Technical Library | 2020-04-14 15:56:32.0
This paper will focus on the application requirements of solder printing small aperture designs, concentrating on 008004 (inch) / 0201 (metric) size components, and the results of a design of experiment printing these challenging apertures. As Moore's law continues to be applied to component miniaturization, the next installment of reduced packaging has arrived in the form of the 008004/0201 for resistors and capacitors. Component size roughly the size of a grain of sand presents specific challenges to the solder printing process. To address these challenges, each aspect of the printing process will need be examined. This includes essential machine requirements, including correct squeegee blades, tooling support, and calibrations, to meet the demanding specifications. The correct match and design of materials will be addressed, focusing on the stencil and substrate design along with solder paste and cleaning solvent requirements. A design of experiment will be reviewed that applies the machine and materials discussed, including the printer and Solder Paste Inspection (SPI) setup and the specific machine parameters used. The results of these DOE's will then be closely examined.
Technical Library | 2011-06-02 15:49:09.0
Modern electronics typically consist of microprocessors and other complex integrated circuits (ICs) such as FPGAs, ADCs, and memory. They are susceptible to electrical, mechanical and thermal modes of failure like other components on a printed circuit boa
Technical Library | 2011-08-04 19:29:53.0
This work covers two major projects aimed at increasing quality and efficiency on a high mix, low volume surface mount electronics production line. Specifically the installation of a ten zone reflow oven and an enhanced changeover method for SMT pick and
Technical Library | 2023-05-22 17:13:17.0
Agenda Overview Independent Testing & Studies-Print studies -Understencil Wipe studies-Durability Testing-Ongoing Studies NanoClear Product Information NanocoatingsComparison Summary Questions
Technical Library | 2014-06-26 16:43:12.0
Edgebond adhesives have been widely used by the industry for improving the shock performance of area array packages. Most of the studies focus on the impact of material properties, such as coefficient of thermal expansion (CTE) and glass transition temperature (Tg), on reliability at room temperature. However, the operating temperature of a component on the printed circuit board bonded with edgebond adhesive can be close to or exceed Tg of the adhesive, where the material properties may be very different than at room temperature.
Technical Library | 2012-11-01 20:54:49.0
First published in the 2012 IPC APEX EXPO technical conference proceedings. The continuous progression toward portable, high frequency microelectronic systems has placed high demands on material performance, notably low dielectric constants (Dk), low loss tangent (Df), low moisture uptake, and good thermal stability. Epoxy resins are the workhorses of the electronic industry. Significant performance enhancements have been obtained through the use of PPE telechelic macromonomers with epoxy resins. However, there is a ceiling on the performance obtainable from epoxy-based resins. Therefore, non-epoxy based dielectric materials are used to fulfill the need for higher performance.
Technical Library | 2012-12-20 14:36:09.0
The increased function of personal electronic devices, such as mobile phones and personal music devices, has driven the need for smaller and smaller active and passive components. This trend toward miniaturization, occurring at the same time as the conversion to RoHS-compliant lead-free assembly, has been a considerable challenge to the electronics assembly industry. The main reason for this is the higher reflow process temperatures required for Pb-free assembly. These higher temperatures can thermally damage the PCB and the components. In addition, the higher reflow temperatures can negatively affect the solder joint quality, especially when coupled with the smaller paste deposits required for these smaller components. If additional thermal processing is required, the risk increases even more. First Published at SMTA's International Conference on Soldering and Reliability in Toronto, May 2011
Technical Library | 2015-12-23 16:57:27.0
The onset of copper barrel cracks is typically induced by the presence of manufacturing defects. In the absence of discernible manufacturing defects, the causes of copper barrel cracks in printed circuit board (PCB) plated through holes is not well understood. Accordingly, there is a need to determine what affects the onset of barrel cracks and then control those causes to mitigate their initiation.The objective of this research is to conduct a design of experiment (DOE) to determine if there is a relationship between PCB fabrication processes and the prevalence of fine barrel cracks. The test vehicle used will be a 16-layer epoxy-based PCB that has two different sized plated through holes as well as buried vias.
Technical Library | 2016-11-30 15:53:15.0
The use of microvias in Printed Circuit Boards (PCBs) for military hardware is increasing as technology drives us toward smaller pitches and denser circuitry. Along with the changes in technology, the industry has changed and captive manufacturing lines are few and far between. As PCBs get more complicated, the testing we perform to verify the material was manufactured to our requirements before they are used in an assembly needs to be reviewed to ensure that it is sufficient for the technology and meets industry needs to better screen for long-term reliability. The Interconnect Stress Testing (IST) protocol currently used to identify manufacturing issues in plated through holes, blind, or buried vias are not necessarily sufficient to identify problems with microvias. There is a need to review the current IST protocol to determine if it is adequate for finding bad microvias or if there is a more reliable test that will screen out manufacturing inconsistencies. The objective of this research is to analyze a large population of PCB IST coupons to determine if there is a more effective IST test to find less reliable microvias in electrically passing PCB product and to screen for manufacturing deficiencies. The proposed IST test procedure will be supported with visual inspection of corresponding microvia cross sections and Printed Wiring Assembly (PWA) acceptance test results. The proposed screening will be shown to only slightly affect PCB yield while showing a large benefit to screening before PCBs are used in an assembly.
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