Technical Library | 2019-05-30 11:02:07.0
In a previous Tech Tip (see Battery Selection for Electronic Systems), considerations were discussed for selecting an appropriate battery for an application. After selection, testing should be performed to confirm that the battery can provide the power required for the specific application. Some battery definitions should be understood when discussing power load qualification testing of batteries.
Technical Library | 2019-08-19 09:46:13.0
Boundary scan is a method for testing interconnects on printed circuit boards (PCBs) or sub-blocks inside an integrated circuit. It has rapidly become the technology of choice for building reliable high technology electronic products with a high degree of testability. Due to the low-cost and integrated circuit (IC) level access capabilities of boundary scan, its use has expanded beyond traditional board test applications into product design and service.
Technical Library | 2020-04-01 14:24:56.0
It happens much too often; manufacturing engineers are brought into a NEW product design phase at the very end of a design and are asked to provide input that should have been provided much earlier. One needs to understand how the circuit board design and quality of the manufacturing process not only effects assembly yield and product reliability, but how it could also affect the results of any testing that is done to circuit packs during prototyping. It is important that any circuit pack (including prototypes) that will be used in reliability, performance and functional testing be designed with the proper features and assembled with a manufacturing process that has been developed to produce a high-quality assembly. If not, the results of any testing might not represent the actual characteristics of the design and provide miss-guidance to future changes.
Technical Library | 2019-06-18 10:18:00.0
ACI Technologies is tasked with decapsulation of electronics components for testing and investigative purposes. In the normal method of decapsulation, an analyst will drill a small indentation, with a rotary tool, in the hermetic sealant material and then apply Nitric acid to eat through the polymeric encapsulant.
Technical Library | 2019-06-21 10:39:15.0
Recently, an ACI Technologies (ACI) customer called to discuss failures that they had observed with some through-hole capacitor parts. The components were experiencing failures following vibration and accelerated stress testing. Upon receipt of the samples, ACI performed three levels of inspection and Energy Dispersive Spectroscopy (EDS) testing to investigate the root cause of the failures. These analyses enabled ACI to verify the elements comprising the solder joints and make the following recommendations in order to prevent future occurrences. The first inspection was to investigate the capacitor leads using optical microscopy, and no anomalies were found that could indicate bad parts from the vendor or improper handling prior to assembly. However, vertical fill in the barrel of the plated through-holes was too close to the IPC-A-610 minimum specification of 75% to determine a pass/fail condition, and therefore required further investigation.
Technical Library | 2019-06-11 09:36:13.0
An experiment was recently performed ACI Technologies for a customer that was interested in comparing the wetting of lead-free solders with varying temperature profiles and atmospheric conditions. In order to deliver an objective measurement of solder wetting (in addition to subjective inspection analysis), a simple wetting indicator pattern was added to the solder stencil in an area on the test vehicle that had exposed and unused copper.
Technical Library | 2010-03-23 11:50:22.0
This document discuss how to design SMT stencil base on IPC-7525. Introduction: PCBA (Printed Circuit Board Assembly) is a segment of printed circuit board technology. This segment of printed circuit board industry is concentrated in assemble all the pieces of electronic industry to one piece before output them to market. This segment covers: interconnection technology, package design technology, system integration technology, board and system test technology
Technical Library | 2019-05-30 11:04:03.0
There exists a need to efficiently remove heat from power electronics within power systems to enhance performance. Thermal management is a critical function to that operation. Reducing the junction temperature of semiconductor power electronic devices enables them to operate at higher currents. Lowering operating temperatures reduces the thermal stress on electronic devices, which improves efficiency and reduces failures. To improve the heat removal process, the current heat transfer design of a power system has been analyzed and a variety of thermal interface materials (TIMs) and cold plate technologies have been evaluated. This paper will review some of these results.
Technical Library | 2024-08-09 06:34:09.0
Quality control in conformal coating applications is vital for ensuring the reliability and longevity of electronic products. Conformal coatings protect printed circuit boards (PCBs) from environmental factors like moisture, dust, and chemicals. To maintain high standards, various inspection methods are employed throughout the coating process. Visual Inspection This is the first line of defense against defects. Inspectors look for uniform coverage, absence of bubbles, and proper curing. Training is essential to ensure that inspectors can identify subtle issues that may affect performance. UV Inspection Most conformal coatings contain a UV tracer, which makes the coating visible under ultraviolet light. UV inspection allows for easy detection of missed areas, ensuring complete coverage. This step is crucial for verifying that the coating has been applied correctly, especially in hard-to-see areas of the PCB. Automated Optical Inspection (AOI) AOI systems offer a more precise and consistent method for inspecting conformal coatings. They use cameras and specialized software to detect defects that might be missed by the human eye. AOI systems can inspect large volumes of PCBs quickly, making them ideal for high-production environments. Thickness Measurement The thickness of the conformal coating is critical for providing adequate protection without affecting the performance of the PCB. Tools such as micrometers, ultrasonic thickness gauges, and eddy current devices are used to measure the coating thickness. Consistent application is key to preventing issues like cracking or insufficient protection. Functional Testing Beyond visual and automated inspections, functional testing is necessary to ensure that the conformal coating does not interfere with the electrical performance of the PCB. This involves subjecting the coated PCB to environmental stress tests, such as thermal cycling, humidity, and salt spray, to assess its reliability in real-world conditions. Process Control and Documentation Implementing strict process controls is essential to maintaining quality. This includes regularly calibrating equipment, training operators, and documenting every step of the process. Proper documentation helps trace issues back to their source and prevents them from recurring. Conclusion Effective quality control in conformal coating applications ensures that PCBs are protected from environmental damage, thereby extending their lifespan and reliability. By employing a combination of visual, UV, and automated inspections, along with thickness measurement and functional testing, manufacturers can achieve the highest standards in coating quality.
Technical Library | 2019-05-21 17:31:39.0
In the field of electronics manufacturing, the end use of the product will always dictate the processes, procedures, and methods, not only for building the product, but also for testing, cleaning, and protecting the assembly in order to assure the level of quality required for proper operation. The need to protect an electronic assembly from its end use environment may stem from anyone of a number of hazardous (or potentially hazardous) conditions. Choosing the type of protective material is dependent upon matching that material’s characteristics with the conditions to be overcome. Naturally, the use of a protective (conformal) coating will require some method of verification to ensure the desired level and type of protection is achieved.
