Used SMT Equipment | Repair/Rework
● Bottom and top heaters reflow solder to remove components with BGA, gull wing leaded QFPs, and bottom termination components. ●Paste dispenser allows placement of precise paste dots. ● Dual mirror system for component alignment for removal an
Technical Library | 2019-07-24 23:55:32.0
Voiding is a key concern for components with thermal planes because interruptions in Z-axis continuity of the solder joint will hinder thermal transfer. When assembling components with solder paste, there is a high propensity for voiding due to the confined nature of the solder paste deposits under the component. Once reflowed, many factors contribute to the amount of voiding in a solder joint such as the reflow profile, designs of the component, board and stencil, and material factors. This study will focus on the solder paste alloy and flux combination as well as profile and board surface finishes.
Technical Library | 2013-07-25 14:02:15.0
Bottom-termination components (BTC), such as QFNs, are becoming more common in PCB assemblies. These components are characterized by hidden solder joints. How are defects on hidden DFN joints detected? Certainly, insufficient solder joints on BTCs cannot be detected by manual visual inspection. Nor can this type of defect be detected by automated optical inspection; the joint is hidden by the component body. Defects such as insufficients are often referred to as "marginal" defects because there is likely enough solder present to make contact between the termination on the bottom-side of the component and the board pad for the component to pass in-circuit and functional test. Should the board be subjected to shock or vibration, however, there is a good chance this solder connection will fracture, leading to an open connection.
Events Calendar | Mon Oct 07 00:00:00 EDT 2019 - Tue Oct 08 00:00:00 EDT 2019 | ,
PCBA Cleanliness End-of-Project Webinar
Technical Library | 2014-08-28 17:09:23.0
The fastest growing package types in the electronics industry today are Bottom Termination Components (BTCs). While the advantages of BTCs are well documented, they pose significant reliability challenges to users. One of the most common drivers for reliability failures is the inappropriate adoption of new technologies. This is especially true for new component packaging like BTCs. Obtaining relevant information can be difficult since information is often segmented and the focus is on design opportunities not on reliability risks (...)Commonly used conformal coating and potting processes have resulted in shortened fatigue life under thermal cycling conditions. Why do conformal coating and potting reduce fatigue life? This paper details work undertaken to understand the mechanisms underlying this reduction. Verification and determination of mechanical properties of some common materials are performed and highlighted. Recommendations for material selection and housing design are also given.
Technical Library | 2015-06-11 21:20:29.0
The use of bottom terminated components (BTC) has become widespread, specifically the use of Quad Flat No-lead (QFN) packages. The small outline and low height of this package type, improved electrical and thermal performance relative to older packaging technology, and low cost make the QFN/BTC attractive for many applications.Over the past 15 years, the implementation of the QFN/BTC package has garnered a great amount of attention due to the assembly and inspection process challenges associated with the package. The difference in solder application parameters between the center pad and the perimeter pads complicates stencil design, and must be given special attention to balance the dissimilar requirements
Technical Library | 2023-11-20 17:30:11.0
Summary for today 1. Electronic component inspection and failure analysis. 2. Component counting and material management. 3. Reverse engineering. 4. Counterfeit detection. 5. Real-time defect verification. 6. Computed tomography (CT) techniques and how to differentiate between 2D, 2.5D, and 3D x-ray inspection. 7. Design for manufacturing (DFM) and design for x-ray inspection (DFXI). 8. Voids, bridging, and head-in-pillow failures in bottom terminated components (BTC). 9. Artificial Intelligence and x-ray inspection
Technical Library | 2019-08-07 22:56:45.0
The requirement to reconsider traditional soldering methods is becoming more relevant as the demand for bottom terminated components (QFN/BTC) increases. Thermal pads under said components are designed to enhance the thermal and electrical performance of the component and ultimately allow the component to run more efficiently. Additionally, low voiding is important in decreasing the current path of the circuit to maximize high speed and RF performances. The demand to develop smaller, more reliable, packages has seen voiding requirements decrease below 15 percent and in some instances, below 10 percent.Earlier work has demonstrated the use of micro-fluxed solder preforms as a mechanism to reduce voiding. The current work builds upon these results to focus on developing an engineered approach to void reduction in leadless components (QFN) through increasing understanding of how processing parameters and a use of custom designed micro-fluxed preforms interact. Leveraging the use of a micro-fluxed solder preform in conjunction with low voiding solder paste, stencil design, and application knowhow are critical factors in determining voiding in QFN packages. The study presented seeks to understand the vectors that can contribute to voiding such as PCB pad finish, reflow profile, reflow atmosphere, via configuration, and ultimately solder design.A collaboration between three companies consisting of solder materials supplier, a power semiconductor supplier, and an electronic assembly manufacturer worked together for an in-depth study into the effectiveness of solder preforms at reducing voiding under some of the most prevalent bottom terminated components packages. The effects of factors such as thermal pad size, finish on PCB, preform types, stencil design, reflow profile and atmosphere, have been evaluated using lead-free SAC305 low voiding solder paste and micro-fluxed preforms. Design and manufacturing rules developed from this work will be discussed.
Technical Library | 2022-12-19 18:59:51.0
Material and Process Characterization studies can be used to quantify the harmful effects that might arise from solder flux and other process residues left on external surfaces after soldering. Residues present on an electronic assembly can cause unwanted electrochemical reactions leading to intermittent performance and total failure. Components with terminations that extend underneath the package can trap flux residue. These bottom terminated components are flush with the bottom of the device and can have small solderable terminations located along the perimeter sides of the package. The clearance between power and ground render high electrical forces, which can propagate electrochemical interactions when exposed to atmospheric moisture (harsh environments). The purpose of this research is to predict and understand the functional performance of residues present under single row QFN component packages. The objective of the research study is to develop and collect a set of guidelines for understanding the relationship between ionic contamination and electrical performance of a BTC component when exposed to atmospheric moisture and the trade-offs between electrical, ionic contamination levels, and cleanliness. Utilizing the knowledge gained from undertaking the testing of QFN components and associated DOE, the team will establish a reference Test Suite and Test Spec for cleanliness.
Events Calendar | Wed Jun 20 00:00:00 EDT 2018 - Wed Jun 20 00:00:00 EDT 2018 | ,
Everything You Need to Know About X-Rays
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