS) (sometimes called Safety of Screen) must be used to validate the HASS to prove that sufficient life is left for a normal use lifetime.

During HASS, stresses may be higher than normal operation to precipitate defects in a short amount of time, however the stresses are within the capability of the design as proven by the HALT. HASS stresses are also typically more aggressive than those used in traditional Environmental Stress Screening (ESS) which makes HASS a more efficient screen than ESS. HASS screens are typically an hour to a few hours whereas ESS screens may take a day to a few days.

The types of stresses used for HASS are similar to those used in HALT. HASS uses combined temperature cycling, random vibration and electrical loading/monitoring. HASS screens are performed in the same type of chamber that is used for HALT. The vibration in HASS is randomly applied over a broad frequency range producing energy to 10,000 Hz in 6 degrees of freedom.

What is a Typical HASS Profile?

A typical HASS profile used by DES is shown in Figure 1. The first part of the HASS profile (0 to ≈ 40 minutes) is a precipitation screen used to precipitate latent defects. The precipitation screen consists of high levels of steady vibration and temperature rate of changes of approximately 40 – 60 °C/minute. The second part of the HASS profile (40 – 75 minutes) is a detection screen used to detect precipitated defects. The detection screen consists of lower levels of modulated vibration and slower temperature rate of changes of approximately 5 – 10 °C/minute. It is sometimes easier to find intermittent defects during the detection screen because the stress levels are lower and the temperature rate of change is slower.

Figure 1.  Sample HASS profile used by DES

Why Use HASS?

• To produce a rugged, reliable product
• To regularly audit or screen your production components to check for and improve manufacturing quality
• To produce a more rugged/reliable product with less field failures and warranty expenses

What are the Benefits of HASS?

HASS screens are shorter than traditional Environmental Stress Screening (ESS) methods. This results in reduced time and cost to screen production.  Since the screens are shorter and more aggressive than ESS:

• Defects are typically found sooner
• Problems are corrected faster
• Fewer defects reach the customers’ hands

Overall product quality and manufacturing process control are improved when using HASS. Reliable products lead to happy customers. Happy customers lead to increased profits/market share!

DES has more than 20 years of experience performing HALT/HASS testing on a variety of medical, commercial, industrial and military products. For more information on HASS, HALT or other testing services, contact DES or call 610.253.6637.

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The HAST acronym stands for Highly Accelerated Temperature/Humidity Stress Test and is sometimes shortened to Highly Accelerated Stress Testing. HAST makes use of accelerated temperature and humidity conditions to precipitate failures which could be caused by long term exposure to humid environments.

HAST has been developed to replace Temperature-Humidity-Bias (THB) testing which has typical conditions of 85 ⁰C and 85 % RH along with a bias voltage applied to the sample. A typical THB test time would be 1000 hours. HAST uses increased test temperatures of 110 to 130 ⁰C which decreases the test time to as low as 96 hours compared to a THB test. Thus, by choosing HAST over THB for an accelerated reliability test, testing can be completed in days, not weeks.

HAST utilizes a positive pressure inside the test chamber along with temperatures above 100 ⁰C and controlled humidity. This requires that the chamber be tightly sealed to prevent leaks so that the test conditions can be maintained. Testing can be performed with or without a voltage bias on the samples.

For a biased test, a DC voltage is applied to the samples. The samples are connected to wires or sockets located inside of the test chamber. Wires inside of the chamber pass through a sealed feedthrough where they are connected to power supplies located outside of the chamber. The bias can be continuous or cyclic DC voltage. Note that cyclic DC voltage is not the same as AC voltage.

Common standards used for HAST are JESD22-A110, JESD22-A118, IEC 60068-2-66. Typical test conditions are:

Delserro Engineering Solutions, Inc. (DES) has many years of experience performing HAST testing and can assist customers in setting up a test using the proper test conditions. So, if you do not know what test conditions that you should use or what specification to choose then we will help you because we are HAST experts!

Contact us or call 610.253.6637 to find out what DES can do for you!

The post A Primer for HAST: Highly Accelerated Stress Testing appeared first on Delserro Engineering Solutions.

Customer Goal

A customer approached DES looking to perform Highly Accelerated Life Testing (HALT) on a new circuit board design.  DES and the customer agreed to test the circuit boards using DES’s traditional HALT test procedure which calls for hot/cold temperature steps followed by rapid temperature ramping, vibration steps and combined temperature and vibration stresses.  HALT testing on electrical componentry is quite common across industry to expose design weaknesses; both mechanical and electrical (What is HALT and Why Perform HALT?).  Typical failures include poor solder connections, overheating, component failure, etc. (What Kind Of Failures Occur During HALT?)

Results

The hot/cold temperature steps exposed soft failures such as power resets and lack of communication for the circuit boards.  One hard failure was also exposed during this stage which proved to be a recurring problem and thus an area of weakness in the product design.  The units functioned properly during the vibration steps and rapid thermal ramping stages.  The combined temperature and vibration stage, however, revealed the same issue as seen in the first stage on two other units.

The circuit board featured potted componentry for purposes exclusive to the customer.  This potted feature cracked on multiple units throughout testing and caused all sorts of communication issues for the units.  In 3 days the customer was able to expose a product design weakness that would most likely have caused a number of warranty and reliability issues.  In the words of the customer:

“The results from this testing have identified strong and
more importantly weak areas in our design.”

– Customer

HALT testing is a necessity for products with electrical circuity in terms of preventing field failures and high product return rates.  Problems such as these can be really damaging to a company’s bottom line if not addressed early in the design process.  Fortunately this customer has had experience with HALT in the past and chose to perform HALT before finalizing the product design.  DES has over 20 years of experience performing HALT testing on a variety of medical, commercial, industrial and military products.  Schedule your next HALT test with us by contacting us or call us at 610.253.6637.

The post Circuit Board HALT Testing Case Study appeared first on Delserro Engineering Solutions.

• What is HALT Highly Accelerated Life Testing and why perform HALT?
• What is a typical HALT procedure?

A Rapid HALT is an abbreviated HALT, typically one day of tests, making it a great cost-effective solution for those seeking faster qualitative results.  Exposing a product to a Rapid HALT early in the design process can help reduce product development time and cost by enabling manufacturers to identify flaws or areas of improvement before it’s too late.

Rapid HALT’s are a good tool for assessing the reliability of different suppliers of components but can also be used to assess the reliability of less complicated products.  For example, DES has performed Rapid HALT’s to evaluate the reliability of different suppliers of power supplies, cooling fans, and LED’s.  DES has also performed a Rapid HALT to study different fastening methods in order to determine which was more robust.

Rapid HALT profiles may vary slightly depending on the product.  Figure 1 illustrates DES’s standard Rapid HALT profile.  Vibration levels are ramped up concurrently with hot and cold temperature cycles.  The stresses are increased until the practical limits of products have been reached.  Examples of practical limits include the melting temperature of solder joints or excessive softening of plastics.  These stress levels are obviously well beyond the scope of most product designs and that is ok.  The purposes of any HALT is time compression by applying higher-than-normal stress levels.  The user should not necessarily focus on what level of stress caused the problem, but should focus on improving the weak points in their product.

Many times our customers are surprised with the Rapid HALT results because the less expensive components perform better.  Thus our customers are able to apply a significant cost reduction to their products.  This results in increased profits and reduced warranty costs.

For more information on HALT or other testing services, contact DES or call 610.253.6637.

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A customer approached DES looking to find an accelerated test solution for an AC powered cooling fan used in one of their products.  The product had been established in the marketplace and the company was now looking for ways to reduce cost by looking at different cooling fan suppliers.  Most fans, however, have a mean life rated for over 20,000 hours, so a typical accelerated life test would require a significant amount of time and money. 

DES Solution

Performing a quantitative accelerated life test on cooling fans presents challenges because they have such a long lifespan.  Reasonably speaking, the shortest quantitative solution for determining the lifespan of a fan could take as long as a couple months.  DES proposed a qualitative solution, a Rapid HALT.  A Rapid HALT (Highly Accelerated Life Test) is designed to apply a variety of stresses, concurrently, to a product in order to significantly time compress a product’s lifespan.  A typical Rapid HALT lasts only one day which is extremely convenient for companies that need results quickly.

Results

A sample size of 3 cooling fans were tested for 4 different fan suppliers.  We will refer to these suppliers as Supplier A, B, C and D.  All 12 fans were placed in the chamber together and a Rapid HALT was conducted.  None of the four suppliers survived testing without some issues but the results were still differentiating.  Supplier A had no electrical issues in any of its samples but the fan blades on all 3 samples vibrated off the armature.  Fans of Supplier B, all experienced sputtering of the fan blade and eventually saw two of its fans current levels drop to 0.  By the time testing was completed, none of the fans were functioning.  Supplier C fared slightly better than A and B.  One of Supplier C’s fans lost current at the most extreme step and never recovered.  The other two however, experienced fan blade sputtering but were functioning normally upon final inspection.  Supplier D performed the best out of the four suppliers and thus would be considered the most durable of the suppliers tested.  Only one of the fans experienced any issues, in which it lost current at the most extreme step.  Upon final inspection all of the fans were functioning normally.

There are other factors to consider such as price and accessibility but these results were able to successfully assist our customer in differentiating between the reliability of the four fan suppliers.  While a HALT is qualitative and will not produce an actual estimated fan lifetime, it is a great comparison tool to evaluate the reliability of different suppliers faster and less expensive than traditional testing techniques.

The post Cooling Fan Reliability Testing Case Study appeared first on Delserro Engineering Solutions.

If the product fails to operate, the temperature or vibration will be changed toward ambient room conditions followed by a short dwell period to see if the product recovers. If the product is non-operational after dwelling at ambient conditions, trouble shooting will take place to find the failed component. The failed component will then be removed, repaired or replaced with a new component (as is practical) in an effort to expand the test stresses.

Relevant Failures

All HALT failures are relevant unless it is determined that the failure was caused by a condition external to the product which is not a test requirement. Relevant failures may include, but are not limited to the following:

• Design and Workmanship Failures
• Failures caused by Poor Manufacturing
• Component Part Failures
• Multiple Failures
• Intermittent Failures
• Built-in-Test Failures

All relevant failures represent an opportunity for improvement and should be thoroughly investigated to determine their root cause. All relevant failures should be evaluated as to whether or not they can be corrected with a reasonable amount of effort and cost. However, all failures that prevent a product from functioning in its normal environment should be fixed! Figures 1 through 3 show examples of relevant HALT failures.

In Figure 1, the mounting tabs used to hold a power supply in place failed during vibration. Larger tabs with better stress relief grooves should be used in this case to better withstand the vibrations. The capacitor leads in Figure 2 failed due to repeated fatigue stresses from vibration. Improved mounting such as placing an adhesive under the capacitor could be used to prevent this type of failure which is common for large components connected by thin metal leads.

In the case of temperature related failures such as seen in Figure 3, the temperature at which failure occurred should be well outside of the expected operating range of the equipment.

Even in this case, an evaluation should be performed to determine if a component with an improved temperature rating can be economically substituted because the failing component may be a weak point in the product design.

Non-Relevant Failures

Failures listed below may be considered as non-relevant:

• Failures directly attributable to erroneous product manufacturing or operation.
• Failures resulting from improper test setup or procedure.
• Dependent failures, unless caused by degradation of items of known limited life.
• Failures occurring during test “down-time” such as during troubleshooting on the bench unrelated to the HALT Procedure.

Care should be taken when determining if a failure is non-relevant as this may result in missing an opportunity for product improvement.

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