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44 DESIGN007 MAGAZINE I DECEMBER 2021 A tight, detailed, and carefully planned test- ing process will guarantee the following: 1. Cost savings: No unnecessary or double tests are conducted. At the same time, the right mix of tests allows for complementary results. 2. Enhanced test reliability while predicting the number of false negatives and improving the manufacturing process in real-time. 3. Tracing the root cause for any discrepancy once occurring and enabling an effective corrective action preventive action (CAPA) plan. 4. Peace of mind for the customer. is evolutionary process intensifies the tests' reliability and even enables a decrease in the number of tests conducted while rely- ing on sample testing only. e incentive is minimizing the expenses involved in the pro- cess and shortening it even further, making it as efficient as possible. If you're looking for an optimal test process, you need to keep an open dialogue between the fabricator and the customer, covering as many iterations as required. Its main goal is to meet the criteria set by the customer. Manufacturing of any electronic system shall embed many inspections; the most generic, yet important ones, are: 1. HATS (highly accelerated thermal shock): is test (IPC-9151D standard-based) evaluates the PCB's survivability aer reflow simulation while inflicting extreme heat/cold conditions on its stackup. e main initiative is to determine how well it will operate under field conditions in which it will be deployed. e via's cop- per plating goes under dissemination and shrinking caused by heating or cooling of the PCB, respectively. is might result in cracks along the via or separation between its layers (delamination). Refraining from conducting this test in the early stages of the PCB design might also reflect upon the PCBA stage when you fail to trace faulty components and replace them (rework). at, in turn, might diminish the level of survivability of the whole system and damage the customer's prestige in the process. PCB Technolo- gies has its in-house HATS lab, making the easy implementation of this test an ordinary course of action. e fabrica- tor must have relevant experience with various raw materials and their dedicated application use to choose the most reliable ones. 2. Holes reliability test: Maintaining design crossing points between PCB and PCBA processes result in tight mechanical interconnection to the PCB PTH, thus providing a proven, reliable interface. For example, a PCB comprising of press-fit components will benefit from defining a hole's diameter and drilling, as well as tests to be conducted during copper plating of the hole (maximum and minimum copper volumes). at way, once the components are pressed in the holes the space allocated for them will match the initial plan. 3. In-circuit test (ICT): based on a separate bed of nails for every PCB, checking the electrical conductivity quality between each board's components. is offers: a. High testability coverage, up to 100% of boards

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