Technical Library | 2008-02-20 21:42:52.0
Tier 2 and Tier 3 EMS companies face increasing pressure from competition in low-cost manufacturing countries to produce assembled boards at lower cost, with increased complexity and to tighter deadlines. They also face an increasing amount of high-mix, small-to-mediumvolume production runs. Even OEMs find it hard to predict what products they will be manufacturing in three to five years time, driving the need to invest in highly flexible production tools that will cater to their needs over the lifetime of the equipment. This paper examines methodologies for optimising the process, improving stock control and providing greater traceability using lean manufacturing techniques.
Technical Library | 1999-08-27 09:29:49.0
Contract packaging houses have to contend with a large mix of die types and products. Flexibility and quick turnaround of package types is a must in this industry. Traditional methods of die encapsulation, (i.e., use of transfer-molding techniques), are only cost effective when producing a large number of components. Liquid encapsulants now provide similar levels of reliability1, and are cost effective...
Technical Library | 1999-08-27 09:27:10.0
Conformal coating is a material that is applied to electronic products or assemblies to protect them from solvents, moisture, dust or other contaminants that may cause harm. Coating also prevents dendrite growth, which may result in product failure. This paper will discuss the variables that affect the application of conformal coatings, and review in detail those variables that impact the process of selective coating of printed circuit boards.
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 | 2020-02-26 23:24:02.0
Shielding electronic systems against electromagnetic interference (EMI) has become a hot topic. Technological advancements toward 5G standards, wireless charging of mobile electronics, in-package antenna integration, and system-inpackage (SiP) adoption are driving the need to apply more effective EMI shielding and isolation to component packages and larger modules. For conformal shielding, EMI shielding materials for exterior package surfaces have mostly been applied with a physical vapor deposition (PVD) process of sputtering, leveraging front-end packaging technologies to back-end packaging applications. However, sputtering technology challenges in scalability and cost along with advancements in dispensable materials are driving considerations for alternative dispensing techniques for EMI shielding.
Technical Library | 2012-11-21 18:57:58.0
The continuing evolution toward advanced miniature packaging has led to ever increasing PCB density and complexity. As the manufacturing process becomes progressively more complicated, there is an ever increasing probability for defects to occur on finished PCB assemblies. For years the Automated Optical Inspection (AOI) industry has relied solely upon two-dimensional (2D) inspection principles to test the quality of workmanship on electronic assemblies. While advancements in conventional 2D optical inspection have made this technology suitable for detecting such defects as missing components, wrong components, proper component orientation, insufficient solder, and solder bridges; there is an inherent limitation in the ability to inspect for co-planarity of ultra-miniature chips, leaded device, BGA and LED packages.
Technical Library | 2009-09-18 14:42:37.0
In recent years, various studies have been issued on cleaning under low standoff components; most however, with incomplete information. It is essential to revisit and describe the latest challenges in the market, identifying obvious gaps in available information. Such information is crucial for potential and existing users to fully address the cleanliness levels under their respective components. With the emergence of lead-free soldering and even smaller components, new challenges have arisen including cleaning in gaps of less than 1-mil.
Technical Library | 2008-10-15 20:16:12.0
Solder paste dispensing is usually considered a slow process. Due to the speed advantages, screen printing is used to apply solder paste whenever possible. However, screen printing is not always an option. Leveraging the high speed of piezo drive technology opens the door to a broad range of solder paste dispensing applications. The ability to dispense dots under 300-μm diameter, even as small as 125 μm, enables BGA rework, small geometry deposits for miniaturized passive components, electrical connections in recessed cavities, and RF shield attach for handheld devices.
Technical Library | 1999-08-27 09:24:56.0
Dispensing conductive adhesives in an automated factory environment creates some special challenges. A robust production process starts with understanding the adhesives in their fluid state and which important parameters must be controlled. Developing this understanding requires experience with a large number of materials and valves over time. Common uses of conductive adhesives in surface mount applications, die attach applications, and gasketing are addressed. As vendors of dispensing equipment, the authors see a constant stream of such applications. Dispensing requirements, techniques, and equipment resulting from this experience are discussed. Guidelines for optimizing quality and speed are given.
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.