Technical Library | 2014-08-19 16:07:15.0
Warpage management consists of planning, measuring, analyzing, sharing, and reacting to data related to the surface shapes of electronics components as they change throughout the reflow assembly process. Leading semiconductor manufacturers have had warpage management systems in place for ten years or more, mainly because microchip package warpage must be understood and compensated for in order to attain high assembly yields. Similarly, newer device architectures such as package-on-package and system-on-a-chip are sensitive to warpage-related assembly issues, and companies involved in the manufacture and assembly of these devices tend to have the most advanced warpage management programs.
Technical Library | 2013-01-31 18:43:15.0
There are three key industry trends that are driving the need for temperature-dependent warpage measurement: the trend toward finer-pitch devices, the emergence of lead-free processing, and changes in device form factors. Warpage measurement has become a key measurement for analysis; prevention and prediction of interconnect defects and has been employed in failure analysis labs and production sites worldwide. First published in the 2012 IPC APEX EXPO technical conference proceedings
Technical Library | 2008-03-13 13:02:50.0
Three full-field optical techniques, shadow moiré, fringe projection and digital image correlation (DIC), are used to measure temperature-dependent warpage for a PBGA package and a PCB component land site from room temperature to 250ºC. The results are qualitatively similar, but imaging resolution and noise properties create offsets between coplanarity values. The paper summarizes strengths and weaknesses for each technique.
Technical Library | 2022-02-21 19:49:16.0
The ability to undertake non-destructive testing on semiconductor devices, during both their manufacture and their subsequent use in printed circuit boards (PCBs), has become ever more important for checking product quality without compromising productivity. The use of x-ray inspection not only provides a potentially non-destructive test but also allows investigation within optically hidden areas, such as the wire bonding within packages and the quality of post solder reflow of area array devices (e.g. BGAs, CSPs and flip chips).
Technical Library | 2007-11-29 17:20:31.0
Programs have been developed to predict the expected yield of flip chip assemblies, based on substrate design and the statistics of actual manufactured boards, as well as placement machine accuracy, variations in bump sizes, and possible substrate warpage. These predictions and the trends they reveal can be used to direct changes in design so that defect levels will fall below the acceptable limits. Shapes of joints are calculated analytically, or when this is not possible, numerically by means of a public domain program called Surface Evolver. The method is illustrated with an example involving the substrate for a flip chip BGA.
Technical Library | 2021-01-13 21:34:29.0
Package-on-Package (PoP) is a popular technology for fabricating chipsets of accelerated processing units. However, the coefficient of thermal expansion mismatch between Si chips and polymer substrates induces thermal warpage during the reflow process. As such, the reflow temperature and reliability of solder joints are critical aspects of PoP. Although Sne58Bi is a good candidate for low-temperature processes, its brittleness causes other reliability issues. In this study, an in-situ observation was performed on composite solders (CSs) made of ...
Technical Library | 2021-05-06 13:41:55.0
Quality control is of vital importance during electronics production. As the methods of producing electronic circuits improve, there is an increasing chance of solder defects during assembling the printed circuit board (PCB). Many technologies have been incorporated for inspecting failed soldering, such as X-ray imaging, optical imaging, and thermal imaging. With some advanced algorithms, the new technologies are expected to control the production quality based on the digital images. However, current algorithms sometimes are not accurate enough to meet the quality control. Specialists are needed to do a follow-up checking. For automated X-ray inspection, joint of interest on the X-ray image is located by region of interest (ROI) and inspected by some algorithms. Some incorrect ROIs deteriorate the inspection algorithm.
Technical Library | 2024-04-29 21:39:52.0
In this paper, we develop and put into practice an Automatic Optical Inspection (AOI) system based on machine vision to check the holes on a printed circuit board (PCB). We incorporate the hardware and software. For the hardware part, we combine a PC, the three-axis positioning system, a lighting device and CCD cameras. For the software part, we utilize image registration, image segmentation, drill numbering, drill contrast, and defect displays to achieve this system. Results indicated that an accuracy of 5µm could be achieved in errors of the PCB holes allowing comparisons to be made. This is significant in inspecting the missing, the multi-hole and the incorrect location of the holes. However, previous work only focusses on one or other feature of the holes. Our research is able to assess multiple features: missing holes, incorrectly located holes and excessive holes. Equally, our results could be displayed as a bar chart and target plot. This has not been achieved before. These displays help users analyze the causes of errors and immediately correct the problems. Additionally, this AOI system is valuable for checking a large number of holes and finding out the defective ones on a PCB. Meanwhile, we apply a 0.1mm image resolution which is better than others used in industry. We set a detecting standard based on 2mm diameter of circles to diagnose the quality of the holes within 10 seconds.
Technical Library | 2015-06-18 12:42:57.0
In the recent past, the Light Emitting Diode (LED) was hailed as the new energy efficient light source that would never have to be replaced. There were claims of 50,000+ hrs lifetime for the humble LED. That story has changed over the last few years as the number and diversity of the LED based products has increased. This is not to say that the original evidence was incorrect, but the initial enthusiastic estimates from the labs did not match the ultimate test, customers. As a result of poor quality products affecting the overall opinion of LED based products, it is critical that manufacturers can be confident in the quality of their product. In current times we want to have products certified, checked and ensure that we have the best quality. For the purposes of this paper we will look at one aspect of LED product, and this is the Lumen maintenance and estimated lifetime. The method described here does not seek to replace using high quality rating labs, but hopefully will allow the manufacturer to know with confidence that their prototype product, upon going to certification labs will be of a high enough quality that no expensive re-designs are required.
Technical Library | 2023-11-20 18:49:11.0
Non-destructive testing during the manufacture of printed wiring boards (PWBs) has become ever more important for checking product quality without compromising productivity. Using x-ray inspection, not only provides a non-destructive test but also allows investigation within optically hidden areas, such as the quality of post solder reflow of area array devices (e.g. BGAs, CSPs and flip chips). As the size of components continues to diminish, today's x-ray inspection systems must provide increased magnification, as well as better quality x-ray images to provide the necessary analytical information. This has led to a number of x-ray manufacturers offering digital x-ray inspection systems, either as standard or as an option, to satisfy these needs. This paper will review the capabilities that these digital x-ray systems offer compared to their analogue counterparts. There is also a discussion of the various types of digital x-ray systems that are available and how the use of different digital detectors influences the operational capabilities that such systems provide.
