Beginners in HALT testing, come and see how experienced seniors conduct HALT tests! (1)

Keywords: Reliability Testing,High Accelerated Life Testing, Environmental Stress Screening, Vibration Testing, HALT/HASS

Every industry has beginners, and HALT is no exception!

What preparations are needed for beginners in HALT?

First, you need to understand a principle: attending a hundred classes on aesthetics is not as good as spending a day walking in nature;Teaching a hundred hours of architectural design is not as effective as letting someone touch a few ancient cities personally;Explaining the techniques of literary writing a hundred times is not as good as actually getting your pants dirty in the market!场里头弄脏自己的裤脚！If you want to truly integrate into the HALT industry, you must get yourself "moving"! Practice is the best teacher, and HALT is here to guide you to validate the unknown world through practice!

We must admit that the current market competition is exceptionally fierce, and customer demands are becoming increasingly high-end and complex. Whether it is individual consumers, government agencies, or other departments within our own companies, everyone expects to get more for less. High reliability, low cost, the latest technology, and durable products are the only treasures that attract customers in the market. But how can we achieve high reliability in products and prove their durability? Should we take years, decades, or even longer to achieve this? If so, the waves of the market will drown you! Accelerated testing is currently the most effective way to obtain this treasure.

Accelerated testing not only proves the high reliability and durability of products, but it is also a comprehensive and rapid means and method to understand products. It can help you "accelerate" time, as if you have equipped your work environment with a time machine, showing you the failures that may occur under possible conditions, and finding things that may take years to discover within days. Meanwhile, computer programs and various scientific formulas allow you to further understand the potential lifespan of the product.

3. Initial TestingSetup

The best way to start testing is to conduct it in a laboratory environment. You might wonder why I use this term? I am a member of several working groups of the IEC (International Electrotechnical Commission). We have found that over the years, the term "environment" means different things to different people. In the old definition of environmental temperature, it refers to the chamber temperature surrounding the product at any given time, and most people adopt it as the room temperature for testing. By using the term "laboratory environment," it ensures and helps people understand that testing starts around room temperature. I do not want anyone to be confused about the temperature of the last laboratory test. Better safe than sorry!

4. A series of tests

Remember that there is no perfect way to run HALT; here are some basic methods to keep in mind. HALT is actually a series of tests. You should have multiple samples available for testing, preferably preparing one sample for each test in the series.

From a purist's perspective, the best way to start is to use a single environment for testing, then run in a combined environment for comparison. These are the six standard tests we recommend, although this can be done in other ways:

• Cooling only

• Heating only

• Vibration only

• Vibration and heating

• Temperature fluctuations

• Temperature fluctuations with vibration

Of course, others can also be added. If you are concerned about the impact of lower temperatures on the product, you may need to add cold with vibration; if you are worried about humidity's effect on the product, you should conduct humidity testing alone, then start combining it with other environments (such as heat and vibration) for testing. Power cycling is also very beneficial.

Before starting the tests, you need to familiarize yourself with and thoroughly understand the product to be tested, learn as much as possible about the final environment it will be placed in, and then conduct the corresponding tests. Remember: the end user's attitude towards the product is always more difficult than you expect, and they want it to keep working no matter what.

5. Proceed step by step

Once you have decided which environment to use, how do you start? The key is to understand your product. Is it as small as a PCB? Is it as large as a tank? How long does it take to stabilize at temperature? Are certain components more prone to failure than others?

Along these lines, how will you know if your product is stable at temperature? Let's take the example of what I will be testing today. It is a console for vehicles, approximately the width of a truck's ceiling. You cannot choose a representative spot on it and assume the entire unit is the same. A simple rule of thumb is:The larger the product or the more diverse the components, the more thermocouples you will need.We need to control a main thermocouple. This should be placed where it represents the entire product or the most sensitive component, depending on our main focus.产品越大或组件越多样化，需要使用的热电耦就越多。我们需要控制一个主热电耦。这应该放置在它代表整个产品或最敏感的组件上，具体取决于我们的主要关注点。

A good starting point for all tests is to begin in a laboratory environment. This is usually around 25°C. If it is necessary to fix the product during testing, connect all wiring that may need to be in place. Please remember,your wiring or cabling will be subjected to the same extreme conditions as your product!

The order of testing is entirely up to you. However, keep in mind that if you start from a single environment and then move to combinations, you will achieve a good baseline as expected. For example: if your first test is thermal cycling vibration and you find a failure, can you determine if it was due to the product that caused the failure? Or was it a combination? If you have already run heating tests and vibration tests separately, you can more easily see the environment or combination of environments that led to the failure.

The next "HALT Testing Beginners, Come See How Experienced Seniors Conduct HALT Tests! (Part 2)" will detail how to conduct thesix standard tests, stay tuned!