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 | 2023-09-23 22:31:52.0
Dry boxes can be implemented at various points within the Mfg. environment; for med-long term inventory, or for short term handling on the production floor, and in some cases (with certain conditions) as a process replacement for baking. Bare boards, raw components and partially assembled PCB's can benefit from ultra-low humidity storage.
Technical Library | 2019-05-31 14:19:24.0
ACI Technologies (ACI) characterized the reliability of surface mount RF components. The RF frequency band of interest was the X band (10.7 to 11.7GHz). A two pronged test for reliability of circuit card assemblies (CCA) was designed for both extreme thermal cycling and vibration. The rapid thermal cycling and extreme vibration testing simulates the total stress encountered by the assembly over the life of the product but accomplishes it in a relatively short period of time. In order to perform the reliability testing, a test vehicle consisting of a printed circuit board with test structures and components, was designed, fabricated, and assembled at ACI.
Technical Library | 2020-06-02 15:16:51.0
A commercial systems manufacturer working on a major defense program contacted the Helpline for urgent assistance with an issue of failed parts during reliability testing. They were attempting to incorporate commercial off-the-shelf (COTS) computer-related hardware into a battlefield system and were experiencing reliability issues. It was noted that the parts were labeled by the vendor as "compliant to military (or MIL) standards" but not clearly identified as tin-lead or lead-free. ACI Technologies has supported a number of customers with lead-free issues and we assisted the customer in developing a short term and long-term solution to their problem.
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 | 2017-12-07 10:35:50.0
Electronics manufacturers protect their circuit boards with conformal coatings. Conformal coatings serve as a barrier from environmental hazards and internal shorts, tin whiskers, and corrosion at the board level. Within conformal coatings different material chemistries specialize in shielding from an array of hazards and can be applied by multiple methods. The most common method is atomized spray which disperses the material into a fine mist. Alternatively, non-atomized coating controls the materials' dispense shape while maintaining the original liquid form. While some applications demand atomized spray and other scenarios overlap between atomized and non-atomized coating, this paper focuses on the circumstances where materials are ideally suited for non-atomized, selective coating.
Technical Library | 2019-05-23 10:42:00.0
Why identify flux residues? The primary purpose of flux is to reduce species of metal oxides from solderable surfaces, and to act as a mechanism for lifting and removing debris. If the assembly is not properly cleaned after manufacturing, flux may continue to reduce metals and may eventually corrode the assembly. When the assembly is powered, the metal ions may precipitate along electromagnetic field lines and form dendritic shorts. In addition, the presence of residue can alter the insulation properties of a board, affect the adhesion of the conformal coating, or interfere with the moving parts of the assembly. In radio frequency (RF) applications, flux may change the RF properties on the surface of the printed circuit board (PCB) such as the dielectric strength, surface resistance, and Q-resonance.
Technical Library | 2019-06-19 11:06:46.0
Tin (Sn) metal displays the characteristic of growing “tin whiskers” from pure tin coatings (most actively on relatively thin, electrodeposited or immersion tin coatings), usually months or years from the initial deposition of the tin. Tin whiskers are electrically conductive, filamentary, single crystals of white (beta phase) tin. These filaments of single crystal tin are usually one to five microns in diameter, and a few microns up to several tens of millimeters long, that grow spontaneously from the tin coatings. Alloying additions of several percent (by weight) of lead (Pb) prevents these electrically conductive tin whiskers from growing. Pb alloyed into the Sn was discovered to prevent the occurrence of tin whiskers in electronic assemblies in the 1950s as the Bell Laboratories solution to the problem of tin whiskers. The alloying of the tin with lead has thus quietly averted incalculable losses from short circuits in electronic equipment for the last 60 years.
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 | 2010-01-13 12:34:10.0
Micro-sectioning (sometimes referred to as cross-sectioning)is a technique, used to characterize materials or to perform a failure mode analysis, for exposing an internal section of a PCB or package. Destructive in nature, cross-sectioning requires encapsulation of the specimen in order to provide support, stability, and protection. Failures that can be investigated through micro-sectional analysis include component defects, thermo-mechanical failures, processing failures related to solder reflow, opens or shorts, voiding and raw material evaluations.
