Technical Library | 2021-07-13 19:51:10.0
Flexible electronics refers to a class of lightweight, flexible and electronic sensing components and electronic devices built on stretchable substrates1 that are used (and can be used) for a broad set of products and applications such as displays and sensors. The most prominent characteristic is that they can bend in contrast to electronic systems built in rigid materials. They are manufactured on flexible plastic substrates, such as polyamide, PEEK2 or transparent conductive polyester films3, or other materials such as paper, textile, or thin glass. The term flexible also refers to the roll-to-roll manufacturing process.
European Commission - Executive Agency for Small and Medium-sized Enterprises (EASME)
Technical Library | 2015-05-28 17:34:48.0
The printed circuit board assembly industry has long embraced the "Smaller, Lighter, Faster" mantra for electronic devices, especially in our ubiquitous mobile devices. As manufacturers increase smart phone functionality and capability, designers must adopt smaller components to facilitate high-density packaging. Measuring over 40% smaller than today's 0402M (0.4mmx0.2mm) microchip, the new 03015M (0.3mm×0.15mm) microchip epitomizes the bleeding-edge of surface mount component miniaturization. This presentation will explore board and component trends, and then delve into three critical areas for successful 03015M adoption: placement equipment, assembly materials, and process controls. Beyond machine requirements, the importance of taping specifications, component shape, solder fillet, spacing gap, and stencil design are explored. We will also examine how Adaptive Process Control can increase production yields and reduce defects by placing components to solder position rather than pad. Understanding the process considerations for 03015M component mounting today will help designers and manufacturers transition to successful placement tomorrow.
Technical Library | 2019-05-21 00:21:26.0
Continue to talk about the dust removal from temperature humidity test chamber. Cleaning and maintenance: 1) Pls remove internal impurities inisde chamber before operation. 2) The power distribution room should be cleaned at least once a year, and the dust can be removed by vacuum cleaner. 3) The exterior chamber must also be cleaned more than once a year, which can be wiped with soapy water. Inspection and maintenance of humidifier: The water storage in humidifier should be replaced once a month to ensure clean water quality, humidifying water tray should be cleaned once a month to ensure smooth flow of water. The inspection of over-temperature protector:during the test: If the temperature is over 20 ℃ ~ 30 ℃ than the maximum value setted,the power supply of the heater will stop, the "OVERHEAT" overt-emperature warning light will automatically turn on but the fan is still in operation, if the equipment runs without operator around,the operator should check the over-temperature protector in advance to ensure wether it has been setted properly before start [wet ball over-temperature protector set to 120 ℃].
Technical Library | 2019-11-17 22:46:45.0
Overview of walk-in temperature and humidity chamber: It also belongs to environmental test equipment, it tests whether the product can resist high temperature, low temperature, humidity, or the physical and chemical changes produced under extreme conditions, the walk-in temperature and humidity chamber volume is large, the product is placed, or a large object can be placed, such as automobile, new energy, television and liquid crystal screen, etc. How to do the routine maintenance of the walk-in temperature and humidity chamber: 1. The wet gauze basically, if there is no special case, s/b usually changed once in 3 months 2. The water channel shall be regularly cleaned, including water cup, water tank, etc., so as to prevent the water from being blocked,affect the humidity test. 3. It is forbidden to test the flammable and explosive products inside working room. 4. Clean the chamber on a regular basis 2. How to operate walk-in temperature and humidity chamber: The operation method is same as standard temperature humidity test chamber,the controller is 7-inch LCD programmable color screen, you only need to setthe temperature point---test time--how many cycles need to be tested, This can be done automatically, and the machine will stop automatically when it is complete. If there is any problem during the operation, the corresponding problem point will be displayed on the machine control screen. Walk-in temperature and humidity chamber is a must equipment for reliability test of Automobile,Aerospace,Electronic parts,etc,the operation and maintenance are easy,it is teh tear down mahcine,Climatest engineers will be dispatched to do on-site support,for instance,we will finish commissioning,train customers how to operate,maintain,welcome to follow our company facebook page:https://www.facebook.com/Climatechambers
Technical Library | 2021-06-15 18:36:00.0
To compensate for the insufficiency and instability of solder paste dispensing and printing that are used in the SMT (Surface Mount Technology) production process, a noncontact solder paste jetting system driven by a piezoelectric stack based on the principle of the nozzle-needle-system is introduced in this paper, in which a miniscule gap exists between the nozzle and needle during the jetting process. Here, the critical jet ejection velocity is discussed through theoretical analysis. The relations between ejection velocity and needle structure, needle velocity, and nozzle diameter were obtained by FLUENT software. Then, the prototype of the solder paste jetting system was fabricated, and the performance was verified by experiments. The effects of the gap between nozzle and needle, the driving voltage, and the nozzle diameter on the jetting performance and droplet diameter were obtained. Solder paste droplets 0.85 mm in diameter were produced when the gap between the nozzle and needle was adjusted to 10 _m, the driving voltage to 80 V, the nozzle diameter to 0.1 mm, and the variation of the droplet diameter was within _3%.
Technical Library | 2020-07-02 13:16:32.0
Principle of shielding 1 The principle of shielding is creating a conductive layer completely surrounding the object you want to shield. This was invented by Michael Faraday and this system is known as a Faraday Cage. 2 Ideally, the shielding layer will be made up of conductive sheets or layers of metal that are connected by means of welding or soldering, without any interruptions. The shielding is perfect when there is no difference in conductivity between the used materials. When dealing with frequencies below 30 MHz, the metal thickness affects shielding effectiveness. We also offer a range of shielding methods for plastic enclosures. A complete absence of interruptions is not a realistic goal since the Faraday cage will have to be opened from time to time so electronics, equipment or people can be moved in or out. Openings are also needed for displays, ventilation, cooling, power supply, signals etc. 3 Shielding works in both directions, items inside the shielded room are shielded from outside influences. (Fig. 3.1)
Technical Library | 2016-04-14 13:49:44.0
A system level test, usually built-in test (BIT), determines that one or more subsystems are faulty. These subsystems sent to the depot or factory repair facility, called units under test (UUTs) often pass that test, an event we call No-Fault-Found (NFF). With more-and more electronics monitored by BIT, it is more likely that an intermittent glitch will trigger a call for a maintenance action resulting in NFF. NFFs are often confused with false alarm (FA), cannot duplicate (CNDs)or retest OK (RTOK) events. NFFs at the depot are caused by FAs, CNDs, RTOKs as well as a number of other complications. Attempting to repair NFF scan waste precious resources, compromise confidence in the product, create customer dissatisfaction, and the repair quality remains a mystery. The problem is compounded by previous work showing that most failure indications calling for repair action at the system level are invalid. NFFs can be caused by real failures or may be a result of system level false alarms. Understanding the cause of the problem may help us distinguish between units under test (UUTs) that we can repair and those that we cannot. In calculating the true cost of repair we must account for wasted effort in attempting to repair unrepairable UUTs.This paper will shed some light on this trade-off. Finally, we will explore approaches for dealing with the NFF issue in a cost effective manner.
Technical Library | 2020-09-02 22:14:36.0
The demand for miniaturization and higher density electronic products has continued steadily for years, and this trend is expected to continue, according to various semiconductor technology and applications roadmaps. The printed circuit board (PCB) must support this trend as the central interconnection of the system. There are several options for fine line circuitry. A typical fine line circuit PCB product using copper foil technology, such as the modified semi-additive process (mSAP), uses a thin base copper layer made by pre-etching. The ultrathin copper foil process (SAP with ultrathin copper foil) is facing a technology limit for the miniaturization due to copper roughness and thickness control. The SAP process using sputtered copper is a solution, but the sputtering process is expensive and has issues with via plating. SAP using electroless copper deposition is another solution, but the process involved is challenged to achieve adequate adhesion and insulation between fine-pitch circuitries. A novel catalyst system--liquid metal ink (LMI)--has been developed that avoids these concerns and promotes a very controlled copper thickness over the substrate, targeting next generation high density interconnect (HDI) to wafer-level packaging substrates and enabling 5-micron level feature sizes. This novel catalyst has a unique feature, high density, and atomic-level deposition. Whereas conventional tin-palladium catalyst systems provide sporadic coverage over the substrate surface, the deposited catalyst covers the entire substrate surface. As a result, the catalyst enables improved uniformity of the copper deposition starting from the initial stage while providing higher adhesion and higher insulation resistance compared to the traditional catalysts used in SAP processes. This article discusses this new catalyst process, which both proposes a typical SAP process using the new catalyst and demonstrates the reliability improvements through a comparison between a new SAP PCB process and a conventional SAP PCB process.
Technical Library | 2014-07-02 16:46:09.0
Growth behaviors of intermetallic compounds (IMCs) and Kirkendall voids in Cu/Sn/Cu microbump were systematically investigated by an in-situ scanning electron microscope observation. Cu–Sn IMC total thickness increased linearly with the square root of the annealing time for 600 h at 150°C, which could be separated as first and second IMC growth steps. Our results showed that the growth behavior of the first void matched the growth behavior of second Cu6Sn5, and that the growth behavior of the second void matched that of the second Cu3Sn. It could be confirmed that double-layer Kirkendall voids growth kinetics were closely related to the Cu–Sn IMC growth mechanism in the Cu/Sn/Cu microbump, which could seriously deteriorate the mechanical and electrical reliabilities of the fine-pitch microbump systems
Technical Library | 2017-10-12 15:45:25.0
The risk associated with whisker growth from pure tin solderable terminations is fully mitigated when all of the pure tin is dissolved into tin-lead solder during SMT reflow. In order to take full advantage of this phenomenon, it is necessary to understand the conditions under which such coverage can be assured. A round robin study has been performed by IPC Task group 8-81f, during which identical sets of test vehicles were assembled at multiple locations, in accordance with IPC J-STD-001, Class 3. All of the test vehicles were analyzed to determine the extent of complete tin dissolution on a variety of component types. Results of this study are presented together with relevant conclusions and recommendations to guide high reliability end-users on the applicability and limitations of this mitigation strategy.
