barcode scanner input asp.net PRINTED CIRCUITS HANDBOOK in Software

Creator Denso QR Bar Code in Software PRINTED CIRCUITS HANDBOOK

PRINTED CIRCUITS HANDBOOK
QR Code JIS X 0510 Recognizer In None
Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications.
QR Code Drawer In None
Using Barcode encoder for Software Control to generate, create QR Code 2d barcode image in Software applications.
these techniques are either less consistent or less well defined than a visual image, still requiring the inspector to make a difficult judgment call. Therefore, a low repeatability rate persists. 53.6.4.5 High-Complexity Boards. Many printed circuit boards today are entirely too complex to allow accurate visual inspection. Components as small as 0402, 0201, or even 01005 passive components are simply too small for accurate visual detection of missing parts and particularly misalignment defects. Add to this the fact that many printed circuit boards have hundreds of these component types per board, and the opportunity for the visual inspector to make a mistake becomes enormous. Further obstacles to accurate inspection are families of boards, where the basic layout of each board type is the same, but specific board types vary by purposely not mounting specific components. In these cases, a missing component can be completely acceptable even in places where the board layout may provide for a component to be mounted. 53.6.4.6 No Quantitative Measurements. Accurate quantitative measurements of dimensions ranging from 0.05 to 0.5 mm are not possible with visual inspection. Quantitative measurements provide much more information about a process step, allowing much tighter process control and providing insight into the causes of process variation, without which process improvement is a hit-or-miss proposition. Some manufacturers have implemented semiautomatic measurement tools to allow operators to take quantitative measurements. Examples include optical-focusing microscopes and semiautomatic laser triangulation equipment. These tools do collect useful quantitative measurements, but are typically limited to sampling. Sampling is required because the tools are very slow. Measurement of solder paste height, volume, and registration with pads is possible because of easy visual access to solder paste depositions as well as their simple rectangular shape. Automated inspection techniques using automated inspection equipment significantly overcome the repeatability and measurement limitations of visual inspection. It is for this reason that many manufacturers are implementing automated inspection.
QR Decoder In None
Using Barcode decoder for Software Control to read, scan read, scan image in Software applications.
Encode Quick Response Code In C#
Using Barcode creation for Visual Studio .NET Control to generate, create QR Code image in .NET framework applications.
AUTOMATED INSPECTION
QR Code ISO/IEC18004 Creator In VS .NET
Using Barcode maker for ASP.NET Control to generate, create QR Code image in ASP.NET applications.
QR Code ISO/IEC18004 Maker In .NET Framework
Using Barcode generator for Visual Studio .NET Control to generate, create QR image in VS .NET applications.
The automation of inspection has evolved into systems that resemble the automated test equipment used to make electrical measurements and find electrical defects (faults). Automated inspection systems generate images of the item to be inspected (normally solder paste, components, or solder joints), digitally analyze the image to locate and measure key features, and, based on these measurements, automatically decide whether a defect exists or not. Just like visual inspection, automated inspection systems do not require physical contact with the printed circuit assembly to generate the desired images. Unlike visual inspection, however, automated inspection removes human subjectivity from defect detection, thereby increasing repeatability rates typically by an order of magnitude. Many of the automated inspection systems also provide accurate, repeatable, quantitative measurements that directly correspond to process parameters, thus providing the means for process control and improvement.2
QR Code Encoder In VB.NET
Using Barcode drawer for VS .NET Control to generate, create Quick Response Code image in Visual Studio .NET applications.
Barcode Creator In None
Using Barcode encoder for Software Control to generate, create barcode image in Software applications.
Measurements by Automated Inspection Systems Figure 53.8 shows examples of measurements made by automated inspection systems. 53.7.1.1 Solder Paste Measurements. Typical solder paste measurements, shown in Fig. 53.8(a), are volume, area of pad covered, height, and misalignment with the pad. These quantitative measurements provide information about the paste viscosity, stencil registration, cleanliness, snap-off, and squeegee speed and pressure that can lead to improvement in the paste printing process.
Paint UCC-128 In None
Using Barcode encoder for Software Control to generate, create GS1 128 image in Software applications.
Making Code 39 Extended In None
Using Barcode generation for Software Control to generate, create ANSI/AIM Code 39 image in Software applications.
ASSEMBLY INSPECTION
Drawing UPC-A Supplement 2 In None
Using Barcode creator for Software Control to generate, create UPC-A Supplement 5 image in Software applications.
ECC200 Creation In None
Using Barcode maker for Software Control to generate, create DataMatrix image in Software applications.
FIGURE 53.8 Measurements made by automated inspection systems: (a) Typical solder paste measurements made by automated inspection systems, including the volume of paste deposition, area of the pad covered by paste, height of the paste deposition, and offset of the paste from the pad; (b) typical component placement attributes inspected by automated inspection systems, including missing component, components misaligned along or across the pads, and skewed components; (c) typical solder joint measurements made by automated inspection systems, including volume of solder, toe and heel fillet heights, distance between fillets, void volume, average solder thickness across the solder joint, and offset between the solder joint and pad.
2/5 Industrial Creator In None
Using Barcode generator for Software Control to generate, create Standard 2 of 5 image in Software applications.
Print GS1 - 12 In C#.NET
Using Barcode encoder for .NET Control to generate, create GS1 - 12 image in .NET framework applications.
53.7.1.2 Pre-Reflow Measurements. Typical pre-reflow component placement measurements, depicted in Fig. 53.8(b), include whether or not the component is missing, misaligned, or skewed.These measurements are usually attribute measurements, just separating good from bad. But quantitative dimensional measurement of the amount of misalignment, just after the placement process step, is also possible. Component placement measurements provide information about the rate of placement accuracy. Optical character recognition (OCR) and optical character verification (OCV) techniques allow for additional levels of verification, including correct part. 53.7.1.3 Post-Reflow Solder Joint Measurements. Solder joint measurements, such as fillet heights, average solder thickness across the pad, void volume, and pin-to-pad offsets, as shown in Fig. 53.8(c), provide information about the paste printing process, the component placement process, and the solder reflow process steps. Attribute measurements, such as solder bridges, opens, or insufficient solder, are most common. Quantitative measurements of solder
Scanning EAN 13 In None
Using Barcode decoder for Software Control to read, scan read, scan image in Software applications.
Bar Code Drawer In None
Using Barcode drawer for Online Control to generate, create barcode image in Online applications.
Creating DataBar In VS .NET
Using Barcode creation for Visual Studio .NET Control to generate, create GS1 DataBar image in .NET applications.
Scan Code 128 Code Set A In .NET
Using Barcode decoder for .NET Control to read, scan read, scan image in .NET applications.
Generate Code 128 Code Set C In .NET Framework
Using Barcode drawer for ASP.NET Control to generate, create Code 128B image in ASP.NET applications.
Decode DataMatrix In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
Copyright © OnBarcode.com . All rights reserved.