The most accurate test strategy... what a nightmare

A nightmare? No… find the best coverage vs the most economical cost.

Developing a test strategy is an important step in the design and manufacture of a product. Therefore, it is beneficial to include a reflection on the test strategy from the first designing phases. However, the test strategy is often overlooked and performed at the end of the design process. At that time, there will be a range of constraints that will make the implementation of the test strategy more complex. The design team will be led to choose a test strategy based solely on the functional test and oriented towards the utilization of the products by its final user. Though it is not a bad option, the costs associated with this type of tests are expensive, and do not necessarily guarantee long-term reliability.

One of the major players in the testing strategy is often forgotten in the analysis and implementation of the test strategy, and this actor happens to be the manufacturing centers. When the manufacturing company is involved in the process of defining the strategy, it is able to advise the customer in the best approach to be chosen while considering the totality of the tools available during the manufacture of the electronic system. Thus, a partnership between the manufacturing center and the design team will ensure optimal and complete test coverage throughout the manufacturing process. The various test phases will allow a sooner identification of defects and quickly identify the adjustments to be made during the production. Therefore, it is easier and cheaper to apply the corrective measures. Several test options are available for customers and at different stages of production. Examples: Electrical inspection, Input inspection, PCBA cross-section, automated visual inspection, in-circuit test, functional test, burn-in test, etc.



With over 35 years of existence, M2S Electronics has developed an expertise in the design of overall tests strategy and the ultimate goal is to minimize the returns of failing products. Therefore, we can say that a good overall test strategy will reduce the cost of failures and thereby increase the profitability of the electronic products sold.

Since most design teams oriented their choices towards a functional test, we will deepen this phase which is the last test before the equipment is delivered. This last step should make it possible to complete a full coverage scheme of the overall test strategy and thus ensure the designers reliability and quality of finished products.

Functional Test

When analyzing the needs for the functional test, it is important to consider several factors. The graph below illustrates some of the elements to be considered in the analysis and which allow defining the direction of the strategy to be put in place.

Standardisation

Over time, the manufacturing center will have experimented with several electronic assembly validation processes, standardized test equipment and software architecture. The selection and standardization of those tools will have strengthened its expertise while allowing it to offer a robust and sustainable functional test tool.

Flexibility

The products to be tested are often highly scalable. Consequently, the functional test must also be flexible. In the long run, the risk of having to implant new tests or to refine certain tests already implemented is present. This is where the expertise of the manufacturing center comes into play, making it possible to foresee the flexibility of test tools in the early stages of design. Having developed many tools, the manufacturer has extensive knowledge of the test equipment available on the market and will be able to share its knowledge on the options that would be most useful to you. In the medium and long term, flexibility has a direct impact on the overall cost of the functional test.

Cost

A manufacturing center that develops standards and designs with flexibility in mind, will maneuver through the various choices, and may have a positive impact on the overall cost. Automation of test methods will be prioritized.

The experience of the manufacturing center in the development of several test routines can easily be adapted to your chosen test strategy, allowing you to save time and money. The use of recognized test equipment and software will facilitate the medium and long-term maintenance of your test bench, and this aspect should not be neglected as to the overall cost of maintenance.

Capacité

Depending on your needs, the manufacturing center can design the most efficient test bench and adapting the strategy to the volume of orders. For a large production quantity, complete automation is required, including programming, calibration, high-voltage testing, functional testing, data collection, identification, etc. The manufacturer can also offer different supports that will allow efficiency and a return on investment very quickly. We only have to think of the traditional "bed of nails".

To conclude this article, it is easy to believe that a testing strategy does not bring value to the final product. However, without a test strategy, companies put themselves at greater risk of receiving customer complaints or product returns. For this reason, it is essential to have planned a test strategy when manufacturing an electronic system. Let us remember that the more the test strategy is thought up early in design, the more efficient and economical it will be in the series production. To this truth one could add that: one of the best allies in designing a test strategy is the manufacturing center.