Technical Library | 2020-12-07 15:26:06.0
Temperature cycling testing is a method of accelerated life testing done to PCCs that are exposed to normal operation temperature variations over its lifetime. During the testing, intermittent "open" failures can first occur at the hot and cold extremes of the test, exposing weaknesses in the design and assembly. A poor/weak solder joint fatigues, a via trace or barrel cracks, loose connections or a component fails all causing an intermittent open. When not at extreme temperatures, the PCC assembly relaxes, the "open" closes creating electrical connectivity. If you are monitoring the PCC under test in-situ you will know that an intermittent failure has occurred, and the test could be stopped for inspection. If in-situ monitoring was not implemented, you would not know if there were intermittent failures or not. The PCC gets powered up and works fine at room temperature.
Technical Library | 2019-05-31 14:15:01.0
ACI Technologies (ACI) is working on a project where one of the challenges is removing a large quantity of heat from audio amplifier circuits. This challenge is further complicated in that the heat generating circuits are located in a rack mounted box that needs to be shielded from electro-magnetic interference (EMI). Mechanically, this means that there cannot be open passages into the rack mounted box. We will first review the basic types of cooling available as commercial off-the-shelf (COTS) systems for the electronics industry, then discuss the pros and cons of each for different applications, and finally reveal the criteria and solution for the ACI project.
Technical Library | 2019-10-21 09:58:50.0
An ACI Technologies customer inquired regarding printed circuit board(PCB) failures that were becoming increasingly prevalent after the SMT (surface mount technology) manufacturing process. The failures were detected by electrical testing, but were undetermined as to the location and specific devices causing the failures. The failures were suspected to be caused predominately in the BGA (ball grid array) devices located on specific sites on this 16 layer construction. Information that was provided on the nature of the failures (i.e., opens or shorts) included high resistance shorts that were occurring in those specified areas. The surface finish was a eutectic HASL (hot air solder leveling) and the solder paste used was a water soluble Sn/Pb(tin/lead).
Technical Library | 2020-03-09 10:50:17.0
A customer called the Helpline seeking advice for cleaning no-clean fluxes prior to applying a conformal coating. The customer's assemblies were manufactured with a no-clean rosin based solder paste (ROL0) and were cleaned with an isopropyl alcohol (IPA) wash. After cleaning, a white residue was sometimes found in areas with high paste concentrations and was interfering with the adhesion of the conformal coating (Figure 1). For conformal coatings to adhere properly, the printed circuit board (PCB) surface must be clean of fluxes and other residues. In addition, ionic contamination left by flux residues can lead to corrosion and dendrite growth, two common causes of electronic opens and shorts. Other residues can lead to unwanted impedance and physical interference with moving parts.
Technical Library | 2023-11-14 02:36:41.0
Understanding In-Circuit Testing (ICT) with PCBA ICT Testing Machine In-Circuit Testing, commonly known as ICT, stands as a sophisticated and precise method within electronics manufacturing. It serves to evaluate the functionality and integrity of individual electronic components on a Printed Circuit Board (PCB). The process employs specialized equipment called ICT Testers, meticulously designed to pinpoint defects, shorts, opens, and other potential issues within the PCB assembly. The Crucial Role of PCBA ICT Testing Machine 1. Quality Assurance ICT is pivotal in ensuring the overall quality and reliability of electronic products. Early identification and rectification of defects in the production process help manufacturers avoid costly recalls, rework, and post-production issues. 2. Cost-Efficiency ICT significantly reduces manufacturing costs by identifying defects at an early stage. This results in fewer defective units reaching the end of the production line, minimizing waste and rework. 3. Faster Time-to-Market Manufacturers can expedite the production process with ICT by swiftly identifying and resolving issues. This leads to faster product launches, providing a competitive edge in the market. Unveiling the Functions of PCBA ICT Testing Machine The ICT Tester, the core of the In-Circuit Testing process, conducts a battery of tests on each PCB, including: 1. Continuity Testing Checks for open circuits, ensuring all connections are properly established. 2. Component Verification Verifies the presence and orientation of components, ensuring alignment with the PCB design. 3. Functional Testing Some ICT Testers execute functional tests, assessing electronic components' performance as per specifications. 4. Short Testing Identifies unintended connections or shorts between different components on the PCB. 5. Insulation Testing Checks for isolation between different circuits, ensuring no undesired connections or paths. 6. Programming and Configuration In some cases, ICT Testers are used to program and configure specific components on the PCB. Advantages of PCBA ICT Testing Machine 1. High Precision ICT offers unparalleled accuracy in defect detection, making it crucial in modern electronics manufacturing. 2. Speed and Efficiency ICT Testers enable rapid testing, allowing manufacturers to assess a large number of PCBs in a short time. 3. Customization ICT Tests can be tailored to suit specific PCB requirements, ensuring thorough evaluation of every design aspect. 4. Data Collection ICT Testers gather valuable data for process optimization and quality control. In-Circuit Testing (ICT) is fundamental in electronics manufacturing, safeguarding product quality, reducing costs, and accelerating time-to-market. The ICT Tester, with its precision and efficiency, positions manufacturers at the forefront of the highly competitive electronics industry. Embracing ICT is not just a choice; it's a necessity for manufacturers striving for excellence in their products. I.C.T is a leading manufacturer of full SMT line machines in the electronic manufacturing industry. Discover how we can enhance product quality, boost performance, and reduce costs. Contact us at info@smt11.com for reliable global supply, unparalleled efficiency, and superior technical service.
Technical Library | 2007-02-01 09:27:47.0
The purpose of the testing was to compare the resistance and check for open circuit conditions of reworked BGA test samples made with and without StencilQuik™ after 500 thermal shock cycles. StencilQuick™ is a product of Best Inc. In this series of tests, the resistance of daisy chain resistance patterns running between the BGA and test board after exposure to thermal shock was measured.
Technical Library | 1999-08-09 11:09:42.0
Organic Solderability Preservatives (OSPs), also known as anti-tarnish, on bare copper printed circuit boards (PCBs) are becoming more prevalent in the electronics industry as the low-cost replacement to Hot Air Solder Leveling (HASL). Introducing the anti-tarnish alternative into the customer sites requires working closely with the coating supplier, assembler, and Original Equipment Manufacturer (OEM) to gain a mutual understanding of respective processing concerns and finished product requirements.
Technical Library | 2017-02-16 16:53:49.0
This experiment considers the reliability of a variety of different electronic components and evaluates them on 0.200” power computing printed circuit boards with OSP. Single-sided assemblies were built separately for the Top-side and Bottom-side of the boards. This data is for boards on the FR4-06 substrate.This paper was originally published by SMTA in the Proceedings of SMTA International.
Technical Library | 2021-12-29 19:37:20.0
The purpose of this study was to compare the strength of the bond between resin and glass cloth for various composites (laminates) and its dependence on utilized soldering pad surface finishes. Moreover, the impact of surface finish application on the thermomechanical properties of the composites was evaluated. Three different laminates with various thermal endurances were included in the study. Soldering pads were covered with OSP and HASL surface finishes. The strength of the cohesion of the resin upper layer was examined utilizing a newly established method designed for pulling tests.
Technical Library | 2021-07-06 21:13:36.0
The surface finishes commonly used on printed circuit boards (PCBs) have an effect on solder paste performance in the surface mount process. Some surface finishes are non-planar like hot air solder level (HASL) which can lead to inconsistencies in solder paste printing. Other surface finishes are difficult to wet during reflow like organic solderability preservative (OSP). What is the overall effect of surface finish on solder paste performance? Which solder paste is best for each surface finish? It is the goal of this paper to answer these questions.
