Technical Library | 2018-06-13 11:42:00.0
The art of screen printing solder paste for the surface mount community has been discussed and presented for several decades. However, the impending introduction of passive Metric 0201 devices has reopened the need to re-evaluate the printing process and the influence of stencil architecture. The impact of introducing apertures with architectural dimensions’ sub 150um whilst accommodating the requirements of the standard suite of surface mount connectors, passives and integrated circuits will require a greater knowledge of the solder paste printing process.The dilemma of including the next generation of surface mount devices into this new heterogeneous environment will create area ratio challenges that fall below todays 0.5 threshold. Within this paper the issues of printing challenging area ratio and their associated aspect ratio will be investigated. The findings will be considered against the next generation of surface mount devices.
Technical Library | 2018-06-27 16:47:13.0
Nowadays, inkjet-printed devices such as transistors are still unstable in air and have poor performances. Moreover, the present electronics applications require a high degree of reliability and quality of their properties. In order to accomplish these application requirements, hybrid electronics is fulfilled by combining the advantages of the printing technologies with the surface-mount technology. In this work, silver nanoparticle-based inkjet ink (AgNP ink) is used as a novel approach to connect surface-mount devices (SMDs) onto inkjet-printed pads, conducted by inkjet printing technology
Technical Library | 1999-05-09 12:51:38.0
This Technical Note outlines, step by step, the easiest ways to remove and replace surface mounted devices, using the lowest possible temperatures. This document discusses the following topics: Removal and replacement of discrete and passive components (capacitors, resistors, SOTs), Removal of two-sided components (SOICs, SOJs, TSOPs), Removal of quad components (PLCCs, QFPs), Replacement of quad components including fine-pitched devices.
Technical Library | 2021-12-02 01:44:00.0
With the advent of Industry 4.0, production processes have been endowed with intelligent cyber-physical systems generating massive amounts of streaming sensor data. Internet of Things technologies have enabled capturing, managing, and processing production data at a large scale in order to utilize this data as an asset for the optimization of production processes. In this work, we focus on the automatic detection of physical defects in the production of surfacemount devices. We show how to build a classification model based on random forests that efficiently detects defect products with a high degree of precision. In fact, the results of our preliminary experimental analysis indicate that our approach is able to correctly determine defects in a simulated production environment of surface-mount devices with a MCC score of 0.96. We investigate the feasibility of utilizing this approach in realistic settings. We believe that our approach will help to advance the production of surface-mount devices.
Technical Library | 2014-08-07 15:13:44.0
Gold embrittlement in SnPb solder is a well-known failure mechanism in electronic assembly. To avoid this issue, prior studies have indicated a maximum gold content of three weight percent. This study attempts to provide similar guidance for Pb-free (SAC305) solder. Standard surface mount devices were assembled with SnPb and SAC305 solder onto printed boards with various thicknesses of gold plating. The gold plating included electroless nickel immersion gold (ENIG) and electrolytic gold of 15, 25, 35, and 50 microinches over nickel. These gold thicknesses resulted in weight percentages between 0.4 to 7.0 weight percent.
Technical Library | 2013-06-20 14:33:12.0
With today's consumer technologies driving the need for denser and more compact devices, the assembly process for surface mounted devices has becoming increasingly more difficult. With the mixture of components requiring a broader range of print deposition volume, various techniques are in use in an attempt to ensure consistent and appropriate paste volume is achieved. Some of these techniques include step etching a stencil locally on a targeted device, promoting electroformed smooth wall nickel stencils, through to laser cutting newer grade stencil materials. This paper focuses on the relevant attributes that affect the properties of solder paste release and introduces the effects of surface free energy with respect to key elements that make up the stencil printing process.
Technical Library | 2022-09-12 14:07:47.0
Unique component handling issues can arise when an assembly factory uses highly-moisture sensitive surface mount devices (SMDs). This work describes how the distribution of moisture within the molded plastic body of a SMD is an important variable for survivability. JEDEC/IPC [1] moisture level rated packages classified as Levels 4-5a are shown to require additional handling constraints beyond the typical out-of-bag exposure time tracking. Nitrogen or desiccated cabinet containment is shown as a safe and effective means for long-term storage provided the effects of prior out-of-bag exposure conditions are taken into account. Moisture diffusion analyses coupled with experimental verification studies show that time in storage is as important a variable as floor-life exposure for highly-moisture sensitive devices. Improvements in floor-life survivability can be obtained by a handling procedure that includes cyclic storage in low humidity containment. SMDs that have exceeded their floor-life limits are analyzed for proper baking schedules. Optimized baking schedules can be adopted depending on a knowledge of the exposure conditions and the moisture sensitivity level of the device.
Technical Library | 2008-03-25 18:15:54.0
Thin film thermoelectric devices offer a fundamentally new operating regime for integrated, active cooling solutions and localized thermal management, yet the assembly methodology used to implement these devices is fully compatible with existing surface mount approaches. In order to take advantage of these unique characteristics, thin film thermoelectric devices need to be designed for the appropriate thermal and form-factor environments, with system-level constraints carefully considered as an integral part of the overall design process.
Technical Library | 2014-05-08 16:34:16.0
Bare die mounting on multi-device substrates has been in use in the microelectronics industry since the 1960s. The aerospace industry’s hybrid modules and IBM’s Solid Logic Technology were early implementations that were developed in the 1960’s. The technologies progressed on a steady level until the mid 1990’s when, with the advent of BGA packaging and chip scale packages, the microelectronics industry started a wholesale move to area array packaging. This paper outlines the challenges for both traditional wire-bond die attached to a printed wiring board (pwb), to the more recent applications of bumped die attached to a high performance substrate.
Technical Library | 2018-03-05 11:22:48.0
Growing demands for smaller electronic assemblies has resulted in reduced sizes of passive components, requiring the introduction of newer components, such as the 01005 devices. Component miniaturization presents significant challenges to the traditional surface mount assembly process. A successful assembly solution for these 01005 devices should be repeatable and reproducible, and should include guidelines for (i) the selection of solder paste and (ii) appropriate stencil and substrate pad design, and should ensure strict process control standards.
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