WindoWorks: a flexible program for computerized testing of accelerator control system electronic circuit boards

The paper shows the possibility of Hierarchical Systems (HS) technology use in the tasks of Printed Circuit Boards (PCB) geometric design and interconnections (conductive pathways) quality testing. It gives formal description of the PCB construction and both the design and testing processes. Presented HS technology allows easy correction of interconnections topology of PCB, the mechanism of information aggregation permits reduction of computer memory, availability of coordinator allows performing decision making tasks on its layers. Possibility of HS technology realization using standard computer program and technical means is shown in the work as well.Keywordshierarchical systemscircuit boarddesign and testing

Integrated-services digital network (ISDN) circuit board fault mechanisms, ISDN device attributes, and test equipment requirements are examined. ISDNs required a high level of integration which causes an increase in digital/analog VLSI faults and perfect board faults (faults in the S-bus interface and voice interface clusters). These faults can be detected by supplementing the in-circuit test with cluster specification or edge connector specification tests. These specification tests can be broken into three categories: digital VLSI tests; S-bus cluster tests; and voice cluster tests. The author discusses the testing challenges that are unique to ISDN circuit boards. The discussion takes into account previous studies of test effectiveness, classical testing theory, and real-world ISDN testing experience. >

A simulation model is used to analyze the effects of various factors on the performance of a complex manufacturing system. The system under study is a large circuit board manufacturing facility. There, circuit boards are assembled and tested on a wide variety of automated machines and manual workstations. The simulation model, written in the SLAM II language, is highly detailed in the manner in which processes are modelled. This becomes especially important in modelling circuit board testing where boards which fail are repaired and recirculated through the test stations. Detailed modelling also allows for numerous process routings among the different product types to be permitted. The model possesses a demonstrated accuracy in its portrayal of the real-world situation.

This paper describes research and development efforts in the application of advanced optical techniques for prognostic analysis of printed circuit boards and their components. Current methods of automated electronic testing require development of costly unique test program sets (TPSs) for each type of board, and only return information related to the current performance characteristics. The use of laser diagnostics in circuit board testing can eliminate the need for TPSs, while identifying compromises in material integrity that leads to hard and soft component failures. Additionally, they may be applied to solve instances of retest OK (RTOK) and no-fault-found events. Our investigation has focused on terahertz (T-Ray) imaging, laser acoustics, and near-infrared (NIR) laser imaging. T-Ray imaging is an emerging laser-based technology characterized by the ability to see through layers of plastic to the embedded metal traces of a circuit board or to the die of an encapsulated microchip. Laser acoustics may be applied to monitor the integrity of solder joints, and NIR laser imaging may be used to identify damage within an integrated circuit (IC). We present the results of our investigation into the combined use of these techniques for fault diagnosis, as well as their relative potential in the electronics test industry.

A printed circuit board with attached components has been subjected to corona discharges for 200 h at a pressure of 8.66 Pa. The preliminary investigations indicate that: (1) High altitude corona discharges produce visible surface degradation on electronic circuit boards and mounted components. (2) The deterioration is most pronounced in the regions where the electric field is greatest. (3) The solder coating has been removed in localized areas of the interconnecting paths and the underlying copper is now exposed. (4) The circuit board becomes covered with a white dust, the composition of which is still unknown. (5) The deterioration increases with increased exposure up to 200 h, the maximum exposure time considered here.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

In this paper we consider a multiperiod resource allocation model in which the resources are storable and substitutable. A specific application of this model relates to the multiperiod production planning for electronic circuit board assembly factories. In this case, resources are electronic components, which are storable, that is, excess components in one period can be used in subsequent periods. Components that can be used in the same function on a circuit board are considered substitutable. Substitutability between components, however, may be dependent upon the specific circuit board on which they reside. Given that there are certain production requirements for the circuit boards, and that some components are in short supply, our algorithm (a) revises the production levels of the affected circuit boards, and (b) efficiently allocates the available components according to the revised production, so as to minimize the maximum weighted deviation from the original production plans. The weights reflect the relative importance of the circuit boards. The objective function uses cumulative production levels and cumulative demands to allow for back-scheduling. We present a primal-dual algorithm that is very efficient. An implementation of the algorithm compares favorably with a standard linear programming code. We solved a problem with 300 components, 20 different circuit boards (average of 10 functions/board) for 10 time periods (approximately 30,000 variables) in less than one minute on a VAX 11/785. We also discuss upper and lower bound extensions, and a lexicographic algorithm to ensure that less critical resources are also allocated effectively.

A heat transfer analysis of a convective air cooled electronic circuit board (ECB) in a vertical electronic circuit boards channel was carried out.To validate the model and the algorithms used in the computations, experimental tests were performed on dummy ECBs. Temperature distribution on an axial ECB and axial temperature distribution of air were measured with thermocouples. The temperature measurements were in good agreement with the computed value.As a working example, the temperature distributions of air flow and the vertical circuit boards with evenly arranged electronic components cooled by forced convective heat transfer were simulated, and typical results were reported and discussed. It is clear that, such a computer program for the thermal analysis of electronic circuit boards is effective and enables the user to choose any arbitrary arrangement of components on the ECB as well as different values of all design parameters. The program can serve as a powerful tool either for checking the performance of an existing ECB or for sensitivity analysis in designing the packaging of new electronic circuit boards.

Electronic circuit boards’ heat dissipation capability directly impacts their service life since the heat dissipation efficiency of components directly impacts the board’s life. This work focused on the problem of the high surface temperature of the electronic components at the control unit stage of a cement production line. Three dimensional CFD model has been developed to simulate all components in this circuit board. A thermographic camera has been used to measure the surface temperatures of the components on the circuit board. Consistency was very good in the results. Two cooling mechanisms were examined, one of which is a traditional technique by forced air cooling technology. The other is using graphene nanosheets coating technology to increase the dissipation of the generated heat to the surrounding atmosphere. Although an electronic fan was very effective in cooling the electronic circuit components, which reduced the temperature by 22.6%, it has two undesirable features: the need to install it in a safe place and the need for power to run it. Graphene nanosheets coatings provide efficient and economical heat dissipation. The thin graphene layer enhances the radiation effect for the heat significantly. The results showed that the smooth aluminium plate coated with graphene and mounted directly to the back part of the transistor behind the plastic chip carrier piece for heat dissipation provided an efficient, sustainable and economical solution in thermal management. In comparison with the fan, the graphene nanosheets coating technology reduces the temperature by an average of 16.4% without consuming any energy.

The New England Lead-free Electronics Consortium is a collaborative effort of New England companies spanning the electronics supply chain, created by the University of Massachusetts Lowell in 1999 and sponsored by the Toxics Use Reduction Institute and the U.S. EPA. The consortium has completed and published the results of three phases of manufacturing and testing of lead-free Printed Wiring Boards (PWBs) with the goal of achieving zero-defect leadfree soldering processes with comparable or superior reliability to that of leaded solder processes. In this fourth phase of testing, which began in 2007, several simulated conditions of assembly and rework processes were evaluated in a matrix of multiple levels of components, PWB lead free surface finishes and solders, and compared to a baseline of leaded equivalent materials and processes. Both Through Hole (THT) and Surface Mount (SMT) Technologies were evaluated. The assembly portion of the testing and rework is completed and the long term reliability and vibration is ongoing. All quality and reliability testing was performed with industry standard methodologies, using specially trained production inspectors for the quality evaluation, and extreme thermal cycling for reliability testing. Our results indicate that with proper selection of currently available (2008) materials and finishes and careful control of the assembly processes, successful lead free assembly and rework can be achieved. Comparison of different strategies for rework, and recommendations for least copper dissolution for THT technology processes are discussed in the published book by the paper authors. Reliability testing to date showed interesting inflection points for leaded versus lead free reliability that has to be resolved by additional thermal cycling, to be published when completed in 2009, together with vibration testing.

Owing to the slow circuit board level maintenance and fault location of wireless communications equipment, and technically demanding problems, the multi-state circuit board testing environment was establish to study the circuit board interface type, input and output signals, power supply and others. Based on the diagnostic strategies of multi-signal flow model optimization design, this paper designed multi-state detection system including automatic testing and manual testing, realizing the rapid detection and failure analysis, processing and positioning of general and special circuit boards.

The finite element modeling of electronic boards is a challenging task due to the complexity of the multi-component board structure. Hence, it is acceptable to attain equivalent orthotropic in-plane mechanical properties and use them throughout the finite element analysis (FEA) simulations. This paper aims to present an artificial intelligence-based methodology, using the artificial neural networks (ANNs), to estimate the in-plane mechanical properties of the printed circuit boards (PCB). In this methodology, the ANN technique used FEA data to find the relationship between the first 10 natural frequencies and the mechanical properties, that is, modulus of elasticity, Poisson’s ratio and the shear modulus, of the test board. Subsequently, the experimentally derived natural frequency data is then imported to the ANN model to identify the equivalent orthotropic properties. The ANN-predicted properties are plugged back into FEA and provided natural frequencies and mode shapes that are in great match with experimental results.

The current research highlights regarding future low-dielectric resins for circuit boards lie in their recyclability and pattern ability. In the present work, we put forward a new idea to simultaneously achieve the recyclability and pattern ability of low-dielectric resins in circuit board. In detail, a series of low-dielectric vitrimers were prepared by copolymerization of fluorinated monomers followed by employing imine cross-linked network. By incorporating fluorine-contained units, the dielectric constant of the vitrimers reached to ∼2.4, while preserving high mechanical strength around 33 MPa. Moreover, after reprocessing three times, the dielectric constants of the PFS-imines remained almost unchanged and 89% of original mechanical strength was recovered. Owing to the increased chain relaxation, PFS-imines can be multiply patterned by directly imprinting at the temperature above Tv . Furthermore, the pattern of PFS-imines is removable and reformed, which may be attributed to their reprocessability. Thus, PFS-imine exhibits pattern ability and recyclability, making it particularly suitable for applications in electronic packaging and circuit boards, compared with that of conventional low-dielectric resins.

This paper presents a new methodology developed to automate test and characterization of mixed-signal cores. The main goal is to establish a connection between the test of mixed mode circuits and the respective design, offering to the designer the means to characterize the designed cores using the same interfaces employed during the simulation: SPICE netlists and waveform viewers involved in the design environment, without the need to turn designers into test experts. The work describes a configurable interface between the computer and the device under test (DUT) that enables the translation of the designer testbench into the characterization lab setup using three levels of configuration: DUT, dedicated printed circuit board interface and test equipment. The control of the platform is performed by proprietary software acting over two different areas: workstation layer (control of the test sequence and hardware involved) and design flow interface (interface with simulation tools). This methodology can contribute to reduce the costs related with the automatic test equipment and also the time devoted to test.

Printed Circuit Board (PCB) testing has traditionally relied on manual inspection methods, which are often timeconsuming, error-prone, and costly. These limitations result in longer processing times, increased production costs, and inconsistent quality assurance. To address these challenges, this paper proposes a Generative AI-Based PCB Testing (GABPT) system designed to automate defect detection and classification in PCBs. The system leverages high-resolution image acquisition, advanced AI-powered image processing, and classification algorithms to identify common defects such as scratches, missing holes, broken paths, mouse bites, short circuits, and absent conductors. Utilizing a Quad ARM Cortex-A72 processor, the system processes captured PCB images in realtime and delivers immediate feedback on defects. The GABPT system aims to reduce human error, accelerate the inspection process, and minimize testing costs. It emphasizes efficient image preprocessing, precise image analysis, and hardware-software integration for reliable defect detection. By automating PCB inspection, the proposed system enhances testing accuracy, promotes cost-effective production, and supports sustainable manufacturing practices, ultimately contributing to the delivery of higher-quality electronic products.

The solder joint microstructure and reliability of 937 I/O Ceramic Ball Grid Array (CBGA) packages assembled on several Printed Circuit Board (PCB) test vehicle designs were studied in these evaluations. These packages were 32.5mm square, full array, and primarily 1.0 mm pitch. In the first study, the packages used Sn3.8Ag0.7Cu solder balls. Primary card assembly was performed using no clean (NC) lead free alloy solder paste, as well as tin lead (Sn/Pb) solder paste. The purpose of this evaluation was to study both pure lead free (Sn3.0Ag0.5Cu – SAC 305 and Sn3.8Ag0.7Cu – 405 systems) and mixed assembly (SAC BGA balls with Sn/Pb card assembly) solder joint reliability performance relative to that of the conventional Sn/Pb alloy. This evaluation included different surface finishes on assembly test vehicles such as OSP and ImmAg, and was done in both air and nitrogen. Additional studies were completed on another PCB test vehicle using a water soluble Sn3.8Ag0.7Cu (SAC 405) solder paste. Geometry factors such as ball, package pad and card pad diameters were evaluated. Package ball alloys SAC 305 and SAC 405 were compared. Mixed assembly performance under slightly different conditions was compared to the results from the above assembly matrix. Solder joints formed were examined “as assembled” and also after accelerated thermal cycling (ATC) using optical and Scanning Electron microscopy, EDX and X-ray methods. This paper contains references to “lead free” solder alloys. Lead free has become an industry standard term meaning that the solder alloy should contain less than the RoHS Directive limit (1,000 ppm) for lead. It does not mean that the solder alloy will necessarily contain no lead at all.