Product testing is an essential consideration during design development, but all too often, manufacturing test is overlooked, or at least not adequately considered, during the design phase. At Hot Solder, we can work with the customer to establish a test strategy, weighing the cost of test equipment and test time against yield and lifetime quality targets. In development, design reviews should include DFT considerations that derive from the test strategy, schematics, and placements need to be reviewed to understand test coverage and test node access. Our test design processes cover all design phases, from concept to new product introduction, assembly and test.

In manufacturing test, the test strategy may comprise a combination of in-circuit, functional, visual and X-ray test protocols. At Hot Solder, we understand the lost opportunity caused by preventable faults such as shorts, opens, and wrong or incorrectly inserted components that would need to be identified and reworked after manufacture. Comprehensive In-Circuit Testing (ICT) will help to eliminate such errors.

Even when all such faults are eliminated, functional faults may still exist in new designs, requiring Functional Board Test (FBT). This process still relies on test engineers’ understanding of circuit functionality and manually developed test procedures. While functional Automatic ICT equipment has been reduced considerably, FBT test costs can still be a considerable undertaking that can take several weeks or months of test engineering development, so the test strategy should seek to minimise reliance on FBT to avoid FBT delaying programmes and incurring unnecessary costs.

The test team at Hot Solder will facilitate your successful product launch by applying expert knowledge to reduce FBT complexity, ensuring maximum yields and minimising rework. We have expertise in Flying probe, In-Circuit Test, Boundary Scan, JTAG, Optical inspection and X-Ray systems.

What is Design for Test?

Design for test (DFT) is a critical aspect of the product development process that ensures products are designed with testability in mind. DFT involves incorporating features into the design of a product that makes it easier and more cost-effective to test and diagnose any potential faults or issues.

DFT can be broken down into three primary objectives: improving test coverage, reducing test time, and lowering test cost. By focusing on these objectives during the design phase, manufacturers can improve product quality, reduce the risk of product failures, and minimize the cost and time associated with testing and debugging.

The first objective of DFT is to improve test coverage. Test coverage refers to the proportion of the product that is tested during the production process. The higher the test coverage, the greater the likelihood of detecting defects and issues before releasing the product. To improve test coverage, manufacturers must design products with a clear understanding of the test requirements and limitations. This includes designing products with diagnostic capabilities and incorporating built-in test equipment (BITE) features that enable fault detection and identification.

The second objective of DFT is to reduce test time. Test time refers to the amount of time required to test a product during the production process. Manufacturers can reduce test time and increase production throughput by designing products with testability. This includes designing products clearly and understanding the test equipment requirements and limitations. Manufacturers can also incorporate features such as boundary scan tests (BST) that enable testing complex circuits and components.

The third objective of DFT is to lower test costs. Test cost refers to the total cost of testing a product during production. By designing products with testability in mind, manufacturers can reduce the overall cost of testing and increase profitability. This includes designing products clearly and understanding the test equipment requirements and limitations. Manufacturers can also incorporate features such as automated test equipment (ATE) that enable automated testing and reduce the need for manual testing.

DFT is critical for ensuring the reliability and quality of products. Without DFT, manufacturers could not test and diagnose faults and issues in a timely and cost-effective manner, leading to potential product failures and recalls. By designing products with testability in mind, manufacturers can reduce the risk of product failures and improve product quality, increasing customer satisfaction and loyalty.

In conclusion, Design for Test (DFT) is an essential aspect of the product development process that focuses on incorporating features into a product’s design, making it easier and more cost-effective to test and diagnose any potential faults or issues. By focusing on test coverage, test time, and test cost during the design phase, manufacturers can improve product quality, reduce the risk of product failures, and minimize the cost and time associated with testing and debugging.